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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#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
72#include <trace/events/tcp.h>
73
74static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
75static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
76 struct request_sock *req);
77
78static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79
80static const struct inet_connection_sock_af_ops ipv6_mapped;
81static const struct inet_connection_sock_af_ops ipv6_specific;
82#ifdef CONFIG_TCP_MD5SIG
83static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
84static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
85#else
86static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
87 const struct in6_addr *addr)
88{
89 return NULL;
90}
91#endif
92
93static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
94{
95 struct dst_entry *dst = skb_dst(skb);
96
97 if (dst && dst_hold_safe(dst)) {
98 const struct rt6_info *rt = (const struct rt6_info *)dst;
99
100 sk->sk_rx_dst = dst;
101 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
102 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
103 }
104}
105
106static u32 tcp_v6_init_seq(const struct sk_buff *skb)
107{
108 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
109 ipv6_hdr(skb)->saddr.s6_addr32,
110 tcp_hdr(skb)->dest,
111 tcp_hdr(skb)->source);
112}
113
114static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
115{
116 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
117 ipv6_hdr(skb)->saddr.s6_addr32);
118}
119
120static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
121 int addr_len)
122{
123 /* This check is replicated from tcp_v6_connect() and intended to
124 * prevent BPF program called below from accessing bytes that are out
125 * of the bound specified by user in addr_len.
126 */
127 if (addr_len < SIN6_LEN_RFC2133)
128 return -EINVAL;
129
130 sock_owned_by_me(sk);
131
132 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
133}
134
135static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
136 int addr_len)
137{
138 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
139 struct inet_sock *inet = inet_sk(sk);
140 struct inet_connection_sock *icsk = inet_csk(sk);
141 struct ipv6_pinfo *np = inet6_sk(sk);
142 struct tcp_sock *tp = tcp_sk(sk);
143 struct in6_addr *saddr = NULL, *final_p, final;
144 struct ipv6_txoptions *opt;
145 struct flowi6 fl6;
146 struct dst_entry *dst;
147 int addr_type;
148 int err;
149 struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
150
151 if (addr_len < SIN6_LEN_RFC2133)
152 return -EINVAL;
153
154 if (usin->sin6_family != AF_INET6)
155 return -EAFNOSUPPORT;
156
157 memset(&fl6, 0, sizeof(fl6));
158
159 if (np->sndflow) {
160 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
161 IP6_ECN_flow_init(fl6.flowlabel);
162 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
163 struct ip6_flowlabel *flowlabel;
164 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
165 if (!flowlabel)
166 return -EINVAL;
167 fl6_sock_release(flowlabel);
168 }
169 }
170
171 /*
172 * connect() to INADDR_ANY means loopback (BSD'ism).
173 */
174
175 if (ipv6_addr_any(&usin->sin6_addr)) {
176 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
177 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
178 &usin->sin6_addr);
179 else
180 usin->sin6_addr = in6addr_loopback;
181 }
182
183 addr_type = ipv6_addr_type(&usin->sin6_addr);
184
185 if (addr_type & IPV6_ADDR_MULTICAST)
186 return -ENETUNREACH;
187
188 if (addr_type&IPV6_ADDR_LINKLOCAL) {
189 if (addr_len >= sizeof(struct sockaddr_in6) &&
190 usin->sin6_scope_id) {
191 /* If interface is set while binding, indices
192 * must coincide.
193 */
194 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
195 return -EINVAL;
196
197 sk->sk_bound_dev_if = usin->sin6_scope_id;
198 }
199
200 /* Connect to link-local address requires an interface */
201 if (!sk->sk_bound_dev_if)
202 return -EINVAL;
203 }
204
205 if (tp->rx_opt.ts_recent_stamp &&
206 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
207 tp->rx_opt.ts_recent = 0;
208 tp->rx_opt.ts_recent_stamp = 0;
209 tp->write_seq = 0;
210 }
211
212 sk->sk_v6_daddr = usin->sin6_addr;
213 np->flow_label = fl6.flowlabel;
214
215 /*
216 * TCP over IPv4
217 */
218
219 if (addr_type & IPV6_ADDR_MAPPED) {
220 u32 exthdrlen = icsk->icsk_ext_hdr_len;
221 struct sockaddr_in sin;
222
223 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
224
225 if (__ipv6_only_sock(sk))
226 return -ENETUNREACH;
227
228 sin.sin_family = AF_INET;
229 sin.sin_port = usin->sin6_port;
230 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
231
232 icsk->icsk_af_ops = &ipv6_mapped;
233 sk->sk_backlog_rcv = tcp_v4_do_rcv;
234#ifdef CONFIG_TCP_MD5SIG
235 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
236#endif
237
238 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
239
240 if (err) {
241 icsk->icsk_ext_hdr_len = exthdrlen;
242 icsk->icsk_af_ops = &ipv6_specific;
243 sk->sk_backlog_rcv = tcp_v6_do_rcv;
244#ifdef CONFIG_TCP_MD5SIG
245 tp->af_specific = &tcp_sock_ipv6_specific;
246#endif
247 goto failure;
248 }
249 np->saddr = sk->sk_v6_rcv_saddr;
250
251 return err;
252 }
253
254 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
255 saddr = &sk->sk_v6_rcv_saddr;
256
257 fl6.flowi6_proto = IPPROTO_TCP;
258 fl6.daddr = sk->sk_v6_daddr;
259 fl6.saddr = saddr ? *saddr : np->saddr;
260 fl6.flowi6_oif = sk->sk_bound_dev_if;
261 fl6.flowi6_mark = sk->sk_mark;
262 fl6.fl6_dport = usin->sin6_port;
263 fl6.fl6_sport = inet->inet_sport;
264 fl6.flowi6_uid = sk->sk_uid;
265
266 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
267 final_p = fl6_update_dst(&fl6, opt, &final);
268
269 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
270
271 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
272 if (IS_ERR(dst)) {
273 err = PTR_ERR(dst);
274 goto failure;
275 }
276
277 if (!saddr) {
278 saddr = &fl6.saddr;
279 sk->sk_v6_rcv_saddr = *saddr;
280 }
281
282 /* set the source address */
283 np->saddr = *saddr;
284 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
285
286 sk->sk_gso_type = SKB_GSO_TCPV6;
287 ip6_dst_store(sk, dst, NULL, NULL);
288
289 icsk->icsk_ext_hdr_len = 0;
290 if (opt)
291 icsk->icsk_ext_hdr_len = opt->opt_flen +
292 opt->opt_nflen;
293
294 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
295
296 inet->inet_dport = usin->sin6_port;
297
298 tcp_set_state(sk, TCP_SYN_SENT);
299 err = inet6_hash_connect(tcp_death_row, sk);
300 if (err)
301 goto late_failure;
302
303 sk_set_txhash(sk);
304
305 if (likely(!tp->repair)) {
306 if (!tp->write_seq)
307 tp->write_seq = secure_tcpv6_seq(np->saddr.s6_addr32,
308 sk->sk_v6_daddr.s6_addr32,
309 inet->inet_sport,
310 inet->inet_dport);
311 tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk),
312 np->saddr.s6_addr32,
313 sk->sk_v6_daddr.s6_addr32);
314 }
315
316 if (tcp_fastopen_defer_connect(sk, &err))
317 return err;
318 if (err)
319 goto late_failure;
320
321 err = tcp_connect(sk);
322 if (err)
323 goto late_failure;
324
325 return 0;
326
327late_failure:
328 tcp_set_state(sk, TCP_CLOSE);
329failure:
330 inet->inet_dport = 0;
331 sk->sk_route_caps = 0;
332 return err;
333}
334
335static void tcp_v6_mtu_reduced(struct sock *sk)
336{
337 struct dst_entry *dst;
338
339 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
340 return;
341
342 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
343 if (!dst)
344 return;
345
346 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
347 tcp_sync_mss(sk, dst_mtu(dst));
348 tcp_simple_retransmit(sk);
349 }
350}
351
352static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
353 u8 type, u8 code, int offset, __be32 info)
354{
355 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
356 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
357 struct net *net = dev_net(skb->dev);
358 struct request_sock *fastopen;
359 struct ipv6_pinfo *np;
360 struct tcp_sock *tp;
361 __u32 seq, snd_una;
362 struct sock *sk;
363 bool fatal;
364 int err;
365
366 sk = __inet6_lookup_established(net, &tcp_hashinfo,
367 &hdr->daddr, th->dest,
368 &hdr->saddr, ntohs(th->source),
369 skb->dev->ifindex, inet6_sdif(skb));
370
371 if (!sk) {
372 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
373 ICMP6_MIB_INERRORS);
374 return;
375 }
376
377 if (sk->sk_state == TCP_TIME_WAIT) {
378 inet_twsk_put(inet_twsk(sk));
379 return;
380 }
381 seq = ntohl(th->seq);
382 fatal = icmpv6_err_convert(type, code, &err);
383 if (sk->sk_state == TCP_NEW_SYN_RECV)
384 return tcp_req_err(sk, seq, fatal);
385
386 bh_lock_sock(sk);
387 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
388 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
389
390 if (sk->sk_state == TCP_CLOSE)
391 goto out;
392
393 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
394 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
395 goto out;
396 }
397
398 tp = tcp_sk(sk);
399 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
400 fastopen = tp->fastopen_rsk;
401 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
402 if (sk->sk_state != TCP_LISTEN &&
403 !between(seq, snd_una, tp->snd_nxt)) {
404 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
405 goto out;
406 }
407
408 np = inet6_sk(sk);
409
410 if (type == NDISC_REDIRECT) {
411 if (!sock_owned_by_user(sk)) {
412 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
413
414 if (dst)
415 dst->ops->redirect(dst, sk, skb);
416 }
417 goto out;
418 }
419
420 if (type == ICMPV6_PKT_TOOBIG) {
421 /* We are not interested in TCP_LISTEN and open_requests
422 * (SYN-ACKs send out by Linux are always <576bytes so
423 * they should go through unfragmented).
424 */
425 if (sk->sk_state == TCP_LISTEN)
426 goto out;
427
428 if (!ip6_sk_accept_pmtu(sk))
429 goto out;
430
431 tp->mtu_info = ntohl(info);
432 if (!sock_owned_by_user(sk))
433 tcp_v6_mtu_reduced(sk);
434 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
435 &sk->sk_tsq_flags))
436 sock_hold(sk);
437 goto out;
438 }
439
440
441 /* Might be for an request_sock */
442 switch (sk->sk_state) {
443 case TCP_SYN_SENT:
444 case TCP_SYN_RECV:
445 /* Only in fast or simultaneous open. If a fast open socket is
446 * is already accepted it is treated as a connected one below.
447 */
448 if (fastopen && !fastopen->sk)
449 break;
450
451 if (!sock_owned_by_user(sk)) {
452 sk->sk_err = err;
453 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
454
455 tcp_done(sk);
456 } else
457 sk->sk_err_soft = err;
458 goto out;
459 }
460
461 if (!sock_owned_by_user(sk) && np->recverr) {
462 sk->sk_err = err;
463 sk->sk_error_report(sk);
464 } else
465 sk->sk_err_soft = err;
466
467out:
468 bh_unlock_sock(sk);
469 sock_put(sk);
470}
471
472
473static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
474 struct flowi *fl,
475 struct request_sock *req,
476 struct tcp_fastopen_cookie *foc,
477 enum tcp_synack_type synack_type)
478{
479 struct inet_request_sock *ireq = inet_rsk(req);
480 struct ipv6_pinfo *np = inet6_sk(sk);
481 struct ipv6_txoptions *opt;
482 struct flowi6 *fl6 = &fl->u.ip6;
483 struct sk_buff *skb;
484 int err = -ENOMEM;
485
486 /* First, grab a route. */
487 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
488 IPPROTO_TCP)) == NULL)
489 goto done;
490
491 skb = tcp_make_synack(sk, dst, req, foc, synack_type);
492
493 if (skb) {
494 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
495 &ireq->ir_v6_rmt_addr);
496
497 fl6->daddr = ireq->ir_v6_rmt_addr;
498 if (np->repflow && ireq->pktopts)
499 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
500
501 rcu_read_lock();
502 opt = ireq->ipv6_opt;
503 if (!opt)
504 opt = rcu_dereference(np->opt);
505 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass);
506 rcu_read_unlock();
507 err = net_xmit_eval(err);
508 }
509
510done:
511 return err;
512}
513
514
515static void tcp_v6_reqsk_destructor(struct request_sock *req)
516{
517 kfree(inet_rsk(req)->ipv6_opt);
518 kfree_skb(inet_rsk(req)->pktopts);
519}
520
521#ifdef CONFIG_TCP_MD5SIG
522static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
523 const struct in6_addr *addr)
524{
525 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
526}
527
528static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
529 const struct sock *addr_sk)
530{
531 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
532}
533
534static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
535 char __user *optval, int optlen)
536{
537 struct tcp_md5sig cmd;
538 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
539 u8 prefixlen;
540
541 if (optlen < sizeof(cmd))
542 return -EINVAL;
543
544 if (copy_from_user(&cmd, optval, sizeof(cmd)))
545 return -EFAULT;
546
547 if (sin6->sin6_family != AF_INET6)
548 return -EINVAL;
549
550 if (optname == TCP_MD5SIG_EXT &&
551 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
552 prefixlen = cmd.tcpm_prefixlen;
553 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
554 prefixlen > 32))
555 return -EINVAL;
556 } else {
557 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
558 }
559
560 if (!cmd.tcpm_keylen) {
561 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
562 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
563 AF_INET, prefixlen);
564 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
565 AF_INET6, prefixlen);
566 }
567
568 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
569 return -EINVAL;
570
571 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
572 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
573 AF_INET, prefixlen, cmd.tcpm_key,
574 cmd.tcpm_keylen, GFP_KERNEL);
575
576 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
577 AF_INET6, prefixlen, cmd.tcpm_key,
578 cmd.tcpm_keylen, GFP_KERNEL);
579}
580
581static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
582 const struct in6_addr *daddr,
583 const struct in6_addr *saddr,
584 const struct tcphdr *th, int nbytes)
585{
586 struct tcp6_pseudohdr *bp;
587 struct scatterlist sg;
588 struct tcphdr *_th;
589
590 bp = hp->scratch;
591 /* 1. TCP pseudo-header (RFC2460) */
592 bp->saddr = *saddr;
593 bp->daddr = *daddr;
594 bp->protocol = cpu_to_be32(IPPROTO_TCP);
595 bp->len = cpu_to_be32(nbytes);
596
597 _th = (struct tcphdr *)(bp + 1);
598 memcpy(_th, th, sizeof(*th));
599 _th->check = 0;
600
601 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
602 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
603 sizeof(*bp) + sizeof(*th));
604 return crypto_ahash_update(hp->md5_req);
605}
606
607static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
608 const struct in6_addr *daddr, struct in6_addr *saddr,
609 const struct tcphdr *th)
610{
611 struct tcp_md5sig_pool *hp;
612 struct ahash_request *req;
613
614 hp = tcp_get_md5sig_pool();
615 if (!hp)
616 goto clear_hash_noput;
617 req = hp->md5_req;
618
619 if (crypto_ahash_init(req))
620 goto clear_hash;
621 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
622 goto clear_hash;
623 if (tcp_md5_hash_key(hp, key))
624 goto clear_hash;
625 ahash_request_set_crypt(req, NULL, md5_hash, 0);
626 if (crypto_ahash_final(req))
627 goto clear_hash;
628
629 tcp_put_md5sig_pool();
630 return 0;
631
632clear_hash:
633 tcp_put_md5sig_pool();
634clear_hash_noput:
635 memset(md5_hash, 0, 16);
636 return 1;
637}
638
639static int tcp_v6_md5_hash_skb(char *md5_hash,
640 const struct tcp_md5sig_key *key,
641 const struct sock *sk,
642 const struct sk_buff *skb)
643{
644 const struct in6_addr *saddr, *daddr;
645 struct tcp_md5sig_pool *hp;
646 struct ahash_request *req;
647 const struct tcphdr *th = tcp_hdr(skb);
648
649 if (sk) { /* valid for establish/request sockets */
650 saddr = &sk->sk_v6_rcv_saddr;
651 daddr = &sk->sk_v6_daddr;
652 } else {
653 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
654 saddr = &ip6h->saddr;
655 daddr = &ip6h->daddr;
656 }
657
658 hp = tcp_get_md5sig_pool();
659 if (!hp)
660 goto clear_hash_noput;
661 req = hp->md5_req;
662
663 if (crypto_ahash_init(req))
664 goto clear_hash;
665
666 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
667 goto clear_hash;
668 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
669 goto clear_hash;
670 if (tcp_md5_hash_key(hp, key))
671 goto clear_hash;
672 ahash_request_set_crypt(req, NULL, md5_hash, 0);
673 if (crypto_ahash_final(req))
674 goto clear_hash;
675
676 tcp_put_md5sig_pool();
677 return 0;
678
679clear_hash:
680 tcp_put_md5sig_pool();
681clear_hash_noput:
682 memset(md5_hash, 0, 16);
683 return 1;
684}
685
686#endif
687
688static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
689 const struct sk_buff *skb)
690{
691#ifdef CONFIG_TCP_MD5SIG
692 const __u8 *hash_location = NULL;
693 struct tcp_md5sig_key *hash_expected;
694 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
695 const struct tcphdr *th = tcp_hdr(skb);
696 int genhash;
697 u8 newhash[16];
698
699 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
700 hash_location = tcp_parse_md5sig_option(th);
701
702 /* We've parsed the options - do we have a hash? */
703 if (!hash_expected && !hash_location)
704 return false;
705
706 if (hash_expected && !hash_location) {
707 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
708 return true;
709 }
710
711 if (!hash_expected && hash_location) {
712 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
713 return true;
714 }
715
716 /* check the signature */
717 genhash = tcp_v6_md5_hash_skb(newhash,
718 hash_expected,
719 NULL, skb);
720
721 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
722 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
723 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
724 genhash ? "failed" : "mismatch",
725 &ip6h->saddr, ntohs(th->source),
726 &ip6h->daddr, ntohs(th->dest));
727 return true;
728 }
729#endif
730 return false;
731}
732
733static void tcp_v6_init_req(struct request_sock *req,
734 const struct sock *sk_listener,
735 struct sk_buff *skb)
736{
737 struct inet_request_sock *ireq = inet_rsk(req);
738 const struct ipv6_pinfo *np = inet6_sk(sk_listener);
739
740 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
741 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
742
743 /* So that link locals have meaning */
744 if (!sk_listener->sk_bound_dev_if &&
745 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
746 ireq->ir_iif = tcp_v6_iif(skb);
747
748 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
749 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
750 np->rxopt.bits.rxinfo ||
751 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
752 np->rxopt.bits.rxohlim || np->repflow)) {
753 refcount_inc(&skb->users);
754 ireq->pktopts = skb;
755 }
756}
757
758static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
759 struct flowi *fl,
760 const struct request_sock *req)
761{
762 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
763}
764
765struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
766 .family = AF_INET6,
767 .obj_size = sizeof(struct tcp6_request_sock),
768 .rtx_syn_ack = tcp_rtx_synack,
769 .send_ack = tcp_v6_reqsk_send_ack,
770 .destructor = tcp_v6_reqsk_destructor,
771 .send_reset = tcp_v6_send_reset,
772 .syn_ack_timeout = tcp_syn_ack_timeout,
773};
774
775static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
776 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
777 sizeof(struct ipv6hdr),
778#ifdef CONFIG_TCP_MD5SIG
779 .req_md5_lookup = tcp_v6_md5_lookup,
780 .calc_md5_hash = tcp_v6_md5_hash_skb,
781#endif
782 .init_req = tcp_v6_init_req,
783#ifdef CONFIG_SYN_COOKIES
784 .cookie_init_seq = cookie_v6_init_sequence,
785#endif
786 .route_req = tcp_v6_route_req,
787 .init_seq = tcp_v6_init_seq,
788 .init_ts_off = tcp_v6_init_ts_off,
789 .send_synack = tcp_v6_send_synack,
790};
791
792static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
793 u32 ack, u32 win, u32 tsval, u32 tsecr,
794 int oif, struct tcp_md5sig_key *key, int rst,
795 u8 tclass, __be32 label)
796{
797 const struct tcphdr *th = tcp_hdr(skb);
798 struct tcphdr *t1;
799 struct sk_buff *buff;
800 struct flowi6 fl6;
801 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
802 struct sock *ctl_sk = net->ipv6.tcp_sk;
803 unsigned int tot_len = sizeof(struct tcphdr);
804 struct dst_entry *dst;
805 __be32 *topt;
806
807 if (tsecr)
808 tot_len += TCPOLEN_TSTAMP_ALIGNED;
809#ifdef CONFIG_TCP_MD5SIG
810 if (key)
811 tot_len += TCPOLEN_MD5SIG_ALIGNED;
812#endif
813
814 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
815 GFP_ATOMIC);
816 if (!buff)
817 return;
818
819 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
820
821 t1 = skb_push(buff, tot_len);
822 skb_reset_transport_header(buff);
823
824 /* Swap the send and the receive. */
825 memset(t1, 0, sizeof(*t1));
826 t1->dest = th->source;
827 t1->source = th->dest;
828 t1->doff = tot_len / 4;
829 t1->seq = htonl(seq);
830 t1->ack_seq = htonl(ack);
831 t1->ack = !rst || !th->ack;
832 t1->rst = rst;
833 t1->window = htons(win);
834
835 topt = (__be32 *)(t1 + 1);
836
837 if (tsecr) {
838 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
839 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
840 *topt++ = htonl(tsval);
841 *topt++ = htonl(tsecr);
842 }
843
844#ifdef CONFIG_TCP_MD5SIG
845 if (key) {
846 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
847 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
848 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
849 &ipv6_hdr(skb)->saddr,
850 &ipv6_hdr(skb)->daddr, t1);
851 }
852#endif
853
854 memset(&fl6, 0, sizeof(fl6));
855 fl6.daddr = ipv6_hdr(skb)->saddr;
856 fl6.saddr = ipv6_hdr(skb)->daddr;
857 fl6.flowlabel = label;
858
859 buff->ip_summed = CHECKSUM_PARTIAL;
860 buff->csum = 0;
861
862 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
863
864 fl6.flowi6_proto = IPPROTO_TCP;
865 if (rt6_need_strict(&fl6.daddr) && !oif)
866 fl6.flowi6_oif = tcp_v6_iif(skb);
867 else {
868 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
869 oif = skb->skb_iif;
870
871 fl6.flowi6_oif = oif;
872 }
873
874 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
875 fl6.fl6_dport = t1->dest;
876 fl6.fl6_sport = t1->source;
877 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
878 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
879
880 /* Pass a socket to ip6_dst_lookup either it is for RST
881 * Underlying function will use this to retrieve the network
882 * namespace
883 */
884 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
885 if (!IS_ERR(dst)) {
886 skb_dst_set(buff, dst);
887 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass);
888 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
889 if (rst)
890 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
891 return;
892 }
893
894 kfree_skb(buff);
895}
896
897static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
898{
899 const struct tcphdr *th = tcp_hdr(skb);
900 u32 seq = 0, ack_seq = 0;
901 struct tcp_md5sig_key *key = NULL;
902#ifdef CONFIG_TCP_MD5SIG
903 const __u8 *hash_location = NULL;
904 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
905 unsigned char newhash[16];
906 int genhash;
907 struct sock *sk1 = NULL;
908#endif
909 int oif = 0;
910
911 if (th->rst)
912 return;
913
914 /* If sk not NULL, it means we did a successful lookup and incoming
915 * route had to be correct. prequeue might have dropped our dst.
916 */
917 if (!sk && !ipv6_unicast_destination(skb))
918 return;
919
920#ifdef CONFIG_TCP_MD5SIG
921 rcu_read_lock();
922 hash_location = tcp_parse_md5sig_option(th);
923 if (sk && sk_fullsock(sk)) {
924 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
925 } else if (hash_location) {
926 /*
927 * active side is lost. Try to find listening socket through
928 * source port, and then find md5 key through listening socket.
929 * we are not loose security here:
930 * Incoming packet is checked with md5 hash with finding key,
931 * no RST generated if md5 hash doesn't match.
932 */
933 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
934 &tcp_hashinfo, NULL, 0,
935 &ipv6h->saddr,
936 th->source, &ipv6h->daddr,
937 ntohs(th->source), tcp_v6_iif(skb),
938 tcp_v6_sdif(skb));
939 if (!sk1)
940 goto out;
941
942 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
943 if (!key)
944 goto out;
945
946 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
947 if (genhash || memcmp(hash_location, newhash, 16) != 0)
948 goto out;
949 }
950#endif
951
952 if (th->ack)
953 seq = ntohl(th->ack_seq);
954 else
955 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
956 (th->doff << 2);
957
958 if (sk) {
959 oif = sk->sk_bound_dev_if;
960 if (sk_fullsock(sk))
961 trace_tcp_send_reset(sk, skb);
962 }
963
964 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
965
966#ifdef CONFIG_TCP_MD5SIG
967out:
968 rcu_read_unlock();
969#endif
970}
971
972static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
973 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
974 struct tcp_md5sig_key *key, u8 tclass,
975 __be32 label)
976{
977 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
978 tclass, label);
979}
980
981static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
982{
983 struct inet_timewait_sock *tw = inet_twsk(sk);
984 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
985
986 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
987 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
988 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
989 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
990 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
991
992 inet_twsk_put(tw);
993}
994
995static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
996 struct request_sock *req)
997{
998 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
999 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1000 */
1001 /* RFC 7323 2.3
1002 * The window field (SEG.WND) of every outgoing segment, with the
1003 * exception of <SYN> segments, MUST be right-shifted by
1004 * Rcv.Wind.Shift bits:
1005 */
1006 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1007 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1008 tcp_rsk(req)->rcv_nxt,
1009 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1010 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1011 req->ts_recent, sk->sk_bound_dev_if,
1012 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr),
1013 0, 0);
1014}
1015
1016
1017static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1018{
1019#ifdef CONFIG_SYN_COOKIES
1020 const struct tcphdr *th = tcp_hdr(skb);
1021
1022 if (!th->syn)
1023 sk = cookie_v6_check(sk, skb);
1024#endif
1025 return sk;
1026}
1027
1028static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1029{
1030 if (skb->protocol == htons(ETH_P_IP))
1031 return tcp_v4_conn_request(sk, skb);
1032
1033 if (!ipv6_unicast_destination(skb))
1034 goto drop;
1035
1036 return tcp_conn_request(&tcp6_request_sock_ops,
1037 &tcp_request_sock_ipv6_ops, sk, skb);
1038
1039drop:
1040 tcp_listendrop(sk);
1041 return 0; /* don't send reset */
1042}
1043
1044static void tcp_v6_restore_cb(struct sk_buff *skb)
1045{
1046 /* We need to move header back to the beginning if xfrm6_policy_check()
1047 * and tcp_v6_fill_cb() are going to be called again.
1048 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1049 */
1050 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1051 sizeof(struct inet6_skb_parm));
1052}
1053
1054static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1055 struct request_sock *req,
1056 struct dst_entry *dst,
1057 struct request_sock *req_unhash,
1058 bool *own_req)
1059{
1060 struct inet_request_sock *ireq;
1061 struct ipv6_pinfo *newnp;
1062 const struct ipv6_pinfo *np = inet6_sk(sk);
1063 struct ipv6_txoptions *opt;
1064 struct tcp6_sock *newtcp6sk;
1065 struct inet_sock *newinet;
1066 struct tcp_sock *newtp;
1067 struct sock *newsk;
1068#ifdef CONFIG_TCP_MD5SIG
1069 struct tcp_md5sig_key *key;
1070#endif
1071 struct flowi6 fl6;
1072
1073 if (skb->protocol == htons(ETH_P_IP)) {
1074 /*
1075 * v6 mapped
1076 */
1077
1078 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1079 req_unhash, own_req);
1080
1081 if (!newsk)
1082 return NULL;
1083
1084 newtcp6sk = (struct tcp6_sock *)newsk;
1085 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1086
1087 newinet = inet_sk(newsk);
1088 newnp = inet6_sk(newsk);
1089 newtp = tcp_sk(newsk);
1090
1091 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1092
1093 newnp->saddr = newsk->sk_v6_rcv_saddr;
1094
1095 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1096 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1097#ifdef CONFIG_TCP_MD5SIG
1098 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1099#endif
1100
1101 newnp->ipv6_mc_list = NULL;
1102 newnp->ipv6_ac_list = NULL;
1103 newnp->ipv6_fl_list = NULL;
1104 newnp->pktoptions = NULL;
1105 newnp->opt = NULL;
1106 newnp->mcast_oif = tcp_v6_iif(skb);
1107 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1108 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1109 if (np->repflow)
1110 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1111
1112 /*
1113 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1114 * here, tcp_create_openreq_child now does this for us, see the comment in
1115 * that function for the gory details. -acme
1116 */
1117
1118 /* It is tricky place. Until this moment IPv4 tcp
1119 worked with IPv6 icsk.icsk_af_ops.
1120 Sync it now.
1121 */
1122 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1123
1124 return newsk;
1125 }
1126
1127 ireq = inet_rsk(req);
1128
1129 if (sk_acceptq_is_full(sk))
1130 goto out_overflow;
1131
1132 if (!dst) {
1133 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1134 if (!dst)
1135 goto out;
1136 }
1137
1138 newsk = tcp_create_openreq_child(sk, req, skb);
1139 if (!newsk)
1140 goto out_nonewsk;
1141
1142 /*
1143 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1144 * count here, tcp_create_openreq_child now does this for us, see the
1145 * comment in that function for the gory details. -acme
1146 */
1147
1148 newsk->sk_gso_type = SKB_GSO_TCPV6;
1149 ip6_dst_store(newsk, dst, NULL, NULL);
1150 inet6_sk_rx_dst_set(newsk, skb);
1151
1152 newtcp6sk = (struct tcp6_sock *)newsk;
1153 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1154
1155 newtp = tcp_sk(newsk);
1156 newinet = inet_sk(newsk);
1157 newnp = inet6_sk(newsk);
1158
1159 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1160
1161 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1162 newnp->saddr = ireq->ir_v6_loc_addr;
1163 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1164 newsk->sk_bound_dev_if = ireq->ir_iif;
1165
1166 /* Now IPv6 options...
1167
1168 First: no IPv4 options.
1169 */
1170 newinet->inet_opt = NULL;
1171 newnp->ipv6_mc_list = NULL;
1172 newnp->ipv6_ac_list = NULL;
1173 newnp->ipv6_fl_list = NULL;
1174
1175 /* Clone RX bits */
1176 newnp->rxopt.all = np->rxopt.all;
1177
1178 newnp->pktoptions = NULL;
1179 newnp->opt = NULL;
1180 newnp->mcast_oif = tcp_v6_iif(skb);
1181 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1182 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1183 if (np->repflow)
1184 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1185
1186 /* Clone native IPv6 options from listening socket (if any)
1187
1188 Yes, keeping reference count would be much more clever,
1189 but we make one more one thing there: reattach optmem
1190 to newsk.
1191 */
1192 opt = ireq->ipv6_opt;
1193 if (!opt)
1194 opt = rcu_dereference(np->opt);
1195 if (opt) {
1196 opt = ipv6_dup_options(newsk, opt);
1197 RCU_INIT_POINTER(newnp->opt, opt);
1198 }
1199 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1200 if (opt)
1201 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1202 opt->opt_flen;
1203
1204 tcp_ca_openreq_child(newsk, dst);
1205
1206 tcp_sync_mss(newsk, dst_mtu(dst));
1207 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1208
1209 tcp_initialize_rcv_mss(newsk);
1210
1211 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1212 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1213
1214#ifdef CONFIG_TCP_MD5SIG
1215 /* Copy over the MD5 key from the original socket */
1216 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1217 if (key) {
1218 /* We're using one, so create a matching key
1219 * on the newsk structure. If we fail to get
1220 * memory, then we end up not copying the key
1221 * across. Shucks.
1222 */
1223 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1224 AF_INET6, 128, key->key, key->keylen,
1225 sk_gfp_mask(sk, GFP_ATOMIC));
1226 }
1227#endif
1228
1229 if (__inet_inherit_port(sk, newsk) < 0) {
1230 inet_csk_prepare_forced_close(newsk);
1231 tcp_done(newsk);
1232 goto out;
1233 }
1234 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1235 if (*own_req) {
1236 tcp_move_syn(newtp, req);
1237
1238 /* Clone pktoptions received with SYN, if we own the req */
1239 if (ireq->pktopts) {
1240 newnp->pktoptions = skb_clone(ireq->pktopts,
1241 sk_gfp_mask(sk, GFP_ATOMIC));
1242 consume_skb(ireq->pktopts);
1243 ireq->pktopts = NULL;
1244 if (newnp->pktoptions) {
1245 tcp_v6_restore_cb(newnp->pktoptions);
1246 skb_set_owner_r(newnp->pktoptions, newsk);
1247 }
1248 }
1249 }
1250
1251 return newsk;
1252
1253out_overflow:
1254 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1255out_nonewsk:
1256 dst_release(dst);
1257out:
1258 tcp_listendrop(sk);
1259 return NULL;
1260}
1261
1262/* The socket must have it's spinlock held when we get
1263 * here, unless it is a TCP_LISTEN socket.
1264 *
1265 * We have a potential double-lock case here, so even when
1266 * doing backlog processing we use the BH locking scheme.
1267 * This is because we cannot sleep with the original spinlock
1268 * held.
1269 */
1270static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1271{
1272 struct ipv6_pinfo *np = inet6_sk(sk);
1273 struct tcp_sock *tp;
1274 struct sk_buff *opt_skb = NULL;
1275
1276 /* Imagine: socket is IPv6. IPv4 packet arrives,
1277 goes to IPv4 receive handler and backlogged.
1278 From backlog it always goes here. Kerboom...
1279 Fortunately, tcp_rcv_established and rcv_established
1280 handle them correctly, but it is not case with
1281 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1282 */
1283
1284 if (skb->protocol == htons(ETH_P_IP))
1285 return tcp_v4_do_rcv(sk, skb);
1286
1287 /*
1288 * socket locking is here for SMP purposes as backlog rcv
1289 * is currently called with bh processing disabled.
1290 */
1291
1292 /* Do Stevens' IPV6_PKTOPTIONS.
1293
1294 Yes, guys, it is the only place in our code, where we
1295 may make it not affecting IPv4.
1296 The rest of code is protocol independent,
1297 and I do not like idea to uglify IPv4.
1298
1299 Actually, all the idea behind IPV6_PKTOPTIONS
1300 looks not very well thought. For now we latch
1301 options, received in the last packet, enqueued
1302 by tcp. Feel free to propose better solution.
1303 --ANK (980728)
1304 */
1305 if (np->rxopt.all)
1306 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1307
1308 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1309 struct dst_entry *dst = sk->sk_rx_dst;
1310
1311 sock_rps_save_rxhash(sk, skb);
1312 sk_mark_napi_id(sk, skb);
1313 if (dst) {
1314 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1315 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1316 dst_release(dst);
1317 sk->sk_rx_dst = NULL;
1318 }
1319 }
1320
1321 tcp_rcv_established(sk, skb, tcp_hdr(skb));
1322 if (opt_skb)
1323 goto ipv6_pktoptions;
1324 return 0;
1325 }
1326
1327 if (tcp_checksum_complete(skb))
1328 goto csum_err;
1329
1330 if (sk->sk_state == TCP_LISTEN) {
1331 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1332
1333 if (!nsk)
1334 goto discard;
1335
1336 if (nsk != sk) {
1337 if (tcp_child_process(sk, nsk, skb))
1338 goto reset;
1339 if (opt_skb)
1340 __kfree_skb(opt_skb);
1341 return 0;
1342 }
1343 } else
1344 sock_rps_save_rxhash(sk, skb);
1345
1346 if (tcp_rcv_state_process(sk, skb))
1347 goto reset;
1348 if (opt_skb)
1349 goto ipv6_pktoptions;
1350 return 0;
1351
1352reset:
1353 tcp_v6_send_reset(sk, skb);
1354discard:
1355 if (opt_skb)
1356 __kfree_skb(opt_skb);
1357 kfree_skb(skb);
1358 return 0;
1359csum_err:
1360 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1361 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1362 goto discard;
1363
1364
1365ipv6_pktoptions:
1366 /* Do you ask, what is it?
1367
1368 1. skb was enqueued by tcp.
1369 2. skb is added to tail of read queue, rather than out of order.
1370 3. socket is not in passive state.
1371 4. Finally, it really contains options, which user wants to receive.
1372 */
1373 tp = tcp_sk(sk);
1374 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1375 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1376 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1377 np->mcast_oif = tcp_v6_iif(opt_skb);
1378 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1379 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1380 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1381 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1382 if (np->repflow)
1383 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1384 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1385 skb_set_owner_r(opt_skb, sk);
1386 tcp_v6_restore_cb(opt_skb);
1387 opt_skb = xchg(&np->pktoptions, opt_skb);
1388 } else {
1389 __kfree_skb(opt_skb);
1390 opt_skb = xchg(&np->pktoptions, NULL);
1391 }
1392 }
1393
1394 kfree_skb(opt_skb);
1395 return 0;
1396}
1397
1398static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1399 const struct tcphdr *th)
1400{
1401 /* This is tricky: we move IP6CB at its correct location into
1402 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1403 * _decode_session6() uses IP6CB().
1404 * barrier() makes sure compiler won't play aliasing games.
1405 */
1406 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1407 sizeof(struct inet6_skb_parm));
1408 barrier();
1409
1410 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1411 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1412 skb->len - th->doff*4);
1413 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1414 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1415 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1416 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1417 TCP_SKB_CB(skb)->sacked = 0;
1418 TCP_SKB_CB(skb)->has_rxtstamp =
1419 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1420}
1421
1422static int tcp_v6_rcv(struct sk_buff *skb)
1423{
1424 int sdif = inet6_sdif(skb);
1425 const struct tcphdr *th;
1426 const struct ipv6hdr *hdr;
1427 bool refcounted;
1428 struct sock *sk;
1429 int ret;
1430 struct net *net = dev_net(skb->dev);
1431
1432 if (skb->pkt_type != PACKET_HOST)
1433 goto discard_it;
1434
1435 /*
1436 * Count it even if it's bad.
1437 */
1438 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1439
1440 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1441 goto discard_it;
1442
1443 th = (const struct tcphdr *)skb->data;
1444
1445 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1446 goto bad_packet;
1447 if (!pskb_may_pull(skb, th->doff*4))
1448 goto discard_it;
1449
1450 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1451 goto csum_error;
1452
1453 th = (const struct tcphdr *)skb->data;
1454 hdr = ipv6_hdr(skb);
1455
1456lookup:
1457 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1458 th->source, th->dest, inet6_iif(skb), sdif,
1459 &refcounted);
1460 if (!sk)
1461 goto no_tcp_socket;
1462
1463process:
1464 if (sk->sk_state == TCP_TIME_WAIT)
1465 goto do_time_wait;
1466
1467 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1468 struct request_sock *req = inet_reqsk(sk);
1469 bool req_stolen = false;
1470 struct sock *nsk;
1471
1472 sk = req->rsk_listener;
1473 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1474 sk_drops_add(sk, skb);
1475 reqsk_put(req);
1476 goto discard_it;
1477 }
1478 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1479 inet_csk_reqsk_queue_drop_and_put(sk, req);
1480 goto lookup;
1481 }
1482 sock_hold(sk);
1483 refcounted = true;
1484 nsk = NULL;
1485 if (!tcp_filter(sk, skb)) {
1486 th = (const struct tcphdr *)skb->data;
1487 hdr = ipv6_hdr(skb);
1488 tcp_v6_fill_cb(skb, hdr, th);
1489 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1490 }
1491 if (!nsk) {
1492 reqsk_put(req);
1493 if (req_stolen) {
1494 /* Another cpu got exclusive access to req
1495 * and created a full blown socket.
1496 * Try to feed this packet to this socket
1497 * instead of discarding it.
1498 */
1499 tcp_v6_restore_cb(skb);
1500 sock_put(sk);
1501 goto lookup;
1502 }
1503 goto discard_and_relse;
1504 }
1505 if (nsk == sk) {
1506 reqsk_put(req);
1507 tcp_v6_restore_cb(skb);
1508 } else if (tcp_child_process(sk, nsk, skb)) {
1509 tcp_v6_send_reset(nsk, skb);
1510 goto discard_and_relse;
1511 } else {
1512 sock_put(sk);
1513 return 0;
1514 }
1515 }
1516 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1517 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1518 goto discard_and_relse;
1519 }
1520
1521 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1522 goto discard_and_relse;
1523
1524 if (tcp_v6_inbound_md5_hash(sk, skb))
1525 goto discard_and_relse;
1526
1527 if (tcp_filter(sk, skb))
1528 goto discard_and_relse;
1529 th = (const struct tcphdr *)skb->data;
1530 hdr = ipv6_hdr(skb);
1531 tcp_v6_fill_cb(skb, hdr, th);
1532
1533 skb->dev = NULL;
1534
1535 if (sk->sk_state == TCP_LISTEN) {
1536 ret = tcp_v6_do_rcv(sk, skb);
1537 goto put_and_return;
1538 }
1539
1540 sk_incoming_cpu_update(sk);
1541
1542 bh_lock_sock_nested(sk);
1543 tcp_segs_in(tcp_sk(sk), skb);
1544 ret = 0;
1545 if (!sock_owned_by_user(sk)) {
1546 ret = tcp_v6_do_rcv(sk, skb);
1547 } else if (tcp_add_backlog(sk, skb)) {
1548 goto discard_and_relse;
1549 }
1550 bh_unlock_sock(sk);
1551
1552put_and_return:
1553 if (refcounted)
1554 sock_put(sk);
1555 return ret ? -1 : 0;
1556
1557no_tcp_socket:
1558 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1559 goto discard_it;
1560
1561 tcp_v6_fill_cb(skb, hdr, th);
1562
1563 if (tcp_checksum_complete(skb)) {
1564csum_error:
1565 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1566bad_packet:
1567 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1568 } else {
1569 tcp_v6_send_reset(NULL, skb);
1570 }
1571
1572discard_it:
1573 kfree_skb(skb);
1574 return 0;
1575
1576discard_and_relse:
1577 sk_drops_add(sk, skb);
1578 if (refcounted)
1579 sock_put(sk);
1580 goto discard_it;
1581
1582do_time_wait:
1583 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1584 inet_twsk_put(inet_twsk(sk));
1585 goto discard_it;
1586 }
1587
1588 tcp_v6_fill_cb(skb, hdr, th);
1589
1590 if (tcp_checksum_complete(skb)) {
1591 inet_twsk_put(inet_twsk(sk));
1592 goto csum_error;
1593 }
1594
1595 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1596 case TCP_TW_SYN:
1597 {
1598 struct sock *sk2;
1599
1600 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1601 skb, __tcp_hdrlen(th),
1602 &ipv6_hdr(skb)->saddr, th->source,
1603 &ipv6_hdr(skb)->daddr,
1604 ntohs(th->dest), tcp_v6_iif(skb),
1605 sdif);
1606 if (sk2) {
1607 struct inet_timewait_sock *tw = inet_twsk(sk);
1608 inet_twsk_deschedule_put(tw);
1609 sk = sk2;
1610 tcp_v6_restore_cb(skb);
1611 refcounted = false;
1612 goto process;
1613 }
1614 }
1615 /* to ACK */
1616 /* fall through */
1617 case TCP_TW_ACK:
1618 tcp_v6_timewait_ack(sk, skb);
1619 break;
1620 case TCP_TW_RST:
1621 tcp_v6_send_reset(sk, skb);
1622 inet_twsk_deschedule_put(inet_twsk(sk));
1623 goto discard_it;
1624 case TCP_TW_SUCCESS:
1625 ;
1626 }
1627 goto discard_it;
1628}
1629
1630static void tcp_v6_early_demux(struct sk_buff *skb)
1631{
1632 const struct ipv6hdr *hdr;
1633 const struct tcphdr *th;
1634 struct sock *sk;
1635
1636 if (skb->pkt_type != PACKET_HOST)
1637 return;
1638
1639 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1640 return;
1641
1642 hdr = ipv6_hdr(skb);
1643 th = tcp_hdr(skb);
1644
1645 if (th->doff < sizeof(struct tcphdr) / 4)
1646 return;
1647
1648 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1649 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1650 &hdr->saddr, th->source,
1651 &hdr->daddr, ntohs(th->dest),
1652 inet6_iif(skb), inet6_sdif(skb));
1653 if (sk) {
1654 skb->sk = sk;
1655 skb->destructor = sock_edemux;
1656 if (sk_fullsock(sk)) {
1657 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1658
1659 if (dst)
1660 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1661 if (dst &&
1662 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1663 skb_dst_set_noref(skb, dst);
1664 }
1665 }
1666}
1667
1668static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1669 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1670 .twsk_unique = tcp_twsk_unique,
1671 .twsk_destructor = tcp_twsk_destructor,
1672};
1673
1674static const struct inet_connection_sock_af_ops ipv6_specific = {
1675 .queue_xmit = inet6_csk_xmit,
1676 .send_check = tcp_v6_send_check,
1677 .rebuild_header = inet6_sk_rebuild_header,
1678 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1679 .conn_request = tcp_v6_conn_request,
1680 .syn_recv_sock = tcp_v6_syn_recv_sock,
1681 .net_header_len = sizeof(struct ipv6hdr),
1682 .net_frag_header_len = sizeof(struct frag_hdr),
1683 .setsockopt = ipv6_setsockopt,
1684 .getsockopt = ipv6_getsockopt,
1685 .addr2sockaddr = inet6_csk_addr2sockaddr,
1686 .sockaddr_len = sizeof(struct sockaddr_in6),
1687#ifdef CONFIG_COMPAT
1688 .compat_setsockopt = compat_ipv6_setsockopt,
1689 .compat_getsockopt = compat_ipv6_getsockopt,
1690#endif
1691 .mtu_reduced = tcp_v6_mtu_reduced,
1692};
1693
1694#ifdef CONFIG_TCP_MD5SIG
1695static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1696 .md5_lookup = tcp_v6_md5_lookup,
1697 .calc_md5_hash = tcp_v6_md5_hash_skb,
1698 .md5_parse = tcp_v6_parse_md5_keys,
1699};
1700#endif
1701
1702/*
1703 * TCP over IPv4 via INET6 API
1704 */
1705static const struct inet_connection_sock_af_ops ipv6_mapped = {
1706 .queue_xmit = ip_queue_xmit,
1707 .send_check = tcp_v4_send_check,
1708 .rebuild_header = inet_sk_rebuild_header,
1709 .sk_rx_dst_set = inet_sk_rx_dst_set,
1710 .conn_request = tcp_v6_conn_request,
1711 .syn_recv_sock = tcp_v6_syn_recv_sock,
1712 .net_header_len = sizeof(struct iphdr),
1713 .setsockopt = ipv6_setsockopt,
1714 .getsockopt = ipv6_getsockopt,
1715 .addr2sockaddr = inet6_csk_addr2sockaddr,
1716 .sockaddr_len = sizeof(struct sockaddr_in6),
1717#ifdef CONFIG_COMPAT
1718 .compat_setsockopt = compat_ipv6_setsockopt,
1719 .compat_getsockopt = compat_ipv6_getsockopt,
1720#endif
1721 .mtu_reduced = tcp_v4_mtu_reduced,
1722};
1723
1724#ifdef CONFIG_TCP_MD5SIG
1725static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1726 .md5_lookup = tcp_v4_md5_lookup,
1727 .calc_md5_hash = tcp_v4_md5_hash_skb,
1728 .md5_parse = tcp_v6_parse_md5_keys,
1729};
1730#endif
1731
1732/* NOTE: A lot of things set to zero explicitly by call to
1733 * sk_alloc() so need not be done here.
1734 */
1735static int tcp_v6_init_sock(struct sock *sk)
1736{
1737 struct inet_connection_sock *icsk = inet_csk(sk);
1738
1739 tcp_init_sock(sk);
1740
1741 icsk->icsk_af_ops = &ipv6_specific;
1742
1743#ifdef CONFIG_TCP_MD5SIG
1744 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1745#endif
1746
1747 return 0;
1748}
1749
1750static void tcp_v6_destroy_sock(struct sock *sk)
1751{
1752 tcp_v4_destroy_sock(sk);
1753 inet6_destroy_sock(sk);
1754}
1755
1756#ifdef CONFIG_PROC_FS
1757/* Proc filesystem TCPv6 sock list dumping. */
1758static void get_openreq6(struct seq_file *seq,
1759 const struct request_sock *req, int i)
1760{
1761 long ttd = req->rsk_timer.expires - jiffies;
1762 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1763 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1764
1765 if (ttd < 0)
1766 ttd = 0;
1767
1768 seq_printf(seq,
1769 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1770 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1771 i,
1772 src->s6_addr32[0], src->s6_addr32[1],
1773 src->s6_addr32[2], src->s6_addr32[3],
1774 inet_rsk(req)->ir_num,
1775 dest->s6_addr32[0], dest->s6_addr32[1],
1776 dest->s6_addr32[2], dest->s6_addr32[3],
1777 ntohs(inet_rsk(req)->ir_rmt_port),
1778 TCP_SYN_RECV,
1779 0, 0, /* could print option size, but that is af dependent. */
1780 1, /* timers active (only the expire timer) */
1781 jiffies_to_clock_t(ttd),
1782 req->num_timeout,
1783 from_kuid_munged(seq_user_ns(seq),
1784 sock_i_uid(req->rsk_listener)),
1785 0, /* non standard timer */
1786 0, /* open_requests have no inode */
1787 0, req);
1788}
1789
1790static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1791{
1792 const struct in6_addr *dest, *src;
1793 __u16 destp, srcp;
1794 int timer_active;
1795 unsigned long timer_expires;
1796 const struct inet_sock *inet = inet_sk(sp);
1797 const struct tcp_sock *tp = tcp_sk(sp);
1798 const struct inet_connection_sock *icsk = inet_csk(sp);
1799 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1800 int rx_queue;
1801 int state;
1802
1803 dest = &sp->sk_v6_daddr;
1804 src = &sp->sk_v6_rcv_saddr;
1805 destp = ntohs(inet->inet_dport);
1806 srcp = ntohs(inet->inet_sport);
1807
1808 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1809 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1810 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1811 timer_active = 1;
1812 timer_expires = icsk->icsk_timeout;
1813 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1814 timer_active = 4;
1815 timer_expires = icsk->icsk_timeout;
1816 } else if (timer_pending(&sp->sk_timer)) {
1817 timer_active = 2;
1818 timer_expires = sp->sk_timer.expires;
1819 } else {
1820 timer_active = 0;
1821 timer_expires = jiffies;
1822 }
1823
1824 state = inet_sk_state_load(sp);
1825 if (state == TCP_LISTEN)
1826 rx_queue = sp->sk_ack_backlog;
1827 else
1828 /* Because we don't lock the socket,
1829 * we might find a transient negative value.
1830 */
1831 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1832
1833 seq_printf(seq,
1834 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1835 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1836 i,
1837 src->s6_addr32[0], src->s6_addr32[1],
1838 src->s6_addr32[2], src->s6_addr32[3], srcp,
1839 dest->s6_addr32[0], dest->s6_addr32[1],
1840 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1841 state,
1842 tp->write_seq - tp->snd_una,
1843 rx_queue,
1844 timer_active,
1845 jiffies_delta_to_clock_t(timer_expires - jiffies),
1846 icsk->icsk_retransmits,
1847 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1848 icsk->icsk_probes_out,
1849 sock_i_ino(sp),
1850 refcount_read(&sp->sk_refcnt), sp,
1851 jiffies_to_clock_t(icsk->icsk_rto),
1852 jiffies_to_clock_t(icsk->icsk_ack.ato),
1853 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1854 tp->snd_cwnd,
1855 state == TCP_LISTEN ?
1856 fastopenq->max_qlen :
1857 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1858 );
1859}
1860
1861static void get_timewait6_sock(struct seq_file *seq,
1862 struct inet_timewait_sock *tw, int i)
1863{
1864 long delta = tw->tw_timer.expires - jiffies;
1865 const struct in6_addr *dest, *src;
1866 __u16 destp, srcp;
1867
1868 dest = &tw->tw_v6_daddr;
1869 src = &tw->tw_v6_rcv_saddr;
1870 destp = ntohs(tw->tw_dport);
1871 srcp = ntohs(tw->tw_sport);
1872
1873 seq_printf(seq,
1874 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1875 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1876 i,
1877 src->s6_addr32[0], src->s6_addr32[1],
1878 src->s6_addr32[2], src->s6_addr32[3], srcp,
1879 dest->s6_addr32[0], dest->s6_addr32[1],
1880 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1881 tw->tw_substate, 0, 0,
1882 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1883 refcount_read(&tw->tw_refcnt), tw);
1884}
1885
1886static int tcp6_seq_show(struct seq_file *seq, void *v)
1887{
1888 struct tcp_iter_state *st;
1889 struct sock *sk = v;
1890
1891 if (v == SEQ_START_TOKEN) {
1892 seq_puts(seq,
1893 " sl "
1894 "local_address "
1895 "remote_address "
1896 "st tx_queue rx_queue tr tm->when retrnsmt"
1897 " uid timeout inode\n");
1898 goto out;
1899 }
1900 st = seq->private;
1901
1902 if (sk->sk_state == TCP_TIME_WAIT)
1903 get_timewait6_sock(seq, v, st->num);
1904 else if (sk->sk_state == TCP_NEW_SYN_RECV)
1905 get_openreq6(seq, v, st->num);
1906 else
1907 get_tcp6_sock(seq, v, st->num);
1908out:
1909 return 0;
1910}
1911
1912static const struct file_operations tcp6_afinfo_seq_fops = {
1913 .open = tcp_seq_open,
1914 .read = seq_read,
1915 .llseek = seq_lseek,
1916 .release = seq_release_net
1917};
1918
1919static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1920 .name = "tcp6",
1921 .family = AF_INET6,
1922 .seq_fops = &tcp6_afinfo_seq_fops,
1923 .seq_ops = {
1924 .show = tcp6_seq_show,
1925 },
1926};
1927
1928int __net_init tcp6_proc_init(struct net *net)
1929{
1930 return tcp_proc_register(net, &tcp6_seq_afinfo);
1931}
1932
1933void tcp6_proc_exit(struct net *net)
1934{
1935 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1936}
1937#endif
1938
1939struct proto tcpv6_prot = {
1940 .name = "TCPv6",
1941 .owner = THIS_MODULE,
1942 .close = tcp_close,
1943 .pre_connect = tcp_v6_pre_connect,
1944 .connect = tcp_v6_connect,
1945 .disconnect = tcp_disconnect,
1946 .accept = inet_csk_accept,
1947 .ioctl = tcp_ioctl,
1948 .init = tcp_v6_init_sock,
1949 .destroy = tcp_v6_destroy_sock,
1950 .shutdown = tcp_shutdown,
1951 .setsockopt = tcp_setsockopt,
1952 .getsockopt = tcp_getsockopt,
1953 .keepalive = tcp_set_keepalive,
1954 .recvmsg = tcp_recvmsg,
1955 .sendmsg = tcp_sendmsg,
1956 .sendpage = tcp_sendpage,
1957 .backlog_rcv = tcp_v6_do_rcv,
1958 .release_cb = tcp_release_cb,
1959 .hash = inet6_hash,
1960 .unhash = inet_unhash,
1961 .get_port = inet_csk_get_port,
1962 .enter_memory_pressure = tcp_enter_memory_pressure,
1963 .leave_memory_pressure = tcp_leave_memory_pressure,
1964 .stream_memory_free = tcp_stream_memory_free,
1965 .sockets_allocated = &tcp_sockets_allocated,
1966 .memory_allocated = &tcp_memory_allocated,
1967 .memory_pressure = &tcp_memory_pressure,
1968 .orphan_count = &tcp_orphan_count,
1969 .sysctl_mem = sysctl_tcp_mem,
1970 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
1971 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
1972 .max_header = MAX_TCP_HEADER,
1973 .obj_size = sizeof(struct tcp6_sock),
1974 .slab_flags = SLAB_TYPESAFE_BY_RCU,
1975 .twsk_prot = &tcp6_timewait_sock_ops,
1976 .rsk_prot = &tcp6_request_sock_ops,
1977 .h.hashinfo = &tcp_hashinfo,
1978 .no_autobind = true,
1979#ifdef CONFIG_COMPAT
1980 .compat_setsockopt = compat_tcp_setsockopt,
1981 .compat_getsockopt = compat_tcp_getsockopt,
1982#endif
1983 .diag_destroy = tcp_abort,
1984};
1985
1986/* thinking of making this const? Don't.
1987 * early_demux can change based on sysctl.
1988 */
1989static struct inet6_protocol tcpv6_protocol = {
1990 .early_demux = tcp_v6_early_demux,
1991 .early_demux_handler = tcp_v6_early_demux,
1992 .handler = tcp_v6_rcv,
1993 .err_handler = tcp_v6_err,
1994 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1995};
1996
1997static struct inet_protosw tcpv6_protosw = {
1998 .type = SOCK_STREAM,
1999 .protocol = IPPROTO_TCP,
2000 .prot = &tcpv6_prot,
2001 .ops = &inet6_stream_ops,
2002 .flags = INET_PROTOSW_PERMANENT |
2003 INET_PROTOSW_ICSK,
2004};
2005
2006static int __net_init tcpv6_net_init(struct net *net)
2007{
2008 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2009 SOCK_RAW, IPPROTO_TCP, net);
2010}
2011
2012static void __net_exit tcpv6_net_exit(struct net *net)
2013{
2014 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2015}
2016
2017static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2018{
2019 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2020}
2021
2022static struct pernet_operations tcpv6_net_ops = {
2023 .init = tcpv6_net_init,
2024 .exit = tcpv6_net_exit,
2025 .exit_batch = tcpv6_net_exit_batch,
2026};
2027
2028int __init tcpv6_init(void)
2029{
2030 int ret;
2031
2032 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2033 if (ret)
2034 goto out;
2035
2036 /* register inet6 protocol */
2037 ret = inet6_register_protosw(&tcpv6_protosw);
2038 if (ret)
2039 goto out_tcpv6_protocol;
2040
2041 ret = register_pernet_subsys(&tcpv6_net_ops);
2042 if (ret)
2043 goto out_tcpv6_protosw;
2044out:
2045 return ret;
2046
2047out_tcpv6_protosw:
2048 inet6_unregister_protosw(&tcpv6_protosw);
2049out_tcpv6_protocol:
2050 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2051 goto out;
2052}
2053
2054void tcpv6_exit(void)
2055{
2056 unregister_pernet_subsys(&tcpv6_net_ops);
2057 inet6_unregister_protosw(&tcpv6_protosw);
2058 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2059}