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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;
78 const struct dccp_hdr *dh;
79 struct dccp_sock *dp;
80 struct ipv6_pinfo *np;
81 struct sock *sk;
82 int err;
83 __u64 seq;
84 struct net *net = dev_net(skb->dev);
85
86 if (!pskb_may_pull(skb, offset + sizeof(*dh)))
87 return -EINVAL;
88 dh = (struct dccp_hdr *)(skb->data + offset);
89 if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh)))
90 return -EINVAL;
91 hdr = (const struct ipv6hdr *)skb->data;
92 dh = (struct dccp_hdr *)(skb->data + offset);
93
94 sk = __inet6_lookup_established(net, &dccp_hashinfo,
95 &hdr->daddr, dh->dccph_dport,
96 &hdr->saddr, ntohs(dh->dccph_sport),
97 inet6_iif(skb), 0);
98
99 if (!sk) {
100 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
101 ICMP6_MIB_INERRORS);
102 return -ENOENT;
103 }
104
105 if (sk->sk_state == DCCP_TIME_WAIT) {
106 inet_twsk_put(inet_twsk(sk));
107 return 0;
108 }
109 seq = dccp_hdr_seq(dh);
110 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
111 dccp_req_err(sk, seq);
112 return 0;
113 }
114
115 bh_lock_sock(sk);
116 if (sock_owned_by_user(sk))
117 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
118
119 if (sk->sk_state == DCCP_CLOSED)
120 goto out;
121
122 dp = dccp_sk(sk);
123 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
124 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
125 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
126 goto out;
127 }
128
129 np = inet6_sk(sk);
130
131 if (type == NDISC_REDIRECT) {
132 if (!sock_owned_by_user(sk)) {
133 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
134
135 if (dst)
136 dst->ops->redirect(dst, sk, skb);
137 }
138 goto out;
139 }
140
141 if (type == ICMPV6_PKT_TOOBIG) {
142 struct dst_entry *dst = NULL;
143
144 if (!ip6_sk_accept_pmtu(sk))
145 goto out;
146
147 if (sock_owned_by_user(sk))
148 goto out;
149 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
150 goto out;
151
152 dst = inet6_csk_update_pmtu(sk, ntohl(info));
153 if (!dst)
154 goto out;
155
156 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
157 dccp_sync_mss(sk, dst_mtu(dst));
158 goto out;
159 }
160
161 icmpv6_err_convert(type, code, &err);
162
163 /* Might be for an request_sock */
164 switch (sk->sk_state) {
165 case DCCP_REQUESTING:
166 case DCCP_RESPOND: /* Cannot happen.
167 It can, it SYNs are crossed. --ANK */
168 if (!sock_owned_by_user(sk)) {
169 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
170 sk->sk_err = err;
171 /*
172 * Wake people up to see the error
173 * (see connect in sock.c)
174 */
175 sk_error_report(sk);
176 dccp_done(sk);
177 } else {
178 WRITE_ONCE(sk->sk_err_soft, err);
179 }
180 goto out;
181 }
182
183 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
184 sk->sk_err = err;
185 sk_error_report(sk);
186 } else {
187 WRITE_ONCE(sk->sk_err_soft, err);
188 }
189out:
190 bh_unlock_sock(sk);
191 sock_put(sk);
192 return 0;
193}
194
195
196static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
197{
198 struct inet_request_sock *ireq = inet_rsk(req);
199 struct ipv6_pinfo *np = inet6_sk(sk);
200 struct sk_buff *skb;
201 struct in6_addr *final_p, final;
202 struct flowi6 fl6;
203 int err = -1;
204 struct dst_entry *dst;
205
206 memset(&fl6, 0, sizeof(fl6));
207 fl6.flowi6_proto = IPPROTO_DCCP;
208 fl6.daddr = ireq->ir_v6_rmt_addr;
209 fl6.saddr = ireq->ir_v6_loc_addr;
210 fl6.flowlabel = 0;
211 fl6.flowi6_oif = ireq->ir_iif;
212 fl6.fl6_dport = ireq->ir_rmt_port;
213 fl6.fl6_sport = htons(ireq->ir_num);
214 security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
215
216
217 rcu_read_lock();
218 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
219 rcu_read_unlock();
220
221 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
222 if (IS_ERR(dst)) {
223 err = PTR_ERR(dst);
224 dst = NULL;
225 goto done;
226 }
227
228 skb = dccp_make_response(sk, dst, req);
229 if (skb != NULL) {
230 struct dccp_hdr *dh = dccp_hdr(skb);
231 struct ipv6_txoptions *opt;
232
233 dh->dccph_checksum = dccp_v6_csum_finish(skb,
234 &ireq->ir_v6_loc_addr,
235 &ireq->ir_v6_rmt_addr);
236 fl6.daddr = ireq->ir_v6_rmt_addr;
237 rcu_read_lock();
238 opt = ireq->ipv6_opt;
239 if (!opt)
240 opt = rcu_dereference(np->opt);
241 err = ip6_xmit(sk, skb, &fl6, READ_ONCE(sk->sk_mark), opt,
242 np->tclass, READ_ONCE(sk->sk_priority));
243 rcu_read_unlock();
244 err = net_xmit_eval(err);
245 }
246
247done:
248 dst_release(dst);
249 return err;
250}
251
252static void dccp_v6_reqsk_destructor(struct request_sock *req)
253{
254 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
255 kfree(inet_rsk(req)->ipv6_opt);
256 kfree_skb(inet_rsk(req)->pktopts);
257}
258
259static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
260{
261 const struct ipv6hdr *rxip6h;
262 struct sk_buff *skb;
263 struct flowi6 fl6;
264 struct net *net = dev_net(skb_dst(rxskb)->dev);
265 struct dccp_v6_pernet *pn;
266 struct sock *ctl_sk;
267 struct dst_entry *dst;
268
269 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
270 return;
271
272 if (!ipv6_unicast_destination(rxskb))
273 return;
274
275 pn = net_generic(net, dccp_v6_pernet_id);
276 ctl_sk = pn->v6_ctl_sk;
277 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
278 if (skb == NULL)
279 return;
280
281 rxip6h = ipv6_hdr(rxskb);
282 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
283 &rxip6h->daddr);
284
285 memset(&fl6, 0, sizeof(fl6));
286 fl6.daddr = rxip6h->saddr;
287 fl6.saddr = rxip6h->daddr;
288
289 fl6.flowi6_proto = IPPROTO_DCCP;
290 fl6.flowi6_oif = inet6_iif(rxskb);
291 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
292 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
293 security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6));
294
295 /* sk = NULL, but it is safe for now. RST socket required. */
296 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
297 if (!IS_ERR(dst)) {
298 skb_dst_set(skb, dst);
299 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
300 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
301 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
302 return;
303 }
304
305 kfree_skb(skb);
306}
307
308static struct request_sock_ops dccp6_request_sock_ops = {
309 .family = AF_INET6,
310 .obj_size = sizeof(struct dccp6_request_sock),
311 .rtx_syn_ack = dccp_v6_send_response,
312 .send_ack = dccp_reqsk_send_ack,
313 .destructor = dccp_v6_reqsk_destructor,
314 .send_reset = dccp_v6_ctl_send_reset,
315 .syn_ack_timeout = dccp_syn_ack_timeout,
316};
317
318static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
319{
320 struct request_sock *req;
321 struct dccp_request_sock *dreq;
322 struct inet_request_sock *ireq;
323 struct ipv6_pinfo *np = inet6_sk(sk);
324 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
325 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
326
327 if (skb->protocol == htons(ETH_P_IP))
328 return dccp_v4_conn_request(sk, skb);
329
330 if (!ipv6_unicast_destination(skb))
331 return 0; /* discard, don't send a reset here */
332
333 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
334 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
335 return 0;
336 }
337
338 if (dccp_bad_service_code(sk, service)) {
339 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
340 goto drop;
341 }
342 /*
343 * There are no SYN attacks on IPv6, yet...
344 */
345 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
346 if (inet_csk_reqsk_queue_is_full(sk))
347 goto drop;
348
349 if (sk_acceptq_is_full(sk))
350 goto drop;
351
352 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
353 if (req == NULL)
354 goto drop;
355
356 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
357 goto drop_and_free;
358
359 dreq = dccp_rsk(req);
360 if (dccp_parse_options(sk, dreq, skb))
361 goto drop_and_free;
362
363 ireq = inet_rsk(req);
364 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
365 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
366 ireq->ireq_family = AF_INET6;
367 ireq->ir_mark = inet_request_mark(sk, skb);
368
369 if (security_inet_conn_request(sk, skb, req))
370 goto drop_and_free;
371
372 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
373 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
374 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
375 refcount_inc(&skb->users);
376 ireq->pktopts = skb;
377 }
378 ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if);
379
380 /* So that link locals have meaning */
381 if (!ireq->ir_iif &&
382 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
383 ireq->ir_iif = inet6_iif(skb);
384
385 /*
386 * Step 3: Process LISTEN state
387 *
388 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
389 *
390 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
391 */
392 dreq->dreq_isr = dcb->dccpd_seq;
393 dreq->dreq_gsr = dreq->dreq_isr;
394 dreq->dreq_iss = dccp_v6_init_sequence(skb);
395 dreq->dreq_gss = dreq->dreq_iss;
396 dreq->dreq_service = service;
397
398 if (dccp_v6_send_response(sk, req))
399 goto drop_and_free;
400
401 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
402 reqsk_put(req);
403 return 0;
404
405drop_and_free:
406 reqsk_free(req);
407drop:
408 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
409 return -1;
410}
411
412static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
413 struct sk_buff *skb,
414 struct request_sock *req,
415 struct dst_entry *dst,
416 struct request_sock *req_unhash,
417 bool *own_req)
418{
419 struct inet_request_sock *ireq = inet_rsk(req);
420 struct ipv6_pinfo *newnp;
421 const struct ipv6_pinfo *np = inet6_sk(sk);
422 struct ipv6_txoptions *opt;
423 struct inet_sock *newinet;
424 struct dccp6_sock *newdp6;
425 struct sock *newsk;
426
427 if (skb->protocol == htons(ETH_P_IP)) {
428 /*
429 * v6 mapped
430 */
431 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
432 req_unhash, own_req);
433 if (newsk == NULL)
434 return NULL;
435
436 newdp6 = (struct dccp6_sock *)newsk;
437 newinet = inet_sk(newsk);
438 newinet->pinet6 = &newdp6->inet6;
439 newnp = inet6_sk(newsk);
440
441 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
442
443 newnp->saddr = newsk->sk_v6_rcv_saddr;
444
445 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
446 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
447 newnp->pktoptions = NULL;
448 newnp->opt = NULL;
449 newnp->ipv6_mc_list = NULL;
450 newnp->ipv6_ac_list = NULL;
451 newnp->ipv6_fl_list = NULL;
452 newnp->mcast_oif = inet_iif(skb);
453 newnp->mcast_hops = ip_hdr(skb)->ttl;
454
455 /*
456 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
457 * here, dccp_create_openreq_child now does this for us, see the comment in
458 * that function for the gory details. -acme
459 */
460
461 /* It is tricky place. Until this moment IPv4 tcp
462 worked with IPv6 icsk.icsk_af_ops.
463 Sync it now.
464 */
465 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
466
467 return newsk;
468 }
469
470
471 if (sk_acceptq_is_full(sk))
472 goto out_overflow;
473
474 if (!dst) {
475 struct flowi6 fl6;
476
477 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
478 if (!dst)
479 goto out;
480 }
481
482 newsk = dccp_create_openreq_child(sk, req, skb);
483 if (newsk == NULL)
484 goto out_nonewsk;
485
486 /*
487 * No need to charge this sock to the relevant IPv6 refcnt debug socks
488 * count here, dccp_create_openreq_child now does this for us, see the
489 * comment in that function for the gory details. -acme
490 */
491
492 ip6_dst_store(newsk, dst, NULL, NULL);
493 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
494 NETIF_F_TSO);
495 newdp6 = (struct dccp6_sock *)newsk;
496 newinet = inet_sk(newsk);
497 newinet->pinet6 = &newdp6->inet6;
498 newnp = inet6_sk(newsk);
499
500 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
501
502 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
503 newnp->saddr = ireq->ir_v6_loc_addr;
504 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
505 newsk->sk_bound_dev_if = ireq->ir_iif;
506
507 /* Now IPv6 options...
508
509 First: no IPv4 options.
510 */
511 newinet->inet_opt = NULL;
512
513 /* Clone RX bits */
514 newnp->rxopt.all = np->rxopt.all;
515
516 newnp->ipv6_mc_list = NULL;
517 newnp->ipv6_ac_list = NULL;
518 newnp->ipv6_fl_list = NULL;
519 newnp->pktoptions = NULL;
520 newnp->opt = NULL;
521 newnp->mcast_oif = inet6_iif(skb);
522 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
523
524 /*
525 * Clone native IPv6 options from listening socket (if any)
526 *
527 * Yes, keeping reference count would be much more clever, but we make
528 * one more one thing there: reattach optmem to newsk.
529 */
530 opt = ireq->ipv6_opt;
531 if (!opt)
532 opt = rcu_dereference(np->opt);
533 if (opt) {
534 opt = ipv6_dup_options(newsk, opt);
535 RCU_INIT_POINTER(newnp->opt, opt);
536 }
537 inet_csk(newsk)->icsk_ext_hdr_len = 0;
538 if (opt)
539 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
540 opt->opt_flen;
541
542 dccp_sync_mss(newsk, dst_mtu(dst));
543
544 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
545 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
546
547 if (__inet_inherit_port(sk, newsk) < 0) {
548 inet_csk_prepare_forced_close(newsk);
549 dccp_done(newsk);
550 goto out;
551 }
552 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL);
553 /* Clone pktoptions received with SYN, if we own the req */
554 if (*own_req && ireq->pktopts) {
555 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
556 consume_skb(ireq->pktopts);
557 ireq->pktopts = NULL;
558 }
559
560 return newsk;
561
562out_overflow:
563 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
564out_nonewsk:
565 dst_release(dst);
566out:
567 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
568 return NULL;
569}
570
571/* The socket must have it's spinlock held when we get
572 * here.
573 *
574 * We have a potential double-lock case here, so even when
575 * doing backlog processing we use the BH locking scheme.
576 * This is because we cannot sleep with the original spinlock
577 * held.
578 */
579static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
580{
581 struct ipv6_pinfo *np = inet6_sk(sk);
582 struct sk_buff *opt_skb = NULL;
583
584 /* Imagine: socket is IPv6. IPv4 packet arrives,
585 goes to IPv4 receive handler and backlogged.
586 From backlog it always goes here. Kerboom...
587 Fortunately, dccp_rcv_established and rcv_established
588 handle them correctly, but it is not case with
589 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
590 */
591
592 if (skb->protocol == htons(ETH_P_IP))
593 return dccp_v4_do_rcv(sk, skb);
594
595 if (sk_filter(sk, skb))
596 goto discard;
597
598 /*
599 * socket locking is here for SMP purposes as backlog rcv is currently
600 * called with bh processing disabled.
601 */
602
603 /* Do Stevens' IPV6_PKTOPTIONS.
604
605 Yes, guys, it is the only place in our code, where we
606 may make it not affecting IPv4.
607 The rest of code is protocol independent,
608 and I do not like idea to uglify IPv4.
609
610 Actually, all the idea behind IPV6_PKTOPTIONS
611 looks not very well thought. For now we latch
612 options, received in the last packet, enqueued
613 by tcp. Feel free to propose better solution.
614 --ANK (980728)
615 */
616 if (np->rxopt.all)
617 opt_skb = skb_clone_and_charge_r(skb, sk);
618
619 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
620 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
621 goto reset;
622 if (opt_skb)
623 goto ipv6_pktoptions;
624 return 0;
625 }
626
627 /*
628 * Step 3: Process LISTEN state
629 * If S.state == LISTEN,
630 * If P.type == Request or P contains a valid Init Cookie option,
631 * (* Must scan the packet's options to check for Init
632 * Cookies. Only Init Cookies are processed here,
633 * however; other options are processed in Step 8. This
634 * scan need only be performed if the endpoint uses Init
635 * Cookies *)
636 * (* Generate a new socket and switch to that socket *)
637 * Set S := new socket for this port pair
638 * S.state = RESPOND
639 * Choose S.ISS (initial seqno) or set from Init Cookies
640 * Initialize S.GAR := S.ISS
641 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
642 * Continue with S.state == RESPOND
643 * (* A Response packet will be generated in Step 11 *)
644 * Otherwise,
645 * Generate Reset(No Connection) unless P.type == Reset
646 * Drop packet and return
647 *
648 * NOTE: the check for the packet types is done in
649 * dccp_rcv_state_process
650 */
651
652 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
653 goto reset;
654 if (opt_skb)
655 goto ipv6_pktoptions;
656 return 0;
657
658reset:
659 dccp_v6_ctl_send_reset(sk, skb);
660discard:
661 if (opt_skb != NULL)
662 __kfree_skb(opt_skb);
663 kfree_skb(skb);
664 return 0;
665
666/* Handling IPV6_PKTOPTIONS skb the similar
667 * way it's done for net/ipv6/tcp_ipv6.c
668 */
669ipv6_pktoptions:
670 if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
671 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
672 WRITE_ONCE(np->mcast_oif, inet6_iif(opt_skb));
673 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
674 WRITE_ONCE(np->mcast_hops, ipv6_hdr(opt_skb)->hop_limit);
675 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
676 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
677 if (inet6_test_bit(REPFLOW, sk))
678 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
679 if (ipv6_opt_accepted(sk, opt_skb,
680 &DCCP_SKB_CB(opt_skb)->header.h6)) {
681 memmove(IP6CB(opt_skb),
682 &DCCP_SKB_CB(opt_skb)->header.h6,
683 sizeof(struct inet6_skb_parm));
684 opt_skb = xchg(&np->pktoptions, opt_skb);
685 } else {
686 __kfree_skb(opt_skb);
687 opt_skb = xchg(&np->pktoptions, NULL);
688 }
689 }
690
691 kfree_skb(opt_skb);
692 return 0;
693}
694
695static int dccp_v6_rcv(struct sk_buff *skb)
696{
697 const struct dccp_hdr *dh;
698 bool refcounted;
699 struct sock *sk;
700 int min_cov;
701
702 /* Step 1: Check header basics */
703
704 if (dccp_invalid_packet(skb))
705 goto discard_it;
706
707 /* Step 1: If header checksum is incorrect, drop packet and return. */
708 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
709 &ipv6_hdr(skb)->daddr)) {
710 DCCP_WARN("dropped packet with invalid checksum\n");
711 goto discard_it;
712 }
713
714 dh = dccp_hdr(skb);
715
716 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
717 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
718
719 if (dccp_packet_without_ack(skb))
720 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
721 else
722 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
723
724lookup:
725 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
726 dh->dccph_sport, dh->dccph_dport,
727 inet6_iif(skb), 0, &refcounted);
728 if (!sk) {
729 dccp_pr_debug("failed to look up flow ID in table and "
730 "get corresponding socket\n");
731 goto no_dccp_socket;
732 }
733
734 /*
735 * Step 2:
736 * ... or S.state == TIMEWAIT,
737 * Generate Reset(No Connection) unless P.type == Reset
738 * Drop packet and return
739 */
740 if (sk->sk_state == DCCP_TIME_WAIT) {
741 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
742 inet_twsk_put(inet_twsk(sk));
743 goto no_dccp_socket;
744 }
745
746 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
747 struct request_sock *req = inet_reqsk(sk);
748 struct sock *nsk;
749
750 sk = req->rsk_listener;
751 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
752 inet_csk_reqsk_queue_drop_and_put(sk, req);
753 goto lookup;
754 }
755 sock_hold(sk);
756 refcounted = true;
757 nsk = dccp_check_req(sk, skb, req);
758 if (!nsk) {
759 reqsk_put(req);
760 goto discard_and_relse;
761 }
762 if (nsk == sk) {
763 reqsk_put(req);
764 } else if (dccp_child_process(sk, nsk, skb)) {
765 dccp_v6_ctl_send_reset(sk, skb);
766 goto discard_and_relse;
767 } else {
768 sock_put(sk);
769 return 0;
770 }
771 }
772 /*
773 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
774 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
775 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
776 */
777 min_cov = dccp_sk(sk)->dccps_pcrlen;
778 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
779 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
780 dh->dccph_cscov, min_cov);
781 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
782 goto discard_and_relse;
783 }
784
785 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
786 goto discard_and_relse;
787 nf_reset_ct(skb);
788
789 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
790 refcounted) ? -1 : 0;
791
792no_dccp_socket:
793 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
794 goto discard_it;
795 /*
796 * Step 2:
797 * If no socket ...
798 * Generate Reset(No Connection) unless P.type == Reset
799 * Drop packet and return
800 */
801 if (dh->dccph_type != DCCP_PKT_RESET) {
802 DCCP_SKB_CB(skb)->dccpd_reset_code =
803 DCCP_RESET_CODE_NO_CONNECTION;
804 dccp_v6_ctl_send_reset(sk, skb);
805 }
806
807discard_it:
808 kfree_skb(skb);
809 return 0;
810
811discard_and_relse:
812 if (refcounted)
813 sock_put(sk);
814 goto discard_it;
815}
816
817static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
818 int addr_len)
819{
820 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
821 struct inet_connection_sock *icsk = inet_csk(sk);
822 struct inet_sock *inet = inet_sk(sk);
823 struct ipv6_pinfo *np = inet6_sk(sk);
824 struct dccp_sock *dp = dccp_sk(sk);
825 struct in6_addr *saddr = NULL, *final_p, final;
826 struct ipv6_txoptions *opt;
827 struct flowi6 fl6;
828 struct dst_entry *dst;
829 int addr_type;
830 int err;
831
832 dp->dccps_role = DCCP_ROLE_CLIENT;
833
834 if (addr_len < SIN6_LEN_RFC2133)
835 return -EINVAL;
836
837 if (usin->sin6_family != AF_INET6)
838 return -EAFNOSUPPORT;
839
840 memset(&fl6, 0, sizeof(fl6));
841
842 if (inet6_test_bit(SNDFLOW, sk)) {
843 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
844 IP6_ECN_flow_init(fl6.flowlabel);
845 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
846 struct ip6_flowlabel *flowlabel;
847 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
848 if (IS_ERR(flowlabel))
849 return -EINVAL;
850 fl6_sock_release(flowlabel);
851 }
852 }
853 /*
854 * connect() to INADDR_ANY means loopback (BSD'ism).
855 */
856 if (ipv6_addr_any(&usin->sin6_addr))
857 usin->sin6_addr.s6_addr[15] = 1;
858
859 addr_type = ipv6_addr_type(&usin->sin6_addr);
860
861 if (addr_type & IPV6_ADDR_MULTICAST)
862 return -ENETUNREACH;
863
864 if (addr_type & IPV6_ADDR_LINKLOCAL) {
865 if (addr_len >= sizeof(struct sockaddr_in6) &&
866 usin->sin6_scope_id) {
867 /* If interface is set while binding, indices
868 * must coincide.
869 */
870 if (sk->sk_bound_dev_if &&
871 sk->sk_bound_dev_if != usin->sin6_scope_id)
872 return -EINVAL;
873
874 sk->sk_bound_dev_if = usin->sin6_scope_id;
875 }
876
877 /* Connect to link-local address requires an interface */
878 if (!sk->sk_bound_dev_if)
879 return -EINVAL;
880 }
881
882 sk->sk_v6_daddr = usin->sin6_addr;
883 np->flow_label = fl6.flowlabel;
884
885 /*
886 * DCCP over IPv4
887 */
888 if (addr_type == IPV6_ADDR_MAPPED) {
889 u32 exthdrlen = icsk->icsk_ext_hdr_len;
890 struct sockaddr_in sin;
891
892 net_dbg_ratelimited("connect: ipv4 mapped\n");
893
894 if (ipv6_only_sock(sk))
895 return -ENETUNREACH;
896
897 sin.sin_family = AF_INET;
898 sin.sin_port = usin->sin6_port;
899 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
900
901 icsk->icsk_af_ops = &dccp_ipv6_mapped;
902 sk->sk_backlog_rcv = dccp_v4_do_rcv;
903
904 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
905 if (err) {
906 icsk->icsk_ext_hdr_len = exthdrlen;
907 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
908 sk->sk_backlog_rcv = dccp_v6_do_rcv;
909 goto failure;
910 }
911 np->saddr = sk->sk_v6_rcv_saddr;
912 return err;
913 }
914
915 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
916 saddr = &sk->sk_v6_rcv_saddr;
917
918 fl6.flowi6_proto = IPPROTO_DCCP;
919 fl6.daddr = sk->sk_v6_daddr;
920 fl6.saddr = saddr ? *saddr : np->saddr;
921 fl6.flowi6_oif = sk->sk_bound_dev_if;
922 fl6.fl6_dport = usin->sin6_port;
923 fl6.fl6_sport = inet->inet_sport;
924 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
925
926 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
927 final_p = fl6_update_dst(&fl6, opt, &final);
928
929 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
930 if (IS_ERR(dst)) {
931 err = PTR_ERR(dst);
932 goto failure;
933 }
934
935 if (saddr == NULL) {
936 saddr = &fl6.saddr;
937
938 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
939 if (err)
940 goto failure;
941 }
942
943 /* set the source address */
944 np->saddr = *saddr;
945 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
946
947 ip6_dst_store(sk, dst, NULL, NULL);
948
949 icsk->icsk_ext_hdr_len = 0;
950 if (opt)
951 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
952
953 inet->inet_dport = usin->sin6_port;
954
955 dccp_set_state(sk, DCCP_REQUESTING);
956 err = inet6_hash_connect(&dccp_death_row, sk);
957 if (err)
958 goto late_failure;
959
960 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
961 sk->sk_v6_daddr.s6_addr32,
962 inet->inet_sport,
963 inet->inet_dport);
964 err = dccp_connect(sk);
965 if (err)
966 goto late_failure;
967
968 return 0;
969
970late_failure:
971 dccp_set_state(sk, DCCP_CLOSED);
972 inet_bhash2_reset_saddr(sk);
973 __sk_dst_reset(sk);
974failure:
975 inet->inet_dport = 0;
976 sk->sk_route_caps = 0;
977 return err;
978}
979
980static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
981 .queue_xmit = inet6_csk_xmit,
982 .send_check = dccp_v6_send_check,
983 .rebuild_header = inet6_sk_rebuild_header,
984 .conn_request = dccp_v6_conn_request,
985 .syn_recv_sock = dccp_v6_request_recv_sock,
986 .net_header_len = sizeof(struct ipv6hdr),
987 .setsockopt = ipv6_setsockopt,
988 .getsockopt = ipv6_getsockopt,
989 .addr2sockaddr = inet6_csk_addr2sockaddr,
990 .sockaddr_len = sizeof(struct sockaddr_in6),
991};
992
993/*
994 * DCCP over IPv4 via INET6 API
995 */
996static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
997 .queue_xmit = ip_queue_xmit,
998 .send_check = dccp_v4_send_check,
999 .rebuild_header = inet_sk_rebuild_header,
1000 .conn_request = dccp_v6_conn_request,
1001 .syn_recv_sock = dccp_v6_request_recv_sock,
1002 .net_header_len = sizeof(struct iphdr),
1003 .setsockopt = ipv6_setsockopt,
1004 .getsockopt = ipv6_getsockopt,
1005 .addr2sockaddr = inet6_csk_addr2sockaddr,
1006 .sockaddr_len = sizeof(struct sockaddr_in6),
1007};
1008
1009static void dccp_v6_sk_destruct(struct sock *sk)
1010{
1011 dccp_destruct_common(sk);
1012 inet6_sock_destruct(sk);
1013}
1014
1015/* NOTE: A lot of things set to zero explicitly by call to
1016 * sk_alloc() so need not be done here.
1017 */
1018static int dccp_v6_init_sock(struct sock *sk)
1019{
1020 static __u8 dccp_v6_ctl_sock_initialized;
1021 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1022
1023 if (err == 0) {
1024 if (unlikely(!dccp_v6_ctl_sock_initialized))
1025 dccp_v6_ctl_sock_initialized = 1;
1026 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1027 sk->sk_destruct = dccp_v6_sk_destruct;
1028 }
1029
1030 return err;
1031}
1032
1033static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1034 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1035};
1036
1037static struct proto dccp_v6_prot = {
1038 .name = "DCCPv6",
1039 .owner = THIS_MODULE,
1040 .close = dccp_close,
1041 .connect = dccp_v6_connect,
1042 .disconnect = dccp_disconnect,
1043 .ioctl = dccp_ioctl,
1044 .init = dccp_v6_init_sock,
1045 .setsockopt = dccp_setsockopt,
1046 .getsockopt = dccp_getsockopt,
1047 .sendmsg = dccp_sendmsg,
1048 .recvmsg = dccp_recvmsg,
1049 .backlog_rcv = dccp_v6_do_rcv,
1050 .hash = inet6_hash,
1051 .unhash = inet_unhash,
1052 .accept = inet_csk_accept,
1053 .get_port = inet_csk_get_port,
1054 .shutdown = dccp_shutdown,
1055 .destroy = dccp_destroy_sock,
1056 .orphan_count = &dccp_orphan_count,
1057 .max_header = MAX_DCCP_HEADER,
1058 .obj_size = sizeof(struct dccp6_sock),
1059 .ipv6_pinfo_offset = offsetof(struct dccp6_sock, inet6),
1060 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1061 .rsk_prot = &dccp6_request_sock_ops,
1062 .twsk_prot = &dccp6_timewait_sock_ops,
1063 .h.hashinfo = &dccp_hashinfo,
1064};
1065
1066static const struct inet6_protocol dccp_v6_protocol = {
1067 .handler = dccp_v6_rcv,
1068 .err_handler = dccp_v6_err,
1069 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1070};
1071
1072static const struct proto_ops inet6_dccp_ops = {
1073 .family = PF_INET6,
1074 .owner = THIS_MODULE,
1075 .release = inet6_release,
1076 .bind = inet6_bind,
1077 .connect = inet_stream_connect,
1078 .socketpair = sock_no_socketpair,
1079 .accept = inet_accept,
1080 .getname = inet6_getname,
1081 .poll = dccp_poll,
1082 .ioctl = inet6_ioctl,
1083 .gettstamp = sock_gettstamp,
1084 .listen = inet_dccp_listen,
1085 .shutdown = inet_shutdown,
1086 .setsockopt = sock_common_setsockopt,
1087 .getsockopt = sock_common_getsockopt,
1088 .sendmsg = inet_sendmsg,
1089 .recvmsg = sock_common_recvmsg,
1090 .mmap = sock_no_mmap,
1091#ifdef CONFIG_COMPAT
1092 .compat_ioctl = inet6_compat_ioctl,
1093#endif
1094};
1095
1096static struct inet_protosw dccp_v6_protosw = {
1097 .type = SOCK_DCCP,
1098 .protocol = IPPROTO_DCCP,
1099 .prot = &dccp_v6_prot,
1100 .ops = &inet6_dccp_ops,
1101 .flags = INET_PROTOSW_ICSK,
1102};
1103
1104static int __net_init dccp_v6_init_net(struct net *net)
1105{
1106 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1107
1108 if (dccp_hashinfo.bhash == NULL)
1109 return -ESOCKTNOSUPPORT;
1110
1111 return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6,
1112 SOCK_DCCP, IPPROTO_DCCP, net);
1113}
1114
1115static void __net_exit dccp_v6_exit_net(struct net *net)
1116{
1117 struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id);
1118
1119 inet_ctl_sock_destroy(pn->v6_ctl_sk);
1120}
1121
1122static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1123{
1124 inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1125}
1126
1127static struct pernet_operations dccp_v6_ops = {
1128 .init = dccp_v6_init_net,
1129 .exit = dccp_v6_exit_net,
1130 .exit_batch = dccp_v6_exit_batch,
1131 .id = &dccp_v6_pernet_id,
1132 .size = sizeof(struct dccp_v6_pernet),
1133};
1134
1135static int __init dccp_v6_init(void)
1136{
1137 int err = proto_register(&dccp_v6_prot, 1);
1138
1139 if (err)
1140 goto out;
1141
1142 inet6_register_protosw(&dccp_v6_protosw);
1143
1144 err = register_pernet_subsys(&dccp_v6_ops);
1145 if (err)
1146 goto out_destroy_ctl_sock;
1147
1148 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1149 if (err)
1150 goto out_unregister_proto;
1151
1152out:
1153 return err;
1154out_unregister_proto:
1155 unregister_pernet_subsys(&dccp_v6_ops);
1156out_destroy_ctl_sock:
1157 inet6_unregister_protosw(&dccp_v6_protosw);
1158 proto_unregister(&dccp_v6_prot);
1159 goto out;
1160}
1161
1162static void __exit dccp_v6_exit(void)
1163{
1164 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1165 unregister_pernet_subsys(&dccp_v6_ops);
1166 inet6_unregister_protosw(&dccp_v6_protosw);
1167 proto_unregister(&dccp_v6_prot);
1168}
1169
1170module_init(dccp_v6_init);
1171module_exit(dccp_v6_exit);
1172
1173/*
1174 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1175 * values directly, Also cover the case where the protocol is not specified,
1176 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1177 */
1178MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1179MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1180MODULE_LICENSE("GPL");
1181MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1182MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");