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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
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");