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[thirdparty/kernel/stable.git] / net / ipv6 / tcp_ipv6.c
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
71 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
72 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
73 struct request_sock *req);
74
75 INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77 static const struct inet_connection_sock_af_ops ipv6_mapped;
78 const struct inet_connection_sock_af_ops ipv6_specific;
79 #ifdef CONFIG_TCP_MD5SIG
80 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
81 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
82 #else
83 static 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 */
96 #define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \
97 struct tcp6_sock, tcp)->inet6)
98
99 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
100 {
101 struct dst_entry *dst = skb_dst(skb);
102
103 if (dst && dst_hold_safe(dst)) {
104 const struct rt6_info *rt = (const struct rt6_info *)dst;
105
106 rcu_assign_pointer(sk->sk_rx_dst, dst);
107 sk->sk_rx_dst_ifindex = skb->skb_iif;
108 sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
109 }
110 }
111
112 static u32 tcp_v6_init_seq(const struct sk_buff *skb)
113 {
114 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
115 ipv6_hdr(skb)->saddr.s6_addr32,
116 tcp_hdr(skb)->dest,
117 tcp_hdr(skb)->source);
118 }
119
120 static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
121 {
122 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
123 ipv6_hdr(skb)->saddr.s6_addr32);
124 }
125
126 static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128 {
129 /* This check is replicated from tcp_v6_connect() and intended to
130 * prevent BPF program called below from accessing bytes that are out
131 * of the bound specified by user in addr_len.
132 */
133 if (addr_len < SIN6_LEN_RFC2133)
134 return -EINVAL;
135
136 sock_owned_by_me(sk);
137
138 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
139 }
140
141 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
142 int addr_len)
143 {
144 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
145 struct inet_connection_sock *icsk = inet_csk(sk);
146 struct in6_addr *saddr = NULL, *final_p, final;
147 struct inet_timewait_death_row *tcp_death_row;
148 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
149 struct inet_sock *inet = inet_sk(sk);
150 struct tcp_sock *tp = tcp_sk(sk);
151 struct net *net = sock_net(sk);
152 struct ipv6_txoptions *opt;
153 struct dst_entry *dst;
154 struct flowi6 fl6;
155 int addr_type;
156 int err;
157
158 if (addr_len < SIN6_LEN_RFC2133)
159 return -EINVAL;
160
161 if (usin->sin6_family != AF_INET6)
162 return -EAFNOSUPPORT;
163
164 memset(&fl6, 0, sizeof(fl6));
165
166 if (np->sndflow) {
167 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
168 IP6_ECN_flow_init(fl6.flowlabel);
169 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
170 struct ip6_flowlabel *flowlabel;
171 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
172 if (IS_ERR(flowlabel))
173 return -EINVAL;
174 fl6_sock_release(flowlabel);
175 }
176 }
177
178 /*
179 * connect() to INADDR_ANY means loopback (BSD'ism).
180 */
181
182 if (ipv6_addr_any(&usin->sin6_addr)) {
183 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
184 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
185 &usin->sin6_addr);
186 else
187 usin->sin6_addr = in6addr_loopback;
188 }
189
190 addr_type = ipv6_addr_type(&usin->sin6_addr);
191
192 if (addr_type & IPV6_ADDR_MULTICAST)
193 return -ENETUNREACH;
194
195 if (addr_type&IPV6_ADDR_LINKLOCAL) {
196 if (addr_len >= sizeof(struct sockaddr_in6) &&
197 usin->sin6_scope_id) {
198 /* If interface is set while binding, indices
199 * must coincide.
200 */
201 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
202 return -EINVAL;
203
204 sk->sk_bound_dev_if = usin->sin6_scope_id;
205 }
206
207 /* Connect to link-local address requires an interface */
208 if (!sk->sk_bound_dev_if)
209 return -EINVAL;
210 }
211
212 if (tp->rx_opt.ts_recent_stamp &&
213 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
214 tp->rx_opt.ts_recent = 0;
215 tp->rx_opt.ts_recent_stamp = 0;
216 WRITE_ONCE(tp->write_seq, 0);
217 }
218
219 sk->sk_v6_daddr = usin->sin6_addr;
220 np->flow_label = fl6.flowlabel;
221
222 /*
223 * TCP over IPv4
224 */
225
226 if (addr_type & IPV6_ADDR_MAPPED) {
227 u32 exthdrlen = icsk->icsk_ext_hdr_len;
228 struct sockaddr_in sin;
229
230 if (ipv6_only_sock(sk))
231 return -ENETUNREACH;
232
233 sin.sin_family = AF_INET;
234 sin.sin_port = usin->sin6_port;
235 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
236
237 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
238 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
239 if (sk_is_mptcp(sk))
240 mptcpv6_handle_mapped(sk, true);
241 sk->sk_backlog_rcv = tcp_v4_do_rcv;
242 #ifdef CONFIG_TCP_MD5SIG
243 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
244 #endif
245
246 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
247
248 if (err) {
249 icsk->icsk_ext_hdr_len = exthdrlen;
250 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
251 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
252 if (sk_is_mptcp(sk))
253 mptcpv6_handle_mapped(sk, false);
254 sk->sk_backlog_rcv = tcp_v6_do_rcv;
255 #ifdef CONFIG_TCP_MD5SIG
256 tp->af_specific = &tcp_sock_ipv6_specific;
257 #endif
258 goto failure;
259 }
260 np->saddr = sk->sk_v6_rcv_saddr;
261
262 return err;
263 }
264
265 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
266 saddr = &sk->sk_v6_rcv_saddr;
267
268 fl6.flowi6_proto = IPPROTO_TCP;
269 fl6.daddr = sk->sk_v6_daddr;
270 fl6.saddr = saddr ? *saddr : np->saddr;
271 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
272 fl6.flowi6_oif = sk->sk_bound_dev_if;
273 fl6.flowi6_mark = sk->sk_mark;
274 fl6.fl6_dport = usin->sin6_port;
275 fl6.fl6_sport = inet->inet_sport;
276 fl6.flowi6_uid = sk->sk_uid;
277
278 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
279 final_p = fl6_update_dst(&fl6, opt, &final);
280
281 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
282
283 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
284 if (IS_ERR(dst)) {
285 err = PTR_ERR(dst);
286 goto failure;
287 }
288
289 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
290
291 if (!saddr) {
292 saddr = &fl6.saddr;
293
294 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
295 if (err)
296 goto failure;
297 }
298
299 /* set the source address */
300 np->saddr = *saddr;
301 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
302
303 sk->sk_gso_type = SKB_GSO_TCPV6;
304 ip6_dst_store(sk, dst, NULL, NULL);
305
306 icsk->icsk_ext_hdr_len = 0;
307 if (opt)
308 icsk->icsk_ext_hdr_len = opt->opt_flen +
309 opt->opt_nflen;
310
311 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
312
313 inet->inet_dport = usin->sin6_port;
314
315 tcp_set_state(sk, TCP_SYN_SENT);
316 err = inet6_hash_connect(tcp_death_row, sk);
317 if (err)
318 goto late_failure;
319
320 sk_set_txhash(sk);
321
322 if (likely(!tp->repair)) {
323 if (!tp->write_seq)
324 WRITE_ONCE(tp->write_seq,
325 secure_tcpv6_seq(np->saddr.s6_addr32,
326 sk->sk_v6_daddr.s6_addr32,
327 inet->inet_sport,
328 inet->inet_dport));
329 tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
330 sk->sk_v6_daddr.s6_addr32);
331 }
332
333 if (tcp_fastopen_defer_connect(sk, &err))
334 return err;
335 if (err)
336 goto late_failure;
337
338 err = tcp_connect(sk);
339 if (err)
340 goto late_failure;
341
342 return 0;
343
344 late_failure:
345 tcp_set_state(sk, TCP_CLOSE);
346 inet_bhash2_reset_saddr(sk);
347 failure:
348 inet->inet_dport = 0;
349 sk->sk_route_caps = 0;
350 return err;
351 }
352
353 static void tcp_v6_mtu_reduced(struct sock *sk)
354 {
355 struct dst_entry *dst;
356 u32 mtu;
357
358 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
359 return;
360
361 mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
362
363 /* Drop requests trying to increase our current mss.
364 * Check done in __ip6_rt_update_pmtu() is too late.
365 */
366 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
367 return;
368
369 dst = inet6_csk_update_pmtu(sk, mtu);
370 if (!dst)
371 return;
372
373 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
374 tcp_sync_mss(sk, dst_mtu(dst));
375 tcp_simple_retransmit(sk);
376 }
377 }
378
379 static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
380 u8 type, u8 code, int offset, __be32 info)
381 {
382 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
383 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
384 struct net *net = dev_net(skb->dev);
385 struct request_sock *fastopen;
386 struct ipv6_pinfo *np;
387 struct tcp_sock *tp;
388 __u32 seq, snd_una;
389 struct sock *sk;
390 bool fatal;
391 int err;
392
393 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
394 &hdr->daddr, th->dest,
395 &hdr->saddr, ntohs(th->source),
396 skb->dev->ifindex, inet6_sdif(skb));
397
398 if (!sk) {
399 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
400 ICMP6_MIB_INERRORS);
401 return -ENOENT;
402 }
403
404 if (sk->sk_state == TCP_TIME_WAIT) {
405 inet_twsk_put(inet_twsk(sk));
406 return 0;
407 }
408 seq = ntohl(th->seq);
409 fatal = icmpv6_err_convert(type, code, &err);
410 if (sk->sk_state == TCP_NEW_SYN_RECV) {
411 tcp_req_err(sk, seq, fatal);
412 return 0;
413 }
414
415 bh_lock_sock(sk);
416 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
417 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
418
419 if (sk->sk_state == TCP_CLOSE)
420 goto out;
421
422 if (static_branch_unlikely(&ip6_min_hopcount)) {
423 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
424 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
425 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
426 goto out;
427 }
428 }
429
430 tp = tcp_sk(sk);
431 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
432 fastopen = rcu_dereference(tp->fastopen_rsk);
433 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
434 if (sk->sk_state != TCP_LISTEN &&
435 !between(seq, snd_una, tp->snd_nxt)) {
436 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
437 goto out;
438 }
439
440 np = tcp_inet6_sk(sk);
441
442 if (type == NDISC_REDIRECT) {
443 if (!sock_owned_by_user(sk)) {
444 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
445
446 if (dst)
447 dst->ops->redirect(dst, sk, skb);
448 }
449 goto out;
450 }
451
452 if (type == ICMPV6_PKT_TOOBIG) {
453 u32 mtu = ntohl(info);
454
455 /* We are not interested in TCP_LISTEN and open_requests
456 * (SYN-ACKs send out by Linux are always <576bytes so
457 * they should go through unfragmented).
458 */
459 if (sk->sk_state == TCP_LISTEN)
460 goto out;
461
462 if (!ip6_sk_accept_pmtu(sk))
463 goto out;
464
465 if (mtu < IPV6_MIN_MTU)
466 goto out;
467
468 WRITE_ONCE(tp->mtu_info, mtu);
469
470 if (!sock_owned_by_user(sk))
471 tcp_v6_mtu_reduced(sk);
472 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
473 &sk->sk_tsq_flags))
474 sock_hold(sk);
475 goto out;
476 }
477
478
479 /* Might be for an request_sock */
480 switch (sk->sk_state) {
481 case TCP_SYN_SENT:
482 case TCP_SYN_RECV:
483 /* Only in fast or simultaneous open. If a fast open socket is
484 * already accepted it is treated as a connected one below.
485 */
486 if (fastopen && !fastopen->sk)
487 break;
488
489 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
490
491 if (!sock_owned_by_user(sk)) {
492 WRITE_ONCE(sk->sk_err, err);
493 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
494
495 tcp_done(sk);
496 } else {
497 WRITE_ONCE(sk->sk_err_soft, err);
498 }
499 goto out;
500 case TCP_LISTEN:
501 break;
502 default:
503 /* check if this ICMP message allows revert of backoff.
504 * (see RFC 6069)
505 */
506 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
507 code == ICMPV6_NOROUTE)
508 tcp_ld_RTO_revert(sk, seq);
509 }
510
511 if (!sock_owned_by_user(sk) && np->recverr) {
512 WRITE_ONCE(sk->sk_err, err);
513 sk_error_report(sk);
514 } else {
515 WRITE_ONCE(sk->sk_err_soft, err);
516 }
517 out:
518 bh_unlock_sock(sk);
519 sock_put(sk);
520 return 0;
521 }
522
523
524 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
525 struct flowi *fl,
526 struct request_sock *req,
527 struct tcp_fastopen_cookie *foc,
528 enum tcp_synack_type synack_type,
529 struct sk_buff *syn_skb)
530 {
531 struct inet_request_sock *ireq = inet_rsk(req);
532 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
533 struct ipv6_txoptions *opt;
534 struct flowi6 *fl6 = &fl->u.ip6;
535 struct sk_buff *skb;
536 int err = -ENOMEM;
537 u8 tclass;
538
539 /* First, grab a route. */
540 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
541 IPPROTO_TCP)) == NULL)
542 goto done;
543
544 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
545
546 if (skb) {
547 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
548 &ireq->ir_v6_rmt_addr);
549
550 fl6->daddr = ireq->ir_v6_rmt_addr;
551 if (np->repflow && ireq->pktopts)
552 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
553
554 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
555 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
556 (np->tclass & INET_ECN_MASK) :
557 np->tclass;
558
559 if (!INET_ECN_is_capable(tclass) &&
560 tcp_bpf_ca_needs_ecn((struct sock *)req))
561 tclass |= INET_ECN_ECT_0;
562
563 rcu_read_lock();
564 opt = ireq->ipv6_opt;
565 if (!opt)
566 opt = rcu_dereference(np->opt);
567 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
568 opt, tclass, sk->sk_priority);
569 rcu_read_unlock();
570 err = net_xmit_eval(err);
571 }
572
573 done:
574 return err;
575 }
576
577
578 static void tcp_v6_reqsk_destructor(struct request_sock *req)
579 {
580 kfree(inet_rsk(req)->ipv6_opt);
581 consume_skb(inet_rsk(req)->pktopts);
582 }
583
584 #ifdef CONFIG_TCP_MD5SIG
585 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
586 const struct in6_addr *addr,
587 int l3index)
588 {
589 return tcp_md5_do_lookup(sk, l3index,
590 (union tcp_md5_addr *)addr, AF_INET6);
591 }
592
593 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
594 const struct sock *addr_sk)
595 {
596 int l3index;
597
598 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
599 addr_sk->sk_bound_dev_if);
600 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
601 l3index);
602 }
603
604 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
605 sockptr_t optval, int optlen)
606 {
607 struct tcp_md5sig cmd;
608 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
609 int l3index = 0;
610 u8 prefixlen;
611 u8 flags;
612
613 if (optlen < sizeof(cmd))
614 return -EINVAL;
615
616 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
617 return -EFAULT;
618
619 if (sin6->sin6_family != AF_INET6)
620 return -EINVAL;
621
622 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
623
624 if (optname == TCP_MD5SIG_EXT &&
625 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
626 prefixlen = cmd.tcpm_prefixlen;
627 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
628 prefixlen > 32))
629 return -EINVAL;
630 } else {
631 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
632 }
633
634 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
635 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
636 struct net_device *dev;
637
638 rcu_read_lock();
639 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
640 if (dev && netif_is_l3_master(dev))
641 l3index = dev->ifindex;
642 rcu_read_unlock();
643
644 /* ok to reference set/not set outside of rcu;
645 * right now device MUST be an L3 master
646 */
647 if (!dev || !l3index)
648 return -EINVAL;
649 }
650
651 if (!cmd.tcpm_keylen) {
652 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
653 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
654 AF_INET, prefixlen,
655 l3index, flags);
656 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
657 AF_INET6, prefixlen, l3index, flags);
658 }
659
660 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
661 return -EINVAL;
662
663 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
664 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
665 AF_INET, prefixlen, l3index, flags,
666 cmd.tcpm_key, cmd.tcpm_keylen);
667
668 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
669 AF_INET6, prefixlen, l3index, flags,
670 cmd.tcpm_key, cmd.tcpm_keylen);
671 }
672
673 static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
674 const struct in6_addr *daddr,
675 const struct in6_addr *saddr,
676 const struct tcphdr *th, int nbytes)
677 {
678 struct tcp6_pseudohdr *bp;
679 struct scatterlist sg;
680 struct tcphdr *_th;
681
682 bp = hp->scratch;
683 /* 1. TCP pseudo-header (RFC2460) */
684 bp->saddr = *saddr;
685 bp->daddr = *daddr;
686 bp->protocol = cpu_to_be32(IPPROTO_TCP);
687 bp->len = cpu_to_be32(nbytes);
688
689 _th = (struct tcphdr *)(bp + 1);
690 memcpy(_th, th, sizeof(*th));
691 _th->check = 0;
692
693 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
694 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
695 sizeof(*bp) + sizeof(*th));
696 return crypto_ahash_update(hp->md5_req);
697 }
698
699 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
700 const struct in6_addr *daddr, struct in6_addr *saddr,
701 const struct tcphdr *th)
702 {
703 struct tcp_md5sig_pool *hp;
704 struct ahash_request *req;
705
706 hp = tcp_get_md5sig_pool();
707 if (!hp)
708 goto clear_hash_noput;
709 req = hp->md5_req;
710
711 if (crypto_ahash_init(req))
712 goto clear_hash;
713 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
714 goto clear_hash;
715 if (tcp_md5_hash_key(hp, key))
716 goto clear_hash;
717 ahash_request_set_crypt(req, NULL, md5_hash, 0);
718 if (crypto_ahash_final(req))
719 goto clear_hash;
720
721 tcp_put_md5sig_pool();
722 return 0;
723
724 clear_hash:
725 tcp_put_md5sig_pool();
726 clear_hash_noput:
727 memset(md5_hash, 0, 16);
728 return 1;
729 }
730
731 static int tcp_v6_md5_hash_skb(char *md5_hash,
732 const struct tcp_md5sig_key *key,
733 const struct sock *sk,
734 const struct sk_buff *skb)
735 {
736 const struct in6_addr *saddr, *daddr;
737 struct tcp_md5sig_pool *hp;
738 struct ahash_request *req;
739 const struct tcphdr *th = tcp_hdr(skb);
740
741 if (sk) { /* valid for establish/request sockets */
742 saddr = &sk->sk_v6_rcv_saddr;
743 daddr = &sk->sk_v6_daddr;
744 } else {
745 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
746 saddr = &ip6h->saddr;
747 daddr = &ip6h->daddr;
748 }
749
750 hp = tcp_get_md5sig_pool();
751 if (!hp)
752 goto clear_hash_noput;
753 req = hp->md5_req;
754
755 if (crypto_ahash_init(req))
756 goto clear_hash;
757
758 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
759 goto clear_hash;
760 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
761 goto clear_hash;
762 if (tcp_md5_hash_key(hp, key))
763 goto clear_hash;
764 ahash_request_set_crypt(req, NULL, md5_hash, 0);
765 if (crypto_ahash_final(req))
766 goto clear_hash;
767
768 tcp_put_md5sig_pool();
769 return 0;
770
771 clear_hash:
772 tcp_put_md5sig_pool();
773 clear_hash_noput:
774 memset(md5_hash, 0, 16);
775 return 1;
776 }
777
778 #endif
779
780 static void tcp_v6_init_req(struct request_sock *req,
781 const struct sock *sk_listener,
782 struct sk_buff *skb)
783 {
784 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
785 struct inet_request_sock *ireq = inet_rsk(req);
786 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
787
788 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
789 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
790
791 /* So that link locals have meaning */
792 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
793 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
794 ireq->ir_iif = tcp_v6_iif(skb);
795
796 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
797 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
798 np->rxopt.bits.rxinfo ||
799 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
800 np->rxopt.bits.rxohlim || np->repflow)) {
801 refcount_inc(&skb->users);
802 ireq->pktopts = skb;
803 }
804 }
805
806 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
807 struct sk_buff *skb,
808 struct flowi *fl,
809 struct request_sock *req)
810 {
811 tcp_v6_init_req(req, sk, skb);
812
813 if (security_inet_conn_request(sk, skb, req))
814 return NULL;
815
816 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
817 }
818
819 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
820 .family = AF_INET6,
821 .obj_size = sizeof(struct tcp6_request_sock),
822 .rtx_syn_ack = tcp_rtx_synack,
823 .send_ack = tcp_v6_reqsk_send_ack,
824 .destructor = tcp_v6_reqsk_destructor,
825 .send_reset = tcp_v6_send_reset,
826 .syn_ack_timeout = tcp_syn_ack_timeout,
827 };
828
829 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
830 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
831 sizeof(struct ipv6hdr),
832 #ifdef CONFIG_TCP_MD5SIG
833 .req_md5_lookup = tcp_v6_md5_lookup,
834 .calc_md5_hash = tcp_v6_md5_hash_skb,
835 #endif
836 #ifdef CONFIG_SYN_COOKIES
837 .cookie_init_seq = cookie_v6_init_sequence,
838 #endif
839 .route_req = tcp_v6_route_req,
840 .init_seq = tcp_v6_init_seq,
841 .init_ts_off = tcp_v6_init_ts_off,
842 .send_synack = tcp_v6_send_synack,
843 };
844
845 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
846 u32 ack, u32 win, u32 tsval, u32 tsecr,
847 int oif, struct tcp_md5sig_key *key, int rst,
848 u8 tclass, __be32 label, u32 priority, u32 txhash)
849 {
850 const struct tcphdr *th = tcp_hdr(skb);
851 struct tcphdr *t1;
852 struct sk_buff *buff;
853 struct flowi6 fl6;
854 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
855 struct sock *ctl_sk = net->ipv6.tcp_sk;
856 unsigned int tot_len = sizeof(struct tcphdr);
857 __be32 mrst = 0, *topt;
858 struct dst_entry *dst;
859 __u32 mark = 0;
860
861 if (tsecr)
862 tot_len += TCPOLEN_TSTAMP_ALIGNED;
863 #ifdef CONFIG_TCP_MD5SIG
864 if (key)
865 tot_len += TCPOLEN_MD5SIG_ALIGNED;
866 #endif
867
868 #ifdef CONFIG_MPTCP
869 if (rst && !key) {
870 mrst = mptcp_reset_option(skb);
871
872 if (mrst)
873 tot_len += sizeof(__be32);
874 }
875 #endif
876
877 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
878 if (!buff)
879 return;
880
881 skb_reserve(buff, MAX_TCP_HEADER);
882
883 t1 = skb_push(buff, tot_len);
884 skb_reset_transport_header(buff);
885
886 /* Swap the send and the receive. */
887 memset(t1, 0, sizeof(*t1));
888 t1->dest = th->source;
889 t1->source = th->dest;
890 t1->doff = tot_len / 4;
891 t1->seq = htonl(seq);
892 t1->ack_seq = htonl(ack);
893 t1->ack = !rst || !th->ack;
894 t1->rst = rst;
895 t1->window = htons(win);
896
897 topt = (__be32 *)(t1 + 1);
898
899 if (tsecr) {
900 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
901 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
902 *topt++ = htonl(tsval);
903 *topt++ = htonl(tsecr);
904 }
905
906 if (mrst)
907 *topt++ = mrst;
908
909 #ifdef CONFIG_TCP_MD5SIG
910 if (key) {
911 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
912 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
913 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
914 &ipv6_hdr(skb)->saddr,
915 &ipv6_hdr(skb)->daddr, t1);
916 }
917 #endif
918
919 memset(&fl6, 0, sizeof(fl6));
920 fl6.daddr = ipv6_hdr(skb)->saddr;
921 fl6.saddr = ipv6_hdr(skb)->daddr;
922 fl6.flowlabel = label;
923
924 buff->ip_summed = CHECKSUM_PARTIAL;
925
926 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
927
928 fl6.flowi6_proto = IPPROTO_TCP;
929 if (rt6_need_strict(&fl6.daddr) && !oif)
930 fl6.flowi6_oif = tcp_v6_iif(skb);
931 else {
932 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
933 oif = skb->skb_iif;
934
935 fl6.flowi6_oif = oif;
936 }
937
938 if (sk) {
939 if (sk->sk_state == TCP_TIME_WAIT)
940 mark = inet_twsk(sk)->tw_mark;
941 else
942 mark = READ_ONCE(sk->sk_mark);
943 skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
944 }
945 if (txhash) {
946 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
947 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
948 }
949 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
950 fl6.fl6_dport = t1->dest;
951 fl6.fl6_sport = t1->source;
952 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
953 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
954
955 /* Pass a socket to ip6_dst_lookup either it is for RST
956 * Underlying function will use this to retrieve the network
957 * namespace
958 */
959 if (sk && sk->sk_state != TCP_TIME_WAIT)
960 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
961 else
962 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
963 if (!IS_ERR(dst)) {
964 skb_dst_set(buff, dst);
965 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
966 tclass & ~INET_ECN_MASK, priority);
967 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
968 if (rst)
969 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
970 return;
971 }
972
973 kfree_skb(buff);
974 }
975
976 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
977 {
978 const struct tcphdr *th = tcp_hdr(skb);
979 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
980 u32 seq = 0, ack_seq = 0;
981 struct tcp_md5sig_key *key = NULL;
982 #ifdef CONFIG_TCP_MD5SIG
983 const __u8 *hash_location = NULL;
984 unsigned char newhash[16];
985 int genhash;
986 struct sock *sk1 = NULL;
987 #endif
988 __be32 label = 0;
989 u32 priority = 0;
990 struct net *net;
991 u32 txhash = 0;
992 int oif = 0;
993
994 if (th->rst)
995 return;
996
997 /* If sk not NULL, it means we did a successful lookup and incoming
998 * route had to be correct. prequeue might have dropped our dst.
999 */
1000 if (!sk && !ipv6_unicast_destination(skb))
1001 return;
1002
1003 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1004 #ifdef CONFIG_TCP_MD5SIG
1005 rcu_read_lock();
1006 hash_location = tcp_parse_md5sig_option(th);
1007 if (sk && sk_fullsock(sk)) {
1008 int l3index;
1009
1010 /* sdif set, means packet ingressed via a device
1011 * in an L3 domain and inet_iif is set to it.
1012 */
1013 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1014 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1015 } else if (hash_location) {
1016 int dif = tcp_v6_iif_l3_slave(skb);
1017 int sdif = tcp_v6_sdif(skb);
1018 int l3index;
1019
1020 /*
1021 * active side is lost. Try to find listening socket through
1022 * source port, and then find md5 key through listening socket.
1023 * we are not loose security here:
1024 * Incoming packet is checked with md5 hash with finding key,
1025 * no RST generated if md5 hash doesn't match.
1026 */
1027 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1028 NULL, 0, &ipv6h->saddr, th->source,
1029 &ipv6h->daddr, ntohs(th->source),
1030 dif, sdif);
1031 if (!sk1)
1032 goto out;
1033
1034 /* sdif set, means packet ingressed via a device
1035 * in an L3 domain and dif is set to it.
1036 */
1037 l3index = tcp_v6_sdif(skb) ? dif : 0;
1038
1039 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1040 if (!key)
1041 goto out;
1042
1043 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1044 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1045 goto out;
1046 }
1047 #endif
1048
1049 if (th->ack)
1050 seq = ntohl(th->ack_seq);
1051 else
1052 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1053 (th->doff << 2);
1054
1055 if (sk) {
1056 oif = sk->sk_bound_dev_if;
1057 if (sk_fullsock(sk)) {
1058 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1059
1060 trace_tcp_send_reset(sk, skb);
1061 if (np->repflow)
1062 label = ip6_flowlabel(ipv6h);
1063 priority = sk->sk_priority;
1064 txhash = sk->sk_txhash;
1065 }
1066 if (sk->sk_state == TCP_TIME_WAIT) {
1067 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1068 priority = inet_twsk(sk)->tw_priority;
1069 txhash = inet_twsk(sk)->tw_txhash;
1070 }
1071 } else {
1072 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1073 label = ip6_flowlabel(ipv6h);
1074 }
1075
1076 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
1077 ipv6_get_dsfield(ipv6h), label, priority, txhash);
1078
1079 #ifdef CONFIG_TCP_MD5SIG
1080 out:
1081 rcu_read_unlock();
1082 #endif
1083 }
1084
1085 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1086 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1087 struct tcp_md5sig_key *key, u8 tclass,
1088 __be32 label, u32 priority, u32 txhash)
1089 {
1090 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1091 tclass, label, priority, txhash);
1092 }
1093
1094 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1095 {
1096 struct inet_timewait_sock *tw = inet_twsk(sk);
1097 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1098
1099 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1100 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1101 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1102 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1103 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
1104 tw->tw_txhash);
1105
1106 inet_twsk_put(tw);
1107 }
1108
1109 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1110 struct request_sock *req)
1111 {
1112 int l3index;
1113
1114 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1115
1116 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1117 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1118 */
1119 /* RFC 7323 2.3
1120 * The window field (SEG.WND) of every outgoing segment, with the
1121 * exception of <SYN> segments, MUST be right-shifted by
1122 * Rcv.Wind.Shift bits:
1123 */
1124 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1125 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1126 tcp_rsk(req)->rcv_nxt,
1127 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1128 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1129 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
1130 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1131 ipv6_get_dsfield(ipv6_hdr(skb)), 0,
1132 READ_ONCE(sk->sk_priority),
1133 READ_ONCE(tcp_rsk(req)->txhash));
1134 }
1135
1136
1137 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1138 {
1139 #ifdef CONFIG_SYN_COOKIES
1140 const struct tcphdr *th = tcp_hdr(skb);
1141
1142 if (!th->syn)
1143 sk = cookie_v6_check(sk, skb);
1144 #endif
1145 return sk;
1146 }
1147
1148 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1149 struct tcphdr *th, u32 *cookie)
1150 {
1151 u16 mss = 0;
1152 #ifdef CONFIG_SYN_COOKIES
1153 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1154 &tcp_request_sock_ipv6_ops, sk, th);
1155 if (mss) {
1156 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1157 tcp_synq_overflow(sk);
1158 }
1159 #endif
1160 return mss;
1161 }
1162
1163 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1164 {
1165 if (skb->protocol == htons(ETH_P_IP))
1166 return tcp_v4_conn_request(sk, skb);
1167
1168 if (!ipv6_unicast_destination(skb))
1169 goto drop;
1170
1171 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1172 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1173 return 0;
1174 }
1175
1176 return tcp_conn_request(&tcp6_request_sock_ops,
1177 &tcp_request_sock_ipv6_ops, sk, skb);
1178
1179 drop:
1180 tcp_listendrop(sk);
1181 return 0; /* don't send reset */
1182 }
1183
1184 static void tcp_v6_restore_cb(struct sk_buff *skb)
1185 {
1186 /* We need to move header back to the beginning if xfrm6_policy_check()
1187 * and tcp_v6_fill_cb() are going to be called again.
1188 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1189 */
1190 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1191 sizeof(struct inet6_skb_parm));
1192 }
1193
1194 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1195 struct request_sock *req,
1196 struct dst_entry *dst,
1197 struct request_sock *req_unhash,
1198 bool *own_req)
1199 {
1200 struct inet_request_sock *ireq;
1201 struct ipv6_pinfo *newnp;
1202 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1203 struct ipv6_txoptions *opt;
1204 struct inet_sock *newinet;
1205 bool found_dup_sk = false;
1206 struct tcp_sock *newtp;
1207 struct sock *newsk;
1208 #ifdef CONFIG_TCP_MD5SIG
1209 struct tcp_md5sig_key *key;
1210 int l3index;
1211 #endif
1212 struct flowi6 fl6;
1213
1214 if (skb->protocol == htons(ETH_P_IP)) {
1215 /*
1216 * v6 mapped
1217 */
1218
1219 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1220 req_unhash, own_req);
1221
1222 if (!newsk)
1223 return NULL;
1224
1225 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1226
1227 newnp = tcp_inet6_sk(newsk);
1228 newtp = tcp_sk(newsk);
1229
1230 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1231
1232 newnp->saddr = newsk->sk_v6_rcv_saddr;
1233
1234 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1235 if (sk_is_mptcp(newsk))
1236 mptcpv6_handle_mapped(newsk, true);
1237 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1238 #ifdef CONFIG_TCP_MD5SIG
1239 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1240 #endif
1241
1242 newnp->ipv6_mc_list = NULL;
1243 newnp->ipv6_ac_list = NULL;
1244 newnp->ipv6_fl_list = NULL;
1245 newnp->pktoptions = NULL;
1246 newnp->opt = NULL;
1247 newnp->mcast_oif = inet_iif(skb);
1248 newnp->mcast_hops = ip_hdr(skb)->ttl;
1249 newnp->rcv_flowinfo = 0;
1250 if (np->repflow)
1251 newnp->flow_label = 0;
1252
1253 /*
1254 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1255 * here, tcp_create_openreq_child now does this for us, see the comment in
1256 * that function for the gory details. -acme
1257 */
1258
1259 /* It is tricky place. Until this moment IPv4 tcp
1260 worked with IPv6 icsk.icsk_af_ops.
1261 Sync it now.
1262 */
1263 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1264
1265 return newsk;
1266 }
1267
1268 ireq = inet_rsk(req);
1269
1270 if (sk_acceptq_is_full(sk))
1271 goto out_overflow;
1272
1273 if (!dst) {
1274 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1275 if (!dst)
1276 goto out;
1277 }
1278
1279 newsk = tcp_create_openreq_child(sk, req, skb);
1280 if (!newsk)
1281 goto out_nonewsk;
1282
1283 /*
1284 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1285 * count here, tcp_create_openreq_child now does this for us, see the
1286 * comment in that function for the gory details. -acme
1287 */
1288
1289 newsk->sk_gso_type = SKB_GSO_TCPV6;
1290 ip6_dst_store(newsk, dst, NULL, NULL);
1291 inet6_sk_rx_dst_set(newsk, skb);
1292
1293 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1294
1295 newtp = tcp_sk(newsk);
1296 newinet = inet_sk(newsk);
1297 newnp = tcp_inet6_sk(newsk);
1298
1299 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1300
1301 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1302 newnp->saddr = ireq->ir_v6_loc_addr;
1303 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1304 newsk->sk_bound_dev_if = ireq->ir_iif;
1305
1306 /* Now IPv6 options...
1307
1308 First: no IPv4 options.
1309 */
1310 newinet->inet_opt = NULL;
1311 newnp->ipv6_mc_list = NULL;
1312 newnp->ipv6_ac_list = NULL;
1313 newnp->ipv6_fl_list = NULL;
1314
1315 /* Clone RX bits */
1316 newnp->rxopt.all = np->rxopt.all;
1317
1318 newnp->pktoptions = NULL;
1319 newnp->opt = NULL;
1320 newnp->mcast_oif = tcp_v6_iif(skb);
1321 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1322 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1323 if (np->repflow)
1324 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1325
1326 /* Set ToS of the new socket based upon the value of incoming SYN.
1327 * ECT bits are set later in tcp_init_transfer().
1328 */
1329 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1330 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1331
1332 /* Clone native IPv6 options from listening socket (if any)
1333
1334 Yes, keeping reference count would be much more clever,
1335 but we make one more one thing there: reattach optmem
1336 to newsk.
1337 */
1338 opt = ireq->ipv6_opt;
1339 if (!opt)
1340 opt = rcu_dereference(np->opt);
1341 if (opt) {
1342 opt = ipv6_dup_options(newsk, opt);
1343 RCU_INIT_POINTER(newnp->opt, opt);
1344 }
1345 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1346 if (opt)
1347 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1348 opt->opt_flen;
1349
1350 tcp_ca_openreq_child(newsk, dst);
1351
1352 tcp_sync_mss(newsk, dst_mtu(dst));
1353 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1354
1355 tcp_initialize_rcv_mss(newsk);
1356
1357 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1358 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1359
1360 #ifdef CONFIG_TCP_MD5SIG
1361 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1362
1363 /* Copy over the MD5 key from the original socket */
1364 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1365 if (key) {
1366 const union tcp_md5_addr *addr;
1367
1368 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1369 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1370 inet_csk_prepare_forced_close(newsk);
1371 tcp_done(newsk);
1372 goto out;
1373 }
1374 }
1375 #endif
1376
1377 if (__inet_inherit_port(sk, newsk) < 0) {
1378 inet_csk_prepare_forced_close(newsk);
1379 tcp_done(newsk);
1380 goto out;
1381 }
1382 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1383 &found_dup_sk);
1384 if (*own_req) {
1385 tcp_move_syn(newtp, req);
1386
1387 /* Clone pktoptions received with SYN, if we own the req */
1388 if (ireq->pktopts) {
1389 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1390 consume_skb(ireq->pktopts);
1391 ireq->pktopts = NULL;
1392 if (newnp->pktoptions)
1393 tcp_v6_restore_cb(newnp->pktoptions);
1394 }
1395 } else {
1396 if (!req_unhash && found_dup_sk) {
1397 /* This code path should only be executed in the
1398 * syncookie case only
1399 */
1400 bh_unlock_sock(newsk);
1401 sock_put(newsk);
1402 newsk = NULL;
1403 }
1404 }
1405
1406 return newsk;
1407
1408 out_overflow:
1409 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1410 out_nonewsk:
1411 dst_release(dst);
1412 out:
1413 tcp_listendrop(sk);
1414 return NULL;
1415 }
1416
1417 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1418 u32));
1419 /* The socket must have it's spinlock held when we get
1420 * here, unless it is a TCP_LISTEN socket.
1421 *
1422 * We have a potential double-lock case here, so even when
1423 * doing backlog processing we use the BH locking scheme.
1424 * This is because we cannot sleep with the original spinlock
1425 * held.
1426 */
1427 INDIRECT_CALLABLE_SCOPE
1428 int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1429 {
1430 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1431 struct sk_buff *opt_skb = NULL;
1432 enum skb_drop_reason reason;
1433 struct tcp_sock *tp;
1434
1435 /* Imagine: socket is IPv6. IPv4 packet arrives,
1436 goes to IPv4 receive handler and backlogged.
1437 From backlog it always goes here. Kerboom...
1438 Fortunately, tcp_rcv_established and rcv_established
1439 handle them correctly, but it is not case with
1440 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1441 */
1442
1443 if (skb->protocol == htons(ETH_P_IP))
1444 return tcp_v4_do_rcv(sk, skb);
1445
1446 /*
1447 * socket locking is here for SMP purposes as backlog rcv
1448 * is currently called with bh processing disabled.
1449 */
1450
1451 /* Do Stevens' IPV6_PKTOPTIONS.
1452
1453 Yes, guys, it is the only place in our code, where we
1454 may make it not affecting IPv4.
1455 The rest of code is protocol independent,
1456 and I do not like idea to uglify IPv4.
1457
1458 Actually, all the idea behind IPV6_PKTOPTIONS
1459 looks not very well thought. For now we latch
1460 options, received in the last packet, enqueued
1461 by tcp. Feel free to propose better solution.
1462 --ANK (980728)
1463 */
1464 if (np->rxopt.all)
1465 opt_skb = skb_clone_and_charge_r(skb, sk);
1466
1467 reason = SKB_DROP_REASON_NOT_SPECIFIED;
1468 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1469 struct dst_entry *dst;
1470
1471 dst = rcu_dereference_protected(sk->sk_rx_dst,
1472 lockdep_sock_is_held(sk));
1473
1474 sock_rps_save_rxhash(sk, skb);
1475 sk_mark_napi_id(sk, skb);
1476 if (dst) {
1477 if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1478 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1479 dst, sk->sk_rx_dst_cookie) == NULL) {
1480 RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1481 dst_release(dst);
1482 }
1483 }
1484
1485 tcp_rcv_established(sk, skb);
1486 if (opt_skb)
1487 goto ipv6_pktoptions;
1488 return 0;
1489 }
1490
1491 if (tcp_checksum_complete(skb))
1492 goto csum_err;
1493
1494 if (sk->sk_state == TCP_LISTEN) {
1495 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1496
1497 if (!nsk)
1498 goto discard;
1499
1500 if (nsk != sk) {
1501 if (tcp_child_process(sk, nsk, skb))
1502 goto reset;
1503 if (opt_skb)
1504 __kfree_skb(opt_skb);
1505 return 0;
1506 }
1507 } else
1508 sock_rps_save_rxhash(sk, skb);
1509
1510 if (tcp_rcv_state_process(sk, skb))
1511 goto reset;
1512 if (opt_skb)
1513 goto ipv6_pktoptions;
1514 return 0;
1515
1516 reset:
1517 tcp_v6_send_reset(sk, skb);
1518 discard:
1519 if (opt_skb)
1520 __kfree_skb(opt_skb);
1521 kfree_skb_reason(skb, reason);
1522 return 0;
1523 csum_err:
1524 reason = SKB_DROP_REASON_TCP_CSUM;
1525 trace_tcp_bad_csum(skb);
1526 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1527 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1528 goto discard;
1529
1530
1531 ipv6_pktoptions:
1532 /* Do you ask, what is it?
1533
1534 1. skb was enqueued by tcp.
1535 2. skb is added to tail of read queue, rather than out of order.
1536 3. socket is not in passive state.
1537 4. Finally, it really contains options, which user wants to receive.
1538 */
1539 tp = tcp_sk(sk);
1540 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1541 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1542 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1543 np->mcast_oif = tcp_v6_iif(opt_skb);
1544 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1545 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1546 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1547 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1548 if (np->repflow)
1549 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1550 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1551 tcp_v6_restore_cb(opt_skb);
1552 opt_skb = xchg(&np->pktoptions, opt_skb);
1553 } else {
1554 __kfree_skb(opt_skb);
1555 opt_skb = xchg(&np->pktoptions, NULL);
1556 }
1557 }
1558
1559 consume_skb(opt_skb);
1560 return 0;
1561 }
1562
1563 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1564 const struct tcphdr *th)
1565 {
1566 /* This is tricky: we move IP6CB at its correct location into
1567 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1568 * _decode_session6() uses IP6CB().
1569 * barrier() makes sure compiler won't play aliasing games.
1570 */
1571 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1572 sizeof(struct inet6_skb_parm));
1573 barrier();
1574
1575 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1576 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1577 skb->len - th->doff*4);
1578 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1579 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1580 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1581 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1582 TCP_SKB_CB(skb)->sacked = 0;
1583 TCP_SKB_CB(skb)->has_rxtstamp =
1584 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1585 }
1586
1587 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1588 {
1589 enum skb_drop_reason drop_reason;
1590 int sdif = inet6_sdif(skb);
1591 int dif = inet6_iif(skb);
1592 const struct tcphdr *th;
1593 const struct ipv6hdr *hdr;
1594 bool refcounted;
1595 struct sock *sk;
1596 int ret;
1597 struct net *net = dev_net(skb->dev);
1598
1599 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1600 if (skb->pkt_type != PACKET_HOST)
1601 goto discard_it;
1602
1603 /*
1604 * Count it even if it's bad.
1605 */
1606 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1607
1608 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1609 goto discard_it;
1610
1611 th = (const struct tcphdr *)skb->data;
1612
1613 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1614 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1615 goto bad_packet;
1616 }
1617 if (!pskb_may_pull(skb, th->doff*4))
1618 goto discard_it;
1619
1620 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1621 goto csum_error;
1622
1623 th = (const struct tcphdr *)skb->data;
1624 hdr = ipv6_hdr(skb);
1625
1626 lookup:
1627 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1628 th->source, th->dest, inet6_iif(skb), sdif,
1629 &refcounted);
1630 if (!sk)
1631 goto no_tcp_socket;
1632
1633 process:
1634 if (sk->sk_state == TCP_TIME_WAIT)
1635 goto do_time_wait;
1636
1637 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1638 struct request_sock *req = inet_reqsk(sk);
1639 bool req_stolen = false;
1640 struct sock *nsk;
1641
1642 sk = req->rsk_listener;
1643 drop_reason = tcp_inbound_md5_hash(sk, skb,
1644 &hdr->saddr, &hdr->daddr,
1645 AF_INET6, dif, sdif);
1646 if (drop_reason) {
1647 sk_drops_add(sk, skb);
1648 reqsk_put(req);
1649 goto discard_it;
1650 }
1651 if (tcp_checksum_complete(skb)) {
1652 reqsk_put(req);
1653 goto csum_error;
1654 }
1655 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1656 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1657 if (!nsk) {
1658 inet_csk_reqsk_queue_drop_and_put(sk, req);
1659 goto lookup;
1660 }
1661 sk = nsk;
1662 /* reuseport_migrate_sock() has already held one sk_refcnt
1663 * before returning.
1664 */
1665 } else {
1666 sock_hold(sk);
1667 }
1668 refcounted = true;
1669 nsk = NULL;
1670 if (!tcp_filter(sk, skb)) {
1671 th = (const struct tcphdr *)skb->data;
1672 hdr = ipv6_hdr(skb);
1673 tcp_v6_fill_cb(skb, hdr, th);
1674 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1675 } else {
1676 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1677 }
1678 if (!nsk) {
1679 reqsk_put(req);
1680 if (req_stolen) {
1681 /* Another cpu got exclusive access to req
1682 * and created a full blown socket.
1683 * Try to feed this packet to this socket
1684 * instead of discarding it.
1685 */
1686 tcp_v6_restore_cb(skb);
1687 sock_put(sk);
1688 goto lookup;
1689 }
1690 goto discard_and_relse;
1691 }
1692 if (nsk == sk) {
1693 reqsk_put(req);
1694 tcp_v6_restore_cb(skb);
1695 } else if (tcp_child_process(sk, nsk, skb)) {
1696 tcp_v6_send_reset(nsk, skb);
1697 goto discard_and_relse;
1698 } else {
1699 sock_put(sk);
1700 return 0;
1701 }
1702 }
1703
1704 if (static_branch_unlikely(&ip6_min_hopcount)) {
1705 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1706 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) {
1707 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1708 drop_reason = SKB_DROP_REASON_TCP_MINTTL;
1709 goto discard_and_relse;
1710 }
1711 }
1712
1713 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1714 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1715 goto discard_and_relse;
1716 }
1717
1718 drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr,
1719 AF_INET6, dif, sdif);
1720 if (drop_reason)
1721 goto discard_and_relse;
1722
1723 nf_reset_ct(skb);
1724
1725 if (tcp_filter(sk, skb)) {
1726 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1727 goto discard_and_relse;
1728 }
1729 th = (const struct tcphdr *)skb->data;
1730 hdr = ipv6_hdr(skb);
1731 tcp_v6_fill_cb(skb, hdr, th);
1732
1733 skb->dev = NULL;
1734
1735 if (sk->sk_state == TCP_LISTEN) {
1736 ret = tcp_v6_do_rcv(sk, skb);
1737 goto put_and_return;
1738 }
1739
1740 sk_incoming_cpu_update(sk);
1741
1742 bh_lock_sock_nested(sk);
1743 tcp_segs_in(tcp_sk(sk), skb);
1744 ret = 0;
1745 if (!sock_owned_by_user(sk)) {
1746 ret = tcp_v6_do_rcv(sk, skb);
1747 } else {
1748 if (tcp_add_backlog(sk, skb, &drop_reason))
1749 goto discard_and_relse;
1750 }
1751 bh_unlock_sock(sk);
1752 put_and_return:
1753 if (refcounted)
1754 sock_put(sk);
1755 return ret ? -1 : 0;
1756
1757 no_tcp_socket:
1758 drop_reason = SKB_DROP_REASON_NO_SOCKET;
1759 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1760 goto discard_it;
1761
1762 tcp_v6_fill_cb(skb, hdr, th);
1763
1764 if (tcp_checksum_complete(skb)) {
1765 csum_error:
1766 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1767 trace_tcp_bad_csum(skb);
1768 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1769 bad_packet:
1770 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1771 } else {
1772 tcp_v6_send_reset(NULL, skb);
1773 }
1774
1775 discard_it:
1776 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1777 kfree_skb_reason(skb, drop_reason);
1778 return 0;
1779
1780 discard_and_relse:
1781 sk_drops_add(sk, skb);
1782 if (refcounted)
1783 sock_put(sk);
1784 goto discard_it;
1785
1786 do_time_wait:
1787 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1788 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1789 inet_twsk_put(inet_twsk(sk));
1790 goto discard_it;
1791 }
1792
1793 tcp_v6_fill_cb(skb, hdr, th);
1794
1795 if (tcp_checksum_complete(skb)) {
1796 inet_twsk_put(inet_twsk(sk));
1797 goto csum_error;
1798 }
1799
1800 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1801 case TCP_TW_SYN:
1802 {
1803 struct sock *sk2;
1804
1805 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1806 skb, __tcp_hdrlen(th),
1807 &ipv6_hdr(skb)->saddr, th->source,
1808 &ipv6_hdr(skb)->daddr,
1809 ntohs(th->dest),
1810 tcp_v6_iif_l3_slave(skb),
1811 sdif);
1812 if (sk2) {
1813 struct inet_timewait_sock *tw = inet_twsk(sk);
1814 inet_twsk_deschedule_put(tw);
1815 sk = sk2;
1816 tcp_v6_restore_cb(skb);
1817 refcounted = false;
1818 goto process;
1819 }
1820 }
1821 /* to ACK */
1822 fallthrough;
1823 case TCP_TW_ACK:
1824 tcp_v6_timewait_ack(sk, skb);
1825 break;
1826 case TCP_TW_RST:
1827 tcp_v6_send_reset(sk, skb);
1828 inet_twsk_deschedule_put(inet_twsk(sk));
1829 goto discard_it;
1830 case TCP_TW_SUCCESS:
1831 ;
1832 }
1833 goto discard_it;
1834 }
1835
1836 void tcp_v6_early_demux(struct sk_buff *skb)
1837 {
1838 struct net *net = dev_net(skb->dev);
1839 const struct ipv6hdr *hdr;
1840 const struct tcphdr *th;
1841 struct sock *sk;
1842
1843 if (skb->pkt_type != PACKET_HOST)
1844 return;
1845
1846 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1847 return;
1848
1849 hdr = ipv6_hdr(skb);
1850 th = tcp_hdr(skb);
1851
1852 if (th->doff < sizeof(struct tcphdr) / 4)
1853 return;
1854
1855 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1856 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
1857 &hdr->saddr, th->source,
1858 &hdr->daddr, ntohs(th->dest),
1859 inet6_iif(skb), inet6_sdif(skb));
1860 if (sk) {
1861 skb->sk = sk;
1862 skb->destructor = sock_edemux;
1863 if (sk_fullsock(sk)) {
1864 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
1865
1866 if (dst)
1867 dst = dst_check(dst, sk->sk_rx_dst_cookie);
1868 if (dst &&
1869 sk->sk_rx_dst_ifindex == skb->skb_iif)
1870 skb_dst_set_noref(skb, dst);
1871 }
1872 }
1873 }
1874
1875 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1876 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1877 .twsk_unique = tcp_twsk_unique,
1878 .twsk_destructor = tcp_twsk_destructor,
1879 };
1880
1881 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1882 {
1883 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
1884 }
1885
1886 const struct inet_connection_sock_af_ops ipv6_specific = {
1887 .queue_xmit = inet6_csk_xmit,
1888 .send_check = tcp_v6_send_check,
1889 .rebuild_header = inet6_sk_rebuild_header,
1890 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1891 .conn_request = tcp_v6_conn_request,
1892 .syn_recv_sock = tcp_v6_syn_recv_sock,
1893 .net_header_len = sizeof(struct ipv6hdr),
1894 .net_frag_header_len = sizeof(struct frag_hdr),
1895 .setsockopt = ipv6_setsockopt,
1896 .getsockopt = ipv6_getsockopt,
1897 .addr2sockaddr = inet6_csk_addr2sockaddr,
1898 .sockaddr_len = sizeof(struct sockaddr_in6),
1899 .mtu_reduced = tcp_v6_mtu_reduced,
1900 };
1901
1902 #ifdef CONFIG_TCP_MD5SIG
1903 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1904 .md5_lookup = tcp_v6_md5_lookup,
1905 .calc_md5_hash = tcp_v6_md5_hash_skb,
1906 .md5_parse = tcp_v6_parse_md5_keys,
1907 };
1908 #endif
1909
1910 /*
1911 * TCP over IPv4 via INET6 API
1912 */
1913 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1914 .queue_xmit = ip_queue_xmit,
1915 .send_check = tcp_v4_send_check,
1916 .rebuild_header = inet_sk_rebuild_header,
1917 .sk_rx_dst_set = inet_sk_rx_dst_set,
1918 .conn_request = tcp_v6_conn_request,
1919 .syn_recv_sock = tcp_v6_syn_recv_sock,
1920 .net_header_len = sizeof(struct iphdr),
1921 .setsockopt = ipv6_setsockopt,
1922 .getsockopt = ipv6_getsockopt,
1923 .addr2sockaddr = inet6_csk_addr2sockaddr,
1924 .sockaddr_len = sizeof(struct sockaddr_in6),
1925 .mtu_reduced = tcp_v4_mtu_reduced,
1926 };
1927
1928 #ifdef CONFIG_TCP_MD5SIG
1929 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1930 .md5_lookup = tcp_v4_md5_lookup,
1931 .calc_md5_hash = tcp_v4_md5_hash_skb,
1932 .md5_parse = tcp_v6_parse_md5_keys,
1933 };
1934 #endif
1935
1936 /* NOTE: A lot of things set to zero explicitly by call to
1937 * sk_alloc() so need not be done here.
1938 */
1939 static int tcp_v6_init_sock(struct sock *sk)
1940 {
1941 struct inet_connection_sock *icsk = inet_csk(sk);
1942
1943 tcp_init_sock(sk);
1944
1945 icsk->icsk_af_ops = &ipv6_specific;
1946
1947 #ifdef CONFIG_TCP_MD5SIG
1948 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1949 #endif
1950
1951 return 0;
1952 }
1953
1954 #ifdef CONFIG_PROC_FS
1955 /* Proc filesystem TCPv6 sock list dumping. */
1956 static void get_openreq6(struct seq_file *seq,
1957 const struct request_sock *req, int i)
1958 {
1959 long ttd = req->rsk_timer.expires - jiffies;
1960 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1961 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1962
1963 if (ttd < 0)
1964 ttd = 0;
1965
1966 seq_printf(seq,
1967 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1968 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1969 i,
1970 src->s6_addr32[0], src->s6_addr32[1],
1971 src->s6_addr32[2], src->s6_addr32[3],
1972 inet_rsk(req)->ir_num,
1973 dest->s6_addr32[0], dest->s6_addr32[1],
1974 dest->s6_addr32[2], dest->s6_addr32[3],
1975 ntohs(inet_rsk(req)->ir_rmt_port),
1976 TCP_SYN_RECV,
1977 0, 0, /* could print option size, but that is af dependent. */
1978 1, /* timers active (only the expire timer) */
1979 jiffies_to_clock_t(ttd),
1980 req->num_timeout,
1981 from_kuid_munged(seq_user_ns(seq),
1982 sock_i_uid(req->rsk_listener)),
1983 0, /* non standard timer */
1984 0, /* open_requests have no inode */
1985 0, req);
1986 }
1987
1988 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1989 {
1990 const struct in6_addr *dest, *src;
1991 __u16 destp, srcp;
1992 int timer_active;
1993 unsigned long timer_expires;
1994 const struct inet_sock *inet = inet_sk(sp);
1995 const struct tcp_sock *tp = tcp_sk(sp);
1996 const struct inet_connection_sock *icsk = inet_csk(sp);
1997 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1998 int rx_queue;
1999 int state;
2000
2001 dest = &sp->sk_v6_daddr;
2002 src = &sp->sk_v6_rcv_saddr;
2003 destp = ntohs(inet->inet_dport);
2004 srcp = ntohs(inet->inet_sport);
2005
2006 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2007 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2008 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2009 timer_active = 1;
2010 timer_expires = icsk->icsk_timeout;
2011 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2012 timer_active = 4;
2013 timer_expires = icsk->icsk_timeout;
2014 } else if (timer_pending(&sp->sk_timer)) {
2015 timer_active = 2;
2016 timer_expires = sp->sk_timer.expires;
2017 } else {
2018 timer_active = 0;
2019 timer_expires = jiffies;
2020 }
2021
2022 state = inet_sk_state_load(sp);
2023 if (state == TCP_LISTEN)
2024 rx_queue = READ_ONCE(sp->sk_ack_backlog);
2025 else
2026 /* Because we don't lock the socket,
2027 * we might find a transient negative value.
2028 */
2029 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2030 READ_ONCE(tp->copied_seq), 0);
2031
2032 seq_printf(seq,
2033 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2034 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2035 i,
2036 src->s6_addr32[0], src->s6_addr32[1],
2037 src->s6_addr32[2], src->s6_addr32[3], srcp,
2038 dest->s6_addr32[0], dest->s6_addr32[1],
2039 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2040 state,
2041 READ_ONCE(tp->write_seq) - tp->snd_una,
2042 rx_queue,
2043 timer_active,
2044 jiffies_delta_to_clock_t(timer_expires - jiffies),
2045 icsk->icsk_retransmits,
2046 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2047 icsk->icsk_probes_out,
2048 sock_i_ino(sp),
2049 refcount_read(&sp->sk_refcnt), sp,
2050 jiffies_to_clock_t(icsk->icsk_rto),
2051 jiffies_to_clock_t(icsk->icsk_ack.ato),
2052 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2053 tcp_snd_cwnd(tp),
2054 state == TCP_LISTEN ?
2055 fastopenq->max_qlen :
2056 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2057 );
2058 }
2059
2060 static void get_timewait6_sock(struct seq_file *seq,
2061 struct inet_timewait_sock *tw, int i)
2062 {
2063 long delta = tw->tw_timer.expires - jiffies;
2064 const struct in6_addr *dest, *src;
2065 __u16 destp, srcp;
2066
2067 dest = &tw->tw_v6_daddr;
2068 src = &tw->tw_v6_rcv_saddr;
2069 destp = ntohs(tw->tw_dport);
2070 srcp = ntohs(tw->tw_sport);
2071
2072 seq_printf(seq,
2073 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2074 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2075 i,
2076 src->s6_addr32[0], src->s6_addr32[1],
2077 src->s6_addr32[2], src->s6_addr32[3], srcp,
2078 dest->s6_addr32[0], dest->s6_addr32[1],
2079 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2080 tw->tw_substate, 0, 0,
2081 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2082 refcount_read(&tw->tw_refcnt), tw);
2083 }
2084
2085 static int tcp6_seq_show(struct seq_file *seq, void *v)
2086 {
2087 struct tcp_iter_state *st;
2088 struct sock *sk = v;
2089
2090 if (v == SEQ_START_TOKEN) {
2091 seq_puts(seq,
2092 " sl "
2093 "local_address "
2094 "remote_address "
2095 "st tx_queue rx_queue tr tm->when retrnsmt"
2096 " uid timeout inode\n");
2097 goto out;
2098 }
2099 st = seq->private;
2100
2101 if (sk->sk_state == TCP_TIME_WAIT)
2102 get_timewait6_sock(seq, v, st->num);
2103 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2104 get_openreq6(seq, v, st->num);
2105 else
2106 get_tcp6_sock(seq, v, st->num);
2107 out:
2108 return 0;
2109 }
2110
2111 static const struct seq_operations tcp6_seq_ops = {
2112 .show = tcp6_seq_show,
2113 .start = tcp_seq_start,
2114 .next = tcp_seq_next,
2115 .stop = tcp_seq_stop,
2116 };
2117
2118 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2119 .family = AF_INET6,
2120 };
2121
2122 int __net_init tcp6_proc_init(struct net *net)
2123 {
2124 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2125 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2126 return -ENOMEM;
2127 return 0;
2128 }
2129
2130 void tcp6_proc_exit(struct net *net)
2131 {
2132 remove_proc_entry("tcp6", net->proc_net);
2133 }
2134 #endif
2135
2136 struct proto tcpv6_prot = {
2137 .name = "TCPv6",
2138 .owner = THIS_MODULE,
2139 .close = tcp_close,
2140 .pre_connect = tcp_v6_pre_connect,
2141 .connect = tcp_v6_connect,
2142 .disconnect = tcp_disconnect,
2143 .accept = inet_csk_accept,
2144 .ioctl = tcp_ioctl,
2145 .init = tcp_v6_init_sock,
2146 .destroy = tcp_v4_destroy_sock,
2147 .shutdown = tcp_shutdown,
2148 .setsockopt = tcp_setsockopt,
2149 .getsockopt = tcp_getsockopt,
2150 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
2151 .keepalive = tcp_set_keepalive,
2152 .recvmsg = tcp_recvmsg,
2153 .sendmsg = tcp_sendmsg,
2154 .splice_eof = tcp_splice_eof,
2155 .backlog_rcv = tcp_v6_do_rcv,
2156 .release_cb = tcp_release_cb,
2157 .hash = inet6_hash,
2158 .unhash = inet_unhash,
2159 .get_port = inet_csk_get_port,
2160 .put_port = inet_put_port,
2161 #ifdef CONFIG_BPF_SYSCALL
2162 .psock_update_sk_prot = tcp_bpf_update_proto,
2163 #endif
2164 .enter_memory_pressure = tcp_enter_memory_pressure,
2165 .leave_memory_pressure = tcp_leave_memory_pressure,
2166 .stream_memory_free = tcp_stream_memory_free,
2167 .sockets_allocated = &tcp_sockets_allocated,
2168
2169 .memory_allocated = &tcp_memory_allocated,
2170 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
2171
2172 .memory_pressure = &tcp_memory_pressure,
2173 .orphan_count = &tcp_orphan_count,
2174 .sysctl_mem = sysctl_tcp_mem,
2175 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2176 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2177 .max_header = MAX_TCP_HEADER,
2178 .obj_size = sizeof(struct tcp6_sock),
2179 .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6),
2180 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2181 .twsk_prot = &tcp6_timewait_sock_ops,
2182 .rsk_prot = &tcp6_request_sock_ops,
2183 .h.hashinfo = NULL,
2184 .no_autobind = true,
2185 .diag_destroy = tcp_abort,
2186 };
2187 EXPORT_SYMBOL_GPL(tcpv6_prot);
2188
2189 static const struct inet6_protocol tcpv6_protocol = {
2190 .handler = tcp_v6_rcv,
2191 .err_handler = tcp_v6_err,
2192 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2193 };
2194
2195 static struct inet_protosw tcpv6_protosw = {
2196 .type = SOCK_STREAM,
2197 .protocol = IPPROTO_TCP,
2198 .prot = &tcpv6_prot,
2199 .ops = &inet6_stream_ops,
2200 .flags = INET_PROTOSW_PERMANENT |
2201 INET_PROTOSW_ICSK,
2202 };
2203
2204 static int __net_init tcpv6_net_init(struct net *net)
2205 {
2206 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2207 SOCK_RAW, IPPROTO_TCP, net);
2208 }
2209
2210 static void __net_exit tcpv6_net_exit(struct net *net)
2211 {
2212 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2213 }
2214
2215 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2216 {
2217 tcp_twsk_purge(net_exit_list, AF_INET6);
2218 }
2219
2220 static struct pernet_operations tcpv6_net_ops = {
2221 .init = tcpv6_net_init,
2222 .exit = tcpv6_net_exit,
2223 .exit_batch = tcpv6_net_exit_batch,
2224 };
2225
2226 int __init tcpv6_init(void)
2227 {
2228 int ret;
2229
2230 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2231 if (ret)
2232 goto out;
2233
2234 /* register inet6 protocol */
2235 ret = inet6_register_protosw(&tcpv6_protosw);
2236 if (ret)
2237 goto out_tcpv6_protocol;
2238
2239 ret = register_pernet_subsys(&tcpv6_net_ops);
2240 if (ret)
2241 goto out_tcpv6_protosw;
2242
2243 ret = mptcpv6_init();
2244 if (ret)
2245 goto out_tcpv6_pernet_subsys;
2246
2247 out:
2248 return ret;
2249
2250 out_tcpv6_pernet_subsys:
2251 unregister_pernet_subsys(&tcpv6_net_ops);
2252 out_tcpv6_protosw:
2253 inet6_unregister_protosw(&tcpv6_protosw);
2254 out_tcpv6_protocol:
2255 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2256 goto out;
2257 }
2258
2259 void tcpv6_exit(void)
2260 {
2261 unregister_pernet_subsys(&tcpv6_net_ops);
2262 inet6_unregister_protosw(&tcpv6_protosw);
2263 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2264 }
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git