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ipv6: Refactor update of IPv6 flowi destination address for srcrt (RH) option
[mirror_ubuntu-artful-kernel.git] / net / dccp / ipv6.c
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
33 #include "dccp.h"
34 #include "ipv6.h"
35 #include "feat.h"
36
37 /* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */
38
39 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
40 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
41
42 static void dccp_v6_hash(struct sock *sk)
43 {
44 if (sk->sk_state != DCCP_CLOSED) {
45 if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) {
46 inet_hash(sk);
47 return;
48 }
49 local_bh_disable();
50 __inet6_hash(sk, NULL);
51 local_bh_enable();
52 }
53 }
54
55 /* add pseudo-header to DCCP checksum stored in skb->csum */
56 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
57 struct in6_addr *saddr,
58 struct in6_addr *daddr)
59 {
60 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
61 }
62
63 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
64 {
65 struct ipv6_pinfo *np = inet6_sk(sk);
66 struct dccp_hdr *dh = dccp_hdr(skb);
67
68 dccp_csum_outgoing(skb);
69 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
70 }
71
72 static inline __u32 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
73 __be16 sport, __be16 dport )
74 {
75 return secure_tcpv6_sequence_number(saddr, daddr, sport, dport);
76 }
77
78 static inline __u32 dccp_v6_init_sequence(struct sk_buff *skb)
79 {
80 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
81 ipv6_hdr(skb)->saddr.s6_addr32,
82 dccp_hdr(skb)->dccph_dport,
83 dccp_hdr(skb)->dccph_sport );
84
85 }
86
87 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
88 u8 type, u8 code, int offset, __be32 info)
89 {
90 struct ipv6hdr *hdr = (struct ipv6hdr *)skb->data;
91 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
92 struct dccp_sock *dp;
93 struct ipv6_pinfo *np;
94 struct sock *sk;
95 int err;
96 __u64 seq;
97 struct net *net = dev_net(skb->dev);
98
99 if (skb->len < offset + sizeof(*dh) ||
100 skb->len < offset + __dccp_basic_hdr_len(dh)) {
101 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
102 ICMP6_MIB_INERRORS);
103 return;
104 }
105
106 sk = inet6_lookup(net, &dccp_hashinfo,
107 &hdr->daddr, dh->dccph_dport,
108 &hdr->saddr, dh->dccph_sport, inet6_iif(skb));
109
110 if (sk == NULL) {
111 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
112 ICMP6_MIB_INERRORS);
113 return;
114 }
115
116 if (sk->sk_state == DCCP_TIME_WAIT) {
117 inet_twsk_put(inet_twsk(sk));
118 return;
119 }
120
121 bh_lock_sock(sk);
122 if (sock_owned_by_user(sk))
123 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
124
125 if (sk->sk_state == DCCP_CLOSED)
126 goto out;
127
128 dp = dccp_sk(sk);
129 seq = dccp_hdr_seq(dh);
130 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
131 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
132 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
133 goto out;
134 }
135
136 np = inet6_sk(sk);
137
138 if (type == ICMPV6_PKT_TOOBIG) {
139 struct dst_entry *dst = NULL;
140
141 if (sock_owned_by_user(sk))
142 goto out;
143 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
144 goto out;
145
146 /* icmp should have updated the destination cache entry */
147 dst = __sk_dst_check(sk, np->dst_cookie);
148 if (dst == NULL) {
149 struct inet_sock *inet = inet_sk(sk);
150 struct flowi fl;
151
152 /* BUGGG_FUTURE: Again, it is not clear how
153 to handle rthdr case. Ignore this complexity
154 for now.
155 */
156 memset(&fl, 0, sizeof(fl));
157 fl.proto = IPPROTO_DCCP;
158 ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
159 ipv6_addr_copy(&fl.fl6_src, &np->saddr);
160 fl.oif = sk->sk_bound_dev_if;
161 fl.fl_ip_dport = inet->inet_dport;
162 fl.fl_ip_sport = inet->inet_sport;
163 security_sk_classify_flow(sk, &fl);
164
165 err = ip6_dst_lookup(sk, &dst, &fl);
166 if (err) {
167 sk->sk_err_soft = -err;
168 goto out;
169 }
170
171 err = xfrm_lookup(net, &dst, &fl, sk, 0);
172 if (err < 0) {
173 sk->sk_err_soft = -err;
174 goto out;
175 }
176 } else
177 dst_hold(dst);
178
179 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
180 dccp_sync_mss(sk, dst_mtu(dst));
181 } /* else let the usual retransmit timer handle it */
182 dst_release(dst);
183 goto out;
184 }
185
186 icmpv6_err_convert(type, code, &err);
187
188 /* Might be for an request_sock */
189 switch (sk->sk_state) {
190 struct request_sock *req, **prev;
191 case DCCP_LISTEN:
192 if (sock_owned_by_user(sk))
193 goto out;
194
195 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
196 &hdr->daddr, &hdr->saddr,
197 inet6_iif(skb));
198 if (req == NULL)
199 goto out;
200
201 /*
202 * ICMPs are not backlogged, hence we cannot get an established
203 * socket here.
204 */
205 WARN_ON(req->sk != NULL);
206
207 if (seq != dccp_rsk(req)->dreq_iss) {
208 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
209 goto out;
210 }
211
212 inet_csk_reqsk_queue_drop(sk, req, prev);
213 goto out;
214
215 case DCCP_REQUESTING:
216 case DCCP_RESPOND: /* Cannot happen.
217 It can, it SYNs are crossed. --ANK */
218 if (!sock_owned_by_user(sk)) {
219 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
220 sk->sk_err = err;
221 /*
222 * Wake people up to see the error
223 * (see connect in sock.c)
224 */
225 sk->sk_error_report(sk);
226 dccp_done(sk);
227 } else
228 sk->sk_err_soft = err;
229 goto out;
230 }
231
232 if (!sock_owned_by_user(sk) && np->recverr) {
233 sk->sk_err = err;
234 sk->sk_error_report(sk);
235 } else
236 sk->sk_err_soft = err;
237
238 out:
239 bh_unlock_sock(sk);
240 sock_put(sk);
241 }
242
243
244 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
245 struct request_values *rv_unused)
246 {
247 struct inet6_request_sock *ireq6 = inet6_rsk(req);
248 struct ipv6_pinfo *np = inet6_sk(sk);
249 struct sk_buff *skb;
250 struct ipv6_txoptions *opt = NULL;
251 struct in6_addr *final_p, final;
252 struct flowi fl;
253 int err = -1;
254 struct dst_entry *dst;
255
256 memset(&fl, 0, sizeof(fl));
257 fl.proto = IPPROTO_DCCP;
258 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
259 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
260 fl.fl6_flowlabel = 0;
261 fl.oif = ireq6->iif;
262 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
263 fl.fl_ip_sport = inet_rsk(req)->loc_port;
264 security_req_classify_flow(req, &fl);
265
266 opt = np->opt;
267
268 final_p = fl6_update_dst(&fl, opt, &final);
269
270 err = ip6_dst_lookup(sk, &dst, &fl);
271 if (err)
272 goto done;
273
274 if (final_p)
275 ipv6_addr_copy(&fl.fl6_dst, final_p);
276
277 err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0);
278 if (err < 0)
279 goto done;
280
281 skb = dccp_make_response(sk, dst, req);
282 if (skb != NULL) {
283 struct dccp_hdr *dh = dccp_hdr(skb);
284
285 dh->dccph_checksum = dccp_v6_csum_finish(skb,
286 &ireq6->loc_addr,
287 &ireq6->rmt_addr);
288 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
289 err = ip6_xmit(sk, skb, &fl, opt);
290 err = net_xmit_eval(err);
291 }
292
293 done:
294 if (opt != NULL && opt != np->opt)
295 sock_kfree_s(sk, opt, opt->tot_len);
296 dst_release(dst);
297 return err;
298 }
299
300 static void dccp_v6_reqsk_destructor(struct request_sock *req)
301 {
302 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
303 if (inet6_rsk(req)->pktopts != NULL)
304 kfree_skb(inet6_rsk(req)->pktopts);
305 }
306
307 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
308 {
309 struct ipv6hdr *rxip6h;
310 struct sk_buff *skb;
311 struct flowi fl;
312 struct net *net = dev_net(skb_dst(rxskb)->dev);
313 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
314 struct dst_entry *dst;
315
316 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
317 return;
318
319 if (!ipv6_unicast_destination(rxskb))
320 return;
321
322 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
323 if (skb == NULL)
324 return;
325
326 rxip6h = ipv6_hdr(rxskb);
327 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
328 &rxip6h->daddr);
329
330 memset(&fl, 0, sizeof(fl));
331 ipv6_addr_copy(&fl.fl6_dst, &rxip6h->saddr);
332 ipv6_addr_copy(&fl.fl6_src, &rxip6h->daddr);
333
334 fl.proto = IPPROTO_DCCP;
335 fl.oif = inet6_iif(rxskb);
336 fl.fl_ip_dport = dccp_hdr(skb)->dccph_dport;
337 fl.fl_ip_sport = dccp_hdr(skb)->dccph_sport;
338 security_skb_classify_flow(rxskb, &fl);
339
340 /* sk = NULL, but it is safe for now. RST socket required. */
341 if (!ip6_dst_lookup(ctl_sk, &dst, &fl)) {
342 if (xfrm_lookup(net, &dst, &fl, NULL, 0) >= 0) {
343 skb_dst_set(skb, dst);
344 ip6_xmit(ctl_sk, skb, &fl, NULL);
345 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
346 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
347 return;
348 }
349 }
350
351 kfree_skb(skb);
352 }
353
354 static struct request_sock_ops dccp6_request_sock_ops = {
355 .family = AF_INET6,
356 .obj_size = sizeof(struct dccp6_request_sock),
357 .rtx_syn_ack = dccp_v6_send_response,
358 .send_ack = dccp_reqsk_send_ack,
359 .destructor = dccp_v6_reqsk_destructor,
360 .send_reset = dccp_v6_ctl_send_reset,
361 };
362
363 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
364 {
365 const struct dccp_hdr *dh = dccp_hdr(skb);
366 const struct ipv6hdr *iph = ipv6_hdr(skb);
367 struct sock *nsk;
368 struct request_sock **prev;
369 /* Find possible connection requests. */
370 struct request_sock *req = inet6_csk_search_req(sk, &prev,
371 dh->dccph_sport,
372 &iph->saddr,
373 &iph->daddr,
374 inet6_iif(skb));
375 if (req != NULL)
376 return dccp_check_req(sk, skb, req, prev);
377
378 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
379 &iph->saddr, dh->dccph_sport,
380 &iph->daddr, ntohs(dh->dccph_dport),
381 inet6_iif(skb));
382 if (nsk != NULL) {
383 if (nsk->sk_state != DCCP_TIME_WAIT) {
384 bh_lock_sock(nsk);
385 return nsk;
386 }
387 inet_twsk_put(inet_twsk(nsk));
388 return NULL;
389 }
390
391 return sk;
392 }
393
394 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
395 {
396 struct request_sock *req;
397 struct dccp_request_sock *dreq;
398 struct inet6_request_sock *ireq6;
399 struct ipv6_pinfo *np = inet6_sk(sk);
400 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
401 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
402
403 if (skb->protocol == htons(ETH_P_IP))
404 return dccp_v4_conn_request(sk, skb);
405
406 if (!ipv6_unicast_destination(skb))
407 return 0; /* discard, don't send a reset here */
408
409 if (dccp_bad_service_code(sk, service)) {
410 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
411 goto drop;
412 }
413 /*
414 * There are no SYN attacks on IPv6, yet...
415 */
416 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
417 if (inet_csk_reqsk_queue_is_full(sk))
418 goto drop;
419
420 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
421 goto drop;
422
423 req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
424 if (req == NULL)
425 goto drop;
426
427 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
428 goto drop_and_free;
429
430 dreq = dccp_rsk(req);
431 if (dccp_parse_options(sk, dreq, skb))
432 goto drop_and_free;
433
434 if (security_inet_conn_request(sk, skb, req))
435 goto drop_and_free;
436
437 ireq6 = inet6_rsk(req);
438 ipv6_addr_copy(&ireq6->rmt_addr, &ipv6_hdr(skb)->saddr);
439 ipv6_addr_copy(&ireq6->loc_addr, &ipv6_hdr(skb)->daddr);
440
441 if (ipv6_opt_accepted(sk, skb) ||
442 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
443 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
444 atomic_inc(&skb->users);
445 ireq6->pktopts = skb;
446 }
447 ireq6->iif = sk->sk_bound_dev_if;
448
449 /* So that link locals have meaning */
450 if (!sk->sk_bound_dev_if &&
451 ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
452 ireq6->iif = inet6_iif(skb);
453
454 /*
455 * Step 3: Process LISTEN state
456 *
457 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
458 *
459 * In fact we defer setting S.GSR, S.SWL, S.SWH to
460 * dccp_create_openreq_child.
461 */
462 dreq->dreq_isr = dcb->dccpd_seq;
463 dreq->dreq_iss = dccp_v6_init_sequence(skb);
464 dreq->dreq_service = service;
465
466 if (dccp_v6_send_response(sk, req, NULL))
467 goto drop_and_free;
468
469 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
470 return 0;
471
472 drop_and_free:
473 reqsk_free(req);
474 drop:
475 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
476 return -1;
477 }
478
479 static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
480 struct sk_buff *skb,
481 struct request_sock *req,
482 struct dst_entry *dst)
483 {
484 struct inet6_request_sock *ireq6 = inet6_rsk(req);
485 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
486 struct inet_sock *newinet;
487 struct dccp_sock *newdp;
488 struct dccp6_sock *newdp6;
489 struct sock *newsk;
490 struct ipv6_txoptions *opt;
491
492 if (skb->protocol == htons(ETH_P_IP)) {
493 /*
494 * v6 mapped
495 */
496 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
497 if (newsk == NULL)
498 return NULL;
499
500 newdp6 = (struct dccp6_sock *)newsk;
501 newdp = dccp_sk(newsk);
502 newinet = inet_sk(newsk);
503 newinet->pinet6 = &newdp6->inet6;
504 newnp = inet6_sk(newsk);
505
506 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
507
508 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
509
510 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
511
512 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
513
514 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
515 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
516 newnp->pktoptions = NULL;
517 newnp->opt = NULL;
518 newnp->mcast_oif = inet6_iif(skb);
519 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
520
521 /*
522 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
523 * here, dccp_create_openreq_child now does this for us, see the comment in
524 * that function for the gory details. -acme
525 */
526
527 /* It is tricky place. Until this moment IPv4 tcp
528 worked with IPv6 icsk.icsk_af_ops.
529 Sync it now.
530 */
531 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
532
533 return newsk;
534 }
535
536 opt = np->opt;
537
538 if (sk_acceptq_is_full(sk))
539 goto out_overflow;
540
541 if (dst == NULL) {
542 struct in6_addr *final_p, final;
543 struct flowi fl;
544
545 memset(&fl, 0, sizeof(fl));
546 fl.proto = IPPROTO_DCCP;
547 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
548 final_p = fl6_update_dst(&fl, opt, &final);
549 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
550 fl.oif = sk->sk_bound_dev_if;
551 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
552 fl.fl_ip_sport = inet_rsk(req)->loc_port;
553 security_sk_classify_flow(sk, &fl);
554
555 if (ip6_dst_lookup(sk, &dst, &fl))
556 goto out;
557
558 if (final_p)
559 ipv6_addr_copy(&fl.fl6_dst, final_p);
560
561 if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
562 goto out;
563 }
564
565 newsk = dccp_create_openreq_child(sk, req, skb);
566 if (newsk == NULL)
567 goto out;
568
569 /*
570 * No need to charge this sock to the relevant IPv6 refcnt debug socks
571 * count here, dccp_create_openreq_child now does this for us, see the
572 * comment in that function for the gory details. -acme
573 */
574
575 __ip6_dst_store(newsk, dst, NULL, NULL);
576 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
577 NETIF_F_TSO);
578 newdp6 = (struct dccp6_sock *)newsk;
579 newinet = inet_sk(newsk);
580 newinet->pinet6 = &newdp6->inet6;
581 newdp = dccp_sk(newsk);
582 newnp = inet6_sk(newsk);
583
584 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
585
586 ipv6_addr_copy(&newnp->daddr, &ireq6->rmt_addr);
587 ipv6_addr_copy(&newnp->saddr, &ireq6->loc_addr);
588 ipv6_addr_copy(&newnp->rcv_saddr, &ireq6->loc_addr);
589 newsk->sk_bound_dev_if = ireq6->iif;
590
591 /* Now IPv6 options...
592
593 First: no IPv4 options.
594 */
595 newinet->opt = NULL;
596
597 /* Clone RX bits */
598 newnp->rxopt.all = np->rxopt.all;
599
600 /* Clone pktoptions received with SYN */
601 newnp->pktoptions = NULL;
602 if (ireq6->pktopts != NULL) {
603 newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
604 kfree_skb(ireq6->pktopts);
605 ireq6->pktopts = NULL;
606 if (newnp->pktoptions)
607 skb_set_owner_r(newnp->pktoptions, newsk);
608 }
609 newnp->opt = NULL;
610 newnp->mcast_oif = inet6_iif(skb);
611 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
612
613 /*
614 * Clone native IPv6 options from listening socket (if any)
615 *
616 * Yes, keeping reference count would be much more clever, but we make
617 * one more one thing there: reattach optmem to newsk.
618 */
619 if (opt != NULL) {
620 newnp->opt = ipv6_dup_options(newsk, opt);
621 if (opt != np->opt)
622 sock_kfree_s(sk, opt, opt->tot_len);
623 }
624
625 inet_csk(newsk)->icsk_ext_hdr_len = 0;
626 if (newnp->opt != NULL)
627 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
628 newnp->opt->opt_flen);
629
630 dccp_sync_mss(newsk, dst_mtu(dst));
631
632 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
633 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
634
635 __inet6_hash(newsk, NULL);
636 __inet_inherit_port(sk, newsk);
637
638 return newsk;
639
640 out_overflow:
641 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
642 out:
643 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
644 if (opt != NULL && opt != np->opt)
645 sock_kfree_s(sk, opt, opt->tot_len);
646 dst_release(dst);
647 return NULL;
648 }
649
650 /* The socket must have it's spinlock held when we get
651 * here.
652 *
653 * We have a potential double-lock case here, so even when
654 * doing backlog processing we use the BH locking scheme.
655 * This is because we cannot sleep with the original spinlock
656 * held.
657 */
658 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
659 {
660 struct ipv6_pinfo *np = inet6_sk(sk);
661 struct sk_buff *opt_skb = NULL;
662
663 /* Imagine: socket is IPv6. IPv4 packet arrives,
664 goes to IPv4 receive handler and backlogged.
665 From backlog it always goes here. Kerboom...
666 Fortunately, dccp_rcv_established and rcv_established
667 handle them correctly, but it is not case with
668 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
669 */
670
671 if (skb->protocol == htons(ETH_P_IP))
672 return dccp_v4_do_rcv(sk, skb);
673
674 if (sk_filter(sk, skb))
675 goto discard;
676
677 /*
678 * socket locking is here for SMP purposes as backlog rcv is currently
679 * called with bh processing disabled.
680 */
681
682 /* Do Stevens' IPV6_PKTOPTIONS.
683
684 Yes, guys, it is the only place in our code, where we
685 may make it not affecting IPv4.
686 The rest of code is protocol independent,
687 and I do not like idea to uglify IPv4.
688
689 Actually, all the idea behind IPV6_PKTOPTIONS
690 looks not very well thought. For now we latch
691 options, received in the last packet, enqueued
692 by tcp. Feel free to propose better solution.
693 --ANK (980728)
694 */
695 if (np->rxopt.all)
696 /*
697 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
698 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
699 */
700 opt_skb = skb_clone(skb, GFP_ATOMIC);
701
702 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
703 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
704 goto reset;
705 if (opt_skb) {
706 /* XXX This is where we would goto ipv6_pktoptions. */
707 __kfree_skb(opt_skb);
708 }
709 return 0;
710 }
711
712 /*
713 * Step 3: Process LISTEN state
714 * If S.state == LISTEN,
715 * If P.type == Request or P contains a valid Init Cookie option,
716 * (* Must scan the packet's options to check for Init
717 * Cookies. Only Init Cookies are processed here,
718 * however; other options are processed in Step 8. This
719 * scan need only be performed if the endpoint uses Init
720 * Cookies *)
721 * (* Generate a new socket and switch to that socket *)
722 * Set S := new socket for this port pair
723 * S.state = RESPOND
724 * Choose S.ISS (initial seqno) or set from Init Cookies
725 * Initialize S.GAR := S.ISS
726 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
727 * Continue with S.state == RESPOND
728 * (* A Response packet will be generated in Step 11 *)
729 * Otherwise,
730 * Generate Reset(No Connection) unless P.type == Reset
731 * Drop packet and return
732 *
733 * NOTE: the check for the packet types is done in
734 * dccp_rcv_state_process
735 */
736 if (sk->sk_state == DCCP_LISTEN) {
737 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
738
739 if (nsk == NULL)
740 goto discard;
741 /*
742 * Queue it on the new socket if the new socket is active,
743 * otherwise we just shortcircuit this and continue with
744 * the new socket..
745 */
746 if (nsk != sk) {
747 if (dccp_child_process(sk, nsk, skb))
748 goto reset;
749 if (opt_skb != NULL)
750 __kfree_skb(opt_skb);
751 return 0;
752 }
753 }
754
755 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
756 goto reset;
757 if (opt_skb) {
758 /* XXX This is where we would goto ipv6_pktoptions. */
759 __kfree_skb(opt_skb);
760 }
761 return 0;
762
763 reset:
764 dccp_v6_ctl_send_reset(sk, skb);
765 discard:
766 if (opt_skb != NULL)
767 __kfree_skb(opt_skb);
768 kfree_skb(skb);
769 return 0;
770 }
771
772 static int dccp_v6_rcv(struct sk_buff *skb)
773 {
774 const struct dccp_hdr *dh;
775 struct sock *sk;
776 int min_cov;
777
778 /* Step 1: Check header basics */
779
780 if (dccp_invalid_packet(skb))
781 goto discard_it;
782
783 /* Step 1: If header checksum is incorrect, drop packet and return. */
784 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
785 &ipv6_hdr(skb)->daddr)) {
786 DCCP_WARN("dropped packet with invalid checksum\n");
787 goto discard_it;
788 }
789
790 dh = dccp_hdr(skb);
791
792 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
793 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
794
795 if (dccp_packet_without_ack(skb))
796 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
797 else
798 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
799
800 /* Step 2:
801 * Look up flow ID in table and get corresponding socket */
802 sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
803 dh->dccph_sport, dh->dccph_dport);
804 /*
805 * Step 2:
806 * If no socket ...
807 */
808 if (sk == NULL) {
809 dccp_pr_debug("failed to look up flow ID in table and "
810 "get corresponding socket\n");
811 goto no_dccp_socket;
812 }
813
814 /*
815 * Step 2:
816 * ... or S.state == TIMEWAIT,
817 * Generate Reset(No Connection) unless P.type == Reset
818 * Drop packet and return
819 */
820 if (sk->sk_state == DCCP_TIME_WAIT) {
821 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
822 inet_twsk_put(inet_twsk(sk));
823 goto no_dccp_socket;
824 }
825
826 /*
827 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
828 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
829 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
830 */
831 min_cov = dccp_sk(sk)->dccps_pcrlen;
832 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
833 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
834 dh->dccph_cscov, min_cov);
835 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
836 goto discard_and_relse;
837 }
838
839 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
840 goto discard_and_relse;
841
842 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
843
844 no_dccp_socket:
845 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
846 goto discard_it;
847 /*
848 * Step 2:
849 * If no socket ...
850 * Generate Reset(No Connection) unless P.type == Reset
851 * Drop packet and return
852 */
853 if (dh->dccph_type != DCCP_PKT_RESET) {
854 DCCP_SKB_CB(skb)->dccpd_reset_code =
855 DCCP_RESET_CODE_NO_CONNECTION;
856 dccp_v6_ctl_send_reset(sk, skb);
857 }
858
859 discard_it:
860 kfree_skb(skb);
861 return 0;
862
863 discard_and_relse:
864 sock_put(sk);
865 goto discard_it;
866 }
867
868 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
869 int addr_len)
870 {
871 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
872 struct inet_connection_sock *icsk = inet_csk(sk);
873 struct inet_sock *inet = inet_sk(sk);
874 struct ipv6_pinfo *np = inet6_sk(sk);
875 struct dccp_sock *dp = dccp_sk(sk);
876 struct in6_addr *saddr = NULL, *final_p, final;
877 struct flowi fl;
878 struct dst_entry *dst;
879 int addr_type;
880 int err;
881
882 dp->dccps_role = DCCP_ROLE_CLIENT;
883
884 if (addr_len < SIN6_LEN_RFC2133)
885 return -EINVAL;
886
887 if (usin->sin6_family != AF_INET6)
888 return -EAFNOSUPPORT;
889
890 memset(&fl, 0, sizeof(fl));
891
892 if (np->sndflow) {
893 fl.fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
894 IP6_ECN_flow_init(fl.fl6_flowlabel);
895 if (fl.fl6_flowlabel & IPV6_FLOWLABEL_MASK) {
896 struct ip6_flowlabel *flowlabel;
897 flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
898 if (flowlabel == NULL)
899 return -EINVAL;
900 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
901 fl6_sock_release(flowlabel);
902 }
903 }
904 /*
905 * connect() to INADDR_ANY means loopback (BSD'ism).
906 */
907 if (ipv6_addr_any(&usin->sin6_addr))
908 usin->sin6_addr.s6_addr[15] = 1;
909
910 addr_type = ipv6_addr_type(&usin->sin6_addr);
911
912 if (addr_type & IPV6_ADDR_MULTICAST)
913 return -ENETUNREACH;
914
915 if (addr_type & IPV6_ADDR_LINKLOCAL) {
916 if (addr_len >= sizeof(struct sockaddr_in6) &&
917 usin->sin6_scope_id) {
918 /* If interface is set while binding, indices
919 * must coincide.
920 */
921 if (sk->sk_bound_dev_if &&
922 sk->sk_bound_dev_if != usin->sin6_scope_id)
923 return -EINVAL;
924
925 sk->sk_bound_dev_if = usin->sin6_scope_id;
926 }
927
928 /* Connect to link-local address requires an interface */
929 if (!sk->sk_bound_dev_if)
930 return -EINVAL;
931 }
932
933 ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
934 np->flow_label = fl.fl6_flowlabel;
935
936 /*
937 * DCCP over IPv4
938 */
939 if (addr_type == IPV6_ADDR_MAPPED) {
940 u32 exthdrlen = icsk->icsk_ext_hdr_len;
941 struct sockaddr_in sin;
942
943 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
944
945 if (__ipv6_only_sock(sk))
946 return -ENETUNREACH;
947
948 sin.sin_family = AF_INET;
949 sin.sin_port = usin->sin6_port;
950 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
951
952 icsk->icsk_af_ops = &dccp_ipv6_mapped;
953 sk->sk_backlog_rcv = dccp_v4_do_rcv;
954
955 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
956 if (err) {
957 icsk->icsk_ext_hdr_len = exthdrlen;
958 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
959 sk->sk_backlog_rcv = dccp_v6_do_rcv;
960 goto failure;
961 }
962 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
963 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &np->rcv_saddr);
964
965 return err;
966 }
967
968 if (!ipv6_addr_any(&np->rcv_saddr))
969 saddr = &np->rcv_saddr;
970
971 fl.proto = IPPROTO_DCCP;
972 ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
973 ipv6_addr_copy(&fl.fl6_src, saddr ? saddr : &np->saddr);
974 fl.oif = sk->sk_bound_dev_if;
975 fl.fl_ip_dport = usin->sin6_port;
976 fl.fl_ip_sport = inet->inet_sport;
977 security_sk_classify_flow(sk, &fl);
978
979 final_p = fl6_update_dst(&fl, np->opt, &final);
980
981 err = ip6_dst_lookup(sk, &dst, &fl);
982 if (err)
983 goto failure;
984
985 if (final_p)
986 ipv6_addr_copy(&fl.fl6_dst, final_p);
987
988 err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
989 if (err < 0) {
990 if (err == -EREMOTE)
991 err = ip6_dst_blackhole(sk, &dst, &fl);
992 if (err < 0)
993 goto failure;
994 }
995
996 if (saddr == NULL) {
997 saddr = &fl.fl6_src;
998 ipv6_addr_copy(&np->rcv_saddr, saddr);
999 }
1000
1001 /* set the source address */
1002 ipv6_addr_copy(&np->saddr, saddr);
1003 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
1004
1005 __ip6_dst_store(sk, dst, NULL, NULL);
1006
1007 icsk->icsk_ext_hdr_len = 0;
1008 if (np->opt != NULL)
1009 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
1010 np->opt->opt_nflen);
1011
1012 inet->inet_dport = usin->sin6_port;
1013
1014 dccp_set_state(sk, DCCP_REQUESTING);
1015 err = inet6_hash_connect(&dccp_death_row, sk);
1016 if (err)
1017 goto late_failure;
1018
1019 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
1020 np->daddr.s6_addr32,
1021 inet->inet_sport,
1022 inet->inet_dport);
1023 err = dccp_connect(sk);
1024 if (err)
1025 goto late_failure;
1026
1027 return 0;
1028
1029 late_failure:
1030 dccp_set_state(sk, DCCP_CLOSED);
1031 __sk_dst_reset(sk);
1032 failure:
1033 inet->inet_dport = 0;
1034 sk->sk_route_caps = 0;
1035 return err;
1036 }
1037
1038 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
1039 .queue_xmit = inet6_csk_xmit,
1040 .send_check = dccp_v6_send_check,
1041 .rebuild_header = inet6_sk_rebuild_header,
1042 .conn_request = dccp_v6_conn_request,
1043 .syn_recv_sock = dccp_v6_request_recv_sock,
1044 .net_header_len = sizeof(struct ipv6hdr),
1045 .setsockopt = ipv6_setsockopt,
1046 .getsockopt = ipv6_getsockopt,
1047 .addr2sockaddr = inet6_csk_addr2sockaddr,
1048 .sockaddr_len = sizeof(struct sockaddr_in6),
1049 .bind_conflict = inet6_csk_bind_conflict,
1050 #ifdef CONFIG_COMPAT
1051 .compat_setsockopt = compat_ipv6_setsockopt,
1052 .compat_getsockopt = compat_ipv6_getsockopt,
1053 #endif
1054 };
1055
1056 /*
1057 * DCCP over IPv4 via INET6 API
1058 */
1059 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1060 .queue_xmit = ip_queue_xmit,
1061 .send_check = dccp_v4_send_check,
1062 .rebuild_header = inet_sk_rebuild_header,
1063 .conn_request = dccp_v6_conn_request,
1064 .syn_recv_sock = dccp_v6_request_recv_sock,
1065 .net_header_len = sizeof(struct iphdr),
1066 .setsockopt = ipv6_setsockopt,
1067 .getsockopt = ipv6_getsockopt,
1068 .addr2sockaddr = inet6_csk_addr2sockaddr,
1069 .sockaddr_len = sizeof(struct sockaddr_in6),
1070 #ifdef CONFIG_COMPAT
1071 .compat_setsockopt = compat_ipv6_setsockopt,
1072 .compat_getsockopt = compat_ipv6_getsockopt,
1073 #endif
1074 };
1075
1076 /* NOTE: A lot of things set to zero explicitly by call to
1077 * sk_alloc() so need not be done here.
1078 */
1079 static int dccp_v6_init_sock(struct sock *sk)
1080 {
1081 static __u8 dccp_v6_ctl_sock_initialized;
1082 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1083
1084 if (err == 0) {
1085 if (unlikely(!dccp_v6_ctl_sock_initialized))
1086 dccp_v6_ctl_sock_initialized = 1;
1087 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1088 }
1089
1090 return err;
1091 }
1092
1093 static void dccp_v6_destroy_sock(struct sock *sk)
1094 {
1095 dccp_destroy_sock(sk);
1096 inet6_destroy_sock(sk);
1097 }
1098
1099 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1100 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1101 };
1102
1103 static struct proto dccp_v6_prot = {
1104 .name = "DCCPv6",
1105 .owner = THIS_MODULE,
1106 .close = dccp_close,
1107 .connect = dccp_v6_connect,
1108 .disconnect = dccp_disconnect,
1109 .ioctl = dccp_ioctl,
1110 .init = dccp_v6_init_sock,
1111 .setsockopt = dccp_setsockopt,
1112 .getsockopt = dccp_getsockopt,
1113 .sendmsg = dccp_sendmsg,
1114 .recvmsg = dccp_recvmsg,
1115 .backlog_rcv = dccp_v6_do_rcv,
1116 .hash = dccp_v6_hash,
1117 .unhash = inet_unhash,
1118 .accept = inet_csk_accept,
1119 .get_port = inet_csk_get_port,
1120 .shutdown = dccp_shutdown,
1121 .destroy = dccp_v6_destroy_sock,
1122 .orphan_count = &dccp_orphan_count,
1123 .max_header = MAX_DCCP_HEADER,
1124 .obj_size = sizeof(struct dccp6_sock),
1125 .slab_flags = SLAB_DESTROY_BY_RCU,
1126 .rsk_prot = &dccp6_request_sock_ops,
1127 .twsk_prot = &dccp6_timewait_sock_ops,
1128 .h.hashinfo = &dccp_hashinfo,
1129 #ifdef CONFIG_COMPAT
1130 .compat_setsockopt = compat_dccp_setsockopt,
1131 .compat_getsockopt = compat_dccp_getsockopt,
1132 #endif
1133 };
1134
1135 static const struct inet6_protocol dccp_v6_protocol = {
1136 .handler = dccp_v6_rcv,
1137 .err_handler = dccp_v6_err,
1138 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1139 };
1140
1141 static const struct proto_ops inet6_dccp_ops = {
1142 .family = PF_INET6,
1143 .owner = THIS_MODULE,
1144 .release = inet6_release,
1145 .bind = inet6_bind,
1146 .connect = inet_stream_connect,
1147 .socketpair = sock_no_socketpair,
1148 .accept = inet_accept,
1149 .getname = inet6_getname,
1150 .poll = dccp_poll,
1151 .ioctl = inet6_ioctl,
1152 .listen = inet_dccp_listen,
1153 .shutdown = inet_shutdown,
1154 .setsockopt = sock_common_setsockopt,
1155 .getsockopt = sock_common_getsockopt,
1156 .sendmsg = inet_sendmsg,
1157 .recvmsg = sock_common_recvmsg,
1158 .mmap = sock_no_mmap,
1159 .sendpage = sock_no_sendpage,
1160 #ifdef CONFIG_COMPAT
1161 .compat_setsockopt = compat_sock_common_setsockopt,
1162 .compat_getsockopt = compat_sock_common_getsockopt,
1163 #endif
1164 };
1165
1166 static struct inet_protosw dccp_v6_protosw = {
1167 .type = SOCK_DCCP,
1168 .protocol = IPPROTO_DCCP,
1169 .prot = &dccp_v6_prot,
1170 .ops = &inet6_dccp_ops,
1171 .flags = INET_PROTOSW_ICSK,
1172 };
1173
1174 static int __net_init dccp_v6_init_net(struct net *net)
1175 {
1176 if (dccp_hashinfo.bhash == NULL)
1177 return -ESOCKTNOSUPPORT;
1178
1179 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1180 SOCK_DCCP, IPPROTO_DCCP, net);
1181 }
1182
1183 static void __net_exit dccp_v6_exit_net(struct net *net)
1184 {
1185 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1186 }
1187
1188 static struct pernet_operations dccp_v6_ops = {
1189 .init = dccp_v6_init_net,
1190 .exit = dccp_v6_exit_net,
1191 };
1192
1193 static int __init dccp_v6_init(void)
1194 {
1195 int err = proto_register(&dccp_v6_prot, 1);
1196
1197 if (err != 0)
1198 goto out;
1199
1200 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1201 if (err != 0)
1202 goto out_unregister_proto;
1203
1204 inet6_register_protosw(&dccp_v6_protosw);
1205
1206 err = register_pernet_subsys(&dccp_v6_ops);
1207 if (err != 0)
1208 goto out_destroy_ctl_sock;
1209 out:
1210 return err;
1211
1212 out_destroy_ctl_sock:
1213 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1214 inet6_unregister_protosw(&dccp_v6_protosw);
1215 out_unregister_proto:
1216 proto_unregister(&dccp_v6_prot);
1217 goto out;
1218 }
1219
1220 static void __exit dccp_v6_exit(void)
1221 {
1222 unregister_pernet_subsys(&dccp_v6_ops);
1223 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1224 inet6_unregister_protosw(&dccp_v6_protosw);
1225 proto_unregister(&dccp_v6_prot);
1226 }
1227
1228 module_init(dccp_v6_init);
1229 module_exit(dccp_v6_exit);
1230
1231 /*
1232 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1233 * values directly, Also cover the case where the protocol is not specified,
1234 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1235 */
1236 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1237 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1238 MODULE_LICENSE("GPL");
1239 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1240 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
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