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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 <linux/slab.h>
24#include <net/checksum.h>
25
26#include <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/xfrm.h>
29
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>
35
36#include "ccid.h"
37#include "dccp.h"
38#include "feat.h"
39
40DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
41
42EXPORT_SYMBOL_GPL(dccp_statistics);
43
44struct percpu_counter dccp_orphan_count;
45EXPORT_SYMBOL_GPL(dccp_orphan_count);
46
47struct inet_hashinfo dccp_hashinfo;
48EXPORT_SYMBOL_GPL(dccp_hashinfo);
49
50/* the maximum queue length for tx in packets. 0 is no limit */
51int sysctl_dccp_tx_qlen __read_mostly = 5;
52
53#ifdef CONFIG_IP_DCCP_DEBUG
54static const char *dccp_state_name(const int state)
55{
56 static const char *const dccp_state_names[] = {
57 [DCCP_OPEN] = "OPEN",
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",
68 };
69
70 if (state >= DCCP_MAX_STATES)
71 return "INVALID STATE!";
72 else
73 return dccp_state_names[state];
74}
75#endif
76
77void dccp_set_state(struct sock *sk, const int state)
78{
79 const int oldstate = sk->sk_state;
80
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);
84
85 switch (state) {
86 case DCCP_OPEN:
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);
92 break;
93
94 case DCCP_CLOSED:
95 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
96 oldstate == DCCP_CLOSING)
97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
98
99 sk->sk_prot->unhash(sk);
100 if (inet_csk(sk)->icsk_bind_hash != NULL &&
101 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
102 inet_put_port(sk);
103 /* fall through */
104 default:
105 if (oldstate == DCCP_OPEN)
106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
107 }
108
109 /* Change state AFTER socket is unhashed to avoid closed
110 * socket sitting in hash tables.
111 */
112 sk->sk_state = state;
113}
114
115EXPORT_SYMBOL_GPL(dccp_set_state);
116
117static void dccp_finish_passive_close(struct sock *sk)
118{
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);
124 break;
125 case DCCP_PASSIVE_CLOSEREQ:
126 /*
127 * Client received CloseReq. We set the `active' flag so that
128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
129 */
130 dccp_send_close(sk, 1);
131 dccp_set_state(sk, DCCP_CLOSING);
132 }
133}
134
135void dccp_done(struct sock *sk)
136{
137 dccp_set_state(sk, DCCP_CLOSED);
138 dccp_clear_xmit_timers(sk);
139
140 sk->sk_shutdown = SHUTDOWN_MASK;
141
142 if (!sock_flag(sk, SOCK_DEAD))
143 sk->sk_state_change(sk);
144 else
145 inet_csk_destroy_sock(sk);
146}
147
148EXPORT_SYMBOL_GPL(dccp_done);
149
150const char *dccp_packet_name(const int type)
151{
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",
163 };
164
165 if (type >= DCCP_NR_PKT_TYPES)
166 return "INVALID";
167 else
168 return dccp_packet_names[type];
169}
170
171EXPORT_SYMBOL_GPL(dccp_packet_name);
172
173int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
174{
175 struct dccp_sock *dp = dccp_sk(sk);
176 struct inet_connection_sock *icsk = inet_csk(sk);
177
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;
188
189 dccp_init_xmit_timers(sk);
190
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);
195 return 0;
196}
197
198EXPORT_SYMBOL_GPL(dccp_init_sock);
199
200void dccp_destroy_sock(struct sock *sk)
201{
202 struct dccp_sock *dp = dccp_sk(sk);
203
204 /*
205 * DCCP doesn't use sk_write_queue, just sk_send_head
206 * for retransmissions
207 */
208 if (sk->sk_send_head != NULL) {
209 kfree_skb(sk->sk_send_head);
210 sk->sk_send_head = NULL;
211 }
212
213 /* Clean up a referenced DCCP bind bucket. */
214 if (inet_csk(sk)->icsk_bind_hash != NULL)
215 inet_put_port(sk);
216
217 kfree(dp->dccps_service_list);
218 dp->dccps_service_list = NULL;
219
220 if (dp->dccps_hc_rx_ackvec != NULL) {
221 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
222 dp->dccps_hc_rx_ackvec = NULL;
223 }
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;
227
228 /* clean up feature negotiation state */
229 dccp_feat_list_purge(&dp->dccps_featneg);
230}
231
232EXPORT_SYMBOL_GPL(dccp_destroy_sock);
233
234static inline int dccp_listen_start(struct sock *sk, int backlog)
235{
236 struct dccp_sock *dp = dccp_sk(sk);
237
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))
241 return -EPROTO;
242 return inet_csk_listen_start(sk, backlog);
243}
244
245static inline int dccp_need_reset(int state)
246{
247 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
248 state != DCCP_REQUESTING;
249}
250
251int dccp_disconnect(struct sock *sk, int flags)
252{
253 struct inet_connection_sock *icsk = inet_csk(sk);
254 struct inet_sock *inet = inet_sk(sk);
255 int err = 0;
256 const int old_state = sk->sk_state;
257
258 if (old_state != DCCP_CLOSED)
259 dccp_set_state(sk, DCCP_CLOSED);
260
261 /*
262 * This corresponds to the ABORT function of RFC793, sec. 3.8
263 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
264 */
265 if (old_state == DCCP_LISTEN) {
266 inet_csk_listen_stop(sk);
267 } else if (dccp_need_reset(old_state)) {
268 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
269 sk->sk_err = ECONNRESET;
270 } else if (old_state == DCCP_REQUESTING)
271 sk->sk_err = ECONNRESET;
272
273 dccp_clear_xmit_timers(sk);
274
275 __skb_queue_purge(&sk->sk_receive_queue);
276 __skb_queue_purge(&sk->sk_write_queue);
277 if (sk->sk_send_head != NULL) {
278 __kfree_skb(sk->sk_send_head);
279 sk->sk_send_head = NULL;
280 }
281
282 inet->inet_dport = 0;
283
284 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
285 inet_reset_saddr(sk);
286
287 sk->sk_shutdown = 0;
288 sock_reset_flag(sk, SOCK_DONE);
289
290 icsk->icsk_backoff = 0;
291 inet_csk_delack_init(sk);
292 __sk_dst_reset(sk);
293
294 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
295
296 sk->sk_error_report(sk);
297 return err;
298}
299
300EXPORT_SYMBOL_GPL(dccp_disconnect);
301
302/*
303 * Wait for a DCCP event.
304 *
305 * Note that we don't need to lock the socket, as the upper poll layers
306 * take care of normal races (between the test and the event) and we don't
307 * go look at any of the socket buffers directly.
308 */
309unsigned int dccp_poll(struct file *file, struct socket *sock,
310 poll_table *wait)
311{
312 unsigned int mask;
313 struct sock *sk = sock->sk;
314
315 sock_poll_wait(file, sk_sleep(sk), wait);
316 if (sk->sk_state == DCCP_LISTEN)
317 return inet_csk_listen_poll(sk);
318
319 /* Socket is not locked. We are protected from async events
320 by poll logic and correct handling of state changes
321 made by another threads is impossible in any case.
322 */
323
324 mask = 0;
325 if (sk->sk_err)
326 mask = POLLERR;
327
328 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
329 mask |= POLLHUP;
330 if (sk->sk_shutdown & RCV_SHUTDOWN)
331 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
332
333 /* Connected? */
334 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
335 if (atomic_read(&sk->sk_rmem_alloc) > 0)
336 mask |= POLLIN | POLLRDNORM;
337
338 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
339 if (sk_stream_is_writeable(sk)) {
340 mask |= POLLOUT | POLLWRNORM;
341 } else { /* send SIGIO later */
342 set_bit(SOCK_ASYNC_NOSPACE,
343 &sk->sk_socket->flags);
344 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
345
346 /* Race breaker. If space is freed after
347 * wspace test but before the flags are set,
348 * IO signal will be lost.
349 */
350 if (sk_stream_is_writeable(sk))
351 mask |= POLLOUT | POLLWRNORM;
352 }
353 }
354 }
355 return mask;
356}
357
358EXPORT_SYMBOL_GPL(dccp_poll);
359
360int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
361{
362 int rc = -ENOTCONN;
363
364 lock_sock(sk);
365
366 if (sk->sk_state == DCCP_LISTEN)
367 goto out;
368
369 switch (cmd) {
370 case SIOCINQ: {
371 struct sk_buff *skb;
372 unsigned long amount = 0;
373
374 skb = skb_peek(&sk->sk_receive_queue);
375 if (skb != NULL) {
376 /*
377 * We will only return the amount of this packet since
378 * that is all that will be read.
379 */
380 amount = skb->len;
381 }
382 rc = put_user(amount, (int __user *)arg);
383 }
384 break;
385 default:
386 rc = -ENOIOCTLCMD;
387 break;
388 }
389out:
390 release_sock(sk);
391 return rc;
392}
393
394EXPORT_SYMBOL_GPL(dccp_ioctl);
395
396static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
397 char __user *optval, unsigned int optlen)
398{
399 struct dccp_sock *dp = dccp_sk(sk);
400 struct dccp_service_list *sl = NULL;
401
402 if (service == DCCP_SERVICE_INVALID_VALUE ||
403 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
404 return -EINVAL;
405
406 if (optlen > sizeof(service)) {
407 sl = kmalloc(optlen, GFP_KERNEL);
408 if (sl == NULL)
409 return -ENOMEM;
410
411 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
412 if (copy_from_user(sl->dccpsl_list,
413 optval + sizeof(service),
414 optlen - sizeof(service)) ||
415 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
416 kfree(sl);
417 return -EFAULT;
418 }
419 }
420
421 lock_sock(sk);
422 dp->dccps_service = service;
423
424 kfree(dp->dccps_service_list);
425
426 dp->dccps_service_list = sl;
427 release_sock(sk);
428 return 0;
429}
430
431static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
432{
433 u8 *list, len;
434 int i, rc;
435
436 if (cscov < 0 || cscov > 15)
437 return -EINVAL;
438 /*
439 * Populate a list of permissible values, in the range cscov...15. This
440 * is necessary since feature negotiation of single values only works if
441 * both sides incidentally choose the same value. Since the list starts
442 * lowest-value first, negotiation will pick the smallest shared value.
443 */
444 if (cscov == 0)
445 return 0;
446 len = 16 - cscov;
447
448 list = kmalloc(len, GFP_KERNEL);
449 if (list == NULL)
450 return -ENOBUFS;
451
452 for (i = 0; i < len; i++)
453 list[i] = cscov++;
454
455 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
456
457 if (rc == 0) {
458 if (rx)
459 dccp_sk(sk)->dccps_pcrlen = cscov;
460 else
461 dccp_sk(sk)->dccps_pcslen = cscov;
462 }
463 kfree(list);
464 return rc;
465}
466
467static int dccp_setsockopt_ccid(struct sock *sk, int type,
468 char __user *optval, unsigned int optlen)
469{
470 u8 *val;
471 int rc = 0;
472
473 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
474 return -EINVAL;
475
476 val = memdup_user(optval, optlen);
477 if (IS_ERR(val))
478 return PTR_ERR(val);
479
480 lock_sock(sk);
481 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
482 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
483
484 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
485 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
486 release_sock(sk);
487
488 kfree(val);
489 return rc;
490}
491
492static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
493 char __user *optval, unsigned int optlen)
494{
495 struct dccp_sock *dp = dccp_sk(sk);
496 int val, err = 0;
497
498 switch (optname) {
499 case DCCP_SOCKOPT_PACKET_SIZE:
500 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
501 return 0;
502 case DCCP_SOCKOPT_CHANGE_L:
503 case DCCP_SOCKOPT_CHANGE_R:
504 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
505 return 0;
506 case DCCP_SOCKOPT_CCID:
507 case DCCP_SOCKOPT_RX_CCID:
508 case DCCP_SOCKOPT_TX_CCID:
509 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
510 }
511
512 if (optlen < (int)sizeof(int))
513 return -EINVAL;
514
515 if (get_user(val, (int __user *)optval))
516 return -EFAULT;
517
518 if (optname == DCCP_SOCKOPT_SERVICE)
519 return dccp_setsockopt_service(sk, val, optval, optlen);
520
521 lock_sock(sk);
522 switch (optname) {
523 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
524 if (dp->dccps_role != DCCP_ROLE_SERVER)
525 err = -EOPNOTSUPP;
526 else
527 dp->dccps_server_timewait = (val != 0);
528 break;
529 case DCCP_SOCKOPT_SEND_CSCOV:
530 err = dccp_setsockopt_cscov(sk, val, false);
531 break;
532 case DCCP_SOCKOPT_RECV_CSCOV:
533 err = dccp_setsockopt_cscov(sk, val, true);
534 break;
535 case DCCP_SOCKOPT_QPOLICY_ID:
536 if (sk->sk_state != DCCP_CLOSED)
537 err = -EISCONN;
538 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
539 err = -EINVAL;
540 else
541 dp->dccps_qpolicy = val;
542 break;
543 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
544 if (val < 0)
545 err = -EINVAL;
546 else
547 dp->dccps_tx_qlen = val;
548 break;
549 default:
550 err = -ENOPROTOOPT;
551 break;
552 }
553 release_sock(sk);
554
555 return err;
556}
557
558int dccp_setsockopt(struct sock *sk, int level, int optname,
559 char __user *optval, unsigned int optlen)
560{
561 if (level != SOL_DCCP)
562 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
563 optname, optval,
564 optlen);
565 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
566}
567
568EXPORT_SYMBOL_GPL(dccp_setsockopt);
569
570#ifdef CONFIG_COMPAT
571int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
572 char __user *optval, unsigned int optlen)
573{
574 if (level != SOL_DCCP)
575 return inet_csk_compat_setsockopt(sk, level, optname,
576 optval, optlen);
577 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
578}
579
580EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
581#endif
582
583static int dccp_getsockopt_service(struct sock *sk, int len,
584 __be32 __user *optval,
585 int __user *optlen)
586{
587 const struct dccp_sock *dp = dccp_sk(sk);
588 const struct dccp_service_list *sl;
589 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
590
591 lock_sock(sk);
592 if ((sl = dp->dccps_service_list) != NULL) {
593 slen = sl->dccpsl_nr * sizeof(u32);
594 total_len += slen;
595 }
596
597 err = -EINVAL;
598 if (total_len > len)
599 goto out;
600
601 err = 0;
602 if (put_user(total_len, optlen) ||
603 put_user(dp->dccps_service, optval) ||
604 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
605 err = -EFAULT;
606out:
607 release_sock(sk);
608 return err;
609}
610
611static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
612 char __user *optval, int __user *optlen)
613{
614 struct dccp_sock *dp;
615 int val, len;
616
617 if (get_user(len, optlen))
618 return -EFAULT;
619
620 if (len < (int)sizeof(int))
621 return -EINVAL;
622
623 dp = dccp_sk(sk);
624
625 switch (optname) {
626 case DCCP_SOCKOPT_PACKET_SIZE:
627 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
628 return 0;
629 case DCCP_SOCKOPT_SERVICE:
630 return dccp_getsockopt_service(sk, len,
631 (__be32 __user *)optval, optlen);
632 case DCCP_SOCKOPT_GET_CUR_MPS:
633 val = dp->dccps_mss_cache;
634 break;
635 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
636 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
637 case DCCP_SOCKOPT_TX_CCID:
638 val = ccid_get_current_tx_ccid(dp);
639 if (val < 0)
640 return -ENOPROTOOPT;
641 break;
642 case DCCP_SOCKOPT_RX_CCID:
643 val = ccid_get_current_rx_ccid(dp);
644 if (val < 0)
645 return -ENOPROTOOPT;
646 break;
647 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
648 val = dp->dccps_server_timewait;
649 break;
650 case DCCP_SOCKOPT_SEND_CSCOV:
651 val = dp->dccps_pcslen;
652 break;
653 case DCCP_SOCKOPT_RECV_CSCOV:
654 val = dp->dccps_pcrlen;
655 break;
656 case DCCP_SOCKOPT_QPOLICY_ID:
657 val = dp->dccps_qpolicy;
658 break;
659 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
660 val = dp->dccps_tx_qlen;
661 break;
662 case 128 ... 191:
663 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
664 len, (u32 __user *)optval, optlen);
665 case 192 ... 255:
666 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
667 len, (u32 __user *)optval, optlen);
668 default:
669 return -ENOPROTOOPT;
670 }
671
672 len = sizeof(val);
673 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
674 return -EFAULT;
675
676 return 0;
677}
678
679int dccp_getsockopt(struct sock *sk, int level, int optname,
680 char __user *optval, int __user *optlen)
681{
682 if (level != SOL_DCCP)
683 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
684 optname, optval,
685 optlen);
686 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
687}
688
689EXPORT_SYMBOL_GPL(dccp_getsockopt);
690
691#ifdef CONFIG_COMPAT
692int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
693 char __user *optval, int __user *optlen)
694{
695 if (level != SOL_DCCP)
696 return inet_csk_compat_getsockopt(sk, level, optname,
697 optval, optlen);
698 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
699}
700
701EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
702#endif
703
704static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
705{
706 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
707
708 /*
709 * Assign an (opaque) qpolicy priority value to skb->priority.
710 *
711 * We are overloading this skb field for use with the qpolicy subystem.
712 * The skb->priority is normally used for the SO_PRIORITY option, which
713 * is initialised from sk_priority. Since the assignment of sk_priority
714 * to skb->priority happens later (on layer 3), we overload this field
715 * for use with queueing priorities as long as the skb is on layer 4.
716 * The default priority value (if nothing is set) is 0.
717 */
718 skb->priority = 0;
719
720 for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
721
722 if (!CMSG_OK(msg, cmsg))
723 return -EINVAL;
724
725 if (cmsg->cmsg_level != SOL_DCCP)
726 continue;
727
728 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
729 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
730 return -EINVAL;
731
732 switch (cmsg->cmsg_type) {
733 case DCCP_SCM_PRIORITY:
734 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
735 return -EINVAL;
736 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
737 break;
738 default:
739 return -EINVAL;
740 }
741 }
742 return 0;
743}
744
745int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
746 size_t len)
747{
748 const struct dccp_sock *dp = dccp_sk(sk);
749 const int flags = msg->msg_flags;
750 const int noblock = flags & MSG_DONTWAIT;
751 struct sk_buff *skb;
752 int rc, size;
753 long timeo;
754
755 if (len > dp->dccps_mss_cache)
756 return -EMSGSIZE;
757
758 lock_sock(sk);
759
760 if (dccp_qpolicy_full(sk)) {
761 rc = -EAGAIN;
762 goto out_release;
763 }
764
765 timeo = sock_sndtimeo(sk, noblock);
766
767 /*
768 * We have to use sk_stream_wait_connect here to set sk_write_pending,
769 * so that the trick in dccp_rcv_request_sent_state_process.
770 */
771 /* Wait for a connection to finish. */
772 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
773 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
774 goto out_release;
775
776 size = sk->sk_prot->max_header + len;
777 release_sock(sk);
778 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
779 lock_sock(sk);
780 if (skb == NULL)
781 goto out_release;
782
783 skb_reserve(skb, sk->sk_prot->max_header);
784 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
785 if (rc != 0)
786 goto out_discard;
787
788 rc = dccp_msghdr_parse(msg, skb);
789 if (rc != 0)
790 goto out_discard;
791
792 dccp_qpolicy_push(sk, skb);
793 /*
794 * The xmit_timer is set if the TX CCID is rate-based and will expire
795 * when congestion control permits to release further packets into the
796 * network. Window-based CCIDs do not use this timer.
797 */
798 if (!timer_pending(&dp->dccps_xmit_timer))
799 dccp_write_xmit(sk);
800out_release:
801 release_sock(sk);
802 return rc ? : len;
803out_discard:
804 kfree_skb(skb);
805 goto out_release;
806}
807
808EXPORT_SYMBOL_GPL(dccp_sendmsg);
809
810int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
811 size_t len, int nonblock, int flags, int *addr_len)
812{
813 const struct dccp_hdr *dh;
814 long timeo;
815
816 lock_sock(sk);
817
818 if (sk->sk_state == DCCP_LISTEN) {
819 len = -ENOTCONN;
820 goto out;
821 }
822
823 timeo = sock_rcvtimeo(sk, nonblock);
824
825 do {
826 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
827
828 if (skb == NULL)
829 goto verify_sock_status;
830
831 dh = dccp_hdr(skb);
832
833 switch (dh->dccph_type) {
834 case DCCP_PKT_DATA:
835 case DCCP_PKT_DATAACK:
836 goto found_ok_skb;
837
838 case DCCP_PKT_CLOSE:
839 case DCCP_PKT_CLOSEREQ:
840 if (!(flags & MSG_PEEK))
841 dccp_finish_passive_close(sk);
842 /* fall through */
843 case DCCP_PKT_RESET:
844 dccp_pr_debug("found fin (%s) ok!\n",
845 dccp_packet_name(dh->dccph_type));
846 len = 0;
847 goto found_fin_ok;
848 default:
849 dccp_pr_debug("packet_type=%s\n",
850 dccp_packet_name(dh->dccph_type));
851 sk_eat_skb(sk, skb, false);
852 }
853verify_sock_status:
854 if (sock_flag(sk, SOCK_DONE)) {
855 len = 0;
856 break;
857 }
858
859 if (sk->sk_err) {
860 len = sock_error(sk);
861 break;
862 }
863
864 if (sk->sk_shutdown & RCV_SHUTDOWN) {
865 len = 0;
866 break;
867 }
868
869 if (sk->sk_state == DCCP_CLOSED) {
870 if (!sock_flag(sk, SOCK_DONE)) {
871 /* This occurs when user tries to read
872 * from never connected socket.
873 */
874 len = -ENOTCONN;
875 break;
876 }
877 len = 0;
878 break;
879 }
880
881 if (!timeo) {
882 len = -EAGAIN;
883 break;
884 }
885
886 if (signal_pending(current)) {
887 len = sock_intr_errno(timeo);
888 break;
889 }
890
891 sk_wait_data(sk, &timeo);
892 continue;
893 found_ok_skb:
894 if (len > skb->len)
895 len = skb->len;
896 else if (len < skb->len)
897 msg->msg_flags |= MSG_TRUNC;
898
899 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
900 /* Exception. Bailout! */
901 len = -EFAULT;
902 break;
903 }
904 if (flags & MSG_TRUNC)
905 len = skb->len;
906 found_fin_ok:
907 if (!(flags & MSG_PEEK))
908 sk_eat_skb(sk, skb, false);
909 break;
910 } while (1);
911out:
912 release_sock(sk);
913 return len;
914}
915
916EXPORT_SYMBOL_GPL(dccp_recvmsg);
917
918int inet_dccp_listen(struct socket *sock, int backlog)
919{
920 struct sock *sk = sock->sk;
921 unsigned char old_state;
922 int err;
923
924 lock_sock(sk);
925
926 err = -EINVAL;
927 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
928 goto out;
929
930 old_state = sk->sk_state;
931 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
932 goto out;
933
934 /* Really, if the socket is already in listen state
935 * we can only allow the backlog to be adjusted.
936 */
937 if (old_state != DCCP_LISTEN) {
938 /*
939 * FIXME: here it probably should be sk->sk_prot->listen_start
940 * see tcp_listen_start
941 */
942 err = dccp_listen_start(sk, backlog);
943 if (err)
944 goto out;
945 }
946 sk->sk_max_ack_backlog = backlog;
947 err = 0;
948
949out:
950 release_sock(sk);
951 return err;
952}
953
954EXPORT_SYMBOL_GPL(inet_dccp_listen);
955
956static void dccp_terminate_connection(struct sock *sk)
957{
958 u8 next_state = DCCP_CLOSED;
959
960 switch (sk->sk_state) {
961 case DCCP_PASSIVE_CLOSE:
962 case DCCP_PASSIVE_CLOSEREQ:
963 dccp_finish_passive_close(sk);
964 break;
965 case DCCP_PARTOPEN:
966 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
967 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
968 /* fall through */
969 case DCCP_OPEN:
970 dccp_send_close(sk, 1);
971
972 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
973 !dccp_sk(sk)->dccps_server_timewait)
974 next_state = DCCP_ACTIVE_CLOSEREQ;
975 else
976 next_state = DCCP_CLOSING;
977 /* fall through */
978 default:
979 dccp_set_state(sk, next_state);
980 }
981}
982
983void dccp_close(struct sock *sk, long timeout)
984{
985 struct dccp_sock *dp = dccp_sk(sk);
986 struct sk_buff *skb;
987 u32 data_was_unread = 0;
988 int state;
989
990 lock_sock(sk);
991
992 sk->sk_shutdown = SHUTDOWN_MASK;
993
994 if (sk->sk_state == DCCP_LISTEN) {
995 dccp_set_state(sk, DCCP_CLOSED);
996
997 /* Special case. */
998 inet_csk_listen_stop(sk);
999
1000 goto adjudge_to_death;
1001 }
1002
1003 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1004
1005 /*
1006 * We need to flush the recv. buffs. We do this only on the
1007 * descriptor close, not protocol-sourced closes, because the
1008 *reader process may not have drained the data yet!
1009 */
1010 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1011 data_was_unread += skb->len;
1012 __kfree_skb(skb);
1013 }
1014
1015 if (data_was_unread) {
1016 /* Unread data was tossed, send an appropriate Reset Code */
1017 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1018 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1019 dccp_set_state(sk, DCCP_CLOSED);
1020 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1021 /* Check zero linger _after_ checking for unread data. */
1022 sk->sk_prot->disconnect(sk, 0);
1023 } else if (sk->sk_state != DCCP_CLOSED) {
1024 /*
1025 * Normal connection termination. May need to wait if there are
1026 * still packets in the TX queue that are delayed by the CCID.
1027 */
1028 dccp_flush_write_queue(sk, &timeout);
1029 dccp_terminate_connection(sk);
1030 }
1031
1032 /*
1033 * Flush write queue. This may be necessary in several cases:
1034 * - we have been closed by the peer but still have application data;
1035 * - abortive termination (unread data or zero linger time),
1036 * - normal termination but queue could not be flushed within time limit
1037 */
1038 __skb_queue_purge(&sk->sk_write_queue);
1039
1040 sk_stream_wait_close(sk, timeout);
1041
1042adjudge_to_death:
1043 state = sk->sk_state;
1044 sock_hold(sk);
1045 sock_orphan(sk);
1046
1047 /*
1048 * It is the last release_sock in its life. It will remove backlog.
1049 */
1050 release_sock(sk);
1051 /*
1052 * Now socket is owned by kernel and we acquire BH lock
1053 * to finish close. No need to check for user refs.
1054 */
1055 local_bh_disable();
1056 bh_lock_sock(sk);
1057 WARN_ON(sock_owned_by_user(sk));
1058
1059 percpu_counter_inc(sk->sk_prot->orphan_count);
1060
1061 /* Have we already been destroyed by a softirq or backlog? */
1062 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1063 goto out;
1064
1065 if (sk->sk_state == DCCP_CLOSED)
1066 inet_csk_destroy_sock(sk);
1067
1068 /* Otherwise, socket is reprieved until protocol close. */
1069
1070out:
1071 bh_unlock_sock(sk);
1072 local_bh_enable();
1073 sock_put(sk);
1074}
1075
1076EXPORT_SYMBOL_GPL(dccp_close);
1077
1078void dccp_shutdown(struct sock *sk, int how)
1079{
1080 dccp_pr_debug("called shutdown(%x)\n", how);
1081}
1082
1083EXPORT_SYMBOL_GPL(dccp_shutdown);
1084
1085static inline int dccp_mib_init(void)
1086{
1087 return snmp_mib_init((void __percpu **)dccp_statistics,
1088 sizeof(struct dccp_mib),
1089 __alignof__(struct dccp_mib));
1090}
1091
1092static inline void dccp_mib_exit(void)
1093{
1094 snmp_mib_free((void __percpu **)dccp_statistics);
1095}
1096
1097static int thash_entries;
1098module_param(thash_entries, int, 0444);
1099MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1100
1101#ifdef CONFIG_IP_DCCP_DEBUG
1102bool dccp_debug;
1103module_param(dccp_debug, bool, 0644);
1104MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1105
1106EXPORT_SYMBOL_GPL(dccp_debug);
1107#endif
1108
1109static int __init dccp_init(void)
1110{
1111 unsigned long goal;
1112 int ehash_order, bhash_order, i;
1113 int rc;
1114
1115 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1116 FIELD_SIZEOF(struct sk_buff, cb));
1117 rc = percpu_counter_init(&dccp_orphan_count, 0);
1118 if (rc)
1119 goto out_fail;
1120 rc = -ENOBUFS;
1121 inet_hashinfo_init(&dccp_hashinfo);
1122 dccp_hashinfo.bind_bucket_cachep =
1123 kmem_cache_create("dccp_bind_bucket",
1124 sizeof(struct inet_bind_bucket), 0,
1125 SLAB_HWCACHE_ALIGN, NULL);
1126 if (!dccp_hashinfo.bind_bucket_cachep)
1127 goto out_free_percpu;
1128
1129 /*
1130 * Size and allocate the main established and bind bucket
1131 * hash tables.
1132 *
1133 * The methodology is similar to that of the buffer cache.
1134 */
1135 if (totalram_pages >= (128 * 1024))
1136 goal = totalram_pages >> (21 - PAGE_SHIFT);
1137 else
1138 goal = totalram_pages >> (23 - PAGE_SHIFT);
1139
1140 if (thash_entries)
1141 goal = (thash_entries *
1142 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1143 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1144 ;
1145 do {
1146 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1147 sizeof(struct inet_ehash_bucket);
1148
1149 while (hash_size & (hash_size - 1))
1150 hash_size--;
1151 dccp_hashinfo.ehash_mask = hash_size - 1;
1152 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1153 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1154 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1155
1156 if (!dccp_hashinfo.ehash) {
1157 DCCP_CRIT("Failed to allocate DCCP established hash table");
1158 goto out_free_bind_bucket_cachep;
1159 }
1160
1161 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1162 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1163
1164 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1165 goto out_free_dccp_ehash;
1166
1167 bhash_order = ehash_order;
1168
1169 do {
1170 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1171 sizeof(struct inet_bind_hashbucket);
1172 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1173 bhash_order > 0)
1174 continue;
1175 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1176 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1177 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1178
1179 if (!dccp_hashinfo.bhash) {
1180 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1181 goto out_free_dccp_locks;
1182 }
1183
1184 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1185 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1186 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1187 }
1188
1189 rc = dccp_mib_init();
1190 if (rc)
1191 goto out_free_dccp_bhash;
1192
1193 rc = dccp_ackvec_init();
1194 if (rc)
1195 goto out_free_dccp_mib;
1196
1197 rc = dccp_sysctl_init();
1198 if (rc)
1199 goto out_ackvec_exit;
1200
1201 rc = ccid_initialize_builtins();
1202 if (rc)
1203 goto out_sysctl_exit;
1204
1205 dccp_timestamping_init();
1206
1207 return 0;
1208
1209out_sysctl_exit:
1210 dccp_sysctl_exit();
1211out_ackvec_exit:
1212 dccp_ackvec_exit();
1213out_free_dccp_mib:
1214 dccp_mib_exit();
1215out_free_dccp_bhash:
1216 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1217out_free_dccp_locks:
1218 inet_ehash_locks_free(&dccp_hashinfo);
1219out_free_dccp_ehash:
1220 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1221out_free_bind_bucket_cachep:
1222 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1223out_free_percpu:
1224 percpu_counter_destroy(&dccp_orphan_count);
1225out_fail:
1226 dccp_hashinfo.bhash = NULL;
1227 dccp_hashinfo.ehash = NULL;
1228 dccp_hashinfo.bind_bucket_cachep = NULL;
1229 return rc;
1230}
1231
1232static void __exit dccp_fini(void)
1233{
1234 ccid_cleanup_builtins();
1235 dccp_mib_exit();
1236 free_pages((unsigned long)dccp_hashinfo.bhash,
1237 get_order(dccp_hashinfo.bhash_size *
1238 sizeof(struct inet_bind_hashbucket)));
1239 free_pages((unsigned long)dccp_hashinfo.ehash,
1240 get_order((dccp_hashinfo.ehash_mask + 1) *
1241 sizeof(struct inet_ehash_bucket)));
1242 inet_ehash_locks_free(&dccp_hashinfo);
1243 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1244 dccp_ackvec_exit();
1245 dccp_sysctl_exit();
1246 percpu_counter_destroy(&dccp_orphan_count);
1247}
1248
1249module_init(dccp_init);
1250module_exit(dccp_fini);
1251
1252MODULE_LICENSE("GPL");
1253MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1254MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
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 <linux/slab.h>
24#include <net/checksum.h>
25
26#include <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/xfrm.h>
29
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>
35
36#include "ccid.h"
37#include "dccp.h"
38#include "feat.h"
39
40DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
41
42EXPORT_SYMBOL_GPL(dccp_statistics);
43
44struct percpu_counter dccp_orphan_count;
45EXPORT_SYMBOL_GPL(dccp_orphan_count);
46
47struct inet_hashinfo dccp_hashinfo;
48EXPORT_SYMBOL_GPL(dccp_hashinfo);
49
50/* the maximum queue length for tx in packets. 0 is no limit */
51int sysctl_dccp_tx_qlen __read_mostly = 5;
52
53#ifdef CONFIG_IP_DCCP_DEBUG
54static const char *dccp_state_name(const int state)
55{
56 static const char *const dccp_state_names[] = {
57 [DCCP_OPEN] = "OPEN",
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",
68 };
69
70 if (state >= DCCP_MAX_STATES)
71 return "INVALID STATE!";
72 else
73 return dccp_state_names[state];
74}
75#endif
76
77void dccp_set_state(struct sock *sk, const int state)
78{
79 const int oldstate = sk->sk_state;
80
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);
84
85 switch (state) {
86 case DCCP_OPEN:
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);
92 break;
93
94 case DCCP_CLOSED:
95 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
96 oldstate == DCCP_CLOSING)
97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
98
99 sk->sk_prot->unhash(sk);
100 if (inet_csk(sk)->icsk_bind_hash != NULL &&
101 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
102 inet_put_port(sk);
103 /* fall through */
104 default:
105 if (oldstate == DCCP_OPEN)
106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
107 }
108
109 /* Change state AFTER socket is unhashed to avoid closed
110 * socket sitting in hash tables.
111 */
112 sk->sk_state = state;
113}
114
115EXPORT_SYMBOL_GPL(dccp_set_state);
116
117static void dccp_finish_passive_close(struct sock *sk)
118{
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);
124 break;
125 case DCCP_PASSIVE_CLOSEREQ:
126 /*
127 * Client received CloseReq. We set the `active' flag so that
128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
129 */
130 dccp_send_close(sk, 1);
131 dccp_set_state(sk, DCCP_CLOSING);
132 }
133}
134
135void dccp_done(struct sock *sk)
136{
137 dccp_set_state(sk, DCCP_CLOSED);
138 dccp_clear_xmit_timers(sk);
139
140 sk->sk_shutdown = SHUTDOWN_MASK;
141
142 if (!sock_flag(sk, SOCK_DEAD))
143 sk->sk_state_change(sk);
144 else
145 inet_csk_destroy_sock(sk);
146}
147
148EXPORT_SYMBOL_GPL(dccp_done);
149
150const char *dccp_packet_name(const int type)
151{
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",
163 };
164
165 if (type >= DCCP_NR_PKT_TYPES)
166 return "INVALID";
167 else
168 return dccp_packet_names[type];
169}
170
171EXPORT_SYMBOL_GPL(dccp_packet_name);
172
173int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
174{
175 struct dccp_sock *dp = dccp_sk(sk);
176 struct inet_connection_sock *icsk = inet_csk(sk);
177
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_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
188 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
189
190 dccp_init_xmit_timers(sk);
191
192 INIT_LIST_HEAD(&dp->dccps_featneg);
193 /* control socket doesn't need feat nego */
194 if (likely(ctl_sock_initialized))
195 return dccp_feat_init(sk);
196 return 0;
197}
198
199EXPORT_SYMBOL_GPL(dccp_init_sock);
200
201void dccp_destroy_sock(struct sock *sk)
202{
203 struct dccp_sock *dp = dccp_sk(sk);
204
205 /*
206 * DCCP doesn't use sk_write_queue, just sk_send_head
207 * for retransmissions
208 */
209 if (sk->sk_send_head != NULL) {
210 kfree_skb(sk->sk_send_head);
211 sk->sk_send_head = NULL;
212 }
213
214 /* Clean up a referenced DCCP bind bucket. */
215 if (inet_csk(sk)->icsk_bind_hash != NULL)
216 inet_put_port(sk);
217
218 kfree(dp->dccps_service_list);
219 dp->dccps_service_list = NULL;
220
221 if (dp->dccps_hc_rx_ackvec != NULL) {
222 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
223 dp->dccps_hc_rx_ackvec = NULL;
224 }
225 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
226 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
227 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
228
229 /* clean up feature negotiation state */
230 dccp_feat_list_purge(&dp->dccps_featneg);
231}
232
233EXPORT_SYMBOL_GPL(dccp_destroy_sock);
234
235static inline int dccp_listen_start(struct sock *sk, int backlog)
236{
237 struct dccp_sock *dp = dccp_sk(sk);
238
239 dp->dccps_role = DCCP_ROLE_LISTEN;
240 /* do not start to listen if feature negotiation setup fails */
241 if (dccp_feat_finalise_settings(dp))
242 return -EPROTO;
243 return inet_csk_listen_start(sk, backlog);
244}
245
246static inline int dccp_need_reset(int state)
247{
248 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
249 state != DCCP_REQUESTING;
250}
251
252int dccp_disconnect(struct sock *sk, int flags)
253{
254 struct inet_connection_sock *icsk = inet_csk(sk);
255 struct inet_sock *inet = inet_sk(sk);
256 int err = 0;
257 const int old_state = sk->sk_state;
258
259 if (old_state != DCCP_CLOSED)
260 dccp_set_state(sk, DCCP_CLOSED);
261
262 /*
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".
265 */
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;
273
274 dccp_clear_xmit_timers(sk);
275
276 __skb_queue_purge(&sk->sk_receive_queue);
277 __skb_queue_purge(&sk->sk_write_queue);
278 if (sk->sk_send_head != NULL) {
279 __kfree_skb(sk->sk_send_head);
280 sk->sk_send_head = NULL;
281 }
282
283 inet->inet_dport = 0;
284
285 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
286 inet_reset_saddr(sk);
287
288 sk->sk_shutdown = 0;
289 sock_reset_flag(sk, SOCK_DONE);
290
291 icsk->icsk_backoff = 0;
292 inet_csk_delack_init(sk);
293 __sk_dst_reset(sk);
294
295 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
296
297 sk->sk_error_report(sk);
298 return err;
299}
300
301EXPORT_SYMBOL_GPL(dccp_disconnect);
302
303/*
304 * Wait for a DCCP event.
305 *
306 * Note that we don't need to lock the socket, as the upper poll layers
307 * take care of normal races (between the test and the event) and we don't
308 * go look at any of the socket buffers directly.
309 */
310unsigned int dccp_poll(struct file *file, struct socket *sock,
311 poll_table *wait)
312{
313 unsigned int mask;
314 struct sock *sk = sock->sk;
315
316 sock_poll_wait(file, sk_sleep(sk), wait);
317 if (sk->sk_state == DCCP_LISTEN)
318 return inet_csk_listen_poll(sk);
319
320 /* Socket is not locked. We are protected from async events
321 by poll logic and correct handling of state changes
322 made by another threads is impossible in any case.
323 */
324
325 mask = 0;
326 if (sk->sk_err)
327 mask = POLLERR;
328
329 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
330 mask |= POLLHUP;
331 if (sk->sk_shutdown & RCV_SHUTDOWN)
332 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
333
334 /* Connected? */
335 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
336 if (atomic_read(&sk->sk_rmem_alloc) > 0)
337 mask |= POLLIN | POLLRDNORM;
338
339 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
340 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
341 mask |= POLLOUT | POLLWRNORM;
342 } else { /* send SIGIO later */
343 set_bit(SOCK_ASYNC_NOSPACE,
344 &sk->sk_socket->flags);
345 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
346
347 /* Race breaker. If space is freed after
348 * wspace test but before the flags are set,
349 * IO signal will be lost.
350 */
351 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
352 mask |= POLLOUT | POLLWRNORM;
353 }
354 }
355 }
356 return mask;
357}
358
359EXPORT_SYMBOL_GPL(dccp_poll);
360
361int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
362{
363 int rc = -ENOTCONN;
364
365 lock_sock(sk);
366
367 if (sk->sk_state == DCCP_LISTEN)
368 goto out;
369
370 switch (cmd) {
371 case SIOCINQ: {
372 struct sk_buff *skb;
373 unsigned long amount = 0;
374
375 skb = skb_peek(&sk->sk_receive_queue);
376 if (skb != NULL) {
377 /*
378 * We will only return the amount of this packet since
379 * that is all that will be read.
380 */
381 amount = skb->len;
382 }
383 rc = put_user(amount, (int __user *)arg);
384 }
385 break;
386 default:
387 rc = -ENOIOCTLCMD;
388 break;
389 }
390out:
391 release_sock(sk);
392 return rc;
393}
394
395EXPORT_SYMBOL_GPL(dccp_ioctl);
396
397static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
398 char __user *optval, unsigned int optlen)
399{
400 struct dccp_sock *dp = dccp_sk(sk);
401 struct dccp_service_list *sl = NULL;
402
403 if (service == DCCP_SERVICE_INVALID_VALUE ||
404 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
405 return -EINVAL;
406
407 if (optlen > sizeof(service)) {
408 sl = kmalloc(optlen, GFP_KERNEL);
409 if (sl == NULL)
410 return -ENOMEM;
411
412 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
413 if (copy_from_user(sl->dccpsl_list,
414 optval + sizeof(service),
415 optlen - sizeof(service)) ||
416 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
417 kfree(sl);
418 return -EFAULT;
419 }
420 }
421
422 lock_sock(sk);
423 dp->dccps_service = service;
424
425 kfree(dp->dccps_service_list);
426
427 dp->dccps_service_list = sl;
428 release_sock(sk);
429 return 0;
430}
431
432static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
433{
434 u8 *list, len;
435 int i, rc;
436
437 if (cscov < 0 || cscov > 15)
438 return -EINVAL;
439 /*
440 * Populate a list of permissible values, in the range cscov...15. This
441 * is necessary since feature negotiation of single values only works if
442 * both sides incidentally choose the same value. Since the list starts
443 * lowest-value first, negotiation will pick the smallest shared value.
444 */
445 if (cscov == 0)
446 return 0;
447 len = 16 - cscov;
448
449 list = kmalloc(len, GFP_KERNEL);
450 if (list == NULL)
451 return -ENOBUFS;
452
453 for (i = 0; i < len; i++)
454 list[i] = cscov++;
455
456 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
457
458 if (rc == 0) {
459 if (rx)
460 dccp_sk(sk)->dccps_pcrlen = cscov;
461 else
462 dccp_sk(sk)->dccps_pcslen = cscov;
463 }
464 kfree(list);
465 return rc;
466}
467
468static int dccp_setsockopt_ccid(struct sock *sk, int type,
469 char __user *optval, unsigned int optlen)
470{
471 u8 *val;
472 int rc = 0;
473
474 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
475 return -EINVAL;
476
477 val = memdup_user(optval, optlen);
478 if (IS_ERR(val))
479 return PTR_ERR(val);
480
481 lock_sock(sk);
482 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
483 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
484
485 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
486 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
487 release_sock(sk);
488
489 kfree(val);
490 return rc;
491}
492
493static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
494 char __user *optval, unsigned int optlen)
495{
496 struct dccp_sock *dp = dccp_sk(sk);
497 int val, err = 0;
498
499 switch (optname) {
500 case DCCP_SOCKOPT_PACKET_SIZE:
501 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
502 return 0;
503 case DCCP_SOCKOPT_CHANGE_L:
504 case DCCP_SOCKOPT_CHANGE_R:
505 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
506 return 0;
507 case DCCP_SOCKOPT_CCID:
508 case DCCP_SOCKOPT_RX_CCID:
509 case DCCP_SOCKOPT_TX_CCID:
510 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
511 }
512
513 if (optlen < (int)sizeof(int))
514 return -EINVAL;
515
516 if (get_user(val, (int __user *)optval))
517 return -EFAULT;
518
519 if (optname == DCCP_SOCKOPT_SERVICE)
520 return dccp_setsockopt_service(sk, val, optval, optlen);
521
522 lock_sock(sk);
523 switch (optname) {
524 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
525 if (dp->dccps_role != DCCP_ROLE_SERVER)
526 err = -EOPNOTSUPP;
527 else
528 dp->dccps_server_timewait = (val != 0);
529 break;
530 case DCCP_SOCKOPT_SEND_CSCOV:
531 err = dccp_setsockopt_cscov(sk, val, false);
532 break;
533 case DCCP_SOCKOPT_RECV_CSCOV:
534 err = dccp_setsockopt_cscov(sk, val, true);
535 break;
536 case DCCP_SOCKOPT_QPOLICY_ID:
537 if (sk->sk_state != DCCP_CLOSED)
538 err = -EISCONN;
539 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
540 err = -EINVAL;
541 else
542 dp->dccps_qpolicy = val;
543 break;
544 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
545 if (val < 0)
546 err = -EINVAL;
547 else
548 dp->dccps_tx_qlen = val;
549 break;
550 default:
551 err = -ENOPROTOOPT;
552 break;
553 }
554 release_sock(sk);
555
556 return err;
557}
558
559int dccp_setsockopt(struct sock *sk, int level, int optname,
560 char __user *optval, unsigned int optlen)
561{
562 if (level != SOL_DCCP)
563 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
564 optname, optval,
565 optlen);
566 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
567}
568
569EXPORT_SYMBOL_GPL(dccp_setsockopt);
570
571#ifdef CONFIG_COMPAT
572int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
573 char __user *optval, unsigned int optlen)
574{
575 if (level != SOL_DCCP)
576 return inet_csk_compat_setsockopt(sk, level, optname,
577 optval, optlen);
578 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
579}
580
581EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
582#endif
583
584static int dccp_getsockopt_service(struct sock *sk, int len,
585 __be32 __user *optval,
586 int __user *optlen)
587{
588 const struct dccp_sock *dp = dccp_sk(sk);
589 const struct dccp_service_list *sl;
590 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
591
592 lock_sock(sk);
593 if ((sl = dp->dccps_service_list) != NULL) {
594 slen = sl->dccpsl_nr * sizeof(u32);
595 total_len += slen;
596 }
597
598 err = -EINVAL;
599 if (total_len > len)
600 goto out;
601
602 err = 0;
603 if (put_user(total_len, optlen) ||
604 put_user(dp->dccps_service, optval) ||
605 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
606 err = -EFAULT;
607out:
608 release_sock(sk);
609 return err;
610}
611
612static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
613 char __user *optval, int __user *optlen)
614{
615 struct dccp_sock *dp;
616 int val, len;
617
618 if (get_user(len, optlen))
619 return -EFAULT;
620
621 if (len < (int)sizeof(int))
622 return -EINVAL;
623
624 dp = dccp_sk(sk);
625
626 switch (optname) {
627 case DCCP_SOCKOPT_PACKET_SIZE:
628 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
629 return 0;
630 case DCCP_SOCKOPT_SERVICE:
631 return dccp_getsockopt_service(sk, len,
632 (__be32 __user *)optval, optlen);
633 case DCCP_SOCKOPT_GET_CUR_MPS:
634 val = dp->dccps_mss_cache;
635 break;
636 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
637 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
638 case DCCP_SOCKOPT_TX_CCID:
639 val = ccid_get_current_tx_ccid(dp);
640 if (val < 0)
641 return -ENOPROTOOPT;
642 break;
643 case DCCP_SOCKOPT_RX_CCID:
644 val = ccid_get_current_rx_ccid(dp);
645 if (val < 0)
646 return -ENOPROTOOPT;
647 break;
648 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
649 val = dp->dccps_server_timewait;
650 break;
651 case DCCP_SOCKOPT_SEND_CSCOV:
652 val = dp->dccps_pcslen;
653 break;
654 case DCCP_SOCKOPT_RECV_CSCOV:
655 val = dp->dccps_pcrlen;
656 break;
657 case DCCP_SOCKOPT_QPOLICY_ID:
658 val = dp->dccps_qpolicy;
659 break;
660 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
661 val = dp->dccps_tx_qlen;
662 break;
663 case 128 ... 191:
664 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
665 len, (u32 __user *)optval, optlen);
666 case 192 ... 255:
667 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
668 len, (u32 __user *)optval, optlen);
669 default:
670 return -ENOPROTOOPT;
671 }
672
673 len = sizeof(val);
674 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
675 return -EFAULT;
676
677 return 0;
678}
679
680int dccp_getsockopt(struct sock *sk, int level, int optname,
681 char __user *optval, int __user *optlen)
682{
683 if (level != SOL_DCCP)
684 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
685 optname, optval,
686 optlen);
687 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
688}
689
690EXPORT_SYMBOL_GPL(dccp_getsockopt);
691
692#ifdef CONFIG_COMPAT
693int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
694 char __user *optval, int __user *optlen)
695{
696 if (level != SOL_DCCP)
697 return inet_csk_compat_getsockopt(sk, level, optname,
698 optval, optlen);
699 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
700}
701
702EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
703#endif
704
705static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
706{
707 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
708
709 /*
710 * Assign an (opaque) qpolicy priority value to skb->priority.
711 *
712 * We are overloading this skb field for use with the qpolicy subystem.
713 * The skb->priority is normally used for the SO_PRIORITY option, which
714 * is initialised from sk_priority. Since the assignment of sk_priority
715 * to skb->priority happens later (on layer 3), we overload this field
716 * for use with queueing priorities as long as the skb is on layer 4.
717 * The default priority value (if nothing is set) is 0.
718 */
719 skb->priority = 0;
720
721 for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
722
723 if (!CMSG_OK(msg, cmsg))
724 return -EINVAL;
725
726 if (cmsg->cmsg_level != SOL_DCCP)
727 continue;
728
729 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
730 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
731 return -EINVAL;
732
733 switch (cmsg->cmsg_type) {
734 case DCCP_SCM_PRIORITY:
735 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
736 return -EINVAL;
737 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
738 break;
739 default:
740 return -EINVAL;
741 }
742 }
743 return 0;
744}
745
746int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
747 size_t len)
748{
749 const struct dccp_sock *dp = dccp_sk(sk);
750 const int flags = msg->msg_flags;
751 const int noblock = flags & MSG_DONTWAIT;
752 struct sk_buff *skb;
753 int rc, size;
754 long timeo;
755
756 if (len > dp->dccps_mss_cache)
757 return -EMSGSIZE;
758
759 lock_sock(sk);
760
761 if (dccp_qpolicy_full(sk)) {
762 rc = -EAGAIN;
763 goto out_release;
764 }
765
766 timeo = sock_sndtimeo(sk, noblock);
767
768 /*
769 * We have to use sk_stream_wait_connect here to set sk_write_pending,
770 * so that the trick in dccp_rcv_request_sent_state_process.
771 */
772 /* Wait for a connection to finish. */
773 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
774 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
775 goto out_release;
776
777 size = sk->sk_prot->max_header + len;
778 release_sock(sk);
779 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
780 lock_sock(sk);
781 if (skb == NULL)
782 goto out_release;
783
784 skb_reserve(skb, sk->sk_prot->max_header);
785 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
786 if (rc != 0)
787 goto out_discard;
788
789 rc = dccp_msghdr_parse(msg, skb);
790 if (rc != 0)
791 goto out_discard;
792
793 dccp_qpolicy_push(sk, skb);
794 /*
795 * The xmit_timer is set if the TX CCID is rate-based and will expire
796 * when congestion control permits to release further packets into the
797 * network. Window-based CCIDs do not use this timer.
798 */
799 if (!timer_pending(&dp->dccps_xmit_timer))
800 dccp_write_xmit(sk);
801out_release:
802 release_sock(sk);
803 return rc ? : len;
804out_discard:
805 kfree_skb(skb);
806 goto out_release;
807}
808
809EXPORT_SYMBOL_GPL(dccp_sendmsg);
810
811int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
812 size_t len, int nonblock, int flags, int *addr_len)
813{
814 const struct dccp_hdr *dh;
815 long timeo;
816
817 lock_sock(sk);
818
819 if (sk->sk_state == DCCP_LISTEN) {
820 len = -ENOTCONN;
821 goto out;
822 }
823
824 timeo = sock_rcvtimeo(sk, nonblock);
825
826 do {
827 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
828
829 if (skb == NULL)
830 goto verify_sock_status;
831
832 dh = dccp_hdr(skb);
833
834 switch (dh->dccph_type) {
835 case DCCP_PKT_DATA:
836 case DCCP_PKT_DATAACK:
837 goto found_ok_skb;
838
839 case DCCP_PKT_CLOSE:
840 case DCCP_PKT_CLOSEREQ:
841 if (!(flags & MSG_PEEK))
842 dccp_finish_passive_close(sk);
843 /* fall through */
844 case DCCP_PKT_RESET:
845 dccp_pr_debug("found fin (%s) ok!\n",
846 dccp_packet_name(dh->dccph_type));
847 len = 0;
848 goto found_fin_ok;
849 default:
850 dccp_pr_debug("packet_type=%s\n",
851 dccp_packet_name(dh->dccph_type));
852 sk_eat_skb(sk, skb, 0);
853 }
854verify_sock_status:
855 if (sock_flag(sk, SOCK_DONE)) {
856 len = 0;
857 break;
858 }
859
860 if (sk->sk_err) {
861 len = sock_error(sk);
862 break;
863 }
864
865 if (sk->sk_shutdown & RCV_SHUTDOWN) {
866 len = 0;
867 break;
868 }
869
870 if (sk->sk_state == DCCP_CLOSED) {
871 if (!sock_flag(sk, SOCK_DONE)) {
872 /* This occurs when user tries to read
873 * from never connected socket.
874 */
875 len = -ENOTCONN;
876 break;
877 }
878 len = 0;
879 break;
880 }
881
882 if (!timeo) {
883 len = -EAGAIN;
884 break;
885 }
886
887 if (signal_pending(current)) {
888 len = sock_intr_errno(timeo);
889 break;
890 }
891
892 sk_wait_data(sk, &timeo);
893 continue;
894 found_ok_skb:
895 if (len > skb->len)
896 len = skb->len;
897 else if (len < skb->len)
898 msg->msg_flags |= MSG_TRUNC;
899
900 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
901 /* Exception. Bailout! */
902 len = -EFAULT;
903 break;
904 }
905 if (flags & MSG_TRUNC)
906 len = skb->len;
907 found_fin_ok:
908 if (!(flags & MSG_PEEK))
909 sk_eat_skb(sk, skb, 0);
910 break;
911 } while (1);
912out:
913 release_sock(sk);
914 return len;
915}
916
917EXPORT_SYMBOL_GPL(dccp_recvmsg);
918
919int inet_dccp_listen(struct socket *sock, int backlog)
920{
921 struct sock *sk = sock->sk;
922 unsigned char old_state;
923 int err;
924
925 lock_sock(sk);
926
927 err = -EINVAL;
928 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
929 goto out;
930
931 old_state = sk->sk_state;
932 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
933 goto out;
934
935 /* Really, if the socket is already in listen state
936 * we can only allow the backlog to be adjusted.
937 */
938 if (old_state != DCCP_LISTEN) {
939 /*
940 * FIXME: here it probably should be sk->sk_prot->listen_start
941 * see tcp_listen_start
942 */
943 err = dccp_listen_start(sk, backlog);
944 if (err)
945 goto out;
946 }
947 sk->sk_max_ack_backlog = backlog;
948 err = 0;
949
950out:
951 release_sock(sk);
952 return err;
953}
954
955EXPORT_SYMBOL_GPL(inet_dccp_listen);
956
957static void dccp_terminate_connection(struct sock *sk)
958{
959 u8 next_state = DCCP_CLOSED;
960
961 switch (sk->sk_state) {
962 case DCCP_PASSIVE_CLOSE:
963 case DCCP_PASSIVE_CLOSEREQ:
964 dccp_finish_passive_close(sk);
965 break;
966 case DCCP_PARTOPEN:
967 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
968 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
969 /* fall through */
970 case DCCP_OPEN:
971 dccp_send_close(sk, 1);
972
973 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
974 !dccp_sk(sk)->dccps_server_timewait)
975 next_state = DCCP_ACTIVE_CLOSEREQ;
976 else
977 next_state = DCCP_CLOSING;
978 /* fall through */
979 default:
980 dccp_set_state(sk, next_state);
981 }
982}
983
984void dccp_close(struct sock *sk, long timeout)
985{
986 struct dccp_sock *dp = dccp_sk(sk);
987 struct sk_buff *skb;
988 u32 data_was_unread = 0;
989 int state;
990
991 lock_sock(sk);
992
993 sk->sk_shutdown = SHUTDOWN_MASK;
994
995 if (sk->sk_state == DCCP_LISTEN) {
996 dccp_set_state(sk, DCCP_CLOSED);
997
998 /* Special case. */
999 inet_csk_listen_stop(sk);
1000
1001 goto adjudge_to_death;
1002 }
1003
1004 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1005
1006 /*
1007 * We need to flush the recv. buffs. We do this only on the
1008 * descriptor close, not protocol-sourced closes, because the
1009 *reader process may not have drained the data yet!
1010 */
1011 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1012 data_was_unread += skb->len;
1013 __kfree_skb(skb);
1014 }
1015
1016 if (data_was_unread) {
1017 /* Unread data was tossed, send an appropriate Reset Code */
1018 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1019 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1020 dccp_set_state(sk, DCCP_CLOSED);
1021 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1022 /* Check zero linger _after_ checking for unread data. */
1023 sk->sk_prot->disconnect(sk, 0);
1024 } else if (sk->sk_state != DCCP_CLOSED) {
1025 /*
1026 * Normal connection termination. May need to wait if there are
1027 * still packets in the TX queue that are delayed by the CCID.
1028 */
1029 dccp_flush_write_queue(sk, &timeout);
1030 dccp_terminate_connection(sk);
1031 }
1032
1033 /*
1034 * Flush write queue. This may be necessary in several cases:
1035 * - we have been closed by the peer but still have application data;
1036 * - abortive termination (unread data or zero linger time),
1037 * - normal termination but queue could not be flushed within time limit
1038 */
1039 __skb_queue_purge(&sk->sk_write_queue);
1040
1041 sk_stream_wait_close(sk, timeout);
1042
1043adjudge_to_death:
1044 state = sk->sk_state;
1045 sock_hold(sk);
1046 sock_orphan(sk);
1047
1048 /*
1049 * It is the last release_sock in its life. It will remove backlog.
1050 */
1051 release_sock(sk);
1052 /*
1053 * Now socket is owned by kernel and we acquire BH lock
1054 * to finish close. No need to check for user refs.
1055 */
1056 local_bh_disable();
1057 bh_lock_sock(sk);
1058 WARN_ON(sock_owned_by_user(sk));
1059
1060 percpu_counter_inc(sk->sk_prot->orphan_count);
1061
1062 /* Have we already been destroyed by a softirq or backlog? */
1063 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1064 goto out;
1065
1066 if (sk->sk_state == DCCP_CLOSED)
1067 inet_csk_destroy_sock(sk);
1068
1069 /* Otherwise, socket is reprieved until protocol close. */
1070
1071out:
1072 bh_unlock_sock(sk);
1073 local_bh_enable();
1074 sock_put(sk);
1075}
1076
1077EXPORT_SYMBOL_GPL(dccp_close);
1078
1079void dccp_shutdown(struct sock *sk, int how)
1080{
1081 dccp_pr_debug("called shutdown(%x)\n", how);
1082}
1083
1084EXPORT_SYMBOL_GPL(dccp_shutdown);
1085
1086static inline int dccp_mib_init(void)
1087{
1088 return snmp_mib_init((void __percpu **)dccp_statistics,
1089 sizeof(struct dccp_mib),
1090 __alignof__(struct dccp_mib));
1091}
1092
1093static inline void dccp_mib_exit(void)
1094{
1095 snmp_mib_free((void __percpu **)dccp_statistics);
1096}
1097
1098static int thash_entries;
1099module_param(thash_entries, int, 0444);
1100MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1101
1102#ifdef CONFIG_IP_DCCP_DEBUG
1103int dccp_debug;
1104module_param(dccp_debug, bool, 0644);
1105MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1106
1107EXPORT_SYMBOL_GPL(dccp_debug);
1108#endif
1109
1110static int __init dccp_init(void)
1111{
1112 unsigned long goal;
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 FIELD_SIZEOF(struct sk_buff, cb));
1118 rc = percpu_counter_init(&dccp_orphan_count, 0);
1119 if (rc)
1120 goto out_fail;
1121 rc = -ENOBUFS;
1122 inet_hashinfo_init(&dccp_hashinfo);
1123 dccp_hashinfo.bind_bucket_cachep =
1124 kmem_cache_create("dccp_bind_bucket",
1125 sizeof(struct inet_bind_bucket), 0,
1126 SLAB_HWCACHE_ALIGN, NULL);
1127 if (!dccp_hashinfo.bind_bucket_cachep)
1128 goto out_free_percpu;
1129
1130 /*
1131 * Size and allocate the main established and bind bucket
1132 * hash tables.
1133 *
1134 * The methodology is similar to that of the buffer cache.
1135 */
1136 if (totalram_pages >= (128 * 1024))
1137 goal = totalram_pages >> (21 - PAGE_SHIFT);
1138 else
1139 goal = totalram_pages >> (23 - PAGE_SHIFT);
1140
1141 if (thash_entries)
1142 goal = (thash_entries *
1143 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1144 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1145 ;
1146 do {
1147 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1148 sizeof(struct inet_ehash_bucket);
1149
1150 while (hash_size & (hash_size - 1))
1151 hash_size--;
1152 dccp_hashinfo.ehash_mask = hash_size - 1;
1153 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1154 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1155 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1156
1157 if (!dccp_hashinfo.ehash) {
1158 DCCP_CRIT("Failed to allocate DCCP established hash table");
1159 goto out_free_bind_bucket_cachep;
1160 }
1161
1162 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1163 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1164 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1165 }
1166
1167 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1168 goto out_free_dccp_ehash;
1169
1170 bhash_order = ehash_order;
1171
1172 do {
1173 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1174 sizeof(struct inet_bind_hashbucket);
1175 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1176 bhash_order > 0)
1177 continue;
1178 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1179 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1180 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1181
1182 if (!dccp_hashinfo.bhash) {
1183 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1184 goto out_free_dccp_locks;
1185 }
1186
1187 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1188 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1189 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1190 }
1191
1192 rc = dccp_mib_init();
1193 if (rc)
1194 goto out_free_dccp_bhash;
1195
1196 rc = dccp_ackvec_init();
1197 if (rc)
1198 goto out_free_dccp_mib;
1199
1200 rc = dccp_sysctl_init();
1201 if (rc)
1202 goto out_ackvec_exit;
1203
1204 rc = ccid_initialize_builtins();
1205 if (rc)
1206 goto out_sysctl_exit;
1207
1208 dccp_timestamping_init();
1209
1210 return 0;
1211
1212out_sysctl_exit:
1213 dccp_sysctl_exit();
1214out_ackvec_exit:
1215 dccp_ackvec_exit();
1216out_free_dccp_mib:
1217 dccp_mib_exit();
1218out_free_dccp_bhash:
1219 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1220out_free_dccp_locks:
1221 inet_ehash_locks_free(&dccp_hashinfo);
1222out_free_dccp_ehash:
1223 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1224out_free_bind_bucket_cachep:
1225 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1226out_free_percpu:
1227 percpu_counter_destroy(&dccp_orphan_count);
1228out_fail:
1229 dccp_hashinfo.bhash = NULL;
1230 dccp_hashinfo.ehash = NULL;
1231 dccp_hashinfo.bind_bucket_cachep = NULL;
1232 return rc;
1233}
1234
1235static void __exit dccp_fini(void)
1236{
1237 ccid_cleanup_builtins();
1238 dccp_mib_exit();
1239 free_pages((unsigned long)dccp_hashinfo.bhash,
1240 get_order(dccp_hashinfo.bhash_size *
1241 sizeof(struct inet_bind_hashbucket)));
1242 free_pages((unsigned long)dccp_hashinfo.ehash,
1243 get_order((dccp_hashinfo.ehash_mask + 1) *
1244 sizeof(struct inet_ehash_bucket)));
1245 inet_ehash_locks_free(&dccp_hashinfo);
1246 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1247 dccp_ackvec_exit();
1248 dccp_sysctl_exit();
1249 percpu_counter_destroy(&dccp_orphan_count);
1250}
1251
1252module_init(dccp_init);
1253module_exit(dccp_fini);
1254
1255MODULE_LICENSE("GPL");
1256MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1257MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");