4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/dccp.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/skbuff.h>
18 #include <linux/netdevice.h>
20 #include <linux/if_arp.h>
21 #include <linux/init.h>
22 #include <linux/random.h>
23 #include <linux/slab.h>
24 #include <net/checksum.h>
26 #include <net/inet_sock.h>
30 #include <asm/ioctls.h>
31 #include <linux/spinlock.h>
32 #include <linux/timer.h>
33 #include <linux/delay.h>
34 #include <linux/poll.h>
40 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
42 EXPORT_SYMBOL_GPL(dccp_statistics);
44 struct percpu_counter dccp_orphan_count;
45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
47 struct inet_hashinfo dccp_hashinfo;
48 EXPORT_SYMBOL_GPL(dccp_hashinfo);
50 /* the maximum queue length for tx in packets. 0 is no limit */
51 int sysctl_dccp_tx_qlen __read_mostly = 5;
53 #ifdef CONFIG_IP_DCCP_DEBUG
54 static const char *dccp_state_name(const int state)
56 static const char *const dccp_state_names[] = {
58 [DCCP_REQUESTING] = "REQUESTING",
59 [DCCP_PARTOPEN] = "PARTOPEN",
60 [DCCP_LISTEN] = "LISTEN",
61 [DCCP_RESPOND] = "RESPOND",
62 [DCCP_CLOSING] = "CLOSING",
63 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ",
64 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE",
65 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
66 [DCCP_TIME_WAIT] = "TIME_WAIT",
67 [DCCP_CLOSED] = "CLOSED",
70 if (state >= DCCP_MAX_STATES)
71 return "INVALID STATE!";
73 return dccp_state_names[state];
77 void dccp_set_state(struct sock *sk, const int state)
79 const int oldstate = sk->sk_state;
81 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk,
82 dccp_state_name(oldstate), dccp_state_name(state));
83 WARN_ON(state == oldstate);
87 if (oldstate != DCCP_OPEN)
88 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
89 /* Client retransmits all Confirm options until entering OPEN */
90 if (oldstate == DCCP_PARTOPEN)
91 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
95 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
96 oldstate == DCCP_CLOSING)
97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
99 sk->sk_prot->unhash(sk);
100 if (inet_csk(sk)->icsk_bind_hash != NULL &&
101 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
105 if (oldstate == DCCP_OPEN)
106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
109 /* Change state AFTER socket is unhashed to avoid closed
110 * socket sitting in hash tables.
112 sk->sk_state = state;
115 EXPORT_SYMBOL_GPL(dccp_set_state);
117 static void dccp_finish_passive_close(struct sock *sk)
119 switch (sk->sk_state) {
120 case DCCP_PASSIVE_CLOSE:
121 /* Node (client or server) has received Close packet. */
122 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
123 dccp_set_state(sk, DCCP_CLOSED);
125 case DCCP_PASSIVE_CLOSEREQ:
127 * Client received CloseReq. We set the `active' flag so that
128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
130 dccp_send_close(sk, 1);
131 dccp_set_state(sk, DCCP_CLOSING);
135 void dccp_done(struct sock *sk)
137 dccp_set_state(sk, DCCP_CLOSED);
138 dccp_clear_xmit_timers(sk);
140 sk->sk_shutdown = SHUTDOWN_MASK;
142 if (!sock_flag(sk, SOCK_DEAD))
143 sk->sk_state_change(sk);
145 inet_csk_destroy_sock(sk);
148 EXPORT_SYMBOL_GPL(dccp_done);
150 const char *dccp_packet_name(const int type)
152 static const char *const dccp_packet_names[] = {
153 [DCCP_PKT_REQUEST] = "REQUEST",
154 [DCCP_PKT_RESPONSE] = "RESPONSE",
155 [DCCP_PKT_DATA] = "DATA",
156 [DCCP_PKT_ACK] = "ACK",
157 [DCCP_PKT_DATAACK] = "DATAACK",
158 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
159 [DCCP_PKT_CLOSE] = "CLOSE",
160 [DCCP_PKT_RESET] = "RESET",
161 [DCCP_PKT_SYNC] = "SYNC",
162 [DCCP_PKT_SYNCACK] = "SYNCACK",
165 if (type >= DCCP_NR_PKT_TYPES)
168 return dccp_packet_names[type];
171 EXPORT_SYMBOL_GPL(dccp_packet_name);
173 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
175 struct dccp_sock *dp = dccp_sk(sk);
176 struct inet_connection_sock *icsk = inet_csk(sk);
178 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
179 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
180 sk->sk_state = DCCP_CLOSED;
181 sk->sk_write_space = dccp_write_space;
182 icsk->icsk_sync_mss = dccp_sync_mss;
183 dp->dccps_mss_cache = 536;
184 dp->dccps_rate_last = jiffies;
185 dp->dccps_role = DCCP_ROLE_UNDEFINED;
186 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
187 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
189 dccp_init_xmit_timers(sk);
191 INIT_LIST_HEAD(&dp->dccps_featneg);
192 /* control socket doesn't need feat nego */
193 if (likely(ctl_sock_initialized))
194 return dccp_feat_init(sk);
198 EXPORT_SYMBOL_GPL(dccp_init_sock);
200 void dccp_destroy_sock(struct sock *sk)
202 struct dccp_sock *dp = dccp_sk(sk);
205 * DCCP doesn't use sk_write_queue, just sk_send_head
206 * for retransmissions
208 if (sk->sk_send_head != NULL) {
209 kfree_skb(sk->sk_send_head);
210 sk->sk_send_head = NULL;
213 /* Clean up a referenced DCCP bind bucket. */
214 if (inet_csk(sk)->icsk_bind_hash != NULL)
217 kfree(dp->dccps_service_list);
218 dp->dccps_service_list = NULL;
220 if (dp->dccps_hc_rx_ackvec != NULL) {
221 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
222 dp->dccps_hc_rx_ackvec = NULL;
224 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
225 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
226 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
228 /* clean up feature negotiation state */
229 dccp_feat_list_purge(&dp->dccps_featneg);
232 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
234 static inline int dccp_listen_start(struct sock *sk, int backlog)
236 struct dccp_sock *dp = dccp_sk(sk);
238 dp->dccps_role = DCCP_ROLE_LISTEN;
239 /* do not start to listen if feature negotiation setup fails */
240 if (dccp_feat_finalise_settings(dp))
242 return inet_csk_listen_start(sk, backlog);
245 static inline int dccp_need_reset(int state)
247 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
248 state != DCCP_REQUESTING;
251 int dccp_disconnect(struct sock *sk, int flags)
253 struct inet_connection_sock *icsk = inet_csk(sk);
254 struct inet_sock *inet = inet_sk(sk);
255 struct dccp_sock *dp = dccp_sk(sk);
257 const int old_state = sk->sk_state;
259 if (old_state != DCCP_CLOSED)
260 dccp_set_state(sk, DCCP_CLOSED);
263 * This corresponds to the ABORT function of RFC793, sec. 3.8
264 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
266 if (old_state == DCCP_LISTEN) {
267 inet_csk_listen_stop(sk);
268 } else if (dccp_need_reset(old_state)) {
269 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
270 sk->sk_err = ECONNRESET;
271 } else if (old_state == DCCP_REQUESTING)
272 sk->sk_err = ECONNRESET;
274 dccp_clear_xmit_timers(sk);
275 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
276 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
277 dp->dccps_hc_rx_ccid = NULL;
278 dp->dccps_hc_tx_ccid = NULL;
280 __skb_queue_purge(&sk->sk_receive_queue);
281 __skb_queue_purge(&sk->sk_write_queue);
282 if (sk->sk_send_head != NULL) {
283 __kfree_skb(sk->sk_send_head);
284 sk->sk_send_head = NULL;
287 inet->inet_dport = 0;
289 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
290 inet_reset_saddr(sk);
293 sock_reset_flag(sk, SOCK_DONE);
295 icsk->icsk_backoff = 0;
296 inet_csk_delack_init(sk);
299 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
301 sk->sk_error_report(sk);
305 EXPORT_SYMBOL_GPL(dccp_disconnect);
308 * Wait for a DCCP event.
310 * Note that we don't need to lock the socket, as the upper poll layers
311 * take care of normal races (between the test and the event) and we don't
312 * go look at any of the socket buffers directly.
314 unsigned int dccp_poll(struct file *file, struct socket *sock,
318 struct sock *sk = sock->sk;
320 sock_poll_wait(file, sk_sleep(sk), wait);
321 if (sk->sk_state == DCCP_LISTEN)
322 return inet_csk_listen_poll(sk);
324 /* Socket is not locked. We are protected from async events
325 by poll logic and correct handling of state changes
326 made by another threads is impossible in any case.
333 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
335 if (sk->sk_shutdown & RCV_SHUTDOWN)
336 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
339 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
340 if (atomic_read(&sk->sk_rmem_alloc) > 0)
341 mask |= POLLIN | POLLRDNORM;
343 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
344 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
345 mask |= POLLOUT | POLLWRNORM;
346 } else { /* send SIGIO later */
347 set_bit(SOCK_ASYNC_NOSPACE,
348 &sk->sk_socket->flags);
349 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
351 /* Race breaker. If space is freed after
352 * wspace test but before the flags are set,
353 * IO signal will be lost.
355 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
356 mask |= POLLOUT | POLLWRNORM;
363 EXPORT_SYMBOL_GPL(dccp_poll);
365 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
371 if (sk->sk_state == DCCP_LISTEN)
377 unsigned long amount = 0;
379 skb = skb_peek(&sk->sk_receive_queue);
382 * We will only return the amount of this packet since
383 * that is all that will be read.
387 rc = put_user(amount, (int __user *)arg);
399 EXPORT_SYMBOL_GPL(dccp_ioctl);
401 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
402 char __user *optval, unsigned int optlen)
404 struct dccp_sock *dp = dccp_sk(sk);
405 struct dccp_service_list *sl = NULL;
407 if (service == DCCP_SERVICE_INVALID_VALUE ||
408 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
411 if (optlen > sizeof(service)) {
412 sl = kmalloc(optlen, GFP_KERNEL);
416 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
417 if (copy_from_user(sl->dccpsl_list,
418 optval + sizeof(service),
419 optlen - sizeof(service)) ||
420 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
427 dp->dccps_service = service;
429 kfree(dp->dccps_service_list);
431 dp->dccps_service_list = sl;
436 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
441 if (cscov < 0 || cscov > 15)
444 * Populate a list of permissible values, in the range cscov...15. This
445 * is necessary since feature negotiation of single values only works if
446 * both sides incidentally choose the same value. Since the list starts
447 * lowest-value first, negotiation will pick the smallest shared value.
453 list = kmalloc(len, GFP_KERNEL);
457 for (i = 0; i < len; i++)
460 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
464 dccp_sk(sk)->dccps_pcrlen = cscov;
466 dccp_sk(sk)->dccps_pcslen = cscov;
472 static int dccp_setsockopt_ccid(struct sock *sk, int type,
473 char __user *optval, unsigned int optlen)
478 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
481 val = memdup_user(optval, optlen);
486 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
487 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
489 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
490 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
497 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
498 char __user *optval, unsigned int optlen)
500 struct dccp_sock *dp = dccp_sk(sk);
504 case DCCP_SOCKOPT_PACKET_SIZE:
505 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
507 case DCCP_SOCKOPT_CHANGE_L:
508 case DCCP_SOCKOPT_CHANGE_R:
509 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
511 case DCCP_SOCKOPT_CCID:
512 case DCCP_SOCKOPT_RX_CCID:
513 case DCCP_SOCKOPT_TX_CCID:
514 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
517 if (optlen < (int)sizeof(int))
520 if (get_user(val, (int __user *)optval))
523 if (optname == DCCP_SOCKOPT_SERVICE)
524 return dccp_setsockopt_service(sk, val, optval, optlen);
528 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
529 if (dp->dccps_role != DCCP_ROLE_SERVER)
532 dp->dccps_server_timewait = (val != 0);
534 case DCCP_SOCKOPT_SEND_CSCOV:
535 err = dccp_setsockopt_cscov(sk, val, false);
537 case DCCP_SOCKOPT_RECV_CSCOV:
538 err = dccp_setsockopt_cscov(sk, val, true);
540 case DCCP_SOCKOPT_QPOLICY_ID:
541 if (sk->sk_state != DCCP_CLOSED)
543 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
546 dp->dccps_qpolicy = val;
548 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
552 dp->dccps_tx_qlen = val;
563 int dccp_setsockopt(struct sock *sk, int level, int optname,
564 char __user *optval, unsigned int optlen)
566 if (level != SOL_DCCP)
567 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
570 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
573 EXPORT_SYMBOL_GPL(dccp_setsockopt);
576 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
577 char __user *optval, unsigned int optlen)
579 if (level != SOL_DCCP)
580 return inet_csk_compat_setsockopt(sk, level, optname,
582 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
585 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
588 static int dccp_getsockopt_service(struct sock *sk, int len,
589 __be32 __user *optval,
592 const struct dccp_sock *dp = dccp_sk(sk);
593 const struct dccp_service_list *sl;
594 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
597 if ((sl = dp->dccps_service_list) != NULL) {
598 slen = sl->dccpsl_nr * sizeof(u32);
607 if (put_user(total_len, optlen) ||
608 put_user(dp->dccps_service, optval) ||
609 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
616 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
617 char __user *optval, int __user *optlen)
619 struct dccp_sock *dp;
622 if (get_user(len, optlen))
625 if (len < (int)sizeof(int))
631 case DCCP_SOCKOPT_PACKET_SIZE:
632 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
634 case DCCP_SOCKOPT_SERVICE:
635 return dccp_getsockopt_service(sk, len,
636 (__be32 __user *)optval, optlen);
637 case DCCP_SOCKOPT_GET_CUR_MPS:
638 val = dp->dccps_mss_cache;
640 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
641 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
642 case DCCP_SOCKOPT_TX_CCID:
643 val = ccid_get_current_tx_ccid(dp);
647 case DCCP_SOCKOPT_RX_CCID:
648 val = ccid_get_current_rx_ccid(dp);
652 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
653 val = dp->dccps_server_timewait;
655 case DCCP_SOCKOPT_SEND_CSCOV:
656 val = dp->dccps_pcslen;
658 case DCCP_SOCKOPT_RECV_CSCOV:
659 val = dp->dccps_pcrlen;
661 case DCCP_SOCKOPT_QPOLICY_ID:
662 val = dp->dccps_qpolicy;
664 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
665 val = dp->dccps_tx_qlen;
668 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
669 len, (u32 __user *)optval, optlen);
671 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
672 len, (u32 __user *)optval, optlen);
678 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
684 int dccp_getsockopt(struct sock *sk, int level, int optname,
685 char __user *optval, int __user *optlen)
687 if (level != SOL_DCCP)
688 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
691 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
694 EXPORT_SYMBOL_GPL(dccp_getsockopt);
697 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
698 char __user *optval, int __user *optlen)
700 if (level != SOL_DCCP)
701 return inet_csk_compat_getsockopt(sk, level, optname,
703 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
706 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
709 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
711 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
714 * Assign an (opaque) qpolicy priority value to skb->priority.
716 * We are overloading this skb field for use with the qpolicy subystem.
717 * The skb->priority is normally used for the SO_PRIORITY option, which
718 * is initialised from sk_priority. Since the assignment of sk_priority
719 * to skb->priority happens later (on layer 3), we overload this field
720 * for use with queueing priorities as long as the skb is on layer 4.
721 * The default priority value (if nothing is set) is 0.
725 for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
727 if (!CMSG_OK(msg, cmsg))
730 if (cmsg->cmsg_level != SOL_DCCP)
733 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
734 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
737 switch (cmsg->cmsg_type) {
738 case DCCP_SCM_PRIORITY:
739 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
741 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
750 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
753 const struct dccp_sock *dp = dccp_sk(sk);
754 const int flags = msg->msg_flags;
755 const int noblock = flags & MSG_DONTWAIT;
760 if (len > dp->dccps_mss_cache)
765 if (dccp_qpolicy_full(sk)) {
770 timeo = sock_sndtimeo(sk, noblock);
773 * We have to use sk_stream_wait_connect here to set sk_write_pending,
774 * so that the trick in dccp_rcv_request_sent_state_process.
776 /* Wait for a connection to finish. */
777 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
778 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
781 size = sk->sk_prot->max_header + len;
783 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
788 if (sk->sk_state == DCCP_CLOSED) {
793 skb_reserve(skb, sk->sk_prot->max_header);
794 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
798 rc = dccp_msghdr_parse(msg, skb);
802 dccp_qpolicy_push(sk, skb);
804 * The xmit_timer is set if the TX CCID is rate-based and will expire
805 * when congestion control permits to release further packets into the
806 * network. Window-based CCIDs do not use this timer.
808 if (!timer_pending(&dp->dccps_xmit_timer))
818 EXPORT_SYMBOL_GPL(dccp_sendmsg);
820 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
821 size_t len, int nonblock, int flags, int *addr_len)
823 const struct dccp_hdr *dh;
828 if (sk->sk_state == DCCP_LISTEN) {
833 timeo = sock_rcvtimeo(sk, nonblock);
836 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
839 goto verify_sock_status;
843 switch (dh->dccph_type) {
845 case DCCP_PKT_DATAACK:
849 case DCCP_PKT_CLOSEREQ:
850 if (!(flags & MSG_PEEK))
851 dccp_finish_passive_close(sk);
854 dccp_pr_debug("found fin (%s) ok!\n",
855 dccp_packet_name(dh->dccph_type));
859 dccp_pr_debug("packet_type=%s\n",
860 dccp_packet_name(dh->dccph_type));
861 sk_eat_skb(sk, skb, 0);
864 if (sock_flag(sk, SOCK_DONE)) {
870 len = sock_error(sk);
874 if (sk->sk_shutdown & RCV_SHUTDOWN) {
879 if (sk->sk_state == DCCP_CLOSED) {
880 if (!sock_flag(sk, SOCK_DONE)) {
881 /* This occurs when user tries to read
882 * from never connected socket.
896 if (signal_pending(current)) {
897 len = sock_intr_errno(timeo);
901 sk_wait_data(sk, &timeo);
906 else if (len < skb->len)
907 msg->msg_flags |= MSG_TRUNC;
909 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
910 /* Exception. Bailout! */
914 if (flags & MSG_TRUNC)
917 if (!(flags & MSG_PEEK))
918 sk_eat_skb(sk, skb, 0);
926 EXPORT_SYMBOL_GPL(dccp_recvmsg);
928 int inet_dccp_listen(struct socket *sock, int backlog)
930 struct sock *sk = sock->sk;
931 unsigned char old_state;
937 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
940 old_state = sk->sk_state;
941 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
944 /* Really, if the socket is already in listen state
945 * we can only allow the backlog to be adjusted.
947 if (old_state != DCCP_LISTEN) {
949 * FIXME: here it probably should be sk->sk_prot->listen_start
950 * see tcp_listen_start
952 err = dccp_listen_start(sk, backlog);
956 sk->sk_max_ack_backlog = backlog;
964 EXPORT_SYMBOL_GPL(inet_dccp_listen);
966 static void dccp_terminate_connection(struct sock *sk)
968 u8 next_state = DCCP_CLOSED;
970 switch (sk->sk_state) {
971 case DCCP_PASSIVE_CLOSE:
972 case DCCP_PASSIVE_CLOSEREQ:
973 dccp_finish_passive_close(sk);
976 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
977 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
980 dccp_send_close(sk, 1);
982 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
983 !dccp_sk(sk)->dccps_server_timewait)
984 next_state = DCCP_ACTIVE_CLOSEREQ;
986 next_state = DCCP_CLOSING;
989 dccp_set_state(sk, next_state);
993 void dccp_close(struct sock *sk, long timeout)
995 struct dccp_sock *dp = dccp_sk(sk);
997 u32 data_was_unread = 0;
1002 sk->sk_shutdown = SHUTDOWN_MASK;
1004 if (sk->sk_state == DCCP_LISTEN) {
1005 dccp_set_state(sk, DCCP_CLOSED);
1008 inet_csk_listen_stop(sk);
1010 goto adjudge_to_death;
1013 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1016 * We need to flush the recv. buffs. We do this only on the
1017 * descriptor close, not protocol-sourced closes, because the
1018 *reader process may not have drained the data yet!
1020 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1021 data_was_unread += skb->len;
1025 /* If socket has been already reset kill it. */
1026 if (sk->sk_state == DCCP_CLOSED)
1027 goto adjudge_to_death;
1029 if (data_was_unread) {
1030 /* Unread data was tossed, send an appropriate Reset Code */
1031 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1032 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1033 dccp_set_state(sk, DCCP_CLOSED);
1034 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1035 /* Check zero linger _after_ checking for unread data. */
1036 sk->sk_prot->disconnect(sk, 0);
1037 } else if (sk->sk_state != DCCP_CLOSED) {
1039 * Normal connection termination. May need to wait if there are
1040 * still packets in the TX queue that are delayed by the CCID.
1042 dccp_flush_write_queue(sk, &timeout);
1043 dccp_terminate_connection(sk);
1047 * Flush write queue. This may be necessary in several cases:
1048 * - we have been closed by the peer but still have application data;
1049 * - abortive termination (unread data or zero linger time),
1050 * - normal termination but queue could not be flushed within time limit
1052 __skb_queue_purge(&sk->sk_write_queue);
1054 sk_stream_wait_close(sk, timeout);
1057 state = sk->sk_state;
1062 * It is the last release_sock in its life. It will remove backlog.
1066 * Now socket is owned by kernel and we acquire BH lock
1067 * to finish close. No need to check for user refs.
1071 WARN_ON(sock_owned_by_user(sk));
1073 percpu_counter_inc(sk->sk_prot->orphan_count);
1075 /* Have we already been destroyed by a softirq or backlog? */
1076 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1079 if (sk->sk_state == DCCP_CLOSED)
1080 inet_csk_destroy_sock(sk);
1082 /* Otherwise, socket is reprieved until protocol close. */
1090 EXPORT_SYMBOL_GPL(dccp_close);
1092 void dccp_shutdown(struct sock *sk, int how)
1094 dccp_pr_debug("called shutdown(%x)\n", how);
1097 EXPORT_SYMBOL_GPL(dccp_shutdown);
1099 static inline int dccp_mib_init(void)
1101 return snmp_mib_init((void __percpu **)dccp_statistics,
1102 sizeof(struct dccp_mib),
1103 __alignof__(struct dccp_mib));
1106 static inline void dccp_mib_exit(void)
1108 snmp_mib_free((void __percpu **)dccp_statistics);
1111 static int thash_entries;
1112 module_param(thash_entries, int, 0444);
1113 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1115 #ifdef CONFIG_IP_DCCP_DEBUG
1117 module_param(dccp_debug, bool, 0644);
1118 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1120 EXPORT_SYMBOL_GPL(dccp_debug);
1123 static int __init dccp_init(void)
1126 int ehash_order, bhash_order, i;
1129 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1130 FIELD_SIZEOF(struct sk_buff, cb));
1131 rc = percpu_counter_init(&dccp_orphan_count, 0);
1135 inet_hashinfo_init(&dccp_hashinfo);
1136 dccp_hashinfo.bind_bucket_cachep =
1137 kmem_cache_create("dccp_bind_bucket",
1138 sizeof(struct inet_bind_bucket), 0,
1139 SLAB_HWCACHE_ALIGN, NULL);
1140 if (!dccp_hashinfo.bind_bucket_cachep)
1141 goto out_free_percpu;
1144 * Size and allocate the main established and bind bucket
1147 * The methodology is similar to that of the buffer cache.
1149 if (totalram_pages >= (128 * 1024))
1150 goal = totalram_pages >> (21 - PAGE_SHIFT);
1152 goal = totalram_pages >> (23 - PAGE_SHIFT);
1155 goal = (thash_entries *
1156 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1157 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1160 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1161 sizeof(struct inet_ehash_bucket);
1163 while (hash_size & (hash_size - 1))
1165 dccp_hashinfo.ehash_mask = hash_size - 1;
1166 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1167 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1168 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1170 if (!dccp_hashinfo.ehash) {
1171 DCCP_CRIT("Failed to allocate DCCP established hash table");
1172 goto out_free_bind_bucket_cachep;
1175 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1176 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1177 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1180 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1181 goto out_free_dccp_ehash;
1183 bhash_order = ehash_order;
1186 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1187 sizeof(struct inet_bind_hashbucket);
1188 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1191 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1192 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1193 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1195 if (!dccp_hashinfo.bhash) {
1196 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1197 goto out_free_dccp_locks;
1200 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1201 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1202 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1205 rc = dccp_mib_init();
1207 goto out_free_dccp_bhash;
1209 rc = dccp_ackvec_init();
1211 goto out_free_dccp_mib;
1213 rc = dccp_sysctl_init();
1215 goto out_ackvec_exit;
1217 rc = ccid_initialize_builtins();
1219 goto out_sysctl_exit;
1221 dccp_timestamping_init();
1231 out_free_dccp_bhash:
1232 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1233 out_free_dccp_locks:
1234 inet_ehash_locks_free(&dccp_hashinfo);
1235 out_free_dccp_ehash:
1236 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1237 out_free_bind_bucket_cachep:
1238 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1240 percpu_counter_destroy(&dccp_orphan_count);
1242 dccp_hashinfo.bhash = NULL;
1243 dccp_hashinfo.ehash = NULL;
1244 dccp_hashinfo.bind_bucket_cachep = NULL;
1248 static void __exit dccp_fini(void)
1250 ccid_cleanup_builtins();
1252 free_pages((unsigned long)dccp_hashinfo.bhash,
1253 get_order(dccp_hashinfo.bhash_size *
1254 sizeof(struct inet_bind_hashbucket)));
1255 free_pages((unsigned long)dccp_hashinfo.ehash,
1256 get_order((dccp_hashinfo.ehash_mask + 1) *
1257 sizeof(struct inet_ehash_bucket)));
1258 inet_ehash_locks_free(&dccp_hashinfo);
1259 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1262 percpu_counter_destroy(&dccp_orphan_count);
1265 module_init(dccp_init);
1266 module_exit(dccp_fini);
1268 MODULE_LICENSE("GPL");
1269 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1270 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");