Linux-libre 5.3.12-gnu
[librecmc/linux-libre.git] / net / dccp / proto.c
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
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
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                 /* fall through */
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
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
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
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
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
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
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
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
252 static inline int dccp_need_reset(int state)
253 {
254         return state != DCCP_CLOSED && state != DCCP_LISTEN &&
255                state != DCCP_REQUESTING;
256 }
257
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  */
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
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 SIOCINQ: {
379                 struct sk_buff *skb;
380                 unsigned long amount = 0;
381
382                 skb = skb_peek(&sk->sk_receive_queue);
383                 if (skb != NULL) {
384                         /*
385                          * We will only return the amount of this packet since
386                          * that is all that will be read.
387                          */
388                         amount = skb->len;
389                 }
390                 rc = put_user(amount, (int __user *)arg);
391         }
392                 break;
393         default:
394                 rc = -ENOIOCTLCMD;
395                 break;
396         }
397 out:
398         release_sock(sk);
399         return rc;
400 }
401
402 EXPORT_SYMBOL_GPL(dccp_ioctl);
403
404 static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
405                                    char __user *optval, unsigned int optlen)
406 {
407         struct dccp_sock *dp = dccp_sk(sk);
408         struct dccp_service_list *sl = NULL;
409
410         if (service == DCCP_SERVICE_INVALID_VALUE ||
411             optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
412                 return -EINVAL;
413
414         if (optlen > sizeof(service)) {
415                 sl = kmalloc(optlen, GFP_KERNEL);
416                 if (sl == NULL)
417                         return -ENOMEM;
418
419                 sl->dccpsl_nr = optlen / sizeof(u32) - 1;
420                 if (copy_from_user(sl->dccpsl_list,
421                                    optval + sizeof(service),
422                                    optlen - sizeof(service)) ||
423                     dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
424                         kfree(sl);
425                         return -EFAULT;
426                 }
427         }
428
429         lock_sock(sk);
430         dp->dccps_service = service;
431
432         kfree(dp->dccps_service_list);
433
434         dp->dccps_service_list = sl;
435         release_sock(sk);
436         return 0;
437 }
438
439 static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
440 {
441         u8 *list, len;
442         int i, rc;
443
444         if (cscov < 0 || cscov > 15)
445                 return -EINVAL;
446         /*
447          * Populate a list of permissible values, in the range cscov...15. This
448          * is necessary since feature negotiation of single values only works if
449          * both sides incidentally choose the same value. Since the list starts
450          * lowest-value first, negotiation will pick the smallest shared value.
451          */
452         if (cscov == 0)
453                 return 0;
454         len = 16 - cscov;
455
456         list = kmalloc(len, GFP_KERNEL);
457         if (list == NULL)
458                 return -ENOBUFS;
459
460         for (i = 0; i < len; i++)
461                 list[i] = cscov++;
462
463         rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
464
465         if (rc == 0) {
466                 if (rx)
467                         dccp_sk(sk)->dccps_pcrlen = cscov;
468                 else
469                         dccp_sk(sk)->dccps_pcslen = cscov;
470         }
471         kfree(list);
472         return rc;
473 }
474
475 static int dccp_setsockopt_ccid(struct sock *sk, int type,
476                                 char __user *optval, unsigned int optlen)
477 {
478         u8 *val;
479         int rc = 0;
480
481         if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
482                 return -EINVAL;
483
484         val = memdup_user(optval, optlen);
485         if (IS_ERR(val))
486                 return PTR_ERR(val);
487
488         lock_sock(sk);
489         if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
490                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
491
492         if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
493                 rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
494         release_sock(sk);
495
496         kfree(val);
497         return rc;
498 }
499
500 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
501                 char __user *optval, unsigned int optlen)
502 {
503         struct dccp_sock *dp = dccp_sk(sk);
504         int val, err = 0;
505
506         switch (optname) {
507         case DCCP_SOCKOPT_PACKET_SIZE:
508                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
509                 return 0;
510         case DCCP_SOCKOPT_CHANGE_L:
511         case DCCP_SOCKOPT_CHANGE_R:
512                 DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
513                 return 0;
514         case DCCP_SOCKOPT_CCID:
515         case DCCP_SOCKOPT_RX_CCID:
516         case DCCP_SOCKOPT_TX_CCID:
517                 return dccp_setsockopt_ccid(sk, optname, optval, optlen);
518         }
519
520         if (optlen < (int)sizeof(int))
521                 return -EINVAL;
522
523         if (get_user(val, (int __user *)optval))
524                 return -EFAULT;
525
526         if (optname == DCCP_SOCKOPT_SERVICE)
527                 return dccp_setsockopt_service(sk, val, optval, optlen);
528
529         lock_sock(sk);
530         switch (optname) {
531         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
532                 if (dp->dccps_role != DCCP_ROLE_SERVER)
533                         err = -EOPNOTSUPP;
534                 else
535                         dp->dccps_server_timewait = (val != 0);
536                 break;
537         case DCCP_SOCKOPT_SEND_CSCOV:
538                 err = dccp_setsockopt_cscov(sk, val, false);
539                 break;
540         case DCCP_SOCKOPT_RECV_CSCOV:
541                 err = dccp_setsockopt_cscov(sk, val, true);
542                 break;
543         case DCCP_SOCKOPT_QPOLICY_ID:
544                 if (sk->sk_state != DCCP_CLOSED)
545                         err = -EISCONN;
546                 else if (val < 0 || val >= DCCPQ_POLICY_MAX)
547                         err = -EINVAL;
548                 else
549                         dp->dccps_qpolicy = val;
550                 break;
551         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
552                 if (val < 0)
553                         err = -EINVAL;
554                 else
555                         dp->dccps_tx_qlen = val;
556                 break;
557         default:
558                 err = -ENOPROTOOPT;
559                 break;
560         }
561         release_sock(sk);
562
563         return err;
564 }
565
566 int dccp_setsockopt(struct sock *sk, int level, int optname,
567                     char __user *optval, unsigned int optlen)
568 {
569         if (level != SOL_DCCP)
570                 return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
571                                                              optname, optval,
572                                                              optlen);
573         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
574 }
575
576 EXPORT_SYMBOL_GPL(dccp_setsockopt);
577
578 #ifdef CONFIG_COMPAT
579 int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
580                            char __user *optval, unsigned int optlen)
581 {
582         if (level != SOL_DCCP)
583                 return inet_csk_compat_setsockopt(sk, level, optname,
584                                                   optval, optlen);
585         return do_dccp_setsockopt(sk, level, optname, optval, optlen);
586 }
587
588 EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
589 #endif
590
591 static int dccp_getsockopt_service(struct sock *sk, int len,
592                                    __be32 __user *optval,
593                                    int __user *optlen)
594 {
595         const struct dccp_sock *dp = dccp_sk(sk);
596         const struct dccp_service_list *sl;
597         int err = -ENOENT, slen = 0, total_len = sizeof(u32);
598
599         lock_sock(sk);
600         if ((sl = dp->dccps_service_list) != NULL) {
601                 slen = sl->dccpsl_nr * sizeof(u32);
602                 total_len += slen;
603         }
604
605         err = -EINVAL;
606         if (total_len > len)
607                 goto out;
608
609         err = 0;
610         if (put_user(total_len, optlen) ||
611             put_user(dp->dccps_service, optval) ||
612             (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
613                 err = -EFAULT;
614 out:
615         release_sock(sk);
616         return err;
617 }
618
619 static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
620                     char __user *optval, int __user *optlen)
621 {
622         struct dccp_sock *dp;
623         int val, len;
624
625         if (get_user(len, optlen))
626                 return -EFAULT;
627
628         if (len < (int)sizeof(int))
629                 return -EINVAL;
630
631         dp = dccp_sk(sk);
632
633         switch (optname) {
634         case DCCP_SOCKOPT_PACKET_SIZE:
635                 DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
636                 return 0;
637         case DCCP_SOCKOPT_SERVICE:
638                 return dccp_getsockopt_service(sk, len,
639                                                (__be32 __user *)optval, optlen);
640         case DCCP_SOCKOPT_GET_CUR_MPS:
641                 val = dp->dccps_mss_cache;
642                 break;
643         case DCCP_SOCKOPT_AVAILABLE_CCIDS:
644                 return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
645         case DCCP_SOCKOPT_TX_CCID:
646                 val = ccid_get_current_tx_ccid(dp);
647                 if (val < 0)
648                         return -ENOPROTOOPT;
649                 break;
650         case DCCP_SOCKOPT_RX_CCID:
651                 val = ccid_get_current_rx_ccid(dp);
652                 if (val < 0)
653                         return -ENOPROTOOPT;
654                 break;
655         case DCCP_SOCKOPT_SERVER_TIMEWAIT:
656                 val = dp->dccps_server_timewait;
657                 break;
658         case DCCP_SOCKOPT_SEND_CSCOV:
659                 val = dp->dccps_pcslen;
660                 break;
661         case DCCP_SOCKOPT_RECV_CSCOV:
662                 val = dp->dccps_pcrlen;
663                 break;
664         case DCCP_SOCKOPT_QPOLICY_ID:
665                 val = dp->dccps_qpolicy;
666                 break;
667         case DCCP_SOCKOPT_QPOLICY_TXQLEN:
668                 val = dp->dccps_tx_qlen;
669                 break;
670         case 128 ... 191:
671                 return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
672                                              len, (u32 __user *)optval, optlen);
673         case 192 ... 255:
674                 return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
675                                              len, (u32 __user *)optval, optlen);
676         default:
677                 return -ENOPROTOOPT;
678         }
679
680         len = sizeof(val);
681         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
682                 return -EFAULT;
683
684         return 0;
685 }
686
687 int dccp_getsockopt(struct sock *sk, int level, int optname,
688                     char __user *optval, int __user *optlen)
689 {
690         if (level != SOL_DCCP)
691                 return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
692                                                              optname, optval,
693                                                              optlen);
694         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
695 }
696
697 EXPORT_SYMBOL_GPL(dccp_getsockopt);
698
699 #ifdef CONFIG_COMPAT
700 int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
701                            char __user *optval, int __user *optlen)
702 {
703         if (level != SOL_DCCP)
704                 return inet_csk_compat_getsockopt(sk, level, optname,
705                                                   optval, optlen);
706         return do_dccp_getsockopt(sk, level, optname, optval, optlen);
707 }
708
709 EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
710 #endif
711
712 static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
713 {
714         struct cmsghdr *cmsg;
715
716         /*
717          * Assign an (opaque) qpolicy priority value to skb->priority.
718          *
719          * We are overloading this skb field for use with the qpolicy subystem.
720          * The skb->priority is normally used for the SO_PRIORITY option, which
721          * is initialised from sk_priority. Since the assignment of sk_priority
722          * to skb->priority happens later (on layer 3), we overload this field
723          * for use with queueing priorities as long as the skb is on layer 4.
724          * The default priority value (if nothing is set) is 0.
725          */
726         skb->priority = 0;
727
728         for_each_cmsghdr(cmsg, msg) {
729                 if (!CMSG_OK(msg, cmsg))
730                         return -EINVAL;
731
732                 if (cmsg->cmsg_level != SOL_DCCP)
733                         continue;
734
735                 if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX &&
736                     !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type))
737                         return -EINVAL;
738
739                 switch (cmsg->cmsg_type) {
740                 case DCCP_SCM_PRIORITY:
741                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
742                                 return -EINVAL;
743                         skb->priority = *(__u32 *)CMSG_DATA(cmsg);
744                         break;
745                 default:
746                         return -EINVAL;
747                 }
748         }
749         return 0;
750 }
751
752 int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
753 {
754         const struct dccp_sock *dp = dccp_sk(sk);
755         const int flags = msg->msg_flags;
756         const int noblock = flags & MSG_DONTWAIT;
757         struct sk_buff *skb;
758         int rc, size;
759         long timeo;
760
761         trace_dccp_probe(sk, len);
762
763         if (len > dp->dccps_mss_cache)
764                 return -EMSGSIZE;
765
766         lock_sock(sk);
767
768         if (dccp_qpolicy_full(sk)) {
769                 rc = -EAGAIN;
770                 goto out_release;
771         }
772
773         timeo = sock_sndtimeo(sk, noblock);
774
775         /*
776          * We have to use sk_stream_wait_connect here to set sk_write_pending,
777          * so that the trick in dccp_rcv_request_sent_state_process.
778          */
779         /* Wait for a connection to finish. */
780         if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
781                 if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
782                         goto out_release;
783
784         size = sk->sk_prot->max_header + len;
785         release_sock(sk);
786         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
787         lock_sock(sk);
788         if (skb == NULL)
789                 goto out_release;
790
791         if (sk->sk_state == DCCP_CLOSED) {
792                 rc = -ENOTCONN;
793                 goto out_discard;
794         }
795
796         skb_reserve(skb, sk->sk_prot->max_header);
797         rc = memcpy_from_msg(skb_put(skb, len), msg, len);
798         if (rc != 0)
799                 goto out_discard;
800
801         rc = dccp_msghdr_parse(msg, skb);
802         if (rc != 0)
803                 goto out_discard;
804
805         dccp_qpolicy_push(sk, skb);
806         /*
807          * The xmit_timer is set if the TX CCID is rate-based and will expire
808          * when congestion control permits to release further packets into the
809          * network. Window-based CCIDs do not use this timer.
810          */
811         if (!timer_pending(&dp->dccps_xmit_timer))
812                 dccp_write_xmit(sk);
813 out_release:
814         release_sock(sk);
815         return rc ? : len;
816 out_discard:
817         kfree_skb(skb);
818         goto out_release;
819 }
820
821 EXPORT_SYMBOL_GPL(dccp_sendmsg);
822
823 int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
824                  int flags, int *addr_len)
825 {
826         const struct dccp_hdr *dh;
827         long timeo;
828
829         lock_sock(sk);
830
831         if (sk->sk_state == DCCP_LISTEN) {
832                 len = -ENOTCONN;
833                 goto out;
834         }
835
836         timeo = sock_rcvtimeo(sk, nonblock);
837
838         do {
839                 struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
840
841                 if (skb == NULL)
842                         goto verify_sock_status;
843
844                 dh = dccp_hdr(skb);
845
846                 switch (dh->dccph_type) {
847                 case DCCP_PKT_DATA:
848                 case DCCP_PKT_DATAACK:
849                         goto found_ok_skb;
850
851                 case DCCP_PKT_CLOSE:
852                 case DCCP_PKT_CLOSEREQ:
853                         if (!(flags & MSG_PEEK))
854                                 dccp_finish_passive_close(sk);
855                         /* fall through */
856                 case DCCP_PKT_RESET:
857                         dccp_pr_debug("found fin (%s) ok!\n",
858                                       dccp_packet_name(dh->dccph_type));
859                         len = 0;
860                         goto found_fin_ok;
861                 default:
862                         dccp_pr_debug("packet_type=%s\n",
863                                       dccp_packet_name(dh->dccph_type));
864                         sk_eat_skb(sk, skb);
865                 }
866 verify_sock_status:
867                 if (sock_flag(sk, SOCK_DONE)) {
868                         len = 0;
869                         break;
870                 }
871
872                 if (sk->sk_err) {
873                         len = sock_error(sk);
874                         break;
875                 }
876
877                 if (sk->sk_shutdown & RCV_SHUTDOWN) {
878                         len = 0;
879                         break;
880                 }
881
882                 if (sk->sk_state == DCCP_CLOSED) {
883                         if (!sock_flag(sk, SOCK_DONE)) {
884                                 /* This occurs when user tries to read
885                                  * from never connected socket.
886                                  */
887                                 len = -ENOTCONN;
888                                 break;
889                         }
890                         len = 0;
891                         break;
892                 }
893
894                 if (!timeo) {
895                         len = -EAGAIN;
896                         break;
897                 }
898
899                 if (signal_pending(current)) {
900                         len = sock_intr_errno(timeo);
901                         break;
902                 }
903
904                 sk_wait_data(sk, &timeo, NULL);
905                 continue;
906         found_ok_skb:
907                 if (len > skb->len)
908                         len = skb->len;
909                 else if (len < skb->len)
910                         msg->msg_flags |= MSG_TRUNC;
911
912                 if (skb_copy_datagram_msg(skb, 0, msg, len)) {
913                         /* Exception. Bailout! */
914                         len = -EFAULT;
915                         break;
916                 }
917                 if (flags & MSG_TRUNC)
918                         len = skb->len;
919         found_fin_ok:
920                 if (!(flags & MSG_PEEK))
921                         sk_eat_skb(sk, skb);
922                 break;
923         } while (1);
924 out:
925         release_sock(sk);
926         return len;
927 }
928
929 EXPORT_SYMBOL_GPL(dccp_recvmsg);
930
931 int inet_dccp_listen(struct socket *sock, int backlog)
932 {
933         struct sock *sk = sock->sk;
934         unsigned char old_state;
935         int err;
936
937         lock_sock(sk);
938
939         err = -EINVAL;
940         if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
941                 goto out;
942
943         old_state = sk->sk_state;
944         if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
945                 goto out;
946
947         sk->sk_max_ack_backlog = backlog;
948         /* Really, if the socket is already in listen state
949          * we can only allow the backlog to be adjusted.
950          */
951         if (old_state != DCCP_LISTEN) {
952                 /*
953                  * FIXME: here it probably should be sk->sk_prot->listen_start
954                  * see tcp_listen_start
955                  */
956                 err = dccp_listen_start(sk, backlog);
957                 if (err)
958                         goto out;
959         }
960         err = 0;
961
962 out:
963         release_sock(sk);
964         return err;
965 }
966
967 EXPORT_SYMBOL_GPL(inet_dccp_listen);
968
969 static void dccp_terminate_connection(struct sock *sk)
970 {
971         u8 next_state = DCCP_CLOSED;
972
973         switch (sk->sk_state) {
974         case DCCP_PASSIVE_CLOSE:
975         case DCCP_PASSIVE_CLOSEREQ:
976                 dccp_finish_passive_close(sk);
977                 break;
978         case DCCP_PARTOPEN:
979                 dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
980                 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
981                 /* fall through */
982         case DCCP_OPEN:
983                 dccp_send_close(sk, 1);
984
985                 if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
986                     !dccp_sk(sk)->dccps_server_timewait)
987                         next_state = DCCP_ACTIVE_CLOSEREQ;
988                 else
989                         next_state = DCCP_CLOSING;
990                 /* fall through */
991         default:
992                 dccp_set_state(sk, next_state);
993         }
994 }
995
996 void dccp_close(struct sock *sk, long timeout)
997 {
998         struct dccp_sock *dp = dccp_sk(sk);
999         struct sk_buff *skb;
1000         u32 data_was_unread = 0;
1001         int state;
1002
1003         lock_sock(sk);
1004
1005         sk->sk_shutdown = SHUTDOWN_MASK;
1006
1007         if (sk->sk_state == DCCP_LISTEN) {
1008                 dccp_set_state(sk, DCCP_CLOSED);
1009
1010                 /* Special case. */
1011                 inet_csk_listen_stop(sk);
1012
1013                 goto adjudge_to_death;
1014         }
1015
1016         sk_stop_timer(sk, &dp->dccps_xmit_timer);
1017
1018         /*
1019          * We need to flush the recv. buffs.  We do this only on the
1020          * descriptor close, not protocol-sourced closes, because the
1021           *reader process may not have drained the data yet!
1022          */
1023         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
1024                 data_was_unread += skb->len;
1025                 __kfree_skb(skb);
1026         }
1027
1028         /* If socket has been already reset kill it. */
1029         if (sk->sk_state == DCCP_CLOSED)
1030                 goto adjudge_to_death;
1031
1032         if (data_was_unread) {
1033                 /* Unread data was tossed, send an appropriate Reset Code */
1034                 DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread);
1035                 dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
1036                 dccp_set_state(sk, DCCP_CLOSED);
1037         } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
1038                 /* Check zero linger _after_ checking for unread data. */
1039                 sk->sk_prot->disconnect(sk, 0);
1040         } else if (sk->sk_state != DCCP_CLOSED) {
1041                 /*
1042                  * Normal connection termination. May need to wait if there are
1043                  * still packets in the TX queue that are delayed by the CCID.
1044                  */
1045                 dccp_flush_write_queue(sk, &timeout);
1046                 dccp_terminate_connection(sk);
1047         }
1048
1049         /*
1050          * Flush write queue. This may be necessary in several cases:
1051          * - we have been closed by the peer but still have application data;
1052          * - abortive termination (unread data or zero linger time),
1053          * - normal termination but queue could not be flushed within time limit
1054          */
1055         __skb_queue_purge(&sk->sk_write_queue);
1056
1057         sk_stream_wait_close(sk, timeout);
1058
1059 adjudge_to_death:
1060         state = sk->sk_state;
1061         sock_hold(sk);
1062         sock_orphan(sk);
1063
1064         /*
1065          * It is the last release_sock in its life. It will remove backlog.
1066          */
1067         release_sock(sk);
1068         /*
1069          * Now socket is owned by kernel and we acquire BH lock
1070          * to finish close. No need to check for user refs.
1071          */
1072         local_bh_disable();
1073         bh_lock_sock(sk);
1074         WARN_ON(sock_owned_by_user(sk));
1075
1076         percpu_counter_inc(sk->sk_prot->orphan_count);
1077
1078         /* Have we already been destroyed by a softirq or backlog? */
1079         if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
1080                 goto out;
1081
1082         if (sk->sk_state == DCCP_CLOSED)
1083                 inet_csk_destroy_sock(sk);
1084
1085         /* Otherwise, socket is reprieved until protocol close. */
1086
1087 out:
1088         bh_unlock_sock(sk);
1089         local_bh_enable();
1090         sock_put(sk);
1091 }
1092
1093 EXPORT_SYMBOL_GPL(dccp_close);
1094
1095 void dccp_shutdown(struct sock *sk, int how)
1096 {
1097         dccp_pr_debug("called shutdown(%x)\n", how);
1098 }
1099
1100 EXPORT_SYMBOL_GPL(dccp_shutdown);
1101
1102 static inline int __init dccp_mib_init(void)
1103 {
1104         dccp_statistics = alloc_percpu(struct dccp_mib);
1105         if (!dccp_statistics)
1106                 return -ENOMEM;
1107         return 0;
1108 }
1109
1110 static inline void dccp_mib_exit(void)
1111 {
1112         free_percpu(dccp_statistics);
1113 }
1114
1115 static int thash_entries;
1116 module_param(thash_entries, int, 0444);
1117 MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
1118
1119 #ifdef CONFIG_IP_DCCP_DEBUG
1120 bool dccp_debug;
1121 module_param(dccp_debug, bool, 0644);
1122 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
1123
1124 EXPORT_SYMBOL_GPL(dccp_debug);
1125 #endif
1126
1127 static int __init dccp_init(void)
1128 {
1129         unsigned long goal;
1130         unsigned long nr_pages = totalram_pages();
1131         int ehash_order, bhash_order, i;
1132         int rc;
1133
1134         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
1135                      FIELD_SIZEOF(struct sk_buff, cb));
1136         rc = percpu_counter_init(&dccp_orphan_count, 0, GFP_KERNEL);
1137         if (rc)
1138                 goto out_fail;
1139         inet_hashinfo_init(&dccp_hashinfo);
1140         rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
1141         if (rc)
1142                 goto out_fail;
1143         rc = -ENOBUFS;
1144         dccp_hashinfo.bind_bucket_cachep =
1145                 kmem_cache_create("dccp_bind_bucket",
1146                                   sizeof(struct inet_bind_bucket), 0,
1147                                   SLAB_HWCACHE_ALIGN, NULL);
1148         if (!dccp_hashinfo.bind_bucket_cachep)
1149                 goto out_free_percpu;
1150
1151         /*
1152          * Size and allocate the main established and bind bucket
1153          * hash tables.
1154          *
1155          * The methodology is similar to that of the buffer cache.
1156          */
1157         if (nr_pages >= (128 * 1024))
1158                 goal = nr_pages >> (21 - PAGE_SHIFT);
1159         else
1160                 goal = nr_pages >> (23 - PAGE_SHIFT);
1161
1162         if (thash_entries)
1163                 goal = (thash_entries *
1164                         sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
1165         for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
1166                 ;
1167         do {
1168                 unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE /
1169                                         sizeof(struct inet_ehash_bucket);
1170
1171                 while (hash_size & (hash_size - 1))
1172                         hash_size--;
1173                 dccp_hashinfo.ehash_mask = hash_size - 1;
1174                 dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
1175                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order);
1176         } while (!dccp_hashinfo.ehash && --ehash_order > 0);
1177
1178         if (!dccp_hashinfo.ehash) {
1179                 DCCP_CRIT("Failed to allocate DCCP established hash table");
1180                 goto out_free_bind_bucket_cachep;
1181         }
1182
1183         for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
1184                 INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
1185
1186         if (inet_ehash_locks_alloc(&dccp_hashinfo))
1187                         goto out_free_dccp_ehash;
1188
1189         bhash_order = ehash_order;
1190
1191         do {
1192                 dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
1193                                         sizeof(struct inet_bind_hashbucket);
1194                 if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
1195                     bhash_order > 0)
1196                         continue;
1197                 dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
1198                         __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order);
1199         } while (!dccp_hashinfo.bhash && --bhash_order >= 0);
1200
1201         if (!dccp_hashinfo.bhash) {
1202                 DCCP_CRIT("Failed to allocate DCCP bind hash table");
1203                 goto out_free_dccp_locks;
1204         }
1205
1206         for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
1207                 spin_lock_init(&dccp_hashinfo.bhash[i].lock);
1208                 INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
1209         }
1210
1211         rc = dccp_mib_init();
1212         if (rc)
1213                 goto out_free_dccp_bhash;
1214
1215         rc = dccp_ackvec_init();
1216         if (rc)
1217                 goto out_free_dccp_mib;
1218
1219         rc = dccp_sysctl_init();
1220         if (rc)
1221                 goto out_ackvec_exit;
1222
1223         rc = ccid_initialize_builtins();
1224         if (rc)
1225                 goto out_sysctl_exit;
1226
1227         dccp_timestamping_init();
1228
1229         return 0;
1230
1231 out_sysctl_exit:
1232         dccp_sysctl_exit();
1233 out_ackvec_exit:
1234         dccp_ackvec_exit();
1235 out_free_dccp_mib:
1236         dccp_mib_exit();
1237 out_free_dccp_bhash:
1238         free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
1239 out_free_dccp_locks:
1240         inet_ehash_locks_free(&dccp_hashinfo);
1241 out_free_dccp_ehash:
1242         free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
1243 out_free_bind_bucket_cachep:
1244         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1245 out_free_percpu:
1246         percpu_counter_destroy(&dccp_orphan_count);
1247 out_fail:
1248         dccp_hashinfo.bhash = NULL;
1249         dccp_hashinfo.ehash = NULL;
1250         dccp_hashinfo.bind_bucket_cachep = NULL;
1251         return rc;
1252 }
1253
1254 static void __exit dccp_fini(void)
1255 {
1256         ccid_cleanup_builtins();
1257         dccp_mib_exit();
1258         free_pages((unsigned long)dccp_hashinfo.bhash,
1259                    get_order(dccp_hashinfo.bhash_size *
1260                              sizeof(struct inet_bind_hashbucket)));
1261         free_pages((unsigned long)dccp_hashinfo.ehash,
1262                    get_order((dccp_hashinfo.ehash_mask + 1) *
1263                              sizeof(struct inet_ehash_bucket)));
1264         inet_ehash_locks_free(&dccp_hashinfo);
1265         kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
1266         dccp_ackvec_exit();
1267         dccp_sysctl_exit();
1268         percpu_counter_destroy(&dccp_orphan_count);
1269 }
1270
1271 module_init(dccp_init);
1272 module_exit(dccp_fini);
1273
1274 MODULE_LICENSE("GPL");
1275 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
1276 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");