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1/*
2 * TCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on:
9 * linux/net/ipv4/tcp.c
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
12 *
13 * Fixes:
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26#include <linux/bottom_half.h>
27#include <linux/module.h>
28#include <linux/errno.h>
29#include <linux/types.h>
30#include <linux/socket.h>
31#include <linux/sockios.h>
32#include <linux/net.h>
33#include <linux/jiffies.h>
34#include <linux/in.h>
35#include <linux/in6.h>
36#include <linux/netdevice.h>
37#include <linux/init.h>
38#include <linux/jhash.h>
39#include <linux/ipsec.h>
40#include <linux/times.h>
41#include <linux/slab.h>
42#include <linux/uaccess.h>
43#include <linux/ipv6.h>
44#include <linux/icmpv6.h>
45#include <linux/random.h>
46
47#include <net/tcp.h>
48#include <net/ndisc.h>
49#include <net/inet6_hashtables.h>
50#include <net/inet6_connection_sock.h>
51#include <net/ipv6.h>
52#include <net/transp_v6.h>
53#include <net/addrconf.h>
54#include <net/ip6_route.h>
55#include <net/ip6_checksum.h>
56#include <net/inet_ecn.h>
57#include <net/protocol.h>
58#include <net/xfrm.h>
59#include <net/snmp.h>
60#include <net/dsfield.h>
61#include <net/timewait_sock.h>
62#include <net/inet_common.h>
63#include <net/secure_seq.h>
64#include <net/busy_poll.h>
65
66#include <linux/proc_fs.h>
67#include <linux/seq_file.h>
68
69#include <crypto/hash.h>
70#include <linux/scatterlist.h>
71
72static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
73static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
74 struct request_sock *req);
75
76static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
77
78static const struct inet_connection_sock_af_ops ipv6_mapped;
79static const struct inet_connection_sock_af_ops ipv6_specific;
80#ifdef CONFIG_TCP_MD5SIG
81static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
82static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
83#else
84static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
85 const struct in6_addr *addr)
86{
87 return NULL;
88}
89#endif
90
91static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
92{
93 struct dst_entry *dst = skb_dst(skb);
94
95 if (dst && dst_hold_safe(dst)) {
96 const struct rt6_info *rt = (const struct rt6_info *)dst;
97
98 sk->sk_rx_dst = dst;
99 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
100 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
101 }
102}
103
104static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
105{
106 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
107 ipv6_hdr(skb)->saddr.s6_addr32,
108 tcp_hdr(skb)->dest,
109 tcp_hdr(skb)->source);
110}
111
112static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
113 int addr_len)
114{
115 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
116 struct inet_sock *inet = inet_sk(sk);
117 struct inet_connection_sock *icsk = inet_csk(sk);
118 struct ipv6_pinfo *np = inet6_sk(sk);
119 struct tcp_sock *tp = tcp_sk(sk);
120 struct in6_addr *saddr = NULL, *final_p, final;
121 struct ipv6_txoptions *opt;
122 struct flowi6 fl6;
123 struct dst_entry *dst;
124 int addr_type;
125 int err;
126
127 if (addr_len < SIN6_LEN_RFC2133)
128 return -EINVAL;
129
130 if (usin->sin6_family != AF_INET6)
131 return -EAFNOSUPPORT;
132
133 memset(&fl6, 0, sizeof(fl6));
134
135 if (np->sndflow) {
136 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
137 IP6_ECN_flow_init(fl6.flowlabel);
138 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
139 struct ip6_flowlabel *flowlabel;
140 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
141 if (!flowlabel)
142 return -EINVAL;
143 fl6_sock_release(flowlabel);
144 }
145 }
146
147 /*
148 * connect() to INADDR_ANY means loopback (BSD'ism).
149 */
150
151 if (ipv6_addr_any(&usin->sin6_addr))
152 usin->sin6_addr.s6_addr[15] = 0x1;
153
154 addr_type = ipv6_addr_type(&usin->sin6_addr);
155
156 if (addr_type & IPV6_ADDR_MULTICAST)
157 return -ENETUNREACH;
158
159 if (addr_type&IPV6_ADDR_LINKLOCAL) {
160 if (addr_len >= sizeof(struct sockaddr_in6) &&
161 usin->sin6_scope_id) {
162 /* If interface is set while binding, indices
163 * must coincide.
164 */
165 if (sk->sk_bound_dev_if &&
166 sk->sk_bound_dev_if != usin->sin6_scope_id)
167 return -EINVAL;
168
169 sk->sk_bound_dev_if = usin->sin6_scope_id;
170 }
171
172 /* Connect to link-local address requires an interface */
173 if (!sk->sk_bound_dev_if)
174 return -EINVAL;
175 }
176
177 if (tp->rx_opt.ts_recent_stamp &&
178 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
179 tp->rx_opt.ts_recent = 0;
180 tp->rx_opt.ts_recent_stamp = 0;
181 tp->write_seq = 0;
182 }
183
184 sk->sk_v6_daddr = usin->sin6_addr;
185 np->flow_label = fl6.flowlabel;
186
187 /*
188 * TCP over IPv4
189 */
190
191 if (addr_type == IPV6_ADDR_MAPPED) {
192 u32 exthdrlen = icsk->icsk_ext_hdr_len;
193 struct sockaddr_in sin;
194
195 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
196
197 if (__ipv6_only_sock(sk))
198 return -ENETUNREACH;
199
200 sin.sin_family = AF_INET;
201 sin.sin_port = usin->sin6_port;
202 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
203
204 icsk->icsk_af_ops = &ipv6_mapped;
205 sk->sk_backlog_rcv = tcp_v4_do_rcv;
206#ifdef CONFIG_TCP_MD5SIG
207 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
208#endif
209
210 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
211
212 if (err) {
213 icsk->icsk_ext_hdr_len = exthdrlen;
214 icsk->icsk_af_ops = &ipv6_specific;
215 sk->sk_backlog_rcv = tcp_v6_do_rcv;
216#ifdef CONFIG_TCP_MD5SIG
217 tp->af_specific = &tcp_sock_ipv6_specific;
218#endif
219 goto failure;
220 }
221 np->saddr = sk->sk_v6_rcv_saddr;
222
223 return err;
224 }
225
226 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
227 saddr = &sk->sk_v6_rcv_saddr;
228
229 fl6.flowi6_proto = IPPROTO_TCP;
230 fl6.daddr = sk->sk_v6_daddr;
231 fl6.saddr = saddr ? *saddr : np->saddr;
232 fl6.flowi6_oif = sk->sk_bound_dev_if;
233 fl6.flowi6_mark = sk->sk_mark;
234 fl6.fl6_dport = usin->sin6_port;
235 fl6.fl6_sport = inet->inet_sport;
236
237 opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
238 final_p = fl6_update_dst(&fl6, opt, &final);
239
240 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
241
242 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
243 if (IS_ERR(dst)) {
244 err = PTR_ERR(dst);
245 goto failure;
246 }
247
248 if (!saddr) {
249 saddr = &fl6.saddr;
250 sk->sk_v6_rcv_saddr = *saddr;
251 }
252
253 /* set the source address */
254 np->saddr = *saddr;
255 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
256
257 sk->sk_gso_type = SKB_GSO_TCPV6;
258 ip6_dst_store(sk, dst, NULL, NULL);
259
260 if (tcp_death_row.sysctl_tw_recycle &&
261 !tp->rx_opt.ts_recent_stamp &&
262 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr))
263 tcp_fetch_timewait_stamp(sk, dst);
264
265 icsk->icsk_ext_hdr_len = 0;
266 if (opt)
267 icsk->icsk_ext_hdr_len = opt->opt_flen +
268 opt->opt_nflen;
269
270 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
271
272 inet->inet_dport = usin->sin6_port;
273
274 tcp_set_state(sk, TCP_SYN_SENT);
275 err = inet6_hash_connect(&tcp_death_row, sk);
276 if (err)
277 goto late_failure;
278
279 sk_set_txhash(sk);
280
281 if (!tp->write_seq && likely(!tp->repair))
282 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
283 sk->sk_v6_daddr.s6_addr32,
284 inet->inet_sport,
285 inet->inet_dport);
286
287 err = tcp_connect(sk);
288 if (err)
289 goto late_failure;
290
291 return 0;
292
293late_failure:
294 tcp_set_state(sk, TCP_CLOSE);
295 __sk_dst_reset(sk);
296failure:
297 inet->inet_dport = 0;
298 sk->sk_route_caps = 0;
299 return err;
300}
301
302static void tcp_v6_mtu_reduced(struct sock *sk)
303{
304 struct dst_entry *dst;
305
306 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
307 return;
308
309 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
310 if (!dst)
311 return;
312
313 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
314 tcp_sync_mss(sk, dst_mtu(dst));
315 tcp_simple_retransmit(sk);
316 }
317}
318
319static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
320 u8 type, u8 code, int offset, __be32 info)
321{
322 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
323 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
324 struct net *net = dev_net(skb->dev);
325 struct request_sock *fastopen;
326 struct ipv6_pinfo *np;
327 struct tcp_sock *tp;
328 __u32 seq, snd_una;
329 struct sock *sk;
330 bool fatal;
331 int err;
332
333 sk = __inet6_lookup_established(net, &tcp_hashinfo,
334 &hdr->daddr, th->dest,
335 &hdr->saddr, ntohs(th->source),
336 skb->dev->ifindex);
337
338 if (!sk) {
339 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
340 ICMP6_MIB_INERRORS);
341 return;
342 }
343
344 if (sk->sk_state == TCP_TIME_WAIT) {
345 inet_twsk_put(inet_twsk(sk));
346 return;
347 }
348 seq = ntohl(th->seq);
349 fatal = icmpv6_err_convert(type, code, &err);
350 if (sk->sk_state == TCP_NEW_SYN_RECV)
351 return tcp_req_err(sk, seq, fatal);
352
353 bh_lock_sock(sk);
354 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
355 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
356
357 if (sk->sk_state == TCP_CLOSE)
358 goto out;
359
360 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
361 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
362 goto out;
363 }
364
365 tp = tcp_sk(sk);
366 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
367 fastopen = tp->fastopen_rsk;
368 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
369 if (sk->sk_state != TCP_LISTEN &&
370 !between(seq, snd_una, tp->snd_nxt)) {
371 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
372 goto out;
373 }
374
375 np = inet6_sk(sk);
376
377 if (type == NDISC_REDIRECT) {
378 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
379
380 if (dst)
381 dst->ops->redirect(dst, sk, skb);
382 goto out;
383 }
384
385 if (type == ICMPV6_PKT_TOOBIG) {
386 /* We are not interested in TCP_LISTEN and open_requests
387 * (SYN-ACKs send out by Linux are always <576bytes so
388 * they should go through unfragmented).
389 */
390 if (sk->sk_state == TCP_LISTEN)
391 goto out;
392
393 if (!ip6_sk_accept_pmtu(sk))
394 goto out;
395
396 tp->mtu_info = ntohl(info);
397 if (!sock_owned_by_user(sk))
398 tcp_v6_mtu_reduced(sk);
399 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
400 &tp->tsq_flags))
401 sock_hold(sk);
402 goto out;
403 }
404
405
406 /* Might be for an request_sock */
407 switch (sk->sk_state) {
408 case TCP_SYN_SENT:
409 case TCP_SYN_RECV:
410 /* Only in fast or simultaneous open. If a fast open socket is
411 * is already accepted it is treated as a connected one below.
412 */
413 if (fastopen && !fastopen->sk)
414 break;
415
416 if (!sock_owned_by_user(sk)) {
417 sk->sk_err = err;
418 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
419
420 tcp_done(sk);
421 } else
422 sk->sk_err_soft = err;
423 goto out;
424 }
425
426 if (!sock_owned_by_user(sk) && np->recverr) {
427 sk->sk_err = err;
428 sk->sk_error_report(sk);
429 } else
430 sk->sk_err_soft = err;
431
432out:
433 bh_unlock_sock(sk);
434 sock_put(sk);
435}
436
437
438static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
439 struct flowi *fl,
440 struct request_sock *req,
441 struct tcp_fastopen_cookie *foc,
442 bool attach_req)
443{
444 struct inet_request_sock *ireq = inet_rsk(req);
445 struct ipv6_pinfo *np = inet6_sk(sk);
446 struct flowi6 *fl6 = &fl->u.ip6;
447 struct sk_buff *skb;
448 int err = -ENOMEM;
449
450 /* First, grab a route. */
451 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
452 IPPROTO_TCP)) == NULL)
453 goto done;
454
455 skb = tcp_make_synack(sk, dst, req, foc, attach_req);
456
457 if (skb) {
458 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
459 &ireq->ir_v6_rmt_addr);
460
461 fl6->daddr = ireq->ir_v6_rmt_addr;
462 if (np->repflow && ireq->pktopts)
463 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
464
465 rcu_read_lock();
466 err = ip6_xmit(sk, skb, fl6, rcu_dereference(np->opt),
467 np->tclass);
468 rcu_read_unlock();
469 err = net_xmit_eval(err);
470 }
471
472done:
473 return err;
474}
475
476
477static void tcp_v6_reqsk_destructor(struct request_sock *req)
478{
479 kfree_skb(inet_rsk(req)->pktopts);
480}
481
482#ifdef CONFIG_TCP_MD5SIG
483static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
484 const struct in6_addr *addr)
485{
486 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
487}
488
489static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
490 const struct sock *addr_sk)
491{
492 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
493}
494
495static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
496 int optlen)
497{
498 struct tcp_md5sig cmd;
499 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
500
501 if (optlen < sizeof(cmd))
502 return -EINVAL;
503
504 if (copy_from_user(&cmd, optval, sizeof(cmd)))
505 return -EFAULT;
506
507 if (sin6->sin6_family != AF_INET6)
508 return -EINVAL;
509
510 if (!cmd.tcpm_keylen) {
511 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
512 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
513 AF_INET);
514 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
515 AF_INET6);
516 }
517
518 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
519 return -EINVAL;
520
521 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
522 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
523 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
524
525 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
526 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
527}
528
529static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
530 const struct in6_addr *daddr,
531 const struct in6_addr *saddr, int nbytes)
532{
533 struct tcp6_pseudohdr *bp;
534 struct scatterlist sg;
535
536 bp = &hp->md5_blk.ip6;
537 /* 1. TCP pseudo-header (RFC2460) */
538 bp->saddr = *saddr;
539 bp->daddr = *daddr;
540 bp->protocol = cpu_to_be32(IPPROTO_TCP);
541 bp->len = cpu_to_be32(nbytes);
542
543 sg_init_one(&sg, bp, sizeof(*bp));
544 ahash_request_set_crypt(hp->md5_req, &sg, NULL, sizeof(*bp));
545 return crypto_ahash_update(hp->md5_req);
546}
547
548static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
549 const struct in6_addr *daddr, struct in6_addr *saddr,
550 const struct tcphdr *th)
551{
552 struct tcp_md5sig_pool *hp;
553 struct ahash_request *req;
554
555 hp = tcp_get_md5sig_pool();
556 if (!hp)
557 goto clear_hash_noput;
558 req = hp->md5_req;
559
560 if (crypto_ahash_init(req))
561 goto clear_hash;
562 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
563 goto clear_hash;
564 if (tcp_md5_hash_header(hp, th))
565 goto clear_hash;
566 if (tcp_md5_hash_key(hp, key))
567 goto clear_hash;
568 ahash_request_set_crypt(req, NULL, md5_hash, 0);
569 if (crypto_ahash_final(req))
570 goto clear_hash;
571
572 tcp_put_md5sig_pool();
573 return 0;
574
575clear_hash:
576 tcp_put_md5sig_pool();
577clear_hash_noput:
578 memset(md5_hash, 0, 16);
579 return 1;
580}
581
582static int tcp_v6_md5_hash_skb(char *md5_hash,
583 const struct tcp_md5sig_key *key,
584 const struct sock *sk,
585 const struct sk_buff *skb)
586{
587 const struct in6_addr *saddr, *daddr;
588 struct tcp_md5sig_pool *hp;
589 struct ahash_request *req;
590 const struct tcphdr *th = tcp_hdr(skb);
591
592 if (sk) { /* valid for establish/request sockets */
593 saddr = &sk->sk_v6_rcv_saddr;
594 daddr = &sk->sk_v6_daddr;
595 } else {
596 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
597 saddr = &ip6h->saddr;
598 daddr = &ip6h->daddr;
599 }
600
601 hp = tcp_get_md5sig_pool();
602 if (!hp)
603 goto clear_hash_noput;
604 req = hp->md5_req;
605
606 if (crypto_ahash_init(req))
607 goto clear_hash;
608
609 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
610 goto clear_hash;
611 if (tcp_md5_hash_header(hp, th))
612 goto clear_hash;
613 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
614 goto clear_hash;
615 if (tcp_md5_hash_key(hp, key))
616 goto clear_hash;
617 ahash_request_set_crypt(req, NULL, md5_hash, 0);
618 if (crypto_ahash_final(req))
619 goto clear_hash;
620
621 tcp_put_md5sig_pool();
622 return 0;
623
624clear_hash:
625 tcp_put_md5sig_pool();
626clear_hash_noput:
627 memset(md5_hash, 0, 16);
628 return 1;
629}
630
631#endif
632
633static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
634 const struct sk_buff *skb)
635{
636#ifdef CONFIG_TCP_MD5SIG
637 const __u8 *hash_location = NULL;
638 struct tcp_md5sig_key *hash_expected;
639 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
640 const struct tcphdr *th = tcp_hdr(skb);
641 int genhash;
642 u8 newhash[16];
643
644 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
645 hash_location = tcp_parse_md5sig_option(th);
646
647 /* We've parsed the options - do we have a hash? */
648 if (!hash_expected && !hash_location)
649 return false;
650
651 if (hash_expected && !hash_location) {
652 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
653 return true;
654 }
655
656 if (!hash_expected && hash_location) {
657 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
658 return true;
659 }
660
661 /* check the signature */
662 genhash = tcp_v6_md5_hash_skb(newhash,
663 hash_expected,
664 NULL, skb);
665
666 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
667 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
668 genhash ? "failed" : "mismatch",
669 &ip6h->saddr, ntohs(th->source),
670 &ip6h->daddr, ntohs(th->dest));
671 return true;
672 }
673#endif
674 return false;
675}
676
677static void tcp_v6_init_req(struct request_sock *req,
678 const struct sock *sk_listener,
679 struct sk_buff *skb)
680{
681 struct inet_request_sock *ireq = inet_rsk(req);
682 const struct ipv6_pinfo *np = inet6_sk(sk_listener);
683
684 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
685 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
686
687 /* So that link locals have meaning */
688 if (!sk_listener->sk_bound_dev_if &&
689 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
690 ireq->ir_iif = tcp_v6_iif(skb);
691
692 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
693 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
694 np->rxopt.bits.rxinfo ||
695 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
696 np->rxopt.bits.rxohlim || np->repflow)) {
697 atomic_inc(&skb->users);
698 ireq->pktopts = skb;
699 }
700}
701
702static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
703 struct flowi *fl,
704 const struct request_sock *req,
705 bool *strict)
706{
707 if (strict)
708 *strict = true;
709 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
710}
711
712struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
713 .family = AF_INET6,
714 .obj_size = sizeof(struct tcp6_request_sock),
715 .rtx_syn_ack = tcp_rtx_synack,
716 .send_ack = tcp_v6_reqsk_send_ack,
717 .destructor = tcp_v6_reqsk_destructor,
718 .send_reset = tcp_v6_send_reset,
719 .syn_ack_timeout = tcp_syn_ack_timeout,
720};
721
722static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
723 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
724 sizeof(struct ipv6hdr),
725#ifdef CONFIG_TCP_MD5SIG
726 .req_md5_lookup = tcp_v6_md5_lookup,
727 .calc_md5_hash = tcp_v6_md5_hash_skb,
728#endif
729 .init_req = tcp_v6_init_req,
730#ifdef CONFIG_SYN_COOKIES
731 .cookie_init_seq = cookie_v6_init_sequence,
732#endif
733 .route_req = tcp_v6_route_req,
734 .init_seq = tcp_v6_init_sequence,
735 .send_synack = tcp_v6_send_synack,
736};
737
738static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
739 u32 ack, u32 win, u32 tsval, u32 tsecr,
740 int oif, struct tcp_md5sig_key *key, int rst,
741 u8 tclass, u32 label)
742{
743 const struct tcphdr *th = tcp_hdr(skb);
744 struct tcphdr *t1;
745 struct sk_buff *buff;
746 struct flowi6 fl6;
747 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
748 struct sock *ctl_sk = net->ipv6.tcp_sk;
749 unsigned int tot_len = sizeof(struct tcphdr);
750 struct dst_entry *dst;
751 __be32 *topt;
752
753 if (tsecr)
754 tot_len += TCPOLEN_TSTAMP_ALIGNED;
755#ifdef CONFIG_TCP_MD5SIG
756 if (key)
757 tot_len += TCPOLEN_MD5SIG_ALIGNED;
758#endif
759
760 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
761 GFP_ATOMIC);
762 if (!buff)
763 return;
764
765 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
766
767 t1 = (struct tcphdr *) skb_push(buff, tot_len);
768 skb_reset_transport_header(buff);
769
770 /* Swap the send and the receive. */
771 memset(t1, 0, sizeof(*t1));
772 t1->dest = th->source;
773 t1->source = th->dest;
774 t1->doff = tot_len / 4;
775 t1->seq = htonl(seq);
776 t1->ack_seq = htonl(ack);
777 t1->ack = !rst || !th->ack;
778 t1->rst = rst;
779 t1->window = htons(win);
780
781 topt = (__be32 *)(t1 + 1);
782
783 if (tsecr) {
784 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
785 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
786 *topt++ = htonl(tsval);
787 *topt++ = htonl(tsecr);
788 }
789
790#ifdef CONFIG_TCP_MD5SIG
791 if (key) {
792 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
793 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
794 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
795 &ipv6_hdr(skb)->saddr,
796 &ipv6_hdr(skb)->daddr, t1);
797 }
798#endif
799
800 memset(&fl6, 0, sizeof(fl6));
801 fl6.daddr = ipv6_hdr(skb)->saddr;
802 fl6.saddr = ipv6_hdr(skb)->daddr;
803 fl6.flowlabel = label;
804
805 buff->ip_summed = CHECKSUM_PARTIAL;
806 buff->csum = 0;
807
808 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
809
810 fl6.flowi6_proto = IPPROTO_TCP;
811 if (rt6_need_strict(&fl6.daddr) && !oif)
812 fl6.flowi6_oif = tcp_v6_iif(skb);
813 else {
814 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
815 oif = skb->skb_iif;
816
817 fl6.flowi6_oif = oif;
818 }
819
820 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
821 fl6.fl6_dport = t1->dest;
822 fl6.fl6_sport = t1->source;
823 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
824
825 /* Pass a socket to ip6_dst_lookup either it is for RST
826 * Underlying function will use this to retrieve the network
827 * namespace
828 */
829 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
830 if (!IS_ERR(dst)) {
831 skb_dst_set(buff, dst);
832 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
833 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
834 if (rst)
835 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
836 return;
837 }
838
839 kfree_skb(buff);
840}
841
842static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
843{
844 const struct tcphdr *th = tcp_hdr(skb);
845 u32 seq = 0, ack_seq = 0;
846 struct tcp_md5sig_key *key = NULL;
847#ifdef CONFIG_TCP_MD5SIG
848 const __u8 *hash_location = NULL;
849 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
850 unsigned char newhash[16];
851 int genhash;
852 struct sock *sk1 = NULL;
853#endif
854 int oif;
855
856 if (th->rst)
857 return;
858
859 /* If sk not NULL, it means we did a successful lookup and incoming
860 * route had to be correct. prequeue might have dropped our dst.
861 */
862 if (!sk && !ipv6_unicast_destination(skb))
863 return;
864
865#ifdef CONFIG_TCP_MD5SIG
866 hash_location = tcp_parse_md5sig_option(th);
867 if (sk && sk_fullsock(sk)) {
868 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
869 } else if (hash_location) {
870 /*
871 * active side is lost. Try to find listening socket through
872 * source port, and then find md5 key through listening socket.
873 * we are not loose security here:
874 * Incoming packet is checked with md5 hash with finding key,
875 * no RST generated if md5 hash doesn't match.
876 */
877 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
878 &tcp_hashinfo, NULL, 0,
879 &ipv6h->saddr,
880 th->source, &ipv6h->daddr,
881 ntohs(th->source), tcp_v6_iif(skb));
882 if (!sk1)
883 return;
884
885 rcu_read_lock();
886 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
887 if (!key)
888 goto release_sk1;
889
890 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
891 if (genhash || memcmp(hash_location, newhash, 16) != 0)
892 goto release_sk1;
893 }
894#endif
895
896 if (th->ack)
897 seq = ntohl(th->ack_seq);
898 else
899 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
900 (th->doff << 2);
901
902 oif = sk ? sk->sk_bound_dev_if : 0;
903 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
904
905#ifdef CONFIG_TCP_MD5SIG
906release_sk1:
907 if (sk1) {
908 rcu_read_unlock();
909 sock_put(sk1);
910 }
911#endif
912}
913
914static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
915 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
916 struct tcp_md5sig_key *key, u8 tclass,
917 u32 label)
918{
919 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
920 tclass, label);
921}
922
923static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
924{
925 struct inet_timewait_sock *tw = inet_twsk(sk);
926 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
927
928 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
929 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
930 tcp_time_stamp + tcptw->tw_ts_offset,
931 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
932 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
933
934 inet_twsk_put(tw);
935}
936
937static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
938 struct request_sock *req)
939{
940 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
941 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
942 */
943 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
944 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
945 tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd,
946 tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
947 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
948 0, 0);
949}
950
951
952static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
953{
954#ifdef CONFIG_SYN_COOKIES
955 const struct tcphdr *th = tcp_hdr(skb);
956
957 if (!th->syn)
958 sk = cookie_v6_check(sk, skb);
959#endif
960 return sk;
961}
962
963static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
964{
965 if (skb->protocol == htons(ETH_P_IP))
966 return tcp_v4_conn_request(sk, skb);
967
968 if (!ipv6_unicast_destination(skb))
969 goto drop;
970
971 return tcp_conn_request(&tcp6_request_sock_ops,
972 &tcp_request_sock_ipv6_ops, sk, skb);
973
974drop:
975 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
976 return 0; /* don't send reset */
977}
978
979static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
980 struct request_sock *req,
981 struct dst_entry *dst,
982 struct request_sock *req_unhash,
983 bool *own_req)
984{
985 struct inet_request_sock *ireq;
986 struct ipv6_pinfo *newnp;
987 const struct ipv6_pinfo *np = inet6_sk(sk);
988 struct ipv6_txoptions *opt;
989 struct tcp6_sock *newtcp6sk;
990 struct inet_sock *newinet;
991 struct tcp_sock *newtp;
992 struct sock *newsk;
993#ifdef CONFIG_TCP_MD5SIG
994 struct tcp_md5sig_key *key;
995#endif
996 struct flowi6 fl6;
997
998 if (skb->protocol == htons(ETH_P_IP)) {
999 /*
1000 * v6 mapped
1001 */
1002
1003 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1004 req_unhash, own_req);
1005
1006 if (!newsk)
1007 return NULL;
1008
1009 newtcp6sk = (struct tcp6_sock *)newsk;
1010 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1011
1012 newinet = inet_sk(newsk);
1013 newnp = inet6_sk(newsk);
1014 newtp = tcp_sk(newsk);
1015
1016 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1017
1018 newnp->saddr = newsk->sk_v6_rcv_saddr;
1019
1020 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1021 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1022#ifdef CONFIG_TCP_MD5SIG
1023 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1024#endif
1025
1026 newnp->ipv6_ac_list = NULL;
1027 newnp->ipv6_fl_list = NULL;
1028 newnp->pktoptions = NULL;
1029 newnp->opt = NULL;
1030 newnp->mcast_oif = tcp_v6_iif(skb);
1031 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1032 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1033 if (np->repflow)
1034 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1035
1036 /*
1037 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1038 * here, tcp_create_openreq_child now does this for us, see the comment in
1039 * that function for the gory details. -acme
1040 */
1041
1042 /* It is tricky place. Until this moment IPv4 tcp
1043 worked with IPv6 icsk.icsk_af_ops.
1044 Sync it now.
1045 */
1046 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1047
1048 return newsk;
1049 }
1050
1051 ireq = inet_rsk(req);
1052
1053 if (sk_acceptq_is_full(sk))
1054 goto out_overflow;
1055
1056 if (!dst) {
1057 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1058 if (!dst)
1059 goto out;
1060 }
1061
1062 newsk = tcp_create_openreq_child(sk, req, skb);
1063 if (!newsk)
1064 goto out_nonewsk;
1065
1066 /*
1067 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1068 * count here, tcp_create_openreq_child now does this for us, see the
1069 * comment in that function for the gory details. -acme
1070 */
1071
1072 newsk->sk_gso_type = SKB_GSO_TCPV6;
1073 ip6_dst_store(newsk, dst, NULL, NULL);
1074 inet6_sk_rx_dst_set(newsk, skb);
1075
1076 newtcp6sk = (struct tcp6_sock *)newsk;
1077 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1078
1079 newtp = tcp_sk(newsk);
1080 newinet = inet_sk(newsk);
1081 newnp = inet6_sk(newsk);
1082
1083 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1084
1085 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1086 newnp->saddr = ireq->ir_v6_loc_addr;
1087 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1088 newsk->sk_bound_dev_if = ireq->ir_iif;
1089
1090 /* Now IPv6 options...
1091
1092 First: no IPv4 options.
1093 */
1094 newinet->inet_opt = NULL;
1095 newnp->ipv6_ac_list = NULL;
1096 newnp->ipv6_fl_list = NULL;
1097
1098 /* Clone RX bits */
1099 newnp->rxopt.all = np->rxopt.all;
1100
1101 newnp->pktoptions = NULL;
1102 newnp->opt = NULL;
1103 newnp->mcast_oif = tcp_v6_iif(skb);
1104 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1105 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1106 if (np->repflow)
1107 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1108
1109 /* Clone native IPv6 options from listening socket (if any)
1110
1111 Yes, keeping reference count would be much more clever,
1112 but we make one more one thing there: reattach optmem
1113 to newsk.
1114 */
1115 opt = rcu_dereference(np->opt);
1116 if (opt) {
1117 opt = ipv6_dup_options(newsk, opt);
1118 RCU_INIT_POINTER(newnp->opt, opt);
1119 }
1120 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1121 if (opt)
1122 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1123 opt->opt_flen;
1124
1125 tcp_ca_openreq_child(newsk, dst);
1126
1127 tcp_sync_mss(newsk, dst_mtu(dst));
1128 newtp->advmss = dst_metric_advmss(dst);
1129 if (tcp_sk(sk)->rx_opt.user_mss &&
1130 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1131 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1132
1133 tcp_initialize_rcv_mss(newsk);
1134
1135 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1136 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1137
1138#ifdef CONFIG_TCP_MD5SIG
1139 /* Copy over the MD5 key from the original socket */
1140 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1141 if (key) {
1142 /* We're using one, so create a matching key
1143 * on the newsk structure. If we fail to get
1144 * memory, then we end up not copying the key
1145 * across. Shucks.
1146 */
1147 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1148 AF_INET6, key->key, key->keylen,
1149 sk_gfp_mask(sk, GFP_ATOMIC));
1150 }
1151#endif
1152
1153 if (__inet_inherit_port(sk, newsk) < 0) {
1154 inet_csk_prepare_forced_close(newsk);
1155 tcp_done(newsk);
1156 goto out;
1157 }
1158 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1159 if (*own_req) {
1160 tcp_move_syn(newtp, req);
1161
1162 /* Clone pktoptions received with SYN, if we own the req */
1163 if (ireq->pktopts) {
1164 newnp->pktoptions = skb_clone(ireq->pktopts,
1165 sk_gfp_mask(sk, GFP_ATOMIC));
1166 consume_skb(ireq->pktopts);
1167 ireq->pktopts = NULL;
1168 if (newnp->pktoptions)
1169 skb_set_owner_r(newnp->pktoptions, newsk);
1170 }
1171 }
1172
1173 return newsk;
1174
1175out_overflow:
1176 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1177out_nonewsk:
1178 dst_release(dst);
1179out:
1180 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1181 return NULL;
1182}
1183
1184/* The socket must have it's spinlock held when we get
1185 * here, unless it is a TCP_LISTEN socket.
1186 *
1187 * We have a potential double-lock case here, so even when
1188 * doing backlog processing we use the BH locking scheme.
1189 * This is because we cannot sleep with the original spinlock
1190 * held.
1191 */
1192static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1193{
1194 struct ipv6_pinfo *np = inet6_sk(sk);
1195 struct tcp_sock *tp;
1196 struct sk_buff *opt_skb = NULL;
1197
1198 /* Imagine: socket is IPv6. IPv4 packet arrives,
1199 goes to IPv4 receive handler and backlogged.
1200 From backlog it always goes here. Kerboom...
1201 Fortunately, tcp_rcv_established and rcv_established
1202 handle them correctly, but it is not case with
1203 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1204 */
1205
1206 if (skb->protocol == htons(ETH_P_IP))
1207 return tcp_v4_do_rcv(sk, skb);
1208
1209 if (sk_filter(sk, skb))
1210 goto discard;
1211
1212 /*
1213 * socket locking is here for SMP purposes as backlog rcv
1214 * is currently called with bh processing disabled.
1215 */
1216
1217 /* Do Stevens' IPV6_PKTOPTIONS.
1218
1219 Yes, guys, it is the only place in our code, where we
1220 may make it not affecting IPv4.
1221 The rest of code is protocol independent,
1222 and I do not like idea to uglify IPv4.
1223
1224 Actually, all the idea behind IPV6_PKTOPTIONS
1225 looks not very well thought. For now we latch
1226 options, received in the last packet, enqueued
1227 by tcp. Feel free to propose better solution.
1228 --ANK (980728)
1229 */
1230 if (np->rxopt.all)
1231 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1232
1233 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1234 struct dst_entry *dst = sk->sk_rx_dst;
1235
1236 sock_rps_save_rxhash(sk, skb);
1237 sk_mark_napi_id(sk, skb);
1238 if (dst) {
1239 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1240 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1241 dst_release(dst);
1242 sk->sk_rx_dst = NULL;
1243 }
1244 }
1245
1246 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1247 if (opt_skb)
1248 goto ipv6_pktoptions;
1249 return 0;
1250 }
1251
1252 if (tcp_checksum_complete(skb))
1253 goto csum_err;
1254
1255 if (sk->sk_state == TCP_LISTEN) {
1256 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1257
1258 if (!nsk)
1259 goto discard;
1260
1261 if (nsk != sk) {
1262 sock_rps_save_rxhash(nsk, skb);
1263 sk_mark_napi_id(nsk, skb);
1264 if (tcp_child_process(sk, nsk, skb))
1265 goto reset;
1266 if (opt_skb)
1267 __kfree_skb(opt_skb);
1268 return 0;
1269 }
1270 } else
1271 sock_rps_save_rxhash(sk, skb);
1272
1273 if (tcp_rcv_state_process(sk, skb))
1274 goto reset;
1275 if (opt_skb)
1276 goto ipv6_pktoptions;
1277 return 0;
1278
1279reset:
1280 tcp_v6_send_reset(sk, skb);
1281discard:
1282 if (opt_skb)
1283 __kfree_skb(opt_skb);
1284 kfree_skb(skb);
1285 return 0;
1286csum_err:
1287 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1288 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1289 goto discard;
1290
1291
1292ipv6_pktoptions:
1293 /* Do you ask, what is it?
1294
1295 1. skb was enqueued by tcp.
1296 2. skb is added to tail of read queue, rather than out of order.
1297 3. socket is not in passive state.
1298 4. Finally, it really contains options, which user wants to receive.
1299 */
1300 tp = tcp_sk(sk);
1301 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1302 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1303 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1304 np->mcast_oif = tcp_v6_iif(opt_skb);
1305 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1306 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1307 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1308 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1309 if (np->repflow)
1310 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1311 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1312 skb_set_owner_r(opt_skb, sk);
1313 opt_skb = xchg(&np->pktoptions, opt_skb);
1314 } else {
1315 __kfree_skb(opt_skb);
1316 opt_skb = xchg(&np->pktoptions, NULL);
1317 }
1318 }
1319
1320 kfree_skb(opt_skb);
1321 return 0;
1322}
1323
1324static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1325 const struct tcphdr *th)
1326{
1327 /* This is tricky: we move IP6CB at its correct location into
1328 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1329 * _decode_session6() uses IP6CB().
1330 * barrier() makes sure compiler won't play aliasing games.
1331 */
1332 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1333 sizeof(struct inet6_skb_parm));
1334 barrier();
1335
1336 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1337 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1338 skb->len - th->doff*4);
1339 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1340 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1341 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1342 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1343 TCP_SKB_CB(skb)->sacked = 0;
1344}
1345
1346static void tcp_v6_restore_cb(struct sk_buff *skb)
1347{
1348 /* We need to move header back to the beginning if xfrm6_policy_check()
1349 * and tcp_v6_fill_cb() are going to be called again.
1350 */
1351 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1352 sizeof(struct inet6_skb_parm));
1353}
1354
1355static int tcp_v6_rcv(struct sk_buff *skb)
1356{
1357 const struct tcphdr *th;
1358 const struct ipv6hdr *hdr;
1359 struct sock *sk;
1360 int ret;
1361 struct net *net = dev_net(skb->dev);
1362
1363 if (skb->pkt_type != PACKET_HOST)
1364 goto discard_it;
1365
1366 /*
1367 * Count it even if it's bad.
1368 */
1369 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1370
1371 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1372 goto discard_it;
1373
1374 th = tcp_hdr(skb);
1375
1376 if (th->doff < sizeof(struct tcphdr)/4)
1377 goto bad_packet;
1378 if (!pskb_may_pull(skb, th->doff*4))
1379 goto discard_it;
1380
1381 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1382 goto csum_error;
1383
1384 th = tcp_hdr(skb);
1385 hdr = ipv6_hdr(skb);
1386
1387lookup:
1388 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1389 th->source, th->dest, inet6_iif(skb));
1390 if (!sk)
1391 goto no_tcp_socket;
1392
1393process:
1394 if (sk->sk_state == TCP_TIME_WAIT)
1395 goto do_time_wait;
1396
1397 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1398 struct request_sock *req = inet_reqsk(sk);
1399 struct sock *nsk;
1400
1401 sk = req->rsk_listener;
1402 tcp_v6_fill_cb(skb, hdr, th);
1403 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1404 reqsk_put(req);
1405 goto discard_it;
1406 }
1407 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1408 inet_csk_reqsk_queue_drop_and_put(sk, req);
1409 goto lookup;
1410 }
1411 sock_hold(sk);
1412 nsk = tcp_check_req(sk, skb, req, false);
1413 if (!nsk) {
1414 reqsk_put(req);
1415 goto discard_and_relse;
1416 }
1417 if (nsk == sk) {
1418 reqsk_put(req);
1419 tcp_v6_restore_cb(skb);
1420 } else if (tcp_child_process(sk, nsk, skb)) {
1421 tcp_v6_send_reset(nsk, skb);
1422 goto discard_and_relse;
1423 } else {
1424 sock_put(sk);
1425 return 0;
1426 }
1427 }
1428 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1429 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1430 goto discard_and_relse;
1431 }
1432
1433 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1434 goto discard_and_relse;
1435
1436 tcp_v6_fill_cb(skb, hdr, th);
1437
1438 if (tcp_v6_inbound_md5_hash(sk, skb))
1439 goto discard_and_relse;
1440
1441 if (sk_filter(sk, skb))
1442 goto discard_and_relse;
1443
1444 skb->dev = NULL;
1445
1446 if (sk->sk_state == TCP_LISTEN) {
1447 ret = tcp_v6_do_rcv(sk, skb);
1448 goto put_and_return;
1449 }
1450
1451 sk_incoming_cpu_update(sk);
1452
1453 bh_lock_sock_nested(sk);
1454 tcp_segs_in(tcp_sk(sk), skb);
1455 ret = 0;
1456 if (!sock_owned_by_user(sk)) {
1457 if (!tcp_prequeue(sk, skb))
1458 ret = tcp_v6_do_rcv(sk, skb);
1459 } else if (unlikely(sk_add_backlog(sk, skb,
1460 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1461 bh_unlock_sock(sk);
1462 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1463 goto discard_and_relse;
1464 }
1465 bh_unlock_sock(sk);
1466
1467put_and_return:
1468 sock_put(sk);
1469 return ret ? -1 : 0;
1470
1471no_tcp_socket:
1472 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1473 goto discard_it;
1474
1475 tcp_v6_fill_cb(skb, hdr, th);
1476
1477 if (tcp_checksum_complete(skb)) {
1478csum_error:
1479 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1480bad_packet:
1481 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1482 } else {
1483 tcp_v6_send_reset(NULL, skb);
1484 }
1485
1486discard_it:
1487 kfree_skb(skb);
1488 return 0;
1489
1490discard_and_relse:
1491 sock_put(sk);
1492 goto discard_it;
1493
1494do_time_wait:
1495 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1496 inet_twsk_put(inet_twsk(sk));
1497 goto discard_it;
1498 }
1499
1500 tcp_v6_fill_cb(skb, hdr, th);
1501
1502 if (tcp_checksum_complete(skb)) {
1503 inet_twsk_put(inet_twsk(sk));
1504 goto csum_error;
1505 }
1506
1507 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1508 case TCP_TW_SYN:
1509 {
1510 struct sock *sk2;
1511
1512 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1513 skb, __tcp_hdrlen(th),
1514 &ipv6_hdr(skb)->saddr, th->source,
1515 &ipv6_hdr(skb)->daddr,
1516 ntohs(th->dest), tcp_v6_iif(skb));
1517 if (sk2) {
1518 struct inet_timewait_sock *tw = inet_twsk(sk);
1519 inet_twsk_deschedule_put(tw);
1520 sk = sk2;
1521 tcp_v6_restore_cb(skb);
1522 goto process;
1523 }
1524 /* Fall through to ACK */
1525 }
1526 case TCP_TW_ACK:
1527 tcp_v6_timewait_ack(sk, skb);
1528 break;
1529 case TCP_TW_RST:
1530 tcp_v6_restore_cb(skb);
1531 tcp_v6_send_reset(sk, skb);
1532 inet_twsk_deschedule_put(inet_twsk(sk));
1533 goto discard_it;
1534 case TCP_TW_SUCCESS:
1535 ;
1536 }
1537 goto discard_it;
1538}
1539
1540static void tcp_v6_early_demux(struct sk_buff *skb)
1541{
1542 const struct ipv6hdr *hdr;
1543 const struct tcphdr *th;
1544 struct sock *sk;
1545
1546 if (skb->pkt_type != PACKET_HOST)
1547 return;
1548
1549 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1550 return;
1551
1552 hdr = ipv6_hdr(skb);
1553 th = tcp_hdr(skb);
1554
1555 if (th->doff < sizeof(struct tcphdr) / 4)
1556 return;
1557
1558 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1559 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1560 &hdr->saddr, th->source,
1561 &hdr->daddr, ntohs(th->dest),
1562 inet6_iif(skb));
1563 if (sk) {
1564 skb->sk = sk;
1565 skb->destructor = sock_edemux;
1566 if (sk_fullsock(sk)) {
1567 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1568
1569 if (dst)
1570 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1571 if (dst &&
1572 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1573 skb_dst_set_noref(skb, dst);
1574 }
1575 }
1576}
1577
1578static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1579 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1580 .twsk_unique = tcp_twsk_unique,
1581 .twsk_destructor = tcp_twsk_destructor,
1582};
1583
1584static const struct inet_connection_sock_af_ops ipv6_specific = {
1585 .queue_xmit = inet6_csk_xmit,
1586 .send_check = tcp_v6_send_check,
1587 .rebuild_header = inet6_sk_rebuild_header,
1588 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1589 .conn_request = tcp_v6_conn_request,
1590 .syn_recv_sock = tcp_v6_syn_recv_sock,
1591 .net_header_len = sizeof(struct ipv6hdr),
1592 .net_frag_header_len = sizeof(struct frag_hdr),
1593 .setsockopt = ipv6_setsockopt,
1594 .getsockopt = ipv6_getsockopt,
1595 .addr2sockaddr = inet6_csk_addr2sockaddr,
1596 .sockaddr_len = sizeof(struct sockaddr_in6),
1597 .bind_conflict = inet6_csk_bind_conflict,
1598#ifdef CONFIG_COMPAT
1599 .compat_setsockopt = compat_ipv6_setsockopt,
1600 .compat_getsockopt = compat_ipv6_getsockopt,
1601#endif
1602 .mtu_reduced = tcp_v6_mtu_reduced,
1603};
1604
1605#ifdef CONFIG_TCP_MD5SIG
1606static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1607 .md5_lookup = tcp_v6_md5_lookup,
1608 .calc_md5_hash = tcp_v6_md5_hash_skb,
1609 .md5_parse = tcp_v6_parse_md5_keys,
1610};
1611#endif
1612
1613/*
1614 * TCP over IPv4 via INET6 API
1615 */
1616static const struct inet_connection_sock_af_ops ipv6_mapped = {
1617 .queue_xmit = ip_queue_xmit,
1618 .send_check = tcp_v4_send_check,
1619 .rebuild_header = inet_sk_rebuild_header,
1620 .sk_rx_dst_set = inet_sk_rx_dst_set,
1621 .conn_request = tcp_v6_conn_request,
1622 .syn_recv_sock = tcp_v6_syn_recv_sock,
1623 .net_header_len = sizeof(struct iphdr),
1624 .setsockopt = ipv6_setsockopt,
1625 .getsockopt = ipv6_getsockopt,
1626 .addr2sockaddr = inet6_csk_addr2sockaddr,
1627 .sockaddr_len = sizeof(struct sockaddr_in6),
1628 .bind_conflict = inet6_csk_bind_conflict,
1629#ifdef CONFIG_COMPAT
1630 .compat_setsockopt = compat_ipv6_setsockopt,
1631 .compat_getsockopt = compat_ipv6_getsockopt,
1632#endif
1633 .mtu_reduced = tcp_v4_mtu_reduced,
1634};
1635
1636#ifdef CONFIG_TCP_MD5SIG
1637static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1638 .md5_lookup = tcp_v4_md5_lookup,
1639 .calc_md5_hash = tcp_v4_md5_hash_skb,
1640 .md5_parse = tcp_v6_parse_md5_keys,
1641};
1642#endif
1643
1644/* NOTE: A lot of things set to zero explicitly by call to
1645 * sk_alloc() so need not be done here.
1646 */
1647static int tcp_v6_init_sock(struct sock *sk)
1648{
1649 struct inet_connection_sock *icsk = inet_csk(sk);
1650
1651 tcp_init_sock(sk);
1652
1653 icsk->icsk_af_ops = &ipv6_specific;
1654
1655#ifdef CONFIG_TCP_MD5SIG
1656 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1657#endif
1658
1659 return 0;
1660}
1661
1662static void tcp_v6_destroy_sock(struct sock *sk)
1663{
1664 tcp_v4_destroy_sock(sk);
1665 inet6_destroy_sock(sk);
1666}
1667
1668#ifdef CONFIG_PROC_FS
1669/* Proc filesystem TCPv6 sock list dumping. */
1670static void get_openreq6(struct seq_file *seq,
1671 const struct request_sock *req, int i)
1672{
1673 long ttd = req->rsk_timer.expires - jiffies;
1674 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1675 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1676
1677 if (ttd < 0)
1678 ttd = 0;
1679
1680 seq_printf(seq,
1681 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1682 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1683 i,
1684 src->s6_addr32[0], src->s6_addr32[1],
1685 src->s6_addr32[2], src->s6_addr32[3],
1686 inet_rsk(req)->ir_num,
1687 dest->s6_addr32[0], dest->s6_addr32[1],
1688 dest->s6_addr32[2], dest->s6_addr32[3],
1689 ntohs(inet_rsk(req)->ir_rmt_port),
1690 TCP_SYN_RECV,
1691 0, 0, /* could print option size, but that is af dependent. */
1692 1, /* timers active (only the expire timer) */
1693 jiffies_to_clock_t(ttd),
1694 req->num_timeout,
1695 from_kuid_munged(seq_user_ns(seq),
1696 sock_i_uid(req->rsk_listener)),
1697 0, /* non standard timer */
1698 0, /* open_requests have no inode */
1699 0, req);
1700}
1701
1702static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1703{
1704 const struct in6_addr *dest, *src;
1705 __u16 destp, srcp;
1706 int timer_active;
1707 unsigned long timer_expires;
1708 const struct inet_sock *inet = inet_sk(sp);
1709 const struct tcp_sock *tp = tcp_sk(sp);
1710 const struct inet_connection_sock *icsk = inet_csk(sp);
1711 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1712 int rx_queue;
1713 int state;
1714
1715 dest = &sp->sk_v6_daddr;
1716 src = &sp->sk_v6_rcv_saddr;
1717 destp = ntohs(inet->inet_dport);
1718 srcp = ntohs(inet->inet_sport);
1719
1720 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1721 timer_active = 1;
1722 timer_expires = icsk->icsk_timeout;
1723 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1724 timer_active = 4;
1725 timer_expires = icsk->icsk_timeout;
1726 } else if (timer_pending(&sp->sk_timer)) {
1727 timer_active = 2;
1728 timer_expires = sp->sk_timer.expires;
1729 } else {
1730 timer_active = 0;
1731 timer_expires = jiffies;
1732 }
1733
1734 state = sk_state_load(sp);
1735 if (state == TCP_LISTEN)
1736 rx_queue = sp->sk_ack_backlog;
1737 else
1738 /* Because we don't lock the socket,
1739 * we might find a transient negative value.
1740 */
1741 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1742
1743 seq_printf(seq,
1744 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1745 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1746 i,
1747 src->s6_addr32[0], src->s6_addr32[1],
1748 src->s6_addr32[2], src->s6_addr32[3], srcp,
1749 dest->s6_addr32[0], dest->s6_addr32[1],
1750 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1751 state,
1752 tp->write_seq - tp->snd_una,
1753 rx_queue,
1754 timer_active,
1755 jiffies_delta_to_clock_t(timer_expires - jiffies),
1756 icsk->icsk_retransmits,
1757 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1758 icsk->icsk_probes_out,
1759 sock_i_ino(sp),
1760 atomic_read(&sp->sk_refcnt), sp,
1761 jiffies_to_clock_t(icsk->icsk_rto),
1762 jiffies_to_clock_t(icsk->icsk_ack.ato),
1763 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1764 tp->snd_cwnd,
1765 state == TCP_LISTEN ?
1766 fastopenq->max_qlen :
1767 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1768 );
1769}
1770
1771static void get_timewait6_sock(struct seq_file *seq,
1772 struct inet_timewait_sock *tw, int i)
1773{
1774 long delta = tw->tw_timer.expires - jiffies;
1775 const struct in6_addr *dest, *src;
1776 __u16 destp, srcp;
1777
1778 dest = &tw->tw_v6_daddr;
1779 src = &tw->tw_v6_rcv_saddr;
1780 destp = ntohs(tw->tw_dport);
1781 srcp = ntohs(tw->tw_sport);
1782
1783 seq_printf(seq,
1784 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1785 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1786 i,
1787 src->s6_addr32[0], src->s6_addr32[1],
1788 src->s6_addr32[2], src->s6_addr32[3], srcp,
1789 dest->s6_addr32[0], dest->s6_addr32[1],
1790 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1791 tw->tw_substate, 0, 0,
1792 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1793 atomic_read(&tw->tw_refcnt), tw);
1794}
1795
1796static int tcp6_seq_show(struct seq_file *seq, void *v)
1797{
1798 struct tcp_iter_state *st;
1799 struct sock *sk = v;
1800
1801 if (v == SEQ_START_TOKEN) {
1802 seq_puts(seq,
1803 " sl "
1804 "local_address "
1805 "remote_address "
1806 "st tx_queue rx_queue tr tm->when retrnsmt"
1807 " uid timeout inode\n");
1808 goto out;
1809 }
1810 st = seq->private;
1811
1812 if (sk->sk_state == TCP_TIME_WAIT)
1813 get_timewait6_sock(seq, v, st->num);
1814 else if (sk->sk_state == TCP_NEW_SYN_RECV)
1815 get_openreq6(seq, v, st->num);
1816 else
1817 get_tcp6_sock(seq, v, st->num);
1818out:
1819 return 0;
1820}
1821
1822static const struct file_operations tcp6_afinfo_seq_fops = {
1823 .owner = THIS_MODULE,
1824 .open = tcp_seq_open,
1825 .read = seq_read,
1826 .llseek = seq_lseek,
1827 .release = seq_release_net
1828};
1829
1830static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1831 .name = "tcp6",
1832 .family = AF_INET6,
1833 .seq_fops = &tcp6_afinfo_seq_fops,
1834 .seq_ops = {
1835 .show = tcp6_seq_show,
1836 },
1837};
1838
1839int __net_init tcp6_proc_init(struct net *net)
1840{
1841 return tcp_proc_register(net, &tcp6_seq_afinfo);
1842}
1843
1844void tcp6_proc_exit(struct net *net)
1845{
1846 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1847}
1848#endif
1849
1850static void tcp_v6_clear_sk(struct sock *sk, int size)
1851{
1852 struct inet_sock *inet = inet_sk(sk);
1853
1854 /* we do not want to clear pinet6 field, because of RCU lookups */
1855 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1856
1857 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1858 memset(&inet->pinet6 + 1, 0, size);
1859}
1860
1861struct proto tcpv6_prot = {
1862 .name = "TCPv6",
1863 .owner = THIS_MODULE,
1864 .close = tcp_close,
1865 .connect = tcp_v6_connect,
1866 .disconnect = tcp_disconnect,
1867 .accept = inet_csk_accept,
1868 .ioctl = tcp_ioctl,
1869 .init = tcp_v6_init_sock,
1870 .destroy = tcp_v6_destroy_sock,
1871 .shutdown = tcp_shutdown,
1872 .setsockopt = tcp_setsockopt,
1873 .getsockopt = tcp_getsockopt,
1874 .recvmsg = tcp_recvmsg,
1875 .sendmsg = tcp_sendmsg,
1876 .sendpage = tcp_sendpage,
1877 .backlog_rcv = tcp_v6_do_rcv,
1878 .release_cb = tcp_release_cb,
1879 .hash = inet6_hash,
1880 .unhash = inet_unhash,
1881 .get_port = inet_csk_get_port,
1882 .enter_memory_pressure = tcp_enter_memory_pressure,
1883 .stream_memory_free = tcp_stream_memory_free,
1884 .sockets_allocated = &tcp_sockets_allocated,
1885 .memory_allocated = &tcp_memory_allocated,
1886 .memory_pressure = &tcp_memory_pressure,
1887 .orphan_count = &tcp_orphan_count,
1888 .sysctl_mem = sysctl_tcp_mem,
1889 .sysctl_wmem = sysctl_tcp_wmem,
1890 .sysctl_rmem = sysctl_tcp_rmem,
1891 .max_header = MAX_TCP_HEADER,
1892 .obj_size = sizeof(struct tcp6_sock),
1893 .slab_flags = SLAB_DESTROY_BY_RCU,
1894 .twsk_prot = &tcp6_timewait_sock_ops,
1895 .rsk_prot = &tcp6_request_sock_ops,
1896 .h.hashinfo = &tcp_hashinfo,
1897 .no_autobind = true,
1898#ifdef CONFIG_COMPAT
1899 .compat_setsockopt = compat_tcp_setsockopt,
1900 .compat_getsockopt = compat_tcp_getsockopt,
1901#endif
1902 .clear_sk = tcp_v6_clear_sk,
1903 .diag_destroy = tcp_abort,
1904};
1905
1906static const struct inet6_protocol tcpv6_protocol = {
1907 .early_demux = tcp_v6_early_demux,
1908 .handler = tcp_v6_rcv,
1909 .err_handler = tcp_v6_err,
1910 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1911};
1912
1913static struct inet_protosw tcpv6_protosw = {
1914 .type = SOCK_STREAM,
1915 .protocol = IPPROTO_TCP,
1916 .prot = &tcpv6_prot,
1917 .ops = &inet6_stream_ops,
1918 .flags = INET_PROTOSW_PERMANENT |
1919 INET_PROTOSW_ICSK,
1920};
1921
1922static int __net_init tcpv6_net_init(struct net *net)
1923{
1924 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1925 SOCK_RAW, IPPROTO_TCP, net);
1926}
1927
1928static void __net_exit tcpv6_net_exit(struct net *net)
1929{
1930 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1931}
1932
1933static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1934{
1935 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
1936}
1937
1938static struct pernet_operations tcpv6_net_ops = {
1939 .init = tcpv6_net_init,
1940 .exit = tcpv6_net_exit,
1941 .exit_batch = tcpv6_net_exit_batch,
1942};
1943
1944int __init tcpv6_init(void)
1945{
1946 int ret;
1947
1948 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1949 if (ret)
1950 goto out;
1951
1952 /* register inet6 protocol */
1953 ret = inet6_register_protosw(&tcpv6_protosw);
1954 if (ret)
1955 goto out_tcpv6_protocol;
1956
1957 ret = register_pernet_subsys(&tcpv6_net_ops);
1958 if (ret)
1959 goto out_tcpv6_protosw;
1960out:
1961 return ret;
1962
1963out_tcpv6_protosw:
1964 inet6_unregister_protosw(&tcpv6_protosw);
1965out_tcpv6_protocol:
1966 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1967 goto out;
1968}
1969
1970void tcpv6_exit(void)
1971{
1972 unregister_pernet_subsys(&tcpv6_net_ops);
1973 inet6_unregister_protosw(&tcpv6_protosw);
1974 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1975}
1/*
2 * TCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on:
9 * linux/net/ipv4/tcp.c
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
12 *
13 * Fixes:
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26#include <linux/bottom_half.h>
27#include <linux/module.h>
28#include <linux/errno.h>
29#include <linux/types.h>
30#include <linux/socket.h>
31#include <linux/sockios.h>
32#include <linux/net.h>
33#include <linux/jiffies.h>
34#include <linux/in.h>
35#include <linux/in6.h>
36#include <linux/netdevice.h>
37#include <linux/init.h>
38#include <linux/jhash.h>
39#include <linux/ipsec.h>
40#include <linux/times.h>
41#include <linux/slab.h>
42
43#include <linux/ipv6.h>
44#include <linux/icmpv6.h>
45#include <linux/random.h>
46
47#include <net/tcp.h>
48#include <net/ndisc.h>
49#include <net/inet6_hashtables.h>
50#include <net/inet6_connection_sock.h>
51#include <net/ipv6.h>
52#include <net/transp_v6.h>
53#include <net/addrconf.h>
54#include <net/ip6_route.h>
55#include <net/ip6_checksum.h>
56#include <net/inet_ecn.h>
57#include <net/protocol.h>
58#include <net/xfrm.h>
59#include <net/snmp.h>
60#include <net/dsfield.h>
61#include <net/timewait_sock.h>
62#include <net/netdma.h>
63#include <net/inet_common.h>
64#include <net/secure_seq.h>
65#include <net/tcp_memcontrol.h>
66
67#include <asm/uaccess.h>
68
69#include <linux/proc_fs.h>
70#include <linux/seq_file.h>
71
72#include <linux/crypto.h>
73#include <linux/scatterlist.h>
74
75static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
76static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
77 struct request_sock *req);
78
79static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
80static void __tcp_v6_send_check(struct sk_buff *skb,
81 const struct in6_addr *saddr,
82 const struct in6_addr *daddr);
83
84static const struct inet_connection_sock_af_ops ipv6_mapped;
85static const struct inet_connection_sock_af_ops ipv6_specific;
86#ifdef CONFIG_TCP_MD5SIG
87static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
88static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
89#else
90static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
91 const struct in6_addr *addr)
92{
93 return NULL;
94}
95#endif
96
97static void tcp_v6_hash(struct sock *sk)
98{
99 if (sk->sk_state != TCP_CLOSE) {
100 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
101 tcp_prot.hash(sk);
102 return;
103 }
104 local_bh_disable();
105 __inet6_hash(sk, NULL);
106 local_bh_enable();
107 }
108}
109
110static __inline__ __sum16 tcp_v6_check(int len,
111 const struct in6_addr *saddr,
112 const struct in6_addr *daddr,
113 __wsum base)
114{
115 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
116}
117
118static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
119{
120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
121 ipv6_hdr(skb)->saddr.s6_addr32,
122 tcp_hdr(skb)->dest,
123 tcp_hdr(skb)->source);
124}
125
126static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128{
129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
130 struct inet_sock *inet = inet_sk(sk);
131 struct inet_connection_sock *icsk = inet_csk(sk);
132 struct ipv6_pinfo *np = inet6_sk(sk);
133 struct tcp_sock *tp = tcp_sk(sk);
134 struct in6_addr *saddr = NULL, *final_p, final;
135 struct rt6_info *rt;
136 struct flowi6 fl6;
137 struct dst_entry *dst;
138 int addr_type;
139 int err;
140
141 if (addr_len < SIN6_LEN_RFC2133)
142 return -EINVAL;
143
144 if (usin->sin6_family != AF_INET6)
145 return -EAFNOSUPPORT;
146
147 memset(&fl6, 0, sizeof(fl6));
148
149 if (np->sndflow) {
150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
151 IP6_ECN_flow_init(fl6.flowlabel);
152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
153 struct ip6_flowlabel *flowlabel;
154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
155 if (flowlabel == NULL)
156 return -EINVAL;
157 usin->sin6_addr = flowlabel->dst;
158 fl6_sock_release(flowlabel);
159 }
160 }
161
162 /*
163 * connect() to INADDR_ANY means loopback (BSD'ism).
164 */
165
166 if(ipv6_addr_any(&usin->sin6_addr))
167 usin->sin6_addr.s6_addr[15] = 0x1;
168
169 addr_type = ipv6_addr_type(&usin->sin6_addr);
170
171 if(addr_type & IPV6_ADDR_MULTICAST)
172 return -ENETUNREACH;
173
174 if (addr_type&IPV6_ADDR_LINKLOCAL) {
175 if (addr_len >= sizeof(struct sockaddr_in6) &&
176 usin->sin6_scope_id) {
177 /* If interface is set while binding, indices
178 * must coincide.
179 */
180 if (sk->sk_bound_dev_if &&
181 sk->sk_bound_dev_if != usin->sin6_scope_id)
182 return -EINVAL;
183
184 sk->sk_bound_dev_if = usin->sin6_scope_id;
185 }
186
187 /* Connect to link-local address requires an interface */
188 if (!sk->sk_bound_dev_if)
189 return -EINVAL;
190 }
191
192 if (tp->rx_opt.ts_recent_stamp &&
193 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
194 tp->rx_opt.ts_recent = 0;
195 tp->rx_opt.ts_recent_stamp = 0;
196 tp->write_seq = 0;
197 }
198
199 np->daddr = usin->sin6_addr;
200 np->flow_label = fl6.flowlabel;
201
202 /*
203 * TCP over IPv4
204 */
205
206 if (addr_type == IPV6_ADDR_MAPPED) {
207 u32 exthdrlen = icsk->icsk_ext_hdr_len;
208 struct sockaddr_in sin;
209
210 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
211
212 if (__ipv6_only_sock(sk))
213 return -ENETUNREACH;
214
215 sin.sin_family = AF_INET;
216 sin.sin_port = usin->sin6_port;
217 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
218
219 icsk->icsk_af_ops = &ipv6_mapped;
220 sk->sk_backlog_rcv = tcp_v4_do_rcv;
221#ifdef CONFIG_TCP_MD5SIG
222 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
223#endif
224
225 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
226
227 if (err) {
228 icsk->icsk_ext_hdr_len = exthdrlen;
229 icsk->icsk_af_ops = &ipv6_specific;
230 sk->sk_backlog_rcv = tcp_v6_do_rcv;
231#ifdef CONFIG_TCP_MD5SIG
232 tp->af_specific = &tcp_sock_ipv6_specific;
233#endif
234 goto failure;
235 } else {
236 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
237 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
238 &np->rcv_saddr);
239 }
240
241 return err;
242 }
243
244 if (!ipv6_addr_any(&np->rcv_saddr))
245 saddr = &np->rcv_saddr;
246
247 fl6.flowi6_proto = IPPROTO_TCP;
248 fl6.daddr = np->daddr;
249 fl6.saddr = saddr ? *saddr : np->saddr;
250 fl6.flowi6_oif = sk->sk_bound_dev_if;
251 fl6.flowi6_mark = sk->sk_mark;
252 fl6.fl6_dport = usin->sin6_port;
253 fl6.fl6_sport = inet->inet_sport;
254
255 final_p = fl6_update_dst(&fl6, np->opt, &final);
256
257 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
258
259 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
260 if (IS_ERR(dst)) {
261 err = PTR_ERR(dst);
262 goto failure;
263 }
264
265 if (saddr == NULL) {
266 saddr = &fl6.saddr;
267 np->rcv_saddr = *saddr;
268 }
269
270 /* set the source address */
271 np->saddr = *saddr;
272 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
273
274 sk->sk_gso_type = SKB_GSO_TCPV6;
275 __ip6_dst_store(sk, dst, NULL, NULL);
276
277 rt = (struct rt6_info *) dst;
278 if (tcp_death_row.sysctl_tw_recycle &&
279 !tp->rx_opt.ts_recent_stamp &&
280 ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
281 struct inet_peer *peer = rt6_get_peer(rt);
282 /*
283 * VJ's idea. We save last timestamp seen from
284 * the destination in peer table, when entering state
285 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
286 * when trying new connection.
287 */
288 if (peer) {
289 inet_peer_refcheck(peer);
290 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
291 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
292 tp->rx_opt.ts_recent = peer->tcp_ts;
293 }
294 }
295 }
296
297 icsk->icsk_ext_hdr_len = 0;
298 if (np->opt)
299 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
300 np->opt->opt_nflen);
301
302 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
303
304 inet->inet_dport = usin->sin6_port;
305
306 tcp_set_state(sk, TCP_SYN_SENT);
307 err = inet6_hash_connect(&tcp_death_row, sk);
308 if (err)
309 goto late_failure;
310
311 if (!tp->write_seq)
312 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
313 np->daddr.s6_addr32,
314 inet->inet_sport,
315 inet->inet_dport);
316
317 err = tcp_connect(sk);
318 if (err)
319 goto late_failure;
320
321 return 0;
322
323late_failure:
324 tcp_set_state(sk, TCP_CLOSE);
325 __sk_dst_reset(sk);
326failure:
327 inet->inet_dport = 0;
328 sk->sk_route_caps = 0;
329 return err;
330}
331
332static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
333 u8 type, u8 code, int offset, __be32 info)
334{
335 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
336 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
337 struct ipv6_pinfo *np;
338 struct sock *sk;
339 int err;
340 struct tcp_sock *tp;
341 __u32 seq;
342 struct net *net = dev_net(skb->dev);
343
344 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
345 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
346
347 if (sk == NULL) {
348 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
349 ICMP6_MIB_INERRORS);
350 return;
351 }
352
353 if (sk->sk_state == TCP_TIME_WAIT) {
354 inet_twsk_put(inet_twsk(sk));
355 return;
356 }
357
358 bh_lock_sock(sk);
359 if (sock_owned_by_user(sk))
360 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
361
362 if (sk->sk_state == TCP_CLOSE)
363 goto out;
364
365 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
366 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
367 goto out;
368 }
369
370 tp = tcp_sk(sk);
371 seq = ntohl(th->seq);
372 if (sk->sk_state != TCP_LISTEN &&
373 !between(seq, tp->snd_una, tp->snd_nxt)) {
374 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
375 goto out;
376 }
377
378 np = inet6_sk(sk);
379
380 if (type == ICMPV6_PKT_TOOBIG) {
381 struct dst_entry *dst;
382
383 if (sock_owned_by_user(sk))
384 goto out;
385 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
386 goto out;
387
388 /* icmp should have updated the destination cache entry */
389 dst = __sk_dst_check(sk, np->dst_cookie);
390
391 if (dst == NULL) {
392 struct inet_sock *inet = inet_sk(sk);
393 struct flowi6 fl6;
394
395 /* BUGGG_FUTURE: Again, it is not clear how
396 to handle rthdr case. Ignore this complexity
397 for now.
398 */
399 memset(&fl6, 0, sizeof(fl6));
400 fl6.flowi6_proto = IPPROTO_TCP;
401 fl6.daddr = np->daddr;
402 fl6.saddr = np->saddr;
403 fl6.flowi6_oif = sk->sk_bound_dev_if;
404 fl6.flowi6_mark = sk->sk_mark;
405 fl6.fl6_dport = inet->inet_dport;
406 fl6.fl6_sport = inet->inet_sport;
407 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
408
409 dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
410 if (IS_ERR(dst)) {
411 sk->sk_err_soft = -PTR_ERR(dst);
412 goto out;
413 }
414
415 } else
416 dst_hold(dst);
417
418 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
419 tcp_sync_mss(sk, dst_mtu(dst));
420 tcp_simple_retransmit(sk);
421 } /* else let the usual retransmit timer handle it */
422 dst_release(dst);
423 goto out;
424 }
425
426 icmpv6_err_convert(type, code, &err);
427
428 /* Might be for an request_sock */
429 switch (sk->sk_state) {
430 struct request_sock *req, **prev;
431 case TCP_LISTEN:
432 if (sock_owned_by_user(sk))
433 goto out;
434
435 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
436 &hdr->saddr, inet6_iif(skb));
437 if (!req)
438 goto out;
439
440 /* ICMPs are not backlogged, hence we cannot get
441 * an established socket here.
442 */
443 WARN_ON(req->sk != NULL);
444
445 if (seq != tcp_rsk(req)->snt_isn) {
446 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
447 goto out;
448 }
449
450 inet_csk_reqsk_queue_drop(sk, req, prev);
451 goto out;
452
453 case TCP_SYN_SENT:
454 case TCP_SYN_RECV: /* Cannot happen.
455 It can, it SYNs are crossed. --ANK */
456 if (!sock_owned_by_user(sk)) {
457 sk->sk_err = err;
458 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
459
460 tcp_done(sk);
461 } else
462 sk->sk_err_soft = err;
463 goto out;
464 }
465
466 if (!sock_owned_by_user(sk) && np->recverr) {
467 sk->sk_err = err;
468 sk->sk_error_report(sk);
469 } else
470 sk->sk_err_soft = err;
471
472out:
473 bh_unlock_sock(sk);
474 sock_put(sk);
475}
476
477
478static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
479 struct request_values *rvp,
480 u16 queue_mapping)
481{
482 struct inet6_request_sock *treq = inet6_rsk(req);
483 struct ipv6_pinfo *np = inet6_sk(sk);
484 struct sk_buff * skb;
485 struct ipv6_txoptions *opt = NULL;
486 struct in6_addr * final_p, final;
487 struct flowi6 fl6;
488 struct dst_entry *dst;
489 int err;
490
491 memset(&fl6, 0, sizeof(fl6));
492 fl6.flowi6_proto = IPPROTO_TCP;
493 fl6.daddr = treq->rmt_addr;
494 fl6.saddr = treq->loc_addr;
495 fl6.flowlabel = 0;
496 fl6.flowi6_oif = treq->iif;
497 fl6.flowi6_mark = sk->sk_mark;
498 fl6.fl6_dport = inet_rsk(req)->rmt_port;
499 fl6.fl6_sport = inet_rsk(req)->loc_port;
500 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
501
502 opt = np->opt;
503 final_p = fl6_update_dst(&fl6, opt, &final);
504
505 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
506 if (IS_ERR(dst)) {
507 err = PTR_ERR(dst);
508 dst = NULL;
509 goto done;
510 }
511 skb = tcp_make_synack(sk, dst, req, rvp);
512 err = -ENOMEM;
513 if (skb) {
514 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
515
516 fl6.daddr = treq->rmt_addr;
517 skb_set_queue_mapping(skb, queue_mapping);
518 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
519 err = net_xmit_eval(err);
520 }
521
522done:
523 if (opt && opt != np->opt)
524 sock_kfree_s(sk, opt, opt->tot_len);
525 dst_release(dst);
526 return err;
527}
528
529static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
530 struct request_values *rvp)
531{
532 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
533 return tcp_v6_send_synack(sk, req, rvp, 0);
534}
535
536static void tcp_v6_reqsk_destructor(struct request_sock *req)
537{
538 kfree_skb(inet6_rsk(req)->pktopts);
539}
540
541#ifdef CONFIG_TCP_MD5SIG
542static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
543 const struct in6_addr *addr)
544{
545 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
546}
547
548static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
549 struct sock *addr_sk)
550{
551 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
552}
553
554static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
555 struct request_sock *req)
556{
557 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
558}
559
560static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
561 int optlen)
562{
563 struct tcp_md5sig cmd;
564 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
565
566 if (optlen < sizeof(cmd))
567 return -EINVAL;
568
569 if (copy_from_user(&cmd, optval, sizeof(cmd)))
570 return -EFAULT;
571
572 if (sin6->sin6_family != AF_INET6)
573 return -EINVAL;
574
575 if (!cmd.tcpm_keylen) {
576 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
577 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
578 AF_INET);
579 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
580 AF_INET6);
581 }
582
583 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
584 return -EINVAL;
585
586 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
587 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
588 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
589
590 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
591 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
592}
593
594static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
595 const struct in6_addr *daddr,
596 const struct in6_addr *saddr, int nbytes)
597{
598 struct tcp6_pseudohdr *bp;
599 struct scatterlist sg;
600
601 bp = &hp->md5_blk.ip6;
602 /* 1. TCP pseudo-header (RFC2460) */
603 bp->saddr = *saddr;
604 bp->daddr = *daddr;
605 bp->protocol = cpu_to_be32(IPPROTO_TCP);
606 bp->len = cpu_to_be32(nbytes);
607
608 sg_init_one(&sg, bp, sizeof(*bp));
609 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
610}
611
612static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
613 const struct in6_addr *daddr, struct in6_addr *saddr,
614 const struct tcphdr *th)
615{
616 struct tcp_md5sig_pool *hp;
617 struct hash_desc *desc;
618
619 hp = tcp_get_md5sig_pool();
620 if (!hp)
621 goto clear_hash_noput;
622 desc = &hp->md5_desc;
623
624 if (crypto_hash_init(desc))
625 goto clear_hash;
626 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
627 goto clear_hash;
628 if (tcp_md5_hash_header(hp, th))
629 goto clear_hash;
630 if (tcp_md5_hash_key(hp, key))
631 goto clear_hash;
632 if (crypto_hash_final(desc, md5_hash))
633 goto clear_hash;
634
635 tcp_put_md5sig_pool();
636 return 0;
637
638clear_hash:
639 tcp_put_md5sig_pool();
640clear_hash_noput:
641 memset(md5_hash, 0, 16);
642 return 1;
643}
644
645static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
646 const struct sock *sk,
647 const struct request_sock *req,
648 const struct sk_buff *skb)
649{
650 const struct in6_addr *saddr, *daddr;
651 struct tcp_md5sig_pool *hp;
652 struct hash_desc *desc;
653 const struct tcphdr *th = tcp_hdr(skb);
654
655 if (sk) {
656 saddr = &inet6_sk(sk)->saddr;
657 daddr = &inet6_sk(sk)->daddr;
658 } else if (req) {
659 saddr = &inet6_rsk(req)->loc_addr;
660 daddr = &inet6_rsk(req)->rmt_addr;
661 } else {
662 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
663 saddr = &ip6h->saddr;
664 daddr = &ip6h->daddr;
665 }
666
667 hp = tcp_get_md5sig_pool();
668 if (!hp)
669 goto clear_hash_noput;
670 desc = &hp->md5_desc;
671
672 if (crypto_hash_init(desc))
673 goto clear_hash;
674
675 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
676 goto clear_hash;
677 if (tcp_md5_hash_header(hp, th))
678 goto clear_hash;
679 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
680 goto clear_hash;
681 if (tcp_md5_hash_key(hp, key))
682 goto clear_hash;
683 if (crypto_hash_final(desc, md5_hash))
684 goto clear_hash;
685
686 tcp_put_md5sig_pool();
687 return 0;
688
689clear_hash:
690 tcp_put_md5sig_pool();
691clear_hash_noput:
692 memset(md5_hash, 0, 16);
693 return 1;
694}
695
696static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
697{
698 const __u8 *hash_location = NULL;
699 struct tcp_md5sig_key *hash_expected;
700 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
701 const struct tcphdr *th = tcp_hdr(skb);
702 int genhash;
703 u8 newhash[16];
704
705 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
706 hash_location = tcp_parse_md5sig_option(th);
707
708 /* We've parsed the options - do we have a hash? */
709 if (!hash_expected && !hash_location)
710 return 0;
711
712 if (hash_expected && !hash_location) {
713 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
714 return 1;
715 }
716
717 if (!hash_expected && hash_location) {
718 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
719 return 1;
720 }
721
722 /* check the signature */
723 genhash = tcp_v6_md5_hash_skb(newhash,
724 hash_expected,
725 NULL, NULL, skb);
726
727 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
728 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
729 genhash ? "failed" : "mismatch",
730 &ip6h->saddr, ntohs(th->source),
731 &ip6h->daddr, ntohs(th->dest));
732 return 1;
733 }
734 return 0;
735}
736#endif
737
738struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
739 .family = AF_INET6,
740 .obj_size = sizeof(struct tcp6_request_sock),
741 .rtx_syn_ack = tcp_v6_rtx_synack,
742 .send_ack = tcp_v6_reqsk_send_ack,
743 .destructor = tcp_v6_reqsk_destructor,
744 .send_reset = tcp_v6_send_reset,
745 .syn_ack_timeout = tcp_syn_ack_timeout,
746};
747
748#ifdef CONFIG_TCP_MD5SIG
749static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
750 .md5_lookup = tcp_v6_reqsk_md5_lookup,
751 .calc_md5_hash = tcp_v6_md5_hash_skb,
752};
753#endif
754
755static void __tcp_v6_send_check(struct sk_buff *skb,
756 const struct in6_addr *saddr, const struct in6_addr *daddr)
757{
758 struct tcphdr *th = tcp_hdr(skb);
759
760 if (skb->ip_summed == CHECKSUM_PARTIAL) {
761 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
762 skb->csum_start = skb_transport_header(skb) - skb->head;
763 skb->csum_offset = offsetof(struct tcphdr, check);
764 } else {
765 th->check = tcp_v6_check(skb->len, saddr, daddr,
766 csum_partial(th, th->doff << 2,
767 skb->csum));
768 }
769}
770
771static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
772{
773 struct ipv6_pinfo *np = inet6_sk(sk);
774
775 __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
776}
777
778static int tcp_v6_gso_send_check(struct sk_buff *skb)
779{
780 const struct ipv6hdr *ipv6h;
781 struct tcphdr *th;
782
783 if (!pskb_may_pull(skb, sizeof(*th)))
784 return -EINVAL;
785
786 ipv6h = ipv6_hdr(skb);
787 th = tcp_hdr(skb);
788
789 th->check = 0;
790 skb->ip_summed = CHECKSUM_PARTIAL;
791 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
792 return 0;
793}
794
795static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
796 struct sk_buff *skb)
797{
798 const struct ipv6hdr *iph = skb_gro_network_header(skb);
799
800 switch (skb->ip_summed) {
801 case CHECKSUM_COMPLETE:
802 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
803 skb->csum)) {
804 skb->ip_summed = CHECKSUM_UNNECESSARY;
805 break;
806 }
807
808 /* fall through */
809 case CHECKSUM_NONE:
810 NAPI_GRO_CB(skb)->flush = 1;
811 return NULL;
812 }
813
814 return tcp_gro_receive(head, skb);
815}
816
817static int tcp6_gro_complete(struct sk_buff *skb)
818{
819 const struct ipv6hdr *iph = ipv6_hdr(skb);
820 struct tcphdr *th = tcp_hdr(skb);
821
822 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
823 &iph->saddr, &iph->daddr, 0);
824 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
825
826 return tcp_gro_complete(skb);
827}
828
829static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
830 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
831{
832 const struct tcphdr *th = tcp_hdr(skb);
833 struct tcphdr *t1;
834 struct sk_buff *buff;
835 struct flowi6 fl6;
836 struct net *net = dev_net(skb_dst(skb)->dev);
837 struct sock *ctl_sk = net->ipv6.tcp_sk;
838 unsigned int tot_len = sizeof(struct tcphdr);
839 struct dst_entry *dst;
840 __be32 *topt;
841
842 if (ts)
843 tot_len += TCPOLEN_TSTAMP_ALIGNED;
844#ifdef CONFIG_TCP_MD5SIG
845 if (key)
846 tot_len += TCPOLEN_MD5SIG_ALIGNED;
847#endif
848
849 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
850 GFP_ATOMIC);
851 if (buff == NULL)
852 return;
853
854 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
855
856 t1 = (struct tcphdr *) skb_push(buff, tot_len);
857 skb_reset_transport_header(buff);
858
859 /* Swap the send and the receive. */
860 memset(t1, 0, sizeof(*t1));
861 t1->dest = th->source;
862 t1->source = th->dest;
863 t1->doff = tot_len / 4;
864 t1->seq = htonl(seq);
865 t1->ack_seq = htonl(ack);
866 t1->ack = !rst || !th->ack;
867 t1->rst = rst;
868 t1->window = htons(win);
869
870 topt = (__be32 *)(t1 + 1);
871
872 if (ts) {
873 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
874 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
875 *topt++ = htonl(tcp_time_stamp);
876 *topt++ = htonl(ts);
877 }
878
879#ifdef CONFIG_TCP_MD5SIG
880 if (key) {
881 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
882 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
883 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
884 &ipv6_hdr(skb)->saddr,
885 &ipv6_hdr(skb)->daddr, t1);
886 }
887#endif
888
889 memset(&fl6, 0, sizeof(fl6));
890 fl6.daddr = ipv6_hdr(skb)->saddr;
891 fl6.saddr = ipv6_hdr(skb)->daddr;
892
893 buff->ip_summed = CHECKSUM_PARTIAL;
894 buff->csum = 0;
895
896 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
897
898 fl6.flowi6_proto = IPPROTO_TCP;
899 fl6.flowi6_oif = inet6_iif(skb);
900 fl6.fl6_dport = t1->dest;
901 fl6.fl6_sport = t1->source;
902 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
903
904 /* Pass a socket to ip6_dst_lookup either it is for RST
905 * Underlying function will use this to retrieve the network
906 * namespace
907 */
908 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
909 if (!IS_ERR(dst)) {
910 skb_dst_set(buff, dst);
911 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
912 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
913 if (rst)
914 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
915 return;
916 }
917
918 kfree_skb(buff);
919}
920
921static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
922{
923 const struct tcphdr *th = tcp_hdr(skb);
924 u32 seq = 0, ack_seq = 0;
925 struct tcp_md5sig_key *key = NULL;
926#ifdef CONFIG_TCP_MD5SIG
927 const __u8 *hash_location = NULL;
928 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
929 unsigned char newhash[16];
930 int genhash;
931 struct sock *sk1 = NULL;
932#endif
933
934 if (th->rst)
935 return;
936
937 if (!ipv6_unicast_destination(skb))
938 return;
939
940#ifdef CONFIG_TCP_MD5SIG
941 hash_location = tcp_parse_md5sig_option(th);
942 if (!sk && hash_location) {
943 /*
944 * active side is lost. Try to find listening socket through
945 * source port, and then find md5 key through listening socket.
946 * we are not loose security here:
947 * Incoming packet is checked with md5 hash with finding key,
948 * no RST generated if md5 hash doesn't match.
949 */
950 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
951 &tcp_hashinfo, &ipv6h->daddr,
952 ntohs(th->source), inet6_iif(skb));
953 if (!sk1)
954 return;
955
956 rcu_read_lock();
957 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
958 if (!key)
959 goto release_sk1;
960
961 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
962 if (genhash || memcmp(hash_location, newhash, 16) != 0)
963 goto release_sk1;
964 } else {
965 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
966 }
967#endif
968
969 if (th->ack)
970 seq = ntohl(th->ack_seq);
971 else
972 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
973 (th->doff << 2);
974
975 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
976
977#ifdef CONFIG_TCP_MD5SIG
978release_sk1:
979 if (sk1) {
980 rcu_read_unlock();
981 sock_put(sk1);
982 }
983#endif
984}
985
986static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
987 struct tcp_md5sig_key *key, u8 tclass)
988{
989 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
990}
991
992static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
993{
994 struct inet_timewait_sock *tw = inet_twsk(sk);
995 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
996
997 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
998 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
999 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
1000 tw->tw_tclass);
1001
1002 inet_twsk_put(tw);
1003}
1004
1005static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1006 struct request_sock *req)
1007{
1008 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1009 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
1010}
1011
1012
1013static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1014{
1015 struct request_sock *req, **prev;
1016 const struct tcphdr *th = tcp_hdr(skb);
1017 struct sock *nsk;
1018
1019 /* Find possible connection requests. */
1020 req = inet6_csk_search_req(sk, &prev, th->source,
1021 &ipv6_hdr(skb)->saddr,
1022 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1023 if (req)
1024 return tcp_check_req(sk, skb, req, prev);
1025
1026 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1027 &ipv6_hdr(skb)->saddr, th->source,
1028 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1029
1030 if (nsk) {
1031 if (nsk->sk_state != TCP_TIME_WAIT) {
1032 bh_lock_sock(nsk);
1033 return nsk;
1034 }
1035 inet_twsk_put(inet_twsk(nsk));
1036 return NULL;
1037 }
1038
1039#ifdef CONFIG_SYN_COOKIES
1040 if (!th->syn)
1041 sk = cookie_v6_check(sk, skb);
1042#endif
1043 return sk;
1044}
1045
1046/* FIXME: this is substantially similar to the ipv4 code.
1047 * Can some kind of merge be done? -- erics
1048 */
1049static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1050{
1051 struct tcp_extend_values tmp_ext;
1052 struct tcp_options_received tmp_opt;
1053 const u8 *hash_location;
1054 struct request_sock *req;
1055 struct inet6_request_sock *treq;
1056 struct ipv6_pinfo *np = inet6_sk(sk);
1057 struct tcp_sock *tp = tcp_sk(sk);
1058 __u32 isn = TCP_SKB_CB(skb)->when;
1059 struct dst_entry *dst = NULL;
1060 bool want_cookie = false;
1061
1062 if (skb->protocol == htons(ETH_P_IP))
1063 return tcp_v4_conn_request(sk, skb);
1064
1065 if (!ipv6_unicast_destination(skb))
1066 goto drop;
1067
1068 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1069 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
1070 if (!want_cookie)
1071 goto drop;
1072 }
1073
1074 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1075 goto drop;
1076
1077 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1078 if (req == NULL)
1079 goto drop;
1080
1081#ifdef CONFIG_TCP_MD5SIG
1082 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1083#endif
1084
1085 tcp_clear_options(&tmp_opt);
1086 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1087 tmp_opt.user_mss = tp->rx_opt.user_mss;
1088 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1089
1090 if (tmp_opt.cookie_plus > 0 &&
1091 tmp_opt.saw_tstamp &&
1092 !tp->rx_opt.cookie_out_never &&
1093 (sysctl_tcp_cookie_size > 0 ||
1094 (tp->cookie_values != NULL &&
1095 tp->cookie_values->cookie_desired > 0))) {
1096 u8 *c;
1097 u32 *d;
1098 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1099 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1100
1101 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1102 goto drop_and_free;
1103
1104 /* Secret recipe starts with IP addresses */
1105 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1106 *mess++ ^= *d++;
1107 *mess++ ^= *d++;
1108 *mess++ ^= *d++;
1109 *mess++ ^= *d++;
1110 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1111 *mess++ ^= *d++;
1112 *mess++ ^= *d++;
1113 *mess++ ^= *d++;
1114 *mess++ ^= *d++;
1115
1116 /* plus variable length Initiator Cookie */
1117 c = (u8 *)mess;
1118 while (l-- > 0)
1119 *c++ ^= *hash_location++;
1120
1121 want_cookie = false; /* not our kind of cookie */
1122 tmp_ext.cookie_out_never = 0; /* false */
1123 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1124 } else if (!tp->rx_opt.cookie_in_always) {
1125 /* redundant indications, but ensure initialization. */
1126 tmp_ext.cookie_out_never = 1; /* true */
1127 tmp_ext.cookie_plus = 0;
1128 } else {
1129 goto drop_and_free;
1130 }
1131 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1132
1133 if (want_cookie && !tmp_opt.saw_tstamp)
1134 tcp_clear_options(&tmp_opt);
1135
1136 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1137 tcp_openreq_init(req, &tmp_opt, skb);
1138
1139 treq = inet6_rsk(req);
1140 treq->rmt_addr = ipv6_hdr(skb)->saddr;
1141 treq->loc_addr = ipv6_hdr(skb)->daddr;
1142 if (!want_cookie || tmp_opt.tstamp_ok)
1143 TCP_ECN_create_request(req, skb);
1144
1145 treq->iif = sk->sk_bound_dev_if;
1146
1147 /* So that link locals have meaning */
1148 if (!sk->sk_bound_dev_if &&
1149 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1150 treq->iif = inet6_iif(skb);
1151
1152 if (!isn) {
1153 struct inet_peer *peer = NULL;
1154
1155 if (ipv6_opt_accepted(sk, skb) ||
1156 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1157 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1158 atomic_inc(&skb->users);
1159 treq->pktopts = skb;
1160 }
1161
1162 if (want_cookie) {
1163 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1164 req->cookie_ts = tmp_opt.tstamp_ok;
1165 goto have_isn;
1166 }
1167
1168 /* VJ's idea. We save last timestamp seen
1169 * from the destination in peer table, when entering
1170 * state TIME-WAIT, and check against it before
1171 * accepting new connection request.
1172 *
1173 * If "isn" is not zero, this request hit alive
1174 * timewait bucket, so that all the necessary checks
1175 * are made in the function processing timewait state.
1176 */
1177 if (tmp_opt.saw_tstamp &&
1178 tcp_death_row.sysctl_tw_recycle &&
1179 (dst = inet6_csk_route_req(sk, req)) != NULL &&
1180 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1181 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1182 &treq->rmt_addr)) {
1183 inet_peer_refcheck(peer);
1184 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1185 (s32)(peer->tcp_ts - req->ts_recent) >
1186 TCP_PAWS_WINDOW) {
1187 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1188 goto drop_and_release;
1189 }
1190 }
1191 /* Kill the following clause, if you dislike this way. */
1192 else if (!sysctl_tcp_syncookies &&
1193 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1194 (sysctl_max_syn_backlog >> 2)) &&
1195 (!peer || !peer->tcp_ts_stamp) &&
1196 (!dst || !dst_metric(dst, RTAX_RTT))) {
1197 /* Without syncookies last quarter of
1198 * backlog is filled with destinations,
1199 * proven to be alive.
1200 * It means that we continue to communicate
1201 * to destinations, already remembered
1202 * to the moment of synflood.
1203 */
1204 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1205 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1206 goto drop_and_release;
1207 }
1208
1209 isn = tcp_v6_init_sequence(skb);
1210 }
1211have_isn:
1212 tcp_rsk(req)->snt_isn = isn;
1213 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1214
1215 if (security_inet_conn_request(sk, skb, req))
1216 goto drop_and_release;
1217
1218 if (tcp_v6_send_synack(sk, req,
1219 (struct request_values *)&tmp_ext,
1220 skb_get_queue_mapping(skb)) ||
1221 want_cookie)
1222 goto drop_and_free;
1223
1224 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1225 return 0;
1226
1227drop_and_release:
1228 dst_release(dst);
1229drop_and_free:
1230 reqsk_free(req);
1231drop:
1232 return 0; /* don't send reset */
1233}
1234
1235static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1236 struct request_sock *req,
1237 struct dst_entry *dst)
1238{
1239 struct inet6_request_sock *treq;
1240 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1241 struct tcp6_sock *newtcp6sk;
1242 struct inet_sock *newinet;
1243 struct tcp_sock *newtp;
1244 struct sock *newsk;
1245 struct ipv6_txoptions *opt;
1246#ifdef CONFIG_TCP_MD5SIG
1247 struct tcp_md5sig_key *key;
1248#endif
1249
1250 if (skb->protocol == htons(ETH_P_IP)) {
1251 /*
1252 * v6 mapped
1253 */
1254
1255 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1256
1257 if (newsk == NULL)
1258 return NULL;
1259
1260 newtcp6sk = (struct tcp6_sock *)newsk;
1261 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1262
1263 newinet = inet_sk(newsk);
1264 newnp = inet6_sk(newsk);
1265 newtp = tcp_sk(newsk);
1266
1267 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1268
1269 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1270
1271 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1272
1273 newnp->rcv_saddr = newnp->saddr;
1274
1275 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1276 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1277#ifdef CONFIG_TCP_MD5SIG
1278 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1279#endif
1280
1281 newnp->ipv6_ac_list = NULL;
1282 newnp->ipv6_fl_list = NULL;
1283 newnp->pktoptions = NULL;
1284 newnp->opt = NULL;
1285 newnp->mcast_oif = inet6_iif(skb);
1286 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1287 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1288
1289 /*
1290 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1291 * here, tcp_create_openreq_child now does this for us, see the comment in
1292 * that function for the gory details. -acme
1293 */
1294
1295 /* It is tricky place. Until this moment IPv4 tcp
1296 worked with IPv6 icsk.icsk_af_ops.
1297 Sync it now.
1298 */
1299 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1300
1301 return newsk;
1302 }
1303
1304 treq = inet6_rsk(req);
1305 opt = np->opt;
1306
1307 if (sk_acceptq_is_full(sk))
1308 goto out_overflow;
1309
1310 if (!dst) {
1311 dst = inet6_csk_route_req(sk, req);
1312 if (!dst)
1313 goto out;
1314 }
1315
1316 newsk = tcp_create_openreq_child(sk, req, skb);
1317 if (newsk == NULL)
1318 goto out_nonewsk;
1319
1320 /*
1321 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1322 * count here, tcp_create_openreq_child now does this for us, see the
1323 * comment in that function for the gory details. -acme
1324 */
1325
1326 newsk->sk_gso_type = SKB_GSO_TCPV6;
1327 __ip6_dst_store(newsk, dst, NULL, NULL);
1328
1329 newtcp6sk = (struct tcp6_sock *)newsk;
1330 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1331
1332 newtp = tcp_sk(newsk);
1333 newinet = inet_sk(newsk);
1334 newnp = inet6_sk(newsk);
1335
1336 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1337
1338 newnp->daddr = treq->rmt_addr;
1339 newnp->saddr = treq->loc_addr;
1340 newnp->rcv_saddr = treq->loc_addr;
1341 newsk->sk_bound_dev_if = treq->iif;
1342
1343 /* Now IPv6 options...
1344
1345 First: no IPv4 options.
1346 */
1347 newinet->inet_opt = NULL;
1348 newnp->ipv6_ac_list = NULL;
1349 newnp->ipv6_fl_list = NULL;
1350
1351 /* Clone RX bits */
1352 newnp->rxopt.all = np->rxopt.all;
1353
1354 /* Clone pktoptions received with SYN */
1355 newnp->pktoptions = NULL;
1356 if (treq->pktopts != NULL) {
1357 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1358 consume_skb(treq->pktopts);
1359 treq->pktopts = NULL;
1360 if (newnp->pktoptions)
1361 skb_set_owner_r(newnp->pktoptions, newsk);
1362 }
1363 newnp->opt = NULL;
1364 newnp->mcast_oif = inet6_iif(skb);
1365 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1366 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1367
1368 /* Clone native IPv6 options from listening socket (if any)
1369
1370 Yes, keeping reference count would be much more clever,
1371 but we make one more one thing there: reattach optmem
1372 to newsk.
1373 */
1374 if (opt) {
1375 newnp->opt = ipv6_dup_options(newsk, opt);
1376 if (opt != np->opt)
1377 sock_kfree_s(sk, opt, opt->tot_len);
1378 }
1379
1380 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1381 if (newnp->opt)
1382 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1383 newnp->opt->opt_flen);
1384
1385 tcp_mtup_init(newsk);
1386 tcp_sync_mss(newsk, dst_mtu(dst));
1387 newtp->advmss = dst_metric_advmss(dst);
1388 if (tcp_sk(sk)->rx_opt.user_mss &&
1389 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1390 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1391
1392 tcp_initialize_rcv_mss(newsk);
1393 if (tcp_rsk(req)->snt_synack)
1394 tcp_valid_rtt_meas(newsk,
1395 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1396 newtp->total_retrans = req->retrans;
1397
1398 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1399 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1400
1401#ifdef CONFIG_TCP_MD5SIG
1402 /* Copy over the MD5 key from the original socket */
1403 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1404 /* We're using one, so create a matching key
1405 * on the newsk structure. If we fail to get
1406 * memory, then we end up not copying the key
1407 * across. Shucks.
1408 */
1409 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1410 AF_INET6, key->key, key->keylen, GFP_ATOMIC);
1411 }
1412#endif
1413
1414 if (__inet_inherit_port(sk, newsk) < 0) {
1415 sock_put(newsk);
1416 goto out;
1417 }
1418 __inet6_hash(newsk, NULL);
1419
1420 return newsk;
1421
1422out_overflow:
1423 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1424out_nonewsk:
1425 if (opt && opt != np->opt)
1426 sock_kfree_s(sk, opt, opt->tot_len);
1427 dst_release(dst);
1428out:
1429 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1430 return NULL;
1431}
1432
1433static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1434{
1435 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1436 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1437 &ipv6_hdr(skb)->daddr, skb->csum)) {
1438 skb->ip_summed = CHECKSUM_UNNECESSARY;
1439 return 0;
1440 }
1441 }
1442
1443 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1444 &ipv6_hdr(skb)->saddr,
1445 &ipv6_hdr(skb)->daddr, 0));
1446
1447 if (skb->len <= 76) {
1448 return __skb_checksum_complete(skb);
1449 }
1450 return 0;
1451}
1452
1453/* The socket must have it's spinlock held when we get
1454 * here.
1455 *
1456 * We have a potential double-lock case here, so even when
1457 * doing backlog processing we use the BH locking scheme.
1458 * This is because we cannot sleep with the original spinlock
1459 * held.
1460 */
1461static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1462{
1463 struct ipv6_pinfo *np = inet6_sk(sk);
1464 struct tcp_sock *tp;
1465 struct sk_buff *opt_skb = NULL;
1466
1467 /* Imagine: socket is IPv6. IPv4 packet arrives,
1468 goes to IPv4 receive handler and backlogged.
1469 From backlog it always goes here. Kerboom...
1470 Fortunately, tcp_rcv_established and rcv_established
1471 handle them correctly, but it is not case with
1472 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1473 */
1474
1475 if (skb->protocol == htons(ETH_P_IP))
1476 return tcp_v4_do_rcv(sk, skb);
1477
1478#ifdef CONFIG_TCP_MD5SIG
1479 if (tcp_v6_inbound_md5_hash (sk, skb))
1480 goto discard;
1481#endif
1482
1483 if (sk_filter(sk, skb))
1484 goto discard;
1485
1486 /*
1487 * socket locking is here for SMP purposes as backlog rcv
1488 * is currently called with bh processing disabled.
1489 */
1490
1491 /* Do Stevens' IPV6_PKTOPTIONS.
1492
1493 Yes, guys, it is the only place in our code, where we
1494 may make it not affecting IPv4.
1495 The rest of code is protocol independent,
1496 and I do not like idea to uglify IPv4.
1497
1498 Actually, all the idea behind IPV6_PKTOPTIONS
1499 looks not very well thought. For now we latch
1500 options, received in the last packet, enqueued
1501 by tcp. Feel free to propose better solution.
1502 --ANK (980728)
1503 */
1504 if (np->rxopt.all)
1505 opt_skb = skb_clone(skb, GFP_ATOMIC);
1506
1507 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1508 sock_rps_save_rxhash(sk, skb);
1509 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1510 goto reset;
1511 if (opt_skb)
1512 goto ipv6_pktoptions;
1513 return 0;
1514 }
1515
1516 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1517 goto csum_err;
1518
1519 if (sk->sk_state == TCP_LISTEN) {
1520 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1521 if (!nsk)
1522 goto discard;
1523
1524 /*
1525 * Queue it on the new socket if the new socket is active,
1526 * otherwise we just shortcircuit this and continue with
1527 * the new socket..
1528 */
1529 if(nsk != sk) {
1530 sock_rps_save_rxhash(nsk, skb);
1531 if (tcp_child_process(sk, nsk, skb))
1532 goto reset;
1533 if (opt_skb)
1534 __kfree_skb(opt_skb);
1535 return 0;
1536 }
1537 } else
1538 sock_rps_save_rxhash(sk, skb);
1539
1540 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1541 goto reset;
1542 if (opt_skb)
1543 goto ipv6_pktoptions;
1544 return 0;
1545
1546reset:
1547 tcp_v6_send_reset(sk, skb);
1548discard:
1549 if (opt_skb)
1550 __kfree_skb(opt_skb);
1551 kfree_skb(skb);
1552 return 0;
1553csum_err:
1554 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1555 goto discard;
1556
1557
1558ipv6_pktoptions:
1559 /* Do you ask, what is it?
1560
1561 1. skb was enqueued by tcp.
1562 2. skb is added to tail of read queue, rather than out of order.
1563 3. socket is not in passive state.
1564 4. Finally, it really contains options, which user wants to receive.
1565 */
1566 tp = tcp_sk(sk);
1567 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1568 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1569 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1570 np->mcast_oif = inet6_iif(opt_skb);
1571 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1572 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1573 if (np->rxopt.bits.rxtclass)
1574 np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1575 if (ipv6_opt_accepted(sk, opt_skb)) {
1576 skb_set_owner_r(opt_skb, sk);
1577 opt_skb = xchg(&np->pktoptions, opt_skb);
1578 } else {
1579 __kfree_skb(opt_skb);
1580 opt_skb = xchg(&np->pktoptions, NULL);
1581 }
1582 }
1583
1584 kfree_skb(opt_skb);
1585 return 0;
1586}
1587
1588static int tcp_v6_rcv(struct sk_buff *skb)
1589{
1590 const struct tcphdr *th;
1591 const struct ipv6hdr *hdr;
1592 struct sock *sk;
1593 int ret;
1594 struct net *net = dev_net(skb->dev);
1595
1596 if (skb->pkt_type != PACKET_HOST)
1597 goto discard_it;
1598
1599 /*
1600 * Count it even if it's bad.
1601 */
1602 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1603
1604 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1605 goto discard_it;
1606
1607 th = tcp_hdr(skb);
1608
1609 if (th->doff < sizeof(struct tcphdr)/4)
1610 goto bad_packet;
1611 if (!pskb_may_pull(skb, th->doff*4))
1612 goto discard_it;
1613
1614 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1615 goto bad_packet;
1616
1617 th = tcp_hdr(skb);
1618 hdr = ipv6_hdr(skb);
1619 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1620 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1621 skb->len - th->doff*4);
1622 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1623 TCP_SKB_CB(skb)->when = 0;
1624 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1625 TCP_SKB_CB(skb)->sacked = 0;
1626
1627 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1628 if (!sk)
1629 goto no_tcp_socket;
1630
1631process:
1632 if (sk->sk_state == TCP_TIME_WAIT)
1633 goto do_time_wait;
1634
1635 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1636 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1637 goto discard_and_relse;
1638 }
1639
1640 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1641 goto discard_and_relse;
1642
1643 if (sk_filter(sk, skb))
1644 goto discard_and_relse;
1645
1646 skb->dev = NULL;
1647
1648 bh_lock_sock_nested(sk);
1649 ret = 0;
1650 if (!sock_owned_by_user(sk)) {
1651#ifdef CONFIG_NET_DMA
1652 struct tcp_sock *tp = tcp_sk(sk);
1653 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1654 tp->ucopy.dma_chan = net_dma_find_channel();
1655 if (tp->ucopy.dma_chan)
1656 ret = tcp_v6_do_rcv(sk, skb);
1657 else
1658#endif
1659 {
1660 if (!tcp_prequeue(sk, skb))
1661 ret = tcp_v6_do_rcv(sk, skb);
1662 }
1663 } else if (unlikely(sk_add_backlog(sk, skb,
1664 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1665 bh_unlock_sock(sk);
1666 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1667 goto discard_and_relse;
1668 }
1669 bh_unlock_sock(sk);
1670
1671 sock_put(sk);
1672 return ret ? -1 : 0;
1673
1674no_tcp_socket:
1675 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1676 goto discard_it;
1677
1678 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1679bad_packet:
1680 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1681 } else {
1682 tcp_v6_send_reset(NULL, skb);
1683 }
1684
1685discard_it:
1686
1687 /*
1688 * Discard frame
1689 */
1690
1691 kfree_skb(skb);
1692 return 0;
1693
1694discard_and_relse:
1695 sock_put(sk);
1696 goto discard_it;
1697
1698do_time_wait:
1699 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1700 inet_twsk_put(inet_twsk(sk));
1701 goto discard_it;
1702 }
1703
1704 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1705 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1706 inet_twsk_put(inet_twsk(sk));
1707 goto discard_it;
1708 }
1709
1710 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1711 case TCP_TW_SYN:
1712 {
1713 struct sock *sk2;
1714
1715 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1716 &ipv6_hdr(skb)->daddr,
1717 ntohs(th->dest), inet6_iif(skb));
1718 if (sk2 != NULL) {
1719 struct inet_timewait_sock *tw = inet_twsk(sk);
1720 inet_twsk_deschedule(tw, &tcp_death_row);
1721 inet_twsk_put(tw);
1722 sk = sk2;
1723 goto process;
1724 }
1725 /* Fall through to ACK */
1726 }
1727 case TCP_TW_ACK:
1728 tcp_v6_timewait_ack(sk, skb);
1729 break;
1730 case TCP_TW_RST:
1731 goto no_tcp_socket;
1732 case TCP_TW_SUCCESS:;
1733 }
1734 goto discard_it;
1735}
1736
1737static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1738{
1739 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1740 struct ipv6_pinfo *np = inet6_sk(sk);
1741 struct inet_peer *peer;
1742
1743 if (!rt ||
1744 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1745 peer = inet_getpeer_v6(&np->daddr, 1);
1746 *release_it = true;
1747 } else {
1748 if (!rt->rt6i_peer)
1749 rt6_bind_peer(rt, 1);
1750 peer = rt->rt6i_peer;
1751 *release_it = false;
1752 }
1753
1754 return peer;
1755}
1756
1757static void *tcp_v6_tw_get_peer(struct sock *sk)
1758{
1759 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1760 const struct inet_timewait_sock *tw = inet_twsk(sk);
1761
1762 if (tw->tw_family == AF_INET)
1763 return tcp_v4_tw_get_peer(sk);
1764
1765 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1766}
1767
1768static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1769 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1770 .twsk_unique = tcp_twsk_unique,
1771 .twsk_destructor= tcp_twsk_destructor,
1772 .twsk_getpeer = tcp_v6_tw_get_peer,
1773};
1774
1775static const struct inet_connection_sock_af_ops ipv6_specific = {
1776 .queue_xmit = inet6_csk_xmit,
1777 .send_check = tcp_v6_send_check,
1778 .rebuild_header = inet6_sk_rebuild_header,
1779 .conn_request = tcp_v6_conn_request,
1780 .syn_recv_sock = tcp_v6_syn_recv_sock,
1781 .get_peer = tcp_v6_get_peer,
1782 .net_header_len = sizeof(struct ipv6hdr),
1783 .net_frag_header_len = sizeof(struct frag_hdr),
1784 .setsockopt = ipv6_setsockopt,
1785 .getsockopt = ipv6_getsockopt,
1786 .addr2sockaddr = inet6_csk_addr2sockaddr,
1787 .sockaddr_len = sizeof(struct sockaddr_in6),
1788 .bind_conflict = inet6_csk_bind_conflict,
1789#ifdef CONFIG_COMPAT
1790 .compat_setsockopt = compat_ipv6_setsockopt,
1791 .compat_getsockopt = compat_ipv6_getsockopt,
1792#endif
1793};
1794
1795#ifdef CONFIG_TCP_MD5SIG
1796static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1797 .md5_lookup = tcp_v6_md5_lookup,
1798 .calc_md5_hash = tcp_v6_md5_hash_skb,
1799 .md5_parse = tcp_v6_parse_md5_keys,
1800};
1801#endif
1802
1803/*
1804 * TCP over IPv4 via INET6 API
1805 */
1806
1807static const struct inet_connection_sock_af_ops ipv6_mapped = {
1808 .queue_xmit = ip_queue_xmit,
1809 .send_check = tcp_v4_send_check,
1810 .rebuild_header = inet_sk_rebuild_header,
1811 .conn_request = tcp_v6_conn_request,
1812 .syn_recv_sock = tcp_v6_syn_recv_sock,
1813 .get_peer = tcp_v4_get_peer,
1814 .net_header_len = sizeof(struct iphdr),
1815 .setsockopt = ipv6_setsockopt,
1816 .getsockopt = ipv6_getsockopt,
1817 .addr2sockaddr = inet6_csk_addr2sockaddr,
1818 .sockaddr_len = sizeof(struct sockaddr_in6),
1819 .bind_conflict = inet6_csk_bind_conflict,
1820#ifdef CONFIG_COMPAT
1821 .compat_setsockopt = compat_ipv6_setsockopt,
1822 .compat_getsockopt = compat_ipv6_getsockopt,
1823#endif
1824};
1825
1826#ifdef CONFIG_TCP_MD5SIG
1827static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1828 .md5_lookup = tcp_v4_md5_lookup,
1829 .calc_md5_hash = tcp_v4_md5_hash_skb,
1830 .md5_parse = tcp_v6_parse_md5_keys,
1831};
1832#endif
1833
1834/* NOTE: A lot of things set to zero explicitly by call to
1835 * sk_alloc() so need not be done here.
1836 */
1837static int tcp_v6_init_sock(struct sock *sk)
1838{
1839 struct inet_connection_sock *icsk = inet_csk(sk);
1840
1841 tcp_init_sock(sk);
1842
1843 icsk->icsk_af_ops = &ipv6_specific;
1844
1845#ifdef CONFIG_TCP_MD5SIG
1846 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1847#endif
1848
1849 return 0;
1850}
1851
1852static void tcp_v6_destroy_sock(struct sock *sk)
1853{
1854 tcp_v4_destroy_sock(sk);
1855 inet6_destroy_sock(sk);
1856}
1857
1858#ifdef CONFIG_PROC_FS
1859/* Proc filesystem TCPv6 sock list dumping. */
1860static void get_openreq6(struct seq_file *seq,
1861 const struct sock *sk, struct request_sock *req, int i, int uid)
1862{
1863 int ttd = req->expires - jiffies;
1864 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1865 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1866
1867 if (ttd < 0)
1868 ttd = 0;
1869
1870 seq_printf(seq,
1871 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1872 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1873 i,
1874 src->s6_addr32[0], src->s6_addr32[1],
1875 src->s6_addr32[2], src->s6_addr32[3],
1876 ntohs(inet_rsk(req)->loc_port),
1877 dest->s6_addr32[0], dest->s6_addr32[1],
1878 dest->s6_addr32[2], dest->s6_addr32[3],
1879 ntohs(inet_rsk(req)->rmt_port),
1880 TCP_SYN_RECV,
1881 0,0, /* could print option size, but that is af dependent. */
1882 1, /* timers active (only the expire timer) */
1883 jiffies_to_clock_t(ttd),
1884 req->retrans,
1885 uid,
1886 0, /* non standard timer */
1887 0, /* open_requests have no inode */
1888 0, req);
1889}
1890
1891static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1892{
1893 const struct in6_addr *dest, *src;
1894 __u16 destp, srcp;
1895 int timer_active;
1896 unsigned long timer_expires;
1897 const struct inet_sock *inet = inet_sk(sp);
1898 const struct tcp_sock *tp = tcp_sk(sp);
1899 const struct inet_connection_sock *icsk = inet_csk(sp);
1900 const struct ipv6_pinfo *np = inet6_sk(sp);
1901
1902 dest = &np->daddr;
1903 src = &np->rcv_saddr;
1904 destp = ntohs(inet->inet_dport);
1905 srcp = ntohs(inet->inet_sport);
1906
1907 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1908 timer_active = 1;
1909 timer_expires = icsk->icsk_timeout;
1910 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1911 timer_active = 4;
1912 timer_expires = icsk->icsk_timeout;
1913 } else if (timer_pending(&sp->sk_timer)) {
1914 timer_active = 2;
1915 timer_expires = sp->sk_timer.expires;
1916 } else {
1917 timer_active = 0;
1918 timer_expires = jiffies;
1919 }
1920
1921 seq_printf(seq,
1922 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1923 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1924 i,
1925 src->s6_addr32[0], src->s6_addr32[1],
1926 src->s6_addr32[2], src->s6_addr32[3], srcp,
1927 dest->s6_addr32[0], dest->s6_addr32[1],
1928 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1929 sp->sk_state,
1930 tp->write_seq-tp->snd_una,
1931 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1932 timer_active,
1933 jiffies_to_clock_t(timer_expires - jiffies),
1934 icsk->icsk_retransmits,
1935 sock_i_uid(sp),
1936 icsk->icsk_probes_out,
1937 sock_i_ino(sp),
1938 atomic_read(&sp->sk_refcnt), sp,
1939 jiffies_to_clock_t(icsk->icsk_rto),
1940 jiffies_to_clock_t(icsk->icsk_ack.ato),
1941 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1942 tp->snd_cwnd,
1943 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1944 );
1945}
1946
1947static void get_timewait6_sock(struct seq_file *seq,
1948 struct inet_timewait_sock *tw, int i)
1949{
1950 const struct in6_addr *dest, *src;
1951 __u16 destp, srcp;
1952 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1953 int ttd = tw->tw_ttd - jiffies;
1954
1955 if (ttd < 0)
1956 ttd = 0;
1957
1958 dest = &tw6->tw_v6_daddr;
1959 src = &tw6->tw_v6_rcv_saddr;
1960 destp = ntohs(tw->tw_dport);
1961 srcp = ntohs(tw->tw_sport);
1962
1963 seq_printf(seq,
1964 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1965 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1966 i,
1967 src->s6_addr32[0], src->s6_addr32[1],
1968 src->s6_addr32[2], src->s6_addr32[3], srcp,
1969 dest->s6_addr32[0], dest->s6_addr32[1],
1970 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1971 tw->tw_substate, 0, 0,
1972 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
1973 atomic_read(&tw->tw_refcnt), tw);
1974}
1975
1976static int tcp6_seq_show(struct seq_file *seq, void *v)
1977{
1978 struct tcp_iter_state *st;
1979
1980 if (v == SEQ_START_TOKEN) {
1981 seq_puts(seq,
1982 " sl "
1983 "local_address "
1984 "remote_address "
1985 "st tx_queue rx_queue tr tm->when retrnsmt"
1986 " uid timeout inode\n");
1987 goto out;
1988 }
1989 st = seq->private;
1990
1991 switch (st->state) {
1992 case TCP_SEQ_STATE_LISTENING:
1993 case TCP_SEQ_STATE_ESTABLISHED:
1994 get_tcp6_sock(seq, v, st->num);
1995 break;
1996 case TCP_SEQ_STATE_OPENREQ:
1997 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1998 break;
1999 case TCP_SEQ_STATE_TIME_WAIT:
2000 get_timewait6_sock(seq, v, st->num);
2001 break;
2002 }
2003out:
2004 return 0;
2005}
2006
2007static const struct file_operations tcp6_afinfo_seq_fops = {
2008 .owner = THIS_MODULE,
2009 .open = tcp_seq_open,
2010 .read = seq_read,
2011 .llseek = seq_lseek,
2012 .release = seq_release_net
2013};
2014
2015static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2016 .name = "tcp6",
2017 .family = AF_INET6,
2018 .seq_fops = &tcp6_afinfo_seq_fops,
2019 .seq_ops = {
2020 .show = tcp6_seq_show,
2021 },
2022};
2023
2024int __net_init tcp6_proc_init(struct net *net)
2025{
2026 return tcp_proc_register(net, &tcp6_seq_afinfo);
2027}
2028
2029void tcp6_proc_exit(struct net *net)
2030{
2031 tcp_proc_unregister(net, &tcp6_seq_afinfo);
2032}
2033#endif
2034
2035struct proto tcpv6_prot = {
2036 .name = "TCPv6",
2037 .owner = THIS_MODULE,
2038 .close = tcp_close,
2039 .connect = tcp_v6_connect,
2040 .disconnect = tcp_disconnect,
2041 .accept = inet_csk_accept,
2042 .ioctl = tcp_ioctl,
2043 .init = tcp_v6_init_sock,
2044 .destroy = tcp_v6_destroy_sock,
2045 .shutdown = tcp_shutdown,
2046 .setsockopt = tcp_setsockopt,
2047 .getsockopt = tcp_getsockopt,
2048 .recvmsg = tcp_recvmsg,
2049 .sendmsg = tcp_sendmsg,
2050 .sendpage = tcp_sendpage,
2051 .backlog_rcv = tcp_v6_do_rcv,
2052 .hash = tcp_v6_hash,
2053 .unhash = inet_unhash,
2054 .get_port = inet_csk_get_port,
2055 .enter_memory_pressure = tcp_enter_memory_pressure,
2056 .sockets_allocated = &tcp_sockets_allocated,
2057 .memory_allocated = &tcp_memory_allocated,
2058 .memory_pressure = &tcp_memory_pressure,
2059 .orphan_count = &tcp_orphan_count,
2060 .sysctl_wmem = sysctl_tcp_wmem,
2061 .sysctl_rmem = sysctl_tcp_rmem,
2062 .max_header = MAX_TCP_HEADER,
2063 .obj_size = sizeof(struct tcp6_sock),
2064 .slab_flags = SLAB_DESTROY_BY_RCU,
2065 .twsk_prot = &tcp6_timewait_sock_ops,
2066 .rsk_prot = &tcp6_request_sock_ops,
2067 .h.hashinfo = &tcp_hashinfo,
2068 .no_autobind = true,
2069#ifdef CONFIG_COMPAT
2070 .compat_setsockopt = compat_tcp_setsockopt,
2071 .compat_getsockopt = compat_tcp_getsockopt,
2072#endif
2073#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
2074 .proto_cgroup = tcp_proto_cgroup,
2075#endif
2076};
2077
2078static const struct inet6_protocol tcpv6_protocol = {
2079 .handler = tcp_v6_rcv,
2080 .err_handler = tcp_v6_err,
2081 .gso_send_check = tcp_v6_gso_send_check,
2082 .gso_segment = tcp_tso_segment,
2083 .gro_receive = tcp6_gro_receive,
2084 .gro_complete = tcp6_gro_complete,
2085 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2086};
2087
2088static struct inet_protosw tcpv6_protosw = {
2089 .type = SOCK_STREAM,
2090 .protocol = IPPROTO_TCP,
2091 .prot = &tcpv6_prot,
2092 .ops = &inet6_stream_ops,
2093 .no_check = 0,
2094 .flags = INET_PROTOSW_PERMANENT |
2095 INET_PROTOSW_ICSK,
2096};
2097
2098static int __net_init tcpv6_net_init(struct net *net)
2099{
2100 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2101 SOCK_RAW, IPPROTO_TCP, net);
2102}
2103
2104static void __net_exit tcpv6_net_exit(struct net *net)
2105{
2106 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2107}
2108
2109static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2110{
2111 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2112}
2113
2114static struct pernet_operations tcpv6_net_ops = {
2115 .init = tcpv6_net_init,
2116 .exit = tcpv6_net_exit,
2117 .exit_batch = tcpv6_net_exit_batch,
2118};
2119
2120int __init tcpv6_init(void)
2121{
2122 int ret;
2123
2124 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2125 if (ret)
2126 goto out;
2127
2128 /* register inet6 protocol */
2129 ret = inet6_register_protosw(&tcpv6_protosw);
2130 if (ret)
2131 goto out_tcpv6_protocol;
2132
2133 ret = register_pernet_subsys(&tcpv6_net_ops);
2134 if (ret)
2135 goto out_tcpv6_protosw;
2136out:
2137 return ret;
2138
2139out_tcpv6_protocol:
2140 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2141out_tcpv6_protosw:
2142 inet6_unregister_protosw(&tcpv6_protosw);
2143 goto out;
2144}
2145
2146void tcpv6_exit(void)
2147{
2148 unregister_pernet_subsys(&tcpv6_net_ops);
2149 inet6_unregister_protosw(&tcpv6_protosw);
2150 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2151}