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Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / net / dccp / ipv6.c
blob9c61f9c02fdb81df0f87f62994ac13330631c59a
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 static void dccp_v6_hash(struct sock *sk)
44 {
45 if (sk->sk_state != DCCP_CLOSED) {
46 if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) {
47 inet_hash(sk);
48 return;
49 }
50 local_bh_disable();
51 __inet6_hash(sk, NULL);
52 local_bh_enable();
53 }
54 }
55
56 /* add pseudo-header to DCCP checksum stored in skb->csum */
57 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
58 const struct in6_addr *saddr,
59 const struct in6_addr *daddr)
60 {
61 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
62 }
63
64 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
65 {
66 struct ipv6_pinfo *np = inet6_sk(sk);
67 struct dccp_hdr *dh = dccp_hdr(skb);
68
69 dccp_csum_outgoing(skb);
70 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
71 }
72
73 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
74 {
75 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
76 ipv6_hdr(skb)->saddr.s6_addr32,
77 dccp_hdr(skb)->dccph_dport,
78 dccp_hdr(skb)->dccph_sport );
79
80 }
81
82 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
83 u8 type, u8 code, int offset, __be32 info)
84 {
85 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
86 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
87 struct dccp_sock *dp;
88 struct ipv6_pinfo *np;
89 struct sock *sk;
90 int err;
91 __u64 seq;
92 struct net *net = dev_net(skb->dev);
93
94 if (skb->len < offset + sizeof(*dh) ||
95 skb->len < offset + __dccp_basic_hdr_len(dh)) {
96 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
97 ICMP6_MIB_INERRORS);
98 return;
99 }
100
101 sk = inet6_lookup(net, &dccp_hashinfo,
102 &hdr->daddr, dh->dccph_dport,
103 &hdr->saddr, dh->dccph_sport, inet6_iif(skb));
104
105 if (sk == NULL) {
106 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
107 ICMP6_MIB_INERRORS);
108 return;
109 }
110
111 if (sk->sk_state == DCCP_TIME_WAIT) {
112 inet_twsk_put(inet_twsk(sk));
113 return;
114 }
115
116 bh_lock_sock(sk);
117 if (sock_owned_by_user(sk))
118 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
119
120 if (sk->sk_state == DCCP_CLOSED)
121 goto out;
122
123 dp = dccp_sk(sk);
124 seq = dccp_hdr_seq(dh);
125 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
126 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
127 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
128 goto out;
129 }
130
131 np = inet6_sk(sk);
132
133 if (type == NDISC_REDIRECT) {
134 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
135
136 if (dst)
137 dst->ops->redirect(dst, sk, skb);
138 }
139
140 if (type == ICMPV6_PKT_TOOBIG) {
141 struct dst_entry *dst = NULL;
142
143 if (sock_owned_by_user(sk))
144 goto out;
145 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
146 goto out;
147
148 dst = inet6_csk_update_pmtu(sk, ntohl(info));
149 if (!dst)
150 goto out;
151
152 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
153 dccp_sync_mss(sk, dst_mtu(dst));
154 goto out;
155 }
156
157 icmpv6_err_convert(type, code, &err);
158
159 /* Might be for an request_sock */
160 switch (sk->sk_state) {
161 struct request_sock *req, **prev;
162 case DCCP_LISTEN:
163 if (sock_owned_by_user(sk))
164 goto out;
165
166 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
167 &hdr->daddr, &hdr->saddr,
168 inet6_iif(skb));
169 if (req == NULL)
170 goto out;
171
172 /*
173 * ICMPs are not backlogged, hence we cannot get an established
174 * socket here.
175 */
176 WARN_ON(req->sk != NULL);
177
178 if (!between48(seq, dccp_rsk(req)->dreq_iss,
179 dccp_rsk(req)->dreq_gss)) {
180 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
181 goto out;
182 }
183
184 inet_csk_reqsk_queue_drop(sk, req, prev);
185 goto out;
186
187 case DCCP_REQUESTING:
188 case DCCP_RESPOND: /* Cannot happen.
189 It can, it SYNs are crossed. --ANK */
190 if (!sock_owned_by_user(sk)) {
191 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
192 sk->sk_err = err;
193 /*
194 * Wake people up to see the error
195 * (see connect in sock.c)
196 */
197 sk->sk_error_report(sk);
198 dccp_done(sk);
199 } else
200 sk->sk_err_soft = err;
201 goto out;
202 }
203
204 if (!sock_owned_by_user(sk) && np->recverr) {
205 sk->sk_err = err;
206 sk->sk_error_report(sk);
207 } else
208 sk->sk_err_soft = err;
209
210 out:
211 bh_unlock_sock(sk);
212 sock_put(sk);
213 }
214
215
216 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
217 {
218 struct inet6_request_sock *ireq6 = inet6_rsk(req);
219 struct ipv6_pinfo *np = inet6_sk(sk);
220 struct sk_buff *skb;
221 struct in6_addr *final_p, final;
222 struct flowi6 fl6;
223 int err = -1;
224 struct dst_entry *dst;
225
226 memset(&fl6, 0, sizeof(fl6));
227 fl6.flowi6_proto = IPPROTO_DCCP;
228 fl6.daddr = ireq6->rmt_addr;
229 fl6.saddr = ireq6->loc_addr;
230 fl6.flowlabel = 0;
231 fl6.flowi6_oif = ireq6->iif;
232 fl6.fl6_dport = inet_rsk(req)->rmt_port;
233 fl6.fl6_sport = inet_rsk(req)->loc_port;
234 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
235
236
237 final_p = fl6_update_dst(&fl6, np->opt, &final);
238
239 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
240 if (IS_ERR(dst)) {
241 err = PTR_ERR(dst);
242 dst = NULL;
243 goto done;
244 }
245
246 skb = dccp_make_response(sk, dst, req);
247 if (skb != NULL) {
248 struct dccp_hdr *dh = dccp_hdr(skb);
249
250 dh->dccph_checksum = dccp_v6_csum_finish(skb,
251 &ireq6->loc_addr,
252 &ireq6->rmt_addr);
253 fl6.daddr = ireq6->rmt_addr;
254 err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
255 err = net_xmit_eval(err);
256 }
257
258 done:
259 dst_release(dst);
260 return err;
261 }
262
263 static void dccp_v6_reqsk_destructor(struct request_sock *req)
264 {
265 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
266 if (inet6_rsk(req)->pktopts != NULL)
267 kfree_skb(inet6_rsk(req)->pktopts);
268 }
269
270 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
271 {
272 const struct ipv6hdr *rxip6h;
273 struct sk_buff *skb;
274 struct flowi6 fl6;
275 struct net *net = dev_net(skb_dst(rxskb)->dev);
276 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
277 struct dst_entry *dst;
278
279 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
280 return;
281
282 if (!ipv6_unicast_destination(rxskb))
283 return;
284
285 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
286 if (skb == NULL)
287 return;
288
289 rxip6h = ipv6_hdr(rxskb);
290 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
291 &rxip6h->daddr);
292
293 memset(&fl6, 0, sizeof(fl6));
294 fl6.daddr = rxip6h->saddr;
295 fl6.saddr = rxip6h->daddr;
296
297 fl6.flowi6_proto = IPPROTO_DCCP;
298 fl6.flowi6_oif = inet6_iif(rxskb);
299 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
300 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
301 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
302
303 /* sk = NULL, but it is safe for now. RST socket required. */
304 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
305 if (!IS_ERR(dst)) {
306 skb_dst_set(skb, dst);
307 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0);
308 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
309 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
310 return;
311 }
312
313 kfree_skb(skb);
314 }
315
316 static struct request_sock_ops dccp6_request_sock_ops = {
317 .family = AF_INET6,
318 .obj_size = sizeof(struct dccp6_request_sock),
319 .rtx_syn_ack = dccp_v6_send_response,
320 .send_ack = dccp_reqsk_send_ack,
321 .destructor = dccp_v6_reqsk_destructor,
322 .send_reset = dccp_v6_ctl_send_reset,
323 .syn_ack_timeout = dccp_syn_ack_timeout,
324 };
325
326 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
327 {
328 const struct dccp_hdr *dh = dccp_hdr(skb);
329 const struct ipv6hdr *iph = ipv6_hdr(skb);
330 struct sock *nsk;
331 struct request_sock **prev;
332 /* Find possible connection requests. */
333 struct request_sock *req = inet6_csk_search_req(sk, &prev,
334 dh->dccph_sport,
335 &iph->saddr,
336 &iph->daddr,
337 inet6_iif(skb));
338 if (req != NULL)
339 return dccp_check_req(sk, skb, req, prev);
340
341 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
342 &iph->saddr, dh->dccph_sport,
343 &iph->daddr, ntohs(dh->dccph_dport),
344 inet6_iif(skb));
345 if (nsk != NULL) {
346 if (nsk->sk_state != DCCP_TIME_WAIT) {
347 bh_lock_sock(nsk);
348 return nsk;
349 }
350 inet_twsk_put(inet_twsk(nsk));
351 return NULL;
352 }
353
354 return sk;
355 }
356
357 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
358 {
359 struct request_sock *req;
360 struct dccp_request_sock *dreq;
361 struct inet6_request_sock *ireq6;
362 struct ipv6_pinfo *np = inet6_sk(sk);
363 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
364 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
365
366 if (skb->protocol == htons(ETH_P_IP))
367 return dccp_v4_conn_request(sk, skb);
368
369 if (!ipv6_unicast_destination(skb))
370 return 0; /* discard, don't send a reset here */
371
372 if (dccp_bad_service_code(sk, service)) {
373 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
374 goto drop;
375 }
376 /*
377 * There are no SYN attacks on IPv6, yet...
378 */
379 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
380 if (inet_csk_reqsk_queue_is_full(sk))
381 goto drop;
382
383 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
384 goto drop;
385
386 req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
387 if (req == NULL)
388 goto drop;
389
390 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
391 goto drop_and_free;
392
393 dreq = dccp_rsk(req);
394 if (dccp_parse_options(sk, dreq, skb))
395 goto drop_and_free;
396
397 if (security_inet_conn_request(sk, skb, req))
398 goto drop_and_free;
399
400 ireq6 = inet6_rsk(req);
401 ireq6->rmt_addr = ipv6_hdr(skb)->saddr;
402 ireq6->loc_addr = ipv6_hdr(skb)->daddr;
403
404 if (ipv6_opt_accepted(sk, skb) ||
405 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
406 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
407 atomic_inc(&skb->users);
408 ireq6->pktopts = skb;
409 }
410 ireq6->iif = sk->sk_bound_dev_if;
411
412 /* So that link locals have meaning */
413 if (!sk->sk_bound_dev_if &&
414 ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
415 ireq6->iif = inet6_iif(skb);
416
417 /*
418 * Step 3: Process LISTEN state
419 *
420 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
421 *
422 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
423 */
424 dreq->dreq_isr = dcb->dccpd_seq;
425 dreq->dreq_gsr = dreq->dreq_isr;
426 dreq->dreq_iss = dccp_v6_init_sequence(skb);
427 dreq->dreq_gss = dreq->dreq_iss;
428 dreq->dreq_service = service;
429
430 if (dccp_v6_send_response(sk, req))
431 goto drop_and_free;
432
433 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
434 return 0;
435
436 drop_and_free:
437 reqsk_free(req);
438 drop:
439 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
440 return -1;
441 }
442
443 static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
444 struct sk_buff *skb,
445 struct request_sock *req,
446 struct dst_entry *dst)
447 {
448 struct inet6_request_sock *ireq6 = inet6_rsk(req);
449 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
450 struct inet_sock *newinet;
451 struct dccp6_sock *newdp6;
452 struct sock *newsk;
453
454 if (skb->protocol == htons(ETH_P_IP)) {
455 /*
456 * v6 mapped
457 */
458 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
459 if (newsk == NULL)
460 return NULL;
461
462 newdp6 = (struct dccp6_sock *)newsk;
463 newinet = inet_sk(newsk);
464 newinet->pinet6 = &newdp6->inet6;
465 newnp = inet6_sk(newsk);
466
467 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
468
469 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
470
471 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
472
473 newnp->rcv_saddr = newnp->saddr;
474
475 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
476 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
477 newnp->pktoptions = NULL;
478 newnp->opt = NULL;
479 newnp->mcast_oif = inet6_iif(skb);
480 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
481
482 /*
483 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
484 * here, dccp_create_openreq_child now does this for us, see the comment in
485 * that function for the gory details. -acme
486 */
487
488 /* It is tricky place. Until this moment IPv4 tcp
489 worked with IPv6 icsk.icsk_af_ops.
490 Sync it now.
491 */
492 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
493
494 return newsk;
495 }
496
497
498 if (sk_acceptq_is_full(sk))
499 goto out_overflow;
500
501 if (dst == NULL) {
502 struct in6_addr *final_p, final;
503 struct flowi6 fl6;
504
505 memset(&fl6, 0, sizeof(fl6));
506 fl6.flowi6_proto = IPPROTO_DCCP;
507 fl6.daddr = ireq6->rmt_addr;
508 final_p = fl6_update_dst(&fl6, np->opt, &final);
509 fl6.saddr = ireq6->loc_addr;
510 fl6.flowi6_oif = sk->sk_bound_dev_if;
511 fl6.fl6_dport = inet_rsk(req)->rmt_port;
512 fl6.fl6_sport = inet_rsk(req)->loc_port;
513 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
514
515 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
516 if (IS_ERR(dst))
517 goto out;
518 }
519
520 newsk = dccp_create_openreq_child(sk, req, skb);
521 if (newsk == NULL)
522 goto out_nonewsk;
523
524 /*
525 * No need to charge this sock to the relevant IPv6 refcnt debug socks
526 * count here, dccp_create_openreq_child now does this for us, see the
527 * comment in that function for the gory details. -acme
528 */
529
530 __ip6_dst_store(newsk, dst, NULL, NULL);
531 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
532 NETIF_F_TSO);
533 newdp6 = (struct dccp6_sock *)newsk;
534 newinet = inet_sk(newsk);
535 newinet->pinet6 = &newdp6->inet6;
536 newnp = inet6_sk(newsk);
537
538 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
539
540 newnp->daddr = ireq6->rmt_addr;
541 newnp->saddr = ireq6->loc_addr;
542 newnp->rcv_saddr = ireq6->loc_addr;
543 newsk->sk_bound_dev_if = ireq6->iif;
544
545 /* Now IPv6 options...
546
547 First: no IPv4 options.
548 */
549 newinet->inet_opt = NULL;
550
551 /* Clone RX bits */
552 newnp->rxopt.all = np->rxopt.all;
553
554 /* Clone pktoptions received with SYN */
555 newnp->pktoptions = NULL;
556 if (ireq6->pktopts != NULL) {
557 newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
558 consume_skb(ireq6->pktopts);
559 ireq6->pktopts = NULL;
560 if (newnp->pktoptions)
561 skb_set_owner_r(newnp->pktoptions, newsk);
562 }
563 newnp->opt = NULL;
564 newnp->mcast_oif = inet6_iif(skb);
565 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
566
567 /*
568 * Clone native IPv6 options from listening socket (if any)
569 *
570 * Yes, keeping reference count would be much more clever, but we make
571 * one more one thing there: reattach optmem to newsk.
572 */
573 if (np->opt != NULL)
574 newnp->opt = ipv6_dup_options(newsk, np->opt);
575
576 inet_csk(newsk)->icsk_ext_hdr_len = 0;
577 if (newnp->opt != NULL)
578 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
579 newnp->opt->opt_flen);
580
581 dccp_sync_mss(newsk, dst_mtu(dst));
582
583 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
584 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
585
586 if (__inet_inherit_port(sk, newsk) < 0) {
587 inet_csk_prepare_forced_close(newsk);
588 dccp_done(newsk);
589 goto out;
590 }
591 __inet6_hash(newsk, NULL);
592
593 return newsk;
594
595 out_overflow:
596 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
597 out_nonewsk:
598 dst_release(dst);
599 out:
600 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
601 return NULL;
602 }
603
604 /* The socket must have it's spinlock held when we get
605 * here.
606 *
607 * We have a potential double-lock case here, so even when
608 * doing backlog processing we use the BH locking scheme.
609 * This is because we cannot sleep with the original spinlock
610 * held.
611 */
612 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
613 {
614 struct ipv6_pinfo *np = inet6_sk(sk);
615 struct sk_buff *opt_skb = NULL;
616
617 /* Imagine: socket is IPv6. IPv4 packet arrives,
618 goes to IPv4 receive handler and backlogged.
619 From backlog it always goes here. Kerboom...
620 Fortunately, dccp_rcv_established and rcv_established
621 handle them correctly, but it is not case with
622 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
623 */
624
625 if (skb->protocol == htons(ETH_P_IP))
626 return dccp_v4_do_rcv(sk, skb);
627
628 if (sk_filter(sk, skb))
629 goto discard;
630
631 /*
632 * socket locking is here for SMP purposes as backlog rcv is currently
633 * called with bh processing disabled.
634 */
635
636 /* Do Stevens' IPV6_PKTOPTIONS.
637
638 Yes, guys, it is the only place in our code, where we
639 may make it not affecting IPv4.
640 The rest of code is protocol independent,
641 and I do not like idea to uglify IPv4.
642
643 Actually, all the idea behind IPV6_PKTOPTIONS
644 looks not very well thought. For now we latch
645 options, received in the last packet, enqueued
646 by tcp. Feel free to propose better solution.
647 --ANK (980728)
648 */
649 if (np->rxopt.all)
650 /*
651 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
652 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
653 */
654 opt_skb = skb_clone(skb, GFP_ATOMIC);
655
656 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
657 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
658 goto reset;
659 if (opt_skb) {
660 /* XXX This is where we would goto ipv6_pktoptions. */
661 __kfree_skb(opt_skb);
662 }
663 return 0;
664 }
665
666 /*
667 * Step 3: Process LISTEN state
668 * If S.state == LISTEN,
669 * If P.type == Request or P contains a valid Init Cookie option,
670 * (* Must scan the packet's options to check for Init
671 * Cookies. Only Init Cookies are processed here,
672 * however; other options are processed in Step 8. This
673 * scan need only be performed if the endpoint uses Init
674 * Cookies *)
675 * (* Generate a new socket and switch to that socket *)
676 * Set S := new socket for this port pair
677 * S.state = RESPOND
678 * Choose S.ISS (initial seqno) or set from Init Cookies
679 * Initialize S.GAR := S.ISS
680 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
681 * Continue with S.state == RESPOND
682 * (* A Response packet will be generated in Step 11 *)
683 * Otherwise,
684 * Generate Reset(No Connection) unless P.type == Reset
685 * Drop packet and return
686 *
687 * NOTE: the check for the packet types is done in
688 * dccp_rcv_state_process
689 */
690 if (sk->sk_state == DCCP_LISTEN) {
691 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
692
693 if (nsk == NULL)
694 goto discard;
695 /*
696 * Queue it on the new socket if the new socket is active,
697 * otherwise we just shortcircuit this and continue with
698 * the new socket..
699 */
700 if (nsk != sk) {
701 if (dccp_child_process(sk, nsk, skb))
702 goto reset;
703 if (opt_skb != NULL)
704 __kfree_skb(opt_skb);
705 return 0;
706 }
707 }
708
709 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
710 goto reset;
711 if (opt_skb) {
712 /* XXX This is where we would goto ipv6_pktoptions. */
713 __kfree_skb(opt_skb);
714 }
715 return 0;
716
717 reset:
718 dccp_v6_ctl_send_reset(sk, skb);
719 discard:
720 if (opt_skb != NULL)
721 __kfree_skb(opt_skb);
722 kfree_skb(skb);
723 return 0;
724 }
725
726 static int dccp_v6_rcv(struct sk_buff *skb)
727 {
728 const struct dccp_hdr *dh;
729 struct sock *sk;
730 int min_cov;
731
732 /* Step 1: Check header basics */
733
734 if (dccp_invalid_packet(skb))
735 goto discard_it;
736
737 /* Step 1: If header checksum is incorrect, drop packet and return. */
738 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
739 &ipv6_hdr(skb)->daddr)) {
740 DCCP_WARN("dropped packet with invalid checksum\n");
741 goto discard_it;
742 }
743
744 dh = dccp_hdr(skb);
745
746 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
747 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
748
749 if (dccp_packet_without_ack(skb))
750 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
751 else
752 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
753
754 /* Step 2:
755 * Look up flow ID in table and get corresponding socket */
756 sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
757 dh->dccph_sport, dh->dccph_dport);
758 /*
759 * Step 2:
760 * If no socket ...
761 */
762 if (sk == NULL) {
763 dccp_pr_debug("failed to look up flow ID in table and "
764 "get corresponding socket\n");
765 goto no_dccp_socket;
766 }
767
768 /*
769 * Step 2:
770 * ... or S.state == TIMEWAIT,
771 * Generate Reset(No Connection) unless P.type == Reset
772 * Drop packet and return
773 */
774 if (sk->sk_state == DCCP_TIME_WAIT) {
775 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
776 inet_twsk_put(inet_twsk(sk));
777 goto no_dccp_socket;
778 }
779
780 /*
781 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
782 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
783 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
784 */
785 min_cov = dccp_sk(sk)->dccps_pcrlen;
786 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
787 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
788 dh->dccph_cscov, min_cov);
789 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
790 goto discard_and_relse;
791 }
792
793 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
794 goto discard_and_relse;
795
796 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
797
798 no_dccp_socket:
799 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
800 goto discard_it;
801 /*
802 * Step 2:
803 * If no socket ...
804 * Generate Reset(No Connection) unless P.type == Reset
805 * Drop packet and return
806 */
807 if (dh->dccph_type != DCCP_PKT_RESET) {
808 DCCP_SKB_CB(skb)->dccpd_reset_code =
809 DCCP_RESET_CODE_NO_CONNECTION;
810 dccp_v6_ctl_send_reset(sk, skb);
811 }
812
813 discard_it:
814 kfree_skb(skb);
815 return 0;
816
817 discard_and_relse:
818 sock_put(sk);
819 goto discard_it;
820 }
821
822 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
823 int addr_len)
824 {
825 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
826 struct inet_connection_sock *icsk = inet_csk(sk);
827 struct inet_sock *inet = inet_sk(sk);
828 struct ipv6_pinfo *np = inet6_sk(sk);
829 struct dccp_sock *dp = dccp_sk(sk);
830 struct in6_addr *saddr = NULL, *final_p, final;
831 struct flowi6 fl6;
832 struct dst_entry *dst;
833 int addr_type;
834 int err;
835
836 dp->dccps_role = DCCP_ROLE_CLIENT;
837
838 if (addr_len < SIN6_LEN_RFC2133)
839 return -EINVAL;
840
841 if (usin->sin6_family != AF_INET6)
842 return -EAFNOSUPPORT;
843
844 memset(&fl6, 0, sizeof(fl6));
845
846 if (np->sndflow) {
847 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
848 IP6_ECN_flow_init(fl6.flowlabel);
849 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
850 struct ip6_flowlabel *flowlabel;
851 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
852 if (flowlabel == NULL)
853 return -EINVAL;
854 usin->sin6_addr = flowlabel->dst;
855 fl6_sock_release(flowlabel);
856 }
857 }
858 /*
859 * connect() to INADDR_ANY means loopback (BSD'ism).
860 */
861 if (ipv6_addr_any(&usin->sin6_addr))
862 usin->sin6_addr.s6_addr[15] = 1;
863
864 addr_type = ipv6_addr_type(&usin->sin6_addr);
865
866 if (addr_type & IPV6_ADDR_MULTICAST)
867 return -ENETUNREACH;
868
869 if (addr_type & IPV6_ADDR_LINKLOCAL) {
870 if (addr_len >= sizeof(struct sockaddr_in6) &&
871 usin->sin6_scope_id) {
872 /* If interface is set while binding, indices
873 * must coincide.
874 */
875 if (sk->sk_bound_dev_if &&
876 sk->sk_bound_dev_if != usin->sin6_scope_id)
877 return -EINVAL;
878
879 sk->sk_bound_dev_if = usin->sin6_scope_id;
880 }
881
882 /* Connect to link-local address requires an interface */
883 if (!sk->sk_bound_dev_if)
884 return -EINVAL;
885 }
886
887 np->daddr = usin->sin6_addr;
888 np->flow_label = fl6.flowlabel;
889
890 /*
891 * DCCP over IPv4
892 */
893 if (addr_type == IPV6_ADDR_MAPPED) {
894 u32 exthdrlen = icsk->icsk_ext_hdr_len;
895 struct sockaddr_in sin;
896
897 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
898
899 if (__ipv6_only_sock(sk))
900 return -ENETUNREACH;
901
902 sin.sin_family = AF_INET;
903 sin.sin_port = usin->sin6_port;
904 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
905
906 icsk->icsk_af_ops = &dccp_ipv6_mapped;
907 sk->sk_backlog_rcv = dccp_v4_do_rcv;
908
909 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
910 if (err) {
911 icsk->icsk_ext_hdr_len = exthdrlen;
912 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
913 sk->sk_backlog_rcv = dccp_v6_do_rcv;
914 goto failure;
915 }
916 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
917 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &np->rcv_saddr);
918
919 return err;
920 }
921
922 if (!ipv6_addr_any(&np->rcv_saddr))
923 saddr = &np->rcv_saddr;
924
925 fl6.flowi6_proto = IPPROTO_DCCP;
926 fl6.daddr = np->daddr;
927 fl6.saddr = saddr ? *saddr : np->saddr;
928 fl6.flowi6_oif = sk->sk_bound_dev_if;
929 fl6.fl6_dport = usin->sin6_port;
930 fl6.fl6_sport = inet->inet_sport;
931 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
932
933 final_p = fl6_update_dst(&fl6, np->opt, &final);
934
935 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
936 if (IS_ERR(dst)) {
937 err = PTR_ERR(dst);
938 goto failure;
939 }
940
941 if (saddr == NULL) {
942 saddr = &fl6.saddr;
943 np->rcv_saddr = *saddr;
944 }
945
946 /* set the source address */
947 np->saddr = *saddr;
948 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
949
950 __ip6_dst_store(sk, dst, NULL, NULL);
951
952 icsk->icsk_ext_hdr_len = 0;
953 if (np->opt != NULL)
954 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
955 np->opt->opt_nflen);
956
957 inet->inet_dport = usin->sin6_port;
958
959 dccp_set_state(sk, DCCP_REQUESTING);
960 err = inet6_hash_connect(&dccp_death_row, sk);
961 if (err)
962 goto late_failure;
963
964 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
965 np->daddr.s6_addr32,
966 inet->inet_sport,
967 inet->inet_dport);
968 err = dccp_connect(sk);
969 if (err)
970 goto late_failure;
971
972 return 0;
973
974 late_failure:
975 dccp_set_state(sk, DCCP_CLOSED);
976 __sk_dst_reset(sk);
977 failure:
978 inet->inet_dport = 0;
979 sk->sk_route_caps = 0;
980 return err;
981 }
982
983 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
984 .queue_xmit = inet6_csk_xmit,
985 .send_check = dccp_v6_send_check,
986 .rebuild_header = inet6_sk_rebuild_header,
987 .conn_request = dccp_v6_conn_request,
988 .syn_recv_sock = dccp_v6_request_recv_sock,
989 .net_header_len = sizeof(struct ipv6hdr),
990 .setsockopt = ipv6_setsockopt,
991 .getsockopt = ipv6_getsockopt,
992 .addr2sockaddr = inet6_csk_addr2sockaddr,
993 .sockaddr_len = sizeof(struct sockaddr_in6),
994 .bind_conflict = inet6_csk_bind_conflict,
995 #ifdef CONFIG_COMPAT
996 .compat_setsockopt = compat_ipv6_setsockopt,
997 .compat_getsockopt = compat_ipv6_getsockopt,
998 #endif
999 };
1000
1001 /*
1002 * DCCP over IPv4 via INET6 API
1003 */
1004 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1005 .queue_xmit = ip_queue_xmit,
1006 .send_check = dccp_v4_send_check,
1007 .rebuild_header = inet_sk_rebuild_header,
1008 .conn_request = dccp_v6_conn_request,
1009 .syn_recv_sock = dccp_v6_request_recv_sock,
1010 .net_header_len = sizeof(struct iphdr),
1011 .setsockopt = ipv6_setsockopt,
1012 .getsockopt = ipv6_getsockopt,
1013 .addr2sockaddr = inet6_csk_addr2sockaddr,
1014 .sockaddr_len = sizeof(struct sockaddr_in6),
1015 #ifdef CONFIG_COMPAT
1016 .compat_setsockopt = compat_ipv6_setsockopt,
1017 .compat_getsockopt = compat_ipv6_getsockopt,
1018 #endif
1019 };
1020
1021 /* NOTE: A lot of things set to zero explicitly by call to
1022 * sk_alloc() so need not be done here.
1023 */
1024 static int dccp_v6_init_sock(struct sock *sk)
1025 {
1026 static __u8 dccp_v6_ctl_sock_initialized;
1027 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1028
1029 if (err == 0) {
1030 if (unlikely(!dccp_v6_ctl_sock_initialized))
1031 dccp_v6_ctl_sock_initialized = 1;
1032 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1033 }
1034
1035 return err;
1036 }
1037
1038 static void dccp_v6_destroy_sock(struct sock *sk)
1039 {
1040 dccp_destroy_sock(sk);
1041 inet6_destroy_sock(sk);
1042 }
1043
1044 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1045 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1046 };
1047
1048 static struct proto dccp_v6_prot = {
1049 .name = "DCCPv6",
1050 .owner = THIS_MODULE,
1051 .close = dccp_close,
1052 .connect = dccp_v6_connect,
1053 .disconnect = dccp_disconnect,
1054 .ioctl = dccp_ioctl,
1055 .init = dccp_v6_init_sock,
1056 .setsockopt = dccp_setsockopt,
1057 .getsockopt = dccp_getsockopt,
1058 .sendmsg = dccp_sendmsg,
1059 .recvmsg = dccp_recvmsg,
1060 .backlog_rcv = dccp_v6_do_rcv,
1061 .hash = dccp_v6_hash,
1062 .unhash = inet_unhash,
1063 .accept = inet_csk_accept,
1064 .get_port = inet_csk_get_port,
1065 .shutdown = dccp_shutdown,
1066 .destroy = dccp_v6_destroy_sock,
1067 .orphan_count = &dccp_orphan_count,
1068 .max_header = MAX_DCCP_HEADER,
1069 .obj_size = sizeof(struct dccp6_sock),
1070 .slab_flags = SLAB_DESTROY_BY_RCU,
1071 .rsk_prot = &dccp6_request_sock_ops,
1072 .twsk_prot = &dccp6_timewait_sock_ops,
1073 .h.hashinfo = &dccp_hashinfo,
1074 #ifdef CONFIG_COMPAT
1075 .compat_setsockopt = compat_dccp_setsockopt,
1076 .compat_getsockopt = compat_dccp_getsockopt,
1077 #endif
1078 };
1079
1080 static const struct inet6_protocol dccp_v6_protocol = {
1081 .handler = dccp_v6_rcv,
1082 .err_handler = dccp_v6_err,
1083 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1084 };
1085
1086 static const struct proto_ops inet6_dccp_ops = {
1087 .family = PF_INET6,
1088 .owner = THIS_MODULE,
1089 .release = inet6_release,
1090 .bind = inet6_bind,
1091 .connect = inet_stream_connect,
1092 .socketpair = sock_no_socketpair,
1093 .accept = inet_accept,
1094 .getname = inet6_getname,
1095 .poll = dccp_poll,
1096 .ioctl = inet6_ioctl,
1097 .listen = inet_dccp_listen,
1098 .shutdown = inet_shutdown,
1099 .setsockopt = sock_common_setsockopt,
1100 .getsockopt = sock_common_getsockopt,
1101 .sendmsg = inet_sendmsg,
1102 .recvmsg = sock_common_recvmsg,
1103 .mmap = sock_no_mmap,
1104 .sendpage = sock_no_sendpage,
1105 #ifdef CONFIG_COMPAT
1106 .compat_setsockopt = compat_sock_common_setsockopt,
1107 .compat_getsockopt = compat_sock_common_getsockopt,
1108 #endif
1109 };
1110
1111 static struct inet_protosw dccp_v6_protosw = {
1112 .type = SOCK_DCCP,
1113 .protocol = IPPROTO_DCCP,
1114 .prot = &dccp_v6_prot,
1115 .ops = &inet6_dccp_ops,
1116 .flags = INET_PROTOSW_ICSK,
1117 };
1118
1119 static int __net_init dccp_v6_init_net(struct net *net)
1120 {
1121 if (dccp_hashinfo.bhash == NULL)
1122 return -ESOCKTNOSUPPORT;
1123
1124 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1125 SOCK_DCCP, IPPROTO_DCCP, net);
1126 }
1127
1128 static void __net_exit dccp_v6_exit_net(struct net *net)
1129 {
1130 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1131 }
1132
1133 static struct pernet_operations dccp_v6_ops = {
1134 .init = dccp_v6_init_net,
1135 .exit = dccp_v6_exit_net,
1136 };
1137
1138 static int __init dccp_v6_init(void)
1139 {
1140 int err = proto_register(&dccp_v6_prot, 1);
1141
1142 if (err != 0)
1143 goto out;
1144
1145 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1146 if (err != 0)
1147 goto out_unregister_proto;
1148
1149 inet6_register_protosw(&dccp_v6_protosw);
1150
1151 err = register_pernet_subsys(&dccp_v6_ops);
1152 if (err != 0)
1153 goto out_destroy_ctl_sock;
1154 out:
1155 return err;
1156
1157 out_destroy_ctl_sock:
1158 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1159 inet6_unregister_protosw(&dccp_v6_protosw);
1160 out_unregister_proto:
1161 proto_unregister(&dccp_v6_prot);
1162 goto out;
1163 }
1164
1165 static void __exit dccp_v6_exit(void)
1166 {
1167 unregister_pernet_subsys(&dccp_v6_ops);
1168 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1169 inet6_unregister_protosw(&dccp_v6_protosw);
1170 proto_unregister(&dccp_v6_prot);
1171 }
1172
1173 module_init(dccp_v6_init);
1174 module_exit(dccp_v6_exit);
1175
1176 /*
1177 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1178 * values directly, Also cover the case where the protocol is not specified,
1179 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1180 */
1181 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1182 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1183 MODULE_LICENSE("GPL");
1184 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1185 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
Linus' kernel tree