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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 pr_warn_once("DCCP is deprecated and scheduled to be removed in 2025, "
195 "please contact the netdev mailing list\n");
196
197 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
198 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
199 sk->sk_state = DCCP_CLOSED;
200 sk->sk_write_space = dccp_write_space;
201 sk->sk_destruct = dccp_sk_destruct;
202 icsk->icsk_sync_mss = dccp_sync_mss;
203 dp->dccps_mss_cache = 536;
204 dp->dccps_rate_last = jiffies;
205 dp->dccps_role = DCCP_ROLE_UNDEFINED;
206 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
207 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
208
209 dccp_init_xmit_timers(sk);
210
211 INIT_LIST_HEAD(&dp->dccps_featneg);
212 /* control socket doesn't need feat nego */
213 if (likely(ctl_sock_initialized))
214 return dccp_feat_init(sk);
215 return 0;
216}
217
218EXPORT_SYMBOL_GPL(dccp_init_sock);
219
220void dccp_destroy_sock(struct sock *sk)
221{
222 struct dccp_sock *dp = dccp_sk(sk);
223
224 __skb_queue_purge(&sk->sk_write_queue);
225 if (sk->sk_send_head != NULL) {
226 kfree_skb(sk->sk_send_head);
227 sk->sk_send_head = NULL;
228 }
229
230 /* Clean up a referenced DCCP bind bucket. */
231 if (inet_csk(sk)->icsk_bind_hash != NULL)
232 inet_put_port(sk);
233
234 kfree(dp->dccps_service_list);
235 dp->dccps_service_list = NULL;
236
237 if (dp->dccps_hc_rx_ackvec != NULL) {
238 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
239 dp->dccps_hc_rx_ackvec = NULL;
240 }
241 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
242 dp->dccps_hc_rx_ccid = NULL;
243
244 /* clean up feature negotiation state */
245 dccp_feat_list_purge(&dp->dccps_featneg);
246}
247
248EXPORT_SYMBOL_GPL(dccp_destroy_sock);
249
250static inline int dccp_need_reset(int state)
251{
252 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
253 state != DCCP_REQUESTING;
254}
255
256int dccp_disconnect(struct sock *sk, int flags)
257{
258 struct inet_connection_sock *icsk = inet_csk(sk);
259 struct inet_sock *inet = inet_sk(sk);
260 struct dccp_sock *dp = dccp_sk(sk);
261 const int old_state = sk->sk_state;
262
263 if (old_state != DCCP_CLOSED)
264 dccp_set_state(sk, DCCP_CLOSED);
265
266 /*
267 * This corresponds to the ABORT function of RFC793, sec. 3.8
268 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
269 */
270 if (old_state == DCCP_LISTEN) {
271 inet_csk_listen_stop(sk);
272 } else if (dccp_need_reset(old_state)) {
273 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
274 sk->sk_err = ECONNRESET;
275 } else if (old_state == DCCP_REQUESTING)
276 sk->sk_err = ECONNRESET;
277
278 dccp_clear_xmit_timers(sk);
279 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
280 dp->dccps_hc_rx_ccid = NULL;
281
282 __skb_queue_purge(&sk->sk_receive_queue);
283 __skb_queue_purge(&sk->sk_write_queue);
284 if (sk->sk_send_head != NULL) {
285 __kfree_skb(sk->sk_send_head);
286 sk->sk_send_head = NULL;
287 }
288
289 inet->inet_dport = 0;
290
291 inet_bhash2_reset_saddr(sk);
292
293 sk->sk_shutdown = 0;
294 sock_reset_flag(sk, SOCK_DONE);
295
296 icsk->icsk_backoff = 0;
297 inet_csk_delack_init(sk);
298 __sk_dst_reset(sk);
299
300 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
301
302 sk_error_report(sk);
303 return 0;
304}
305
306EXPORT_SYMBOL_GPL(dccp_disconnect);
307
308/*
309 * Wait for a DCCP event.
310 *
311 * Note that we don't need to lock the socket, as the upper poll layers
312 * take care of normal races (between the test and the event) and we don't
313 * go look at any of the socket buffers directly.
314 */
315__poll_t dccp_poll(struct file *file, struct socket *sock,
316 poll_table *wait)
317{
318 struct sock *sk = sock->sk;
319 __poll_t mask;
320 u8 shutdown;
321 int state;
322
323 sock_poll_wait(file, sock, wait);
324
325 state = inet_sk_state_load(sk);
326 if (state == DCCP_LISTEN)
327 return inet_csk_listen_poll(sk);
328
329 /* Socket is not locked. We are protected from async events
330 by poll logic and correct handling of state changes
331 made by another threads is impossible in any case.
332 */
333
334 mask = 0;
335 if (READ_ONCE(sk->sk_err))
336 mask = EPOLLERR;
337 shutdown = READ_ONCE(sk->sk_shutdown);
338
339 if (shutdown == SHUTDOWN_MASK || state == DCCP_CLOSED)
340 mask |= EPOLLHUP;
341 if (shutdown & RCV_SHUTDOWN)
342 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
343
344 /* Connected? */
345 if ((1 << state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
346 if (atomic_read(&sk->sk_rmem_alloc) > 0)
347 mask |= EPOLLIN | EPOLLRDNORM;
348
349 if (!(shutdown & SEND_SHUTDOWN)) {
350 if (sk_stream_is_writeable(sk)) {
351 mask |= EPOLLOUT | EPOLLWRNORM;
352 } else { /* send SIGIO later */
353 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
354 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
355
356 /* Race breaker. If space is freed after
357 * wspace test but before the flags are set,
358 * IO signal will be lost.
359 */
360 if (sk_stream_is_writeable(sk))
361 mask |= EPOLLOUT | EPOLLWRNORM;
362 }
363 }
364 }
365 return mask;
366}
367EXPORT_SYMBOL_GPL(dccp_poll);
368
369int dccp_ioctl(struct sock *sk, int cmd, int *karg)
370{
371 int rc = -ENOTCONN;
372
373 lock_sock(sk);
374
375 if (sk->sk_state == DCCP_LISTEN)
376 goto out;
377
378 switch (cmd) {
379 case SIOCOUTQ: {
380 *karg = sk_wmem_alloc_get(sk);
381 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
382 * always 0, comparably to UDP.
383 */
384
385 rc = 0;
386 }
387 break;
388 case SIOCINQ: {
389 struct sk_buff *skb;
390 *karg = 0;
391
392 skb = skb_peek(&sk->sk_receive_queue);
393 if (skb != NULL) {
394 /*
395 * We will only return the amount of this packet since
396 * that is all that will be read.
397 */
398 *karg = skb->len;
399 }
400 rc = 0;
401 }
402 break;
403 default:
404 rc = -ENOIOCTLCMD;
405 break;
406 }
407out:
408 release_sock(sk);
409 return rc;
410}
411
412EXPORT_SYMBOL_GPL(dccp_ioctl);
413
414static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
415 sockptr_t optval, unsigned int optlen)
416{
417 struct dccp_sock *dp = dccp_sk(sk);
418 struct dccp_service_list *sl = NULL;
419
420 if (service == DCCP_SERVICE_INVALID_VALUE ||
421 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
422 return -EINVAL;
423
424 if (optlen > sizeof(service)) {
425 sl = kmalloc(optlen, GFP_KERNEL);
426 if (sl == NULL)
427 return -ENOMEM;
428
429 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
430 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
431 sizeof(service), optlen - sizeof(service)) ||
432 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
433 kfree(sl);
434 return -EFAULT;
435 }
436 }
437
438 lock_sock(sk);
439 dp->dccps_service = service;
440
441 kfree(dp->dccps_service_list);
442
443 dp->dccps_service_list = sl;
444 release_sock(sk);
445 return 0;
446}
447
448static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
449{
450 u8 *list, len;
451 int i, rc;
452
453 if (cscov < 0 || cscov > 15)
454 return -EINVAL;
455 /*
456 * Populate a list of permissible values, in the range cscov...15. This
457 * is necessary since feature negotiation of single values only works if
458 * both sides incidentally choose the same value. Since the list starts
459 * lowest-value first, negotiation will pick the smallest shared value.
460 */
461 if (cscov == 0)
462 return 0;
463 len = 16 - cscov;
464
465 list = kmalloc(len, GFP_KERNEL);
466 if (list == NULL)
467 return -ENOBUFS;
468
469 for (i = 0; i < len; i++)
470 list[i] = cscov++;
471
472 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
473
474 if (rc == 0) {
475 if (rx)
476 dccp_sk(sk)->dccps_pcrlen = cscov;
477 else
478 dccp_sk(sk)->dccps_pcslen = cscov;
479 }
480 kfree(list);
481 return rc;
482}
483
484static int dccp_setsockopt_ccid(struct sock *sk, int type,
485 sockptr_t optval, unsigned int optlen)
486{
487 u8 *val;
488 int rc = 0;
489
490 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
491 return -EINVAL;
492
493 val = memdup_sockptr(optval, optlen);
494 if (IS_ERR(val))
495 return PTR_ERR(val);
496
497 lock_sock(sk);
498 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
499 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
500
501 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
502 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
503 release_sock(sk);
504
505 kfree(val);
506 return rc;
507}
508
509static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
510 sockptr_t optval, unsigned int optlen)
511{
512 struct dccp_sock *dp = dccp_sk(sk);
513 int val, err = 0;
514
515 switch (optname) {
516 case DCCP_SOCKOPT_PACKET_SIZE:
517 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
518 return 0;
519 case DCCP_SOCKOPT_CHANGE_L:
520 case DCCP_SOCKOPT_CHANGE_R:
521 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
522 return 0;
523 case DCCP_SOCKOPT_CCID:
524 case DCCP_SOCKOPT_RX_CCID:
525 case DCCP_SOCKOPT_TX_CCID:
526 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
527 }
528
529 if (optlen < (int)sizeof(int))
530 return -EINVAL;
531
532 if (copy_from_sockptr(&val, optval, sizeof(int)))
533 return -EFAULT;
534
535 if (optname == DCCP_SOCKOPT_SERVICE)
536 return dccp_setsockopt_service(sk, val, optval, optlen);
537
538 lock_sock(sk);
539 switch (optname) {
540 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
541 if (dp->dccps_role != DCCP_ROLE_SERVER)
542 err = -EOPNOTSUPP;
543 else
544 dp->dccps_server_timewait = (val != 0);
545 break;
546 case DCCP_SOCKOPT_SEND_CSCOV:
547 err = dccp_setsockopt_cscov(sk, val, false);
548 break;
549 case DCCP_SOCKOPT_RECV_CSCOV:
550 err = dccp_setsockopt_cscov(sk, val, true);
551 break;
552 case DCCP_SOCKOPT_QPOLICY_ID:
553 if (sk->sk_state != DCCP_CLOSED)
554 err = -EISCONN;
555 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
556 err = -EINVAL;
557 else
558 dp->dccps_qpolicy = val;
559 break;
560 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
561 if (val < 0)
562 err = -EINVAL;
563 else
564 dp->dccps_tx_qlen = val;
565 break;
566 default:
567 err = -ENOPROTOOPT;
568 break;
569 }
570 release_sock(sk);
571
572 return err;
573}
574
575int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
576 unsigned int optlen)
577{
578 if (level != SOL_DCCP)
579 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
580 optname, optval,
581 optlen);
582 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
583}
584
585EXPORT_SYMBOL_GPL(dccp_setsockopt);
586
587static int dccp_getsockopt_service(struct sock *sk, int len,
588 __be32 __user *optval,
589 int __user *optlen)
590{
591 const struct dccp_sock *dp = dccp_sk(sk);
592 const struct dccp_service_list *sl;
593 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
594
595 lock_sock(sk);
596 if ((sl = dp->dccps_service_list) != NULL) {
597 slen = sl->dccpsl_nr * sizeof(u32);
598 total_len += slen;
599 }
600
601 err = -EINVAL;
602 if (total_len > len)
603 goto out;
604
605 err = 0;
606 if (put_user(total_len, optlen) ||
607 put_user(dp->dccps_service, optval) ||
608 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
609 err = -EFAULT;
610out:
611 release_sock(sk);
612 return err;
613}
614
615static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
616 char __user *optval, int __user *optlen)
617{
618 struct dccp_sock *dp;
619 int val, len;
620
621 if (get_user(len, optlen))
622 return -EFAULT;
623
624 if (len < (int)sizeof(int))
625 return -EINVAL;
626
627 dp = dccp_sk(sk);
628
629 switch (optname) {
630 case DCCP_SOCKOPT_PACKET_SIZE:
631 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
632 return 0;
633 case DCCP_SOCKOPT_SERVICE:
634 return dccp_getsockopt_service(sk, len,
635 (__be32 __user *)optval, optlen);
636 case DCCP_SOCKOPT_GET_CUR_MPS:
637 val = READ_ONCE(dp->dccps_mss_cache);
638 break;
639 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
640 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
641 case DCCP_SOCKOPT_TX_CCID:
642 val = ccid_get_current_tx_ccid(dp);
643 if (val < 0)
644 return -ENOPROTOOPT;
645 break;
646 case DCCP_SOCKOPT_RX_CCID:
647 val = ccid_get_current_rx_ccid(dp);
648 if (val < 0)
649 return -ENOPROTOOPT;
650 break;
651 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
652 val = dp->dccps_server_timewait;
653 break;
654 case DCCP_SOCKOPT_SEND_CSCOV:
655 val = dp->dccps_pcslen;
656 break;
657 case DCCP_SOCKOPT_RECV_CSCOV:
658 val = dp->dccps_pcrlen;
659 break;
660 case DCCP_SOCKOPT_QPOLICY_ID:
661 val = dp->dccps_qpolicy;
662 break;
663 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
664 val = dp->dccps_tx_qlen;
665 break;
666 case 128 ... 191:
667 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
668 len, (u32 __user *)optval, optlen);
669 case 192 ... 255:
670 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
671 len, (u32 __user *)optval, optlen);
672 default:
673 return -ENOPROTOOPT;
674 }
675
676 len = sizeof(val);
677 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
678 return -EFAULT;
679
680 return 0;
681}
682
683int dccp_getsockopt(struct sock *sk, int level, int optname,
684 char __user *optval, int __user *optlen)
685{
686 if (level != SOL_DCCP)
687 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
688 optname, optval,
689 optlen);
690 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
691}
692
693EXPORT_SYMBOL_GPL(dccp_getsockopt);
694
695static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
696{
697 struct cmsghdr *cmsg;
698
699 /*
700 * Assign an (opaque) qpolicy priority value to skb->priority.
701 *
702 * We are overloading this skb field for use with the qpolicy subystem.
703 * The skb->priority is normally used for the SO_PRIORITY option, which
704 * is initialised from sk_priority. Since the assignment of sk_priority
705 * to skb->priority happens later (on layer 3), we overload this field
706 * for use with queueing priorities as long as the skb is on layer 4.
707 * The default priority value (if nothing is set) is 0.
708 */
709 skb->priority = 0;
710
711 for_each_cmsghdr(cmsg, msg) {
712 if (!CMSG_OK(msg, cmsg))
713 return -EINVAL;
714
715 if (cmsg->cmsg_level != SOL_DCCP)
716 continue;
717
718 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
719 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
720 return -EINVAL;
721
722 switch (cmsg->cmsg_type) {
723 case DCCP_SCM_PRIORITY:
724 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
725 return -EINVAL;
726 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
727 break;
728 default:
729 return -EINVAL;
730 }
731 }
732 return 0;
733}
734
735int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
736{
737 const struct dccp_sock *dp = dccp_sk(sk);
738 const int flags = msg->msg_flags;
739 const int noblock = flags & MSG_DONTWAIT;
740 struct sk_buff *skb;
741 int rc, size;
742 long timeo;
743
744 trace_dccp_probe(sk, len);
745
746 if (len > READ_ONCE(dp->dccps_mss_cache))
747 return -EMSGSIZE;
748
749 lock_sock(sk);
750
751 timeo = sock_sndtimeo(sk, noblock);
752
753 /*
754 * We have to use sk_stream_wait_connect here to set sk_write_pending,
755 * so that the trick in dccp_rcv_request_sent_state_process.
756 */
757 /* Wait for a connection to finish. */
758 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
759 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
760 goto out_release;
761
762 size = sk->sk_prot->max_header + len;
763 release_sock(sk);
764 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
765 lock_sock(sk);
766 if (skb == NULL)
767 goto out_release;
768
769 if (dccp_qpolicy_full(sk)) {
770 rc = -EAGAIN;
771 goto out_discard;
772 }
773
774 if (sk->sk_state == DCCP_CLOSED) {
775 rc = -ENOTCONN;
776 goto out_discard;
777 }
778
779 /* We need to check dccps_mss_cache after socket is locked. */
780 if (len > dp->dccps_mss_cache) {
781 rc = -EMSGSIZE;
782 goto out_discard;
783 }
784
785 skb_reserve(skb, sk->sk_prot->max_header);
786 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
787 if (rc != 0)
788 goto out_discard;
789
790 rc = dccp_msghdr_parse(msg, skb);
791 if (rc != 0)
792 goto out_discard;
793
794 dccp_qpolicy_push(sk, skb);
795 /*
796 * The xmit_timer is set if the TX CCID is rate-based and will expire
797 * when congestion control permits to release further packets into the
798 * network. Window-based CCIDs do not use this timer.
799 */
800 if (!timer_pending(&dp->dccps_xmit_timer))
801 dccp_write_xmit(sk);
802out_release:
803 release_sock(sk);
804 return rc ? : len;
805out_discard:
806 kfree_skb(skb);
807 goto out_release;
808}
809
810EXPORT_SYMBOL_GPL(dccp_sendmsg);
811
812int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
813 int *addr_len)
814{
815 const struct dccp_hdr *dh;
816 long timeo;
817
818 lock_sock(sk);
819
820 if (sk->sk_state == DCCP_LISTEN) {
821 len = -ENOTCONN;
822 goto out;
823 }
824
825 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
826
827 do {
828 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
829
830 if (skb == NULL)
831 goto verify_sock_status;
832
833 dh = dccp_hdr(skb);
834
835 switch (dh->dccph_type) {
836 case DCCP_PKT_DATA:
837 case DCCP_PKT_DATAACK:
838 goto found_ok_skb;
839
840 case DCCP_PKT_CLOSE:
841 case DCCP_PKT_CLOSEREQ:
842 if (!(flags & MSG_PEEK))
843 dccp_finish_passive_close(sk);
844 fallthrough;
845 case DCCP_PKT_RESET:
846 dccp_pr_debug("found fin (%s) ok!\n",
847 dccp_packet_name(dh->dccph_type));
848 len = 0;
849 goto found_fin_ok;
850 default:
851 dccp_pr_debug("packet_type=%s\n",
852 dccp_packet_name(dh->dccph_type));
853 sk_eat_skb(sk, skb);
854 }
855verify_sock_status:
856 if (sock_flag(sk, SOCK_DONE)) {
857 len = 0;
858 break;
859 }
860
861 if (sk->sk_err) {
862 len = sock_error(sk);
863 break;
864 }
865
866 if (sk->sk_shutdown & RCV_SHUTDOWN) {
867 len = 0;
868 break;
869 }
870
871 if (sk->sk_state == DCCP_CLOSED) {
872 if (!sock_flag(sk, SOCK_DONE)) {
873 /* This occurs when user tries to read
874 * from never connected socket.
875 */
876 len = -ENOTCONN;
877 break;
878 }
879 len = 0;
880 break;
881 }
882
883 if (!timeo) {
884 len = -EAGAIN;
885 break;
886 }
887
888 if (signal_pending(current)) {
889 len = sock_intr_errno(timeo);
890 break;
891 }
892
893 sk_wait_data(sk, &timeo, NULL);
894 continue;
895 found_ok_skb:
896 if (len > skb->len)
897 len = skb->len;
898 else if (len < skb->len)
899 msg->msg_flags |= MSG_TRUNC;
900
901 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
902 /* Exception. Bailout! */
903 len = -EFAULT;
904 break;
905 }
906 if (flags & MSG_TRUNC)
907 len = skb->len;
908 found_fin_ok:
909 if (!(flags & MSG_PEEK))
910 sk_eat_skb(sk, skb);
911 break;
912 } while (1);
913out:
914 release_sock(sk);
915 return len;
916}
917
918EXPORT_SYMBOL_GPL(dccp_recvmsg);
919
920int inet_dccp_listen(struct socket *sock, int backlog)
921{
922 struct sock *sk = sock->sk;
923 unsigned char old_state;
924 int err;
925
926 lock_sock(sk);
927
928 err = -EINVAL;
929 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
930 goto out;
931
932 old_state = sk->sk_state;
933 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
934 goto out;
935
936 WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
937 /* Really, if the socket is already in listen state
938 * we can only allow the backlog to be adjusted.
939 */
940 if (old_state != DCCP_LISTEN) {
941 struct dccp_sock *dp = dccp_sk(sk);
942
943 dp->dccps_role = DCCP_ROLE_LISTEN;
944
945 /* do not start to listen if feature negotiation setup fails */
946 if (dccp_feat_finalise_settings(dp)) {
947 err = -EPROTO;
948 goto out;
949 }
950
951 err = inet_csk_listen_start(sk);
952 if (err)
953 goto out;
954 }
955 err = 0;
956
957out:
958 release_sock(sk);
959 return err;
960}
961
962EXPORT_SYMBOL_GPL(inet_dccp_listen);
963
964static void dccp_terminate_connection(struct sock *sk)
965{
966 u8 next_state = DCCP_CLOSED;
967
968 switch (sk->sk_state) {
969 case DCCP_PASSIVE_CLOSE:
970 case DCCP_PASSIVE_CLOSEREQ:
971 dccp_finish_passive_close(sk);
972 break;
973 case DCCP_PARTOPEN:
974 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
975 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
976 fallthrough;
977 case DCCP_OPEN:
978 dccp_send_close(sk, 1);
979
980 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
981 !dccp_sk(sk)->dccps_server_timewait)
982 next_state = DCCP_ACTIVE_CLOSEREQ;
983 else
984 next_state = DCCP_CLOSING;
985 fallthrough;
986 default:
987 dccp_set_state(sk, next_state);
988 }
989}
990
991void dccp_close(struct sock *sk, long timeout)
992{
993 struct dccp_sock *dp = dccp_sk(sk);
994 struct sk_buff *skb;
995 u32 data_was_unread = 0;
996 int state;
997
998 lock_sock(sk);
999
1000 sk->sk_shutdown = SHUTDOWN_MASK;
1001
1002 if (sk->sk_state == DCCP_LISTEN) {
1003 dccp_set_state(sk, DCCP_CLOSED);
1004
1005 /* Special case. */
1006 inet_csk_listen_stop(sk);
1007
1008 goto adjudge_to_death;
1009 }
1010
1011 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1012
1013 /*
1014 * We need to flush the recv. buffs. We do this only on the
1015 * descriptor close, not protocol-sourced closes, because the
1016 *reader process may not have drained the data yet!
1017 */
1018 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1019 data_was_unread += skb->len;
1020 __kfree_skb(skb);
1021 }
1022
1023 /* If socket has been already reset kill it. */
1024 if (sk->sk_state == DCCP_CLOSED)
1025 goto adjudge_to_death;
1026
1027 if (data_was_unread) {
1028 /* Unread data was tossed, send an appropriate Reset Code */
1029 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1030 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1031 dccp_set_state(sk, DCCP_CLOSED);
1032 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1033 /* Check zero linger _after_ checking for unread data. */
1034 sk->sk_prot->disconnect(sk, 0);
1035 } else if (sk->sk_state != DCCP_CLOSED) {
1036 /*
1037 * Normal connection termination. May need to wait if there are
1038 * still packets in the TX queue that are delayed by the CCID.
1039 */
1040 dccp_flush_write_queue(sk, &timeout);
1041 dccp_terminate_connection(sk);
1042 }
1043
1044 /*
1045 * Flush write queue. This may be necessary in several cases:
1046 * - we have been closed by the peer but still have application data;
1047 * - abortive termination (unread data or zero linger time),
1048 * - normal termination but queue could not be flushed within time limit
1049 */
1050 __skb_queue_purge(&sk->sk_write_queue);
1051
1052 sk_stream_wait_close(sk, timeout);
1053
1054adjudge_to_death:
1055 state = sk->sk_state;
1056 sock_hold(sk);
1057 sock_orphan(sk);
1058
1059 /*
1060 * It is the last release_sock in its life. It will remove backlog.
1061 */
1062 release_sock(sk);
1063 /*
1064 * Now socket is owned by kernel and we acquire BH lock
1065 * to finish close. No need to check for user refs.
1066 */
1067 local_bh_disable();
1068 bh_lock_sock(sk);
1069 WARN_ON(sock_owned_by_user(sk));
1070
1071 this_cpu_inc(dccp_orphan_count);
1072
1073 /* Have we already been destroyed by a softirq or backlog? */
1074 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1075 goto out;
1076
1077 if (sk->sk_state == DCCP_CLOSED)
1078 inet_csk_destroy_sock(sk);
1079
1080 /* Otherwise, socket is reprieved until protocol close. */
1081
1082out:
1083 bh_unlock_sock(sk);
1084 local_bh_enable();
1085 sock_put(sk);
1086}
1087
1088EXPORT_SYMBOL_GPL(dccp_close);
1089
1090void dccp_shutdown(struct sock *sk, int how)
1091{
1092 dccp_pr_debug("called shutdown(%x)\n", how);
1093}
1094
1095EXPORT_SYMBOL_GPL(dccp_shutdown);
1096
1097static inline int __init dccp_mib_init(void)
1098{
1099 dccp_statistics = alloc_percpu(struct dccp_mib);
1100 if (!dccp_statistics)
1101 return -ENOMEM;
1102 return 0;
1103}
1104
1105static inline void dccp_mib_exit(void)
1106{
1107 free_percpu(dccp_statistics);
1108}
1109
1110static int thash_entries;
1111module_param(thash_entries, int, 0444);
1112MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1113
1114#ifdef CONFIG_IP_DCCP_DEBUG
1115bool dccp_debug;
1116module_param(dccp_debug, bool, 0644);
1117MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1118
1119EXPORT_SYMBOL_GPL(dccp_debug);
1120#endif
1121
1122static int __init dccp_init(void)
1123{
1124 unsigned long goal;
1125 unsigned long nr_pages = totalram_pages();
1126 int ehash_order, bhash_order, i;
1127 int rc;
1128
1129 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1130 sizeof_field(struct sk_buff, cb));
1131 rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1132 if (rc)
1133 goto out_fail;
1134 rc = -ENOBUFS;
1135 dccp_hashinfo.bind_bucket_cachep =
1136 kmem_cache_create("dccp_bind_bucket",
1137 sizeof(struct inet_bind_bucket), 0,
1138 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1139 if (!dccp_hashinfo.bind_bucket_cachep)
1140 goto out_free_hashinfo2;
1141 dccp_hashinfo.bind2_bucket_cachep =
1142 kmem_cache_create("dccp_bind2_bucket",
1143 sizeof(struct inet_bind2_bucket), 0,
1144 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1145 if (!dccp_hashinfo.bind2_bucket_cachep)
1146 goto out_free_bind_bucket_cachep;
1147
1148 /*
1149 * Size and allocate the main established and bind bucket
1150 * hash tables.
1151 *
1152 * The methodology is similar to that of the buffer cache.
1153 */
1154 if (nr_pages >= (128 * 1024))
1155 goal = nr_pages >> (21 - PAGE_SHIFT);
1156 else
1157 goal = nr_pages >> (23 - PAGE_SHIFT);
1158
1159 if (thash_entries)
1160 goal = (thash_entries *
1161 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1162 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1163 ;
1164 do {
1165 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1166 sizeof(struct inet_ehash_bucket);
1167
1168 while (hash_size & (hash_size - 1))
1169 hash_size--;
1170 dccp_hashinfo.ehash_mask = hash_size - 1;
1171 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1172 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1173 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1174
1175 if (!dccp_hashinfo.ehash) {
1176 DCCP_CRIT("Failed to allocate DCCP established hash table");
1177 goto out_free_bind2_bucket_cachep;
1178 }
1179
1180 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1181 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1182
1183 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1184 goto out_free_dccp_ehash;
1185
1186 bhash_order = ehash_order;
1187
1188 do {
1189 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1190 sizeof(struct inet_bind_hashbucket);
1191 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1192 bhash_order > 0)
1193 continue;
1194 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1195 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1196 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1197
1198 if (!dccp_hashinfo.bhash) {
1199 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1200 goto out_free_dccp_locks;
1201 }
1202
1203 dccp_hashinfo.bhash2 = (struct inet_bind_hashbucket *)
1204 __get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order);
1205
1206 if (!dccp_hashinfo.bhash2) {
1207 DCCP_CRIT("Failed to allocate DCCP bind2 hash table");
1208 goto out_free_dccp_bhash;
1209 }
1210
1211 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1212 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1213 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1214 spin_lock_init(&dccp_hashinfo.bhash2[i].lock);
1215 INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain);
1216 }
1217
1218 dccp_hashinfo.pernet = false;
1219
1220 rc = dccp_mib_init();
1221 if (rc)
1222 goto out_free_dccp_bhash2;
1223
1224 rc = dccp_ackvec_init();
1225 if (rc)
1226 goto out_free_dccp_mib;
1227
1228 rc = dccp_sysctl_init();
1229 if (rc)
1230 goto out_ackvec_exit;
1231
1232 rc = ccid_initialize_builtins();
1233 if (rc)
1234 goto out_sysctl_exit;
1235
1236 dccp_timestamping_init();
1237
1238 return 0;
1239
1240out_sysctl_exit:
1241 dccp_sysctl_exit();
1242out_ackvec_exit:
1243 dccp_ackvec_exit();
1244out_free_dccp_mib:
1245 dccp_mib_exit();
1246out_free_dccp_bhash2:
1247 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1248out_free_dccp_bhash:
1249 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1250out_free_dccp_locks:
1251 inet_ehash_locks_free(&dccp_hashinfo);
1252out_free_dccp_ehash:
1253 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1254out_free_bind2_bucket_cachep:
1255 kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
1256out_free_bind_bucket_cachep:
1257 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1258out_free_hashinfo2:
1259 inet_hashinfo2_free_mod(&dccp_hashinfo);
1260out_fail:
1261 dccp_hashinfo.bhash = NULL;
1262 dccp_hashinfo.bhash2 = NULL;
1263 dccp_hashinfo.ehash = NULL;
1264 dccp_hashinfo.bind_bucket_cachep = NULL;
1265 dccp_hashinfo.bind2_bucket_cachep = NULL;
1266 return rc;
1267}
1268
1269static void __exit dccp_fini(void)
1270{
1271 int bhash_order = get_order(dccp_hashinfo.bhash_size *
1272 sizeof(struct inet_bind_hashbucket));
1273
1274 ccid_cleanup_builtins();
1275 dccp_mib_exit();
1276 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1277 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1278 free_pages((unsigned long)dccp_hashinfo.ehash,
1279 get_order((dccp_hashinfo.ehash_mask + 1) *
1280 sizeof(struct inet_ehash_bucket)));
1281 inet_ehash_locks_free(&dccp_hashinfo);
1282 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1283 dccp_ackvec_exit();
1284 dccp_sysctl_exit();
1285 inet_hashinfo2_free_mod(&dccp_hashinfo);
1286}
1287
1288module_init(dccp_init);
1289module_exit(dccp_fini);
1290
1291MODULE_LICENSE("GPL");
1292MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1293MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");