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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
45struct percpu_counter dccp_orphan_count;
46EXPORT_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
174static void dccp_sk_destruct(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 inet_sock_destruct(sk);
181}
182
183int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
184{
185 struct dccp_sock *dp = dccp_sk(sk);
186 struct inet_connection_sock *icsk = inet_csk(sk);
187
188 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
189 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
190 sk->sk_state = DCCP_CLOSED;
191 sk->sk_write_space = dccp_write_space;
192 sk->sk_destruct = dccp_sk_destruct;
193 icsk->icsk_sync_mss = dccp_sync_mss;
194 dp->dccps_mss_cache = 536;
195 dp->dccps_rate_last = jiffies;
196 dp->dccps_role = DCCP_ROLE_UNDEFINED;
197 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
198 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
199
200 dccp_init_xmit_timers(sk);
201
202 INIT_LIST_HEAD(&dp->dccps_featneg);
203 /* control socket doesn't need feat nego */
204 if (likely(ctl_sock_initialized))
205 return dccp_feat_init(sk);
206 return 0;
207}
208
209EXPORT_SYMBOL_GPL(dccp_init_sock);
210
211void dccp_destroy_sock(struct sock *sk)
212{
213 struct dccp_sock *dp = dccp_sk(sk);
214
215 __skb_queue_purge(&sk->sk_write_queue);
216 if (sk->sk_send_head != NULL) {
217 kfree_skb(sk->sk_send_head);
218 sk->sk_send_head = NULL;
219 }
220
221 /* Clean up a referenced DCCP bind bucket. */
222 if (inet_csk(sk)->icsk_bind_hash != NULL)
223 inet_put_port(sk);
224
225 kfree(dp->dccps_service_list);
226 dp->dccps_service_list = NULL;
227
228 if (dp->dccps_hc_rx_ackvec != NULL) {
229 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
230 dp->dccps_hc_rx_ackvec = NULL;
231 }
232 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
233 dp->dccps_hc_rx_ccid = NULL;
234
235 /* clean up feature negotiation state */
236 dccp_feat_list_purge(&dp->dccps_featneg);
237}
238
239EXPORT_SYMBOL_GPL(dccp_destroy_sock);
240
241static inline int dccp_listen_start(struct sock *sk, int backlog)
242{
243 struct dccp_sock *dp = dccp_sk(sk);
244
245 dp->dccps_role = DCCP_ROLE_LISTEN;
246 /* do not start to listen if feature negotiation setup fails */
247 if (dccp_feat_finalise_settings(dp))
248 return -EPROTO;
249 return inet_csk_listen_start(sk, backlog);
250}
251
252static inline int dccp_need_reset(int state)
253{
254 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
255 state != DCCP_REQUESTING;
256}
257
258int dccp_disconnect(struct sock *sk, int flags)
259{
260 struct inet_connection_sock *icsk = inet_csk(sk);
261 struct inet_sock *inet = inet_sk(sk);
262 struct dccp_sock *dp = dccp_sk(sk);
263 const int old_state = sk->sk_state;
264
265 if (old_state != DCCP_CLOSED)
266 dccp_set_state(sk, DCCP_CLOSED);
267
268 /*
269 * This corresponds to the ABORT function of RFC793, sec. 3.8
270 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
271 */
272 if (old_state == DCCP_LISTEN) {
273 inet_csk_listen_stop(sk);
274 } else if (dccp_need_reset(old_state)) {
275 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
276 sk->sk_err = ECONNRESET;
277 } else if (old_state == DCCP_REQUESTING)
278 sk->sk_err = ECONNRESET;
279
280 dccp_clear_xmit_timers(sk);
281 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
282 dp->dccps_hc_rx_ccid = NULL;
283
284 __skb_queue_purge(&sk->sk_receive_queue);
285 __skb_queue_purge(&sk->sk_write_queue);
286 if (sk->sk_send_head != NULL) {
287 __kfree_skb(sk->sk_send_head);
288 sk->sk_send_head = NULL;
289 }
290
291 inet->inet_dport = 0;
292
293 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
294 inet_reset_saddr(sk);
295
296 sk->sk_shutdown = 0;
297 sock_reset_flag(sk, SOCK_DONE);
298
299 icsk->icsk_backoff = 0;
300 inet_csk_delack_init(sk);
301 __sk_dst_reset(sk);
302
303 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
304
305 sk_error_report(sk);
306 return 0;
307}
308
309EXPORT_SYMBOL_GPL(dccp_disconnect);
310
311/*
312 * Wait for a DCCP event.
313 *
314 * Note that we don't need to lock the socket, as the upper poll layers
315 * take care of normal races (between the test and the event) and we don't
316 * go look at any of the socket buffers directly.
317 */
318__poll_t dccp_poll(struct file *file, struct socket *sock,
319 poll_table *wait)
320{
321 __poll_t mask;
322 struct sock *sk = sock->sk;
323
324 sock_poll_wait(file, sock, wait);
325 if (sk->sk_state == DCCP_LISTEN)
326 return inet_csk_listen_poll(sk);
327
328 /* Socket is not locked. We are protected from async events
329 by poll logic and correct handling of state changes
330 made by another threads is impossible in any case.
331 */
332
333 mask = 0;
334 if (sk->sk_err)
335 mask = EPOLLERR;
336
337 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
338 mask |= EPOLLHUP;
339 if (sk->sk_shutdown & RCV_SHUTDOWN)
340 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
341
342 /* Connected? */
343 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
344 if (atomic_read(&sk->sk_rmem_alloc) > 0)
345 mask |= EPOLLIN | EPOLLRDNORM;
346
347 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
348 if (sk_stream_is_writeable(sk)) {
349 mask |= EPOLLOUT | EPOLLWRNORM;
350 } else { /* send SIGIO later */
351 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
352 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
353
354 /* Race breaker. If space is freed after
355 * wspace test but before the flags are set,
356 * IO signal will be lost.
357 */
358 if (sk_stream_is_writeable(sk))
359 mask |= EPOLLOUT | EPOLLWRNORM;
360 }
361 }
362 }
363 return mask;
364}
365
366EXPORT_SYMBOL_GPL(dccp_poll);
367
368int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
369{
370 int rc = -ENOTCONN;
371
372 lock_sock(sk);
373
374 if (sk->sk_state == DCCP_LISTEN)
375 goto out;
376
377 switch (cmd) {
378 case SIOCOUTQ: {
379 int amount = sk_wmem_alloc_get(sk);
380 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
381 * always 0, comparably to UDP.
382 */
383
384 rc = put_user(amount, (int __user *)arg);
385 }
386 break;
387 case SIOCINQ: {
388 struct sk_buff *skb;
389 unsigned long amount = 0;
390
391 skb = skb_peek(&sk->sk_receive_queue);
392 if (skb != NULL) {
393 /*
394 * We will only return the amount of this packet since
395 * that is all that will be read.
396 */
397 amount = skb->len;
398 }
399 rc = put_user(amount, (int __user *)arg);
400 }
401 break;
402 default:
403 rc = -ENOIOCTLCMD;
404 break;
405 }
406out:
407 release_sock(sk);
408 return rc;
409}
410
411EXPORT_SYMBOL_GPL(dccp_ioctl);
412
413static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
414 sockptr_t optval, unsigned int optlen)
415{
416 struct dccp_sock *dp = dccp_sk(sk);
417 struct dccp_service_list *sl = NULL;
418
419 if (service == DCCP_SERVICE_INVALID_VALUE ||
420 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
421 return -EINVAL;
422
423 if (optlen > sizeof(service)) {
424 sl = kmalloc(optlen, GFP_KERNEL);
425 if (sl == NULL)
426 return -ENOMEM;
427
428 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
429 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
430 sizeof(service), optlen - sizeof(service)) ||
431 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
432 kfree(sl);
433 return -EFAULT;
434 }
435 }
436
437 lock_sock(sk);
438 dp->dccps_service = service;
439
440 kfree(dp->dccps_service_list);
441
442 dp->dccps_service_list = sl;
443 release_sock(sk);
444 return 0;
445}
446
447static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
448{
449 u8 *list, len;
450 int i, rc;
451
452 if (cscov < 0 || cscov > 15)
453 return -EINVAL;
454 /*
455 * Populate a list of permissible values, in the range cscov...15. This
456 * is necessary since feature negotiation of single values only works if
457 * both sides incidentally choose the same value. Since the list starts
458 * lowest-value first, negotiation will pick the smallest shared value.
459 */
460 if (cscov == 0)
461 return 0;
462 len = 16 - cscov;
463
464 list = kmalloc(len, GFP_KERNEL);
465 if (list == NULL)
466 return -ENOBUFS;
467
468 for (i = 0; i < len; i++)
469 list[i] = cscov++;
470
471 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
472
473 if (rc == 0) {
474 if (rx)
475 dccp_sk(sk)->dccps_pcrlen = cscov;
476 else
477 dccp_sk(sk)->dccps_pcslen = cscov;
478 }
479 kfree(list);
480 return rc;
481}
482
483static int dccp_setsockopt_ccid(struct sock *sk, int type,
484 sockptr_t optval, unsigned int optlen)
485{
486 u8 *val;
487 int rc = 0;
488
489 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
490 return -EINVAL;
491
492 val = memdup_sockptr(optval, optlen);
493 if (IS_ERR(val))
494 return PTR_ERR(val);
495
496 lock_sock(sk);
497 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
498 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
499
500 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
501 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
502 release_sock(sk);
503
504 kfree(val);
505 return rc;
506}
507
508static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
509 sockptr_t optval, unsigned int optlen)
510{
511 struct dccp_sock *dp = dccp_sk(sk);
512 int val, err = 0;
513
514 switch (optname) {
515 case DCCP_SOCKOPT_PACKET_SIZE:
516 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
517 return 0;
518 case DCCP_SOCKOPT_CHANGE_L:
519 case DCCP_SOCKOPT_CHANGE_R:
520 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
521 return 0;
522 case DCCP_SOCKOPT_CCID:
523 case DCCP_SOCKOPT_RX_CCID:
524 case DCCP_SOCKOPT_TX_CCID:
525 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
526 }
527
528 if (optlen < (int)sizeof(int))
529 return -EINVAL;
530
531 if (copy_from_sockptr(&val, optval, sizeof(int)))
532 return -EFAULT;
533
534 if (optname == DCCP_SOCKOPT_SERVICE)
535 return dccp_setsockopt_service(sk, val, optval, optlen);
536
537 lock_sock(sk);
538 switch (optname) {
539 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
540 if (dp->dccps_role != DCCP_ROLE_SERVER)
541 err = -EOPNOTSUPP;
542 else
543 dp->dccps_server_timewait = (val != 0);
544 break;
545 case DCCP_SOCKOPT_SEND_CSCOV:
546 err = dccp_setsockopt_cscov(sk, val, false);
547 break;
548 case DCCP_SOCKOPT_RECV_CSCOV:
549 err = dccp_setsockopt_cscov(sk, val, true);
550 break;
551 case DCCP_SOCKOPT_QPOLICY_ID:
552 if (sk->sk_state != DCCP_CLOSED)
553 err = -EISCONN;
554 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
555 err = -EINVAL;
556 else
557 dp->dccps_qpolicy = val;
558 break;
559 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
560 if (val < 0)
561 err = -EINVAL;
562 else
563 dp->dccps_tx_qlen = val;
564 break;
565 default:
566 err = -ENOPROTOOPT;
567 break;
568 }
569 release_sock(sk);
570
571 return err;
572}
573
574int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
575 unsigned int optlen)
576{
577 if (level != SOL_DCCP)
578 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
579 optname, optval,
580 optlen);
581 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
582}
583
584EXPORT_SYMBOL_GPL(dccp_setsockopt);
585
586static int dccp_getsockopt_service(struct sock *sk, int len,
587 __be32 __user *optval,
588 int __user *optlen)
589{
590 const struct dccp_sock *dp = dccp_sk(sk);
591 const struct dccp_service_list *sl;
592 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
593
594 lock_sock(sk);
595 if ((sl = dp->dccps_service_list) != NULL) {
596 slen = sl->dccpsl_nr * sizeof(u32);
597 total_len += slen;
598 }
599
600 err = -EINVAL;
601 if (total_len > len)
602 goto out;
603
604 err = 0;
605 if (put_user(total_len, optlen) ||
606 put_user(dp->dccps_service, optval) ||
607 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
608 err = -EFAULT;
609out:
610 release_sock(sk);
611 return err;
612}
613
614static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
615 char __user *optval, int __user *optlen)
616{
617 struct dccp_sock *dp;
618 int val, len;
619
620 if (get_user(len, optlen))
621 return -EFAULT;
622
623 if (len < (int)sizeof(int))
624 return -EINVAL;
625
626 dp = dccp_sk(sk);
627
628 switch (optname) {
629 case DCCP_SOCKOPT_PACKET_SIZE:
630 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
631 return 0;
632 case DCCP_SOCKOPT_SERVICE:
633 return dccp_getsockopt_service(sk, len,
634 (__be32 __user *)optval, optlen);
635 case DCCP_SOCKOPT_GET_CUR_MPS:
636 val = dp->dccps_mss_cache;
637 break;
638 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
639 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
640 case DCCP_SOCKOPT_TX_CCID:
641 val = ccid_get_current_tx_ccid(dp);
642 if (val < 0)
643 return -ENOPROTOOPT;
644 break;
645 case DCCP_SOCKOPT_RX_CCID:
646 val = ccid_get_current_rx_ccid(dp);
647 if (val < 0)
648 return -ENOPROTOOPT;
649 break;
650 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
651 val = dp->dccps_server_timewait;
652 break;
653 case DCCP_SOCKOPT_SEND_CSCOV:
654 val = dp->dccps_pcslen;
655 break;
656 case DCCP_SOCKOPT_RECV_CSCOV:
657 val = dp->dccps_pcrlen;
658 break;
659 case DCCP_SOCKOPT_QPOLICY_ID:
660 val = dp->dccps_qpolicy;
661 break;
662 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
663 val = dp->dccps_tx_qlen;
664 break;
665 case 128 ... 191:
666 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
667 len, (u32 __user *)optval, optlen);
668 case 192 ... 255:
669 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
670 len, (u32 __user *)optval, optlen);
671 default:
672 return -ENOPROTOOPT;
673 }
674
675 len = sizeof(val);
676 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
677 return -EFAULT;
678
679 return 0;
680}
681
682int dccp_getsockopt(struct sock *sk, int level, int optname,
683 char __user *optval, int __user *optlen)
684{
685 if (level != SOL_DCCP)
686 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
687 optname, optval,
688 optlen);
689 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
690}
691
692EXPORT_SYMBOL_GPL(dccp_getsockopt);
693
694static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
695{
696 struct cmsghdr *cmsg;
697
698 /*
699 * Assign an (opaque) qpolicy priority value to skb->priority.
700 *
701 * We are overloading this skb field for use with the qpolicy subystem.
702 * The skb->priority is normally used for the SO_PRIORITY option, which
703 * is initialised from sk_priority. Since the assignment of sk_priority
704 * to skb->priority happens later (on layer 3), we overload this field
705 * for use with queueing priorities as long as the skb is on layer 4.
706 * The default priority value (if nothing is set) is 0.
707 */
708 skb->priority = 0;
709
710 for_each_cmsghdr(cmsg, msg) {
711 if (!CMSG_OK(msg, cmsg))
712 return -EINVAL;
713
714 if (cmsg->cmsg_level != SOL_DCCP)
715 continue;
716
717 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
718 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
719 return -EINVAL;
720
721 switch (cmsg->cmsg_type) {
722 case DCCP_SCM_PRIORITY:
723 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
724 return -EINVAL;
725 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
726 break;
727 default:
728 return -EINVAL;
729 }
730 }
731 return 0;
732}
733
734int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
735{
736 const struct dccp_sock *dp = dccp_sk(sk);
737 const int flags = msg->msg_flags;
738 const int noblock = flags & MSG_DONTWAIT;
739 struct sk_buff *skb;
740 int rc, size;
741 long timeo;
742
743 trace_dccp_probe(sk, len);
744
745 if (len > dp->dccps_mss_cache)
746 return -EMSGSIZE;
747
748 lock_sock(sk);
749
750 if (dccp_qpolicy_full(sk)) {
751 rc = -EAGAIN;
752 goto out_release;
753 }
754
755 timeo = sock_sndtimeo(sk, noblock);
756
757 /*
758 * We have to use sk_stream_wait_connect here to set sk_write_pending,
759 * so that the trick in dccp_rcv_request_sent_state_process.
760 */
761 /* Wait for a connection to finish. */
762 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
763 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
764 goto out_release;
765
766 size = sk->sk_prot->max_header + len;
767 release_sock(sk);
768 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
769 lock_sock(sk);
770 if (skb == NULL)
771 goto out_release;
772
773 if (sk->sk_state == DCCP_CLOSED) {
774 rc = -ENOTCONN;
775 goto out_discard;
776 }
777
778 skb_reserve(skb, sk->sk_prot->max_header);
779 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
780 if (rc != 0)
781 goto out_discard;
782
783 rc = dccp_msghdr_parse(msg, skb);
784 if (rc != 0)
785 goto out_discard;
786
787 dccp_qpolicy_push(sk, skb);
788 /*
789 * The xmit_timer is set if the TX CCID is rate-based and will expire
790 * when congestion control permits to release further packets into the
791 * network. Window-based CCIDs do not use this timer.
792 */
793 if (!timer_pending(&dp->dccps_xmit_timer))
794 dccp_write_xmit(sk);
795out_release:
796 release_sock(sk);
797 return rc ? : len;
798out_discard:
799 kfree_skb(skb);
800 goto out_release;
801}
802
803EXPORT_SYMBOL_GPL(dccp_sendmsg);
804
805int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
806 int flags, int *addr_len)
807{
808 const struct dccp_hdr *dh;
809 long timeo;
810
811 lock_sock(sk);
812
813 if (sk->sk_state == DCCP_LISTEN) {
814 len = -ENOTCONN;
815 goto out;
816 }
817
818 timeo = sock_rcvtimeo(sk, nonblock);
819
820 do {
821 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
822
823 if (skb == NULL)
824 goto verify_sock_status;
825
826 dh = dccp_hdr(skb);
827
828 switch (dh->dccph_type) {
829 case DCCP_PKT_DATA:
830 case DCCP_PKT_DATAACK:
831 goto found_ok_skb;
832
833 case DCCP_PKT_CLOSE:
834 case DCCP_PKT_CLOSEREQ:
835 if (!(flags & MSG_PEEK))
836 dccp_finish_passive_close(sk);
837 fallthrough;
838 case DCCP_PKT_RESET:
839 dccp_pr_debug("found fin (%s) ok!\n",
840 dccp_packet_name(dh->dccph_type));
841 len = 0;
842 goto found_fin_ok;
843 default:
844 dccp_pr_debug("packet_type=%s\n",
845 dccp_packet_name(dh->dccph_type));
846 sk_eat_skb(sk, skb);
847 }
848verify_sock_status:
849 if (sock_flag(sk, SOCK_DONE)) {
850 len = 0;
851 break;
852 }
853
854 if (sk->sk_err) {
855 len = sock_error(sk);
856 break;
857 }
858
859 if (sk->sk_shutdown & RCV_SHUTDOWN) {
860 len = 0;
861 break;
862 }
863
864 if (sk->sk_state == DCCP_CLOSED) {
865 if (!sock_flag(sk, SOCK_DONE)) {
866 /* This occurs when user tries to read
867 * from never connected socket.
868 */
869 len = -ENOTCONN;
870 break;
871 }
872 len = 0;
873 break;
874 }
875
876 if (!timeo) {
877 len = -EAGAIN;
878 break;
879 }
880
881 if (signal_pending(current)) {
882 len = sock_intr_errno(timeo);
883 break;
884 }
885
886 sk_wait_data(sk, &timeo, NULL);
887 continue;
888 found_ok_skb:
889 if (len > skb->len)
890 len = skb->len;
891 else if (len < skb->len)
892 msg->msg_flags |= MSG_TRUNC;
893
894 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
895 /* Exception. Bailout! */
896 len = -EFAULT;
897 break;
898 }
899 if (flags & MSG_TRUNC)
900 len = skb->len;
901 found_fin_ok:
902 if (!(flags & MSG_PEEK))
903 sk_eat_skb(sk, skb);
904 break;
905 } while (1);
906out:
907 release_sock(sk);
908 return len;
909}
910
911EXPORT_SYMBOL_GPL(dccp_recvmsg);
912
913int inet_dccp_listen(struct socket *sock, int backlog)
914{
915 struct sock *sk = sock->sk;
916 unsigned char old_state;
917 int err;
918
919 lock_sock(sk);
920
921 err = -EINVAL;
922 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
923 goto out;
924
925 old_state = sk->sk_state;
926 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
927 goto out;
928
929 WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
930 /* Really, if the socket is already in listen state
931 * we can only allow the backlog to be adjusted.
932 */
933 if (old_state != DCCP_LISTEN) {
934 /*
935 * FIXME: here it probably should be sk->sk_prot->listen_start
936 * see tcp_listen_start
937 */
938 err = dccp_listen_start(sk, backlog);
939 if (err)
940 goto out;
941 }
942 err = 0;
943
944out:
945 release_sock(sk);
946 return err;
947}
948
949EXPORT_SYMBOL_GPL(inet_dccp_listen);
950
951static void dccp_terminate_connection(struct sock *sk)
952{
953 u8 next_state = DCCP_CLOSED;
954
955 switch (sk->sk_state) {
956 case DCCP_PASSIVE_CLOSE:
957 case DCCP_PASSIVE_CLOSEREQ:
958 dccp_finish_passive_close(sk);
959 break;
960 case DCCP_PARTOPEN:
961 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
962 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
963 fallthrough;
964 case DCCP_OPEN:
965 dccp_send_close(sk, 1);
966
967 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
968 !dccp_sk(sk)->dccps_server_timewait)
969 next_state = DCCP_ACTIVE_CLOSEREQ;
970 else
971 next_state = DCCP_CLOSING;
972 fallthrough;
973 default:
974 dccp_set_state(sk, next_state);
975 }
976}
977
978void dccp_close(struct sock *sk, long timeout)
979{
980 struct dccp_sock *dp = dccp_sk(sk);
981 struct sk_buff *skb;
982 u32 data_was_unread = 0;
983 int state;
984
985 lock_sock(sk);
986
987 sk->sk_shutdown = SHUTDOWN_MASK;
988
989 if (sk->sk_state == DCCP_LISTEN) {
990 dccp_set_state(sk, DCCP_CLOSED);
991
992 /* Special case. */
993 inet_csk_listen_stop(sk);
994
995 goto adjudge_to_death;
996 }
997
998 sk_stop_timer(sk, &dp->dccps_xmit_timer);
999
1000 /*
1001 * We need to flush the recv. buffs. We do this only on the
1002 * descriptor close, not protocol-sourced closes, because the
1003 *reader process may not have drained the data yet!
1004 */
1005 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1006 data_was_unread += skb->len;
1007 __kfree_skb(skb);
1008 }
1009
1010 /* If socket has been already reset kill it. */
1011 if (sk->sk_state == DCCP_CLOSED)
1012 goto adjudge_to_death;
1013
1014 if (data_was_unread) {
1015 /* Unread data was tossed, send an appropriate Reset Code */
1016 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1017 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1018 dccp_set_state(sk, DCCP_CLOSED);
1019 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1020 /* Check zero linger _after_ checking for unread data. */
1021 sk->sk_prot->disconnect(sk, 0);
1022 } else if (sk->sk_state != DCCP_CLOSED) {
1023 /*
1024 * Normal connection termination. May need to wait if there are
1025 * still packets in the TX queue that are delayed by the CCID.
1026 */
1027 dccp_flush_write_queue(sk, &timeout);
1028 dccp_terminate_connection(sk);
1029 }
1030
1031 /*
1032 * Flush write queue. This may be necessary in several cases:
1033 * - we have been closed by the peer but still have application data;
1034 * - abortive termination (unread data or zero linger time),
1035 * - normal termination but queue could not be flushed within time limit
1036 */
1037 __skb_queue_purge(&sk->sk_write_queue);
1038
1039 sk_stream_wait_close(sk, timeout);
1040
1041adjudge_to_death:
1042 state = sk->sk_state;
1043 sock_hold(sk);
1044 sock_orphan(sk);
1045
1046 /*
1047 * It is the last release_sock in its life. It will remove backlog.
1048 */
1049 release_sock(sk);
1050 /*
1051 * Now socket is owned by kernel and we acquire BH lock
1052 * to finish close. No need to check for user refs.
1053 */
1054 local_bh_disable();
1055 bh_lock_sock(sk);
1056 WARN_ON(sock_owned_by_user(sk));
1057
1058 percpu_counter_inc(sk->sk_prot->orphan_count);
1059
1060 /* Have we already been destroyed by a softirq or backlog? */
1061 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1062 goto out;
1063
1064 if (sk->sk_state == DCCP_CLOSED)
1065 inet_csk_destroy_sock(sk);
1066
1067 /* Otherwise, socket is reprieved until protocol close. */
1068
1069out:
1070 bh_unlock_sock(sk);
1071 local_bh_enable();
1072 sock_put(sk);
1073}
1074
1075EXPORT_SYMBOL_GPL(dccp_close);
1076
1077void dccp_shutdown(struct sock *sk, int how)
1078{
1079 dccp_pr_debug("called shutdown(%x)\n", how);
1080}
1081
1082EXPORT_SYMBOL_GPL(dccp_shutdown);
1083
1084static inline int __init dccp_mib_init(void)
1085{
1086 dccp_statistics = alloc_percpu(struct dccp_mib);
1087 if (!dccp_statistics)
1088 return -ENOMEM;
1089 return 0;
1090}
1091
1092static inline void dccp_mib_exit(void)
1093{
1094 free_percpu(dccp_statistics);
1095}
1096
1097static int thash_entries;
1098module_param(thash_entries, int, 0444);
1099MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1100
1101#ifdef CONFIG_IP_DCCP_DEBUG
1102bool dccp_debug;
1103module_param(dccp_debug, bool, 0644);
1104MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1105
1106EXPORT_SYMBOL_GPL(dccp_debug);
1107#endif
1108
1109static int __init dccp_init(void)
1110{
1111 unsigned long goal;
1112 unsigned long nr_pages = totalram_pages();
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 sizeof_field(struct sk_buff, cb));
1118 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1119 if (rc)
1120 goto out_fail;
1121 inet_hashinfo_init(&dccp_hashinfo);
1122 rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1123 if (rc)
1124 goto out_free_percpu;
1125 rc = -ENOBUFS;
1126 dccp_hashinfo.bind_bucket_cachep =
1127 kmem_cache_create("dccp_bind_bucket",
1128 sizeof(struct inet_bind_bucket), 0,
1129 SLAB_HWCACHE_ALIGN, NULL);
1130 if (!dccp_hashinfo.bind_bucket_cachep)
1131 goto out_free_hashinfo2;
1132
1133 /*
1134 * Size and allocate the main established and bind bucket
1135 * hash tables.
1136 *
1137 * The methodology is similar to that of the buffer cache.
1138 */
1139 if (nr_pages >= (128 * 1024))
1140 goal = nr_pages >> (21 - PAGE_SHIFT);
1141 else
1142 goal = nr_pages >> (23 - PAGE_SHIFT);
1143
1144 if (thash_entries)
1145 goal = (thash_entries *
1146 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1147 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1148 ;
1149 do {
1150 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1151 sizeof(struct inet_ehash_bucket);
1152
1153 while (hash_size & (hash_size - 1))
1154 hash_size--;
1155 dccp_hashinfo.ehash_mask = hash_size - 1;
1156 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1157 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1158 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1159
1160 if (!dccp_hashinfo.ehash) {
1161 DCCP_CRIT("Failed to allocate DCCP established hash table");
1162 goto out_free_bind_bucket_cachep;
1163 }
1164
1165 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1166 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1167
1168 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1169 goto out_free_dccp_ehash;
1170
1171 bhash_order = ehash_order;
1172
1173 do {
1174 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1175 sizeof(struct inet_bind_hashbucket);
1176 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1177 bhash_order > 0)
1178 continue;
1179 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1180 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1181 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1182
1183 if (!dccp_hashinfo.bhash) {
1184 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1185 goto out_free_dccp_locks;
1186 }
1187
1188 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1189 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1190 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1191 }
1192
1193 rc = dccp_mib_init();
1194 if (rc)
1195 goto out_free_dccp_bhash;
1196
1197 rc = dccp_ackvec_init();
1198 if (rc)
1199 goto out_free_dccp_mib;
1200
1201 rc = dccp_sysctl_init();
1202 if (rc)
1203 goto out_ackvec_exit;
1204
1205 rc = ccid_initialize_builtins();
1206 if (rc)
1207 goto out_sysctl_exit;
1208
1209 dccp_timestamping_init();
1210
1211 return 0;
1212
1213out_sysctl_exit:
1214 dccp_sysctl_exit();
1215out_ackvec_exit:
1216 dccp_ackvec_exit();
1217out_free_dccp_mib:
1218 dccp_mib_exit();
1219out_free_dccp_bhash:
1220 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1221out_free_dccp_locks:
1222 inet_ehash_locks_free(&dccp_hashinfo);
1223out_free_dccp_ehash:
1224 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1225out_free_bind_bucket_cachep:
1226 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1227out_free_hashinfo2:
1228 inet_hashinfo2_free_mod(&dccp_hashinfo);
1229out_free_percpu:
1230 percpu_counter_destroy(&dccp_orphan_count);
1231out_fail:
1232 dccp_hashinfo.bhash = NULL;
1233 dccp_hashinfo.ehash = NULL;
1234 dccp_hashinfo.bind_bucket_cachep = NULL;
1235 return rc;
1236}
1237
1238static void __exit dccp_fini(void)
1239{
1240 ccid_cleanup_builtins();
1241 dccp_mib_exit();
1242 free_pages((unsigned long)dccp_hashinfo.bhash,
1243 get_order(dccp_hashinfo.bhash_size *
1244 sizeof(struct inet_bind_hashbucket)));
1245 free_pages((unsigned long)dccp_hashinfo.ehash,
1246 get_order((dccp_hashinfo.ehash_mask + 1) *
1247 sizeof(struct inet_ehash_bucket)));
1248 inet_ehash_locks_free(&dccp_hashinfo);
1249 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1250 dccp_ackvec_exit();
1251 dccp_sysctl_exit();
1252 inet_hashinfo2_free_mod(&dccp_hashinfo);
1253 percpu_counter_destroy(&dccp_orphan_count);
1254}
1255
1256module_init(dccp_init);
1257module_exit(dccp_fini);
1258
1259MODULE_LICENSE("GPL");
1260MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1261MODULE_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_wspace(sk) >= sk_stream_min_wspace(sk)) {
340 mask |= POLLOUT | POLLWRNORM;
341 } else { /* send SIGIO later */
342 set_bit(SOCK_ASYNC_NOSPACE,
343 &sk->sk_socket->flags);
344 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
345
346 /* Race breaker. If space is freed after
347 * wspace test but before the flags are set,
348 * IO signal will be lost.
349 */
350 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
351 mask |= POLLOUT | POLLWRNORM;
352 }
353 }
354 }
355 return mask;
356}
357
358EXPORT_SYMBOL_GPL(dccp_poll);
359
360int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
361{
362 int rc = -ENOTCONN;
363
364 lock_sock(sk);
365
366 if (sk->sk_state == DCCP_LISTEN)
367 goto out;
368
369 switch (cmd) {
370 case SIOCINQ: {
371 struct sk_buff *skb;
372 unsigned long amount = 0;
373
374 skb = skb_peek(&sk->sk_receive_queue);
375 if (skb != NULL) {
376 /*
377 * We will only return the amount of this packet since
378 * that is all that will be read.
379 */
380 amount = skb->len;
381 }
382 rc = put_user(amount, (int __user *)arg);
383 }
384 break;
385 default:
386 rc = -ENOIOCTLCMD;
387 break;
388 }
389out:
390 release_sock(sk);
391 return rc;
392}
393
394EXPORT_SYMBOL_GPL(dccp_ioctl);
395
396static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
397 char __user *optval, unsigned int optlen)
398{
399 struct dccp_sock *dp = dccp_sk(sk);
400 struct dccp_service_list *sl = NULL;
401
402 if (service == DCCP_SERVICE_INVALID_VALUE ||
403 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
404 return -EINVAL;
405
406 if (optlen > sizeof(service)) {
407 sl = kmalloc(optlen, GFP_KERNEL);
408 if (sl == NULL)
409 return -ENOMEM;
410
411 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
412 if (copy_from_user(sl->dccpsl_list,
413 optval + sizeof(service),
414 optlen - sizeof(service)) ||
415 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
416 kfree(sl);
417 return -EFAULT;
418 }
419 }
420
421 lock_sock(sk);
422 dp->dccps_service = service;
423
424 kfree(dp->dccps_service_list);
425
426 dp->dccps_service_list = sl;
427 release_sock(sk);
428 return 0;
429}
430
431static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
432{
433 u8 *list, len;
434 int i, rc;
435
436 if (cscov < 0 || cscov > 15)
437 return -EINVAL;
438 /*
439 * Populate a list of permissible values, in the range cscov...15. This
440 * is necessary since feature negotiation of single values only works if
441 * both sides incidentally choose the same value. Since the list starts
442 * lowest-value first, negotiation will pick the smallest shared value.
443 */
444 if (cscov == 0)
445 return 0;
446 len = 16 - cscov;
447
448 list = kmalloc(len, GFP_KERNEL);
449 if (list == NULL)
450 return -ENOBUFS;
451
452 for (i = 0; i < len; i++)
453 list[i] = cscov++;
454
455 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
456
457 if (rc == 0) {
458 if (rx)
459 dccp_sk(sk)->dccps_pcrlen = cscov;
460 else
461 dccp_sk(sk)->dccps_pcslen = cscov;
462 }
463 kfree(list);
464 return rc;
465}
466
467static int dccp_setsockopt_ccid(struct sock *sk, int type,
468 char __user *optval, unsigned int optlen)
469{
470 u8 *val;
471 int rc = 0;
472
473 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
474 return -EINVAL;
475
476 val = memdup_user(optval, optlen);
477 if (IS_ERR(val))
478 return PTR_ERR(val);
479
480 lock_sock(sk);
481 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
482 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
483
484 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
485 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
486 release_sock(sk);
487
488 kfree(val);
489 return rc;
490}
491
492static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
493 char __user *optval, unsigned int optlen)
494{
495 struct dccp_sock *dp = dccp_sk(sk);
496 int val, err = 0;
497
498 switch (optname) {
499 case DCCP_SOCKOPT_PACKET_SIZE:
500 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
501 return 0;
502 case DCCP_SOCKOPT_CHANGE_L:
503 case DCCP_SOCKOPT_CHANGE_R:
504 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
505 return 0;
506 case DCCP_SOCKOPT_CCID:
507 case DCCP_SOCKOPT_RX_CCID:
508 case DCCP_SOCKOPT_TX_CCID:
509 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
510 }
511
512 if (optlen < (int)sizeof(int))
513 return -EINVAL;
514
515 if (get_user(val, (int __user *)optval))
516 return -EFAULT;
517
518 if (optname == DCCP_SOCKOPT_SERVICE)
519 return dccp_setsockopt_service(sk, val, optval, optlen);
520
521 lock_sock(sk);
522 switch (optname) {
523 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
524 if (dp->dccps_role != DCCP_ROLE_SERVER)
525 err = -EOPNOTSUPP;
526 else
527 dp->dccps_server_timewait = (val != 0);
528 break;
529 case DCCP_SOCKOPT_SEND_CSCOV:
530 err = dccp_setsockopt_cscov(sk, val, false);
531 break;
532 case DCCP_SOCKOPT_RECV_CSCOV:
533 err = dccp_setsockopt_cscov(sk, val, true);
534 break;
535 case DCCP_SOCKOPT_QPOLICY_ID:
536 if (sk->sk_state != DCCP_CLOSED)
537 err = -EISCONN;
538 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
539 err = -EINVAL;
540 else
541 dp->dccps_qpolicy = val;
542 break;
543 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
544 if (val < 0)
545 err = -EINVAL;
546 else
547 dp->dccps_tx_qlen = val;
548 break;
549 default:
550 err = -ENOPROTOOPT;
551 break;
552 }
553 release_sock(sk);
554
555 return err;
556}
557
558int dccp_setsockopt(struct sock *sk, int level, int optname,
559 char __user *optval, unsigned int optlen)
560{
561 if (level != SOL_DCCP)
562 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
563 optname, optval,
564 optlen);
565 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
566}
567
568EXPORT_SYMBOL_GPL(dccp_setsockopt);
569
570#ifdef CONFIG_COMPAT
571int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
572 char __user *optval, unsigned int optlen)
573{
574 if (level != SOL_DCCP)
575 return inet_csk_compat_setsockopt(sk, level, optname,
576 optval, optlen);
577 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
578}
579
580EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
581#endif
582
583static int dccp_getsockopt_service(struct sock *sk, int len,
584 __be32 __user *optval,
585 int __user *optlen)
586{
587 const struct dccp_sock *dp = dccp_sk(sk);
588 const struct dccp_service_list *sl;
589 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
590
591 lock_sock(sk);
592 if ((sl = dp->dccps_service_list) != NULL) {
593 slen = sl->dccpsl_nr * sizeof(u32);
594 total_len += slen;
595 }
596
597 err = -EINVAL;
598 if (total_len > len)
599 goto out;
600
601 err = 0;
602 if (put_user(total_len, optlen) ||
603 put_user(dp->dccps_service, optval) ||
604 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
605 err = -EFAULT;
606out:
607 release_sock(sk);
608 return err;
609}
610
611static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
612 char __user *optval, int __user *optlen)
613{
614 struct dccp_sock *dp;
615 int val, len;
616
617 if (get_user(len, optlen))
618 return -EFAULT;
619
620 if (len < (int)sizeof(int))
621 return -EINVAL;
622
623 dp = dccp_sk(sk);
624
625 switch (optname) {
626 case DCCP_SOCKOPT_PACKET_SIZE:
627 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
628 return 0;
629 case DCCP_SOCKOPT_SERVICE:
630 return dccp_getsockopt_service(sk, len,
631 (__be32 __user *)optval, optlen);
632 case DCCP_SOCKOPT_GET_CUR_MPS:
633 val = dp->dccps_mss_cache;
634 break;
635 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
636 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
637 case DCCP_SOCKOPT_TX_CCID:
638 val = ccid_get_current_tx_ccid(dp);
639 if (val < 0)
640 return -ENOPROTOOPT;
641 break;
642 case DCCP_SOCKOPT_RX_CCID:
643 val = ccid_get_current_rx_ccid(dp);
644 if (val < 0)
645 return -ENOPROTOOPT;
646 break;
647 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
648 val = dp->dccps_server_timewait;
649 break;
650 case DCCP_SOCKOPT_SEND_CSCOV:
651 val = dp->dccps_pcslen;
652 break;
653 case DCCP_SOCKOPT_RECV_CSCOV:
654 val = dp->dccps_pcrlen;
655 break;
656 case DCCP_SOCKOPT_QPOLICY_ID:
657 val = dp->dccps_qpolicy;
658 break;
659 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
660 val = dp->dccps_tx_qlen;
661 break;
662 case 128 ... 191:
663 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
664 len, (u32 __user *)optval, optlen);
665 case 192 ... 255:
666 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
667 len, (u32 __user *)optval, optlen);
668 default:
669 return -ENOPROTOOPT;
670 }
671
672 len = sizeof(val);
673 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
674 return -EFAULT;
675
676 return 0;
677}
678
679int dccp_getsockopt(struct sock *sk, int level, int optname,
680 char __user *optval, int __user *optlen)
681{
682 if (level != SOL_DCCP)
683 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
684 optname, optval,
685 optlen);
686 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
687}
688
689EXPORT_SYMBOL_GPL(dccp_getsockopt);
690
691#ifdef CONFIG_COMPAT
692int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
693 char __user *optval, int __user *optlen)
694{
695 if (level != SOL_DCCP)
696 return inet_csk_compat_getsockopt(sk, level, optname,
697 optval, optlen);
698 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
699}
700
701EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
702#endif
703
704static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
705{
706 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
707
708 /*
709 * Assign an (opaque) qpolicy priority value to skb->priority.
710 *
711 * We are overloading this skb field for use with the qpolicy subystem.
712 * The skb->priority is normally used for the SO_PRIORITY option, which
713 * is initialised from sk_priority. Since the assignment of sk_priority
714 * to skb->priority happens later (on layer 3), we overload this field
715 * for use with queueing priorities as long as the skb is on layer 4.
716 * The default priority value (if nothing is set) is 0.
717 */
718 skb->priority = 0;
719
720 for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
721
722 if (!CMSG_OK(msg, cmsg))
723 return -EINVAL;
724
725 if (cmsg->cmsg_level != SOL_DCCP)
726 continue;
727
728 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
729 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
730 return -EINVAL;
731
732 switch (cmsg->cmsg_type) {
733 case DCCP_SCM_PRIORITY:
734 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
735 return -EINVAL;
736 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
737 break;
738 default:
739 return -EINVAL;
740 }
741 }
742 return 0;
743}
744
745int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
746 size_t len)
747{
748 const struct dccp_sock *dp = dccp_sk(sk);
749 const int flags = msg->msg_flags;
750 const int noblock = flags & MSG_DONTWAIT;
751 struct sk_buff *skb;
752 int rc, size;
753 long timeo;
754
755 if (len > dp->dccps_mss_cache)
756 return -EMSGSIZE;
757
758 lock_sock(sk);
759
760 if (dccp_qpolicy_full(sk)) {
761 rc = -EAGAIN;
762 goto out_release;
763 }
764
765 timeo = sock_sndtimeo(sk, noblock);
766
767 /*
768 * We have to use sk_stream_wait_connect here to set sk_write_pending,
769 * so that the trick in dccp_rcv_request_sent_state_process.
770 */
771 /* Wait for a connection to finish. */
772 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
773 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
774 goto out_release;
775
776 size = sk->sk_prot->max_header + len;
777 release_sock(sk);
778 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
779 lock_sock(sk);
780 if (skb == NULL)
781 goto out_release;
782
783 skb_reserve(skb, sk->sk_prot->max_header);
784 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
785 if (rc != 0)
786 goto out_discard;
787
788 rc = dccp_msghdr_parse(msg, skb);
789 if (rc != 0)
790 goto out_discard;
791
792 dccp_qpolicy_push(sk, skb);
793 /*
794 * The xmit_timer is set if the TX CCID is rate-based and will expire
795 * when congestion control permits to release further packets into the
796 * network. Window-based CCIDs do not use this timer.
797 */
798 if (!timer_pending(&dp->dccps_xmit_timer))
799 dccp_write_xmit(sk);
800out_release:
801 release_sock(sk);
802 return rc ? : len;
803out_discard:
804 kfree_skb(skb);
805 goto out_release;
806}
807
808EXPORT_SYMBOL_GPL(dccp_sendmsg);
809
810int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
811 size_t len, int nonblock, int flags, int *addr_len)
812{
813 const struct dccp_hdr *dh;
814 long timeo;
815
816 lock_sock(sk);
817
818 if (sk->sk_state == DCCP_LISTEN) {
819 len = -ENOTCONN;
820 goto out;
821 }
822
823 timeo = sock_rcvtimeo(sk, nonblock);
824
825 do {
826 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
827
828 if (skb == NULL)
829 goto verify_sock_status;
830
831 dh = dccp_hdr(skb);
832
833 switch (dh->dccph_type) {
834 case DCCP_PKT_DATA:
835 case DCCP_PKT_DATAACK:
836 goto found_ok_skb;
837
838 case DCCP_PKT_CLOSE:
839 case DCCP_PKT_CLOSEREQ:
840 if (!(flags & MSG_PEEK))
841 dccp_finish_passive_close(sk);
842 /* fall through */
843 case DCCP_PKT_RESET:
844 dccp_pr_debug("found fin (%s) ok!\n",
845 dccp_packet_name(dh->dccph_type));
846 len = 0;
847 goto found_fin_ok;
848 default:
849 dccp_pr_debug("packet_type=%s\n",
850 dccp_packet_name(dh->dccph_type));
851 sk_eat_skb(sk, skb, false);
852 }
853verify_sock_status:
854 if (sock_flag(sk, SOCK_DONE)) {
855 len = 0;
856 break;
857 }
858
859 if (sk->sk_err) {
860 len = sock_error(sk);
861 break;
862 }
863
864 if (sk->sk_shutdown & RCV_SHUTDOWN) {
865 len = 0;
866 break;
867 }
868
869 if (sk->sk_state == DCCP_CLOSED) {
870 if (!sock_flag(sk, SOCK_DONE)) {
871 /* This occurs when user tries to read
872 * from never connected socket.
873 */
874 len = -ENOTCONN;
875 break;
876 }
877 len = 0;
878 break;
879 }
880
881 if (!timeo) {
882 len = -EAGAIN;
883 break;
884 }
885
886 if (signal_pending(current)) {
887 len = sock_intr_errno(timeo);
888 break;
889 }
890
891 sk_wait_data(sk, &timeo);
892 continue;
893 found_ok_skb:
894 if (len > skb->len)
895 len = skb->len;
896 else if (len < skb->len)
897 msg->msg_flags |= MSG_TRUNC;
898
899 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
900 /* Exception. Bailout! */
901 len = -EFAULT;
902 break;
903 }
904 if (flags & MSG_TRUNC)
905 len = skb->len;
906 found_fin_ok:
907 if (!(flags & MSG_PEEK))
908 sk_eat_skb(sk, skb, false);
909 break;
910 } while (1);
911out:
912 release_sock(sk);
913 return len;
914}
915
916EXPORT_SYMBOL_GPL(dccp_recvmsg);
917
918int inet_dccp_listen(struct socket *sock, int backlog)
919{
920 struct sock *sk = sock->sk;
921 unsigned char old_state;
922 int err;
923
924 lock_sock(sk);
925
926 err = -EINVAL;
927 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
928 goto out;
929
930 old_state = sk->sk_state;
931 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
932 goto out;
933
934 /* Really, if the socket is already in listen state
935 * we can only allow the backlog to be adjusted.
936 */
937 if (old_state != DCCP_LISTEN) {
938 /*
939 * FIXME: here it probably should be sk->sk_prot->listen_start
940 * see tcp_listen_start
941 */
942 err = dccp_listen_start(sk, backlog);
943 if (err)
944 goto out;
945 }
946 sk->sk_max_ack_backlog = backlog;
947 err = 0;
948
949out:
950 release_sock(sk);
951 return err;
952}
953
954EXPORT_SYMBOL_GPL(inet_dccp_listen);
955
956static void dccp_terminate_connection(struct sock *sk)
957{
958 u8 next_state = DCCP_CLOSED;
959
960 switch (sk->sk_state) {
961 case DCCP_PASSIVE_CLOSE:
962 case DCCP_PASSIVE_CLOSEREQ:
963 dccp_finish_passive_close(sk);
964 break;
965 case DCCP_PARTOPEN:
966 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
967 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
968 /* fall through */
969 case DCCP_OPEN:
970 dccp_send_close(sk, 1);
971
972 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
973 !dccp_sk(sk)->dccps_server_timewait)
974 next_state = DCCP_ACTIVE_CLOSEREQ;
975 else
976 next_state = DCCP_CLOSING;
977 /* fall through */
978 default:
979 dccp_set_state(sk, next_state);
980 }
981}
982
983void dccp_close(struct sock *sk, long timeout)
984{
985 struct dccp_sock *dp = dccp_sk(sk);
986 struct sk_buff *skb;
987 u32 data_was_unread = 0;
988 int state;
989
990 lock_sock(sk);
991
992 sk->sk_shutdown = SHUTDOWN_MASK;
993
994 if (sk->sk_state == DCCP_LISTEN) {
995 dccp_set_state(sk, DCCP_CLOSED);
996
997 /* Special case. */
998 inet_csk_listen_stop(sk);
999
1000 goto adjudge_to_death;
1001 }
1002
1003 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1004
1005 /*
1006 * We need to flush the recv. buffs. We do this only on the
1007 * descriptor close, not protocol-sourced closes, because the
1008 *reader process may not have drained the data yet!
1009 */
1010 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1011 data_was_unread += skb->len;
1012 __kfree_skb(skb);
1013 }
1014
1015 if (data_was_unread) {
1016 /* Unread data was tossed, send an appropriate Reset Code */
1017 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1018 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1019 dccp_set_state(sk, DCCP_CLOSED);
1020 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1021 /* Check zero linger _after_ checking for unread data. */
1022 sk->sk_prot->disconnect(sk, 0);
1023 } else if (sk->sk_state != DCCP_CLOSED) {
1024 /*
1025 * Normal connection termination. May need to wait if there are
1026 * still packets in the TX queue that are delayed by the CCID.
1027 */
1028 dccp_flush_write_queue(sk, &timeout);
1029 dccp_terminate_connection(sk);
1030 }
1031
1032 /*
1033 * Flush write queue. This may be necessary in several cases:
1034 * - we have been closed by the peer but still have application data;
1035 * - abortive termination (unread data or zero linger time),
1036 * - normal termination but queue could not be flushed within time limit
1037 */
1038 __skb_queue_purge(&sk->sk_write_queue);
1039
1040 sk_stream_wait_close(sk, timeout);
1041
1042adjudge_to_death:
1043 state = sk->sk_state;
1044 sock_hold(sk);
1045 sock_orphan(sk);
1046
1047 /*
1048 * It is the last release_sock in its life. It will remove backlog.
1049 */
1050 release_sock(sk);
1051 /*
1052 * Now socket is owned by kernel and we acquire BH lock
1053 * to finish close. No need to check for user refs.
1054 */
1055 local_bh_disable();
1056 bh_lock_sock(sk);
1057 WARN_ON(sock_owned_by_user(sk));
1058
1059 percpu_counter_inc(sk->sk_prot->orphan_count);
1060
1061 /* Have we already been destroyed by a softirq or backlog? */
1062 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1063 goto out;
1064
1065 if (sk->sk_state == DCCP_CLOSED)
1066 inet_csk_destroy_sock(sk);
1067
1068 /* Otherwise, socket is reprieved until protocol close. */
1069
1070out:
1071 bh_unlock_sock(sk);
1072 local_bh_enable();
1073 sock_put(sk);
1074}
1075
1076EXPORT_SYMBOL_GPL(dccp_close);
1077
1078void dccp_shutdown(struct sock *sk, int how)
1079{
1080 dccp_pr_debug("called shutdown(%x)\n", how);
1081}
1082
1083EXPORT_SYMBOL_GPL(dccp_shutdown);
1084
1085static inline int dccp_mib_init(void)
1086{
1087 return snmp_mib_init((void __percpu **)dccp_statistics,
1088 sizeof(struct dccp_mib),
1089 __alignof__(struct dccp_mib));
1090}
1091
1092static inline void dccp_mib_exit(void)
1093{
1094 snmp_mib_free((void __percpu **)dccp_statistics);
1095}
1096
1097static int thash_entries;
1098module_param(thash_entries, int, 0444);
1099MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1100
1101#ifdef CONFIG_IP_DCCP_DEBUG
1102bool dccp_debug;
1103module_param(dccp_debug, bool, 0644);
1104MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1105
1106EXPORT_SYMBOL_GPL(dccp_debug);
1107#endif
1108
1109static int __init dccp_init(void)
1110{
1111 unsigned long goal;
1112 int ehash_order, bhash_order, i;
1113 int rc;
1114
1115 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1116 FIELD_SIZEOF(struct sk_buff, cb));
1117 rc = percpu_counter_init(&dccp_orphan_count, 0);
1118 if (rc)
1119 goto out_fail;
1120 rc = -ENOBUFS;
1121 inet_hashinfo_init(&dccp_hashinfo);
1122 dccp_hashinfo.bind_bucket_cachep =
1123 kmem_cache_create("dccp_bind_bucket",
1124 sizeof(struct inet_bind_bucket), 0,
1125 SLAB_HWCACHE_ALIGN, NULL);
1126 if (!dccp_hashinfo.bind_bucket_cachep)
1127 goto out_free_percpu;
1128
1129 /*
1130 * Size and allocate the main established and bind bucket
1131 * hash tables.
1132 *
1133 * The methodology is similar to that of the buffer cache.
1134 */
1135 if (totalram_pages >= (128 * 1024))
1136 goal = totalram_pages >> (21 - PAGE_SHIFT);
1137 else
1138 goal = totalram_pages >> (23 - PAGE_SHIFT);
1139
1140 if (thash_entries)
1141 goal = (thash_entries *
1142 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1143 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1144 ;
1145 do {
1146 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1147 sizeof(struct inet_ehash_bucket);
1148
1149 while (hash_size & (hash_size - 1))
1150 hash_size--;
1151 dccp_hashinfo.ehash_mask = hash_size - 1;
1152 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1153 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1154 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1155
1156 if (!dccp_hashinfo.ehash) {
1157 DCCP_CRIT("Failed to allocate DCCP established hash table");
1158 goto out_free_bind_bucket_cachep;
1159 }
1160
1161 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1162 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1163 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1164 }
1165
1166 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1167 goto out_free_dccp_ehash;
1168
1169 bhash_order = ehash_order;
1170
1171 do {
1172 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1173 sizeof(struct inet_bind_hashbucket);
1174 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1175 bhash_order > 0)
1176 continue;
1177 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1178 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1179 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1180
1181 if (!dccp_hashinfo.bhash) {
1182 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1183 goto out_free_dccp_locks;
1184 }
1185
1186 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1187 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1188 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1189 }
1190
1191 rc = dccp_mib_init();
1192 if (rc)
1193 goto out_free_dccp_bhash;
1194
1195 rc = dccp_ackvec_init();
1196 if (rc)
1197 goto out_free_dccp_mib;
1198
1199 rc = dccp_sysctl_init();
1200 if (rc)
1201 goto out_ackvec_exit;
1202
1203 rc = ccid_initialize_builtins();
1204 if (rc)
1205 goto out_sysctl_exit;
1206
1207 dccp_timestamping_init();
1208
1209 return 0;
1210
1211out_sysctl_exit:
1212 dccp_sysctl_exit();
1213out_ackvec_exit:
1214 dccp_ackvec_exit();
1215out_free_dccp_mib:
1216 dccp_mib_exit();
1217out_free_dccp_bhash:
1218 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1219out_free_dccp_locks:
1220 inet_ehash_locks_free(&dccp_hashinfo);
1221out_free_dccp_ehash:
1222 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1223out_free_bind_bucket_cachep:
1224 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1225out_free_percpu:
1226 percpu_counter_destroy(&dccp_orphan_count);
1227out_fail:
1228 dccp_hashinfo.bhash = NULL;
1229 dccp_hashinfo.ehash = NULL;
1230 dccp_hashinfo.bind_bucket_cachep = NULL;
1231 return rc;
1232}
1233
1234static void __exit dccp_fini(void)
1235{
1236 ccid_cleanup_builtins();
1237 dccp_mib_exit();
1238 free_pages((unsigned long)dccp_hashinfo.bhash,
1239 get_order(dccp_hashinfo.bhash_size *
1240 sizeof(struct inet_bind_hashbucket)));
1241 free_pages((unsigned long)dccp_hashinfo.ehash,
1242 get_order((dccp_hashinfo.ehash_mask + 1) *
1243 sizeof(struct inet_ehash_bucket)));
1244 inet_ehash_locks_free(&dccp_hashinfo);
1245 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1246 dccp_ackvec_exit();
1247 dccp_sysctl_exit();
1248 percpu_counter_destroy(&dccp_orphan_count);
1249}
1250
1251module_init(dccp_init);
1252module_exit(dccp_fini);
1253
1254MODULE_LICENSE("GPL");
1255MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1256MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");