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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");
1/*
2 * net/dccp/proto.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/dccp.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/skbuff.h>
18#include <linux/netdevice.h>
19#include <linux/in.h>
20#include <linux/if_arp.h>
21#include <linux/init.h>
22#include <linux/random.h>
23#include <linux/slab.h>
24#include <net/checksum.h>
25
26#include <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/xfrm.h>
29
30#include <asm/ioctls.h>
31#include <linux/spinlock.h>
32#include <linux/timer.h>
33#include <linux/delay.h>
34#include <linux/poll.h>
35
36#include "ccid.h"
37#include "dccp.h"
38#include "feat.h"
39
40DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
41
42EXPORT_SYMBOL_GPL(dccp_statistics);
43
44struct percpu_counter dccp_orphan_count;
45EXPORT_SYMBOL_GPL(dccp_orphan_count);
46
47struct inet_hashinfo dccp_hashinfo;
48EXPORT_SYMBOL_GPL(dccp_hashinfo);
49
50/* the maximum queue length for tx in packets. 0 is no limit */
51int sysctl_dccp_tx_qlen __read_mostly = 5;
52
53#ifdef CONFIG_IP_DCCP_DEBUG
54static const char *dccp_state_name(const int state)
55{
56 static const char *const dccp_state_names[] = {
57 [DCCP_OPEN] = "OPEN",
58 [DCCP_REQUESTING] = "REQUESTING",
59 [DCCP_PARTOPEN] = "PARTOPEN",
60 [DCCP_LISTEN] = "LISTEN",
61 [DCCP_RESPOND] = "RESPOND",
62 [DCCP_CLOSING] = "CLOSING",
63 [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ",
64 [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE",
65 [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ",
66 [DCCP_TIME_WAIT] = "TIME_WAIT",
67 [DCCP_CLOSED] = "CLOSED",
68 };
69
70 if (state >= DCCP_MAX_STATES)
71 return "INVALID STATE!";
72 else
73 return dccp_state_names[state];
74}
75#endif
76
77void dccp_set_state(struct sock *sk, const int state)
78{
79 const int oldstate = sk->sk_state;
80
81 dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk,
82 dccp_state_name(oldstate), dccp_state_name(state));
83 WARN_ON(state == oldstate);
84
85 switch (state) {
86 case DCCP_OPEN:
87 if (oldstate != DCCP_OPEN)
88 DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
89 /* Client retransmits all Confirm options until entering OPEN */
90 if (oldstate == DCCP_PARTOPEN)
91 dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
92 break;
93
94 case DCCP_CLOSED:
95 if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
96 oldstate == DCCP_CLOSING)
97 DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);
98
99 sk->sk_prot->unhash(sk);
100 if (inet_csk(sk)->icsk_bind_hash != NULL &&
101 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
102 inet_put_port(sk);
103 /* fall through */
104 default:
105 if (oldstate == DCCP_OPEN)
106 DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
107 }
108
109 /* Change state AFTER socket is unhashed to avoid closed
110 * socket sitting in hash tables.
111 */
112 sk->sk_state = state;
113}
114
115EXPORT_SYMBOL_GPL(dccp_set_state);
116
117static void dccp_finish_passive_close(struct sock *sk)
118{
119 switch (sk->sk_state) {
120 case DCCP_PASSIVE_CLOSE:
121 /* Node (client or server) has received Close packet. */
122 dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
123 dccp_set_state(sk, DCCP_CLOSED);
124 break;
125 case DCCP_PASSIVE_CLOSEREQ:
126 /*
127 * Client received CloseReq. We set the `active' flag so that
128 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
129 */
130 dccp_send_close(sk, 1);
131 dccp_set_state(sk, DCCP_CLOSING);
132 }
133}
134
135void dccp_done(struct sock *sk)
136{
137 dccp_set_state(sk, DCCP_CLOSED);
138 dccp_clear_xmit_timers(sk);
139
140 sk->sk_shutdown = SHUTDOWN_MASK;
141
142 if (!sock_flag(sk, SOCK_DEAD))
143 sk->sk_state_change(sk);
144 else
145 inet_csk_destroy_sock(sk);
146}
147
148EXPORT_SYMBOL_GPL(dccp_done);
149
150const char *dccp_packet_name(const int type)
151{
152 static const char *const dccp_packet_names[] = {
153 [DCCP_PKT_REQUEST] = "REQUEST",
154 [DCCP_PKT_RESPONSE] = "RESPONSE",
155 [DCCP_PKT_DATA] = "DATA",
156 [DCCP_PKT_ACK] = "ACK",
157 [DCCP_PKT_DATAACK] = "DATAACK",
158 [DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
159 [DCCP_PKT_CLOSE] = "CLOSE",
160 [DCCP_PKT_RESET] = "RESET",
161 [DCCP_PKT_SYNC] = "SYNC",
162 [DCCP_PKT_SYNCACK] = "SYNCACK",
163 };
164
165 if (type >= DCCP_NR_PKT_TYPES)
166 return "INVALID";
167 else
168 return dccp_packet_names[type];
169}
170
171EXPORT_SYMBOL_GPL(dccp_packet_name);
172
173int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
174{
175 struct dccp_sock *dp = dccp_sk(sk);
176 struct inet_connection_sock *icsk = inet_csk(sk);
177
178 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
179 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
180 sk->sk_state = DCCP_CLOSED;
181 sk->sk_write_space = dccp_write_space;
182 icsk->icsk_sync_mss = dccp_sync_mss;
183 dp->dccps_mss_cache = 536;
184 dp->dccps_rate_last = jiffies;
185 dp->dccps_role = DCCP_ROLE_UNDEFINED;
186 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
187 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
188
189 dccp_init_xmit_timers(sk);
190
191 INIT_LIST_HEAD(&dp->dccps_featneg);
192 /* control socket doesn't need feat nego */
193 if (likely(ctl_sock_initialized))
194 return dccp_feat_init(sk);
195 return 0;
196}
197
198EXPORT_SYMBOL_GPL(dccp_init_sock);
199
200void dccp_destroy_sock(struct sock *sk)
201{
202 struct dccp_sock *dp = dccp_sk(sk);
203
204 /*
205 * DCCP doesn't use sk_write_queue, just sk_send_head
206 * for retransmissions
207 */
208 if (sk->sk_send_head != NULL) {
209 kfree_skb(sk->sk_send_head);
210 sk->sk_send_head = NULL;
211 }
212
213 /* Clean up a referenced DCCP bind bucket. */
214 if (inet_csk(sk)->icsk_bind_hash != NULL)
215 inet_put_port(sk);
216
217 kfree(dp->dccps_service_list);
218 dp->dccps_service_list = NULL;
219
220 if (dp->dccps_hc_rx_ackvec != NULL) {
221 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
222 dp->dccps_hc_rx_ackvec = NULL;
223 }
224 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
225 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
226 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
227
228 /* clean up feature negotiation state */
229 dccp_feat_list_purge(&dp->dccps_featneg);
230}
231
232EXPORT_SYMBOL_GPL(dccp_destroy_sock);
233
234static inline int dccp_listen_start(struct sock *sk, int backlog)
235{
236 struct dccp_sock *dp = dccp_sk(sk);
237
238 dp->dccps_role = DCCP_ROLE_LISTEN;
239 /* do not start to listen if feature negotiation setup fails */
240 if (dccp_feat_finalise_settings(dp))
241 return -EPROTO;
242 return inet_csk_listen_start(sk, backlog);
243}
244
245static inline int dccp_need_reset(int state)
246{
247 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
248 state != DCCP_REQUESTING;
249}
250
251int dccp_disconnect(struct sock *sk, int flags)
252{
253 struct inet_connection_sock *icsk = inet_csk(sk);
254 struct inet_sock *inet = inet_sk(sk);
255 int err = 0;
256 const int old_state = sk->sk_state;
257
258 if (old_state != DCCP_CLOSED)
259 dccp_set_state(sk, DCCP_CLOSED);
260
261 /*
262 * This corresponds to the ABORT function of RFC793, sec. 3.8
263 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
264 */
265 if (old_state == DCCP_LISTEN) {
266 inet_csk_listen_stop(sk);
267 } else if (dccp_need_reset(old_state)) {
268 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
269 sk->sk_err = ECONNRESET;
270 } else if (old_state == DCCP_REQUESTING)
271 sk->sk_err = ECONNRESET;
272
273 dccp_clear_xmit_timers(sk);
274
275 __skb_queue_purge(&sk->sk_receive_queue);
276 __skb_queue_purge(&sk->sk_write_queue);
277 if (sk->sk_send_head != NULL) {
278 __kfree_skb(sk->sk_send_head);
279 sk->sk_send_head = NULL;
280 }
281
282 inet->inet_dport = 0;
283
284 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
285 inet_reset_saddr(sk);
286
287 sk->sk_shutdown = 0;
288 sock_reset_flag(sk, SOCK_DONE);
289
290 icsk->icsk_backoff = 0;
291 inet_csk_delack_init(sk);
292 __sk_dst_reset(sk);
293
294 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
295
296 sk->sk_error_report(sk);
297 return err;
298}
299
300EXPORT_SYMBOL_GPL(dccp_disconnect);
301
302/*
303 * Wait for a DCCP event.
304 *
305 * Note that we don't need to lock the socket, as the upper poll layers
306 * take care of normal races (between the test and the event) and we don't
307 * go look at any of the socket buffers directly.
308 */
309unsigned int dccp_poll(struct file *file, struct socket *sock,
310 poll_table *wait)
311{
312 unsigned int mask;
313 struct sock *sk = sock->sk;
314
315 sock_poll_wait(file, sk_sleep(sk), wait);
316 if (sk->sk_state == DCCP_LISTEN)
317 return inet_csk_listen_poll(sk);
318
319 /* Socket is not locked. We are protected from async events
320 by poll logic and correct handling of state changes
321 made by another threads is impossible in any case.
322 */
323
324 mask = 0;
325 if (sk->sk_err)
326 mask = POLLERR;
327
328 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
329 mask |= POLLHUP;
330 if (sk->sk_shutdown & RCV_SHUTDOWN)
331 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
332
333 /* Connected? */
334 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
335 if (atomic_read(&sk->sk_rmem_alloc) > 0)
336 mask |= POLLIN | POLLRDNORM;
337
338 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
339 if (sk_stream_is_writeable(sk)) {
340 mask |= POLLOUT | POLLWRNORM;
341 } else { /* send SIGIO later */
342 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
343 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
344
345 /* Race breaker. If space is freed after
346 * wspace test but before the flags are set,
347 * IO signal will be lost.
348 */
349 if (sk_stream_is_writeable(sk))
350 mask |= POLLOUT | POLLWRNORM;
351 }
352 }
353 }
354 return mask;
355}
356
357EXPORT_SYMBOL_GPL(dccp_poll);
358
359int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
360{
361 int rc = -ENOTCONN;
362
363 lock_sock(sk);
364
365 if (sk->sk_state == DCCP_LISTEN)
366 goto out;
367
368 switch (cmd) {
369 case SIOCINQ: {
370 struct sk_buff *skb;
371 unsigned long amount = 0;
372
373 skb = skb_peek(&sk->sk_receive_queue);
374 if (skb != NULL) {
375 /*
376 * We will only return the amount of this packet since
377 * that is all that will be read.
378 */
379 amount = skb->len;
380 }
381 rc = put_user(amount, (int __user *)arg);
382 }
383 break;
384 default:
385 rc = -ENOIOCTLCMD;
386 break;
387 }
388out:
389 release_sock(sk);
390 return rc;
391}
392
393EXPORT_SYMBOL_GPL(dccp_ioctl);
394
395static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
396 char __user *optval, unsigned int optlen)
397{
398 struct dccp_sock *dp = dccp_sk(sk);
399 struct dccp_service_list *sl = NULL;
400
401 if (service == DCCP_SERVICE_INVALID_VALUE ||
402 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
403 return -EINVAL;
404
405 if (optlen > sizeof(service)) {
406 sl = kmalloc(optlen, GFP_KERNEL);
407 if (sl == NULL)
408 return -ENOMEM;
409
410 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
411 if (copy_from_user(sl->dccpsl_list,
412 optval + sizeof(service),
413 optlen - sizeof(service)) ||
414 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
415 kfree(sl);
416 return -EFAULT;
417 }
418 }
419
420 lock_sock(sk);
421 dp->dccps_service = service;
422
423 kfree(dp->dccps_service_list);
424
425 dp->dccps_service_list = sl;
426 release_sock(sk);
427 return 0;
428}
429
430static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
431{
432 u8 *list, len;
433 int i, rc;
434
435 if (cscov < 0 || cscov > 15)
436 return -EINVAL;
437 /*
438 * Populate a list of permissible values, in the range cscov...15. This
439 * is necessary since feature negotiation of single values only works if
440 * both sides incidentally choose the same value. Since the list starts
441 * lowest-value first, negotiation will pick the smallest shared value.
442 */
443 if (cscov == 0)
444 return 0;
445 len = 16 - cscov;
446
447 list = kmalloc(len, GFP_KERNEL);
448 if (list == NULL)
449 return -ENOBUFS;
450
451 for (i = 0; i < len; i++)
452 list[i] = cscov++;
453
454 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
455
456 if (rc == 0) {
457 if (rx)
458 dccp_sk(sk)->dccps_pcrlen = cscov;
459 else
460 dccp_sk(sk)->dccps_pcslen = cscov;
461 }
462 kfree(list);
463 return rc;
464}
465
466static int dccp_setsockopt_ccid(struct sock *sk, int type,
467 char __user *optval, unsigned int optlen)
468{
469 u8 *val;
470 int rc = 0;
471
472 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
473 return -EINVAL;
474
475 val = memdup_user(optval, optlen);
476 if (IS_ERR(val))
477 return PTR_ERR(val);
478
479 lock_sock(sk);
480 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
481 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
482
483 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
484 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
485 release_sock(sk);
486
487 kfree(val);
488 return rc;
489}
490
491static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
492 char __user *optval, unsigned int optlen)
493{
494 struct dccp_sock *dp = dccp_sk(sk);
495 int val, err = 0;
496
497 switch (optname) {
498 case DCCP_SOCKOPT_PACKET_SIZE:
499 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
500 return 0;
501 case DCCP_SOCKOPT_CHANGE_L:
502 case DCCP_SOCKOPT_CHANGE_R:
503 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
504 return 0;
505 case DCCP_SOCKOPT_CCID:
506 case DCCP_SOCKOPT_RX_CCID:
507 case DCCP_SOCKOPT_TX_CCID:
508 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
509 }
510
511 if (optlen < (int)sizeof(int))
512 return -EINVAL;
513
514 if (get_user(val, (int __user *)optval))
515 return -EFAULT;
516
517 if (optname == DCCP_SOCKOPT_SERVICE)
518 return dccp_setsockopt_service(sk, val, optval, optlen);
519
520 lock_sock(sk);
521 switch (optname) {
522 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
523 if (dp->dccps_role != DCCP_ROLE_SERVER)
524 err = -EOPNOTSUPP;
525 else
526 dp->dccps_server_timewait = (val != 0);
527 break;
528 case DCCP_SOCKOPT_SEND_CSCOV:
529 err = dccp_setsockopt_cscov(sk, val, false);
530 break;
531 case DCCP_SOCKOPT_RECV_CSCOV:
532 err = dccp_setsockopt_cscov(sk, val, true);
533 break;
534 case DCCP_SOCKOPT_QPOLICY_ID:
535 if (sk->sk_state != DCCP_CLOSED)
536 err = -EISCONN;
537 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
538 err = -EINVAL;
539 else
540 dp->dccps_qpolicy = val;
541 break;
542 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
543 if (val < 0)
544 err = -EINVAL;
545 else
546 dp->dccps_tx_qlen = val;
547 break;
548 default:
549 err = -ENOPROTOOPT;
550 break;
551 }
552 release_sock(sk);
553
554 return err;
555}
556
557int dccp_setsockopt(struct sock *sk, int level, int optname,
558 char __user *optval, unsigned int optlen)
559{
560 if (level != SOL_DCCP)
561 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
562 optname, optval,
563 optlen);
564 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
565}
566
567EXPORT_SYMBOL_GPL(dccp_setsockopt);
568
569#ifdef CONFIG_COMPAT
570int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
571 char __user *optval, unsigned int optlen)
572{
573 if (level != SOL_DCCP)
574 return inet_csk_compat_setsockopt(sk, level, optname,
575 optval, optlen);
576 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
577}
578
579EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
580#endif
581
582static int dccp_getsockopt_service(struct sock *sk, int len,
583 __be32 __user *optval,
584 int __user *optlen)
585{
586 const struct dccp_sock *dp = dccp_sk(sk);
587 const struct dccp_service_list *sl;
588 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
589
590 lock_sock(sk);
591 if ((sl = dp->dccps_service_list) != NULL) {
592 slen = sl->dccpsl_nr * sizeof(u32);
593 total_len += slen;
594 }
595
596 err = -EINVAL;
597 if (total_len > len)
598 goto out;
599
600 err = 0;
601 if (put_user(total_len, optlen) ||
602 put_user(dp->dccps_service, optval) ||
603 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
604 err = -EFAULT;
605out:
606 release_sock(sk);
607 return err;
608}
609
610static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
611 char __user *optval, int __user *optlen)
612{
613 struct dccp_sock *dp;
614 int val, len;
615
616 if (get_user(len, optlen))
617 return -EFAULT;
618
619 if (len < (int)sizeof(int))
620 return -EINVAL;
621
622 dp = dccp_sk(sk);
623
624 switch (optname) {
625 case DCCP_SOCKOPT_PACKET_SIZE:
626 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
627 return 0;
628 case DCCP_SOCKOPT_SERVICE:
629 return dccp_getsockopt_service(sk, len,
630 (__be32 __user *)optval, optlen);
631 case DCCP_SOCKOPT_GET_CUR_MPS:
632 val = dp->dccps_mss_cache;
633 break;
634 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
635 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
636 case DCCP_SOCKOPT_TX_CCID:
637 val = ccid_get_current_tx_ccid(dp);
638 if (val < 0)
639 return -ENOPROTOOPT;
640 break;
641 case DCCP_SOCKOPT_RX_CCID:
642 val = ccid_get_current_rx_ccid(dp);
643 if (val < 0)
644 return -ENOPROTOOPT;
645 break;
646 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
647 val = dp->dccps_server_timewait;
648 break;
649 case DCCP_SOCKOPT_SEND_CSCOV:
650 val = dp->dccps_pcslen;
651 break;
652 case DCCP_SOCKOPT_RECV_CSCOV:
653 val = dp->dccps_pcrlen;
654 break;
655 case DCCP_SOCKOPT_QPOLICY_ID:
656 val = dp->dccps_qpolicy;
657 break;
658 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
659 val = dp->dccps_tx_qlen;
660 break;
661 case 128 ... 191:
662 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
663 len, (u32 __user *)optval, optlen);
664 case 192 ... 255:
665 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
666 len, (u32 __user *)optval, optlen);
667 default:
668 return -ENOPROTOOPT;
669 }
670
671 len = sizeof(val);
672 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
673 return -EFAULT;
674
675 return 0;
676}
677
678int dccp_getsockopt(struct sock *sk, int level, int optname,
679 char __user *optval, int __user *optlen)
680{
681 if (level != SOL_DCCP)
682 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
683 optname, optval,
684 optlen);
685 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
686}
687
688EXPORT_SYMBOL_GPL(dccp_getsockopt);
689
690#ifdef CONFIG_COMPAT
691int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
692 char __user *optval, int __user *optlen)
693{
694 if (level != SOL_DCCP)
695 return inet_csk_compat_getsockopt(sk, level, optname,
696 optval, optlen);
697 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
698}
699
700EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
701#endif
702
703static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
704{
705 struct cmsghdr *cmsg;
706
707 /*
708 * Assign an (opaque) qpolicy priority value to skb->priority.
709 *
710 * We are overloading this skb field for use with the qpolicy subystem.
711 * The skb->priority is normally used for the SO_PRIORITY option, which
712 * is initialised from sk_priority. Since the assignment of sk_priority
713 * to skb->priority happens later (on layer 3), we overload this field
714 * for use with queueing priorities as long as the skb is on layer 4.
715 * The default priority value (if nothing is set) is 0.
716 */
717 skb->priority = 0;
718
719 for_each_cmsghdr(cmsg, msg) {
720 if (!CMSG_OK(msg, cmsg))
721 return -EINVAL;
722
723 if (cmsg->cmsg_level != SOL_DCCP)
724 continue;
725
726 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
727 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
728 return -EINVAL;
729
730 switch (cmsg->cmsg_type) {
731 case DCCP_SCM_PRIORITY:
732 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
733 return -EINVAL;
734 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
735 break;
736 default:
737 return -EINVAL;
738 }
739 }
740 return 0;
741}
742
743int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
744{
745 const struct dccp_sock *dp = dccp_sk(sk);
746 const int flags = msg->msg_flags;
747 const int noblock = flags & MSG_DONTWAIT;
748 struct sk_buff *skb;
749 int rc, size;
750 long timeo;
751
752 if (len > dp->dccps_mss_cache)
753 return -EMSGSIZE;
754
755 lock_sock(sk);
756
757 if (dccp_qpolicy_full(sk)) {
758 rc = -EAGAIN;
759 goto out_release;
760 }
761
762 timeo = sock_sndtimeo(sk, noblock);
763
764 /*
765 * We have to use sk_stream_wait_connect here to set sk_write_pending,
766 * so that the trick in dccp_rcv_request_sent_state_process.
767 */
768 /* Wait for a connection to finish. */
769 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
770 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
771 goto out_release;
772
773 size = sk->sk_prot->max_header + len;
774 release_sock(sk);
775 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
776 lock_sock(sk);
777 if (skb == NULL)
778 goto out_release;
779
780 skb_reserve(skb, sk->sk_prot->max_header);
781 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
782 if (rc != 0)
783 goto out_discard;
784
785 rc = dccp_msghdr_parse(msg, skb);
786 if (rc != 0)
787 goto out_discard;
788
789 dccp_qpolicy_push(sk, skb);
790 /*
791 * The xmit_timer is set if the TX CCID is rate-based and will expire
792 * when congestion control permits to release further packets into the
793 * network. Window-based CCIDs do not use this timer.
794 */
795 if (!timer_pending(&dp->dccps_xmit_timer))
796 dccp_write_xmit(sk);
797out_release:
798 release_sock(sk);
799 return rc ? : len;
800out_discard:
801 kfree_skb(skb);
802 goto out_release;
803}
804
805EXPORT_SYMBOL_GPL(dccp_sendmsg);
806
807int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
808 int flags, int *addr_len)
809{
810 const struct dccp_hdr *dh;
811 long timeo;
812
813 lock_sock(sk);
814
815 if (sk->sk_state == DCCP_LISTEN) {
816 len = -ENOTCONN;
817 goto out;
818 }
819
820 timeo = sock_rcvtimeo(sk, nonblock);
821
822 do {
823 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
824
825 if (skb == NULL)
826 goto verify_sock_status;
827
828 dh = dccp_hdr(skb);
829
830 switch (dh->dccph_type) {
831 case DCCP_PKT_DATA:
832 case DCCP_PKT_DATAACK:
833 goto found_ok_skb;
834
835 case DCCP_PKT_CLOSE:
836 case DCCP_PKT_CLOSEREQ:
837 if (!(flags & MSG_PEEK))
838 dccp_finish_passive_close(sk);
839 /* fall through */
840 case DCCP_PKT_RESET:
841 dccp_pr_debug("found fin (%s) ok!\n",
842 dccp_packet_name(dh->dccph_type));
843 len = 0;
844 goto found_fin_ok;
845 default:
846 dccp_pr_debug("packet_type=%s\n",
847 dccp_packet_name(dh->dccph_type));
848 sk_eat_skb(sk, skb);
849 }
850verify_sock_status:
851 if (sock_flag(sk, SOCK_DONE)) {
852 len = 0;
853 break;
854 }
855
856 if (sk->sk_err) {
857 len = sock_error(sk);
858 break;
859 }
860
861 if (sk->sk_shutdown & RCV_SHUTDOWN) {
862 len = 0;
863 break;
864 }
865
866 if (sk->sk_state == DCCP_CLOSED) {
867 if (!sock_flag(sk, SOCK_DONE)) {
868 /* This occurs when user tries to read
869 * from never connected socket.
870 */
871 len = -ENOTCONN;
872 break;
873 }
874 len = 0;
875 break;
876 }
877
878 if (!timeo) {
879 len = -EAGAIN;
880 break;
881 }
882
883 if (signal_pending(current)) {
884 len = sock_intr_errno(timeo);
885 break;
886 }
887
888 sk_wait_data(sk, &timeo, NULL);
889 continue;
890 found_ok_skb:
891 if (len > skb->len)
892 len = skb->len;
893 else if (len < skb->len)
894 msg->msg_flags |= MSG_TRUNC;
895
896 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
897 /* Exception. Bailout! */
898 len = -EFAULT;
899 break;
900 }
901 if (flags & MSG_TRUNC)
902 len = skb->len;
903 found_fin_ok:
904 if (!(flags & MSG_PEEK))
905 sk_eat_skb(sk, skb);
906 break;
907 } while (1);
908out:
909 release_sock(sk);
910 return len;
911}
912
913EXPORT_SYMBOL_GPL(dccp_recvmsg);
914
915int inet_dccp_listen(struct socket *sock, int backlog)
916{
917 struct sock *sk = sock->sk;
918 unsigned char old_state;
919 int err;
920
921 lock_sock(sk);
922
923 err = -EINVAL;
924 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
925 goto out;
926
927 old_state = sk->sk_state;
928 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
929 goto out;
930
931 /* Really, if the socket is already in listen state
932 * we can only allow the backlog to be adjusted.
933 */
934 if (old_state != DCCP_LISTEN) {
935 /*
936 * FIXME: here it probably should be sk->sk_prot->listen_start
937 * see tcp_listen_start
938 */
939 err = dccp_listen_start(sk, backlog);
940 if (err)
941 goto out;
942 }
943 sk->sk_max_ack_backlog = backlog;
944 err = 0;
945
946out:
947 release_sock(sk);
948 return err;
949}
950
951EXPORT_SYMBOL_GPL(inet_dccp_listen);
952
953static void dccp_terminate_connection(struct sock *sk)
954{
955 u8 next_state = DCCP_CLOSED;
956
957 switch (sk->sk_state) {
958 case DCCP_PASSIVE_CLOSE:
959 case DCCP_PASSIVE_CLOSEREQ:
960 dccp_finish_passive_close(sk);
961 break;
962 case DCCP_PARTOPEN:
963 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
964 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
965 /* fall through */
966 case DCCP_OPEN:
967 dccp_send_close(sk, 1);
968
969 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
970 !dccp_sk(sk)->dccps_server_timewait)
971 next_state = DCCP_ACTIVE_CLOSEREQ;
972 else
973 next_state = DCCP_CLOSING;
974 /* fall through */
975 default:
976 dccp_set_state(sk, next_state);
977 }
978}
979
980void dccp_close(struct sock *sk, long timeout)
981{
982 struct dccp_sock *dp = dccp_sk(sk);
983 struct sk_buff *skb;
984 u32 data_was_unread = 0;
985 int state;
986
987 lock_sock(sk);
988
989 sk->sk_shutdown = SHUTDOWN_MASK;
990
991 if (sk->sk_state == DCCP_LISTEN) {
992 dccp_set_state(sk, DCCP_CLOSED);
993
994 /* Special case. */
995 inet_csk_listen_stop(sk);
996
997 goto adjudge_to_death;
998 }
999
1000 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1001
1002 /*
1003 * We need to flush the recv. buffs. We do this only on the
1004 * descriptor close, not protocol-sourced closes, because the
1005 *reader process may not have drained the data yet!
1006 */
1007 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1008 data_was_unread += skb->len;
1009 __kfree_skb(skb);
1010 }
1011
1012 if (data_was_unread) {
1013 /* Unread data was tossed, send an appropriate Reset Code */
1014 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1015 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1016 dccp_set_state(sk, DCCP_CLOSED);
1017 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1018 /* Check zero linger _after_ checking for unread data. */
1019 sk->sk_prot->disconnect(sk, 0);
1020 } else if (sk->sk_state != DCCP_CLOSED) {
1021 /*
1022 * Normal connection termination. May need to wait if there are
1023 * still packets in the TX queue that are delayed by the CCID.
1024 */
1025 dccp_flush_write_queue(sk, &timeout);
1026 dccp_terminate_connection(sk);
1027 }
1028
1029 /*
1030 * Flush write queue. This may be necessary in several cases:
1031 * - we have been closed by the peer but still have application data;
1032 * - abortive termination (unread data or zero linger time),
1033 * - normal termination but queue could not be flushed within time limit
1034 */
1035 __skb_queue_purge(&sk->sk_write_queue);
1036
1037 sk_stream_wait_close(sk, timeout);
1038
1039adjudge_to_death:
1040 state = sk->sk_state;
1041 sock_hold(sk);
1042 sock_orphan(sk);
1043
1044 /*
1045 * It is the last release_sock in its life. It will remove backlog.
1046 */
1047 release_sock(sk);
1048 /*
1049 * Now socket is owned by kernel and we acquire BH lock
1050 * to finish close. No need to check for user refs.
1051 */
1052 local_bh_disable();
1053 bh_lock_sock(sk);
1054 WARN_ON(sock_owned_by_user(sk));
1055
1056 percpu_counter_inc(sk->sk_prot->orphan_count);
1057
1058 /* Have we already been destroyed by a softirq or backlog? */
1059 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1060 goto out;
1061
1062 if (sk->sk_state == DCCP_CLOSED)
1063 inet_csk_destroy_sock(sk);
1064
1065 /* Otherwise, socket is reprieved until protocol close. */
1066
1067out:
1068 bh_unlock_sock(sk);
1069 local_bh_enable();
1070 sock_put(sk);
1071}
1072
1073EXPORT_SYMBOL_GPL(dccp_close);
1074
1075void dccp_shutdown(struct sock *sk, int how)
1076{
1077 dccp_pr_debug("called shutdown(%x)\n", how);
1078}
1079
1080EXPORT_SYMBOL_GPL(dccp_shutdown);
1081
1082static inline int __init dccp_mib_init(void)
1083{
1084 dccp_statistics = alloc_percpu(struct dccp_mib);
1085 if (!dccp_statistics)
1086 return -ENOMEM;
1087 return 0;
1088}
1089
1090static inline void dccp_mib_exit(void)
1091{
1092 free_percpu(dccp_statistics);
1093}
1094
1095static int thash_entries;
1096module_param(thash_entries, int, 0444);
1097MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1098
1099#ifdef CONFIG_IP_DCCP_DEBUG
1100bool dccp_debug;
1101module_param(dccp_debug, bool, 0644);
1102MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1103
1104EXPORT_SYMBOL_GPL(dccp_debug);
1105#endif
1106
1107static int __init dccp_init(void)
1108{
1109 unsigned long goal;
1110 int ehash_order, bhash_order, i;
1111 int rc;
1112
1113 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1114 FIELD_SIZEOF(struct sk_buff, cb));
1115 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1116 if (rc)
1117 goto out_fail;
1118 rc = -ENOBUFS;
1119 inet_hashinfo_init(&dccp_hashinfo);
1120 dccp_hashinfo.bind_bucket_cachep =
1121 kmem_cache_create("dccp_bind_bucket",
1122 sizeof(struct inet_bind_bucket), 0,
1123 SLAB_HWCACHE_ALIGN, NULL);
1124 if (!dccp_hashinfo.bind_bucket_cachep)
1125 goto out_free_percpu;
1126
1127 /*
1128 * Size and allocate the main established and bind bucket
1129 * hash tables.
1130 *
1131 * The methodology is similar to that of the buffer cache.
1132 */
1133 if (totalram_pages >= (128 * 1024))
1134 goal = totalram_pages >> (21 - PAGE_SHIFT);
1135 else
1136 goal = totalram_pages >> (23 - PAGE_SHIFT);
1137
1138 if (thash_entries)
1139 goal = (thash_entries *
1140 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1141 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1142 ;
1143 do {
1144 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1145 sizeof(struct inet_ehash_bucket);
1146
1147 while (hash_size & (hash_size - 1))
1148 hash_size--;
1149 dccp_hashinfo.ehash_mask = hash_size - 1;
1150 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1151 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1152 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1153
1154 if (!dccp_hashinfo.ehash) {
1155 DCCP_CRIT("Failed to allocate DCCP established hash table");
1156 goto out_free_bind_bucket_cachep;
1157 }
1158
1159 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1160 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1161
1162 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1163 goto out_free_dccp_ehash;
1164
1165 bhash_order = ehash_order;
1166
1167 do {
1168 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1169 sizeof(struct inet_bind_hashbucket);
1170 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1171 bhash_order > 0)
1172 continue;
1173 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1174 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1175 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1176
1177 if (!dccp_hashinfo.bhash) {
1178 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1179 goto out_free_dccp_locks;
1180 }
1181
1182 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1183 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1184 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1185 }
1186
1187 rc = dccp_mib_init();
1188 if (rc)
1189 goto out_free_dccp_bhash;
1190
1191 rc = dccp_ackvec_init();
1192 if (rc)
1193 goto out_free_dccp_mib;
1194
1195 rc = dccp_sysctl_init();
1196 if (rc)
1197 goto out_ackvec_exit;
1198
1199 rc = ccid_initialize_builtins();
1200 if (rc)
1201 goto out_sysctl_exit;
1202
1203 dccp_timestamping_init();
1204
1205 return 0;
1206
1207out_sysctl_exit:
1208 dccp_sysctl_exit();
1209out_ackvec_exit:
1210 dccp_ackvec_exit();
1211out_free_dccp_mib:
1212 dccp_mib_exit();
1213out_free_dccp_bhash:
1214 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1215out_free_dccp_locks:
1216 inet_ehash_locks_free(&dccp_hashinfo);
1217out_free_dccp_ehash:
1218 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1219out_free_bind_bucket_cachep:
1220 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1221out_free_percpu:
1222 percpu_counter_destroy(&dccp_orphan_count);
1223out_fail:
1224 dccp_hashinfo.bhash = NULL;
1225 dccp_hashinfo.ehash = NULL;
1226 dccp_hashinfo.bind_bucket_cachep = NULL;
1227 return rc;
1228}
1229
1230static void __exit dccp_fini(void)
1231{
1232 ccid_cleanup_builtins();
1233 dccp_mib_exit();
1234 free_pages((unsigned long)dccp_hashinfo.bhash,
1235 get_order(dccp_hashinfo.bhash_size *
1236 sizeof(struct inet_bind_hashbucket)));
1237 free_pages((unsigned long)dccp_hashinfo.ehash,
1238 get_order((dccp_hashinfo.ehash_mask + 1) *
1239 sizeof(struct inet_ehash_bucket)));
1240 inet_ehash_locks_free(&dccp_hashinfo);
1241 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1242 dccp_ackvec_exit();
1243 dccp_sysctl_exit();
1244 percpu_counter_destroy(&dccp_orphan_count);
1245}
1246
1247module_init(dccp_init);
1248module_exit(dccp_fini);
1249
1250MODULE_LICENSE("GPL");
1251MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1252MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");