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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_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 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
343 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
344
345 /* Race breaker. If space is freed after
346 * wspace test but before the flags are set,
347 * IO signal will be lost.
348 */
349 if (sk_stream_is_writeable(sk))
350 mask |= POLLOUT | POLLWRNORM;
351 }
352 }
353 }
354 return mask;
355}
356
357EXPORT_SYMBOL_GPL(dccp_poll);
358
359int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
360{
361 int rc = -ENOTCONN;
362
363 lock_sock(sk);
364
365 if (sk->sk_state == DCCP_LISTEN)
366 goto out;
367
368 switch (cmd) {
369 case SIOCINQ: {
370 struct sk_buff *skb;
371 unsigned long amount = 0;
372
373 skb = skb_peek(&sk->sk_receive_queue);
374 if (skb != NULL) {
375 /*
376 * We will only return the amount of this packet since
377 * that is all that will be read.
378 */
379 amount = skb->len;
380 }
381 rc = put_user(amount, (int __user *)arg);
382 }
383 break;
384 default:
385 rc = -ENOIOCTLCMD;
386 break;
387 }
388out:
389 release_sock(sk);
390 return rc;
391}
392
393EXPORT_SYMBOL_GPL(dccp_ioctl);
394
395static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
396 char __user *optval, unsigned int optlen)
397{
398 struct dccp_sock *dp = dccp_sk(sk);
399 struct dccp_service_list *sl = NULL;
400
401 if (service == DCCP_SERVICE_INVALID_VALUE ||
402 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
403 return -EINVAL;
404
405 if (optlen > sizeof(service)) {
406 sl = kmalloc(optlen, GFP_KERNEL);
407 if (sl == NULL)
408 return -ENOMEM;
409
410 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
411 if (copy_from_user(sl->dccpsl_list,
412 optval + sizeof(service),
413 optlen - sizeof(service)) ||
414 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
415 kfree(sl);
416 return -EFAULT;
417 }
418 }
419
420 lock_sock(sk);
421 dp->dccps_service = service;
422
423 kfree(dp->dccps_service_list);
424
425 dp->dccps_service_list = sl;
426 release_sock(sk);
427 return 0;
428}
429
430static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
431{
432 u8 *list, len;
433 int i, rc;
434
435 if (cscov < 0 || cscov > 15)
436 return -EINVAL;
437 /*
438 * Populate a list of permissible values, in the range cscov...15. This
439 * is necessary since feature negotiation of single values only works if
440 * both sides incidentally choose the same value. Since the list starts
441 * lowest-value first, negotiation will pick the smallest shared value.
442 */
443 if (cscov == 0)
444 return 0;
445 len = 16 - cscov;
446
447 list = kmalloc(len, GFP_KERNEL);
448 if (list == NULL)
449 return -ENOBUFS;
450
451 for (i = 0; i < len; i++)
452 list[i] = cscov++;
453
454 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
455
456 if (rc == 0) {
457 if (rx)
458 dccp_sk(sk)->dccps_pcrlen = cscov;
459 else
460 dccp_sk(sk)->dccps_pcslen = cscov;
461 }
462 kfree(list);
463 return rc;
464}
465
466static int dccp_setsockopt_ccid(struct sock *sk, int type,
467 char __user *optval, unsigned int optlen)
468{
469 u8 *val;
470 int rc = 0;
471
472 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
473 return -EINVAL;
474
475 val = memdup_user(optval, optlen);
476 if (IS_ERR(val))
477 return PTR_ERR(val);
478
479 lock_sock(sk);
480 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
481 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
482
483 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
484 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
485 release_sock(sk);
486
487 kfree(val);
488 return rc;
489}
490
491static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
492 char __user *optval, unsigned int optlen)
493{
494 struct dccp_sock *dp = dccp_sk(sk);
495 int val, err = 0;
496
497 switch (optname) {
498 case DCCP_SOCKOPT_PACKET_SIZE:
499 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
500 return 0;
501 case DCCP_SOCKOPT_CHANGE_L:
502 case DCCP_SOCKOPT_CHANGE_R:
503 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
504 return 0;
505 case DCCP_SOCKOPT_CCID:
506 case DCCP_SOCKOPT_RX_CCID:
507 case DCCP_SOCKOPT_TX_CCID:
508 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
509 }
510
511 if (optlen < (int)sizeof(int))
512 return -EINVAL;
513
514 if (get_user(val, (int __user *)optval))
515 return -EFAULT;
516
517 if (optname == DCCP_SOCKOPT_SERVICE)
518 return dccp_setsockopt_service(sk, val, optval, optlen);
519
520 lock_sock(sk);
521 switch (optname) {
522 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
523 if (dp->dccps_role != DCCP_ROLE_SERVER)
524 err = -EOPNOTSUPP;
525 else
526 dp->dccps_server_timewait = (val != 0);
527 break;
528 case DCCP_SOCKOPT_SEND_CSCOV:
529 err = dccp_setsockopt_cscov(sk, val, false);
530 break;
531 case DCCP_SOCKOPT_RECV_CSCOV:
532 err = dccp_setsockopt_cscov(sk, val, true);
533 break;
534 case DCCP_SOCKOPT_QPOLICY_ID:
535 if (sk->sk_state != DCCP_CLOSED)
536 err = -EISCONN;
537 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
538 err = -EINVAL;
539 else
540 dp->dccps_qpolicy = val;
541 break;
542 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
543 if (val < 0)
544 err = -EINVAL;
545 else
546 dp->dccps_tx_qlen = val;
547 break;
548 default:
549 err = -ENOPROTOOPT;
550 break;
551 }
552 release_sock(sk);
553
554 return err;
555}
556
557int dccp_setsockopt(struct sock *sk, int level, int optname,
558 char __user *optval, unsigned int optlen)
559{
560 if (level != SOL_DCCP)
561 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
562 optname, optval,
563 optlen);
564 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
565}
566
567EXPORT_SYMBOL_GPL(dccp_setsockopt);
568
569#ifdef CONFIG_COMPAT
570int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
571 char __user *optval, unsigned int optlen)
572{
573 if (level != SOL_DCCP)
574 return inet_csk_compat_setsockopt(sk, level, optname,
575 optval, optlen);
576 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
577}
578
579EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
580#endif
581
582static int dccp_getsockopt_service(struct sock *sk, int len,
583 __be32 __user *optval,
584 int __user *optlen)
585{
586 const struct dccp_sock *dp = dccp_sk(sk);
587 const struct dccp_service_list *sl;
588 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
589
590 lock_sock(sk);
591 if ((sl = dp->dccps_service_list) != NULL) {
592 slen = sl->dccpsl_nr * sizeof(u32);
593 total_len += slen;
594 }
595
596 err = -EINVAL;
597 if (total_len > len)
598 goto out;
599
600 err = 0;
601 if (put_user(total_len, optlen) ||
602 put_user(dp->dccps_service, optval) ||
603 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
604 err = -EFAULT;
605out:
606 release_sock(sk);
607 return err;
608}
609
610static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
611 char __user *optval, int __user *optlen)
612{
613 struct dccp_sock *dp;
614 int val, len;
615
616 if (get_user(len, optlen))
617 return -EFAULT;
618
619 if (len < (int)sizeof(int))
620 return -EINVAL;
621
622 dp = dccp_sk(sk);
623
624 switch (optname) {
625 case DCCP_SOCKOPT_PACKET_SIZE:
626 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
627 return 0;
628 case DCCP_SOCKOPT_SERVICE:
629 return dccp_getsockopt_service(sk, len,
630 (__be32 __user *)optval, optlen);
631 case DCCP_SOCKOPT_GET_CUR_MPS:
632 val = dp->dccps_mss_cache;
633 break;
634 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
635 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
636 case DCCP_SOCKOPT_TX_CCID:
637 val = ccid_get_current_tx_ccid(dp);
638 if (val < 0)
639 return -ENOPROTOOPT;
640 break;
641 case DCCP_SOCKOPT_RX_CCID:
642 val = ccid_get_current_rx_ccid(dp);
643 if (val < 0)
644 return -ENOPROTOOPT;
645 break;
646 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
647 val = dp->dccps_server_timewait;
648 break;
649 case DCCP_SOCKOPT_SEND_CSCOV:
650 val = dp->dccps_pcslen;
651 break;
652 case DCCP_SOCKOPT_RECV_CSCOV:
653 val = dp->dccps_pcrlen;
654 break;
655 case DCCP_SOCKOPT_QPOLICY_ID:
656 val = dp->dccps_qpolicy;
657 break;
658 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
659 val = dp->dccps_tx_qlen;
660 break;
661 case 128 ... 191:
662 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
663 len, (u32 __user *)optval, optlen);
664 case 192 ... 255:
665 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
666 len, (u32 __user *)optval, optlen);
667 default:
668 return -ENOPROTOOPT;
669 }
670
671 len = sizeof(val);
672 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
673 return -EFAULT;
674
675 return 0;
676}
677
678int dccp_getsockopt(struct sock *sk, int level, int optname,
679 char __user *optval, int __user *optlen)
680{
681 if (level != SOL_DCCP)
682 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
683 optname, optval,
684 optlen);
685 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
686}
687
688EXPORT_SYMBOL_GPL(dccp_getsockopt);
689
690#ifdef CONFIG_COMPAT
691int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
692 char __user *optval, int __user *optlen)
693{
694 if (level != SOL_DCCP)
695 return inet_csk_compat_getsockopt(sk, level, optname,
696 optval, optlen);
697 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
698}
699
700EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
701#endif
702
703static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
704{
705 struct cmsghdr *cmsg;
706
707 /*
708 * Assign an (opaque) qpolicy priority value to skb->priority.
709 *
710 * We are overloading this skb field for use with the qpolicy subystem.
711 * The skb->priority is normally used for the SO_PRIORITY option, which
712 * is initialised from sk_priority. Since the assignment of sk_priority
713 * to skb->priority happens later (on layer 3), we overload this field
714 * for use with queueing priorities as long as the skb is on layer 4.
715 * The default priority value (if nothing is set) is 0.
716 */
717 skb->priority = 0;
718
719 for_each_cmsghdr(cmsg, msg) {
720 if (!CMSG_OK(msg, cmsg))
721 return -EINVAL;
722
723 if (cmsg->cmsg_level != SOL_DCCP)
724 continue;
725
726 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
727 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
728 return -EINVAL;
729
730 switch (cmsg->cmsg_type) {
731 case DCCP_SCM_PRIORITY:
732 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
733 return -EINVAL;
734 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
735 break;
736 default:
737 return -EINVAL;
738 }
739 }
740 return 0;
741}
742
743int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
744{
745 const struct dccp_sock *dp = dccp_sk(sk);
746 const int flags = msg->msg_flags;
747 const int noblock = flags & MSG_DONTWAIT;
748 struct sk_buff *skb;
749 int rc, size;
750 long timeo;
751
752 if (len > dp->dccps_mss_cache)
753 return -EMSGSIZE;
754
755 lock_sock(sk);
756
757 if (dccp_qpolicy_full(sk)) {
758 rc = -EAGAIN;
759 goto out_release;
760 }
761
762 timeo = sock_sndtimeo(sk, noblock);
763
764 /*
765 * We have to use sk_stream_wait_connect here to set sk_write_pending,
766 * so that the trick in dccp_rcv_request_sent_state_process.
767 */
768 /* Wait for a connection to finish. */
769 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
770 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
771 goto out_release;
772
773 size = sk->sk_prot->max_header + len;
774 release_sock(sk);
775 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
776 lock_sock(sk);
777 if (skb == NULL)
778 goto out_release;
779
780 skb_reserve(skb, sk->sk_prot->max_header);
781 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
782 if (rc != 0)
783 goto out_discard;
784
785 rc = dccp_msghdr_parse(msg, skb);
786 if (rc != 0)
787 goto out_discard;
788
789 dccp_qpolicy_push(sk, skb);
790 /*
791 * The xmit_timer is set if the TX CCID is rate-based and will expire
792 * when congestion control permits to release further packets into the
793 * network. Window-based CCIDs do not use this timer.
794 */
795 if (!timer_pending(&dp->dccps_xmit_timer))
796 dccp_write_xmit(sk);
797out_release:
798 release_sock(sk);
799 return rc ? : len;
800out_discard:
801 kfree_skb(skb);
802 goto out_release;
803}
804
805EXPORT_SYMBOL_GPL(dccp_sendmsg);
806
807int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
808 int flags, int *addr_len)
809{
810 const struct dccp_hdr *dh;
811 long timeo;
812
813 lock_sock(sk);
814
815 if (sk->sk_state == DCCP_LISTEN) {
816 len = -ENOTCONN;
817 goto out;
818 }
819
820 timeo = sock_rcvtimeo(sk, nonblock);
821
822 do {
823 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
824
825 if (skb == NULL)
826 goto verify_sock_status;
827
828 dh = dccp_hdr(skb);
829
830 switch (dh->dccph_type) {
831 case DCCP_PKT_DATA:
832 case DCCP_PKT_DATAACK:
833 goto found_ok_skb;
834
835 case DCCP_PKT_CLOSE:
836 case DCCP_PKT_CLOSEREQ:
837 if (!(flags & MSG_PEEK))
838 dccp_finish_passive_close(sk);
839 /* fall through */
840 case DCCP_PKT_RESET:
841 dccp_pr_debug("found fin (%s) ok!\n",
842 dccp_packet_name(dh->dccph_type));
843 len = 0;
844 goto found_fin_ok;
845 default:
846 dccp_pr_debug("packet_type=%s\n",
847 dccp_packet_name(dh->dccph_type));
848 sk_eat_skb(sk, skb);
849 }
850verify_sock_status:
851 if (sock_flag(sk, SOCK_DONE)) {
852 len = 0;
853 break;
854 }
855
856 if (sk->sk_err) {
857 len = sock_error(sk);
858 break;
859 }
860
861 if (sk->sk_shutdown & RCV_SHUTDOWN) {
862 len = 0;
863 break;
864 }
865
866 if (sk->sk_state == DCCP_CLOSED) {
867 if (!sock_flag(sk, SOCK_DONE)) {
868 /* This occurs when user tries to read
869 * from never connected socket.
870 */
871 len = -ENOTCONN;
872 break;
873 }
874 len = 0;
875 break;
876 }
877
878 if (!timeo) {
879 len = -EAGAIN;
880 break;
881 }
882
883 if (signal_pending(current)) {
884 len = sock_intr_errno(timeo);
885 break;
886 }
887
888 sk_wait_data(sk, &timeo, NULL);
889 continue;
890 found_ok_skb:
891 if (len > skb->len)
892 len = skb->len;
893 else if (len < skb->len)
894 msg->msg_flags |= MSG_TRUNC;
895
896 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
897 /* Exception. Bailout! */
898 len = -EFAULT;
899 break;
900 }
901 if (flags & MSG_TRUNC)
902 len = skb->len;
903 found_fin_ok:
904 if (!(flags & MSG_PEEK))
905 sk_eat_skb(sk, skb);
906 break;
907 } while (1);
908out:
909 release_sock(sk);
910 return len;
911}
912
913EXPORT_SYMBOL_GPL(dccp_recvmsg);
914
915int inet_dccp_listen(struct socket *sock, int backlog)
916{
917 struct sock *sk = sock->sk;
918 unsigned char old_state;
919 int err;
920
921 lock_sock(sk);
922
923 err = -EINVAL;
924 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
925 goto out;
926
927 old_state = sk->sk_state;
928 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
929 goto out;
930
931 /* Really, if the socket is already in listen state
932 * we can only allow the backlog to be adjusted.
933 */
934 if (old_state != DCCP_LISTEN) {
935 /*
936 * FIXME: here it probably should be sk->sk_prot->listen_start
937 * see tcp_listen_start
938 */
939 err = dccp_listen_start(sk, backlog);
940 if (err)
941 goto out;
942 }
943 sk->sk_max_ack_backlog = backlog;
944 err = 0;
945
946out:
947 release_sock(sk);
948 return err;
949}
950
951EXPORT_SYMBOL_GPL(inet_dccp_listen);
952
953static void dccp_terminate_connection(struct sock *sk)
954{
955 u8 next_state = DCCP_CLOSED;
956
957 switch (sk->sk_state) {
958 case DCCP_PASSIVE_CLOSE:
959 case DCCP_PASSIVE_CLOSEREQ:
960 dccp_finish_passive_close(sk);
961 break;
962 case DCCP_PARTOPEN:
963 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
964 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
965 /* fall through */
966 case DCCP_OPEN:
967 dccp_send_close(sk, 1);
968
969 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
970 !dccp_sk(sk)->dccps_server_timewait)
971 next_state = DCCP_ACTIVE_CLOSEREQ;
972 else
973 next_state = DCCP_CLOSING;
974 /* fall through */
975 default:
976 dccp_set_state(sk, next_state);
977 }
978}
979
980void dccp_close(struct sock *sk, long timeout)
981{
982 struct dccp_sock *dp = dccp_sk(sk);
983 struct sk_buff *skb;
984 u32 data_was_unread = 0;
985 int state;
986
987 lock_sock(sk);
988
989 sk->sk_shutdown = SHUTDOWN_MASK;
990
991 if (sk->sk_state == DCCP_LISTEN) {
992 dccp_set_state(sk, DCCP_CLOSED);
993
994 /* Special case. */
995 inet_csk_listen_stop(sk);
996
997 goto adjudge_to_death;
998 }
999
1000 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1001
1002 /*
1003 * We need to flush the recv. buffs. We do this only on the
1004 * descriptor close, not protocol-sourced closes, because the
1005 *reader process may not have drained the data yet!
1006 */
1007 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1008 data_was_unread += skb->len;
1009 __kfree_skb(skb);
1010 }
1011
1012 if (data_was_unread) {
1013 /* Unread data was tossed, send an appropriate Reset Code */
1014 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1015 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1016 dccp_set_state(sk, DCCP_CLOSED);
1017 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1018 /* Check zero linger _after_ checking for unread data. */
1019 sk->sk_prot->disconnect(sk, 0);
1020 } else if (sk->sk_state != DCCP_CLOSED) {
1021 /*
1022 * Normal connection termination. May need to wait if there are
1023 * still packets in the TX queue that are delayed by the CCID.
1024 */
1025 dccp_flush_write_queue(sk, &timeout);
1026 dccp_terminate_connection(sk);
1027 }
1028
1029 /*
1030 * Flush write queue. This may be necessary in several cases:
1031 * - we have been closed by the peer but still have application data;
1032 * - abortive termination (unread data or zero linger time),
1033 * - normal termination but queue could not be flushed within time limit
1034 */
1035 __skb_queue_purge(&sk->sk_write_queue);
1036
1037 sk_stream_wait_close(sk, timeout);
1038
1039adjudge_to_death:
1040 state = sk->sk_state;
1041 sock_hold(sk);
1042 sock_orphan(sk);
1043
1044 /*
1045 * It is the last release_sock in its life. It will remove backlog.
1046 */
1047 release_sock(sk);
1048 /*
1049 * Now socket is owned by kernel and we acquire BH lock
1050 * to finish close. No need to check for user refs.
1051 */
1052 local_bh_disable();
1053 bh_lock_sock(sk);
1054 WARN_ON(sock_owned_by_user(sk));
1055
1056 percpu_counter_inc(sk->sk_prot->orphan_count);
1057
1058 /* Have we already been destroyed by a softirq or backlog? */
1059 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1060 goto out;
1061
1062 if (sk->sk_state == DCCP_CLOSED)
1063 inet_csk_destroy_sock(sk);
1064
1065 /* Otherwise, socket is reprieved until protocol close. */
1066
1067out:
1068 bh_unlock_sock(sk);
1069 local_bh_enable();
1070 sock_put(sk);
1071}
1072
1073EXPORT_SYMBOL_GPL(dccp_close);
1074
1075void dccp_shutdown(struct sock *sk, int how)
1076{
1077 dccp_pr_debug("called shutdown(%x)\n", how);
1078}
1079
1080EXPORT_SYMBOL_GPL(dccp_shutdown);
1081
1082static inline int __init dccp_mib_init(void)
1083{
1084 dccp_statistics = alloc_percpu(struct dccp_mib);
1085 if (!dccp_statistics)
1086 return -ENOMEM;
1087 return 0;
1088}
1089
1090static inline void dccp_mib_exit(void)
1091{
1092 free_percpu(dccp_statistics);
1093}
1094
1095static int thash_entries;
1096module_param(thash_entries, int, 0444);
1097MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1098
1099#ifdef CONFIG_IP_DCCP_DEBUG
1100bool dccp_debug;
1101module_param(dccp_debug, bool, 0644);
1102MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1103
1104EXPORT_SYMBOL_GPL(dccp_debug);
1105#endif
1106
1107static int __init dccp_init(void)
1108{
1109 unsigned long goal;
1110 int ehash_order, bhash_order, i;
1111 int rc;
1112
1113 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1114 FIELD_SIZEOF(struct sk_buff, cb));
1115 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1116 if (rc)
1117 goto out_fail;
1118 rc = -ENOBUFS;
1119 inet_hashinfo_init(&dccp_hashinfo);
1120 dccp_hashinfo.bind_bucket_cachep =
1121 kmem_cache_create("dccp_bind_bucket",
1122 sizeof(struct inet_bind_bucket), 0,
1123 SLAB_HWCACHE_ALIGN, NULL);
1124 if (!dccp_hashinfo.bind_bucket_cachep)
1125 goto out_free_percpu;
1126
1127 /*
1128 * Size and allocate the main established and bind bucket
1129 * hash tables.
1130 *
1131 * The methodology is similar to that of the buffer cache.
1132 */
1133 if (totalram_pages >= (128 * 1024))
1134 goal = totalram_pages >> (21 - PAGE_SHIFT);
1135 else
1136 goal = totalram_pages >> (23 - PAGE_SHIFT);
1137
1138 if (thash_entries)
1139 goal = (thash_entries *
1140 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1141 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1142 ;
1143 do {
1144 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1145 sizeof(struct inet_ehash_bucket);
1146
1147 while (hash_size & (hash_size - 1))
1148 hash_size--;
1149 dccp_hashinfo.ehash_mask = hash_size - 1;
1150 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1151 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1152 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1153
1154 if (!dccp_hashinfo.ehash) {
1155 DCCP_CRIT("Failed to allocate DCCP established hash table");
1156 goto out_free_bind_bucket_cachep;
1157 }
1158
1159 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1160 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1161
1162 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1163 goto out_free_dccp_ehash;
1164
1165 bhash_order = ehash_order;
1166
1167 do {
1168 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1169 sizeof(struct inet_bind_hashbucket);
1170 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1171 bhash_order > 0)
1172 continue;
1173 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1174 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1175 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1176
1177 if (!dccp_hashinfo.bhash) {
1178 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1179 goto out_free_dccp_locks;
1180 }
1181
1182 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1183 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1184 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1185 }
1186
1187 rc = dccp_mib_init();
1188 if (rc)
1189 goto out_free_dccp_bhash;
1190
1191 rc = dccp_ackvec_init();
1192 if (rc)
1193 goto out_free_dccp_mib;
1194
1195 rc = dccp_sysctl_init();
1196 if (rc)
1197 goto out_ackvec_exit;
1198
1199 rc = ccid_initialize_builtins();
1200 if (rc)
1201 goto out_sysctl_exit;
1202
1203 dccp_timestamping_init();
1204
1205 return 0;
1206
1207out_sysctl_exit:
1208 dccp_sysctl_exit();
1209out_ackvec_exit:
1210 dccp_ackvec_exit();
1211out_free_dccp_mib:
1212 dccp_mib_exit();
1213out_free_dccp_bhash:
1214 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1215out_free_dccp_locks:
1216 inet_ehash_locks_free(&dccp_hashinfo);
1217out_free_dccp_ehash:
1218 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1219out_free_bind_bucket_cachep:
1220 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1221out_free_percpu:
1222 percpu_counter_destroy(&dccp_orphan_count);
1223out_fail:
1224 dccp_hashinfo.bhash = NULL;
1225 dccp_hashinfo.ehash = NULL;
1226 dccp_hashinfo.bind_bucket_cachep = NULL;
1227 return rc;
1228}
1229
1230static void __exit dccp_fini(void)
1231{
1232 ccid_cleanup_builtins();
1233 dccp_mib_exit();
1234 free_pages((unsigned long)dccp_hashinfo.bhash,
1235 get_order(dccp_hashinfo.bhash_size *
1236 sizeof(struct inet_bind_hashbucket)));
1237 free_pages((unsigned long)dccp_hashinfo.ehash,
1238 get_order((dccp_hashinfo.ehash_mask + 1) *
1239 sizeof(struct inet_ehash_bucket)));
1240 inet_ehash_locks_free(&dccp_hashinfo);
1241 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1242 dccp_ackvec_exit();
1243 dccp_sysctl_exit();
1244 percpu_counter_destroy(&dccp_orphan_count);
1245}
1246
1247module_init(dccp_init);
1248module_exit(dccp_fini);
1249
1250MODULE_LICENSE("GPL");
1251MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1252MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");