mirror of
https://github.com/torvalds/linux.git
synced 2024-12-13 06:32:50 +00:00
561713cf47
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
463 lines
12 KiB
C
463 lines
12 KiB
C
/*
|
|
* net/dccp/options.c
|
|
*
|
|
* An implementation of the DCCP protocol
|
|
* Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
|
|
* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
|
|
* Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
#include <linux/config.h>
|
|
#include <linux/dccp.h>
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
|
|
#include "ackvec.h"
|
|
#include "ccid.h"
|
|
#include "dccp.h"
|
|
|
|
/* stores the default values for new connection. may be changed with sysctl */
|
|
static const struct dccp_options dccpo_default_values = {
|
|
.dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW,
|
|
.dccpo_rx_ccid = DCCPF_INITIAL_CCID,
|
|
.dccpo_tx_ccid = DCCPF_INITIAL_CCID,
|
|
.dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR,
|
|
.dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT,
|
|
};
|
|
|
|
void dccp_options_init(struct dccp_options *dccpo)
|
|
{
|
|
memcpy(dccpo, &dccpo_default_values, sizeof(*dccpo));
|
|
}
|
|
|
|
static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
|
|
{
|
|
u32 value = 0;
|
|
|
|
if (len > 3)
|
|
value += *bf++ << 24;
|
|
if (len > 2)
|
|
value += *bf++ << 16;
|
|
if (len > 1)
|
|
value += *bf++ << 8;
|
|
if (len > 0)
|
|
value += *bf;
|
|
|
|
return value;
|
|
}
|
|
|
|
int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
#ifdef CONFIG_IP_DCCP_DEBUG
|
|
const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
|
|
"CLIENT rx opt: " : "server rx opt: ";
|
|
#endif
|
|
const struct dccp_hdr *dh = dccp_hdr(skb);
|
|
const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
|
|
unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
|
|
unsigned char *opt_ptr = options;
|
|
const unsigned char *opt_end = (unsigned char *)dh +
|
|
(dh->dccph_doff * 4);
|
|
struct dccp_options_received *opt_recv = &dp->dccps_options_received;
|
|
unsigned char opt, len;
|
|
unsigned char *value;
|
|
u32 elapsed_time;
|
|
|
|
memset(opt_recv, 0, sizeof(*opt_recv));
|
|
|
|
while (opt_ptr != opt_end) {
|
|
opt = *opt_ptr++;
|
|
len = 0;
|
|
value = NULL;
|
|
|
|
/* Check if this isn't a single byte option */
|
|
if (opt > DCCPO_MAX_RESERVED) {
|
|
if (opt_ptr == opt_end)
|
|
goto out_invalid_option;
|
|
|
|
len = *opt_ptr++;
|
|
if (len < 3)
|
|
goto out_invalid_option;
|
|
/*
|
|
* Remove the type and len fields, leaving
|
|
* just the value size
|
|
*/
|
|
len -= 2;
|
|
value = opt_ptr;
|
|
opt_ptr += len;
|
|
|
|
if (opt_ptr > opt_end)
|
|
goto out_invalid_option;
|
|
}
|
|
|
|
switch (opt) {
|
|
case DCCPO_PADDING:
|
|
break;
|
|
case DCCPO_NDP_COUNT:
|
|
if (len > 3)
|
|
goto out_invalid_option;
|
|
|
|
opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
|
|
dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
|
|
opt_recv->dccpor_ndp);
|
|
break;
|
|
case DCCPO_ACK_VECTOR_0:
|
|
case DCCPO_ACK_VECTOR_1:
|
|
if (pkt_type == DCCP_PKT_DATA)
|
|
continue;
|
|
|
|
if (dp->dccps_options.dccpo_send_ack_vector &&
|
|
dccp_ackvec_parse(sk, skb, opt, value, len))
|
|
goto out_invalid_option;
|
|
break;
|
|
case DCCPO_TIMESTAMP:
|
|
if (len != 4)
|
|
goto out_invalid_option;
|
|
|
|
opt_recv->dccpor_timestamp = ntohl(*(u32 *)value);
|
|
|
|
dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
|
|
dccp_timestamp(sk, &dp->dccps_timestamp_time);
|
|
|
|
dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
|
|
debug_prefix, opt_recv->dccpor_timestamp,
|
|
(unsigned long long)
|
|
DCCP_SKB_CB(skb)->dccpd_ack_seq);
|
|
break;
|
|
case DCCPO_TIMESTAMP_ECHO:
|
|
if (len != 4 && len != 6 && len != 8)
|
|
goto out_invalid_option;
|
|
|
|
opt_recv->dccpor_timestamp_echo = ntohl(*(u32 *)value);
|
|
|
|
dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
|
|
debug_prefix,
|
|
opt_recv->dccpor_timestamp_echo,
|
|
len + 2,
|
|
(unsigned long long)
|
|
DCCP_SKB_CB(skb)->dccpd_ack_seq);
|
|
|
|
|
|
if (len == 4)
|
|
break;
|
|
|
|
if (len == 6)
|
|
elapsed_time = ntohs(*(u16 *)(value + 4));
|
|
else
|
|
elapsed_time = ntohl(*(u32 *)(value + 4));
|
|
|
|
/* Give precedence to the biggest ELAPSED_TIME */
|
|
if (elapsed_time > opt_recv->dccpor_elapsed_time)
|
|
opt_recv->dccpor_elapsed_time = elapsed_time;
|
|
break;
|
|
case DCCPO_ELAPSED_TIME:
|
|
if (len != 2 && len != 4)
|
|
goto out_invalid_option;
|
|
|
|
if (pkt_type == DCCP_PKT_DATA)
|
|
continue;
|
|
|
|
if (len == 2)
|
|
elapsed_time = ntohs(*(u16 *)value);
|
|
else
|
|
elapsed_time = ntohl(*(u32 *)value);
|
|
|
|
if (elapsed_time > opt_recv->dccpor_elapsed_time)
|
|
opt_recv->dccpor_elapsed_time = elapsed_time;
|
|
|
|
dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
|
|
elapsed_time);
|
|
break;
|
|
/*
|
|
* From draft-ietf-dccp-spec-11.txt:
|
|
*
|
|
* Option numbers 128 through 191 are for
|
|
* options sent from the HC-Sender to the
|
|
* HC-Receiver; option numbers 192 through 255
|
|
* are for options sent from the HC-Receiver to
|
|
* the HC-Sender.
|
|
*/
|
|
case 128 ... 191: {
|
|
const u16 idx = value - options;
|
|
|
|
if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
|
|
opt, len, idx,
|
|
value) != 0)
|
|
goto out_invalid_option;
|
|
}
|
|
break;
|
|
case 192 ... 255: {
|
|
const u16 idx = value - options;
|
|
|
|
if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
|
|
opt, len, idx,
|
|
value) != 0)
|
|
goto out_invalid_option;
|
|
}
|
|
break;
|
|
default:
|
|
pr_info("DCCP(%p): option %d(len=%d) not "
|
|
"implemented, ignoring\n",
|
|
sk, opt, len);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_invalid_option:
|
|
DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
|
|
DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
|
|
pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
|
|
return -1;
|
|
}
|
|
|
|
static void dccp_encode_value_var(const u32 value, unsigned char *to,
|
|
const unsigned int len)
|
|
{
|
|
if (len > 3)
|
|
*to++ = (value & 0xFF000000) >> 24;
|
|
if (len > 2)
|
|
*to++ = (value & 0xFF0000) >> 16;
|
|
if (len > 1)
|
|
*to++ = (value & 0xFF00) >> 8;
|
|
if (len > 0)
|
|
*to++ = (value & 0xFF);
|
|
}
|
|
|
|
static inline int dccp_ndp_len(const int ndp)
|
|
{
|
|
return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
|
|
}
|
|
|
|
void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
|
|
const unsigned char option,
|
|
const void *value, const unsigned char len)
|
|
{
|
|
unsigned char *to;
|
|
|
|
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
|
|
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
|
|
"%d option!\n", option);
|
|
return;
|
|
}
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
|
|
|
|
to = skb_push(skb, len + 2);
|
|
*to++ = option;
|
|
*to++ = len + 2;
|
|
|
|
memcpy(to, value, len);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_insert_option);
|
|
|
|
static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
int ndp = dp->dccps_ndp_count;
|
|
|
|
if (dccp_non_data_packet(skb))
|
|
++dp->dccps_ndp_count;
|
|
else
|
|
dp->dccps_ndp_count = 0;
|
|
|
|
if (ndp > 0) {
|
|
unsigned char *ptr;
|
|
const int ndp_len = dccp_ndp_len(ndp);
|
|
const int len = ndp_len + 2;
|
|
|
|
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
|
|
return;
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
|
|
|
|
ptr = skb_push(skb, len);
|
|
*ptr++ = DCCPO_NDP_COUNT;
|
|
*ptr++ = len;
|
|
dccp_encode_value_var(ndp, ptr, ndp_len);
|
|
}
|
|
}
|
|
|
|
static inline int dccp_elapsed_time_len(const u32 elapsed_time)
|
|
{
|
|
return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
|
|
}
|
|
|
|
void dccp_insert_option_elapsed_time(struct sock *sk,
|
|
struct sk_buff *skb,
|
|
u32 elapsed_time)
|
|
{
|
|
#ifdef CONFIG_IP_DCCP_DEBUG
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
|
|
"CLIENT TX opt: " : "server TX opt: ";
|
|
#endif
|
|
const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
|
|
const int len = 2 + elapsed_time_len;
|
|
unsigned char *to;
|
|
|
|
if (elapsed_time_len == 0)
|
|
return;
|
|
|
|
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
|
|
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
|
|
"insert elapsed time!\n");
|
|
return;
|
|
}
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
|
|
|
|
to = skb_push(skb, len);
|
|
*to++ = DCCPO_ELAPSED_TIME;
|
|
*to++ = len;
|
|
|
|
if (elapsed_time_len == 2) {
|
|
const u16 var16 = htons((u16)elapsed_time);
|
|
memcpy(to, &var16, 2);
|
|
} else {
|
|
const u32 var32 = htonl(elapsed_time);
|
|
memcpy(to, &var32, 4);
|
|
}
|
|
|
|
dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
|
|
debug_prefix, elapsed_time,
|
|
len,
|
|
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
|
|
|
|
void dccp_timestamp(const struct sock *sk, struct timeval *tv)
|
|
{
|
|
const struct dccp_sock *dp = dccp_sk(sk);
|
|
|
|
do_gettimeofday(tv);
|
|
tv->tv_sec -= dp->dccps_epoch.tv_sec;
|
|
tv->tv_usec -= dp->dccps_epoch.tv_usec;
|
|
|
|
while (tv->tv_usec < 0) {
|
|
tv->tv_sec--;
|
|
tv->tv_usec += USEC_PER_SEC;
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_timestamp);
|
|
|
|
void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct timeval tv;
|
|
u32 now;
|
|
|
|
dccp_timestamp(sk, &tv);
|
|
now = timeval_usecs(&tv) / 10;
|
|
/* yes this will overflow but that is the point as we want a
|
|
* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
|
|
|
|
now = htonl(now);
|
|
dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
|
|
|
|
static void dccp_insert_option_timestamp_echo(struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
#ifdef CONFIG_IP_DCCP_DEBUG
|
|
const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
|
|
"CLIENT TX opt: " : "server TX opt: ";
|
|
#endif
|
|
struct timeval now;
|
|
u32 tstamp_echo;
|
|
u32 elapsed_time;
|
|
int len, elapsed_time_len;
|
|
unsigned char *to;
|
|
|
|
dccp_timestamp(sk, &now);
|
|
elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
|
|
elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
|
|
len = 6 + elapsed_time_len;
|
|
|
|
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
|
|
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
|
|
"timestamp echo!\n");
|
|
return;
|
|
}
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
|
|
|
|
to = skb_push(skb, len);
|
|
*to++ = DCCPO_TIMESTAMP_ECHO;
|
|
*to++ = len;
|
|
|
|
tstamp_echo = htonl(dp->dccps_timestamp_echo);
|
|
memcpy(to, &tstamp_echo, 4);
|
|
to += 4;
|
|
|
|
if (elapsed_time_len == 2) {
|
|
const u16 var16 = htons((u16)elapsed_time);
|
|
memcpy(to, &var16, 2);
|
|
} else if (elapsed_time_len == 4) {
|
|
const u32 var32 = htonl(elapsed_time);
|
|
memcpy(to, &var32, 4);
|
|
}
|
|
|
|
dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
|
|
debug_prefix, dp->dccps_timestamp_echo,
|
|
len,
|
|
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
|
|
|
|
dp->dccps_timestamp_echo = 0;
|
|
dp->dccps_timestamp_time.tv_sec = 0;
|
|
dp->dccps_timestamp_time.tv_usec = 0;
|
|
}
|
|
|
|
void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
|
|
|
|
if (dp->dccps_options.dccpo_send_ndp_count)
|
|
dccp_insert_option_ndp(sk, skb);
|
|
|
|
if (!dccp_packet_without_ack(skb)) {
|
|
if (dp->dccps_options.dccpo_send_ack_vector &&
|
|
dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
|
|
dccp_insert_option_ackvec(sk, skb);
|
|
if (dp->dccps_timestamp_echo != 0)
|
|
dccp_insert_option_timestamp_echo(sk, skb);
|
|
}
|
|
|
|
if (dp->dccps_hc_rx_insert_options) {
|
|
ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
|
|
dp->dccps_hc_rx_insert_options = 0;
|
|
}
|
|
if (dp->dccps_hc_tx_insert_options) {
|
|
ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
|
|
dp->dccps_hc_tx_insert_options = 0;
|
|
}
|
|
|
|
/* XXX: insert other options when appropriate */
|
|
|
|
if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
|
|
/* The length of all options has to be a multiple of 4 */
|
|
int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
|
|
|
|
if (padding != 0) {
|
|
padding = 4 - padding;
|
|
memset(skb_push(skb, padding), 0, padding);
|
|
DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
|
|
}
|
|
}
|
|
}
|