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>
27 #include <net/inet_common.h>
31 #include <asm/ioctls.h>
32 #include <linux/spinlock.h>
33 #include <linux/timer.h>
34 #include <linux/delay.h>
35 #include <linux/poll.h>
41 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
43 EXPORT_SYMBOL_GPL(dccp_statistics);
45 struct percpu_counter dccp_orphan_count;
46 EXPORT_SYMBOL_GPL(dccp_orphan_count);
48 struct inet_hashinfo dccp_hashinfo;
49 EXPORT_SYMBOL_GPL(dccp_hashinfo);
51 /* the maximum queue length for tx in packets. 0 is no limit */
52 int sysctl_dccp_tx_qlen __read_mostly = 5;
54 #ifdef CONFIG_IP_DCCP_DEBUG
55 static const char *dccp_state_name(const int state)
57 static const char *const dccp_state_names[] = {
59 [DCCP_REQUESTING] = "REQUESTING",
60 [DCCP_PARTOPEN] = "PARTOPEN",
61 [DCCP_LISTEN] = "LISTEN",
62 [DCCP_RESPOND] = "RESPOND",
63 [DCCP_CLOSING] = "CLOSING",
64 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ",
65 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE",
66 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
67 [DCCP_TIME_WAIT] = "TIME_WAIT",
68 [DCCP_CLOSED] = "CLOSED",
71 if (state >= DCCP_MAX_STATES)
72 return "INVALID STATE!";
74 return dccp_state_names[state];
78 void dccp_set_state(struct sock *sk, const int state)
80 const int oldstate = sk->sk_state;
82 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk,
83 dccp_state_name(oldstate), dccp_state_name(state));
84 WARN_ON(state == oldstate);
88 if (oldstate != DCCP_OPEN)
89 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
90 /* Client retransmits all Confirm options until entering OPEN */
91 if (oldstate == DCCP_PARTOPEN)
92 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
96 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
97 oldstate == DCCP_CLOSING)
98 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
100 sk->sk_prot->unhash(sk);
101 if (inet_csk(sk)->icsk_bind_hash != NULL &&
102 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
106 if (oldstate == DCCP_OPEN)
107 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
110 /* Change state AFTER socket is unhashed to avoid closed
111 * socket sitting in hash tables.
113 sk->sk_state = state;
116 EXPORT_SYMBOL_GPL(dccp_set_state);
118 static void dccp_finish_passive_close(struct sock *sk)
120 switch (sk->sk_state) {
121 case DCCP_PASSIVE_CLOSE:
122 /* Node (client or server) has received Close packet. */
123 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
124 dccp_set_state(sk, DCCP_CLOSED);
126 case DCCP_PASSIVE_CLOSEREQ:
128 * Client received CloseReq. We set the `active' flag so that
129 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
131 dccp_send_close(sk, 1);
132 dccp_set_state(sk, DCCP_CLOSING);
136 void dccp_done(struct sock *sk)
138 dccp_set_state(sk, DCCP_CLOSED);
139 dccp_clear_xmit_timers(sk);
141 sk->sk_shutdown = SHUTDOWN_MASK;
143 if (!sock_flag(sk, SOCK_DEAD))
144 sk->sk_state_change(sk);
146 inet_csk_destroy_sock(sk);
149 EXPORT_SYMBOL_GPL(dccp_done);
151 const char *dccp_packet_name(const int type)
153 static const char *const dccp_packet_names[] = {
154 [DCCP_PKT_REQUEST] = "REQUEST",
155 [DCCP_PKT_RESPONSE] = "RESPONSE",
156 [DCCP_PKT_DATA] = "DATA",
157 [DCCP_PKT_ACK] = "ACK",
158 [DCCP_PKT_DATAACK] = "DATAACK",
159 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
160 [DCCP_PKT_CLOSE] = "CLOSE",
161 [DCCP_PKT_RESET] = "RESET",
162 [DCCP_PKT_SYNC] = "SYNC",
163 [DCCP_PKT_SYNCACK] = "SYNCACK",
166 if (type >= DCCP_NR_PKT_TYPES)
169 return dccp_packet_names[type];
172 EXPORT_SYMBOL_GPL(dccp_packet_name);
174 static void dccp_sk_destruct(struct sock *sk)
176 struct dccp_sock *dp = dccp_sk(sk);
178 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
179 dp->dccps_hc_tx_ccid = NULL;
180 inet_sock_destruct(sk);
183 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
185 struct dccp_sock *dp = dccp_sk(sk);
186 struct inet_connection_sock *icsk = inet_csk(sk);
188 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
189 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
190 sk->sk_state = DCCP_CLOSED;
191 sk->sk_write_space = dccp_write_space;
192 sk->sk_destruct = dccp_sk_destruct;
193 icsk->icsk_sync_mss = dccp_sync_mss;
194 dp->dccps_mss_cache = 536;
195 dp->dccps_rate_last = jiffies;
196 dp->dccps_role = DCCP_ROLE_UNDEFINED;
197 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
198 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
200 dccp_init_xmit_timers(sk);
202 INIT_LIST_HEAD(&dp->dccps_featneg);
203 /* control socket doesn't need feat nego */
204 if (likely(ctl_sock_initialized))
205 return dccp_feat_init(sk);
209 EXPORT_SYMBOL_GPL(dccp_init_sock);
211 void dccp_destroy_sock(struct sock *sk)
213 struct dccp_sock *dp = dccp_sk(sk);
215 __skb_queue_purge(&sk->sk_write_queue);
216 if (sk->sk_send_head != NULL) {
217 kfree_skb(sk->sk_send_head);
218 sk->sk_send_head = NULL;
221 /* Clean up a referenced DCCP bind bucket. */
222 if (inet_csk(sk)->icsk_bind_hash != NULL)
225 kfree(dp->dccps_service_list);
226 dp->dccps_service_list = NULL;
228 if (dp->dccps_hc_rx_ackvec != NULL) {
229 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
230 dp->dccps_hc_rx_ackvec = NULL;
232 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
233 dp->dccps_hc_rx_ccid = NULL;
235 /* clean up feature negotiation state */
236 dccp_feat_list_purge(&dp->dccps_featneg);
239 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
241 static inline int dccp_listen_start(struct sock *sk, int backlog)
243 struct dccp_sock *dp = dccp_sk(sk);
245 dp->dccps_role = DCCP_ROLE_LISTEN;
246 /* do not start to listen if feature negotiation setup fails */
247 if (dccp_feat_finalise_settings(dp))
249 return inet_csk_listen_start(sk, backlog);
252 static inline int dccp_need_reset(int state)
254 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
255 state != DCCP_REQUESTING;
258 int dccp_disconnect(struct sock *sk, int flags)
260 struct inet_connection_sock *icsk = inet_csk(sk);
261 struct inet_sock *inet = inet_sk(sk);
262 struct dccp_sock *dp = dccp_sk(sk);
264 const int old_state = sk->sk_state;
266 if (old_state != DCCP_CLOSED)
267 dccp_set_state(sk, DCCP_CLOSED);
270 * This corresponds to the ABORT function of RFC793, sec. 3.8
271 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
273 if (old_state == DCCP_LISTEN) {
274 inet_csk_listen_stop(sk);
275 } else if (dccp_need_reset(old_state)) {
276 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
277 sk->sk_err = ECONNRESET;
278 } else if (old_state == DCCP_REQUESTING)
279 sk->sk_err = ECONNRESET;
281 dccp_clear_xmit_timers(sk);
282 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
283 dp->dccps_hc_rx_ccid = NULL;
285 __skb_queue_purge(&sk->sk_receive_queue);
286 __skb_queue_purge(&sk->sk_write_queue);
287 if (sk->sk_send_head != NULL) {
288 __kfree_skb(sk->sk_send_head);
289 sk->sk_send_head = NULL;
292 inet->inet_dport = 0;
294 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
295 inet_reset_saddr(sk);
298 sock_reset_flag(sk, SOCK_DONE);
300 icsk->icsk_backoff = 0;
301 inet_csk_delack_init(sk);
304 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
306 sk->sk_error_report(sk);
310 EXPORT_SYMBOL_GPL(dccp_disconnect);
313 * Wait for a DCCP event.
315 * Note that we don't need to lock the socket, as the upper poll layers
316 * take care of normal races (between the test and the event) and we don't
317 * go look at any of the socket buffers directly.
319 unsigned int dccp_poll(struct file *file, struct socket *sock,
323 struct sock *sk = sock->sk;
325 sock_poll_wait(file, sk_sleep(sk), wait);
326 if (sk->sk_state == DCCP_LISTEN)
327 return inet_csk_listen_poll(sk);
329 /* Socket is not locked. We are protected from async events
330 by poll logic and correct handling of state changes
331 made by another threads is impossible in any case.
338 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
340 if (sk->sk_shutdown & RCV_SHUTDOWN)
341 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
344 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
345 if (atomic_read(&sk->sk_rmem_alloc) > 0)
346 mask |= POLLIN | POLLRDNORM;
348 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
349 if (sk_stream_is_writeable(sk)) {
350 mask |= POLLOUT | POLLWRNORM;
351 } else { /* send SIGIO later */
352 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
353 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
355 /* Race breaker. If space is freed after
356 * wspace test but before the flags are set,
357 * IO signal will be lost.
359 if (sk_stream_is_writeable(sk))
360 mask |= POLLOUT | POLLWRNORM;
367 EXPORT_SYMBOL_GPL(dccp_poll);
369 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
375 if (sk->sk_state == DCCP_LISTEN)
381 unsigned long amount = 0;
383 skb = skb_peek(&sk->sk_receive_queue);
386 * We will only return the amount of this packet since
387 * that is all that will be read.
391 rc = put_user(amount, (int __user *)arg);
403 EXPORT_SYMBOL_GPL(dccp_ioctl);
405 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
406 char __user *optval, unsigned int optlen)
408 struct dccp_sock *dp = dccp_sk(sk);
409 struct dccp_service_list *sl = NULL;
411 if (service == DCCP_SERVICE_INVALID_VALUE ||
412 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
415 if (optlen > sizeof(service)) {
416 sl = kmalloc(optlen, GFP_KERNEL);
420 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
421 if (copy_from_user(sl->dccpsl_list,
422 optval + sizeof(service),
423 optlen - sizeof(service)) ||
424 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
431 dp->dccps_service = service;
433 kfree(dp->dccps_service_list);
435 dp->dccps_service_list = sl;
440 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
445 if (cscov < 0 || cscov > 15)
448 * Populate a list of permissible values, in the range cscov...15. This
449 * is necessary since feature negotiation of single values only works if
450 * both sides incidentally choose the same value. Since the list starts
451 * lowest-value first, negotiation will pick the smallest shared value.
457 list = kmalloc(len, GFP_KERNEL);
461 for (i = 0; i < len; i++)
464 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
468 dccp_sk(sk)->dccps_pcrlen = cscov;
470 dccp_sk(sk)->dccps_pcslen = cscov;
476 static int dccp_setsockopt_ccid(struct sock *sk, int type,
477 char __user *optval, unsigned int optlen)
482 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
485 val = memdup_user(optval, optlen);
490 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
491 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
493 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
494 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
501 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
502 char __user *optval, unsigned int optlen)
504 struct dccp_sock *dp = dccp_sk(sk);
508 case DCCP_SOCKOPT_PACKET_SIZE:
509 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
511 case DCCP_SOCKOPT_CHANGE_L:
512 case DCCP_SOCKOPT_CHANGE_R:
513 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
515 case DCCP_SOCKOPT_CCID:
516 case DCCP_SOCKOPT_RX_CCID:
517 case DCCP_SOCKOPT_TX_CCID:
518 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
521 if (optlen < (int)sizeof(int))
524 if (get_user(val, (int __user *)optval))
527 if (optname == DCCP_SOCKOPT_SERVICE)
528 return dccp_setsockopt_service(sk, val, optval, optlen);
532 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
533 if (dp->dccps_role != DCCP_ROLE_SERVER)
536 dp->dccps_server_timewait = (val != 0);
538 case DCCP_SOCKOPT_SEND_CSCOV:
539 err = dccp_setsockopt_cscov(sk, val, false);
541 case DCCP_SOCKOPT_RECV_CSCOV:
542 err = dccp_setsockopt_cscov(sk, val, true);
544 case DCCP_SOCKOPT_QPOLICY_ID:
545 if (sk->sk_state != DCCP_CLOSED)
547 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
550 dp->dccps_qpolicy = val;
552 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
556 dp->dccps_tx_qlen = val;
567 int dccp_setsockopt(struct sock *sk, int level, int optname,
568 char __user *optval, unsigned int optlen)
570 if (level != SOL_DCCP)
571 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
574 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
577 EXPORT_SYMBOL_GPL(dccp_setsockopt);
580 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
581 char __user *optval, unsigned int optlen)
583 if (level != SOL_DCCP)
584 return inet_csk_compat_setsockopt(sk, level, optname,
586 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
589 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
592 static int dccp_getsockopt_service(struct sock *sk, int len,
593 __be32 __user *optval,
596 const struct dccp_sock *dp = dccp_sk(sk);
597 const struct dccp_service_list *sl;
598 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
601 if ((sl = dp->dccps_service_list) != NULL) {
602 slen = sl->dccpsl_nr * sizeof(u32);
611 if (put_user(total_len, optlen) ||
612 put_user(dp->dccps_service, optval) ||
613 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
620 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
621 char __user *optval, int __user *optlen)
623 struct dccp_sock *dp;
626 if (get_user(len, optlen))
629 if (len < (int)sizeof(int))
635 case DCCP_SOCKOPT_PACKET_SIZE:
636 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
638 case DCCP_SOCKOPT_SERVICE:
639 return dccp_getsockopt_service(sk, len,
640 (__be32 __user *)optval, optlen);
641 case DCCP_SOCKOPT_GET_CUR_MPS:
642 val = dp->dccps_mss_cache;
644 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
645 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
646 case DCCP_SOCKOPT_TX_CCID:
647 val = ccid_get_current_tx_ccid(dp);
651 case DCCP_SOCKOPT_RX_CCID:
652 val = ccid_get_current_rx_ccid(dp);
656 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
657 val = dp->dccps_server_timewait;
659 case DCCP_SOCKOPT_SEND_CSCOV:
660 val = dp->dccps_pcslen;
662 case DCCP_SOCKOPT_RECV_CSCOV:
663 val = dp->dccps_pcrlen;
665 case DCCP_SOCKOPT_QPOLICY_ID:
666 val = dp->dccps_qpolicy;
668 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
669 val = dp->dccps_tx_qlen;
672 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
673 len, (u32 __user *)optval, optlen);
675 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
676 len, (u32 __user *)optval, optlen);
682 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
688 int dccp_getsockopt(struct sock *sk, int level, int optname,
689 char __user *optval, int __user *optlen)
691 if (level != SOL_DCCP)
692 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
695 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
698 EXPORT_SYMBOL_GPL(dccp_getsockopt);
701 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
702 char __user *optval, int __user *optlen)
704 if (level != SOL_DCCP)
705 return inet_csk_compat_getsockopt(sk, level, optname,
707 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
710 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
713 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
715 struct cmsghdr *cmsg;
718 * Assign an (opaque) qpolicy priority value to skb->priority.
720 * We are overloading this skb field for use with the qpolicy subystem.
721 * The skb->priority is normally used for the SO_PRIORITY option, which
722 * is initialised from sk_priority. Since the assignment of sk_priority
723 * to skb->priority happens later (on layer 3), we overload this field
724 * for use with queueing priorities as long as the skb is on layer 4.
725 * The default priority value (if nothing is set) is 0.
729 for_each_cmsghdr(cmsg, msg) {
730 if (!CMSG_OK(msg, cmsg))
733 if (cmsg->cmsg_level != SOL_DCCP)
736 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
737 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
740 switch (cmsg->cmsg_type) {
741 case DCCP_SCM_PRIORITY:
742 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
744 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
753 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
755 const struct dccp_sock *dp = dccp_sk(sk);
756 const int flags = msg->msg_flags;
757 const int noblock = flags & MSG_DONTWAIT;
762 if (len > dp->dccps_mss_cache)
767 if (dccp_qpolicy_full(sk)) {
772 timeo = sock_sndtimeo(sk, noblock);
775 * We have to use sk_stream_wait_connect here to set sk_write_pending,
776 * so that the trick in dccp_rcv_request_sent_state_process.
778 /* Wait for a connection to finish. */
779 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
780 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
783 size = sk->sk_prot->max_header + len;
785 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
790 if (sk->sk_state == DCCP_CLOSED) {
795 skb_reserve(skb, sk->sk_prot->max_header);
796 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
800 rc = dccp_msghdr_parse(msg, skb);
804 dccp_qpolicy_push(sk, skb);
806 * The xmit_timer is set if the TX CCID is rate-based and will expire
807 * when congestion control permits to release further packets into the
808 * network. Window-based CCIDs do not use this timer.
810 if (!timer_pending(&dp->dccps_xmit_timer))
820 EXPORT_SYMBOL_GPL(dccp_sendmsg);
822 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
823 int flags, int *addr_len)
825 const struct dccp_hdr *dh;
830 if (sk->sk_state == DCCP_LISTEN) {
835 timeo = sock_rcvtimeo(sk, nonblock);
838 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
841 goto verify_sock_status;
845 switch (dh->dccph_type) {
847 case DCCP_PKT_DATAACK:
851 case DCCP_PKT_CLOSEREQ:
852 if (!(flags & MSG_PEEK))
853 dccp_finish_passive_close(sk);
856 dccp_pr_debug("found fin (%s) ok!\n",
857 dccp_packet_name(dh->dccph_type));
861 dccp_pr_debug("packet_type=%s\n",
862 dccp_packet_name(dh->dccph_type));
866 if (sock_flag(sk, SOCK_DONE)) {
872 len = sock_error(sk);
876 if (sk->sk_shutdown & RCV_SHUTDOWN) {
881 if (sk->sk_state == DCCP_CLOSED) {
882 if (!sock_flag(sk, SOCK_DONE)) {
883 /* This occurs when user tries to read
884 * from never connected socket.
898 if (signal_pending(current)) {
899 len = sock_intr_errno(timeo);
903 sk_wait_data(sk, &timeo, NULL);
908 else if (len < skb->len)
909 msg->msg_flags |= MSG_TRUNC;
911 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
912 /* Exception. Bailout! */
916 if (flags & MSG_TRUNC)
919 if (!(flags & MSG_PEEK))
928 EXPORT_SYMBOL_GPL(dccp_recvmsg);
930 int inet_dccp_listen(struct socket *sock, int backlog)
932 struct sock *sk = sock->sk;
933 unsigned char old_state;
939 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
942 old_state = sk->sk_state;
943 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
946 /* Really, if the socket is already in listen state
947 * we can only allow the backlog to be adjusted.
949 if (old_state != DCCP_LISTEN) {
951 * FIXME: here it probably should be sk->sk_prot->listen_start
952 * see tcp_listen_start
954 err = dccp_listen_start(sk, backlog);
958 sk->sk_max_ack_backlog = backlog;
966 EXPORT_SYMBOL_GPL(inet_dccp_listen);
968 static void dccp_terminate_connection(struct sock *sk)
970 u8 next_state = DCCP_CLOSED;
972 switch (sk->sk_state) {
973 case DCCP_PASSIVE_CLOSE:
974 case DCCP_PASSIVE_CLOSEREQ:
975 dccp_finish_passive_close(sk);
978 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
979 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
982 dccp_send_close(sk, 1);
984 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
985 !dccp_sk(sk)->dccps_server_timewait)
986 next_state = DCCP_ACTIVE_CLOSEREQ;
988 next_state = DCCP_CLOSING;
991 dccp_set_state(sk, next_state);
995 void dccp_close(struct sock *sk, long timeout)
997 struct dccp_sock *dp = dccp_sk(sk);
999 u32 data_was_unread = 0;
1004 sk->sk_shutdown = SHUTDOWN_MASK;
1006 if (sk->sk_state == DCCP_LISTEN) {
1007 dccp_set_state(sk, DCCP_CLOSED);
1010 inet_csk_listen_stop(sk);
1012 goto adjudge_to_death;
1015 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1018 * We need to flush the recv. buffs. We do this only on the
1019 * descriptor close, not protocol-sourced closes, because the
1020 *reader process may not have drained the data yet!
1022 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1023 data_was_unread += skb->len;
1027 /* If socket has been already reset kill it. */
1028 if (sk->sk_state == DCCP_CLOSED)
1029 goto adjudge_to_death;
1031 if (data_was_unread) {
1032 /* Unread data was tossed, send an appropriate Reset Code */
1033 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1034 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1035 dccp_set_state(sk, DCCP_CLOSED);
1036 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1037 /* Check zero linger _after_ checking for unread data. */
1038 sk->sk_prot->disconnect(sk, 0);
1039 } else if (sk->sk_state != DCCP_CLOSED) {
1041 * Normal connection termination. May need to wait if there are
1042 * still packets in the TX queue that are delayed by the CCID.
1044 dccp_flush_write_queue(sk, &timeout);
1045 dccp_terminate_connection(sk);
1049 * Flush write queue. This may be necessary in several cases:
1050 * - we have been closed by the peer but still have application data;
1051 * - abortive termination (unread data or zero linger time),
1052 * - normal termination but queue could not be flushed within time limit
1054 __skb_queue_purge(&sk->sk_write_queue);
1056 sk_stream_wait_close(sk, timeout);
1059 state = sk->sk_state;
1064 * It is the last release_sock in its life. It will remove backlog.
1068 * Now socket is owned by kernel and we acquire BH lock
1069 * to finish close. No need to check for user refs.
1073 WARN_ON(sock_owned_by_user(sk));
1075 percpu_counter_inc(sk->sk_prot->orphan_count);
1077 /* Have we already been destroyed by a softirq or backlog? */
1078 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1081 if (sk->sk_state == DCCP_CLOSED)
1082 inet_csk_destroy_sock(sk);
1084 /* Otherwise, socket is reprieved until protocol close. */
1092 EXPORT_SYMBOL_GPL(dccp_close);
1094 void dccp_shutdown(struct sock *sk, int how)
1096 dccp_pr_debug("called shutdown(%x)\n", how);
1099 EXPORT_SYMBOL_GPL(dccp_shutdown);
1101 static inline int __init dccp_mib_init(void)
1103 dccp_statistics = alloc_percpu(struct dccp_mib);
1104 if (!dccp_statistics)
1109 static inline void dccp_mib_exit(void)
1111 free_percpu(dccp_statistics);
1114 static int thash_entries;
1115 module_param(thash_entries, int, 0444);
1116 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1118 #ifdef CONFIG_IP_DCCP_DEBUG
1120 module_param(dccp_debug, bool, 0644);
1121 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1123 EXPORT_SYMBOL_GPL(dccp_debug);
1126 static int __init dccp_init(void)
1129 int ehash_order, bhash_order, i;
1132 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1133 FIELD_SIZEOF(struct sk_buff, cb));
1134 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1138 inet_hashinfo_init(&dccp_hashinfo);
1139 dccp_hashinfo.bind_bucket_cachep =
1140 kmem_cache_create("dccp_bind_bucket",
1141 sizeof(struct inet_bind_bucket), 0,
1142 SLAB_HWCACHE_ALIGN, NULL);
1143 if (!dccp_hashinfo.bind_bucket_cachep)
1144 goto out_free_percpu;
1147 * Size and allocate the main established and bind bucket
1150 * The methodology is similar to that of the buffer cache.
1152 if (totalram_pages >= (128 * 1024))
1153 goal = totalram_pages >> (21 - PAGE_SHIFT);
1155 goal = totalram_pages >> (23 - PAGE_SHIFT);
1158 goal = (thash_entries *
1159 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1160 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1163 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1164 sizeof(struct inet_ehash_bucket);
1166 while (hash_size & (hash_size - 1))
1168 dccp_hashinfo.ehash_mask = hash_size - 1;
1169 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1170 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1171 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1173 if (!dccp_hashinfo.ehash) {
1174 DCCP_CRIT("Failed to allocate DCCP established hash table");
1175 goto out_free_bind_bucket_cachep;
1178 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1179 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1181 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1182 goto out_free_dccp_ehash;
1184 bhash_order = ehash_order;
1187 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1188 sizeof(struct inet_bind_hashbucket);
1189 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1192 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1193 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1194 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1196 if (!dccp_hashinfo.bhash) {
1197 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1198 goto out_free_dccp_locks;
1201 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1202 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1203 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1206 rc = dccp_mib_init();
1208 goto out_free_dccp_bhash;
1210 rc = dccp_ackvec_init();
1212 goto out_free_dccp_mib;
1214 rc = dccp_sysctl_init();
1216 goto out_ackvec_exit;
1218 rc = ccid_initialize_builtins();
1220 goto out_sysctl_exit;
1222 dccp_timestamping_init();
1232 out_free_dccp_bhash:
1233 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1234 out_free_dccp_locks:
1235 inet_ehash_locks_free(&dccp_hashinfo);
1236 out_free_dccp_ehash:
1237 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1238 out_free_bind_bucket_cachep:
1239 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1241 percpu_counter_destroy(&dccp_orphan_count);
1243 dccp_hashinfo.bhash = NULL;
1244 dccp_hashinfo.ehash = NULL;
1245 dccp_hashinfo.bind_bucket_cachep = NULL;
1249 static void __exit dccp_fini(void)
1251 ccid_cleanup_builtins();
1253 free_pages((unsigned long)dccp_hashinfo.bhash,
1254 get_order(dccp_hashinfo.bhash_size *
1255 sizeof(struct inet_bind_hashbucket)));
1256 free_pages((unsigned long)dccp_hashinfo.ehash,
1257 get_order((dccp_hashinfo.ehash_mask + 1) *
1258 sizeof(struct inet_ehash_bucket)));
1259 inet_ehash_locks_free(&dccp_hashinfo);
1260 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1263 percpu_counter_destroy(&dccp_orphan_count);
1266 module_init(dccp_init);
1267 module_exit(dccp_fini);
1269 MODULE_LICENSE("GPL");
1270 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1271 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");