Linux 2.6.20.7
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / dccp / proto.c
blob88ed359b606cc5a40d94e0e497ec5ca0862cf425
1 /*
2 * net/dccp/proto.c
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>
19 #include <linux/in.h>
20 #include <linux/if_arp.h>
21 #include <linux/init.h>
22 #include <linux/random.h>
23 #include <net/checksum.h>
25 #include <net/inet_sock.h>
26 #include <net/sock.h>
27 #include <net/xfrm.h>
29 #include <asm/semaphore.h>
30 #include <linux/spinlock.h>
31 #include <linux/timer.h>
32 #include <linux/delay.h>
33 #include <linux/poll.h>
35 #include "ccid.h"
36 #include "dccp.h"
37 #include "feat.h"
39 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
41 EXPORT_SYMBOL_GPL(dccp_statistics);
43 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
47 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
48 .lhash_lock = RW_LOCK_UNLOCKED,
49 .lhash_users = ATOMIC_INIT(0),
50 .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
53 EXPORT_SYMBOL_GPL(dccp_hashinfo);
55 /* the maximum queue length for tx in packets. 0 is no limit */
56 int sysctl_dccp_tx_qlen __read_mostly = 5;
58 void dccp_set_state(struct sock *sk, const int state)
60 const int oldstate = sk->sk_state;
62 dccp_pr_debug("%s(%p) %-10.10s -> %s\n",
63 dccp_role(sk), sk,
64 dccp_state_name(oldstate), dccp_state_name(state));
65 WARN_ON(state == oldstate);
67 switch (state) {
68 case DCCP_OPEN:
69 if (oldstate != DCCP_OPEN)
70 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
71 break;
73 case DCCP_CLOSED:
74 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
75 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
77 sk->sk_prot->unhash(sk);
78 if (inet_csk(sk)->icsk_bind_hash != NULL &&
79 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
80 inet_put_port(&dccp_hashinfo, sk);
81 /* fall through */
82 default:
83 if (oldstate == DCCP_OPEN)
84 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
87 /* Change state AFTER socket is unhashed to avoid closed
88 * socket sitting in hash tables.
90 sk->sk_state = state;
93 EXPORT_SYMBOL_GPL(dccp_set_state);
95 void dccp_done(struct sock *sk)
97 dccp_set_state(sk, DCCP_CLOSED);
98 dccp_clear_xmit_timers(sk);
100 sk->sk_shutdown = SHUTDOWN_MASK;
102 if (!sock_flag(sk, SOCK_DEAD))
103 sk->sk_state_change(sk);
104 else
105 inet_csk_destroy_sock(sk);
108 EXPORT_SYMBOL_GPL(dccp_done);
110 const char *dccp_packet_name(const int type)
112 static const char *dccp_packet_names[] = {
113 [DCCP_PKT_REQUEST] = "REQUEST",
114 [DCCP_PKT_RESPONSE] = "RESPONSE",
115 [DCCP_PKT_DATA] = "DATA",
116 [DCCP_PKT_ACK] = "ACK",
117 [DCCP_PKT_DATAACK] = "DATAACK",
118 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
119 [DCCP_PKT_CLOSE] = "CLOSE",
120 [DCCP_PKT_RESET] = "RESET",
121 [DCCP_PKT_SYNC] = "SYNC",
122 [DCCP_PKT_SYNCACK] = "SYNCACK",
125 if (type >= DCCP_NR_PKT_TYPES)
126 return "INVALID";
127 else
128 return dccp_packet_names[type];
131 EXPORT_SYMBOL_GPL(dccp_packet_name);
133 const char *dccp_state_name(const int state)
135 static char *dccp_state_names[] = {
136 [DCCP_OPEN] = "OPEN",
137 [DCCP_REQUESTING] = "REQUESTING",
138 [DCCP_PARTOPEN] = "PARTOPEN",
139 [DCCP_LISTEN] = "LISTEN",
140 [DCCP_RESPOND] = "RESPOND",
141 [DCCP_CLOSING] = "CLOSING",
142 [DCCP_TIME_WAIT] = "TIME_WAIT",
143 [DCCP_CLOSED] = "CLOSED",
146 if (state >= DCCP_MAX_STATES)
147 return "INVALID STATE!";
148 else
149 return dccp_state_names[state];
152 EXPORT_SYMBOL_GPL(dccp_state_name);
154 void dccp_hash(struct sock *sk)
156 inet_hash(&dccp_hashinfo, sk);
159 EXPORT_SYMBOL_GPL(dccp_hash);
161 void dccp_unhash(struct sock *sk)
163 inet_unhash(&dccp_hashinfo, sk);
166 EXPORT_SYMBOL_GPL(dccp_unhash);
168 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
170 struct dccp_sock *dp = dccp_sk(sk);
171 struct dccp_minisock *dmsk = dccp_msk(sk);
172 struct inet_connection_sock *icsk = inet_csk(sk);
174 dccp_minisock_init(&dp->dccps_minisock);
175 do_gettimeofday(&dp->dccps_epoch);
178 * FIXME: We're hardcoding the CCID, and doing this at this point makes
179 * the listening (master) sock get CCID control blocks, which is not
180 * necessary, but for now, to not mess with the test userspace apps,
181 * lets leave it here, later the real solution is to do this in a
182 * setsockopt(CCIDs-I-want/accept). -acme
184 if (likely(ctl_sock_initialized)) {
185 int rc = dccp_feat_init(dmsk);
187 if (rc)
188 return rc;
190 if (dmsk->dccpms_send_ack_vector) {
191 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
192 if (dp->dccps_hc_rx_ackvec == NULL)
193 return -ENOMEM;
195 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
196 sk, GFP_KERNEL);
197 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
198 sk, GFP_KERNEL);
199 if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
200 dp->dccps_hc_tx_ccid == NULL)) {
201 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
202 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
203 if (dmsk->dccpms_send_ack_vector) {
204 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
205 dp->dccps_hc_rx_ackvec = NULL;
207 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
208 return -ENOMEM;
210 } else {
211 /* control socket doesn't need feat nego */
212 INIT_LIST_HEAD(&dmsk->dccpms_pending);
213 INIT_LIST_HEAD(&dmsk->dccpms_conf);
216 dccp_init_xmit_timers(sk);
217 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
218 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
219 sk->sk_state = DCCP_CLOSED;
220 sk->sk_write_space = dccp_write_space;
221 icsk->icsk_sync_mss = dccp_sync_mss;
222 dp->dccps_mss_cache = 536;
223 dp->dccps_role = DCCP_ROLE_UNDEFINED;
224 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
225 dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
227 return 0;
230 EXPORT_SYMBOL_GPL(dccp_init_sock);
232 int dccp_destroy_sock(struct sock *sk)
234 struct dccp_sock *dp = dccp_sk(sk);
235 struct dccp_minisock *dmsk = dccp_msk(sk);
238 * DCCP doesn't use sk_write_queue, just sk_send_head
239 * for retransmissions
241 if (sk->sk_send_head != NULL) {
242 kfree_skb(sk->sk_send_head);
243 sk->sk_send_head = NULL;
246 /* Clean up a referenced DCCP bind bucket. */
247 if (inet_csk(sk)->icsk_bind_hash != NULL)
248 inet_put_port(&dccp_hashinfo, sk);
250 kfree(dp->dccps_service_list);
251 dp->dccps_service_list = NULL;
253 if (dmsk->dccpms_send_ack_vector) {
254 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
255 dp->dccps_hc_rx_ackvec = NULL;
257 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
258 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
259 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
261 /* clean up feature negotiation state */
262 dccp_feat_clean(dmsk);
264 return 0;
267 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
269 static inline int dccp_listen_start(struct sock *sk, int backlog)
271 struct dccp_sock *dp = dccp_sk(sk);
273 dp->dccps_role = DCCP_ROLE_LISTEN;
274 return inet_csk_listen_start(sk, backlog);
277 int dccp_disconnect(struct sock *sk, int flags)
279 struct inet_connection_sock *icsk = inet_csk(sk);
280 struct inet_sock *inet = inet_sk(sk);
281 int err = 0;
282 const int old_state = sk->sk_state;
284 if (old_state != DCCP_CLOSED)
285 dccp_set_state(sk, DCCP_CLOSED);
287 /* ABORT function of RFC793 */
288 if (old_state == DCCP_LISTEN) {
289 inet_csk_listen_stop(sk);
290 /* FIXME: do the active reset thing */
291 } else if (old_state == DCCP_REQUESTING)
292 sk->sk_err = ECONNRESET;
294 dccp_clear_xmit_timers(sk);
295 __skb_queue_purge(&sk->sk_receive_queue);
296 if (sk->sk_send_head != NULL) {
297 __kfree_skb(sk->sk_send_head);
298 sk->sk_send_head = NULL;
301 inet->dport = 0;
303 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
304 inet_reset_saddr(sk);
306 sk->sk_shutdown = 0;
307 sock_reset_flag(sk, SOCK_DONE);
309 icsk->icsk_backoff = 0;
310 inet_csk_delack_init(sk);
311 __sk_dst_reset(sk);
313 BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
315 sk->sk_error_report(sk);
316 return err;
319 EXPORT_SYMBOL_GPL(dccp_disconnect);
322 * Wait for a DCCP event.
324 * Note that we don't need to lock the socket, as the upper poll layers
325 * take care of normal races (between the test and the event) and we don't
326 * go look at any of the socket buffers directly.
328 unsigned int dccp_poll(struct file *file, struct socket *sock,
329 poll_table *wait)
331 unsigned int mask;
332 struct sock *sk = sock->sk;
334 poll_wait(file, sk->sk_sleep, wait);
335 if (sk->sk_state == DCCP_LISTEN)
336 return inet_csk_listen_poll(sk);
338 /* Socket is not locked. We are protected from async events
339 by poll logic and correct handling of state changes
340 made by another threads is impossible in any case.
343 mask = 0;
344 if (sk->sk_err)
345 mask = POLLERR;
347 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
348 mask |= POLLHUP;
349 if (sk->sk_shutdown & RCV_SHUTDOWN)
350 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
352 /* Connected? */
353 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
354 if (atomic_read(&sk->sk_rmem_alloc) > 0)
355 mask |= POLLIN | POLLRDNORM;
357 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
358 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
359 mask |= POLLOUT | POLLWRNORM;
360 } else { /* send SIGIO later */
361 set_bit(SOCK_ASYNC_NOSPACE,
362 &sk->sk_socket->flags);
363 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
365 /* Race breaker. If space is freed after
366 * wspace test but before the flags are set,
367 * IO signal will be lost.
369 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
370 mask |= POLLOUT | POLLWRNORM;
374 return mask;
377 EXPORT_SYMBOL_GPL(dccp_poll);
379 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
381 dccp_pr_debug("entry\n");
382 return -ENOIOCTLCMD;
385 EXPORT_SYMBOL_GPL(dccp_ioctl);
387 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
388 char __user *optval, int optlen)
390 struct dccp_sock *dp = dccp_sk(sk);
391 struct dccp_service_list *sl = NULL;
393 if (service == DCCP_SERVICE_INVALID_VALUE ||
394 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
395 return -EINVAL;
397 if (optlen > sizeof(service)) {
398 sl = kmalloc(optlen, GFP_KERNEL);
399 if (sl == NULL)
400 return -ENOMEM;
402 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
403 if (copy_from_user(sl->dccpsl_list,
404 optval + sizeof(service),
405 optlen - sizeof(service)) ||
406 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
407 kfree(sl);
408 return -EFAULT;
412 lock_sock(sk);
413 dp->dccps_service = service;
415 kfree(dp->dccps_service_list);
417 dp->dccps_service_list = sl;
418 release_sock(sk);
419 return 0;
422 /* byte 1 is feature. the rest is the preference list */
423 static int dccp_setsockopt_change(struct sock *sk, int type,
424 struct dccp_so_feat __user *optval)
426 struct dccp_so_feat opt;
427 u8 *val;
428 int rc;
430 if (copy_from_user(&opt, optval, sizeof(opt)))
431 return -EFAULT;
433 val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
434 if (!val)
435 return -ENOMEM;
437 if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
438 rc = -EFAULT;
439 goto out_free_val;
442 rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
443 val, opt.dccpsf_len, GFP_KERNEL);
444 if (rc)
445 goto out_free_val;
447 out:
448 return rc;
450 out_free_val:
451 kfree(val);
452 goto out;
455 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
456 char __user *optval, int optlen)
458 struct dccp_sock *dp = dccp_sk(sk);
459 int val, err = 0;
461 if (optlen < sizeof(int))
462 return -EINVAL;
464 if (get_user(val, (int __user *)optval))
465 return -EFAULT;
467 if (optname == DCCP_SOCKOPT_SERVICE)
468 return dccp_setsockopt_service(sk, val, optval, optlen);
470 lock_sock(sk);
471 switch (optname) {
472 case DCCP_SOCKOPT_PACKET_SIZE:
473 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
474 err = 0;
475 break;
476 case DCCP_SOCKOPT_CHANGE_L:
477 if (optlen != sizeof(struct dccp_so_feat))
478 err = -EINVAL;
479 else
480 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
481 (struct dccp_so_feat __user *)
482 optval);
483 break;
484 case DCCP_SOCKOPT_CHANGE_R:
485 if (optlen != sizeof(struct dccp_so_feat))
486 err = -EINVAL;
487 else
488 err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
489 (struct dccp_so_feat __user *)
490 optval);
491 break;
492 case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */
493 if (val < 0 || val > 15)
494 err = -EINVAL;
495 else
496 dp->dccps_pcslen = val;
497 break;
498 case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */
499 if (val < 0 || val > 15)
500 err = -EINVAL;
501 else {
502 dp->dccps_pcrlen = val;
503 /* FIXME: add feature negotiation,
504 * ChangeL(MinimumChecksumCoverage, val) */
506 break;
507 default:
508 err = -ENOPROTOOPT;
509 break;
512 release_sock(sk);
513 return err;
516 int dccp_setsockopt(struct sock *sk, int level, int optname,
517 char __user *optval, int optlen)
519 if (level != SOL_DCCP)
520 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
521 optname, optval,
522 optlen);
523 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
526 EXPORT_SYMBOL_GPL(dccp_setsockopt);
528 #ifdef CONFIG_COMPAT
529 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
530 char __user *optval, int optlen)
532 if (level != SOL_DCCP)
533 return inet_csk_compat_setsockopt(sk, level, optname,
534 optval, optlen);
535 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
538 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
539 #endif
541 static int dccp_getsockopt_service(struct sock *sk, int len,
542 __be32 __user *optval,
543 int __user *optlen)
545 const struct dccp_sock *dp = dccp_sk(sk);
546 const struct dccp_service_list *sl;
547 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
549 lock_sock(sk);
550 if ((sl = dp->dccps_service_list) != NULL) {
551 slen = sl->dccpsl_nr * sizeof(u32);
552 total_len += slen;
555 err = -EINVAL;
556 if (total_len > len)
557 goto out;
559 err = 0;
560 if (put_user(total_len, optlen) ||
561 put_user(dp->dccps_service, optval) ||
562 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
563 err = -EFAULT;
564 out:
565 release_sock(sk);
566 return err;
569 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
570 char __user *optval, int __user *optlen)
572 struct dccp_sock *dp;
573 int val, len;
575 if (get_user(len, optlen))
576 return -EFAULT;
578 if (len < (int)sizeof(int))
579 return -EINVAL;
581 dp = dccp_sk(sk);
583 switch (optname) {
584 case DCCP_SOCKOPT_PACKET_SIZE:
585 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
586 return 0;
587 case DCCP_SOCKOPT_SERVICE:
588 return dccp_getsockopt_service(sk, len,
589 (__be32 __user *)optval, optlen);
590 case DCCP_SOCKOPT_SEND_CSCOV:
591 val = dp->dccps_pcslen;
592 len = sizeof(val);
593 break;
594 case DCCP_SOCKOPT_RECV_CSCOV:
595 val = dp->dccps_pcrlen;
596 len = sizeof(val);
597 break;
598 case 128 ... 191:
599 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
600 len, (u32 __user *)optval, optlen);
601 case 192 ... 255:
602 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
603 len, (u32 __user *)optval, optlen);
604 default:
605 return -ENOPROTOOPT;
608 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
609 return -EFAULT;
611 return 0;
614 int dccp_getsockopt(struct sock *sk, int level, int optname,
615 char __user *optval, int __user *optlen)
617 if (level != SOL_DCCP)
618 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
619 optname, optval,
620 optlen);
621 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
624 EXPORT_SYMBOL_GPL(dccp_getsockopt);
626 #ifdef CONFIG_COMPAT
627 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
628 char __user *optval, int __user *optlen)
630 if (level != SOL_DCCP)
631 return inet_csk_compat_getsockopt(sk, level, optname,
632 optval, optlen);
633 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
636 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
637 #endif
639 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
640 size_t len)
642 const struct dccp_sock *dp = dccp_sk(sk);
643 const int flags = msg->msg_flags;
644 const int noblock = flags & MSG_DONTWAIT;
645 struct sk_buff *skb;
646 int rc, size;
647 long timeo;
649 if (len > dp->dccps_mss_cache)
650 return -EMSGSIZE;
652 lock_sock(sk);
654 if (sysctl_dccp_tx_qlen &&
655 (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
656 rc = -EAGAIN;
657 goto out_release;
660 timeo = sock_sndtimeo(sk, noblock);
663 * We have to use sk_stream_wait_connect here to set sk_write_pending,
664 * so that the trick in dccp_rcv_request_sent_state_process.
666 /* Wait for a connection to finish. */
667 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN | DCCPF_CLOSING))
668 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
669 goto out_release;
671 size = sk->sk_prot->max_header + len;
672 release_sock(sk);
673 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
674 lock_sock(sk);
675 if (skb == NULL)
676 goto out_release;
678 skb_reserve(skb, sk->sk_prot->max_header);
679 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
680 if (rc != 0)
681 goto out_discard;
683 skb_queue_tail(&sk->sk_write_queue, skb);
684 dccp_write_xmit(sk,0);
685 out_release:
686 release_sock(sk);
687 return rc ? : len;
688 out_discard:
689 kfree_skb(skb);
690 goto out_release;
693 EXPORT_SYMBOL_GPL(dccp_sendmsg);
695 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
696 size_t len, int nonblock, int flags, int *addr_len)
698 const struct dccp_hdr *dh;
699 long timeo;
701 lock_sock(sk);
703 if (sk->sk_state == DCCP_LISTEN) {
704 len = -ENOTCONN;
705 goto out;
708 timeo = sock_rcvtimeo(sk, nonblock);
710 do {
711 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
713 if (skb == NULL)
714 goto verify_sock_status;
716 dh = dccp_hdr(skb);
718 if (dh->dccph_type == DCCP_PKT_DATA ||
719 dh->dccph_type == DCCP_PKT_DATAACK)
720 goto found_ok_skb;
722 if (dh->dccph_type == DCCP_PKT_RESET ||
723 dh->dccph_type == DCCP_PKT_CLOSE) {
724 dccp_pr_debug("found fin ok!\n");
725 len = 0;
726 goto found_fin_ok;
728 dccp_pr_debug("packet_type=%s\n",
729 dccp_packet_name(dh->dccph_type));
730 sk_eat_skb(sk, skb, 0);
731 verify_sock_status:
732 if (sock_flag(sk, SOCK_DONE)) {
733 len = 0;
734 break;
737 if (sk->sk_err) {
738 len = sock_error(sk);
739 break;
742 if (sk->sk_shutdown & RCV_SHUTDOWN) {
743 len = 0;
744 break;
747 if (sk->sk_state == DCCP_CLOSED) {
748 if (!sock_flag(sk, SOCK_DONE)) {
749 /* This occurs when user tries to read
750 * from never connected socket.
752 len = -ENOTCONN;
753 break;
755 len = 0;
756 break;
759 if (!timeo) {
760 len = -EAGAIN;
761 break;
764 if (signal_pending(current)) {
765 len = sock_intr_errno(timeo);
766 break;
769 sk_wait_data(sk, &timeo);
770 continue;
771 found_ok_skb:
772 if (len > skb->len)
773 len = skb->len;
774 else if (len < skb->len)
775 msg->msg_flags |= MSG_TRUNC;
777 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
778 /* Exception. Bailout! */
779 len = -EFAULT;
780 break;
782 found_fin_ok:
783 if (!(flags & MSG_PEEK))
784 sk_eat_skb(sk, skb, 0);
785 break;
786 } while (1);
787 out:
788 release_sock(sk);
789 return len;
792 EXPORT_SYMBOL_GPL(dccp_recvmsg);
794 int inet_dccp_listen(struct socket *sock, int backlog)
796 struct sock *sk = sock->sk;
797 unsigned char old_state;
798 int err;
800 lock_sock(sk);
802 err = -EINVAL;
803 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
804 goto out;
806 old_state = sk->sk_state;
807 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
808 goto out;
810 /* Really, if the socket is already in listen state
811 * we can only allow the backlog to be adjusted.
813 if (old_state != DCCP_LISTEN) {
815 * FIXME: here it probably should be sk->sk_prot->listen_start
816 * see tcp_listen_start
818 err = dccp_listen_start(sk, backlog);
819 if (err)
820 goto out;
822 sk->sk_max_ack_backlog = backlog;
823 err = 0;
825 out:
826 release_sock(sk);
827 return err;
830 EXPORT_SYMBOL_GPL(inet_dccp_listen);
832 static const unsigned char dccp_new_state[] = {
833 /* current state: new state: action: */
834 [0] = DCCP_CLOSED,
835 [DCCP_OPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
836 [DCCP_REQUESTING] = DCCP_CLOSED,
837 [DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
838 [DCCP_LISTEN] = DCCP_CLOSED,
839 [DCCP_RESPOND] = DCCP_CLOSED,
840 [DCCP_CLOSING] = DCCP_CLOSED,
841 [DCCP_TIME_WAIT] = DCCP_CLOSED,
842 [DCCP_CLOSED] = DCCP_CLOSED,
845 static int dccp_close_state(struct sock *sk)
847 const int next = dccp_new_state[sk->sk_state];
848 const int ns = next & DCCP_STATE_MASK;
850 if (ns != sk->sk_state)
851 dccp_set_state(sk, ns);
853 return next & DCCP_ACTION_FIN;
856 void dccp_close(struct sock *sk, long timeout)
858 struct dccp_sock *dp = dccp_sk(sk);
859 struct sk_buff *skb;
860 int state;
862 lock_sock(sk);
864 sk->sk_shutdown = SHUTDOWN_MASK;
866 if (sk->sk_state == DCCP_LISTEN) {
867 dccp_set_state(sk, DCCP_CLOSED);
869 /* Special case. */
870 inet_csk_listen_stop(sk);
872 goto adjudge_to_death;
875 sk_stop_timer(sk, &dp->dccps_xmit_timer);
878 * We need to flush the recv. buffs. We do this only on the
879 * descriptor close, not protocol-sourced closes, because the
880 *reader process may not have drained the data yet!
882 /* FIXME: check for unread data */
883 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
884 __kfree_skb(skb);
887 if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
888 /* Check zero linger _after_ checking for unread data. */
889 sk->sk_prot->disconnect(sk, 0);
890 } else if (dccp_close_state(sk)) {
891 dccp_send_close(sk, 1);
894 sk_stream_wait_close(sk, timeout);
896 adjudge_to_death:
897 state = sk->sk_state;
898 sock_hold(sk);
899 sock_orphan(sk);
900 atomic_inc(sk->sk_prot->orphan_count);
903 * It is the last release_sock in its life. It will remove backlog.
905 release_sock(sk);
907 * Now socket is owned by kernel and we acquire BH lock
908 * to finish close. No need to check for user refs.
910 local_bh_disable();
911 bh_lock_sock(sk);
912 BUG_TRAP(!sock_owned_by_user(sk));
914 /* Have we already been destroyed by a softirq or backlog? */
915 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
916 goto out;
919 * The last release_sock may have processed the CLOSE or RESET
920 * packet moving sock to CLOSED state, if not we have to fire
921 * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
922 * in draft-ietf-dccp-spec-11. -acme
924 if (sk->sk_state == DCCP_CLOSING) {
925 /* FIXME: should start at 2 * RTT */
926 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
927 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
928 inet_csk(sk)->icsk_rto,
929 DCCP_RTO_MAX);
930 #if 0
931 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
932 dccp_set_state(sk, DCCP_CLOSED);
933 #endif
936 if (sk->sk_state == DCCP_CLOSED)
937 inet_csk_destroy_sock(sk);
939 /* Otherwise, socket is reprieved until protocol close. */
941 out:
942 bh_unlock_sock(sk);
943 local_bh_enable();
944 sock_put(sk);
947 EXPORT_SYMBOL_GPL(dccp_close);
949 void dccp_shutdown(struct sock *sk, int how)
951 dccp_pr_debug("entry\n");
954 EXPORT_SYMBOL_GPL(dccp_shutdown);
956 static int __init dccp_mib_init(void)
958 int rc = -ENOMEM;
960 dccp_statistics[0] = alloc_percpu(struct dccp_mib);
961 if (dccp_statistics[0] == NULL)
962 goto out;
964 dccp_statistics[1] = alloc_percpu(struct dccp_mib);
965 if (dccp_statistics[1] == NULL)
966 goto out_free_one;
968 rc = 0;
969 out:
970 return rc;
971 out_free_one:
972 free_percpu(dccp_statistics[0]);
973 dccp_statistics[0] = NULL;
974 goto out;
978 static void dccp_mib_exit(void)
980 free_percpu(dccp_statistics[0]);
981 free_percpu(dccp_statistics[1]);
982 dccp_statistics[0] = dccp_statistics[1] = NULL;
985 static int thash_entries;
986 module_param(thash_entries, int, 0444);
987 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
989 #ifdef CONFIG_IP_DCCP_DEBUG
990 int dccp_debug;
991 module_param(dccp_debug, int, 0444);
992 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
994 EXPORT_SYMBOL_GPL(dccp_debug);
995 #endif
997 static int __init dccp_init(void)
999 unsigned long goal;
1000 int ehash_order, bhash_order, i;
1001 int rc = -ENOBUFS;
1003 dccp_hashinfo.bind_bucket_cachep =
1004 kmem_cache_create("dccp_bind_bucket",
1005 sizeof(struct inet_bind_bucket), 0,
1006 SLAB_HWCACHE_ALIGN, NULL, NULL);
1007 if (!dccp_hashinfo.bind_bucket_cachep)
1008 goto out;
1011 * Size and allocate the main established and bind bucket
1012 * hash tables.
1014 * The methodology is similar to that of the buffer cache.
1016 if (num_physpages >= (128 * 1024))
1017 goal = num_physpages >> (21 - PAGE_SHIFT);
1018 else
1019 goal = num_physpages >> (23 - PAGE_SHIFT);
1021 if (thash_entries)
1022 goal = (thash_entries *
1023 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1024 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1026 do {
1027 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1028 sizeof(struct inet_ehash_bucket);
1029 dccp_hashinfo.ehash_size >>= 1;
1030 while (dccp_hashinfo.ehash_size &
1031 (dccp_hashinfo.ehash_size - 1))
1032 dccp_hashinfo.ehash_size--;
1033 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1034 __get_free_pages(GFP_ATOMIC, ehash_order);
1035 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1037 if (!dccp_hashinfo.ehash) {
1038 DCCP_CRIT("Failed to allocate DCCP established hash table");
1039 goto out_free_bind_bucket_cachep;
1042 for (i = 0; i < (dccp_hashinfo.ehash_size << 1); i++) {
1043 rwlock_init(&dccp_hashinfo.ehash[i].lock);
1044 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
1047 bhash_order = ehash_order;
1049 do {
1050 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1051 sizeof(struct inet_bind_hashbucket);
1052 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1053 bhash_order > 0)
1054 continue;
1055 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1056 __get_free_pages(GFP_ATOMIC, bhash_order);
1057 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1059 if (!dccp_hashinfo.bhash) {
1060 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1061 goto out_free_dccp_ehash;
1064 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1065 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1066 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1069 rc = dccp_mib_init();
1070 if (rc)
1071 goto out_free_dccp_bhash;
1073 rc = dccp_ackvec_init();
1074 if (rc)
1075 goto out_free_dccp_mib;
1077 rc = dccp_sysctl_init();
1078 if (rc)
1079 goto out_ackvec_exit;
1080 out:
1081 return rc;
1082 out_ackvec_exit:
1083 dccp_ackvec_exit();
1084 out_free_dccp_mib:
1085 dccp_mib_exit();
1086 out_free_dccp_bhash:
1087 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1088 dccp_hashinfo.bhash = NULL;
1089 out_free_dccp_ehash:
1090 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1091 dccp_hashinfo.ehash = NULL;
1092 out_free_bind_bucket_cachep:
1093 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1094 dccp_hashinfo.bind_bucket_cachep = NULL;
1095 goto out;
1098 static void __exit dccp_fini(void)
1100 dccp_mib_exit();
1101 free_pages((unsigned long)dccp_hashinfo.bhash,
1102 get_order(dccp_hashinfo.bhash_size *
1103 sizeof(struct inet_bind_hashbucket)));
1104 free_pages((unsigned long)dccp_hashinfo.ehash,
1105 get_order(dccp_hashinfo.ehash_size *
1106 sizeof(struct inet_ehash_bucket)));
1107 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1108 dccp_ackvec_exit();
1109 dccp_sysctl_exit();
1112 module_init(dccp_init);
1113 module_exit(dccp_fini);
1115 MODULE_LICENSE("GPL");
1116 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1117 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");