Merge master.kernel.org:/pub/scm/linux/kernel/git/acme/net-2.6
[linux-3.10.git] / net / dccp / ipv4.c
1 /*
2  *  net/dccp/ipv4.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
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/config.h>
14 #include <linux/dccp.h>
15 #include <linux/icmp.h>
16 #include <linux/module.h>
17 #include <linux/skbuff.h>
18 #include <linux/random.h>
19
20 #include <net/icmp.h>
21 #include <net/inet_hashtables.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <net/xfrm.h>
25
26 #include "ackvec.h"
27 #include "ccid.h"
28 #include "dccp.h"
29
30 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
31         .lhash_lock     = RW_LOCK_UNLOCKED,
32         .lhash_users    = ATOMIC_INIT(0),
33         .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
34 };
35
36 EXPORT_SYMBOL_GPL(dccp_hashinfo);
37
38 static int dccp_v4_get_port(struct sock *sk, const unsigned short snum)
39 {
40         return inet_csk_get_port(&dccp_hashinfo, sk, snum);
41 }
42
43 static void dccp_v4_hash(struct sock *sk)
44 {
45         inet_hash(&dccp_hashinfo, sk);
46 }
47
48 static void dccp_v4_unhash(struct sock *sk)
49 {
50         inet_unhash(&dccp_hashinfo, sk);
51 }
52
53 /* called with local bh disabled */
54 static int __dccp_v4_check_established(struct sock *sk, const __u16 lport,
55                                       struct inet_timewait_sock **twp)
56 {
57         struct inet_sock *inet = inet_sk(sk);
58         const u32 daddr = inet->rcv_saddr;
59         const u32 saddr = inet->daddr;
60         const int dif = sk->sk_bound_dev_if;
61         INET_ADDR_COOKIE(acookie, saddr, daddr)
62         const __u32 ports = INET_COMBINED_PORTS(inet->dport, lport);
63         unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
64         struct inet_ehash_bucket *head = inet_ehash_bucket(&dccp_hashinfo, hash);
65         const struct sock *sk2;
66         const struct hlist_node *node;
67         struct inet_timewait_sock *tw;
68
69         prefetch(head->chain.first);
70         write_lock(&head->lock);
71
72         /* Check TIME-WAIT sockets first. */
73         sk_for_each(sk2, node, &(head + dccp_hashinfo.ehash_size)->chain) {
74                 tw = inet_twsk(sk2);
75
76                 if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
77                         goto not_unique;
78         }
79         tw = NULL;
80
81         /* And established part... */
82         sk_for_each(sk2, node, &head->chain) {
83                 if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif))
84                         goto not_unique;
85         }
86
87         /* Must record num and sport now. Otherwise we will see
88          * in hash table socket with a funny identity. */
89         inet->num = lport;
90         inet->sport = htons(lport);
91         sk->sk_hash = hash;
92         BUG_TRAP(sk_unhashed(sk));
93         __sk_add_node(sk, &head->chain);
94         sock_prot_inc_use(sk->sk_prot);
95         write_unlock(&head->lock);
96
97         if (twp != NULL) {
98                 *twp = tw;
99                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
100         } else if (tw != NULL) {
101                 /* Silly. Should hash-dance instead... */
102                 inet_twsk_deschedule(tw, &dccp_death_row);
103                 NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
104
105                 inet_twsk_put(tw);
106         }
107
108         return 0;
109
110 not_unique:
111         write_unlock(&head->lock);
112         return -EADDRNOTAVAIL;
113 }
114
115 /*
116  * Bind a port for a connect operation and hash it.
117  */
118 static int dccp_v4_hash_connect(struct sock *sk)
119 {
120         const unsigned short snum = inet_sk(sk)->num;
121         struct inet_bind_hashbucket *head;
122         struct inet_bind_bucket *tb;
123         int ret;
124
125         if (snum == 0) {
126                 int low = sysctl_local_port_range[0];
127                 int high = sysctl_local_port_range[1];
128                 int remaining = (high - low) + 1;
129                 int rover = net_random() % (high - low) + low;
130                 struct hlist_node *node;
131                 struct inet_timewait_sock *tw = NULL;
132
133                 local_bh_disable();
134                 do {
135                         head = &dccp_hashinfo.bhash[inet_bhashfn(rover,
136                                                     dccp_hashinfo.bhash_size)];
137                         spin_lock(&head->lock);
138
139                         /* Does not bother with rcv_saddr checks,
140                          * because the established check is already
141                          * unique enough.
142                          */
143                         inet_bind_bucket_for_each(tb, node, &head->chain) {
144                                 if (tb->port == rover) {
145                                         BUG_TRAP(!hlist_empty(&tb->owners));
146                                         if (tb->fastreuse >= 0)
147                                                 goto next_port;
148                                         if (!__dccp_v4_check_established(sk,
149                                                                          rover,
150                                                                          &tw))
151                                                 goto ok;
152                                         goto next_port;
153                                 }
154                         }
155
156                         tb = inet_bind_bucket_create(dccp_hashinfo.bind_bucket_cachep,
157                                                      head, rover);
158                         if (tb == NULL) {
159                                 spin_unlock(&head->lock);
160                                 break;
161                         }
162                         tb->fastreuse = -1;
163                         goto ok;
164
165                 next_port:
166                         spin_unlock(&head->lock);
167                         if (++rover > high)
168                                 rover = low;
169                 } while (--remaining > 0);
170
171                 local_bh_enable();
172
173                 return -EADDRNOTAVAIL;
174
175 ok:
176                 /* All locks still held and bhs disabled */
177                 inet_bind_hash(sk, tb, rover);
178                 if (sk_unhashed(sk)) {
179                         inet_sk(sk)->sport = htons(rover);
180                         __inet_hash(&dccp_hashinfo, sk, 0);
181                 }
182                 spin_unlock(&head->lock);
183
184                 if (tw != NULL) {
185                         inet_twsk_deschedule(tw, &dccp_death_row);
186                         inet_twsk_put(tw);
187                 }
188
189                 ret = 0;
190                 goto out;
191         }
192
193         head = &dccp_hashinfo.bhash[inet_bhashfn(snum,
194                                                  dccp_hashinfo.bhash_size)];
195         tb   = inet_csk(sk)->icsk_bind_hash;
196         spin_lock_bh(&head->lock);
197         if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
198                 __inet_hash(&dccp_hashinfo, sk, 0);
199                 spin_unlock_bh(&head->lock);
200                 return 0;
201         } else {
202                 spin_unlock(&head->lock);
203                 /* No definite answer... Walk to established hash table */
204                 ret = __dccp_v4_check_established(sk, snum, NULL);
205 out:
206                 local_bh_enable();
207                 return ret;
208         }
209 }
210
211 static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
212                            int addr_len)
213 {
214         struct inet_sock *inet = inet_sk(sk);
215         struct dccp_sock *dp = dccp_sk(sk);
216         const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
217         struct rtable *rt;
218         u32 daddr, nexthop;
219         int tmp;
220         int err;
221
222         dp->dccps_role = DCCP_ROLE_CLIENT;
223
224         if (dccp_service_not_initialized(sk))
225                 return -EPROTO;
226
227         if (addr_len < sizeof(struct sockaddr_in))
228                 return -EINVAL;
229
230         if (usin->sin_family != AF_INET)
231                 return -EAFNOSUPPORT;
232
233         nexthop = daddr = usin->sin_addr.s_addr;
234         if (inet->opt != NULL && inet->opt->srr) {
235                 if (daddr == 0)
236                         return -EINVAL;
237                 nexthop = inet->opt->faddr;
238         }
239
240         tmp = ip_route_connect(&rt, nexthop, inet->saddr,
241                                RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
242                                IPPROTO_DCCP,
243                                inet->sport, usin->sin_port, sk);
244         if (tmp < 0)
245                 return tmp;
246
247         if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
248                 ip_rt_put(rt);
249                 return -ENETUNREACH;
250         }
251
252         if (inet->opt == NULL || !inet->opt->srr)
253                 daddr = rt->rt_dst;
254
255         if (inet->saddr == 0)
256                 inet->saddr = rt->rt_src;
257         inet->rcv_saddr = inet->saddr;
258
259         inet->dport = usin->sin_port;
260         inet->daddr = daddr;
261
262         dp->dccps_ext_header_len = 0;
263         if (inet->opt != NULL)
264                 dp->dccps_ext_header_len = inet->opt->optlen;
265         /*
266          * Socket identity is still unknown (sport may be zero).
267          * However we set state to DCCP_REQUESTING and not releasing socket
268          * lock select source port, enter ourselves into the hash tables and
269          * complete initialization after this.
270          */
271         dccp_set_state(sk, DCCP_REQUESTING);
272         err = dccp_v4_hash_connect(sk);
273         if (err != 0)
274                 goto failure;
275
276         err = ip_route_newports(&rt, inet->sport, inet->dport, sk);
277         if (err != 0)
278                 goto failure;
279
280         /* OK, now commit destination to socket.  */
281         sk_setup_caps(sk, &rt->u.dst);
282
283         dp->dccps_gar =
284                 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
285                                                             inet->daddr,
286                                                             inet->sport,
287                                                             usin->sin_port);
288         dccp_update_gss(sk, dp->dccps_iss);
289
290         /*
291          * SWL and AWL are initially adjusted so that they are not less than
292          * the initial Sequence Numbers received and sent, respectively:
293          *      SWL := max(GSR + 1 - floor(W/4), ISR),
294          *      AWL := max(GSS - W' + 1, ISS).
295          * These adjustments MUST be applied only at the beginning of the
296          * connection.
297          */
298         dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
299
300         inet->id = dp->dccps_iss ^ jiffies;
301
302         err = dccp_connect(sk);
303         rt = NULL;
304         if (err != 0)
305                 goto failure;
306 out:
307         return err;
308 failure:
309         /*
310          * This unhashes the socket and releases the local port, if necessary.
311          */
312         dccp_set_state(sk, DCCP_CLOSED);
313         ip_rt_put(rt);
314         sk->sk_route_caps = 0;
315         inet->dport = 0;
316         goto out;
317 }
318
319 /*
320  * This routine does path mtu discovery as defined in RFC1191.
321  */
322 static inline void dccp_do_pmtu_discovery(struct sock *sk,
323                                           const struct iphdr *iph,
324                                           u32 mtu)
325 {
326         struct dst_entry *dst;
327         const struct inet_sock *inet = inet_sk(sk);
328         const struct dccp_sock *dp = dccp_sk(sk);
329
330         /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
331          * send out by Linux are always < 576bytes so they should go through
332          * unfragmented).
333          */
334         if (sk->sk_state == DCCP_LISTEN)
335                 return;
336
337         /* We don't check in the destentry if pmtu discovery is forbidden
338          * on this route. We just assume that no packet_to_big packets
339          * are send back when pmtu discovery is not active.
340          * There is a small race when the user changes this flag in the
341          * route, but I think that's acceptable.
342          */
343         if ((dst = __sk_dst_check(sk, 0)) == NULL)
344                 return;
345
346         dst->ops->update_pmtu(dst, mtu);
347
348         /* Something is about to be wrong... Remember soft error
349          * for the case, if this connection will not able to recover.
350          */
351         if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
352                 sk->sk_err_soft = EMSGSIZE;
353
354         mtu = dst_mtu(dst);
355
356         if (inet->pmtudisc != IP_PMTUDISC_DONT &&
357             dp->dccps_pmtu_cookie > mtu) {
358                 dccp_sync_mss(sk, mtu);
359
360                 /*
361                  * From: draft-ietf-dccp-spec-11.txt
362                  *
363                  *      DCCP-Sync packets are the best choice for upward
364                  *      probing, since DCCP-Sync probes do not risk application
365                  *      data loss.
366                  */
367                 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
368         } /* else let the usual retransmit timer handle it */
369 }
370
371 static void dccp_v4_ctl_send_ack(struct sk_buff *rxskb)
372 {
373         int err;
374         struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
375         const int dccp_hdr_ack_len = sizeof(struct dccp_hdr) +
376                                      sizeof(struct dccp_hdr_ext) +
377                                      sizeof(struct dccp_hdr_ack_bits);
378         struct sk_buff *skb;
379
380         if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
381                 return;
382
383         skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC);
384         if (skb == NULL)
385                 return;
386
387         /* Reserve space for headers. */
388         skb_reserve(skb, MAX_DCCP_HEADER);
389
390         skb->dst = dst_clone(rxskb->dst);
391
392         skb->h.raw = skb_push(skb, dccp_hdr_ack_len);
393         dh = dccp_hdr(skb);
394         memset(dh, 0, dccp_hdr_ack_len);
395
396         /* Build DCCP header and checksum it. */
397         dh->dccph_type     = DCCP_PKT_ACK;
398         dh->dccph_sport    = rxdh->dccph_dport;
399         dh->dccph_dport    = rxdh->dccph_sport;
400         dh->dccph_doff     = dccp_hdr_ack_len / 4;
401         dh->dccph_x        = 1;
402
403         dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
404         dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
405                          DCCP_SKB_CB(rxskb)->dccpd_seq);
406
407         bh_lock_sock(dccp_ctl_socket->sk);
408         err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk,
409                                     rxskb->nh.iph->daddr,
410                                     rxskb->nh.iph->saddr, NULL);
411         bh_unlock_sock(dccp_ctl_socket->sk);
412
413         if (err == NET_XMIT_CN || err == 0) {
414                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
415                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
416         }
417 }
418
419 static void dccp_v4_reqsk_send_ack(struct sk_buff *skb,
420                                    struct request_sock *req)
421 {
422         dccp_v4_ctl_send_ack(skb);
423 }
424
425 static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
426                                  struct dst_entry *dst)
427 {
428         int err = -1;
429         struct sk_buff *skb;
430
431         /* First, grab a route. */
432         
433         if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
434                 goto out;
435
436         skb = dccp_make_response(sk, dst, req);
437         if (skb != NULL) {
438                 const struct inet_request_sock *ireq = inet_rsk(req);
439
440                 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
441                 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
442                                             ireq->rmt_addr,
443                                             ireq->opt);
444                 if (err == NET_XMIT_CN)
445                         err = 0;
446         }
447
448 out:
449         dst_release(dst);
450         return err;
451 }
452
453 /*
454  * This routine is called by the ICMP module when it gets some sort of error
455  * condition. If err < 0 then the socket should be closed and the error
456  * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
457  * After adjustment header points to the first 8 bytes of the tcp header. We
458  * need to find the appropriate port.
459  *
460  * The locking strategy used here is very "optimistic". When someone else
461  * accesses the socket the ICMP is just dropped and for some paths there is no
462  * check at all. A more general error queue to queue errors for later handling
463  * is probably better.
464  */
465 void dccp_v4_err(struct sk_buff *skb, u32 info)
466 {
467         const struct iphdr *iph = (struct iphdr *)skb->data;
468         const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
469                                                         (iph->ihl << 2));
470         struct dccp_sock *dp;
471         struct inet_sock *inet;
472         const int type = skb->h.icmph->type;
473         const int code = skb->h.icmph->code;
474         struct sock *sk;
475         __u64 seq;
476         int err;
477
478         if (skb->len < (iph->ihl << 2) + 8) {
479                 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
480                 return;
481         }
482
483         sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport,
484                          iph->saddr, dh->dccph_sport, inet_iif(skb));
485         if (sk == NULL) {
486                 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
487                 return;
488         }
489
490         if (sk->sk_state == DCCP_TIME_WAIT) {
491                 inet_twsk_put((struct inet_timewait_sock *)sk);
492                 return;
493         }
494
495         bh_lock_sock(sk);
496         /* If too many ICMPs get dropped on busy
497          * servers this needs to be solved differently.
498          */
499         if (sock_owned_by_user(sk))
500                 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
501
502         if (sk->sk_state == DCCP_CLOSED)
503                 goto out;
504
505         dp = dccp_sk(sk);
506         seq = dccp_hdr_seq(skb);
507         if (sk->sk_state != DCCP_LISTEN &&
508             !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
509                 NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS);
510                 goto out;
511         }
512
513         switch (type) {
514         case ICMP_SOURCE_QUENCH:
515                 /* Just silently ignore these. */
516                 goto out;
517         case ICMP_PARAMETERPROB:
518                 err = EPROTO;
519                 break;
520         case ICMP_DEST_UNREACH:
521                 if (code > NR_ICMP_UNREACH)
522                         goto out;
523
524                 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
525                         if (!sock_owned_by_user(sk))
526                                 dccp_do_pmtu_discovery(sk, iph, info);
527                         goto out;
528                 }
529
530                 err = icmp_err_convert[code].errno;
531                 break;
532         case ICMP_TIME_EXCEEDED:
533                 err = EHOSTUNREACH;
534                 break;
535         default:
536                 goto out;
537         }
538
539         switch (sk->sk_state) {
540                 struct request_sock *req , **prev;
541         case DCCP_LISTEN:
542                 if (sock_owned_by_user(sk))
543                         goto out;
544                 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
545                                           iph->daddr, iph->saddr);
546                 if (!req)
547                         goto out;
548
549                 /*
550                  * ICMPs are not backlogged, hence we cannot get an established
551                  * socket here.
552                  */
553                 BUG_TRAP(!req->sk);
554
555                 if (seq != dccp_rsk(req)->dreq_iss) {
556                         NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
557                         goto out;
558                 }
559                 /*
560                  * Still in RESPOND, just remove it silently.
561                  * There is no good way to pass the error to the newly
562                  * created socket, and POSIX does not want network
563                  * errors returned from accept().
564                  */
565                 inet_csk_reqsk_queue_drop(sk, req, prev);
566                 goto out;
567
568         case DCCP_REQUESTING:
569         case DCCP_RESPOND:
570                 if (!sock_owned_by_user(sk)) {
571                         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
572                         sk->sk_err = err;
573
574                         sk->sk_error_report(sk);
575
576                         dccp_done(sk);
577                 } else
578                         sk->sk_err_soft = err;
579                 goto out;
580         }
581
582         /* If we've already connected we will keep trying
583          * until we time out, or the user gives up.
584          *
585          * rfc1122 4.2.3.9 allows to consider as hard errors
586          * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
587          * but it is obsoleted by pmtu discovery).
588          *
589          * Note, that in modern internet, where routing is unreliable
590          * and in each dark corner broken firewalls sit, sending random
591          * errors ordered by their masters even this two messages finally lose
592          * their original sense (even Linux sends invalid PORT_UNREACHs)
593          *
594          * Now we are in compliance with RFCs.
595          *                                                      --ANK (980905)
596          */
597
598         inet = inet_sk(sk);
599         if (!sock_owned_by_user(sk) && inet->recverr) {
600                 sk->sk_err = err;
601                 sk->sk_error_report(sk);
602         } else /* Only an error on timeout */
603                 sk->sk_err_soft = err;
604 out:
605         bh_unlock_sock(sk);
606         sock_put(sk);
607 }
608
609 int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code)
610 {
611         struct sk_buff *skb;
612         /*
613          * FIXME: what if rebuild_header fails?
614          * Should we be doing a rebuild_header here?
615          */
616         int err = inet_sk_rebuild_header(sk);
617
618         if (err != 0)
619                 return err;
620
621         skb = dccp_make_reset(sk, sk->sk_dst_cache, code);
622         if (skb != NULL) {
623                 const struct inet_sock *inet = inet_sk(sk);
624
625                 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
626                 err = ip_build_and_send_pkt(skb, sk,
627                                             inet->saddr, inet->daddr, NULL);
628                 if (err == NET_XMIT_CN)
629                         err = 0;
630         }
631
632         return err;
633 }
634
635 static inline u64 dccp_v4_init_sequence(const struct sock *sk,
636                                         const struct sk_buff *skb)
637 {
638         return secure_dccp_sequence_number(skb->nh.iph->daddr,
639                                            skb->nh.iph->saddr,
640                                            dccp_hdr(skb)->dccph_dport,
641                                            dccp_hdr(skb)->dccph_sport);
642 }
643
644 static inline int dccp_bad_service_code(const struct sock *sk,
645                                         const __u32 service)
646 {
647         const struct dccp_sock *dp = dccp_sk(sk);
648
649         if (dp->dccps_service == service)
650                 return 0;
651         return !dccp_list_has_service(dp->dccps_service_list, service);
652 }
653
654 int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
655 {
656         struct inet_request_sock *ireq;
657         struct dccp_sock dp;
658         struct request_sock *req;
659         struct dccp_request_sock *dreq;
660         const __u32 saddr = skb->nh.iph->saddr;
661         const __u32 daddr = skb->nh.iph->daddr;
662         const __u32 service = dccp_hdr_request(skb)->dccph_req_service;
663         struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
664         __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
665         struct dst_entry *dst = NULL;
666
667         /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
668         if (((struct rtable *)skb->dst)->rt_flags &
669             (RTCF_BROADCAST | RTCF_MULTICAST)) {
670                 reset_code = DCCP_RESET_CODE_NO_CONNECTION;
671                 goto drop;
672         }
673
674         if (dccp_bad_service_code(sk, service)) {
675                 reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
676                 goto drop;
677         }
678         /*
679          * TW buckets are converted to open requests without
680          * limitations, they conserve resources and peer is
681          * evidently real one.
682          */
683         if (inet_csk_reqsk_queue_is_full(sk))
684                 goto drop;
685
686         /*
687          * Accept backlog is full. If we have already queued enough
688          * of warm entries in syn queue, drop request. It is better than
689          * clogging syn queue with openreqs with exponentially increasing
690          * timeout.
691          */
692         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
693                 goto drop;
694
695         req = reqsk_alloc(sk->sk_prot->rsk_prot);
696         if (req == NULL)
697                 goto drop;
698
699         /* FIXME: process options */
700
701         dccp_openreq_init(req, &dp, skb);
702
703         ireq = inet_rsk(req);
704         ireq->loc_addr = daddr;
705         ireq->rmt_addr = saddr;
706         /* FIXME: Merge Aristeu's option parsing code when ready */
707         req->rcv_wnd    = 100; /* Fake, option parsing will get the
708                                   right value */
709         ireq->opt       = NULL;
710
711         /* 
712          * Step 3: Process LISTEN state
713          *
714          * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
715          *
716          * In fact we defer setting S.GSR, S.SWL, S.SWH to
717          * dccp_create_openreq_child.
718          */
719         dreq = dccp_rsk(req);
720         dreq->dreq_isr     = dcb->dccpd_seq;
721         dreq->dreq_iss     = dccp_v4_init_sequence(sk, skb);
722         dreq->dreq_service = service;
723
724         if (dccp_v4_send_response(sk, req, dst))
725                 goto drop_and_free;
726
727         inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
728         return 0;
729
730 drop_and_free:
731         /*
732          * FIXME: should be reqsk_free after implementing req->rsk_ops
733          */
734         __reqsk_free(req);
735 drop:
736         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
737         dcb->dccpd_reset_code = reset_code;
738         return -1;
739 }
740
741 /*
742  * The three way handshake has completed - we got a valid ACK or DATAACK -
743  * now create the new socket.
744  *
745  * This is the equivalent of TCP's tcp_v4_syn_recv_sock
746  */
747 struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
748                                        struct request_sock *req,
749                                        struct dst_entry *dst)
750 {
751         struct inet_request_sock *ireq;
752         struct inet_sock *newinet;
753         struct dccp_sock *newdp;
754         struct sock *newsk;
755
756         if (sk_acceptq_is_full(sk))
757                 goto exit_overflow;
758
759         if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
760                 goto exit;
761
762         newsk = dccp_create_openreq_child(sk, req, skb);
763         if (newsk == NULL)
764                 goto exit;
765
766         sk_setup_caps(newsk, dst);
767
768         newdp              = dccp_sk(newsk);
769         newinet            = inet_sk(newsk);
770         ireq               = inet_rsk(req);
771         newinet->daddr     = ireq->rmt_addr;
772         newinet->rcv_saddr = ireq->loc_addr;
773         newinet->saddr     = ireq->loc_addr;
774         newinet->opt       = ireq->opt;
775         ireq->opt          = NULL;
776         newinet->mc_index  = inet_iif(skb);
777         newinet->mc_ttl    = skb->nh.iph->ttl;
778         newinet->id        = jiffies;
779
780         dccp_sync_mss(newsk, dst_mtu(dst));
781
782         __inet_hash(&dccp_hashinfo, newsk, 0);
783         __inet_inherit_port(&dccp_hashinfo, sk, newsk);
784
785         return newsk;
786
787 exit_overflow:
788         NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
789 exit:
790         NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
791         dst_release(dst);
792         return NULL;
793 }
794
795 static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
796 {
797         const struct dccp_hdr *dh = dccp_hdr(skb);
798         const struct iphdr *iph = skb->nh.iph;
799         struct sock *nsk;
800         struct request_sock **prev;
801         /* Find possible connection requests. */
802         struct request_sock *req = inet_csk_search_req(sk, &prev,
803                                                        dh->dccph_sport,
804                                                        iph->saddr, iph->daddr);
805         if (req != NULL)
806                 return dccp_check_req(sk, skb, req, prev);
807
808         nsk = __inet_lookup_established(&dccp_hashinfo,
809                                         iph->saddr, dh->dccph_sport,
810                                         iph->daddr, ntohs(dh->dccph_dport),
811                                         inet_iif(skb));
812         if (nsk != NULL) {
813                 if (nsk->sk_state != DCCP_TIME_WAIT) {
814                         bh_lock_sock(nsk);
815                         return nsk;
816                 }
817                 inet_twsk_put((struct inet_timewait_sock *)nsk);
818                 return NULL;
819         }
820
821         return sk;
822 }
823
824 int dccp_v4_checksum(const struct sk_buff *skb, const u32 saddr,
825                      const u32 daddr)
826 {
827         const struct dccp_hdr* dh = dccp_hdr(skb);
828         int checksum_len;
829         u32 tmp;
830
831         if (dh->dccph_cscov == 0)
832                 checksum_len = skb->len;
833         else {
834                 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
835                 checksum_len = checksum_len < skb->len ? checksum_len :
836                                                          skb->len;
837         }
838
839         tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
840         return csum_tcpudp_magic(saddr, daddr, checksum_len,
841                                  IPPROTO_DCCP, tmp);
842 }
843
844 static int dccp_v4_verify_checksum(struct sk_buff *skb,
845                                    const u32 saddr, const u32 daddr)
846 {
847         struct dccp_hdr *dh = dccp_hdr(skb);
848         int checksum_len;
849         u32 tmp;
850
851         if (dh->dccph_cscov == 0)
852                 checksum_len = skb->len;
853         else {
854                 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
855                 checksum_len = checksum_len < skb->len ? checksum_len :
856                                                          skb->len;
857         }
858         tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
859         return csum_tcpudp_magic(saddr, daddr, checksum_len,
860                                  IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
861 }
862
863 static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
864                                            struct sk_buff *skb)
865 {
866         struct rtable *rt;
867         struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif,
868                             .nl_u = { .ip4_u =
869                                       { .daddr = skb->nh.iph->saddr,
870                                         .saddr = skb->nh.iph->daddr,
871                                         .tos = RT_CONN_FLAGS(sk) } },
872                             .proto = sk->sk_protocol,
873                             .uli_u = { .ports =
874                                        { .sport = dccp_hdr(skb)->dccph_dport,
875                                          .dport = dccp_hdr(skb)->dccph_sport }
876                                      }
877                           };
878
879         if (ip_route_output_flow(&rt, &fl, sk, 0)) {
880                 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
881                 return NULL;
882         }
883
884         return &rt->u.dst;
885 }
886
887 static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
888 {
889         int err;
890         struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
891         const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
892                                        sizeof(struct dccp_hdr_ext) +
893                                        sizeof(struct dccp_hdr_reset);
894         struct sk_buff *skb;
895         struct dst_entry *dst;
896         u64 seqno;
897
898         /* Never send a reset in response to a reset. */
899         if (rxdh->dccph_type == DCCP_PKT_RESET)
900                 return;
901
902         if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
903                 return;
904
905         dst = dccp_v4_route_skb(dccp_ctl_socket->sk, rxskb);
906         if (dst == NULL)
907                 return;
908
909         skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC);
910         if (skb == NULL)
911                 goto out;
912
913         /* Reserve space for headers. */
914         skb_reserve(skb, MAX_DCCP_HEADER);
915         skb->dst = dst_clone(dst);
916
917         skb->h.raw = skb_push(skb, dccp_hdr_reset_len);
918         dh = dccp_hdr(skb);
919         memset(dh, 0, dccp_hdr_reset_len);
920
921         /* Build DCCP header and checksum it. */
922         dh->dccph_type     = DCCP_PKT_RESET;
923         dh->dccph_sport    = rxdh->dccph_dport;
924         dh->dccph_dport    = rxdh->dccph_sport;
925         dh->dccph_doff     = dccp_hdr_reset_len / 4;
926         dh->dccph_x        = 1;
927         dccp_hdr_reset(skb)->dccph_reset_code =
928                                 DCCP_SKB_CB(rxskb)->dccpd_reset_code;
929
930         /* See "8.3.1. Abnormal Termination" in draft-ietf-dccp-spec-11 */
931         seqno = 0;
932         if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
933                 dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
934
935         dccp_hdr_set_seq(dh, seqno);
936         dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
937                          DCCP_SKB_CB(rxskb)->dccpd_seq);
938
939         dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
940                                               rxskb->nh.iph->daddr);
941
942         bh_lock_sock(dccp_ctl_socket->sk);
943         err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk,
944                                     rxskb->nh.iph->daddr,
945                                     rxskb->nh.iph->saddr, NULL);
946         bh_unlock_sock(dccp_ctl_socket->sk);
947
948         if (err == NET_XMIT_CN || err == 0) {
949                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
950                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
951         }
952 out:
953          dst_release(dst);
954 }
955
956 int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
957 {
958         struct dccp_hdr *dh = dccp_hdr(skb);
959
960         if (sk->sk_state == DCCP_OPEN) { /* Fast path */
961                 if (dccp_rcv_established(sk, skb, dh, skb->len))
962                         goto reset;
963                 return 0;
964         }
965
966         /*
967          *  Step 3: Process LISTEN state
968          *     If S.state == LISTEN,
969          *        If P.type == Request or P contains a valid Init Cookie
970          *              option,
971          *           * Must scan the packet's options to check for an Init
972          *              Cookie.  Only the Init Cookie is processed here,
973          *              however; other options are processed in Step 8.  This
974          *              scan need only be performed if the endpoint uses Init
975          *              Cookies *
976          *           * Generate a new socket and switch to that socket *
977          *           Set S := new socket for this port pair
978          *           S.state = RESPOND
979          *           Choose S.ISS (initial seqno) or set from Init Cookie
980          *           Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
981          *           Continue with S.state == RESPOND
982          *           * A Response packet will be generated in Step 11 *
983          *        Otherwise,
984          *           Generate Reset(No Connection) unless P.type == Reset
985          *           Drop packet and return
986          *
987          * NOTE: the check for the packet types is done in
988          *       dccp_rcv_state_process
989          */
990         if (sk->sk_state == DCCP_LISTEN) {
991                 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
992
993                 if (nsk == NULL)
994                         goto discard;
995
996                 if (nsk != sk) {
997                         if (dccp_child_process(sk, nsk, skb))
998                                 goto reset;
999                         return 0;
1000                 }
1001         }
1002
1003         if (dccp_rcv_state_process(sk, skb, dh, skb->len))
1004                 goto reset;
1005         return 0;
1006
1007 reset:
1008         dccp_v4_ctl_send_reset(skb);
1009 discard:
1010         kfree_skb(skb);
1011         return 0;
1012 }
1013
1014 static inline int dccp_invalid_packet(struct sk_buff *skb)
1015 {
1016         const struct dccp_hdr *dh;
1017
1018         if (skb->pkt_type != PACKET_HOST)
1019                 return 1;
1020
1021         if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
1022                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n");
1023                 return 1;
1024         }
1025
1026         dh = dccp_hdr(skb);
1027
1028         /* If the packet type is not understood, drop packet and return */
1029         if (dh->dccph_type >= DCCP_PKT_INVALID) {
1030                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n");
1031                 return 1;
1032         }
1033
1034         /*
1035          * If P.Data Offset is too small for packet type, or too large for
1036          * packet, drop packet and return
1037          */
1038         if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
1039                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
1040                                             "too small 1\n",
1041                                dh->dccph_doff);
1042                 return 1;
1043         }
1044
1045         if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
1046                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
1047                                             "too small 2\n",
1048                                dh->dccph_doff);
1049                 return 1;
1050         }
1051
1052         dh = dccp_hdr(skb);
1053
1054         /*
1055          * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
1056          * has short sequence numbers), drop packet and return
1057          */
1058         if (dh->dccph_x == 0 &&
1059             dh->dccph_type != DCCP_PKT_DATA &&
1060             dh->dccph_type != DCCP_PKT_ACK &&
1061             dh->dccph_type != DCCP_PKT_DATAACK) {
1062                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack "
1063                                             "nor DataAck and P.X == 0\n",
1064                                dccp_packet_name(dh->dccph_type));
1065                 return 1;
1066         }
1067
1068         /* If the header checksum is incorrect, drop packet and return */
1069         if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
1070                                     skb->nh.iph->daddr) < 0) {
1071                 LIMIT_NETDEBUG(KERN_WARNING "DCCP: header checksum is "
1072                                             "incorrect\n");
1073                 return 1;
1074         }
1075
1076         return 0;
1077 }
1078
1079 /* this is called when real data arrives */
1080 int dccp_v4_rcv(struct sk_buff *skb)
1081 {
1082         const struct dccp_hdr *dh;
1083         struct sock *sk;
1084         int rc;
1085
1086         /* Step 1: Check header basics: */
1087
1088         if (dccp_invalid_packet(skb))
1089                 goto discard_it;
1090
1091         dh = dccp_hdr(skb);
1092
1093         DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(skb);
1094         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
1095
1096         dccp_pr_debug("%8.8s "
1097                       "src=%u.%u.%u.%u@%-5d "
1098                       "dst=%u.%u.%u.%u@%-5d seq=%llu",
1099                       dccp_packet_name(dh->dccph_type),
1100                       NIPQUAD(skb->nh.iph->saddr), ntohs(dh->dccph_sport),
1101                       NIPQUAD(skb->nh.iph->daddr), ntohs(dh->dccph_dport),
1102                       (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
1103
1104         if (dccp_packet_without_ack(skb)) {
1105                 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
1106                 dccp_pr_debug_cat("\n");
1107         } else {
1108                 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
1109                 dccp_pr_debug_cat(", ack=%llu\n",
1110                                   (unsigned long long)
1111                                   DCCP_SKB_CB(skb)->dccpd_ack_seq);
1112         }
1113
1114         /* Step 2:
1115          *      Look up flow ID in table and get corresponding socket */
1116         sk = __inet_lookup(&dccp_hashinfo,
1117                            skb->nh.iph->saddr, dh->dccph_sport,
1118                            skb->nh.iph->daddr, ntohs(dh->dccph_dport),
1119                            inet_iif(skb));
1120
1121         /* 
1122          * Step 2:
1123          *      If no socket ...
1124          *              Generate Reset(No Connection) unless P.type == Reset
1125          *              Drop packet and return
1126          */
1127         if (sk == NULL) {
1128                 dccp_pr_debug("failed to look up flow ID in table and "
1129                               "get corresponding socket\n");
1130                 goto no_dccp_socket;
1131         }
1132
1133         /* 
1134          * Step 2:
1135          *      ... or S.state == TIMEWAIT,
1136          *              Generate Reset(No Connection) unless P.type == Reset
1137          *              Drop packet and return
1138          */
1139                
1140         if (sk->sk_state == DCCP_TIME_WAIT) {
1141                 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: "
1142                               "do_time_wait\n");
1143                 goto do_time_wait;
1144         }
1145
1146         if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
1147                 dccp_pr_debug("xfrm4_policy_check failed\n");
1148                 goto discard_and_relse;
1149         }
1150
1151         if (sk_filter(sk, skb, 0)) {
1152                 dccp_pr_debug("sk_filter failed\n");
1153                 goto discard_and_relse;
1154         }
1155
1156         skb->dev = NULL;
1157
1158         bh_lock_sock(sk);
1159         rc = 0;
1160         if (!sock_owned_by_user(sk))
1161                 rc = dccp_v4_do_rcv(sk, skb);
1162         else
1163                 sk_add_backlog(sk, skb);
1164         bh_unlock_sock(sk);
1165
1166         sock_put(sk);
1167         return rc;
1168
1169 no_dccp_socket:
1170         if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1171                 goto discard_it;
1172         /*
1173          * Step 2:
1174          *              Generate Reset(No Connection) unless P.type == Reset
1175          *              Drop packet and return
1176          */
1177         if (dh->dccph_type != DCCP_PKT_RESET) {
1178                 DCCP_SKB_CB(skb)->dccpd_reset_code =
1179                                         DCCP_RESET_CODE_NO_CONNECTION;
1180                 dccp_v4_ctl_send_reset(skb);
1181         }
1182
1183 discard_it:
1184         /* Discard frame. */
1185         kfree_skb(skb);
1186         return 0;
1187
1188 discard_and_relse:
1189         sock_put(sk);
1190         goto discard_it;
1191
1192 do_time_wait:
1193         inet_twsk_put((struct inet_timewait_sock *)sk);
1194         goto no_dccp_socket;
1195 }
1196
1197 static int dccp_v4_init_sock(struct sock *sk)
1198 {
1199         struct dccp_sock *dp = dccp_sk(sk);
1200         static int dccp_ctl_socket_init = 1;
1201
1202         dccp_options_init(&dp->dccps_options);
1203         do_gettimeofday(&dp->dccps_epoch);
1204
1205         if (dp->dccps_options.dccpo_send_ack_vector) {
1206                 dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(DCCP_MAX_ACKVEC_LEN,
1207                                                            GFP_KERNEL);
1208                 if (dp->dccps_hc_rx_ackvec == NULL)
1209                         return -ENOMEM;
1210         }
1211
1212         /*
1213          * FIXME: We're hardcoding the CCID, and doing this at this point makes
1214          * the listening (master) sock get CCID control blocks, which is not
1215          * necessary, but for now, to not mess with the test userspace apps,
1216          * lets leave it here, later the real solution is to do this in a
1217          * setsockopt(CCIDs-I-want/accept). -acme
1218          */
1219         if (likely(!dccp_ctl_socket_init)) {
1220                 dp->dccps_hc_rx_ccid = ccid_init(dp->dccps_options.dccpo_rx_ccid,
1221                                                  sk);
1222                 dp->dccps_hc_tx_ccid = ccid_init(dp->dccps_options.dccpo_tx_ccid,
1223                                                  sk);
1224                 if (dp->dccps_hc_rx_ccid == NULL ||
1225                     dp->dccps_hc_tx_ccid == NULL) {
1226                         ccid_exit(dp->dccps_hc_rx_ccid, sk);
1227                         ccid_exit(dp->dccps_hc_tx_ccid, sk);
1228                         if (dp->dccps_options.dccpo_send_ack_vector) {
1229                                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
1230                                 dp->dccps_hc_rx_ackvec = NULL;
1231                         }
1232                         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1233                         return -ENOMEM;
1234                 }
1235         } else
1236                 dccp_ctl_socket_init = 0;
1237
1238         dccp_init_xmit_timers(sk);
1239         inet_csk(sk)->icsk_rto = DCCP_TIMEOUT_INIT;
1240         sk->sk_state = DCCP_CLOSED;
1241         sk->sk_write_space = dccp_write_space;
1242         dp->dccps_mss_cache = 536;
1243         dp->dccps_role = DCCP_ROLE_UNDEFINED;
1244         dp->dccps_service = DCCP_SERVICE_INVALID_VALUE;
1245
1246         return 0;
1247 }
1248
1249 static int dccp_v4_destroy_sock(struct sock *sk)
1250 {
1251         struct dccp_sock *dp = dccp_sk(sk);
1252
1253         /*
1254          * DCCP doesn't use sk_qrite_queue, just sk_send_head
1255          * for retransmissions
1256          */
1257         if (sk->sk_send_head != NULL) {
1258                 kfree_skb(sk->sk_send_head);
1259                 sk->sk_send_head = NULL;
1260         }
1261
1262         /* Clean up a referenced DCCP bind bucket. */
1263         if (inet_csk(sk)->icsk_bind_hash != NULL)
1264                 inet_put_port(&dccp_hashinfo, sk);
1265
1266         if (dp->dccps_service_list != NULL) {
1267                 kfree(dp->dccps_service_list);
1268                 dp->dccps_service_list = NULL;
1269         }
1270
1271         ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
1272         ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
1273         if (dp->dccps_options.dccpo_send_ack_vector) {
1274                 dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
1275                 dp->dccps_hc_rx_ackvec = NULL;
1276         }
1277         ccid_exit(dp->dccps_hc_rx_ccid, sk);
1278         ccid_exit(dp->dccps_hc_tx_ccid, sk);
1279         dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
1280
1281         return 0;
1282 }
1283
1284 static void dccp_v4_reqsk_destructor(struct request_sock *req)
1285 {
1286         kfree(inet_rsk(req)->opt);
1287 }
1288
1289 static struct request_sock_ops dccp_request_sock_ops = {
1290         .family         = PF_INET,
1291         .obj_size       = sizeof(struct dccp_request_sock),
1292         .rtx_syn_ack    = dccp_v4_send_response,
1293         .send_ack       = dccp_v4_reqsk_send_ack,
1294         .destructor     = dccp_v4_reqsk_destructor,
1295         .send_reset     = dccp_v4_ctl_send_reset,
1296 };
1297
1298 struct proto dccp_v4_prot = {
1299         .name                   = "DCCP",
1300         .owner                  = THIS_MODULE,
1301         .close                  = dccp_close,
1302         .connect                = dccp_v4_connect,
1303         .disconnect             = dccp_disconnect,
1304         .ioctl                  = dccp_ioctl,
1305         .init                   = dccp_v4_init_sock,
1306         .setsockopt             = dccp_setsockopt,
1307         .getsockopt             = dccp_getsockopt,
1308         .sendmsg                = dccp_sendmsg,
1309         .recvmsg                = dccp_recvmsg,
1310         .backlog_rcv            = dccp_v4_do_rcv,
1311         .hash                   = dccp_v4_hash,
1312         .unhash                 = dccp_v4_unhash,
1313         .accept                 = inet_csk_accept,
1314         .get_port               = dccp_v4_get_port,
1315         .shutdown               = dccp_shutdown,
1316         .destroy                = dccp_v4_destroy_sock,
1317         .orphan_count           = &dccp_orphan_count,
1318         .max_header             = MAX_DCCP_HEADER,
1319         .obj_size               = sizeof(struct dccp_sock),
1320         .rsk_prot               = &dccp_request_sock_ops,
1321         .twsk_obj_size          = sizeof(struct inet_timewait_sock),
1322 };