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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/dccp/proto.c
4 *
5 * An implementation of the DCCP protocol
6 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 */
8
9#include <linux/dccp.h>
10#include <linux/module.h>
11#include <linux/types.h>
12#include <linux/sched.h>
13#include <linux/kernel.h>
14#include <linux/skbuff.h>
15#include <linux/netdevice.h>
16#include <linux/in.h>
17#include <linux/if_arp.h>
18#include <linux/init.h>
19#include <linux/random.h>
20#include <linux/slab.h>
21#include <net/checksum.h>
22
23#include <net/inet_sock.h>
24#include <net/inet_common.h>
25#include <net/sock.h>
26#include <net/xfrm.h>
27
28#include <asm/ioctls.h>
29#include <linux/spinlock.h>
30#include <linux/timer.h>
31#include <linux/delay.h>
32#include <linux/poll.h>
33
34#include "ccid.h"
35#include "dccp.h"
36#include "feat.h"
37
38#define CREATE_TRACE_POINTS
39#include "trace.h"
40
41DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
42
43EXPORT_SYMBOL_GPL(dccp_statistics);
44
45DEFINE_PER_CPU(unsigned int, dccp_orphan_count);
46EXPORT_PER_CPU_SYMBOL_GPL(dccp_orphan_count);
47
48struct inet_hashinfo dccp_hashinfo;
49EXPORT_SYMBOL_GPL(dccp_hashinfo);
50
51/* the maximum queue length for tx in packets. 0 is no limit */
52int sysctl_dccp_tx_qlen __read_mostly = 5;
53
54#ifdef CONFIG_IP_DCCP_DEBUG
55static const char *dccp_state_name(const int state)
56{
57 static const char *const dccp_state_names[] = {
58 [DCCP_OPEN] = "OPEN",
59 [DCCP_REQUESTING] = "REQUESTING",
60 [DCCP_PARTOPEN] = "PARTOPEN",
61 [DCCP_LISTEN] = "LISTEN",
62 [DCCP_RESPOND] = "RESPOND",
63 [DCCP_CLOSING] = "CLOSING",
64 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ",
65 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE",
66 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
67 [DCCP_TIME_WAIT] = "TIME_WAIT",
68 [DCCP_CLOSED] = "CLOSED",
69 };
70
71 if (state >= DCCP_MAX_STATES)
72 return "INVALID STATE!";
73 else
74 return dccp_state_names[state];
75}
76#endif
77
78void dccp_set_state(struct sock *sk, const int state)
79{
80 const int oldstate = sk->sk_state;
81
82 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk,
83 dccp_state_name(oldstate), dccp_state_name(state));
84 WARN_ON(state == oldstate);
85
86 switch (state) {
87 case DCCP_OPEN:
88 if (oldstate != DCCP_OPEN)
89 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
90 /* Client retransmits all Confirm options until entering OPEN */
91 if (oldstate == DCCP_PARTOPEN)
92 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
93 break;
94
95 case DCCP_CLOSED:
96 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
97 oldstate == DCCP_CLOSING)
98 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
99
100 sk->sk_prot->unhash(sk);
101 if (inet_csk(sk)->icsk_bind_hash != NULL &&
102 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
103 inet_put_port(sk);
104 fallthrough;
105 default:
106 if (oldstate == DCCP_OPEN)
107 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
108 }
109
110 /* Change state AFTER socket is unhashed to avoid closed
111 * socket sitting in hash tables.
112 */
113 inet_sk_set_state(sk, state);
114}
115
116EXPORT_SYMBOL_GPL(dccp_set_state);
117
118static void dccp_finish_passive_close(struct sock *sk)
119{
120 switch (sk->sk_state) {
121 case DCCP_PASSIVE_CLOSE:
122 /* Node (client or server) has received Close packet. */
123 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
124 dccp_set_state(sk, DCCP_CLOSED);
125 break;
126 case DCCP_PASSIVE_CLOSEREQ:
127 /*
128 * Client received CloseReq. We set the `active' flag so that
129 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
130 */
131 dccp_send_close(sk, 1);
132 dccp_set_state(sk, DCCP_CLOSING);
133 }
134}
135
136void dccp_done(struct sock *sk)
137{
138 dccp_set_state(sk, DCCP_CLOSED);
139 dccp_clear_xmit_timers(sk);
140
141 sk->sk_shutdown = SHUTDOWN_MASK;
142
143 if (!sock_flag(sk, SOCK_DEAD))
144 sk->sk_state_change(sk);
145 else
146 inet_csk_destroy_sock(sk);
147}
148
149EXPORT_SYMBOL_GPL(dccp_done);
150
151const char *dccp_packet_name(const int type)
152{
153 static const char *const dccp_packet_names[] = {
154 [DCCP_PKT_REQUEST] = "REQUEST",
155 [DCCP_PKT_RESPONSE] = "RESPONSE",
156 [DCCP_PKT_DATA] = "DATA",
157 [DCCP_PKT_ACK] = "ACK",
158 [DCCP_PKT_DATAACK] = "DATAACK",
159 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
160 [DCCP_PKT_CLOSE] = "CLOSE",
161 [DCCP_PKT_RESET] = "RESET",
162 [DCCP_PKT_SYNC] = "SYNC",
163 [DCCP_PKT_SYNCACK] = "SYNCACK",
164 };
165
166 if (type >= DCCP_NR_PKT_TYPES)
167 return "INVALID";
168 else
169 return dccp_packet_names[type];
170}
171
172EXPORT_SYMBOL_GPL(dccp_packet_name);
173
174void dccp_destruct_common(struct sock *sk)
175{
176 struct dccp_sock *dp = dccp_sk(sk);
177
178 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
179 dp->dccps_hc_tx_ccid = NULL;
180}
181EXPORT_SYMBOL_GPL(dccp_destruct_common);
182
183static void dccp_sk_destruct(struct sock *sk)
184{
185 dccp_destruct_common(sk);
186 inet_sock_destruct(sk);
187}
188
189int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
190{
191 struct dccp_sock *dp = dccp_sk(sk);
192 struct inet_connection_sock *icsk = inet_csk(sk);
193
194 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
195 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
196 sk->sk_state = DCCP_CLOSED;
197 sk->sk_write_space = dccp_write_space;
198 sk->sk_destruct = dccp_sk_destruct;
199 icsk->icsk_sync_mss = dccp_sync_mss;
200 dp->dccps_mss_cache = 536;
201 dp->dccps_rate_last = jiffies;
202 dp->dccps_role = DCCP_ROLE_UNDEFINED;
203 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
204 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
205
206 dccp_init_xmit_timers(sk);
207
208 INIT_LIST_HEAD(&dp->dccps_featneg);
209 /* control socket doesn't need feat nego */
210 if (likely(ctl_sock_initialized))
211 return dccp_feat_init(sk);
212 return 0;
213}
214
215EXPORT_SYMBOL_GPL(dccp_init_sock);
216
217void dccp_destroy_sock(struct sock *sk)
218{
219 struct dccp_sock *dp = dccp_sk(sk);
220
221 __skb_queue_purge(&sk->sk_write_queue);
222 if (sk->sk_send_head != NULL) {
223 kfree_skb(sk->sk_send_head);
224 sk->sk_send_head = NULL;
225 }
226
227 /* Clean up a referenced DCCP bind bucket. */
228 if (inet_csk(sk)->icsk_bind_hash != NULL)
229 inet_put_port(sk);
230
231 kfree(dp->dccps_service_list);
232 dp->dccps_service_list = NULL;
233
234 if (dp->dccps_hc_rx_ackvec != NULL) {
235 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
236 dp->dccps_hc_rx_ackvec = NULL;
237 }
238 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
239 dp->dccps_hc_rx_ccid = NULL;
240
241 /* clean up feature negotiation state */
242 dccp_feat_list_purge(&dp->dccps_featneg);
243}
244
245EXPORT_SYMBOL_GPL(dccp_destroy_sock);
246
247static inline int dccp_need_reset(int state)
248{
249 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
250 state != DCCP_REQUESTING;
251}
252
253int dccp_disconnect(struct sock *sk, int flags)
254{
255 struct inet_connection_sock *icsk = inet_csk(sk);
256 struct inet_sock *inet = inet_sk(sk);
257 struct dccp_sock *dp = dccp_sk(sk);
258 const int old_state = sk->sk_state;
259
260 if (old_state != DCCP_CLOSED)
261 dccp_set_state(sk, DCCP_CLOSED);
262
263 /*
264 * This corresponds to the ABORT function of RFC793, sec. 3.8
265 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
266 */
267 if (old_state == DCCP_LISTEN) {
268 inet_csk_listen_stop(sk);
269 } else if (dccp_need_reset(old_state)) {
270 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
271 sk->sk_err = ECONNRESET;
272 } else if (old_state == DCCP_REQUESTING)
273 sk->sk_err = ECONNRESET;
274
275 dccp_clear_xmit_timers(sk);
276 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
277 dp->dccps_hc_rx_ccid = NULL;
278
279 __skb_queue_purge(&sk->sk_receive_queue);
280 __skb_queue_purge(&sk->sk_write_queue);
281 if (sk->sk_send_head != NULL) {
282 __kfree_skb(sk->sk_send_head);
283 sk->sk_send_head = NULL;
284 }
285
286 inet->inet_dport = 0;
287
288 inet_bhash2_reset_saddr(sk);
289
290 sk->sk_shutdown = 0;
291 sock_reset_flag(sk, SOCK_DONE);
292
293 icsk->icsk_backoff = 0;
294 inet_csk_delack_init(sk);
295 __sk_dst_reset(sk);
296
297 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
298
299 sk_error_report(sk);
300 return 0;
301}
302
303EXPORT_SYMBOL_GPL(dccp_disconnect);
304
305/*
306 * Wait for a DCCP event.
307 *
308 * Note that we don't need to lock the socket, as the upper poll layers
309 * take care of normal races (between the test and the event) and we don't
310 * go look at any of the socket buffers directly.
311 */
312__poll_t dccp_poll(struct file *file, struct socket *sock,
313 poll_table *wait)
314{
315 __poll_t mask;
316 struct sock *sk = sock->sk;
317
318 sock_poll_wait(file, sock, wait);
319 if (sk->sk_state == DCCP_LISTEN)
320 return inet_csk_listen_poll(sk);
321
322 /* Socket is not locked. We are protected from async events
323 by poll logic and correct handling of state changes
324 made by another threads is impossible in any case.
325 */
326
327 mask = 0;
328 if (sk->sk_err)
329 mask = EPOLLERR;
330
331 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
332 mask |= EPOLLHUP;
333 if (sk->sk_shutdown & RCV_SHUTDOWN)
334 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
335
336 /* Connected? */
337 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
338 if (atomic_read(&sk->sk_rmem_alloc) > 0)
339 mask |= EPOLLIN | EPOLLRDNORM;
340
341 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
342 if (sk_stream_is_writeable(sk)) {
343 mask |= EPOLLOUT | EPOLLWRNORM;
344 } else { /* send SIGIO later */
345 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
346 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
347
348 /* Race breaker. If space is freed after
349 * wspace test but before the flags are set,
350 * IO signal will be lost.
351 */
352 if (sk_stream_is_writeable(sk))
353 mask |= EPOLLOUT | EPOLLWRNORM;
354 }
355 }
356 }
357 return mask;
358}
359
360EXPORT_SYMBOL_GPL(dccp_poll);
361
362int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
363{
364 int rc = -ENOTCONN;
365
366 lock_sock(sk);
367
368 if (sk->sk_state == DCCP_LISTEN)
369 goto out;
370
371 switch (cmd) {
372 case SIOCOUTQ: {
373 int amount = sk_wmem_alloc_get(sk);
374 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
375 * always 0, comparably to UDP.
376 */
377
378 rc = put_user(amount, (int __user *)arg);
379 }
380 break;
381 case SIOCINQ: {
382 struct sk_buff *skb;
383 unsigned long amount = 0;
384
385 skb = skb_peek(&sk->sk_receive_queue);
386 if (skb != NULL) {
387 /*
388 * We will only return the amount of this packet since
389 * that is all that will be read.
390 */
391 amount = skb->len;
392 }
393 rc = put_user(amount, (int __user *)arg);
394 }
395 break;
396 default:
397 rc = -ENOIOCTLCMD;
398 break;
399 }
400out:
401 release_sock(sk);
402 return rc;
403}
404
405EXPORT_SYMBOL_GPL(dccp_ioctl);
406
407static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
408 sockptr_t optval, unsigned int optlen)
409{
410 struct dccp_sock *dp = dccp_sk(sk);
411 struct dccp_service_list *sl = NULL;
412
413 if (service == DCCP_SERVICE_INVALID_VALUE ||
414 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
415 return -EINVAL;
416
417 if (optlen > sizeof(service)) {
418 sl = kmalloc(optlen, GFP_KERNEL);
419 if (sl == NULL)
420 return -ENOMEM;
421
422 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
423 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
424 sizeof(service), optlen - sizeof(service)) ||
425 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
426 kfree(sl);
427 return -EFAULT;
428 }
429 }
430
431 lock_sock(sk);
432 dp->dccps_service = service;
433
434 kfree(dp->dccps_service_list);
435
436 dp->dccps_service_list = sl;
437 release_sock(sk);
438 return 0;
439}
440
441static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
442{
443 u8 *list, len;
444 int i, rc;
445
446 if (cscov < 0 || cscov > 15)
447 return -EINVAL;
448 /*
449 * Populate a list of permissible values, in the range cscov...15. This
450 * is necessary since feature negotiation of single values only works if
451 * both sides incidentally choose the same value. Since the list starts
452 * lowest-value first, negotiation will pick the smallest shared value.
453 */
454 if (cscov == 0)
455 return 0;
456 len = 16 - cscov;
457
458 list = kmalloc(len, GFP_KERNEL);
459 if (list == NULL)
460 return -ENOBUFS;
461
462 for (i = 0; i < len; i++)
463 list[i] = cscov++;
464
465 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
466
467 if (rc == 0) {
468 if (rx)
469 dccp_sk(sk)->dccps_pcrlen = cscov;
470 else
471 dccp_sk(sk)->dccps_pcslen = cscov;
472 }
473 kfree(list);
474 return rc;
475}
476
477static int dccp_setsockopt_ccid(struct sock *sk, int type,
478 sockptr_t optval, unsigned int optlen)
479{
480 u8 *val;
481 int rc = 0;
482
483 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
484 return -EINVAL;
485
486 val = memdup_sockptr(optval, optlen);
487 if (IS_ERR(val))
488 return PTR_ERR(val);
489
490 lock_sock(sk);
491 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
492 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
493
494 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
495 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
496 release_sock(sk);
497
498 kfree(val);
499 return rc;
500}
501
502static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
503 sockptr_t optval, unsigned int optlen)
504{
505 struct dccp_sock *dp = dccp_sk(sk);
506 int val, err = 0;
507
508 switch (optname) {
509 case DCCP_SOCKOPT_PACKET_SIZE:
510 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
511 return 0;
512 case DCCP_SOCKOPT_CHANGE_L:
513 case DCCP_SOCKOPT_CHANGE_R:
514 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
515 return 0;
516 case DCCP_SOCKOPT_CCID:
517 case DCCP_SOCKOPT_RX_CCID:
518 case DCCP_SOCKOPT_TX_CCID:
519 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
520 }
521
522 if (optlen < (int)sizeof(int))
523 return -EINVAL;
524
525 if (copy_from_sockptr(&val, optval, sizeof(int)))
526 return -EFAULT;
527
528 if (optname == DCCP_SOCKOPT_SERVICE)
529 return dccp_setsockopt_service(sk, val, optval, optlen);
530
531 lock_sock(sk);
532 switch (optname) {
533 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
534 if (dp->dccps_role != DCCP_ROLE_SERVER)
535 err = -EOPNOTSUPP;
536 else
537 dp->dccps_server_timewait = (val != 0);
538 break;
539 case DCCP_SOCKOPT_SEND_CSCOV:
540 err = dccp_setsockopt_cscov(sk, val, false);
541 break;
542 case DCCP_SOCKOPT_RECV_CSCOV:
543 err = dccp_setsockopt_cscov(sk, val, true);
544 break;
545 case DCCP_SOCKOPT_QPOLICY_ID:
546 if (sk->sk_state != DCCP_CLOSED)
547 err = -EISCONN;
548 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
549 err = -EINVAL;
550 else
551 dp->dccps_qpolicy = val;
552 break;
553 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
554 if (val < 0)
555 err = -EINVAL;
556 else
557 dp->dccps_tx_qlen = val;
558 break;
559 default:
560 err = -ENOPROTOOPT;
561 break;
562 }
563 release_sock(sk);
564
565 return err;
566}
567
568int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
569 unsigned int optlen)
570{
571 if (level != SOL_DCCP)
572 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
573 optname, optval,
574 optlen);
575 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
576}
577
578EXPORT_SYMBOL_GPL(dccp_setsockopt);
579
580static int dccp_getsockopt_service(struct sock *sk, int len,
581 __be32 __user *optval,
582 int __user *optlen)
583{
584 const struct dccp_sock *dp = dccp_sk(sk);
585 const struct dccp_service_list *sl;
586 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
587
588 lock_sock(sk);
589 if ((sl = dp->dccps_service_list) != NULL) {
590 slen = sl->dccpsl_nr * sizeof(u32);
591 total_len += slen;
592 }
593
594 err = -EINVAL;
595 if (total_len > len)
596 goto out;
597
598 err = 0;
599 if (put_user(total_len, optlen) ||
600 put_user(dp->dccps_service, optval) ||
601 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
602 err = -EFAULT;
603out:
604 release_sock(sk);
605 return err;
606}
607
608static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
609 char __user *optval, int __user *optlen)
610{
611 struct dccp_sock *dp;
612 int val, len;
613
614 if (get_user(len, optlen))
615 return -EFAULT;
616
617 if (len < (int)sizeof(int))
618 return -EINVAL;
619
620 dp = dccp_sk(sk);
621
622 switch (optname) {
623 case DCCP_SOCKOPT_PACKET_SIZE:
624 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
625 return 0;
626 case DCCP_SOCKOPT_SERVICE:
627 return dccp_getsockopt_service(sk, len,
628 (__be32 __user *)optval, optlen);
629 case DCCP_SOCKOPT_GET_CUR_MPS:
630 val = dp->dccps_mss_cache;
631 break;
632 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
633 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
634 case DCCP_SOCKOPT_TX_CCID:
635 val = ccid_get_current_tx_ccid(dp);
636 if (val < 0)
637 return -ENOPROTOOPT;
638 break;
639 case DCCP_SOCKOPT_RX_CCID:
640 val = ccid_get_current_rx_ccid(dp);
641 if (val < 0)
642 return -ENOPROTOOPT;
643 break;
644 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
645 val = dp->dccps_server_timewait;
646 break;
647 case DCCP_SOCKOPT_SEND_CSCOV:
648 val = dp->dccps_pcslen;
649 break;
650 case DCCP_SOCKOPT_RECV_CSCOV:
651 val = dp->dccps_pcrlen;
652 break;
653 case DCCP_SOCKOPT_QPOLICY_ID:
654 val = dp->dccps_qpolicy;
655 break;
656 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
657 val = dp->dccps_tx_qlen;
658 break;
659 case 128 ... 191:
660 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
661 len, (u32 __user *)optval, optlen);
662 case 192 ... 255:
663 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
664 len, (u32 __user *)optval, optlen);
665 default:
666 return -ENOPROTOOPT;
667 }
668
669 len = sizeof(val);
670 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
671 return -EFAULT;
672
673 return 0;
674}
675
676int dccp_getsockopt(struct sock *sk, int level, int optname,
677 char __user *optval, int __user *optlen)
678{
679 if (level != SOL_DCCP)
680 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
681 optname, optval,
682 optlen);
683 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
684}
685
686EXPORT_SYMBOL_GPL(dccp_getsockopt);
687
688static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
689{
690 struct cmsghdr *cmsg;
691
692 /*
693 * Assign an (opaque) qpolicy priority value to skb->priority.
694 *
695 * We are overloading this skb field for use with the qpolicy subystem.
696 * The skb->priority is normally used for the SO_PRIORITY option, which
697 * is initialised from sk_priority. Since the assignment of sk_priority
698 * to skb->priority happens later (on layer 3), we overload this field
699 * for use with queueing priorities as long as the skb is on layer 4.
700 * The default priority value (if nothing is set) is 0.
701 */
702 skb->priority = 0;
703
704 for_each_cmsghdr(cmsg, msg) {
705 if (!CMSG_OK(msg, cmsg))
706 return -EINVAL;
707
708 if (cmsg->cmsg_level != SOL_DCCP)
709 continue;
710
711 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
712 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
713 return -EINVAL;
714
715 switch (cmsg->cmsg_type) {
716 case DCCP_SCM_PRIORITY:
717 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
718 return -EINVAL;
719 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
720 break;
721 default:
722 return -EINVAL;
723 }
724 }
725 return 0;
726}
727
728int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
729{
730 const struct dccp_sock *dp = dccp_sk(sk);
731 const int flags = msg->msg_flags;
732 const int noblock = flags & MSG_DONTWAIT;
733 struct sk_buff *skb;
734 int rc, size;
735 long timeo;
736
737 trace_dccp_probe(sk, len);
738
739 if (len > dp->dccps_mss_cache)
740 return -EMSGSIZE;
741
742 lock_sock(sk);
743
744 timeo = sock_sndtimeo(sk, noblock);
745
746 /*
747 * We have to use sk_stream_wait_connect here to set sk_write_pending,
748 * so that the trick in dccp_rcv_request_sent_state_process.
749 */
750 /* Wait for a connection to finish. */
751 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
752 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
753 goto out_release;
754
755 size = sk->sk_prot->max_header + len;
756 release_sock(sk);
757 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
758 lock_sock(sk);
759 if (skb == NULL)
760 goto out_release;
761
762 if (dccp_qpolicy_full(sk)) {
763 rc = -EAGAIN;
764 goto out_discard;
765 }
766
767 if (sk->sk_state == DCCP_CLOSED) {
768 rc = -ENOTCONN;
769 goto out_discard;
770 }
771
772 skb_reserve(skb, sk->sk_prot->max_header);
773 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
774 if (rc != 0)
775 goto out_discard;
776
777 rc = dccp_msghdr_parse(msg, skb);
778 if (rc != 0)
779 goto out_discard;
780
781 dccp_qpolicy_push(sk, skb);
782 /*
783 * The xmit_timer is set if the TX CCID is rate-based and will expire
784 * when congestion control permits to release further packets into the
785 * network. Window-based CCIDs do not use this timer.
786 */
787 if (!timer_pending(&dp->dccps_xmit_timer))
788 dccp_write_xmit(sk);
789out_release:
790 release_sock(sk);
791 return rc ? : len;
792out_discard:
793 kfree_skb(skb);
794 goto out_release;
795}
796
797EXPORT_SYMBOL_GPL(dccp_sendmsg);
798
799int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
800 int *addr_len)
801{
802 const struct dccp_hdr *dh;
803 long timeo;
804
805 lock_sock(sk);
806
807 if (sk->sk_state == DCCP_LISTEN) {
808 len = -ENOTCONN;
809 goto out;
810 }
811
812 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
813
814 do {
815 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
816
817 if (skb == NULL)
818 goto verify_sock_status;
819
820 dh = dccp_hdr(skb);
821
822 switch (dh->dccph_type) {
823 case DCCP_PKT_DATA:
824 case DCCP_PKT_DATAACK:
825 goto found_ok_skb;
826
827 case DCCP_PKT_CLOSE:
828 case DCCP_PKT_CLOSEREQ:
829 if (!(flags & MSG_PEEK))
830 dccp_finish_passive_close(sk);
831 fallthrough;
832 case DCCP_PKT_RESET:
833 dccp_pr_debug("found fin (%s) ok!\n",
834 dccp_packet_name(dh->dccph_type));
835 len = 0;
836 goto found_fin_ok;
837 default:
838 dccp_pr_debug("packet_type=%s\n",
839 dccp_packet_name(dh->dccph_type));
840 sk_eat_skb(sk, skb);
841 }
842verify_sock_status:
843 if (sock_flag(sk, SOCK_DONE)) {
844 len = 0;
845 break;
846 }
847
848 if (sk->sk_err) {
849 len = sock_error(sk);
850 break;
851 }
852
853 if (sk->sk_shutdown & RCV_SHUTDOWN) {
854 len = 0;
855 break;
856 }
857
858 if (sk->sk_state == DCCP_CLOSED) {
859 if (!sock_flag(sk, SOCK_DONE)) {
860 /* This occurs when user tries to read
861 * from never connected socket.
862 */
863 len = -ENOTCONN;
864 break;
865 }
866 len = 0;
867 break;
868 }
869
870 if (!timeo) {
871 len = -EAGAIN;
872 break;
873 }
874
875 if (signal_pending(current)) {
876 len = sock_intr_errno(timeo);
877 break;
878 }
879
880 sk_wait_data(sk, &timeo, NULL);
881 continue;
882 found_ok_skb:
883 if (len > skb->len)
884 len = skb->len;
885 else if (len < skb->len)
886 msg->msg_flags |= MSG_TRUNC;
887
888 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
889 /* Exception. Bailout! */
890 len = -EFAULT;
891 break;
892 }
893 if (flags & MSG_TRUNC)
894 len = skb->len;
895 found_fin_ok:
896 if (!(flags & MSG_PEEK))
897 sk_eat_skb(sk, skb);
898 break;
899 } while (1);
900out:
901 release_sock(sk);
902 return len;
903}
904
905EXPORT_SYMBOL_GPL(dccp_recvmsg);
906
907int inet_dccp_listen(struct socket *sock, int backlog)
908{
909 struct sock *sk = sock->sk;
910 unsigned char old_state;
911 int err;
912
913 lock_sock(sk);
914
915 err = -EINVAL;
916 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
917 goto out;
918
919 old_state = sk->sk_state;
920 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
921 goto out;
922
923 WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
924 /* Really, if the socket is already in listen state
925 * we can only allow the backlog to be adjusted.
926 */
927 if (old_state != DCCP_LISTEN) {
928 struct dccp_sock *dp = dccp_sk(sk);
929
930 dp->dccps_role = DCCP_ROLE_LISTEN;
931
932 /* do not start to listen if feature negotiation setup fails */
933 if (dccp_feat_finalise_settings(dp)) {
934 err = -EPROTO;
935 goto out;
936 }
937
938 err = inet_csk_listen_start(sk);
939 if (err)
940 goto out;
941 }
942 err = 0;
943
944out:
945 release_sock(sk);
946 return err;
947}
948
949EXPORT_SYMBOL_GPL(inet_dccp_listen);
950
951static void dccp_terminate_connection(struct sock *sk)
952{
953 u8 next_state = DCCP_CLOSED;
954
955 switch (sk->sk_state) {
956 case DCCP_PASSIVE_CLOSE:
957 case DCCP_PASSIVE_CLOSEREQ:
958 dccp_finish_passive_close(sk);
959 break;
960 case DCCP_PARTOPEN:
961 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
962 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
963 fallthrough;
964 case DCCP_OPEN:
965 dccp_send_close(sk, 1);
966
967 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
968 !dccp_sk(sk)->dccps_server_timewait)
969 next_state = DCCP_ACTIVE_CLOSEREQ;
970 else
971 next_state = DCCP_CLOSING;
972 fallthrough;
973 default:
974 dccp_set_state(sk, next_state);
975 }
976}
977
978void dccp_close(struct sock *sk, long timeout)
979{
980 struct dccp_sock *dp = dccp_sk(sk);
981 struct sk_buff *skb;
982 u32 data_was_unread = 0;
983 int state;
984
985 lock_sock(sk);
986
987 sk->sk_shutdown = SHUTDOWN_MASK;
988
989 if (sk->sk_state == DCCP_LISTEN) {
990 dccp_set_state(sk, DCCP_CLOSED);
991
992 /* Special case. */
993 inet_csk_listen_stop(sk);
994
995 goto adjudge_to_death;
996 }
997
998 sk_stop_timer(sk, &dp->dccps_xmit_timer);
999
1000 /*
1001 * We need to flush the recv. buffs. We do this only on the
1002 * descriptor close, not protocol-sourced closes, because the
1003 *reader process may not have drained the data yet!
1004 */
1005 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1006 data_was_unread += skb->len;
1007 __kfree_skb(skb);
1008 }
1009
1010 /* If socket has been already reset kill it. */
1011 if (sk->sk_state == DCCP_CLOSED)
1012 goto adjudge_to_death;
1013
1014 if (data_was_unread) {
1015 /* Unread data was tossed, send an appropriate Reset Code */
1016 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1017 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1018 dccp_set_state(sk, DCCP_CLOSED);
1019 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1020 /* Check zero linger _after_ checking for unread data. */
1021 sk->sk_prot->disconnect(sk, 0);
1022 } else if (sk->sk_state != DCCP_CLOSED) {
1023 /*
1024 * Normal connection termination. May need to wait if there are
1025 * still packets in the TX queue that are delayed by the CCID.
1026 */
1027 dccp_flush_write_queue(sk, &timeout);
1028 dccp_terminate_connection(sk);
1029 }
1030
1031 /*
1032 * Flush write queue. This may be necessary in several cases:
1033 * - we have been closed by the peer but still have application data;
1034 * - abortive termination (unread data or zero linger time),
1035 * - normal termination but queue could not be flushed within time limit
1036 */
1037 __skb_queue_purge(&sk->sk_write_queue);
1038
1039 sk_stream_wait_close(sk, timeout);
1040
1041adjudge_to_death:
1042 state = sk->sk_state;
1043 sock_hold(sk);
1044 sock_orphan(sk);
1045
1046 /*
1047 * It is the last release_sock in its life. It will remove backlog.
1048 */
1049 release_sock(sk);
1050 /*
1051 * Now socket is owned by kernel and we acquire BH lock
1052 * to finish close. No need to check for user refs.
1053 */
1054 local_bh_disable();
1055 bh_lock_sock(sk);
1056 WARN_ON(sock_owned_by_user(sk));
1057
1058 this_cpu_inc(dccp_orphan_count);
1059
1060 /* Have we already been destroyed by a softirq or backlog? */
1061 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1062 goto out;
1063
1064 if (sk->sk_state == DCCP_CLOSED)
1065 inet_csk_destroy_sock(sk);
1066
1067 /* Otherwise, socket is reprieved until protocol close. */
1068
1069out:
1070 bh_unlock_sock(sk);
1071 local_bh_enable();
1072 sock_put(sk);
1073}
1074
1075EXPORT_SYMBOL_GPL(dccp_close);
1076
1077void dccp_shutdown(struct sock *sk, int how)
1078{
1079 dccp_pr_debug("called shutdown(%x)\n", how);
1080}
1081
1082EXPORT_SYMBOL_GPL(dccp_shutdown);
1083
1084static inline int __init dccp_mib_init(void)
1085{
1086 dccp_statistics = alloc_percpu(struct dccp_mib);
1087 if (!dccp_statistics)
1088 return -ENOMEM;
1089 return 0;
1090}
1091
1092static inline void dccp_mib_exit(void)
1093{
1094 free_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 unsigned long nr_pages = totalram_pages();
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 sizeof_field(struct sk_buff, cb));
1118 rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1119 if (rc)
1120 goto out_fail;
1121 rc = -ENOBUFS;
1122 dccp_hashinfo.bind_bucket_cachep =
1123 kmem_cache_create("dccp_bind_bucket",
1124 sizeof(struct inet_bind_bucket), 0,
1125 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1126 if (!dccp_hashinfo.bind_bucket_cachep)
1127 goto out_free_hashinfo2;
1128 dccp_hashinfo.bind2_bucket_cachep =
1129 kmem_cache_create("dccp_bind2_bucket",
1130 sizeof(struct inet_bind2_bucket), 0,
1131 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1132 if (!dccp_hashinfo.bind2_bucket_cachep)
1133 goto out_free_bind_bucket_cachep;
1134
1135 /*
1136 * Size and allocate the main established and bind bucket
1137 * hash tables.
1138 *
1139 * The methodology is similar to that of the buffer cache.
1140 */
1141 if (nr_pages >= (128 * 1024))
1142 goal = nr_pages >> (21 - PAGE_SHIFT);
1143 else
1144 goal = nr_pages >> (23 - PAGE_SHIFT);
1145
1146 if (thash_entries)
1147 goal = (thash_entries *
1148 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1149 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1150 ;
1151 do {
1152 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1153 sizeof(struct inet_ehash_bucket);
1154
1155 while (hash_size & (hash_size - 1))
1156 hash_size--;
1157 dccp_hashinfo.ehash_mask = hash_size - 1;
1158 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1159 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1160 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1161
1162 if (!dccp_hashinfo.ehash) {
1163 DCCP_CRIT("Failed to allocate DCCP established hash table");
1164 goto out_free_bind2_bucket_cachep;
1165 }
1166
1167 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1168 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1169
1170 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1171 goto out_free_dccp_ehash;
1172
1173 bhash_order = ehash_order;
1174
1175 do {
1176 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1177 sizeof(struct inet_bind_hashbucket);
1178 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1179 bhash_order > 0)
1180 continue;
1181 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1182 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1183 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1184
1185 if (!dccp_hashinfo.bhash) {
1186 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1187 goto out_free_dccp_locks;
1188 }
1189
1190 dccp_hashinfo.bhash2 = (struct inet_bind_hashbucket *)
1191 __get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order);
1192
1193 if (!dccp_hashinfo.bhash2) {
1194 DCCP_CRIT("Failed to allocate DCCP bind2 hash table");
1195 goto out_free_dccp_bhash;
1196 }
1197
1198 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1199 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1200 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1201 spin_lock_init(&dccp_hashinfo.bhash2[i].lock);
1202 INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain);
1203 }
1204
1205 dccp_hashinfo.pernet = false;
1206
1207 rc = dccp_mib_init();
1208 if (rc)
1209 goto out_free_dccp_bhash2;
1210
1211 rc = dccp_ackvec_init();
1212 if (rc)
1213 goto out_free_dccp_mib;
1214
1215 rc = dccp_sysctl_init();
1216 if (rc)
1217 goto out_ackvec_exit;
1218
1219 rc = ccid_initialize_builtins();
1220 if (rc)
1221 goto out_sysctl_exit;
1222
1223 dccp_timestamping_init();
1224
1225 return 0;
1226
1227out_sysctl_exit:
1228 dccp_sysctl_exit();
1229out_ackvec_exit:
1230 dccp_ackvec_exit();
1231out_free_dccp_mib:
1232 dccp_mib_exit();
1233out_free_dccp_bhash2:
1234 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1235out_free_dccp_bhash:
1236 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1237out_free_dccp_locks:
1238 inet_ehash_locks_free(&dccp_hashinfo);
1239out_free_dccp_ehash:
1240 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1241out_free_bind2_bucket_cachep:
1242 kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
1243out_free_bind_bucket_cachep:
1244 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1245out_free_hashinfo2:
1246 inet_hashinfo2_free_mod(&dccp_hashinfo);
1247out_fail:
1248 dccp_hashinfo.bhash = NULL;
1249 dccp_hashinfo.bhash2 = NULL;
1250 dccp_hashinfo.ehash = NULL;
1251 dccp_hashinfo.bind_bucket_cachep = NULL;
1252 dccp_hashinfo.bind2_bucket_cachep = NULL;
1253 return rc;
1254}
1255
1256static void __exit dccp_fini(void)
1257{
1258 int bhash_order = get_order(dccp_hashinfo.bhash_size *
1259 sizeof(struct inet_bind_hashbucket));
1260
1261 ccid_cleanup_builtins();
1262 dccp_mib_exit();
1263 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1264 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1265 free_pages((unsigned long)dccp_hashinfo.ehash,
1266 get_order((dccp_hashinfo.ehash_mask + 1) *
1267 sizeof(struct inet_ehash_bucket)));
1268 inet_ehash_locks_free(&dccp_hashinfo);
1269 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1270 dccp_ackvec_exit();
1271 dccp_sysctl_exit();
1272 inet_hashinfo2_free_mod(&dccp_hashinfo);
1273}
1274
1275module_init(dccp_init);
1276module_exit(dccp_fini);
1277
1278MODULE_LICENSE("GPL");
1279MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1280MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");