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Linux 4.1.16
[linux/fpc-iii.git] / net / dccp / ipv6.c
bloba0490508d21352e8effff0688a190f518b8ab214
1 /*
2 * DCCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Based on net/dccp6/ipv6.c
6 *
7 * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15 #include <linux/module.h>
16 #include <linux/random.h>
17 #include <linux/slab.h>
18 #include <linux/xfrm.h>
19
20 #include <net/addrconf.h>
21 #include <net/inet_common.h>
22 #include <net/inet_hashtables.h>
23 #include <net/inet_sock.h>
24 #include <net/inet6_connection_sock.h>
25 #include <net/inet6_hashtables.h>
26 #include <net/ip6_route.h>
27 #include <net/ipv6.h>
28 #include <net/protocol.h>
29 #include <net/transp_v6.h>
30 #include <net/ip6_checksum.h>
31 #include <net/xfrm.h>
32 #include <net/secure_seq.h>
33
34 #include "dccp.h"
35 #include "ipv6.h"
36 #include "feat.h"
37
38 /* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */
39
40 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
41 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
42
43 /* add pseudo-header to DCCP checksum stored in skb->csum */
44 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
45 const struct in6_addr *saddr,
46 const struct in6_addr *daddr)
47 {
48 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
49 }
50
51 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
52 {
53 struct ipv6_pinfo *np = inet6_sk(sk);
54 struct dccp_hdr *dh = dccp_hdr(skb);
55
56 dccp_csum_outgoing(skb);
57 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
58 }
59
60 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
61 {
62 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
63 ipv6_hdr(skb)->saddr.s6_addr32,
64 dccp_hdr(skb)->dccph_dport,
65 dccp_hdr(skb)->dccph_sport );
66
67 }
68
69 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
70 u8 type, u8 code, int offset, __be32 info)
71 {
72 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
73 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
74 struct dccp_sock *dp;
75 struct ipv6_pinfo *np;
76 struct sock *sk;
77 int err;
78 __u64 seq;
79 struct net *net = dev_net(skb->dev);
80
81 if (skb->len < offset + sizeof(*dh) ||
82 skb->len < offset + __dccp_basic_hdr_len(dh)) {
83 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
84 ICMP6_MIB_INERRORS);
85 return;
86 }
87
88 sk = __inet6_lookup_established(net, &dccp_hashinfo,
89 &hdr->daddr, dh->dccph_dport,
90 &hdr->saddr, ntohs(dh->dccph_sport),
91 inet6_iif(skb));
92
93 if (!sk) {
94 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
95 ICMP6_MIB_INERRORS);
96 return;
97 }
98
99 if (sk->sk_state == DCCP_TIME_WAIT) {
100 inet_twsk_put(inet_twsk(sk));
101 return;
102 }
103 seq = dccp_hdr_seq(dh);
104 if (sk->sk_state == DCCP_NEW_SYN_RECV)
105 return dccp_req_err(sk, seq);
106
107 bh_lock_sock(sk);
108 if (sock_owned_by_user(sk))
109 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
110
111 if (sk->sk_state == DCCP_CLOSED)
112 goto out;
113
114 dp = dccp_sk(sk);
115 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
116 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
117 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
118 goto out;
119 }
120
121 np = inet6_sk(sk);
122
123 if (type == NDISC_REDIRECT) {
124 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
125
126 if (dst)
127 dst->ops->redirect(dst, sk, skb);
128 goto out;
129 }
130
131 if (type == ICMPV6_PKT_TOOBIG) {
132 struct dst_entry *dst = NULL;
133
134 if (!ip6_sk_accept_pmtu(sk))
135 goto out;
136
137 if (sock_owned_by_user(sk))
138 goto out;
139 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
140 goto out;
141
142 dst = inet6_csk_update_pmtu(sk, ntohl(info));
143 if (!dst)
144 goto out;
145
146 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
147 dccp_sync_mss(sk, dst_mtu(dst));
148 goto out;
149 }
150
151 icmpv6_err_convert(type, code, &err);
152
153 /* Might be for an request_sock */
154 switch (sk->sk_state) {
155 case DCCP_REQUESTING:
156 case DCCP_RESPOND: /* Cannot happen.
157 It can, it SYNs are crossed. --ANK */
158 if (!sock_owned_by_user(sk)) {
159 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
160 sk->sk_err = err;
161 /*
162 * Wake people up to see the error
163 * (see connect in sock.c)
164 */
165 sk->sk_error_report(sk);
166 dccp_done(sk);
167 } else
168 sk->sk_err_soft = err;
169 goto out;
170 }
171
172 if (!sock_owned_by_user(sk) && np->recverr) {
173 sk->sk_err = err;
174 sk->sk_error_report(sk);
175 } else
176 sk->sk_err_soft = err;
177
178 out:
179 bh_unlock_sock(sk);
180 sock_put(sk);
181 }
182
183
184 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
185 {
186 struct inet_request_sock *ireq = inet_rsk(req);
187 struct ipv6_pinfo *np = inet6_sk(sk);
188 struct sk_buff *skb;
189 struct in6_addr *final_p, final;
190 struct flowi6 fl6;
191 int err = -1;
192 struct dst_entry *dst;
193
194 memset(&fl6, 0, sizeof(fl6));
195 fl6.flowi6_proto = IPPROTO_DCCP;
196 fl6.daddr = ireq->ir_v6_rmt_addr;
197 fl6.saddr = ireq->ir_v6_loc_addr;
198 fl6.flowlabel = 0;
199 fl6.flowi6_oif = ireq->ir_iif;
200 fl6.fl6_dport = ireq->ir_rmt_port;
201 fl6.fl6_sport = htons(ireq->ir_num);
202 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
203
204
205 rcu_read_lock();
206 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
207 rcu_read_unlock();
208
209 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
210 if (IS_ERR(dst)) {
211 err = PTR_ERR(dst);
212 dst = NULL;
213 goto done;
214 }
215
216 skb = dccp_make_response(sk, dst, req);
217 if (skb != NULL) {
218 struct dccp_hdr *dh = dccp_hdr(skb);
219
220 dh->dccph_checksum = dccp_v6_csum_finish(skb,
221 &ireq->ir_v6_loc_addr,
222 &ireq->ir_v6_rmt_addr);
223 fl6.daddr = ireq->ir_v6_rmt_addr;
224 rcu_read_lock();
225 err = ip6_xmit(sk, skb, &fl6, rcu_dereference(np->opt),
226 np->tclass);
227 rcu_read_unlock();
228 err = net_xmit_eval(err);
229 }
230
231 done:
232 dst_release(dst);
233 return err;
234 }
235
236 static void dccp_v6_reqsk_destructor(struct request_sock *req)
237 {
238 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
239 kfree_skb(inet_rsk(req)->pktopts);
240 }
241
242 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
243 {
244 const struct ipv6hdr *rxip6h;
245 struct sk_buff *skb;
246 struct flowi6 fl6;
247 struct net *net = dev_net(skb_dst(rxskb)->dev);
248 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
249 struct dst_entry *dst;
250
251 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
252 return;
253
254 if (!ipv6_unicast_destination(rxskb))
255 return;
256
257 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
258 if (skb == NULL)
259 return;
260
261 rxip6h = ipv6_hdr(rxskb);
262 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
263 &rxip6h->daddr);
264
265 memset(&fl6, 0, sizeof(fl6));
266 fl6.daddr = rxip6h->saddr;
267 fl6.saddr = rxip6h->daddr;
268
269 fl6.flowi6_proto = IPPROTO_DCCP;
270 fl6.flowi6_oif = inet6_iif(rxskb);
271 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
272 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
273 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
274
275 /* sk = NULL, but it is safe for now. RST socket required. */
276 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
277 if (!IS_ERR(dst)) {
278 skb_dst_set(skb, dst);
279 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0);
280 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
281 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
282 return;
283 }
284
285 kfree_skb(skb);
286 }
287
288 static struct request_sock_ops dccp6_request_sock_ops = {
289 .family = AF_INET6,
290 .obj_size = sizeof(struct dccp6_request_sock),
291 .rtx_syn_ack = dccp_v6_send_response,
292 .send_ack = dccp_reqsk_send_ack,
293 .destructor = dccp_v6_reqsk_destructor,
294 .send_reset = dccp_v6_ctl_send_reset,
295 .syn_ack_timeout = dccp_syn_ack_timeout,
296 };
297
298 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
299 {
300 const struct dccp_hdr *dh = dccp_hdr(skb);
301 const struct ipv6hdr *iph = ipv6_hdr(skb);
302 struct request_sock *req;
303 struct sock *nsk;
304
305 req = inet6_csk_search_req(sk, dh->dccph_sport, &iph->saddr,
306 &iph->daddr, inet6_iif(skb));
307 if (req) {
308 nsk = dccp_check_req(sk, skb, req);
309 if (!nsk)
310 reqsk_put(req);
311 return nsk;
312 }
313 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
314 &iph->saddr, dh->dccph_sport,
315 &iph->daddr, ntohs(dh->dccph_dport),
316 inet6_iif(skb));
317 if (nsk != NULL) {
318 if (nsk->sk_state != DCCP_TIME_WAIT) {
319 bh_lock_sock(nsk);
320 return nsk;
321 }
322 inet_twsk_put(inet_twsk(nsk));
323 return NULL;
324 }
325
326 return sk;
327 }
328
329 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
330 {
331 struct request_sock *req;
332 struct dccp_request_sock *dreq;
333 struct inet_request_sock *ireq;
334 struct ipv6_pinfo *np = inet6_sk(sk);
335 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
336 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
337
338 if (skb->protocol == htons(ETH_P_IP))
339 return dccp_v4_conn_request(sk, skb);
340
341 if (!ipv6_unicast_destination(skb))
342 return 0; /* discard, don't send a reset here */
343
344 if (dccp_bad_service_code(sk, service)) {
345 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
346 goto drop;
347 }
348 /*
349 * There are no SYN attacks on IPv6, yet...
350 */
351 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
352 if (inet_csk_reqsk_queue_is_full(sk))
353 goto drop;
354
355 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
356 goto drop;
357
358 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk);
359 if (req == NULL)
360 goto drop;
361
362 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
363 goto drop_and_free;
364
365 dreq = dccp_rsk(req);
366 if (dccp_parse_options(sk, dreq, skb))
367 goto drop_and_free;
368
369 if (security_inet_conn_request(sk, skb, req))
370 goto drop_and_free;
371
372 ireq = inet_rsk(req);
373 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
374 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
375 ireq->ireq_family = AF_INET6;
376
377 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
378 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
379 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
380 atomic_inc(&skb->users);
381 ireq->pktopts = skb;
382 }
383 ireq->ir_iif = sk->sk_bound_dev_if;
384
385 /* So that link locals have meaning */
386 if (!sk->sk_bound_dev_if &&
387 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
388 ireq->ir_iif = inet6_iif(skb);
389
390 /*
391 * Step 3: Process LISTEN state
392 *
393 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
394 *
395 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
396 */
397 dreq->dreq_isr = dcb->dccpd_seq;
398 dreq->dreq_gsr = dreq->dreq_isr;
399 dreq->dreq_iss = dccp_v6_init_sequence(skb);
400 dreq->dreq_gss = dreq->dreq_iss;
401 dreq->dreq_service = service;
402
403 if (dccp_v6_send_response(sk, req))
404 goto drop_and_free;
405
406 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
407 return 0;
408
409 drop_and_free:
410 reqsk_free(req);
411 drop:
412 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
413 return -1;
414 }
415
416 static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
417 struct sk_buff *skb,
418 struct request_sock *req,
419 struct dst_entry *dst)
420 {
421 struct inet_request_sock *ireq = inet_rsk(req);
422 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
423 struct ipv6_txoptions *opt;
424 struct inet_sock *newinet;
425 struct dccp6_sock *newdp6;
426 struct sock *newsk;
427
428 if (skb->protocol == htons(ETH_P_IP)) {
429 /*
430 * v6 mapped
431 */
432 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
433 if (newsk == NULL)
434 return NULL;
435
436 newdp6 = (struct dccp6_sock *)newsk;
437 newinet = inet_sk(newsk);
438 newinet->pinet6 = &newdp6->inet6;
439 newnp = inet6_sk(newsk);
440
441 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
442
443 newnp->saddr = newsk->sk_v6_rcv_saddr;
444
445 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
446 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
447 newnp->pktoptions = NULL;
448 newnp->opt = NULL;
449 newnp->mcast_oif = inet6_iif(skb);
450 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
451
452 /*
453 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
454 * here, dccp_create_openreq_child now does this for us, see the comment in
455 * that function for the gory details. -acme
456 */
457
458 /* It is tricky place. Until this moment IPv4 tcp
459 worked with IPv6 icsk.icsk_af_ops.
460 Sync it now.
461 */
462 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
463
464 return newsk;
465 }
466
467
468 if (sk_acceptq_is_full(sk))
469 goto out_overflow;
470
471 if (dst == NULL) {
472 struct in6_addr *final_p, final;
473 struct flowi6 fl6;
474
475 memset(&fl6, 0, sizeof(fl6));
476 fl6.flowi6_proto = IPPROTO_DCCP;
477 fl6.daddr = ireq->ir_v6_rmt_addr;
478 final_p = fl6_update_dst(&fl6, np->opt, &final);
479 fl6.saddr = ireq->ir_v6_loc_addr;
480 fl6.flowi6_oif = sk->sk_bound_dev_if;
481 fl6.fl6_dport = ireq->ir_rmt_port;
482 fl6.fl6_sport = htons(ireq->ir_num);
483 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
484
485 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
486 if (IS_ERR(dst))
487 goto out;
488 }
489
490 newsk = dccp_create_openreq_child(sk, req, skb);
491 if (newsk == NULL)
492 goto out_nonewsk;
493
494 /*
495 * No need to charge this sock to the relevant IPv6 refcnt debug socks
496 * count here, dccp_create_openreq_child now does this for us, see the
497 * comment in that function for the gory details. -acme
498 */
499
500 __ip6_dst_store(newsk, dst, NULL, NULL);
501 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
502 NETIF_F_TSO);
503 newdp6 = (struct dccp6_sock *)newsk;
504 newinet = inet_sk(newsk);
505 newinet->pinet6 = &newdp6->inet6;
506 newnp = inet6_sk(newsk);
507
508 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
509
510 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
511 newnp->saddr = ireq->ir_v6_loc_addr;
512 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
513 newsk->sk_bound_dev_if = ireq->ir_iif;
514
515 /* Now IPv6 options...
516
517 First: no IPv4 options.
518 */
519 newinet->inet_opt = NULL;
520
521 /* Clone RX bits */
522 newnp->rxopt.all = np->rxopt.all;
523
524 /* Clone pktoptions received with SYN */
525 newnp->pktoptions = NULL;
526 if (ireq->pktopts != NULL) {
527 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
528 consume_skb(ireq->pktopts);
529 ireq->pktopts = NULL;
530 if (newnp->pktoptions)
531 skb_set_owner_r(newnp->pktoptions, newsk);
532 }
533 newnp->opt = NULL;
534 newnp->mcast_oif = inet6_iif(skb);
535 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
536
537 /*
538 * Clone native IPv6 options from listening socket (if any)
539 *
540 * Yes, keeping reference count would be much more clever, but we make
541 * one more one thing there: reattach optmem to newsk.
542 */
543 opt = rcu_dereference(np->opt);
544 if (opt) {
545 opt = ipv6_dup_options(newsk, opt);
546 RCU_INIT_POINTER(newnp->opt, opt);
547 }
548 inet_csk(newsk)->icsk_ext_hdr_len = 0;
549 if (opt)
550 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
551 opt->opt_flen;
552
553 dccp_sync_mss(newsk, dst_mtu(dst));
554
555 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
556 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
557
558 if (__inet_inherit_port(sk, newsk) < 0) {
559 inet_csk_prepare_forced_close(newsk);
560 dccp_done(newsk);
561 goto out;
562 }
563 __inet_hash(newsk, NULL);
564
565 return newsk;
566
567 out_overflow:
568 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
569 out_nonewsk:
570 dst_release(dst);
571 out:
572 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
573 return NULL;
574 }
575
576 /* The socket must have it's spinlock held when we get
577 * here.
578 *
579 * We have a potential double-lock case here, so even when
580 * doing backlog processing we use the BH locking scheme.
581 * This is because we cannot sleep with the original spinlock
582 * held.
583 */
584 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
585 {
586 struct ipv6_pinfo *np = inet6_sk(sk);
587 struct sk_buff *opt_skb = NULL;
588
589 /* Imagine: socket is IPv6. IPv4 packet arrives,
590 goes to IPv4 receive handler and backlogged.
591 From backlog it always goes here. Kerboom...
592 Fortunately, dccp_rcv_established and rcv_established
593 handle them correctly, but it is not case with
594 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
595 */
596
597 if (skb->protocol == htons(ETH_P_IP))
598 return dccp_v4_do_rcv(sk, skb);
599
600 if (sk_filter(sk, skb))
601 goto discard;
602
603 /*
604 * socket locking is here for SMP purposes as backlog rcv is currently
605 * called with bh processing disabled.
606 */
607
608 /* Do Stevens' IPV6_PKTOPTIONS.
609
610 Yes, guys, it is the only place in our code, where we
611 may make it not affecting IPv4.
612 The rest of code is protocol independent,
613 and I do not like idea to uglify IPv4.
614
615 Actually, all the idea behind IPV6_PKTOPTIONS
616 looks not very well thought. For now we latch
617 options, received in the last packet, enqueued
618 by tcp. Feel free to propose better solution.
619 --ANK (980728)
620 */
621 if (np->rxopt.all)
622 /*
623 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
624 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
625 */
626 opt_skb = skb_clone(skb, GFP_ATOMIC);
627
628 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
629 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
630 goto reset;
631 if (opt_skb) {
632 /* XXX This is where we would goto ipv6_pktoptions. */
633 __kfree_skb(opt_skb);
634 }
635 return 0;
636 }
637
638 /*
639 * Step 3: Process LISTEN state
640 * If S.state == LISTEN,
641 * If P.type == Request or P contains a valid Init Cookie option,
642 * (* Must scan the packet's options to check for Init
643 * Cookies. Only Init Cookies are processed here,
644 * however; other options are processed in Step 8. This
645 * scan need only be performed if the endpoint uses Init
646 * Cookies *)
647 * (* Generate a new socket and switch to that socket *)
648 * Set S := new socket for this port pair
649 * S.state = RESPOND
650 * Choose S.ISS (initial seqno) or set from Init Cookies
651 * Initialize S.GAR := S.ISS
652 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
653 * Continue with S.state == RESPOND
654 * (* A Response packet will be generated in Step 11 *)
655 * Otherwise,
656 * Generate Reset(No Connection) unless P.type == Reset
657 * Drop packet and return
658 *
659 * NOTE: the check for the packet types is done in
660 * dccp_rcv_state_process
661 */
662 if (sk->sk_state == DCCP_LISTEN) {
663 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
664
665 if (nsk == NULL)
666 goto discard;
667 /*
668 * Queue it on the new socket if the new socket is active,
669 * otherwise we just shortcircuit this and continue with
670 * the new socket..
671 */
672 if (nsk != sk) {
673 if (dccp_child_process(sk, nsk, skb))
674 goto reset;
675 if (opt_skb != NULL)
676 __kfree_skb(opt_skb);
677 return 0;
678 }
679 }
680
681 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
682 goto reset;
683 if (opt_skb) {
684 /* XXX This is where we would goto ipv6_pktoptions. */
685 __kfree_skb(opt_skb);
686 }
687 return 0;
688
689 reset:
690 dccp_v6_ctl_send_reset(sk, skb);
691 discard:
692 if (opt_skb != NULL)
693 __kfree_skb(opt_skb);
694 kfree_skb(skb);
695 return 0;
696 }
697
698 static int dccp_v6_rcv(struct sk_buff *skb)
699 {
700 const struct dccp_hdr *dh;
701 struct sock *sk;
702 int min_cov;
703
704 /* Step 1: Check header basics */
705
706 if (dccp_invalid_packet(skb))
707 goto discard_it;
708
709 /* Step 1: If header checksum is incorrect, drop packet and return. */
710 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
711 &ipv6_hdr(skb)->daddr)) {
712 DCCP_WARN("dropped packet with invalid checksum\n");
713 goto discard_it;
714 }
715
716 dh = dccp_hdr(skb);
717
718 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
719 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
720
721 if (dccp_packet_without_ack(skb))
722 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
723 else
724 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
725
726 /* Step 2:
727 * Look up flow ID in table and get corresponding socket */
728 sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
729 dh->dccph_sport, dh->dccph_dport,
730 inet6_iif(skb));
731 /*
732 * Step 2:
733 * If no socket ...
734 */
735 if (sk == NULL) {
736 dccp_pr_debug("failed to look up flow ID in table and "
737 "get corresponding socket\n");
738 goto no_dccp_socket;
739 }
740
741 /*
742 * Step 2:
743 * ... or S.state == TIMEWAIT,
744 * Generate Reset(No Connection) unless P.type == Reset
745 * Drop packet and return
746 */
747 if (sk->sk_state == DCCP_TIME_WAIT) {
748 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
749 inet_twsk_put(inet_twsk(sk));
750 goto no_dccp_socket;
751 }
752
753 /*
754 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
755 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
756 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
757 */
758 min_cov = dccp_sk(sk)->dccps_pcrlen;
759 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
760 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
761 dh->dccph_cscov, min_cov);
762 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
763 goto discard_and_relse;
764 }
765
766 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
767 goto discard_and_relse;
768
769 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
770
771 no_dccp_socket:
772 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
773 goto discard_it;
774 /*
775 * Step 2:
776 * If no socket ...
777 * Generate Reset(No Connection) unless P.type == Reset
778 * Drop packet and return
779 */
780 if (dh->dccph_type != DCCP_PKT_RESET) {
781 DCCP_SKB_CB(skb)->dccpd_reset_code =
782 DCCP_RESET_CODE_NO_CONNECTION;
783 dccp_v6_ctl_send_reset(sk, skb);
784 }
785
786 discard_it:
787 kfree_skb(skb);
788 return 0;
789
790 discard_and_relse:
791 sock_put(sk);
792 goto discard_it;
793 }
794
795 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
796 int addr_len)
797 {
798 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
799 struct inet_connection_sock *icsk = inet_csk(sk);
800 struct inet_sock *inet = inet_sk(sk);
801 struct ipv6_pinfo *np = inet6_sk(sk);
802 struct dccp_sock *dp = dccp_sk(sk);
803 struct in6_addr *saddr = NULL, *final_p, final;
804 struct ipv6_txoptions *opt;
805 struct flowi6 fl6;
806 struct dst_entry *dst;
807 int addr_type;
808 int err;
809
810 dp->dccps_role = DCCP_ROLE_CLIENT;
811
812 if (addr_len < SIN6_LEN_RFC2133)
813 return -EINVAL;
814
815 if (usin->sin6_family != AF_INET6)
816 return -EAFNOSUPPORT;
817
818 memset(&fl6, 0, sizeof(fl6));
819
820 if (np->sndflow) {
821 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
822 IP6_ECN_flow_init(fl6.flowlabel);
823 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
824 struct ip6_flowlabel *flowlabel;
825 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
826 if (flowlabel == NULL)
827 return -EINVAL;
828 fl6_sock_release(flowlabel);
829 }
830 }
831 /*
832 * connect() to INADDR_ANY means loopback (BSD'ism).
833 */
834 if (ipv6_addr_any(&usin->sin6_addr))
835 usin->sin6_addr.s6_addr[15] = 1;
836
837 addr_type = ipv6_addr_type(&usin->sin6_addr);
838
839 if (addr_type & IPV6_ADDR_MULTICAST)
840 return -ENETUNREACH;
841
842 if (addr_type & IPV6_ADDR_LINKLOCAL) {
843 if (addr_len >= sizeof(struct sockaddr_in6) &&
844 usin->sin6_scope_id) {
845 /* If interface is set while binding, indices
846 * must coincide.
847 */
848 if (sk->sk_bound_dev_if &&
849 sk->sk_bound_dev_if != usin->sin6_scope_id)
850 return -EINVAL;
851
852 sk->sk_bound_dev_if = usin->sin6_scope_id;
853 }
854
855 /* Connect to link-local address requires an interface */
856 if (!sk->sk_bound_dev_if)
857 return -EINVAL;
858 }
859
860 sk->sk_v6_daddr = usin->sin6_addr;
861 np->flow_label = fl6.flowlabel;
862
863 /*
864 * DCCP over IPv4
865 */
866 if (addr_type == IPV6_ADDR_MAPPED) {
867 u32 exthdrlen = icsk->icsk_ext_hdr_len;
868 struct sockaddr_in sin;
869
870 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
871
872 if (__ipv6_only_sock(sk))
873 return -ENETUNREACH;
874
875 sin.sin_family = AF_INET;
876 sin.sin_port = usin->sin6_port;
877 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
878
879 icsk->icsk_af_ops = &dccp_ipv6_mapped;
880 sk->sk_backlog_rcv = dccp_v4_do_rcv;
881
882 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
883 if (err) {
884 icsk->icsk_ext_hdr_len = exthdrlen;
885 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
886 sk->sk_backlog_rcv = dccp_v6_do_rcv;
887 goto failure;
888 }
889 np->saddr = sk->sk_v6_rcv_saddr;
890 return err;
891 }
892
893 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
894 saddr = &sk->sk_v6_rcv_saddr;
895
896 fl6.flowi6_proto = IPPROTO_DCCP;
897 fl6.daddr = sk->sk_v6_daddr;
898 fl6.saddr = saddr ? *saddr : np->saddr;
899 fl6.flowi6_oif = sk->sk_bound_dev_if;
900 fl6.fl6_dport = usin->sin6_port;
901 fl6.fl6_sport = inet->inet_sport;
902 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
903
904 opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
905 final_p = fl6_update_dst(&fl6, opt, &final);
906
907 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
908 if (IS_ERR(dst)) {
909 err = PTR_ERR(dst);
910 goto failure;
911 }
912
913 if (saddr == NULL) {
914 saddr = &fl6.saddr;
915 sk->sk_v6_rcv_saddr = *saddr;
916 }
917
918 /* set the source address */
919 np->saddr = *saddr;
920 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
921
922 __ip6_dst_store(sk, dst, NULL, NULL);
923
924 icsk->icsk_ext_hdr_len = 0;
925 if (opt)
926 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
927
928 inet->inet_dport = usin->sin6_port;
929
930 dccp_set_state(sk, DCCP_REQUESTING);
931 err = inet6_hash_connect(&dccp_death_row, sk);
932 if (err)
933 goto late_failure;
934
935 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
936 sk->sk_v6_daddr.s6_addr32,
937 inet->inet_sport,
938 inet->inet_dport);
939 err = dccp_connect(sk);
940 if (err)
941 goto late_failure;
942
943 return 0;
944
945 late_failure:
946 dccp_set_state(sk, DCCP_CLOSED);
947 __sk_dst_reset(sk);
948 failure:
949 inet->inet_dport = 0;
950 sk->sk_route_caps = 0;
951 return err;
952 }
953
954 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
955 .queue_xmit = inet6_csk_xmit,
956 .send_check = dccp_v6_send_check,
957 .rebuild_header = inet6_sk_rebuild_header,
958 .conn_request = dccp_v6_conn_request,
959 .syn_recv_sock = dccp_v6_request_recv_sock,
960 .net_header_len = sizeof(struct ipv6hdr),
961 .setsockopt = ipv6_setsockopt,
962 .getsockopt = ipv6_getsockopt,
963 .addr2sockaddr = inet6_csk_addr2sockaddr,
964 .sockaddr_len = sizeof(struct sockaddr_in6),
965 .bind_conflict = inet6_csk_bind_conflict,
966 #ifdef CONFIG_COMPAT
967 .compat_setsockopt = compat_ipv6_setsockopt,
968 .compat_getsockopt = compat_ipv6_getsockopt,
969 #endif
970 };
971
972 /*
973 * DCCP over IPv4 via INET6 API
974 */
975 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
976 .queue_xmit = ip_queue_xmit,
977 .send_check = dccp_v4_send_check,
978 .rebuild_header = inet_sk_rebuild_header,
979 .conn_request = dccp_v6_conn_request,
980 .syn_recv_sock = dccp_v6_request_recv_sock,
981 .net_header_len = sizeof(struct iphdr),
982 .setsockopt = ipv6_setsockopt,
983 .getsockopt = ipv6_getsockopt,
984 .addr2sockaddr = inet6_csk_addr2sockaddr,
985 .sockaddr_len = sizeof(struct sockaddr_in6),
986 #ifdef CONFIG_COMPAT
987 .compat_setsockopt = compat_ipv6_setsockopt,
988 .compat_getsockopt = compat_ipv6_getsockopt,
989 #endif
990 };
991
992 /* NOTE: A lot of things set to zero explicitly by call to
993 * sk_alloc() so need not be done here.
994 */
995 static int dccp_v6_init_sock(struct sock *sk)
996 {
997 static __u8 dccp_v6_ctl_sock_initialized;
998 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
999
1000 if (err == 0) {
1001 if (unlikely(!dccp_v6_ctl_sock_initialized))
1002 dccp_v6_ctl_sock_initialized = 1;
1003 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1004 }
1005
1006 return err;
1007 }
1008
1009 static void dccp_v6_destroy_sock(struct sock *sk)
1010 {
1011 dccp_destroy_sock(sk);
1012 inet6_destroy_sock(sk);
1013 }
1014
1015 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1016 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1017 };
1018
1019 static struct proto dccp_v6_prot = {
1020 .name = "DCCPv6",
1021 .owner = THIS_MODULE,
1022 .close = dccp_close,
1023 .connect = dccp_v6_connect,
1024 .disconnect = dccp_disconnect,
1025 .ioctl = dccp_ioctl,
1026 .init = dccp_v6_init_sock,
1027 .setsockopt = dccp_setsockopt,
1028 .getsockopt = dccp_getsockopt,
1029 .sendmsg = dccp_sendmsg,
1030 .recvmsg = dccp_recvmsg,
1031 .backlog_rcv = dccp_v6_do_rcv,
1032 .hash = inet_hash,
1033 .unhash = inet_unhash,
1034 .accept = inet_csk_accept,
1035 .get_port = inet_csk_get_port,
1036 .shutdown = dccp_shutdown,
1037 .destroy = dccp_v6_destroy_sock,
1038 .orphan_count = &dccp_orphan_count,
1039 .max_header = MAX_DCCP_HEADER,
1040 .obj_size = sizeof(struct dccp6_sock),
1041 .slab_flags = SLAB_DESTROY_BY_RCU,
1042 .rsk_prot = &dccp6_request_sock_ops,
1043 .twsk_prot = &dccp6_timewait_sock_ops,
1044 .h.hashinfo = &dccp_hashinfo,
1045 #ifdef CONFIG_COMPAT
1046 .compat_setsockopt = compat_dccp_setsockopt,
1047 .compat_getsockopt = compat_dccp_getsockopt,
1048 #endif
1049 };
1050
1051 static const struct inet6_protocol dccp_v6_protocol = {
1052 .handler = dccp_v6_rcv,
1053 .err_handler = dccp_v6_err,
1054 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1055 };
1056
1057 static const struct proto_ops inet6_dccp_ops = {
1058 .family = PF_INET6,
1059 .owner = THIS_MODULE,
1060 .release = inet6_release,
1061 .bind = inet6_bind,
1062 .connect = inet_stream_connect,
1063 .socketpair = sock_no_socketpair,
1064 .accept = inet_accept,
1065 .getname = inet6_getname,
1066 .poll = dccp_poll,
1067 .ioctl = inet6_ioctl,
1068 .listen = inet_dccp_listen,
1069 .shutdown = inet_shutdown,
1070 .setsockopt = sock_common_setsockopt,
1071 .getsockopt = sock_common_getsockopt,
1072 .sendmsg = inet_sendmsg,
1073 .recvmsg = sock_common_recvmsg,
1074 .mmap = sock_no_mmap,
1075 .sendpage = sock_no_sendpage,
1076 #ifdef CONFIG_COMPAT
1077 .compat_setsockopt = compat_sock_common_setsockopt,
1078 .compat_getsockopt = compat_sock_common_getsockopt,
1079 #endif
1080 };
1081
1082 static struct inet_protosw dccp_v6_protosw = {
1083 .type = SOCK_DCCP,
1084 .protocol = IPPROTO_DCCP,
1085 .prot = &dccp_v6_prot,
1086 .ops = &inet6_dccp_ops,
1087 .flags = INET_PROTOSW_ICSK,
1088 };
1089
1090 static int __net_init dccp_v6_init_net(struct net *net)
1091 {
1092 if (dccp_hashinfo.bhash == NULL)
1093 return -ESOCKTNOSUPPORT;
1094
1095 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1096 SOCK_DCCP, IPPROTO_DCCP, net);
1097 }
1098
1099 static void __net_exit dccp_v6_exit_net(struct net *net)
1100 {
1101 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1102 }
1103
1104 static struct pernet_operations dccp_v6_ops = {
1105 .init = dccp_v6_init_net,
1106 .exit = dccp_v6_exit_net,
1107 };
1108
1109 static int __init dccp_v6_init(void)
1110 {
1111 int err = proto_register(&dccp_v6_prot, 1);
1112
1113 if (err != 0)
1114 goto out;
1115
1116 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1117 if (err != 0)
1118 goto out_unregister_proto;
1119
1120 inet6_register_protosw(&dccp_v6_protosw);
1121
1122 err = register_pernet_subsys(&dccp_v6_ops);
1123 if (err != 0)
1124 goto out_destroy_ctl_sock;
1125 out:
1126 return err;
1127
1128 out_destroy_ctl_sock:
1129 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1130 inet6_unregister_protosw(&dccp_v6_protosw);
1131 out_unregister_proto:
1132 proto_unregister(&dccp_v6_prot);
1133 goto out;
1134 }
1135
1136 static void __exit dccp_v6_exit(void)
1137 {
1138 unregister_pernet_subsys(&dccp_v6_ops);
1139 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1140 inet6_unregister_protosw(&dccp_v6_protosw);
1141 proto_unregister(&dccp_v6_prot);
1142 }
1143
1144 module_init(dccp_v6_init);
1145 module_exit(dccp_v6_exit);
1146
1147 /*
1148 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1149 * values directly, Also cover the case where the protocol is not specified,
1150 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1151 */
1152 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1153 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1154 MODULE_LICENSE("GPL");
1155 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1156 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
Linux with added FPC-III support