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dccp: Policy-based packet dequeueing infrastructure
[deliverable/linux.git] / net / dccp / proto.c
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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 switch (cmsg->cmsg_type) {
730 case DCCP_SCM_PRIORITY:
731 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
732 return -EINVAL;
733 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
734 break;
735 default:
736 return -EINVAL;
737 }
738 }
739 return 0;
740}
741
742int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
743 size_t len)
744{
745 const struct dccp_sock *dp = dccp_sk(sk);
746 const int flags = msg->msg_flags;
747 const int noblock = flags & MSG_DONTWAIT;
748 struct sk_buff *skb;
749 int rc, size;
750 long timeo;
751
752 if (len > dp->dccps_mss_cache)
753 return -EMSGSIZE;
754
755 lock_sock(sk);
756
757 if (dccp_qpolicy_full(sk)) {
758 rc = -EAGAIN;
759 goto out_release;
760 }
761
762 timeo = sock_sndtimeo(sk, noblock);
763
764 /*
765 * We have to use sk_stream_wait_connect here to set sk_write_pending,
766 * so that the trick in dccp_rcv_request_sent_state_process.
767 */
768 /* Wait for a connection to finish. */
769 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
770 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
771 goto out_release;
772
773 size = sk->sk_prot->max_header + len;
774 release_sock(sk);
775 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
776 lock_sock(sk);
777 if (skb == NULL)
778 goto out_release;
779
780 skb_reserve(skb, sk->sk_prot->max_header);
781 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
782 if (rc != 0)
783 goto out_discard;
784
785 rc = dccp_msghdr_parse(msg, skb);
786 if (rc != 0)
787 goto out_discard;
788
789 dccp_qpolicy_push(sk, skb);
790 /*
791 * The xmit_timer is set if the TX CCID is rate-based and will expire
792 * when congestion control permits to release further packets into the
793 * network. Window-based CCIDs do not use this timer.
794 */
795 if (!timer_pending(&dp->dccps_xmit_timer))
796 dccp_write_xmit(sk);
797out_release:
798 release_sock(sk);
799 return rc ? : len;
800out_discard:
801 kfree_skb(skb);
802 goto out_release;
803}
804
805EXPORT_SYMBOL_GPL(dccp_sendmsg);
806
807int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
808 size_t len, int nonblock, int flags, int *addr_len)
809{
810 const struct dccp_hdr *dh;
811 long timeo;
812
813 lock_sock(sk);
814
815 if (sk->sk_state == DCCP_LISTEN) {
816 len = -ENOTCONN;
817 goto out;
818 }
819
820 timeo = sock_rcvtimeo(sk, nonblock);
821
822 do {
823 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
824
825 if (skb == NULL)
826 goto verify_sock_status;
827
828 dh = dccp_hdr(skb);
829
830 switch (dh->dccph_type) {
831 case DCCP_PKT_DATA:
832 case DCCP_PKT_DATAACK:
833 goto found_ok_skb;
834
835 case DCCP_PKT_CLOSE:
836 case DCCP_PKT_CLOSEREQ:
837 if (!(flags & MSG_PEEK))
838 dccp_finish_passive_close(sk);
839 /* fall through */
840 case DCCP_PKT_RESET:
841 dccp_pr_debug("found fin (%s) ok!\n",
842 dccp_packet_name(dh->dccph_type));
843 len = 0;
844 goto found_fin_ok;
845 default:
846 dccp_pr_debug("packet_type=%s\n",
847 dccp_packet_name(dh->dccph_type));
848 sk_eat_skb(sk, skb, 0);
849 }
850verify_sock_status:
851 if (sock_flag(sk, SOCK_DONE)) {
852 len = 0;
853 break;
854 }
855
856 if (sk->sk_err) {
857 len = sock_error(sk);
858 break;
859 }
860
861 if (sk->sk_shutdown & RCV_SHUTDOWN) {
862 len = 0;
863 break;
864 }
865
866 if (sk->sk_state == DCCP_CLOSED) {
867 if (!sock_flag(sk, SOCK_DONE)) {
868 /* This occurs when user tries to read
869 * from never connected socket.
870 */
871 len = -ENOTCONN;
872 break;
873 }
874 len = 0;
875 break;
876 }
877
878 if (!timeo) {
879 len = -EAGAIN;
880 break;
881 }
882
883 if (signal_pending(current)) {
884 len = sock_intr_errno(timeo);
885 break;
886 }
887
888 sk_wait_data(sk, &timeo);
889 continue;
890 found_ok_skb:
891 if (len > skb->len)
892 len = skb->len;
893 else if (len < skb->len)
894 msg->msg_flags |= MSG_TRUNC;
895
896 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
897 /* Exception. Bailout! */
898 len = -EFAULT;
899 break;
900 }
901 if (flags & MSG_TRUNC)
902 len = skb->len;
903 found_fin_ok:
904 if (!(flags & MSG_PEEK))
905 sk_eat_skb(sk, skb, 0);
906 break;
907 } while (1);
908out:
909 release_sock(sk);
910 return len;
911}
912
913EXPORT_SYMBOL_GPL(dccp_recvmsg);
914
915int inet_dccp_listen(struct socket *sock, int backlog)
916{
917 struct sock *sk = sock->sk;
918 unsigned char old_state;
919 int err;
920
921 lock_sock(sk);
922
923 err = -EINVAL;
924 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
925 goto out;
926
927 old_state = sk->sk_state;
928 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
929 goto out;
930
931 /* Really, if the socket is already in listen state
932 * we can only allow the backlog to be adjusted.
933 */
934 if (old_state != DCCP_LISTEN) {
935 /*
936 * FIXME: here it probably should be sk->sk_prot->listen_start
937 * see tcp_listen_start
938 */
939 err = dccp_listen_start(sk, backlog);
940 if (err)
941 goto out;
942 }
943 sk->sk_max_ack_backlog = backlog;
944 err = 0;
945
946out:
947 release_sock(sk);
948 return err;
949}
950
951EXPORT_SYMBOL_GPL(inet_dccp_listen);
952
953static void dccp_terminate_connection(struct sock *sk)
954{
955 u8 next_state = DCCP_CLOSED;
956
957 switch (sk->sk_state) {
958 case DCCP_PASSIVE_CLOSE:
959 case DCCP_PASSIVE_CLOSEREQ:
960 dccp_finish_passive_close(sk);
961 break;
962 case DCCP_PARTOPEN:
963 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
964 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
965 /* fall through */
966 case DCCP_OPEN:
967 dccp_send_close(sk, 1);
968
969 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
970 !dccp_sk(sk)->dccps_server_timewait)
971 next_state = DCCP_ACTIVE_CLOSEREQ;
972 else
973 next_state = DCCP_CLOSING;
974 /* fall through */
975 default:
976 dccp_set_state(sk, next_state);
977 }
978}
979
980void dccp_close(struct sock *sk, long timeout)
981{
982 struct dccp_sock *dp = dccp_sk(sk);
983 struct sk_buff *skb;
984 u32 data_was_unread = 0;
985 int state;
986
987 lock_sock(sk);
988
989 sk->sk_shutdown = SHUTDOWN_MASK;
990
991 if (sk->sk_state == DCCP_LISTEN) {
992 dccp_set_state(sk, DCCP_CLOSED);
993
994 /* Special case. */
995 inet_csk_listen_stop(sk);
996
997 goto adjudge_to_death;
998 }
999
1000 sk_stop_timer(sk, &dp->dccps_xmit_timer);
1001
1002 /*
1003 * We need to flush the recv. buffs. We do this only on the
1004 * descriptor close, not protocol-sourced closes, because the
1005 *reader process may not have drained the data yet!
1006 */
1007 while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1008 data_was_unread += skb->len;
1009 __kfree_skb(skb);
1010 }
1011
1012 if (data_was_unread) {
1013 /* Unread data was tossed, send an appropriate Reset Code */
1014 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1015 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1016 dccp_set_state(sk, DCCP_CLOSED);
1017 } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1018 /* Check zero linger _after_ checking for unread data. */
1019 sk->sk_prot->disconnect(sk, 0);
1020 } else if (sk->sk_state != DCCP_CLOSED) {
1021 /*
1022 * Normal connection termination. May need to wait if there are
1023 * still packets in the TX queue that are delayed by the CCID.
1024 */
1025 dccp_flush_write_queue(sk, &timeout);
1026 dccp_terminate_connection(sk);
1027 }
1028
1029 /*
1030 * Flush write queue. This may be necessary in several cases:
1031 * - we have been closed by the peer but still have application data;
1032 * - abortive termination (unread data or zero linger time),
1033 * - normal termination but queue could not be flushed within time limit
1034 */
1035 __skb_queue_purge(&sk->sk_write_queue);
1036
1037 sk_stream_wait_close(sk, timeout);
1038
1039adjudge_to_death:
1040 state = sk->sk_state;
1041 sock_hold(sk);
1042 sock_orphan(sk);
1043
1044 /*
1045 * It is the last release_sock in its life. It will remove backlog.
1046 */
1047 release_sock(sk);
1048 /*
1049 * Now socket is owned by kernel and we acquire BH lock
1050 * to finish close. No need to check for user refs.
1051 */
1052 local_bh_disable();
1053 bh_lock_sock(sk);
1054 WARN_ON(sock_owned_by_user(sk));
1055
1056 percpu_counter_inc(sk->sk_prot->orphan_count);
1057
1058 /* Have we already been destroyed by a softirq or backlog? */
1059 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1060 goto out;
1061
1062 if (sk->sk_state == DCCP_CLOSED)
1063 inet_csk_destroy_sock(sk);
1064
1065 /* Otherwise, socket is reprieved until protocol close. */
1066
1067out:
1068 bh_unlock_sock(sk);
1069 local_bh_enable();
1070 sock_put(sk);
1071}
1072
1073EXPORT_SYMBOL_GPL(dccp_close);
1074
1075void dccp_shutdown(struct sock *sk, int how)
1076{
1077 dccp_pr_debug("called shutdown(%x)\n", how);
1078}
1079
1080EXPORT_SYMBOL_GPL(dccp_shutdown);
1081
1082static inline int dccp_mib_init(void)
1083{
1084 return snmp_mib_init((void __percpu **)dccp_statistics,
1085 sizeof(struct dccp_mib),
1086 __alignof__(struct dccp_mib));
1087}
1088
1089static inline void dccp_mib_exit(void)
1090{
1091 snmp_mib_free((void __percpu **)dccp_statistics);
1092}
1093
1094static int thash_entries;
1095module_param(thash_entries, int, 0444);
1096MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1097
1098#ifdef CONFIG_IP_DCCP_DEBUG
1099int dccp_debug;
1100module_param(dccp_debug, bool, 0644);
1101MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1102
1103EXPORT_SYMBOL_GPL(dccp_debug);
1104#endif
1105
1106static int __init dccp_init(void)
1107{
1108 unsigned long goal;
1109 int ehash_order, bhash_order, i;
1110 int rc;
1111
1112 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1113 FIELD_SIZEOF(struct sk_buff, cb));
1114 rc = percpu_counter_init(&dccp_orphan_count, 0);
1115 if (rc)
1116 goto out_fail;
1117 rc = -ENOBUFS;
1118 inet_hashinfo_init(&dccp_hashinfo);
1119 dccp_hashinfo.bind_bucket_cachep =
1120 kmem_cache_create("dccp_bind_bucket",
1121 sizeof(struct inet_bind_bucket), 0,
1122 SLAB_HWCACHE_ALIGN, NULL);
1123 if (!dccp_hashinfo.bind_bucket_cachep)
1124 goto out_free_percpu;
1125
1126 /*
1127 * Size and allocate the main established and bind bucket
1128 * hash tables.
1129 *
1130 * The methodology is similar to that of the buffer cache.
1131 */
1132 if (totalram_pages >= (128 * 1024))
1133 goal = totalram_pages >> (21 - PAGE_SHIFT);
1134 else
1135 goal = totalram_pages >> (23 - PAGE_SHIFT);
1136
1137 if (thash_entries)
1138 goal = (thash_entries *
1139 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1140 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1141 ;
1142 do {
1143 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1144 sizeof(struct inet_ehash_bucket);
1145
1146 while (hash_size & (hash_size - 1))
1147 hash_size--;
1148 dccp_hashinfo.ehash_mask = hash_size - 1;
1149 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1150 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1151 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1152
1153 if (!dccp_hashinfo.ehash) {
1154 DCCP_CRIT("Failed to allocate DCCP established hash table");
1155 goto out_free_bind_bucket_cachep;
1156 }
1157
1158 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) {
1159 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1160 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
1161 }
1162
1163 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1164 goto out_free_dccp_ehash;
1165
1166 bhash_order = ehash_order;
1167
1168 do {
1169 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1170 sizeof(struct inet_bind_hashbucket);
1171 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1172 bhash_order > 0)
1173 continue;
1174 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1175 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1176 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1177
1178 if (!dccp_hashinfo.bhash) {
1179 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1180 goto out_free_dccp_locks;
1181 }
1182
1183 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1184 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1185 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1186 }
1187
1188 rc = dccp_mib_init();
1189 if (rc)
1190 goto out_free_dccp_bhash;
1191
1192 rc = dccp_ackvec_init();
1193 if (rc)
1194 goto out_free_dccp_mib;
1195
1196 rc = dccp_sysctl_init();
1197 if (rc)
1198 goto out_ackvec_exit;
1199
1200 rc = ccid_initialize_builtins();
1201 if (rc)
1202 goto out_sysctl_exit;
1203
1204 dccp_timestamping_init();
1205
1206 return 0;
1207
1208out_sysctl_exit:
1209 dccp_sysctl_exit();
1210out_ackvec_exit:
1211 dccp_ackvec_exit();
1212out_free_dccp_mib:
1213 dccp_mib_exit();
1214out_free_dccp_bhash:
1215 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1216out_free_dccp_locks:
1217 inet_ehash_locks_free(&dccp_hashinfo);
1218out_free_dccp_ehash:
1219 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1220out_free_bind_bucket_cachep:
1221 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1222out_free_percpu:
1223 percpu_counter_destroy(&dccp_orphan_count);
1224out_fail:
1225 dccp_hashinfo.bhash = NULL;
1226 dccp_hashinfo.ehash = NULL;
1227 dccp_hashinfo.bind_bucket_cachep = NULL;
1228 return rc;
1229}
1230
1231static void __exit dccp_fini(void)
1232{
1233 ccid_cleanup_builtins();
1234 dccp_mib_exit();
1235 free_pages((unsigned long)dccp_hashinfo.bhash,
1236 get_order(dccp_hashinfo.bhash_size *
1237 sizeof(struct inet_bind_hashbucket)));
1238 free_pages((unsigned long)dccp_hashinfo.ehash,
1239 get_order((dccp_hashinfo.ehash_mask + 1) *
1240 sizeof(struct inet_ehash_bucket)));
1241 inet_ehash_locks_free(&dccp_hashinfo);
1242 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1243 dccp_ackvec_exit();
1244 dccp_sysctl_exit();
1245 percpu_counter_destroy(&dccp_orphan_count);
1246}
1247
1248module_init(dccp_init);
1249module_exit(dccp_fini);
1250
1251MODULE_LICENSE("GPL");
1252MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1253MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
Linux kernel - Deliverables
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