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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
40static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
41static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
42
43static 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 */
57static 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
64static 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, &sk->sk_v6_daddr);
71}
72
73static 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
82static 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 goto out;
139 }
140
141 if (type == ICMPV6_PKT_TOOBIG) {
142 struct dst_entry *dst = NULL;
143
144 if (!ip6_sk_accept_pmtu(sk))
145 goto out;
146
147 if (sock_owned_by_user(sk))
148 goto out;
149 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
150 goto out;
151
152 dst = inet6_csk_update_pmtu(sk, ntohl(info));
153 if (!dst)
154 goto out;
155
156 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
157 dccp_sync_mss(sk, dst_mtu(dst));
158 goto out;
159 }
160
161 icmpv6_err_convert(type, code, &err);
162
163 /* Might be for an request_sock */
164 switch (sk->sk_state) {
165 struct request_sock *req, **prev;
166 case DCCP_LISTEN:
167 if (sock_owned_by_user(sk))
168 goto out;
169
170 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
171 &hdr->daddr, &hdr->saddr,
172 inet6_iif(skb));
173 if (req == NULL)
174 goto out;
175
176 /*
177 * ICMPs are not backlogged, hence we cannot get an established
178 * socket here.
179 */
180 WARN_ON(req->sk != NULL);
181
182 if (!between48(seq, dccp_rsk(req)->dreq_iss,
183 dccp_rsk(req)->dreq_gss)) {
184 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
185 goto out;
186 }
187
188 inet_csk_reqsk_queue_drop(sk, req, prev);
189 goto out;
190
191 case DCCP_REQUESTING:
192 case DCCP_RESPOND: /* Cannot happen.
193 It can, it SYNs are crossed. --ANK */
194 if (!sock_owned_by_user(sk)) {
195 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
196 sk->sk_err = err;
197 /*
198 * Wake people up to see the error
199 * (see connect in sock.c)
200 */
201 sk->sk_error_report(sk);
202 dccp_done(sk);
203 } else
204 sk->sk_err_soft = err;
205 goto out;
206 }
207
208 if (!sock_owned_by_user(sk) && np->recverr) {
209 sk->sk_err = err;
210 sk->sk_error_report(sk);
211 } else
212 sk->sk_err_soft = err;
213
214out:
215 bh_unlock_sock(sk);
216 sock_put(sk);
217}
218
219
220static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
221{
222 struct inet_request_sock *ireq = inet_rsk(req);
223 struct ipv6_pinfo *np = inet6_sk(sk);
224 struct sk_buff *skb;
225 struct in6_addr *final_p, final;
226 struct flowi6 fl6;
227 int err = -1;
228 struct dst_entry *dst;
229
230 memset(&fl6, 0, sizeof(fl6));
231 fl6.flowi6_proto = IPPROTO_DCCP;
232 fl6.daddr = ireq->ir_v6_rmt_addr;
233 fl6.saddr = ireq->ir_v6_loc_addr;
234 fl6.flowlabel = 0;
235 fl6.flowi6_oif = ireq->ir_iif;
236 fl6.fl6_dport = ireq->ir_rmt_port;
237 fl6.fl6_sport = htons(ireq->ir_num);
238 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
239
240
241 final_p = fl6_update_dst(&fl6, np->opt, &final);
242
243 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
244 if (IS_ERR(dst)) {
245 err = PTR_ERR(dst);
246 dst = NULL;
247 goto done;
248 }
249
250 skb = dccp_make_response(sk, dst, req);
251 if (skb != NULL) {
252 struct dccp_hdr *dh = dccp_hdr(skb);
253
254 dh->dccph_checksum = dccp_v6_csum_finish(skb,
255 &ireq->ir_v6_loc_addr,
256 &ireq->ir_v6_rmt_addr);
257 fl6.daddr = ireq->ir_v6_rmt_addr;
258 err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
259 err = net_xmit_eval(err);
260 }
261
262done:
263 dst_release(dst);
264 return err;
265}
266
267static void dccp_v6_reqsk_destructor(struct request_sock *req)
268{
269 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
270 kfree_skb(inet_rsk(req)->pktopts);
271}
272
273static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
274{
275 const struct ipv6hdr *rxip6h;
276 struct sk_buff *skb;
277 struct flowi6 fl6;
278 struct net *net = dev_net(skb_dst(rxskb)->dev);
279 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
280 struct dst_entry *dst;
281
282 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
283 return;
284
285 if (!ipv6_unicast_destination(rxskb))
286 return;
287
288 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
289 if (skb == NULL)
290 return;
291
292 rxip6h = ipv6_hdr(rxskb);
293 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
294 &rxip6h->daddr);
295
296 memset(&fl6, 0, sizeof(fl6));
297 fl6.daddr = rxip6h->saddr;
298 fl6.saddr = rxip6h->daddr;
299
300 fl6.flowi6_proto = IPPROTO_DCCP;
301 fl6.flowi6_oif = inet6_iif(rxskb);
302 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
303 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
304 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
305
306 /* sk = NULL, but it is safe for now. RST socket required. */
307 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
308 if (!IS_ERR(dst)) {
309 skb_dst_set(skb, dst);
310 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0);
311 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
312 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
313 return;
314 }
315
316 kfree_skb(skb);
317}
318
319static struct request_sock_ops dccp6_request_sock_ops = {
320 .family = AF_INET6,
321 .obj_size = sizeof(struct dccp6_request_sock),
322 .rtx_syn_ack = dccp_v6_send_response,
323 .send_ack = dccp_reqsk_send_ack,
324 .destructor = dccp_v6_reqsk_destructor,
325 .send_reset = dccp_v6_ctl_send_reset,
326 .syn_ack_timeout = dccp_syn_ack_timeout,
327};
328
329static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
330{
331 const struct dccp_hdr *dh = dccp_hdr(skb);
332 const struct ipv6hdr *iph = ipv6_hdr(skb);
333 struct sock *nsk;
334 struct request_sock **prev;
335 /* Find possible connection requests. */
336 struct request_sock *req = inet6_csk_search_req(sk, &prev,
337 dh->dccph_sport,
338 &iph->saddr,
339 &iph->daddr,
340 inet6_iif(skb));
341 if (req != NULL)
342 return dccp_check_req(sk, skb, req, prev);
343
344 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
345 &iph->saddr, dh->dccph_sport,
346 &iph->daddr, ntohs(dh->dccph_dport),
347 inet6_iif(skb));
348 if (nsk != NULL) {
349 if (nsk->sk_state != DCCP_TIME_WAIT) {
350 bh_lock_sock(nsk);
351 return nsk;
352 }
353 inet_twsk_put(inet_twsk(nsk));
354 return NULL;
355 }
356
357 return sk;
358}
359
360static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
361{
362 struct request_sock *req;
363 struct dccp_request_sock *dreq;
364 struct inet_request_sock *ireq;
365 struct ipv6_pinfo *np = inet6_sk(sk);
366 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
367 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
368
369 if (skb->protocol == htons(ETH_P_IP))
370 return dccp_v4_conn_request(sk, skb);
371
372 if (!ipv6_unicast_destination(skb))
373 return 0; /* discard, don't send a reset here */
374
375 if (dccp_bad_service_code(sk, service)) {
376 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
377 goto drop;
378 }
379 /*
380 * There are no SYN attacks on IPv6, yet...
381 */
382 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
383 if (inet_csk_reqsk_queue_is_full(sk))
384 goto drop;
385
386 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
387 goto drop;
388
389 req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
390 if (req == NULL)
391 goto drop;
392
393 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
394 goto drop_and_free;
395
396 dreq = dccp_rsk(req);
397 if (dccp_parse_options(sk, dreq, skb))
398 goto drop_and_free;
399
400 if (security_inet_conn_request(sk, skb, req))
401 goto drop_and_free;
402
403 ireq = inet_rsk(req);
404 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
405 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
406
407 if (ipv6_opt_accepted(sk, skb) ||
408 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
409 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
410 atomic_inc(&skb->users);
411 ireq->pktopts = skb;
412 }
413 ireq->ir_iif = sk->sk_bound_dev_if;
414
415 /* So that link locals have meaning */
416 if (!sk->sk_bound_dev_if &&
417 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
418 ireq->ir_iif = inet6_iif(skb);
419
420 /*
421 * Step 3: Process LISTEN state
422 *
423 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
424 *
425 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
426 */
427 dreq->dreq_isr = dcb->dccpd_seq;
428 dreq->dreq_gsr = dreq->dreq_isr;
429 dreq->dreq_iss = dccp_v6_init_sequence(skb);
430 dreq->dreq_gss = dreq->dreq_iss;
431 dreq->dreq_service = service;
432
433 if (dccp_v6_send_response(sk, req))
434 goto drop_and_free;
435
436 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
437 return 0;
438
439drop_and_free:
440 reqsk_free(req);
441drop:
442 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
443 return -1;
444}
445
446static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
447 struct sk_buff *skb,
448 struct request_sock *req,
449 struct dst_entry *dst)
450{
451 struct inet_request_sock *ireq = inet_rsk(req);
452 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
453 struct inet_sock *newinet;
454 struct dccp6_sock *newdp6;
455 struct sock *newsk;
456
457 if (skb->protocol == htons(ETH_P_IP)) {
458 /*
459 * v6 mapped
460 */
461 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
462 if (newsk == NULL)
463 return NULL;
464
465 newdp6 = (struct dccp6_sock *)newsk;
466 newinet = inet_sk(newsk);
467 newinet->pinet6 = &newdp6->inet6;
468 newnp = inet6_sk(newsk);
469
470 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
471
472 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
473
474 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
475
476 newsk->sk_v6_rcv_saddr = newnp->saddr;
477
478 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
479 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
480 newnp->pktoptions = NULL;
481 newnp->opt = NULL;
482 newnp->mcast_oif = inet6_iif(skb);
483 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
484
485 /*
486 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
487 * here, dccp_create_openreq_child now does this for us, see the comment in
488 * that function for the gory details. -acme
489 */
490
491 /* It is tricky place. Until this moment IPv4 tcp
492 worked with IPv6 icsk.icsk_af_ops.
493 Sync it now.
494 */
495 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
496
497 return newsk;
498 }
499
500
501 if (sk_acceptq_is_full(sk))
502 goto out_overflow;
503
504 if (dst == NULL) {
505 struct in6_addr *final_p, final;
506 struct flowi6 fl6;
507
508 memset(&fl6, 0, sizeof(fl6));
509 fl6.flowi6_proto = IPPROTO_DCCP;
510 fl6.daddr = ireq->ir_v6_rmt_addr;
511 final_p = fl6_update_dst(&fl6, np->opt, &final);
512 fl6.saddr = ireq->ir_v6_loc_addr;
513 fl6.flowi6_oif = sk->sk_bound_dev_if;
514 fl6.fl6_dport = ireq->ir_rmt_port;
515 fl6.fl6_sport = htons(ireq->ir_num);
516 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
517
518 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
519 if (IS_ERR(dst))
520 goto out;
521 }
522
523 newsk = dccp_create_openreq_child(sk, req, skb);
524 if (newsk == NULL)
525 goto out_nonewsk;
526
527 /*
528 * No need to charge this sock to the relevant IPv6 refcnt debug socks
529 * count here, dccp_create_openreq_child now does this for us, see the
530 * comment in that function for the gory details. -acme
531 */
532
533 __ip6_dst_store(newsk, dst, NULL, NULL);
534 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
535 NETIF_F_TSO);
536 newdp6 = (struct dccp6_sock *)newsk;
537 newinet = inet_sk(newsk);
538 newinet->pinet6 = &newdp6->inet6;
539 newnp = inet6_sk(newsk);
540
541 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
542
543 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
544 newnp->saddr = ireq->ir_v6_loc_addr;
545 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
546 newsk->sk_bound_dev_if = ireq->ir_iif;
547
548 /* Now IPv6 options...
549
550 First: no IPv4 options.
551 */
552 newinet->inet_opt = NULL;
553
554 /* Clone RX bits */
555 newnp->rxopt.all = np->rxopt.all;
556
557 /* Clone pktoptions received with SYN */
558 newnp->pktoptions = NULL;
559 if (ireq->pktopts != NULL) {
560 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
561 consume_skb(ireq->pktopts);
562 ireq->pktopts = NULL;
563 if (newnp->pktoptions)
564 skb_set_owner_r(newnp->pktoptions, newsk);
565 }
566 newnp->opt = NULL;
567 newnp->mcast_oif = inet6_iif(skb);
568 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
569
570 /*
571 * Clone native IPv6 options from listening socket (if any)
572 *
573 * Yes, keeping reference count would be much more clever, but we make
574 * one more one thing there: reattach optmem to newsk.
575 */
576 if (np->opt != NULL)
577 newnp->opt = ipv6_dup_options(newsk, np->opt);
578
579 inet_csk(newsk)->icsk_ext_hdr_len = 0;
580 if (newnp->opt != NULL)
581 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
582 newnp->opt->opt_flen);
583
584 dccp_sync_mss(newsk, dst_mtu(dst));
585
586 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
587 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
588
589 if (__inet_inherit_port(sk, newsk) < 0) {
590 inet_csk_prepare_forced_close(newsk);
591 dccp_done(newsk);
592 goto out;
593 }
594 __inet6_hash(newsk, NULL);
595
596 return newsk;
597
598out_overflow:
599 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
600out_nonewsk:
601 dst_release(dst);
602out:
603 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
604 return NULL;
605}
606
607/* The socket must have it's spinlock held when we get
608 * here.
609 *
610 * We have a potential double-lock case here, so even when
611 * doing backlog processing we use the BH locking scheme.
612 * This is because we cannot sleep with the original spinlock
613 * held.
614 */
615static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
616{
617 struct ipv6_pinfo *np = inet6_sk(sk);
618 struct sk_buff *opt_skb = NULL;
619
620 /* Imagine: socket is IPv6. IPv4 packet arrives,
621 goes to IPv4 receive handler and backlogged.
622 From backlog it always goes here. Kerboom...
623 Fortunately, dccp_rcv_established and rcv_established
624 handle them correctly, but it is not case with
625 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
626 */
627
628 if (skb->protocol == htons(ETH_P_IP))
629 return dccp_v4_do_rcv(sk, skb);
630
631 if (sk_filter(sk, skb))
632 goto discard;
633
634 /*
635 * socket locking is here for SMP purposes as backlog rcv is currently
636 * called with bh processing disabled.
637 */
638
639 /* Do Stevens' IPV6_PKTOPTIONS.
640
641 Yes, guys, it is the only place in our code, where we
642 may make it not affecting IPv4.
643 The rest of code is protocol independent,
644 and I do not like idea to uglify IPv4.
645
646 Actually, all the idea behind IPV6_PKTOPTIONS
647 looks not very well thought. For now we latch
648 options, received in the last packet, enqueued
649 by tcp. Feel free to propose better solution.
650 --ANK (980728)
651 */
652 if (np->rxopt.all)
653 /*
654 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
655 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
656 */
657 opt_skb = skb_clone(skb, GFP_ATOMIC);
658
659 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
660 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
661 goto reset;
662 if (opt_skb) {
663 /* XXX This is where we would goto ipv6_pktoptions. */
664 __kfree_skb(opt_skb);
665 }
666 return 0;
667 }
668
669 /*
670 * Step 3: Process LISTEN state
671 * If S.state == LISTEN,
672 * If P.type == Request or P contains a valid Init Cookie option,
673 * (* Must scan the packet's options to check for Init
674 * Cookies. Only Init Cookies are processed here,
675 * however; other options are processed in Step 8. This
676 * scan need only be performed if the endpoint uses Init
677 * Cookies *)
678 * (* Generate a new socket and switch to that socket *)
679 * Set S := new socket for this port pair
680 * S.state = RESPOND
681 * Choose S.ISS (initial seqno) or set from Init Cookies
682 * Initialize S.GAR := S.ISS
683 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
684 * Continue with S.state == RESPOND
685 * (* A Response packet will be generated in Step 11 *)
686 * Otherwise,
687 * Generate Reset(No Connection) unless P.type == Reset
688 * Drop packet and return
689 *
690 * NOTE: the check for the packet types is done in
691 * dccp_rcv_state_process
692 */
693 if (sk->sk_state == DCCP_LISTEN) {
694 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
695
696 if (nsk == NULL)
697 goto discard;
698 /*
699 * Queue it on the new socket if the new socket is active,
700 * otherwise we just shortcircuit this and continue with
701 * the new socket..
702 */
703 if (nsk != sk) {
704 if (dccp_child_process(sk, nsk, skb))
705 goto reset;
706 if (opt_skb != NULL)
707 __kfree_skb(opt_skb);
708 return 0;
709 }
710 }
711
712 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
713 goto reset;
714 if (opt_skb) {
715 /* XXX This is where we would goto ipv6_pktoptions. */
716 __kfree_skb(opt_skb);
717 }
718 return 0;
719
720reset:
721 dccp_v6_ctl_send_reset(sk, skb);
722discard:
723 if (opt_skb != NULL)
724 __kfree_skb(opt_skb);
725 kfree_skb(skb);
726 return 0;
727}
728
729static int dccp_v6_rcv(struct sk_buff *skb)
730{
731 const struct dccp_hdr *dh;
732 struct sock *sk;
733 int min_cov;
734
735 /* Step 1: Check header basics */
736
737 if (dccp_invalid_packet(skb))
738 goto discard_it;
739
740 /* Step 1: If header checksum is incorrect, drop packet and return. */
741 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
742 &ipv6_hdr(skb)->daddr)) {
743 DCCP_WARN("dropped packet with invalid checksum\n");
744 goto discard_it;
745 }
746
747 dh = dccp_hdr(skb);
748
749 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
750 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
751
752 if (dccp_packet_without_ack(skb))
753 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
754 else
755 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
756
757 /* Step 2:
758 * Look up flow ID in table and get corresponding socket */
759 sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
760 dh->dccph_sport, dh->dccph_dport);
761 /*
762 * Step 2:
763 * If no socket ...
764 */
765 if (sk == NULL) {
766 dccp_pr_debug("failed to look up flow ID in table and "
767 "get corresponding socket\n");
768 goto no_dccp_socket;
769 }
770
771 /*
772 * Step 2:
773 * ... or S.state == TIMEWAIT,
774 * Generate Reset(No Connection) unless P.type == Reset
775 * Drop packet and return
776 */
777 if (sk->sk_state == DCCP_TIME_WAIT) {
778 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
779 inet_twsk_put(inet_twsk(sk));
780 goto no_dccp_socket;
781 }
782
783 /*
784 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
785 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
786 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
787 */
788 min_cov = dccp_sk(sk)->dccps_pcrlen;
789 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
790 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
791 dh->dccph_cscov, min_cov);
792 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
793 goto discard_and_relse;
794 }
795
796 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
797 goto discard_and_relse;
798
799 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
800
801no_dccp_socket:
802 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
803 goto discard_it;
804 /*
805 * Step 2:
806 * If no socket ...
807 * Generate Reset(No Connection) unless P.type == Reset
808 * Drop packet and return
809 */
810 if (dh->dccph_type != DCCP_PKT_RESET) {
811 DCCP_SKB_CB(skb)->dccpd_reset_code =
812 DCCP_RESET_CODE_NO_CONNECTION;
813 dccp_v6_ctl_send_reset(sk, skb);
814 }
815
816discard_it:
817 kfree_skb(skb);
818 return 0;
819
820discard_and_relse:
821 sock_put(sk);
822 goto discard_it;
823}
824
825static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
826 int addr_len)
827{
828 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
829 struct inet_connection_sock *icsk = inet_csk(sk);
830 struct inet_sock *inet = inet_sk(sk);
831 struct ipv6_pinfo *np = inet6_sk(sk);
832 struct dccp_sock *dp = dccp_sk(sk);
833 struct in6_addr *saddr = NULL, *final_p, final;
834 struct flowi6 fl6;
835 struct dst_entry *dst;
836 int addr_type;
837 int err;
838
839 dp->dccps_role = DCCP_ROLE_CLIENT;
840
841 if (addr_len < SIN6_LEN_RFC2133)
842 return -EINVAL;
843
844 if (usin->sin6_family != AF_INET6)
845 return -EAFNOSUPPORT;
846
847 memset(&fl6, 0, sizeof(fl6));
848
849 if (np->sndflow) {
850 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
851 IP6_ECN_flow_init(fl6.flowlabel);
852 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
853 struct ip6_flowlabel *flowlabel;
854 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
855 if (flowlabel == NULL)
856 return -EINVAL;
857 fl6_sock_release(flowlabel);
858 }
859 }
860 /*
861 * connect() to INADDR_ANY means loopback (BSD'ism).
862 */
863 if (ipv6_addr_any(&usin->sin6_addr))
864 usin->sin6_addr.s6_addr[15] = 1;
865
866 addr_type = ipv6_addr_type(&usin->sin6_addr);
867
868 if (addr_type & IPV6_ADDR_MULTICAST)
869 return -ENETUNREACH;
870
871 if (addr_type & IPV6_ADDR_LINKLOCAL) {
872 if (addr_len >= sizeof(struct sockaddr_in6) &&
873 usin->sin6_scope_id) {
874 /* If interface is set while binding, indices
875 * must coincide.
876 */
877 if (sk->sk_bound_dev_if &&
878 sk->sk_bound_dev_if != usin->sin6_scope_id)
879 return -EINVAL;
880
881 sk->sk_bound_dev_if = usin->sin6_scope_id;
882 }
883
884 /* Connect to link-local address requires an interface */
885 if (!sk->sk_bound_dev_if)
886 return -EINVAL;
887 }
888
889 sk->sk_v6_daddr = usin->sin6_addr;
890 np->flow_label = fl6.flowlabel;
891
892 /*
893 * DCCP over IPv4
894 */
895 if (addr_type == IPV6_ADDR_MAPPED) {
896 u32 exthdrlen = icsk->icsk_ext_hdr_len;
897 struct sockaddr_in sin;
898
899 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
900
901 if (__ipv6_only_sock(sk))
902 return -ENETUNREACH;
903
904 sin.sin_family = AF_INET;
905 sin.sin_port = usin->sin6_port;
906 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
907
908 icsk->icsk_af_ops = &dccp_ipv6_mapped;
909 sk->sk_backlog_rcv = dccp_v4_do_rcv;
910
911 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
912 if (err) {
913 icsk->icsk_ext_hdr_len = exthdrlen;
914 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
915 sk->sk_backlog_rcv = dccp_v6_do_rcv;
916 goto failure;
917 }
918 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
919 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &sk->sk_v6_rcv_saddr);
920
921 return err;
922 }
923
924 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
925 saddr = &sk->sk_v6_rcv_saddr;
926
927 fl6.flowi6_proto = IPPROTO_DCCP;
928 fl6.daddr = sk->sk_v6_daddr;
929 fl6.saddr = saddr ? *saddr : np->saddr;
930 fl6.flowi6_oif = sk->sk_bound_dev_if;
931 fl6.fl6_dport = usin->sin6_port;
932 fl6.fl6_sport = inet->inet_sport;
933 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
934
935 final_p = fl6_update_dst(&fl6, np->opt, &final);
936
937 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
938 if (IS_ERR(dst)) {
939 err = PTR_ERR(dst);
940 goto failure;
941 }
942
943 if (saddr == NULL) {
944 saddr = &fl6.saddr;
945 sk->sk_v6_rcv_saddr = *saddr;
946 }
947
948 /* set the source address */
949 np->saddr = *saddr;
950 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
951
952 __ip6_dst_store(sk, dst, NULL, NULL);
953
954 icsk->icsk_ext_hdr_len = 0;
955 if (np->opt != NULL)
956 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
957 np->opt->opt_nflen);
958
959 inet->inet_dport = usin->sin6_port;
960
961 dccp_set_state(sk, DCCP_REQUESTING);
962 err = inet6_hash_connect(&dccp_death_row, sk);
963 if (err)
964 goto late_failure;
965
966 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
967 sk->sk_v6_daddr.s6_addr32,
968 inet->inet_sport,
969 inet->inet_dport);
970 err = dccp_connect(sk);
971 if (err)
972 goto late_failure;
973
974 return 0;
975
976late_failure:
977 dccp_set_state(sk, DCCP_CLOSED);
978 __sk_dst_reset(sk);
979failure:
980 inet->inet_dport = 0;
981 sk->sk_route_caps = 0;
982 return err;
983}
984
985static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
986 .queue_xmit = inet6_csk_xmit,
987 .send_check = dccp_v6_send_check,
988 .rebuild_header = inet6_sk_rebuild_header,
989 .conn_request = dccp_v6_conn_request,
990 .syn_recv_sock = dccp_v6_request_recv_sock,
991 .net_header_len = sizeof(struct ipv6hdr),
992 .setsockopt = ipv6_setsockopt,
993 .getsockopt = ipv6_getsockopt,
994 .addr2sockaddr = inet6_csk_addr2sockaddr,
995 .sockaddr_len = sizeof(struct sockaddr_in6),
996 .bind_conflict = inet6_csk_bind_conflict,
997#ifdef CONFIG_COMPAT
998 .compat_setsockopt = compat_ipv6_setsockopt,
999 .compat_getsockopt = compat_ipv6_getsockopt,
1000#endif
1001};
1002
1003/*
1004 * DCCP over IPv4 via INET6 API
1005 */
1006static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1007 .queue_xmit = ip_queue_xmit,
1008 .send_check = dccp_v4_send_check,
1009 .rebuild_header = inet_sk_rebuild_header,
1010 .conn_request = dccp_v6_conn_request,
1011 .syn_recv_sock = dccp_v6_request_recv_sock,
1012 .net_header_len = sizeof(struct iphdr),
1013 .setsockopt = ipv6_setsockopt,
1014 .getsockopt = ipv6_getsockopt,
1015 .addr2sockaddr = inet6_csk_addr2sockaddr,
1016 .sockaddr_len = sizeof(struct sockaddr_in6),
1017#ifdef CONFIG_COMPAT
1018 .compat_setsockopt = compat_ipv6_setsockopt,
1019 .compat_getsockopt = compat_ipv6_getsockopt,
1020#endif
1021};
1022
1023/* NOTE: A lot of things set to zero explicitly by call to
1024 * sk_alloc() so need not be done here.
1025 */
1026static int dccp_v6_init_sock(struct sock *sk)
1027{
1028 static __u8 dccp_v6_ctl_sock_initialized;
1029 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1030
1031 if (err == 0) {
1032 if (unlikely(!dccp_v6_ctl_sock_initialized))
1033 dccp_v6_ctl_sock_initialized = 1;
1034 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1035 }
1036
1037 return err;
1038}
1039
1040static void dccp_v6_destroy_sock(struct sock *sk)
1041{
1042 dccp_destroy_sock(sk);
1043 inet6_destroy_sock(sk);
1044}
1045
1046static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1047 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1048};
1049
1050static struct proto dccp_v6_prot = {
1051 .name = "DCCPv6",
1052 .owner = THIS_MODULE,
1053 .close = dccp_close,
1054 .connect = dccp_v6_connect,
1055 .disconnect = dccp_disconnect,
1056 .ioctl = dccp_ioctl,
1057 .init = dccp_v6_init_sock,
1058 .setsockopt = dccp_setsockopt,
1059 .getsockopt = dccp_getsockopt,
1060 .sendmsg = dccp_sendmsg,
1061 .recvmsg = dccp_recvmsg,
1062 .backlog_rcv = dccp_v6_do_rcv,
1063 .hash = dccp_v6_hash,
1064 .unhash = inet_unhash,
1065 .accept = inet_csk_accept,
1066 .get_port = inet_csk_get_port,
1067 .shutdown = dccp_shutdown,
1068 .destroy = dccp_v6_destroy_sock,
1069 .orphan_count = &dccp_orphan_count,
1070 .max_header = MAX_DCCP_HEADER,
1071 .obj_size = sizeof(struct dccp6_sock),
1072 .slab_flags = SLAB_DESTROY_BY_RCU,
1073 .rsk_prot = &dccp6_request_sock_ops,
1074 .twsk_prot = &dccp6_timewait_sock_ops,
1075 .h.hashinfo = &dccp_hashinfo,
1076#ifdef CONFIG_COMPAT
1077 .compat_setsockopt = compat_dccp_setsockopt,
1078 .compat_getsockopt = compat_dccp_getsockopt,
1079#endif
1080};
1081
1082static const struct inet6_protocol dccp_v6_protocol = {
1083 .handler = dccp_v6_rcv,
1084 .err_handler = dccp_v6_err,
1085 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1086};
1087
1088static const struct proto_ops inet6_dccp_ops = {
1089 .family = PF_INET6,
1090 .owner = THIS_MODULE,
1091 .release = inet6_release,
1092 .bind = inet6_bind,
1093 .connect = inet_stream_connect,
1094 .socketpair = sock_no_socketpair,
1095 .accept = inet_accept,
1096 .getname = inet6_getname,
1097 .poll = dccp_poll,
1098 .ioctl = inet6_ioctl,
1099 .listen = inet_dccp_listen,
1100 .shutdown = inet_shutdown,
1101 .setsockopt = sock_common_setsockopt,
1102 .getsockopt = sock_common_getsockopt,
1103 .sendmsg = inet_sendmsg,
1104 .recvmsg = sock_common_recvmsg,
1105 .mmap = sock_no_mmap,
1106 .sendpage = sock_no_sendpage,
1107#ifdef CONFIG_COMPAT
1108 .compat_setsockopt = compat_sock_common_setsockopt,
1109 .compat_getsockopt = compat_sock_common_getsockopt,
1110#endif
1111};
1112
1113static struct inet_protosw dccp_v6_protosw = {
1114 .type = SOCK_DCCP,
1115 .protocol = IPPROTO_DCCP,
1116 .prot = &dccp_v6_prot,
1117 .ops = &inet6_dccp_ops,
1118 .flags = INET_PROTOSW_ICSK,
1119};
1120
1121static int __net_init dccp_v6_init_net(struct net *net)
1122{
1123 if (dccp_hashinfo.bhash == NULL)
1124 return -ESOCKTNOSUPPORT;
1125
1126 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1127 SOCK_DCCP, IPPROTO_DCCP, net);
1128}
1129
1130static void __net_exit dccp_v6_exit_net(struct net *net)
1131{
1132 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1133}
1134
1135static struct pernet_operations dccp_v6_ops = {
1136 .init = dccp_v6_init_net,
1137 .exit = dccp_v6_exit_net,
1138};
1139
1140static int __init dccp_v6_init(void)
1141{
1142 int err = proto_register(&dccp_v6_prot, 1);
1143
1144 if (err != 0)
1145 goto out;
1146
1147 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1148 if (err != 0)
1149 goto out_unregister_proto;
1150
1151 inet6_register_protosw(&dccp_v6_protosw);
1152
1153 err = register_pernet_subsys(&dccp_v6_ops);
1154 if (err != 0)
1155 goto out_destroy_ctl_sock;
1156out:
1157 return err;
1158
1159out_destroy_ctl_sock:
1160 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1161 inet6_unregister_protosw(&dccp_v6_protosw);
1162out_unregister_proto:
1163 proto_unregister(&dccp_v6_prot);
1164 goto out;
1165}
1166
1167static void __exit dccp_v6_exit(void)
1168{
1169 unregister_pernet_subsys(&dccp_v6_ops);
1170 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1171 inet6_unregister_protosw(&dccp_v6_protosw);
1172 proto_unregister(&dccp_v6_prot);
1173}
1174
1175module_init(dccp_v6_init);
1176module_exit(dccp_v6_exit);
1177
1178/*
1179 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1180 * values directly, Also cover the case where the protocol is not specified,
1181 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1182 */
1183MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1184MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1185MODULE_LICENSE("GPL");
1186MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1187MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * DCCP over IPv6
4 * Linux INET6 implementation
5 *
6 * Based on net/dccp6/ipv6.c
7 *
8 * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
9 */
10
11#include <linux/module.h>
12#include <linux/random.h>
13#include <linux/slab.h>
14#include <linux/xfrm.h>
15#include <linux/string.h>
16
17#include <net/addrconf.h>
18#include <net/inet_common.h>
19#include <net/inet_hashtables.h>
20#include <net/inet_sock.h>
21#include <net/inet6_connection_sock.h>
22#include <net/inet6_hashtables.h>
23#include <net/ip6_route.h>
24#include <net/ipv6.h>
25#include <net/protocol.h>
26#include <net/transp_v6.h>
27#include <net/ip6_checksum.h>
28#include <net/xfrm.h>
29#include <net/secure_seq.h>
30#include <net/sock.h>
31
32#include "dccp.h"
33#include "ipv6.h"
34#include "feat.h"
35
36/* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */
37
38static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
39static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
40
41/* add pseudo-header to DCCP checksum stored in skb->csum */
42static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
43 const struct in6_addr *saddr,
44 const struct in6_addr *daddr)
45{
46 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
47}
48
49static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
50{
51 struct ipv6_pinfo *np = inet6_sk(sk);
52 struct dccp_hdr *dh = dccp_hdr(skb);
53
54 dccp_csum_outgoing(skb);
55 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
56}
57
58static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
59{
60 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
61 ipv6_hdr(skb)->saddr.s6_addr32,
62 dccp_hdr(skb)->dccph_dport,
63 dccp_hdr(skb)->dccph_sport );
64
65}
66
67static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
68 u8 type, u8 code, int offset, __be32 info)
69{
70 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
71 const struct dccp_hdr *dh;
72 struct dccp_sock *dp;
73 struct ipv6_pinfo *np;
74 struct sock *sk;
75 int err;
76 __u64 seq;
77 struct net *net = dev_net(skb->dev);
78
79 /* Only need dccph_dport & dccph_sport which are the first
80 * 4 bytes in dccp header.
81 * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
82 */
83 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
84 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
85 dh = (struct dccp_hdr *)(skb->data + offset);
86
87 sk = __inet6_lookup_established(net, &dccp_hashinfo,
88 &hdr->daddr, dh->dccph_dport,
89 &hdr->saddr, ntohs(dh->dccph_sport),
90 inet6_iif(skb), 0);
91
92 if (!sk) {
93 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
94 ICMP6_MIB_INERRORS);
95 return -ENOENT;
96 }
97
98 if (sk->sk_state == DCCP_TIME_WAIT) {
99 inet_twsk_put(inet_twsk(sk));
100 return 0;
101 }
102 seq = dccp_hdr_seq(dh);
103 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
104 dccp_req_err(sk, seq);
105 return 0;
106 }
107
108 bh_lock_sock(sk);
109 if (sock_owned_by_user(sk))
110 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
111
112 if (sk->sk_state == DCCP_CLOSED)
113 goto out;
114
115 dp = dccp_sk(sk);
116 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
117 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
118 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
119 goto out;
120 }
121
122 np = inet6_sk(sk);
123
124 if (type == NDISC_REDIRECT) {
125 if (!sock_owned_by_user(sk)) {
126 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
127
128 if (dst)
129 dst->ops->redirect(dst, sk, skb);
130 }
131 goto out;
132 }
133
134 if (type == ICMPV6_PKT_TOOBIG) {
135 struct dst_entry *dst = NULL;
136
137 if (!ip6_sk_accept_pmtu(sk))
138 goto out;
139
140 if (sock_owned_by_user(sk))
141 goto out;
142 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
143 goto out;
144
145 dst = inet6_csk_update_pmtu(sk, ntohl(info));
146 if (!dst)
147 goto out;
148
149 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
150 dccp_sync_mss(sk, dst_mtu(dst));
151 goto out;
152 }
153
154 icmpv6_err_convert(type, code, &err);
155
156 /* Might be for an request_sock */
157 switch (sk->sk_state) {
158 case DCCP_REQUESTING:
159 case DCCP_RESPOND: /* Cannot happen.
160 It can, it SYNs are crossed. --ANK */
161 if (!sock_owned_by_user(sk)) {
162 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
163 sk->sk_err = err;
164 /*
165 * Wake people up to see the error
166 * (see connect in sock.c)
167 */
168 sk->sk_error_report(sk);
169 dccp_done(sk);
170 } else
171 sk->sk_err_soft = err;
172 goto out;
173 }
174
175 if (!sock_owned_by_user(sk) && np->recverr) {
176 sk->sk_err = err;
177 sk->sk_error_report(sk);
178 } else
179 sk->sk_err_soft = err;
180
181out:
182 bh_unlock_sock(sk);
183 sock_put(sk);
184 return 0;
185}
186
187
188static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
189{
190 struct inet_request_sock *ireq = inet_rsk(req);
191 struct ipv6_pinfo *np = inet6_sk(sk);
192 struct sk_buff *skb;
193 struct in6_addr *final_p, final;
194 struct flowi6 fl6;
195 int err = -1;
196 struct dst_entry *dst;
197
198 memset(&fl6, 0, sizeof(fl6));
199 fl6.flowi6_proto = IPPROTO_DCCP;
200 fl6.daddr = ireq->ir_v6_rmt_addr;
201 fl6.saddr = ireq->ir_v6_loc_addr;
202 fl6.flowlabel = 0;
203 fl6.flowi6_oif = ireq->ir_iif;
204 fl6.fl6_dport = ireq->ir_rmt_port;
205 fl6.fl6_sport = htons(ireq->ir_num);
206 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
207
208
209 rcu_read_lock();
210 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
211 rcu_read_unlock();
212
213 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
214 if (IS_ERR(dst)) {
215 err = PTR_ERR(dst);
216 dst = NULL;
217 goto done;
218 }
219
220 skb = dccp_make_response(sk, dst, req);
221 if (skb != NULL) {
222 struct dccp_hdr *dh = dccp_hdr(skb);
223 struct ipv6_txoptions *opt;
224
225 dh->dccph_checksum = dccp_v6_csum_finish(skb,
226 &ireq->ir_v6_loc_addr,
227 &ireq->ir_v6_rmt_addr);
228 fl6.daddr = ireq->ir_v6_rmt_addr;
229 rcu_read_lock();
230 opt = ireq->ipv6_opt;
231 if (!opt)
232 opt = rcu_dereference(np->opt);
233 err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass,
234 sk->sk_priority);
235 rcu_read_unlock();
236 err = net_xmit_eval(err);
237 }
238
239done:
240 dst_release(dst);
241 return err;
242}
243
244static void dccp_v6_reqsk_destructor(struct request_sock *req)
245{
246 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
247 kfree(inet_rsk(req)->ipv6_opt);
248 kfree_skb(inet_rsk(req)->pktopts);
249}
250
251static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
252{
253 const struct ipv6hdr *rxip6h;
254 struct sk_buff *skb;
255 struct flowi6 fl6;
256 struct net *net = dev_net(skb_dst(rxskb)->dev);
257 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
258 struct dst_entry *dst;
259
260 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
261 return;
262
263 if (!ipv6_unicast_destination(rxskb))
264 return;
265
266 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
267 if (skb == NULL)
268 return;
269
270 rxip6h = ipv6_hdr(rxskb);
271 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
272 &rxip6h->daddr);
273
274 memset(&fl6, 0, sizeof(fl6));
275 fl6.daddr = rxip6h->saddr;
276 fl6.saddr = rxip6h->daddr;
277
278 fl6.flowi6_proto = IPPROTO_DCCP;
279 fl6.flowi6_oif = inet6_iif(rxskb);
280 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
281 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
282 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
283
284 /* sk = NULL, but it is safe for now. RST socket required. */
285 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
286 if (!IS_ERR(dst)) {
287 skb_dst_set(skb, dst);
288 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
289 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
290 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
291 return;
292 }
293
294 kfree_skb(skb);
295}
296
297static struct request_sock_ops dccp6_request_sock_ops = {
298 .family = AF_INET6,
299 .obj_size = sizeof(struct dccp6_request_sock),
300 .rtx_syn_ack = dccp_v6_send_response,
301 .send_ack = dccp_reqsk_send_ack,
302 .destructor = dccp_v6_reqsk_destructor,
303 .send_reset = dccp_v6_ctl_send_reset,
304 .syn_ack_timeout = dccp_syn_ack_timeout,
305};
306
307static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
308{
309 struct request_sock *req;
310 struct dccp_request_sock *dreq;
311 struct inet_request_sock *ireq;
312 struct ipv6_pinfo *np = inet6_sk(sk);
313 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
314 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
315
316 if (skb->protocol == htons(ETH_P_IP))
317 return dccp_v4_conn_request(sk, skb);
318
319 if (!ipv6_unicast_destination(skb))
320 return 0; /* discard, don't send a reset here */
321
322 if (dccp_bad_service_code(sk, service)) {
323 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
324 goto drop;
325 }
326 /*
327 * There are no SYN attacks on IPv6, yet...
328 */
329 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
330 if (inet_csk_reqsk_queue_is_full(sk))
331 goto drop;
332
333 if (sk_acceptq_is_full(sk))
334 goto drop;
335
336 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
337 if (req == NULL)
338 goto drop;
339
340 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
341 goto drop_and_free;
342
343 dreq = dccp_rsk(req);
344 if (dccp_parse_options(sk, dreq, skb))
345 goto drop_and_free;
346
347 if (security_inet_conn_request(sk, skb, req))
348 goto drop_and_free;
349
350 ireq = inet_rsk(req);
351 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
352 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
353 ireq->ireq_family = AF_INET6;
354 ireq->ir_mark = inet_request_mark(sk, skb);
355
356 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
357 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
358 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
359 refcount_inc(&skb->users);
360 ireq->pktopts = skb;
361 }
362 ireq->ir_iif = sk->sk_bound_dev_if;
363
364 /* So that link locals have meaning */
365 if (!sk->sk_bound_dev_if &&
366 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
367 ireq->ir_iif = inet6_iif(skb);
368
369 /*
370 * Step 3: Process LISTEN state
371 *
372 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
373 *
374 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
375 */
376 dreq->dreq_isr = dcb->dccpd_seq;
377 dreq->dreq_gsr = dreq->dreq_isr;
378 dreq->dreq_iss = dccp_v6_init_sequence(skb);
379 dreq->dreq_gss = dreq->dreq_iss;
380 dreq->dreq_service = service;
381
382 if (dccp_v6_send_response(sk, req))
383 goto drop_and_free;
384
385 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
386 reqsk_put(req);
387 return 0;
388
389drop_and_free:
390 reqsk_free(req);
391drop:
392 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
393 return -1;
394}
395
396static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
397 struct sk_buff *skb,
398 struct request_sock *req,
399 struct dst_entry *dst,
400 struct request_sock *req_unhash,
401 bool *own_req)
402{
403 struct inet_request_sock *ireq = inet_rsk(req);
404 struct ipv6_pinfo *newnp;
405 const struct ipv6_pinfo *np = inet6_sk(sk);
406 struct ipv6_txoptions *opt;
407 struct inet_sock *newinet;
408 struct dccp6_sock *newdp6;
409 struct sock *newsk;
410
411 if (skb->protocol == htons(ETH_P_IP)) {
412 /*
413 * v6 mapped
414 */
415 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
416 req_unhash, own_req);
417 if (newsk == NULL)
418 return NULL;
419
420 newdp6 = (struct dccp6_sock *)newsk;
421 newinet = inet_sk(newsk);
422 newinet->pinet6 = &newdp6->inet6;
423 newnp = inet6_sk(newsk);
424
425 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
426
427 newnp->saddr = newsk->sk_v6_rcv_saddr;
428
429 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
430 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
431 newnp->pktoptions = NULL;
432 newnp->opt = NULL;
433 newnp->ipv6_mc_list = NULL;
434 newnp->ipv6_ac_list = NULL;
435 newnp->ipv6_fl_list = NULL;
436 newnp->mcast_oif = inet_iif(skb);
437 newnp->mcast_hops = ip_hdr(skb)->ttl;
438
439 /*
440 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
441 * here, dccp_create_openreq_child now does this for us, see the comment in
442 * that function for the gory details. -acme
443 */
444
445 /* It is tricky place. Until this moment IPv4 tcp
446 worked with IPv6 icsk.icsk_af_ops.
447 Sync it now.
448 */
449 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
450
451 return newsk;
452 }
453
454
455 if (sk_acceptq_is_full(sk))
456 goto out_overflow;
457
458 if (!dst) {
459 struct flowi6 fl6;
460
461 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
462 if (!dst)
463 goto out;
464 }
465
466 newsk = dccp_create_openreq_child(sk, req, skb);
467 if (newsk == NULL)
468 goto out_nonewsk;
469
470 /*
471 * No need to charge this sock to the relevant IPv6 refcnt debug socks
472 * count here, dccp_create_openreq_child now does this for us, see the
473 * comment in that function for the gory details. -acme
474 */
475
476 ip6_dst_store(newsk, dst, NULL, NULL);
477 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
478 NETIF_F_TSO);
479 newdp6 = (struct dccp6_sock *)newsk;
480 newinet = inet_sk(newsk);
481 newinet->pinet6 = &newdp6->inet6;
482 newnp = inet6_sk(newsk);
483
484 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
485
486 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
487 newnp->saddr = ireq->ir_v6_loc_addr;
488 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
489 newsk->sk_bound_dev_if = ireq->ir_iif;
490
491 /* Now IPv6 options...
492
493 First: no IPv4 options.
494 */
495 newinet->inet_opt = NULL;
496
497 /* Clone RX bits */
498 newnp->rxopt.all = np->rxopt.all;
499
500 newnp->ipv6_mc_list = NULL;
501 newnp->ipv6_ac_list = NULL;
502 newnp->ipv6_fl_list = NULL;
503 newnp->pktoptions = NULL;
504 newnp->opt = NULL;
505 newnp->mcast_oif = inet6_iif(skb);
506 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
507
508 /*
509 * Clone native IPv6 options from listening socket (if any)
510 *
511 * Yes, keeping reference count would be much more clever, but we make
512 * one more one thing there: reattach optmem to newsk.
513 */
514 opt = ireq->ipv6_opt;
515 if (!opt)
516 opt = rcu_dereference(np->opt);
517 if (opt) {
518 opt = ipv6_dup_options(newsk, opt);
519 RCU_INIT_POINTER(newnp->opt, opt);
520 }
521 inet_csk(newsk)->icsk_ext_hdr_len = 0;
522 if (opt)
523 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
524 opt->opt_flen;
525
526 dccp_sync_mss(newsk, dst_mtu(dst));
527
528 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
529 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
530
531 if (__inet_inherit_port(sk, newsk) < 0) {
532 inet_csk_prepare_forced_close(newsk);
533 dccp_done(newsk);
534 goto out;
535 }
536 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
537 /* Clone pktoptions received with SYN, if we own the req */
538 if (*own_req && ireq->pktopts) {
539 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
540 consume_skb(ireq->pktopts);
541 ireq->pktopts = NULL;
542 if (newnp->pktoptions)
543 skb_set_owner_r(newnp->pktoptions, newsk);
544 }
545
546 return newsk;
547
548out_overflow:
549 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
550out_nonewsk:
551 dst_release(dst);
552out:
553 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
554 return NULL;
555}
556
557/* The socket must have it's spinlock held when we get
558 * here.
559 *
560 * We have a potential double-lock case here, so even when
561 * doing backlog processing we use the BH locking scheme.
562 * This is because we cannot sleep with the original spinlock
563 * held.
564 */
565static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
566{
567 struct ipv6_pinfo *np = inet6_sk(sk);
568 struct sk_buff *opt_skb = NULL;
569
570 /* Imagine: socket is IPv6. IPv4 packet arrives,
571 goes to IPv4 receive handler and backlogged.
572 From backlog it always goes here. Kerboom...
573 Fortunately, dccp_rcv_established and rcv_established
574 handle them correctly, but it is not case with
575 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
576 */
577
578 if (skb->protocol == htons(ETH_P_IP))
579 return dccp_v4_do_rcv(sk, skb);
580
581 if (sk_filter(sk, skb))
582 goto discard;
583
584 /*
585 * socket locking is here for SMP purposes as backlog rcv is currently
586 * called with bh processing disabled.
587 */
588
589 /* Do Stevens' IPV6_PKTOPTIONS.
590
591 Yes, guys, it is the only place in our code, where we
592 may make it not affecting IPv4.
593 The rest of code is protocol independent,
594 and I do not like idea to uglify IPv4.
595
596 Actually, all the idea behind IPV6_PKTOPTIONS
597 looks not very well thought. For now we latch
598 options, received in the last packet, enqueued
599 by tcp. Feel free to propose better solution.
600 --ANK (980728)
601 */
602 if (np->rxopt.all)
603 opt_skb = skb_clone(skb, GFP_ATOMIC);
604
605 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
606 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
607 goto reset;
608 if (opt_skb)
609 goto ipv6_pktoptions;
610 return 0;
611 }
612
613 /*
614 * Step 3: Process LISTEN state
615 * If S.state == LISTEN,
616 * If P.type == Request or P contains a valid Init Cookie option,
617 * (* Must scan the packet's options to check for Init
618 * Cookies. Only Init Cookies are processed here,
619 * however; other options are processed in Step 8. This
620 * scan need only be performed if the endpoint uses Init
621 * Cookies *)
622 * (* Generate a new socket and switch to that socket *)
623 * Set S := new socket for this port pair
624 * S.state = RESPOND
625 * Choose S.ISS (initial seqno) or set from Init Cookies
626 * Initialize S.GAR := S.ISS
627 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
628 * Continue with S.state == RESPOND
629 * (* A Response packet will be generated in Step 11 *)
630 * Otherwise,
631 * Generate Reset(No Connection) unless P.type == Reset
632 * Drop packet and return
633 *
634 * NOTE: the check for the packet types is done in
635 * dccp_rcv_state_process
636 */
637
638 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
639 goto reset;
640 if (opt_skb)
641 goto ipv6_pktoptions;
642 return 0;
643
644reset:
645 dccp_v6_ctl_send_reset(sk, skb);
646discard:
647 if (opt_skb != NULL)
648 __kfree_skb(opt_skb);
649 kfree_skb(skb);
650 return 0;
651
652/* Handling IPV6_PKTOPTIONS skb the similar
653 * way it's done for net/ipv6/tcp_ipv6.c
654 */
655ipv6_pktoptions:
656 if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
657 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
658 np->mcast_oif = inet6_iif(opt_skb);
659 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
660 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
661 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
662 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
663 if (np->repflow)
664 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
665 if (ipv6_opt_accepted(sk, opt_skb,
666 &DCCP_SKB_CB(opt_skb)->header.h6)) {
667 skb_set_owner_r(opt_skb, sk);
668 memmove(IP6CB(opt_skb),
669 &DCCP_SKB_CB(opt_skb)->header.h6,
670 sizeof(struct inet6_skb_parm));
671 opt_skb = xchg(&np->pktoptions, opt_skb);
672 } else {
673 __kfree_skb(opt_skb);
674 opt_skb = xchg(&np->pktoptions, NULL);
675 }
676 }
677
678 kfree_skb(opt_skb);
679 return 0;
680}
681
682static int dccp_v6_rcv(struct sk_buff *skb)
683{
684 const struct dccp_hdr *dh;
685 bool refcounted;
686 struct sock *sk;
687 int min_cov;
688
689 /* Step 1: Check header basics */
690
691 if (dccp_invalid_packet(skb))
692 goto discard_it;
693
694 /* Step 1: If header checksum is incorrect, drop packet and return. */
695 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
696 &ipv6_hdr(skb)->daddr)) {
697 DCCP_WARN("dropped packet with invalid checksum\n");
698 goto discard_it;
699 }
700
701 dh = dccp_hdr(skb);
702
703 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
704 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
705
706 if (dccp_packet_without_ack(skb))
707 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
708 else
709 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
710
711lookup:
712 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
713 dh->dccph_sport, dh->dccph_dport,
714 inet6_iif(skb), 0, &refcounted);
715 if (!sk) {
716 dccp_pr_debug("failed to look up flow ID in table and "
717 "get corresponding socket\n");
718 goto no_dccp_socket;
719 }
720
721 /*
722 * Step 2:
723 * ... or S.state == TIMEWAIT,
724 * Generate Reset(No Connection) unless P.type == Reset
725 * Drop packet and return
726 */
727 if (sk->sk_state == DCCP_TIME_WAIT) {
728 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
729 inet_twsk_put(inet_twsk(sk));
730 goto no_dccp_socket;
731 }
732
733 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
734 struct request_sock *req = inet_reqsk(sk);
735 struct sock *nsk;
736
737 sk = req->rsk_listener;
738 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
739 inet_csk_reqsk_queue_drop_and_put(sk, req);
740 goto lookup;
741 }
742 sock_hold(sk);
743 refcounted = true;
744 nsk = dccp_check_req(sk, skb, req);
745 if (!nsk) {
746 reqsk_put(req);
747 goto discard_and_relse;
748 }
749 if (nsk == sk) {
750 reqsk_put(req);
751 } else if (dccp_child_process(sk, nsk, skb)) {
752 dccp_v6_ctl_send_reset(sk, skb);
753 goto discard_and_relse;
754 } else {
755 sock_put(sk);
756 return 0;
757 }
758 }
759 /*
760 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
761 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
762 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
763 */
764 min_cov = dccp_sk(sk)->dccps_pcrlen;
765 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
766 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
767 dh->dccph_cscov, min_cov);
768 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
769 goto discard_and_relse;
770 }
771
772 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
773 goto discard_and_relse;
774
775 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
776 refcounted) ? -1 : 0;
777
778no_dccp_socket:
779 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
780 goto discard_it;
781 /*
782 * Step 2:
783 * If no socket ...
784 * Generate Reset(No Connection) unless P.type == Reset
785 * Drop packet and return
786 */
787 if (dh->dccph_type != DCCP_PKT_RESET) {
788 DCCP_SKB_CB(skb)->dccpd_reset_code =
789 DCCP_RESET_CODE_NO_CONNECTION;
790 dccp_v6_ctl_send_reset(sk, skb);
791 }
792
793discard_it:
794 kfree_skb(skb);
795 return 0;
796
797discard_and_relse:
798 if (refcounted)
799 sock_put(sk);
800 goto discard_it;
801}
802
803static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
804 int addr_len)
805{
806 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
807 struct inet_connection_sock *icsk = inet_csk(sk);
808 struct inet_sock *inet = inet_sk(sk);
809 struct ipv6_pinfo *np = inet6_sk(sk);
810 struct dccp_sock *dp = dccp_sk(sk);
811 struct in6_addr *saddr = NULL, *final_p, final;
812 struct ipv6_txoptions *opt;
813 struct flowi6 fl6;
814 struct dst_entry *dst;
815 int addr_type;
816 int err;
817
818 dp->dccps_role = DCCP_ROLE_CLIENT;
819
820 if (addr_len < SIN6_LEN_RFC2133)
821 return -EINVAL;
822
823 if (usin->sin6_family != AF_INET6)
824 return -EAFNOSUPPORT;
825
826 memset(&fl6, 0, sizeof(fl6));
827
828 if (np->sndflow) {
829 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
830 IP6_ECN_flow_init(fl6.flowlabel);
831 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
832 struct ip6_flowlabel *flowlabel;
833 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
834 if (IS_ERR(flowlabel))
835 return -EINVAL;
836 fl6_sock_release(flowlabel);
837 }
838 }
839 /*
840 * connect() to INADDR_ANY means loopback (BSD'ism).
841 */
842 if (ipv6_addr_any(&usin->sin6_addr))
843 usin->sin6_addr.s6_addr[15] = 1;
844
845 addr_type = ipv6_addr_type(&usin->sin6_addr);
846
847 if (addr_type & IPV6_ADDR_MULTICAST)
848 return -ENETUNREACH;
849
850 if (addr_type & IPV6_ADDR_LINKLOCAL) {
851 if (addr_len >= sizeof(struct sockaddr_in6) &&
852 usin->sin6_scope_id) {
853 /* If interface is set while binding, indices
854 * must coincide.
855 */
856 if (sk->sk_bound_dev_if &&
857 sk->sk_bound_dev_if != usin->sin6_scope_id)
858 return -EINVAL;
859
860 sk->sk_bound_dev_if = usin->sin6_scope_id;
861 }
862
863 /* Connect to link-local address requires an interface */
864 if (!sk->sk_bound_dev_if)
865 return -EINVAL;
866 }
867
868 sk->sk_v6_daddr = usin->sin6_addr;
869 np->flow_label = fl6.flowlabel;
870
871 /*
872 * DCCP over IPv4
873 */
874 if (addr_type == IPV6_ADDR_MAPPED) {
875 u32 exthdrlen = icsk->icsk_ext_hdr_len;
876 struct sockaddr_in sin;
877
878 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
879
880 if (__ipv6_only_sock(sk))
881 return -ENETUNREACH;
882
883 sin.sin_family = AF_INET;
884 sin.sin_port = usin->sin6_port;
885 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
886
887 icsk->icsk_af_ops = &dccp_ipv6_mapped;
888 sk->sk_backlog_rcv = dccp_v4_do_rcv;
889
890 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
891 if (err) {
892 icsk->icsk_ext_hdr_len = exthdrlen;
893 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
894 sk->sk_backlog_rcv = dccp_v6_do_rcv;
895 goto failure;
896 }
897 np->saddr = sk->sk_v6_rcv_saddr;
898 return err;
899 }
900
901 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
902 saddr = &sk->sk_v6_rcv_saddr;
903
904 fl6.flowi6_proto = IPPROTO_DCCP;
905 fl6.daddr = sk->sk_v6_daddr;
906 fl6.saddr = saddr ? *saddr : np->saddr;
907 fl6.flowi6_oif = sk->sk_bound_dev_if;
908 fl6.fl6_dport = usin->sin6_port;
909 fl6.fl6_sport = inet->inet_sport;
910 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
911
912 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
913 final_p = fl6_update_dst(&fl6, opt, &final);
914
915 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
916 if (IS_ERR(dst)) {
917 err = PTR_ERR(dst);
918 goto failure;
919 }
920
921 if (saddr == NULL) {
922 saddr = &fl6.saddr;
923 sk->sk_v6_rcv_saddr = *saddr;
924 }
925
926 /* set the source address */
927 np->saddr = *saddr;
928 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
929
930 ip6_dst_store(sk, dst, NULL, NULL);
931
932 icsk->icsk_ext_hdr_len = 0;
933 if (opt)
934 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
935
936 inet->inet_dport = usin->sin6_port;
937
938 dccp_set_state(sk, DCCP_REQUESTING);
939 err = inet6_hash_connect(&dccp_death_row, sk);
940 if (err)
941 goto late_failure;
942
943 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
944 sk->sk_v6_daddr.s6_addr32,
945 inet->inet_sport,
946 inet->inet_dport);
947 err = dccp_connect(sk);
948 if (err)
949 goto late_failure;
950
951 return 0;
952
953late_failure:
954 dccp_set_state(sk, DCCP_CLOSED);
955 __sk_dst_reset(sk);
956failure:
957 inet->inet_dport = 0;
958 sk->sk_route_caps = 0;
959 return err;
960}
961
962static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
963 .queue_xmit = inet6_csk_xmit,
964 .send_check = dccp_v6_send_check,
965 .rebuild_header = inet6_sk_rebuild_header,
966 .conn_request = dccp_v6_conn_request,
967 .syn_recv_sock = dccp_v6_request_recv_sock,
968 .net_header_len = sizeof(struct ipv6hdr),
969 .setsockopt = ipv6_setsockopt,
970 .getsockopt = ipv6_getsockopt,
971 .addr2sockaddr = inet6_csk_addr2sockaddr,
972 .sockaddr_len = sizeof(struct sockaddr_in6),
973#ifdef CONFIG_COMPAT
974 .compat_setsockopt = compat_ipv6_setsockopt,
975 .compat_getsockopt = compat_ipv6_getsockopt,
976#endif
977};
978
979/*
980 * DCCP over IPv4 via INET6 API
981 */
982static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
983 .queue_xmit = ip_queue_xmit,
984 .send_check = dccp_v4_send_check,
985 .rebuild_header = inet_sk_rebuild_header,
986 .conn_request = dccp_v6_conn_request,
987 .syn_recv_sock = dccp_v6_request_recv_sock,
988 .net_header_len = sizeof(struct iphdr),
989 .setsockopt = ipv6_setsockopt,
990 .getsockopt = ipv6_getsockopt,
991 .addr2sockaddr = inet6_csk_addr2sockaddr,
992 .sockaddr_len = sizeof(struct sockaddr_in6),
993#ifdef CONFIG_COMPAT
994 .compat_setsockopt = compat_ipv6_setsockopt,
995 .compat_getsockopt = compat_ipv6_getsockopt,
996#endif
997};
998
999/* NOTE: A lot of things set to zero explicitly by call to
1000 * sk_alloc() so need not be done here.
1001 */
1002static int dccp_v6_init_sock(struct sock *sk)
1003{
1004 static __u8 dccp_v6_ctl_sock_initialized;
1005 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1006
1007 if (err == 0) {
1008 if (unlikely(!dccp_v6_ctl_sock_initialized))
1009 dccp_v6_ctl_sock_initialized = 1;
1010 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1011 }
1012
1013 return err;
1014}
1015
1016static void dccp_v6_destroy_sock(struct sock *sk)
1017{
1018 dccp_destroy_sock(sk);
1019 inet6_destroy_sock(sk);
1020}
1021
1022static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1023 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1024};
1025
1026static struct proto dccp_v6_prot = {
1027 .name = "DCCPv6",
1028 .owner = THIS_MODULE,
1029 .close = dccp_close,
1030 .connect = dccp_v6_connect,
1031 .disconnect = dccp_disconnect,
1032 .ioctl = dccp_ioctl,
1033 .init = dccp_v6_init_sock,
1034 .setsockopt = dccp_setsockopt,
1035 .getsockopt = dccp_getsockopt,
1036 .sendmsg = dccp_sendmsg,
1037 .recvmsg = dccp_recvmsg,
1038 .backlog_rcv = dccp_v6_do_rcv,
1039 .hash = inet6_hash,
1040 .unhash = inet_unhash,
1041 .accept = inet_csk_accept,
1042 .get_port = inet_csk_get_port,
1043 .shutdown = dccp_shutdown,
1044 .destroy = dccp_v6_destroy_sock,
1045 .orphan_count = &dccp_orphan_count,
1046 .max_header = MAX_DCCP_HEADER,
1047 .obj_size = sizeof(struct dccp6_sock),
1048 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1049 .rsk_prot = &dccp6_request_sock_ops,
1050 .twsk_prot = &dccp6_timewait_sock_ops,
1051 .h.hashinfo = &dccp_hashinfo,
1052#ifdef CONFIG_COMPAT
1053 .compat_setsockopt = compat_dccp_setsockopt,
1054 .compat_getsockopt = compat_dccp_getsockopt,
1055#endif
1056};
1057
1058static const struct inet6_protocol dccp_v6_protocol = {
1059 .handler = dccp_v6_rcv,
1060 .err_handler = dccp_v6_err,
1061 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1062};
1063
1064static const struct proto_ops inet6_dccp_ops = {
1065 .family = PF_INET6,
1066 .owner = THIS_MODULE,
1067 .release = inet6_release,
1068 .bind = inet6_bind,
1069 .connect = inet_stream_connect,
1070 .socketpair = sock_no_socketpair,
1071 .accept = inet_accept,
1072 .getname = inet6_getname,
1073 .poll = dccp_poll,
1074 .ioctl = inet6_ioctl,
1075 .gettstamp = sock_gettstamp,
1076 .listen = inet_dccp_listen,
1077 .shutdown = inet_shutdown,
1078 .setsockopt = sock_common_setsockopt,
1079 .getsockopt = sock_common_getsockopt,
1080 .sendmsg = inet_sendmsg,
1081 .recvmsg = sock_common_recvmsg,
1082 .mmap = sock_no_mmap,
1083 .sendpage = sock_no_sendpage,
1084#ifdef CONFIG_COMPAT
1085 .compat_setsockopt = compat_sock_common_setsockopt,
1086 .compat_getsockopt = compat_sock_common_getsockopt,
1087#endif
1088};
1089
1090static struct inet_protosw dccp_v6_protosw = {
1091 .type = SOCK_DCCP,
1092 .protocol = IPPROTO_DCCP,
1093 .prot = &dccp_v6_prot,
1094 .ops = &inet6_dccp_ops,
1095 .flags = INET_PROTOSW_ICSK,
1096};
1097
1098static int __net_init dccp_v6_init_net(struct net *net)
1099{
1100 if (dccp_hashinfo.bhash == NULL)
1101 return -ESOCKTNOSUPPORT;
1102
1103 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1104 SOCK_DCCP, IPPROTO_DCCP, net);
1105}
1106
1107static void __net_exit dccp_v6_exit_net(struct net *net)
1108{
1109 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1110}
1111
1112static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1113{
1114 inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1115}
1116
1117static struct pernet_operations dccp_v6_ops = {
1118 .init = dccp_v6_init_net,
1119 .exit = dccp_v6_exit_net,
1120 .exit_batch = dccp_v6_exit_batch,
1121};
1122
1123static int __init dccp_v6_init(void)
1124{
1125 int err = proto_register(&dccp_v6_prot, 1);
1126
1127 if (err)
1128 goto out;
1129
1130 inet6_register_protosw(&dccp_v6_protosw);
1131
1132 err = register_pernet_subsys(&dccp_v6_ops);
1133 if (err)
1134 goto out_destroy_ctl_sock;
1135
1136 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1137 if (err)
1138 goto out_unregister_proto;
1139
1140out:
1141 return err;
1142out_unregister_proto:
1143 unregister_pernet_subsys(&dccp_v6_ops);
1144out_destroy_ctl_sock:
1145 inet6_unregister_protosw(&dccp_v6_protosw);
1146 proto_unregister(&dccp_v6_prot);
1147 goto out;
1148}
1149
1150static void __exit dccp_v6_exit(void)
1151{
1152 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1153 unregister_pernet_subsys(&dccp_v6_ops);
1154 inet6_unregister_protosw(&dccp_v6_protosw);
1155 proto_unregister(&dccp_v6_prot);
1156}
1157
1158module_init(dccp_v6_init);
1159module_exit(dccp_v6_exit);
1160
1161/*
1162 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1163 * values directly, Also cover the case where the protocol is not specified,
1164 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1165 */
1166MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1167MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1168MODULE_LICENSE("GPL");
1169MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1170MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");