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linux/net/dccp/proto.c
Gerrit Renker 59348b19ef [DCCP]: Simplified conditions due to use of enum:8 states 
This reaps the benefit of the earlier patch, which changed the type of
CCID 3 states to use enums, in that many conditions are now simplified
and the number of possible (unexpected) values is greatly reduced.

In a few instances, this also allowed to simplify pre-conditions; where
care has been taken to retain logical equivalence.

[DCCP]: Introduce a consistent BUG/WARN message scheme

This refines the existing set of DCCP messages so that
 * BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts
 * DCCP_CRIT (for severe warnings) is not rate-limited
 * DCCP_WARN() is introduced as rate-limited wrapper

Using these allows a faster and cleaner transition to their original
counterparts once the code has matured into a full DCCP implementation.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:24:38 -08:00

1116 lines
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/*
* net/dccp/proto.c
*
* An implementation of the DCCP protocol
* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* 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/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/random.h>
#include <net/checksum.h>
#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/xfrm.h>
#include <asm/semaphore.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include "ccid.h"
#include "dccp.h"
#include "feat.h"
DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
EXPORT_SYMBOL_GPL(dccp_statistics);
atomic_t dccp_orphan_count = ATOMIC_INIT(0);
EXPORT_SYMBOL_GPL(dccp_orphan_count);
struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
.lhash_lock = RW_LOCK_UNLOCKED,
.lhash_users = ATOMIC_INIT(0),
.lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
};
EXPORT_SYMBOL_GPL(dccp_hashinfo);
/* the maximum queue length for tx in packets. 0 is no limit */
int sysctl_dccp_tx_qlen __read_mostly = 5;
void dccp_set_state(struct sock *sk, const int state)
{
const int oldstate = sk->sk_state;
dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
dccp_role(sk), sk,
dccp_state_name(oldstate), dccp_state_name(state));
WARN_ON(state == oldstate);
switch (state) {
case DCCP_OPEN:
if (oldstate != DCCP_OPEN)
DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
break;
case DCCP_CLOSED:
if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
sk->sk_prot->unhash(sk);
if (inet_csk(sk)->icsk_bind_hash != NULL &&
!(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
inet_put_port(&dccp_hashinfo, sk);
/* fall through */
default:
if (oldstate == DCCP_OPEN)
DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
}
/* Change state AFTER socket is unhashed to avoid closed
* socket sitting in hash tables.
*/
sk->sk_state = state;
}
EXPORT_SYMBOL_GPL(dccp_set_state);
void dccp_done(struct sock *sk)
{
dccp_set_state(sk, DCCP_CLOSED);
dccp_clear_xmit_timers(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_state_change(sk);
else
inet_csk_destroy_sock(sk);
}
EXPORT_SYMBOL_GPL(dccp_done);
const char *dccp_packet_name(const int type)
{
static const char *dccp_packet_names[] = {
[DCCP_PKT_REQUEST] = "REQUEST",
[DCCP_PKT_RESPONSE] = "RESPONSE",
[DCCP_PKT_DATA] = "DATA",
[DCCP_PKT_ACK] = "ACK",
[DCCP_PKT_DATAACK] = "DATAACK",
[DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
[DCCP_PKT_CLOSE] = "CLOSE",
[DCCP_PKT_RESET] = "RESET",
[DCCP_PKT_SYNC] = "SYNC",
[DCCP_PKT_SYNCACK] = "SYNCACK",
};
if (type >= DCCP_NR_PKT_TYPES)
return "INVALID";
else
return dccp_packet_names[type];
}
EXPORT_SYMBOL_GPL(dccp_packet_name);
const char *dccp_state_name(const int state)
{
static char *dccp_state_names[] = {
[DCCP_OPEN] = "OPEN",
[DCCP_REQUESTING] = "REQUESTING",
[DCCP_PARTOPEN] = "PARTOPEN",
[DCCP_LISTEN] = "LISTEN",
[DCCP_RESPOND] = "RESPOND",
[DCCP_CLOSING] = "CLOSING",
[DCCP_TIME_WAIT] = "TIME_WAIT",
[DCCP_CLOSED] = "CLOSED",
};
if (state >= DCCP_MAX_STATES)
return "INVALID STATE!";
else
return dccp_state_names[state];
}
EXPORT_SYMBOL_GPL(dccp_state_name);
void dccp_hash(struct sock *sk)
{
inet_hash(&dccp_hashinfo, sk);
}
EXPORT_SYMBOL_GPL(dccp_hash);
void dccp_unhash(struct sock *sk)
{
inet_unhash(&dccp_hashinfo, sk);
}
EXPORT_SYMBOL_GPL(dccp_unhash);
int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
{
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_minisock *dmsk = dccp_msk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
dccp_minisock_init(&dp->dccps_minisock);
do_gettimeofday(&dp->dccps_epoch);
/*
* FIXME: We're hardcoding the CCID, and doing this at this point makes
* the listening (master) sock get CCID control blocks, which is not
* necessary, but for now, to not mess with the test userspace apps,
* lets leave it here, later the real solution is to do this in a
* setsockopt(CCIDs-I-want/accept). -acme
*/
if (likely(ctl_sock_initialized)) {
int rc = dccp_feat_init(dmsk);
if (rc)
return rc;
if (dmsk->dccpms_send_ack_vector) {
dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
if (dp->dccps_hc_rx_ackvec == NULL)
return -ENOMEM;
}
dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
sk, GFP_KERNEL);
dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
sk, GFP_KERNEL);
if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
dp->dccps_hc_tx_ccid == NULL)) {
ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
if (dmsk->dccpms_send_ack_vector) {
dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
dp->dccps_hc_rx_ackvec = NULL;
}
dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
return -ENOMEM;
}
} else {
/* control socket doesn't need feat nego */
INIT_LIST_HEAD(&dmsk->dccpms_pending);
INIT_LIST_HEAD(&dmsk->dccpms_conf);
}
dccp_init_xmit_timers(sk);
icsk->icsk_rto = DCCP_TIMEOUT_INIT;
icsk->icsk_syn_retries = sysctl_dccp_request_retries;
sk->sk_state = DCCP_CLOSED;
sk->sk_write_space = dccp_write_space;
icsk->icsk_sync_mss = dccp_sync_mss;
dp->dccps_mss_cache = 536;
dp->dccps_role = DCCP_ROLE_UNDEFINED;
dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
return 0;
}
EXPORT_SYMBOL_GPL(dccp_init_sock);
int dccp_destroy_sock(struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_minisock *dmsk = dccp_msk(sk);
/*
* DCCP doesn't use sk_write_queue, just sk_send_head
* for retransmissions
*/
if (sk->sk_send_head != NULL) {
kfree_skb(sk->sk_send_head);
sk->sk_send_head = NULL;
}
/* Clean up a referenced DCCP bind bucket. */
if (inet_csk(sk)->icsk_bind_hash != NULL)
inet_put_port(&dccp_hashinfo, sk);
kfree(dp->dccps_service_list);
dp->dccps_service_list = NULL;
if (dmsk->dccpms_send_ack_vector) {
dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
dp->dccps_hc_rx_ackvec = NULL;
}
ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
/* clean up feature negotiation state */
dccp_feat_clean(dmsk);
return 0;
}
EXPORT_SYMBOL_GPL(dccp_destroy_sock);
static inline int dccp_listen_start(struct sock *sk, int backlog)
{
struct dccp_sock *dp = dccp_sk(sk);
dp->dccps_role = DCCP_ROLE_LISTEN;
return inet_csk_listen_start(sk, backlog);
}
int dccp_disconnect(struct sock *sk, int flags)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct inet_sock *inet = inet_sk(sk);
int err = 0;
const int old_state = sk->sk_state;
if (old_state != DCCP_CLOSED)
dccp_set_state(sk, DCCP_CLOSED);
/* ABORT function of RFC793 */
if (old_state == DCCP_LISTEN) {
inet_csk_listen_stop(sk);
/* FIXME: do the active reset thing */
} else if (old_state == DCCP_REQUESTING)
sk->sk_err = ECONNRESET;
dccp_clear_xmit_timers(sk);
__skb_queue_purge(&sk->sk_receive_queue);
if (sk->sk_send_head != NULL) {
__kfree_skb(sk->sk_send_head);
sk->sk_send_head = NULL;
}
inet->dport = 0;
if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
inet_reset_saddr(sk);
sk->sk_shutdown = 0;
sock_reset_flag(sk, SOCK_DONE);
icsk->icsk_backoff = 0;
inet_csk_delack_init(sk);
__sk_dst_reset(sk);
BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
sk->sk_error_report(sk);
return err;
}
EXPORT_SYMBOL_GPL(dccp_disconnect);
/*
* Wait for a DCCP event.
*
* Note that we don't need to lock the socket, as the upper poll layers
* take care of normal races (between the test and the event) and we don't
* go look at any of the socket buffers directly.
*/
unsigned int dccp_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
unsigned int mask;
struct sock *sk = sock->sk;
poll_wait(file, sk->sk_sleep, wait);
if (sk->sk_state == DCCP_LISTEN)
return inet_csk_listen_poll(sk);
/* Socket is not locked. We are protected from async events
by poll logic and correct handling of state changes
made by another threads is impossible in any case.
*/
mask = 0;
if (sk->sk_err)
mask = POLLERR;
if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
mask |= POLLHUP;
if (sk->sk_shutdown & RCV_SHUTDOWN)
mask |= POLLIN | POLLRDNORM | POLLRDHUP;
/* Connected? */
if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
if (atomic_read(&sk->sk_rmem_alloc) > 0)
mask |= POLLIN | POLLRDNORM;
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
mask |= POLLOUT | POLLWRNORM;
} else { /* send SIGIO later */
set_bit(SOCK_ASYNC_NOSPACE,
&sk->sk_socket->flags);
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
/* Race breaker. If space is freed after
* wspace test but before the flags are set,
* IO signal will be lost.
*/
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
mask |= POLLOUT | POLLWRNORM;
}
}
}
return mask;
}
EXPORT_SYMBOL_GPL(dccp_poll);
int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
dccp_pr_debug("entry\n");
return -ENOIOCTLCMD;
}
EXPORT_SYMBOL_GPL(dccp_ioctl);
static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
char __user *optval, int optlen)
{
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_service_list *sl = NULL;
if (service == DCCP_SERVICE_INVALID_VALUE ||
optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
return -EINVAL;
if (optlen > sizeof(service)) {
sl = kmalloc(optlen, GFP_KERNEL);
if (sl == NULL)
return -ENOMEM;
sl->dccpsl_nr = optlen / sizeof(u32) - 1;
if (copy_from_user(sl->dccpsl_list,
optval + sizeof(service),
optlen - sizeof(service)) ||
dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
kfree(sl);
return -EFAULT;
}
}
lock_sock(sk);
dp->dccps_service = service;
kfree(dp->dccps_service_list);
dp->dccps_service_list = sl;
release_sock(sk);
return 0;
}
/* byte 1 is feature. the rest is the preference list */
static int dccp_setsockopt_change(struct sock *sk, int type,
struct dccp_so_feat __user *optval)
{
struct dccp_so_feat opt;
u8 *val;
int rc;
if (copy_from_user(&opt, optval, sizeof(opt)))
return -EFAULT;
val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
if (!val)
return -ENOMEM;
if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
rc = -EFAULT;
goto out_free_val;
}
rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
val, opt.dccpsf_len, GFP_KERNEL);
if (rc)
goto out_free_val;
out:
return rc;
out_free_val:
kfree(val);
goto out;
}
static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
struct dccp_sock *dp = dccp_sk(sk);
int val, err = 0;
if (optlen < sizeof(int))
return -EINVAL;
if (get_user(val, (int __user *)optval))
return -EFAULT;
if (optname == DCCP_SOCKOPT_SERVICE)
return dccp_setsockopt_service(sk, val, optval, optlen);
lock_sock(sk);
switch (optname) {
case DCCP_SOCKOPT_PACKET_SIZE:
dp->dccps_packet_size = val;
break;
case DCCP_SOCKOPT_CHANGE_L:
if (optlen != sizeof(struct dccp_so_feat))
err = -EINVAL;
else
err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
(struct dccp_so_feat __user *)
optval);
break;
case DCCP_SOCKOPT_CHANGE_R:
if (optlen != sizeof(struct dccp_so_feat))
err = -EINVAL;
else
err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
(struct dccp_so_feat __user *)
optval);
break;
case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */
if (val < 0 || val > 15)
err = -EINVAL;
else
dp->dccps_pcslen = val;
break;
case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */
if (val < 0 || val > 15)
err = -EINVAL;
else {
dp->dccps_pcrlen = val;
/* FIXME: add feature negotiation,
* ChangeL(MinimumChecksumCoverage, val) */
}
break;
default:
err = -ENOPROTOOPT;
break;
}
release_sock(sk);
return err;
}
int dccp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
if (level != SOL_DCCP)
return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
optname, optval,
optlen);
return do_dccp_setsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL_GPL(dccp_setsockopt);
#ifdef CONFIG_COMPAT
int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
if (level != SOL_DCCP)
return inet_csk_compat_setsockopt(sk, level, optname,
optval, optlen);
return do_dccp_setsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
#endif
static int dccp_getsockopt_service(struct sock *sk, int len,
__be32 __user *optval,
int __user *optlen)
{
const struct dccp_sock *dp = dccp_sk(sk);
const struct dccp_service_list *sl;
int err = -ENOENT, slen = 0, total_len = sizeof(u32);
lock_sock(sk);
if ((sl = dp->dccps_service_list) != NULL) {
slen = sl->dccpsl_nr * sizeof(u32);
total_len += slen;
}
err = -EINVAL;
if (total_len > len)
goto out;
err = 0;
if (put_user(total_len, optlen) ||
put_user(dp->dccps_service, optval) ||
(sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
err = -EFAULT;
out:
release_sock(sk);
return err;
}
static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
struct dccp_sock *dp;
int val, len;
if (get_user(len, optlen))
return -EFAULT;
if (len < sizeof(int))
return -EINVAL;
dp = dccp_sk(sk);
switch (optname) {
case DCCP_SOCKOPT_PACKET_SIZE:
val = dp->dccps_packet_size;
len = sizeof(dp->dccps_packet_size);
break;
case DCCP_SOCKOPT_SERVICE:
return dccp_getsockopt_service(sk, len,
(__be32 __user *)optval, optlen);
case DCCP_SOCKOPT_SEND_CSCOV:
val = dp->dccps_pcslen;
break;
case DCCP_SOCKOPT_RECV_CSCOV:
val = dp->dccps_pcrlen;
break;
case 128 ... 191:
return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
len, (u32 __user *)optval, optlen);
case 192 ... 255:
return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
len, (u32 __user *)optval, optlen);
default:
return -ENOPROTOOPT;
}
if (put_user(len, optlen) || copy_to_user(optval, &val, len))
return -EFAULT;
return 0;
}
int dccp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
if (level != SOL_DCCP)
return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
optname, optval,
optlen);
return do_dccp_getsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL_GPL(dccp_getsockopt);
#ifdef CONFIG_COMPAT
int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
if (level != SOL_DCCP)
return inet_csk_compat_getsockopt(sk, level, optname,
optval, optlen);
return do_dccp_getsockopt(sk, level, optname, optval, optlen);
}
EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
#endif
int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
const struct dccp_sock *dp = dccp_sk(sk);
const int flags = msg->msg_flags;
const int noblock = flags & MSG_DONTWAIT;
struct sk_buff *skb;
int rc, size;
long timeo;
if (len > dp->dccps_mss_cache)
return -EMSGSIZE;
lock_sock(sk);
if (sysctl_dccp_tx_qlen &&
(sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
rc = -EAGAIN;
goto out_release;
}
timeo = sock_sndtimeo(sk, noblock);
/*
* We have to use sk_stream_wait_connect here to set sk_write_pending,
* so that the trick in dccp_rcv_request_sent_state_process.
*/
/* Wait for a connection to finish. */
if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
goto out_release;
size = sk->sk_prot->max_header + len;
release_sock(sk);
skb = sock_alloc_send_skb(sk, size, noblock, &rc);
lock_sock(sk);
if (skb == NULL)
goto out_release;
skb_reserve(skb, sk->sk_prot->max_header);
rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
if (rc != 0)
goto out_discard;
skb_queue_tail(&sk->sk_write_queue, skb);
dccp_write_xmit(sk,0);
out_release:
release_sock(sk);
return rc ? : len;
out_discard:
kfree_skb(skb);
goto out_release;
}
EXPORT_SYMBOL_GPL(dccp_sendmsg);
int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len, int nonblock, int flags, int *addr_len)
{
const struct dccp_hdr *dh;
long timeo;
lock_sock(sk);
if (sk->sk_state == DCCP_LISTEN) {
len = -ENOTCONN;
goto out;
}
timeo = sock_rcvtimeo(sk, nonblock);
do {
struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
if (skb == NULL)
goto verify_sock_status;
dh = dccp_hdr(skb);
if (dh->dccph_type == DCCP_PKT_DATA ||
dh->dccph_type == DCCP_PKT_DATAACK)
goto found_ok_skb;
if (dh->dccph_type == DCCP_PKT_RESET ||
dh->dccph_type == DCCP_PKT_CLOSE) {
dccp_pr_debug("found fin ok!\n");
len = 0;
goto found_fin_ok;
}
dccp_pr_debug("packet_type=%s\n",
dccp_packet_name(dh->dccph_type));
sk_eat_skb(sk, skb, 0);
verify_sock_status:
if (sock_flag(sk, SOCK_DONE)) {
len = 0;
break;
}
if (sk->sk_err) {
len = sock_error(sk);
break;
}
if (sk->sk_shutdown & RCV_SHUTDOWN) {
len = 0;
break;
}
if (sk->sk_state == DCCP_CLOSED) {
if (!sock_flag(sk, SOCK_DONE)) {
/* This occurs when user tries to read
* from never connected socket.
*/
len = -ENOTCONN;
break;
}
len = 0;
break;
}
if (!timeo) {
len = -EAGAIN;
break;
}
if (signal_pending(current)) {
len = sock_intr_errno(timeo);
break;
}
sk_wait_data(sk, &timeo);
continue;
found_ok_skb:
if (len > skb->len)
len = skb->len;
else if (len < skb->len)
msg->msg_flags |= MSG_TRUNC;
if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
/* Exception. Bailout! */
len = -EFAULT;
break;
}
found_fin_ok:
if (!(flags & MSG_PEEK))
sk_eat_skb(sk, skb, 0);
break;
} while (1);
out:
release_sock(sk);
return len;
}
EXPORT_SYMBOL_GPL(dccp_recvmsg);
int inet_dccp_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
unsigned char old_state;
int err;
lock_sock(sk);
err = -EINVAL;
if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
goto out;
old_state = sk->sk_state;
if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
goto out;
/* Really, if the socket is already in listen state
* we can only allow the backlog to be adjusted.
*/
if (old_state != DCCP_LISTEN) {
/*
* FIXME: here it probably should be sk->sk_prot->listen_start
* see tcp_listen_start
*/
err = dccp_listen_start(sk, backlog);
if (err)
goto out;
}
sk->sk_max_ack_backlog = backlog;
err = 0;
out:
release_sock(sk);
return err;
}
EXPORT_SYMBOL_GPL(inet_dccp_listen);
static const unsigned char dccp_new_state[] = {
/* current state: new state: action: */
[0] = DCCP_CLOSED,
[DCCP_OPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
[DCCP_REQUESTING] = DCCP_CLOSED,
[DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
[DCCP_LISTEN] = DCCP_CLOSED,
[DCCP_RESPOND] = DCCP_CLOSED,
[DCCP_CLOSING] = DCCP_CLOSED,
[DCCP_TIME_WAIT] = DCCP_CLOSED,
[DCCP_CLOSED] = DCCP_CLOSED,
};
static int dccp_close_state(struct sock *sk)
{
const int next = dccp_new_state[sk->sk_state];
const int ns = next & DCCP_STATE_MASK;
if (ns != sk->sk_state)
dccp_set_state(sk, ns);
return next & DCCP_ACTION_FIN;
}
void dccp_close(struct sock *sk, long timeout)
{
struct dccp_sock *dp = dccp_sk(sk);
struct sk_buff *skb;
int state;
lock_sock(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
if (sk->sk_state == DCCP_LISTEN) {
dccp_set_state(sk, DCCP_CLOSED);
/* Special case. */
inet_csk_listen_stop(sk);
goto adjudge_to_death;
}
sk_stop_timer(sk, &dp->dccps_xmit_timer);
/*
* We need to flush the recv. buffs. We do this only on the
* descriptor close, not protocol-sourced closes, because the
*reader process may not have drained the data yet!
*/
/* FIXME: check for unread data */
while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
__kfree_skb(skb);
}
if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
/* Check zero linger _after_ checking for unread data. */
sk->sk_prot->disconnect(sk, 0);
} else if (dccp_close_state(sk)) {
dccp_send_close(sk, 1);
}
sk_stream_wait_close(sk, timeout);
adjudge_to_death:
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
atomic_inc(sk->sk_prot->orphan_count);
/*
* It is the last release_sock in its life. It will remove backlog.
*/
release_sock(sk);
/*
* Now socket is owned by kernel and we acquire BH lock
* to finish close. No need to check for user refs.
*/
local_bh_disable();
bh_lock_sock(sk);
BUG_TRAP(!sock_owned_by_user(sk));
/* Have we already been destroyed by a softirq or backlog? */
if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
goto out;
/*
* The last release_sock may have processed the CLOSE or RESET
* packet moving sock to CLOSED state, if not we have to fire
* the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
* in draft-ietf-dccp-spec-11. -acme
*/
if (sk->sk_state == DCCP_CLOSING) {
/* FIXME: should start at 2 * RTT */
/* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
inet_csk(sk)->icsk_rto,
DCCP_RTO_MAX);
#if 0
/* Yeah, we should use sk->sk_prot->orphan_count, etc */
dccp_set_state(sk, DCCP_CLOSED);
#endif
}
if (sk->sk_state == DCCP_CLOSED)
inet_csk_destroy_sock(sk);
/* Otherwise, socket is reprieved until protocol close. */
out:
bh_unlock_sock(sk);
local_bh_enable();
sock_put(sk);
}
EXPORT_SYMBOL_GPL(dccp_close);
void dccp_shutdown(struct sock *sk, int how)
{
dccp_pr_debug("entry\n");
}
EXPORT_SYMBOL_GPL(dccp_shutdown);
static int __init dccp_mib_init(void)
{
int rc = -ENOMEM;
dccp_statistics[0] = alloc_percpu(struct dccp_mib);
if (dccp_statistics[0] == NULL)
goto out;
dccp_statistics[1] = alloc_percpu(struct dccp_mib);
if (dccp_statistics[1] == NULL)
goto out_free_one;
rc = 0;
out:
return rc;
out_free_one:
free_percpu(dccp_statistics[0]);
dccp_statistics[0] = NULL;
goto out;
}
static void dccp_mib_exit(void)
{
free_percpu(dccp_statistics[0]);
free_percpu(dccp_statistics[1]);
dccp_statistics[0] = dccp_statistics[1] = NULL;
}
static int thash_entries;
module_param(thash_entries, int, 0444);
MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
#ifdef CONFIG_IP_DCCP_DEBUG
int dccp_debug;
module_param(dccp_debug, int, 0444);
MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
EXPORT_SYMBOL_GPL(dccp_debug);
#endif
static int __init dccp_init(void)
{
unsigned long goal;
int ehash_order, bhash_order, i;
int rc = -ENOBUFS;
dccp_hashinfo.bind_bucket_cachep =
kmem_cache_create("dccp_bind_bucket",
sizeof(struct inet_bind_bucket), 0,
SLAB_HWCACHE_ALIGN, NULL, NULL);
if (!dccp_hashinfo.bind_bucket_cachep)
goto out;
/*
* Size and allocate the main established and bind bucket
* hash tables.
*
* The methodology is similar to that of the buffer cache.
*/
if (num_physpages >= (128 * 1024))
goal = num_physpages >> (21 - PAGE_SHIFT);
else
goal = num_physpages >> (23 - PAGE_SHIFT);
if (thash_entries)
goal = (thash_entries *
sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
;
do {
dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
sizeof(struct inet_ehash_bucket);
dccp_hashinfo.ehash_size >>= 1;
while (dccp_hashinfo.ehash_size &
(dccp_hashinfo.ehash_size - 1))
dccp_hashinfo.ehash_size--;
dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
__get_free_pages(GFP_ATOMIC, ehash_order);
} while (!dccp_hashinfo.ehash && --ehash_order > 0);
if (!dccp_hashinfo.ehash) {
DCCP_CRIT("Failed to allocate DCCP established hash table");
goto out_free_bind_bucket_cachep;
}
for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
rwlock_init(&dccp_hashinfo.ehash[i].lock);
INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
}
bhash_order = ehash_order;
do {
dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
sizeof(struct inet_bind_hashbucket);
if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
bhash_order > 0)
continue;
dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
__get_free_pages(GFP_ATOMIC, bhash_order);
} while (!dccp_hashinfo.bhash && --bhash_order >= 0);
if (!dccp_hashinfo.bhash) {
DCCP_CRIT("Failed to allocate DCCP bind hash table");
goto out_free_dccp_ehash;
}
for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
spin_lock_init(&dccp_hashinfo.bhash[i].lock);
INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
}
rc = dccp_mib_init();
if (rc)
goto out_free_dccp_bhash;
rc = dccp_ackvec_init();
if (rc)
goto out_free_dccp_mib;
rc = dccp_sysctl_init();
if (rc)
goto out_ackvec_exit;
out:
return rc;
out_ackvec_exit:
dccp_ackvec_exit();
out_free_dccp_mib:
dccp_mib_exit();
out_free_dccp_bhash:
free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
dccp_hashinfo.bhash = NULL;
out_free_dccp_ehash:
free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
dccp_hashinfo.ehash = NULL;
out_free_bind_bucket_cachep:
kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
dccp_hashinfo.bind_bucket_cachep = NULL;
goto out;
}
static void __exit dccp_fini(void)
{
dccp_mib_exit();
free_pages((unsigned long)dccp_hashinfo.bhash,
get_order(dccp_hashinfo.bhash_size *
sizeof(struct inet_bind_hashbucket)));
free_pages((unsigned long)dccp_hashinfo.ehash,
get_order(dccp_hashinfo.ehash_size *
sizeof(struct inet_ehash_bucket)));
kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
dccp_ackvec_exit();
dccp_sysctl_exit();
}
module_init(dccp_init);
module_exit(dccp_fini);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
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