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ANDROID: binder: don't queue async transactions to thread.
[linux/fpc-iii.git] / net / dccp / ipv6.c
blob1b58eac8aad326b6db09a4cee82fdcc178c2afad
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
40 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
41 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
42
43 /* add pseudo-header to DCCP checksum stored in skb->csum */
44 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
45 const struct in6_addr *saddr,
46 const struct in6_addr *daddr)
47 {
48 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
49 }
50
51 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
52 {
53 struct ipv6_pinfo *np = inet6_sk(sk);
54 struct dccp_hdr *dh = dccp_hdr(skb);
55
56 dccp_csum_outgoing(skb);
57 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
58 }
59
60 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
61 {
62 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
63 ipv6_hdr(skb)->saddr.s6_addr32,
64 dccp_hdr(skb)->dccph_dport,
65 dccp_hdr(skb)->dccph_sport );
66
67 }
68
69 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
70 u8 type, u8 code, int offset, __be32 info)
71 {
72 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
73 const struct dccp_hdr *dh;
74 struct dccp_sock *dp;
75 struct ipv6_pinfo *np;
76 struct sock *sk;
77 int err;
78 __u64 seq;
79 struct net *net = dev_net(skb->dev);
80
81 /* Only need dccph_dport & dccph_sport which are the first
82 * 4 bytes in dccp header.
83 * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
84 */
85 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
86 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
87 dh = (struct dccp_hdr *)(skb->data + offset);
88
89 sk = __inet6_lookup_established(net, &dccp_hashinfo,
90 &hdr->daddr, dh->dccph_dport,
91 &hdr->saddr, ntohs(dh->dccph_sport),
92 inet6_iif(skb));
93
94 if (!sk) {
95 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
96 ICMP6_MIB_INERRORS);
97 return;
98 }
99
100 if (sk->sk_state == DCCP_TIME_WAIT) {
101 inet_twsk_put(inet_twsk(sk));
102 return;
103 }
104 seq = dccp_hdr_seq(dh);
105 if (sk->sk_state == DCCP_NEW_SYN_RECV)
106 return dccp_req_err(sk, seq);
107
108 bh_lock_sock(sk);
109 if (sock_owned_by_user(sk))
110 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
111
112 if (sk->sk_state == DCCP_CLOSED)
113 goto out;
114
115 dp = dccp_sk(sk);
116 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
117 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
118 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
119 goto out;
120 }
121
122 np = inet6_sk(sk);
123
124 if (type == NDISC_REDIRECT) {
125 if (!sock_owned_by_user(sk)) {
126 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
127
128 if (dst)
129 dst->ops->redirect(dst, sk, skb);
130 }
131 goto out;
132 }
133
134 if (type == ICMPV6_PKT_TOOBIG) {
135 struct dst_entry *dst = NULL;
136
137 if (!ip6_sk_accept_pmtu(sk))
138 goto out;
139
140 if (sock_owned_by_user(sk))
141 goto out;
142 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
143 goto out;
144
145 dst = inet6_csk_update_pmtu(sk, ntohl(info));
146 if (!dst)
147 goto out;
148
149 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
150 dccp_sync_mss(sk, dst_mtu(dst));
151 goto out;
152 }
153
154 icmpv6_err_convert(type, code, &err);
155
156 /* Might be for an request_sock */
157 switch (sk->sk_state) {
158 case DCCP_REQUESTING:
159 case DCCP_RESPOND: /* Cannot happen.
160 It can, it SYNs are crossed. --ANK */
161 if (!sock_owned_by_user(sk)) {
162 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
163 sk->sk_err = err;
164 /*
165 * Wake people up to see the error
166 * (see connect in sock.c)
167 */
168 sk->sk_error_report(sk);
169 dccp_done(sk);
170 } else
171 sk->sk_err_soft = err;
172 goto out;
173 }
174
175 if (!sock_owned_by_user(sk) && np->recverr) {
176 sk->sk_err = err;
177 sk->sk_error_report(sk);
178 } else
179 sk->sk_err_soft = err;
180
181 out:
182 bh_unlock_sock(sk);
183 sock_put(sk);
184 }
185
186
187 static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
188 {
189 struct inet_request_sock *ireq = inet_rsk(req);
190 struct ipv6_pinfo *np = inet6_sk(sk);
191 struct sk_buff *skb;
192 struct in6_addr *final_p, final;
193 struct flowi6 fl6;
194 int err = -1;
195 struct dst_entry *dst;
196
197 memset(&fl6, 0, sizeof(fl6));
198 fl6.flowi6_proto = IPPROTO_DCCP;
199 fl6.daddr = ireq->ir_v6_rmt_addr;
200 fl6.saddr = ireq->ir_v6_loc_addr;
201 fl6.flowlabel = 0;
202 fl6.flowi6_oif = ireq->ir_iif;
203 fl6.fl6_dport = ireq->ir_rmt_port;
204 fl6.fl6_sport = htons(ireq->ir_num);
205 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
206
207
208 rcu_read_lock();
209 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
210 rcu_read_unlock();
211
212 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
213 if (IS_ERR(dst)) {
214 err = PTR_ERR(dst);
215 dst = NULL;
216 goto done;
217 }
218
219 skb = dccp_make_response(sk, dst, req);
220 if (skb != NULL) {
221 struct dccp_hdr *dh = dccp_hdr(skb);
222 struct ipv6_txoptions *opt;
223
224 dh->dccph_checksum = dccp_v6_csum_finish(skb,
225 &ireq->ir_v6_loc_addr,
226 &ireq->ir_v6_rmt_addr);
227 fl6.daddr = ireq->ir_v6_rmt_addr;
228 rcu_read_lock();
229 opt = ireq->ipv6_opt;
230 if (!opt)
231 opt = rcu_dereference(np->opt);
232 err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass);
233 rcu_read_unlock();
234 err = net_xmit_eval(err);
235 }
236
237 done:
238 dst_release(dst);
239 return err;
240 }
241
242 static void dccp_v6_reqsk_destructor(struct request_sock *req)
243 {
244 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
245 kfree(inet_rsk(req)->ipv6_opt);
246 kfree_skb(inet_rsk(req)->pktopts);
247 }
248
249 static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
250 {
251 const struct ipv6hdr *rxip6h;
252 struct sk_buff *skb;
253 struct flowi6 fl6;
254 struct net *net = dev_net(skb_dst(rxskb)->dev);
255 struct sock *ctl_sk = net->dccp.v6_ctl_sk;
256 struct dst_entry *dst;
257
258 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
259 return;
260
261 if (!ipv6_unicast_destination(rxskb))
262 return;
263
264 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
265 if (skb == NULL)
266 return;
267
268 rxip6h = ipv6_hdr(rxskb);
269 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
270 &rxip6h->daddr);
271
272 memset(&fl6, 0, sizeof(fl6));
273 fl6.daddr = rxip6h->saddr;
274 fl6.saddr = rxip6h->daddr;
275
276 fl6.flowi6_proto = IPPROTO_DCCP;
277 fl6.flowi6_oif = inet6_iif(rxskb);
278 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
279 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
280 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
281
282 /* sk = NULL, but it is safe for now. RST socket required. */
283 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
284 if (!IS_ERR(dst)) {
285 skb_dst_set(skb, dst);
286 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0);
287 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
288 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
289 return;
290 }
291
292 kfree_skb(skb);
293 }
294
295 static struct request_sock_ops dccp6_request_sock_ops = {
296 .family = AF_INET6,
297 .obj_size = sizeof(struct dccp6_request_sock),
298 .rtx_syn_ack = dccp_v6_send_response,
299 .send_ack = dccp_reqsk_send_ack,
300 .destructor = dccp_v6_reqsk_destructor,
301 .send_reset = dccp_v6_ctl_send_reset,
302 .syn_ack_timeout = dccp_syn_ack_timeout,
303 };
304
305 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
306 {
307 struct request_sock *req;
308 struct dccp_request_sock *dreq;
309 struct inet_request_sock *ireq;
310 struct ipv6_pinfo *np = inet6_sk(sk);
311 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
312 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
313
314 if (skb->protocol == htons(ETH_P_IP))
315 return dccp_v4_conn_request(sk, skb);
316
317 if (!ipv6_unicast_destination(skb))
318 return 0; /* discard, don't send a reset here */
319
320 if (dccp_bad_service_code(sk, service)) {
321 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
322 goto drop;
323 }
324 /*
325 * There are no SYN attacks on IPv6, yet...
326 */
327 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
328 if (inet_csk_reqsk_queue_is_full(sk))
329 goto drop;
330
331 if (sk_acceptq_is_full(sk))
332 goto drop;
333
334 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
335 if (req == NULL)
336 goto drop;
337
338 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
339 goto drop_and_free;
340
341 dreq = dccp_rsk(req);
342 if (dccp_parse_options(sk, dreq, skb))
343 goto drop_and_free;
344
345 if (security_inet_conn_request(sk, skb, req))
346 goto drop_and_free;
347
348 ireq = inet_rsk(req);
349 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
350 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
351 ireq->ireq_family = AF_INET6;
352
353 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
354 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
355 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
356 refcount_inc(&skb->users);
357 ireq->pktopts = skb;
358 }
359 ireq->ir_iif = sk->sk_bound_dev_if;
360
361 /* So that link locals have meaning */
362 if (!sk->sk_bound_dev_if &&
363 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
364 ireq->ir_iif = inet6_iif(skb);
365
366 /*
367 * Step 3: Process LISTEN state
368 *
369 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
370 *
371 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
372 */
373 dreq->dreq_isr = dcb->dccpd_seq;
374 dreq->dreq_gsr = dreq->dreq_isr;
375 dreq->dreq_iss = dccp_v6_init_sequence(skb);
376 dreq->dreq_gss = dreq->dreq_iss;
377 dreq->dreq_service = service;
378
379 if (dccp_v6_send_response(sk, req))
380 goto drop_and_free;
381
382 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
383 reqsk_put(req);
384 return 0;
385
386 drop_and_free:
387 reqsk_free(req);
388 drop:
389 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
390 return -1;
391 }
392
393 static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
394 struct sk_buff *skb,
395 struct request_sock *req,
396 struct dst_entry *dst,
397 struct request_sock *req_unhash,
398 bool *own_req)
399 {
400 struct inet_request_sock *ireq = inet_rsk(req);
401 struct ipv6_pinfo *newnp;
402 const struct ipv6_pinfo *np = inet6_sk(sk);
403 struct ipv6_txoptions *opt;
404 struct inet_sock *newinet;
405 struct dccp6_sock *newdp6;
406 struct sock *newsk;
407
408 if (skb->protocol == htons(ETH_P_IP)) {
409 /*
410 * v6 mapped
411 */
412 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
413 req_unhash, own_req);
414 if (newsk == NULL)
415 return NULL;
416
417 newdp6 = (struct dccp6_sock *)newsk;
418 newinet = inet_sk(newsk);
419 newinet->pinet6 = &newdp6->inet6;
420 newnp = inet6_sk(newsk);
421
422 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
423
424 newnp->saddr = newsk->sk_v6_rcv_saddr;
425
426 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
427 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
428 newnp->pktoptions = NULL;
429 newnp->opt = NULL;
430 newnp->ipv6_mc_list = NULL;
431 newnp->ipv6_ac_list = NULL;
432 newnp->ipv6_fl_list = NULL;
433 newnp->mcast_oif = inet6_iif(skb);
434 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
435
436 /*
437 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
438 * here, dccp_create_openreq_child now does this for us, see the comment in
439 * that function for the gory details. -acme
440 */
441
442 /* It is tricky place. Until this moment IPv4 tcp
443 worked with IPv6 icsk.icsk_af_ops.
444 Sync it now.
445 */
446 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
447
448 return newsk;
449 }
450
451
452 if (sk_acceptq_is_full(sk))
453 goto out_overflow;
454
455 if (!dst) {
456 struct flowi6 fl6;
457
458 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
459 if (!dst)
460 goto out;
461 }
462
463 newsk = dccp_create_openreq_child(sk, req, skb);
464 if (newsk == NULL)
465 goto out_nonewsk;
466
467 /*
468 * No need to charge this sock to the relevant IPv6 refcnt debug socks
469 * count here, dccp_create_openreq_child now does this for us, see the
470 * comment in that function for the gory details. -acme
471 */
472
473 ip6_dst_store(newsk, dst, NULL, NULL);
474 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
475 NETIF_F_TSO);
476 newdp6 = (struct dccp6_sock *)newsk;
477 newinet = inet_sk(newsk);
478 newinet->pinet6 = &newdp6->inet6;
479 newnp = inet6_sk(newsk);
480
481 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
482
483 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
484 newnp->saddr = ireq->ir_v6_loc_addr;
485 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
486 newsk->sk_bound_dev_if = ireq->ir_iif;
487
488 /* Now IPv6 options...
489
490 First: no IPv4 options.
491 */
492 newinet->inet_opt = NULL;
493
494 /* Clone RX bits */
495 newnp->rxopt.all = np->rxopt.all;
496
497 newnp->ipv6_mc_list = NULL;
498 newnp->ipv6_ac_list = NULL;
499 newnp->ipv6_fl_list = NULL;
500 newnp->pktoptions = NULL;
501 newnp->opt = NULL;
502 newnp->mcast_oif = inet6_iif(skb);
503 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
504
505 /*
506 * Clone native IPv6 options from listening socket (if any)
507 *
508 * Yes, keeping reference count would be much more clever, but we make
509 * one more one thing there: reattach optmem to newsk.
510 */
511 opt = ireq->ipv6_opt;
512 if (!opt)
513 opt = rcu_dereference(np->opt);
514 if (opt) {
515 opt = ipv6_dup_options(newsk, opt);
516 RCU_INIT_POINTER(newnp->opt, opt);
517 }
518 inet_csk(newsk)->icsk_ext_hdr_len = 0;
519 if (opt)
520 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
521 opt->opt_flen;
522
523 dccp_sync_mss(newsk, dst_mtu(dst));
524
525 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
526 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
527
528 if (__inet_inherit_port(sk, newsk) < 0) {
529 inet_csk_prepare_forced_close(newsk);
530 dccp_done(newsk);
531 goto out;
532 }
533 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
534 /* Clone pktoptions received with SYN, if we own the req */
535 if (*own_req && ireq->pktopts) {
536 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
537 consume_skb(ireq->pktopts);
538 ireq->pktopts = NULL;
539 if (newnp->pktoptions)
540 skb_set_owner_r(newnp->pktoptions, newsk);
541 }
542
543 return newsk;
544
545 out_overflow:
546 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
547 out_nonewsk:
548 dst_release(dst);
549 out:
550 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
551 return NULL;
552 }
553
554 /* The socket must have it's spinlock held when we get
555 * here.
556 *
557 * We have a potential double-lock case here, so even when
558 * doing backlog processing we use the BH locking scheme.
559 * This is because we cannot sleep with the original spinlock
560 * held.
561 */
562 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
563 {
564 struct ipv6_pinfo *np = inet6_sk(sk);
565 struct sk_buff *opt_skb = NULL;
566
567 /* Imagine: socket is IPv6. IPv4 packet arrives,
568 goes to IPv4 receive handler and backlogged.
569 From backlog it always goes here. Kerboom...
570 Fortunately, dccp_rcv_established and rcv_established
571 handle them correctly, but it is not case with
572 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
573 */
574
575 if (skb->protocol == htons(ETH_P_IP))
576 return dccp_v4_do_rcv(sk, skb);
577
578 if (sk_filter(sk, skb))
579 goto discard;
580
581 /*
582 * socket locking is here for SMP purposes as backlog rcv is currently
583 * called with bh processing disabled.
584 */
585
586 /* Do Stevens' IPV6_PKTOPTIONS.
587
588 Yes, guys, it is the only place in our code, where we
589 may make it not affecting IPv4.
590 The rest of code is protocol independent,
591 and I do not like idea to uglify IPv4.
592
593 Actually, all the idea behind IPV6_PKTOPTIONS
594 looks not very well thought. For now we latch
595 options, received in the last packet, enqueued
596 by tcp. Feel free to propose better solution.
597 --ANK (980728)
598 */
599 if (np->rxopt.all)
600 /*
601 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
602 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
603 */
604 opt_skb = skb_clone(skb, GFP_ATOMIC);
605
606 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
607 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
608 goto reset;
609 if (opt_skb) {
610 /* XXX This is where we would goto ipv6_pktoptions. */
611 __kfree_skb(opt_skb);
612 }
613 return 0;
614 }
615
616 /*
617 * Step 3: Process LISTEN state
618 * If S.state == LISTEN,
619 * If P.type == Request or P contains a valid Init Cookie option,
620 * (* Must scan the packet's options to check for Init
621 * Cookies. Only Init Cookies are processed here,
622 * however; other options are processed in Step 8. This
623 * scan need only be performed if the endpoint uses Init
624 * Cookies *)
625 * (* Generate a new socket and switch to that socket *)
626 * Set S := new socket for this port pair
627 * S.state = RESPOND
628 * Choose S.ISS (initial seqno) or set from Init Cookies
629 * Initialize S.GAR := S.ISS
630 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
631 * Continue with S.state == RESPOND
632 * (* A Response packet will be generated in Step 11 *)
633 * Otherwise,
634 * Generate Reset(No Connection) unless P.type == Reset
635 * Drop packet and return
636 *
637 * NOTE: the check for the packet types is done in
638 * dccp_rcv_state_process
639 */
640
641 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
642 goto reset;
643 if (opt_skb) {
644 /* XXX This is where we would goto ipv6_pktoptions. */
645 __kfree_skb(opt_skb);
646 }
647 return 0;
648
649 reset:
650 dccp_v6_ctl_send_reset(sk, skb);
651 discard:
652 if (opt_skb != NULL)
653 __kfree_skb(opt_skb);
654 kfree_skb(skb);
655 return 0;
656 }
657
658 static int dccp_v6_rcv(struct sk_buff *skb)
659 {
660 const struct dccp_hdr *dh;
661 bool refcounted;
662 struct sock *sk;
663 int min_cov;
664
665 /* Step 1: Check header basics */
666
667 if (dccp_invalid_packet(skb))
668 goto discard_it;
669
670 /* Step 1: If header checksum is incorrect, drop packet and return. */
671 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
672 &ipv6_hdr(skb)->daddr)) {
673 DCCP_WARN("dropped packet with invalid checksum\n");
674 goto discard_it;
675 }
676
677 dh = dccp_hdr(skb);
678
679 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
680 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
681
682 if (dccp_packet_without_ack(skb))
683 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
684 else
685 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
686
687 lookup:
688 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
689 dh->dccph_sport, dh->dccph_dport,
690 inet6_iif(skb), &refcounted);
691 if (!sk) {
692 dccp_pr_debug("failed to look up flow ID in table and "
693 "get corresponding socket\n");
694 goto no_dccp_socket;
695 }
696
697 /*
698 * Step 2:
699 * ... or S.state == TIMEWAIT,
700 * Generate Reset(No Connection) unless P.type == Reset
701 * Drop packet and return
702 */
703 if (sk->sk_state == DCCP_TIME_WAIT) {
704 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
705 inet_twsk_put(inet_twsk(sk));
706 goto no_dccp_socket;
707 }
708
709 if (sk->sk_state == DCCP_NEW_SYN_RECV) {
710 struct request_sock *req = inet_reqsk(sk);
711 struct sock *nsk;
712
713 sk = req->rsk_listener;
714 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
715 inet_csk_reqsk_queue_drop_and_put(sk, req);
716 goto lookup;
717 }
718 sock_hold(sk);
719 refcounted = true;
720 nsk = dccp_check_req(sk, skb, req);
721 if (!nsk) {
722 reqsk_put(req);
723 goto discard_and_relse;
724 }
725 if (nsk == sk) {
726 reqsk_put(req);
727 } else if (dccp_child_process(sk, nsk, skb)) {
728 dccp_v6_ctl_send_reset(sk, skb);
729 goto discard_and_relse;
730 } else {
731 sock_put(sk);
732 return 0;
733 }
734 }
735 /*
736 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
737 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
738 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
739 */
740 min_cov = dccp_sk(sk)->dccps_pcrlen;
741 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
742 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
743 dh->dccph_cscov, min_cov);
744 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
745 goto discard_and_relse;
746 }
747
748 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
749 goto discard_and_relse;
750
751 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
752 refcounted) ? -1 : 0;
753
754 no_dccp_socket:
755 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
756 goto discard_it;
757 /*
758 * Step 2:
759 * If no socket ...
760 * Generate Reset(No Connection) unless P.type == Reset
761 * Drop packet and return
762 */
763 if (dh->dccph_type != DCCP_PKT_RESET) {
764 DCCP_SKB_CB(skb)->dccpd_reset_code =
765 DCCP_RESET_CODE_NO_CONNECTION;
766 dccp_v6_ctl_send_reset(sk, skb);
767 }
768
769 discard_it:
770 kfree_skb(skb);
771 return 0;
772
773 discard_and_relse:
774 if (refcounted)
775 sock_put(sk);
776 goto discard_it;
777 }
778
779 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
780 int addr_len)
781 {
782 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
783 struct inet_connection_sock *icsk = inet_csk(sk);
784 struct inet_sock *inet = inet_sk(sk);
785 struct ipv6_pinfo *np = inet6_sk(sk);
786 struct dccp_sock *dp = dccp_sk(sk);
787 struct in6_addr *saddr = NULL, *final_p, final;
788 struct ipv6_txoptions *opt;
789 struct flowi6 fl6;
790 struct dst_entry *dst;
791 int addr_type;
792 int err;
793
794 dp->dccps_role = DCCP_ROLE_CLIENT;
795
796 if (addr_len < SIN6_LEN_RFC2133)
797 return -EINVAL;
798
799 if (usin->sin6_family != AF_INET6)
800 return -EAFNOSUPPORT;
801
802 memset(&fl6, 0, sizeof(fl6));
803
804 if (np->sndflow) {
805 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
806 IP6_ECN_flow_init(fl6.flowlabel);
807 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
808 struct ip6_flowlabel *flowlabel;
809 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
810 if (flowlabel == NULL)
811 return -EINVAL;
812 fl6_sock_release(flowlabel);
813 }
814 }
815 /*
816 * connect() to INADDR_ANY means loopback (BSD'ism).
817 */
818 if (ipv6_addr_any(&usin->sin6_addr))
819 usin->sin6_addr.s6_addr[15] = 1;
820
821 addr_type = ipv6_addr_type(&usin->sin6_addr);
822
823 if (addr_type & IPV6_ADDR_MULTICAST)
824 return -ENETUNREACH;
825
826 if (addr_type & IPV6_ADDR_LINKLOCAL) {
827 if (addr_len >= sizeof(struct sockaddr_in6) &&
828 usin->sin6_scope_id) {
829 /* If interface is set while binding, indices
830 * must coincide.
831 */
832 if (sk->sk_bound_dev_if &&
833 sk->sk_bound_dev_if != usin->sin6_scope_id)
834 return -EINVAL;
835
836 sk->sk_bound_dev_if = usin->sin6_scope_id;
837 }
838
839 /* Connect to link-local address requires an interface */
840 if (!sk->sk_bound_dev_if)
841 return -EINVAL;
842 }
843
844 sk->sk_v6_daddr = usin->sin6_addr;
845 np->flow_label = fl6.flowlabel;
846
847 /*
848 * DCCP over IPv4
849 */
850 if (addr_type == IPV6_ADDR_MAPPED) {
851 u32 exthdrlen = icsk->icsk_ext_hdr_len;
852 struct sockaddr_in sin;
853
854 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
855
856 if (__ipv6_only_sock(sk))
857 return -ENETUNREACH;
858
859 sin.sin_family = AF_INET;
860 sin.sin_port = usin->sin6_port;
861 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
862
863 icsk->icsk_af_ops = &dccp_ipv6_mapped;
864 sk->sk_backlog_rcv = dccp_v4_do_rcv;
865
866 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
867 if (err) {
868 icsk->icsk_ext_hdr_len = exthdrlen;
869 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
870 sk->sk_backlog_rcv = dccp_v6_do_rcv;
871 goto failure;
872 }
873 np->saddr = sk->sk_v6_rcv_saddr;
874 return err;
875 }
876
877 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
878 saddr = &sk->sk_v6_rcv_saddr;
879
880 fl6.flowi6_proto = IPPROTO_DCCP;
881 fl6.daddr = sk->sk_v6_daddr;
882 fl6.saddr = saddr ? *saddr : np->saddr;
883 fl6.flowi6_oif = sk->sk_bound_dev_if;
884 fl6.fl6_dport = usin->sin6_port;
885 fl6.fl6_sport = inet->inet_sport;
886 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
887
888 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
889 final_p = fl6_update_dst(&fl6, opt, &final);
890
891 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
892 if (IS_ERR(dst)) {
893 err = PTR_ERR(dst);
894 goto failure;
895 }
896
897 if (saddr == NULL) {
898 saddr = &fl6.saddr;
899 sk->sk_v6_rcv_saddr = *saddr;
900 }
901
902 /* set the source address */
903 np->saddr = *saddr;
904 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
905
906 ip6_dst_store(sk, dst, NULL, NULL);
907
908 icsk->icsk_ext_hdr_len = 0;
909 if (opt)
910 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
911
912 inet->inet_dport = usin->sin6_port;
913
914 dccp_set_state(sk, DCCP_REQUESTING);
915 err = inet6_hash_connect(&dccp_death_row, sk);
916 if (err)
917 goto late_failure;
918
919 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
920 sk->sk_v6_daddr.s6_addr32,
921 inet->inet_sport,
922 inet->inet_dport);
923 err = dccp_connect(sk);
924 if (err)
925 goto late_failure;
926
927 return 0;
928
929 late_failure:
930 dccp_set_state(sk, DCCP_CLOSED);
931 __sk_dst_reset(sk);
932 failure:
933 inet->inet_dport = 0;
934 sk->sk_route_caps = 0;
935 return err;
936 }
937
938 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
939 .queue_xmit = inet6_csk_xmit,
940 .send_check = dccp_v6_send_check,
941 .rebuild_header = inet6_sk_rebuild_header,
942 .conn_request = dccp_v6_conn_request,
943 .syn_recv_sock = dccp_v6_request_recv_sock,
944 .net_header_len = sizeof(struct ipv6hdr),
945 .setsockopt = ipv6_setsockopt,
946 .getsockopt = ipv6_getsockopt,
947 .addr2sockaddr = inet6_csk_addr2sockaddr,
948 .sockaddr_len = sizeof(struct sockaddr_in6),
949 #ifdef CONFIG_COMPAT
950 .compat_setsockopt = compat_ipv6_setsockopt,
951 .compat_getsockopt = compat_ipv6_getsockopt,
952 #endif
953 };
954
955 /*
956 * DCCP over IPv4 via INET6 API
957 */
958 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
959 .queue_xmit = ip_queue_xmit,
960 .send_check = dccp_v4_send_check,
961 .rebuild_header = inet_sk_rebuild_header,
962 .conn_request = dccp_v6_conn_request,
963 .syn_recv_sock = dccp_v6_request_recv_sock,
964 .net_header_len = sizeof(struct iphdr),
965 .setsockopt = ipv6_setsockopt,
966 .getsockopt = ipv6_getsockopt,
967 .addr2sockaddr = inet6_csk_addr2sockaddr,
968 .sockaddr_len = sizeof(struct sockaddr_in6),
969 #ifdef CONFIG_COMPAT
970 .compat_setsockopt = compat_ipv6_setsockopt,
971 .compat_getsockopt = compat_ipv6_getsockopt,
972 #endif
973 };
974
975 /* NOTE: A lot of things set to zero explicitly by call to
976 * sk_alloc() so need not be done here.
977 */
978 static int dccp_v6_init_sock(struct sock *sk)
979 {
980 static __u8 dccp_v6_ctl_sock_initialized;
981 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
982
983 if (err == 0) {
984 if (unlikely(!dccp_v6_ctl_sock_initialized))
985 dccp_v6_ctl_sock_initialized = 1;
986 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
987 }
988
989 return err;
990 }
991
992 static void dccp_v6_destroy_sock(struct sock *sk)
993 {
994 dccp_destroy_sock(sk);
995 inet6_destroy_sock(sk);
996 }
997
998 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
999 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1000 };
1001
1002 static struct proto dccp_v6_prot = {
1003 .name = "DCCPv6",
1004 .owner = THIS_MODULE,
1005 .close = dccp_close,
1006 .connect = dccp_v6_connect,
1007 .disconnect = dccp_disconnect,
1008 .ioctl = dccp_ioctl,
1009 .init = dccp_v6_init_sock,
1010 .setsockopt = dccp_setsockopt,
1011 .getsockopt = dccp_getsockopt,
1012 .sendmsg = dccp_sendmsg,
1013 .recvmsg = dccp_recvmsg,
1014 .backlog_rcv = dccp_v6_do_rcv,
1015 .hash = inet6_hash,
1016 .unhash = inet_unhash,
1017 .accept = inet_csk_accept,
1018 .get_port = inet_csk_get_port,
1019 .shutdown = dccp_shutdown,
1020 .destroy = dccp_v6_destroy_sock,
1021 .orphan_count = &dccp_orphan_count,
1022 .max_header = MAX_DCCP_HEADER,
1023 .obj_size = sizeof(struct dccp6_sock),
1024 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1025 .rsk_prot = &dccp6_request_sock_ops,
1026 .twsk_prot = &dccp6_timewait_sock_ops,
1027 .h.hashinfo = &dccp_hashinfo,
1028 #ifdef CONFIG_COMPAT
1029 .compat_setsockopt = compat_dccp_setsockopt,
1030 .compat_getsockopt = compat_dccp_getsockopt,
1031 #endif
1032 };
1033
1034 static const struct inet6_protocol dccp_v6_protocol = {
1035 .handler = dccp_v6_rcv,
1036 .err_handler = dccp_v6_err,
1037 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1038 };
1039
1040 static const struct proto_ops inet6_dccp_ops = {
1041 .family = PF_INET6,
1042 .owner = THIS_MODULE,
1043 .release = inet6_release,
1044 .bind = inet6_bind,
1045 .connect = inet_stream_connect,
1046 .socketpair = sock_no_socketpair,
1047 .accept = inet_accept,
1048 .getname = inet6_getname,
1049 .poll = dccp_poll,
1050 .ioctl = inet6_ioctl,
1051 .listen = inet_dccp_listen,
1052 .shutdown = inet_shutdown,
1053 .setsockopt = sock_common_setsockopt,
1054 .getsockopt = sock_common_getsockopt,
1055 .sendmsg = inet_sendmsg,
1056 .recvmsg = sock_common_recvmsg,
1057 .mmap = sock_no_mmap,
1058 .sendpage = sock_no_sendpage,
1059 #ifdef CONFIG_COMPAT
1060 .compat_setsockopt = compat_sock_common_setsockopt,
1061 .compat_getsockopt = compat_sock_common_getsockopt,
1062 #endif
1063 };
1064
1065 static struct inet_protosw dccp_v6_protosw = {
1066 .type = SOCK_DCCP,
1067 .protocol = IPPROTO_DCCP,
1068 .prot = &dccp_v6_prot,
1069 .ops = &inet6_dccp_ops,
1070 .flags = INET_PROTOSW_ICSK,
1071 };
1072
1073 static int __net_init dccp_v6_init_net(struct net *net)
1074 {
1075 if (dccp_hashinfo.bhash == NULL)
1076 return -ESOCKTNOSUPPORT;
1077
1078 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1079 SOCK_DCCP, IPPROTO_DCCP, net);
1080 }
1081
1082 static void __net_exit dccp_v6_exit_net(struct net *net)
1083 {
1084 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1085 }
1086
1087 static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1088 {
1089 inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1090 }
1091
1092 static struct pernet_operations dccp_v6_ops = {
1093 .init = dccp_v6_init_net,
1094 .exit = dccp_v6_exit_net,
1095 .exit_batch = dccp_v6_exit_batch,
1096 };
1097
1098 static int __init dccp_v6_init(void)
1099 {
1100 int err = proto_register(&dccp_v6_prot, 1);
1101
1102 if (err)
1103 goto out;
1104
1105 inet6_register_protosw(&dccp_v6_protosw);
1106
1107 err = register_pernet_subsys(&dccp_v6_ops);
1108 if (err)
1109 goto out_destroy_ctl_sock;
1110
1111 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1112 if (err)
1113 goto out_unregister_proto;
1114
1115 out:
1116 return err;
1117 out_unregister_proto:
1118 unregister_pernet_subsys(&dccp_v6_ops);
1119 out_destroy_ctl_sock:
1120 inet6_unregister_protosw(&dccp_v6_protosw);
1121 proto_unregister(&dccp_v6_prot);
1122 goto out;
1123 }
1124
1125 static void __exit dccp_v6_exit(void)
1126 {
1127 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1128 unregister_pernet_subsys(&dccp_v6_ops);
1129 inet6_unregister_protosw(&dccp_v6_protosw);
1130 proto_unregister(&dccp_v6_prot);
1131 }
1132
1133 module_init(dccp_v6_init);
1134 module_exit(dccp_v6_exit);
1135
1136 /*
1137 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1138 * values directly, Also cover the case where the protocol is not specified,
1139 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1140 */
1141 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1142 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1143 MODULE_LICENSE("GPL");
1144 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1145 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
Linux with added FPC-III support