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Merge tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
[linux/fpc-iii.git] / net / ipv6 / tcp_ipv6.c
blob0e1509b02cb3065d5841b55c7ea54fa4d668585b
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 static 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 static 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
103 static 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 sk->sk_rx_dst = dst;
111 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
112 tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
113 }
114 }
115
116 static 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
124 static 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
130 static 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
145 static 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_sock *inet = inet_sk(sk);
150 struct inet_connection_sock *icsk = inet_csk(sk);
151 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
152 struct tcp_sock *tp = tcp_sk(sk);
153 struct in6_addr *saddr = NULL, *final_p, final;
154 struct ipv6_txoptions *opt;
155 struct flowi6 fl6;
156 struct dst_entry *dst;
157 int addr_type;
158 int err;
159 struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
160
161 if (addr_len < SIN6_LEN_RFC2133)
162 return -EINVAL;
163
164 if (usin->sin6_family != AF_INET6)
165 return -EAFNOSUPPORT;
166
167 memset(&fl6, 0, sizeof(fl6));
168
169 if (np->sndflow) {
170 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
171 IP6_ECN_flow_init(fl6.flowlabel);
172 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
173 struct ip6_flowlabel *flowlabel;
174 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
175 if (IS_ERR(flowlabel))
176 return -EINVAL;
177 fl6_sock_release(flowlabel);
178 }
179 }
180
181 /*
182 * connect() to INADDR_ANY means loopback (BSD'ism).
183 */
184
185 if (ipv6_addr_any(&usin->sin6_addr)) {
186 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
187 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
188 &usin->sin6_addr);
189 else
190 usin->sin6_addr = in6addr_loopback;
191 }
192
193 addr_type = ipv6_addr_type(&usin->sin6_addr);
194
195 if (addr_type & IPV6_ADDR_MULTICAST)
196 return -ENETUNREACH;
197
198 if (addr_type&IPV6_ADDR_LINKLOCAL) {
199 if (addr_len >= sizeof(struct sockaddr_in6) &&
200 usin->sin6_scope_id) {
201 /* If interface is set while binding, indices
202 * must coincide.
203 */
204 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
205 return -EINVAL;
206
207 sk->sk_bound_dev_if = usin->sin6_scope_id;
208 }
209
210 /* Connect to link-local address requires an interface */
211 if (!sk->sk_bound_dev_if)
212 return -EINVAL;
213 }
214
215 if (tp->rx_opt.ts_recent_stamp &&
216 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
217 tp->rx_opt.ts_recent = 0;
218 tp->rx_opt.ts_recent_stamp = 0;
219 WRITE_ONCE(tp->write_seq, 0);
220 }
221
222 sk->sk_v6_daddr = usin->sin6_addr;
223 np->flow_label = fl6.flowlabel;
224
225 /*
226 * TCP over IPv4
227 */
228
229 if (addr_type & IPV6_ADDR_MAPPED) {
230 u32 exthdrlen = icsk->icsk_ext_hdr_len;
231 struct sockaddr_in sin;
232
233 if (__ipv6_only_sock(sk))
234 return -ENETUNREACH;
235
236 sin.sin_family = AF_INET;
237 sin.sin_port = usin->sin6_port;
238 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
239
240 icsk->icsk_af_ops = &ipv6_mapped;
241 if (sk_is_mptcp(sk))
242 mptcpv6_handle_mapped(sk, true);
243 sk->sk_backlog_rcv = tcp_v4_do_rcv;
244 #ifdef CONFIG_TCP_MD5SIG
245 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
246 #endif
247
248 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
249
250 if (err) {
251 icsk->icsk_ext_hdr_len = exthdrlen;
252 icsk->icsk_af_ops = &ipv6_specific;
253 if (sk_is_mptcp(sk))
254 mptcpv6_handle_mapped(sk, false);
255 sk->sk_backlog_rcv = tcp_v6_do_rcv;
256 #ifdef CONFIG_TCP_MD5SIG
257 tp->af_specific = &tcp_sock_ipv6_specific;
258 #endif
259 goto failure;
260 }
261 np->saddr = sk->sk_v6_rcv_saddr;
262
263 return err;
264 }
265
266 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
267 saddr = &sk->sk_v6_rcv_saddr;
268
269 fl6.flowi6_proto = IPPROTO_TCP;
270 fl6.daddr = sk->sk_v6_daddr;
271 fl6.saddr = saddr ? *saddr : np->saddr;
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(sock_net(sk), sk, &fl6, final_p);
284 if (IS_ERR(dst)) {
285 err = PTR_ERR(dst);
286 goto failure;
287 }
288
289 if (!saddr) {
290 saddr = &fl6.saddr;
291 sk->sk_v6_rcv_saddr = *saddr;
292 }
293
294 /* set the source address */
295 np->saddr = *saddr;
296 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
297
298 sk->sk_gso_type = SKB_GSO_TCPV6;
299 ip6_dst_store(sk, dst, NULL, NULL);
300
301 icsk->icsk_ext_hdr_len = 0;
302 if (opt)
303 icsk->icsk_ext_hdr_len = opt->opt_flen +
304 opt->opt_nflen;
305
306 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
307
308 inet->inet_dport = usin->sin6_port;
309
310 tcp_set_state(sk, TCP_SYN_SENT);
311 err = inet6_hash_connect(tcp_death_row, sk);
312 if (err)
313 goto late_failure;
314
315 sk_set_txhash(sk);
316
317 if (likely(!tp->repair)) {
318 if (!tp->write_seq)
319 WRITE_ONCE(tp->write_seq,
320 secure_tcpv6_seq(np->saddr.s6_addr32,
321 sk->sk_v6_daddr.s6_addr32,
322 inet->inet_sport,
323 inet->inet_dport));
324 tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk),
325 np->saddr.s6_addr32,
326 sk->sk_v6_daddr.s6_addr32);
327 }
328
329 if (tcp_fastopen_defer_connect(sk, &err))
330 return err;
331 if (err)
332 goto late_failure;
333
334 err = tcp_connect(sk);
335 if (err)
336 goto late_failure;
337
338 return 0;
339
340 late_failure:
341 tcp_set_state(sk, TCP_CLOSE);
342 failure:
343 inet->inet_dport = 0;
344 sk->sk_route_caps = 0;
345 return err;
346 }
347
348 static void tcp_v6_mtu_reduced(struct sock *sk)
349 {
350 struct dst_entry *dst;
351
352 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
353 return;
354
355 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
356 if (!dst)
357 return;
358
359 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
360 tcp_sync_mss(sk, dst_mtu(dst));
361 tcp_simple_retransmit(sk);
362 }
363 }
364
365 static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
366 u8 type, u8 code, int offset, __be32 info)
367 {
368 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
369 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
370 struct net *net = dev_net(skb->dev);
371 struct request_sock *fastopen;
372 struct ipv6_pinfo *np;
373 struct tcp_sock *tp;
374 __u32 seq, snd_una;
375 struct sock *sk;
376 bool fatal;
377 int err;
378
379 sk = __inet6_lookup_established(net, &tcp_hashinfo,
380 &hdr->daddr, th->dest,
381 &hdr->saddr, ntohs(th->source),
382 skb->dev->ifindex, inet6_sdif(skb));
383
384 if (!sk) {
385 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
386 ICMP6_MIB_INERRORS);
387 return -ENOENT;
388 }
389
390 if (sk->sk_state == TCP_TIME_WAIT) {
391 inet_twsk_put(inet_twsk(sk));
392 return 0;
393 }
394 seq = ntohl(th->seq);
395 fatal = icmpv6_err_convert(type, code, &err);
396 if (sk->sk_state == TCP_NEW_SYN_RECV) {
397 tcp_req_err(sk, seq, fatal);
398 return 0;
399 }
400
401 bh_lock_sock(sk);
402 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
403 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
404
405 if (sk->sk_state == TCP_CLOSE)
406 goto out;
407
408 if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
409 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
410 goto out;
411 }
412
413 tp = tcp_sk(sk);
414 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
415 fastopen = rcu_dereference(tp->fastopen_rsk);
416 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
417 if (sk->sk_state != TCP_LISTEN &&
418 !between(seq, snd_una, tp->snd_nxt)) {
419 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
420 goto out;
421 }
422
423 np = tcp_inet6_sk(sk);
424
425 if (type == NDISC_REDIRECT) {
426 if (!sock_owned_by_user(sk)) {
427 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
428
429 if (dst)
430 dst->ops->redirect(dst, sk, skb);
431 }
432 goto out;
433 }
434
435 if (type == ICMPV6_PKT_TOOBIG) {
436 /* We are not interested in TCP_LISTEN and open_requests
437 * (SYN-ACKs send out by Linux are always <576bytes so
438 * they should go through unfragmented).
439 */
440 if (sk->sk_state == TCP_LISTEN)
441 goto out;
442
443 if (!ip6_sk_accept_pmtu(sk))
444 goto out;
445
446 tp->mtu_info = ntohl(info);
447 if (!sock_owned_by_user(sk))
448 tcp_v6_mtu_reduced(sk);
449 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
450 &sk->sk_tsq_flags))
451 sock_hold(sk);
452 goto out;
453 }
454
455
456 /* Might be for an request_sock */
457 switch (sk->sk_state) {
458 case TCP_SYN_SENT:
459 case TCP_SYN_RECV:
460 /* Only in fast or simultaneous open. If a fast open socket is
461 * already accepted it is treated as a connected one below.
462 */
463 if (fastopen && !fastopen->sk)
464 break;
465
466 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
467
468 if (!sock_owned_by_user(sk)) {
469 sk->sk_err = err;
470 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
471
472 tcp_done(sk);
473 } else
474 sk->sk_err_soft = err;
475 goto out;
476 case TCP_LISTEN:
477 break;
478 default:
479 /* check if this ICMP message allows revert of backoff.
480 * (see RFC 6069)
481 */
482 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
483 code == ICMPV6_NOROUTE)
484 tcp_ld_RTO_revert(sk, seq);
485 }
486
487 if (!sock_owned_by_user(sk) && np->recverr) {
488 sk->sk_err = err;
489 sk->sk_error_report(sk);
490 } else
491 sk->sk_err_soft = err;
492
493 out:
494 bh_unlock_sock(sk);
495 sock_put(sk);
496 return 0;
497 }
498
499
500 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
501 struct flowi *fl,
502 struct request_sock *req,
503 struct tcp_fastopen_cookie *foc,
504 enum tcp_synack_type synack_type,
505 struct sk_buff *syn_skb)
506 {
507 struct inet_request_sock *ireq = inet_rsk(req);
508 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
509 struct ipv6_txoptions *opt;
510 struct flowi6 *fl6 = &fl->u.ip6;
511 struct sk_buff *skb;
512 int err = -ENOMEM;
513 u8 tclass;
514
515 /* First, grab a route. */
516 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
517 IPPROTO_TCP)) == NULL)
518 goto done;
519
520 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
521
522 if (skb) {
523 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
524 &ireq->ir_v6_rmt_addr);
525
526 fl6->daddr = ireq->ir_v6_rmt_addr;
527 if (np->repflow && ireq->pktopts)
528 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
529
530 tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ?
531 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
532 (np->tclass & INET_ECN_MASK) :
533 np->tclass;
534
535 if (!INET_ECN_is_capable(tclass) &&
536 tcp_bpf_ca_needs_ecn((struct sock *)req))
537 tclass |= INET_ECN_ECT_0;
538
539 rcu_read_lock();
540 opt = ireq->ipv6_opt;
541 if (!opt)
542 opt = rcu_dereference(np->opt);
543 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt,
544 tclass, sk->sk_priority);
545 rcu_read_unlock();
546 err = net_xmit_eval(err);
547 }
548
549 done:
550 return err;
551 }
552
553
554 static void tcp_v6_reqsk_destructor(struct request_sock *req)
555 {
556 kfree(inet_rsk(req)->ipv6_opt);
557 kfree_skb(inet_rsk(req)->pktopts);
558 }
559
560 #ifdef CONFIG_TCP_MD5SIG
561 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
562 const struct in6_addr *addr,
563 int l3index)
564 {
565 return tcp_md5_do_lookup(sk, l3index,
566 (union tcp_md5_addr *)addr, AF_INET6);
567 }
568
569 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
570 const struct sock *addr_sk)
571 {
572 int l3index;
573
574 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
575 addr_sk->sk_bound_dev_if);
576 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
577 l3index);
578 }
579
580 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
581 sockptr_t optval, int optlen)
582 {
583 struct tcp_md5sig cmd;
584 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
585 int l3index = 0;
586 u8 prefixlen;
587
588 if (optlen < sizeof(cmd))
589 return -EINVAL;
590
591 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
592 return -EFAULT;
593
594 if (sin6->sin6_family != AF_INET6)
595 return -EINVAL;
596
597 if (optname == TCP_MD5SIG_EXT &&
598 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
599 prefixlen = cmd.tcpm_prefixlen;
600 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
601 prefixlen > 32))
602 return -EINVAL;
603 } else {
604 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
605 }
606
607 if (optname == TCP_MD5SIG_EXT &&
608 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
609 struct net_device *dev;
610
611 rcu_read_lock();
612 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
613 if (dev && netif_is_l3_master(dev))
614 l3index = dev->ifindex;
615 rcu_read_unlock();
616
617 /* ok to reference set/not set outside of rcu;
618 * right now device MUST be an L3 master
619 */
620 if (!dev || !l3index)
621 return -EINVAL;
622 }
623
624 if (!cmd.tcpm_keylen) {
625 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
626 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
627 AF_INET, prefixlen,
628 l3index);
629 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
630 AF_INET6, prefixlen, l3index);
631 }
632
633 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
634 return -EINVAL;
635
636 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
637 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
638 AF_INET, prefixlen, l3index,
639 cmd.tcpm_key, cmd.tcpm_keylen,
640 GFP_KERNEL);
641
642 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
643 AF_INET6, prefixlen, l3index,
644 cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
645 }
646
647 static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
648 const struct in6_addr *daddr,
649 const struct in6_addr *saddr,
650 const struct tcphdr *th, int nbytes)
651 {
652 struct tcp6_pseudohdr *bp;
653 struct scatterlist sg;
654 struct tcphdr *_th;
655
656 bp = hp->scratch;
657 /* 1. TCP pseudo-header (RFC2460) */
658 bp->saddr = *saddr;
659 bp->daddr = *daddr;
660 bp->protocol = cpu_to_be32(IPPROTO_TCP);
661 bp->len = cpu_to_be32(nbytes);
662
663 _th = (struct tcphdr *)(bp + 1);
664 memcpy(_th, th, sizeof(*th));
665 _th->check = 0;
666
667 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
668 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
669 sizeof(*bp) + sizeof(*th));
670 return crypto_ahash_update(hp->md5_req);
671 }
672
673 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
674 const struct in6_addr *daddr, struct in6_addr *saddr,
675 const struct tcphdr *th)
676 {
677 struct tcp_md5sig_pool *hp;
678 struct ahash_request *req;
679
680 hp = tcp_get_md5sig_pool();
681 if (!hp)
682 goto clear_hash_noput;
683 req = hp->md5_req;
684
685 if (crypto_ahash_init(req))
686 goto clear_hash;
687 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
688 goto clear_hash;
689 if (tcp_md5_hash_key(hp, key))
690 goto clear_hash;
691 ahash_request_set_crypt(req, NULL, md5_hash, 0);
692 if (crypto_ahash_final(req))
693 goto clear_hash;
694
695 tcp_put_md5sig_pool();
696 return 0;
697
698 clear_hash:
699 tcp_put_md5sig_pool();
700 clear_hash_noput:
701 memset(md5_hash, 0, 16);
702 return 1;
703 }
704
705 static int tcp_v6_md5_hash_skb(char *md5_hash,
706 const struct tcp_md5sig_key *key,
707 const struct sock *sk,
708 const struct sk_buff *skb)
709 {
710 const struct in6_addr *saddr, *daddr;
711 struct tcp_md5sig_pool *hp;
712 struct ahash_request *req;
713 const struct tcphdr *th = tcp_hdr(skb);
714
715 if (sk) { /* valid for establish/request sockets */
716 saddr = &sk->sk_v6_rcv_saddr;
717 daddr = &sk->sk_v6_daddr;
718 } else {
719 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
720 saddr = &ip6h->saddr;
721 daddr = &ip6h->daddr;
722 }
723
724 hp = tcp_get_md5sig_pool();
725 if (!hp)
726 goto clear_hash_noput;
727 req = hp->md5_req;
728
729 if (crypto_ahash_init(req))
730 goto clear_hash;
731
732 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
733 goto clear_hash;
734 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
735 goto clear_hash;
736 if (tcp_md5_hash_key(hp, key))
737 goto clear_hash;
738 ahash_request_set_crypt(req, NULL, md5_hash, 0);
739 if (crypto_ahash_final(req))
740 goto clear_hash;
741
742 tcp_put_md5sig_pool();
743 return 0;
744
745 clear_hash:
746 tcp_put_md5sig_pool();
747 clear_hash_noput:
748 memset(md5_hash, 0, 16);
749 return 1;
750 }
751
752 #endif
753
754 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
755 const struct sk_buff *skb,
756 int dif, int sdif)
757 {
758 #ifdef CONFIG_TCP_MD5SIG
759 const __u8 *hash_location = NULL;
760 struct tcp_md5sig_key *hash_expected;
761 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
762 const struct tcphdr *th = tcp_hdr(skb);
763 int genhash, l3index;
764 u8 newhash[16];
765
766 /* sdif set, means packet ingressed via a device
767 * in an L3 domain and dif is set to the l3mdev
768 */
769 l3index = sdif ? dif : 0;
770
771 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index);
772 hash_location = tcp_parse_md5sig_option(th);
773
774 /* We've parsed the options - do we have a hash? */
775 if (!hash_expected && !hash_location)
776 return false;
777
778 if (hash_expected && !hash_location) {
779 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
780 return true;
781 }
782
783 if (!hash_expected && hash_location) {
784 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
785 return true;
786 }
787
788 /* check the signature */
789 genhash = tcp_v6_md5_hash_skb(newhash,
790 hash_expected,
791 NULL, skb);
792
793 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
794 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
795 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
796 genhash ? "failed" : "mismatch",
797 &ip6h->saddr, ntohs(th->source),
798 &ip6h->daddr, ntohs(th->dest), l3index);
799 return true;
800 }
801 #endif
802 return false;
803 }
804
805 static void tcp_v6_init_req(struct request_sock *req,
806 const struct sock *sk_listener,
807 struct sk_buff *skb)
808 {
809 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
810 struct inet_request_sock *ireq = inet_rsk(req);
811 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
812
813 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
814 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
815
816 /* So that link locals have meaning */
817 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
818 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
819 ireq->ir_iif = tcp_v6_iif(skb);
820
821 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
822 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
823 np->rxopt.bits.rxinfo ||
824 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
825 np->rxopt.bits.rxohlim || np->repflow)) {
826 refcount_inc(&skb->users);
827 ireq->pktopts = skb;
828 }
829 }
830
831 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
832 struct sk_buff *skb,
833 struct flowi *fl,
834 struct request_sock *req)
835 {
836 tcp_v6_init_req(req, sk, skb);
837
838 if (security_inet_conn_request(sk, skb, req))
839 return NULL;
840
841 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
842 }
843
844 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
845 .family = AF_INET6,
846 .obj_size = sizeof(struct tcp6_request_sock),
847 .rtx_syn_ack = tcp_rtx_synack,
848 .send_ack = tcp_v6_reqsk_send_ack,
849 .destructor = tcp_v6_reqsk_destructor,
850 .send_reset = tcp_v6_send_reset,
851 .syn_ack_timeout = tcp_syn_ack_timeout,
852 };
853
854 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
855 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
856 sizeof(struct ipv6hdr),
857 #ifdef CONFIG_TCP_MD5SIG
858 .req_md5_lookup = tcp_v6_md5_lookup,
859 .calc_md5_hash = tcp_v6_md5_hash_skb,
860 #endif
861 #ifdef CONFIG_SYN_COOKIES
862 .cookie_init_seq = cookie_v6_init_sequence,
863 #endif
864 .route_req = tcp_v6_route_req,
865 .init_seq = tcp_v6_init_seq,
866 .init_ts_off = tcp_v6_init_ts_off,
867 .send_synack = tcp_v6_send_synack,
868 };
869
870 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
871 u32 ack, u32 win, u32 tsval, u32 tsecr,
872 int oif, struct tcp_md5sig_key *key, int rst,
873 u8 tclass, __be32 label, u32 priority)
874 {
875 const struct tcphdr *th = tcp_hdr(skb);
876 struct tcphdr *t1;
877 struct sk_buff *buff;
878 struct flowi6 fl6;
879 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
880 struct sock *ctl_sk = net->ipv6.tcp_sk;
881 unsigned int tot_len = sizeof(struct tcphdr);
882 struct dst_entry *dst;
883 __be32 *topt;
884 __u32 mark = 0;
885
886 if (tsecr)
887 tot_len += TCPOLEN_TSTAMP_ALIGNED;
888 #ifdef CONFIG_TCP_MD5SIG
889 if (key)
890 tot_len += TCPOLEN_MD5SIG_ALIGNED;
891 #endif
892
893 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
894 GFP_ATOMIC);
895 if (!buff)
896 return;
897
898 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
899
900 t1 = skb_push(buff, tot_len);
901 skb_reset_transport_header(buff);
902
903 /* Swap the send and the receive. */
904 memset(t1, 0, sizeof(*t1));
905 t1->dest = th->source;
906 t1->source = th->dest;
907 t1->doff = tot_len / 4;
908 t1->seq = htonl(seq);
909 t1->ack_seq = htonl(ack);
910 t1->ack = !rst || !th->ack;
911 t1->rst = rst;
912 t1->window = htons(win);
913
914 topt = (__be32 *)(t1 + 1);
915
916 if (tsecr) {
917 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
918 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
919 *topt++ = htonl(tsval);
920 *topt++ = htonl(tsecr);
921 }
922
923 #ifdef CONFIG_TCP_MD5SIG
924 if (key) {
925 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
926 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
927 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
928 &ipv6_hdr(skb)->saddr,
929 &ipv6_hdr(skb)->daddr, t1);
930 }
931 #endif
932
933 memset(&fl6, 0, sizeof(fl6));
934 fl6.daddr = ipv6_hdr(skb)->saddr;
935 fl6.saddr = ipv6_hdr(skb)->daddr;
936 fl6.flowlabel = label;
937
938 buff->ip_summed = CHECKSUM_PARTIAL;
939 buff->csum = 0;
940
941 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
942
943 fl6.flowi6_proto = IPPROTO_TCP;
944 if (rt6_need_strict(&fl6.daddr) && !oif)
945 fl6.flowi6_oif = tcp_v6_iif(skb);
946 else {
947 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
948 oif = skb->skb_iif;
949
950 fl6.flowi6_oif = oif;
951 }
952
953 if (sk) {
954 if (sk->sk_state == TCP_TIME_WAIT) {
955 mark = inet_twsk(sk)->tw_mark;
956 /* autoflowlabel relies on buff->hash */
957 skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
958 PKT_HASH_TYPE_L4);
959 } else {
960 mark = sk->sk_mark;
961 }
962 buff->tstamp = tcp_transmit_time(sk);
963 }
964 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
965 fl6.fl6_dport = t1->dest;
966 fl6.fl6_sport = t1->source;
967 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
968 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
969
970 /* Pass a socket to ip6_dst_lookup either it is for RST
971 * Underlying function will use this to retrieve the network
972 * namespace
973 */
974 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
975 if (!IS_ERR(dst)) {
976 skb_dst_set(buff, dst);
977 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
978 tclass & ~INET_ECN_MASK, priority);
979 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
980 if (rst)
981 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
982 return;
983 }
984
985 kfree_skb(buff);
986 }
987
988 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
989 {
990 const struct tcphdr *th = tcp_hdr(skb);
991 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
992 u32 seq = 0, ack_seq = 0;
993 struct tcp_md5sig_key *key = NULL;
994 #ifdef CONFIG_TCP_MD5SIG
995 const __u8 *hash_location = NULL;
996 unsigned char newhash[16];
997 int genhash;
998 struct sock *sk1 = NULL;
999 #endif
1000 __be32 label = 0;
1001 u32 priority = 0;
1002 struct net *net;
1003 int oif = 0;
1004
1005 if (th->rst)
1006 return;
1007
1008 /* If sk not NULL, it means we did a successful lookup and incoming
1009 * route had to be correct. prequeue might have dropped our dst.
1010 */
1011 if (!sk && !ipv6_unicast_destination(skb))
1012 return;
1013
1014 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1015 #ifdef CONFIG_TCP_MD5SIG
1016 rcu_read_lock();
1017 hash_location = tcp_parse_md5sig_option(th);
1018 if (sk && sk_fullsock(sk)) {
1019 int l3index;
1020
1021 /* sdif set, means packet ingressed via a device
1022 * in an L3 domain and inet_iif is set to it.
1023 */
1024 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1025 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1026 } else if (hash_location) {
1027 int dif = tcp_v6_iif_l3_slave(skb);
1028 int sdif = tcp_v6_sdif(skb);
1029 int l3index;
1030
1031 /*
1032 * active side is lost. Try to find listening socket through
1033 * source port, and then find md5 key through listening socket.
1034 * we are not loose security here:
1035 * Incoming packet is checked with md5 hash with finding key,
1036 * no RST generated if md5 hash doesn't match.
1037 */
1038 sk1 = inet6_lookup_listener(net,
1039 &tcp_hashinfo, NULL, 0,
1040 &ipv6h->saddr,
1041 th->source, &ipv6h->daddr,
1042 ntohs(th->source), dif, sdif);
1043 if (!sk1)
1044 goto out;
1045
1046 /* sdif set, means packet ingressed via a device
1047 * in an L3 domain and dif is set to it.
1048 */
1049 l3index = tcp_v6_sdif(skb) ? dif : 0;
1050
1051 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1052 if (!key)
1053 goto out;
1054
1055 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1056 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1057 goto out;
1058 }
1059 #endif
1060
1061 if (th->ack)
1062 seq = ntohl(th->ack_seq);
1063 else
1064 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1065 (th->doff << 2);
1066
1067 if (sk) {
1068 oif = sk->sk_bound_dev_if;
1069 if (sk_fullsock(sk)) {
1070 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1071
1072 trace_tcp_send_reset(sk, skb);
1073 if (np->repflow)
1074 label = ip6_flowlabel(ipv6h);
1075 priority = sk->sk_priority;
1076 }
1077 if (sk->sk_state == TCP_TIME_WAIT) {
1078 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1079 priority = inet_twsk(sk)->tw_priority;
1080 }
1081 } else {
1082 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1083 label = ip6_flowlabel(ipv6h);
1084 }
1085
1086 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
1087 ipv6_get_dsfield(ipv6h), label, priority);
1088
1089 #ifdef CONFIG_TCP_MD5SIG
1090 out:
1091 rcu_read_unlock();
1092 #endif
1093 }
1094
1095 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1096 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1097 struct tcp_md5sig_key *key, u8 tclass,
1098 __be32 label, u32 priority)
1099 {
1100 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1101 tclass, label, priority);
1102 }
1103
1104 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1105 {
1106 struct inet_timewait_sock *tw = inet_twsk(sk);
1107 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1108
1109 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1110 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1111 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1112 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1113 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
1114
1115 inet_twsk_put(tw);
1116 }
1117
1118 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1119 struct request_sock *req)
1120 {
1121 int l3index;
1122
1123 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1124
1125 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1126 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1127 */
1128 /* RFC 7323 2.3
1129 * The window field (SEG.WND) of every outgoing segment, with the
1130 * exception of <SYN> segments, MUST be right-shifted by
1131 * Rcv.Wind.Shift bits:
1132 */
1133 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1134 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1135 tcp_rsk(req)->rcv_nxt,
1136 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1137 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1138 req->ts_recent, sk->sk_bound_dev_if,
1139 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1140 ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority);
1141 }
1142
1143
1144 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1145 {
1146 #ifdef CONFIG_SYN_COOKIES
1147 const struct tcphdr *th = tcp_hdr(skb);
1148
1149 if (!th->syn)
1150 sk = cookie_v6_check(sk, skb);
1151 #endif
1152 return sk;
1153 }
1154
1155 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1156 struct tcphdr *th, u32 *cookie)
1157 {
1158 u16 mss = 0;
1159 #ifdef CONFIG_SYN_COOKIES
1160 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1161 &tcp_request_sock_ipv6_ops, sk, th);
1162 if (mss) {
1163 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1164 tcp_synq_overflow(sk);
1165 }
1166 #endif
1167 return mss;
1168 }
1169
1170 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1171 {
1172 if (skb->protocol == htons(ETH_P_IP))
1173 return tcp_v4_conn_request(sk, skb);
1174
1175 if (!ipv6_unicast_destination(skb))
1176 goto drop;
1177
1178 return tcp_conn_request(&tcp6_request_sock_ops,
1179 &tcp_request_sock_ipv6_ops, sk, skb);
1180
1181 drop:
1182 tcp_listendrop(sk);
1183 return 0; /* don't send reset */
1184 }
1185
1186 static 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
1196 static 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 newinet = inet_sk(newsk);
1230 newnp = tcp_inet6_sk(newsk);
1231 newtp = tcp_sk(newsk);
1232
1233 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1234
1235 newnp->saddr = newsk->sk_v6_rcv_saddr;
1236
1237 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1238 if (sk_is_mptcp(newsk))
1239 mptcpv6_handle_mapped(newsk, true);
1240 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1241 #ifdef CONFIG_TCP_MD5SIG
1242 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1243 #endif
1244
1245 newnp->ipv6_mc_list = NULL;
1246 newnp->ipv6_ac_list = NULL;
1247 newnp->ipv6_fl_list = NULL;
1248 newnp->pktoptions = NULL;
1249 newnp->opt = NULL;
1250 newnp->mcast_oif = inet_iif(skb);
1251 newnp->mcast_hops = ip_hdr(skb)->ttl;
1252 newnp->rcv_flowinfo = 0;
1253 if (np->repflow)
1254 newnp->flow_label = 0;
1255
1256 /*
1257 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1258 * here, tcp_create_openreq_child now does this for us, see the comment in
1259 * that function for the gory details. -acme
1260 */
1261
1262 /* It is tricky place. Until this moment IPv4 tcp
1263 worked with IPv6 icsk.icsk_af_ops.
1264 Sync it now.
1265 */
1266 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1267
1268 return newsk;
1269 }
1270
1271 ireq = inet_rsk(req);
1272
1273 if (sk_acceptq_is_full(sk))
1274 goto out_overflow;
1275
1276 if (!dst) {
1277 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1278 if (!dst)
1279 goto out;
1280 }
1281
1282 newsk = tcp_create_openreq_child(sk, req, skb);
1283 if (!newsk)
1284 goto out_nonewsk;
1285
1286 /*
1287 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1288 * count here, tcp_create_openreq_child now does this for us, see the
1289 * comment in that function for the gory details. -acme
1290 */
1291
1292 newsk->sk_gso_type = SKB_GSO_TCPV6;
1293 ip6_dst_store(newsk, dst, NULL, NULL);
1294 inet6_sk_rx_dst_set(newsk, skb);
1295
1296 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1297
1298 newtp = tcp_sk(newsk);
1299 newinet = inet_sk(newsk);
1300 newnp = tcp_inet6_sk(newsk);
1301
1302 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1303
1304 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1305 newnp->saddr = ireq->ir_v6_loc_addr;
1306 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1307 newsk->sk_bound_dev_if = ireq->ir_iif;
1308
1309 /* Now IPv6 options...
1310
1311 First: no IPv4 options.
1312 */
1313 newinet->inet_opt = NULL;
1314 newnp->ipv6_mc_list = NULL;
1315 newnp->ipv6_ac_list = NULL;
1316 newnp->ipv6_fl_list = NULL;
1317
1318 /* Clone RX bits */
1319 newnp->rxopt.all = np->rxopt.all;
1320
1321 newnp->pktoptions = NULL;
1322 newnp->opt = NULL;
1323 newnp->mcast_oif = tcp_v6_iif(skb);
1324 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1325 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1326 if (np->repflow)
1327 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1328
1329 /* Set ToS of the new socket based upon the value of incoming SYN.
1330 * ECT bits are set later in tcp_init_transfer().
1331 */
1332 if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)
1333 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1334
1335 /* Clone native IPv6 options from listening socket (if any)
1336
1337 Yes, keeping reference count would be much more clever,
1338 but we make one more one thing there: reattach optmem
1339 to newsk.
1340 */
1341 opt = ireq->ipv6_opt;
1342 if (!opt)
1343 opt = rcu_dereference(np->opt);
1344 if (opt) {
1345 opt = ipv6_dup_options(newsk, opt);
1346 RCU_INIT_POINTER(newnp->opt, opt);
1347 }
1348 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1349 if (opt)
1350 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1351 opt->opt_flen;
1352
1353 tcp_ca_openreq_child(newsk, dst);
1354
1355 tcp_sync_mss(newsk, dst_mtu(dst));
1356 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1357
1358 tcp_initialize_rcv_mss(newsk);
1359
1360 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1361 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1362
1363 #ifdef CONFIG_TCP_MD5SIG
1364 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1365
1366 /* Copy over the MD5 key from the original socket */
1367 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1368 if (key) {
1369 /* We're using one, so create a matching key
1370 * on the newsk structure. If we fail to get
1371 * memory, then we end up not copying the key
1372 * across. Shucks.
1373 */
1374 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1375 AF_INET6, 128, l3index, key->key, key->keylen,
1376 sk_gfp_mask(sk, GFP_ATOMIC));
1377 }
1378 #endif
1379
1380 if (__inet_inherit_port(sk, newsk) < 0) {
1381 inet_csk_prepare_forced_close(newsk);
1382 tcp_done(newsk);
1383 goto out;
1384 }
1385 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1386 &found_dup_sk);
1387 if (*own_req) {
1388 tcp_move_syn(newtp, req);
1389
1390 /* Clone pktoptions received with SYN, if we own the req */
1391 if (ireq->pktopts) {
1392 newnp->pktoptions = skb_clone(ireq->pktopts,
1393 sk_gfp_mask(sk, GFP_ATOMIC));
1394 consume_skb(ireq->pktopts);
1395 ireq->pktopts = NULL;
1396 if (newnp->pktoptions) {
1397 tcp_v6_restore_cb(newnp->pktoptions);
1398 skb_set_owner_r(newnp->pktoptions, newsk);
1399 }
1400 }
1401 } else {
1402 if (!req_unhash && found_dup_sk) {
1403 /* This code path should only be executed in the
1404 * syncookie case only
1405 */
1406 bh_unlock_sock(newsk);
1407 sock_put(newsk);
1408 newsk = NULL;
1409 }
1410 }
1411
1412 return newsk;
1413
1414 out_overflow:
1415 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1416 out_nonewsk:
1417 dst_release(dst);
1418 out:
1419 tcp_listendrop(sk);
1420 return NULL;
1421 }
1422
1423 /* The socket must have it's spinlock held when we get
1424 * here, unless it is a TCP_LISTEN socket.
1425 *
1426 * We have a potential double-lock case here, so even when
1427 * doing backlog processing we use the BH locking scheme.
1428 * This is because we cannot sleep with the original spinlock
1429 * held.
1430 */
1431 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1432 {
1433 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1434 struct sk_buff *opt_skb = NULL;
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(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1468
1469 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1470 struct dst_entry *dst = sk->sk_rx_dst;
1471
1472 sock_rps_save_rxhash(sk, skb);
1473 sk_mark_napi_id(sk, skb);
1474 if (dst) {
1475 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1476 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1477 dst_release(dst);
1478 sk->sk_rx_dst = NULL;
1479 }
1480 }
1481
1482 tcp_rcv_established(sk, skb);
1483 if (opt_skb)
1484 goto ipv6_pktoptions;
1485 return 0;
1486 }
1487
1488 if (tcp_checksum_complete(skb))
1489 goto csum_err;
1490
1491 if (sk->sk_state == TCP_LISTEN) {
1492 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1493
1494 if (!nsk)
1495 goto discard;
1496
1497 if (nsk != sk) {
1498 if (tcp_child_process(sk, nsk, skb))
1499 goto reset;
1500 if (opt_skb)
1501 __kfree_skb(opt_skb);
1502 return 0;
1503 }
1504 } else
1505 sock_rps_save_rxhash(sk, skb);
1506
1507 if (tcp_rcv_state_process(sk, skb))
1508 goto reset;
1509 if (opt_skb)
1510 goto ipv6_pktoptions;
1511 return 0;
1512
1513 reset:
1514 tcp_v6_send_reset(sk, skb);
1515 discard:
1516 if (opt_skb)
1517 __kfree_skb(opt_skb);
1518 kfree_skb(skb);
1519 return 0;
1520 csum_err:
1521 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1522 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1523 goto discard;
1524
1525
1526 ipv6_pktoptions:
1527 /* Do you ask, what is it?
1528
1529 1. skb was enqueued by tcp.
1530 2. skb is added to tail of read queue, rather than out of order.
1531 3. socket is not in passive state.
1532 4. Finally, it really contains options, which user wants to receive.
1533 */
1534 tp = tcp_sk(sk);
1535 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1536 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1537 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1538 np->mcast_oif = tcp_v6_iif(opt_skb);
1539 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1540 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1541 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1542 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1543 if (np->repflow)
1544 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1545 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1546 skb_set_owner_r(opt_skb, sk);
1547 tcp_v6_restore_cb(opt_skb);
1548 opt_skb = xchg(&np->pktoptions, opt_skb);
1549 } else {
1550 __kfree_skb(opt_skb);
1551 opt_skb = xchg(&np->pktoptions, NULL);
1552 }
1553 }
1554
1555 kfree_skb(opt_skb);
1556 return 0;
1557 }
1558
1559 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1560 const struct tcphdr *th)
1561 {
1562 /* This is tricky: we move IP6CB at its correct location into
1563 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1564 * _decode_session6() uses IP6CB().
1565 * barrier() makes sure compiler won't play aliasing games.
1566 */
1567 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1568 sizeof(struct inet6_skb_parm));
1569 barrier();
1570
1571 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1572 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1573 skb->len - th->doff*4);
1574 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1575 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1576 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1577 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1578 TCP_SKB_CB(skb)->sacked = 0;
1579 TCP_SKB_CB(skb)->has_rxtstamp =
1580 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1581 }
1582
1583 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1584 {
1585 struct sk_buff *skb_to_free;
1586 int sdif = inet6_sdif(skb);
1587 int dif = inet6_iif(skb);
1588 const struct tcphdr *th;
1589 const struct ipv6hdr *hdr;
1590 bool refcounted;
1591 struct sock *sk;
1592 int ret;
1593 struct net *net = dev_net(skb->dev);
1594
1595 if (skb->pkt_type != PACKET_HOST)
1596 goto discard_it;
1597
1598 /*
1599 * Count it even if it's bad.
1600 */
1601 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1602
1603 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1604 goto discard_it;
1605
1606 th = (const struct tcphdr *)skb->data;
1607
1608 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1609 goto bad_packet;
1610 if (!pskb_may_pull(skb, th->doff*4))
1611 goto discard_it;
1612
1613 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1614 goto csum_error;
1615
1616 th = (const struct tcphdr *)skb->data;
1617 hdr = ipv6_hdr(skb);
1618
1619 lookup:
1620 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1621 th->source, th->dest, inet6_iif(skb), sdif,
1622 &refcounted);
1623 if (!sk)
1624 goto no_tcp_socket;
1625
1626 process:
1627 if (sk->sk_state == TCP_TIME_WAIT)
1628 goto do_time_wait;
1629
1630 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1631 struct request_sock *req = inet_reqsk(sk);
1632 bool req_stolen = false;
1633 struct sock *nsk;
1634
1635 sk = req->rsk_listener;
1636 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) {
1637 sk_drops_add(sk, skb);
1638 reqsk_put(req);
1639 goto discard_it;
1640 }
1641 if (tcp_checksum_complete(skb)) {
1642 reqsk_put(req);
1643 goto csum_error;
1644 }
1645 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1646 inet_csk_reqsk_queue_drop_and_put(sk, req);
1647 goto lookup;
1648 }
1649 sock_hold(sk);
1650 refcounted = true;
1651 nsk = NULL;
1652 if (!tcp_filter(sk, skb)) {
1653 th = (const struct tcphdr *)skb->data;
1654 hdr = ipv6_hdr(skb);
1655 tcp_v6_fill_cb(skb, hdr, th);
1656 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1657 }
1658 if (!nsk) {
1659 reqsk_put(req);
1660 if (req_stolen) {
1661 /* Another cpu got exclusive access to req
1662 * and created a full blown socket.
1663 * Try to feed this packet to this socket
1664 * instead of discarding it.
1665 */
1666 tcp_v6_restore_cb(skb);
1667 sock_put(sk);
1668 goto lookup;
1669 }
1670 goto discard_and_relse;
1671 }
1672 if (nsk == sk) {
1673 reqsk_put(req);
1674 tcp_v6_restore_cb(skb);
1675 } else if (tcp_child_process(sk, nsk, skb)) {
1676 tcp_v6_send_reset(nsk, skb);
1677 goto discard_and_relse;
1678 } else {
1679 sock_put(sk);
1680 return 0;
1681 }
1682 }
1683 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
1684 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1685 goto discard_and_relse;
1686 }
1687
1688 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1689 goto discard_and_relse;
1690
1691 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
1692 goto discard_and_relse;
1693
1694 if (tcp_filter(sk, skb))
1695 goto discard_and_relse;
1696 th = (const struct tcphdr *)skb->data;
1697 hdr = ipv6_hdr(skb);
1698 tcp_v6_fill_cb(skb, hdr, th);
1699
1700 skb->dev = NULL;
1701
1702 if (sk->sk_state == TCP_LISTEN) {
1703 ret = tcp_v6_do_rcv(sk, skb);
1704 goto put_and_return;
1705 }
1706
1707 sk_incoming_cpu_update(sk);
1708
1709 bh_lock_sock_nested(sk);
1710 tcp_segs_in(tcp_sk(sk), skb);
1711 ret = 0;
1712 if (!sock_owned_by_user(sk)) {
1713 skb_to_free = sk->sk_rx_skb_cache;
1714 sk->sk_rx_skb_cache = NULL;
1715 ret = tcp_v6_do_rcv(sk, skb);
1716 } else {
1717 if (tcp_add_backlog(sk, skb))
1718 goto discard_and_relse;
1719 skb_to_free = NULL;
1720 }
1721 bh_unlock_sock(sk);
1722 if (skb_to_free)
1723 __kfree_skb(skb_to_free);
1724 put_and_return:
1725 if (refcounted)
1726 sock_put(sk);
1727 return ret ? -1 : 0;
1728
1729 no_tcp_socket:
1730 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1731 goto discard_it;
1732
1733 tcp_v6_fill_cb(skb, hdr, th);
1734
1735 if (tcp_checksum_complete(skb)) {
1736 csum_error:
1737 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1738 bad_packet:
1739 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1740 } else {
1741 tcp_v6_send_reset(NULL, skb);
1742 }
1743
1744 discard_it:
1745 kfree_skb(skb);
1746 return 0;
1747
1748 discard_and_relse:
1749 sk_drops_add(sk, skb);
1750 if (refcounted)
1751 sock_put(sk);
1752 goto discard_it;
1753
1754 do_time_wait:
1755 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1756 inet_twsk_put(inet_twsk(sk));
1757 goto discard_it;
1758 }
1759
1760 tcp_v6_fill_cb(skb, hdr, th);
1761
1762 if (tcp_checksum_complete(skb)) {
1763 inet_twsk_put(inet_twsk(sk));
1764 goto csum_error;
1765 }
1766
1767 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1768 case TCP_TW_SYN:
1769 {
1770 struct sock *sk2;
1771
1772 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1773 skb, __tcp_hdrlen(th),
1774 &ipv6_hdr(skb)->saddr, th->source,
1775 &ipv6_hdr(skb)->daddr,
1776 ntohs(th->dest),
1777 tcp_v6_iif_l3_slave(skb),
1778 sdif);
1779 if (sk2) {
1780 struct inet_timewait_sock *tw = inet_twsk(sk);
1781 inet_twsk_deschedule_put(tw);
1782 sk = sk2;
1783 tcp_v6_restore_cb(skb);
1784 refcounted = false;
1785 goto process;
1786 }
1787 }
1788 /* to ACK */
1789 fallthrough;
1790 case TCP_TW_ACK:
1791 tcp_v6_timewait_ack(sk, skb);
1792 break;
1793 case TCP_TW_RST:
1794 tcp_v6_send_reset(sk, skb);
1795 inet_twsk_deschedule_put(inet_twsk(sk));
1796 goto discard_it;
1797 case TCP_TW_SUCCESS:
1798 ;
1799 }
1800 goto discard_it;
1801 }
1802
1803 INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
1804 {
1805 const struct ipv6hdr *hdr;
1806 const struct tcphdr *th;
1807 struct sock *sk;
1808
1809 if (skb->pkt_type != PACKET_HOST)
1810 return;
1811
1812 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1813 return;
1814
1815 hdr = ipv6_hdr(skb);
1816 th = tcp_hdr(skb);
1817
1818 if (th->doff < sizeof(struct tcphdr) / 4)
1819 return;
1820
1821 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1822 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1823 &hdr->saddr, th->source,
1824 &hdr->daddr, ntohs(th->dest),
1825 inet6_iif(skb), inet6_sdif(skb));
1826 if (sk) {
1827 skb->sk = sk;
1828 skb->destructor = sock_edemux;
1829 if (sk_fullsock(sk)) {
1830 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1831
1832 if (dst)
1833 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
1834 if (dst &&
1835 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1836 skb_dst_set_noref(skb, dst);
1837 }
1838 }
1839 }
1840
1841 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1842 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1843 .twsk_unique = tcp_twsk_unique,
1844 .twsk_destructor = tcp_twsk_destructor,
1845 };
1846
1847 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1848 {
1849 struct ipv6_pinfo *np = inet6_sk(sk);
1850
1851 __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
1852 }
1853
1854 const struct inet_connection_sock_af_ops ipv6_specific = {
1855 .queue_xmit = inet6_csk_xmit,
1856 .send_check = tcp_v6_send_check,
1857 .rebuild_header = inet6_sk_rebuild_header,
1858 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1859 .conn_request = tcp_v6_conn_request,
1860 .syn_recv_sock = tcp_v6_syn_recv_sock,
1861 .net_header_len = sizeof(struct ipv6hdr),
1862 .net_frag_header_len = sizeof(struct frag_hdr),
1863 .setsockopt = ipv6_setsockopt,
1864 .getsockopt = ipv6_getsockopt,
1865 .addr2sockaddr = inet6_csk_addr2sockaddr,
1866 .sockaddr_len = sizeof(struct sockaddr_in6),
1867 .mtu_reduced = tcp_v6_mtu_reduced,
1868 };
1869
1870 #ifdef CONFIG_TCP_MD5SIG
1871 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1872 .md5_lookup = tcp_v6_md5_lookup,
1873 .calc_md5_hash = tcp_v6_md5_hash_skb,
1874 .md5_parse = tcp_v6_parse_md5_keys,
1875 };
1876 #endif
1877
1878 /*
1879 * TCP over IPv4 via INET6 API
1880 */
1881 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1882 .queue_xmit = ip_queue_xmit,
1883 .send_check = tcp_v4_send_check,
1884 .rebuild_header = inet_sk_rebuild_header,
1885 .sk_rx_dst_set = inet_sk_rx_dst_set,
1886 .conn_request = tcp_v6_conn_request,
1887 .syn_recv_sock = tcp_v6_syn_recv_sock,
1888 .net_header_len = sizeof(struct iphdr),
1889 .setsockopt = ipv6_setsockopt,
1890 .getsockopt = ipv6_getsockopt,
1891 .addr2sockaddr = inet6_csk_addr2sockaddr,
1892 .sockaddr_len = sizeof(struct sockaddr_in6),
1893 .mtu_reduced = tcp_v4_mtu_reduced,
1894 };
1895
1896 #ifdef CONFIG_TCP_MD5SIG
1897 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1898 .md5_lookup = tcp_v4_md5_lookup,
1899 .calc_md5_hash = tcp_v4_md5_hash_skb,
1900 .md5_parse = tcp_v6_parse_md5_keys,
1901 };
1902 #endif
1903
1904 /* NOTE: A lot of things set to zero explicitly by call to
1905 * sk_alloc() so need not be done here.
1906 */
1907 static int tcp_v6_init_sock(struct sock *sk)
1908 {
1909 struct inet_connection_sock *icsk = inet_csk(sk);
1910
1911 tcp_init_sock(sk);
1912
1913 icsk->icsk_af_ops = &ipv6_specific;
1914
1915 #ifdef CONFIG_TCP_MD5SIG
1916 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1917 #endif
1918
1919 return 0;
1920 }
1921
1922 static void tcp_v6_destroy_sock(struct sock *sk)
1923 {
1924 tcp_v4_destroy_sock(sk);
1925 inet6_destroy_sock(sk);
1926 }
1927
1928 #ifdef CONFIG_PROC_FS
1929 /* Proc filesystem TCPv6 sock list dumping. */
1930 static void get_openreq6(struct seq_file *seq,
1931 const struct request_sock *req, int i)
1932 {
1933 long ttd = req->rsk_timer.expires - jiffies;
1934 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1935 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1936
1937 if (ttd < 0)
1938 ttd = 0;
1939
1940 seq_printf(seq,
1941 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1942 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1943 i,
1944 src->s6_addr32[0], src->s6_addr32[1],
1945 src->s6_addr32[2], src->s6_addr32[3],
1946 inet_rsk(req)->ir_num,
1947 dest->s6_addr32[0], dest->s6_addr32[1],
1948 dest->s6_addr32[2], dest->s6_addr32[3],
1949 ntohs(inet_rsk(req)->ir_rmt_port),
1950 TCP_SYN_RECV,
1951 0, 0, /* could print option size, but that is af dependent. */
1952 1, /* timers active (only the expire timer) */
1953 jiffies_to_clock_t(ttd),
1954 req->num_timeout,
1955 from_kuid_munged(seq_user_ns(seq),
1956 sock_i_uid(req->rsk_listener)),
1957 0, /* non standard timer */
1958 0, /* open_requests have no inode */
1959 0, req);
1960 }
1961
1962 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1963 {
1964 const struct in6_addr *dest, *src;
1965 __u16 destp, srcp;
1966 int timer_active;
1967 unsigned long timer_expires;
1968 const struct inet_sock *inet = inet_sk(sp);
1969 const struct tcp_sock *tp = tcp_sk(sp);
1970 const struct inet_connection_sock *icsk = inet_csk(sp);
1971 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1972 int rx_queue;
1973 int state;
1974
1975 dest = &sp->sk_v6_daddr;
1976 src = &sp->sk_v6_rcv_saddr;
1977 destp = ntohs(inet->inet_dport);
1978 srcp = ntohs(inet->inet_sport);
1979
1980 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1981 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1982 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1983 timer_active = 1;
1984 timer_expires = icsk->icsk_timeout;
1985 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1986 timer_active = 4;
1987 timer_expires = icsk->icsk_timeout;
1988 } else if (timer_pending(&sp->sk_timer)) {
1989 timer_active = 2;
1990 timer_expires = sp->sk_timer.expires;
1991 } else {
1992 timer_active = 0;
1993 timer_expires = jiffies;
1994 }
1995
1996 state = inet_sk_state_load(sp);
1997 if (state == TCP_LISTEN)
1998 rx_queue = READ_ONCE(sp->sk_ack_backlog);
1999 else
2000 /* Because we don't lock the socket,
2001 * we might find a transient negative value.
2002 */
2003 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2004 READ_ONCE(tp->copied_seq), 0);
2005
2006 seq_printf(seq,
2007 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2008 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2009 i,
2010 src->s6_addr32[0], src->s6_addr32[1],
2011 src->s6_addr32[2], src->s6_addr32[3], srcp,
2012 dest->s6_addr32[0], dest->s6_addr32[1],
2013 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2014 state,
2015 READ_ONCE(tp->write_seq) - tp->snd_una,
2016 rx_queue,
2017 timer_active,
2018 jiffies_delta_to_clock_t(timer_expires - jiffies),
2019 icsk->icsk_retransmits,
2020 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2021 icsk->icsk_probes_out,
2022 sock_i_ino(sp),
2023 refcount_read(&sp->sk_refcnt), sp,
2024 jiffies_to_clock_t(icsk->icsk_rto),
2025 jiffies_to_clock_t(icsk->icsk_ack.ato),
2026 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2027 tp->snd_cwnd,
2028 state == TCP_LISTEN ?
2029 fastopenq->max_qlen :
2030 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2031 );
2032 }
2033
2034 static void get_timewait6_sock(struct seq_file *seq,
2035 struct inet_timewait_sock *tw, int i)
2036 {
2037 long delta = tw->tw_timer.expires - jiffies;
2038 const struct in6_addr *dest, *src;
2039 __u16 destp, srcp;
2040
2041 dest = &tw->tw_v6_daddr;
2042 src = &tw->tw_v6_rcv_saddr;
2043 destp = ntohs(tw->tw_dport);
2044 srcp = ntohs(tw->tw_sport);
2045
2046 seq_printf(seq,
2047 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2048 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2049 i,
2050 src->s6_addr32[0], src->s6_addr32[1],
2051 src->s6_addr32[2], src->s6_addr32[3], srcp,
2052 dest->s6_addr32[0], dest->s6_addr32[1],
2053 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2054 tw->tw_substate, 0, 0,
2055 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2056 refcount_read(&tw->tw_refcnt), tw);
2057 }
2058
2059 static int tcp6_seq_show(struct seq_file *seq, void *v)
2060 {
2061 struct tcp_iter_state *st;
2062 struct sock *sk = v;
2063
2064 if (v == SEQ_START_TOKEN) {
2065 seq_puts(seq,
2066 " sl "
2067 "local_address "
2068 "remote_address "
2069 "st tx_queue rx_queue tr tm->when retrnsmt"
2070 " uid timeout inode\n");
2071 goto out;
2072 }
2073 st = seq->private;
2074
2075 if (sk->sk_state == TCP_TIME_WAIT)
2076 get_timewait6_sock(seq, v, st->num);
2077 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2078 get_openreq6(seq, v, st->num);
2079 else
2080 get_tcp6_sock(seq, v, st->num);
2081 out:
2082 return 0;
2083 }
2084
2085 static const struct seq_operations tcp6_seq_ops = {
2086 .show = tcp6_seq_show,
2087 .start = tcp_seq_start,
2088 .next = tcp_seq_next,
2089 .stop = tcp_seq_stop,
2090 };
2091
2092 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2093 .family = AF_INET6,
2094 };
2095
2096 int __net_init tcp6_proc_init(struct net *net)
2097 {
2098 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2099 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2100 return -ENOMEM;
2101 return 0;
2102 }
2103
2104 void tcp6_proc_exit(struct net *net)
2105 {
2106 remove_proc_entry("tcp6", net->proc_net);
2107 }
2108 #endif
2109
2110 struct proto tcpv6_prot = {
2111 .name = "TCPv6",
2112 .owner = THIS_MODULE,
2113 .close = tcp_close,
2114 .pre_connect = tcp_v6_pre_connect,
2115 .connect = tcp_v6_connect,
2116 .disconnect = tcp_disconnect,
2117 .accept = inet_csk_accept,
2118 .ioctl = tcp_ioctl,
2119 .init = tcp_v6_init_sock,
2120 .destroy = tcp_v6_destroy_sock,
2121 .shutdown = tcp_shutdown,
2122 .setsockopt = tcp_setsockopt,
2123 .getsockopt = tcp_getsockopt,
2124 .keepalive = tcp_set_keepalive,
2125 .recvmsg = tcp_recvmsg,
2126 .sendmsg = tcp_sendmsg,
2127 .sendpage = tcp_sendpage,
2128 .backlog_rcv = tcp_v6_do_rcv,
2129 .release_cb = tcp_release_cb,
2130 .hash = inet6_hash,
2131 .unhash = inet_unhash,
2132 .get_port = inet_csk_get_port,
2133 .enter_memory_pressure = tcp_enter_memory_pressure,
2134 .leave_memory_pressure = tcp_leave_memory_pressure,
2135 .stream_memory_free = tcp_stream_memory_free,
2136 .sockets_allocated = &tcp_sockets_allocated,
2137 .memory_allocated = &tcp_memory_allocated,
2138 .memory_pressure = &tcp_memory_pressure,
2139 .orphan_count = &tcp_orphan_count,
2140 .sysctl_mem = sysctl_tcp_mem,
2141 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2142 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2143 .max_header = MAX_TCP_HEADER,
2144 .obj_size = sizeof(struct tcp6_sock),
2145 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2146 .twsk_prot = &tcp6_timewait_sock_ops,
2147 .rsk_prot = &tcp6_request_sock_ops,
2148 .h.hashinfo = &tcp_hashinfo,
2149 .no_autobind = true,
2150 .diag_destroy = tcp_abort,
2151 };
2152 EXPORT_SYMBOL_GPL(tcpv6_prot);
2153
2154 /* thinking of making this const? Don't.
2155 * early_demux can change based on sysctl.
2156 */
2157 static struct inet6_protocol tcpv6_protocol = {
2158 .early_demux = tcp_v6_early_demux,
2159 .early_demux_handler = tcp_v6_early_demux,
2160 .handler = tcp_v6_rcv,
2161 .err_handler = tcp_v6_err,
2162 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2163 };
2164
2165 static struct inet_protosw tcpv6_protosw = {
2166 .type = SOCK_STREAM,
2167 .protocol = IPPROTO_TCP,
2168 .prot = &tcpv6_prot,
2169 .ops = &inet6_stream_ops,
2170 .flags = INET_PROTOSW_PERMANENT |
2171 INET_PROTOSW_ICSK,
2172 };
2173
2174 static int __net_init tcpv6_net_init(struct net *net)
2175 {
2176 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2177 SOCK_RAW, IPPROTO_TCP, net);
2178 }
2179
2180 static void __net_exit tcpv6_net_exit(struct net *net)
2181 {
2182 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2183 }
2184
2185 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2186 {
2187 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2188 }
2189
2190 static struct pernet_operations tcpv6_net_ops = {
2191 .init = tcpv6_net_init,
2192 .exit = tcpv6_net_exit,
2193 .exit_batch = tcpv6_net_exit_batch,
2194 };
2195
2196 int __init tcpv6_init(void)
2197 {
2198 int ret;
2199
2200 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2201 if (ret)
2202 goto out;
2203
2204 /* register inet6 protocol */
2205 ret = inet6_register_protosw(&tcpv6_protosw);
2206 if (ret)
2207 goto out_tcpv6_protocol;
2208
2209 ret = register_pernet_subsys(&tcpv6_net_ops);
2210 if (ret)
2211 goto out_tcpv6_protosw;
2212
2213 ret = mptcpv6_init();
2214 if (ret)
2215 goto out_tcpv6_pernet_subsys;
2216
2217 out:
2218 return ret;
2219
2220 out_tcpv6_pernet_subsys:
2221 unregister_pernet_subsys(&tcpv6_net_ops);
2222 out_tcpv6_protosw:
2223 inet6_unregister_protosw(&tcpv6_protosw);
2224 out_tcpv6_protocol:
2225 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2226 goto out;
2227 }
2228
2229 void tcpv6_exit(void)
2230 {
2231 unregister_pernet_subsys(&tcpv6_net_ops);
2232 inet6_unregister_protosw(&tcpv6_protosw);
2233 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2234 }
Linux with added FPC-III support