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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
75static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77static const struct inet_connection_sock_af_ops ipv6_mapped;
78static const 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{
86 return NULL;
87}
88#endif
89
90/* Helper returning the inet6 address from a given tcp socket.
91 * It can be used in TCP stack instead of inet6_sk(sk).
92 * This avoids a dereference and allow compiler optimizations.
93 * It is a specialized version of inet6_sk_generic().
94 */
95static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
96{
97 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
98
99 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
100}
101
102static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
103{
104 struct dst_entry *dst = skb_dst(skb);
105
106 if (dst && dst_hold_safe(dst)) {
107 const struct rt6_info *rt = (const struct rt6_info *)dst;
108
109 sk->sk_rx_dst = dst;
110 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
111 tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
112 }
113}
114
115static u32 tcp_v6_init_seq(const struct sk_buff *skb)
116{
117 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
118 ipv6_hdr(skb)->saddr.s6_addr32,
119 tcp_hdr(skb)->dest,
120 tcp_hdr(skb)->source);
121}
122
123static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
124{
125 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
126 ipv6_hdr(skb)->saddr.s6_addr32);
127}
128
129static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
130 int addr_len)
131{
132 /* This check is replicated from tcp_v6_connect() and intended to
133 * prevent BPF program called below from accessing bytes that are out
134 * of the bound specified by user in addr_len.
135 */
136 if (addr_len < SIN6_LEN_RFC2133)
137 return -EINVAL;
138
139 sock_owned_by_me(sk);
140
141 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
142}
143
144static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
145 int addr_len)
146{
147 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
148 struct inet_sock *inet = inet_sk(sk);
149 struct inet_connection_sock *icsk = inet_csk(sk);
150 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
151 struct tcp_sock *tp = tcp_sk(sk);
152 struct in6_addr *saddr = NULL, *final_p, final;
153 struct ipv6_txoptions *opt;
154 struct flowi6 fl6;
155 struct dst_entry *dst;
156 int addr_type;
157 int err;
158 struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
159
160 if (addr_len < SIN6_LEN_RFC2133)
161 return -EINVAL;
162
163 if (usin->sin6_family != AF_INET6)
164 return -EAFNOSUPPORT;
165
166 memset(&fl6, 0, sizeof(fl6));
167
168 if (np->sndflow) {
169 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
170 IP6_ECN_flow_init(fl6.flowlabel);
171 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
172 struct ip6_flowlabel *flowlabel;
173 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
174 if (IS_ERR(flowlabel))
175 return -EINVAL;
176 fl6_sock_release(flowlabel);
177 }
178 }
179
180 /*
181 * connect() to INADDR_ANY means loopback (BSD'ism).
182 */
183
184 if (ipv6_addr_any(&usin->sin6_addr)) {
185 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
186 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
187 &usin->sin6_addr);
188 else
189 usin->sin6_addr = in6addr_loopback;
190 }
191
192 addr_type = ipv6_addr_type(&usin->sin6_addr);
193
194 if (addr_type & IPV6_ADDR_MULTICAST)
195 return -ENETUNREACH;
196
197 if (addr_type&IPV6_ADDR_LINKLOCAL) {
198 if (addr_len >= sizeof(struct sockaddr_in6) &&
199 usin->sin6_scope_id) {
200 /* If interface is set while binding, indices
201 * must coincide.
202 */
203 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
204 return -EINVAL;
205
206 sk->sk_bound_dev_if = usin->sin6_scope_id;
207 }
208
209 /* Connect to link-local address requires an interface */
210 if (!sk->sk_bound_dev_if)
211 return -EINVAL;
212 }
213
214 if (tp->rx_opt.ts_recent_stamp &&
215 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
216 tp->rx_opt.ts_recent = 0;
217 tp->rx_opt.ts_recent_stamp = 0;
218 WRITE_ONCE(tp->write_seq, 0);
219 }
220
221 sk->sk_v6_daddr = usin->sin6_addr;
222 np->flow_label = fl6.flowlabel;
223
224 /*
225 * TCP over IPv4
226 */
227
228 if (addr_type & IPV6_ADDR_MAPPED) {
229 u32 exthdrlen = icsk->icsk_ext_hdr_len;
230 struct sockaddr_in sin;
231
232 if (__ipv6_only_sock(sk))
233 return -ENETUNREACH;
234
235 sin.sin_family = AF_INET;
236 sin.sin_port = usin->sin6_port;
237 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
238
239 icsk->icsk_af_ops = &ipv6_mapped;
240 sk->sk_backlog_rcv = tcp_v4_do_rcv;
241#ifdef CONFIG_TCP_MD5SIG
242 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
243#endif
244
245 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
246
247 if (err) {
248 icsk->icsk_ext_hdr_len = exthdrlen;
249 icsk->icsk_af_ops = &ipv6_specific;
250 sk->sk_backlog_rcv = tcp_v6_do_rcv;
251#ifdef CONFIG_TCP_MD5SIG
252 tp->af_specific = &tcp_sock_ipv6_specific;
253#endif
254 goto failure;
255 }
256 np->saddr = sk->sk_v6_rcv_saddr;
257
258 return err;
259 }
260
261 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
262 saddr = &sk->sk_v6_rcv_saddr;
263
264 fl6.flowi6_proto = IPPROTO_TCP;
265 fl6.daddr = sk->sk_v6_daddr;
266 fl6.saddr = saddr ? *saddr : np->saddr;
267 fl6.flowi6_oif = sk->sk_bound_dev_if;
268 fl6.flowi6_mark = sk->sk_mark;
269 fl6.fl6_dport = usin->sin6_port;
270 fl6.fl6_sport = inet->inet_sport;
271 fl6.flowi6_uid = sk->sk_uid;
272
273 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
274 final_p = fl6_update_dst(&fl6, opt, &final);
275
276 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
277
278 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
279 if (IS_ERR(dst)) {
280 err = PTR_ERR(dst);
281 goto failure;
282 }
283
284 if (!saddr) {
285 saddr = &fl6.saddr;
286 sk->sk_v6_rcv_saddr = *saddr;
287 }
288
289 /* set the source address */
290 np->saddr = *saddr;
291 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
292
293 sk->sk_gso_type = SKB_GSO_TCPV6;
294 ip6_dst_store(sk, dst, NULL, NULL);
295
296 icsk->icsk_ext_hdr_len = 0;
297 if (opt)
298 icsk->icsk_ext_hdr_len = opt->opt_flen +
299 opt->opt_nflen;
300
301 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
302
303 inet->inet_dport = usin->sin6_port;
304
305 tcp_set_state(sk, TCP_SYN_SENT);
306 err = inet6_hash_connect(tcp_death_row, sk);
307 if (err)
308 goto late_failure;
309
310 sk_set_txhash(sk);
311
312 if (likely(!tp->repair)) {
313 if (!tp->write_seq)
314 WRITE_ONCE(tp->write_seq,
315 secure_tcpv6_seq(np->saddr.s6_addr32,
316 sk->sk_v6_daddr.s6_addr32,
317 inet->inet_sport,
318 inet->inet_dport));
319 tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk),
320 np->saddr.s6_addr32,
321 sk->sk_v6_daddr.s6_addr32);
322 }
323
324 if (tcp_fastopen_defer_connect(sk, &err))
325 return err;
326 if (err)
327 goto late_failure;
328
329 err = tcp_connect(sk);
330 if (err)
331 goto late_failure;
332
333 return 0;
334
335late_failure:
336 tcp_set_state(sk, TCP_CLOSE);
337failure:
338 inet->inet_dport = 0;
339 sk->sk_route_caps = 0;
340 return err;
341}
342
343static void tcp_v6_mtu_reduced(struct sock *sk)
344{
345 struct dst_entry *dst;
346
347 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
348 return;
349
350 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
351 if (!dst)
352 return;
353
354 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
355 tcp_sync_mss(sk, dst_mtu(dst));
356 tcp_simple_retransmit(sk);
357 }
358}
359
360static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
361 u8 type, u8 code, int offset, __be32 info)
362{
363 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
364 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
365 struct net *net = dev_net(skb->dev);
366 struct request_sock *fastopen;
367 struct ipv6_pinfo *np;
368 struct tcp_sock *tp;
369 __u32 seq, snd_una;
370 struct sock *sk;
371 bool fatal;
372 int err;
373
374 sk = __inet6_lookup_established(net, &tcp_hashinfo,
375 &hdr->daddr, th->dest,
376 &hdr->saddr, ntohs(th->source),
377 skb->dev->ifindex, inet6_sdif(skb));
378
379 if (!sk) {
380 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
381 ICMP6_MIB_INERRORS);
382 return -ENOENT;
383 }
384
385 if (sk->sk_state == TCP_TIME_WAIT) {
386 inet_twsk_put(inet_twsk(sk));
387 return 0;
388 }
389 seq = ntohl(th->seq);
390 fatal = icmpv6_err_convert(type, code, &err);
391 if (sk->sk_state == TCP_NEW_SYN_RECV) {
392 tcp_req_err(sk, seq, fatal);
393 return 0;
394 }
395
396 bh_lock_sock(sk);
397 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
398 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
399
400 if (sk->sk_state == TCP_CLOSE)
401 goto out;
402
403 if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
404 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
405 goto out;
406 }
407
408 tp = tcp_sk(sk);
409 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
410 fastopen = rcu_dereference(tp->fastopen_rsk);
411 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
412 if (sk->sk_state != TCP_LISTEN &&
413 !between(seq, snd_una, tp->snd_nxt)) {
414 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
415 goto out;
416 }
417
418 np = tcp_inet6_sk(sk);
419
420 if (type == NDISC_REDIRECT) {
421 if (!sock_owned_by_user(sk)) {
422 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
423
424 if (dst)
425 dst->ops->redirect(dst, sk, skb);
426 }
427 goto out;
428 }
429
430 if (type == ICMPV6_PKT_TOOBIG) {
431 /* We are not interested in TCP_LISTEN and open_requests
432 * (SYN-ACKs send out by Linux are always <576bytes so
433 * they should go through unfragmented).
434 */
435 if (sk->sk_state == TCP_LISTEN)
436 goto out;
437
438 if (!ip6_sk_accept_pmtu(sk))
439 goto out;
440
441 tp->mtu_info = ntohl(info);
442 if (!sock_owned_by_user(sk))
443 tcp_v6_mtu_reduced(sk);
444 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
445 &sk->sk_tsq_flags))
446 sock_hold(sk);
447 goto out;
448 }
449
450
451 /* Might be for an request_sock */
452 switch (sk->sk_state) {
453 case TCP_SYN_SENT:
454 case TCP_SYN_RECV:
455 /* Only in fast or simultaneous open. If a fast open socket is
456 * is already accepted it is treated as a connected one below.
457 */
458 if (fastopen && !fastopen->sk)
459 break;
460
461 if (!sock_owned_by_user(sk)) {
462 sk->sk_err = err;
463 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
464
465 tcp_done(sk);
466 } else
467 sk->sk_err_soft = err;
468 goto out;
469 }
470
471 if (!sock_owned_by_user(sk) && np->recverr) {
472 sk->sk_err = err;
473 sk->sk_error_report(sk);
474 } else
475 sk->sk_err_soft = err;
476
477out:
478 bh_unlock_sock(sk);
479 sock_put(sk);
480 return 0;
481}
482
483
484static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
485 struct flowi *fl,
486 struct request_sock *req,
487 struct tcp_fastopen_cookie *foc,
488 enum tcp_synack_type synack_type)
489{
490 struct inet_request_sock *ireq = inet_rsk(req);
491 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
492 struct ipv6_txoptions *opt;
493 struct flowi6 *fl6 = &fl->u.ip6;
494 struct sk_buff *skb;
495 int err = -ENOMEM;
496
497 /* First, grab a route. */
498 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
499 IPPROTO_TCP)) == NULL)
500 goto done;
501
502 skb = tcp_make_synack(sk, dst, req, foc, synack_type);
503
504 if (skb) {
505 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
506 &ireq->ir_v6_rmt_addr);
507
508 fl6->daddr = ireq->ir_v6_rmt_addr;
509 if (np->repflow && ireq->pktopts)
510 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
511
512 rcu_read_lock();
513 opt = ireq->ipv6_opt;
514 if (!opt)
515 opt = rcu_dereference(np->opt);
516 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass,
517 sk->sk_priority);
518 rcu_read_unlock();
519 err = net_xmit_eval(err);
520 }
521
522done:
523 return err;
524}
525
526
527static void tcp_v6_reqsk_destructor(struct request_sock *req)
528{
529 kfree(inet_rsk(req)->ipv6_opt);
530 kfree_skb(inet_rsk(req)->pktopts);
531}
532
533#ifdef CONFIG_TCP_MD5SIG
534static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
535 const struct in6_addr *addr)
536{
537 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
538}
539
540static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
541 const struct sock *addr_sk)
542{
543 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
544}
545
546static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
547 char __user *optval, int optlen)
548{
549 struct tcp_md5sig cmd;
550 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
551 u8 prefixlen;
552
553 if (optlen < sizeof(cmd))
554 return -EINVAL;
555
556 if (copy_from_user(&cmd, optval, sizeof(cmd)))
557 return -EFAULT;
558
559 if (sin6->sin6_family != AF_INET6)
560 return -EINVAL;
561
562 if (optname == TCP_MD5SIG_EXT &&
563 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
564 prefixlen = cmd.tcpm_prefixlen;
565 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
566 prefixlen > 32))
567 return -EINVAL;
568 } else {
569 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
570 }
571
572 if (!cmd.tcpm_keylen) {
573 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
574 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
575 AF_INET, prefixlen);
576 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
577 AF_INET6, prefixlen);
578 }
579
580 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
581 return -EINVAL;
582
583 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
584 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
585 AF_INET, prefixlen, cmd.tcpm_key,
586 cmd.tcpm_keylen, GFP_KERNEL);
587
588 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
589 AF_INET6, prefixlen, cmd.tcpm_key,
590 cmd.tcpm_keylen, GFP_KERNEL);
591}
592
593static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
594 const struct in6_addr *daddr,
595 const struct in6_addr *saddr,
596 const struct tcphdr *th, int nbytes)
597{
598 struct tcp6_pseudohdr *bp;
599 struct scatterlist sg;
600 struct tcphdr *_th;
601
602 bp = hp->scratch;
603 /* 1. TCP pseudo-header (RFC2460) */
604 bp->saddr = *saddr;
605 bp->daddr = *daddr;
606 bp->protocol = cpu_to_be32(IPPROTO_TCP);
607 bp->len = cpu_to_be32(nbytes);
608
609 _th = (struct tcphdr *)(bp + 1);
610 memcpy(_th, th, sizeof(*th));
611 _th->check = 0;
612
613 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
614 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
615 sizeof(*bp) + sizeof(*th));
616 return crypto_ahash_update(hp->md5_req);
617}
618
619static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
620 const struct in6_addr *daddr, struct in6_addr *saddr,
621 const struct tcphdr *th)
622{
623 struct tcp_md5sig_pool *hp;
624 struct ahash_request *req;
625
626 hp = tcp_get_md5sig_pool();
627 if (!hp)
628 goto clear_hash_noput;
629 req = hp->md5_req;
630
631 if (crypto_ahash_init(req))
632 goto clear_hash;
633 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
634 goto clear_hash;
635 if (tcp_md5_hash_key(hp, key))
636 goto clear_hash;
637 ahash_request_set_crypt(req, NULL, md5_hash, 0);
638 if (crypto_ahash_final(req))
639 goto clear_hash;
640
641 tcp_put_md5sig_pool();
642 return 0;
643
644clear_hash:
645 tcp_put_md5sig_pool();
646clear_hash_noput:
647 memset(md5_hash, 0, 16);
648 return 1;
649}
650
651static int tcp_v6_md5_hash_skb(char *md5_hash,
652 const struct tcp_md5sig_key *key,
653 const struct sock *sk,
654 const struct sk_buff *skb)
655{
656 const struct in6_addr *saddr, *daddr;
657 struct tcp_md5sig_pool *hp;
658 struct ahash_request *req;
659 const struct tcphdr *th = tcp_hdr(skb);
660
661 if (sk) { /* valid for establish/request sockets */
662 saddr = &sk->sk_v6_rcv_saddr;
663 daddr = &sk->sk_v6_daddr;
664 } else {
665 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
666 saddr = &ip6h->saddr;
667 daddr = &ip6h->daddr;
668 }
669
670 hp = tcp_get_md5sig_pool();
671 if (!hp)
672 goto clear_hash_noput;
673 req = hp->md5_req;
674
675 if (crypto_ahash_init(req))
676 goto clear_hash;
677
678 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
679 goto clear_hash;
680 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
681 goto clear_hash;
682 if (tcp_md5_hash_key(hp, key))
683 goto clear_hash;
684 ahash_request_set_crypt(req, NULL, md5_hash, 0);
685 if (crypto_ahash_final(req))
686 goto clear_hash;
687
688 tcp_put_md5sig_pool();
689 return 0;
690
691clear_hash:
692 tcp_put_md5sig_pool();
693clear_hash_noput:
694 memset(md5_hash, 0, 16);
695 return 1;
696}
697
698#endif
699
700static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
701 const struct sk_buff *skb)
702{
703#ifdef CONFIG_TCP_MD5SIG
704 const __u8 *hash_location = NULL;
705 struct tcp_md5sig_key *hash_expected;
706 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
707 const struct tcphdr *th = tcp_hdr(skb);
708 int genhash;
709 u8 newhash[16];
710
711 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
712 hash_location = tcp_parse_md5sig_option(th);
713
714 /* We've parsed the options - do we have a hash? */
715 if (!hash_expected && !hash_location)
716 return false;
717
718 if (hash_expected && !hash_location) {
719 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
720 return true;
721 }
722
723 if (!hash_expected && hash_location) {
724 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
725 return true;
726 }
727
728 /* check the signature */
729 genhash = tcp_v6_md5_hash_skb(newhash,
730 hash_expected,
731 NULL, skb);
732
733 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
734 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
735 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
736 genhash ? "failed" : "mismatch",
737 &ip6h->saddr, ntohs(th->source),
738 &ip6h->daddr, ntohs(th->dest));
739 return true;
740 }
741#endif
742 return false;
743}
744
745static void tcp_v6_init_req(struct request_sock *req,
746 const struct sock *sk_listener,
747 struct sk_buff *skb)
748{
749 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
750 struct inet_request_sock *ireq = inet_rsk(req);
751 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
752
753 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
754 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
755
756 /* So that link locals have meaning */
757 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
758 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
759 ireq->ir_iif = tcp_v6_iif(skb);
760
761 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
762 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
763 np->rxopt.bits.rxinfo ||
764 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
765 np->rxopt.bits.rxohlim || np->repflow)) {
766 refcount_inc(&skb->users);
767 ireq->pktopts = skb;
768 }
769}
770
771static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
772 struct flowi *fl,
773 const struct request_sock *req)
774{
775 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
776}
777
778struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
779 .family = AF_INET6,
780 .obj_size = sizeof(struct tcp6_request_sock),
781 .rtx_syn_ack = tcp_rtx_synack,
782 .send_ack = tcp_v6_reqsk_send_ack,
783 .destructor = tcp_v6_reqsk_destructor,
784 .send_reset = tcp_v6_send_reset,
785 .syn_ack_timeout = tcp_syn_ack_timeout,
786};
787
788static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
789 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
790 sizeof(struct ipv6hdr),
791#ifdef CONFIG_TCP_MD5SIG
792 .req_md5_lookup = tcp_v6_md5_lookup,
793 .calc_md5_hash = tcp_v6_md5_hash_skb,
794#endif
795 .init_req = tcp_v6_init_req,
796#ifdef CONFIG_SYN_COOKIES
797 .cookie_init_seq = cookie_v6_init_sequence,
798#endif
799 .route_req = tcp_v6_route_req,
800 .init_seq = tcp_v6_init_seq,
801 .init_ts_off = tcp_v6_init_ts_off,
802 .send_synack = tcp_v6_send_synack,
803};
804
805static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
806 u32 ack, u32 win, u32 tsval, u32 tsecr,
807 int oif, struct tcp_md5sig_key *key, int rst,
808 u8 tclass, __be32 label, u32 priority)
809{
810 const struct tcphdr *th = tcp_hdr(skb);
811 struct tcphdr *t1;
812 struct sk_buff *buff;
813 struct flowi6 fl6;
814 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
815 struct sock *ctl_sk = net->ipv6.tcp_sk;
816 unsigned int tot_len = sizeof(struct tcphdr);
817 struct dst_entry *dst;
818 __be32 *topt;
819 __u32 mark = 0;
820
821 if (tsecr)
822 tot_len += TCPOLEN_TSTAMP_ALIGNED;
823#ifdef CONFIG_TCP_MD5SIG
824 if (key)
825 tot_len += TCPOLEN_MD5SIG_ALIGNED;
826#endif
827
828 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
829 GFP_ATOMIC);
830 if (!buff)
831 return;
832
833 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
834
835 t1 = skb_push(buff, tot_len);
836 skb_reset_transport_header(buff);
837
838 /* Swap the send and the receive. */
839 memset(t1, 0, sizeof(*t1));
840 t1->dest = th->source;
841 t1->source = th->dest;
842 t1->doff = tot_len / 4;
843 t1->seq = htonl(seq);
844 t1->ack_seq = htonl(ack);
845 t1->ack = !rst || !th->ack;
846 t1->rst = rst;
847 t1->window = htons(win);
848
849 topt = (__be32 *)(t1 + 1);
850
851 if (tsecr) {
852 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
853 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
854 *topt++ = htonl(tsval);
855 *topt++ = htonl(tsecr);
856 }
857
858#ifdef CONFIG_TCP_MD5SIG
859 if (key) {
860 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
861 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
862 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
863 &ipv6_hdr(skb)->saddr,
864 &ipv6_hdr(skb)->daddr, t1);
865 }
866#endif
867
868 memset(&fl6, 0, sizeof(fl6));
869 fl6.daddr = ipv6_hdr(skb)->saddr;
870 fl6.saddr = ipv6_hdr(skb)->daddr;
871 fl6.flowlabel = label;
872
873 buff->ip_summed = CHECKSUM_PARTIAL;
874 buff->csum = 0;
875
876 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
877
878 fl6.flowi6_proto = IPPROTO_TCP;
879 if (rt6_need_strict(&fl6.daddr) && !oif)
880 fl6.flowi6_oif = tcp_v6_iif(skb);
881 else {
882 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
883 oif = skb->skb_iif;
884
885 fl6.flowi6_oif = oif;
886 }
887
888 if (sk) {
889 if (sk->sk_state == TCP_TIME_WAIT) {
890 mark = inet_twsk(sk)->tw_mark;
891 /* autoflowlabel relies on buff->hash */
892 skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
893 PKT_HASH_TYPE_L4);
894 } else {
895 mark = sk->sk_mark;
896 }
897 buff->tstamp = tcp_transmit_time(sk);
898 }
899 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
900 fl6.fl6_dport = t1->dest;
901 fl6.fl6_sport = t1->source;
902 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
903 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
904
905 /* Pass a socket to ip6_dst_lookup either it is for RST
906 * Underlying function will use this to retrieve the network
907 * namespace
908 */
909 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
910 if (!IS_ERR(dst)) {
911 skb_dst_set(buff, dst);
912 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass,
913 priority);
914 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
915 if (rst)
916 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
917 return;
918 }
919
920 kfree_skb(buff);
921}
922
923static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
924{
925 const struct tcphdr *th = tcp_hdr(skb);
926 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
927 u32 seq = 0, ack_seq = 0;
928 struct tcp_md5sig_key *key = NULL;
929#ifdef CONFIG_TCP_MD5SIG
930 const __u8 *hash_location = NULL;
931 unsigned char newhash[16];
932 int genhash;
933 struct sock *sk1 = NULL;
934#endif
935 __be32 label = 0;
936 u32 priority = 0;
937 struct net *net;
938 int oif = 0;
939
940 if (th->rst)
941 return;
942
943 /* If sk not NULL, it means we did a successful lookup and incoming
944 * route had to be correct. prequeue might have dropped our dst.
945 */
946 if (!sk && !ipv6_unicast_destination(skb))
947 return;
948
949 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
950#ifdef CONFIG_TCP_MD5SIG
951 rcu_read_lock();
952 hash_location = tcp_parse_md5sig_option(th);
953 if (sk && sk_fullsock(sk)) {
954 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
955 } else if (hash_location) {
956 /*
957 * active side is lost. Try to find listening socket through
958 * source port, and then find md5 key through listening socket.
959 * we are not loose security here:
960 * Incoming packet is checked with md5 hash with finding key,
961 * no RST generated if md5 hash doesn't match.
962 */
963 sk1 = inet6_lookup_listener(net,
964 &tcp_hashinfo, NULL, 0,
965 &ipv6h->saddr,
966 th->source, &ipv6h->daddr,
967 ntohs(th->source),
968 tcp_v6_iif_l3_slave(skb),
969 tcp_v6_sdif(skb));
970 if (!sk1)
971 goto out;
972
973 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
974 if (!key)
975 goto out;
976
977 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
978 if (genhash || memcmp(hash_location, newhash, 16) != 0)
979 goto out;
980 }
981#endif
982
983 if (th->ack)
984 seq = ntohl(th->ack_seq);
985 else
986 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
987 (th->doff << 2);
988
989 if (sk) {
990 oif = sk->sk_bound_dev_if;
991 if (sk_fullsock(sk)) {
992 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
993
994 trace_tcp_send_reset(sk, skb);
995 if (np->repflow)
996 label = ip6_flowlabel(ipv6h);
997 priority = sk->sk_priority;
998 }
999 if (sk->sk_state == TCP_TIME_WAIT) {
1000 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1001 priority = inet_twsk(sk)->tw_priority;
1002 }
1003 } else {
1004 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1005 label = ip6_flowlabel(ipv6h);
1006 }
1007
1008 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0,
1009 label, priority);
1010
1011#ifdef CONFIG_TCP_MD5SIG
1012out:
1013 rcu_read_unlock();
1014#endif
1015}
1016
1017static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1018 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1019 struct tcp_md5sig_key *key, u8 tclass,
1020 __be32 label, u32 priority)
1021{
1022 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1023 tclass, label, priority);
1024}
1025
1026static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1027{
1028 struct inet_timewait_sock *tw = inet_twsk(sk);
1029 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1030
1031 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1032 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1033 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1034 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1035 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
1036
1037 inet_twsk_put(tw);
1038}
1039
1040static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1041 struct request_sock *req)
1042{
1043 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1044 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1045 */
1046 /* RFC 7323 2.3
1047 * The window field (SEG.WND) of every outgoing segment, with the
1048 * exception of <SYN> segments, MUST be right-shifted by
1049 * Rcv.Wind.Shift bits:
1050 */
1051 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1052 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1053 tcp_rsk(req)->rcv_nxt,
1054 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1055 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1056 req->ts_recent, sk->sk_bound_dev_if,
1057 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr),
1058 0, 0, sk->sk_priority);
1059}
1060
1061
1062static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1063{
1064#ifdef CONFIG_SYN_COOKIES
1065 const struct tcphdr *th = tcp_hdr(skb);
1066
1067 if (!th->syn)
1068 sk = cookie_v6_check(sk, skb);
1069#endif
1070 return sk;
1071}
1072
1073u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1074 struct tcphdr *th, u32 *cookie)
1075{
1076 u16 mss = 0;
1077#ifdef CONFIG_SYN_COOKIES
1078 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1079 &tcp_request_sock_ipv6_ops, sk, th);
1080 if (mss) {
1081 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1082 tcp_synq_overflow(sk);
1083 }
1084#endif
1085 return mss;
1086}
1087
1088static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1089{
1090 if (skb->protocol == htons(ETH_P_IP))
1091 return tcp_v4_conn_request(sk, skb);
1092
1093 if (!ipv6_unicast_destination(skb))
1094 goto drop;
1095
1096 return tcp_conn_request(&tcp6_request_sock_ops,
1097 &tcp_request_sock_ipv6_ops, sk, skb);
1098
1099drop:
1100 tcp_listendrop(sk);
1101 return 0; /* don't send reset */
1102}
1103
1104static void tcp_v6_restore_cb(struct sk_buff *skb)
1105{
1106 /* We need to move header back to the beginning if xfrm6_policy_check()
1107 * and tcp_v6_fill_cb() are going to be called again.
1108 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1109 */
1110 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1111 sizeof(struct inet6_skb_parm));
1112}
1113
1114static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1115 struct request_sock *req,
1116 struct dst_entry *dst,
1117 struct request_sock *req_unhash,
1118 bool *own_req)
1119{
1120 struct inet_request_sock *ireq;
1121 struct ipv6_pinfo *newnp;
1122 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1123 struct ipv6_txoptions *opt;
1124 struct inet_sock *newinet;
1125 struct tcp_sock *newtp;
1126 struct sock *newsk;
1127#ifdef CONFIG_TCP_MD5SIG
1128 struct tcp_md5sig_key *key;
1129#endif
1130 struct flowi6 fl6;
1131
1132 if (skb->protocol == htons(ETH_P_IP)) {
1133 /*
1134 * v6 mapped
1135 */
1136
1137 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1138 req_unhash, own_req);
1139
1140 if (!newsk)
1141 return NULL;
1142
1143 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1144
1145 newinet = inet_sk(newsk);
1146 newnp = tcp_inet6_sk(newsk);
1147 newtp = tcp_sk(newsk);
1148
1149 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1150
1151 newnp->saddr = newsk->sk_v6_rcv_saddr;
1152
1153 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1154 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1155#ifdef CONFIG_TCP_MD5SIG
1156 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1157#endif
1158
1159 newnp->ipv6_mc_list = NULL;
1160 newnp->ipv6_ac_list = NULL;
1161 newnp->ipv6_fl_list = NULL;
1162 newnp->pktoptions = NULL;
1163 newnp->opt = NULL;
1164 newnp->mcast_oif = inet_iif(skb);
1165 newnp->mcast_hops = ip_hdr(skb)->ttl;
1166 newnp->rcv_flowinfo = 0;
1167 if (np->repflow)
1168 newnp->flow_label = 0;
1169
1170 /*
1171 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1172 * here, tcp_create_openreq_child now does this for us, see the comment in
1173 * that function for the gory details. -acme
1174 */
1175
1176 /* It is tricky place. Until this moment IPv4 tcp
1177 worked with IPv6 icsk.icsk_af_ops.
1178 Sync it now.
1179 */
1180 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1181
1182 return newsk;
1183 }
1184
1185 ireq = inet_rsk(req);
1186
1187 if (sk_acceptq_is_full(sk))
1188 goto out_overflow;
1189
1190 if (!dst) {
1191 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1192 if (!dst)
1193 goto out;
1194 }
1195
1196 newsk = tcp_create_openreq_child(sk, req, skb);
1197 if (!newsk)
1198 goto out_nonewsk;
1199
1200 /*
1201 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1202 * count here, tcp_create_openreq_child now does this for us, see the
1203 * comment in that function for the gory details. -acme
1204 */
1205
1206 newsk->sk_gso_type = SKB_GSO_TCPV6;
1207 ip6_dst_store(newsk, dst, NULL, NULL);
1208 inet6_sk_rx_dst_set(newsk, skb);
1209
1210 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1211
1212 newtp = tcp_sk(newsk);
1213 newinet = inet_sk(newsk);
1214 newnp = tcp_inet6_sk(newsk);
1215
1216 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1217
1218 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1219 newnp->saddr = ireq->ir_v6_loc_addr;
1220 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1221 newsk->sk_bound_dev_if = ireq->ir_iif;
1222
1223 /* Now IPv6 options...
1224
1225 First: no IPv4 options.
1226 */
1227 newinet->inet_opt = NULL;
1228 newnp->ipv6_mc_list = NULL;
1229 newnp->ipv6_ac_list = NULL;
1230 newnp->ipv6_fl_list = NULL;
1231
1232 /* Clone RX bits */
1233 newnp->rxopt.all = np->rxopt.all;
1234
1235 newnp->pktoptions = NULL;
1236 newnp->opt = NULL;
1237 newnp->mcast_oif = tcp_v6_iif(skb);
1238 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1239 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1240 if (np->repflow)
1241 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1242
1243 /* Clone native IPv6 options from listening socket (if any)
1244
1245 Yes, keeping reference count would be much more clever,
1246 but we make one more one thing there: reattach optmem
1247 to newsk.
1248 */
1249 opt = ireq->ipv6_opt;
1250 if (!opt)
1251 opt = rcu_dereference(np->opt);
1252 if (opt) {
1253 opt = ipv6_dup_options(newsk, opt);
1254 RCU_INIT_POINTER(newnp->opt, opt);
1255 }
1256 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1257 if (opt)
1258 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1259 opt->opt_flen;
1260
1261 tcp_ca_openreq_child(newsk, dst);
1262
1263 tcp_sync_mss(newsk, dst_mtu(dst));
1264 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1265
1266 tcp_initialize_rcv_mss(newsk);
1267
1268 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1269 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1270
1271#ifdef CONFIG_TCP_MD5SIG
1272 /* Copy over the MD5 key from the original socket */
1273 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1274 if (key) {
1275 /* We're using one, so create a matching key
1276 * on the newsk structure. If we fail to get
1277 * memory, then we end up not copying the key
1278 * across. Shucks.
1279 */
1280 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1281 AF_INET6, 128, key->key, key->keylen,
1282 sk_gfp_mask(sk, GFP_ATOMIC));
1283 }
1284#endif
1285
1286 if (__inet_inherit_port(sk, newsk) < 0) {
1287 inet_csk_prepare_forced_close(newsk);
1288 tcp_done(newsk);
1289 goto out;
1290 }
1291 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1292 if (*own_req) {
1293 tcp_move_syn(newtp, req);
1294
1295 /* Clone pktoptions received with SYN, if we own the req */
1296 if (ireq->pktopts) {
1297 newnp->pktoptions = skb_clone(ireq->pktopts,
1298 sk_gfp_mask(sk, GFP_ATOMIC));
1299 consume_skb(ireq->pktopts);
1300 ireq->pktopts = NULL;
1301 if (newnp->pktoptions) {
1302 tcp_v6_restore_cb(newnp->pktoptions);
1303 skb_set_owner_r(newnp->pktoptions, newsk);
1304 }
1305 }
1306 }
1307
1308 return newsk;
1309
1310out_overflow:
1311 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1312out_nonewsk:
1313 dst_release(dst);
1314out:
1315 tcp_listendrop(sk);
1316 return NULL;
1317}
1318
1319/* The socket must have it's spinlock held when we get
1320 * here, unless it is a TCP_LISTEN socket.
1321 *
1322 * We have a potential double-lock case here, so even when
1323 * doing backlog processing we use the BH locking scheme.
1324 * This is because we cannot sleep with the original spinlock
1325 * held.
1326 */
1327static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1328{
1329 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1330 struct sk_buff *opt_skb = NULL;
1331 struct tcp_sock *tp;
1332
1333 /* Imagine: socket is IPv6. IPv4 packet arrives,
1334 goes to IPv4 receive handler and backlogged.
1335 From backlog it always goes here. Kerboom...
1336 Fortunately, tcp_rcv_established and rcv_established
1337 handle them correctly, but it is not case with
1338 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1339 */
1340
1341 if (skb->protocol == htons(ETH_P_IP))
1342 return tcp_v4_do_rcv(sk, skb);
1343
1344 /*
1345 * socket locking is here for SMP purposes as backlog rcv
1346 * is currently called with bh processing disabled.
1347 */
1348
1349 /* Do Stevens' IPV6_PKTOPTIONS.
1350
1351 Yes, guys, it is the only place in our code, where we
1352 may make it not affecting IPv4.
1353 The rest of code is protocol independent,
1354 and I do not like idea to uglify IPv4.
1355
1356 Actually, all the idea behind IPV6_PKTOPTIONS
1357 looks not very well thought. For now we latch
1358 options, received in the last packet, enqueued
1359 by tcp. Feel free to propose better solution.
1360 --ANK (980728)
1361 */
1362 if (np->rxopt.all)
1363 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1364
1365 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1366 struct dst_entry *dst = sk->sk_rx_dst;
1367
1368 sock_rps_save_rxhash(sk, skb);
1369 sk_mark_napi_id(sk, skb);
1370 if (dst) {
1371 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1372 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1373 dst_release(dst);
1374 sk->sk_rx_dst = NULL;
1375 }
1376 }
1377
1378 tcp_rcv_established(sk, skb);
1379 if (opt_skb)
1380 goto ipv6_pktoptions;
1381 return 0;
1382 }
1383
1384 if (tcp_checksum_complete(skb))
1385 goto csum_err;
1386
1387 if (sk->sk_state == TCP_LISTEN) {
1388 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1389
1390 if (!nsk)
1391 goto discard;
1392
1393 if (nsk != sk) {
1394 if (tcp_child_process(sk, nsk, skb))
1395 goto reset;
1396 if (opt_skb)
1397 __kfree_skb(opt_skb);
1398 return 0;
1399 }
1400 } else
1401 sock_rps_save_rxhash(sk, skb);
1402
1403 if (tcp_rcv_state_process(sk, skb))
1404 goto reset;
1405 if (opt_skb)
1406 goto ipv6_pktoptions;
1407 return 0;
1408
1409reset:
1410 tcp_v6_send_reset(sk, skb);
1411discard:
1412 if (opt_skb)
1413 __kfree_skb(opt_skb);
1414 kfree_skb(skb);
1415 return 0;
1416csum_err:
1417 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1418 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1419 goto discard;
1420
1421
1422ipv6_pktoptions:
1423 /* Do you ask, what is it?
1424
1425 1. skb was enqueued by tcp.
1426 2. skb is added to tail of read queue, rather than out of order.
1427 3. socket is not in passive state.
1428 4. Finally, it really contains options, which user wants to receive.
1429 */
1430 tp = tcp_sk(sk);
1431 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1432 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1433 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1434 np->mcast_oif = tcp_v6_iif(opt_skb);
1435 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1436 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1437 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1438 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1439 if (np->repflow)
1440 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1441 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1442 skb_set_owner_r(opt_skb, sk);
1443 tcp_v6_restore_cb(opt_skb);
1444 opt_skb = xchg(&np->pktoptions, opt_skb);
1445 } else {
1446 __kfree_skb(opt_skb);
1447 opt_skb = xchg(&np->pktoptions, NULL);
1448 }
1449 }
1450
1451 kfree_skb(opt_skb);
1452 return 0;
1453}
1454
1455static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1456 const struct tcphdr *th)
1457{
1458 /* This is tricky: we move IP6CB at its correct location into
1459 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1460 * _decode_session6() uses IP6CB().
1461 * barrier() makes sure compiler won't play aliasing games.
1462 */
1463 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1464 sizeof(struct inet6_skb_parm));
1465 barrier();
1466
1467 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1468 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1469 skb->len - th->doff*4);
1470 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1471 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1472 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1473 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1474 TCP_SKB_CB(skb)->sacked = 0;
1475 TCP_SKB_CB(skb)->has_rxtstamp =
1476 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1477}
1478
1479INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1480{
1481 struct sk_buff *skb_to_free;
1482 int sdif = inet6_sdif(skb);
1483 const struct tcphdr *th;
1484 const struct ipv6hdr *hdr;
1485 bool refcounted;
1486 struct sock *sk;
1487 int ret;
1488 struct net *net = dev_net(skb->dev);
1489
1490 if (skb->pkt_type != PACKET_HOST)
1491 goto discard_it;
1492
1493 /*
1494 * Count it even if it's bad.
1495 */
1496 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1497
1498 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1499 goto discard_it;
1500
1501 th = (const struct tcphdr *)skb->data;
1502
1503 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1504 goto bad_packet;
1505 if (!pskb_may_pull(skb, th->doff*4))
1506 goto discard_it;
1507
1508 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1509 goto csum_error;
1510
1511 th = (const struct tcphdr *)skb->data;
1512 hdr = ipv6_hdr(skb);
1513
1514lookup:
1515 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1516 th->source, th->dest, inet6_iif(skb), sdif,
1517 &refcounted);
1518 if (!sk)
1519 goto no_tcp_socket;
1520
1521process:
1522 if (sk->sk_state == TCP_TIME_WAIT)
1523 goto do_time_wait;
1524
1525 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1526 struct request_sock *req = inet_reqsk(sk);
1527 bool req_stolen = false;
1528 struct sock *nsk;
1529
1530 sk = req->rsk_listener;
1531 if (tcp_v6_inbound_md5_hash(sk, skb)) {
1532 sk_drops_add(sk, skb);
1533 reqsk_put(req);
1534 goto discard_it;
1535 }
1536 if (tcp_checksum_complete(skb)) {
1537 reqsk_put(req);
1538 goto csum_error;
1539 }
1540 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1541 inet_csk_reqsk_queue_drop_and_put(sk, req);
1542 goto lookup;
1543 }
1544 sock_hold(sk);
1545 refcounted = true;
1546 nsk = NULL;
1547 if (!tcp_filter(sk, skb)) {
1548 th = (const struct tcphdr *)skb->data;
1549 hdr = ipv6_hdr(skb);
1550 tcp_v6_fill_cb(skb, hdr, th);
1551 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1552 }
1553 if (!nsk) {
1554 reqsk_put(req);
1555 if (req_stolen) {
1556 /* Another cpu got exclusive access to req
1557 * and created a full blown socket.
1558 * Try to feed this packet to this socket
1559 * instead of discarding it.
1560 */
1561 tcp_v6_restore_cb(skb);
1562 sock_put(sk);
1563 goto lookup;
1564 }
1565 goto discard_and_relse;
1566 }
1567 if (nsk == sk) {
1568 reqsk_put(req);
1569 tcp_v6_restore_cb(skb);
1570 } else if (tcp_child_process(sk, nsk, skb)) {
1571 tcp_v6_send_reset(nsk, skb);
1572 goto discard_and_relse;
1573 } else {
1574 sock_put(sk);
1575 return 0;
1576 }
1577 }
1578 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
1579 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1580 goto discard_and_relse;
1581 }
1582
1583 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1584 goto discard_and_relse;
1585
1586 if (tcp_v6_inbound_md5_hash(sk, skb))
1587 goto discard_and_relse;
1588
1589 if (tcp_filter(sk, skb))
1590 goto discard_and_relse;
1591 th = (const struct tcphdr *)skb->data;
1592 hdr = ipv6_hdr(skb);
1593 tcp_v6_fill_cb(skb, hdr, th);
1594
1595 skb->dev = NULL;
1596
1597 if (sk->sk_state == TCP_LISTEN) {
1598 ret = tcp_v6_do_rcv(sk, skb);
1599 goto put_and_return;
1600 }
1601
1602 sk_incoming_cpu_update(sk);
1603
1604 bh_lock_sock_nested(sk);
1605 tcp_segs_in(tcp_sk(sk), skb);
1606 ret = 0;
1607 if (!sock_owned_by_user(sk)) {
1608 skb_to_free = sk->sk_rx_skb_cache;
1609 sk->sk_rx_skb_cache = NULL;
1610 ret = tcp_v6_do_rcv(sk, skb);
1611 } else {
1612 if (tcp_add_backlog(sk, skb))
1613 goto discard_and_relse;
1614 skb_to_free = NULL;
1615 }
1616 bh_unlock_sock(sk);
1617 if (skb_to_free)
1618 __kfree_skb(skb_to_free);
1619put_and_return:
1620 if (refcounted)
1621 sock_put(sk);
1622 return ret ? -1 : 0;
1623
1624no_tcp_socket:
1625 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1626 goto discard_it;
1627
1628 tcp_v6_fill_cb(skb, hdr, th);
1629
1630 if (tcp_checksum_complete(skb)) {
1631csum_error:
1632 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1633bad_packet:
1634 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1635 } else {
1636 tcp_v6_send_reset(NULL, skb);
1637 }
1638
1639discard_it:
1640 kfree_skb(skb);
1641 return 0;
1642
1643discard_and_relse:
1644 sk_drops_add(sk, skb);
1645 if (refcounted)
1646 sock_put(sk);
1647 goto discard_it;
1648
1649do_time_wait:
1650 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1651 inet_twsk_put(inet_twsk(sk));
1652 goto discard_it;
1653 }
1654
1655 tcp_v6_fill_cb(skb, hdr, th);
1656
1657 if (tcp_checksum_complete(skb)) {
1658 inet_twsk_put(inet_twsk(sk));
1659 goto csum_error;
1660 }
1661
1662 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1663 case TCP_TW_SYN:
1664 {
1665 struct sock *sk2;
1666
1667 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1668 skb, __tcp_hdrlen(th),
1669 &ipv6_hdr(skb)->saddr, th->source,
1670 &ipv6_hdr(skb)->daddr,
1671 ntohs(th->dest),
1672 tcp_v6_iif_l3_slave(skb),
1673 sdif);
1674 if (sk2) {
1675 struct inet_timewait_sock *tw = inet_twsk(sk);
1676 inet_twsk_deschedule_put(tw);
1677 sk = sk2;
1678 tcp_v6_restore_cb(skb);
1679 refcounted = false;
1680 goto process;
1681 }
1682 }
1683 /* to ACK */
1684 /* fall through */
1685 case TCP_TW_ACK:
1686 tcp_v6_timewait_ack(sk, skb);
1687 break;
1688 case TCP_TW_RST:
1689 tcp_v6_send_reset(sk, skb);
1690 inet_twsk_deschedule_put(inet_twsk(sk));
1691 goto discard_it;
1692 case TCP_TW_SUCCESS:
1693 ;
1694 }
1695 goto discard_it;
1696}
1697
1698INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
1699{
1700 const struct ipv6hdr *hdr;
1701 const struct tcphdr *th;
1702 struct sock *sk;
1703
1704 if (skb->pkt_type != PACKET_HOST)
1705 return;
1706
1707 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1708 return;
1709
1710 hdr = ipv6_hdr(skb);
1711 th = tcp_hdr(skb);
1712
1713 if (th->doff < sizeof(struct tcphdr) / 4)
1714 return;
1715
1716 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1717 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1718 &hdr->saddr, th->source,
1719 &hdr->daddr, ntohs(th->dest),
1720 inet6_iif(skb), inet6_sdif(skb));
1721 if (sk) {
1722 skb->sk = sk;
1723 skb->destructor = sock_edemux;
1724 if (sk_fullsock(sk)) {
1725 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1726
1727 if (dst)
1728 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
1729 if (dst &&
1730 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1731 skb_dst_set_noref(skb, dst);
1732 }
1733 }
1734}
1735
1736static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1737 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1738 .twsk_unique = tcp_twsk_unique,
1739 .twsk_destructor = tcp_twsk_destructor,
1740};
1741
1742static const struct inet_connection_sock_af_ops ipv6_specific = {
1743 .queue_xmit = inet6_csk_xmit,
1744 .send_check = tcp_v6_send_check,
1745 .rebuild_header = inet6_sk_rebuild_header,
1746 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1747 .conn_request = tcp_v6_conn_request,
1748 .syn_recv_sock = tcp_v6_syn_recv_sock,
1749 .net_header_len = sizeof(struct ipv6hdr),
1750 .net_frag_header_len = sizeof(struct frag_hdr),
1751 .setsockopt = ipv6_setsockopt,
1752 .getsockopt = ipv6_getsockopt,
1753 .addr2sockaddr = inet6_csk_addr2sockaddr,
1754 .sockaddr_len = sizeof(struct sockaddr_in6),
1755#ifdef CONFIG_COMPAT
1756 .compat_setsockopt = compat_ipv6_setsockopt,
1757 .compat_getsockopt = compat_ipv6_getsockopt,
1758#endif
1759 .mtu_reduced = tcp_v6_mtu_reduced,
1760};
1761
1762#ifdef CONFIG_TCP_MD5SIG
1763static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1764 .md5_lookup = tcp_v6_md5_lookup,
1765 .calc_md5_hash = tcp_v6_md5_hash_skb,
1766 .md5_parse = tcp_v6_parse_md5_keys,
1767};
1768#endif
1769
1770/*
1771 * TCP over IPv4 via INET6 API
1772 */
1773static const struct inet_connection_sock_af_ops ipv6_mapped = {
1774 .queue_xmit = ip_queue_xmit,
1775 .send_check = tcp_v4_send_check,
1776 .rebuild_header = inet_sk_rebuild_header,
1777 .sk_rx_dst_set = inet_sk_rx_dst_set,
1778 .conn_request = tcp_v6_conn_request,
1779 .syn_recv_sock = tcp_v6_syn_recv_sock,
1780 .net_header_len = sizeof(struct iphdr),
1781 .setsockopt = ipv6_setsockopt,
1782 .getsockopt = ipv6_getsockopt,
1783 .addr2sockaddr = inet6_csk_addr2sockaddr,
1784 .sockaddr_len = sizeof(struct sockaddr_in6),
1785#ifdef CONFIG_COMPAT
1786 .compat_setsockopt = compat_ipv6_setsockopt,
1787 .compat_getsockopt = compat_ipv6_getsockopt,
1788#endif
1789 .mtu_reduced = tcp_v4_mtu_reduced,
1790};
1791
1792#ifdef CONFIG_TCP_MD5SIG
1793static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1794 .md5_lookup = tcp_v4_md5_lookup,
1795 .calc_md5_hash = tcp_v4_md5_hash_skb,
1796 .md5_parse = tcp_v6_parse_md5_keys,
1797};
1798#endif
1799
1800/* NOTE: A lot of things set to zero explicitly by call to
1801 * sk_alloc() so need not be done here.
1802 */
1803static int tcp_v6_init_sock(struct sock *sk)
1804{
1805 struct inet_connection_sock *icsk = inet_csk(sk);
1806
1807 tcp_init_sock(sk);
1808
1809 icsk->icsk_af_ops = &ipv6_specific;
1810
1811#ifdef CONFIG_TCP_MD5SIG
1812 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1813#endif
1814
1815 return 0;
1816}
1817
1818static void tcp_v6_destroy_sock(struct sock *sk)
1819{
1820 tcp_v4_destroy_sock(sk);
1821 inet6_destroy_sock(sk);
1822}
1823
1824#ifdef CONFIG_PROC_FS
1825/* Proc filesystem TCPv6 sock list dumping. */
1826static void get_openreq6(struct seq_file *seq,
1827 const struct request_sock *req, int i)
1828{
1829 long ttd = req->rsk_timer.expires - jiffies;
1830 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1831 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1832
1833 if (ttd < 0)
1834 ttd = 0;
1835
1836 seq_printf(seq,
1837 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1838 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1839 i,
1840 src->s6_addr32[0], src->s6_addr32[1],
1841 src->s6_addr32[2], src->s6_addr32[3],
1842 inet_rsk(req)->ir_num,
1843 dest->s6_addr32[0], dest->s6_addr32[1],
1844 dest->s6_addr32[2], dest->s6_addr32[3],
1845 ntohs(inet_rsk(req)->ir_rmt_port),
1846 TCP_SYN_RECV,
1847 0, 0, /* could print option size, but that is af dependent. */
1848 1, /* timers active (only the expire timer) */
1849 jiffies_to_clock_t(ttd),
1850 req->num_timeout,
1851 from_kuid_munged(seq_user_ns(seq),
1852 sock_i_uid(req->rsk_listener)),
1853 0, /* non standard timer */
1854 0, /* open_requests have no inode */
1855 0, req);
1856}
1857
1858static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1859{
1860 const struct in6_addr *dest, *src;
1861 __u16 destp, srcp;
1862 int timer_active;
1863 unsigned long timer_expires;
1864 const struct inet_sock *inet = inet_sk(sp);
1865 const struct tcp_sock *tp = tcp_sk(sp);
1866 const struct inet_connection_sock *icsk = inet_csk(sp);
1867 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1868 int rx_queue;
1869 int state;
1870
1871 dest = &sp->sk_v6_daddr;
1872 src = &sp->sk_v6_rcv_saddr;
1873 destp = ntohs(inet->inet_dport);
1874 srcp = ntohs(inet->inet_sport);
1875
1876 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1877 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1878 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1879 timer_active = 1;
1880 timer_expires = icsk->icsk_timeout;
1881 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1882 timer_active = 4;
1883 timer_expires = icsk->icsk_timeout;
1884 } else if (timer_pending(&sp->sk_timer)) {
1885 timer_active = 2;
1886 timer_expires = sp->sk_timer.expires;
1887 } else {
1888 timer_active = 0;
1889 timer_expires = jiffies;
1890 }
1891
1892 state = inet_sk_state_load(sp);
1893 if (state == TCP_LISTEN)
1894 rx_queue = sp->sk_ack_backlog;
1895 else
1896 /* Because we don't lock the socket,
1897 * we might find a transient negative value.
1898 */
1899 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
1900 READ_ONCE(tp->copied_seq), 0);
1901
1902 seq_printf(seq,
1903 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1904 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1905 i,
1906 src->s6_addr32[0], src->s6_addr32[1],
1907 src->s6_addr32[2], src->s6_addr32[3], srcp,
1908 dest->s6_addr32[0], dest->s6_addr32[1],
1909 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1910 state,
1911 READ_ONCE(tp->write_seq) - tp->snd_una,
1912 rx_queue,
1913 timer_active,
1914 jiffies_delta_to_clock_t(timer_expires - jiffies),
1915 icsk->icsk_retransmits,
1916 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1917 icsk->icsk_probes_out,
1918 sock_i_ino(sp),
1919 refcount_read(&sp->sk_refcnt), sp,
1920 jiffies_to_clock_t(icsk->icsk_rto),
1921 jiffies_to_clock_t(icsk->icsk_ack.ato),
1922 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
1923 tp->snd_cwnd,
1924 state == TCP_LISTEN ?
1925 fastopenq->max_qlen :
1926 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1927 );
1928}
1929
1930static void get_timewait6_sock(struct seq_file *seq,
1931 struct inet_timewait_sock *tw, int i)
1932{
1933 long delta = tw->tw_timer.expires - jiffies;
1934 const struct in6_addr *dest, *src;
1935 __u16 destp, srcp;
1936
1937 dest = &tw->tw_v6_daddr;
1938 src = &tw->tw_v6_rcv_saddr;
1939 destp = ntohs(tw->tw_dport);
1940 srcp = ntohs(tw->tw_sport);
1941
1942 seq_printf(seq,
1943 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1944 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1945 i,
1946 src->s6_addr32[0], src->s6_addr32[1],
1947 src->s6_addr32[2], src->s6_addr32[3], srcp,
1948 dest->s6_addr32[0], dest->s6_addr32[1],
1949 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1950 tw->tw_substate, 0, 0,
1951 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1952 refcount_read(&tw->tw_refcnt), tw);
1953}
1954
1955static int tcp6_seq_show(struct seq_file *seq, void *v)
1956{
1957 struct tcp_iter_state *st;
1958 struct sock *sk = v;
1959
1960 if (v == SEQ_START_TOKEN) {
1961 seq_puts(seq,
1962 " sl "
1963 "local_address "
1964 "remote_address "
1965 "st tx_queue rx_queue tr tm->when retrnsmt"
1966 " uid timeout inode\n");
1967 goto out;
1968 }
1969 st = seq->private;
1970
1971 if (sk->sk_state == TCP_TIME_WAIT)
1972 get_timewait6_sock(seq, v, st->num);
1973 else if (sk->sk_state == TCP_NEW_SYN_RECV)
1974 get_openreq6(seq, v, st->num);
1975 else
1976 get_tcp6_sock(seq, v, st->num);
1977out:
1978 return 0;
1979}
1980
1981static const struct seq_operations tcp6_seq_ops = {
1982 .show = tcp6_seq_show,
1983 .start = tcp_seq_start,
1984 .next = tcp_seq_next,
1985 .stop = tcp_seq_stop,
1986};
1987
1988static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1989 .family = AF_INET6,
1990};
1991
1992int __net_init tcp6_proc_init(struct net *net)
1993{
1994 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
1995 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
1996 return -ENOMEM;
1997 return 0;
1998}
1999
2000void tcp6_proc_exit(struct net *net)
2001{
2002 remove_proc_entry("tcp6", net->proc_net);
2003}
2004#endif
2005
2006struct proto tcpv6_prot = {
2007 .name = "TCPv6",
2008 .owner = THIS_MODULE,
2009 .close = tcp_close,
2010 .pre_connect = tcp_v6_pre_connect,
2011 .connect = tcp_v6_connect,
2012 .disconnect = tcp_disconnect,
2013 .accept = inet_csk_accept,
2014 .ioctl = tcp_ioctl,
2015 .init = tcp_v6_init_sock,
2016 .destroy = tcp_v6_destroy_sock,
2017 .shutdown = tcp_shutdown,
2018 .setsockopt = tcp_setsockopt,
2019 .getsockopt = tcp_getsockopt,
2020 .keepalive = tcp_set_keepalive,
2021 .recvmsg = tcp_recvmsg,
2022 .sendmsg = tcp_sendmsg,
2023 .sendpage = tcp_sendpage,
2024 .backlog_rcv = tcp_v6_do_rcv,
2025 .release_cb = tcp_release_cb,
2026 .hash = inet6_hash,
2027 .unhash = inet_unhash,
2028 .get_port = inet_csk_get_port,
2029 .enter_memory_pressure = tcp_enter_memory_pressure,
2030 .leave_memory_pressure = tcp_leave_memory_pressure,
2031 .stream_memory_free = tcp_stream_memory_free,
2032 .sockets_allocated = &tcp_sockets_allocated,
2033 .memory_allocated = &tcp_memory_allocated,
2034 .memory_pressure = &tcp_memory_pressure,
2035 .orphan_count = &tcp_orphan_count,
2036 .sysctl_mem = sysctl_tcp_mem,
2037 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2038 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2039 .max_header = MAX_TCP_HEADER,
2040 .obj_size = sizeof(struct tcp6_sock),
2041 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2042 .twsk_prot = &tcp6_timewait_sock_ops,
2043 .rsk_prot = &tcp6_request_sock_ops,
2044 .h.hashinfo = &tcp_hashinfo,
2045 .no_autobind = true,
2046#ifdef CONFIG_COMPAT
2047 .compat_setsockopt = compat_tcp_setsockopt,
2048 .compat_getsockopt = compat_tcp_getsockopt,
2049#endif
2050 .diag_destroy = tcp_abort,
2051};
2052
2053/* thinking of making this const? Don't.
2054 * early_demux can change based on sysctl.
2055 */
2056static struct inet6_protocol tcpv6_protocol = {
2057 .early_demux = tcp_v6_early_demux,
2058 .early_demux_handler = tcp_v6_early_demux,
2059 .handler = tcp_v6_rcv,
2060 .err_handler = tcp_v6_err,
2061 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2062};
2063
2064static struct inet_protosw tcpv6_protosw = {
2065 .type = SOCK_STREAM,
2066 .protocol = IPPROTO_TCP,
2067 .prot = &tcpv6_prot,
2068 .ops = &inet6_stream_ops,
2069 .flags = INET_PROTOSW_PERMANENT |
2070 INET_PROTOSW_ICSK,
2071};
2072
2073static int __net_init tcpv6_net_init(struct net *net)
2074{
2075 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2076 SOCK_RAW, IPPROTO_TCP, net);
2077}
2078
2079static void __net_exit tcpv6_net_exit(struct net *net)
2080{
2081 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2082}
2083
2084static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2085{
2086 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2087}
2088
2089static struct pernet_operations tcpv6_net_ops = {
2090 .init = tcpv6_net_init,
2091 .exit = tcpv6_net_exit,
2092 .exit_batch = tcpv6_net_exit_batch,
2093};
2094
2095int __init tcpv6_init(void)
2096{
2097 int ret;
2098
2099 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2100 if (ret)
2101 goto out;
2102
2103 /* register inet6 protocol */
2104 ret = inet6_register_protosw(&tcpv6_protosw);
2105 if (ret)
2106 goto out_tcpv6_protocol;
2107
2108 ret = register_pernet_subsys(&tcpv6_net_ops);
2109 if (ret)
2110 goto out_tcpv6_protosw;
2111out:
2112 return ret;
2113
2114out_tcpv6_protosw:
2115 inet6_unregister_protosw(&tcpv6_protosw);
2116out_tcpv6_protocol:
2117 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2118 goto out;
2119}
2120
2121void tcpv6_exit(void)
2122{
2123 unregister_pernet_subsys(&tcpv6_net_ops);
2124 inet6_unregister_protosw(&tcpv6_protosw);
2125 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2126}
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}