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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/netns/generic.h>
31#include <net/sock.h>
32
33#include "dccp.h"
34#include "ipv6.h"
35#include "feat.h"
36
37struct dccp_v6_pernet {
38 struct sock *v6_ctl_sk;
39};
40
41static unsigned int dccp_v6_pernet_id __read_mostly;
42
43/* The per-net v6_ctl_sk is used for sending RSTs and ACKs */
44
45static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
46static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
47
48/* add pseudo-header to DCCP checksum stored in skb->csum */
49static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
50 const struct in6_addr *saddr,
51 const struct in6_addr *daddr)
52{
53 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
54}
55
56static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
57{
58 struct ipv6_pinfo *np = inet6_sk(sk);
59 struct dccp_hdr *dh = dccp_hdr(skb);
60
61 dccp_csum_outgoing(skb);
62 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
63}
64
65static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
66{
67 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
68 ipv6_hdr(skb)->saddr.s6_addr32,
69 dccp_hdr(skb)->dccph_dport,
70 dccp_hdr(skb)->dccph_sport );
71
72}
73
74static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
75 u8 type, u8 code, int offset, __be32 info)
76{
77 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
78 const struct dccp_hdr *dh;
79 struct dccp_sock *dp;
80 struct ipv6_pinfo *np;
81 struct sock *sk;
82 int err;
83 __u64 seq;
84 struct net *net = dev_net(skb->dev);
85
86 /* Only need dccph_dport & dccph_sport which are the first
87 * 4 bytes in dccp header.
88 * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
89 */
90 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
91 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
92 dh = (struct dccp_hdr *)(skb->data + offset);
93
94 sk = __inet6_lookup_established(net, &dccp_hashinfo,
95 &hdr->daddr, dh->dccph_dport,
96 &hdr->saddr, ntohs(dh->dccph_sport),
97 inet6_iif(skb), 0);
98
99 if (!sk) {
100 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
101 ICMP6_MIB_INERRORS);
102 return -ENOENT;
103 }
104
105 if (sk->sk_state == DCCP_TIME_WAIT) {
106 inet_twsk_put(inet_twsk(sk));
107 return 0;
108 }
109 seq = dccp_hdr_seq(dh);
110 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
111 dccp_req_err(sk, seq);
112 return 0;
113 }
114
115 bh_lock_sock(sk);
116 if (sock_owned_by_user(sk))
117 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
118
119 if (sk->sk_state == DCCP_CLOSED)
120 goto out;
121
122 dp = dccp_sk(sk);
123 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
124 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
125 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
126 goto out;
127 }
128
129 np = inet6_sk(sk);
130
131 if (type == NDISC_REDIRECT) {
132 if (!sock_owned_by_user(sk)) {
133 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
134
135 if (dst)
136 dst->ops->redirect(dst, sk, skb);
137 }
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 case DCCP_REQUESTING:
166 case DCCP_RESPOND: /* Cannot happen.
167 It can, it SYNs are crossed. --ANK */
168 if (!sock_owned_by_user(sk)) {
169 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
170 sk->sk_err = err;
171 /*
172 * Wake people up to see the error
173 * (see connect in sock.c)
174 */
175 sk_error_report(sk);
176 dccp_done(sk);
177 } else
178 sk->sk_err_soft = err;
179 goto out;
180 }
181
182 if (!sock_owned_by_user(sk) && np->recverr) {
183 sk->sk_err = err;
184 sk_error_report(sk);
185 } else
186 sk->sk_err_soft = err;
187
188out:
189 bh_unlock_sock(sk);
190 sock_put(sk);
191 return 0;
192}
193
194
195static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
196{
197 struct inet_request_sock *ireq = inet_rsk(req);
198 struct ipv6_pinfo *np = inet6_sk(sk);
199 struct sk_buff *skb;
200 struct in6_addr *final_p, final;
201 struct flowi6 fl6;
202 int err = -1;
203 struct dst_entry *dst;
204
205 memset(&fl6, 0, sizeof(fl6));
206 fl6.flowi6_proto = IPPROTO_DCCP;
207 fl6.daddr = ireq->ir_v6_rmt_addr;
208 fl6.saddr = ireq->ir_v6_loc_addr;
209 fl6.flowlabel = 0;
210 fl6.flowi6_oif = ireq->ir_iif;
211 fl6.fl6_dport = ireq->ir_rmt_port;
212 fl6.fl6_sport = htons(ireq->ir_num);
213 security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
214
215
216 rcu_read_lock();
217 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
218 rcu_read_unlock();
219
220 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
221 if (IS_ERR(dst)) {
222 err = PTR_ERR(dst);
223 dst = NULL;
224 goto done;
225 }
226
227 skb = dccp_make_response(sk, dst, req);
228 if (skb != NULL) {
229 struct dccp_hdr *dh = dccp_hdr(skb);
230 struct ipv6_txoptions *opt;
231
232 dh->dccph_checksum = dccp_v6_csum_finish(skb,
233 &ireq->ir_v6_loc_addr,
234 &ireq->ir_v6_rmt_addr);
235 fl6.daddr = ireq->ir_v6_rmt_addr;
236 rcu_read_lock();
237 opt = ireq->ipv6_opt;
238 if (!opt)
239 opt = rcu_dereference(np->opt);
240 err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass,
241 sk->sk_priority);
242 rcu_read_unlock();
243 err = net_xmit_eval(err);
244 }
245
246done:
247 dst_release(dst);
248 return err;
249}
250
251static void dccp_v6_reqsk_destructor(struct request_sock *req)
252{
253 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
254 kfree(inet_rsk(req)->ipv6_opt);
255 kfree_skb(inet_rsk(req)->pktopts);
256}
257
258static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
259{
260 const struct ipv6hdr *rxip6h;
261 struct sk_buff *skb;
262 struct flowi6 fl6;
263 struct net *net = dev_net(skb_dst(rxskb)->dev);
264 struct dccp_v6_pernet *pn;
265 struct sock *ctl_sk;
266 struct dst_entry *dst;
267
268 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
269 return;
270
271 if (!ipv6_unicast_destination(rxskb))
272 return;
273
274 pn = net_generic(net, dccp_v6_pernet_id);
275 ctl_sk = pn->v6_ctl_sk;
276 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
277 if (skb == NULL)
278 return;
279
280 rxip6h = ipv6_hdr(rxskb);
281 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
282 &rxip6h->daddr);
283
284 memset(&fl6, 0, sizeof(fl6));
285 fl6.daddr = rxip6h->saddr;
286 fl6.saddr = rxip6h->daddr;
287
288 fl6.flowi6_proto = IPPROTO_DCCP;
289 fl6.flowi6_oif = inet6_iif(rxskb);
290 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
291 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
292 security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6));
293
294 /* sk = NULL, but it is safe for now. RST socket required. */
295 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
296 if (!IS_ERR(dst)) {
297 skb_dst_set(skb, dst);
298 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
299 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
300 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
301 return;
302 }
303
304 kfree_skb(skb);
305}
306
307static struct request_sock_ops dccp6_request_sock_ops = {
308 .family = AF_INET6,
309 .obj_size = sizeof(struct dccp6_request_sock),
310 .rtx_syn_ack = dccp_v6_send_response,
311 .send_ack = dccp_reqsk_send_ack,
312 .destructor = dccp_v6_reqsk_destructor,
313 .send_reset = dccp_v6_ctl_send_reset,
314 .syn_ack_timeout = dccp_syn_ack_timeout,
315};
316
317static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
318{
319 struct request_sock *req;
320 struct dccp_request_sock *dreq;
321 struct inet_request_sock *ireq;
322 struct ipv6_pinfo *np = inet6_sk(sk);
323 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
324 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
325
326 if (skb->protocol == htons(ETH_P_IP))
327 return dccp_v4_conn_request(sk, skb);
328
329 if (!ipv6_unicast_destination(skb))
330 return 0; /* discard, don't send a reset here */
331
332 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
333 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
334 return 0;
335 }
336
337 if (dccp_bad_service_code(sk, service)) {
338 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
339 goto drop;
340 }
341 /*
342 * There are no SYN attacks on IPv6, yet...
343 */
344 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
345 if (inet_csk_reqsk_queue_is_full(sk))
346 goto drop;
347
348 if (sk_acceptq_is_full(sk))
349 goto drop;
350
351 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
352 if (req == NULL)
353 goto drop;
354
355 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
356 goto drop_and_free;
357
358 dreq = dccp_rsk(req);
359 if (dccp_parse_options(sk, dreq, skb))
360 goto drop_and_free;
361
362 if (security_inet_conn_request(sk, skb, req))
363 goto drop_and_free;
364
365 ireq = inet_rsk(req);
366 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
367 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
368 ireq->ireq_family = AF_INET6;
369 ireq->ir_mark = inet_request_mark(sk, skb);
370
371 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
372 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
373 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
374 refcount_inc(&skb->users);
375 ireq->pktopts = skb;
376 }
377 ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if);
378
379 /* So that link locals have meaning */
380 if (!ireq->ir_iif &&
381 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
382 ireq->ir_iif = inet6_iif(skb);
383
384 /*
385 * Step 3: Process LISTEN state
386 *
387 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
388 *
389 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
390 */
391 dreq->dreq_isr = dcb->dccpd_seq;
392 dreq->dreq_gsr = dreq->dreq_isr;
393 dreq->dreq_iss = dccp_v6_init_sequence(skb);
394 dreq->dreq_gss = dreq->dreq_iss;
395 dreq->dreq_service = service;
396
397 if (dccp_v6_send_response(sk, req))
398 goto drop_and_free;
399
400 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
401 reqsk_put(req);
402 return 0;
403
404drop_and_free:
405 reqsk_free(req);
406drop:
407 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
408 return -1;
409}
410
411static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
412 struct sk_buff *skb,
413 struct request_sock *req,
414 struct dst_entry *dst,
415 struct request_sock *req_unhash,
416 bool *own_req)
417{
418 struct inet_request_sock *ireq = inet_rsk(req);
419 struct ipv6_pinfo *newnp;
420 const struct ipv6_pinfo *np = inet6_sk(sk);
421 struct ipv6_txoptions *opt;
422 struct inet_sock *newinet;
423 struct dccp6_sock *newdp6;
424 struct sock *newsk;
425
426 if (skb->protocol == htons(ETH_P_IP)) {
427 /*
428 * v6 mapped
429 */
430 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
431 req_unhash, own_req);
432 if (newsk == NULL)
433 return NULL;
434
435 newdp6 = (struct dccp6_sock *)newsk;
436 newinet = inet_sk(newsk);
437 newinet->pinet6 = &newdp6->inet6;
438 newnp = inet6_sk(newsk);
439
440 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
441
442 newnp->saddr = newsk->sk_v6_rcv_saddr;
443
444 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
445 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
446 newnp->pktoptions = NULL;
447 newnp->opt = NULL;
448 newnp->ipv6_mc_list = NULL;
449 newnp->ipv6_ac_list = NULL;
450 newnp->ipv6_fl_list = NULL;
451 newnp->mcast_oif = inet_iif(skb);
452 newnp->mcast_hops = ip_hdr(skb)->ttl;
453
454 /*
455 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
456 * here, dccp_create_openreq_child now does this for us, see the comment in
457 * that function for the gory details. -acme
458 */
459
460 /* It is tricky place. Until this moment IPv4 tcp
461 worked with IPv6 icsk.icsk_af_ops.
462 Sync it now.
463 */
464 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
465
466 return newsk;
467 }
468
469
470 if (sk_acceptq_is_full(sk))
471 goto out_overflow;
472
473 if (!dst) {
474 struct flowi6 fl6;
475
476 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
477 if (!dst)
478 goto out;
479 }
480
481 newsk = dccp_create_openreq_child(sk, req, skb);
482 if (newsk == NULL)
483 goto out_nonewsk;
484
485 /*
486 * No need to charge this sock to the relevant IPv6 refcnt debug socks
487 * count here, dccp_create_openreq_child now does this for us, see the
488 * comment in that function for the gory details. -acme
489 */
490
491 ip6_dst_store(newsk, dst, NULL, NULL);
492 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
493 NETIF_F_TSO);
494 newdp6 = (struct dccp6_sock *)newsk;
495 newinet = inet_sk(newsk);
496 newinet->pinet6 = &newdp6->inet6;
497 newnp = inet6_sk(newsk);
498
499 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
500
501 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
502 newnp->saddr = ireq->ir_v6_loc_addr;
503 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
504 newsk->sk_bound_dev_if = ireq->ir_iif;
505
506 /* Now IPv6 options...
507
508 First: no IPv4 options.
509 */
510 newinet->inet_opt = NULL;
511
512 /* Clone RX bits */
513 newnp->rxopt.all = np->rxopt.all;
514
515 newnp->ipv6_mc_list = NULL;
516 newnp->ipv6_ac_list = NULL;
517 newnp->ipv6_fl_list = NULL;
518 newnp->pktoptions = NULL;
519 newnp->opt = NULL;
520 newnp->mcast_oif = inet6_iif(skb);
521 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
522
523 /*
524 * Clone native IPv6 options from listening socket (if any)
525 *
526 * Yes, keeping reference count would be much more clever, but we make
527 * one more one thing there: reattach optmem to newsk.
528 */
529 opt = ireq->ipv6_opt;
530 if (!opt)
531 opt = rcu_dereference(np->opt);
532 if (opt) {
533 opt = ipv6_dup_options(newsk, opt);
534 RCU_INIT_POINTER(newnp->opt, opt);
535 }
536 inet_csk(newsk)->icsk_ext_hdr_len = 0;
537 if (opt)
538 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
539 opt->opt_flen;
540
541 dccp_sync_mss(newsk, dst_mtu(dst));
542
543 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
544 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
545
546 if (__inet_inherit_port(sk, newsk) < 0) {
547 inet_csk_prepare_forced_close(newsk);
548 dccp_done(newsk);
549 goto out;
550 }
551 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL);
552 /* Clone pktoptions received with SYN, if we own the req */
553 if (*own_req && ireq->pktopts) {
554 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
555 consume_skb(ireq->pktopts);
556 ireq->pktopts = NULL;
557 }
558
559 return newsk;
560
561out_overflow:
562 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
563out_nonewsk:
564 dst_release(dst);
565out:
566 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
567 return NULL;
568}
569
570/* The socket must have it's spinlock held when we get
571 * here.
572 *
573 * We have a potential double-lock case here, so even when
574 * doing backlog processing we use the BH locking scheme.
575 * This is because we cannot sleep with the original spinlock
576 * held.
577 */
578static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
579{
580 struct ipv6_pinfo *np = inet6_sk(sk);
581 struct sk_buff *opt_skb = NULL;
582
583 /* Imagine: socket is IPv6. IPv4 packet arrives,
584 goes to IPv4 receive handler and backlogged.
585 From backlog it always goes here. Kerboom...
586 Fortunately, dccp_rcv_established and rcv_established
587 handle them correctly, but it is not case with
588 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
589 */
590
591 if (skb->protocol == htons(ETH_P_IP))
592 return dccp_v4_do_rcv(sk, skb);
593
594 if (sk_filter(sk, skb))
595 goto discard;
596
597 /*
598 * socket locking is here for SMP purposes as backlog rcv is currently
599 * called with bh processing disabled.
600 */
601
602 /* Do Stevens' IPV6_PKTOPTIONS.
603
604 Yes, guys, it is the only place in our code, where we
605 may make it not affecting IPv4.
606 The rest of code is protocol independent,
607 and I do not like idea to uglify IPv4.
608
609 Actually, all the idea behind IPV6_PKTOPTIONS
610 looks not very well thought. For now we latch
611 options, received in the last packet, enqueued
612 by tcp. Feel free to propose better solution.
613 --ANK (980728)
614 */
615 if (np->rxopt.all)
616 opt_skb = skb_clone_and_charge_r(skb, sk);
617
618 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
619 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
620 goto reset;
621 if (opt_skb)
622 goto ipv6_pktoptions;
623 return 0;
624 }
625
626 /*
627 * Step 3: Process LISTEN state
628 * If S.state == LISTEN,
629 * If P.type == Request or P contains a valid Init Cookie option,
630 * (* Must scan the packet's options to check for Init
631 * Cookies. Only Init Cookies are processed here,
632 * however; other options are processed in Step 8. This
633 * scan need only be performed if the endpoint uses Init
634 * Cookies *)
635 * (* Generate a new socket and switch to that socket *)
636 * Set S := new socket for this port pair
637 * S.state = RESPOND
638 * Choose S.ISS (initial seqno) or set from Init Cookies
639 * Initialize S.GAR := S.ISS
640 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
641 * Continue with S.state == RESPOND
642 * (* A Response packet will be generated in Step 11 *)
643 * Otherwise,
644 * Generate Reset(No Connection) unless P.type == Reset
645 * Drop packet and return
646 *
647 * NOTE: the check for the packet types is done in
648 * dccp_rcv_state_process
649 */
650
651 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
652 goto reset;
653 if (opt_skb)
654 goto ipv6_pktoptions;
655 return 0;
656
657reset:
658 dccp_v6_ctl_send_reset(sk, skb);
659discard:
660 if (opt_skb != NULL)
661 __kfree_skb(opt_skb);
662 kfree_skb(skb);
663 return 0;
664
665/* Handling IPV6_PKTOPTIONS skb the similar
666 * way it's done for net/ipv6/tcp_ipv6.c
667 */
668ipv6_pktoptions:
669 if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
670 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
671 np->mcast_oif = inet6_iif(opt_skb);
672 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
673 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
674 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
675 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
676 if (np->repflow)
677 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
678 if (ipv6_opt_accepted(sk, opt_skb,
679 &DCCP_SKB_CB(opt_skb)->header.h6)) {
680 memmove(IP6CB(opt_skb),
681 &DCCP_SKB_CB(opt_skb)->header.h6,
682 sizeof(struct inet6_skb_parm));
683 opt_skb = xchg(&np->pktoptions, opt_skb);
684 } else {
685 __kfree_skb(opt_skb);
686 opt_skb = xchg(&np->pktoptions, NULL);
687 }
688 }
689
690 kfree_skb(opt_skb);
691 return 0;
692}
693
694static int dccp_v6_rcv(struct sk_buff *skb)
695{
696 const struct dccp_hdr *dh;
697 bool refcounted;
698 struct sock *sk;
699 int min_cov;
700
701 /* Step 1: Check header basics */
702
703 if (dccp_invalid_packet(skb))
704 goto discard_it;
705
706 /* Step 1: If header checksum is incorrect, drop packet and return. */
707 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
708 &ipv6_hdr(skb)->daddr)) {
709 DCCP_WARN("dropped packet with invalid checksum\n");
710 goto discard_it;
711 }
712
713 dh = dccp_hdr(skb);
714
715 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
716 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
717
718 if (dccp_packet_without_ack(skb))
719 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
720 else
721 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
722
723lookup:
724 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
725 dh->dccph_sport, dh->dccph_dport,
726 inet6_iif(skb), 0, &refcounted);
727 if (!sk) {
728 dccp_pr_debug("failed to look up flow ID in table and "
729 "get corresponding socket\n");
730 goto no_dccp_socket;
731 }
732
733 /*
734 * Step 2:
735 * ... or S.state == TIMEWAIT,
736 * Generate Reset(No Connection) unless P.type == Reset
737 * Drop packet and return
738 */
739 if (sk->sk_state == DCCP_TIME_WAIT) {
740 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
741 inet_twsk_put(inet_twsk(sk));
742 goto no_dccp_socket;
743 }
744
745 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
746 struct request_sock *req = inet_reqsk(sk);
747 struct sock *nsk;
748
749 sk = req->rsk_listener;
750 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
751 inet_csk_reqsk_queue_drop_and_put(sk, req);
752 goto lookup;
753 }
754 sock_hold(sk);
755 refcounted = true;
756 nsk = dccp_check_req(sk, skb, req);
757 if (!nsk) {
758 reqsk_put(req);
759 goto discard_and_relse;
760 }
761 if (nsk == sk) {
762 reqsk_put(req);
763 } else if (dccp_child_process(sk, nsk, skb)) {
764 dccp_v6_ctl_send_reset(sk, skb);
765 goto discard_and_relse;
766 } else {
767 sock_put(sk);
768 return 0;
769 }
770 }
771 /*
772 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
773 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
774 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
775 */
776 min_cov = dccp_sk(sk)->dccps_pcrlen;
777 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
778 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
779 dh->dccph_cscov, min_cov);
780 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
781 goto discard_and_relse;
782 }
783
784 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
785 goto discard_and_relse;
786
787 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
788 refcounted) ? -1 : 0;
789
790no_dccp_socket:
791 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
792 goto discard_it;
793 /*
794 * Step 2:
795 * If no socket ...
796 * Generate Reset(No Connection) unless P.type == Reset
797 * Drop packet and return
798 */
799 if (dh->dccph_type != DCCP_PKT_RESET) {
800 DCCP_SKB_CB(skb)->dccpd_reset_code =
801 DCCP_RESET_CODE_NO_CONNECTION;
802 dccp_v6_ctl_send_reset(sk, skb);
803 }
804
805discard_it:
806 kfree_skb(skb);
807 return 0;
808
809discard_and_relse:
810 if (refcounted)
811 sock_put(sk);
812 goto discard_it;
813}
814
815static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
816 int addr_len)
817{
818 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
819 struct inet_connection_sock *icsk = inet_csk(sk);
820 struct inet_sock *inet = inet_sk(sk);
821 struct ipv6_pinfo *np = inet6_sk(sk);
822 struct dccp_sock *dp = dccp_sk(sk);
823 struct in6_addr *saddr = NULL, *final_p, final;
824 struct ipv6_txoptions *opt;
825 struct flowi6 fl6;
826 struct dst_entry *dst;
827 int addr_type;
828 int err;
829
830 dp->dccps_role = DCCP_ROLE_CLIENT;
831
832 if (addr_len < SIN6_LEN_RFC2133)
833 return -EINVAL;
834
835 if (usin->sin6_family != AF_INET6)
836 return -EAFNOSUPPORT;
837
838 memset(&fl6, 0, sizeof(fl6));
839
840 if (np->sndflow) {
841 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
842 IP6_ECN_flow_init(fl6.flowlabel);
843 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
844 struct ip6_flowlabel *flowlabel;
845 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
846 if (IS_ERR(flowlabel))
847 return -EINVAL;
848 fl6_sock_release(flowlabel);
849 }
850 }
851 /*
852 * connect() to INADDR_ANY means loopback (BSD'ism).
853 */
854 if (ipv6_addr_any(&usin->sin6_addr))
855 usin->sin6_addr.s6_addr[15] = 1;
856
857 addr_type = ipv6_addr_type(&usin->sin6_addr);
858
859 if (addr_type & IPV6_ADDR_MULTICAST)
860 return -ENETUNREACH;
861
862 if (addr_type & IPV6_ADDR_LINKLOCAL) {
863 if (addr_len >= sizeof(struct sockaddr_in6) &&
864 usin->sin6_scope_id) {
865 /* If interface is set while binding, indices
866 * must coincide.
867 */
868 if (sk->sk_bound_dev_if &&
869 sk->sk_bound_dev_if != usin->sin6_scope_id)
870 return -EINVAL;
871
872 sk->sk_bound_dev_if = usin->sin6_scope_id;
873 }
874
875 /* Connect to link-local address requires an interface */
876 if (!sk->sk_bound_dev_if)
877 return -EINVAL;
878 }
879
880 sk->sk_v6_daddr = usin->sin6_addr;
881 np->flow_label = fl6.flowlabel;
882
883 /*
884 * DCCP over IPv4
885 */
886 if (addr_type == IPV6_ADDR_MAPPED) {
887 u32 exthdrlen = icsk->icsk_ext_hdr_len;
888 struct sockaddr_in sin;
889
890 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
891
892 if (ipv6_only_sock(sk))
893 return -ENETUNREACH;
894
895 sin.sin_family = AF_INET;
896 sin.sin_port = usin->sin6_port;
897 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
898
899 icsk->icsk_af_ops = &dccp_ipv6_mapped;
900 sk->sk_backlog_rcv = dccp_v4_do_rcv;
901
902 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
903 if (err) {
904 icsk->icsk_ext_hdr_len = exthdrlen;
905 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
906 sk->sk_backlog_rcv = dccp_v6_do_rcv;
907 goto failure;
908 }
909 np->saddr = sk->sk_v6_rcv_saddr;
910 return err;
911 }
912
913 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
914 saddr = &sk->sk_v6_rcv_saddr;
915
916 fl6.flowi6_proto = IPPROTO_DCCP;
917 fl6.daddr = sk->sk_v6_daddr;
918 fl6.saddr = saddr ? *saddr : np->saddr;
919 fl6.flowi6_oif = sk->sk_bound_dev_if;
920 fl6.fl6_dport = usin->sin6_port;
921 fl6.fl6_sport = inet->inet_sport;
922 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
923
924 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
925 final_p = fl6_update_dst(&fl6, opt, &final);
926
927 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
928 if (IS_ERR(dst)) {
929 err = PTR_ERR(dst);
930 goto failure;
931 }
932
933 if (saddr == NULL) {
934 saddr = &fl6.saddr;
935
936 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
937 if (err)
938 goto failure;
939 }
940
941 /* set the source address */
942 np->saddr = *saddr;
943 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
944
945 ip6_dst_store(sk, dst, NULL, NULL);
946
947 icsk->icsk_ext_hdr_len = 0;
948 if (opt)
949 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
950
951 inet->inet_dport = usin->sin6_port;
952
953 dccp_set_state(sk, DCCP_REQUESTING);
954 err = inet6_hash_connect(&dccp_death_row, sk);
955 if (err)
956 goto late_failure;
957
958 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
959 sk->sk_v6_daddr.s6_addr32,
960 inet->inet_sport,
961 inet->inet_dport);
962 err = dccp_connect(sk);
963 if (err)
964 goto late_failure;
965
966 return 0;
967
968late_failure:
969 dccp_set_state(sk, DCCP_CLOSED);
970 inet_bhash2_reset_saddr(sk);
971 __sk_dst_reset(sk);
972failure:
973 inet->inet_dport = 0;
974 sk->sk_route_caps = 0;
975 return err;
976}
977
978static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
979 .queue_xmit = inet6_csk_xmit,
980 .send_check = dccp_v6_send_check,
981 .rebuild_header = inet6_sk_rebuild_header,
982 .conn_request = dccp_v6_conn_request,
983 .syn_recv_sock = dccp_v6_request_recv_sock,
984 .net_header_len = sizeof(struct ipv6hdr),
985 .setsockopt = ipv6_setsockopt,
986 .getsockopt = ipv6_getsockopt,
987 .addr2sockaddr = inet6_csk_addr2sockaddr,
988 .sockaddr_len = sizeof(struct sockaddr_in6),
989};
990
991/*
992 * DCCP over IPv4 via INET6 API
993 */
994static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
995 .queue_xmit = ip_queue_xmit,
996 .send_check = dccp_v4_send_check,
997 .rebuild_header = inet_sk_rebuild_header,
998 .conn_request = dccp_v6_conn_request,
999 .syn_recv_sock = dccp_v6_request_recv_sock,
1000 .net_header_len = sizeof(struct iphdr),
1001 .setsockopt = ipv6_setsockopt,
1002 .getsockopt = ipv6_getsockopt,
1003 .addr2sockaddr = inet6_csk_addr2sockaddr,
1004 .sockaddr_len = sizeof(struct sockaddr_in6),
1005};
1006
1007static void dccp_v6_sk_destruct(struct sock *sk)
1008{
1009 dccp_destruct_common(sk);
1010 inet6_sock_destruct(sk);
1011}
1012
1013/* NOTE: A lot of things set to zero explicitly by call to
1014 * sk_alloc() so need not be done here.
1015 */
1016static int dccp_v6_init_sock(struct sock *sk)
1017{
1018 static __u8 dccp_v6_ctl_sock_initialized;
1019 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1020
1021 if (err == 0) {
1022 if (unlikely(!dccp_v6_ctl_sock_initialized))
1023 dccp_v6_ctl_sock_initialized = 1;
1024 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1025 sk->sk_destruct = dccp_v6_sk_destruct;
1026 }
1027
1028 return err;
1029}
1030
1031static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1032 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1033};
1034
1035static struct proto dccp_v6_prot = {
1036 .name = "DCCPv6",
1037 .owner = THIS_MODULE,
1038 .close = dccp_close,
1039 .connect = dccp_v6_connect,
1040 .disconnect = dccp_disconnect,
1041 .ioctl = dccp_ioctl,
1042 .init = dccp_v6_init_sock,
1043 .setsockopt = dccp_setsockopt,
1044 .getsockopt = dccp_getsockopt,
1045 .sendmsg = dccp_sendmsg,
1046 .recvmsg = dccp_recvmsg,
1047 .backlog_rcv = dccp_v6_do_rcv,
1048 .hash = inet6_hash,
1049 .unhash = inet_unhash,
1050 .accept = inet_csk_accept,
1051 .get_port = inet_csk_get_port,
1052 .shutdown = dccp_shutdown,
1053 .destroy = dccp_destroy_sock,
1054 .orphan_count = &dccp_orphan_count,
1055 .max_header = MAX_DCCP_HEADER,
1056 .obj_size = sizeof(struct dccp6_sock),
1057 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1058 .rsk_prot = &dccp6_request_sock_ops,
1059 .twsk_prot = &dccp6_timewait_sock_ops,
1060 .h.hashinfo = &dccp_hashinfo,
1061};
1062
1063static const struct inet6_protocol dccp_v6_protocol = {
1064 .handler = dccp_v6_rcv,
1065 .err_handler = dccp_v6_err,
1066 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1067};
1068
1069static const struct proto_ops inet6_dccp_ops = {
1070 .family = PF_INET6,
1071 .owner = THIS_MODULE,
1072 .release = inet6_release,
1073 .bind = inet6_bind,
1074 .connect = inet_stream_connect,
1075 .socketpair = sock_no_socketpair,
1076 .accept = inet_accept,
1077 .getname = inet6_getname,
1078 .poll = dccp_poll,
1079 .ioctl = inet6_ioctl,
1080 .gettstamp = sock_gettstamp,
1081 .listen = inet_dccp_listen,
1082 .shutdown = inet_shutdown,
1083 .setsockopt = sock_common_setsockopt,
1084 .getsockopt = sock_common_getsockopt,
1085 .sendmsg = inet_sendmsg,
1086 .recvmsg = sock_common_recvmsg,
1087 .mmap = sock_no_mmap,
1088 .sendpage = sock_no_sendpage,
1089#ifdef CONFIG_COMPAT
1090 .compat_ioctl = inet6_compat_ioctl,
1091#endif
1092};
1093
1094static struct inet_protosw dccp_v6_protosw = {
1095 .type = SOCK_DCCP,
1096 .protocol = IPPROTO_DCCP,
1097 .prot = &dccp_v6_prot,
1098 .ops = &inet6_dccp_ops,
1099 .flags = INET_PROTOSW_ICSK,
1100};
1101
1102static int __net_init dccp_v6_init_net(struct net *net)
1103{
1104 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1105
1106 if (dccp_hashinfo.bhash == NULL)
1107 return -ESOCKTNOSUPPORT;
1108
1109 return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6,
1110 SOCK_DCCP, IPPROTO_DCCP, net);
1111}
1112
1113static void __net_exit dccp_v6_exit_net(struct net *net)
1114{
1115 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1116
1117 inet_ctl_sock_destroy(pn->v6_ctl_sk);
1118}
1119
1120static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1121{
1122 inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1123}
1124
1125static struct pernet_operations dccp_v6_ops = {
1126 .init = dccp_v6_init_net,
1127 .exit = dccp_v6_exit_net,
1128 .exit_batch = dccp_v6_exit_batch,
1129 .id = &dccp_v6_pernet_id,
1130 .size = sizeof(struct dccp_v6_pernet),
1131};
1132
1133static int __init dccp_v6_init(void)
1134{
1135 int err = proto_register(&dccp_v6_prot, 1);
1136
1137 if (err)
1138 goto out;
1139
1140 inet6_register_protosw(&dccp_v6_protosw);
1141
1142 err = register_pernet_subsys(&dccp_v6_ops);
1143 if (err)
1144 goto out_destroy_ctl_sock;
1145
1146 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1147 if (err)
1148 goto out_unregister_proto;
1149
1150out:
1151 return err;
1152out_unregister_proto:
1153 unregister_pernet_subsys(&dccp_v6_ops);
1154out_destroy_ctl_sock:
1155 inet6_unregister_protosw(&dccp_v6_protosw);
1156 proto_unregister(&dccp_v6_prot);
1157 goto out;
1158}
1159
1160static void __exit dccp_v6_exit(void)
1161{
1162 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1163 unregister_pernet_subsys(&dccp_v6_ops);
1164 inet6_unregister_protosw(&dccp_v6_protosw);
1165 proto_unregister(&dccp_v6_prot);
1166}
1167
1168module_init(dccp_v6_init);
1169module_exit(dccp_v6_exit);
1170
1171/*
1172 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1173 * values directly, Also cover the case where the protocol is not specified,
1174 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1175 */
1176MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1177MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1178MODULE_LICENSE("GPL");
1179MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1180MODULE_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/netns/generic.h>
31#include <net/sock.h>
32
33#include "dccp.h"
34#include "ipv6.h"
35#include "feat.h"
36
37struct dccp_v6_pernet {
38 struct sock *v6_ctl_sk;
39};
40
41static unsigned int dccp_v6_pernet_id __read_mostly;
42
43/* The per-net v6_ctl_sk is used for sending RSTs and ACKs */
44
45static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
46static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
47
48/* add pseudo-header to DCCP checksum stored in skb->csum */
49static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
50 const struct in6_addr *saddr,
51 const struct in6_addr *daddr)
52{
53 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
54}
55
56static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
57{
58 struct ipv6_pinfo *np = inet6_sk(sk);
59 struct dccp_hdr *dh = dccp_hdr(skb);
60
61 dccp_csum_outgoing(skb);
62 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
63}
64
65static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
66{
67 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
68 ipv6_hdr(skb)->saddr.s6_addr32,
69 dccp_hdr(skb)->dccph_dport,
70 dccp_hdr(skb)->dccph_sport );
71
72}
73
74static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
75 u8 type, u8 code, int offset, __be32 info)
76{
77 const struct ipv6hdr *hdr;
78 const struct dccp_hdr *dh;
79 struct dccp_sock *dp;
80 struct ipv6_pinfo *np;
81 struct sock *sk;
82 int err;
83 __u64 seq;
84 struct net *net = dev_net(skb->dev);
85
86 if (!pskb_may_pull(skb, offset + sizeof(*dh)))
87 return -EINVAL;
88 dh = (struct dccp_hdr *)(skb->data + offset);
89 if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh)))
90 return -EINVAL;
91 hdr = (const struct ipv6hdr *)skb->data;
92 dh = (struct dccp_hdr *)(skb->data + offset);
93
94 sk = __inet6_lookup_established(net, &dccp_hashinfo,
95 &hdr->daddr, dh->dccph_dport,
96 &hdr->saddr, ntohs(dh->dccph_sport),
97 inet6_iif(skb), 0);
98
99 if (!sk) {
100 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
101 ICMP6_MIB_INERRORS);
102 return -ENOENT;
103 }
104
105 if (sk->sk_state == DCCP_TIME_WAIT) {
106 inet_twsk_put(inet_twsk(sk));
107 return 0;
108 }
109 seq = dccp_hdr_seq(dh);
110 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
111 dccp_req_err(sk, seq);
112 return 0;
113 }
114
115 bh_lock_sock(sk);
116 if (sock_owned_by_user(sk))
117 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
118
119 if (sk->sk_state == DCCP_CLOSED)
120 goto out;
121
122 dp = dccp_sk(sk);
123 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
124 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
125 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
126 goto out;
127 }
128
129 np = inet6_sk(sk);
130
131 if (type == NDISC_REDIRECT) {
132 if (!sock_owned_by_user(sk)) {
133 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
134
135 if (dst)
136 dst->ops->redirect(dst, sk, skb);
137 }
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 case DCCP_REQUESTING:
166 case DCCP_RESPOND: /* Cannot happen.
167 It can, it SYNs are crossed. --ANK */
168 if (!sock_owned_by_user(sk)) {
169 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
170 sk->sk_err = err;
171 /*
172 * Wake people up to see the error
173 * (see connect in sock.c)
174 */
175 sk_error_report(sk);
176 dccp_done(sk);
177 } else {
178 WRITE_ONCE(sk->sk_err_soft, err);
179 }
180 goto out;
181 }
182
183 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
184 sk->sk_err = err;
185 sk_error_report(sk);
186 } else {
187 WRITE_ONCE(sk->sk_err_soft, err);
188 }
189out:
190 bh_unlock_sock(sk);
191 sock_put(sk);
192 return 0;
193}
194
195
196static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
197{
198 struct inet_request_sock *ireq = inet_rsk(req);
199 struct ipv6_pinfo *np = inet6_sk(sk);
200 struct sk_buff *skb;
201 struct in6_addr *final_p, final;
202 struct flowi6 fl6;
203 int err = -1;
204 struct dst_entry *dst;
205
206 memset(&fl6, 0, sizeof(fl6));
207 fl6.flowi6_proto = IPPROTO_DCCP;
208 fl6.daddr = ireq->ir_v6_rmt_addr;
209 fl6.saddr = ireq->ir_v6_loc_addr;
210 fl6.flowlabel = 0;
211 fl6.flowi6_oif = ireq->ir_iif;
212 fl6.fl6_dport = ireq->ir_rmt_port;
213 fl6.fl6_sport = htons(ireq->ir_num);
214 security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
215
216
217 rcu_read_lock();
218 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
219 rcu_read_unlock();
220
221 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
222 if (IS_ERR(dst)) {
223 err = PTR_ERR(dst);
224 dst = NULL;
225 goto done;
226 }
227
228 skb = dccp_make_response(sk, dst, req);
229 if (skb != NULL) {
230 struct dccp_hdr *dh = dccp_hdr(skb);
231 struct ipv6_txoptions *opt;
232
233 dh->dccph_checksum = dccp_v6_csum_finish(skb,
234 &ireq->ir_v6_loc_addr,
235 &ireq->ir_v6_rmt_addr);
236 fl6.daddr = ireq->ir_v6_rmt_addr;
237 rcu_read_lock();
238 opt = ireq->ipv6_opt;
239 if (!opt)
240 opt = rcu_dereference(np->opt);
241 err = ip6_xmit(sk, skb, &fl6, READ_ONCE(sk->sk_mark), opt,
242 np->tclass, READ_ONCE(sk->sk_priority));
243 rcu_read_unlock();
244 err = net_xmit_eval(err);
245 }
246
247done:
248 dst_release(dst);
249 return err;
250}
251
252static void dccp_v6_reqsk_destructor(struct request_sock *req)
253{
254 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
255 kfree(inet_rsk(req)->ipv6_opt);
256 kfree_skb(inet_rsk(req)->pktopts);
257}
258
259static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
260{
261 const struct ipv6hdr *rxip6h;
262 struct sk_buff *skb;
263 struct flowi6 fl6;
264 struct net *net = dev_net(skb_dst(rxskb)->dev);
265 struct dccp_v6_pernet *pn;
266 struct sock *ctl_sk;
267 struct dst_entry *dst;
268
269 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
270 return;
271
272 if (!ipv6_unicast_destination(rxskb))
273 return;
274
275 pn = net_generic(net, dccp_v6_pernet_id);
276 ctl_sk = pn->v6_ctl_sk;
277 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
278 if (skb == NULL)
279 return;
280
281 rxip6h = ipv6_hdr(rxskb);
282 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
283 &rxip6h->daddr);
284
285 memset(&fl6, 0, sizeof(fl6));
286 fl6.daddr = rxip6h->saddr;
287 fl6.saddr = rxip6h->daddr;
288
289 fl6.flowi6_proto = IPPROTO_DCCP;
290 fl6.flowi6_oif = inet6_iif(rxskb);
291 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
292 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
293 security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6));
294
295 /* sk = NULL, but it is safe for now. RST socket required. */
296 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
297 if (!IS_ERR(dst)) {
298 skb_dst_set(skb, dst);
299 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
300 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
301 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
302 return;
303 }
304
305 kfree_skb(skb);
306}
307
308static struct request_sock_ops dccp6_request_sock_ops = {
309 .family = AF_INET6,
310 .obj_size = sizeof(struct dccp6_request_sock),
311 .rtx_syn_ack = dccp_v6_send_response,
312 .send_ack = dccp_reqsk_send_ack,
313 .destructor = dccp_v6_reqsk_destructor,
314 .send_reset = dccp_v6_ctl_send_reset,
315 .syn_ack_timeout = dccp_syn_ack_timeout,
316};
317
318static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
319{
320 struct request_sock *req;
321 struct dccp_request_sock *dreq;
322 struct inet_request_sock *ireq;
323 struct ipv6_pinfo *np = inet6_sk(sk);
324 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
325 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
326
327 if (skb->protocol == htons(ETH_P_IP))
328 return dccp_v4_conn_request(sk, skb);
329
330 if (!ipv6_unicast_destination(skb))
331 return 0; /* discard, don't send a reset here */
332
333 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
334 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
335 return 0;
336 }
337
338 if (dccp_bad_service_code(sk, service)) {
339 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
340 goto drop;
341 }
342 /*
343 * There are no SYN attacks on IPv6, yet...
344 */
345 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
346 if (inet_csk_reqsk_queue_is_full(sk))
347 goto drop;
348
349 if (sk_acceptq_is_full(sk))
350 goto drop;
351
352 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
353 if (req == NULL)
354 goto drop;
355
356 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
357 goto drop_and_free;
358
359 dreq = dccp_rsk(req);
360 if (dccp_parse_options(sk, dreq, skb))
361 goto drop_and_free;
362
363 ireq = inet_rsk(req);
364 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
365 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
366 ireq->ireq_family = AF_INET6;
367 ireq->ir_mark = inet_request_mark(sk, skb);
368
369 if (security_inet_conn_request(sk, skb, req))
370 goto drop_and_free;
371
372 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
373 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
374 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
375 refcount_inc(&skb->users);
376 ireq->pktopts = skb;
377 }
378 ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if);
379
380 /* So that link locals have meaning */
381 if (!ireq->ir_iif &&
382 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
383 ireq->ir_iif = inet6_iif(skb);
384
385 /*
386 * Step 3: Process LISTEN state
387 *
388 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
389 *
390 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
391 */
392 dreq->dreq_isr = dcb->dccpd_seq;
393 dreq->dreq_gsr = dreq->dreq_isr;
394 dreq->dreq_iss = dccp_v6_init_sequence(skb);
395 dreq->dreq_gss = dreq->dreq_iss;
396 dreq->dreq_service = service;
397
398 if (dccp_v6_send_response(sk, req))
399 goto drop_and_free;
400
401 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
402 reqsk_put(req);
403 return 0;
404
405drop_and_free:
406 reqsk_free(req);
407drop:
408 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
409 return -1;
410}
411
412static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
413 struct sk_buff *skb,
414 struct request_sock *req,
415 struct dst_entry *dst,
416 struct request_sock *req_unhash,
417 bool *own_req)
418{
419 struct inet_request_sock *ireq = inet_rsk(req);
420 struct ipv6_pinfo *newnp;
421 const struct ipv6_pinfo *np = inet6_sk(sk);
422 struct ipv6_txoptions *opt;
423 struct inet_sock *newinet;
424 struct dccp6_sock *newdp6;
425 struct sock *newsk;
426
427 if (skb->protocol == htons(ETH_P_IP)) {
428 /*
429 * v6 mapped
430 */
431 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
432 req_unhash, own_req);
433 if (newsk == NULL)
434 return NULL;
435
436 newdp6 = (struct dccp6_sock *)newsk;
437 newinet = inet_sk(newsk);
438 newinet->pinet6 = &newdp6->inet6;
439 newnp = inet6_sk(newsk);
440
441 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
442
443 newnp->saddr = newsk->sk_v6_rcv_saddr;
444
445 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
446 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
447 newnp->pktoptions = NULL;
448 newnp->opt = NULL;
449 newnp->ipv6_mc_list = NULL;
450 newnp->ipv6_ac_list = NULL;
451 newnp->ipv6_fl_list = NULL;
452 newnp->mcast_oif = inet_iif(skb);
453 newnp->mcast_hops = ip_hdr(skb)->ttl;
454
455 /*
456 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
457 * here, dccp_create_openreq_child now does this for us, see the comment in
458 * that function for the gory details. -acme
459 */
460
461 /* It is tricky place. Until this moment IPv4 tcp
462 worked with IPv6 icsk.icsk_af_ops.
463 Sync it now.
464 */
465 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
466
467 return newsk;
468 }
469
470
471 if (sk_acceptq_is_full(sk))
472 goto out_overflow;
473
474 if (!dst) {
475 struct flowi6 fl6;
476
477 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
478 if (!dst)
479 goto out;
480 }
481
482 newsk = dccp_create_openreq_child(sk, req, skb);
483 if (newsk == NULL)
484 goto out_nonewsk;
485
486 /*
487 * No need to charge this sock to the relevant IPv6 refcnt debug socks
488 * count here, dccp_create_openreq_child now does this for us, see the
489 * comment in that function for the gory details. -acme
490 */
491
492 ip6_dst_store(newsk, dst, NULL, NULL);
493 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
494 NETIF_F_TSO);
495 newdp6 = (struct dccp6_sock *)newsk;
496 newinet = inet_sk(newsk);
497 newinet->pinet6 = &newdp6->inet6;
498 newnp = inet6_sk(newsk);
499
500 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
501
502 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
503 newnp->saddr = ireq->ir_v6_loc_addr;
504 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
505 newsk->sk_bound_dev_if = ireq->ir_iif;
506
507 /* Now IPv6 options...
508
509 First: no IPv4 options.
510 */
511 newinet->inet_opt = NULL;
512
513 /* Clone RX bits */
514 newnp->rxopt.all = np->rxopt.all;
515
516 newnp->ipv6_mc_list = NULL;
517 newnp->ipv6_ac_list = NULL;
518 newnp->ipv6_fl_list = NULL;
519 newnp->pktoptions = NULL;
520 newnp->opt = NULL;
521 newnp->mcast_oif = inet6_iif(skb);
522 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
523
524 /*
525 * Clone native IPv6 options from listening socket (if any)
526 *
527 * Yes, keeping reference count would be much more clever, but we make
528 * one more one thing there: reattach optmem to newsk.
529 */
530 opt = ireq->ipv6_opt;
531 if (!opt)
532 opt = rcu_dereference(np->opt);
533 if (opt) {
534 opt = ipv6_dup_options(newsk, opt);
535 RCU_INIT_POINTER(newnp->opt, opt);
536 }
537 inet_csk(newsk)->icsk_ext_hdr_len = 0;
538 if (opt)
539 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
540 opt->opt_flen;
541
542 dccp_sync_mss(newsk, dst_mtu(dst));
543
544 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
545 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
546
547 if (__inet_inherit_port(sk, newsk) < 0) {
548 inet_csk_prepare_forced_close(newsk);
549 dccp_done(newsk);
550 goto out;
551 }
552 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL);
553 /* Clone pktoptions received with SYN, if we own the req */
554 if (*own_req && ireq->pktopts) {
555 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
556 consume_skb(ireq->pktopts);
557 ireq->pktopts = NULL;
558 }
559
560 return newsk;
561
562out_overflow:
563 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
564out_nonewsk:
565 dst_release(dst);
566out:
567 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
568 return NULL;
569}
570
571/* The socket must have it's spinlock held when we get
572 * here.
573 *
574 * We have a potential double-lock case here, so even when
575 * doing backlog processing we use the BH locking scheme.
576 * This is because we cannot sleep with the original spinlock
577 * held.
578 */
579static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
580{
581 struct ipv6_pinfo *np = inet6_sk(sk);
582 struct sk_buff *opt_skb = NULL;
583
584 /* Imagine: socket is IPv6. IPv4 packet arrives,
585 goes to IPv4 receive handler and backlogged.
586 From backlog it always goes here. Kerboom...
587 Fortunately, dccp_rcv_established and rcv_established
588 handle them correctly, but it is not case with
589 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
590 */
591
592 if (skb->protocol == htons(ETH_P_IP))
593 return dccp_v4_do_rcv(sk, skb);
594
595 if (sk_filter(sk, skb))
596 goto discard;
597
598 /*
599 * socket locking is here for SMP purposes as backlog rcv is currently
600 * called with bh processing disabled.
601 */
602
603 /* Do Stevens' IPV6_PKTOPTIONS.
604
605 Yes, guys, it is the only place in our code, where we
606 may make it not affecting IPv4.
607 The rest of code is protocol independent,
608 and I do not like idea to uglify IPv4.
609
610 Actually, all the idea behind IPV6_PKTOPTIONS
611 looks not very well thought. For now we latch
612 options, received in the last packet, enqueued
613 by tcp. Feel free to propose better solution.
614 --ANK (980728)
615 */
616 if (np->rxopt.all)
617 opt_skb = skb_clone_and_charge_r(skb, sk);
618
619 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
620 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
621 goto reset;
622 if (opt_skb)
623 goto ipv6_pktoptions;
624 return 0;
625 }
626
627 /*
628 * Step 3: Process LISTEN state
629 * If S.state == LISTEN,
630 * If P.type == Request or P contains a valid Init Cookie option,
631 * (* Must scan the packet's options to check for Init
632 * Cookies. Only Init Cookies are processed here,
633 * however; other options are processed in Step 8. This
634 * scan need only be performed if the endpoint uses Init
635 * Cookies *)
636 * (* Generate a new socket and switch to that socket *)
637 * Set S := new socket for this port pair
638 * S.state = RESPOND
639 * Choose S.ISS (initial seqno) or set from Init Cookies
640 * Initialize S.GAR := S.ISS
641 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
642 * Continue with S.state == RESPOND
643 * (* A Response packet will be generated in Step 11 *)
644 * Otherwise,
645 * Generate Reset(No Connection) unless P.type == Reset
646 * Drop packet and return
647 *
648 * NOTE: the check for the packet types is done in
649 * dccp_rcv_state_process
650 */
651
652 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
653 goto reset;
654 if (opt_skb)
655 goto ipv6_pktoptions;
656 return 0;
657
658reset:
659 dccp_v6_ctl_send_reset(sk, skb);
660discard:
661 if (opt_skb != NULL)
662 __kfree_skb(opt_skb);
663 kfree_skb(skb);
664 return 0;
665
666/* Handling IPV6_PKTOPTIONS skb the similar
667 * way it's done for net/ipv6/tcp_ipv6.c
668 */
669ipv6_pktoptions:
670 if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
671 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
672 WRITE_ONCE(np->mcast_oif, inet6_iif(opt_skb));
673 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
674 WRITE_ONCE(np->mcast_hops, ipv6_hdr(opt_skb)->hop_limit);
675 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
676 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
677 if (inet6_test_bit(REPFLOW, sk))
678 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
679 if (ipv6_opt_accepted(sk, opt_skb,
680 &DCCP_SKB_CB(opt_skb)->header.h6)) {
681 memmove(IP6CB(opt_skb),
682 &DCCP_SKB_CB(opt_skb)->header.h6,
683 sizeof(struct inet6_skb_parm));
684 opt_skb = xchg(&np->pktoptions, opt_skb);
685 } else {
686 __kfree_skb(opt_skb);
687 opt_skb = xchg(&np->pktoptions, NULL);
688 }
689 }
690
691 kfree_skb(opt_skb);
692 return 0;
693}
694
695static int dccp_v6_rcv(struct sk_buff *skb)
696{
697 const struct dccp_hdr *dh;
698 bool refcounted;
699 struct sock *sk;
700 int min_cov;
701
702 /* Step 1: Check header basics */
703
704 if (dccp_invalid_packet(skb))
705 goto discard_it;
706
707 /* Step 1: If header checksum is incorrect, drop packet and return. */
708 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
709 &ipv6_hdr(skb)->daddr)) {
710 DCCP_WARN("dropped packet with invalid checksum\n");
711 goto discard_it;
712 }
713
714 dh = dccp_hdr(skb);
715
716 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
717 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
718
719 if (dccp_packet_without_ack(skb))
720 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
721 else
722 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
723
724lookup:
725 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
726 dh->dccph_sport, dh->dccph_dport,
727 inet6_iif(skb), 0, &refcounted);
728 if (!sk) {
729 dccp_pr_debug("failed to look up flow ID in table and "
730 "get corresponding socket\n");
731 goto no_dccp_socket;
732 }
733
734 /*
735 * Step 2:
736 * ... or S.state == TIMEWAIT,
737 * Generate Reset(No Connection) unless P.type == Reset
738 * Drop packet and return
739 */
740 if (sk->sk_state == DCCP_TIME_WAIT) {
741 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
742 inet_twsk_put(inet_twsk(sk));
743 goto no_dccp_socket;
744 }
745
746 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
747 struct request_sock *req = inet_reqsk(sk);
748 struct sock *nsk;
749
750 sk = req->rsk_listener;
751 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
752 inet_csk_reqsk_queue_drop_and_put(sk, req);
753 goto lookup;
754 }
755 sock_hold(sk);
756 refcounted = true;
757 nsk = dccp_check_req(sk, skb, req);
758 if (!nsk) {
759 reqsk_put(req);
760 goto discard_and_relse;
761 }
762 if (nsk == sk) {
763 reqsk_put(req);
764 } else if (dccp_child_process(sk, nsk, skb)) {
765 dccp_v6_ctl_send_reset(sk, skb);
766 goto discard_and_relse;
767 } else {
768 sock_put(sk);
769 return 0;
770 }
771 }
772 /*
773 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
774 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
775 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
776 */
777 min_cov = dccp_sk(sk)->dccps_pcrlen;
778 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
779 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
780 dh->dccph_cscov, min_cov);
781 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
782 goto discard_and_relse;
783 }
784
785 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
786 goto discard_and_relse;
787 nf_reset_ct(skb);
788
789 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
790 refcounted) ? -1 : 0;
791
792no_dccp_socket:
793 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
794 goto discard_it;
795 /*
796 * Step 2:
797 * If no socket ...
798 * Generate Reset(No Connection) unless P.type == Reset
799 * Drop packet and return
800 */
801 if (dh->dccph_type != DCCP_PKT_RESET) {
802 DCCP_SKB_CB(skb)->dccpd_reset_code =
803 DCCP_RESET_CODE_NO_CONNECTION;
804 dccp_v6_ctl_send_reset(sk, skb);
805 }
806
807discard_it:
808 kfree_skb(skb);
809 return 0;
810
811discard_and_relse:
812 if (refcounted)
813 sock_put(sk);
814 goto discard_it;
815}
816
817static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
818 int addr_len)
819{
820 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
821 struct inet_connection_sock *icsk = inet_csk(sk);
822 struct inet_sock *inet = inet_sk(sk);
823 struct ipv6_pinfo *np = inet6_sk(sk);
824 struct dccp_sock *dp = dccp_sk(sk);
825 struct in6_addr *saddr = NULL, *final_p, final;
826 struct ipv6_txoptions *opt;
827 struct flowi6 fl6;
828 struct dst_entry *dst;
829 int addr_type;
830 int err;
831
832 dp->dccps_role = DCCP_ROLE_CLIENT;
833
834 if (addr_len < SIN6_LEN_RFC2133)
835 return -EINVAL;
836
837 if (usin->sin6_family != AF_INET6)
838 return -EAFNOSUPPORT;
839
840 memset(&fl6, 0, sizeof(fl6));
841
842 if (inet6_test_bit(SNDFLOW, sk)) {
843 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
844 IP6_ECN_flow_init(fl6.flowlabel);
845 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
846 struct ip6_flowlabel *flowlabel;
847 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
848 if (IS_ERR(flowlabel))
849 return -EINVAL;
850 fl6_sock_release(flowlabel);
851 }
852 }
853 /*
854 * connect() to INADDR_ANY means loopback (BSD'ism).
855 */
856 if (ipv6_addr_any(&usin->sin6_addr))
857 usin->sin6_addr.s6_addr[15] = 1;
858
859 addr_type = ipv6_addr_type(&usin->sin6_addr);
860
861 if (addr_type & IPV6_ADDR_MULTICAST)
862 return -ENETUNREACH;
863
864 if (addr_type & IPV6_ADDR_LINKLOCAL) {
865 if (addr_len >= sizeof(struct sockaddr_in6) &&
866 usin->sin6_scope_id) {
867 /* If interface is set while binding, indices
868 * must coincide.
869 */
870 if (sk->sk_bound_dev_if &&
871 sk->sk_bound_dev_if != usin->sin6_scope_id)
872 return -EINVAL;
873
874 sk->sk_bound_dev_if = usin->sin6_scope_id;
875 }
876
877 /* Connect to link-local address requires an interface */
878 if (!sk->sk_bound_dev_if)
879 return -EINVAL;
880 }
881
882 sk->sk_v6_daddr = usin->sin6_addr;
883 np->flow_label = fl6.flowlabel;
884
885 /*
886 * DCCP over IPv4
887 */
888 if (addr_type == IPV6_ADDR_MAPPED) {
889 u32 exthdrlen = icsk->icsk_ext_hdr_len;
890 struct sockaddr_in sin;
891
892 net_dbg_ratelimited("connect: ipv4 mapped\n");
893
894 if (ipv6_only_sock(sk))
895 return -ENETUNREACH;
896
897 sin.sin_family = AF_INET;
898 sin.sin_port = usin->sin6_port;
899 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
900
901 icsk->icsk_af_ops = &dccp_ipv6_mapped;
902 sk->sk_backlog_rcv = dccp_v4_do_rcv;
903
904 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
905 if (err) {
906 icsk->icsk_ext_hdr_len = exthdrlen;
907 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
908 sk->sk_backlog_rcv = dccp_v6_do_rcv;
909 goto failure;
910 }
911 np->saddr = sk->sk_v6_rcv_saddr;
912 return err;
913 }
914
915 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
916 saddr = &sk->sk_v6_rcv_saddr;
917
918 fl6.flowi6_proto = IPPROTO_DCCP;
919 fl6.daddr = sk->sk_v6_daddr;
920 fl6.saddr = saddr ? *saddr : np->saddr;
921 fl6.flowi6_oif = sk->sk_bound_dev_if;
922 fl6.fl6_dport = usin->sin6_port;
923 fl6.fl6_sport = inet->inet_sport;
924 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
925
926 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
927 final_p = fl6_update_dst(&fl6, opt, &final);
928
929 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
930 if (IS_ERR(dst)) {
931 err = PTR_ERR(dst);
932 goto failure;
933 }
934
935 if (saddr == NULL) {
936 saddr = &fl6.saddr;
937
938 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
939 if (err)
940 goto failure;
941 }
942
943 /* set the source address */
944 np->saddr = *saddr;
945 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
946
947 ip6_dst_store(sk, dst, NULL, NULL);
948
949 icsk->icsk_ext_hdr_len = 0;
950 if (opt)
951 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
952
953 inet->inet_dport = usin->sin6_port;
954
955 dccp_set_state(sk, DCCP_REQUESTING);
956 err = inet6_hash_connect(&dccp_death_row, sk);
957 if (err)
958 goto late_failure;
959
960 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
961 sk->sk_v6_daddr.s6_addr32,
962 inet->inet_sport,
963 inet->inet_dport);
964 err = dccp_connect(sk);
965 if (err)
966 goto late_failure;
967
968 return 0;
969
970late_failure:
971 dccp_set_state(sk, DCCP_CLOSED);
972 inet_bhash2_reset_saddr(sk);
973 __sk_dst_reset(sk);
974failure:
975 inet->inet_dport = 0;
976 sk->sk_route_caps = 0;
977 return err;
978}
979
980static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
981 .queue_xmit = inet6_csk_xmit,
982 .send_check = dccp_v6_send_check,
983 .rebuild_header = inet6_sk_rebuild_header,
984 .conn_request = dccp_v6_conn_request,
985 .syn_recv_sock = dccp_v6_request_recv_sock,
986 .net_header_len = sizeof(struct ipv6hdr),
987 .setsockopt = ipv6_setsockopt,
988 .getsockopt = ipv6_getsockopt,
989 .addr2sockaddr = inet6_csk_addr2sockaddr,
990 .sockaddr_len = sizeof(struct sockaddr_in6),
991};
992
993/*
994 * DCCP over IPv4 via INET6 API
995 */
996static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
997 .queue_xmit = ip_queue_xmit,
998 .send_check = dccp_v4_send_check,
999 .rebuild_header = inet_sk_rebuild_header,
1000 .conn_request = dccp_v6_conn_request,
1001 .syn_recv_sock = dccp_v6_request_recv_sock,
1002 .net_header_len = sizeof(struct iphdr),
1003 .setsockopt = ipv6_setsockopt,
1004 .getsockopt = ipv6_getsockopt,
1005 .addr2sockaddr = inet6_csk_addr2sockaddr,
1006 .sockaddr_len = sizeof(struct sockaddr_in6),
1007};
1008
1009static void dccp_v6_sk_destruct(struct sock *sk)
1010{
1011 dccp_destruct_common(sk);
1012 inet6_sock_destruct(sk);
1013}
1014
1015/* NOTE: A lot of things set to zero explicitly by call to
1016 * sk_alloc() so need not be done here.
1017 */
1018static int dccp_v6_init_sock(struct sock *sk)
1019{
1020 static __u8 dccp_v6_ctl_sock_initialized;
1021 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1022
1023 if (err == 0) {
1024 if (unlikely(!dccp_v6_ctl_sock_initialized))
1025 dccp_v6_ctl_sock_initialized = 1;
1026 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1027 sk->sk_destruct = dccp_v6_sk_destruct;
1028 }
1029
1030 return err;
1031}
1032
1033static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1034 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1035};
1036
1037static struct proto dccp_v6_prot = {
1038 .name = "DCCPv6",
1039 .owner = THIS_MODULE,
1040 .close = dccp_close,
1041 .connect = dccp_v6_connect,
1042 .disconnect = dccp_disconnect,
1043 .ioctl = dccp_ioctl,
1044 .init = dccp_v6_init_sock,
1045 .setsockopt = dccp_setsockopt,
1046 .getsockopt = dccp_getsockopt,
1047 .sendmsg = dccp_sendmsg,
1048 .recvmsg = dccp_recvmsg,
1049 .backlog_rcv = dccp_v6_do_rcv,
1050 .hash = inet6_hash,
1051 .unhash = inet_unhash,
1052 .accept = inet_csk_accept,
1053 .get_port = inet_csk_get_port,
1054 .shutdown = dccp_shutdown,
1055 .destroy = dccp_destroy_sock,
1056 .orphan_count = &dccp_orphan_count,
1057 .max_header = MAX_DCCP_HEADER,
1058 .obj_size = sizeof(struct dccp6_sock),
1059 .ipv6_pinfo_offset = offsetof(struct dccp6_sock, inet6),
1060 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1061 .rsk_prot = &dccp6_request_sock_ops,
1062 .twsk_prot = &dccp6_timewait_sock_ops,
1063 .h.hashinfo = &dccp_hashinfo,
1064};
1065
1066static const struct inet6_protocol dccp_v6_protocol = {
1067 .handler = dccp_v6_rcv,
1068 .err_handler = dccp_v6_err,
1069 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1070};
1071
1072static const struct proto_ops inet6_dccp_ops = {
1073 .family = PF_INET6,
1074 .owner = THIS_MODULE,
1075 .release = inet6_release,
1076 .bind = inet6_bind,
1077 .connect = inet_stream_connect,
1078 .socketpair = sock_no_socketpair,
1079 .accept = inet_accept,
1080 .getname = inet6_getname,
1081 .poll = dccp_poll,
1082 .ioctl = inet6_ioctl,
1083 .gettstamp = sock_gettstamp,
1084 .listen = inet_dccp_listen,
1085 .shutdown = inet_shutdown,
1086 .setsockopt = sock_common_setsockopt,
1087 .getsockopt = sock_common_getsockopt,
1088 .sendmsg = inet_sendmsg,
1089 .recvmsg = sock_common_recvmsg,
1090 .mmap = sock_no_mmap,
1091#ifdef CONFIG_COMPAT
1092 .compat_ioctl = inet6_compat_ioctl,
1093#endif
1094};
1095
1096static struct inet_protosw dccp_v6_protosw = {
1097 .type = SOCK_DCCP,
1098 .protocol = IPPROTO_DCCP,
1099 .prot = &dccp_v6_prot,
1100 .ops = &inet6_dccp_ops,
1101 .flags = INET_PROTOSW_ICSK,
1102};
1103
1104static int __net_init dccp_v6_init_net(struct net *net)
1105{
1106 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1107
1108 if (dccp_hashinfo.bhash == NULL)
1109 return -ESOCKTNOSUPPORT;
1110
1111 return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6,
1112 SOCK_DCCP, IPPROTO_DCCP, net);
1113}
1114
1115static void __net_exit dccp_v6_exit_net(struct net *net)
1116{
1117 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1118
1119 inet_ctl_sock_destroy(pn->v6_ctl_sk);
1120}
1121
1122static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1123{
1124 inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1125}
1126
1127static struct pernet_operations dccp_v6_ops = {
1128 .init = dccp_v6_init_net,
1129 .exit = dccp_v6_exit_net,
1130 .exit_batch = dccp_v6_exit_batch,
1131 .id = &dccp_v6_pernet_id,
1132 .size = sizeof(struct dccp_v6_pernet),
1133};
1134
1135static int __init dccp_v6_init(void)
1136{
1137 int err = proto_register(&dccp_v6_prot, 1);
1138
1139 if (err)
1140 goto out;
1141
1142 inet6_register_protosw(&dccp_v6_protosw);
1143
1144 err = register_pernet_subsys(&dccp_v6_ops);
1145 if (err)
1146 goto out_destroy_ctl_sock;
1147
1148 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1149 if (err)
1150 goto out_unregister_proto;
1151
1152out:
1153 return err;
1154out_unregister_proto:
1155 unregister_pernet_subsys(&dccp_v6_ops);
1156out_destroy_ctl_sock:
1157 inet6_unregister_protosw(&dccp_v6_protosw);
1158 proto_unregister(&dccp_v6_prot);
1159 goto out;
1160}
1161
1162static void __exit dccp_v6_exit(void)
1163{
1164 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1165 unregister_pernet_subsys(&dccp_v6_ops);
1166 inet6_unregister_protosw(&dccp_v6_protosw);
1167 proto_unregister(&dccp_v6_prot);
1168}
1169
1170module_init(dccp_v6_init);
1171module_exit(dccp_v6_exit);
1172
1173/*
1174 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1175 * values directly, Also cover the case where the protocol is not specified,
1176 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1177 */
1178MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1179MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1180MODULE_LICENSE("GPL");
1181MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1182MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");