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Merge branch 'fixes-jgarzik' of git://git.kernel.org/pub/scm/linux/kernel/git/linvill...
[deliverable/linux.git] / net / dccp / proto.c
1 /*
2 * net/dccp/proto.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
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.
10 */
11
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>
24
25 #include <net/inet_sock.h>
26 #include <net/sock.h>
27 #include <net/xfrm.h>
28
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>
34
35 #include "ccid.h"
36 #include "dccp.h"
37 #include "feat.h"
38
39 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
40
41 EXPORT_SYMBOL_GPL(dccp_statistics);
42
43 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
44
45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
46
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),
51 };
52
53 EXPORT_SYMBOL_GPL(dccp_hashinfo);
54
55 /* the maximum queue length for tx in packets. 0 is no limit */
56 int sysctl_dccp_tx_qlen __read_mostly = 5;
57
58 void dccp_set_state(struct sock *sk, const int state)
59 {
60 const int oldstate = sk->sk_state;
61
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);
66
67 switch (state) {
68 case DCCP_OPEN:
69 if (oldstate != DCCP_OPEN)
70 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
71 break;
72
73 case DCCP_CLOSED:
74 if (oldstate == DCCP_CLOSING || oldstate == DCCP_OPEN)
75 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
76
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);
85 }
86
87 /* Change state AFTER socket is unhashed to avoid closed
88 * socket sitting in hash tables.
89 */
90 sk->sk_state = state;
91 }
92
93 EXPORT_SYMBOL_GPL(dccp_set_state);
94
95 void dccp_done(struct sock *sk)
96 {
97 dccp_set_state(sk, DCCP_CLOSED);
98 dccp_clear_xmit_timers(sk);
99
100 sk->sk_shutdown = SHUTDOWN_MASK;
101
102 if (!sock_flag(sk, SOCK_DEAD))
103 sk->sk_state_change(sk);
104 else
105 inet_csk_destroy_sock(sk);
106 }
107
108 EXPORT_SYMBOL_GPL(dccp_done);
109
110 const char *dccp_packet_name(const int type)
111 {
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",
123 };
124
125 if (type >= DCCP_NR_PKT_TYPES)
126 return "INVALID";
127 else
128 return dccp_packet_names[type];
129 }
130
131 EXPORT_SYMBOL_GPL(dccp_packet_name);
132
133 const char *dccp_state_name(const int state)
134 {
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",
144 };
145
146 if (state >= DCCP_MAX_STATES)
147 return "INVALID STATE!";
148 else
149 return dccp_state_names[state];
150 }
151
152 EXPORT_SYMBOL_GPL(dccp_state_name);
153
154 void dccp_hash(struct sock *sk)
155 {
156 inet_hash(&dccp_hashinfo, sk);
157 }
158
159 EXPORT_SYMBOL_GPL(dccp_hash);
160
161 void dccp_unhash(struct sock *sk)
162 {
163 inet_unhash(&dccp_hashinfo, sk);
164 }
165
166 EXPORT_SYMBOL_GPL(dccp_unhash);
167
168 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
169 {
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);
173
174 dccp_minisock_init(&dp->dccps_minisock);
175
176 /*
177 * FIXME: We're hardcoding the CCID, and doing this at this point makes
178 * the listening (master) sock get CCID control blocks, which is not
179 * necessary, but for now, to not mess with the test userspace apps,
180 * lets leave it here, later the real solution is to do this in a
181 * setsockopt(CCIDs-I-want/accept). -acme
182 */
183 if (likely(ctl_sock_initialized)) {
184 int rc = dccp_feat_init(dmsk);
185
186 if (rc)
187 return rc;
188
189 if (dmsk->dccpms_send_ack_vector) {
190 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
191 if (dp->dccps_hc_rx_ackvec == NULL)
192 return -ENOMEM;
193 }
194 dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid,
195 sk, GFP_KERNEL);
196 dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid,
197 sk, GFP_KERNEL);
198 if (unlikely(dp->dccps_hc_rx_ccid == NULL ||
199 dp->dccps_hc_tx_ccid == NULL)) {
200 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
201 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
202 if (dmsk->dccpms_send_ack_vector) {
203 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
204 dp->dccps_hc_rx_ackvec = NULL;
205 }
206 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
207 return -ENOMEM;
208 }
209 } else {
210 /* control socket doesn't need feat nego */
211 INIT_LIST_HEAD(&dmsk->dccpms_pending);
212 INIT_LIST_HEAD(&dmsk->dccpms_conf);
213 }
214
215 dccp_init_xmit_timers(sk);
216 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
217 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
218 sk->sk_state = DCCP_CLOSED;
219 sk->sk_write_space = dccp_write_space;
220 icsk->icsk_sync_mss = dccp_sync_mss;
221 dp->dccps_mss_cache = 536;
222 dp->dccps_rate_last = jiffies;
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;
226
227 return 0;
228 }
229
230 EXPORT_SYMBOL_GPL(dccp_init_sock);
231
232 int dccp_destroy_sock(struct sock *sk)
233 {
234 struct dccp_sock *dp = dccp_sk(sk);
235 struct dccp_minisock *dmsk = dccp_msk(sk);
236
237 /*
238 * DCCP doesn't use sk_write_queue, just sk_send_head
239 * for retransmissions
240 */
241 if (sk->sk_send_head != NULL) {
242 kfree_skb(sk->sk_send_head);
243 sk->sk_send_head = NULL;
244 }
245
246 /* Clean up a referenced DCCP bind bucket. */
247 if (inet_csk(sk)->icsk_bind_hash != NULL)
248 inet_put_port(&dccp_hashinfo, sk);
249
250 kfree(dp->dccps_service_list);
251 dp->dccps_service_list = NULL;
252
253 if (dmsk->dccpms_send_ack_vector) {
254 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
255 dp->dccps_hc_rx_ackvec = NULL;
256 }
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;
260
261 /* clean up feature negotiation state */
262 dccp_feat_clean(dmsk);
263
264 return 0;
265 }
266
267 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
268
269 static inline int dccp_listen_start(struct sock *sk, int backlog)
270 {
271 struct dccp_sock *dp = dccp_sk(sk);
272
273 dp->dccps_role = DCCP_ROLE_LISTEN;
274 return inet_csk_listen_start(sk, backlog);
275 }
276
277 int dccp_disconnect(struct sock *sk, int flags)
278 {
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;
283
284 if (old_state != DCCP_CLOSED)
285 dccp_set_state(sk, DCCP_CLOSED);
286
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;
293
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;
299 }
300
301 inet->dport = 0;
302
303 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
304 inet_reset_saddr(sk);
305
306 sk->sk_shutdown = 0;
307 sock_reset_flag(sk, SOCK_DONE);
308
309 icsk->icsk_backoff = 0;
310 inet_csk_delack_init(sk);
311 __sk_dst_reset(sk);
312
313 BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
314
315 sk->sk_error_report(sk);
316 return err;
317 }
318
319 EXPORT_SYMBOL_GPL(dccp_disconnect);
320
321 /*
322 * Wait for a DCCP event.
323 *
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.
327 */
328 unsigned int dccp_poll(struct file *file, struct socket *sock,
329 poll_table *wait)
330 {
331 unsigned int mask;
332 struct sock *sk = sock->sk;
333
334 poll_wait(file, sk->sk_sleep, wait);
335 if (sk->sk_state == DCCP_LISTEN)
336 return inet_csk_listen_poll(sk);
337
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.
341 */
342
343 mask = 0;
344 if (sk->sk_err)
345 mask = POLLERR;
346
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;
351
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;
356
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);
364
365 /* Race breaker. If space is freed after
366 * wspace test but before the flags are set,
367 * IO signal will be lost.
368 */
369 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
370 mask |= POLLOUT | POLLWRNORM;
371 }
372 }
373 }
374 return mask;
375 }
376
377 EXPORT_SYMBOL_GPL(dccp_poll);
378
379 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
380 {
381 dccp_pr_debug("entry\n");
382 return -ENOIOCTLCMD;
383 }
384
385 EXPORT_SYMBOL_GPL(dccp_ioctl);
386
387 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
388 char __user *optval, int optlen)
389 {
390 struct dccp_sock *dp = dccp_sk(sk);
391 struct dccp_service_list *sl = NULL;
392
393 if (service == DCCP_SERVICE_INVALID_VALUE ||
394 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
395 return -EINVAL;
396
397 if (optlen > sizeof(service)) {
398 sl = kmalloc(optlen, GFP_KERNEL);
399 if (sl == NULL)
400 return -ENOMEM;
401
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;
409 }
410 }
411
412 lock_sock(sk);
413 dp->dccps_service = service;
414
415 kfree(dp->dccps_service_list);
416
417 dp->dccps_service_list = sl;
418 release_sock(sk);
419 return 0;
420 }
421
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)
425 {
426 struct dccp_so_feat opt;
427 u8 *val;
428 int rc;
429
430 if (copy_from_user(&opt, optval, sizeof(opt)))
431 return -EFAULT;
432
433 val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
434 if (!val)
435 return -ENOMEM;
436
437 if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
438 rc = -EFAULT;
439 goto out_free_val;
440 }
441
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;
446
447 out:
448 return rc;
449
450 out_free_val:
451 kfree(val);
452 goto out;
453 }
454
455 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
456 char __user *optval, int optlen)
457 {
458 struct dccp_sock *dp = dccp_sk(sk);
459 int val, err = 0;
460
461 if (optlen < sizeof(int))
462 return -EINVAL;
463
464 if (get_user(val, (int __user *)optval))
465 return -EFAULT;
466
467 if (optname == DCCP_SOCKOPT_SERVICE)
468 return dccp_setsockopt_service(sk, val, optval, optlen);
469
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) */
505 }
506 break;
507 default:
508 err = -ENOPROTOOPT;
509 break;
510 }
511
512 release_sock(sk);
513 return err;
514 }
515
516 int dccp_setsockopt(struct sock *sk, int level, int optname,
517 char __user *optval, int optlen)
518 {
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);
524 }
525
526 EXPORT_SYMBOL_GPL(dccp_setsockopt);
527
528 #ifdef CONFIG_COMPAT
529 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
530 char __user *optval, int optlen)
531 {
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);
536 }
537
538 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
539 #endif
540
541 static int dccp_getsockopt_service(struct sock *sk, int len,
542 __be32 __user *optval,
543 int __user *optlen)
544 {
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);
548
549 lock_sock(sk);
550 if ((sl = dp->dccps_service_list) != NULL) {
551 slen = sl->dccpsl_nr * sizeof(u32);
552 total_len += slen;
553 }
554
555 err = -EINVAL;
556 if (total_len > len)
557 goto out;
558
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;
567 }
568
569 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
570 char __user *optval, int __user *optlen)
571 {
572 struct dccp_sock *dp;
573 int val, len;
574
575 if (get_user(len, optlen))
576 return -EFAULT;
577
578 if (len < (int)sizeof(int))
579 return -EINVAL;
580
581 dp = dccp_sk(sk);
582
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_GET_CUR_MPS:
591 val = dp->dccps_mss_cache;
592 len = sizeof(val);
593 break;
594 case DCCP_SOCKOPT_SEND_CSCOV:
595 val = dp->dccps_pcslen;
596 len = sizeof(val);
597 break;
598 case DCCP_SOCKOPT_RECV_CSCOV:
599 val = dp->dccps_pcrlen;
600 len = sizeof(val);
601 break;
602 case 128 ... 191:
603 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
604 len, (u32 __user *)optval, optlen);
605 case 192 ... 255:
606 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
607 len, (u32 __user *)optval, optlen);
608 default:
609 return -ENOPROTOOPT;
610 }
611
612 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
613 return -EFAULT;
614
615 return 0;
616 }
617
618 int dccp_getsockopt(struct sock *sk, int level, int optname,
619 char __user *optval, int __user *optlen)
620 {
621 if (level != SOL_DCCP)
622 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
623 optname, optval,
624 optlen);
625 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
626 }
627
628 EXPORT_SYMBOL_GPL(dccp_getsockopt);
629
630 #ifdef CONFIG_COMPAT
631 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
632 char __user *optval, int __user *optlen)
633 {
634 if (level != SOL_DCCP)
635 return inet_csk_compat_getsockopt(sk, level, optname,
636 optval, optlen);
637 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
638 }
639
640 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
641 #endif
642
643 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
644 size_t len)
645 {
646 const struct dccp_sock *dp = dccp_sk(sk);
647 const int flags = msg->msg_flags;
648 const int noblock = flags & MSG_DONTWAIT;
649 struct sk_buff *skb;
650 int rc, size;
651 long timeo;
652
653 if (len > dp->dccps_mss_cache)
654 return -EMSGSIZE;
655
656 lock_sock(sk);
657
658 if (sysctl_dccp_tx_qlen &&
659 (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
660 rc = -EAGAIN;
661 goto out_release;
662 }
663
664 timeo = sock_sndtimeo(sk, noblock);
665
666 /*
667 * We have to use sk_stream_wait_connect here to set sk_write_pending,
668 * so that the trick in dccp_rcv_request_sent_state_process.
669 */
670 /* Wait for a connection to finish. */
671 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
672 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
673 goto out_release;
674
675 size = sk->sk_prot->max_header + len;
676 release_sock(sk);
677 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
678 lock_sock(sk);
679 if (skb == NULL)
680 goto out_release;
681
682 skb_reserve(skb, sk->sk_prot->max_header);
683 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
684 if (rc != 0)
685 goto out_discard;
686
687 skb_queue_tail(&sk->sk_write_queue, skb);
688 dccp_write_xmit(sk,0);
689 out_release:
690 release_sock(sk);
691 return rc ? : len;
692 out_discard:
693 kfree_skb(skb);
694 goto out_release;
695 }
696
697 EXPORT_SYMBOL_GPL(dccp_sendmsg);
698
699 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
700 size_t len, int nonblock, int flags, int *addr_len)
701 {
702 const struct dccp_hdr *dh;
703 long timeo;
704
705 lock_sock(sk);
706
707 if (sk->sk_state == DCCP_LISTEN) {
708 len = -ENOTCONN;
709 goto out;
710 }
711
712 timeo = sock_rcvtimeo(sk, nonblock);
713
714 do {
715 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
716
717 if (skb == NULL)
718 goto verify_sock_status;
719
720 dh = dccp_hdr(skb);
721
722 if (dh->dccph_type == DCCP_PKT_DATA ||
723 dh->dccph_type == DCCP_PKT_DATAACK)
724 goto found_ok_skb;
725
726 if (dh->dccph_type == DCCP_PKT_RESET ||
727 dh->dccph_type == DCCP_PKT_CLOSE) {
728 dccp_pr_debug("found fin ok!\n");
729 len = 0;
730 goto found_fin_ok;
731 }
732 dccp_pr_debug("packet_type=%s\n",
733 dccp_packet_name(dh->dccph_type));
734 sk_eat_skb(sk, skb, 0);
735 verify_sock_status:
736 if (sock_flag(sk, SOCK_DONE)) {
737 len = 0;
738 break;
739 }
740
741 if (sk->sk_err) {
742 len = sock_error(sk);
743 break;
744 }
745
746 if (sk->sk_shutdown & RCV_SHUTDOWN) {
747 len = 0;
748 break;
749 }
750
751 if (sk->sk_state == DCCP_CLOSED) {
752 if (!sock_flag(sk, SOCK_DONE)) {
753 /* This occurs when user tries to read
754 * from never connected socket.
755 */
756 len = -ENOTCONN;
757 break;
758 }
759 len = 0;
760 break;
761 }
762
763 if (!timeo) {
764 len = -EAGAIN;
765 break;
766 }
767
768 if (signal_pending(current)) {
769 len = sock_intr_errno(timeo);
770 break;
771 }
772
773 sk_wait_data(sk, &timeo);
774 continue;
775 found_ok_skb:
776 if (len > skb->len)
777 len = skb->len;
778 else if (len < skb->len)
779 msg->msg_flags |= MSG_TRUNC;
780
781 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
782 /* Exception. Bailout! */
783 len = -EFAULT;
784 break;
785 }
786 found_fin_ok:
787 if (!(flags & MSG_PEEK))
788 sk_eat_skb(sk, skb, 0);
789 break;
790 } while (1);
791 out:
792 release_sock(sk);
793 return len;
794 }
795
796 EXPORT_SYMBOL_GPL(dccp_recvmsg);
797
798 int inet_dccp_listen(struct socket *sock, int backlog)
799 {
800 struct sock *sk = sock->sk;
801 unsigned char old_state;
802 int err;
803
804 lock_sock(sk);
805
806 err = -EINVAL;
807 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
808 goto out;
809
810 old_state = sk->sk_state;
811 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
812 goto out;
813
814 /* Really, if the socket is already in listen state
815 * we can only allow the backlog to be adjusted.
816 */
817 if (old_state != DCCP_LISTEN) {
818 /*
819 * FIXME: here it probably should be sk->sk_prot->listen_start
820 * see tcp_listen_start
821 */
822 err = dccp_listen_start(sk, backlog);
823 if (err)
824 goto out;
825 }
826 sk->sk_max_ack_backlog = backlog;
827 err = 0;
828
829 out:
830 release_sock(sk);
831 return err;
832 }
833
834 EXPORT_SYMBOL_GPL(inet_dccp_listen);
835
836 static const unsigned char dccp_new_state[] = {
837 /* current state: new state: action: */
838 [0] = DCCP_CLOSED,
839 [DCCP_OPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
840 [DCCP_REQUESTING] = DCCP_CLOSED,
841 [DCCP_PARTOPEN] = DCCP_CLOSING | DCCP_ACTION_FIN,
842 [DCCP_LISTEN] = DCCP_CLOSED,
843 [DCCP_RESPOND] = DCCP_CLOSED,
844 [DCCP_CLOSING] = DCCP_CLOSED,
845 [DCCP_TIME_WAIT] = DCCP_CLOSED,
846 [DCCP_CLOSED] = DCCP_CLOSED,
847 };
848
849 static int dccp_close_state(struct sock *sk)
850 {
851 const int next = dccp_new_state[sk->sk_state];
852 const int ns = next & DCCP_STATE_MASK;
853
854 if (ns != sk->sk_state)
855 dccp_set_state(sk, ns);
856
857 return next & DCCP_ACTION_FIN;
858 }
859
860 void dccp_close(struct sock *sk, long timeout)
861 {
862 struct dccp_sock *dp = dccp_sk(sk);
863 struct sk_buff *skb;
864 int state;
865
866 lock_sock(sk);
867
868 sk->sk_shutdown = SHUTDOWN_MASK;
869
870 if (sk->sk_state == DCCP_LISTEN) {
871 dccp_set_state(sk, DCCP_CLOSED);
872
873 /* Special case. */
874 inet_csk_listen_stop(sk);
875
876 goto adjudge_to_death;
877 }
878
879 sk_stop_timer(sk, &dp->dccps_xmit_timer);
880
881 /*
882 * We need to flush the recv. buffs. We do this only on the
883 * descriptor close, not protocol-sourced closes, because the
884 *reader process may not have drained the data yet!
885 */
886 /* FIXME: check for unread data */
887 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
888 __kfree_skb(skb);
889 }
890
891 if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
892 /* Check zero linger _after_ checking for unread data. */
893 sk->sk_prot->disconnect(sk, 0);
894 } else if (dccp_close_state(sk)) {
895 dccp_send_close(sk, 1);
896 }
897
898 sk_stream_wait_close(sk, timeout);
899
900 adjudge_to_death:
901 state = sk->sk_state;
902 sock_hold(sk);
903 sock_orphan(sk);
904 atomic_inc(sk->sk_prot->orphan_count);
905
906 /*
907 * It is the last release_sock in its life. It will remove backlog.
908 */
909 release_sock(sk);
910 /*
911 * Now socket is owned by kernel and we acquire BH lock
912 * to finish close. No need to check for user refs.
913 */
914 local_bh_disable();
915 bh_lock_sock(sk);
916 BUG_TRAP(!sock_owned_by_user(sk));
917
918 /* Have we already been destroyed by a softirq or backlog? */
919 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
920 goto out;
921
922 /*
923 * The last release_sock may have processed the CLOSE or RESET
924 * packet moving sock to CLOSED state, if not we have to fire
925 * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"
926 * in draft-ietf-dccp-spec-11. -acme
927 */
928 if (sk->sk_state == DCCP_CLOSING) {
929 /* FIXME: should start at 2 * RTT */
930 /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */
931 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
932 inet_csk(sk)->icsk_rto,
933 DCCP_RTO_MAX);
934 #if 0
935 /* Yeah, we should use sk->sk_prot->orphan_count, etc */
936 dccp_set_state(sk, DCCP_CLOSED);
937 #endif
938 }
939
940 if (sk->sk_state == DCCP_CLOSED)
941 inet_csk_destroy_sock(sk);
942
943 /* Otherwise, socket is reprieved until protocol close. */
944
945 out:
946 bh_unlock_sock(sk);
947 local_bh_enable();
948 sock_put(sk);
949 }
950
951 EXPORT_SYMBOL_GPL(dccp_close);
952
953 void dccp_shutdown(struct sock *sk, int how)
954 {
955 dccp_pr_debug("entry\n");
956 }
957
958 EXPORT_SYMBOL_GPL(dccp_shutdown);
959
960 static int __init dccp_mib_init(void)
961 {
962 int rc = -ENOMEM;
963
964 dccp_statistics[0] = alloc_percpu(struct dccp_mib);
965 if (dccp_statistics[0] == NULL)
966 goto out;
967
968 dccp_statistics[1] = alloc_percpu(struct dccp_mib);
969 if (dccp_statistics[1] == NULL)
970 goto out_free_one;
971
972 rc = 0;
973 out:
974 return rc;
975 out_free_one:
976 free_percpu(dccp_statistics[0]);
977 dccp_statistics[0] = NULL;
978 goto out;
979
980 }
981
982 static void dccp_mib_exit(void)
983 {
984 free_percpu(dccp_statistics[0]);
985 free_percpu(dccp_statistics[1]);
986 dccp_statistics[0] = dccp_statistics[1] = NULL;
987 }
988
989 static int thash_entries;
990 module_param(thash_entries, int, 0444);
991 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
992
993 #ifdef CONFIG_IP_DCCP_DEBUG
994 int dccp_debug;
995 module_param(dccp_debug, bool, 0444);
996 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
997
998 EXPORT_SYMBOL_GPL(dccp_debug);
999 #endif
1000
1001 static int __init dccp_init(void)
1002 {
1003 unsigned long goal;
1004 int ehash_order, bhash_order, i;
1005 int rc = -ENOBUFS;
1006
1007 dccp_hashinfo.bind_bucket_cachep =
1008 kmem_cache_create("dccp_bind_bucket",
1009 sizeof(struct inet_bind_bucket), 0,
1010 SLAB_HWCACHE_ALIGN, NULL);
1011 if (!dccp_hashinfo.bind_bucket_cachep)
1012 goto out;
1013
1014 /*
1015 * Size and allocate the main established and bind bucket
1016 * hash tables.
1017 *
1018 * The methodology is similar to that of the buffer cache.
1019 */
1020 if (num_physpages >= (128 * 1024))
1021 goal = num_physpages >> (21 - PAGE_SHIFT);
1022 else
1023 goal = num_physpages >> (23 - PAGE_SHIFT);
1024
1025 if (thash_entries)
1026 goal = (thash_entries *
1027 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1028 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1029 ;
1030 do {
1031 dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
1032 sizeof(struct inet_ehash_bucket);
1033 while (dccp_hashinfo.ehash_size &
1034 (dccp_hashinfo.ehash_size - 1))
1035 dccp_hashinfo.ehash_size--;
1036 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1037 __get_free_pages(GFP_ATOMIC, ehash_order);
1038 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1039
1040 if (!dccp_hashinfo.ehash) {
1041 DCCP_CRIT("Failed to allocate DCCP established hash table");
1042 goto out_free_bind_bucket_cachep;
1043 }
1044
1045 for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
1046 rwlock_init(&dccp_hashinfo.ehash[i].lock);
1047 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
1048 INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].twchain);
1049 }
1050
1051 bhash_order = ehash_order;
1052
1053 do {
1054 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1055 sizeof(struct inet_bind_hashbucket);
1056 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1057 bhash_order > 0)
1058 continue;
1059 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1060 __get_free_pages(GFP_ATOMIC, bhash_order);
1061 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1062
1063 if (!dccp_hashinfo.bhash) {
1064 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1065 goto out_free_dccp_ehash;
1066 }
1067
1068 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1069 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1070 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1071 }
1072
1073 rc = dccp_mib_init();
1074 if (rc)
1075 goto out_free_dccp_bhash;
1076
1077 rc = dccp_ackvec_init();
1078 if (rc)
1079 goto out_free_dccp_mib;
1080
1081 rc = dccp_sysctl_init();
1082 if (rc)
1083 goto out_ackvec_exit;
1084
1085 dccp_timestamping_init();
1086 out:
1087 return rc;
1088 out_ackvec_exit:
1089 dccp_ackvec_exit();
1090 out_free_dccp_mib:
1091 dccp_mib_exit();
1092 out_free_dccp_bhash:
1093 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1094 dccp_hashinfo.bhash = NULL;
1095 out_free_dccp_ehash:
1096 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1097 dccp_hashinfo.ehash = NULL;
1098 out_free_bind_bucket_cachep:
1099 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1100 dccp_hashinfo.bind_bucket_cachep = NULL;
1101 goto out;
1102 }
1103
1104 static void __exit dccp_fini(void)
1105 {
1106 dccp_mib_exit();
1107 free_pages((unsigned long)dccp_hashinfo.bhash,
1108 get_order(dccp_hashinfo.bhash_size *
1109 sizeof(struct inet_bind_hashbucket)));
1110 free_pages((unsigned long)dccp_hashinfo.ehash,
1111 get_order(dccp_hashinfo.ehash_size *
1112 sizeof(struct inet_ehash_bucket)));
1113 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1114 dccp_ackvec_exit();
1115 dccp_sysctl_exit();
1116 }
1117
1118 module_init(dccp_init);
1119 module_exit(dccp_fini);
1120
1121 MODULE_LICENSE("GPL");
1122 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1123 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
Linux kernel - Deliverables
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