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
41 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
42
43 EXPORT_SYMBOL_GPL(dccp_statistics);
44
45 DEFINE_PER_CPU(unsigned int, dccp_orphan_count);
46 EXPORT_PER_CPU_SYMBOL_GPL(dccp_orphan_count);
47
48 struct inet_hashinfo dccp_hashinfo;
49 EXPORT_SYMBOL_GPL(dccp_hashinfo);
50
51 /* the maximum queue length for tx in packets. 0 is no limit */
52 int sysctl_dccp_tx_qlen __read_mostly = 5;
53
54 #ifdef CONFIG_IP_DCCP_DEBUG
55 static 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
78 void 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
116 EXPORT_SYMBOL_GPL(dccp_set_state);
117
118 static 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
136 void 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
149 EXPORT_SYMBOL_GPL(dccp_done);
150
151 const 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
172 EXPORT_SYMBOL_GPL(dccp_packet_name);
173
174 void 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 }
181 EXPORT_SYMBOL_GPL(dccp_destruct_common);
182
183 static void dccp_sk_destruct(struct sock *sk)
184 {
185 dccp_destruct_common(sk);
186 inet_sock_destruct(sk);
187 }
188
189 int 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
218 EXPORT_SYMBOL_GPL(dccp_init_sock);
219
220 void 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
248 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
249
250 static inline int dccp_need_reset(int state)
251 {
252 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
253 state != DCCP_REQUESTING;
254 }
255
256 int 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
306 EXPORT_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 }
367 EXPORT_SYMBOL_GPL(dccp_poll);
368
369 int 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 }
407 out:
408 release_sock(sk);
409 return rc;
410 }
411
412 EXPORT_SYMBOL_GPL(dccp_ioctl);
413
414 static 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
448 static 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
484 static 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
509 static 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
575 int 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
585 EXPORT_SYMBOL_GPL(dccp_setsockopt);
586
587 static 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;
610 out:
611 release_sock(sk);
612 return err;
613 }
614
615 static 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
683 int 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
693 EXPORT_SYMBOL_GPL(dccp_getsockopt);
694
695 static 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
735 int 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);
802 out_release:
803 release_sock(sk);
804 return rc ? : len;
805 out_discard:
806 kfree_skb(skb);
807 goto out_release;
808 }
809
810 EXPORT_SYMBOL_GPL(dccp_sendmsg);
811
812 int 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 }
855 verify_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);
913 out:
914 release_sock(sk);
915 return len;
916 }
917
918 EXPORT_SYMBOL_GPL(dccp_recvmsg);
919
920 int 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
957 out:
958 release_sock(sk);
959 return err;
960 }
961
962 EXPORT_SYMBOL_GPL(inet_dccp_listen);
963
964 static 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
991 void 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
1054 adjudge_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
1082 out:
1083 bh_unlock_sock(sk);
1084 local_bh_enable();
1085 sock_put(sk);
1086 }
1087
1088 EXPORT_SYMBOL_GPL(dccp_close);
1089
1090 void dccp_shutdown(struct sock *sk, int how)
1091 {
1092 dccp_pr_debug("called shutdown(%x)\n", how);
1093 }
1094
1095 EXPORT_SYMBOL_GPL(dccp_shutdown);
1096
1097 static 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
1105 static inline void dccp_mib_exit(void)
1106 {
1107 free_percpu(dccp_statistics);
1108 }
1109
1110 static int thash_entries;
1111 module_param(thash_entries, int, 0444);
1112 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1113
1114 #ifdef CONFIG_IP_DCCP_DEBUG
1115 bool dccp_debug;
1116 module_param(dccp_debug, bool, 0644);
1117 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1118
1119 EXPORT_SYMBOL_GPL(dccp_debug);
1120 #endif
1121
1122 static 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
1240 out_sysctl_exit:
1241 dccp_sysctl_exit();
1242 out_ackvec_exit:
1243 dccp_ackvec_exit();
1244 out_free_dccp_mib:
1245 dccp_mib_exit();
1246 out_free_dccp_bhash2:
1247 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1248 out_free_dccp_bhash:
1249 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1250 out_free_dccp_locks:
1251 inet_ehash_locks_free(&dccp_hashinfo);
1252 out_free_dccp_ehash:
1253 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1254 out_free_bind2_bucket_cachep:
1255 kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
1256 out_free_bind_bucket_cachep:
1257 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1258 out_free_hashinfo2:
1259 inet_hashinfo2_free_mod(&dccp_hashinfo);
1260 out_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
1269 static 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
1288 module_init(dccp_init);
1289 module_exit(dccp_fini);
1290
1291 MODULE_LICENSE("GPL");
1292 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1293 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
1294
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