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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, &np->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 == ICMPV6_PKT_TOOBIG) {
134 struct dst_entry *dst = NULL;
135
136 if (sock_owned_by_user(sk))
137 goto out;
138 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
139 goto out;
140
141 /* icmp should have updated the destination cache entry */
142 dst = __sk_dst_check(sk, np->dst_cookie);
143 if (dst == NULL) {
144 struct inet_sock *inet = inet_sk(sk);
145 struct flowi6 fl6;
146
147 /* BUGGG_FUTURE: Again, it is not clear how
148 to handle rthdr case. Ignore this complexity
149 for now.
150 */
151 memset(&fl6, 0, sizeof(fl6));
152 fl6.flowi6_proto = IPPROTO_DCCP;
153 ipv6_addr_copy(&fl6.daddr, &np->daddr);
154 ipv6_addr_copy(&fl6.saddr, &np->saddr);
155 fl6.flowi6_oif = sk->sk_bound_dev_if;
156 fl6.fl6_dport = inet->inet_dport;
157 fl6.fl6_sport = inet->inet_sport;
158 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
159
160 dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
161 if (IS_ERR(dst)) {
162 sk->sk_err_soft = -PTR_ERR(dst);
163 goto out;
164 }
165 } else
166 dst_hold(dst);
167
168 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
169 dccp_sync_mss(sk, dst_mtu(dst));
170 } /* else let the usual retransmit timer handle it */
171 dst_release(dst);
172 goto out;
173 }
174
175 icmpv6_err_convert(type, code, &err);
176
177 /* Might be for an request_sock */
178 switch (sk->sk_state) {
179 struct request_sock *req, **prev;
180 case DCCP_LISTEN:
181 if (sock_owned_by_user(sk))
182 goto out;
183
184 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
185 &hdr->daddr, &hdr->saddr,
186 inet6_iif(skb));
187 if (req == NULL)
188 goto out;
189
190 /*
191 * ICMPs are not backlogged, hence we cannot get an established
192 * socket here.
193 */
194 WARN_ON(req->sk != NULL);
195
196 if (seq != dccp_rsk(req)->dreq_iss) {
197 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
198 goto out;
199 }
200
201 inet_csk_reqsk_queue_drop(sk, req, prev);
202 goto out;
203
204 case DCCP_REQUESTING:
205 case DCCP_RESPOND: /* Cannot happen.
206 It can, it SYNs are crossed. --ANK */
207 if (!sock_owned_by_user(sk)) {
208 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
209 sk->sk_err = err;
210 /*
211 * Wake people up to see the error
212 * (see connect in sock.c)
213 */
214 sk->sk_error_report(sk);
215 dccp_done(sk);
216 } else
217 sk->sk_err_soft = err;
218 goto out;
219 }
220
221 if (!sock_owned_by_user(sk) && np->recverr) {
222 sk->sk_err = err;
223 sk->sk_error_report(sk);
224 } else
225 sk->sk_err_soft = err;
226
227out:
228 bh_unlock_sock(sk);
229 sock_put(sk);
230}
231
232
233static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
234 struct request_values *rv_unused)
235{
236 struct inet6_request_sock *ireq6 = inet6_rsk(req);
237 struct ipv6_pinfo *np = inet6_sk(sk);
238 struct sk_buff *skb;
239 struct ipv6_txoptions *opt = NULL;
240 struct in6_addr *final_p, final;
241 struct flowi6 fl6;
242 int err = -1;
243 struct dst_entry *dst;
244
245 memset(&fl6, 0, sizeof(fl6));
246 fl6.flowi6_proto = IPPROTO_DCCP;
247 ipv6_addr_copy(&fl6.daddr, &ireq6->rmt_addr);
248 ipv6_addr_copy(&fl6.saddr, &ireq6->loc_addr);
249 fl6.flowlabel = 0;
250 fl6.flowi6_oif = ireq6->iif;
251 fl6.fl6_dport = inet_rsk(req)->rmt_port;
252 fl6.fl6_sport = inet_rsk(req)->loc_port;
253 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
254
255 opt = np->opt;
256
257 final_p = fl6_update_dst(&fl6, opt, &final);
258
259 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
260 if (IS_ERR(dst)) {
261 err = PTR_ERR(dst);
262 dst = NULL;
263 goto done;
264 }
265
266 skb = dccp_make_response(sk, dst, req);
267 if (skb != NULL) {
268 struct dccp_hdr *dh = dccp_hdr(skb);
269
270 dh->dccph_checksum = dccp_v6_csum_finish(skb,
271 &ireq6->loc_addr,
272 &ireq6->rmt_addr);
273 ipv6_addr_copy(&fl6.daddr, &ireq6->rmt_addr);
274 err = ip6_xmit(sk, skb, &fl6, opt);
275 err = net_xmit_eval(err);
276 }
277
278done:
279 if (opt != NULL && opt != np->opt)
280 sock_kfree_s(sk, opt, opt->tot_len);
281 dst_release(dst);
282 return err;
283}
284
285static void dccp_v6_reqsk_destructor(struct request_sock *req)
286{
287 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
288 if (inet6_rsk(req)->pktopts != NULL)
289 kfree_skb(inet6_rsk(req)->pktopts);
290}
291
292static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
293{
294 const struct ipv6hdr *rxip6h;
295 struct sk_buff *skb;
296 struct flowi6 fl6;
297 struct net *net = dev_net(skb_dst(rxskb)->dev);
298 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
299 struct dst_entry *dst;
300
301 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
302 return;
303
304 if (!ipv6_unicast_destination(rxskb))
305 return;
306
307 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
308 if (skb == NULL)
309 return;
310
311 rxip6h = ipv6_hdr(rxskb);
312 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
313 &rxip6h->daddr);
314
315 memset(&fl6, 0, sizeof(fl6));
316 ipv6_addr_copy(&fl6.daddr, &rxip6h->saddr);
317 ipv6_addr_copy(&fl6.saddr, &rxip6h->daddr);
318
319 fl6.flowi6_proto = IPPROTO_DCCP;
320 fl6.flowi6_oif = inet6_iif(rxskb);
321 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
322 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
323 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
324
325 /* sk = NULL, but it is safe for now. RST socket required. */
326 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
327 if (!IS_ERR(dst)) {
328 skb_dst_set(skb, dst);
329 ip6_xmit(ctl_sk, skb, &fl6, NULL);
330 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
331 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
332 return;
333 }
334
335 kfree_skb(skb);
336}
337
338static struct request_sock_ops dccp6_request_sock_ops = {
339 .family = AF_INET6,
340 .obj_size = sizeof(struct dccp6_request_sock),
341 .rtx_syn_ack = dccp_v6_send_response,
342 .send_ack = dccp_reqsk_send_ack,
343 .destructor = dccp_v6_reqsk_destructor,
344 .send_reset = dccp_v6_ctl_send_reset,
345};
346
347static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
348{
349 const struct dccp_hdr *dh = dccp_hdr(skb);
350 const struct ipv6hdr *iph = ipv6_hdr(skb);
351 struct sock *nsk;
352 struct request_sock **prev;
353 /* Find possible connection requests. */
354 struct request_sock *req = inet6_csk_search_req(sk, &prev,
355 dh->dccph_sport,
356 &iph->saddr,
357 &iph->daddr,
358 inet6_iif(skb));
359 if (req != NULL)
360 return dccp_check_req(sk, skb, req, prev);
361
362 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
363 &iph->saddr, dh->dccph_sport,
364 &iph->daddr, ntohs(dh->dccph_dport),
365 inet6_iif(skb));
366 if (nsk != NULL) {
367 if (nsk->sk_state != DCCP_TIME_WAIT) {
368 bh_lock_sock(nsk);
369 return nsk;
370 }
371 inet_twsk_put(inet_twsk(nsk));
372 return NULL;
373 }
374
375 return sk;
376}
377
378static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
379{
380 struct request_sock *req;
381 struct dccp_request_sock *dreq;
382 struct inet6_request_sock *ireq6;
383 struct ipv6_pinfo *np = inet6_sk(sk);
384 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
385 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
386
387 if (skb->protocol == htons(ETH_P_IP))
388 return dccp_v4_conn_request(sk, skb);
389
390 if (!ipv6_unicast_destination(skb))
391 return 0; /* discard, don't send a reset here */
392
393 if (dccp_bad_service_code(sk, service)) {
394 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
395 goto drop;
396 }
397 /*
398 * There are no SYN attacks on IPv6, yet...
399 */
400 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
401 if (inet_csk_reqsk_queue_is_full(sk))
402 goto drop;
403
404 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
405 goto drop;
406
407 req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
408 if (req == NULL)
409 goto drop;
410
411 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
412 goto drop_and_free;
413
414 dreq = dccp_rsk(req);
415 if (dccp_parse_options(sk, dreq, skb))
416 goto drop_and_free;
417
418 if (security_inet_conn_request(sk, skb, req))
419 goto drop_and_free;
420
421 ireq6 = inet6_rsk(req);
422 ipv6_addr_copy(&ireq6->rmt_addr, &ipv6_hdr(skb)->saddr);
423 ipv6_addr_copy(&ireq6->loc_addr, &ipv6_hdr(skb)->daddr);
424
425 if (ipv6_opt_accepted(sk, skb) ||
426 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
427 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
428 atomic_inc(&skb->users);
429 ireq6->pktopts = skb;
430 }
431 ireq6->iif = sk->sk_bound_dev_if;
432
433 /* So that link locals have meaning */
434 if (!sk->sk_bound_dev_if &&
435 ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
436 ireq6->iif = inet6_iif(skb);
437
438 /*
439 * Step 3: Process LISTEN state
440 *
441 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
442 *
443 * In fact we defer setting S.GSR, S.SWL, S.SWH to
444 * dccp_create_openreq_child.
445 */
446 dreq->dreq_isr = dcb->dccpd_seq;
447 dreq->dreq_iss = dccp_v6_init_sequence(skb);
448 dreq->dreq_service = service;
449
450 if (dccp_v6_send_response(sk, req, NULL))
451 goto drop_and_free;
452
453 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
454 return 0;
455
456drop_and_free:
457 reqsk_free(req);
458drop:
459 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
460 return -1;
461}
462
463static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
464 struct sk_buff *skb,
465 struct request_sock *req,
466 struct dst_entry *dst)
467{
468 struct inet6_request_sock *ireq6 = inet6_rsk(req);
469 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
470 struct inet_sock *newinet;
471 struct dccp6_sock *newdp6;
472 struct sock *newsk;
473 struct ipv6_txoptions *opt;
474
475 if (skb->protocol == htons(ETH_P_IP)) {
476 /*
477 * v6 mapped
478 */
479 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
480 if (newsk == NULL)
481 return NULL;
482
483 newdp6 = (struct dccp6_sock *)newsk;
484 newinet = inet_sk(newsk);
485 newinet->pinet6 = &newdp6->inet6;
486 newnp = inet6_sk(newsk);
487
488 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
489
490 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
491
492 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
493
494 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
495
496 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
497 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
498 newnp->pktoptions = NULL;
499 newnp->opt = NULL;
500 newnp->mcast_oif = inet6_iif(skb);
501 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
502
503 /*
504 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
505 * here, dccp_create_openreq_child now does this for us, see the comment in
506 * that function for the gory details. -acme
507 */
508
509 /* It is tricky place. Until this moment IPv4 tcp
510 worked with IPv6 icsk.icsk_af_ops.
511 Sync it now.
512 */
513 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
514
515 return newsk;
516 }
517
518 opt = np->opt;
519
520 if (sk_acceptq_is_full(sk))
521 goto out_overflow;
522
523 if (dst == NULL) {
524 struct in6_addr *final_p, final;
525 struct flowi6 fl6;
526
527 memset(&fl6, 0, sizeof(fl6));
528 fl6.flowi6_proto = IPPROTO_DCCP;
529 ipv6_addr_copy(&fl6.daddr, &ireq6->rmt_addr);
530 final_p = fl6_update_dst(&fl6, opt, &final);
531 ipv6_addr_copy(&fl6.saddr, &ireq6->loc_addr);
532 fl6.flowi6_oif = sk->sk_bound_dev_if;
533 fl6.fl6_dport = inet_rsk(req)->rmt_port;
534 fl6.fl6_sport = inet_rsk(req)->loc_port;
535 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
536
537 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
538 if (IS_ERR(dst))
539 goto out;
540 }
541
542 newsk = dccp_create_openreq_child(sk, req, skb);
543 if (newsk == NULL)
544 goto out_nonewsk;
545
546 /*
547 * No need to charge this sock to the relevant IPv6 refcnt debug socks
548 * count here, dccp_create_openreq_child now does this for us, see the
549 * comment in that function for the gory details. -acme
550 */
551
552 __ip6_dst_store(newsk, dst, NULL, NULL);
553 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
554 NETIF_F_TSO);
555 newdp6 = (struct dccp6_sock *)newsk;
556 newinet = inet_sk(newsk);
557 newinet->pinet6 = &newdp6->inet6;
558 newnp = inet6_sk(newsk);
559
560 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
561
562 ipv6_addr_copy(&newnp->daddr, &ireq6->rmt_addr);
563 ipv6_addr_copy(&newnp->saddr, &ireq6->loc_addr);
564 ipv6_addr_copy(&newnp->rcv_saddr, &ireq6->loc_addr);
565 newsk->sk_bound_dev_if = ireq6->iif;
566
567 /* Now IPv6 options...
568
569 First: no IPv4 options.
570 */
571 newinet->inet_opt = NULL;
572
573 /* Clone RX bits */
574 newnp->rxopt.all = np->rxopt.all;
575
576 /* Clone pktoptions received with SYN */
577 newnp->pktoptions = NULL;
578 if (ireq6->pktopts != NULL) {
579 newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
580 kfree_skb(ireq6->pktopts);
581 ireq6->pktopts = NULL;
582 if (newnp->pktoptions)
583 skb_set_owner_r(newnp->pktoptions, newsk);
584 }
585 newnp->opt = NULL;
586 newnp->mcast_oif = inet6_iif(skb);
587 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
588
589 /*
590 * Clone native IPv6 options from listening socket (if any)
591 *
592 * Yes, keeping reference count would be much more clever, but we make
593 * one more one thing there: reattach optmem to newsk.
594 */
595 if (opt != NULL) {
596 newnp->opt = ipv6_dup_options(newsk, opt);
597 if (opt != np->opt)
598 sock_kfree_s(sk, opt, opt->tot_len);
599 }
600
601 inet_csk(newsk)->icsk_ext_hdr_len = 0;
602 if (newnp->opt != NULL)
603 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
604 newnp->opt->opt_flen);
605
606 dccp_sync_mss(newsk, dst_mtu(dst));
607
608 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
609 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
610
611 if (__inet_inherit_port(sk, newsk) < 0) {
612 sock_put(newsk);
613 goto out;
614 }
615 __inet6_hash(newsk, NULL);
616
617 return newsk;
618
619out_overflow:
620 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
621out_nonewsk:
622 dst_release(dst);
623out:
624 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
625 if (opt != NULL && opt != np->opt)
626 sock_kfree_s(sk, opt, opt->tot_len);
627 return NULL;
628}
629
630/* The socket must have it's spinlock held when we get
631 * here.
632 *
633 * We have a potential double-lock case here, so even when
634 * doing backlog processing we use the BH locking scheme.
635 * This is because we cannot sleep with the original spinlock
636 * held.
637 */
638static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
639{
640 struct ipv6_pinfo *np = inet6_sk(sk);
641 struct sk_buff *opt_skb = NULL;
642
643 /* Imagine: socket is IPv6. IPv4 packet arrives,
644 goes to IPv4 receive handler and backlogged.
645 From backlog it always goes here. Kerboom...
646 Fortunately, dccp_rcv_established and rcv_established
647 handle them correctly, but it is not case with
648 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
649 */
650
651 if (skb->protocol == htons(ETH_P_IP))
652 return dccp_v4_do_rcv(sk, skb);
653
654 if (sk_filter(sk, skb))
655 goto discard;
656
657 /*
658 * socket locking is here for SMP purposes as backlog rcv is currently
659 * called with bh processing disabled.
660 */
661
662 /* Do Stevens' IPV6_PKTOPTIONS.
663
664 Yes, guys, it is the only place in our code, where we
665 may make it not affecting IPv4.
666 The rest of code is protocol independent,
667 and I do not like idea to uglify IPv4.
668
669 Actually, all the idea behind IPV6_PKTOPTIONS
670 looks not very well thought. For now we latch
671 options, received in the last packet, enqueued
672 by tcp. Feel free to propose better solution.
673 --ANK (980728)
674 */
675 if (np->rxopt.all)
676 /*
677 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
678 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
679 */
680 opt_skb = skb_clone(skb, GFP_ATOMIC);
681
682 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
683 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
684 goto reset;
685 if (opt_skb) {
686 /* XXX This is where we would goto ipv6_pktoptions. */
687 __kfree_skb(opt_skb);
688 }
689 return 0;
690 }
691
692 /*
693 * Step 3: Process LISTEN state
694 * If S.state == LISTEN,
695 * If P.type == Request or P contains a valid Init Cookie option,
696 * (* Must scan the packet's options to check for Init
697 * Cookies. Only Init Cookies are processed here,
698 * however; other options are processed in Step 8. This
699 * scan need only be performed if the endpoint uses Init
700 * Cookies *)
701 * (* Generate a new socket and switch to that socket *)
702 * Set S := new socket for this port pair
703 * S.state = RESPOND
704 * Choose S.ISS (initial seqno) or set from Init Cookies
705 * Initialize S.GAR := S.ISS
706 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
707 * Continue with S.state == RESPOND
708 * (* A Response packet will be generated in Step 11 *)
709 * Otherwise,
710 * Generate Reset(No Connection) unless P.type == Reset
711 * Drop packet and return
712 *
713 * NOTE: the check for the packet types is done in
714 * dccp_rcv_state_process
715 */
716 if (sk->sk_state == DCCP_LISTEN) {
717 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
718
719 if (nsk == NULL)
720 goto discard;
721 /*
722 * Queue it on the new socket if the new socket is active,
723 * otherwise we just shortcircuit this and continue with
724 * the new socket..
725 */
726 if (nsk != sk) {
727 if (dccp_child_process(sk, nsk, skb))
728 goto reset;
729 if (opt_skb != NULL)
730 __kfree_skb(opt_skb);
731 return 0;
732 }
733 }
734
735 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
736 goto reset;
737 if (opt_skb) {
738 /* XXX This is where we would goto ipv6_pktoptions. */
739 __kfree_skb(opt_skb);
740 }
741 return 0;
742
743reset:
744 dccp_v6_ctl_send_reset(sk, skb);
745discard:
746 if (opt_skb != NULL)
747 __kfree_skb(opt_skb);
748 kfree_skb(skb);
749 return 0;
750}
751
752static int dccp_v6_rcv(struct sk_buff *skb)
753{
754 const struct dccp_hdr *dh;
755 struct sock *sk;
756 int min_cov;
757
758 /* Step 1: Check header basics */
759
760 if (dccp_invalid_packet(skb))
761 goto discard_it;
762
763 /* Step 1: If header checksum is incorrect, drop packet and return. */
764 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
765 &ipv6_hdr(skb)->daddr)) {
766 DCCP_WARN("dropped packet with invalid checksum\n");
767 goto discard_it;
768 }
769
770 dh = dccp_hdr(skb);
771
772 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
773 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
774
775 if (dccp_packet_without_ack(skb))
776 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
777 else
778 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
779
780 /* Step 2:
781 * Look up flow ID in table and get corresponding socket */
782 sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
783 dh->dccph_sport, dh->dccph_dport);
784 /*
785 * Step 2:
786 * If no socket ...
787 */
788 if (sk == NULL) {
789 dccp_pr_debug("failed to look up flow ID in table and "
790 "get corresponding socket\n");
791 goto no_dccp_socket;
792 }
793
794 /*
795 * Step 2:
796 * ... or S.state == TIMEWAIT,
797 * Generate Reset(No Connection) unless P.type == Reset
798 * Drop packet and return
799 */
800 if (sk->sk_state == DCCP_TIME_WAIT) {
801 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
802 inet_twsk_put(inet_twsk(sk));
803 goto no_dccp_socket;
804 }
805
806 /*
807 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
808 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
809 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
810 */
811 min_cov = dccp_sk(sk)->dccps_pcrlen;
812 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
813 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
814 dh->dccph_cscov, min_cov);
815 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
816 goto discard_and_relse;
817 }
818
819 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
820 goto discard_and_relse;
821
822 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
823
824no_dccp_socket:
825 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
826 goto discard_it;
827 /*
828 * Step 2:
829 * If no socket ...
830 * Generate Reset(No Connection) unless P.type == Reset
831 * Drop packet and return
832 */
833 if (dh->dccph_type != DCCP_PKT_RESET) {
834 DCCP_SKB_CB(skb)->dccpd_reset_code =
835 DCCP_RESET_CODE_NO_CONNECTION;
836 dccp_v6_ctl_send_reset(sk, skb);
837 }
838
839discard_it:
840 kfree_skb(skb);
841 return 0;
842
843discard_and_relse:
844 sock_put(sk);
845 goto discard_it;
846}
847
848static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
849 int addr_len)
850{
851 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
852 struct inet_connection_sock *icsk = inet_csk(sk);
853 struct inet_sock *inet = inet_sk(sk);
854 struct ipv6_pinfo *np = inet6_sk(sk);
855 struct dccp_sock *dp = dccp_sk(sk);
856 struct in6_addr *saddr = NULL, *final_p, final;
857 struct flowi6 fl6;
858 struct dst_entry *dst;
859 int addr_type;
860 int err;
861
862 dp->dccps_role = DCCP_ROLE_CLIENT;
863
864 if (addr_len < SIN6_LEN_RFC2133)
865 return -EINVAL;
866
867 if (usin->sin6_family != AF_INET6)
868 return -EAFNOSUPPORT;
869
870 memset(&fl6, 0, sizeof(fl6));
871
872 if (np->sndflow) {
873 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
874 IP6_ECN_flow_init(fl6.flowlabel);
875 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
876 struct ip6_flowlabel *flowlabel;
877 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
878 if (flowlabel == NULL)
879 return -EINVAL;
880 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
881 fl6_sock_release(flowlabel);
882 }
883 }
884 /*
885 * connect() to INADDR_ANY means loopback (BSD'ism).
886 */
887 if (ipv6_addr_any(&usin->sin6_addr))
888 usin->sin6_addr.s6_addr[15] = 1;
889
890 addr_type = ipv6_addr_type(&usin->sin6_addr);
891
892 if (addr_type & IPV6_ADDR_MULTICAST)
893 return -ENETUNREACH;
894
895 if (addr_type & IPV6_ADDR_LINKLOCAL) {
896 if (addr_len >= sizeof(struct sockaddr_in6) &&
897 usin->sin6_scope_id) {
898 /* If interface is set while binding, indices
899 * must coincide.
900 */
901 if (sk->sk_bound_dev_if &&
902 sk->sk_bound_dev_if != usin->sin6_scope_id)
903 return -EINVAL;
904
905 sk->sk_bound_dev_if = usin->sin6_scope_id;
906 }
907
908 /* Connect to link-local address requires an interface */
909 if (!sk->sk_bound_dev_if)
910 return -EINVAL;
911 }
912
913 ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
914 np->flow_label = fl6.flowlabel;
915
916 /*
917 * DCCP over IPv4
918 */
919 if (addr_type == IPV6_ADDR_MAPPED) {
920 u32 exthdrlen = icsk->icsk_ext_hdr_len;
921 struct sockaddr_in sin;
922
923 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
924
925 if (__ipv6_only_sock(sk))
926 return -ENETUNREACH;
927
928 sin.sin_family = AF_INET;
929 sin.sin_port = usin->sin6_port;
930 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
931
932 icsk->icsk_af_ops = &dccp_ipv6_mapped;
933 sk->sk_backlog_rcv = dccp_v4_do_rcv;
934
935 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
936 if (err) {
937 icsk->icsk_ext_hdr_len = exthdrlen;
938 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
939 sk->sk_backlog_rcv = dccp_v6_do_rcv;
940 goto failure;
941 }
942 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
943 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &np->rcv_saddr);
944
945 return err;
946 }
947
948 if (!ipv6_addr_any(&np->rcv_saddr))
949 saddr = &np->rcv_saddr;
950
951 fl6.flowi6_proto = IPPROTO_DCCP;
952 ipv6_addr_copy(&fl6.daddr, &np->daddr);
953 ipv6_addr_copy(&fl6.saddr, saddr ? saddr : &np->saddr);
954 fl6.flowi6_oif = sk->sk_bound_dev_if;
955 fl6.fl6_dport = usin->sin6_port;
956 fl6.fl6_sport = inet->inet_sport;
957 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
958
959 final_p = fl6_update_dst(&fl6, np->opt, &final);
960
961 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
962 if (IS_ERR(dst)) {
963 err = PTR_ERR(dst);
964 goto failure;
965 }
966
967 if (saddr == NULL) {
968 saddr = &fl6.saddr;
969 ipv6_addr_copy(&np->rcv_saddr, saddr);
970 }
971
972 /* set the source address */
973 ipv6_addr_copy(&np->saddr, saddr);
974 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
975
976 __ip6_dst_store(sk, dst, NULL, NULL);
977
978 icsk->icsk_ext_hdr_len = 0;
979 if (np->opt != NULL)
980 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
981 np->opt->opt_nflen);
982
983 inet->inet_dport = usin->sin6_port;
984
985 dccp_set_state(sk, DCCP_REQUESTING);
986 err = inet6_hash_connect(&dccp_death_row, sk);
987 if (err)
988 goto late_failure;
989
990 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
991 np->daddr.s6_addr32,
992 inet->inet_sport,
993 inet->inet_dport);
994 err = dccp_connect(sk);
995 if (err)
996 goto late_failure;
997
998 return 0;
999
1000late_failure:
1001 dccp_set_state(sk, DCCP_CLOSED);
1002 __sk_dst_reset(sk);
1003failure:
1004 inet->inet_dport = 0;
1005 sk->sk_route_caps = 0;
1006 return err;
1007}
1008
1009static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
1010 .queue_xmit = inet6_csk_xmit,
1011 .send_check = dccp_v6_send_check,
1012 .rebuild_header = inet6_sk_rebuild_header,
1013 .conn_request = dccp_v6_conn_request,
1014 .syn_recv_sock = dccp_v6_request_recv_sock,
1015 .net_header_len = sizeof(struct ipv6hdr),
1016 .setsockopt = ipv6_setsockopt,
1017 .getsockopt = ipv6_getsockopt,
1018 .addr2sockaddr = inet6_csk_addr2sockaddr,
1019 .sockaddr_len = sizeof(struct sockaddr_in6),
1020 .bind_conflict = inet6_csk_bind_conflict,
1021#ifdef CONFIG_COMPAT
1022 .compat_setsockopt = compat_ipv6_setsockopt,
1023 .compat_getsockopt = compat_ipv6_getsockopt,
1024#endif
1025};
1026
1027/*
1028 * DCCP over IPv4 via INET6 API
1029 */
1030static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1031 .queue_xmit = ip_queue_xmit,
1032 .send_check = dccp_v4_send_check,
1033 .rebuild_header = inet_sk_rebuild_header,
1034 .conn_request = dccp_v6_conn_request,
1035 .syn_recv_sock = dccp_v6_request_recv_sock,
1036 .net_header_len = sizeof(struct iphdr),
1037 .setsockopt = ipv6_setsockopt,
1038 .getsockopt = ipv6_getsockopt,
1039 .addr2sockaddr = inet6_csk_addr2sockaddr,
1040 .sockaddr_len = sizeof(struct sockaddr_in6),
1041#ifdef CONFIG_COMPAT
1042 .compat_setsockopt = compat_ipv6_setsockopt,
1043 .compat_getsockopt = compat_ipv6_getsockopt,
1044#endif
1045};
1046
1047/* NOTE: A lot of things set to zero explicitly by call to
1048 * sk_alloc() so need not be done here.
1049 */
1050static int dccp_v6_init_sock(struct sock *sk)
1051{
1052 static __u8 dccp_v6_ctl_sock_initialized;
1053 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1054
1055 if (err == 0) {
1056 if (unlikely(!dccp_v6_ctl_sock_initialized))
1057 dccp_v6_ctl_sock_initialized = 1;
1058 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1059 }
1060
1061 return err;
1062}
1063
1064static void dccp_v6_destroy_sock(struct sock *sk)
1065{
1066 dccp_destroy_sock(sk);
1067 inet6_destroy_sock(sk);
1068}
1069
1070static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1071 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1072};
1073
1074static struct proto dccp_v6_prot = {
1075 .name = "DCCPv6",
1076 .owner = THIS_MODULE,
1077 .close = dccp_close,
1078 .connect = dccp_v6_connect,
1079 .disconnect = dccp_disconnect,
1080 .ioctl = dccp_ioctl,
1081 .init = dccp_v6_init_sock,
1082 .setsockopt = dccp_setsockopt,
1083 .getsockopt = dccp_getsockopt,
1084 .sendmsg = dccp_sendmsg,
1085 .recvmsg = dccp_recvmsg,
1086 .backlog_rcv = dccp_v6_do_rcv,
1087 .hash = dccp_v6_hash,
1088 .unhash = inet_unhash,
1089 .accept = inet_csk_accept,
1090 .get_port = inet_csk_get_port,
1091 .shutdown = dccp_shutdown,
1092 .destroy = dccp_v6_destroy_sock,
1093 .orphan_count = &dccp_orphan_count,
1094 .max_header = MAX_DCCP_HEADER,
1095 .obj_size = sizeof(struct dccp6_sock),
1096 .slab_flags = SLAB_DESTROY_BY_RCU,
1097 .rsk_prot = &dccp6_request_sock_ops,
1098 .twsk_prot = &dccp6_timewait_sock_ops,
1099 .h.hashinfo = &dccp_hashinfo,
1100#ifdef CONFIG_COMPAT
1101 .compat_setsockopt = compat_dccp_setsockopt,
1102 .compat_getsockopt = compat_dccp_getsockopt,
1103#endif
1104};
1105
1106static const struct inet6_protocol dccp_v6_protocol = {
1107 .handler = dccp_v6_rcv,
1108 .err_handler = dccp_v6_err,
1109 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1110};
1111
1112static const struct proto_ops inet6_dccp_ops = {
1113 .family = PF_INET6,
1114 .owner = THIS_MODULE,
1115 .release = inet6_release,
1116 .bind = inet6_bind,
1117 .connect = inet_stream_connect,
1118 .socketpair = sock_no_socketpair,
1119 .accept = inet_accept,
1120 .getname = inet6_getname,
1121 .poll = dccp_poll,
1122 .ioctl = inet6_ioctl,
1123 .listen = inet_dccp_listen,
1124 .shutdown = inet_shutdown,
1125 .setsockopt = sock_common_setsockopt,
1126 .getsockopt = sock_common_getsockopt,
1127 .sendmsg = inet_sendmsg,
1128 .recvmsg = sock_common_recvmsg,
1129 .mmap = sock_no_mmap,
1130 .sendpage = sock_no_sendpage,
1131#ifdef CONFIG_COMPAT
1132 .compat_setsockopt = compat_sock_common_setsockopt,
1133 .compat_getsockopt = compat_sock_common_getsockopt,
1134#endif
1135};
1136
1137static struct inet_protosw dccp_v6_protosw = {
1138 .type = SOCK_DCCP,
1139 .protocol = IPPROTO_DCCP,
1140 .prot = &dccp_v6_prot,
1141 .ops = &inet6_dccp_ops,
1142 .flags = INET_PROTOSW_ICSK,
1143};
1144
1145static int __net_init dccp_v6_init_net(struct net *net)
1146{
1147 if (dccp_hashinfo.bhash == NULL)
1148 return -ESOCKTNOSUPPORT;
1149
1150 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1151 SOCK_DCCP, IPPROTO_DCCP, net);
1152}
1153
1154static void __net_exit dccp_v6_exit_net(struct net *net)
1155{
1156 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1157}
1158
1159static struct pernet_operations dccp_v6_ops = {
1160 .init = dccp_v6_init_net,
1161 .exit = dccp_v6_exit_net,
1162};
1163
1164static int __init dccp_v6_init(void)
1165{
1166 int err = proto_register(&dccp_v6_prot, 1);
1167
1168 if (err != 0)
1169 goto out;
1170
1171 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1172 if (err != 0)
1173 goto out_unregister_proto;
1174
1175 inet6_register_protosw(&dccp_v6_protosw);
1176
1177 err = register_pernet_subsys(&dccp_v6_ops);
1178 if (err != 0)
1179 goto out_destroy_ctl_sock;
1180out:
1181 return err;
1182
1183out_destroy_ctl_sock:
1184 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1185 inet6_unregister_protosw(&dccp_v6_protosw);
1186out_unregister_proto:
1187 proto_unregister(&dccp_v6_prot);
1188 goto out;
1189}
1190
1191static void __exit dccp_v6_exit(void)
1192{
1193 unregister_pernet_subsys(&dccp_v6_ops);
1194 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1195 inet6_unregister_protosw(&dccp_v6_protosw);
1196 proto_unregister(&dccp_v6_prot);
1197}
1198
1199module_init(dccp_v6_init);
1200module_exit(dccp_v6_exit);
1201
1202/*
1203 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1204 * values directly, Also cover the case where the protocol is not specified,
1205 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1206 */
1207MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1208MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1209MODULE_LICENSE("GPL");
1210MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1211MODULE_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#include <net/rstreason.h>
33
34#include "dccp.h"
35#include "ipv6.h"
36#include "feat.h"
37
38struct dccp_v6_pernet {
39 struct sock *v6_ctl_sk;
40};
41
42static unsigned int dccp_v6_pernet_id __read_mostly;
43
44/* The per-net v6_ctl_sk is used for sending RSTs and ACKs */
45
46static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
47static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
48
49/* add pseudo-header to DCCP checksum stored in skb->csum */
50static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
51 const struct in6_addr *saddr,
52 const struct in6_addr *daddr)
53{
54 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
55}
56
57static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
58{
59 struct ipv6_pinfo *np = inet6_sk(sk);
60 struct dccp_hdr *dh = dccp_hdr(skb);
61
62 dccp_csum_outgoing(skb);
63 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
64}
65
66static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
67{
68 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
69 ipv6_hdr(skb)->saddr.s6_addr32,
70 dccp_hdr(skb)->dccph_dport,
71 dccp_hdr(skb)->dccph_sport );
72
73}
74
75static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
76 u8 type, u8 code, int offset, __be32 info)
77{
78 const struct ipv6hdr *hdr;
79 const struct dccp_hdr *dh;
80 struct dccp_sock *dp;
81 struct ipv6_pinfo *np;
82 struct sock *sk;
83 int err;
84 __u64 seq;
85 struct net *net = dev_net(skb->dev);
86
87 if (!pskb_may_pull(skb, offset + sizeof(*dh)))
88 return -EINVAL;
89 dh = (struct dccp_hdr *)(skb->data + offset);
90 if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh)))
91 return -EINVAL;
92 hdr = (const struct ipv6hdr *)skb->data;
93 dh = (struct dccp_hdr *)(skb->data + offset);
94
95 sk = __inet6_lookup_established(net, &dccp_hashinfo,
96 &hdr->daddr, dh->dccph_dport,
97 &hdr->saddr, ntohs(dh->dccph_sport),
98 inet6_iif(skb), 0);
99
100 if (!sk) {
101 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
102 ICMP6_MIB_INERRORS);
103 return -ENOENT;
104 }
105
106 if (sk->sk_state == DCCP_TIME_WAIT) {
107 inet_twsk_put(inet_twsk(sk));
108 return 0;
109 }
110 seq = dccp_hdr_seq(dh);
111 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
112 dccp_req_err(sk, seq);
113 return 0;
114 }
115
116 bh_lock_sock(sk);
117 if (sock_owned_by_user(sk))
118 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
119
120 if (sk->sk_state == DCCP_CLOSED)
121 goto out;
122
123 dp = dccp_sk(sk);
124 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
125 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
126 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
127 goto out;
128 }
129
130 np = inet6_sk(sk);
131
132 if (type == NDISC_REDIRECT) {
133 if (!sock_owned_by_user(sk)) {
134 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
135
136 if (dst)
137 dst->ops->redirect(dst, sk, skb);
138 }
139 goto out;
140 }
141
142 if (type == ICMPV6_PKT_TOOBIG) {
143 struct dst_entry *dst = NULL;
144
145 if (!ip6_sk_accept_pmtu(sk))
146 goto out;
147
148 if (sock_owned_by_user(sk))
149 goto out;
150 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
151 goto out;
152
153 dst = inet6_csk_update_pmtu(sk, ntohl(info));
154 if (!dst)
155 goto out;
156
157 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
158 dccp_sync_mss(sk, dst_mtu(dst));
159 goto out;
160 }
161
162 icmpv6_err_convert(type, code, &err);
163
164 /* Might be for an request_sock */
165 switch (sk->sk_state) {
166 case DCCP_REQUESTING:
167 case DCCP_RESPOND: /* Cannot happen.
168 It can, it SYNs are crossed. --ANK */
169 if (!sock_owned_by_user(sk)) {
170 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
171 sk->sk_err = err;
172 /*
173 * Wake people up to see the error
174 * (see connect in sock.c)
175 */
176 sk_error_report(sk);
177 dccp_done(sk);
178 } else {
179 WRITE_ONCE(sk->sk_err_soft, err);
180 }
181 goto out;
182 }
183
184 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
185 sk->sk_err = err;
186 sk_error_report(sk);
187 } else {
188 WRITE_ONCE(sk->sk_err_soft, err);
189 }
190out:
191 bh_unlock_sock(sk);
192 sock_put(sk);
193 return 0;
194}
195
196
197static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
198{
199 struct inet_request_sock *ireq = inet_rsk(req);
200 struct ipv6_pinfo *np = inet6_sk(sk);
201 struct sk_buff *skb;
202 struct in6_addr *final_p, final;
203 struct flowi6 fl6;
204 int err = -1;
205 struct dst_entry *dst;
206
207 memset(&fl6, 0, sizeof(fl6));
208 fl6.flowi6_proto = IPPROTO_DCCP;
209 fl6.daddr = ireq->ir_v6_rmt_addr;
210 fl6.saddr = ireq->ir_v6_loc_addr;
211 fl6.flowlabel = 0;
212 fl6.flowi6_oif = ireq->ir_iif;
213 fl6.fl6_dport = ireq->ir_rmt_port;
214 fl6.fl6_sport = htons(ireq->ir_num);
215 security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
216
217
218 rcu_read_lock();
219 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
220 rcu_read_unlock();
221
222 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
223 if (IS_ERR(dst)) {
224 err = PTR_ERR(dst);
225 dst = NULL;
226 goto done;
227 }
228
229 skb = dccp_make_response(sk, dst, req);
230 if (skb != NULL) {
231 struct dccp_hdr *dh = dccp_hdr(skb);
232 struct ipv6_txoptions *opt;
233
234 dh->dccph_checksum = dccp_v6_csum_finish(skb,
235 &ireq->ir_v6_loc_addr,
236 &ireq->ir_v6_rmt_addr);
237 fl6.daddr = ireq->ir_v6_rmt_addr;
238 rcu_read_lock();
239 opt = ireq->ipv6_opt;
240 if (!opt)
241 opt = rcu_dereference(np->opt);
242 err = ip6_xmit(sk, skb, &fl6, READ_ONCE(sk->sk_mark), opt,
243 np->tclass, READ_ONCE(sk->sk_priority));
244 rcu_read_unlock();
245 err = net_xmit_eval(err);
246 }
247
248done:
249 dst_release(dst);
250 return err;
251}
252
253static void dccp_v6_reqsk_destructor(struct request_sock *req)
254{
255 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
256 kfree(inet_rsk(req)->ipv6_opt);
257 kfree_skb(inet_rsk(req)->pktopts);
258}
259
260static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb,
261 enum sk_rst_reason reason)
262{
263 const struct ipv6hdr *rxip6h;
264 struct sk_buff *skb;
265 struct flowi6 fl6;
266 struct net *net = dev_net(skb_dst(rxskb)->dev);
267 struct dccp_v6_pernet *pn;
268 struct sock *ctl_sk;
269 struct dst_entry *dst;
270
271 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
272 return;
273
274 if (!ipv6_unicast_destination(rxskb))
275 return;
276
277 pn = net_generic(net, dccp_v6_pernet_id);
278 ctl_sk = pn->v6_ctl_sk;
279 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
280 if (skb == NULL)
281 return;
282
283 rxip6h = ipv6_hdr(rxskb);
284 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
285 &rxip6h->daddr);
286
287 memset(&fl6, 0, sizeof(fl6));
288 fl6.daddr = rxip6h->saddr;
289 fl6.saddr = rxip6h->daddr;
290
291 fl6.flowi6_proto = IPPROTO_DCCP;
292 fl6.flowi6_oif = inet6_iif(rxskb);
293 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
294 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
295 security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6));
296
297 /* sk = NULL, but it is safe for now. RST socket required. */
298 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
299 if (!IS_ERR(dst)) {
300 skb_dst_set(skb, dst);
301 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
302 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
303 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
304 return;
305 }
306
307 kfree_skb(skb);
308}
309
310static struct request_sock_ops dccp6_request_sock_ops = {
311 .family = AF_INET6,
312 .obj_size = sizeof(struct dccp6_request_sock),
313 .rtx_syn_ack = dccp_v6_send_response,
314 .send_ack = dccp_reqsk_send_ack,
315 .destructor = dccp_v6_reqsk_destructor,
316 .send_reset = dccp_v6_ctl_send_reset,
317 .syn_ack_timeout = dccp_syn_ack_timeout,
318};
319
320static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
321{
322 struct request_sock *req;
323 struct dccp_request_sock *dreq;
324 struct inet_request_sock *ireq;
325 struct ipv6_pinfo *np = inet6_sk(sk);
326 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
327 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
328
329 if (skb->protocol == htons(ETH_P_IP))
330 return dccp_v4_conn_request(sk, skb);
331
332 if (!ipv6_unicast_destination(skb))
333 return 0; /* discard, don't send a reset here */
334
335 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
336 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
337 return 0;
338 }
339
340 if (dccp_bad_service_code(sk, service)) {
341 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
342 goto drop;
343 }
344 /*
345 * There are no SYN attacks on IPv6, yet...
346 */
347 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
348 if (inet_csk_reqsk_queue_is_full(sk))
349 goto drop;
350
351 if (sk_acceptq_is_full(sk))
352 goto drop;
353
354 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
355 if (req == NULL)
356 goto drop;
357
358 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
359 goto drop_and_free;
360
361 dreq = dccp_rsk(req);
362 if (dccp_parse_options(sk, dreq, skb))
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 (security_inet_conn_request(sk, skb, req))
372 goto drop_and_free;
373
374 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
375 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
376 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
377 refcount_inc(&skb->users);
378 ireq->pktopts = skb;
379 }
380 ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if);
381
382 /* So that link locals have meaning */
383 if (!ireq->ir_iif &&
384 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
385 ireq->ir_iif = inet6_iif(skb);
386
387 /*
388 * Step 3: Process LISTEN state
389 *
390 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
391 *
392 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
393 */
394 dreq->dreq_isr = dcb->dccpd_seq;
395 dreq->dreq_gsr = dreq->dreq_isr;
396 dreq->dreq_iss = dccp_v6_init_sequence(skb);
397 dreq->dreq_gss = dreq->dreq_iss;
398 dreq->dreq_service = service;
399
400 if (dccp_v6_send_response(sk, req))
401 goto drop_and_free;
402
403 if (unlikely(!inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT)))
404 reqsk_free(req);
405 else
406 reqsk_put(req);
407
408 return 0;
409
410drop_and_free:
411 reqsk_free(req);
412drop:
413 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
414 return -1;
415}
416
417static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
418 struct sk_buff *skb,
419 struct request_sock *req,
420 struct dst_entry *dst,
421 struct request_sock *req_unhash,
422 bool *own_req)
423{
424 struct inet_request_sock *ireq = inet_rsk(req);
425 struct ipv6_pinfo *newnp;
426 const struct ipv6_pinfo *np = inet6_sk(sk);
427 struct ipv6_txoptions *opt;
428 struct inet_sock *newinet;
429 struct dccp6_sock *newdp6;
430 struct sock *newsk;
431
432 if (skb->protocol == htons(ETH_P_IP)) {
433 /*
434 * v6 mapped
435 */
436 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
437 req_unhash, own_req);
438 if (newsk == NULL)
439 return NULL;
440
441 newdp6 = (struct dccp6_sock *)newsk;
442 newinet = inet_sk(newsk);
443 newinet->pinet6 = &newdp6->inet6;
444 newnp = inet6_sk(newsk);
445
446 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
447
448 newnp->saddr = newsk->sk_v6_rcv_saddr;
449
450 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
451 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
452 newnp->pktoptions = NULL;
453 newnp->opt = NULL;
454 newnp->ipv6_mc_list = NULL;
455 newnp->ipv6_ac_list = NULL;
456 newnp->ipv6_fl_list = NULL;
457 newnp->mcast_oif = inet_iif(skb);
458 newnp->mcast_hops = ip_hdr(skb)->ttl;
459
460 /*
461 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
462 * here, dccp_create_openreq_child now does this for us, see the comment in
463 * that function for the gory details. -acme
464 */
465
466 /* It is tricky place. Until this moment IPv4 tcp
467 worked with IPv6 icsk.icsk_af_ops.
468 Sync it now.
469 */
470 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
471
472 return newsk;
473 }
474
475
476 if (sk_acceptq_is_full(sk))
477 goto out_overflow;
478
479 if (!dst) {
480 struct flowi6 fl6;
481
482 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
483 if (!dst)
484 goto out;
485 }
486
487 newsk = dccp_create_openreq_child(sk, req, skb);
488 if (newsk == NULL)
489 goto out_nonewsk;
490
491 /*
492 * No need to charge this sock to the relevant IPv6 refcnt debug socks
493 * count here, dccp_create_openreq_child now does this for us, see the
494 * comment in that function for the gory details. -acme
495 */
496
497 ip6_dst_store(newsk, dst, NULL, NULL);
498 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
499 NETIF_F_TSO);
500 newdp6 = (struct dccp6_sock *)newsk;
501 newinet = inet_sk(newsk);
502 newinet->pinet6 = &newdp6->inet6;
503 newnp = inet6_sk(newsk);
504
505 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
506
507 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
508 newnp->saddr = ireq->ir_v6_loc_addr;
509 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
510 newsk->sk_bound_dev_if = ireq->ir_iif;
511
512 /* Now IPv6 options...
513
514 First: no IPv4 options.
515 */
516 newinet->inet_opt = NULL;
517
518 /* Clone RX bits */
519 newnp->rxopt.all = np->rxopt.all;
520
521 newnp->ipv6_mc_list = NULL;
522 newnp->ipv6_ac_list = NULL;
523 newnp->ipv6_fl_list = NULL;
524 newnp->pktoptions = NULL;
525 newnp->opt = NULL;
526 newnp->mcast_oif = inet6_iif(skb);
527 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
528
529 /*
530 * Clone native IPv6 options from listening socket (if any)
531 *
532 * Yes, keeping reference count would be much more clever, but we make
533 * one more one thing there: reattach optmem to newsk.
534 */
535 opt = ireq->ipv6_opt;
536 if (!opt)
537 opt = rcu_dereference(np->opt);
538 if (opt) {
539 opt = ipv6_dup_options(newsk, opt);
540 RCU_INIT_POINTER(newnp->opt, opt);
541 }
542 inet_csk(newsk)->icsk_ext_hdr_len = 0;
543 if (opt)
544 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
545 opt->opt_flen;
546
547 dccp_sync_mss(newsk, dst_mtu(dst));
548
549 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
550 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
551
552 if (__inet_inherit_port(sk, newsk) < 0) {
553 inet_csk_prepare_forced_close(newsk);
554 dccp_done(newsk);
555 goto out;
556 }
557 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL);
558 /* Clone pktoptions received with SYN, if we own the req */
559 if (*own_req && ireq->pktopts) {
560 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
561 consume_skb(ireq->pktopts);
562 ireq->pktopts = NULL;
563 }
564
565 return newsk;
566
567out_overflow:
568 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
569out_nonewsk:
570 dst_release(dst);
571out:
572 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
573 return NULL;
574}
575
576/* The socket must have it's spinlock held when we get
577 * here.
578 *
579 * We have a potential double-lock case here, so even when
580 * doing backlog processing we use the BH locking scheme.
581 * This is because we cannot sleep with the original spinlock
582 * held.
583 */
584static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
585{
586 struct ipv6_pinfo *np = inet6_sk(sk);
587 struct sk_buff *opt_skb = NULL;
588
589 /* Imagine: socket is IPv6. IPv4 packet arrives,
590 goes to IPv4 receive handler and backlogged.
591 From backlog it always goes here. Kerboom...
592 Fortunately, dccp_rcv_established and rcv_established
593 handle them correctly, but it is not case with
594 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
595 */
596
597 if (skb->protocol == htons(ETH_P_IP))
598 return dccp_v4_do_rcv(sk, skb);
599
600 if (sk_filter(sk, skb))
601 goto discard;
602
603 /*
604 * socket locking is here for SMP purposes as backlog rcv is currently
605 * called with bh processing disabled.
606 */
607
608 /* Do Stevens' IPV6_PKTOPTIONS.
609
610 Yes, guys, it is the only place in our code, where we
611 may make it not affecting IPv4.
612 The rest of code is protocol independent,
613 and I do not like idea to uglify IPv4.
614
615 Actually, all the idea behind IPV6_PKTOPTIONS
616 looks not very well thought. For now we latch
617 options, received in the last packet, enqueued
618 by tcp. Feel free to propose better solution.
619 --ANK (980728)
620 */
621 if (np->rxopt.all && sk->sk_state != DCCP_LISTEN)
622 opt_skb = skb_clone_and_charge_r(skb, sk);
623
624 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
625 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
626 goto reset;
627 if (opt_skb)
628 goto ipv6_pktoptions;
629 return 0;
630 }
631
632 /*
633 * Step 3: Process LISTEN state
634 * If S.state == LISTEN,
635 * If P.type == Request or P contains a valid Init Cookie option,
636 * (* Must scan the packet's options to check for Init
637 * Cookies. Only Init Cookies are processed here,
638 * however; other options are processed in Step 8. This
639 * scan need only be performed if the endpoint uses Init
640 * Cookies *)
641 * (* Generate a new socket and switch to that socket *)
642 * Set S := new socket for this port pair
643 * S.state = RESPOND
644 * Choose S.ISS (initial seqno) or set from Init Cookies
645 * Initialize S.GAR := S.ISS
646 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
647 * Continue with S.state == RESPOND
648 * (* A Response packet will be generated in Step 11 *)
649 * Otherwise,
650 * Generate Reset(No Connection) unless P.type == Reset
651 * Drop packet and return
652 *
653 * NOTE: the check for the packet types is done in
654 * dccp_rcv_state_process
655 */
656
657 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
658 goto reset;
659 if (opt_skb)
660 goto ipv6_pktoptions;
661 return 0;
662
663reset:
664 dccp_v6_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED);
665discard:
666 if (opt_skb != NULL)
667 __kfree_skb(opt_skb);
668 kfree_skb(skb);
669 return 0;
670
671/* Handling IPV6_PKTOPTIONS skb the similar
672 * way it's done for net/ipv6/tcp_ipv6.c
673 */
674ipv6_pktoptions:
675 if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
676 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
677 WRITE_ONCE(np->mcast_oif, inet6_iif(opt_skb));
678 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
679 WRITE_ONCE(np->mcast_hops, ipv6_hdr(opt_skb)->hop_limit);
680 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
681 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
682 if (inet6_test_bit(REPFLOW, sk))
683 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
684 if (ipv6_opt_accepted(sk, opt_skb,
685 &DCCP_SKB_CB(opt_skb)->header.h6)) {
686 memmove(IP6CB(opt_skb),
687 &DCCP_SKB_CB(opt_skb)->header.h6,
688 sizeof(struct inet6_skb_parm));
689 opt_skb = xchg(&np->pktoptions, opt_skb);
690 } else {
691 __kfree_skb(opt_skb);
692 opt_skb = xchg(&np->pktoptions, NULL);
693 }
694 }
695
696 kfree_skb(opt_skb);
697 return 0;
698}
699
700static int dccp_v6_rcv(struct sk_buff *skb)
701{
702 const struct dccp_hdr *dh;
703 bool refcounted;
704 struct sock *sk;
705 int min_cov;
706
707 /* Step 1: Check header basics */
708
709 if (dccp_invalid_packet(skb))
710 goto discard_it;
711
712 /* Step 1: If header checksum is incorrect, drop packet and return. */
713 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
714 &ipv6_hdr(skb)->daddr)) {
715 DCCP_WARN("dropped packet with invalid checksum\n");
716 goto discard_it;
717 }
718
719 dh = dccp_hdr(skb);
720
721 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
722 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
723
724 if (dccp_packet_without_ack(skb))
725 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
726 else
727 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
728
729lookup:
730 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
731 dh->dccph_sport, dh->dccph_dport,
732 inet6_iif(skb), 0, &refcounted);
733 if (!sk) {
734 dccp_pr_debug("failed to look up flow ID in table and "
735 "get corresponding socket\n");
736 goto no_dccp_socket;
737 }
738
739 /*
740 * Step 2:
741 * ... or S.state == TIMEWAIT,
742 * Generate Reset(No Connection) unless P.type == Reset
743 * Drop packet and return
744 */
745 if (sk->sk_state == DCCP_TIME_WAIT) {
746 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
747 inet_twsk_put(inet_twsk(sk));
748 goto no_dccp_socket;
749 }
750
751 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
752 struct request_sock *req = inet_reqsk(sk);
753 struct sock *nsk;
754
755 sk = req->rsk_listener;
756 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
757 inet_csk_reqsk_queue_drop_and_put(sk, req);
758 goto lookup;
759 }
760 sock_hold(sk);
761 refcounted = true;
762 nsk = dccp_check_req(sk, skb, req);
763 if (!nsk) {
764 reqsk_put(req);
765 goto discard_and_relse;
766 }
767 if (nsk == sk) {
768 reqsk_put(req);
769 } else if (dccp_child_process(sk, nsk, skb)) {
770 dccp_v6_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED);
771 goto discard_and_relse;
772 } else {
773 sock_put(sk);
774 return 0;
775 }
776 }
777 /*
778 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
779 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
780 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
781 */
782 min_cov = dccp_sk(sk)->dccps_pcrlen;
783 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
784 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
785 dh->dccph_cscov, min_cov);
786 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
787 goto discard_and_relse;
788 }
789
790 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
791 goto discard_and_relse;
792 nf_reset_ct(skb);
793
794 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
795 refcounted) ? -1 : 0;
796
797no_dccp_socket:
798 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
799 goto discard_it;
800 /*
801 * Step 2:
802 * If no socket ...
803 * Generate Reset(No Connection) unless P.type == Reset
804 * Drop packet and return
805 */
806 if (dh->dccph_type != DCCP_PKT_RESET) {
807 DCCP_SKB_CB(skb)->dccpd_reset_code =
808 DCCP_RESET_CODE_NO_CONNECTION;
809 dccp_v6_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED);
810 }
811
812discard_it:
813 kfree_skb(skb);
814 return 0;
815
816discard_and_relse:
817 if (refcounted)
818 sock_put(sk);
819 goto discard_it;
820}
821
822static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
823 int addr_len)
824{
825 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
826 struct inet_connection_sock *icsk = inet_csk(sk);
827 struct inet_sock *inet = inet_sk(sk);
828 struct ipv6_pinfo *np = inet6_sk(sk);
829 struct dccp_sock *dp = dccp_sk(sk);
830 struct in6_addr *saddr = NULL, *final_p, final;
831 struct ipv6_txoptions *opt;
832 struct flowi6 fl6;
833 struct dst_entry *dst;
834 int addr_type;
835 int err;
836
837 dp->dccps_role = DCCP_ROLE_CLIENT;
838
839 if (addr_len < SIN6_LEN_RFC2133)
840 return -EINVAL;
841
842 if (usin->sin6_family != AF_INET6)
843 return -EAFNOSUPPORT;
844
845 memset(&fl6, 0, sizeof(fl6));
846
847 if (inet6_test_bit(SNDFLOW, sk)) {
848 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
849 IP6_ECN_flow_init(fl6.flowlabel);
850 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
851 struct ip6_flowlabel *flowlabel;
852 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
853 if (IS_ERR(flowlabel))
854 return -EINVAL;
855 fl6_sock_release(flowlabel);
856 }
857 }
858 /*
859 * connect() to INADDR_ANY means loopback (BSD'ism).
860 */
861 if (ipv6_addr_any(&usin->sin6_addr))
862 usin->sin6_addr.s6_addr[15] = 1;
863
864 addr_type = ipv6_addr_type(&usin->sin6_addr);
865
866 if (addr_type & IPV6_ADDR_MULTICAST)
867 return -ENETUNREACH;
868
869 if (addr_type & IPV6_ADDR_LINKLOCAL) {
870 if (addr_len >= sizeof(struct sockaddr_in6) &&
871 usin->sin6_scope_id) {
872 /* If interface is set while binding, indices
873 * must coincide.
874 */
875 if (sk->sk_bound_dev_if &&
876 sk->sk_bound_dev_if != usin->sin6_scope_id)
877 return -EINVAL;
878
879 sk->sk_bound_dev_if = usin->sin6_scope_id;
880 }
881
882 /* Connect to link-local address requires an interface */
883 if (!sk->sk_bound_dev_if)
884 return -EINVAL;
885 }
886
887 sk->sk_v6_daddr = usin->sin6_addr;
888 np->flow_label = fl6.flowlabel;
889
890 /*
891 * DCCP over IPv4
892 */
893 if (addr_type == IPV6_ADDR_MAPPED) {
894 u32 exthdrlen = icsk->icsk_ext_hdr_len;
895 struct sockaddr_in sin;
896
897 net_dbg_ratelimited("connect: ipv4 mapped\n");
898
899 if (ipv6_only_sock(sk))
900 return -ENETUNREACH;
901
902 sin.sin_family = AF_INET;
903 sin.sin_port = usin->sin6_port;
904 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
905
906 icsk->icsk_af_ops = &dccp_ipv6_mapped;
907 sk->sk_backlog_rcv = dccp_v4_do_rcv;
908
909 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
910 if (err) {
911 icsk->icsk_ext_hdr_len = exthdrlen;
912 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
913 sk->sk_backlog_rcv = dccp_v6_do_rcv;
914 goto failure;
915 }
916 np->saddr = sk->sk_v6_rcv_saddr;
917 return err;
918 }
919
920 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
921 saddr = &sk->sk_v6_rcv_saddr;
922
923 fl6.flowi6_proto = IPPROTO_DCCP;
924 fl6.daddr = sk->sk_v6_daddr;
925 fl6.saddr = saddr ? *saddr : np->saddr;
926 fl6.flowi6_oif = sk->sk_bound_dev_if;
927 fl6.fl6_dport = usin->sin6_port;
928 fl6.fl6_sport = inet->inet_sport;
929 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
930
931 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
932 final_p = fl6_update_dst(&fl6, opt, &final);
933
934 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
935 if (IS_ERR(dst)) {
936 err = PTR_ERR(dst);
937 goto failure;
938 }
939
940 if (saddr == NULL) {
941 saddr = &fl6.saddr;
942
943 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
944 if (err)
945 goto failure;
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 (opt)
956 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
957
958 inet->inet_dport = usin->sin6_port;
959
960 dccp_set_state(sk, DCCP_REQUESTING);
961 err = inet6_hash_connect(&dccp_death_row, sk);
962 if (err)
963 goto late_failure;
964
965 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
966 sk->sk_v6_daddr.s6_addr32,
967 inet->inet_sport,
968 inet->inet_dport);
969 err = dccp_connect(sk);
970 if (err)
971 goto late_failure;
972
973 return 0;
974
975late_failure:
976 dccp_set_state(sk, DCCP_CLOSED);
977 inet_bhash2_reset_saddr(sk);
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};
997
998/*
999 * DCCP over IPv4 via INET6 API
1000 */
1001static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1002 .queue_xmit = ip_queue_xmit,
1003 .send_check = dccp_v4_send_check,
1004 .rebuild_header = inet_sk_rebuild_header,
1005 .conn_request = dccp_v6_conn_request,
1006 .syn_recv_sock = dccp_v6_request_recv_sock,
1007 .net_header_len = sizeof(struct iphdr),
1008 .setsockopt = ipv6_setsockopt,
1009 .getsockopt = ipv6_getsockopt,
1010 .addr2sockaddr = inet6_csk_addr2sockaddr,
1011 .sockaddr_len = sizeof(struct sockaddr_in6),
1012};
1013
1014static void dccp_v6_sk_destruct(struct sock *sk)
1015{
1016 dccp_destruct_common(sk);
1017 inet6_sock_destruct(sk);
1018}
1019
1020/* NOTE: A lot of things set to zero explicitly by call to
1021 * sk_alloc() so need not be done here.
1022 */
1023static int dccp_v6_init_sock(struct sock *sk)
1024{
1025 static __u8 dccp_v6_ctl_sock_initialized;
1026 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1027
1028 if (err == 0) {
1029 if (unlikely(!dccp_v6_ctl_sock_initialized))
1030 dccp_v6_ctl_sock_initialized = 1;
1031 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1032 sk->sk_destruct = dccp_v6_sk_destruct;
1033 }
1034
1035 return err;
1036}
1037
1038static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1039 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1040};
1041
1042static struct proto dccp_v6_prot = {
1043 .name = "DCCPv6",
1044 .owner = THIS_MODULE,
1045 .close = dccp_close,
1046 .connect = dccp_v6_connect,
1047 .disconnect = dccp_disconnect,
1048 .ioctl = dccp_ioctl,
1049 .init = dccp_v6_init_sock,
1050 .setsockopt = dccp_setsockopt,
1051 .getsockopt = dccp_getsockopt,
1052 .sendmsg = dccp_sendmsg,
1053 .recvmsg = dccp_recvmsg,
1054 .backlog_rcv = dccp_v6_do_rcv,
1055 .hash = inet6_hash,
1056 .unhash = inet_unhash,
1057 .accept = inet_csk_accept,
1058 .get_port = inet_csk_get_port,
1059 .shutdown = dccp_shutdown,
1060 .destroy = dccp_destroy_sock,
1061 .orphan_count = &dccp_orphan_count,
1062 .max_header = MAX_DCCP_HEADER,
1063 .obj_size = sizeof(struct dccp6_sock),
1064 .ipv6_pinfo_offset = offsetof(struct dccp6_sock, inet6),
1065 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1066 .rsk_prot = &dccp6_request_sock_ops,
1067 .twsk_prot = &dccp6_timewait_sock_ops,
1068 .h.hashinfo = &dccp_hashinfo,
1069};
1070
1071static const struct inet6_protocol dccp_v6_protocol = {
1072 .handler = dccp_v6_rcv,
1073 .err_handler = dccp_v6_err,
1074 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1075};
1076
1077static const struct proto_ops inet6_dccp_ops = {
1078 .family = PF_INET6,
1079 .owner = THIS_MODULE,
1080 .release = inet6_release,
1081 .bind = inet6_bind,
1082 .connect = inet_stream_connect,
1083 .socketpair = sock_no_socketpair,
1084 .accept = inet_accept,
1085 .getname = inet6_getname,
1086 .poll = dccp_poll,
1087 .ioctl = inet6_ioctl,
1088 .gettstamp = sock_gettstamp,
1089 .listen = inet_dccp_listen,
1090 .shutdown = inet_shutdown,
1091 .setsockopt = sock_common_setsockopt,
1092 .getsockopt = sock_common_getsockopt,
1093 .sendmsg = inet_sendmsg,
1094 .recvmsg = sock_common_recvmsg,
1095 .mmap = sock_no_mmap,
1096#ifdef CONFIG_COMPAT
1097 .compat_ioctl = inet6_compat_ioctl,
1098#endif
1099};
1100
1101static struct inet_protosw dccp_v6_protosw = {
1102 .type = SOCK_DCCP,
1103 .protocol = IPPROTO_DCCP,
1104 .prot = &dccp_v6_prot,
1105 .ops = &inet6_dccp_ops,
1106 .flags = INET_PROTOSW_ICSK,
1107};
1108
1109static int __net_init dccp_v6_init_net(struct net *net)
1110{
1111 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1112
1113 if (dccp_hashinfo.bhash == NULL)
1114 return -ESOCKTNOSUPPORT;
1115
1116 return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6,
1117 SOCK_DCCP, IPPROTO_DCCP, net);
1118}
1119
1120static void __net_exit dccp_v6_exit_net(struct net *net)
1121{
1122 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1123
1124 inet_ctl_sock_destroy(pn->v6_ctl_sk);
1125}
1126
1127static struct pernet_operations dccp_v6_ops = {
1128 .init = dccp_v6_init_net,
1129 .exit = dccp_v6_exit_net,
1130 .id = &dccp_v6_pernet_id,
1131 .size = sizeof(struct dccp_v6_pernet),
1132};
1133
1134static int __init dccp_v6_init(void)
1135{
1136 int err = proto_register(&dccp_v6_prot, 1);
1137
1138 if (err)
1139 goto out;
1140
1141 inet6_register_protosw(&dccp_v6_protosw);
1142
1143 err = register_pernet_subsys(&dccp_v6_ops);
1144 if (err)
1145 goto out_destroy_ctl_sock;
1146
1147 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1148 if (err)
1149 goto out_unregister_proto;
1150
1151out:
1152 return err;
1153out_unregister_proto:
1154 unregister_pernet_subsys(&dccp_v6_ops);
1155out_destroy_ctl_sock:
1156 inet6_unregister_protosw(&dccp_v6_protosw);
1157 proto_unregister(&dccp_v6_prot);
1158 goto out;
1159}
1160
1161static void __exit dccp_v6_exit(void)
1162{
1163 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1164 unregister_pernet_subsys(&dccp_v6_ops);
1165 inet6_unregister_protosw(&dccp_v6_protosw);
1166 proto_unregister(&dccp_v6_prot);
1167}
1168
1169module_init(dccp_v6_init);
1170module_exit(dccp_v6_exit);
1171
1172/*
1173 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1174 * values directly, Also cover the case where the protocol is not specified,
1175 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1176 */
1177MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1178MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1179MODULE_LICENSE("GPL");
1180MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1181MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");