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
41 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
42
43 EXPORT_SYMBOL_GPL(dccp_statistics);
44
45 struct percpu_counter dccp_orphan_count;
46 EXPORT_SYMBOL_GPL(dccp_orphan_count);
47
48 struct inet_hashinfo dccp_hashinfo;
49 EXPORT_SYMBOL_GPL(dccp_hashinfo);
50
51 /* the maximum queue length for tx in packets. 0 is no limit */
52 int sysctl_dccp_tx_qlen __read_mostly = 5;
53
54 #ifdef CONFIG_IP_DCCP_DEBUG
dccp_state_name(const int state)55 static 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
dccp_set_state(struct sock * sk,const int state)78 void 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
116 EXPORT_SYMBOL_GPL(dccp_set_state);
117
dccp_finish_passive_close(struct sock * sk)118 static 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
dccp_done(struct sock * sk)136 void 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
149 EXPORT_SYMBOL_GPL(dccp_done);
150
dccp_packet_name(const int type)151 const 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
172 EXPORT_SYMBOL_GPL(dccp_packet_name);
173
dccp_sk_destruct(struct sock * sk)174 static void dccp_sk_destruct(struct sock *sk)
175 {
176 struct dccp_sock *dp = dccp_sk(sk);
177
178 ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
179 dp->dccps_hc_tx_ccid = NULL;
180 inet_sock_destruct(sk);
181 }
182
dccp_init_sock(struct sock * sk,const __u8 ctl_sock_initialized)183 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
184 {
185 struct dccp_sock *dp = dccp_sk(sk);
186 struct inet_connection_sock *icsk = inet_csk(sk);
187
188 icsk->icsk_rto = DCCP_TIMEOUT_INIT;
189 icsk->icsk_syn_retries = sysctl_dccp_request_retries;
190 sk->sk_state = DCCP_CLOSED;
191 sk->sk_write_space = dccp_write_space;
192 sk->sk_destruct = dccp_sk_destruct;
193 icsk->icsk_sync_mss = dccp_sync_mss;
194 dp->dccps_mss_cache = 536;
195 dp->dccps_rate_last = jiffies;
196 dp->dccps_role = DCCP_ROLE_UNDEFINED;
197 dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
198 dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
199
200 dccp_init_xmit_timers(sk);
201
202 INIT_LIST_HEAD(&dp->dccps_featneg);
203 /* control socket doesn't need feat nego */
204 if (likely(ctl_sock_initialized))
205 return dccp_feat_init(sk);
206 return 0;
207 }
208
209 EXPORT_SYMBOL_GPL(dccp_init_sock);
210
dccp_destroy_sock(struct sock * sk)211 void dccp_destroy_sock(struct sock *sk)
212 {
213 struct dccp_sock *dp = dccp_sk(sk);
214
215 __skb_queue_purge(&sk->sk_write_queue);
216 if (sk->sk_send_head != NULL) {
217 kfree_skb(sk->sk_send_head);
218 sk->sk_send_head = NULL;
219 }
220
221 /* Clean up a referenced DCCP bind bucket. */
222 if (inet_csk(sk)->icsk_bind_hash != NULL)
223 inet_put_port(sk);
224
225 kfree(dp->dccps_service_list);
226 dp->dccps_service_list = NULL;
227
228 if (dp->dccps_hc_rx_ackvec != NULL) {
229 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
230 dp->dccps_hc_rx_ackvec = NULL;
231 }
232 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
233 dp->dccps_hc_rx_ccid = NULL;
234
235 /* clean up feature negotiation state */
236 dccp_feat_list_purge(&dp->dccps_featneg);
237 }
238
239 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
240
dccp_listen_start(struct sock * sk,int backlog)241 static inline int dccp_listen_start(struct sock *sk, int backlog)
242 {
243 struct dccp_sock *dp = dccp_sk(sk);
244
245 dp->dccps_role = DCCP_ROLE_LISTEN;
246 /* do not start to listen if feature negotiation setup fails */
247 if (dccp_feat_finalise_settings(dp))
248 return -EPROTO;
249 return inet_csk_listen_start(sk, backlog);
250 }
251
dccp_need_reset(int state)252 static inline int dccp_need_reset(int state)
253 {
254 return state != DCCP_CLOSED && state != DCCP_LISTEN &&
255 state != DCCP_REQUESTING;
256 }
257
dccp_disconnect(struct sock * sk,int flags)258 int dccp_disconnect(struct sock *sk, int flags)
259 {
260 struct inet_connection_sock *icsk = inet_csk(sk);
261 struct inet_sock *inet = inet_sk(sk);
262 struct dccp_sock *dp = dccp_sk(sk);
263 const int old_state = sk->sk_state;
264
265 if (old_state != DCCP_CLOSED)
266 dccp_set_state(sk, DCCP_CLOSED);
267
268 /*
269 * This corresponds to the ABORT function of RFC793, sec. 3.8
270 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
271 */
272 if (old_state == DCCP_LISTEN) {
273 inet_csk_listen_stop(sk);
274 } else if (dccp_need_reset(old_state)) {
275 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
276 sk->sk_err = ECONNRESET;
277 } else if (old_state == DCCP_REQUESTING)
278 sk->sk_err = ECONNRESET;
279
280 dccp_clear_xmit_timers(sk);
281 ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
282 dp->dccps_hc_rx_ccid = NULL;
283
284 __skb_queue_purge(&sk->sk_receive_queue);
285 __skb_queue_purge(&sk->sk_write_queue);
286 if (sk->sk_send_head != NULL) {
287 __kfree_skb(sk->sk_send_head);
288 sk->sk_send_head = NULL;
289 }
290
291 inet->inet_dport = 0;
292
293 if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
294 inet_reset_saddr(sk);
295
296 sk->sk_shutdown = 0;
297 sock_reset_flag(sk, SOCK_DONE);
298
299 icsk->icsk_backoff = 0;
300 inet_csk_delack_init(sk);
301 __sk_dst_reset(sk);
302
303 WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
304
305 sk->sk_error_report(sk);
306 return 0;
307 }
308
309 EXPORT_SYMBOL_GPL(dccp_disconnect);
310
311 /*
312 * Wait for a DCCP event.
313 *
314 * Note that we don't need to lock the socket, as the upper poll layers
315 * take care of normal races (between the test and the event) and we don't
316 * go look at any of the socket buffers directly.
317 */
dccp_poll(struct file * file,struct socket * sock,poll_table * wait)318 __poll_t dccp_poll(struct file *file, struct socket *sock,
319 poll_table *wait)
320 {
321 __poll_t mask;
322 struct sock *sk = sock->sk;
323
324 sock_poll_wait(file, sock, wait);
325 if (sk->sk_state == DCCP_LISTEN)
326 return inet_csk_listen_poll(sk);
327
328 /* Socket is not locked. We are protected from async events
329 by poll logic and correct handling of state changes
330 made by another threads is impossible in any case.
331 */
332
333 mask = 0;
334 if (sk->sk_err)
335 mask = EPOLLERR;
336
337 if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
338 mask |= EPOLLHUP;
339 if (sk->sk_shutdown & RCV_SHUTDOWN)
340 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
341
342 /* Connected? */
343 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
344 if (atomic_read(&sk->sk_rmem_alloc) > 0)
345 mask |= EPOLLIN | EPOLLRDNORM;
346
347 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
348 if (sk_stream_is_writeable(sk)) {
349 mask |= EPOLLOUT | EPOLLWRNORM;
350 } else { /* send SIGIO later */
351 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
352 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
353
354 /* Race breaker. If space is freed after
355 * wspace test but before the flags are set,
356 * IO signal will be lost.
357 */
358 if (sk_stream_is_writeable(sk))
359 mask |= EPOLLOUT | EPOLLWRNORM;
360 }
361 }
362 }
363 return mask;
364 }
365
366 EXPORT_SYMBOL_GPL(dccp_poll);
367
dccp_ioctl(struct sock * sk,int cmd,unsigned long arg)368 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
369 {
370 int rc = -ENOTCONN;
371
372 lock_sock(sk);
373
374 if (sk->sk_state == DCCP_LISTEN)
375 goto out;
376
377 switch (cmd) {
378 case SIOCOUTQ: {
379 int amount = sk_wmem_alloc_get(sk);
380 /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and
381 * always 0, comparably to UDP.
382 */
383
384 rc = put_user(amount, (int __user *)arg);
385 }
386 break;
387 case SIOCINQ: {
388 struct sk_buff *skb;
389 unsigned long amount = 0;
390
391 skb = skb_peek(&sk->sk_receive_queue);
392 if (skb != NULL) {
393 /*
394 * We will only return the amount of this packet since
395 * that is all that will be read.
396 */
397 amount = skb->len;
398 }
399 rc = put_user(amount, (int __user *)arg);
400 }
401 break;
402 default:
403 rc = -ENOIOCTLCMD;
404 break;
405 }
406 out:
407 release_sock(sk);
408 return rc;
409 }
410
411 EXPORT_SYMBOL_GPL(dccp_ioctl);
412
dccp_setsockopt_service(struct sock * sk,const __be32 service,sockptr_t optval,unsigned int optlen)413 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
414 sockptr_t optval, unsigned int optlen)
415 {
416 struct dccp_sock *dp = dccp_sk(sk);
417 struct dccp_service_list *sl = NULL;
418
419 if (service == DCCP_SERVICE_INVALID_VALUE ||
420 optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
421 return -EINVAL;
422
423 if (optlen > sizeof(service)) {
424 sl = kmalloc(optlen, GFP_KERNEL);
425 if (sl == NULL)
426 return -ENOMEM;
427
428 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
429 if (copy_from_sockptr_offset(sl->dccpsl_list, optval,
430 sizeof(service), optlen - sizeof(service)) ||
431 dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
432 kfree(sl);
433 return -EFAULT;
434 }
435 }
436
437 lock_sock(sk);
438 dp->dccps_service = service;
439
440 kfree(dp->dccps_service_list);
441
442 dp->dccps_service_list = sl;
443 release_sock(sk);
444 return 0;
445 }
446
dccp_setsockopt_cscov(struct sock * sk,int cscov,bool rx)447 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
448 {
449 u8 *list, len;
450 int i, rc;
451
452 if (cscov < 0 || cscov > 15)
453 return -EINVAL;
454 /*
455 * Populate a list of permissible values, in the range cscov...15. This
456 * is necessary since feature negotiation of single values only works if
457 * both sides incidentally choose the same value. Since the list starts
458 * lowest-value first, negotiation will pick the smallest shared value.
459 */
460 if (cscov == 0)
461 return 0;
462 len = 16 - cscov;
463
464 list = kmalloc(len, GFP_KERNEL);
465 if (list == NULL)
466 return -ENOBUFS;
467
468 for (i = 0; i < len; i++)
469 list[i] = cscov++;
470
471 rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
472
473 if (rc == 0) {
474 if (rx)
475 dccp_sk(sk)->dccps_pcrlen = cscov;
476 else
477 dccp_sk(sk)->dccps_pcslen = cscov;
478 }
479 kfree(list);
480 return rc;
481 }
482
dccp_setsockopt_ccid(struct sock * sk,int type,sockptr_t optval,unsigned int optlen)483 static int dccp_setsockopt_ccid(struct sock *sk, int type,
484 sockptr_t optval, unsigned int optlen)
485 {
486 u8 *val;
487 int rc = 0;
488
489 if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
490 return -EINVAL;
491
492 val = memdup_sockptr(optval, optlen);
493 if (IS_ERR(val))
494 return PTR_ERR(val);
495
496 lock_sock(sk);
497 if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
498 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
499
500 if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
501 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
502 release_sock(sk);
503
504 kfree(val);
505 return rc;
506 }
507
do_dccp_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)508 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
509 sockptr_t optval, unsigned int optlen)
510 {
511 struct dccp_sock *dp = dccp_sk(sk);
512 int val, err = 0;
513
514 switch (optname) {
515 case DCCP_SOCKOPT_PACKET_SIZE:
516 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
517 return 0;
518 case DCCP_SOCKOPT_CHANGE_L:
519 case DCCP_SOCKOPT_CHANGE_R:
520 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
521 return 0;
522 case DCCP_SOCKOPT_CCID:
523 case DCCP_SOCKOPT_RX_CCID:
524 case DCCP_SOCKOPT_TX_CCID:
525 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
526 }
527
528 if (optlen < (int)sizeof(int))
529 return -EINVAL;
530
531 if (copy_from_sockptr(&val, optval, sizeof(int)))
532 return -EFAULT;
533
534 if (optname == DCCP_SOCKOPT_SERVICE)
535 return dccp_setsockopt_service(sk, val, optval, optlen);
536
537 lock_sock(sk);
538 switch (optname) {
539 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
540 if (dp->dccps_role != DCCP_ROLE_SERVER)
541 err = -EOPNOTSUPP;
542 else
543 dp->dccps_server_timewait = (val != 0);
544 break;
545 case DCCP_SOCKOPT_SEND_CSCOV:
546 err = dccp_setsockopt_cscov(sk, val, false);
547 break;
548 case DCCP_SOCKOPT_RECV_CSCOV:
549 err = dccp_setsockopt_cscov(sk, val, true);
550 break;
551 case DCCP_SOCKOPT_QPOLICY_ID:
552 if (sk->sk_state != DCCP_CLOSED)
553 err = -EISCONN;
554 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
555 err = -EINVAL;
556 else
557 dp->dccps_qpolicy = val;
558 break;
559 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
560 if (val < 0)
561 err = -EINVAL;
562 else
563 dp->dccps_tx_qlen = val;
564 break;
565 default:
566 err = -ENOPROTOOPT;
567 break;
568 }
569 release_sock(sk);
570
571 return err;
572 }
573
dccp_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)574 int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
575 unsigned int optlen)
576 {
577 if (level != SOL_DCCP)
578 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
579 optname, optval,
580 optlen);
581 return do_dccp_setsockopt(sk, level, optname, optval, optlen);
582 }
583
584 EXPORT_SYMBOL_GPL(dccp_setsockopt);
585
dccp_getsockopt_service(struct sock * sk,int len,__be32 __user * optval,int __user * optlen)586 static int dccp_getsockopt_service(struct sock *sk, int len,
587 __be32 __user *optval,
588 int __user *optlen)
589 {
590 const struct dccp_sock *dp = dccp_sk(sk);
591 const struct dccp_service_list *sl;
592 int err = -ENOENT, slen = 0, total_len = sizeof(u32);
593
594 lock_sock(sk);
595 if ((sl = dp->dccps_service_list) != NULL) {
596 slen = sl->dccpsl_nr * sizeof(u32);
597 total_len += slen;
598 }
599
600 err = -EINVAL;
601 if (total_len > len)
602 goto out;
603
604 err = 0;
605 if (put_user(total_len, optlen) ||
606 put_user(dp->dccps_service, optval) ||
607 (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
608 err = -EFAULT;
609 out:
610 release_sock(sk);
611 return err;
612 }
613
do_dccp_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)614 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
615 char __user *optval, int __user *optlen)
616 {
617 struct dccp_sock *dp;
618 int val, len;
619
620 if (get_user(len, optlen))
621 return -EFAULT;
622
623 if (len < (int)sizeof(int))
624 return -EINVAL;
625
626 dp = dccp_sk(sk);
627
628 switch (optname) {
629 case DCCP_SOCKOPT_PACKET_SIZE:
630 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
631 return 0;
632 case DCCP_SOCKOPT_SERVICE:
633 return dccp_getsockopt_service(sk, len,
634 (__be32 __user *)optval, optlen);
635 case DCCP_SOCKOPT_GET_CUR_MPS:
636 val = dp->dccps_mss_cache;
637 break;
638 case DCCP_SOCKOPT_AVAILABLE_CCIDS:
639 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
640 case DCCP_SOCKOPT_TX_CCID:
641 val = ccid_get_current_tx_ccid(dp);
642 if (val < 0)
643 return -ENOPROTOOPT;
644 break;
645 case DCCP_SOCKOPT_RX_CCID:
646 val = ccid_get_current_rx_ccid(dp);
647 if (val < 0)
648 return -ENOPROTOOPT;
649 break;
650 case DCCP_SOCKOPT_SERVER_TIMEWAIT:
651 val = dp->dccps_server_timewait;
652 break;
653 case DCCP_SOCKOPT_SEND_CSCOV:
654 val = dp->dccps_pcslen;
655 break;
656 case DCCP_SOCKOPT_RECV_CSCOV:
657 val = dp->dccps_pcrlen;
658 break;
659 case DCCP_SOCKOPT_QPOLICY_ID:
660 val = dp->dccps_qpolicy;
661 break;
662 case DCCP_SOCKOPT_QPOLICY_TXQLEN:
663 val = dp->dccps_tx_qlen;
664 break;
665 case 128 ... 191:
666 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
667 len, (u32 __user *)optval, optlen);
668 case 192 ... 255:
669 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
670 len, (u32 __user *)optval, optlen);
671 default:
672 return -ENOPROTOOPT;
673 }
674
675 len = sizeof(val);
676 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
677 return -EFAULT;
678
679 return 0;
680 }
681
dccp_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)682 int dccp_getsockopt(struct sock *sk, int level, int optname,
683 char __user *optval, int __user *optlen)
684 {
685 if (level != SOL_DCCP)
686 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
687 optname, optval,
688 optlen);
689 return do_dccp_getsockopt(sk, level, optname, optval, optlen);
690 }
691
692 EXPORT_SYMBOL_GPL(dccp_getsockopt);
693
dccp_msghdr_parse(struct msghdr * msg,struct sk_buff * skb)694 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
695 {
696 struct cmsghdr *cmsg;
697
698 /*
699 * Assign an (opaque) qpolicy priority value to skb->priority.
700 *
701 * We are overloading this skb field for use with the qpolicy subystem.
702 * The skb->priority is normally used for the SO_PRIORITY option, which
703 * is initialised from sk_priority. Since the assignment of sk_priority
704 * to skb->priority happens later (on layer 3), we overload this field
705 * for use with queueing priorities as long as the skb is on layer 4.
706 * The default priority value (if nothing is set) is 0.
707 */
708 skb->priority = 0;
709
710 for_each_cmsghdr(cmsg, msg) {
711 if (!CMSG_OK(msg, cmsg))
712 return -EINVAL;
713
714 if (cmsg->cmsg_level != SOL_DCCP)
715 continue;
716
717 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
718 !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
719 return -EINVAL;
720
721 switch (cmsg->cmsg_type) {
722 case DCCP_SCM_PRIORITY:
723 if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
724 return -EINVAL;
725 skb->priority = *(__u32 *)CMSG_DATA(cmsg);
726 break;
727 default:
728 return -EINVAL;
729 }
730 }
731 return 0;
732 }
733
dccp_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)734 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
735 {
736 const struct dccp_sock *dp = dccp_sk(sk);
737 const int flags = msg->msg_flags;
738 const int noblock = flags & MSG_DONTWAIT;
739 struct sk_buff *skb;
740 int rc, size;
741 long timeo;
742
743 trace_dccp_probe(sk, len);
744
745 if (len > dp->dccps_mss_cache)
746 return -EMSGSIZE;
747
748 lock_sock(sk);
749
750 if (dccp_qpolicy_full(sk)) {
751 rc = -EAGAIN;
752 goto out_release;
753 }
754
755 timeo = sock_sndtimeo(sk, noblock);
756
757 /*
758 * We have to use sk_stream_wait_connect here to set sk_write_pending,
759 * so that the trick in dccp_rcv_request_sent_state_process.
760 */
761 /* Wait for a connection to finish. */
762 if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
763 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
764 goto out_release;
765
766 size = sk->sk_prot->max_header + len;
767 release_sock(sk);
768 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
769 lock_sock(sk);
770 if (skb == NULL)
771 goto out_release;
772
773 if (sk->sk_state == DCCP_CLOSED) {
774 rc = -ENOTCONN;
775 goto out_discard;
776 }
777
778 skb_reserve(skb, sk->sk_prot->max_header);
779 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
780 if (rc != 0)
781 goto out_discard;
782
783 rc = dccp_msghdr_parse(msg, skb);
784 if (rc != 0)
785 goto out_discard;
786
787 dccp_qpolicy_push(sk, skb);
788 /*
789 * The xmit_timer is set if the TX CCID is rate-based and will expire
790 * when congestion control permits to release further packets into the
791 * network. Window-based CCIDs do not use this timer.
792 */
793 if (!timer_pending(&dp->dccps_xmit_timer))
794 dccp_write_xmit(sk);
795 out_release:
796 release_sock(sk);
797 return rc ? : len;
798 out_discard:
799 kfree_skb(skb);
800 goto out_release;
801 }
802
803 EXPORT_SYMBOL_GPL(dccp_sendmsg);
804
dccp_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int nonblock,int flags,int * addr_len)805 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
806 int flags, int *addr_len)
807 {
808 const struct dccp_hdr *dh;
809 long timeo;
810
811 lock_sock(sk);
812
813 if (sk->sk_state == DCCP_LISTEN) {
814 len = -ENOTCONN;
815 goto out;
816 }
817
818 timeo = sock_rcvtimeo(sk, nonblock);
819
820 do {
821 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
822
823 if (skb == NULL)
824 goto verify_sock_status;
825
826 dh = dccp_hdr(skb);
827
828 switch (dh->dccph_type) {
829 case DCCP_PKT_DATA:
830 case DCCP_PKT_DATAACK:
831 goto found_ok_skb;
832
833 case DCCP_PKT_CLOSE:
834 case DCCP_PKT_CLOSEREQ:
835 if (!(flags & MSG_PEEK))
836 dccp_finish_passive_close(sk);
837 fallthrough;
838 case DCCP_PKT_RESET:
839 dccp_pr_debug("found fin (%s) ok!\n",
840 dccp_packet_name(dh->dccph_type));
841 len = 0;
842 goto found_fin_ok;
843 default:
844 dccp_pr_debug("packet_type=%s\n",
845 dccp_packet_name(dh->dccph_type));
846 sk_eat_skb(sk, skb);
847 }
848 verify_sock_status:
849 if (sock_flag(sk, SOCK_DONE)) {
850 len = 0;
851 break;
852 }
853
854 if (sk->sk_err) {
855 len = sock_error(sk);
856 break;
857 }
858
859 if (sk->sk_shutdown & RCV_SHUTDOWN) {
860 len = 0;
861 break;
862 }
863
864 if (sk->sk_state == DCCP_CLOSED) {
865 if (!sock_flag(sk, SOCK_DONE)) {
866 /* This occurs when user tries to read
867 * from never connected socket.
868 */
869 len = -ENOTCONN;
870 break;
871 }
872 len = 0;
873 break;
874 }
875
876 if (!timeo) {
877 len = -EAGAIN;
878 break;
879 }
880
881 if (signal_pending(current)) {
882 len = sock_intr_errno(timeo);
883 break;
884 }
885
886 sk_wait_data(sk, &timeo, NULL);
887 continue;
888 found_ok_skb:
889 if (len > skb->len)
890 len = skb->len;
891 else if (len < skb->len)
892 msg->msg_flags |= MSG_TRUNC;
893
894 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
895 /* Exception. Bailout! */
896 len = -EFAULT;
897 break;
898 }
899 if (flags & MSG_TRUNC)
900 len = skb->len;
901 found_fin_ok:
902 if (!(flags & MSG_PEEK))
903 sk_eat_skb(sk, skb);
904 break;
905 } while (1);
906 out:
907 release_sock(sk);
908 return len;
909 }
910
911 EXPORT_SYMBOL_GPL(dccp_recvmsg);
912
inet_dccp_listen(struct socket * sock,int backlog)913 int inet_dccp_listen(struct socket *sock, int backlog)
914 {
915 struct sock *sk = sock->sk;
916 unsigned char old_state;
917 int err;
918
919 lock_sock(sk);
920
921 err = -EINVAL;
922 if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
923 goto out;
924
925 old_state = sk->sk_state;
926 if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
927 goto out;
928
929 WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
930 /* Really, if the socket is already in listen state
931 * we can only allow the backlog to be adjusted.
932 */
933 if (old_state != DCCP_LISTEN) {
934 /*
935 * FIXME: here it probably should be sk->sk_prot->listen_start
936 * see tcp_listen_start
937 */
938 err = dccp_listen_start(sk, backlog);
939 if (err)
940 goto out;
941 }
942 err = 0;
943
944 out:
945 release_sock(sk);
946 return err;
947 }
948
949 EXPORT_SYMBOL_GPL(inet_dccp_listen);
950
dccp_terminate_connection(struct sock * sk)951 static 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
dccp_close(struct sock * sk,long timeout)978 void 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
1041 adjudge_to_death:
1042 state = sk->sk_state;
1043 sock_hold(sk);
1044 sock_orphan(sk);
1045
1046 /*
1047 * It is the last release_sock in its life. It will remove backlog.
1048 */
1049 release_sock(sk);
1050 /*
1051 * Now socket is owned by kernel and we acquire BH lock
1052 * to finish close. No need to check for user refs.
1053 */
1054 local_bh_disable();
1055 bh_lock_sock(sk);
1056 WARN_ON(sock_owned_by_user(sk));
1057
1058 percpu_counter_inc(sk->sk_prot->orphan_count);
1059
1060 /* Have we already been destroyed by a softirq or backlog? */
1061 if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1062 goto out;
1063
1064 if (sk->sk_state == DCCP_CLOSED)
1065 inet_csk_destroy_sock(sk);
1066
1067 /* Otherwise, socket is reprieved until protocol close. */
1068
1069 out:
1070 bh_unlock_sock(sk);
1071 local_bh_enable();
1072 sock_put(sk);
1073 }
1074
1075 EXPORT_SYMBOL_GPL(dccp_close);
1076
dccp_shutdown(struct sock * sk,int how)1077 void dccp_shutdown(struct sock *sk, int how)
1078 {
1079 dccp_pr_debug("called shutdown(%x)\n", how);
1080 }
1081
1082 EXPORT_SYMBOL_GPL(dccp_shutdown);
1083
dccp_mib_init(void)1084 static 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
dccp_mib_exit(void)1092 static inline void dccp_mib_exit(void)
1093 {
1094 free_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
dccp_init(void)1109 static int __init dccp_init(void)
1110 {
1111 unsigned long goal;
1112 unsigned long nr_pages = totalram_pages();
1113 int ehash_order, bhash_order, i;
1114 int rc;
1115
1116 BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1117 sizeof_field(struct sk_buff, cb));
1118 rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1119 if (rc)
1120 goto out_fail;
1121 inet_hashinfo_init(&dccp_hashinfo);
1122 rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1123 if (rc)
1124 goto out_free_percpu;
1125 rc = -ENOBUFS;
1126 dccp_hashinfo.bind_bucket_cachep =
1127 kmem_cache_create("dccp_bind_bucket",
1128 sizeof(struct inet_bind_bucket), 0,
1129 SLAB_HWCACHE_ALIGN, NULL);
1130 if (!dccp_hashinfo.bind_bucket_cachep)
1131 goto out_free_hashinfo2;
1132
1133 /*
1134 * Size and allocate the main established and bind bucket
1135 * hash tables.
1136 *
1137 * The methodology is similar to that of the buffer cache.
1138 */
1139 if (nr_pages >= (128 * 1024))
1140 goal = nr_pages >> (21 - PAGE_SHIFT);
1141 else
1142 goal = nr_pages >> (23 - PAGE_SHIFT);
1143
1144 if (thash_entries)
1145 goal = (thash_entries *
1146 sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1147 for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1148 ;
1149 do {
1150 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1151 sizeof(struct inet_ehash_bucket);
1152
1153 while (hash_size & (hash_size - 1))
1154 hash_size--;
1155 dccp_hashinfo.ehash_mask = hash_size - 1;
1156 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1157 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1158 } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1159
1160 if (!dccp_hashinfo.ehash) {
1161 DCCP_CRIT("Failed to allocate DCCP established hash table");
1162 goto out_free_bind_bucket_cachep;
1163 }
1164
1165 for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1166 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1167
1168 if (inet_ehash_locks_alloc(&dccp_hashinfo))
1169 goto out_free_dccp_ehash;
1170
1171 bhash_order = ehash_order;
1172
1173 do {
1174 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1175 sizeof(struct inet_bind_hashbucket);
1176 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1177 bhash_order > 0)
1178 continue;
1179 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1180 __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1181 } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1182
1183 if (!dccp_hashinfo.bhash) {
1184 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1185 goto out_free_dccp_locks;
1186 }
1187
1188 for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1189 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1190 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1191 }
1192
1193 rc = dccp_mib_init();
1194 if (rc)
1195 goto out_free_dccp_bhash;
1196
1197 rc = dccp_ackvec_init();
1198 if (rc)
1199 goto out_free_dccp_mib;
1200
1201 rc = dccp_sysctl_init();
1202 if (rc)
1203 goto out_ackvec_exit;
1204
1205 rc = ccid_initialize_builtins();
1206 if (rc)
1207 goto out_sysctl_exit;
1208
1209 dccp_timestamping_init();
1210
1211 return 0;
1212
1213 out_sysctl_exit:
1214 dccp_sysctl_exit();
1215 out_ackvec_exit:
1216 dccp_ackvec_exit();
1217 out_free_dccp_mib:
1218 dccp_mib_exit();
1219 out_free_dccp_bhash:
1220 free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1221 out_free_dccp_locks:
1222 inet_ehash_locks_free(&dccp_hashinfo);
1223 out_free_dccp_ehash:
1224 free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1225 out_free_bind_bucket_cachep:
1226 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1227 out_free_hashinfo2:
1228 inet_hashinfo2_free_mod(&dccp_hashinfo);
1229 out_free_percpu:
1230 percpu_counter_destroy(&dccp_orphan_count);
1231 out_fail:
1232 dccp_hashinfo.bhash = NULL;
1233 dccp_hashinfo.ehash = NULL;
1234 dccp_hashinfo.bind_bucket_cachep = NULL;
1235 return rc;
1236 }
1237
dccp_fini(void)1238 static void __exit dccp_fini(void)
1239 {
1240 ccid_cleanup_builtins();
1241 dccp_mib_exit();
1242 free_pages((unsigned long)dccp_hashinfo.bhash,
1243 get_order(dccp_hashinfo.bhash_size *
1244 sizeof(struct inet_bind_hashbucket)));
1245 free_pages((unsigned long)dccp_hashinfo.ehash,
1246 get_order((dccp_hashinfo.ehash_mask + 1) *
1247 sizeof(struct inet_ehash_bucket)));
1248 inet_ehash_locks_free(&dccp_hashinfo);
1249 kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1250 dccp_ackvec_exit();
1251 dccp_sysctl_exit();
1252 inet_hashinfo2_free_mod(&dccp_hashinfo);
1253 percpu_counter_destroy(&dccp_orphan_count);
1254 }
1255
1256 module_init(dccp_init);
1257 module_exit(dccp_fini);
1258
1259 MODULE_LICENSE("GPL");
1260 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1261 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");
1262
