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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/netdma.h>
63#include <net/inet_common.h>
64#include <net/secure_seq.h>
65#include <net/tcp_memcontrol.h>
66#include <net/busy_poll.h>
67
68#include <linux/proc_fs.h>
69#include <linux/seq_file.h>
70
71#include <linux/crypto.h>
72#include <linux/scatterlist.h>
73
74static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
75static void tcp_v6_reqsk_send_ack(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(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 const struct rt6_info *rt = (const struct rt6_info *)dst;
97
98 dst_hold(dst);
99 sk->sk_rx_dst = dst;
100 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
101 if (rt->rt6i_node)
102 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
103}
104
105static void tcp_v6_hash(struct sock *sk)
106{
107 if (sk->sk_state != TCP_CLOSE) {
108 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
109 tcp_prot.hash(sk);
110 return;
111 }
112 local_bh_disable();
113 __inet6_hash(sk, NULL);
114 local_bh_enable();
115 }
116}
117
118static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
119{
120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
121 ipv6_hdr(skb)->saddr.s6_addr32,
122 tcp_hdr(skb)->dest,
123 tcp_hdr(skb)->source);
124}
125
126static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128{
129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
130 struct inet_sock *inet = inet_sk(sk);
131 struct inet_connection_sock *icsk = inet_csk(sk);
132 struct ipv6_pinfo *np = inet6_sk(sk);
133 struct tcp_sock *tp = tcp_sk(sk);
134 struct in6_addr *saddr = NULL, *final_p, final;
135 struct rt6_info *rt;
136 struct flowi6 fl6;
137 struct dst_entry *dst;
138 int addr_type;
139 int err;
140
141 if (addr_len < SIN6_LEN_RFC2133)
142 return -EINVAL;
143
144 if (usin->sin6_family != AF_INET6)
145 return -EAFNOSUPPORT;
146
147 memset(&fl6, 0, sizeof(fl6));
148
149 if (np->sndflow) {
150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
151 IP6_ECN_flow_init(fl6.flowlabel);
152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
153 struct ip6_flowlabel *flowlabel;
154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
155 if (flowlabel == NULL)
156 return -EINVAL;
157 fl6_sock_release(flowlabel);
158 }
159 }
160
161 /*
162 * connect() to INADDR_ANY means loopback (BSD'ism).
163 */
164
165 if (ipv6_addr_any(&usin->sin6_addr))
166 usin->sin6_addr.s6_addr[15] = 0x1;
167
168 addr_type = ipv6_addr_type(&usin->sin6_addr);
169
170 if (addr_type & IPV6_ADDR_MULTICAST)
171 return -ENETUNREACH;
172
173 if (addr_type&IPV6_ADDR_LINKLOCAL) {
174 if (addr_len >= sizeof(struct sockaddr_in6) &&
175 usin->sin6_scope_id) {
176 /* If interface is set while binding, indices
177 * must coincide.
178 */
179 if (sk->sk_bound_dev_if &&
180 sk->sk_bound_dev_if != usin->sin6_scope_id)
181 return -EINVAL;
182
183 sk->sk_bound_dev_if = usin->sin6_scope_id;
184 }
185
186 /* Connect to link-local address requires an interface */
187 if (!sk->sk_bound_dev_if)
188 return -EINVAL;
189 }
190
191 if (tp->rx_opt.ts_recent_stamp &&
192 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
193 tp->rx_opt.ts_recent = 0;
194 tp->rx_opt.ts_recent_stamp = 0;
195 tp->write_seq = 0;
196 }
197
198 sk->sk_v6_daddr = usin->sin6_addr;
199 np->flow_label = fl6.flowlabel;
200
201 /*
202 * TCP over IPv4
203 */
204
205 if (addr_type == IPV6_ADDR_MAPPED) {
206 u32 exthdrlen = icsk->icsk_ext_hdr_len;
207 struct sockaddr_in sin;
208
209 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
210
211 if (__ipv6_only_sock(sk))
212 return -ENETUNREACH;
213
214 sin.sin_family = AF_INET;
215 sin.sin_port = usin->sin6_port;
216 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
217
218 icsk->icsk_af_ops = &ipv6_mapped;
219 sk->sk_backlog_rcv = tcp_v4_do_rcv;
220#ifdef CONFIG_TCP_MD5SIG
221 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
222#endif
223
224 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
225
226 if (err) {
227 icsk->icsk_ext_hdr_len = exthdrlen;
228 icsk->icsk_af_ops = &ipv6_specific;
229 sk->sk_backlog_rcv = tcp_v6_do_rcv;
230#ifdef CONFIG_TCP_MD5SIG
231 tp->af_specific = &tcp_sock_ipv6_specific;
232#endif
233 goto failure;
234 } else {
235 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
236 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
237 &sk->sk_v6_rcv_saddr);
238 }
239
240 return err;
241 }
242
243 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
244 saddr = &sk->sk_v6_rcv_saddr;
245
246 fl6.flowi6_proto = IPPROTO_TCP;
247 fl6.daddr = sk->sk_v6_daddr;
248 fl6.saddr = saddr ? *saddr : np->saddr;
249 fl6.flowi6_oif = sk->sk_bound_dev_if;
250 fl6.flowi6_mark = sk->sk_mark;
251 fl6.fl6_dport = usin->sin6_port;
252 fl6.fl6_sport = inet->inet_sport;
253
254 final_p = fl6_update_dst(&fl6, np->opt, &final);
255
256 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
257
258 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
259 if (IS_ERR(dst)) {
260 err = PTR_ERR(dst);
261 goto failure;
262 }
263
264 if (saddr == NULL) {
265 saddr = &fl6.saddr;
266 sk->sk_v6_rcv_saddr = *saddr;
267 }
268
269 /* set the source address */
270 np->saddr = *saddr;
271 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
272
273 sk->sk_gso_type = SKB_GSO_TCPV6;
274 __ip6_dst_store(sk, dst, NULL, NULL);
275
276 rt = (struct rt6_info *) dst;
277 if (tcp_death_row.sysctl_tw_recycle &&
278 !tp->rx_opt.ts_recent_stamp &&
279 ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
280 tcp_fetch_timewait_stamp(sk, dst);
281
282 icsk->icsk_ext_hdr_len = 0;
283 if (np->opt)
284 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
285 np->opt->opt_nflen);
286
287 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
288
289 inet->inet_dport = usin->sin6_port;
290
291 tcp_set_state(sk, TCP_SYN_SENT);
292 err = inet6_hash_connect(&tcp_death_row, sk);
293 if (err)
294 goto late_failure;
295
296 if (!tp->write_seq && likely(!tp->repair))
297 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
298 sk->sk_v6_daddr.s6_addr32,
299 inet->inet_sport,
300 inet->inet_dport);
301
302 err = tcp_connect(sk);
303 if (err)
304 goto late_failure;
305
306 return 0;
307
308late_failure:
309 tcp_set_state(sk, TCP_CLOSE);
310 __sk_dst_reset(sk);
311failure:
312 inet->inet_dport = 0;
313 sk->sk_route_caps = 0;
314 return err;
315}
316
317static void tcp_v6_mtu_reduced(struct sock *sk)
318{
319 struct dst_entry *dst;
320
321 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
322 return;
323
324 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
325 if (!dst)
326 return;
327
328 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
329 tcp_sync_mss(sk, dst_mtu(dst));
330 tcp_simple_retransmit(sk);
331 }
332}
333
334static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
335 u8 type, u8 code, int offset, __be32 info)
336{
337 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
338 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
339 struct ipv6_pinfo *np;
340 struct sock *sk;
341 int err;
342 struct tcp_sock *tp;
343 __u32 seq;
344 struct net *net = dev_net(skb->dev);
345
346 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
347 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
348
349 if (sk == NULL) {
350 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
351 ICMP6_MIB_INERRORS);
352 return;
353 }
354
355 if (sk->sk_state == TCP_TIME_WAIT) {
356 inet_twsk_put(inet_twsk(sk));
357 return;
358 }
359
360 bh_lock_sock(sk);
361 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
362 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
363
364 if (sk->sk_state == TCP_CLOSE)
365 goto out;
366
367 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
368 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
369 goto out;
370 }
371
372 tp = tcp_sk(sk);
373 seq = ntohl(th->seq);
374 if (sk->sk_state != TCP_LISTEN &&
375 !between(seq, tp->snd_una, tp->snd_nxt)) {
376 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
377 goto out;
378 }
379
380 np = inet6_sk(sk);
381
382 if (type == NDISC_REDIRECT) {
383 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
384
385 if (dst)
386 dst->ops->redirect(dst, sk, skb);
387 goto out;
388 }
389
390 if (type == ICMPV6_PKT_TOOBIG) {
391 /* We are not interested in TCP_LISTEN and open_requests
392 * (SYN-ACKs send out by Linux are always <576bytes so
393 * they should go through unfragmented).
394 */
395 if (sk->sk_state == TCP_LISTEN)
396 goto out;
397
398 if (!ip6_sk_accept_pmtu(sk))
399 goto out;
400
401 tp->mtu_info = ntohl(info);
402 if (!sock_owned_by_user(sk))
403 tcp_v6_mtu_reduced(sk);
404 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
405 &tp->tsq_flags))
406 sock_hold(sk);
407 goto out;
408 }
409
410 icmpv6_err_convert(type, code, &err);
411
412 /* Might be for an request_sock */
413 switch (sk->sk_state) {
414 struct request_sock *req, **prev;
415 case TCP_LISTEN:
416 if (sock_owned_by_user(sk))
417 goto out;
418
419 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
420 &hdr->saddr, inet6_iif(skb));
421 if (!req)
422 goto out;
423
424 /* ICMPs are not backlogged, hence we cannot get
425 * an established socket here.
426 */
427 WARN_ON(req->sk != NULL);
428
429 if (seq != tcp_rsk(req)->snt_isn) {
430 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
431 goto out;
432 }
433
434 inet_csk_reqsk_queue_drop(sk, req, prev);
435 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
436 goto out;
437
438 case TCP_SYN_SENT:
439 case TCP_SYN_RECV: /* Cannot happen.
440 It can, it SYNs are crossed. --ANK */
441 if (!sock_owned_by_user(sk)) {
442 sk->sk_err = err;
443 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
444
445 tcp_done(sk);
446 } else
447 sk->sk_err_soft = err;
448 goto out;
449 }
450
451 if (!sock_owned_by_user(sk) && np->recverr) {
452 sk->sk_err = err;
453 sk->sk_error_report(sk);
454 } else
455 sk->sk_err_soft = err;
456
457out:
458 bh_unlock_sock(sk);
459 sock_put(sk);
460}
461
462
463static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
464 struct flowi6 *fl6,
465 struct request_sock *req,
466 u16 queue_mapping)
467{
468 struct inet_request_sock *ireq = inet_rsk(req);
469 struct ipv6_pinfo *np = inet6_sk(sk);
470 struct sk_buff *skb;
471 int err = -ENOMEM;
472
473 /* First, grab a route. */
474 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
475 goto done;
476
477 skb = tcp_make_synack(sk, dst, req, NULL);
478
479 if (skb) {
480 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
481 &ireq->ir_v6_rmt_addr);
482
483 fl6->daddr = ireq->ir_v6_rmt_addr;
484 if (np->repflow && (ireq->pktopts != NULL))
485 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
486
487 skb_set_queue_mapping(skb, queue_mapping);
488 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
489 err = net_xmit_eval(err);
490 }
491
492done:
493 return err;
494}
495
496static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
497{
498 struct flowi6 fl6;
499 int res;
500
501 res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
502 if (!res) {
503 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
504 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);
505 }
506 return res;
507}
508
509static void tcp_v6_reqsk_destructor(struct request_sock *req)
510{
511 kfree_skb(inet_rsk(req)->pktopts);
512}
513
514#ifdef CONFIG_TCP_MD5SIG
515static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
516 const struct in6_addr *addr)
517{
518 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
519}
520
521static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
522 struct sock *addr_sk)
523{
524 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
525}
526
527static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
528 struct request_sock *req)
529{
530 return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
531}
532
533static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
534 int optlen)
535{
536 struct tcp_md5sig cmd;
537 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
538
539 if (optlen < sizeof(cmd))
540 return -EINVAL;
541
542 if (copy_from_user(&cmd, optval, sizeof(cmd)))
543 return -EFAULT;
544
545 if (sin6->sin6_family != AF_INET6)
546 return -EINVAL;
547
548 if (!cmd.tcpm_keylen) {
549 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
550 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
551 AF_INET);
552 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
553 AF_INET6);
554 }
555
556 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
557 return -EINVAL;
558
559 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
560 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
561 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
562
563 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
564 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
565}
566
567static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
568 const struct in6_addr *daddr,
569 const struct in6_addr *saddr, int nbytes)
570{
571 struct tcp6_pseudohdr *bp;
572 struct scatterlist sg;
573
574 bp = &hp->md5_blk.ip6;
575 /* 1. TCP pseudo-header (RFC2460) */
576 bp->saddr = *saddr;
577 bp->daddr = *daddr;
578 bp->protocol = cpu_to_be32(IPPROTO_TCP);
579 bp->len = cpu_to_be32(nbytes);
580
581 sg_init_one(&sg, bp, sizeof(*bp));
582 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
583}
584
585static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
586 const struct in6_addr *daddr, struct in6_addr *saddr,
587 const struct tcphdr *th)
588{
589 struct tcp_md5sig_pool *hp;
590 struct hash_desc *desc;
591
592 hp = tcp_get_md5sig_pool();
593 if (!hp)
594 goto clear_hash_noput;
595 desc = &hp->md5_desc;
596
597 if (crypto_hash_init(desc))
598 goto clear_hash;
599 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
600 goto clear_hash;
601 if (tcp_md5_hash_header(hp, th))
602 goto clear_hash;
603 if (tcp_md5_hash_key(hp, key))
604 goto clear_hash;
605 if (crypto_hash_final(desc, md5_hash))
606 goto clear_hash;
607
608 tcp_put_md5sig_pool();
609 return 0;
610
611clear_hash:
612 tcp_put_md5sig_pool();
613clear_hash_noput:
614 memset(md5_hash, 0, 16);
615 return 1;
616}
617
618static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
619 const struct sock *sk,
620 const struct request_sock *req,
621 const struct sk_buff *skb)
622{
623 const struct in6_addr *saddr, *daddr;
624 struct tcp_md5sig_pool *hp;
625 struct hash_desc *desc;
626 const struct tcphdr *th = tcp_hdr(skb);
627
628 if (sk) {
629 saddr = &inet6_sk(sk)->saddr;
630 daddr = &sk->sk_v6_daddr;
631 } else if (req) {
632 saddr = &inet_rsk(req)->ir_v6_loc_addr;
633 daddr = &inet_rsk(req)->ir_v6_rmt_addr;
634 } else {
635 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
636 saddr = &ip6h->saddr;
637 daddr = &ip6h->daddr;
638 }
639
640 hp = tcp_get_md5sig_pool();
641 if (!hp)
642 goto clear_hash_noput;
643 desc = &hp->md5_desc;
644
645 if (crypto_hash_init(desc))
646 goto clear_hash;
647
648 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
649 goto clear_hash;
650 if (tcp_md5_hash_header(hp, th))
651 goto clear_hash;
652 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
653 goto clear_hash;
654 if (tcp_md5_hash_key(hp, key))
655 goto clear_hash;
656 if (crypto_hash_final(desc, md5_hash))
657 goto clear_hash;
658
659 tcp_put_md5sig_pool();
660 return 0;
661
662clear_hash:
663 tcp_put_md5sig_pool();
664clear_hash_noput:
665 memset(md5_hash, 0, 16);
666 return 1;
667}
668
669static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
670{
671 const __u8 *hash_location = NULL;
672 struct tcp_md5sig_key *hash_expected;
673 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
674 const struct tcphdr *th = tcp_hdr(skb);
675 int genhash;
676 u8 newhash[16];
677
678 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
679 hash_location = tcp_parse_md5sig_option(th);
680
681 /* We've parsed the options - do we have a hash? */
682 if (!hash_expected && !hash_location)
683 return 0;
684
685 if (hash_expected && !hash_location) {
686 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
687 return 1;
688 }
689
690 if (!hash_expected && hash_location) {
691 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
692 return 1;
693 }
694
695 /* check the signature */
696 genhash = tcp_v6_md5_hash_skb(newhash,
697 hash_expected,
698 NULL, NULL, skb);
699
700 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
701 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
702 genhash ? "failed" : "mismatch",
703 &ip6h->saddr, ntohs(th->source),
704 &ip6h->daddr, ntohs(th->dest));
705 return 1;
706 }
707 return 0;
708}
709#endif
710
711struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
712 .family = AF_INET6,
713 .obj_size = sizeof(struct tcp6_request_sock),
714 .rtx_syn_ack = tcp_v6_rtx_synack,
715 .send_ack = tcp_v6_reqsk_send_ack,
716 .destructor = tcp_v6_reqsk_destructor,
717 .send_reset = tcp_v6_send_reset,
718 .syn_ack_timeout = tcp_syn_ack_timeout,
719};
720
721#ifdef CONFIG_TCP_MD5SIG
722static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
723 .md5_lookup = tcp_v6_reqsk_md5_lookup,
724 .calc_md5_hash = tcp_v6_md5_hash_skb,
725};
726#endif
727
728static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
729 u32 tsval, u32 tsecr, int oif,
730 struct tcp_md5sig_key *key, int rst, u8 tclass,
731 u32 label)
732{
733 const struct tcphdr *th = tcp_hdr(skb);
734 struct tcphdr *t1;
735 struct sk_buff *buff;
736 struct flowi6 fl6;
737 struct net *net = dev_net(skb_dst(skb)->dev);
738 struct sock *ctl_sk = net->ipv6.tcp_sk;
739 unsigned int tot_len = sizeof(struct tcphdr);
740 struct dst_entry *dst;
741 __be32 *topt;
742
743 if (tsecr)
744 tot_len += TCPOLEN_TSTAMP_ALIGNED;
745#ifdef CONFIG_TCP_MD5SIG
746 if (key)
747 tot_len += TCPOLEN_MD5SIG_ALIGNED;
748#endif
749
750 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
751 GFP_ATOMIC);
752 if (buff == NULL)
753 return;
754
755 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
756
757 t1 = (struct tcphdr *) skb_push(buff, tot_len);
758 skb_reset_transport_header(buff);
759
760 /* Swap the send and the receive. */
761 memset(t1, 0, sizeof(*t1));
762 t1->dest = th->source;
763 t1->source = th->dest;
764 t1->doff = tot_len / 4;
765 t1->seq = htonl(seq);
766 t1->ack_seq = htonl(ack);
767 t1->ack = !rst || !th->ack;
768 t1->rst = rst;
769 t1->window = htons(win);
770
771 topt = (__be32 *)(t1 + 1);
772
773 if (tsecr) {
774 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
775 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
776 *topt++ = htonl(tsval);
777 *topt++ = htonl(tsecr);
778 }
779
780#ifdef CONFIG_TCP_MD5SIG
781 if (key) {
782 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
783 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
784 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
785 &ipv6_hdr(skb)->saddr,
786 &ipv6_hdr(skb)->daddr, t1);
787 }
788#endif
789
790 memset(&fl6, 0, sizeof(fl6));
791 fl6.daddr = ipv6_hdr(skb)->saddr;
792 fl6.saddr = ipv6_hdr(skb)->daddr;
793 fl6.flowlabel = label;
794
795 buff->ip_summed = CHECKSUM_PARTIAL;
796 buff->csum = 0;
797
798 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
799
800 fl6.flowi6_proto = IPPROTO_TCP;
801 if (rt6_need_strict(&fl6.daddr) && !oif)
802 fl6.flowi6_oif = inet6_iif(skb);
803 else
804 fl6.flowi6_oif = oif;
805 fl6.fl6_dport = t1->dest;
806 fl6.fl6_sport = t1->source;
807 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
808
809 /* Pass a socket to ip6_dst_lookup either it is for RST
810 * Underlying function will use this to retrieve the network
811 * namespace
812 */
813 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
814 if (!IS_ERR(dst)) {
815 skb_dst_set(buff, dst);
816 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
817 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
818 if (rst)
819 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
820 return;
821 }
822
823 kfree_skb(buff);
824}
825
826static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
827{
828 const struct tcphdr *th = tcp_hdr(skb);
829 u32 seq = 0, ack_seq = 0;
830 struct tcp_md5sig_key *key = NULL;
831#ifdef CONFIG_TCP_MD5SIG
832 const __u8 *hash_location = NULL;
833 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
834 unsigned char newhash[16];
835 int genhash;
836 struct sock *sk1 = NULL;
837#endif
838 int oif;
839
840 if (th->rst)
841 return;
842
843 if (!ipv6_unicast_destination(skb))
844 return;
845
846#ifdef CONFIG_TCP_MD5SIG
847 hash_location = tcp_parse_md5sig_option(th);
848 if (!sk && hash_location) {
849 /*
850 * active side is lost. Try to find listening socket through
851 * source port, and then find md5 key through listening socket.
852 * we are not loose security here:
853 * Incoming packet is checked with md5 hash with finding key,
854 * no RST generated if md5 hash doesn't match.
855 */
856 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
857 &tcp_hashinfo, &ipv6h->saddr,
858 th->source, &ipv6h->daddr,
859 ntohs(th->source), inet6_iif(skb));
860 if (!sk1)
861 return;
862
863 rcu_read_lock();
864 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
865 if (!key)
866 goto release_sk1;
867
868 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
869 if (genhash || memcmp(hash_location, newhash, 16) != 0)
870 goto release_sk1;
871 } else {
872 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
873 }
874#endif
875
876 if (th->ack)
877 seq = ntohl(th->ack_seq);
878 else
879 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
880 (th->doff << 2);
881
882 oif = sk ? sk->sk_bound_dev_if : 0;
883 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
884
885#ifdef CONFIG_TCP_MD5SIG
886release_sk1:
887 if (sk1) {
888 rcu_read_unlock();
889 sock_put(sk1);
890 }
891#endif
892}
893
894static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
895 u32 win, u32 tsval, u32 tsecr, int oif,
896 struct tcp_md5sig_key *key, u8 tclass,
897 u32 label)
898{
899 tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, oif, key, 0, tclass,
900 label);
901}
902
903static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
904{
905 struct inet_timewait_sock *tw = inet_twsk(sk);
906 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
907
908 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
909 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
910 tcp_time_stamp + tcptw->tw_ts_offset,
911 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
912 tw->tw_tclass, (tw->tw_flowlabel << 12));
913
914 inet_twsk_put(tw);
915}
916
917static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
918 struct request_sock *req)
919{
920 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
921 req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
922 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
923 0, 0);
924}
925
926
927static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
928{
929 struct request_sock *req, **prev;
930 const struct tcphdr *th = tcp_hdr(skb);
931 struct sock *nsk;
932
933 /* Find possible connection requests. */
934 req = inet6_csk_search_req(sk, &prev, th->source,
935 &ipv6_hdr(skb)->saddr,
936 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
937 if (req)
938 return tcp_check_req(sk, skb, req, prev, false);
939
940 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
941 &ipv6_hdr(skb)->saddr, th->source,
942 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
943
944 if (nsk) {
945 if (nsk->sk_state != TCP_TIME_WAIT) {
946 bh_lock_sock(nsk);
947 return nsk;
948 }
949 inet_twsk_put(inet_twsk(nsk));
950 return NULL;
951 }
952
953#ifdef CONFIG_SYN_COOKIES
954 if (!th->syn)
955 sk = cookie_v6_check(sk, skb);
956#endif
957 return sk;
958}
959
960/* FIXME: this is substantially similar to the ipv4 code.
961 * Can some kind of merge be done? -- erics
962 */
963static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
964{
965 struct tcp_options_received tmp_opt;
966 struct request_sock *req;
967 struct inet_request_sock *ireq;
968 struct ipv6_pinfo *np = inet6_sk(sk);
969 struct tcp_sock *tp = tcp_sk(sk);
970 __u32 isn = TCP_SKB_CB(skb)->when;
971 struct dst_entry *dst = NULL;
972 struct flowi6 fl6;
973 bool want_cookie = false;
974
975 if (skb->protocol == htons(ETH_P_IP))
976 return tcp_v4_conn_request(sk, skb);
977
978 if (!ipv6_unicast_destination(skb))
979 goto drop;
980
981 if ((sysctl_tcp_syncookies == 2 ||
982 inet_csk_reqsk_queue_is_full(sk)) && !isn) {
983 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
984 if (!want_cookie)
985 goto drop;
986 }
987
988 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
989 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
990 goto drop;
991 }
992
993 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
994 if (req == NULL)
995 goto drop;
996
997#ifdef CONFIG_TCP_MD5SIG
998 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
999#endif
1000
1001 tcp_clear_options(&tmp_opt);
1002 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1003 tmp_opt.user_mss = tp->rx_opt.user_mss;
1004 tcp_parse_options(skb, &tmp_opt, 0, NULL);
1005
1006 if (want_cookie && !tmp_opt.saw_tstamp)
1007 tcp_clear_options(&tmp_opt);
1008
1009 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1010 tcp_openreq_init(req, &tmp_opt, skb);
1011
1012 ireq = inet_rsk(req);
1013 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
1014 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
1015 if (!want_cookie || tmp_opt.tstamp_ok)
1016 TCP_ECN_create_request(req, skb, sock_net(sk));
1017
1018 ireq->ir_iif = sk->sk_bound_dev_if;
1019
1020 /* So that link locals have meaning */
1021 if (!sk->sk_bound_dev_if &&
1022 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
1023 ireq->ir_iif = inet6_iif(skb);
1024
1025 if (!isn) {
1026 if (ipv6_opt_accepted(sk, skb) ||
1027 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1028 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim ||
1029 np->repflow) {
1030 atomic_inc(&skb->users);
1031 ireq->pktopts = skb;
1032 }
1033
1034 if (want_cookie) {
1035 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1036 req->cookie_ts = tmp_opt.tstamp_ok;
1037 goto have_isn;
1038 }
1039
1040 /* VJ's idea. We save last timestamp seen
1041 * from the destination in peer table, when entering
1042 * state TIME-WAIT, and check against it before
1043 * accepting new connection request.
1044 *
1045 * If "isn" is not zero, this request hit alive
1046 * timewait bucket, so that all the necessary checks
1047 * are made in the function processing timewait state.
1048 */
1049 if (tmp_opt.saw_tstamp &&
1050 tcp_death_row.sysctl_tw_recycle &&
1051 (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1052 if (!tcp_peer_is_proven(req, dst, true)) {
1053 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1054 goto drop_and_release;
1055 }
1056 }
1057 /* Kill the following clause, if you dislike this way. */
1058 else if (!sysctl_tcp_syncookies &&
1059 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1060 (sysctl_max_syn_backlog >> 2)) &&
1061 !tcp_peer_is_proven(req, dst, false)) {
1062 /* Without syncookies last quarter of
1063 * backlog is filled with destinations,
1064 * proven to be alive.
1065 * It means that we continue to communicate
1066 * to destinations, already remembered
1067 * to the moment of synflood.
1068 */
1069 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1070 &ireq->ir_v6_rmt_addr, ntohs(tcp_hdr(skb)->source));
1071 goto drop_and_release;
1072 }
1073
1074 isn = tcp_v6_init_sequence(skb);
1075 }
1076have_isn:
1077 tcp_rsk(req)->snt_isn = isn;
1078
1079 if (security_inet_conn_request(sk, skb, req))
1080 goto drop_and_release;
1081
1082 if (tcp_v6_send_synack(sk, dst, &fl6, req,
1083 skb_get_queue_mapping(skb)) ||
1084 want_cookie)
1085 goto drop_and_free;
1086
1087 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1088 tcp_rsk(req)->listener = NULL;
1089 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1090 return 0;
1091
1092drop_and_release:
1093 dst_release(dst);
1094drop_and_free:
1095 reqsk_free(req);
1096drop:
1097 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1098 return 0; /* don't send reset */
1099}
1100
1101static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1102 struct request_sock *req,
1103 struct dst_entry *dst)
1104{
1105 struct inet_request_sock *ireq;
1106 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1107 struct tcp6_sock *newtcp6sk;
1108 struct inet_sock *newinet;
1109 struct tcp_sock *newtp;
1110 struct sock *newsk;
1111#ifdef CONFIG_TCP_MD5SIG
1112 struct tcp_md5sig_key *key;
1113#endif
1114 struct flowi6 fl6;
1115
1116 if (skb->protocol == htons(ETH_P_IP)) {
1117 /*
1118 * v6 mapped
1119 */
1120
1121 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1122
1123 if (newsk == NULL)
1124 return NULL;
1125
1126 newtcp6sk = (struct tcp6_sock *)newsk;
1127 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1128
1129 newinet = inet_sk(newsk);
1130 newnp = inet6_sk(newsk);
1131 newtp = tcp_sk(newsk);
1132
1133 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1134
1135 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
1136
1137 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1138
1139 newsk->sk_v6_rcv_saddr = newnp->saddr;
1140
1141 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1142 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1143#ifdef CONFIG_TCP_MD5SIG
1144 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1145#endif
1146
1147 newnp->ipv6_ac_list = NULL;
1148 newnp->ipv6_fl_list = NULL;
1149 newnp->pktoptions = NULL;
1150 newnp->opt = NULL;
1151 newnp->mcast_oif = inet6_iif(skb);
1152 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1153 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1154 if (np->repflow)
1155 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1156
1157 /*
1158 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1159 * here, tcp_create_openreq_child now does this for us, see the comment in
1160 * that function for the gory details. -acme
1161 */
1162
1163 /* It is tricky place. Until this moment IPv4 tcp
1164 worked with IPv6 icsk.icsk_af_ops.
1165 Sync it now.
1166 */
1167 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1168
1169 return newsk;
1170 }
1171
1172 ireq = inet_rsk(req);
1173
1174 if (sk_acceptq_is_full(sk))
1175 goto out_overflow;
1176
1177 if (!dst) {
1178 dst = inet6_csk_route_req(sk, &fl6, req);
1179 if (!dst)
1180 goto out;
1181 }
1182
1183 newsk = tcp_create_openreq_child(sk, req, skb);
1184 if (newsk == NULL)
1185 goto out_nonewsk;
1186
1187 /*
1188 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1189 * count here, tcp_create_openreq_child now does this for us, see the
1190 * comment in that function for the gory details. -acme
1191 */
1192
1193 newsk->sk_gso_type = SKB_GSO_TCPV6;
1194 __ip6_dst_store(newsk, dst, NULL, NULL);
1195 inet6_sk_rx_dst_set(newsk, skb);
1196
1197 newtcp6sk = (struct tcp6_sock *)newsk;
1198 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1199
1200 newtp = tcp_sk(newsk);
1201 newinet = inet_sk(newsk);
1202 newnp = inet6_sk(newsk);
1203
1204 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1205
1206 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1207 newnp->saddr = ireq->ir_v6_loc_addr;
1208 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1209 newsk->sk_bound_dev_if = ireq->ir_iif;
1210
1211 /* Now IPv6 options...
1212
1213 First: no IPv4 options.
1214 */
1215 newinet->inet_opt = NULL;
1216 newnp->ipv6_ac_list = NULL;
1217 newnp->ipv6_fl_list = NULL;
1218
1219 /* Clone RX bits */
1220 newnp->rxopt.all = np->rxopt.all;
1221
1222 /* Clone pktoptions received with SYN */
1223 newnp->pktoptions = NULL;
1224 if (ireq->pktopts != NULL) {
1225 newnp->pktoptions = skb_clone(ireq->pktopts,
1226 sk_gfp_atomic(sk, GFP_ATOMIC));
1227 consume_skb(ireq->pktopts);
1228 ireq->pktopts = NULL;
1229 if (newnp->pktoptions)
1230 skb_set_owner_r(newnp->pktoptions, newsk);
1231 }
1232 newnp->opt = NULL;
1233 newnp->mcast_oif = inet6_iif(skb);
1234 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1235 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1236 if (np->repflow)
1237 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1238
1239 /* Clone native IPv6 options from listening socket (if any)
1240
1241 Yes, keeping reference count would be much more clever,
1242 but we make one more one thing there: reattach optmem
1243 to newsk.
1244 */
1245 if (np->opt)
1246 newnp->opt = ipv6_dup_options(newsk, np->opt);
1247
1248 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1249 if (newnp->opt)
1250 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1251 newnp->opt->opt_flen);
1252
1253 tcp_sync_mss(newsk, dst_mtu(dst));
1254 newtp->advmss = dst_metric_advmss(dst);
1255 if (tcp_sk(sk)->rx_opt.user_mss &&
1256 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1257 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1258
1259 tcp_initialize_rcv_mss(newsk);
1260
1261 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1262 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1263
1264#ifdef CONFIG_TCP_MD5SIG
1265 /* Copy over the MD5 key from the original socket */
1266 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1267 if (key != NULL) {
1268 /* We're using one, so create a matching key
1269 * on the newsk structure. If we fail to get
1270 * memory, then we end up not copying the key
1271 * across. Shucks.
1272 */
1273 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1274 AF_INET6, key->key, key->keylen,
1275 sk_gfp_atomic(sk, GFP_ATOMIC));
1276 }
1277#endif
1278
1279 if (__inet_inherit_port(sk, newsk) < 0) {
1280 inet_csk_prepare_forced_close(newsk);
1281 tcp_done(newsk);
1282 goto out;
1283 }
1284 __inet6_hash(newsk, NULL);
1285
1286 return newsk;
1287
1288out_overflow:
1289 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1290out_nonewsk:
1291 dst_release(dst);
1292out:
1293 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1294 return NULL;
1295}
1296
1297static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1298{
1299 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1300 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1301 &ipv6_hdr(skb)->daddr, skb->csum)) {
1302 skb->ip_summed = CHECKSUM_UNNECESSARY;
1303 return 0;
1304 }
1305 }
1306
1307 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1308 &ipv6_hdr(skb)->saddr,
1309 &ipv6_hdr(skb)->daddr, 0));
1310
1311 if (skb->len <= 76)
1312 return __skb_checksum_complete(skb);
1313 return 0;
1314}
1315
1316/* The socket must have it's spinlock held when we get
1317 * here.
1318 *
1319 * We have a potential double-lock case here, so even when
1320 * doing backlog processing we use the BH locking scheme.
1321 * This is because we cannot sleep with the original spinlock
1322 * held.
1323 */
1324static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1325{
1326 struct ipv6_pinfo *np = inet6_sk(sk);
1327 struct tcp_sock *tp;
1328 struct sk_buff *opt_skb = NULL;
1329
1330 /* Imagine: socket is IPv6. IPv4 packet arrives,
1331 goes to IPv4 receive handler and backlogged.
1332 From backlog it always goes here. Kerboom...
1333 Fortunately, tcp_rcv_established and rcv_established
1334 handle them correctly, but it is not case with
1335 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1336 */
1337
1338 if (skb->protocol == htons(ETH_P_IP))
1339 return tcp_v4_do_rcv(sk, skb);
1340
1341#ifdef CONFIG_TCP_MD5SIG
1342 if (tcp_v6_inbound_md5_hash(sk, skb))
1343 goto discard;
1344#endif
1345
1346 if (sk_filter(sk, skb))
1347 goto discard;
1348
1349 /*
1350 * socket locking is here for SMP purposes as backlog rcv
1351 * is currently called with bh processing disabled.
1352 */
1353
1354 /* Do Stevens' IPV6_PKTOPTIONS.
1355
1356 Yes, guys, it is the only place in our code, where we
1357 may make it not affecting IPv4.
1358 The rest of code is protocol independent,
1359 and I do not like idea to uglify IPv4.
1360
1361 Actually, all the idea behind IPV6_PKTOPTIONS
1362 looks not very well thought. For now we latch
1363 options, received in the last packet, enqueued
1364 by tcp. Feel free to propose better solution.
1365 --ANK (980728)
1366 */
1367 if (np->rxopt.all)
1368 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1369
1370 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1371 struct dst_entry *dst = sk->sk_rx_dst;
1372
1373 sock_rps_save_rxhash(sk, skb);
1374 if (dst) {
1375 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1376 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1377 dst_release(dst);
1378 sk->sk_rx_dst = NULL;
1379 }
1380 }
1381
1382 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1383 if (opt_skb)
1384 goto ipv6_pktoptions;
1385 return 0;
1386 }
1387
1388 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1389 goto csum_err;
1390
1391 if (sk->sk_state == TCP_LISTEN) {
1392 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1393 if (!nsk)
1394 goto discard;
1395
1396 /*
1397 * Queue it on the new socket if the new socket is active,
1398 * otherwise we just shortcircuit this and continue with
1399 * the new socket..
1400 */
1401 if (nsk != sk) {
1402 sock_rps_save_rxhash(nsk, skb);
1403 if (tcp_child_process(sk, nsk, skb))
1404 goto reset;
1405 if (opt_skb)
1406 __kfree_skb(opt_skb);
1407 return 0;
1408 }
1409 } else
1410 sock_rps_save_rxhash(sk, skb);
1411
1412 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1413 goto reset;
1414 if (opt_skb)
1415 goto ipv6_pktoptions;
1416 return 0;
1417
1418reset:
1419 tcp_v6_send_reset(sk, skb);
1420discard:
1421 if (opt_skb)
1422 __kfree_skb(opt_skb);
1423 kfree_skb(skb);
1424 return 0;
1425csum_err:
1426 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1427 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1428 goto discard;
1429
1430
1431ipv6_pktoptions:
1432 /* Do you ask, what is it?
1433
1434 1. skb was enqueued by tcp.
1435 2. skb is added to tail of read queue, rather than out of order.
1436 3. socket is not in passive state.
1437 4. Finally, it really contains options, which user wants to receive.
1438 */
1439 tp = tcp_sk(sk);
1440 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1441 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1442 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1443 np->mcast_oif = inet6_iif(opt_skb);
1444 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1445 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1446 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1447 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1448 if (np->repflow)
1449 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1450 if (ipv6_opt_accepted(sk, opt_skb)) {
1451 skb_set_owner_r(opt_skb, sk);
1452 opt_skb = xchg(&np->pktoptions, opt_skb);
1453 } else {
1454 __kfree_skb(opt_skb);
1455 opt_skb = xchg(&np->pktoptions, NULL);
1456 }
1457 }
1458
1459 kfree_skb(opt_skb);
1460 return 0;
1461}
1462
1463static int tcp_v6_rcv(struct sk_buff *skb)
1464{
1465 const struct tcphdr *th;
1466 const struct ipv6hdr *hdr;
1467 struct sock *sk;
1468 int ret;
1469 struct net *net = dev_net(skb->dev);
1470
1471 if (skb->pkt_type != PACKET_HOST)
1472 goto discard_it;
1473
1474 /*
1475 * Count it even if it's bad.
1476 */
1477 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1478
1479 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1480 goto discard_it;
1481
1482 th = tcp_hdr(skb);
1483
1484 if (th->doff < sizeof(struct tcphdr)/4)
1485 goto bad_packet;
1486 if (!pskb_may_pull(skb, th->doff*4))
1487 goto discard_it;
1488
1489 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1490 goto csum_error;
1491
1492 th = tcp_hdr(skb);
1493 hdr = ipv6_hdr(skb);
1494 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1495 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1496 skb->len - th->doff*4);
1497 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1498 TCP_SKB_CB(skb)->when = 0;
1499 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1500 TCP_SKB_CB(skb)->sacked = 0;
1501
1502 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1503 if (!sk)
1504 goto no_tcp_socket;
1505
1506process:
1507 if (sk->sk_state == TCP_TIME_WAIT)
1508 goto do_time_wait;
1509
1510 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1511 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1512 goto discard_and_relse;
1513 }
1514
1515 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1516 goto discard_and_relse;
1517
1518 if (sk_filter(sk, skb))
1519 goto discard_and_relse;
1520
1521 sk_mark_napi_id(sk, skb);
1522 skb->dev = NULL;
1523
1524 bh_lock_sock_nested(sk);
1525 ret = 0;
1526 if (!sock_owned_by_user(sk)) {
1527#ifdef CONFIG_NET_DMA
1528 struct tcp_sock *tp = tcp_sk(sk);
1529 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1530 tp->ucopy.dma_chan = net_dma_find_channel();
1531 if (tp->ucopy.dma_chan)
1532 ret = tcp_v6_do_rcv(sk, skb);
1533 else
1534#endif
1535 {
1536 if (!tcp_prequeue(sk, skb))
1537 ret = tcp_v6_do_rcv(sk, skb);
1538 }
1539 } else if (unlikely(sk_add_backlog(sk, skb,
1540 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1541 bh_unlock_sock(sk);
1542 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1543 goto discard_and_relse;
1544 }
1545 bh_unlock_sock(sk);
1546
1547 sock_put(sk);
1548 return ret ? -1 : 0;
1549
1550no_tcp_socket:
1551 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1552 goto discard_it;
1553
1554 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1555csum_error:
1556 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1557bad_packet:
1558 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1559 } else {
1560 tcp_v6_send_reset(NULL, skb);
1561 }
1562
1563discard_it:
1564 kfree_skb(skb);
1565 return 0;
1566
1567discard_and_relse:
1568 sock_put(sk);
1569 goto discard_it;
1570
1571do_time_wait:
1572 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1573 inet_twsk_put(inet_twsk(sk));
1574 goto discard_it;
1575 }
1576
1577 if (skb->len < (th->doff<<2)) {
1578 inet_twsk_put(inet_twsk(sk));
1579 goto bad_packet;
1580 }
1581 if (tcp_checksum_complete(skb)) {
1582 inet_twsk_put(inet_twsk(sk));
1583 goto csum_error;
1584 }
1585
1586 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1587 case TCP_TW_SYN:
1588 {
1589 struct sock *sk2;
1590
1591 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1592 &ipv6_hdr(skb)->saddr, th->source,
1593 &ipv6_hdr(skb)->daddr,
1594 ntohs(th->dest), inet6_iif(skb));
1595 if (sk2 != NULL) {
1596 struct inet_timewait_sock *tw = inet_twsk(sk);
1597 inet_twsk_deschedule(tw, &tcp_death_row);
1598 inet_twsk_put(tw);
1599 sk = sk2;
1600 goto process;
1601 }
1602 /* Fall through to ACK */
1603 }
1604 case TCP_TW_ACK:
1605 tcp_v6_timewait_ack(sk, skb);
1606 break;
1607 case TCP_TW_RST:
1608 goto no_tcp_socket;
1609 case TCP_TW_SUCCESS:
1610 ;
1611 }
1612 goto discard_it;
1613}
1614
1615static void tcp_v6_early_demux(struct sk_buff *skb)
1616{
1617 const struct ipv6hdr *hdr;
1618 const struct tcphdr *th;
1619 struct sock *sk;
1620
1621 if (skb->pkt_type != PACKET_HOST)
1622 return;
1623
1624 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1625 return;
1626
1627 hdr = ipv6_hdr(skb);
1628 th = tcp_hdr(skb);
1629
1630 if (th->doff < sizeof(struct tcphdr) / 4)
1631 return;
1632
1633 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1634 &hdr->saddr, th->source,
1635 &hdr->daddr, ntohs(th->dest),
1636 inet6_iif(skb));
1637 if (sk) {
1638 skb->sk = sk;
1639 skb->destructor = sock_edemux;
1640 if (sk->sk_state != TCP_TIME_WAIT) {
1641 struct dst_entry *dst = sk->sk_rx_dst;
1642
1643 if (dst)
1644 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1645 if (dst &&
1646 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1647 skb_dst_set_noref(skb, dst);
1648 }
1649 }
1650}
1651
1652static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1653 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1654 .twsk_unique = tcp_twsk_unique,
1655 .twsk_destructor = tcp_twsk_destructor,
1656};
1657
1658static const struct inet_connection_sock_af_ops ipv6_specific = {
1659 .queue_xmit = inet6_csk_xmit,
1660 .send_check = tcp_v6_send_check,
1661 .rebuild_header = inet6_sk_rebuild_header,
1662 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1663 .conn_request = tcp_v6_conn_request,
1664 .syn_recv_sock = tcp_v6_syn_recv_sock,
1665 .net_header_len = sizeof(struct ipv6hdr),
1666 .net_frag_header_len = sizeof(struct frag_hdr),
1667 .setsockopt = ipv6_setsockopt,
1668 .getsockopt = ipv6_getsockopt,
1669 .addr2sockaddr = inet6_csk_addr2sockaddr,
1670 .sockaddr_len = sizeof(struct sockaddr_in6),
1671 .bind_conflict = inet6_csk_bind_conflict,
1672#ifdef CONFIG_COMPAT
1673 .compat_setsockopt = compat_ipv6_setsockopt,
1674 .compat_getsockopt = compat_ipv6_getsockopt,
1675#endif
1676};
1677
1678#ifdef CONFIG_TCP_MD5SIG
1679static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1680 .md5_lookup = tcp_v6_md5_lookup,
1681 .calc_md5_hash = tcp_v6_md5_hash_skb,
1682 .md5_parse = tcp_v6_parse_md5_keys,
1683};
1684#endif
1685
1686/*
1687 * TCP over IPv4 via INET6 API
1688 */
1689static const struct inet_connection_sock_af_ops ipv6_mapped = {
1690 .queue_xmit = ip_queue_xmit,
1691 .send_check = tcp_v4_send_check,
1692 .rebuild_header = inet_sk_rebuild_header,
1693 .sk_rx_dst_set = inet_sk_rx_dst_set,
1694 .conn_request = tcp_v6_conn_request,
1695 .syn_recv_sock = tcp_v6_syn_recv_sock,
1696 .net_header_len = sizeof(struct iphdr),
1697 .setsockopt = ipv6_setsockopt,
1698 .getsockopt = ipv6_getsockopt,
1699 .addr2sockaddr = inet6_csk_addr2sockaddr,
1700 .sockaddr_len = sizeof(struct sockaddr_in6),
1701 .bind_conflict = inet6_csk_bind_conflict,
1702#ifdef CONFIG_COMPAT
1703 .compat_setsockopt = compat_ipv6_setsockopt,
1704 .compat_getsockopt = compat_ipv6_getsockopt,
1705#endif
1706};
1707
1708#ifdef CONFIG_TCP_MD5SIG
1709static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1710 .md5_lookup = tcp_v4_md5_lookup,
1711 .calc_md5_hash = tcp_v4_md5_hash_skb,
1712 .md5_parse = tcp_v6_parse_md5_keys,
1713};
1714#endif
1715
1716/* NOTE: A lot of things set to zero explicitly by call to
1717 * sk_alloc() so need not be done here.
1718 */
1719static int tcp_v6_init_sock(struct sock *sk)
1720{
1721 struct inet_connection_sock *icsk = inet_csk(sk);
1722
1723 tcp_init_sock(sk);
1724
1725 icsk->icsk_af_ops = &ipv6_specific;
1726
1727#ifdef CONFIG_TCP_MD5SIG
1728 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1729#endif
1730
1731 return 0;
1732}
1733
1734static void tcp_v6_destroy_sock(struct sock *sk)
1735{
1736 tcp_v4_destroy_sock(sk);
1737 inet6_destroy_sock(sk);
1738}
1739
1740#ifdef CONFIG_PROC_FS
1741/* Proc filesystem TCPv6 sock list dumping. */
1742static void get_openreq6(struct seq_file *seq,
1743 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1744{
1745 int ttd = req->expires - jiffies;
1746 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1747 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1748
1749 if (ttd < 0)
1750 ttd = 0;
1751
1752 seq_printf(seq,
1753 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1754 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1755 i,
1756 src->s6_addr32[0], src->s6_addr32[1],
1757 src->s6_addr32[2], src->s6_addr32[3],
1758 inet_rsk(req)->ir_num,
1759 dest->s6_addr32[0], dest->s6_addr32[1],
1760 dest->s6_addr32[2], dest->s6_addr32[3],
1761 ntohs(inet_rsk(req)->ir_rmt_port),
1762 TCP_SYN_RECV,
1763 0, 0, /* could print option size, but that is af dependent. */
1764 1, /* timers active (only the expire timer) */
1765 jiffies_to_clock_t(ttd),
1766 req->num_timeout,
1767 from_kuid_munged(seq_user_ns(seq), uid),
1768 0, /* non standard timer */
1769 0, /* open_requests have no inode */
1770 0, req);
1771}
1772
1773static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1774{
1775 const struct in6_addr *dest, *src;
1776 __u16 destp, srcp;
1777 int timer_active;
1778 unsigned long timer_expires;
1779 const struct inet_sock *inet = inet_sk(sp);
1780 const struct tcp_sock *tp = tcp_sk(sp);
1781 const struct inet_connection_sock *icsk = inet_csk(sp);
1782
1783 dest = &sp->sk_v6_daddr;
1784 src = &sp->sk_v6_rcv_saddr;
1785 destp = ntohs(inet->inet_dport);
1786 srcp = ntohs(inet->inet_sport);
1787
1788 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1789 timer_active = 1;
1790 timer_expires = icsk->icsk_timeout;
1791 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1792 timer_active = 4;
1793 timer_expires = icsk->icsk_timeout;
1794 } else if (timer_pending(&sp->sk_timer)) {
1795 timer_active = 2;
1796 timer_expires = sp->sk_timer.expires;
1797 } else {
1798 timer_active = 0;
1799 timer_expires = jiffies;
1800 }
1801
1802 seq_printf(seq,
1803 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1804 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1805 i,
1806 src->s6_addr32[0], src->s6_addr32[1],
1807 src->s6_addr32[2], src->s6_addr32[3], srcp,
1808 dest->s6_addr32[0], dest->s6_addr32[1],
1809 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1810 sp->sk_state,
1811 tp->write_seq-tp->snd_una,
1812 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1813 timer_active,
1814 jiffies_delta_to_clock_t(timer_expires - jiffies),
1815 icsk->icsk_retransmits,
1816 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1817 icsk->icsk_probes_out,
1818 sock_i_ino(sp),
1819 atomic_read(&sp->sk_refcnt), sp,
1820 jiffies_to_clock_t(icsk->icsk_rto),
1821 jiffies_to_clock_t(icsk->icsk_ack.ato),
1822 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1823 tp->snd_cwnd,
1824 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1825 );
1826}
1827
1828static void get_timewait6_sock(struct seq_file *seq,
1829 struct inet_timewait_sock *tw, int i)
1830{
1831 const struct in6_addr *dest, *src;
1832 __u16 destp, srcp;
1833 s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1834
1835 dest = &tw->tw_v6_daddr;
1836 src = &tw->tw_v6_rcv_saddr;
1837 destp = ntohs(tw->tw_dport);
1838 srcp = ntohs(tw->tw_sport);
1839
1840 seq_printf(seq,
1841 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1842 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1843 i,
1844 src->s6_addr32[0], src->s6_addr32[1],
1845 src->s6_addr32[2], src->s6_addr32[3], srcp,
1846 dest->s6_addr32[0], dest->s6_addr32[1],
1847 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1848 tw->tw_substate, 0, 0,
1849 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1850 atomic_read(&tw->tw_refcnt), tw);
1851}
1852
1853static int tcp6_seq_show(struct seq_file *seq, void *v)
1854{
1855 struct tcp_iter_state *st;
1856 struct sock *sk = v;
1857
1858 if (v == SEQ_START_TOKEN) {
1859 seq_puts(seq,
1860 " sl "
1861 "local_address "
1862 "remote_address "
1863 "st tx_queue rx_queue tr tm->when retrnsmt"
1864 " uid timeout inode\n");
1865 goto out;
1866 }
1867 st = seq->private;
1868
1869 switch (st->state) {
1870 case TCP_SEQ_STATE_LISTENING:
1871 case TCP_SEQ_STATE_ESTABLISHED:
1872 if (sk->sk_state == TCP_TIME_WAIT)
1873 get_timewait6_sock(seq, v, st->num);
1874 else
1875 get_tcp6_sock(seq, v, st->num);
1876 break;
1877 case TCP_SEQ_STATE_OPENREQ:
1878 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1879 break;
1880 }
1881out:
1882 return 0;
1883}
1884
1885static const struct file_operations tcp6_afinfo_seq_fops = {
1886 .owner = THIS_MODULE,
1887 .open = tcp_seq_open,
1888 .read = seq_read,
1889 .llseek = seq_lseek,
1890 .release = seq_release_net
1891};
1892
1893static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1894 .name = "tcp6",
1895 .family = AF_INET6,
1896 .seq_fops = &tcp6_afinfo_seq_fops,
1897 .seq_ops = {
1898 .show = tcp6_seq_show,
1899 },
1900};
1901
1902int __net_init tcp6_proc_init(struct net *net)
1903{
1904 return tcp_proc_register(net, &tcp6_seq_afinfo);
1905}
1906
1907void tcp6_proc_exit(struct net *net)
1908{
1909 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1910}
1911#endif
1912
1913static void tcp_v6_clear_sk(struct sock *sk, int size)
1914{
1915 struct inet_sock *inet = inet_sk(sk);
1916
1917 /* we do not want to clear pinet6 field, because of RCU lookups */
1918 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1919
1920 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1921 memset(&inet->pinet6 + 1, 0, size);
1922}
1923
1924struct proto tcpv6_prot = {
1925 .name = "TCPv6",
1926 .owner = THIS_MODULE,
1927 .close = tcp_close,
1928 .connect = tcp_v6_connect,
1929 .disconnect = tcp_disconnect,
1930 .accept = inet_csk_accept,
1931 .ioctl = tcp_ioctl,
1932 .init = tcp_v6_init_sock,
1933 .destroy = tcp_v6_destroy_sock,
1934 .shutdown = tcp_shutdown,
1935 .setsockopt = tcp_setsockopt,
1936 .getsockopt = tcp_getsockopt,
1937 .recvmsg = tcp_recvmsg,
1938 .sendmsg = tcp_sendmsg,
1939 .sendpage = tcp_sendpage,
1940 .backlog_rcv = tcp_v6_do_rcv,
1941 .release_cb = tcp_release_cb,
1942 .mtu_reduced = tcp_v6_mtu_reduced,
1943 .hash = tcp_v6_hash,
1944 .unhash = inet_unhash,
1945 .get_port = inet_csk_get_port,
1946 .enter_memory_pressure = tcp_enter_memory_pressure,
1947 .stream_memory_free = tcp_stream_memory_free,
1948 .sockets_allocated = &tcp_sockets_allocated,
1949 .memory_allocated = &tcp_memory_allocated,
1950 .memory_pressure = &tcp_memory_pressure,
1951 .orphan_count = &tcp_orphan_count,
1952 .sysctl_mem = sysctl_tcp_mem,
1953 .sysctl_wmem = sysctl_tcp_wmem,
1954 .sysctl_rmem = sysctl_tcp_rmem,
1955 .max_header = MAX_TCP_HEADER,
1956 .obj_size = sizeof(struct tcp6_sock),
1957 .slab_flags = SLAB_DESTROY_BY_RCU,
1958 .twsk_prot = &tcp6_timewait_sock_ops,
1959 .rsk_prot = &tcp6_request_sock_ops,
1960 .h.hashinfo = &tcp_hashinfo,
1961 .no_autobind = true,
1962#ifdef CONFIG_COMPAT
1963 .compat_setsockopt = compat_tcp_setsockopt,
1964 .compat_getsockopt = compat_tcp_getsockopt,
1965#endif
1966#ifdef CONFIG_MEMCG_KMEM
1967 .proto_cgroup = tcp_proto_cgroup,
1968#endif
1969 .clear_sk = tcp_v6_clear_sk,
1970};
1971
1972static const struct inet6_protocol tcpv6_protocol = {
1973 .early_demux = tcp_v6_early_demux,
1974 .handler = tcp_v6_rcv,
1975 .err_handler = tcp_v6_err,
1976 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1977};
1978
1979static struct inet_protosw tcpv6_protosw = {
1980 .type = SOCK_STREAM,
1981 .protocol = IPPROTO_TCP,
1982 .prot = &tcpv6_prot,
1983 .ops = &inet6_stream_ops,
1984 .no_check = 0,
1985 .flags = INET_PROTOSW_PERMANENT |
1986 INET_PROTOSW_ICSK,
1987};
1988
1989static int __net_init tcpv6_net_init(struct net *net)
1990{
1991 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1992 SOCK_RAW, IPPROTO_TCP, net);
1993}
1994
1995static void __net_exit tcpv6_net_exit(struct net *net)
1996{
1997 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1998}
1999
2000static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2001{
2002 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2003}
2004
2005static struct pernet_operations tcpv6_net_ops = {
2006 .init = tcpv6_net_init,
2007 .exit = tcpv6_net_exit,
2008 .exit_batch = tcpv6_net_exit_batch,
2009};
2010
2011int __init tcpv6_init(void)
2012{
2013 int ret;
2014
2015 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2016 if (ret)
2017 goto out;
2018
2019 /* register inet6 protocol */
2020 ret = inet6_register_protosw(&tcpv6_protosw);
2021 if (ret)
2022 goto out_tcpv6_protocol;
2023
2024 ret = register_pernet_subsys(&tcpv6_net_ops);
2025 if (ret)
2026 goto out_tcpv6_protosw;
2027out:
2028 return ret;
2029
2030out_tcpv6_protosw:
2031 inet6_unregister_protosw(&tcpv6_protosw);
2032out_tcpv6_protocol:
2033 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2034 goto out;
2035}
2036
2037void tcpv6_exit(void)
2038{
2039 unregister_pernet_subsys(&tcpv6_net_ops);
2040 inet6_unregister_protosw(&tcpv6_protosw);
2041 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2042}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * TCP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on:
10 * linux/net/ipv4/tcp.c
11 * linux/net/ipv4/tcp_input.c
12 * linux/net/ipv4/tcp_output.c
13 *
14 * Fixes:
15 * Hideaki YOSHIFUJI : sin6_scope_id support
16 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
17 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
18 * a single port at the same time.
19 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
20 */
21
22#include <linux/bottom_half.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/jiffies.h>
30#include <linux/in.h>
31#include <linux/in6.h>
32#include <linux/netdevice.h>
33#include <linux/init.h>
34#include <linux/jhash.h>
35#include <linux/ipsec.h>
36#include <linux/times.h>
37#include <linux/slab.h>
38#include <linux/uaccess.h>
39#include <linux/ipv6.h>
40#include <linux/icmpv6.h>
41#include <linux/random.h>
42#include <linux/indirect_call_wrapper.h>
43
44#include <net/tcp.h>
45#include <net/ndisc.h>
46#include <net/inet6_hashtables.h>
47#include <net/inet6_connection_sock.h>
48#include <net/ipv6.h>
49#include <net/transp_v6.h>
50#include <net/addrconf.h>
51#include <net/ip6_route.h>
52#include <net/ip6_checksum.h>
53#include <net/inet_ecn.h>
54#include <net/protocol.h>
55#include <net/xfrm.h>
56#include <net/snmp.h>
57#include <net/dsfield.h>
58#include <net/timewait_sock.h>
59#include <net/inet_common.h>
60#include <net/secure_seq.h>
61#include <net/busy_poll.h>
62
63#include <linux/proc_fs.h>
64#include <linux/seq_file.h>
65
66#include <crypto/hash.h>
67#include <linux/scatterlist.h>
68
69#include <trace/events/tcp.h>
70
71static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
72static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
73 struct request_sock *req);
74
75INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77static const struct inet_connection_sock_af_ops ipv6_mapped;
78const struct inet_connection_sock_af_ops ipv6_specific;
79#ifdef CONFIG_TCP_MD5SIG
80static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
81static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
82#else
83static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
84 const struct in6_addr *addr,
85 int l3index)
86{
87 return NULL;
88}
89#endif
90
91/* Helper returning the inet6 address from a given tcp socket.
92 * It can be used in TCP stack instead of inet6_sk(sk).
93 * This avoids a dereference and allow compiler optimizations.
94 * It is a specialized version of inet6_sk_generic().
95 */
96static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
97{
98 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
99
100 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
101}
102
103static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
104{
105 struct dst_entry *dst = skb_dst(skb);
106
107 if (dst && dst_hold_safe(dst)) {
108 const struct rt6_info *rt = (const struct rt6_info *)dst;
109
110 rcu_assign_pointer(sk->sk_rx_dst, dst);
111 sk->sk_rx_dst_ifindex = skb->skb_iif;
112 sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
113 }
114}
115
116static u32 tcp_v6_init_seq(const struct sk_buff *skb)
117{
118 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
119 ipv6_hdr(skb)->saddr.s6_addr32,
120 tcp_hdr(skb)->dest,
121 tcp_hdr(skb)->source);
122}
123
124static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
125{
126 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
127 ipv6_hdr(skb)->saddr.s6_addr32);
128}
129
130static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
131 int addr_len)
132{
133 /* This check is replicated from tcp_v6_connect() and intended to
134 * prevent BPF program called below from accessing bytes that are out
135 * of the bound specified by user in addr_len.
136 */
137 if (addr_len < SIN6_LEN_RFC2133)
138 return -EINVAL;
139
140 sock_owned_by_me(sk);
141
142 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
143}
144
145static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
146 int addr_len)
147{
148 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
149 struct inet_connection_sock *icsk = inet_csk(sk);
150 struct in6_addr *saddr = NULL, *final_p, final;
151 struct inet_timewait_death_row *tcp_death_row;
152 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
153 struct inet_sock *inet = inet_sk(sk);
154 struct tcp_sock *tp = tcp_sk(sk);
155 struct net *net = sock_net(sk);
156 struct ipv6_txoptions *opt;
157 struct dst_entry *dst;
158 struct flowi6 fl6;
159 int addr_type;
160 int err;
161
162 if (addr_len < SIN6_LEN_RFC2133)
163 return -EINVAL;
164
165 if (usin->sin6_family != AF_INET6)
166 return -EAFNOSUPPORT;
167
168 memset(&fl6, 0, sizeof(fl6));
169
170 if (np->sndflow) {
171 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
172 IP6_ECN_flow_init(fl6.flowlabel);
173 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
174 struct ip6_flowlabel *flowlabel;
175 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
176 if (IS_ERR(flowlabel))
177 return -EINVAL;
178 fl6_sock_release(flowlabel);
179 }
180 }
181
182 /*
183 * connect() to INADDR_ANY means loopback (BSD'ism).
184 */
185
186 if (ipv6_addr_any(&usin->sin6_addr)) {
187 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
188 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
189 &usin->sin6_addr);
190 else
191 usin->sin6_addr = in6addr_loopback;
192 }
193
194 addr_type = ipv6_addr_type(&usin->sin6_addr);
195
196 if (addr_type & IPV6_ADDR_MULTICAST)
197 return -ENETUNREACH;
198
199 if (addr_type&IPV6_ADDR_LINKLOCAL) {
200 if (addr_len >= sizeof(struct sockaddr_in6) &&
201 usin->sin6_scope_id) {
202 /* If interface is set while binding, indices
203 * must coincide.
204 */
205 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
206 return -EINVAL;
207
208 sk->sk_bound_dev_if = usin->sin6_scope_id;
209 }
210
211 /* Connect to link-local address requires an interface */
212 if (!sk->sk_bound_dev_if)
213 return -EINVAL;
214 }
215
216 if (tp->rx_opt.ts_recent_stamp &&
217 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
218 tp->rx_opt.ts_recent = 0;
219 tp->rx_opt.ts_recent_stamp = 0;
220 WRITE_ONCE(tp->write_seq, 0);
221 }
222
223 sk->sk_v6_daddr = usin->sin6_addr;
224 np->flow_label = fl6.flowlabel;
225
226 /*
227 * TCP over IPv4
228 */
229
230 if (addr_type & IPV6_ADDR_MAPPED) {
231 u32 exthdrlen = icsk->icsk_ext_hdr_len;
232 struct sockaddr_in sin;
233
234 if (ipv6_only_sock(sk))
235 return -ENETUNREACH;
236
237 sin.sin_family = AF_INET;
238 sin.sin_port = usin->sin6_port;
239 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
240
241 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
242 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
243 if (sk_is_mptcp(sk))
244 mptcpv6_handle_mapped(sk, true);
245 sk->sk_backlog_rcv = tcp_v4_do_rcv;
246#ifdef CONFIG_TCP_MD5SIG
247 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
248#endif
249
250 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
251
252 if (err) {
253 icsk->icsk_ext_hdr_len = exthdrlen;
254 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
255 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
256 if (sk_is_mptcp(sk))
257 mptcpv6_handle_mapped(sk, false);
258 sk->sk_backlog_rcv = tcp_v6_do_rcv;
259#ifdef CONFIG_TCP_MD5SIG
260 tp->af_specific = &tcp_sock_ipv6_specific;
261#endif
262 goto failure;
263 }
264 np->saddr = sk->sk_v6_rcv_saddr;
265
266 return err;
267 }
268
269 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
270 saddr = &sk->sk_v6_rcv_saddr;
271
272 fl6.flowi6_proto = IPPROTO_TCP;
273 fl6.daddr = sk->sk_v6_daddr;
274 fl6.saddr = saddr ? *saddr : np->saddr;
275 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
276 fl6.flowi6_oif = sk->sk_bound_dev_if;
277 fl6.flowi6_mark = sk->sk_mark;
278 fl6.fl6_dport = usin->sin6_port;
279 fl6.fl6_sport = inet->inet_sport;
280 fl6.flowi6_uid = sk->sk_uid;
281
282 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
283 final_p = fl6_update_dst(&fl6, opt, &final);
284
285 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
286
287 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
288 if (IS_ERR(dst)) {
289 err = PTR_ERR(dst);
290 goto failure;
291 }
292
293 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
294
295 if (!saddr) {
296 saddr = &fl6.saddr;
297
298 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
299 if (err)
300 goto failure;
301 }
302
303 /* set the source address */
304 np->saddr = *saddr;
305 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
306
307 sk->sk_gso_type = SKB_GSO_TCPV6;
308 ip6_dst_store(sk, dst, NULL, NULL);
309
310 icsk->icsk_ext_hdr_len = 0;
311 if (opt)
312 icsk->icsk_ext_hdr_len = opt->opt_flen +
313 opt->opt_nflen;
314
315 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
316
317 inet->inet_dport = usin->sin6_port;
318
319 tcp_set_state(sk, TCP_SYN_SENT);
320 err = inet6_hash_connect(tcp_death_row, sk);
321 if (err)
322 goto late_failure;
323
324 sk_set_txhash(sk);
325
326 if (likely(!tp->repair)) {
327 if (!tp->write_seq)
328 WRITE_ONCE(tp->write_seq,
329 secure_tcpv6_seq(np->saddr.s6_addr32,
330 sk->sk_v6_daddr.s6_addr32,
331 inet->inet_sport,
332 inet->inet_dport));
333 tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
334 sk->sk_v6_daddr.s6_addr32);
335 }
336
337 if (tcp_fastopen_defer_connect(sk, &err))
338 return err;
339 if (err)
340 goto late_failure;
341
342 err = tcp_connect(sk);
343 if (err)
344 goto late_failure;
345
346 return 0;
347
348late_failure:
349 tcp_set_state(sk, TCP_CLOSE);
350 inet_bhash2_reset_saddr(sk);
351failure:
352 inet->inet_dport = 0;
353 sk->sk_route_caps = 0;
354 return err;
355}
356
357static void tcp_v6_mtu_reduced(struct sock *sk)
358{
359 struct dst_entry *dst;
360 u32 mtu;
361
362 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
363 return;
364
365 mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
366
367 /* Drop requests trying to increase our current mss.
368 * Check done in __ip6_rt_update_pmtu() is too late.
369 */
370 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
371 return;
372
373 dst = inet6_csk_update_pmtu(sk, mtu);
374 if (!dst)
375 return;
376
377 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
378 tcp_sync_mss(sk, dst_mtu(dst));
379 tcp_simple_retransmit(sk);
380 }
381}
382
383static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
384 u8 type, u8 code, int offset, __be32 info)
385{
386 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
387 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
388 struct net *net = dev_net(skb->dev);
389 struct request_sock *fastopen;
390 struct ipv6_pinfo *np;
391 struct tcp_sock *tp;
392 __u32 seq, snd_una;
393 struct sock *sk;
394 bool fatal;
395 int err;
396
397 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
398 &hdr->daddr, th->dest,
399 &hdr->saddr, ntohs(th->source),
400 skb->dev->ifindex, inet6_sdif(skb));
401
402 if (!sk) {
403 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
404 ICMP6_MIB_INERRORS);
405 return -ENOENT;
406 }
407
408 if (sk->sk_state == TCP_TIME_WAIT) {
409 inet_twsk_put(inet_twsk(sk));
410 return 0;
411 }
412 seq = ntohl(th->seq);
413 fatal = icmpv6_err_convert(type, code, &err);
414 if (sk->sk_state == TCP_NEW_SYN_RECV) {
415 tcp_req_err(sk, seq, fatal);
416 return 0;
417 }
418
419 bh_lock_sock(sk);
420 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
421 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
422
423 if (sk->sk_state == TCP_CLOSE)
424 goto out;
425
426 if (static_branch_unlikely(&ip6_min_hopcount)) {
427 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
428 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
429 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
430 goto out;
431 }
432 }
433
434 tp = tcp_sk(sk);
435 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
436 fastopen = rcu_dereference(tp->fastopen_rsk);
437 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
438 if (sk->sk_state != TCP_LISTEN &&
439 !between(seq, snd_una, tp->snd_nxt)) {
440 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
441 goto out;
442 }
443
444 np = tcp_inet6_sk(sk);
445
446 if (type == NDISC_REDIRECT) {
447 if (!sock_owned_by_user(sk)) {
448 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
449
450 if (dst)
451 dst->ops->redirect(dst, sk, skb);
452 }
453 goto out;
454 }
455
456 if (type == ICMPV6_PKT_TOOBIG) {
457 u32 mtu = ntohl(info);
458
459 /* We are not interested in TCP_LISTEN and open_requests
460 * (SYN-ACKs send out by Linux are always <576bytes so
461 * they should go through unfragmented).
462 */
463 if (sk->sk_state == TCP_LISTEN)
464 goto out;
465
466 if (!ip6_sk_accept_pmtu(sk))
467 goto out;
468
469 if (mtu < IPV6_MIN_MTU)
470 goto out;
471
472 WRITE_ONCE(tp->mtu_info, mtu);
473
474 if (!sock_owned_by_user(sk))
475 tcp_v6_mtu_reduced(sk);
476 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
477 &sk->sk_tsq_flags))
478 sock_hold(sk);
479 goto out;
480 }
481
482
483 /* Might be for an request_sock */
484 switch (sk->sk_state) {
485 case TCP_SYN_SENT:
486 case TCP_SYN_RECV:
487 /* Only in fast or simultaneous open. If a fast open socket is
488 * already accepted it is treated as a connected one below.
489 */
490 if (fastopen && !fastopen->sk)
491 break;
492
493 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
494
495 if (!sock_owned_by_user(sk)) {
496 sk->sk_err = err;
497 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
498
499 tcp_done(sk);
500 } else
501 sk->sk_err_soft = err;
502 goto out;
503 case TCP_LISTEN:
504 break;
505 default:
506 /* check if this ICMP message allows revert of backoff.
507 * (see RFC 6069)
508 */
509 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
510 code == ICMPV6_NOROUTE)
511 tcp_ld_RTO_revert(sk, seq);
512 }
513
514 if (!sock_owned_by_user(sk) && np->recverr) {
515 sk->sk_err = err;
516 sk_error_report(sk);
517 } else
518 sk->sk_err_soft = err;
519
520out:
521 bh_unlock_sock(sk);
522 sock_put(sk);
523 return 0;
524}
525
526
527static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
528 struct flowi *fl,
529 struct request_sock *req,
530 struct tcp_fastopen_cookie *foc,
531 enum tcp_synack_type synack_type,
532 struct sk_buff *syn_skb)
533{
534 struct inet_request_sock *ireq = inet_rsk(req);
535 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
536 struct ipv6_txoptions *opt;
537 struct flowi6 *fl6 = &fl->u.ip6;
538 struct sk_buff *skb;
539 int err = -ENOMEM;
540 u8 tclass;
541
542 /* First, grab a route. */
543 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
544 IPPROTO_TCP)) == NULL)
545 goto done;
546
547 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
548
549 if (skb) {
550 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
551 &ireq->ir_v6_rmt_addr);
552
553 fl6->daddr = ireq->ir_v6_rmt_addr;
554 if (np->repflow && ireq->pktopts)
555 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
556
557 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
558 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
559 (np->tclass & INET_ECN_MASK) :
560 np->tclass;
561
562 if (!INET_ECN_is_capable(tclass) &&
563 tcp_bpf_ca_needs_ecn((struct sock *)req))
564 tclass |= INET_ECN_ECT_0;
565
566 rcu_read_lock();
567 opt = ireq->ipv6_opt;
568 if (!opt)
569 opt = rcu_dereference(np->opt);
570 err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt,
571 tclass, sk->sk_priority);
572 rcu_read_unlock();
573 err = net_xmit_eval(err);
574 }
575
576done:
577 return err;
578}
579
580
581static void tcp_v6_reqsk_destructor(struct request_sock *req)
582{
583 kfree(inet_rsk(req)->ipv6_opt);
584 consume_skb(inet_rsk(req)->pktopts);
585}
586
587#ifdef CONFIG_TCP_MD5SIG
588static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
589 const struct in6_addr *addr,
590 int l3index)
591{
592 return tcp_md5_do_lookup(sk, l3index,
593 (union tcp_md5_addr *)addr, AF_INET6);
594}
595
596static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
597 const struct sock *addr_sk)
598{
599 int l3index;
600
601 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
602 addr_sk->sk_bound_dev_if);
603 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
604 l3index);
605}
606
607static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
608 sockptr_t optval, int optlen)
609{
610 struct tcp_md5sig cmd;
611 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
612 int l3index = 0;
613 u8 prefixlen;
614 u8 flags;
615
616 if (optlen < sizeof(cmd))
617 return -EINVAL;
618
619 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
620 return -EFAULT;
621
622 if (sin6->sin6_family != AF_INET6)
623 return -EINVAL;
624
625 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
626
627 if (optname == TCP_MD5SIG_EXT &&
628 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
629 prefixlen = cmd.tcpm_prefixlen;
630 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
631 prefixlen > 32))
632 return -EINVAL;
633 } else {
634 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
635 }
636
637 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
638 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
639 struct net_device *dev;
640
641 rcu_read_lock();
642 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
643 if (dev && netif_is_l3_master(dev))
644 l3index = dev->ifindex;
645 rcu_read_unlock();
646
647 /* ok to reference set/not set outside of rcu;
648 * right now device MUST be an L3 master
649 */
650 if (!dev || !l3index)
651 return -EINVAL;
652 }
653
654 if (!cmd.tcpm_keylen) {
655 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
656 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
657 AF_INET, prefixlen,
658 l3index, flags);
659 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
660 AF_INET6, prefixlen, l3index, flags);
661 }
662
663 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
664 return -EINVAL;
665
666 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
667 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
668 AF_INET, prefixlen, l3index, flags,
669 cmd.tcpm_key, cmd.tcpm_keylen);
670
671 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
672 AF_INET6, prefixlen, l3index, flags,
673 cmd.tcpm_key, cmd.tcpm_keylen);
674}
675
676static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
677 const struct in6_addr *daddr,
678 const struct in6_addr *saddr,
679 const struct tcphdr *th, int nbytes)
680{
681 struct tcp6_pseudohdr *bp;
682 struct scatterlist sg;
683 struct tcphdr *_th;
684
685 bp = hp->scratch;
686 /* 1. TCP pseudo-header (RFC2460) */
687 bp->saddr = *saddr;
688 bp->daddr = *daddr;
689 bp->protocol = cpu_to_be32(IPPROTO_TCP);
690 bp->len = cpu_to_be32(nbytes);
691
692 _th = (struct tcphdr *)(bp + 1);
693 memcpy(_th, th, sizeof(*th));
694 _th->check = 0;
695
696 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
697 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
698 sizeof(*bp) + sizeof(*th));
699 return crypto_ahash_update(hp->md5_req);
700}
701
702static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
703 const struct in6_addr *daddr, struct in6_addr *saddr,
704 const struct tcphdr *th)
705{
706 struct tcp_md5sig_pool *hp;
707 struct ahash_request *req;
708
709 hp = tcp_get_md5sig_pool();
710 if (!hp)
711 goto clear_hash_noput;
712 req = hp->md5_req;
713
714 if (crypto_ahash_init(req))
715 goto clear_hash;
716 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
717 goto clear_hash;
718 if (tcp_md5_hash_key(hp, key))
719 goto clear_hash;
720 ahash_request_set_crypt(req, NULL, md5_hash, 0);
721 if (crypto_ahash_final(req))
722 goto clear_hash;
723
724 tcp_put_md5sig_pool();
725 return 0;
726
727clear_hash:
728 tcp_put_md5sig_pool();
729clear_hash_noput:
730 memset(md5_hash, 0, 16);
731 return 1;
732}
733
734static int tcp_v6_md5_hash_skb(char *md5_hash,
735 const struct tcp_md5sig_key *key,
736 const struct sock *sk,
737 const struct sk_buff *skb)
738{
739 const struct in6_addr *saddr, *daddr;
740 struct tcp_md5sig_pool *hp;
741 struct ahash_request *req;
742 const struct tcphdr *th = tcp_hdr(skb);
743
744 if (sk) { /* valid for establish/request sockets */
745 saddr = &sk->sk_v6_rcv_saddr;
746 daddr = &sk->sk_v6_daddr;
747 } else {
748 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
749 saddr = &ip6h->saddr;
750 daddr = &ip6h->daddr;
751 }
752
753 hp = tcp_get_md5sig_pool();
754 if (!hp)
755 goto clear_hash_noput;
756 req = hp->md5_req;
757
758 if (crypto_ahash_init(req))
759 goto clear_hash;
760
761 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
762 goto clear_hash;
763 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
764 goto clear_hash;
765 if (tcp_md5_hash_key(hp, key))
766 goto clear_hash;
767 ahash_request_set_crypt(req, NULL, md5_hash, 0);
768 if (crypto_ahash_final(req))
769 goto clear_hash;
770
771 tcp_put_md5sig_pool();
772 return 0;
773
774clear_hash:
775 tcp_put_md5sig_pool();
776clear_hash_noput:
777 memset(md5_hash, 0, 16);
778 return 1;
779}
780
781#endif
782
783static void tcp_v6_init_req(struct request_sock *req,
784 const struct sock *sk_listener,
785 struct sk_buff *skb)
786{
787 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
788 struct inet_request_sock *ireq = inet_rsk(req);
789 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
790
791 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
792 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
793
794 /* So that link locals have meaning */
795 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
796 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
797 ireq->ir_iif = tcp_v6_iif(skb);
798
799 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
800 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
801 np->rxopt.bits.rxinfo ||
802 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
803 np->rxopt.bits.rxohlim || np->repflow)) {
804 refcount_inc(&skb->users);
805 ireq->pktopts = skb;
806 }
807}
808
809static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
810 struct sk_buff *skb,
811 struct flowi *fl,
812 struct request_sock *req)
813{
814 tcp_v6_init_req(req, sk, skb);
815
816 if (security_inet_conn_request(sk, skb, req))
817 return NULL;
818
819 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
820}
821
822struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
823 .family = AF_INET6,
824 .obj_size = sizeof(struct tcp6_request_sock),
825 .rtx_syn_ack = tcp_rtx_synack,
826 .send_ack = tcp_v6_reqsk_send_ack,
827 .destructor = tcp_v6_reqsk_destructor,
828 .send_reset = tcp_v6_send_reset,
829 .syn_ack_timeout = tcp_syn_ack_timeout,
830};
831
832const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
833 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
834 sizeof(struct ipv6hdr),
835#ifdef CONFIG_TCP_MD5SIG
836 .req_md5_lookup = tcp_v6_md5_lookup,
837 .calc_md5_hash = tcp_v6_md5_hash_skb,
838#endif
839#ifdef CONFIG_SYN_COOKIES
840 .cookie_init_seq = cookie_v6_init_sequence,
841#endif
842 .route_req = tcp_v6_route_req,
843 .init_seq = tcp_v6_init_seq,
844 .init_ts_off = tcp_v6_init_ts_off,
845 .send_synack = tcp_v6_send_synack,
846};
847
848static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
849 u32 ack, u32 win, u32 tsval, u32 tsecr,
850 int oif, struct tcp_md5sig_key *key, int rst,
851 u8 tclass, __be32 label, u32 priority, u32 txhash)
852{
853 const struct tcphdr *th = tcp_hdr(skb);
854 struct tcphdr *t1;
855 struct sk_buff *buff;
856 struct flowi6 fl6;
857 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
858 struct sock *ctl_sk = net->ipv6.tcp_sk;
859 unsigned int tot_len = sizeof(struct tcphdr);
860 __be32 mrst = 0, *topt;
861 struct dst_entry *dst;
862 __u32 mark = 0;
863
864 if (tsecr)
865 tot_len += TCPOLEN_TSTAMP_ALIGNED;
866#ifdef CONFIG_TCP_MD5SIG
867 if (key)
868 tot_len += TCPOLEN_MD5SIG_ALIGNED;
869#endif
870
871#ifdef CONFIG_MPTCP
872 if (rst && !key) {
873 mrst = mptcp_reset_option(skb);
874
875 if (mrst)
876 tot_len += sizeof(__be32);
877 }
878#endif
879
880 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
881 if (!buff)
882 return;
883
884 skb_reserve(buff, MAX_TCP_HEADER);
885
886 t1 = skb_push(buff, tot_len);
887 skb_reset_transport_header(buff);
888
889 /* Swap the send and the receive. */
890 memset(t1, 0, sizeof(*t1));
891 t1->dest = th->source;
892 t1->source = th->dest;
893 t1->doff = tot_len / 4;
894 t1->seq = htonl(seq);
895 t1->ack_seq = htonl(ack);
896 t1->ack = !rst || !th->ack;
897 t1->rst = rst;
898 t1->window = htons(win);
899
900 topt = (__be32 *)(t1 + 1);
901
902 if (tsecr) {
903 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
904 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
905 *topt++ = htonl(tsval);
906 *topt++ = htonl(tsecr);
907 }
908
909 if (mrst)
910 *topt++ = mrst;
911
912#ifdef CONFIG_TCP_MD5SIG
913 if (key) {
914 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
915 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
916 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
917 &ipv6_hdr(skb)->saddr,
918 &ipv6_hdr(skb)->daddr, t1);
919 }
920#endif
921
922 memset(&fl6, 0, sizeof(fl6));
923 fl6.daddr = ipv6_hdr(skb)->saddr;
924 fl6.saddr = ipv6_hdr(skb)->daddr;
925 fl6.flowlabel = label;
926
927 buff->ip_summed = CHECKSUM_PARTIAL;
928
929 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
930
931 fl6.flowi6_proto = IPPROTO_TCP;
932 if (rt6_need_strict(&fl6.daddr) && !oif)
933 fl6.flowi6_oif = tcp_v6_iif(skb);
934 else {
935 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
936 oif = skb->skb_iif;
937
938 fl6.flowi6_oif = oif;
939 }
940
941 if (sk) {
942 if (sk->sk_state == TCP_TIME_WAIT)
943 mark = inet_twsk(sk)->tw_mark;
944 else
945 mark = sk->sk_mark;
946 skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
947 }
948 if (txhash) {
949 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
950 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
951 }
952 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
953 fl6.fl6_dport = t1->dest;
954 fl6.fl6_sport = t1->source;
955 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
956 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
957
958 /* Pass a socket to ip6_dst_lookup either it is for RST
959 * Underlying function will use this to retrieve the network
960 * namespace
961 */
962 if (sk && sk->sk_state != TCP_TIME_WAIT)
963 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
964 else
965 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
966 if (!IS_ERR(dst)) {
967 skb_dst_set(buff, dst);
968 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
969 tclass & ~INET_ECN_MASK, priority);
970 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
971 if (rst)
972 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
973 return;
974 }
975
976 kfree_skb(buff);
977}
978
979static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
980{
981 const struct tcphdr *th = tcp_hdr(skb);
982 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
983 u32 seq = 0, ack_seq = 0;
984 struct tcp_md5sig_key *key = NULL;
985#ifdef CONFIG_TCP_MD5SIG
986 const __u8 *hash_location = NULL;
987 unsigned char newhash[16];
988 int genhash;
989 struct sock *sk1 = NULL;
990#endif
991 __be32 label = 0;
992 u32 priority = 0;
993 struct net *net;
994 u32 txhash = 0;
995 int oif = 0;
996
997 if (th->rst)
998 return;
999
1000 /* If sk not NULL, it means we did a successful lookup and incoming
1001 * route had to be correct. prequeue might have dropped our dst.
1002 */
1003 if (!sk && !ipv6_unicast_destination(skb))
1004 return;
1005
1006 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1007#ifdef CONFIG_TCP_MD5SIG
1008 rcu_read_lock();
1009 hash_location = tcp_parse_md5sig_option(th);
1010 if (sk && sk_fullsock(sk)) {
1011 int l3index;
1012
1013 /* sdif set, means packet ingressed via a device
1014 * in an L3 domain and inet_iif is set to it.
1015 */
1016 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1017 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1018 } else if (hash_location) {
1019 int dif = tcp_v6_iif_l3_slave(skb);
1020 int sdif = tcp_v6_sdif(skb);
1021 int l3index;
1022
1023 /*
1024 * active side is lost. Try to find listening socket through
1025 * source port, and then find md5 key through listening socket.
1026 * we are not loose security here:
1027 * Incoming packet is checked with md5 hash with finding key,
1028 * no RST generated if md5 hash doesn't match.
1029 */
1030 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1031 NULL, 0, &ipv6h->saddr, th->source,
1032 &ipv6h->daddr, ntohs(th->source),
1033 dif, sdif);
1034 if (!sk1)
1035 goto out;
1036
1037 /* sdif set, means packet ingressed via a device
1038 * in an L3 domain and dif is set to it.
1039 */
1040 l3index = tcp_v6_sdif(skb) ? dif : 0;
1041
1042 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1043 if (!key)
1044 goto out;
1045
1046 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1047 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1048 goto out;
1049 }
1050#endif
1051
1052 if (th->ack)
1053 seq = ntohl(th->ack_seq);
1054 else
1055 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1056 (th->doff << 2);
1057
1058 if (sk) {
1059 oif = sk->sk_bound_dev_if;
1060 if (sk_fullsock(sk)) {
1061 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1062
1063 trace_tcp_send_reset(sk, skb);
1064 if (np->repflow)
1065 label = ip6_flowlabel(ipv6h);
1066 priority = sk->sk_priority;
1067 txhash = sk->sk_hash;
1068 }
1069 if (sk->sk_state == TCP_TIME_WAIT) {
1070 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1071 priority = inet_twsk(sk)->tw_priority;
1072 txhash = inet_twsk(sk)->tw_txhash;
1073 }
1074 } else {
1075 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1076 label = ip6_flowlabel(ipv6h);
1077 }
1078
1079 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
1080 ipv6_get_dsfield(ipv6h), label, priority, txhash);
1081
1082#ifdef CONFIG_TCP_MD5SIG
1083out:
1084 rcu_read_unlock();
1085#endif
1086}
1087
1088static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1089 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1090 struct tcp_md5sig_key *key, u8 tclass,
1091 __be32 label, u32 priority, u32 txhash)
1092{
1093 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1094 tclass, label, priority, txhash);
1095}
1096
1097static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1098{
1099 struct inet_timewait_sock *tw = inet_twsk(sk);
1100 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1101
1102 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1103 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1104 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1105 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1106 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
1107 tw->tw_txhash);
1108
1109 inet_twsk_put(tw);
1110}
1111
1112static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1113 struct request_sock *req)
1114{
1115 int l3index;
1116
1117 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1118
1119 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1120 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1121 */
1122 /* RFC 7323 2.3
1123 * The window field (SEG.WND) of every outgoing segment, with the
1124 * exception of <SYN> segments, MUST be right-shifted by
1125 * Rcv.Wind.Shift bits:
1126 */
1127 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1128 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1129 tcp_rsk(req)->rcv_nxt,
1130 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1131 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1132 req->ts_recent, sk->sk_bound_dev_if,
1133 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1134 ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority,
1135 tcp_rsk(req)->txhash);
1136}
1137
1138
1139static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1140{
1141#ifdef CONFIG_SYN_COOKIES
1142 const struct tcphdr *th = tcp_hdr(skb);
1143
1144 if (!th->syn)
1145 sk = cookie_v6_check(sk, skb);
1146#endif
1147 return sk;
1148}
1149
1150u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1151 struct tcphdr *th, u32 *cookie)
1152{
1153 u16 mss = 0;
1154#ifdef CONFIG_SYN_COOKIES
1155 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1156 &tcp_request_sock_ipv6_ops, sk, th);
1157 if (mss) {
1158 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1159 tcp_synq_overflow(sk);
1160 }
1161#endif
1162 return mss;
1163}
1164
1165static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1166{
1167 if (skb->protocol == htons(ETH_P_IP))
1168 return tcp_v4_conn_request(sk, skb);
1169
1170 if (!ipv6_unicast_destination(skb))
1171 goto drop;
1172
1173 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1174 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1175 return 0;
1176 }
1177
1178 return tcp_conn_request(&tcp6_request_sock_ops,
1179 &tcp_request_sock_ipv6_ops, sk, skb);
1180
1181drop:
1182 tcp_listendrop(sk);
1183 return 0; /* don't send reset */
1184}
1185
1186static void tcp_v6_restore_cb(struct sk_buff *skb)
1187{
1188 /* We need to move header back to the beginning if xfrm6_policy_check()
1189 * and tcp_v6_fill_cb() are going to be called again.
1190 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1191 */
1192 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1193 sizeof(struct inet6_skb_parm));
1194}
1195
1196static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1197 struct request_sock *req,
1198 struct dst_entry *dst,
1199 struct request_sock *req_unhash,
1200 bool *own_req)
1201{
1202 struct inet_request_sock *ireq;
1203 struct ipv6_pinfo *newnp;
1204 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1205 struct ipv6_txoptions *opt;
1206 struct inet_sock *newinet;
1207 bool found_dup_sk = false;
1208 struct tcp_sock *newtp;
1209 struct sock *newsk;
1210#ifdef CONFIG_TCP_MD5SIG
1211 struct tcp_md5sig_key *key;
1212 int l3index;
1213#endif
1214 struct flowi6 fl6;
1215
1216 if (skb->protocol == htons(ETH_P_IP)) {
1217 /*
1218 * v6 mapped
1219 */
1220
1221 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1222 req_unhash, own_req);
1223
1224 if (!newsk)
1225 return NULL;
1226
1227 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1228
1229 newnp = tcp_inet6_sk(newsk);
1230 newtp = tcp_sk(newsk);
1231
1232 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1233
1234 newnp->saddr = newsk->sk_v6_rcv_saddr;
1235
1236 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1237 if (sk_is_mptcp(newsk))
1238 mptcpv6_handle_mapped(newsk, true);
1239 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1240#ifdef CONFIG_TCP_MD5SIG
1241 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1242#endif
1243
1244 newnp->ipv6_mc_list = NULL;
1245 newnp->ipv6_ac_list = NULL;
1246 newnp->ipv6_fl_list = NULL;
1247 newnp->pktoptions = NULL;
1248 newnp->opt = NULL;
1249 newnp->mcast_oif = inet_iif(skb);
1250 newnp->mcast_hops = ip_hdr(skb)->ttl;
1251 newnp->rcv_flowinfo = 0;
1252 if (np->repflow)
1253 newnp->flow_label = 0;
1254
1255 /*
1256 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1257 * here, tcp_create_openreq_child now does this for us, see the comment in
1258 * that function for the gory details. -acme
1259 */
1260
1261 /* It is tricky place. Until this moment IPv4 tcp
1262 worked with IPv6 icsk.icsk_af_ops.
1263 Sync it now.
1264 */
1265 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1266
1267 return newsk;
1268 }
1269
1270 ireq = inet_rsk(req);
1271
1272 if (sk_acceptq_is_full(sk))
1273 goto out_overflow;
1274
1275 if (!dst) {
1276 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1277 if (!dst)
1278 goto out;
1279 }
1280
1281 newsk = tcp_create_openreq_child(sk, req, skb);
1282 if (!newsk)
1283 goto out_nonewsk;
1284
1285 /*
1286 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1287 * count here, tcp_create_openreq_child now does this for us, see the
1288 * comment in that function for the gory details. -acme
1289 */
1290
1291 newsk->sk_gso_type = SKB_GSO_TCPV6;
1292 ip6_dst_store(newsk, dst, NULL, NULL);
1293 inet6_sk_rx_dst_set(newsk, skb);
1294
1295 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1296
1297 newtp = tcp_sk(newsk);
1298 newinet = inet_sk(newsk);
1299 newnp = tcp_inet6_sk(newsk);
1300
1301 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1302
1303 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1304 newnp->saddr = ireq->ir_v6_loc_addr;
1305 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1306 newsk->sk_bound_dev_if = ireq->ir_iif;
1307
1308 /* Now IPv6 options...
1309
1310 First: no IPv4 options.
1311 */
1312 newinet->inet_opt = NULL;
1313 newnp->ipv6_mc_list = NULL;
1314 newnp->ipv6_ac_list = NULL;
1315 newnp->ipv6_fl_list = NULL;
1316
1317 /* Clone RX bits */
1318 newnp->rxopt.all = np->rxopt.all;
1319
1320 newnp->pktoptions = NULL;
1321 newnp->opt = NULL;
1322 newnp->mcast_oif = tcp_v6_iif(skb);
1323 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1324 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1325 if (np->repflow)
1326 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1327
1328 /* Set ToS of the new socket based upon the value of incoming SYN.
1329 * ECT bits are set later in tcp_init_transfer().
1330 */
1331 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1332 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1333
1334 /* Clone native IPv6 options from listening socket (if any)
1335
1336 Yes, keeping reference count would be much more clever,
1337 but we make one more one thing there: reattach optmem
1338 to newsk.
1339 */
1340 opt = ireq->ipv6_opt;
1341 if (!opt)
1342 opt = rcu_dereference(np->opt);
1343 if (opt) {
1344 opt = ipv6_dup_options(newsk, opt);
1345 RCU_INIT_POINTER(newnp->opt, opt);
1346 }
1347 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1348 if (opt)
1349 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1350 opt->opt_flen;
1351
1352 tcp_ca_openreq_child(newsk, dst);
1353
1354 tcp_sync_mss(newsk, dst_mtu(dst));
1355 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1356
1357 tcp_initialize_rcv_mss(newsk);
1358
1359 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1360 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1361
1362#ifdef CONFIG_TCP_MD5SIG
1363 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1364
1365 /* Copy over the MD5 key from the original socket */
1366 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1367 if (key) {
1368 const union tcp_md5_addr *addr;
1369
1370 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1371 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1372 inet_csk_prepare_forced_close(newsk);
1373 tcp_done(newsk);
1374 goto out;
1375 }
1376 }
1377#endif
1378
1379 if (__inet_inherit_port(sk, newsk) < 0) {
1380 inet_csk_prepare_forced_close(newsk);
1381 tcp_done(newsk);
1382 goto out;
1383 }
1384 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1385 &found_dup_sk);
1386 if (*own_req) {
1387 tcp_move_syn(newtp, req);
1388
1389 /* Clone pktoptions received with SYN, if we own the req */
1390 if (ireq->pktopts) {
1391 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1392 consume_skb(ireq->pktopts);
1393 ireq->pktopts = NULL;
1394 if (newnp->pktoptions)
1395 tcp_v6_restore_cb(newnp->pktoptions);
1396 }
1397 } else {
1398 if (!req_unhash && found_dup_sk) {
1399 /* This code path should only be executed in the
1400 * syncookie case only
1401 */
1402 bh_unlock_sock(newsk);
1403 sock_put(newsk);
1404 newsk = NULL;
1405 }
1406 }
1407
1408 return newsk;
1409
1410out_overflow:
1411 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1412out_nonewsk:
1413 dst_release(dst);
1414out:
1415 tcp_listendrop(sk);
1416 return NULL;
1417}
1418
1419INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1420 u32));
1421/* The socket must have it's spinlock held when we get
1422 * here, unless it is a TCP_LISTEN socket.
1423 *
1424 * We have a potential double-lock case here, so even when
1425 * doing backlog processing we use the BH locking scheme.
1426 * This is because we cannot sleep with the original spinlock
1427 * held.
1428 */
1429INDIRECT_CALLABLE_SCOPE
1430int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1431{
1432 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1433 struct sk_buff *opt_skb = NULL;
1434 enum skb_drop_reason reason;
1435 struct tcp_sock *tp;
1436
1437 /* Imagine: socket is IPv6. IPv4 packet arrives,
1438 goes to IPv4 receive handler and backlogged.
1439 From backlog it always goes here. Kerboom...
1440 Fortunately, tcp_rcv_established and rcv_established
1441 handle them correctly, but it is not case with
1442 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1443 */
1444
1445 if (skb->protocol == htons(ETH_P_IP))
1446 return tcp_v4_do_rcv(sk, skb);
1447
1448 /*
1449 * socket locking is here for SMP purposes as backlog rcv
1450 * is currently called with bh processing disabled.
1451 */
1452
1453 /* Do Stevens' IPV6_PKTOPTIONS.
1454
1455 Yes, guys, it is the only place in our code, where we
1456 may make it not affecting IPv4.
1457 The rest of code is protocol independent,
1458 and I do not like idea to uglify IPv4.
1459
1460 Actually, all the idea behind IPV6_PKTOPTIONS
1461 looks not very well thought. For now we latch
1462 options, received in the last packet, enqueued
1463 by tcp. Feel free to propose better solution.
1464 --ANK (980728)
1465 */
1466 if (np->rxopt.all)
1467 opt_skb = skb_clone_and_charge_r(skb, sk);
1468
1469 reason = SKB_DROP_REASON_NOT_SPECIFIED;
1470 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1471 struct dst_entry *dst;
1472
1473 dst = rcu_dereference_protected(sk->sk_rx_dst,
1474 lockdep_sock_is_held(sk));
1475
1476 sock_rps_save_rxhash(sk, skb);
1477 sk_mark_napi_id(sk, skb);
1478 if (dst) {
1479 if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1480 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1481 dst, sk->sk_rx_dst_cookie) == NULL) {
1482 RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1483 dst_release(dst);
1484 }
1485 }
1486
1487 tcp_rcv_established(sk, skb);
1488 if (opt_skb)
1489 goto ipv6_pktoptions;
1490 return 0;
1491 }
1492
1493 if (tcp_checksum_complete(skb))
1494 goto csum_err;
1495
1496 if (sk->sk_state == TCP_LISTEN) {
1497 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1498
1499 if (!nsk)
1500 goto discard;
1501
1502 if (nsk != sk) {
1503 if (tcp_child_process(sk, nsk, skb))
1504 goto reset;
1505 if (opt_skb)
1506 __kfree_skb(opt_skb);
1507 return 0;
1508 }
1509 } else
1510 sock_rps_save_rxhash(sk, skb);
1511
1512 if (tcp_rcv_state_process(sk, skb))
1513 goto reset;
1514 if (opt_skb)
1515 goto ipv6_pktoptions;
1516 return 0;
1517
1518reset:
1519 tcp_v6_send_reset(sk, skb);
1520discard:
1521 if (opt_skb)
1522 __kfree_skb(opt_skb);
1523 kfree_skb_reason(skb, reason);
1524 return 0;
1525csum_err:
1526 reason = SKB_DROP_REASON_TCP_CSUM;
1527 trace_tcp_bad_csum(skb);
1528 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1529 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1530 goto discard;
1531
1532
1533ipv6_pktoptions:
1534 /* Do you ask, what is it?
1535
1536 1. skb was enqueued by tcp.
1537 2. skb is added to tail of read queue, rather than out of order.
1538 3. socket is not in passive state.
1539 4. Finally, it really contains options, which user wants to receive.
1540 */
1541 tp = tcp_sk(sk);
1542 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1543 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1544 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1545 np->mcast_oif = tcp_v6_iif(opt_skb);
1546 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1547 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1548 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1549 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1550 if (np->repflow)
1551 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1552 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1553 tcp_v6_restore_cb(opt_skb);
1554 opt_skb = xchg(&np->pktoptions, opt_skb);
1555 } else {
1556 __kfree_skb(opt_skb);
1557 opt_skb = xchg(&np->pktoptions, NULL);
1558 }
1559 }
1560
1561 consume_skb(opt_skb);
1562 return 0;
1563}
1564
1565static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1566 const struct tcphdr *th)
1567{
1568 /* This is tricky: we move IP6CB at its correct location into
1569 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1570 * _decode_session6() uses IP6CB().
1571 * barrier() makes sure compiler won't play aliasing games.
1572 */
1573 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1574 sizeof(struct inet6_skb_parm));
1575 barrier();
1576
1577 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1578 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1579 skb->len - th->doff*4);
1580 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1581 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1582 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1583 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1584 TCP_SKB_CB(skb)->sacked = 0;
1585 TCP_SKB_CB(skb)->has_rxtstamp =
1586 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1587}
1588
1589INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1590{
1591 enum skb_drop_reason drop_reason;
1592 int sdif = inet6_sdif(skb);
1593 int dif = inet6_iif(skb);
1594 const struct tcphdr *th;
1595 const struct ipv6hdr *hdr;
1596 bool refcounted;
1597 struct sock *sk;
1598 int ret;
1599 struct net *net = dev_net(skb->dev);
1600
1601 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1602 if (skb->pkt_type != PACKET_HOST)
1603 goto discard_it;
1604
1605 /*
1606 * Count it even if it's bad.
1607 */
1608 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1609
1610 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1611 goto discard_it;
1612
1613 th = (const struct tcphdr *)skb->data;
1614
1615 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1616 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1617 goto bad_packet;
1618 }
1619 if (!pskb_may_pull(skb, th->doff*4))
1620 goto discard_it;
1621
1622 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1623 goto csum_error;
1624
1625 th = (const struct tcphdr *)skb->data;
1626 hdr = ipv6_hdr(skb);
1627
1628lookup:
1629 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1630 th->source, th->dest, inet6_iif(skb), sdif,
1631 &refcounted);
1632 if (!sk)
1633 goto no_tcp_socket;
1634
1635process:
1636 if (sk->sk_state == TCP_TIME_WAIT)
1637 goto do_time_wait;
1638
1639 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1640 struct request_sock *req = inet_reqsk(sk);
1641 bool req_stolen = false;
1642 struct sock *nsk;
1643
1644 sk = req->rsk_listener;
1645 drop_reason = tcp_inbound_md5_hash(sk, skb,
1646 &hdr->saddr, &hdr->daddr,
1647 AF_INET6, dif, sdif);
1648 if (drop_reason) {
1649 sk_drops_add(sk, skb);
1650 reqsk_put(req);
1651 goto discard_it;
1652 }
1653 if (tcp_checksum_complete(skb)) {
1654 reqsk_put(req);
1655 goto csum_error;
1656 }
1657 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1658 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1659 if (!nsk) {
1660 inet_csk_reqsk_queue_drop_and_put(sk, req);
1661 goto lookup;
1662 }
1663 sk = nsk;
1664 /* reuseport_migrate_sock() has already held one sk_refcnt
1665 * before returning.
1666 */
1667 } else {
1668 sock_hold(sk);
1669 }
1670 refcounted = true;
1671 nsk = NULL;
1672 if (!tcp_filter(sk, skb)) {
1673 th = (const struct tcphdr *)skb->data;
1674 hdr = ipv6_hdr(skb);
1675 tcp_v6_fill_cb(skb, hdr, th);
1676 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1677 } else {
1678 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1679 }
1680 if (!nsk) {
1681 reqsk_put(req);
1682 if (req_stolen) {
1683 /* Another cpu got exclusive access to req
1684 * and created a full blown socket.
1685 * Try to feed this packet to this socket
1686 * instead of discarding it.
1687 */
1688 tcp_v6_restore_cb(skb);
1689 sock_put(sk);
1690 goto lookup;
1691 }
1692 goto discard_and_relse;
1693 }
1694 if (nsk == sk) {
1695 reqsk_put(req);
1696 tcp_v6_restore_cb(skb);
1697 } else if (tcp_child_process(sk, nsk, skb)) {
1698 tcp_v6_send_reset(nsk, skb);
1699 goto discard_and_relse;
1700 } else {
1701 sock_put(sk);
1702 return 0;
1703 }
1704 }
1705
1706 if (static_branch_unlikely(&ip6_min_hopcount)) {
1707 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1708 if (hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
1709 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1710 goto discard_and_relse;
1711 }
1712 }
1713
1714 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1715 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1716 goto discard_and_relse;
1717 }
1718
1719 drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr,
1720 AF_INET6, dif, sdif);
1721 if (drop_reason)
1722 goto discard_and_relse;
1723
1724 if (tcp_filter(sk, skb)) {
1725 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1726 goto discard_and_relse;
1727 }
1728 th = (const struct tcphdr *)skb->data;
1729 hdr = ipv6_hdr(skb);
1730 tcp_v6_fill_cb(skb, hdr, th);
1731
1732 skb->dev = NULL;
1733
1734 if (sk->sk_state == TCP_LISTEN) {
1735 ret = tcp_v6_do_rcv(sk, skb);
1736 goto put_and_return;
1737 }
1738
1739 sk_incoming_cpu_update(sk);
1740
1741 bh_lock_sock_nested(sk);
1742 tcp_segs_in(tcp_sk(sk), skb);
1743 ret = 0;
1744 if (!sock_owned_by_user(sk)) {
1745 ret = tcp_v6_do_rcv(sk, skb);
1746 } else {
1747 if (tcp_add_backlog(sk, skb, &drop_reason))
1748 goto discard_and_relse;
1749 }
1750 bh_unlock_sock(sk);
1751put_and_return:
1752 if (refcounted)
1753 sock_put(sk);
1754 return ret ? -1 : 0;
1755
1756no_tcp_socket:
1757 drop_reason = SKB_DROP_REASON_NO_SOCKET;
1758 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1759 goto discard_it;
1760
1761 tcp_v6_fill_cb(skb, hdr, th);
1762
1763 if (tcp_checksum_complete(skb)) {
1764csum_error:
1765 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1766 trace_tcp_bad_csum(skb);
1767 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1768bad_packet:
1769 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1770 } else {
1771 tcp_v6_send_reset(NULL, skb);
1772 }
1773
1774discard_it:
1775 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1776 kfree_skb_reason(skb, drop_reason);
1777 return 0;
1778
1779discard_and_relse:
1780 sk_drops_add(sk, skb);
1781 if (refcounted)
1782 sock_put(sk);
1783 goto discard_it;
1784
1785do_time_wait:
1786 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1787 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1788 inet_twsk_put(inet_twsk(sk));
1789 goto discard_it;
1790 }
1791
1792 tcp_v6_fill_cb(skb, hdr, th);
1793
1794 if (tcp_checksum_complete(skb)) {
1795 inet_twsk_put(inet_twsk(sk));
1796 goto csum_error;
1797 }
1798
1799 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1800 case TCP_TW_SYN:
1801 {
1802 struct sock *sk2;
1803
1804 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1805 skb, __tcp_hdrlen(th),
1806 &ipv6_hdr(skb)->saddr, th->source,
1807 &ipv6_hdr(skb)->daddr,
1808 ntohs(th->dest),
1809 tcp_v6_iif_l3_slave(skb),
1810 sdif);
1811 if (sk2) {
1812 struct inet_timewait_sock *tw = inet_twsk(sk);
1813 inet_twsk_deschedule_put(tw);
1814 sk = sk2;
1815 tcp_v6_restore_cb(skb);
1816 refcounted = false;
1817 goto process;
1818 }
1819 }
1820 /* to ACK */
1821 fallthrough;
1822 case TCP_TW_ACK:
1823 tcp_v6_timewait_ack(sk, skb);
1824 break;
1825 case TCP_TW_RST:
1826 tcp_v6_send_reset(sk, skb);
1827 inet_twsk_deschedule_put(inet_twsk(sk));
1828 goto discard_it;
1829 case TCP_TW_SUCCESS:
1830 ;
1831 }
1832 goto discard_it;
1833}
1834
1835void tcp_v6_early_demux(struct sk_buff *skb)
1836{
1837 struct net *net = dev_net(skb->dev);
1838 const struct ipv6hdr *hdr;
1839 const struct tcphdr *th;
1840 struct sock *sk;
1841
1842 if (skb->pkt_type != PACKET_HOST)
1843 return;
1844
1845 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1846 return;
1847
1848 hdr = ipv6_hdr(skb);
1849 th = tcp_hdr(skb);
1850
1851 if (th->doff < sizeof(struct tcphdr) / 4)
1852 return;
1853
1854 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1855 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
1856 &hdr->saddr, th->source,
1857 &hdr->daddr, ntohs(th->dest),
1858 inet6_iif(skb), inet6_sdif(skb));
1859 if (sk) {
1860 skb->sk = sk;
1861 skb->destructor = sock_edemux;
1862 if (sk_fullsock(sk)) {
1863 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
1864
1865 if (dst)
1866 dst = dst_check(dst, sk->sk_rx_dst_cookie);
1867 if (dst &&
1868 sk->sk_rx_dst_ifindex == skb->skb_iif)
1869 skb_dst_set_noref(skb, dst);
1870 }
1871 }
1872}
1873
1874static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1875 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1876 .twsk_unique = tcp_twsk_unique,
1877 .twsk_destructor = tcp_twsk_destructor,
1878};
1879
1880INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1881{
1882 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
1883}
1884
1885const struct inet_connection_sock_af_ops ipv6_specific = {
1886 .queue_xmit = inet6_csk_xmit,
1887 .send_check = tcp_v6_send_check,
1888 .rebuild_header = inet6_sk_rebuild_header,
1889 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1890 .conn_request = tcp_v6_conn_request,
1891 .syn_recv_sock = tcp_v6_syn_recv_sock,
1892 .net_header_len = sizeof(struct ipv6hdr),
1893 .net_frag_header_len = sizeof(struct frag_hdr),
1894 .setsockopt = ipv6_setsockopt,
1895 .getsockopt = ipv6_getsockopt,
1896 .addr2sockaddr = inet6_csk_addr2sockaddr,
1897 .sockaddr_len = sizeof(struct sockaddr_in6),
1898 .mtu_reduced = tcp_v6_mtu_reduced,
1899};
1900
1901#ifdef CONFIG_TCP_MD5SIG
1902static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1903 .md5_lookup = tcp_v6_md5_lookup,
1904 .calc_md5_hash = tcp_v6_md5_hash_skb,
1905 .md5_parse = tcp_v6_parse_md5_keys,
1906};
1907#endif
1908
1909/*
1910 * TCP over IPv4 via INET6 API
1911 */
1912static const struct inet_connection_sock_af_ops ipv6_mapped = {
1913 .queue_xmit = ip_queue_xmit,
1914 .send_check = tcp_v4_send_check,
1915 .rebuild_header = inet_sk_rebuild_header,
1916 .sk_rx_dst_set = inet_sk_rx_dst_set,
1917 .conn_request = tcp_v6_conn_request,
1918 .syn_recv_sock = tcp_v6_syn_recv_sock,
1919 .net_header_len = sizeof(struct iphdr),
1920 .setsockopt = ipv6_setsockopt,
1921 .getsockopt = ipv6_getsockopt,
1922 .addr2sockaddr = inet6_csk_addr2sockaddr,
1923 .sockaddr_len = sizeof(struct sockaddr_in6),
1924 .mtu_reduced = tcp_v4_mtu_reduced,
1925};
1926
1927#ifdef CONFIG_TCP_MD5SIG
1928static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1929 .md5_lookup = tcp_v4_md5_lookup,
1930 .calc_md5_hash = tcp_v4_md5_hash_skb,
1931 .md5_parse = tcp_v6_parse_md5_keys,
1932};
1933#endif
1934
1935/* NOTE: A lot of things set to zero explicitly by call to
1936 * sk_alloc() so need not be done here.
1937 */
1938static int tcp_v6_init_sock(struct sock *sk)
1939{
1940 struct inet_connection_sock *icsk = inet_csk(sk);
1941
1942 tcp_init_sock(sk);
1943
1944 icsk->icsk_af_ops = &ipv6_specific;
1945
1946#ifdef CONFIG_TCP_MD5SIG
1947 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1948#endif
1949
1950 return 0;
1951}
1952
1953#ifdef CONFIG_PROC_FS
1954/* Proc filesystem TCPv6 sock list dumping. */
1955static void get_openreq6(struct seq_file *seq,
1956 const struct request_sock *req, int i)
1957{
1958 long ttd = req->rsk_timer.expires - jiffies;
1959 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1960 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1961
1962 if (ttd < 0)
1963 ttd = 0;
1964
1965 seq_printf(seq,
1966 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1967 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1968 i,
1969 src->s6_addr32[0], src->s6_addr32[1],
1970 src->s6_addr32[2], src->s6_addr32[3],
1971 inet_rsk(req)->ir_num,
1972 dest->s6_addr32[0], dest->s6_addr32[1],
1973 dest->s6_addr32[2], dest->s6_addr32[3],
1974 ntohs(inet_rsk(req)->ir_rmt_port),
1975 TCP_SYN_RECV,
1976 0, 0, /* could print option size, but that is af dependent. */
1977 1, /* timers active (only the expire timer) */
1978 jiffies_to_clock_t(ttd),
1979 req->num_timeout,
1980 from_kuid_munged(seq_user_ns(seq),
1981 sock_i_uid(req->rsk_listener)),
1982 0, /* non standard timer */
1983 0, /* open_requests have no inode */
1984 0, req);
1985}
1986
1987static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1988{
1989 const struct in6_addr *dest, *src;
1990 __u16 destp, srcp;
1991 int timer_active;
1992 unsigned long timer_expires;
1993 const struct inet_sock *inet = inet_sk(sp);
1994 const struct tcp_sock *tp = tcp_sk(sp);
1995 const struct inet_connection_sock *icsk = inet_csk(sp);
1996 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1997 int rx_queue;
1998 int state;
1999
2000 dest = &sp->sk_v6_daddr;
2001 src = &sp->sk_v6_rcv_saddr;
2002 destp = ntohs(inet->inet_dport);
2003 srcp = ntohs(inet->inet_sport);
2004
2005 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2006 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2007 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2008 timer_active = 1;
2009 timer_expires = icsk->icsk_timeout;
2010 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2011 timer_active = 4;
2012 timer_expires = icsk->icsk_timeout;
2013 } else if (timer_pending(&sp->sk_timer)) {
2014 timer_active = 2;
2015 timer_expires = sp->sk_timer.expires;
2016 } else {
2017 timer_active = 0;
2018 timer_expires = jiffies;
2019 }
2020
2021 state = inet_sk_state_load(sp);
2022 if (state == TCP_LISTEN)
2023 rx_queue = READ_ONCE(sp->sk_ack_backlog);
2024 else
2025 /* Because we don't lock the socket,
2026 * we might find a transient negative value.
2027 */
2028 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2029 READ_ONCE(tp->copied_seq), 0);
2030
2031 seq_printf(seq,
2032 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2033 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2034 i,
2035 src->s6_addr32[0], src->s6_addr32[1],
2036 src->s6_addr32[2], src->s6_addr32[3], srcp,
2037 dest->s6_addr32[0], dest->s6_addr32[1],
2038 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2039 state,
2040 READ_ONCE(tp->write_seq) - tp->snd_una,
2041 rx_queue,
2042 timer_active,
2043 jiffies_delta_to_clock_t(timer_expires - jiffies),
2044 icsk->icsk_retransmits,
2045 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2046 icsk->icsk_probes_out,
2047 sock_i_ino(sp),
2048 refcount_read(&sp->sk_refcnt), sp,
2049 jiffies_to_clock_t(icsk->icsk_rto),
2050 jiffies_to_clock_t(icsk->icsk_ack.ato),
2051 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2052 tcp_snd_cwnd(tp),
2053 state == TCP_LISTEN ?
2054 fastopenq->max_qlen :
2055 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2056 );
2057}
2058
2059static void get_timewait6_sock(struct seq_file *seq,
2060 struct inet_timewait_sock *tw, int i)
2061{
2062 long delta = tw->tw_timer.expires - jiffies;
2063 const struct in6_addr *dest, *src;
2064 __u16 destp, srcp;
2065
2066 dest = &tw->tw_v6_daddr;
2067 src = &tw->tw_v6_rcv_saddr;
2068 destp = ntohs(tw->tw_dport);
2069 srcp = ntohs(tw->tw_sport);
2070
2071 seq_printf(seq,
2072 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2073 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2074 i,
2075 src->s6_addr32[0], src->s6_addr32[1],
2076 src->s6_addr32[2], src->s6_addr32[3], srcp,
2077 dest->s6_addr32[0], dest->s6_addr32[1],
2078 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2079 tw->tw_substate, 0, 0,
2080 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2081 refcount_read(&tw->tw_refcnt), tw);
2082}
2083
2084static int tcp6_seq_show(struct seq_file *seq, void *v)
2085{
2086 struct tcp_iter_state *st;
2087 struct sock *sk = v;
2088
2089 if (v == SEQ_START_TOKEN) {
2090 seq_puts(seq,
2091 " sl "
2092 "local_address "
2093 "remote_address "
2094 "st tx_queue rx_queue tr tm->when retrnsmt"
2095 " uid timeout inode\n");
2096 goto out;
2097 }
2098 st = seq->private;
2099
2100 if (sk->sk_state == TCP_TIME_WAIT)
2101 get_timewait6_sock(seq, v, st->num);
2102 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2103 get_openreq6(seq, v, st->num);
2104 else
2105 get_tcp6_sock(seq, v, st->num);
2106out:
2107 return 0;
2108}
2109
2110static const struct seq_operations tcp6_seq_ops = {
2111 .show = tcp6_seq_show,
2112 .start = tcp_seq_start,
2113 .next = tcp_seq_next,
2114 .stop = tcp_seq_stop,
2115};
2116
2117static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2118 .family = AF_INET6,
2119};
2120
2121int __net_init tcp6_proc_init(struct net *net)
2122{
2123 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2124 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2125 return -ENOMEM;
2126 return 0;
2127}
2128
2129void tcp6_proc_exit(struct net *net)
2130{
2131 remove_proc_entry("tcp6", net->proc_net);
2132}
2133#endif
2134
2135struct proto tcpv6_prot = {
2136 .name = "TCPv6",
2137 .owner = THIS_MODULE,
2138 .close = tcp_close,
2139 .pre_connect = tcp_v6_pre_connect,
2140 .connect = tcp_v6_connect,
2141 .disconnect = tcp_disconnect,
2142 .accept = inet_csk_accept,
2143 .ioctl = tcp_ioctl,
2144 .init = tcp_v6_init_sock,
2145 .destroy = tcp_v4_destroy_sock,
2146 .shutdown = tcp_shutdown,
2147 .setsockopt = tcp_setsockopt,
2148 .getsockopt = tcp_getsockopt,
2149 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
2150 .keepalive = tcp_set_keepalive,
2151 .recvmsg = tcp_recvmsg,
2152 .sendmsg = tcp_sendmsg,
2153 .sendpage = tcp_sendpage,
2154 .backlog_rcv = tcp_v6_do_rcv,
2155 .release_cb = tcp_release_cb,
2156 .hash = inet6_hash,
2157 .unhash = inet_unhash,
2158 .get_port = inet_csk_get_port,
2159 .put_port = inet_put_port,
2160#ifdef CONFIG_BPF_SYSCALL
2161 .psock_update_sk_prot = tcp_bpf_update_proto,
2162#endif
2163 .enter_memory_pressure = tcp_enter_memory_pressure,
2164 .leave_memory_pressure = tcp_leave_memory_pressure,
2165 .stream_memory_free = tcp_stream_memory_free,
2166 .sockets_allocated = &tcp_sockets_allocated,
2167
2168 .memory_allocated = &tcp_memory_allocated,
2169 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
2170
2171 .memory_pressure = &tcp_memory_pressure,
2172 .orphan_count = &tcp_orphan_count,
2173 .sysctl_mem = sysctl_tcp_mem,
2174 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2175 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2176 .max_header = MAX_TCP_HEADER,
2177 .obj_size = sizeof(struct tcp6_sock),
2178 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2179 .twsk_prot = &tcp6_timewait_sock_ops,
2180 .rsk_prot = &tcp6_request_sock_ops,
2181 .h.hashinfo = NULL,
2182 .no_autobind = true,
2183 .diag_destroy = tcp_abort,
2184};
2185EXPORT_SYMBOL_GPL(tcpv6_prot);
2186
2187static const struct inet6_protocol tcpv6_protocol = {
2188 .handler = tcp_v6_rcv,
2189 .err_handler = tcp_v6_err,
2190 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2191};
2192
2193static struct inet_protosw tcpv6_protosw = {
2194 .type = SOCK_STREAM,
2195 .protocol = IPPROTO_TCP,
2196 .prot = &tcpv6_prot,
2197 .ops = &inet6_stream_ops,
2198 .flags = INET_PROTOSW_PERMANENT |
2199 INET_PROTOSW_ICSK,
2200};
2201
2202static int __net_init tcpv6_net_init(struct net *net)
2203{
2204 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2205 SOCK_RAW, IPPROTO_TCP, net);
2206}
2207
2208static void __net_exit tcpv6_net_exit(struct net *net)
2209{
2210 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2211}
2212
2213static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2214{
2215 tcp_twsk_purge(net_exit_list, AF_INET6);
2216}
2217
2218static struct pernet_operations tcpv6_net_ops = {
2219 .init = tcpv6_net_init,
2220 .exit = tcpv6_net_exit,
2221 .exit_batch = tcpv6_net_exit_batch,
2222};
2223
2224int __init tcpv6_init(void)
2225{
2226 int ret;
2227
2228 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2229 if (ret)
2230 goto out;
2231
2232 /* register inet6 protocol */
2233 ret = inet6_register_protosw(&tcpv6_protosw);
2234 if (ret)
2235 goto out_tcpv6_protocol;
2236
2237 ret = register_pernet_subsys(&tcpv6_net_ops);
2238 if (ret)
2239 goto out_tcpv6_protosw;
2240
2241 ret = mptcpv6_init();
2242 if (ret)
2243 goto out_tcpv6_pernet_subsys;
2244
2245out:
2246 return ret;
2247
2248out_tcpv6_pernet_subsys:
2249 unregister_pernet_subsys(&tcpv6_net_ops);
2250out_tcpv6_protosw:
2251 inet6_unregister_protosw(&tcpv6_protosw);
2252out_tcpv6_protocol:
2253 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2254 goto out;
2255}
2256
2257void tcpv6_exit(void)
2258{
2259 unregister_pernet_subsys(&tcpv6_net_ops);
2260 inet6_unregister_protosw(&tcpv6_protosw);
2261 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2262}