linux/net/strparser/strparser.c

573 lines
13 KiB
C
Raw Normal View History

strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/*
* Stream Parser
*
* Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*/
#include <linux/bpf.h>
#include <linux/errno.h>
#include <linux/errqueue.h>
#include <linux/file.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/poll.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
#include <net/strparser.h>
#include <net/netns/generic.h>
#include <net/sock.h>
static struct workqueue_struct *strp_wq;
struct _strp_msg {
/* Internal cb structure. struct strp_msg must be first for passing
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
* to upper layer.
*/
struct strp_msg strp;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
int accum_len;
int early_eaten;
};
static inline struct _strp_msg *_strp_msg(struct sk_buff *skb)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
return (struct _strp_msg *)((void *)skb->cb +
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
offsetof(struct qdisc_skb_cb, data));
}
/* Lower lock held */
static void strp_abort_strp(struct strparser *strp, int err)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
/* Unrecoverable error in receive */
del_timer(&strp->msg_timer);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (strp->stopped)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return;
strp->stopped = 1;
if (strp->sk) {
struct sock *sk = strp->sk;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Report an error on the lower socket */
sk->sk_err = err;
sk->sk_error_report(sk);
}
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
static void strp_start_timer(struct strparser *strp, long timeo)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
if (timeo)
mod_timer(&strp->msg_timer, timeo);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
/* Lower lock held */
static void strp_parser_err(struct strparser *strp, int err,
read_descriptor_t *desc)
{
desc->error = err;
kfree_skb(strp->skb_head);
strp->skb_head = NULL;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp->cb.abort_parser(strp, err);
}
static inline int strp_peek_len(struct strparser *strp)
{
if (strp->sk) {
struct socket *sock = strp->sk->sk_socket;
return sock->ops->peek_len(sock);
}
/* If we don't have an associated socket there's nothing to peek.
* Return int max to avoid stopping the strparser.
*/
return INT_MAX;
}
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Lower socket lock held */
static int __strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
unsigned int orig_offset, size_t orig_len,
size_t max_msg_size, long timeo)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
struct strparser *strp = (struct strparser *)desc->arg.data;
struct _strp_msg *stm;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
struct sk_buff *head, *skb;
size_t eaten = 0, cand_len;
ssize_t extra;
int err;
bool cloned_orig = false;
if (strp->paused)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return 0;
head = strp->skb_head;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (head) {
/* Message already in progress */
stm = _strp_msg(head);
if (unlikely(stm->early_eaten)) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Already some number of bytes on the receive sock
* data saved in skb_head, just indicate they
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
* are consumed.
*/
eaten = orig_len <= stm->early_eaten ?
orig_len : stm->early_eaten;
stm->early_eaten -= eaten;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return eaten;
}
if (unlikely(orig_offset)) {
/* Getting data with a non-zero offset when a message is
* in progress is not expected. If it does happen, we
* need to clone and pull since we can't deal with
* offsets in the skbs for a message expect in the head.
*/
orig_skb = skb_clone(orig_skb, GFP_ATOMIC);
if (!orig_skb) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->error = -ENOMEM;
return 0;
}
if (!pskb_pull(orig_skb, orig_offset)) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
kfree_skb(orig_skb);
desc->error = -ENOMEM;
return 0;
}
cloned_orig = true;
orig_offset = 0;
}
if (!strp->skb_nextp) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* We are going to append to the frags_list of head.
* Need to unshare the frag_list.
*/
err = skb_unclone(head, GFP_ATOMIC);
if (err) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->error = err;
return 0;
}
if (unlikely(skb_shinfo(head)->frag_list)) {
/* We can't append to an sk_buff that already
* has a frag_list. We create a new head, point
* the frag_list of that to the old head, and
* then are able to use the old head->next for
* appending to the message.
*/
if (WARN_ON(head->next)) {
desc->error = -EINVAL;
return 0;
}
skb = alloc_skb(0, GFP_ATOMIC);
if (!skb) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->error = -ENOMEM;
return 0;
}
skb->len = head->len;
skb->data_len = head->len;
skb->truesize = head->truesize;
*_strp_msg(skb) = *_strp_msg(head);
strp->skb_nextp = &head->next;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
skb_shinfo(skb)->frag_list = head;
strp->skb_head = skb;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
head = skb;
} else {
strp->skb_nextp =
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
&skb_shinfo(head)->frag_list;
}
}
}
while (eaten < orig_len) {
/* Always clone since we will consume something */
skb = skb_clone(orig_skb, GFP_ATOMIC);
if (!skb) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->error = -ENOMEM;
break;
}
cand_len = orig_len - eaten;
head = strp->skb_head;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (!head) {
head = skb;
strp->skb_head = head;
/* Will set skb_nextp on next packet if needed */
strp->skb_nextp = NULL;
stm = _strp_msg(head);
memset(stm, 0, sizeof(*stm));
stm->strp.offset = orig_offset + eaten;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
} else {
/* Unclone since we may be appending to an skb that we
* already share a frag_list with.
*/
err = skb_unclone(skb, GFP_ATOMIC);
if (err) {
STRP_STATS_INCR(strp->stats.mem_fail);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->error = err;
break;
}
stm = _strp_msg(head);
*strp->skb_nextp = skb;
strp->skb_nextp = &skb->next;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
head->data_len += skb->len;
head->len += skb->len;
head->truesize += skb->truesize;
}
if (!stm->strp.full_len) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
ssize_t len;
len = (*strp->cb.parse_msg)(strp, head);
if (!len) {
/* Need more header to determine length */
if (!stm->accum_len) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Start RX timer for new message */
strp_start_timer(strp, timeo);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
stm->accum_len += cand_len;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
eaten += cand_len;
STRP_STATS_INCR(strp->stats.need_more_hdr);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
WARN_ON(eaten != orig_len);
break;
} else if (len < 0) {
if (len == -ESTRPIPE && stm->accum_len) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
len = -ENODATA;
strp->unrecov_intr = 1;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
} else {
strp->interrupted = 1;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
strp_parser_err(strp, len, desc);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
break;
} else if (len > max_msg_size) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Message length exceeds maximum allowed */
STRP_STATS_INCR(strp->stats.msg_too_big);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp_parser_err(strp, -EMSGSIZE, desc);
break;
} else if (len <= (ssize_t)head->len -
skb->len - stm->strp.offset) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Length must be into new skb (and also
* greater than zero)
*/
STRP_STATS_INCR(strp->stats.bad_hdr_len);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp_parser_err(strp, -EPROTO, desc);
break;
}
stm->strp.full_len = len;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
extra = (ssize_t)(stm->accum_len + cand_len) -
stm->strp.full_len;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (extra < 0) {
/* Message not complete yet. */
if (stm->strp.full_len - stm->accum_len >
strp_peek_len(strp)) {
/* Don't have the whole message in the socket
* buffer. Set strp->need_bytes to wait for
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
* the rest of the message. Also, set "early
* eaten" since we've already buffered the skb
* but don't consume yet per strp_read_sock.
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
*/
if (!stm->accum_len) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Start RX timer for new message */
strp_start_timer(strp, timeo);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
strp->need_bytes = stm->strp.full_len -
stm->accum_len;
stm->accum_len += cand_len;
stm->early_eaten = cand_len;
STRP_STATS_ADD(strp->stats.bytes, cand_len);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc->count = 0; /* Stop reading socket */
break;
}
stm->accum_len += cand_len;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
eaten += cand_len;
WARN_ON(eaten != orig_len);
break;
}
/* Positive extra indicates ore bytes than needed for the
* message
*/
WARN_ON(extra > cand_len);
eaten += (cand_len - extra);
/* Hurray, we have a new message! */
del_timer(&strp->msg_timer);
strp->skb_head = NULL;
STRP_STATS_INCR(strp->stats.msgs);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Give skb to upper layer */
strp->cb.rcv_msg(strp, head);
if (unlikely(strp->paused)) {
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
/* Upper layer paused strp */
break;
}
}
if (cloned_orig)
kfree_skb(orig_skb);
STRP_STATS_ADD(strp->stats.bytes, eaten);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return eaten;
}
int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
unsigned int orig_offset, size_t orig_len,
size_t max_msg_size, long timeo)
{
read_descriptor_t desc; /* Dummy arg to strp_recv */
desc.arg.data = strp;
return __strp_recv(&desc, orig_skb, orig_offset, orig_len,
max_msg_size, timeo);
}
EXPORT_SYMBOL_GPL(strp_process);
static int strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
unsigned int orig_offset, size_t orig_len)
{
struct strparser *strp = (struct strparser *)desc->arg.data;
return __strp_recv(desc, orig_skb, orig_offset, orig_len,
strp->sk->sk_rcvbuf, strp->sk->sk_rcvtimeo);
}
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
static int default_read_sock_done(struct strparser *strp, int err)
{
return err;
}
/* Called with lock held on lower socket */
static int strp_read_sock(struct strparser *strp)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
struct socket *sock = strp->sk->sk_socket;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
read_descriptor_t desc;
desc.arg.data = strp;
desc.error = 0;
desc.count = 1; /* give more than one skb per call */
/* sk should be locked here, so okay to do read_sock */
sock->ops->read_sock(strp->sk, &desc, strp_recv);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
desc.error = strp->cb.read_sock_done(strp, desc.error);
return desc.error;
}
/* Lower sock lock held */
void strp_data_ready(struct strparser *strp)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
if (unlikely(strp->stopped))
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return;
/* This check is needed to synchronize with do_strp_work.
* do_strp_work acquires a process lock (lock_sock) whereas
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
* the lock held here is bh_lock_sock. The two locks can be
* held by different threads at the same time, but bh_lock_sock
* allows a thread in BH context to safely check if the process
* lock is held. In this case, if the lock is held, queue work.
*/
if (sock_owned_by_user(strp->sk)) {
queue_work(strp_wq, &strp->work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return;
}
if (strp->paused)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return;
if (strp->need_bytes) {
if (strp_peek_len(strp) >= strp->need_bytes)
strp->need_bytes = 0;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
else
return;
}
if (strp_read_sock(strp) == -ENOMEM)
queue_work(strp_wq, &strp->work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
EXPORT_SYMBOL_GPL(strp_data_ready);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
static void do_strp_work(struct strparser *strp)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
read_descriptor_t rd_desc;
/* We need the read lock to synchronize with strp_data_ready. We
* need the socket lock for calling strp_read_sock.
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
*/
strp->cb.lock(strp);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (unlikely(strp->stopped))
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
goto out;
if (strp->paused)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
goto out;
rd_desc.arg.data = strp;
if (strp_read_sock(strp) == -ENOMEM)
queue_work(strp_wq, &strp->work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
out:
strp->cb.unlock(strp);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
static void strp_work(struct work_struct *w)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
do_strp_work(container_of(w, struct strparser, work));
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
static void strp_msg_timeout(unsigned long arg)
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
{
struct strparser *strp = (struct strparser *)arg;
/* Message assembly timed out */
STRP_STATS_INCR(strp->stats.msg_timeouts);
strp->cb.lock(strp);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp->cb.abort_parser(strp, ETIMEDOUT);
strp->cb.unlock(strp);
}
static void strp_sock_lock(struct strparser *strp)
{
lock_sock(strp->sk);
}
static void strp_sock_unlock(struct strparser *strp)
{
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
release_sock(strp->sk);
}
int strp_init(struct strparser *strp, struct sock *sk,
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
struct strp_callbacks *cb)
{
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (!cb || !cb->rcv_msg || !cb->parse_msg)
return -EINVAL;
/* The sk (sock) arg determines the mode of the stream parser.
*
* If the sock is set then the strparser is in receive callback mode.
* The upper layer calls strp_data_ready to kick receive processing
* and strparser calls the read_sock function on the socket to
* get packets.
*
* If the sock is not set then the strparser is in general mode.
* The upper layer calls strp_process for each skb to be parsed.
*/
if (sk) {
struct socket *sock = sk->sk_socket;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (!sock->ops->read_sock || !sock->ops->peek_len)
return -EAFNOSUPPORT;
} else {
if (!cb->lock || !cb->unlock)
return -EINVAL;
}
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
memset(strp, 0, sizeof(*strp));
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp->sk = sk;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp->cb.lock = cb->lock ? : strp_sock_lock;
strp->cb.unlock = cb->unlock ? : strp_sock_unlock;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
strp->cb.rcv_msg = cb->rcv_msg;
strp->cb.parse_msg = cb->parse_msg;
strp->cb.read_sock_done = cb->read_sock_done ? : default_read_sock_done;
strp->cb.abort_parser = cb->abort_parser ? : strp_abort_strp;
setup_timer(&strp->msg_timer, strp_msg_timeout,
(unsigned long)strp);
INIT_WORK(&strp->work, strp_work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
return 0;
}
EXPORT_SYMBOL_GPL(strp_init);
void strp_unpause(struct strparser *strp)
{
strp->paused = 0;
/* Sync setting paused with RX work */
smp_mb();
queue_work(strp_wq, &strp->work);
}
EXPORT_SYMBOL_GPL(strp_unpause);
/* strp must already be stopped so that strp_recv will no longer be called.
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
* Note that strp_done is not called with the lower socket held.
*/
void strp_done(struct strparser *strp)
{
WARN_ON(!strp->stopped);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
del_timer_sync(&strp->msg_timer);
cancel_work_sync(&strp->work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
if (strp->skb_head) {
kfree_skb(strp->skb_head);
strp->skb_head = NULL;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
}
EXPORT_SYMBOL_GPL(strp_done);
void strp_stop(struct strparser *strp)
{
strp->stopped = 1;
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
EXPORT_SYMBOL_GPL(strp_stop);
void strp_check_rcv(struct strparser *strp)
{
queue_work(strp_wq, &strp->work);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
EXPORT_SYMBOL_GPL(strp_check_rcv);
static int __init strp_mod_init(void)
{
strp_wq = create_singlethread_workqueue("kstrp");
return 0;
}
static void __exit strp_mod_exit(void)
{
destroy_workqueue(strp_wq);
strparser: Stream parser for messages This patch introduces a utility for parsing application layer protocol messages in a TCP stream. This is a generalization of the mechanism implemented of Kernel Connection Multiplexor. The API includes a context structure, a set of callbacks, utility functions, and a data ready function. A stream parser instance is defined by a strparse structure that is bound to a TCP socket. The function to initialize the structure is: int strp_init(struct strparser *strp, struct sock *csk, struct strp_callbacks *cb); csk is the TCP socket being bound to and cb are the parser callbacks. The upper layer calls strp_tcp_data_ready when data is ready on the lower socket for strparser to process. This should be called from a data_ready callback that is set on the socket: void strp_tcp_data_ready(struct strparser *strp); A parser is bound to a TCP socket by setting data_ready function to strp_tcp_data_ready so that all receive indications on the socket go through the parser. This is assumes that sk_user_data is set to the strparser structure. There are four callbacks. - parse_msg is called to parse the message (returns length or error). - rcv_msg is called when a complete message has been received - read_sock_done is called when data_ready function exits - abort_parser is called to abort the parser The input to parse_msg is an skbuff which contains next message under construction. The backend processing of parse_msg will parse the application layer protocol headers to determine the length of the message in the stream. The possible return values are: >0 : indicates length of successfully parsed message 0 : indicates more data must be received to parse the message -ESTRPIPE : current message should not be processed by the kernel, return control of the socket to userspace which can proceed to read the messages itself other < 0 : Error is parsing, give control back to userspace assuming that synchronzation is lost and the stream is unrecoverable (application expected to close TCP socket) In the case of error return (< 0) strparse will stop the parser and report and error to userspace. The application must deal with the error. To handle the error the strparser is unbound from the TCP socket. If the error indicates that the stream TCP socket is at recoverable point (ESTRPIPE) then the application can read the TCP socket to process the stream. Once the application has dealt with the exceptions in the stream, it may again bind the socket to a strparser to continue data operations. Note that ENODATA may be returned to the application. In this case parse_msg returned -ESTRPIPE, however strparser was unable to maintain synchronization of the stream (i.e. some of the message in question was already read by the parser). strp_pause and strp_unpause are used to provide flow control. For instance, if rcv_msg is called but the upper layer can't immediately consume the message it can hold the message and pause strparser. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 21:51:01 +00:00
}
module_init(strp_mod_init);
module_exit(strp_mod_exit);
MODULE_LICENSE("GPL");