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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 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
195 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
196 sk->sk_state = DCCP_CLOSED;
197 sk->sk_write_space = dccp_write_space;
198 sk->sk_destruct = dccp_sk_destruct;
199 icsk->icsk_sync_mss = dccp_sync_mss;
200 dp->dccps_mss_cache = 536;
201 dp->dccps_rate_last = jiffies;
202 dp->dccps_role = DCCP_ROLE_UNDEFINED;
203 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
204 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
205
206 dccp_init_xmit_timers(sk);
207
208 INIT_LIST_HEAD(&dp->dccps_featneg);
209 /* control socket doesn't need feat nego */
210 if (likely(ctl_sock_initialized))
211 return dccp_feat_init(sk);
212 return 0;
213}
214
215EXPORT_SYMBOL_GPL(dccp_init_sock);
216
217void dccp_destroy_sock(struct sock *sk)
218{
219 struct dccp_sock *dp = dccp_sk(sk);
220
221 __skb_queue_purge(&sk->sk_write_queue);
222 if (sk->sk_send_head != NULL) {
223 kfree_skb(sk->sk_send_head);
224 sk->sk_send_head = NULL;
225 }
226
227 /* Clean up a referenced DCCP bind bucket. */
228 if (inet_csk(sk)->icsk_bind_hash != NULL)
229 inet_put_port(sk);
230
231 kfree(dp->dccps_service_list);
232 dp->dccps_service_list = NULL;
233
234 if (dp->dccps_hc_rx_ackvec != NULL) {
235 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
236 dp->dccps_hc_rx_ackvec = NULL;
237 }
238 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
239 dp->dccps_hc_rx_ccid = NULL;
240
241 /* clean up feature negotiation state */
242 dccp_feat_list_purge(&dp->dccps_featneg);
243}
244
245EXPORT_SYMBOL_GPL(dccp_destroy_sock);
246
247static inline int dccp_need_reset(int state)
248{
249 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
250 state != DCCP_REQUESTING;
251}
252
253int dccp_disconnect(struct sock *sk, int flags)
254{
255 struct inet_connection_sock *icsk = inet_csk(sk);
256 struct inet_sock *inet = inet_sk(sk);
257 struct dccp_sock *dp = dccp_sk(sk);
258 const int old_state = sk->sk_state;
259
260 if (old_state != DCCP_CLOSED)
261 dccp_set_state(sk, DCCP_CLOSED);
262
263 /*
264 * This corresponds to the ABORT function of RFC793, sec. 3.8
265 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
266 */
267 if (old_state == DCCP_LISTEN) {
268 inet_csk_listen_stop(sk);
269 } else if (dccp_need_reset(old_state)) {
270 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
271 sk->sk_err = ECONNRESET;
272 } else if (old_state == DCCP_REQUESTING)
273 sk->sk_err = ECONNRESET;
274
275 dccp_clear_xmit_timers(sk);
276 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
277 dp->dccps_hc_rx_ccid = NULL;
278
279 __skb_queue_purge(&sk->sk_receive_queue);
280 __skb_queue_purge(&sk->sk_write_queue);
281 if (sk->sk_send_head != NULL) {
282 __kfree_skb(sk->sk_send_head);
283 sk->sk_send_head = NULL;
284 }
285
286 inet->inet_dport = 0;
287
288 inet_bhash2_reset_saddr(sk);
289
290 sk->sk_shutdown = 0;
291 sock_reset_flag(sk, SOCK_DONE);
292
293 icsk->icsk_backoff = 0;
294 inet_csk_delack_init(sk);
295 __sk_dst_reset(sk);
296
297 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
298
299 sk_error_report(sk);
300 return 0;
301}
302
303EXPORT_SYMBOL_GPL(dccp_disconnect);
304
305/*
306 * Wait for a DCCP event.
307 *
308 * Note that we don't need to lock the socket, as the upper poll layers
309 * take care of normal races (between the test and the event) and we don't
310 * go look at any of the socket buffers directly.
311 */
312__poll_t dccp_poll(struct file *file, struct socket *sock,
313 poll_table *wait)
314{
315 __poll_t mask;
316 struct sock *sk = sock->sk;
317
318 sock_poll_wait(file, sock, wait);
319 if (sk->sk_state == DCCP_LISTEN)
320 return inet_csk_listen_poll(sk);
321
322 /* Socket is not locked. We are protected from async events
323 by poll logic and correct handling of state changes
324 made by another threads is impossible in any case.
325 */
326
327 mask = 0;
328 if (sk->sk_err)
329 mask = EPOLLERR;
330
331 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
332 mask |= EPOLLHUP;
333 if (sk->sk_shutdown & RCV_SHUTDOWN)
334 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
335
336 /* Connected? */
337 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
338 if (atomic_read(&sk->sk_rmem_alloc) > 0)
339 mask |= EPOLLIN | EPOLLRDNORM;
340
341 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
342 if (sk_stream_is_writeable(sk)) {
343 mask |= EPOLLOUT | EPOLLWRNORM;
344 } else { /* send SIGIO later */
345 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
346 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
347
348 /* Race breaker. If space is freed after
349 * wspace test but before the flags are set,
350 * IO signal will be lost.
351 */
352 if (sk_stream_is_writeable(sk))
353 mask |= EPOLLOUT | EPOLLWRNORM;
354 }
355 }
356 }
357 return mask;
358}
359
360EXPORT_SYMBOL_GPL(dccp_poll);
361
362int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
363{
364 int rc = -ENOTCONN;
365
366 lock_sock(sk);
367
368 if (sk->sk_state == DCCP_LISTEN)
369 goto out;
370
371 switch (cmd) {
372 case SIOCOUTQ: {
373 int amount = sk_wmem_alloc_get(sk);
374 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
375 * always 0, comparably to UDP.
376 */
377
378 rc = put_user(amount, (int __user *)arg);
379 }
380 break;
381 case SIOCINQ: {
382 struct sk_buff *skb;
383 unsigned long amount = 0;
384
385 skb = skb_peek(&sk->sk_receive_queue);
386 if (skb != NULL) {
387 /*
388 * We will only return the amount of this packet since
389 * that is all that will be read.
390 */
391 amount = skb->len;
392 }
393 rc = put_user(amount, (int __user *)arg);
394 }
395 break;
396 default:
397 rc = -ENOIOCTLCMD;
398 break;
399 }
400out:
401 release_sock(sk);
402 return rc;
403}
404
405EXPORT_SYMBOL_GPL(dccp_ioctl);
406
407static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
408 sockptr_t optval, unsigned int optlen)
409{
410 struct dccp_sock *dp = dccp_sk(sk);
411 struct dccp_service_list *sl = NULL;
412
413 if (service == DCCP_SERVICE_INVALID_VALUE ||
414 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
415 return -EINVAL;
416
417 if (optlen > sizeof(service)) {
418 sl = kmalloc(optlen, GFP_KERNEL);
419 if (sl == NULL)
420 return -ENOMEM;
421
422 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
423 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
424 sizeof(service), optlen - sizeof(service)) ||
425 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
426 kfree(sl);
427 return -EFAULT;
428 }
429 }
430
431 lock_sock(sk);
432 dp->dccps_service = service;
433
434 kfree(dp->dccps_service_list);
435
436 dp->dccps_service_list = sl;
437 release_sock(sk);
438 return 0;
439}
440
441static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
442{
443 u8 *list, len;
444 int i, rc;
445
446 if (cscov < 0 || cscov > 15)
447 return -EINVAL;
448 /*
449 * Populate a list of permissible values, in the range cscov...15. This
450 * is necessary since feature negotiation of single values only works if
451 * both sides incidentally choose the same value. Since the list starts
452 * lowest-value first, negotiation will pick the smallest shared value.
453 */
454 if (cscov == 0)
455 return 0;
456 len = 16 - cscov;
457
458 list = kmalloc(len, GFP_KERNEL);
459 if (list == NULL)
460 return -ENOBUFS;
461
462 for (i = 0; i < len; i++)
463 list[i] = cscov++;
464
465 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
466
467 if (rc == 0) {
468 if (rx)
469 dccp_sk(sk)->dccps_pcrlen = cscov;
470 else
471 dccp_sk(sk)->dccps_pcslen = cscov;
472 }
473 kfree(list);
474 return rc;
475}
476
477static int dccp_setsockopt_ccid(struct sock *sk, int type,
478 sockptr_t optval, unsigned int optlen)
479{
480 u8 *val;
481 int rc = 0;
482
483 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
484 return -EINVAL;
485
486 val = memdup_sockptr(optval, optlen);
487 if (IS_ERR(val))
488 return PTR_ERR(val);
489
490 lock_sock(sk);
491 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
492 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
493
494 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
495 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
496 release_sock(sk);
497
498 kfree(val);
499 return rc;
500}
501
502static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
503 sockptr_t optval, unsigned int optlen)
504{
505 struct dccp_sock *dp = dccp_sk(sk);
506 int val, err = 0;
507
508 switch (optname) {
509 case DCCP_SOCKOPT_PACKET_SIZE:
510 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
511 return 0;
512 case DCCP_SOCKOPT_CHANGE_L:
513 case DCCP_SOCKOPT_CHANGE_R:
514 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
515 return 0;
516 case DCCP_SOCKOPT_CCID:
517 case DCCP_SOCKOPT_RX_CCID:
518 case DCCP_SOCKOPT_TX_CCID:
519 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
520 }
521
522 if (optlen < (int)sizeof(int))
523 return -EINVAL;
524
525 if (copy_from_sockptr(&val, optval, sizeof(int)))
526 return -EFAULT;
527
528 if (optname == DCCP_SOCKOPT_SERVICE)
529 return dccp_setsockopt_service(sk, val, optval, optlen);
530
531 lock_sock(sk);
532 switch (optname) {
533 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
534 if (dp->dccps_role != DCCP_ROLE_SERVER)
535 err = -EOPNOTSUPP;
536 else
537 dp->dccps_server_timewait = (val != 0);
538 break;
539 case DCCP_SOCKOPT_SEND_CSCOV:
540 err = dccp_setsockopt_cscov(sk, val, false);
541 break;
542 case DCCP_SOCKOPT_RECV_CSCOV:
543 err = dccp_setsockopt_cscov(sk, val, true);
544 break;
545 case DCCP_SOCKOPT_QPOLICY_ID:
546 if (sk->sk_state != DCCP_CLOSED)
547 err = -EISCONN;
548 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
549 err = -EINVAL;
550 else
551 dp->dccps_qpolicy = val;
552 break;
553 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
554 if (val < 0)
555 err = -EINVAL;
556 else
557 dp->dccps_tx_qlen = val;
558 break;
559 default:
560 err = -ENOPROTOOPT;
561 break;
562 }
563 release_sock(sk);
564
565 return err;
566}
567
568int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
569 unsigned int optlen)
570{
571 if (level != SOL_DCCP)
572 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
573 optname, optval,
574 optlen);
575 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
576}
577
578EXPORT_SYMBOL_GPL(dccp_setsockopt);
579
580static int dccp_getsockopt_service(struct sock *sk, int len,
581 __be32 __user *optval,
582 int __user *optlen)
583{
584 const struct dccp_sock *dp = dccp_sk(sk);
585 const struct dccp_service_list *sl;
586 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
587
588 lock_sock(sk);
589 if ((sl = dp->dccps_service_list) != NULL) {
590 slen = sl->dccpsl_nr * sizeof(u32);
591 total_len += slen;
592 }
593
594 err = -EINVAL;
595 if (total_len > len)
596 goto out;
597
598 err = 0;
599 if (put_user(total_len, optlen) ||
600 put_user(dp->dccps_service, optval) ||
601 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
602 err = -EFAULT;
603out:
604 release_sock(sk);
605 return err;
606}
607
608static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
609 char __user *optval, int __user *optlen)
610{
611 struct dccp_sock *dp;
612 int val, len;
613
614 if (get_user(len, optlen))
615 return -EFAULT;
616
617 if (len < (int)sizeof(int))
618 return -EINVAL;
619
620 dp = dccp_sk(sk);
621
622 switch (optname) {
623 case DCCP_SOCKOPT_PACKET_SIZE:
624 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
625 return 0;
626 case DCCP_SOCKOPT_SERVICE:
627 return dccp_getsockopt_service(sk, len,
628 (__be32 __user *)optval, optlen);
629 case DCCP_SOCKOPT_GET_CUR_MPS:
630 val = dp->dccps_mss_cache;
631 break;
632 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
633 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
634 case DCCP_SOCKOPT_TX_CCID:
635 val = ccid_get_current_tx_ccid(dp);
636 if (val < 0)
637 return -ENOPROTOOPT;
638 break;
639 case DCCP_SOCKOPT_RX_CCID:
640 val = ccid_get_current_rx_ccid(dp);
641 if (val < 0)
642 return -ENOPROTOOPT;
643 break;
644 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
645 val = dp->dccps_server_timewait;
646 break;
647 case DCCP_SOCKOPT_SEND_CSCOV:
648 val = dp->dccps_pcslen;
649 break;
650 case DCCP_SOCKOPT_RECV_CSCOV:
651 val = dp->dccps_pcrlen;
652 break;
653 case DCCP_SOCKOPT_QPOLICY_ID:
654 val = dp->dccps_qpolicy;
655 break;
656 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
657 val = dp->dccps_tx_qlen;
658 break;
659 case 128 ... 191:
660 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
661 len, (u32 __user *)optval, optlen);
662 case 192 ... 255:
663 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
664 len, (u32 __user *)optval, optlen);
665 default:
666 return -ENOPROTOOPT;
667 }
668
669 len = sizeof(val);
670 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
671 return -EFAULT;
672
673 return 0;
674}
675
676int dccp_getsockopt(struct sock *sk, int level, int optname,
677 char __user *optval, int __user *optlen)
678{
679 if (level != SOL_DCCP)
680 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
681 optname, optval,
682 optlen);
683 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
684}
685
686EXPORT_SYMBOL_GPL(dccp_getsockopt);
687
688static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
689{
690 struct cmsghdr *cmsg;
691
692 /*
693 * Assign an (opaque) qpolicy priority value to skb->priority.
694 *
695 * We are overloading this skb field for use with the qpolicy subystem.
696 * The skb->priority is normally used for the SO_PRIORITY option, which
697 * is initialised from sk_priority. Since the assignment of sk_priority
698 * to skb->priority happens later (on layer 3), we overload this field
699 * for use with queueing priorities as long as the skb is on layer 4.
700 * The default priority value (if nothing is set) is 0.
701 */
702 skb->priority = 0;
703
704 for_each_cmsghdr(cmsg, msg) {
705 if (!CMSG_OK(msg, cmsg))
706 return -EINVAL;
707
708 if (cmsg->cmsg_level != SOL_DCCP)
709 continue;
710
711 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
712 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
713 return -EINVAL;
714
715 switch (cmsg->cmsg_type) {
716 case DCCP_SCM_PRIORITY:
717 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
718 return -EINVAL;
719 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
720 break;
721 default:
722 return -EINVAL;
723 }
724 }
725 return 0;
726}
727
728int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
729{
730 const struct dccp_sock *dp = dccp_sk(sk);
731 const int flags = msg->msg_flags;
732 const int noblock = flags & MSG_DONTWAIT;
733 struct sk_buff *skb;
734 int rc, size;
735 long timeo;
736
737 trace_dccp_probe(sk, len);
738
739 if (len > dp->dccps_mss_cache)
740 return -EMSGSIZE;
741
742 lock_sock(sk);
743
744 timeo = sock_sndtimeo(sk, noblock);
745
746 /*
747 * We have to use sk_stream_wait_connect here to set sk_write_pending,
748 * so that the trick in dccp_rcv_request_sent_state_process.
749 */
750 /* Wait for a connection to finish. */
751 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
752 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
753 goto out_release;
754
755 size = sk->sk_prot->max_header + len;
756 release_sock(sk);
757 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
758 lock_sock(sk);
759 if (skb == NULL)
760 goto out_release;
761
762 if (dccp_qpolicy_full(sk)) {
763 rc = -EAGAIN;
764 goto out_discard;
765 }
766
767 if (sk->sk_state == DCCP_CLOSED) {
768 rc = -ENOTCONN;
769 goto out_discard;
770 }
771
772 skb_reserve(skb, sk->sk_prot->max_header);
773 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
774 if (rc != 0)
775 goto out_discard;
776
777 rc = dccp_msghdr_parse(msg, skb);
778 if (rc != 0)
779 goto out_discard;
780
781 dccp_qpolicy_push(sk, skb);
782 /*
783 * The xmit_timer is set if the TX CCID is rate-based and will expire
784 * when congestion control permits to release further packets into the
785 * network. Window-based CCIDs do not use this timer.
786 */
787 if (!timer_pending(&dp->dccps_xmit_timer))
788 dccp_write_xmit(sk);
789out_release:
790 release_sock(sk);
791 return rc ? : len;
792out_discard:
793 kfree_skb(skb);
794 goto out_release;
795}
796
797EXPORT_SYMBOL_GPL(dccp_sendmsg);
798
799int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
800 int *addr_len)
801{
802 const struct dccp_hdr *dh;
803 long timeo;
804
805 lock_sock(sk);
806
807 if (sk->sk_state == DCCP_LISTEN) {
808 len = -ENOTCONN;
809 goto out;
810 }
811
812 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
813
814 do {
815 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
816
817 if (skb == NULL)
818 goto verify_sock_status;
819
820 dh = dccp_hdr(skb);
821
822 switch (dh->dccph_type) {
823 case DCCP_PKT_DATA:
824 case DCCP_PKT_DATAACK:
825 goto found_ok_skb;
826
827 case DCCP_PKT_CLOSE:
828 case DCCP_PKT_CLOSEREQ:
829 if (!(flags & MSG_PEEK))
830 dccp_finish_passive_close(sk);
831 fallthrough;
832 case DCCP_PKT_RESET:
833 dccp_pr_debug("found fin (%s) ok!\n",
834 dccp_packet_name(dh->dccph_type));
835 len = 0;
836 goto found_fin_ok;
837 default:
838 dccp_pr_debug("packet_type=%s\n",
839 dccp_packet_name(dh->dccph_type));
840 sk_eat_skb(sk, skb);
841 }
842verify_sock_status:
843 if (sock_flag(sk, SOCK_DONE)) {
844 len = 0;
845 break;
846 }
847
848 if (sk->sk_err) {
849 len = sock_error(sk);
850 break;
851 }
852
853 if (sk->sk_shutdown & RCV_SHUTDOWN) {
854 len = 0;
855 break;
856 }
857
858 if (sk->sk_state == DCCP_CLOSED) {
859 if (!sock_flag(sk, SOCK_DONE)) {
860 /* This occurs when user tries to read
861 * from never connected socket.
862 */
863 len = -ENOTCONN;
864 break;
865 }
866 len = 0;
867 break;
868 }
869
870 if (!timeo) {
871 len = -EAGAIN;
872 break;
873 }
874
875 if (signal_pending(current)) {
876 len = sock_intr_errno(timeo);
877 break;
878 }
879
880 sk_wait_data(sk, &timeo, NULL);
881 continue;
882 found_ok_skb:
883 if (len > skb->len)
884 len = skb->len;
885 else if (len < skb->len)
886 msg->msg_flags |= MSG_TRUNC;
887
888 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
889 /* Exception. Bailout! */
890 len = -EFAULT;
891 break;
892 }
893 if (flags & MSG_TRUNC)
894 len = skb->len;
895 found_fin_ok:
896 if (!(flags & MSG_PEEK))
897 sk_eat_skb(sk, skb);
898 break;
899 } while (1);
900out:
901 release_sock(sk);
902 return len;
903}
904
905EXPORT_SYMBOL_GPL(dccp_recvmsg);
906
907int inet_dccp_listen(struct socket *sock, int backlog)
908{
909 struct sock *sk = sock->sk;
910 unsigned char old_state;
911 int err;
912
913 lock_sock(sk);
914
915 err = -EINVAL;
916 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
917 goto out;
918
919 old_state = sk->sk_state;
920 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
921 goto out;
922
923 WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
924 /* Really, if the socket is already in listen state
925 * we can only allow the backlog to be adjusted.
926 */
927 if (old_state != DCCP_LISTEN) {
928 struct dccp_sock *dp = dccp_sk(sk);
929
930 dp->dccps_role = DCCP_ROLE_LISTEN;
931
932 /* do not start to listen if feature negotiation setup fails */
933 if (dccp_feat_finalise_settings(dp)) {
934 err = -EPROTO;
935 goto out;
936 }
937
938 err = inet_csk_listen_start(sk);
939 if (err)
940 goto out;
941 }
942 err = 0;
943
944out:
945 release_sock(sk);
946 return err;
947}
948
949EXPORT_SYMBOL_GPL(inet_dccp_listen);
950
951static void dccp_terminate_connection(struct sock *sk)
952{
953 u8 next_state = DCCP_CLOSED;
954
955 switch (sk->sk_state) {
956 case DCCP_PASSIVE_CLOSE:
957 case DCCP_PASSIVE_CLOSEREQ:
958 dccp_finish_passive_close(sk);
959 break;
960 case DCCP_PARTOPEN:
961 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
962 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
963 fallthrough;
964 case DCCP_OPEN:
965 dccp_send_close(sk, 1);
966
967 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
968 !dccp_sk(sk)->dccps_server_timewait)
969 next_state = DCCP_ACTIVE_CLOSEREQ;
970 else
971 next_state = DCCP_CLOSING;
972 fallthrough;
973 default:
974 dccp_set_state(sk, next_state);
975 }
976}
977
978void dccp_close(struct sock *sk, long timeout)
979{
980 struct dccp_sock *dp = dccp_sk(sk);
981 struct sk_buff *skb;
982 u32 data_was_unread = 0;
983 int state;
984
985 lock_sock(sk);
986
987 sk->sk_shutdown = SHUTDOWN_MASK;
988
989 if (sk->sk_state == DCCP_LISTEN) {
990 dccp_set_state(sk, DCCP_CLOSED);
991
992 /* Special case. */
993 inet_csk_listen_stop(sk);
994
995 goto adjudge_to_death;
996 }
997
998 sk_stop_timer(sk, &dp->dccps_xmit_timer);
999
1000 /*
1001 * We need to flush the recv. buffs. We do this only on the
1002 * descriptor close, not protocol-sourced closes, because the
1003 *reader process may not have drained the data yet!
1004 */
1005 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1006 data_was_unread += skb->len;
1007 __kfree_skb(skb);
1008 }
1009
1010 /* If socket has been already reset kill it. */
1011 if (sk->sk_state == DCCP_CLOSED)
1012 goto adjudge_to_death;
1013
1014 if (data_was_unread) {
1015 /* Unread data was tossed, send an appropriate Reset Code */
1016 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1017 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1018 dccp_set_state(sk, DCCP_CLOSED);
1019 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1020 /* Check zero linger _after_ checking for unread data. */
1021 sk->sk_prot->disconnect(sk, 0);
1022 } else if (sk->sk_state != DCCP_CLOSED) {
1023 /*
1024 * Normal connection termination. May need to wait if there are
1025 * still packets in the TX queue that are delayed by the CCID.
1026 */
1027 dccp_flush_write_queue(sk, &timeout);
1028 dccp_terminate_connection(sk);
1029 }
1030
1031 /*
1032 * Flush write queue. This may be necessary in several cases:
1033 * - we have been closed by the peer but still have application data;
1034 * - abortive termination (unread data or zero linger time),
1035 * - normal termination but queue could not be flushed within time limit
1036 */
1037 __skb_queue_purge(&sk->sk_write_queue);
1038
1039 sk_stream_wait_close(sk, timeout);
1040
1041adjudge_to_death:
1042 state = sk->sk_state;
1043 sock_hold(sk);
1044 sock_orphan(sk);
1045
1046 /*
1047 * It is the last release_sock in its life. It will remove backlog.
1048 */
1049 release_sock(sk);
1050 /*
1051 * Now socket is owned by kernel and we acquire BH lock
1052 * to finish close. No need to check for user refs.
1053 */
1054 local_bh_disable();
1055 bh_lock_sock(sk);
1056 WARN_ON(sock_owned_by_user(sk));
1057
1058 this_cpu_inc(dccp_orphan_count);
1059
1060 /* Have we already been destroyed by a softirq or backlog? */
1061 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1062 goto out;
1063
1064 if (sk->sk_state == DCCP_CLOSED)
1065 inet_csk_destroy_sock(sk);
1066
1067 /* Otherwise, socket is reprieved until protocol close. */
1068
1069out:
1070 bh_unlock_sock(sk);
1071 local_bh_enable();
1072 sock_put(sk);
1073}
1074
1075EXPORT_SYMBOL_GPL(dccp_close);
1076
1077void dccp_shutdown(struct sock *sk, int how)
1078{
1079 dccp_pr_debug("called shutdown(%x)\n", how);
1080}
1081
1082EXPORT_SYMBOL_GPL(dccp_shutdown);
1083
1084static inline int __init dccp_mib_init(void)
1085{
1086 dccp_statistics = alloc_percpu(struct dccp_mib);
1087 if (!dccp_statistics)
1088 return -ENOMEM;
1089 return 0;
1090}
1091
1092static inline void dccp_mib_exit(void)
1093{
1094 free_percpu(dccp_statistics);
1095}
1096
1097static int thash_entries;
1098module_param(thash_entries, int, 0444);
1099MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1100
1101#ifdef CONFIG_IP_DCCP_DEBUG
1102bool dccp_debug;
1103module_param(dccp_debug, bool, 0644);
1104MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1105
1106EXPORT_SYMBOL_GPL(dccp_debug);
1107#endif
1108
1109static int __init dccp_init(void)
1110{
1111 unsigned long goal;
1112 unsigned long nr_pages = totalram_pages();
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 sizeof_field(struct sk_buff, cb));
1118 rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1119 if (rc)
1120 goto out_fail;
1121 rc = -ENOBUFS;
1122 dccp_hashinfo.bind_bucket_cachep =
1123 kmem_cache_create("dccp_bind_bucket",
1124 sizeof(struct inet_bind_bucket), 0,
1125 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1126 if (!dccp_hashinfo.bind_bucket_cachep)
1127 goto out_free_hashinfo2;
1128 dccp_hashinfo.bind2_bucket_cachep =
1129 kmem_cache_create("dccp_bind2_bucket",
1130 sizeof(struct inet_bind2_bucket), 0,
1131 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
1132 if (!dccp_hashinfo.bind2_bucket_cachep)
1133 goto out_free_bind_bucket_cachep;
1134
1135 /*
1136 * Size and allocate the main established and bind bucket
1137 * hash tables.
1138 *
1139 * The methodology is similar to that of the buffer cache.
1140 */
1141 if (nr_pages >= (128 * 1024))
1142 goal = nr_pages >> (21 - PAGE_SHIFT);
1143 else
1144 goal = nr_pages >> (23 - PAGE_SHIFT);
1145
1146 if (thash_entries)
1147 goal = (thash_entries *
1148 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1149 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1150 ;
1151 do {
1152 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1153 sizeof(struct inet_ehash_bucket);
1154
1155 while (hash_size & (hash_size - 1))
1156 hash_size--;
1157 dccp_hashinfo.ehash_mask = hash_size - 1;
1158 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1159 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1160 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1161
1162 if (!dccp_hashinfo.ehash) {
1163 DCCP_CRIT("Failed to allocate DCCP established hash table");
1164 goto out_free_bind2_bucket_cachep;
1165 }
1166
1167 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1168 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1169
1170 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1171 goto out_free_dccp_ehash;
1172
1173 bhash_order = ehash_order;
1174
1175 do {
1176 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1177 sizeof(struct inet_bind_hashbucket);
1178 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1179 bhash_order > 0)
1180 continue;
1181 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1182 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1183 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1184
1185 if (!dccp_hashinfo.bhash) {
1186 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1187 goto out_free_dccp_locks;
1188 }
1189
1190 dccp_hashinfo.bhash2 = (struct inet_bind_hashbucket *)
1191 __get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order);
1192
1193 if (!dccp_hashinfo.bhash2) {
1194 DCCP_CRIT("Failed to allocate DCCP bind2 hash table");
1195 goto out_free_dccp_bhash;
1196 }
1197
1198 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1199 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1200 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1201 spin_lock_init(&dccp_hashinfo.bhash2[i].lock);
1202 INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain);
1203 }
1204
1205 dccp_hashinfo.pernet = false;
1206
1207 rc = dccp_mib_init();
1208 if (rc)
1209 goto out_free_dccp_bhash2;
1210
1211 rc = dccp_ackvec_init();
1212 if (rc)
1213 goto out_free_dccp_mib;
1214
1215 rc = dccp_sysctl_init();
1216 if (rc)
1217 goto out_ackvec_exit;
1218
1219 rc = ccid_initialize_builtins();
1220 if (rc)
1221 goto out_sysctl_exit;
1222
1223 dccp_timestamping_init();
1224
1225 return 0;
1226
1227out_sysctl_exit:
1228 dccp_sysctl_exit();
1229out_ackvec_exit:
1230 dccp_ackvec_exit();
1231out_free_dccp_mib:
1232 dccp_mib_exit();
1233out_free_dccp_bhash2:
1234 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1235out_free_dccp_bhash:
1236 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1237out_free_dccp_locks:
1238 inet_ehash_locks_free(&dccp_hashinfo);
1239out_free_dccp_ehash:
1240 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1241out_free_bind2_bucket_cachep:
1242 kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
1243out_free_bind_bucket_cachep:
1244 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1245out_free_hashinfo2:
1246 inet_hashinfo2_free_mod(&dccp_hashinfo);
1247out_fail:
1248 dccp_hashinfo.bhash = NULL;
1249 dccp_hashinfo.bhash2 = NULL;
1250 dccp_hashinfo.ehash = NULL;
1251 dccp_hashinfo.bind_bucket_cachep = NULL;
1252 dccp_hashinfo.bind2_bucket_cachep = NULL;
1253 return rc;
1254}
1255
1256static void __exit dccp_fini(void)
1257{
1258 int bhash_order = get_order(dccp_hashinfo.bhash_size *
1259 sizeof(struct inet_bind_hashbucket));
1260
1261 ccid_cleanup_builtins();
1262 dccp_mib_exit();
1263 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1264 free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
1265 free_pages((unsigned long)dccp_hashinfo.ehash,
1266 get_order((dccp_hashinfo.ehash_mask + 1) *
1267 sizeof(struct inet_ehash_bucket)));
1268 inet_ehash_locks_free(&dccp_hashinfo);
1269 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1270 dccp_ackvec_exit();
1271 dccp_sysctl_exit();
1272 inet_hashinfo2_free_mod(&dccp_hashinfo);
1273}
1274
1275module_init(dccp_init);
1276module_exit(dccp_fini);
1277
1278MODULE_LICENSE("GPL");
1279MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1280MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
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_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
188 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
189
190 dccp_init_xmit_timers(sk);
191
192 INIT_LIST_HEAD(&dp->dccps_featneg);
193 /* control socket doesn't need feat nego */
194 if (likely(ctl_sock_initialized))
195 return dccp_feat_init(sk);
196 return 0;
197}
198
199EXPORT_SYMBOL_GPL(dccp_init_sock);
200
201void dccp_destroy_sock(struct sock *sk)
202{
203 struct dccp_sock *dp = dccp_sk(sk);
204
205 /*
206 * DCCP doesn't use sk_write_queue, just sk_send_head
207 * for retransmissions
208 */
209 if (sk->sk_send_head != NULL) {
210 kfree_skb(sk->sk_send_head);
211 sk->sk_send_head = NULL;
212 }
213
214 /* Clean up a referenced DCCP bind bucket. */
215 if (inet_csk(sk)->icsk_bind_hash != NULL)
216 inet_put_port(sk);
217
218 kfree(dp->dccps_service_list);
219 dp->dccps_service_list = NULL;
220
221 if (dp->dccps_hc_rx_ackvec != NULL) {
222 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
223 dp->dccps_hc_rx_ackvec = NULL;
224 }
225 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
226 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
227 dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
228
229 /* clean up feature negotiation state */
230 dccp_feat_list_purge(&dp->dccps_featneg);
231}
232
233EXPORT_SYMBOL_GPL(dccp_destroy_sock);
234
235static inline int dccp_listen_start(struct sock *sk, int backlog)
236{
237 struct dccp_sock *dp = dccp_sk(sk);
238
239 dp->dccps_role = DCCP_ROLE_LISTEN;
240 /* do not start to listen if feature negotiation setup fails */
241 if (dccp_feat_finalise_settings(dp))
242 return -EPROTO;
243 return inet_csk_listen_start(sk, backlog);
244}
245
246static inline int dccp_need_reset(int state)
247{
248 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
249 state != DCCP_REQUESTING;
250}
251
252int dccp_disconnect(struct sock *sk, int flags)
253{
254 struct inet_connection_sock *icsk = inet_csk(sk);
255 struct inet_sock *inet = inet_sk(sk);
256 int err = 0;
257 const int old_state = sk->sk_state;
258
259 if (old_state != DCCP_CLOSED)
260 dccp_set_state(sk, DCCP_CLOSED);
261
262 /*
263 * This corresponds to the ABORT function of RFC793, sec. 3.8
264 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
265 */
266 if (old_state == DCCP_LISTEN) {
267 inet_csk_listen_stop(sk);
268 } else if (dccp_need_reset(old_state)) {
269 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
270 sk->sk_err = ECONNRESET;
271 } else if (old_state == DCCP_REQUESTING)
272 sk->sk_err = ECONNRESET;
273
274 dccp_clear_xmit_timers(sk);
275
276 __skb_queue_purge(&sk->sk_receive_queue);
277 __skb_queue_purge(&sk->sk_write_queue);
278 if (sk->sk_send_head != NULL) {
279 __kfree_skb(sk->sk_send_head);
280 sk->sk_send_head = NULL;
281 }
282
283 inet->inet_dport = 0;
284
285 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
286 inet_reset_saddr(sk);
287
288 sk->sk_shutdown = 0;
289 sock_reset_flag(sk, SOCK_DONE);
290
291 icsk->icsk_backoff = 0;
292 inet_csk_delack_init(sk);
293 __sk_dst_reset(sk);
294
295 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
296
297 sk->sk_error_report(sk);
298 return err;
299}
300
301EXPORT_SYMBOL_GPL(dccp_disconnect);
302
303/*
304 * Wait for a DCCP event.
305 *
306 * Note that we don't need to lock the socket, as the upper poll layers
307 * take care of normal races (between the test and the event) and we don't
308 * go look at any of the socket buffers directly.
309 */
310unsigned int dccp_poll(struct file *file, struct socket *sock,
311 poll_table *wait)
312{
313 unsigned int mask;
314 struct sock *sk = sock->sk;
315
316 sock_poll_wait(file, sk_sleep(sk), wait);
317 if (sk->sk_state == DCCP_LISTEN)
318 return inet_csk_listen_poll(sk);
319
320 /* Socket is not locked. We are protected from async events
321 by poll logic and correct handling of state changes
322 made by another threads is impossible in any case.
323 */
324
325 mask = 0;
326 if (sk->sk_err)
327 mask = POLLERR;
328
329 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
330 mask |= POLLHUP;
331 if (sk->sk_shutdown & RCV_SHUTDOWN)
332 mask |= POLLIN | POLLRDNORM | POLLRDHUP;
333
334 /* Connected? */
335 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
336 if (atomic_read(&sk->sk_rmem_alloc) > 0)
337 mask |= POLLIN | POLLRDNORM;
338
339 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
340 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
341 mask |= POLLOUT | POLLWRNORM;
342 } else { /* send SIGIO later */
343 set_bit(SOCK_ASYNC_NOSPACE,
344 &sk->sk_socket->flags);
345 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
346
347 /* Race breaker. If space is freed after
348 * wspace test but before the flags are set,
349 * IO signal will be lost.
350 */
351 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
352 mask |= POLLOUT | POLLWRNORM;
353 }
354 }
355 }
356 return mask;
357}
358
359EXPORT_SYMBOL_GPL(dccp_poll);
360
361int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
362{
363 int rc = -ENOTCONN;
364
365 lock_sock(sk);
366
367 if (sk->sk_state == DCCP_LISTEN)
368 goto out;
369
370 switch (cmd) {
371 case SIOCINQ: {
372 struct sk_buff *skb;
373 unsigned long amount = 0;
374
375 skb = skb_peek(&sk->sk_receive_queue);
376 if (skb != NULL) {
377 /*
378 * We will only return the amount of this packet since
379 * that is all that will be read.
380 */
381 amount = skb->len;
382 }
383 rc = put_user(amount, (int __user *)arg);
384 }
385 break;
386 default:
387 rc = -ENOIOCTLCMD;
388 break;
389 }
390out:
391 release_sock(sk);
392 return rc;
393}
394
395EXPORT_SYMBOL_GPL(dccp_ioctl);
396
397static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
398 char __user *optval, unsigned int optlen)
399{
400 struct dccp_sock *dp = dccp_sk(sk);
401 struct dccp_service_list *sl = NULL;
402
403 if (service == DCCP_SERVICE_INVALID_VALUE ||
404 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
405 return -EINVAL;
406
407 if (optlen > sizeof(service)) {
408 sl = kmalloc(optlen, GFP_KERNEL);
409 if (sl == NULL)
410 return -ENOMEM;
411
412 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
413 if (copy_from_user(sl->dccpsl_list,
414 optval + sizeof(service),
415 optlen - sizeof(service)) ||
416 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
417 kfree(sl);
418 return -EFAULT;
419 }
420 }
421
422 lock_sock(sk);
423 dp->dccps_service = service;
424
425 kfree(dp->dccps_service_list);
426
427 dp->dccps_service_list = sl;
428 release_sock(sk);
429 return 0;
430}
431
432static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
433{
434 u8 *list, len;
435 int i, rc;
436
437 if (cscov < 0 || cscov > 15)
438 return -EINVAL;
439 /*
440 * Populate a list of permissible values, in the range cscov...15. This
441 * is necessary since feature negotiation of single values only works if
442 * both sides incidentally choose the same value. Since the list starts
443 * lowest-value first, negotiation will pick the smallest shared value.
444 */
445 if (cscov == 0)
446 return 0;
447 len = 16 - cscov;
448
449 list = kmalloc(len, GFP_KERNEL);
450 if (list == NULL)
451 return -ENOBUFS;
452
453 for (i = 0; i < len; i++)
454 list[i] = cscov++;
455
456 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
457
458 if (rc == 0) {
459 if (rx)
460 dccp_sk(sk)->dccps_pcrlen = cscov;
461 else
462 dccp_sk(sk)->dccps_pcslen = cscov;
463 }
464 kfree(list);
465 return rc;
466}
467
468static int dccp_setsockopt_ccid(struct sock *sk, int type,
469 char __user *optval, unsigned int optlen)
470{
471 u8 *val;
472 int rc = 0;
473
474 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
475 return -EINVAL;
476
477 val = memdup_user(optval, optlen);
478 if (IS_ERR(val))
479 return PTR_ERR(val);
480
481 lock_sock(sk);
482 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
483 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
484
485 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
486 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
487 release_sock(sk);
488
489 kfree(val);
490 return rc;
491}
492
493static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
494 char __user *optval, unsigned int optlen)
495{
496 struct dccp_sock *dp = dccp_sk(sk);
497 int val, err = 0;
498
499 switch (optname) {
500 case DCCP_SOCKOPT_PACKET_SIZE:
501 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
502 return 0;
503 case DCCP_SOCKOPT_CHANGE_L:
504 case DCCP_SOCKOPT_CHANGE_R:
505 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
506 return 0;
507 case DCCP_SOCKOPT_CCID:
508 case DCCP_SOCKOPT_RX_CCID:
509 case DCCP_SOCKOPT_TX_CCID:
510 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
511 }
512
513 if (optlen < (int)sizeof(int))
514 return -EINVAL;
515
516 if (get_user(val, (int __user *)optval))
517 return -EFAULT;
518
519 if (optname == DCCP_SOCKOPT_SERVICE)
520 return dccp_setsockopt_service(sk, val, optval, optlen);
521
522 lock_sock(sk);
523 switch (optname) {
524 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
525 if (dp->dccps_role != DCCP_ROLE_SERVER)
526 err = -EOPNOTSUPP;
527 else
528 dp->dccps_server_timewait = (val != 0);
529 break;
530 case DCCP_SOCKOPT_SEND_CSCOV:
531 err = dccp_setsockopt_cscov(sk, val, false);
532 break;
533 case DCCP_SOCKOPT_RECV_CSCOV:
534 err = dccp_setsockopt_cscov(sk, val, true);
535 break;
536 case DCCP_SOCKOPT_QPOLICY_ID:
537 if (sk->sk_state != DCCP_CLOSED)
538 err = -EISCONN;
539 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
540 err = -EINVAL;
541 else
542 dp->dccps_qpolicy = val;
543 break;
544 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
545 if (val < 0)
546 err = -EINVAL;
547 else
548 dp->dccps_tx_qlen = val;
549 break;
550 default:
551 err = -ENOPROTOOPT;
552 break;
553 }
554 release_sock(sk);
555
556 return err;
557}
558
559int dccp_setsockopt(struct sock *sk, int level, int optname,
560 char __user *optval, unsigned int optlen)
561{
562 if (level != SOL_DCCP)
563 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
564 optname, optval,
565 optlen);
566 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
567}
568
569EXPORT_SYMBOL_GPL(dccp_setsockopt);
570
571#ifdef CONFIG_COMPAT
572int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
573 char __user *optval, unsigned int optlen)
574{
575 if (level != SOL_DCCP)
576 return inet_csk_compat_setsockopt(sk, level, optname,
577 optval, optlen);
578 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
579}
580
581EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
582#endif
583
584static int dccp_getsockopt_service(struct sock *sk, int len,
585 __be32 __user *optval,
586 int __user *optlen)
587{
588 const struct dccp_sock *dp = dccp_sk(sk);
589 const struct dccp_service_list *sl;
590 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
591
592 lock_sock(sk);
593 if ((sl = dp->dccps_service_list) != NULL) {
594 slen = sl->dccpsl_nr * sizeof(u32);
595 total_len += slen;
596 }
597
598 err = -EINVAL;
599 if (total_len > len)
600 goto out;
601
602 err = 0;
603 if (put_user(total_len, optlen) ||
604 put_user(dp->dccps_service, optval) ||
605 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
606 err = -EFAULT;
607out:
608 release_sock(sk);
609 return err;
610}
611
612static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
613 char __user *optval, int __user *optlen)
614{
615 struct dccp_sock *dp;
616 int val, len;
617
618 if (get_user(len, optlen))
619 return -EFAULT;
620
621 if (len < (int)sizeof(int))
622 return -EINVAL;
623
624 dp = dccp_sk(sk);
625
626 switch (optname) {
627 case DCCP_SOCKOPT_PACKET_SIZE:
628 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
629 return 0;
630 case DCCP_SOCKOPT_SERVICE:
631 return dccp_getsockopt_service(sk, len,
632 (__be32 __user *)optval, optlen);
633 case DCCP_SOCKOPT_GET_CUR_MPS:
634 val = dp->dccps_mss_cache;
635 break;
636 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
637 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
638 case DCCP_SOCKOPT_TX_CCID:
639 val = ccid_get_current_tx_ccid(dp);
640 if (val < 0)
641 return -ENOPROTOOPT;
642 break;
643 case DCCP_SOCKOPT_RX_CCID:
644 val = ccid_get_current_rx_ccid(dp);
645 if (val < 0)
646 return -ENOPROTOOPT;
647 break;
648 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
649 val = dp->dccps_server_timewait;
650 break;
651 case DCCP_SOCKOPT_SEND_CSCOV:
652 val = dp->dccps_pcslen;
653 break;
654 case DCCP_SOCKOPT_RECV_CSCOV:
655 val = dp->dccps_pcrlen;
656 break;
657 case DCCP_SOCKOPT_QPOLICY_ID:
658 val = dp->dccps_qpolicy;
659 break;
660 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
661 val = dp->dccps_tx_qlen;
662 break;
663 case 128 ... 191:
664 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
665 len, (u32 __user *)optval, optlen);
666 case 192 ... 255:
667 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
668 len, (u32 __user *)optval, optlen);
669 default:
670 return -ENOPROTOOPT;
671 }
672
673 len = sizeof(val);
674 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
675 return -EFAULT;
676
677 return 0;
678}
679
680int dccp_getsockopt(struct sock *sk, int level, int optname,
681 char __user *optval, int __user *optlen)
682{
683 if (level != SOL_DCCP)
684 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
685 optname, optval,
686 optlen);
687 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
688}
689
690EXPORT_SYMBOL_GPL(dccp_getsockopt);
691
692#ifdef CONFIG_COMPAT
693int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
694 char __user *optval, int __user *optlen)
695{
696 if (level != SOL_DCCP)
697 return inet_csk_compat_getsockopt(sk, level, optname,
698 optval, optlen);
699 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
700}
701
702EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
703#endif
704
705static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
706{
707 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
708
709 /*
710 * Assign an (opaque) qpolicy priority value to skb->priority.
711 *
712 * We are overloading this skb field for use with the qpolicy subystem.
713 * The skb->priority is normally used for the SO_PRIORITY option, which
714 * is initialised from sk_priority. Since the assignment of sk_priority
715 * to skb->priority happens later (on layer 3), we overload this field
716 * for use with queueing priorities as long as the skb is on layer 4.
717 * The default priority value (if nothing is set) is 0.
718 */
719 skb->priority = 0;
720
721 for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
722
723 if (!CMSG_OK(msg, cmsg))
724 return -EINVAL;
725
726 if (cmsg->cmsg_level != SOL_DCCP)
727 continue;
728
729 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
730 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
731 return -EINVAL;
732
733 switch (cmsg->cmsg_type) {
734 case DCCP_SCM_PRIORITY:
735 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
736 return -EINVAL;
737 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
738 break;
739 default:
740 return -EINVAL;
741 }
742 }
743 return 0;
744}
745
746int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
747 size_t len)
748{
749 const struct dccp_sock *dp = dccp_sk(sk);
750 const int flags = msg->msg_flags;
751 const int noblock = flags & MSG_DONTWAIT;
752 struct sk_buff *skb;
753 int rc, size;
754 long timeo;
755
756 if (len > dp->dccps_mss_cache)
757 return -EMSGSIZE;
758
759 lock_sock(sk);
760
761 if (dccp_qpolicy_full(sk)) {
762 rc = -EAGAIN;
763 goto out_release;
764 }
765
766 timeo = sock_sndtimeo(sk, noblock);
767
768 /*
769 * We have to use sk_stream_wait_connect here to set sk_write_pending,
770 * so that the trick in dccp_rcv_request_sent_state_process.
771 */
772 /* Wait for a connection to finish. */
773 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
774 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
775 goto out_release;
776
777 size = sk->sk_prot->max_header + len;
778 release_sock(sk);
779 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
780 lock_sock(sk);
781 if (skb == NULL)
782 goto out_release;
783
784 skb_reserve(skb, sk->sk_prot->max_header);
785 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
786 if (rc != 0)
787 goto out_discard;
788
789 rc = dccp_msghdr_parse(msg, skb);
790 if (rc != 0)
791 goto out_discard;
792
793 dccp_qpolicy_push(sk, skb);
794 /*
795 * The xmit_timer is set if the TX CCID is rate-based and will expire
796 * when congestion control permits to release further packets into the
797 * network. Window-based CCIDs do not use this timer.
798 */
799 if (!timer_pending(&dp->dccps_xmit_timer))
800 dccp_write_xmit(sk);
801out_release:
802 release_sock(sk);
803 return rc ? : len;
804out_discard:
805 kfree_skb(skb);
806 goto out_release;
807}
808
809EXPORT_SYMBOL_GPL(dccp_sendmsg);
810
811int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
812 size_t len, int nonblock, int flags, int *addr_len)
813{
814 const struct dccp_hdr *dh;
815 long timeo;
816
817 lock_sock(sk);
818
819 if (sk->sk_state == DCCP_LISTEN) {
820 len = -ENOTCONN;
821 goto out;
822 }
823
824 timeo = sock_rcvtimeo(sk, nonblock);
825
826 do {
827 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
828
829 if (skb == NULL)
830 goto verify_sock_status;
831
832 dh = dccp_hdr(skb);
833
834 switch (dh->dccph_type) {
835 case DCCP_PKT_DATA:
836 case DCCP_PKT_DATAACK:
837 goto found_ok_skb;
838
839 case DCCP_PKT_CLOSE:
840 case DCCP_PKT_CLOSEREQ:
841 if (!(flags & MSG_PEEK))
842 dccp_finish_passive_close(sk);
843 /* fall through */
844 case DCCP_PKT_RESET:
845 dccp_pr_debug("found fin (%s) ok!\n",
846 dccp_packet_name(dh->dccph_type));
847 len = 0;
848 goto found_fin_ok;
849 default:
850 dccp_pr_debug("packet_type=%s\n",
851 dccp_packet_name(dh->dccph_type));
852 sk_eat_skb(sk, skb, 0);
853 }
854verify_sock_status:
855 if (sock_flag(sk, SOCK_DONE)) {
856 len = 0;
857 break;
858 }
859
860 if (sk->sk_err) {
861 len = sock_error(sk);
862 break;
863 }
864
865 if (sk->sk_shutdown & RCV_SHUTDOWN) {
866 len = 0;
867 break;
868 }
869
870 if (sk->sk_state == DCCP_CLOSED) {
871 if (!sock_flag(sk, SOCK_DONE)) {
872 /* This occurs when user tries to read
873 * from never connected socket.
874 */
875 len = -ENOTCONN;
876 break;
877 }
878 len = 0;
879 break;
880 }
881
882 if (!timeo) {
883 len = -EAGAIN;
884 break;
885 }
886
887 if (signal_pending(current)) {
888 len = sock_intr_errno(timeo);
889 break;
890 }
891
892 sk_wait_data(sk, &timeo);
893 continue;
894 found_ok_skb:
895 if (len > skb->len)
896 len = skb->len;
897 else if (len < skb->len)
898 msg->msg_flags |= MSG_TRUNC;
899
900 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
901 /* Exception. Bailout! */
902 len = -EFAULT;
903 break;
904 }
905 if (flags & MSG_TRUNC)
906 len = skb->len;
907 found_fin_ok:
908 if (!(flags & MSG_PEEK))
909 sk_eat_skb(sk, skb, 0);
910 break;
911 } while (1);
912out:
913 release_sock(sk);
914 return len;
915}
916
917EXPORT_SYMBOL_GPL(dccp_recvmsg);
918
919int inet_dccp_listen(struct socket *sock, int backlog)
920{
921 struct sock *sk = sock->sk;
922 unsigned char old_state;
923 int err;
924
925 lock_sock(sk);
926
927 err = -EINVAL;
928 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
929 goto out;
930
931 old_state = sk->sk_state;
932 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
933 goto out;
934
935 /* Really, if the socket is already in listen state
936 * we can only allow the backlog to be adjusted.
937 */
938 if (old_state != DCCP_LISTEN) {
939 /*
940 * FIXME: here it probably should be sk->sk_prot->listen_start
941 * see tcp_listen_start
942 */
943 err = dccp_listen_start(sk, backlog);
944 if (err)
945 goto out;
946 }
947 sk->sk_max_ack_backlog = backlog;
948 err = 0;
949
950out:
951 release_sock(sk);
952 return err;
953}
954
955EXPORT_SYMBOL_GPL(inet_dccp_listen);
956
957static void dccp_terminate_connection(struct sock *sk)
958{
959 u8 next_state = DCCP_CLOSED;
960
961 switch (sk->sk_state) {
962 case DCCP_PASSIVE_CLOSE:
963 case DCCP_PASSIVE_CLOSEREQ:
964 dccp_finish_passive_close(sk);
965 break;
966 case DCCP_PARTOPEN:
967 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
968 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
969 /* fall through */
970 case DCCP_OPEN:
971 dccp_send_close(sk, 1);
972
973 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
974 !dccp_sk(sk)->dccps_server_timewait)
975 next_state = DCCP_ACTIVE_CLOSEREQ;
976 else
977 next_state = DCCP_CLOSING;
978 /* fall through */
979 default:
980 dccp_set_state(sk, next_state);
981 }
982}
983
984void dccp_close(struct sock *sk, long timeout)
985{
986 struct dccp_sock *dp = dccp_sk(sk);
987 struct sk_buff *skb;
988 u32 data_was_unread = 0;
989 int state;
990
991 lock_sock(sk);
992
993 sk->sk_shutdown = SHUTDOWN_MASK;
994
995 if (sk->sk_state == DCCP_LISTEN) {
996 dccp_set_state(sk, DCCP_CLOSED);
997
998 /* Special case. */
999 inet_csk_listen_stop(sk);
1000
1001 goto adjudge_to_death;
1002 }
1003
1004 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1005
1006 /*
1007 * We need to flush the recv. buffs. We do this only on the
1008 * descriptor close, not protocol-sourced closes, because the
1009 *reader process may not have drained the data yet!
1010 */
1011 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1012 data_was_unread += skb->len;
1013 __kfree_skb(skb);
1014 }
1015
1016 if (data_was_unread) {
1017 /* Unread data was tossed, send an appropriate Reset Code */
1018 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1019 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1020 dccp_set_state(sk, DCCP_CLOSED);
1021 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1022 /* Check zero linger _after_ checking for unread data. */
1023 sk->sk_prot->disconnect(sk, 0);
1024 } else if (sk->sk_state != DCCP_CLOSED) {
1025 /*
1026 * Normal connection termination. May need to wait if there are
1027 * still packets in the TX queue that are delayed by the CCID.
1028 */
1029 dccp_flush_write_queue(sk, &timeout);
1030 dccp_terminate_connection(sk);
1031 }
1032
1033 /*
1034 * Flush write queue. This may be necessary in several cases:
1035 * - we have been closed by the peer but still have application data;
1036 * - abortive termination (unread data or zero linger time),
1037 * - normal termination but queue could not be flushed within time limit
1038 */
1039 __skb_queue_purge(&sk->sk_write_queue);
1040
1041 sk_stream_wait_close(sk, timeout);
1042
1043adjudge_to_death:
1044 state = sk->sk_state;
1045 sock_hold(sk);
1046 sock_orphan(sk);
1047
1048 /*
1049 * It is the last release_sock in its life. It will remove backlog.
1050 */
1051 release_sock(sk);
1052 /*
1053 * Now socket is owned by kernel and we acquire BH lock
1054 * to finish close. No need to check for user refs.
1055 */
1056 local_bh_disable();
1057 bh_lock_sock(sk);
1058 WARN_ON(sock_owned_by_user(sk));
1059
1060 percpu_counter_inc(sk->sk_prot->orphan_count);
1061
1062 /* Have we already been destroyed by a softirq or backlog? */
1063 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1064 goto out;
1065
1066 if (sk->sk_state == DCCP_CLOSED)
1067 inet_csk_destroy_sock(sk);
1068
1069 /* Otherwise, socket is reprieved until protocol close. */
1070
1071out:
1072 bh_unlock_sock(sk);
1073 local_bh_enable();
1074 sock_put(sk);
1075}
1076
1077EXPORT_SYMBOL_GPL(dccp_close);
1078
1079void dccp_shutdown(struct sock *sk, int how)
1080{
1081 dccp_pr_debug("called shutdown(%x)\n", how);
1082}
1083
1084EXPORT_SYMBOL_GPL(dccp_shutdown);
1085
1086static inline int dccp_mib_init(void)
1087{
1088 return snmp_mib_init((void __percpu **)dccp_statistics,
1089 sizeof(struct dccp_mib),
1090 __alignof__(struct dccp_mib));
1091}
1092
1093static inline void dccp_mib_exit(void)
1094{
1095 snmp_mib_free((void __percpu **)dccp_statistics);
1096}
1097
1098static int thash_entries;
1099module_param(thash_entries, int, 0444);
1100MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1101
1102#ifdef CONFIG_IP_DCCP_DEBUG
1103int dccp_debug;
1104module_param(dccp_debug, bool, 0644);
1105MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1106
1107EXPORT_SYMBOL_GPL(dccp_debug);
1108#endif
1109
1110static int __init dccp_init(void)
1111{
1112 unsigned long goal;
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 FIELD_SIZEOF(struct sk_buff, cb));
1118 rc = percpu_counter_init(&dccp_orphan_count, 0);
1119 if (rc)
1120 goto out_fail;
1121 rc = -ENOBUFS;
1122 inet_hashinfo_init(&dccp_hashinfo);
1123 dccp_hashinfo.bind_bucket_cachep =
1124 kmem_cache_create("dccp_bind_bucket",
1125 sizeof(struct inet_bind_bucket), 0,
1126 SLAB_HWCACHE_ALIGN, NULL);
1127 if (!dccp_hashinfo.bind_bucket_cachep)
1128 goto out_free_percpu;
1129
1130 /*
1131 * Size and allocate the main established and bind bucket
1132 * hash tables.
1133 *
1134 * The methodology is similar to that of the buffer cache.
1135 */
1136 if (totalram_pages >= (128 * 1024))
1137 goal = totalram_pages >> (21 - PAGE_SHIFT);
1138 else
1139 goal = totalram_pages >> (23 - PAGE_SHIFT);
1140
1141 if (thash_entries)
1142 goal = (thash_entries *
1143 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1144 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1145 ;
1146 do {
1147 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1148 sizeof(struct inet_ehash_bucket);
1149
1150 while (hash_size & (hash_size - 1))
1151 hash_size--;
1152 dccp_hashinfo.ehash_mask = hash_size - 1;
1153 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1154 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1155 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1156
1157 if (!dccp_hashinfo.ehash) {
1158 DCCP_CRIT("Failed to allocate DCCP established hash table");
1159 goto out_free_bind_bucket_cachep;
1160 }
1161
1162 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1163 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1164 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1165 }
1166
1167 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1168 goto out_free_dccp_ehash;
1169
1170 bhash_order = ehash_order;
1171
1172 do {
1173 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1174 sizeof(struct inet_bind_hashbucket);
1175 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1176 bhash_order > 0)
1177 continue;
1178 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1179 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1180 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1181
1182 if (!dccp_hashinfo.bhash) {
1183 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1184 goto out_free_dccp_locks;
1185 }
1186
1187 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1188 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1189 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1190 }
1191
1192 rc = dccp_mib_init();
1193 if (rc)
1194 goto out_free_dccp_bhash;
1195
1196 rc = dccp_ackvec_init();
1197 if (rc)
1198 goto out_free_dccp_mib;
1199
1200 rc = dccp_sysctl_init();
1201 if (rc)
1202 goto out_ackvec_exit;
1203
1204 rc = ccid_initialize_builtins();
1205 if (rc)
1206 goto out_sysctl_exit;
1207
1208 dccp_timestamping_init();
1209
1210 return 0;
1211
1212out_sysctl_exit:
1213 dccp_sysctl_exit();
1214out_ackvec_exit:
1215 dccp_ackvec_exit();
1216out_free_dccp_mib:
1217 dccp_mib_exit();
1218out_free_dccp_bhash:
1219 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1220out_free_dccp_locks:
1221 inet_ehash_locks_free(&dccp_hashinfo);
1222out_free_dccp_ehash:
1223 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1224out_free_bind_bucket_cachep:
1225 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1226out_free_percpu:
1227 percpu_counter_destroy(&dccp_orphan_count);
1228out_fail:
1229 dccp_hashinfo.bhash = NULL;
1230 dccp_hashinfo.ehash = NULL;
1231 dccp_hashinfo.bind_bucket_cachep = NULL;
1232 return rc;
1233}
1234
1235static void __exit dccp_fini(void)
1236{
1237 ccid_cleanup_builtins();
1238 dccp_mib_exit();
1239 free_pages((unsigned long)dccp_hashinfo.bhash,
1240 get_order(dccp_hashinfo.bhash_size *
1241 sizeof(struct inet_bind_hashbucket)));
1242 free_pages((unsigned long)dccp_hashinfo.ehash,
1243 get_order((dccp_hashinfo.ehash_mask + 1) *
1244 sizeof(struct inet_ehash_bucket)));
1245 inet_ehash_locks_free(&dccp_hashinfo);
1246 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1247 dccp_ackvec_exit();
1248 dccp_sysctl_exit();
1249 percpu_counter_destroy(&dccp_orphan_count);
1250}
1251
1252module_init(dccp_init);
1253module_exit(dccp_fini);
1254
1255MODULE_LICENSE("GPL");
1256MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1257MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");