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dm thin: wake worker when discard is prepared
[linux-2.6.git] / net / dccp / proto.c
blob6c7c78b839403f7582c8fd9daef4cfe0e1e571a0
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
40 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
41
42 EXPORT_SYMBOL_GPL(dccp_statistics);
43
44 struct percpu_counter dccp_orphan_count;
45 EXPORT_SYMBOL_GPL(dccp_orphan_count);
46
47 struct inet_hashinfo dccp_hashinfo;
48 EXPORT_SYMBOL_GPL(dccp_hashinfo);
49
50 /* the maximum queue length for tx in packets. 0 is no limit */
51 int sysctl_dccp_tx_qlen __read_mostly = 5;
52
53 #ifdef CONFIG_IP_DCCP_DEBUG
54 static 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
77 void 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
115 EXPORT_SYMBOL_GPL(dccp_set_state);
116
117 static 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
135 void 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
148 EXPORT_SYMBOL_GPL(dccp_done);
149
150 const 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
171 EXPORT_SYMBOL_GPL(dccp_packet_name);
172
173 int 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
198 EXPORT_SYMBOL_GPL(dccp_init_sock);
199
200 void 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
232 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
233
234 static 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
245 static inline int dccp_need_reset(int state)
246 {
247 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
248 state != DCCP_REQUESTING;
249 }
250
251 int 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
300 EXPORT_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 */
309 unsigned 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
358 EXPORT_SYMBOL_GPL(dccp_poll);
359
360 int 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 }
389 out:
390 release_sock(sk);
391 return rc;
392 }
393
394 EXPORT_SYMBOL_GPL(dccp_ioctl);
395
396 static 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
431 static 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
467 static 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
492 static 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
558 int 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
568 EXPORT_SYMBOL_GPL(dccp_setsockopt);
569
570 #ifdef CONFIG_COMPAT
571 int 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
580 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
581 #endif
582
583 static 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;
606 out:
607 release_sock(sk);
608 return err;
609 }
610
611 static 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
679 int 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
689 EXPORT_SYMBOL_GPL(dccp_getsockopt);
690
691 #ifdef CONFIG_COMPAT
692 int 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
701 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
702 #endif
703
704 static 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
745 int 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);
800 out_release:
801 release_sock(sk);
802 return rc ? : len;
803 out_discard:
804 kfree_skb(skb);
805 goto out_release;
806 }
807
808 EXPORT_SYMBOL_GPL(dccp_sendmsg);
809
810 int 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 }
853 verify_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);
911 out:
912 release_sock(sk);
913 return len;
914 }
915
916 EXPORT_SYMBOL_GPL(dccp_recvmsg);
917
918 int 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
949 out:
950 release_sock(sk);
951 return err;
952 }
953
954 EXPORT_SYMBOL_GPL(inet_dccp_listen);
955
956 static 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
983 void 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
1042 adjudge_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
1070 out:
1071 bh_unlock_sock(sk);
1072 local_bh_enable();
1073 sock_put(sk);
1074 }
1075
1076 EXPORT_SYMBOL_GPL(dccp_close);
1077
1078 void dccp_shutdown(struct sock *sk, int how)
1079 {
1080 dccp_pr_debug("called shutdown(%x)\n", how);
1081 }
1082
1083 EXPORT_SYMBOL_GPL(dccp_shutdown);
1084
1085 static 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
1092 static inline void dccp_mib_exit(void)
1093 {
1094 snmp_mib_free((void __percpu **)dccp_statistics);
1095 }
1096
1097 static int thash_entries;
1098 module_param(thash_entries, int, 0444);
1099 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1100
1101 #ifdef CONFIG_IP_DCCP_DEBUG
1102 bool dccp_debug;
1103 module_param(dccp_debug, bool, 0644);
1104 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1105
1106 EXPORT_SYMBOL_GPL(dccp_debug);
1107 #endif
1108
1109 static 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
1211 out_sysctl_exit:
1212 dccp_sysctl_exit();
1213 out_ackvec_exit:
1214 dccp_ackvec_exit();
1215 out_free_dccp_mib:
1216 dccp_mib_exit();
1217 out_free_dccp_bhash:
1218 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1219 out_free_dccp_locks:
1220 inet_ehash_locks_free(&dccp_hashinfo);
1221 out_free_dccp_ehash:
1222 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1223 out_free_bind_bucket_cachep:
1224 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1225 out_free_percpu:
1226 percpu_counter_destroy(&dccp_orphan_count);
1227 out_fail:
1228 dccp_hashinfo.bhash = NULL;
1229 dccp_hashinfo.ehash = NULL;
1230 dccp_hashinfo.bind_bucket_cachep = NULL;
1231 return rc;
1232 }
1233
1234 static 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
1251 module_init(dccp_init);
1252 module_exit(dccp_fini);
1253
1254 MODULE_LICENSE("GPL");
1255 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1256 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
Linus' kernel tree