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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * TCP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on:
10 * linux/net/ipv4/tcp.c
11 * linux/net/ipv4/tcp_input.c
12 * linux/net/ipv4/tcp_output.c
13 *
14 * Fixes:
15 * Hideaki YOSHIFUJI : sin6_scope_id support
16 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
17 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
18 * a single port at the same time.
19 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
20 */
21
22#include <linux/bottom_half.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/jiffies.h>
30#include <linux/in.h>
31#include <linux/in6.h>
32#include <linux/netdevice.h>
33#include <linux/init.h>
34#include <linux/jhash.h>
35#include <linux/ipsec.h>
36#include <linux/times.h>
37#include <linux/slab.h>
38#include <linux/uaccess.h>
39#include <linux/ipv6.h>
40#include <linux/icmpv6.h>
41#include <linux/random.h>
42#include <linux/indirect_call_wrapper.h>
43
44#include <net/tcp.h>
45#include <net/ndisc.h>
46#include <net/inet6_hashtables.h>
47#include <net/inet6_connection_sock.h>
48#include <net/ipv6.h>
49#include <net/transp_v6.h>
50#include <net/addrconf.h>
51#include <net/ip6_route.h>
52#include <net/ip6_checksum.h>
53#include <net/inet_ecn.h>
54#include <net/protocol.h>
55#include <net/xfrm.h>
56#include <net/snmp.h>
57#include <net/dsfield.h>
58#include <net/timewait_sock.h>
59#include <net/inet_common.h>
60#include <net/secure_seq.h>
61#include <net/busy_poll.h>
62
63#include <linux/proc_fs.h>
64#include <linux/seq_file.h>
65
66#include <crypto/hash.h>
67#include <linux/scatterlist.h>
68
69#include <trace/events/tcp.h>
70
71static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
72static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
73 struct request_sock *req);
74
75static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77static const struct inet_connection_sock_af_ops ipv6_mapped;
78const struct inet_connection_sock_af_ops ipv6_specific;
79#ifdef CONFIG_TCP_MD5SIG
80static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
81static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
82#else
83static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
84 const struct in6_addr *addr,
85 int l3index)
86{
87 return NULL;
88}
89#endif
90
91/* Helper returning the inet6 address from a given tcp socket.
92 * It can be used in TCP stack instead of inet6_sk(sk).
93 * This avoids a dereference and allow compiler optimizations.
94 * It is a specialized version of inet6_sk_generic().
95 */
96static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
97{
98 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
99
100 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
101}
102
103static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
104{
105 struct dst_entry *dst = skb_dst(skb);
106
107 if (dst && dst_hold_safe(dst)) {
108 const struct rt6_info *rt = (const struct rt6_info *)dst;
109
110 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
116static u32 tcp_v6_init_seq(const struct sk_buff *skb)
117{
118 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
119 ipv6_hdr(skb)->saddr.s6_addr32,
120 tcp_hdr(skb)->dest,
121 tcp_hdr(skb)->source);
122}
123
124static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
125{
126 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
127 ipv6_hdr(skb)->saddr.s6_addr32);
128}
129
130static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
131 int addr_len)
132{
133 /* This check is replicated from tcp_v6_connect() and intended to
134 * prevent BPF program called below from accessing bytes that are out
135 * of the bound specified by user in addr_len.
136 */
137 if (addr_len < SIN6_LEN_RFC2133)
138 return -EINVAL;
139
140 sock_owned_by_me(sk);
141
142 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
143}
144
145static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
146 int addr_len)
147{
148 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
149 struct inet_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(&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
340late_failure:
341 tcp_set_state(sk, TCP_CLOSE);
342failure:
343 inet->inet_dport = 0;
344 sk->sk_route_caps = 0;
345 return err;
346}
347
348static 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
365static 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 * is 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
493out:
494 bh_unlock_sock(sk);
495 sock_put(sk);
496 return 0;
497}
498
499
500static 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{
506 struct inet_request_sock *ireq = inet_rsk(req);
507 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
508 struct ipv6_txoptions *opt;
509 struct flowi6 *fl6 = &fl->u.ip6;
510 struct sk_buff *skb;
511 int err = -ENOMEM;
512
513 /* First, grab a route. */
514 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
515 IPPROTO_TCP)) == NULL)
516 goto done;
517
518 skb = tcp_make_synack(sk, dst, req, foc, synack_type);
519
520 if (skb) {
521 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
522 &ireq->ir_v6_rmt_addr);
523
524 fl6->daddr = ireq->ir_v6_rmt_addr;
525 if (np->repflow && ireq->pktopts)
526 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
527
528 rcu_read_lock();
529 opt = ireq->ipv6_opt;
530 if (!opt)
531 opt = rcu_dereference(np->opt);
532 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass,
533 sk->sk_priority);
534 rcu_read_unlock();
535 err = net_xmit_eval(err);
536 }
537
538done:
539 return err;
540}
541
542
543static void tcp_v6_reqsk_destructor(struct request_sock *req)
544{
545 kfree(inet_rsk(req)->ipv6_opt);
546 kfree_skb(inet_rsk(req)->pktopts);
547}
548
549#ifdef CONFIG_TCP_MD5SIG
550static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
551 const struct in6_addr *addr,
552 int l3index)
553{
554 return tcp_md5_do_lookup(sk, l3index,
555 (union tcp_md5_addr *)addr, AF_INET6);
556}
557
558static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
559 const struct sock *addr_sk)
560{
561 int l3index;
562
563 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
564 addr_sk->sk_bound_dev_if);
565 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
566 l3index);
567}
568
569static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
570 sockptr_t optval, int optlen)
571{
572 struct tcp_md5sig cmd;
573 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
574 int l3index = 0;
575 u8 prefixlen;
576
577 if (optlen < sizeof(cmd))
578 return -EINVAL;
579
580 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
581 return -EFAULT;
582
583 if (sin6->sin6_family != AF_INET6)
584 return -EINVAL;
585
586 if (optname == TCP_MD5SIG_EXT &&
587 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
588 prefixlen = cmd.tcpm_prefixlen;
589 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
590 prefixlen > 32))
591 return -EINVAL;
592 } else {
593 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
594 }
595
596 if (optname == TCP_MD5SIG_EXT &&
597 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
598 struct net_device *dev;
599
600 rcu_read_lock();
601 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
602 if (dev && netif_is_l3_master(dev))
603 l3index = dev->ifindex;
604 rcu_read_unlock();
605
606 /* ok to reference set/not set outside of rcu;
607 * right now device MUST be an L3 master
608 */
609 if (!dev || !l3index)
610 return -EINVAL;
611 }
612
613 if (!cmd.tcpm_keylen) {
614 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
615 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
616 AF_INET, prefixlen,
617 l3index);
618 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
619 AF_INET6, prefixlen, l3index);
620 }
621
622 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
623 return -EINVAL;
624
625 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
626 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
627 AF_INET, prefixlen, l3index,
628 cmd.tcpm_key, cmd.tcpm_keylen,
629 GFP_KERNEL);
630
631 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
632 AF_INET6, prefixlen, l3index,
633 cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
634}
635
636static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
637 const struct in6_addr *daddr,
638 const struct in6_addr *saddr,
639 const struct tcphdr *th, int nbytes)
640{
641 struct tcp6_pseudohdr *bp;
642 struct scatterlist sg;
643 struct tcphdr *_th;
644
645 bp = hp->scratch;
646 /* 1. TCP pseudo-header (RFC2460) */
647 bp->saddr = *saddr;
648 bp->daddr = *daddr;
649 bp->protocol = cpu_to_be32(IPPROTO_TCP);
650 bp->len = cpu_to_be32(nbytes);
651
652 _th = (struct tcphdr *)(bp + 1);
653 memcpy(_th, th, sizeof(*th));
654 _th->check = 0;
655
656 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
657 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
658 sizeof(*bp) + sizeof(*th));
659 return crypto_ahash_update(hp->md5_req);
660}
661
662static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
663 const struct in6_addr *daddr, struct in6_addr *saddr,
664 const struct tcphdr *th)
665{
666 struct tcp_md5sig_pool *hp;
667 struct ahash_request *req;
668
669 hp = tcp_get_md5sig_pool();
670 if (!hp)
671 goto clear_hash_noput;
672 req = hp->md5_req;
673
674 if (crypto_ahash_init(req))
675 goto clear_hash;
676 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
677 goto clear_hash;
678 if (tcp_md5_hash_key(hp, key))
679 goto clear_hash;
680 ahash_request_set_crypt(req, NULL, md5_hash, 0);
681 if (crypto_ahash_final(req))
682 goto clear_hash;
683
684 tcp_put_md5sig_pool();
685 return 0;
686
687clear_hash:
688 tcp_put_md5sig_pool();
689clear_hash_noput:
690 memset(md5_hash, 0, 16);
691 return 1;
692}
693
694static int tcp_v6_md5_hash_skb(char *md5_hash,
695 const struct tcp_md5sig_key *key,
696 const struct sock *sk,
697 const struct sk_buff *skb)
698{
699 const struct in6_addr *saddr, *daddr;
700 struct tcp_md5sig_pool *hp;
701 struct ahash_request *req;
702 const struct tcphdr *th = tcp_hdr(skb);
703
704 if (sk) { /* valid for establish/request sockets */
705 saddr = &sk->sk_v6_rcv_saddr;
706 daddr = &sk->sk_v6_daddr;
707 } else {
708 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
709 saddr = &ip6h->saddr;
710 daddr = &ip6h->daddr;
711 }
712
713 hp = tcp_get_md5sig_pool();
714 if (!hp)
715 goto clear_hash_noput;
716 req = hp->md5_req;
717
718 if (crypto_ahash_init(req))
719 goto clear_hash;
720
721 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
722 goto clear_hash;
723 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
724 goto clear_hash;
725 if (tcp_md5_hash_key(hp, key))
726 goto clear_hash;
727 ahash_request_set_crypt(req, NULL, md5_hash, 0);
728 if (crypto_ahash_final(req))
729 goto clear_hash;
730
731 tcp_put_md5sig_pool();
732 return 0;
733
734clear_hash:
735 tcp_put_md5sig_pool();
736clear_hash_noput:
737 memset(md5_hash, 0, 16);
738 return 1;
739}
740
741#endif
742
743static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
744 const struct sk_buff *skb,
745 int dif, int sdif)
746{
747#ifdef CONFIG_TCP_MD5SIG
748 const __u8 *hash_location = NULL;
749 struct tcp_md5sig_key *hash_expected;
750 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
751 const struct tcphdr *th = tcp_hdr(skb);
752 int genhash, l3index;
753 u8 newhash[16];
754
755 /* sdif set, means packet ingressed via a device
756 * in an L3 domain and dif is set to the l3mdev
757 */
758 l3index = sdif ? dif : 0;
759
760 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index);
761 hash_location = tcp_parse_md5sig_option(th);
762
763 /* We've parsed the options - do we have a hash? */
764 if (!hash_expected && !hash_location)
765 return false;
766
767 if (hash_expected && !hash_location) {
768 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
769 return true;
770 }
771
772 if (!hash_expected && hash_location) {
773 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
774 return true;
775 }
776
777 /* check the signature */
778 genhash = tcp_v6_md5_hash_skb(newhash,
779 hash_expected,
780 NULL, skb);
781
782 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
783 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
784 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
785 genhash ? "failed" : "mismatch",
786 &ip6h->saddr, ntohs(th->source),
787 &ip6h->daddr, ntohs(th->dest), l3index);
788 return true;
789 }
790#endif
791 return false;
792}
793
794static void tcp_v6_init_req(struct request_sock *req,
795 const struct sock *sk_listener,
796 struct sk_buff *skb)
797{
798 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
799 struct inet_request_sock *ireq = inet_rsk(req);
800 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
801
802 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
803 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
804
805 /* So that link locals have meaning */
806 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
807 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
808 ireq->ir_iif = tcp_v6_iif(skb);
809
810 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
811 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
812 np->rxopt.bits.rxinfo ||
813 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
814 np->rxopt.bits.rxohlim || np->repflow)) {
815 refcount_inc(&skb->users);
816 ireq->pktopts = skb;
817 }
818}
819
820static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
821 struct flowi *fl,
822 const struct request_sock *req)
823{
824 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
825}
826
827struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
828 .family = AF_INET6,
829 .obj_size = sizeof(struct tcp6_request_sock),
830 .rtx_syn_ack = tcp_rtx_synack,
831 .send_ack = tcp_v6_reqsk_send_ack,
832 .destructor = tcp_v6_reqsk_destructor,
833 .send_reset = tcp_v6_send_reset,
834 .syn_ack_timeout = tcp_syn_ack_timeout,
835};
836
837const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
838 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
839 sizeof(struct ipv6hdr),
840#ifdef CONFIG_TCP_MD5SIG
841 .req_md5_lookup = tcp_v6_md5_lookup,
842 .calc_md5_hash = tcp_v6_md5_hash_skb,
843#endif
844 .init_req = tcp_v6_init_req,
845#ifdef CONFIG_SYN_COOKIES
846 .cookie_init_seq = cookie_v6_init_sequence,
847#endif
848 .route_req = tcp_v6_route_req,
849 .init_seq = tcp_v6_init_seq,
850 .init_ts_off = tcp_v6_init_ts_off,
851 .send_synack = tcp_v6_send_synack,
852};
853
854static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
855 u32 ack, u32 win, u32 tsval, u32 tsecr,
856 int oif, struct tcp_md5sig_key *key, int rst,
857 u8 tclass, __be32 label, u32 priority)
858{
859 const struct tcphdr *th = tcp_hdr(skb);
860 struct tcphdr *t1;
861 struct sk_buff *buff;
862 struct flowi6 fl6;
863 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
864 struct sock *ctl_sk = net->ipv6.tcp_sk;
865 unsigned int tot_len = sizeof(struct tcphdr);
866 struct dst_entry *dst;
867 __be32 *topt;
868 __u32 mark = 0;
869
870 if (tsecr)
871 tot_len += TCPOLEN_TSTAMP_ALIGNED;
872#ifdef CONFIG_TCP_MD5SIG
873 if (key)
874 tot_len += TCPOLEN_MD5SIG_ALIGNED;
875#endif
876
877 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
878 GFP_ATOMIC);
879 if (!buff)
880 return;
881
882 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
883
884 t1 = skb_push(buff, tot_len);
885 skb_reset_transport_header(buff);
886
887 /* Swap the send and the receive. */
888 memset(t1, 0, sizeof(*t1));
889 t1->dest = th->source;
890 t1->source = th->dest;
891 t1->doff = tot_len / 4;
892 t1->seq = htonl(seq);
893 t1->ack_seq = htonl(ack);
894 t1->ack = !rst || !th->ack;
895 t1->rst = rst;
896 t1->window = htons(win);
897
898 topt = (__be32 *)(t1 + 1);
899
900 if (tsecr) {
901 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
902 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
903 *topt++ = htonl(tsval);
904 *topt++ = htonl(tsecr);
905 }
906
907#ifdef CONFIG_TCP_MD5SIG
908 if (key) {
909 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
910 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
911 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
912 &ipv6_hdr(skb)->saddr,
913 &ipv6_hdr(skb)->daddr, t1);
914 }
915#endif
916
917 memset(&fl6, 0, sizeof(fl6));
918 fl6.daddr = ipv6_hdr(skb)->saddr;
919 fl6.saddr = ipv6_hdr(skb)->daddr;
920 fl6.flowlabel = label;
921
922 buff->ip_summed = CHECKSUM_PARTIAL;
923 buff->csum = 0;
924
925 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
926
927 fl6.flowi6_proto = IPPROTO_TCP;
928 if (rt6_need_strict(&fl6.daddr) && !oif)
929 fl6.flowi6_oif = tcp_v6_iif(skb);
930 else {
931 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
932 oif = skb->skb_iif;
933
934 fl6.flowi6_oif = oif;
935 }
936
937 if (sk) {
938 if (sk->sk_state == TCP_TIME_WAIT) {
939 mark = inet_twsk(sk)->tw_mark;
940 /* autoflowlabel relies on buff->hash */
941 skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
942 PKT_HASH_TYPE_L4);
943 } else {
944 mark = sk->sk_mark;
945 }
946 buff->tstamp = tcp_transmit_time(sk);
947 }
948 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
949 fl6.fl6_dport = t1->dest;
950 fl6.fl6_sport = t1->source;
951 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
952 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
953
954 /* Pass a socket to ip6_dst_lookup either it is for RST
955 * Underlying function will use this to retrieve the network
956 * namespace
957 */
958 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
959 if (!IS_ERR(dst)) {
960 skb_dst_set(buff, dst);
961 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass,
962 priority);
963 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
964 if (rst)
965 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
966 return;
967 }
968
969 kfree_skb(buff);
970}
971
972static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
973{
974 const struct tcphdr *th = tcp_hdr(skb);
975 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
976 u32 seq = 0, ack_seq = 0;
977 struct tcp_md5sig_key *key = NULL;
978#ifdef CONFIG_TCP_MD5SIG
979 const __u8 *hash_location = NULL;
980 unsigned char newhash[16];
981 int genhash;
982 struct sock *sk1 = NULL;
983#endif
984 __be32 label = 0;
985 u32 priority = 0;
986 struct net *net;
987 int oif = 0;
988
989 if (th->rst)
990 return;
991
992 /* If sk not NULL, it means we did a successful lookup and incoming
993 * route had to be correct. prequeue might have dropped our dst.
994 */
995 if (!sk && !ipv6_unicast_destination(skb))
996 return;
997
998 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
999#ifdef CONFIG_TCP_MD5SIG
1000 rcu_read_lock();
1001 hash_location = tcp_parse_md5sig_option(th);
1002 if (sk && sk_fullsock(sk)) {
1003 int l3index;
1004
1005 /* sdif set, means packet ingressed via a device
1006 * in an L3 domain and inet_iif is set to it.
1007 */
1008 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1009 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1010 } else if (hash_location) {
1011 int dif = tcp_v6_iif_l3_slave(skb);
1012 int sdif = tcp_v6_sdif(skb);
1013 int l3index;
1014
1015 /*
1016 * active side is lost. Try to find listening socket through
1017 * source port, and then find md5 key through listening socket.
1018 * we are not loose security here:
1019 * Incoming packet is checked with md5 hash with finding key,
1020 * no RST generated if md5 hash doesn't match.
1021 */
1022 sk1 = inet6_lookup_listener(net,
1023 &tcp_hashinfo, NULL, 0,
1024 &ipv6h->saddr,
1025 th->source, &ipv6h->daddr,
1026 ntohs(th->source), dif, sdif);
1027 if (!sk1)
1028 goto out;
1029
1030 /* sdif set, means packet ingressed via a device
1031 * in an L3 domain and dif is set to it.
1032 */
1033 l3index = tcp_v6_sdif(skb) ? dif : 0;
1034
1035 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1036 if (!key)
1037 goto out;
1038
1039 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1040 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1041 goto out;
1042 }
1043#endif
1044
1045 if (th->ack)
1046 seq = ntohl(th->ack_seq);
1047 else
1048 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1049 (th->doff << 2);
1050
1051 if (sk) {
1052 oif = sk->sk_bound_dev_if;
1053 if (sk_fullsock(sk)) {
1054 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1055
1056 trace_tcp_send_reset(sk, skb);
1057 if (np->repflow)
1058 label = ip6_flowlabel(ipv6h);
1059 priority = sk->sk_priority;
1060 }
1061 if (sk->sk_state == TCP_TIME_WAIT) {
1062 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1063 priority = inet_twsk(sk)->tw_priority;
1064 }
1065 } else {
1066 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1067 label = ip6_flowlabel(ipv6h);
1068 }
1069
1070 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0,
1071 label, priority);
1072
1073#ifdef CONFIG_TCP_MD5SIG
1074out:
1075 rcu_read_unlock();
1076#endif
1077}
1078
1079static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1080 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1081 struct tcp_md5sig_key *key, u8 tclass,
1082 __be32 label, u32 priority)
1083{
1084 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1085 tclass, label, priority);
1086}
1087
1088static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1089{
1090 struct inet_timewait_sock *tw = inet_twsk(sk);
1091 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1092
1093 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1094 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1095 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1096 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1097 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
1098
1099 inet_twsk_put(tw);
1100}
1101
1102static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1103 struct request_sock *req)
1104{
1105 int l3index;
1106
1107 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1108
1109 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1110 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1111 */
1112 /* RFC 7323 2.3
1113 * The window field (SEG.WND) of every outgoing segment, with the
1114 * exception of <SYN> segments, MUST be right-shifted by
1115 * Rcv.Wind.Shift bits:
1116 */
1117 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1118 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1119 tcp_rsk(req)->rcv_nxt,
1120 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1121 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1122 req->ts_recent, sk->sk_bound_dev_if,
1123 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1124 0, 0, sk->sk_priority);
1125}
1126
1127
1128static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1129{
1130#ifdef CONFIG_SYN_COOKIES
1131 const struct tcphdr *th = tcp_hdr(skb);
1132
1133 if (!th->syn)
1134 sk = cookie_v6_check(sk, skb);
1135#endif
1136 return sk;
1137}
1138
1139u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1140 struct tcphdr *th, u32 *cookie)
1141{
1142 u16 mss = 0;
1143#ifdef CONFIG_SYN_COOKIES
1144 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1145 &tcp_request_sock_ipv6_ops, sk, th);
1146 if (mss) {
1147 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1148 tcp_synq_overflow(sk);
1149 }
1150#endif
1151 return mss;
1152}
1153
1154static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1155{
1156 if (skb->protocol == htons(ETH_P_IP))
1157 return tcp_v4_conn_request(sk, skb);
1158
1159 if (!ipv6_unicast_destination(skb))
1160 goto drop;
1161
1162 return tcp_conn_request(&tcp6_request_sock_ops,
1163 &tcp_request_sock_ipv6_ops, sk, skb);
1164
1165drop:
1166 tcp_listendrop(sk);
1167 return 0; /* don't send reset */
1168}
1169
1170static void tcp_v6_restore_cb(struct sk_buff *skb)
1171{
1172 /* We need to move header back to the beginning if xfrm6_policy_check()
1173 * and tcp_v6_fill_cb() are going to be called again.
1174 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1175 */
1176 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1177 sizeof(struct inet6_skb_parm));
1178}
1179
1180static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1181 struct request_sock *req,
1182 struct dst_entry *dst,
1183 struct request_sock *req_unhash,
1184 bool *own_req)
1185{
1186 struct inet_request_sock *ireq;
1187 struct ipv6_pinfo *newnp;
1188 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1189 struct ipv6_txoptions *opt;
1190 struct inet_sock *newinet;
1191 struct tcp_sock *newtp;
1192 struct sock *newsk;
1193#ifdef CONFIG_TCP_MD5SIG
1194 struct tcp_md5sig_key *key;
1195 int l3index;
1196#endif
1197 struct flowi6 fl6;
1198
1199 if (skb->protocol == htons(ETH_P_IP)) {
1200 /*
1201 * v6 mapped
1202 */
1203
1204 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1205 req_unhash, own_req);
1206
1207 if (!newsk)
1208 return NULL;
1209
1210 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1211
1212 newinet = inet_sk(newsk);
1213 newnp = tcp_inet6_sk(newsk);
1214 newtp = tcp_sk(newsk);
1215
1216 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1217
1218 newnp->saddr = newsk->sk_v6_rcv_saddr;
1219
1220 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1221 if (sk_is_mptcp(newsk))
1222 mptcpv6_handle_mapped(newsk, true);
1223 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1224#ifdef CONFIG_TCP_MD5SIG
1225 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1226#endif
1227
1228 newnp->ipv6_mc_list = NULL;
1229 newnp->ipv6_ac_list = NULL;
1230 newnp->ipv6_fl_list = NULL;
1231 newnp->pktoptions = NULL;
1232 newnp->opt = NULL;
1233 newnp->mcast_oif = inet_iif(skb);
1234 newnp->mcast_hops = ip_hdr(skb)->ttl;
1235 newnp->rcv_flowinfo = 0;
1236 if (np->repflow)
1237 newnp->flow_label = 0;
1238
1239 /*
1240 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1241 * here, tcp_create_openreq_child now does this for us, see the comment in
1242 * that function for the gory details. -acme
1243 */
1244
1245 /* It is tricky place. Until this moment IPv4 tcp
1246 worked with IPv6 icsk.icsk_af_ops.
1247 Sync it now.
1248 */
1249 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1250
1251 return newsk;
1252 }
1253
1254 ireq = inet_rsk(req);
1255
1256 if (sk_acceptq_is_full(sk))
1257 goto out_overflow;
1258
1259 if (!dst) {
1260 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1261 if (!dst)
1262 goto out;
1263 }
1264
1265 newsk = tcp_create_openreq_child(sk, req, skb);
1266 if (!newsk)
1267 goto out_nonewsk;
1268
1269 /*
1270 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1271 * count here, tcp_create_openreq_child now does this for us, see the
1272 * comment in that function for the gory details. -acme
1273 */
1274
1275 newsk->sk_gso_type = SKB_GSO_TCPV6;
1276 ip6_dst_store(newsk, dst, NULL, NULL);
1277 inet6_sk_rx_dst_set(newsk, skb);
1278
1279 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1280
1281 newtp = tcp_sk(newsk);
1282 newinet = inet_sk(newsk);
1283 newnp = tcp_inet6_sk(newsk);
1284
1285 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1286
1287 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1288 newnp->saddr = ireq->ir_v6_loc_addr;
1289 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1290 newsk->sk_bound_dev_if = ireq->ir_iif;
1291
1292 /* Now IPv6 options...
1293
1294 First: no IPv4 options.
1295 */
1296 newinet->inet_opt = NULL;
1297 newnp->ipv6_mc_list = NULL;
1298 newnp->ipv6_ac_list = NULL;
1299 newnp->ipv6_fl_list = NULL;
1300
1301 /* Clone RX bits */
1302 newnp->rxopt.all = np->rxopt.all;
1303
1304 newnp->pktoptions = NULL;
1305 newnp->opt = NULL;
1306 newnp->mcast_oif = tcp_v6_iif(skb);
1307 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1308 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1309 if (np->repflow)
1310 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1311
1312 /* Clone native IPv6 options from listening socket (if any)
1313
1314 Yes, keeping reference count would be much more clever,
1315 but we make one more one thing there: reattach optmem
1316 to newsk.
1317 */
1318 opt = ireq->ipv6_opt;
1319 if (!opt)
1320 opt = rcu_dereference(np->opt);
1321 if (opt) {
1322 opt = ipv6_dup_options(newsk, opt);
1323 RCU_INIT_POINTER(newnp->opt, opt);
1324 }
1325 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1326 if (opt)
1327 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1328 opt->opt_flen;
1329
1330 tcp_ca_openreq_child(newsk, dst);
1331
1332 tcp_sync_mss(newsk, dst_mtu(dst));
1333 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1334
1335 tcp_initialize_rcv_mss(newsk);
1336
1337 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1338 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1339
1340#ifdef CONFIG_TCP_MD5SIG
1341 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1342
1343 /* Copy over the MD5 key from the original socket */
1344 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1345 if (key) {
1346 /* We're using one, so create a matching key
1347 * on the newsk structure. If we fail to get
1348 * memory, then we end up not copying the key
1349 * across. Shucks.
1350 */
1351 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1352 AF_INET6, 128, l3index, key->key, key->keylen,
1353 sk_gfp_mask(sk, GFP_ATOMIC));
1354 }
1355#endif
1356
1357 if (__inet_inherit_port(sk, newsk) < 0) {
1358 inet_csk_prepare_forced_close(newsk);
1359 tcp_done(newsk);
1360 goto out;
1361 }
1362 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1363 if (*own_req) {
1364 tcp_move_syn(newtp, req);
1365
1366 /* Clone pktoptions received with SYN, if we own the req */
1367 if (ireq->pktopts) {
1368 newnp->pktoptions = skb_clone(ireq->pktopts,
1369 sk_gfp_mask(sk, GFP_ATOMIC));
1370 consume_skb(ireq->pktopts);
1371 ireq->pktopts = NULL;
1372 if (newnp->pktoptions) {
1373 tcp_v6_restore_cb(newnp->pktoptions);
1374 skb_set_owner_r(newnp->pktoptions, newsk);
1375 }
1376 }
1377 }
1378
1379 return newsk;
1380
1381out_overflow:
1382 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1383out_nonewsk:
1384 dst_release(dst);
1385out:
1386 tcp_listendrop(sk);
1387 return NULL;
1388}
1389
1390/* The socket must have it's spinlock held when we get
1391 * here, unless it is a TCP_LISTEN socket.
1392 *
1393 * We have a potential double-lock case here, so even when
1394 * doing backlog processing we use the BH locking scheme.
1395 * This is because we cannot sleep with the original spinlock
1396 * held.
1397 */
1398static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1399{
1400 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1401 struct sk_buff *opt_skb = NULL;
1402 struct tcp_sock *tp;
1403
1404 /* Imagine: socket is IPv6. IPv4 packet arrives,
1405 goes to IPv4 receive handler and backlogged.
1406 From backlog it always goes here. Kerboom...
1407 Fortunately, tcp_rcv_established and rcv_established
1408 handle them correctly, but it is not case with
1409 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1410 */
1411
1412 if (skb->protocol == htons(ETH_P_IP))
1413 return tcp_v4_do_rcv(sk, skb);
1414
1415 /*
1416 * socket locking is here for SMP purposes as backlog rcv
1417 * is currently called with bh processing disabled.
1418 */
1419
1420 /* Do Stevens' IPV6_PKTOPTIONS.
1421
1422 Yes, guys, it is the only place in our code, where we
1423 may make it not affecting IPv4.
1424 The rest of code is protocol independent,
1425 and I do not like idea to uglify IPv4.
1426
1427 Actually, all the idea behind IPV6_PKTOPTIONS
1428 looks not very well thought. For now we latch
1429 options, received in the last packet, enqueued
1430 by tcp. Feel free to propose better solution.
1431 --ANK (980728)
1432 */
1433 if (np->rxopt.all)
1434 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1435
1436 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1437 struct dst_entry *dst = sk->sk_rx_dst;
1438
1439 sock_rps_save_rxhash(sk, skb);
1440 sk_mark_napi_id(sk, skb);
1441 if (dst) {
1442 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1443 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1444 dst_release(dst);
1445 sk->sk_rx_dst = NULL;
1446 }
1447 }
1448
1449 tcp_rcv_established(sk, skb);
1450 if (opt_skb)
1451 goto ipv6_pktoptions;
1452 return 0;
1453 }
1454
1455 if (tcp_checksum_complete(skb))
1456 goto csum_err;
1457
1458 if (sk->sk_state == TCP_LISTEN) {
1459 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1460
1461 if (!nsk)
1462 goto discard;
1463
1464 if (nsk != sk) {
1465 if (tcp_child_process(sk, nsk, skb))
1466 goto reset;
1467 if (opt_skb)
1468 __kfree_skb(opt_skb);
1469 return 0;
1470 }
1471 } else
1472 sock_rps_save_rxhash(sk, skb);
1473
1474 if (tcp_rcv_state_process(sk, skb))
1475 goto reset;
1476 if (opt_skb)
1477 goto ipv6_pktoptions;
1478 return 0;
1479
1480reset:
1481 tcp_v6_send_reset(sk, skb);
1482discard:
1483 if (opt_skb)
1484 __kfree_skb(opt_skb);
1485 kfree_skb(skb);
1486 return 0;
1487csum_err:
1488 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1489 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1490 goto discard;
1491
1492
1493ipv6_pktoptions:
1494 /* Do you ask, what is it?
1495
1496 1. skb was enqueued by tcp.
1497 2. skb is added to tail of read queue, rather than out of order.
1498 3. socket is not in passive state.
1499 4. Finally, it really contains options, which user wants to receive.
1500 */
1501 tp = tcp_sk(sk);
1502 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1503 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1504 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1505 np->mcast_oif = tcp_v6_iif(opt_skb);
1506 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1507 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1508 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1509 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1510 if (np->repflow)
1511 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1512 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1513 skb_set_owner_r(opt_skb, sk);
1514 tcp_v6_restore_cb(opt_skb);
1515 opt_skb = xchg(&np->pktoptions, opt_skb);
1516 } else {
1517 __kfree_skb(opt_skb);
1518 opt_skb = xchg(&np->pktoptions, NULL);
1519 }
1520 }
1521
1522 kfree_skb(opt_skb);
1523 return 0;
1524}
1525
1526static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1527 const struct tcphdr *th)
1528{
1529 /* This is tricky: we move IP6CB at its correct location into
1530 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1531 * _decode_session6() uses IP6CB().
1532 * barrier() makes sure compiler won't play aliasing games.
1533 */
1534 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1535 sizeof(struct inet6_skb_parm));
1536 barrier();
1537
1538 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1539 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1540 skb->len - th->doff*4);
1541 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1542 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1543 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1544 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1545 TCP_SKB_CB(skb)->sacked = 0;
1546 TCP_SKB_CB(skb)->has_rxtstamp =
1547 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1548}
1549
1550INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1551{
1552 struct sk_buff *skb_to_free;
1553 int sdif = inet6_sdif(skb);
1554 int dif = inet6_iif(skb);
1555 const struct tcphdr *th;
1556 const struct ipv6hdr *hdr;
1557 bool refcounted;
1558 struct sock *sk;
1559 int ret;
1560 struct net *net = dev_net(skb->dev);
1561
1562 if (skb->pkt_type != PACKET_HOST)
1563 goto discard_it;
1564
1565 /*
1566 * Count it even if it's bad.
1567 */
1568 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1569
1570 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1571 goto discard_it;
1572
1573 th = (const struct tcphdr *)skb->data;
1574
1575 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1576 goto bad_packet;
1577 if (!pskb_may_pull(skb, th->doff*4))
1578 goto discard_it;
1579
1580 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1581 goto csum_error;
1582
1583 th = (const struct tcphdr *)skb->data;
1584 hdr = ipv6_hdr(skb);
1585
1586lookup:
1587 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1588 th->source, th->dest, inet6_iif(skb), sdif,
1589 &refcounted);
1590 if (!sk)
1591 goto no_tcp_socket;
1592
1593process:
1594 if (sk->sk_state == TCP_TIME_WAIT)
1595 goto do_time_wait;
1596
1597 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1598 struct request_sock *req = inet_reqsk(sk);
1599 bool req_stolen = false;
1600 struct sock *nsk;
1601
1602 sk = req->rsk_listener;
1603 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) {
1604 sk_drops_add(sk, skb);
1605 reqsk_put(req);
1606 goto discard_it;
1607 }
1608 if (tcp_checksum_complete(skb)) {
1609 reqsk_put(req);
1610 goto csum_error;
1611 }
1612 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1613 inet_csk_reqsk_queue_drop_and_put(sk, req);
1614 goto lookup;
1615 }
1616 sock_hold(sk);
1617 refcounted = true;
1618 nsk = NULL;
1619 if (!tcp_filter(sk, skb)) {
1620 th = (const struct tcphdr *)skb->data;
1621 hdr = ipv6_hdr(skb);
1622 tcp_v6_fill_cb(skb, hdr, th);
1623 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1624 }
1625 if (!nsk) {
1626 reqsk_put(req);
1627 if (req_stolen) {
1628 /* Another cpu got exclusive access to req
1629 * and created a full blown socket.
1630 * Try to feed this packet to this socket
1631 * instead of discarding it.
1632 */
1633 tcp_v6_restore_cb(skb);
1634 sock_put(sk);
1635 goto lookup;
1636 }
1637 goto discard_and_relse;
1638 }
1639 if (nsk == sk) {
1640 reqsk_put(req);
1641 tcp_v6_restore_cb(skb);
1642 } else if (tcp_child_process(sk, nsk, skb)) {
1643 tcp_v6_send_reset(nsk, skb);
1644 goto discard_and_relse;
1645 } else {
1646 sock_put(sk);
1647 return 0;
1648 }
1649 }
1650 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
1651 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1652 goto discard_and_relse;
1653 }
1654
1655 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1656 goto discard_and_relse;
1657
1658 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
1659 goto discard_and_relse;
1660
1661 if (tcp_filter(sk, skb))
1662 goto discard_and_relse;
1663 th = (const struct tcphdr *)skb->data;
1664 hdr = ipv6_hdr(skb);
1665 tcp_v6_fill_cb(skb, hdr, th);
1666
1667 skb->dev = NULL;
1668
1669 if (sk->sk_state == TCP_LISTEN) {
1670 ret = tcp_v6_do_rcv(sk, skb);
1671 goto put_and_return;
1672 }
1673
1674 sk_incoming_cpu_update(sk);
1675
1676 bh_lock_sock_nested(sk);
1677 tcp_segs_in(tcp_sk(sk), skb);
1678 ret = 0;
1679 if (!sock_owned_by_user(sk)) {
1680 skb_to_free = sk->sk_rx_skb_cache;
1681 sk->sk_rx_skb_cache = NULL;
1682 ret = tcp_v6_do_rcv(sk, skb);
1683 } else {
1684 if (tcp_add_backlog(sk, skb))
1685 goto discard_and_relse;
1686 skb_to_free = NULL;
1687 }
1688 bh_unlock_sock(sk);
1689 if (skb_to_free)
1690 __kfree_skb(skb_to_free);
1691put_and_return:
1692 if (refcounted)
1693 sock_put(sk);
1694 return ret ? -1 : 0;
1695
1696no_tcp_socket:
1697 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1698 goto discard_it;
1699
1700 tcp_v6_fill_cb(skb, hdr, th);
1701
1702 if (tcp_checksum_complete(skb)) {
1703csum_error:
1704 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1705bad_packet:
1706 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1707 } else {
1708 tcp_v6_send_reset(NULL, skb);
1709 }
1710
1711discard_it:
1712 kfree_skb(skb);
1713 return 0;
1714
1715discard_and_relse:
1716 sk_drops_add(sk, skb);
1717 if (refcounted)
1718 sock_put(sk);
1719 goto discard_it;
1720
1721do_time_wait:
1722 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1723 inet_twsk_put(inet_twsk(sk));
1724 goto discard_it;
1725 }
1726
1727 tcp_v6_fill_cb(skb, hdr, th);
1728
1729 if (tcp_checksum_complete(skb)) {
1730 inet_twsk_put(inet_twsk(sk));
1731 goto csum_error;
1732 }
1733
1734 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1735 case TCP_TW_SYN:
1736 {
1737 struct sock *sk2;
1738
1739 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1740 skb, __tcp_hdrlen(th),
1741 &ipv6_hdr(skb)->saddr, th->source,
1742 &ipv6_hdr(skb)->daddr,
1743 ntohs(th->dest),
1744 tcp_v6_iif_l3_slave(skb),
1745 sdif);
1746 if (sk2) {
1747 struct inet_timewait_sock *tw = inet_twsk(sk);
1748 inet_twsk_deschedule_put(tw);
1749 sk = sk2;
1750 tcp_v6_restore_cb(skb);
1751 refcounted = false;
1752 goto process;
1753 }
1754 }
1755 /* to ACK */
1756 fallthrough;
1757 case TCP_TW_ACK:
1758 tcp_v6_timewait_ack(sk, skb);
1759 break;
1760 case TCP_TW_RST:
1761 tcp_v6_send_reset(sk, skb);
1762 inet_twsk_deschedule_put(inet_twsk(sk));
1763 goto discard_it;
1764 case TCP_TW_SUCCESS:
1765 ;
1766 }
1767 goto discard_it;
1768}
1769
1770INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
1771{
1772 const struct ipv6hdr *hdr;
1773 const struct tcphdr *th;
1774 struct sock *sk;
1775
1776 if (skb->pkt_type != PACKET_HOST)
1777 return;
1778
1779 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1780 return;
1781
1782 hdr = ipv6_hdr(skb);
1783 th = tcp_hdr(skb);
1784
1785 if (th->doff < sizeof(struct tcphdr) / 4)
1786 return;
1787
1788 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1789 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1790 &hdr->saddr, th->source,
1791 &hdr->daddr, ntohs(th->dest),
1792 inet6_iif(skb), inet6_sdif(skb));
1793 if (sk) {
1794 skb->sk = sk;
1795 skb->destructor = sock_edemux;
1796 if (sk_fullsock(sk)) {
1797 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1798
1799 if (dst)
1800 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
1801 if (dst &&
1802 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1803 skb_dst_set_noref(skb, dst);
1804 }
1805 }
1806}
1807
1808static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1809 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1810 .twsk_unique = tcp_twsk_unique,
1811 .twsk_destructor = tcp_twsk_destructor,
1812};
1813
1814INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1815{
1816 struct ipv6_pinfo *np = inet6_sk(sk);
1817
1818 __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
1819}
1820
1821const struct inet_connection_sock_af_ops ipv6_specific = {
1822 .queue_xmit = inet6_csk_xmit,
1823 .send_check = tcp_v6_send_check,
1824 .rebuild_header = inet6_sk_rebuild_header,
1825 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1826 .conn_request = tcp_v6_conn_request,
1827 .syn_recv_sock = tcp_v6_syn_recv_sock,
1828 .net_header_len = sizeof(struct ipv6hdr),
1829 .net_frag_header_len = sizeof(struct frag_hdr),
1830 .setsockopt = ipv6_setsockopt,
1831 .getsockopt = ipv6_getsockopt,
1832 .addr2sockaddr = inet6_csk_addr2sockaddr,
1833 .sockaddr_len = sizeof(struct sockaddr_in6),
1834 .mtu_reduced = tcp_v6_mtu_reduced,
1835};
1836
1837#ifdef CONFIG_TCP_MD5SIG
1838static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1839 .md5_lookup = tcp_v6_md5_lookup,
1840 .calc_md5_hash = tcp_v6_md5_hash_skb,
1841 .md5_parse = tcp_v6_parse_md5_keys,
1842};
1843#endif
1844
1845/*
1846 * TCP over IPv4 via INET6 API
1847 */
1848static const struct inet_connection_sock_af_ops ipv6_mapped = {
1849 .queue_xmit = ip_queue_xmit,
1850 .send_check = tcp_v4_send_check,
1851 .rebuild_header = inet_sk_rebuild_header,
1852 .sk_rx_dst_set = inet_sk_rx_dst_set,
1853 .conn_request = tcp_v6_conn_request,
1854 .syn_recv_sock = tcp_v6_syn_recv_sock,
1855 .net_header_len = sizeof(struct iphdr),
1856 .setsockopt = ipv6_setsockopt,
1857 .getsockopt = ipv6_getsockopt,
1858 .addr2sockaddr = inet6_csk_addr2sockaddr,
1859 .sockaddr_len = sizeof(struct sockaddr_in6),
1860 .mtu_reduced = tcp_v4_mtu_reduced,
1861};
1862
1863#ifdef CONFIG_TCP_MD5SIG
1864static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1865 .md5_lookup = tcp_v4_md5_lookup,
1866 .calc_md5_hash = tcp_v4_md5_hash_skb,
1867 .md5_parse = tcp_v6_parse_md5_keys,
1868};
1869#endif
1870
1871/* NOTE: A lot of things set to zero explicitly by call to
1872 * sk_alloc() so need not be done here.
1873 */
1874static int tcp_v6_init_sock(struct sock *sk)
1875{
1876 struct inet_connection_sock *icsk = inet_csk(sk);
1877
1878 tcp_init_sock(sk);
1879
1880 icsk->icsk_af_ops = &ipv6_specific;
1881
1882#ifdef CONFIG_TCP_MD5SIG
1883 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1884#endif
1885
1886 return 0;
1887}
1888
1889static void tcp_v6_destroy_sock(struct sock *sk)
1890{
1891 tcp_v4_destroy_sock(sk);
1892 inet6_destroy_sock(sk);
1893}
1894
1895#ifdef CONFIG_PROC_FS
1896/* Proc filesystem TCPv6 sock list dumping. */
1897static void get_openreq6(struct seq_file *seq,
1898 const struct request_sock *req, int i)
1899{
1900 long ttd = req->rsk_timer.expires - jiffies;
1901 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1902 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1903
1904 if (ttd < 0)
1905 ttd = 0;
1906
1907 seq_printf(seq,
1908 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1909 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1910 i,
1911 src->s6_addr32[0], src->s6_addr32[1],
1912 src->s6_addr32[2], src->s6_addr32[3],
1913 inet_rsk(req)->ir_num,
1914 dest->s6_addr32[0], dest->s6_addr32[1],
1915 dest->s6_addr32[2], dest->s6_addr32[3],
1916 ntohs(inet_rsk(req)->ir_rmt_port),
1917 TCP_SYN_RECV,
1918 0, 0, /* could print option size, but that is af dependent. */
1919 1, /* timers active (only the expire timer) */
1920 jiffies_to_clock_t(ttd),
1921 req->num_timeout,
1922 from_kuid_munged(seq_user_ns(seq),
1923 sock_i_uid(req->rsk_listener)),
1924 0, /* non standard timer */
1925 0, /* open_requests have no inode */
1926 0, req);
1927}
1928
1929static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1930{
1931 const struct in6_addr *dest, *src;
1932 __u16 destp, srcp;
1933 int timer_active;
1934 unsigned long timer_expires;
1935 const struct inet_sock *inet = inet_sk(sp);
1936 const struct tcp_sock *tp = tcp_sk(sp);
1937 const struct inet_connection_sock *icsk = inet_csk(sp);
1938 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1939 int rx_queue;
1940 int state;
1941
1942 dest = &sp->sk_v6_daddr;
1943 src = &sp->sk_v6_rcv_saddr;
1944 destp = ntohs(inet->inet_dport);
1945 srcp = ntohs(inet->inet_sport);
1946
1947 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1948 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1949 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1950 timer_active = 1;
1951 timer_expires = icsk->icsk_timeout;
1952 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1953 timer_active = 4;
1954 timer_expires = icsk->icsk_timeout;
1955 } else if (timer_pending(&sp->sk_timer)) {
1956 timer_active = 2;
1957 timer_expires = sp->sk_timer.expires;
1958 } else {
1959 timer_active = 0;
1960 timer_expires = jiffies;
1961 }
1962
1963 state = inet_sk_state_load(sp);
1964 if (state == TCP_LISTEN)
1965 rx_queue = READ_ONCE(sp->sk_ack_backlog);
1966 else
1967 /* Because we don't lock the socket,
1968 * we might find a transient negative value.
1969 */
1970 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
1971 READ_ONCE(tp->copied_seq), 0);
1972
1973 seq_printf(seq,
1974 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1975 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1976 i,
1977 src->s6_addr32[0], src->s6_addr32[1],
1978 src->s6_addr32[2], src->s6_addr32[3], srcp,
1979 dest->s6_addr32[0], dest->s6_addr32[1],
1980 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1981 state,
1982 READ_ONCE(tp->write_seq) - tp->snd_una,
1983 rx_queue,
1984 timer_active,
1985 jiffies_delta_to_clock_t(timer_expires - jiffies),
1986 icsk->icsk_retransmits,
1987 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1988 icsk->icsk_probes_out,
1989 sock_i_ino(sp),
1990 refcount_read(&sp->sk_refcnt), sp,
1991 jiffies_to_clock_t(icsk->icsk_rto),
1992 jiffies_to_clock_t(icsk->icsk_ack.ato),
1993 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
1994 tp->snd_cwnd,
1995 state == TCP_LISTEN ?
1996 fastopenq->max_qlen :
1997 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1998 );
1999}
2000
2001static void get_timewait6_sock(struct seq_file *seq,
2002 struct inet_timewait_sock *tw, int i)
2003{
2004 long delta = tw->tw_timer.expires - jiffies;
2005 const struct in6_addr *dest, *src;
2006 __u16 destp, srcp;
2007
2008 dest = &tw->tw_v6_daddr;
2009 src = &tw->tw_v6_rcv_saddr;
2010 destp = ntohs(tw->tw_dport);
2011 srcp = ntohs(tw->tw_sport);
2012
2013 seq_printf(seq,
2014 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2015 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2016 i,
2017 src->s6_addr32[0], src->s6_addr32[1],
2018 src->s6_addr32[2], src->s6_addr32[3], srcp,
2019 dest->s6_addr32[0], dest->s6_addr32[1],
2020 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2021 tw->tw_substate, 0, 0,
2022 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2023 refcount_read(&tw->tw_refcnt), tw);
2024}
2025
2026static int tcp6_seq_show(struct seq_file *seq, void *v)
2027{
2028 struct tcp_iter_state *st;
2029 struct sock *sk = v;
2030
2031 if (v == SEQ_START_TOKEN) {
2032 seq_puts(seq,
2033 " sl "
2034 "local_address "
2035 "remote_address "
2036 "st tx_queue rx_queue tr tm->when retrnsmt"
2037 " uid timeout inode\n");
2038 goto out;
2039 }
2040 st = seq->private;
2041
2042 if (sk->sk_state == TCP_TIME_WAIT)
2043 get_timewait6_sock(seq, v, st->num);
2044 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2045 get_openreq6(seq, v, st->num);
2046 else
2047 get_tcp6_sock(seq, v, st->num);
2048out:
2049 return 0;
2050}
2051
2052static const struct seq_operations tcp6_seq_ops = {
2053 .show = tcp6_seq_show,
2054 .start = tcp_seq_start,
2055 .next = tcp_seq_next,
2056 .stop = tcp_seq_stop,
2057};
2058
2059static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2060 .family = AF_INET6,
2061};
2062
2063int __net_init tcp6_proc_init(struct net *net)
2064{
2065 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2066 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2067 return -ENOMEM;
2068 return 0;
2069}
2070
2071void tcp6_proc_exit(struct net *net)
2072{
2073 remove_proc_entry("tcp6", net->proc_net);
2074}
2075#endif
2076
2077struct proto tcpv6_prot = {
2078 .name = "TCPv6",
2079 .owner = THIS_MODULE,
2080 .close = tcp_close,
2081 .pre_connect = tcp_v6_pre_connect,
2082 .connect = tcp_v6_connect,
2083 .disconnect = tcp_disconnect,
2084 .accept = inet_csk_accept,
2085 .ioctl = tcp_ioctl,
2086 .init = tcp_v6_init_sock,
2087 .destroy = tcp_v6_destroy_sock,
2088 .shutdown = tcp_shutdown,
2089 .setsockopt = tcp_setsockopt,
2090 .getsockopt = tcp_getsockopt,
2091 .keepalive = tcp_set_keepalive,
2092 .recvmsg = tcp_recvmsg,
2093 .sendmsg = tcp_sendmsg,
2094 .sendpage = tcp_sendpage,
2095 .backlog_rcv = tcp_v6_do_rcv,
2096 .release_cb = tcp_release_cb,
2097 .hash = inet6_hash,
2098 .unhash = inet_unhash,
2099 .get_port = inet_csk_get_port,
2100 .enter_memory_pressure = tcp_enter_memory_pressure,
2101 .leave_memory_pressure = tcp_leave_memory_pressure,
2102 .stream_memory_free = tcp_stream_memory_free,
2103 .sockets_allocated = &tcp_sockets_allocated,
2104 .memory_allocated = &tcp_memory_allocated,
2105 .memory_pressure = &tcp_memory_pressure,
2106 .orphan_count = &tcp_orphan_count,
2107 .sysctl_mem = sysctl_tcp_mem,
2108 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2109 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2110 .max_header = MAX_TCP_HEADER,
2111 .obj_size = sizeof(struct tcp6_sock),
2112 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2113 .twsk_prot = &tcp6_timewait_sock_ops,
2114 .rsk_prot = &tcp6_request_sock_ops,
2115 .h.hashinfo = &tcp_hashinfo,
2116 .no_autobind = true,
2117 .diag_destroy = tcp_abort,
2118};
2119EXPORT_SYMBOL_GPL(tcpv6_prot);
2120
2121/* thinking of making this const? Don't.
2122 * early_demux can change based on sysctl.
2123 */
2124static struct inet6_protocol tcpv6_protocol = {
2125 .early_demux = tcp_v6_early_demux,
2126 .early_demux_handler = tcp_v6_early_demux,
2127 .handler = tcp_v6_rcv,
2128 .err_handler = tcp_v6_err,
2129 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2130};
2131
2132static struct inet_protosw tcpv6_protosw = {
2133 .type = SOCK_STREAM,
2134 .protocol = IPPROTO_TCP,
2135 .prot = &tcpv6_prot,
2136 .ops = &inet6_stream_ops,
2137 .flags = INET_PROTOSW_PERMANENT |
2138 INET_PROTOSW_ICSK,
2139};
2140
2141static int __net_init tcpv6_net_init(struct net *net)
2142{
2143 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2144 SOCK_RAW, IPPROTO_TCP, net);
2145}
2146
2147static void __net_exit tcpv6_net_exit(struct net *net)
2148{
2149 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2150}
2151
2152static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2153{
2154 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2155}
2156
2157static struct pernet_operations tcpv6_net_ops = {
2158 .init = tcpv6_net_init,
2159 .exit = tcpv6_net_exit,
2160 .exit_batch = tcpv6_net_exit_batch,
2161};
2162
2163int __init tcpv6_init(void)
2164{
2165 int ret;
2166
2167 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2168 if (ret)
2169 goto out;
2170
2171 /* register inet6 protocol */
2172 ret = inet6_register_protosw(&tcpv6_protosw);
2173 if (ret)
2174 goto out_tcpv6_protocol;
2175
2176 ret = register_pernet_subsys(&tcpv6_net_ops);
2177 if (ret)
2178 goto out_tcpv6_protosw;
2179
2180 ret = mptcpv6_init();
2181 if (ret)
2182 goto out_tcpv6_pernet_subsys;
2183
2184out:
2185 return ret;
2186
2187out_tcpv6_pernet_subsys:
2188 unregister_pernet_subsys(&tcpv6_net_ops);
2189out_tcpv6_protosw:
2190 inet6_unregister_protosw(&tcpv6_protosw);
2191out_tcpv6_protocol:
2192 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2193 goto out;
2194}
2195
2196void tcpv6_exit(void)
2197{
2198 unregister_pernet_subsys(&tcpv6_net_ops);
2199 inet6_unregister_protosw(&tcpv6_protosw);
2200 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2201}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * TCP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on:
10 * linux/net/ipv4/tcp.c
11 * linux/net/ipv4/tcp_input.c
12 * linux/net/ipv4/tcp_output.c
13 *
14 * Fixes:
15 * Hideaki YOSHIFUJI : sin6_scope_id support
16 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
17 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
18 * a single port at the same time.
19 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
20 */
21
22#include <linux/bottom_half.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/jiffies.h>
30#include <linux/in.h>
31#include <linux/in6.h>
32#include <linux/netdevice.h>
33#include <linux/init.h>
34#include <linux/jhash.h>
35#include <linux/ipsec.h>
36#include <linux/times.h>
37#include <linux/slab.h>
38#include <linux/uaccess.h>
39#include <linux/ipv6.h>
40#include <linux/icmpv6.h>
41#include <linux/random.h>
42#include <linux/indirect_call_wrapper.h>
43
44#include <net/tcp.h>
45#include <net/ndisc.h>
46#include <net/inet6_hashtables.h>
47#include <net/inet6_connection_sock.h>
48#include <net/ipv6.h>
49#include <net/transp_v6.h>
50#include <net/addrconf.h>
51#include <net/ip6_route.h>
52#include <net/ip6_checksum.h>
53#include <net/inet_ecn.h>
54#include <net/protocol.h>
55#include <net/xfrm.h>
56#include <net/snmp.h>
57#include <net/dsfield.h>
58#include <net/timewait_sock.h>
59#include <net/inet_common.h>
60#include <net/secure_seq.h>
61#include <net/busy_poll.h>
62
63#include <linux/proc_fs.h>
64#include <linux/seq_file.h>
65
66#include <crypto/hash.h>
67#include <linux/scatterlist.h>
68
69#include <trace/events/tcp.h>
70
71static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
72static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
73 struct request_sock *req);
74
75static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77static const struct inet_connection_sock_af_ops ipv6_mapped;
78const struct inet_connection_sock_af_ops ipv6_specific;
79#ifdef CONFIG_TCP_MD5SIG
80static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
81static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
82#else
83static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
84 const struct in6_addr *addr,
85 int l3index)
86{
87 return NULL;
88}
89#endif
90
91/* Helper returning the inet6 address from a given tcp socket.
92 * It can be used in TCP stack instead of inet6_sk(sk).
93 * This avoids a dereference and allow compiler optimizations.
94 * It is a specialized version of inet6_sk_generic().
95 */
96static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
97{
98 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
99
100 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
101}
102
103static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
104{
105 struct dst_entry *dst = skb_dst(skb);
106
107 if (dst && dst_hold_safe(dst)) {
108 const struct rt6_info *rt = (const struct rt6_info *)dst;
109
110 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
116static u32 tcp_v6_init_seq(const struct sk_buff *skb)
117{
118 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
119 ipv6_hdr(skb)->saddr.s6_addr32,
120 tcp_hdr(skb)->dest,
121 tcp_hdr(skb)->source);
122}
123
124static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
125{
126 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
127 ipv6_hdr(skb)->saddr.s6_addr32);
128}
129
130static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
131 int addr_len)
132{
133 /* This check is replicated from tcp_v6_connect() and intended to
134 * prevent BPF program called below from accessing bytes that are out
135 * of the bound specified by user in addr_len.
136 */
137 if (addr_len < SIN6_LEN_RFC2133)
138 return -EINVAL;
139
140 sock_owned_by_me(sk);
141
142 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
143}
144
145static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
146 int addr_len)
147{
148 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
149 struct inet_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
340late_failure:
341 tcp_set_state(sk, TCP_CLOSE);
342failure:
343 inet->inet_dport = 0;
344 sk->sk_route_caps = 0;
345 return err;
346}
347
348static void tcp_v6_mtu_reduced(struct sock *sk)
349{
350 struct dst_entry *dst;
351 u32 mtu;
352
353 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
354 return;
355
356 mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
357
358 /* Drop requests trying to increase our current mss.
359 * Check done in __ip6_rt_update_pmtu() is too late.
360 */
361 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
362 return;
363
364 dst = inet6_csk_update_pmtu(sk, mtu);
365 if (!dst)
366 return;
367
368 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
369 tcp_sync_mss(sk, dst_mtu(dst));
370 tcp_simple_retransmit(sk);
371 }
372}
373
374static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
375 u8 type, u8 code, int offset, __be32 info)
376{
377 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
378 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
379 struct net *net = dev_net(skb->dev);
380 struct request_sock *fastopen;
381 struct ipv6_pinfo *np;
382 struct tcp_sock *tp;
383 __u32 seq, snd_una;
384 struct sock *sk;
385 bool fatal;
386 int err;
387
388 sk = __inet6_lookup_established(net, &tcp_hashinfo,
389 &hdr->daddr, th->dest,
390 &hdr->saddr, ntohs(th->source),
391 skb->dev->ifindex, inet6_sdif(skb));
392
393 if (!sk) {
394 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
395 ICMP6_MIB_INERRORS);
396 return -ENOENT;
397 }
398
399 if (sk->sk_state == TCP_TIME_WAIT) {
400 inet_twsk_put(inet_twsk(sk));
401 return 0;
402 }
403 seq = ntohl(th->seq);
404 fatal = icmpv6_err_convert(type, code, &err);
405 if (sk->sk_state == TCP_NEW_SYN_RECV) {
406 tcp_req_err(sk, seq, fatal);
407 return 0;
408 }
409
410 bh_lock_sock(sk);
411 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
412 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
413
414 if (sk->sk_state == TCP_CLOSE)
415 goto out;
416
417 if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
418 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
419 goto out;
420 }
421
422 tp = tcp_sk(sk);
423 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
424 fastopen = rcu_dereference(tp->fastopen_rsk);
425 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
426 if (sk->sk_state != TCP_LISTEN &&
427 !between(seq, snd_una, tp->snd_nxt)) {
428 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
429 goto out;
430 }
431
432 np = tcp_inet6_sk(sk);
433
434 if (type == NDISC_REDIRECT) {
435 if (!sock_owned_by_user(sk)) {
436 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
437
438 if (dst)
439 dst->ops->redirect(dst, sk, skb);
440 }
441 goto out;
442 }
443
444 if (type == ICMPV6_PKT_TOOBIG) {
445 u32 mtu = ntohl(info);
446
447 /* We are not interested in TCP_LISTEN and open_requests
448 * (SYN-ACKs send out by Linux are always <576bytes so
449 * they should go through unfragmented).
450 */
451 if (sk->sk_state == TCP_LISTEN)
452 goto out;
453
454 if (!ip6_sk_accept_pmtu(sk))
455 goto out;
456
457 if (mtu < IPV6_MIN_MTU)
458 goto out;
459
460 WRITE_ONCE(tp->mtu_info, mtu);
461
462 if (!sock_owned_by_user(sk))
463 tcp_v6_mtu_reduced(sk);
464 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
465 &sk->sk_tsq_flags))
466 sock_hold(sk);
467 goto out;
468 }
469
470
471 /* Might be for an request_sock */
472 switch (sk->sk_state) {
473 case TCP_SYN_SENT:
474 case TCP_SYN_RECV:
475 /* Only in fast or simultaneous open. If a fast open socket is
476 * already accepted it is treated as a connected one below.
477 */
478 if (fastopen && !fastopen->sk)
479 break;
480
481 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
482
483 if (!sock_owned_by_user(sk)) {
484 sk->sk_err = err;
485 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
486
487 tcp_done(sk);
488 } else
489 sk->sk_err_soft = err;
490 goto out;
491 case TCP_LISTEN:
492 break;
493 default:
494 /* check if this ICMP message allows revert of backoff.
495 * (see RFC 6069)
496 */
497 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
498 code == ICMPV6_NOROUTE)
499 tcp_ld_RTO_revert(sk, seq);
500 }
501
502 if (!sock_owned_by_user(sk) && np->recverr) {
503 sk->sk_err = err;
504 sk_error_report(sk);
505 } else
506 sk->sk_err_soft = err;
507
508out:
509 bh_unlock_sock(sk);
510 sock_put(sk);
511 return 0;
512}
513
514
515static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
516 struct flowi *fl,
517 struct request_sock *req,
518 struct tcp_fastopen_cookie *foc,
519 enum tcp_synack_type synack_type,
520 struct sk_buff *syn_skb)
521{
522 struct inet_request_sock *ireq = inet_rsk(req);
523 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
524 struct ipv6_txoptions *opt;
525 struct flowi6 *fl6 = &fl->u.ip6;
526 struct sk_buff *skb;
527 int err = -ENOMEM;
528 u8 tclass;
529
530 /* First, grab a route. */
531 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
532 IPPROTO_TCP)) == NULL)
533 goto done;
534
535 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
536
537 if (skb) {
538 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
539 &ireq->ir_v6_rmt_addr);
540
541 fl6->daddr = ireq->ir_v6_rmt_addr;
542 if (np->repflow && ireq->pktopts)
543 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
544
545 tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ?
546 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
547 (np->tclass & INET_ECN_MASK) :
548 np->tclass;
549
550 if (!INET_ECN_is_capable(tclass) &&
551 tcp_bpf_ca_needs_ecn((struct sock *)req))
552 tclass |= INET_ECN_ECT_0;
553
554 rcu_read_lock();
555 opt = ireq->ipv6_opt;
556 if (!opt)
557 opt = rcu_dereference(np->opt);
558 err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt,
559 tclass, sk->sk_priority);
560 rcu_read_unlock();
561 err = net_xmit_eval(err);
562 }
563
564done:
565 return err;
566}
567
568
569static void tcp_v6_reqsk_destructor(struct request_sock *req)
570{
571 kfree(inet_rsk(req)->ipv6_opt);
572 kfree_skb(inet_rsk(req)->pktopts);
573}
574
575#ifdef CONFIG_TCP_MD5SIG
576static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
577 const struct in6_addr *addr,
578 int l3index)
579{
580 return tcp_md5_do_lookup(sk, l3index,
581 (union tcp_md5_addr *)addr, AF_INET6);
582}
583
584static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
585 const struct sock *addr_sk)
586{
587 int l3index;
588
589 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
590 addr_sk->sk_bound_dev_if);
591 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
592 l3index);
593}
594
595static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
596 sockptr_t optval, int optlen)
597{
598 struct tcp_md5sig cmd;
599 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
600 int l3index = 0;
601 u8 prefixlen;
602
603 if (optlen < sizeof(cmd))
604 return -EINVAL;
605
606 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
607 return -EFAULT;
608
609 if (sin6->sin6_family != AF_INET6)
610 return -EINVAL;
611
612 if (optname == TCP_MD5SIG_EXT &&
613 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
614 prefixlen = cmd.tcpm_prefixlen;
615 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
616 prefixlen > 32))
617 return -EINVAL;
618 } else {
619 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
620 }
621
622 if (optname == TCP_MD5SIG_EXT &&
623 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
624 struct net_device *dev;
625
626 rcu_read_lock();
627 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
628 if (dev && netif_is_l3_master(dev))
629 l3index = dev->ifindex;
630 rcu_read_unlock();
631
632 /* ok to reference set/not set outside of rcu;
633 * right now device MUST be an L3 master
634 */
635 if (!dev || !l3index)
636 return -EINVAL;
637 }
638
639 if (!cmd.tcpm_keylen) {
640 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
641 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
642 AF_INET, prefixlen,
643 l3index);
644 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
645 AF_INET6, prefixlen, l3index);
646 }
647
648 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
649 return -EINVAL;
650
651 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
652 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
653 AF_INET, prefixlen, l3index,
654 cmd.tcpm_key, cmd.tcpm_keylen,
655 GFP_KERNEL);
656
657 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
658 AF_INET6, prefixlen, l3index,
659 cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
660}
661
662static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
663 const struct in6_addr *daddr,
664 const struct in6_addr *saddr,
665 const struct tcphdr *th, int nbytes)
666{
667 struct tcp6_pseudohdr *bp;
668 struct scatterlist sg;
669 struct tcphdr *_th;
670
671 bp = hp->scratch;
672 /* 1. TCP pseudo-header (RFC2460) */
673 bp->saddr = *saddr;
674 bp->daddr = *daddr;
675 bp->protocol = cpu_to_be32(IPPROTO_TCP);
676 bp->len = cpu_to_be32(nbytes);
677
678 _th = (struct tcphdr *)(bp + 1);
679 memcpy(_th, th, sizeof(*th));
680 _th->check = 0;
681
682 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
683 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
684 sizeof(*bp) + sizeof(*th));
685 return crypto_ahash_update(hp->md5_req);
686}
687
688static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
689 const struct in6_addr *daddr, struct in6_addr *saddr,
690 const struct tcphdr *th)
691{
692 struct tcp_md5sig_pool *hp;
693 struct ahash_request *req;
694
695 hp = tcp_get_md5sig_pool();
696 if (!hp)
697 goto clear_hash_noput;
698 req = hp->md5_req;
699
700 if (crypto_ahash_init(req))
701 goto clear_hash;
702 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
703 goto clear_hash;
704 if (tcp_md5_hash_key(hp, key))
705 goto clear_hash;
706 ahash_request_set_crypt(req, NULL, md5_hash, 0);
707 if (crypto_ahash_final(req))
708 goto clear_hash;
709
710 tcp_put_md5sig_pool();
711 return 0;
712
713clear_hash:
714 tcp_put_md5sig_pool();
715clear_hash_noput:
716 memset(md5_hash, 0, 16);
717 return 1;
718}
719
720static int tcp_v6_md5_hash_skb(char *md5_hash,
721 const struct tcp_md5sig_key *key,
722 const struct sock *sk,
723 const struct sk_buff *skb)
724{
725 const struct in6_addr *saddr, *daddr;
726 struct tcp_md5sig_pool *hp;
727 struct ahash_request *req;
728 const struct tcphdr *th = tcp_hdr(skb);
729
730 if (sk) { /* valid for establish/request sockets */
731 saddr = &sk->sk_v6_rcv_saddr;
732 daddr = &sk->sk_v6_daddr;
733 } else {
734 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
735 saddr = &ip6h->saddr;
736 daddr = &ip6h->daddr;
737 }
738
739 hp = tcp_get_md5sig_pool();
740 if (!hp)
741 goto clear_hash_noput;
742 req = hp->md5_req;
743
744 if (crypto_ahash_init(req))
745 goto clear_hash;
746
747 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
748 goto clear_hash;
749 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
750 goto clear_hash;
751 if (tcp_md5_hash_key(hp, key))
752 goto clear_hash;
753 ahash_request_set_crypt(req, NULL, md5_hash, 0);
754 if (crypto_ahash_final(req))
755 goto clear_hash;
756
757 tcp_put_md5sig_pool();
758 return 0;
759
760clear_hash:
761 tcp_put_md5sig_pool();
762clear_hash_noput:
763 memset(md5_hash, 0, 16);
764 return 1;
765}
766
767#endif
768
769static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
770 const struct sk_buff *skb,
771 int dif, int sdif)
772{
773#ifdef CONFIG_TCP_MD5SIG
774 const __u8 *hash_location = NULL;
775 struct tcp_md5sig_key *hash_expected;
776 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
777 const struct tcphdr *th = tcp_hdr(skb);
778 int genhash, l3index;
779 u8 newhash[16];
780
781 /* sdif set, means packet ingressed via a device
782 * in an L3 domain and dif is set to the l3mdev
783 */
784 l3index = sdif ? dif : 0;
785
786 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index);
787 hash_location = tcp_parse_md5sig_option(th);
788
789 /* We've parsed the options - do we have a hash? */
790 if (!hash_expected && !hash_location)
791 return false;
792
793 if (hash_expected && !hash_location) {
794 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
795 return true;
796 }
797
798 if (!hash_expected && hash_location) {
799 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
800 return true;
801 }
802
803 /* check the signature */
804 genhash = tcp_v6_md5_hash_skb(newhash,
805 hash_expected,
806 NULL, skb);
807
808 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
809 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
810 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
811 genhash ? "failed" : "mismatch",
812 &ip6h->saddr, ntohs(th->source),
813 &ip6h->daddr, ntohs(th->dest), l3index);
814 return true;
815 }
816#endif
817 return false;
818}
819
820static void tcp_v6_init_req(struct request_sock *req,
821 const struct sock *sk_listener,
822 struct sk_buff *skb)
823{
824 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
825 struct inet_request_sock *ireq = inet_rsk(req);
826 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
827
828 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
829 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
830
831 /* So that link locals have meaning */
832 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
833 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
834 ireq->ir_iif = tcp_v6_iif(skb);
835
836 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
837 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
838 np->rxopt.bits.rxinfo ||
839 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
840 np->rxopt.bits.rxohlim || np->repflow)) {
841 refcount_inc(&skb->users);
842 ireq->pktopts = skb;
843 }
844}
845
846static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
847 struct sk_buff *skb,
848 struct flowi *fl,
849 struct request_sock *req)
850{
851 tcp_v6_init_req(req, sk, skb);
852
853 if (security_inet_conn_request(sk, skb, req))
854 return NULL;
855
856 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
857}
858
859struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
860 .family = AF_INET6,
861 .obj_size = sizeof(struct tcp6_request_sock),
862 .rtx_syn_ack = tcp_rtx_synack,
863 .send_ack = tcp_v6_reqsk_send_ack,
864 .destructor = tcp_v6_reqsk_destructor,
865 .send_reset = tcp_v6_send_reset,
866 .syn_ack_timeout = tcp_syn_ack_timeout,
867};
868
869const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
870 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
871 sizeof(struct ipv6hdr),
872#ifdef CONFIG_TCP_MD5SIG
873 .req_md5_lookup = tcp_v6_md5_lookup,
874 .calc_md5_hash = tcp_v6_md5_hash_skb,
875#endif
876#ifdef CONFIG_SYN_COOKIES
877 .cookie_init_seq = cookie_v6_init_sequence,
878#endif
879 .route_req = tcp_v6_route_req,
880 .init_seq = tcp_v6_init_seq,
881 .init_ts_off = tcp_v6_init_ts_off,
882 .send_synack = tcp_v6_send_synack,
883};
884
885static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
886 u32 ack, u32 win, u32 tsval, u32 tsecr,
887 int oif, struct tcp_md5sig_key *key, int rst,
888 u8 tclass, __be32 label, u32 priority)
889{
890 const struct tcphdr *th = tcp_hdr(skb);
891 struct tcphdr *t1;
892 struct sk_buff *buff;
893 struct flowi6 fl6;
894 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
895 struct sock *ctl_sk = net->ipv6.tcp_sk;
896 unsigned int tot_len = sizeof(struct tcphdr);
897 __be32 mrst = 0, *topt;
898 struct dst_entry *dst;
899 __u32 mark = 0;
900
901 if (tsecr)
902 tot_len += TCPOLEN_TSTAMP_ALIGNED;
903#ifdef CONFIG_TCP_MD5SIG
904 if (key)
905 tot_len += TCPOLEN_MD5SIG_ALIGNED;
906#endif
907
908#ifdef CONFIG_MPTCP
909 if (rst && !key) {
910 mrst = mptcp_reset_option(skb);
911
912 if (mrst)
913 tot_len += sizeof(__be32);
914 }
915#endif
916
917 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
918 GFP_ATOMIC);
919 if (!buff)
920 return;
921
922 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
923
924 t1 = skb_push(buff, tot_len);
925 skb_reset_transport_header(buff);
926
927 /* Swap the send and the receive. */
928 memset(t1, 0, sizeof(*t1));
929 t1->dest = th->source;
930 t1->source = th->dest;
931 t1->doff = tot_len / 4;
932 t1->seq = htonl(seq);
933 t1->ack_seq = htonl(ack);
934 t1->ack = !rst || !th->ack;
935 t1->rst = rst;
936 t1->window = htons(win);
937
938 topt = (__be32 *)(t1 + 1);
939
940 if (tsecr) {
941 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
942 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
943 *topt++ = htonl(tsval);
944 *topt++ = htonl(tsecr);
945 }
946
947 if (mrst)
948 *topt++ = mrst;
949
950#ifdef CONFIG_TCP_MD5SIG
951 if (key) {
952 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
953 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
954 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
955 &ipv6_hdr(skb)->saddr,
956 &ipv6_hdr(skb)->daddr, t1);
957 }
958#endif
959
960 memset(&fl6, 0, sizeof(fl6));
961 fl6.daddr = ipv6_hdr(skb)->saddr;
962 fl6.saddr = ipv6_hdr(skb)->daddr;
963 fl6.flowlabel = label;
964
965 buff->ip_summed = CHECKSUM_PARTIAL;
966 buff->csum = 0;
967
968 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
969
970 fl6.flowi6_proto = IPPROTO_TCP;
971 if (rt6_need_strict(&fl6.daddr) && !oif)
972 fl6.flowi6_oif = tcp_v6_iif(skb);
973 else {
974 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
975 oif = skb->skb_iif;
976
977 fl6.flowi6_oif = oif;
978 }
979
980 if (sk) {
981 if (sk->sk_state == TCP_TIME_WAIT) {
982 mark = inet_twsk(sk)->tw_mark;
983 /* autoflowlabel relies on buff->hash */
984 skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
985 PKT_HASH_TYPE_L4);
986 } else {
987 mark = sk->sk_mark;
988 }
989 buff->tstamp = tcp_transmit_time(sk);
990 }
991 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
992 fl6.fl6_dport = t1->dest;
993 fl6.fl6_sport = t1->source;
994 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
995 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
996
997 /* Pass a socket to ip6_dst_lookup either it is for RST
998 * Underlying function will use this to retrieve the network
999 * namespace
1000 */
1001 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
1002 if (!IS_ERR(dst)) {
1003 skb_dst_set(buff, dst);
1004 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
1005 tclass & ~INET_ECN_MASK, priority);
1006 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
1007 if (rst)
1008 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
1009 return;
1010 }
1011
1012 kfree_skb(buff);
1013}
1014
1015static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
1016{
1017 const struct tcphdr *th = tcp_hdr(skb);
1018 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1019 u32 seq = 0, ack_seq = 0;
1020 struct tcp_md5sig_key *key = NULL;
1021#ifdef CONFIG_TCP_MD5SIG
1022 const __u8 *hash_location = NULL;
1023 unsigned char newhash[16];
1024 int genhash;
1025 struct sock *sk1 = NULL;
1026#endif
1027 __be32 label = 0;
1028 u32 priority = 0;
1029 struct net *net;
1030 int oif = 0;
1031
1032 if (th->rst)
1033 return;
1034
1035 /* If sk not NULL, it means we did a successful lookup and incoming
1036 * route had to be correct. prequeue might have dropped our dst.
1037 */
1038 if (!sk && !ipv6_unicast_destination(skb))
1039 return;
1040
1041 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1042#ifdef CONFIG_TCP_MD5SIG
1043 rcu_read_lock();
1044 hash_location = tcp_parse_md5sig_option(th);
1045 if (sk && sk_fullsock(sk)) {
1046 int l3index;
1047
1048 /* sdif set, means packet ingressed via a device
1049 * in an L3 domain and inet_iif is set to it.
1050 */
1051 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1052 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1053 } else if (hash_location) {
1054 int dif = tcp_v6_iif_l3_slave(skb);
1055 int sdif = tcp_v6_sdif(skb);
1056 int l3index;
1057
1058 /*
1059 * active side is lost. Try to find listening socket through
1060 * source port, and then find md5 key through listening socket.
1061 * we are not loose security here:
1062 * Incoming packet is checked with md5 hash with finding key,
1063 * no RST generated if md5 hash doesn't match.
1064 */
1065 sk1 = inet6_lookup_listener(net,
1066 &tcp_hashinfo, NULL, 0,
1067 &ipv6h->saddr,
1068 th->source, &ipv6h->daddr,
1069 ntohs(th->source), dif, sdif);
1070 if (!sk1)
1071 goto out;
1072
1073 /* sdif set, means packet ingressed via a device
1074 * in an L3 domain and dif is set to it.
1075 */
1076 l3index = tcp_v6_sdif(skb) ? dif : 0;
1077
1078 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1079 if (!key)
1080 goto out;
1081
1082 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1083 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1084 goto out;
1085 }
1086#endif
1087
1088 if (th->ack)
1089 seq = ntohl(th->ack_seq);
1090 else
1091 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1092 (th->doff << 2);
1093
1094 if (sk) {
1095 oif = sk->sk_bound_dev_if;
1096 if (sk_fullsock(sk)) {
1097 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1098
1099 trace_tcp_send_reset(sk, skb);
1100 if (np->repflow)
1101 label = ip6_flowlabel(ipv6h);
1102 priority = sk->sk_priority;
1103 }
1104 if (sk->sk_state == TCP_TIME_WAIT) {
1105 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1106 priority = inet_twsk(sk)->tw_priority;
1107 }
1108 } else {
1109 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1110 label = ip6_flowlabel(ipv6h);
1111 }
1112
1113 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
1114 ipv6_get_dsfield(ipv6h), label, priority);
1115
1116#ifdef CONFIG_TCP_MD5SIG
1117out:
1118 rcu_read_unlock();
1119#endif
1120}
1121
1122static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1123 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1124 struct tcp_md5sig_key *key, u8 tclass,
1125 __be32 label, u32 priority)
1126{
1127 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1128 tclass, label, priority);
1129}
1130
1131static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1132{
1133 struct inet_timewait_sock *tw = inet_twsk(sk);
1134 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1135
1136 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1137 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1138 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1139 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1140 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
1141
1142 inet_twsk_put(tw);
1143}
1144
1145static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1146 struct request_sock *req)
1147{
1148 int l3index;
1149
1150 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1151
1152 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1153 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1154 */
1155 /* RFC 7323 2.3
1156 * The window field (SEG.WND) of every outgoing segment, with the
1157 * exception of <SYN> segments, MUST be right-shifted by
1158 * Rcv.Wind.Shift bits:
1159 */
1160 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1161 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1162 tcp_rsk(req)->rcv_nxt,
1163 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1164 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1165 req->ts_recent, sk->sk_bound_dev_if,
1166 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1167 ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority);
1168}
1169
1170
1171static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1172{
1173#ifdef CONFIG_SYN_COOKIES
1174 const struct tcphdr *th = tcp_hdr(skb);
1175
1176 if (!th->syn)
1177 sk = cookie_v6_check(sk, skb);
1178#endif
1179 return sk;
1180}
1181
1182u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1183 struct tcphdr *th, u32 *cookie)
1184{
1185 u16 mss = 0;
1186#ifdef CONFIG_SYN_COOKIES
1187 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1188 &tcp_request_sock_ipv6_ops, sk, th);
1189 if (mss) {
1190 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1191 tcp_synq_overflow(sk);
1192 }
1193#endif
1194 return mss;
1195}
1196
1197static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1198{
1199 if (skb->protocol == htons(ETH_P_IP))
1200 return tcp_v4_conn_request(sk, skb);
1201
1202 if (!ipv6_unicast_destination(skb))
1203 goto drop;
1204
1205 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1206 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1207 return 0;
1208 }
1209
1210 return tcp_conn_request(&tcp6_request_sock_ops,
1211 &tcp_request_sock_ipv6_ops, sk, skb);
1212
1213drop:
1214 tcp_listendrop(sk);
1215 return 0; /* don't send reset */
1216}
1217
1218static void tcp_v6_restore_cb(struct sk_buff *skb)
1219{
1220 /* We need to move header back to the beginning if xfrm6_policy_check()
1221 * and tcp_v6_fill_cb() are going to be called again.
1222 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1223 */
1224 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1225 sizeof(struct inet6_skb_parm));
1226}
1227
1228static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1229 struct request_sock *req,
1230 struct dst_entry *dst,
1231 struct request_sock *req_unhash,
1232 bool *own_req)
1233{
1234 struct inet_request_sock *ireq;
1235 struct ipv6_pinfo *newnp;
1236 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1237 struct ipv6_txoptions *opt;
1238 struct inet_sock *newinet;
1239 bool found_dup_sk = false;
1240 struct tcp_sock *newtp;
1241 struct sock *newsk;
1242#ifdef CONFIG_TCP_MD5SIG
1243 struct tcp_md5sig_key *key;
1244 int l3index;
1245#endif
1246 struct flowi6 fl6;
1247
1248 if (skb->protocol == htons(ETH_P_IP)) {
1249 /*
1250 * v6 mapped
1251 */
1252
1253 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1254 req_unhash, own_req);
1255
1256 if (!newsk)
1257 return NULL;
1258
1259 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1260
1261 newinet = inet_sk(newsk);
1262 newnp = tcp_inet6_sk(newsk);
1263 newtp = tcp_sk(newsk);
1264
1265 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1266
1267 newnp->saddr = newsk->sk_v6_rcv_saddr;
1268
1269 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1270 if (sk_is_mptcp(newsk))
1271 mptcpv6_handle_mapped(newsk, true);
1272 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1273#ifdef CONFIG_TCP_MD5SIG
1274 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1275#endif
1276
1277 newnp->ipv6_mc_list = NULL;
1278 newnp->ipv6_ac_list = NULL;
1279 newnp->ipv6_fl_list = NULL;
1280 newnp->pktoptions = NULL;
1281 newnp->opt = NULL;
1282 newnp->mcast_oif = inet_iif(skb);
1283 newnp->mcast_hops = ip_hdr(skb)->ttl;
1284 newnp->rcv_flowinfo = 0;
1285 if (np->repflow)
1286 newnp->flow_label = 0;
1287
1288 /*
1289 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1290 * here, tcp_create_openreq_child now does this for us, see the comment in
1291 * that function for the gory details. -acme
1292 */
1293
1294 /* It is tricky place. Until this moment IPv4 tcp
1295 worked with IPv6 icsk.icsk_af_ops.
1296 Sync it now.
1297 */
1298 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1299
1300 return newsk;
1301 }
1302
1303 ireq = inet_rsk(req);
1304
1305 if (sk_acceptq_is_full(sk))
1306 goto out_overflow;
1307
1308 if (!dst) {
1309 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1310 if (!dst)
1311 goto out;
1312 }
1313
1314 newsk = tcp_create_openreq_child(sk, req, skb);
1315 if (!newsk)
1316 goto out_nonewsk;
1317
1318 /*
1319 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1320 * count here, tcp_create_openreq_child now does this for us, see the
1321 * comment in that function for the gory details. -acme
1322 */
1323
1324 newsk->sk_gso_type = SKB_GSO_TCPV6;
1325 ip6_dst_store(newsk, dst, NULL, NULL);
1326 inet6_sk_rx_dst_set(newsk, skb);
1327
1328 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1329
1330 newtp = tcp_sk(newsk);
1331 newinet = inet_sk(newsk);
1332 newnp = tcp_inet6_sk(newsk);
1333
1334 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1335
1336 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1337 newnp->saddr = ireq->ir_v6_loc_addr;
1338 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1339 newsk->sk_bound_dev_if = ireq->ir_iif;
1340
1341 /* Now IPv6 options...
1342
1343 First: no IPv4 options.
1344 */
1345 newinet->inet_opt = NULL;
1346 newnp->ipv6_mc_list = NULL;
1347 newnp->ipv6_ac_list = NULL;
1348 newnp->ipv6_fl_list = NULL;
1349
1350 /* Clone RX bits */
1351 newnp->rxopt.all = np->rxopt.all;
1352
1353 newnp->pktoptions = NULL;
1354 newnp->opt = NULL;
1355 newnp->mcast_oif = tcp_v6_iif(skb);
1356 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1357 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1358 if (np->repflow)
1359 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1360
1361 /* Set ToS of the new socket based upon the value of incoming SYN.
1362 * ECT bits are set later in tcp_init_transfer().
1363 */
1364 if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)
1365 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1366
1367 /* Clone native IPv6 options from listening socket (if any)
1368
1369 Yes, keeping reference count would be much more clever,
1370 but we make one more one thing there: reattach optmem
1371 to newsk.
1372 */
1373 opt = ireq->ipv6_opt;
1374 if (!opt)
1375 opt = rcu_dereference(np->opt);
1376 if (opt) {
1377 opt = ipv6_dup_options(newsk, opt);
1378 RCU_INIT_POINTER(newnp->opt, opt);
1379 }
1380 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1381 if (opt)
1382 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1383 opt->opt_flen;
1384
1385 tcp_ca_openreq_child(newsk, dst);
1386
1387 tcp_sync_mss(newsk, dst_mtu(dst));
1388 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1389
1390 tcp_initialize_rcv_mss(newsk);
1391
1392 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1393 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1394
1395#ifdef CONFIG_TCP_MD5SIG
1396 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1397
1398 /* Copy over the MD5 key from the original socket */
1399 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1400 if (key) {
1401 /* We're using one, so create a matching key
1402 * on the newsk structure. If we fail to get
1403 * memory, then we end up not copying the key
1404 * across. Shucks.
1405 */
1406 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1407 AF_INET6, 128, l3index, key->key, key->keylen,
1408 sk_gfp_mask(sk, GFP_ATOMIC));
1409 }
1410#endif
1411
1412 if (__inet_inherit_port(sk, newsk) < 0) {
1413 inet_csk_prepare_forced_close(newsk);
1414 tcp_done(newsk);
1415 goto out;
1416 }
1417 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1418 &found_dup_sk);
1419 if (*own_req) {
1420 tcp_move_syn(newtp, req);
1421
1422 /* Clone pktoptions received with SYN, if we own the req */
1423 if (ireq->pktopts) {
1424 newnp->pktoptions = skb_clone(ireq->pktopts,
1425 sk_gfp_mask(sk, GFP_ATOMIC));
1426 consume_skb(ireq->pktopts);
1427 ireq->pktopts = NULL;
1428 if (newnp->pktoptions) {
1429 tcp_v6_restore_cb(newnp->pktoptions);
1430 skb_set_owner_r(newnp->pktoptions, newsk);
1431 }
1432 }
1433 } else {
1434 if (!req_unhash && found_dup_sk) {
1435 /* This code path should only be executed in the
1436 * syncookie case only
1437 */
1438 bh_unlock_sock(newsk);
1439 sock_put(newsk);
1440 newsk = NULL;
1441 }
1442 }
1443
1444 return newsk;
1445
1446out_overflow:
1447 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1448out_nonewsk:
1449 dst_release(dst);
1450out:
1451 tcp_listendrop(sk);
1452 return NULL;
1453}
1454
1455INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1456 u32));
1457/* The socket must have it's spinlock held when we get
1458 * here, unless it is a TCP_LISTEN socket.
1459 *
1460 * We have a potential double-lock case here, so even when
1461 * doing backlog processing we use the BH locking scheme.
1462 * This is because we cannot sleep with the original spinlock
1463 * held.
1464 */
1465static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1466{
1467 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1468 struct sk_buff *opt_skb = NULL;
1469 struct tcp_sock *tp;
1470
1471 /* Imagine: socket is IPv6. IPv4 packet arrives,
1472 goes to IPv4 receive handler and backlogged.
1473 From backlog it always goes here. Kerboom...
1474 Fortunately, tcp_rcv_established and rcv_established
1475 handle them correctly, but it is not case with
1476 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1477 */
1478
1479 if (skb->protocol == htons(ETH_P_IP))
1480 return tcp_v4_do_rcv(sk, skb);
1481
1482 /*
1483 * socket locking is here for SMP purposes as backlog rcv
1484 * is currently called with bh processing disabled.
1485 */
1486
1487 /* Do Stevens' IPV6_PKTOPTIONS.
1488
1489 Yes, guys, it is the only place in our code, where we
1490 may make it not affecting IPv4.
1491 The rest of code is protocol independent,
1492 and I do not like idea to uglify IPv4.
1493
1494 Actually, all the idea behind IPV6_PKTOPTIONS
1495 looks not very well thought. For now we latch
1496 options, received in the last packet, enqueued
1497 by tcp. Feel free to propose better solution.
1498 --ANK (980728)
1499 */
1500 if (np->rxopt.all)
1501 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1502
1503 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1504 struct dst_entry *dst = sk->sk_rx_dst;
1505
1506 sock_rps_save_rxhash(sk, skb);
1507 sk_mark_napi_id(sk, skb);
1508 if (dst) {
1509 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1510 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1511 dst, np->rx_dst_cookie) == NULL) {
1512 dst_release(dst);
1513 sk->sk_rx_dst = NULL;
1514 }
1515 }
1516
1517 tcp_rcv_established(sk, skb);
1518 if (opt_skb)
1519 goto ipv6_pktoptions;
1520 return 0;
1521 }
1522
1523 if (tcp_checksum_complete(skb))
1524 goto csum_err;
1525
1526 if (sk->sk_state == TCP_LISTEN) {
1527 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1528
1529 if (!nsk)
1530 goto discard;
1531
1532 if (nsk != sk) {
1533 if (tcp_child_process(sk, nsk, skb))
1534 goto reset;
1535 if (opt_skb)
1536 __kfree_skb(opt_skb);
1537 return 0;
1538 }
1539 } else
1540 sock_rps_save_rxhash(sk, skb);
1541
1542 if (tcp_rcv_state_process(sk, skb))
1543 goto reset;
1544 if (opt_skb)
1545 goto ipv6_pktoptions;
1546 return 0;
1547
1548reset:
1549 tcp_v6_send_reset(sk, skb);
1550discard:
1551 if (opt_skb)
1552 __kfree_skb(opt_skb);
1553 kfree_skb(skb);
1554 return 0;
1555csum_err:
1556 trace_tcp_bad_csum(skb);
1557 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1558 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1559 goto discard;
1560
1561
1562ipv6_pktoptions:
1563 /* Do you ask, what is it?
1564
1565 1. skb was enqueued by tcp.
1566 2. skb is added to tail of read queue, rather than out of order.
1567 3. socket is not in passive state.
1568 4. Finally, it really contains options, which user wants to receive.
1569 */
1570 tp = tcp_sk(sk);
1571 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1572 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1573 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1574 np->mcast_oif = tcp_v6_iif(opt_skb);
1575 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1576 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1577 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1578 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1579 if (np->repflow)
1580 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1581 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1582 skb_set_owner_r(opt_skb, sk);
1583 tcp_v6_restore_cb(opt_skb);
1584 opt_skb = xchg(&np->pktoptions, opt_skb);
1585 } else {
1586 __kfree_skb(opt_skb);
1587 opt_skb = xchg(&np->pktoptions, NULL);
1588 }
1589 }
1590
1591 kfree_skb(opt_skb);
1592 return 0;
1593}
1594
1595static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1596 const struct tcphdr *th)
1597{
1598 /* This is tricky: we move IP6CB at its correct location into
1599 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1600 * _decode_session6() uses IP6CB().
1601 * barrier() makes sure compiler won't play aliasing games.
1602 */
1603 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1604 sizeof(struct inet6_skb_parm));
1605 barrier();
1606
1607 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1608 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1609 skb->len - th->doff*4);
1610 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1611 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1612 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1613 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1614 TCP_SKB_CB(skb)->sacked = 0;
1615 TCP_SKB_CB(skb)->has_rxtstamp =
1616 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1617}
1618
1619INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1620{
1621 struct sk_buff *skb_to_free;
1622 int sdif = inet6_sdif(skb);
1623 int dif = inet6_iif(skb);
1624 const struct tcphdr *th;
1625 const struct ipv6hdr *hdr;
1626 bool refcounted;
1627 struct sock *sk;
1628 int ret;
1629 struct net *net = dev_net(skb->dev);
1630
1631 if (skb->pkt_type != PACKET_HOST)
1632 goto discard_it;
1633
1634 /*
1635 * Count it even if it's bad.
1636 */
1637 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1638
1639 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1640 goto discard_it;
1641
1642 th = (const struct tcphdr *)skb->data;
1643
1644 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1645 goto bad_packet;
1646 if (!pskb_may_pull(skb, th->doff*4))
1647 goto discard_it;
1648
1649 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1650 goto csum_error;
1651
1652 th = (const struct tcphdr *)skb->data;
1653 hdr = ipv6_hdr(skb);
1654
1655lookup:
1656 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1657 th->source, th->dest, inet6_iif(skb), sdif,
1658 &refcounted);
1659 if (!sk)
1660 goto no_tcp_socket;
1661
1662process:
1663 if (sk->sk_state == TCP_TIME_WAIT)
1664 goto do_time_wait;
1665
1666 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1667 struct request_sock *req = inet_reqsk(sk);
1668 bool req_stolen = false;
1669 struct sock *nsk;
1670
1671 sk = req->rsk_listener;
1672 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) {
1673 sk_drops_add(sk, skb);
1674 reqsk_put(req);
1675 goto discard_it;
1676 }
1677 if (tcp_checksum_complete(skb)) {
1678 reqsk_put(req);
1679 goto csum_error;
1680 }
1681 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1682 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1683 if (!nsk) {
1684 inet_csk_reqsk_queue_drop_and_put(sk, req);
1685 goto lookup;
1686 }
1687 sk = nsk;
1688 /* reuseport_migrate_sock() has already held one sk_refcnt
1689 * before returning.
1690 */
1691 } else {
1692 sock_hold(sk);
1693 }
1694 refcounted = true;
1695 nsk = NULL;
1696 if (!tcp_filter(sk, skb)) {
1697 th = (const struct tcphdr *)skb->data;
1698 hdr = ipv6_hdr(skb);
1699 tcp_v6_fill_cb(skb, hdr, th);
1700 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1701 }
1702 if (!nsk) {
1703 reqsk_put(req);
1704 if (req_stolen) {
1705 /* Another cpu got exclusive access to req
1706 * and created a full blown socket.
1707 * Try to feed this packet to this socket
1708 * instead of discarding it.
1709 */
1710 tcp_v6_restore_cb(skb);
1711 sock_put(sk);
1712 goto lookup;
1713 }
1714 goto discard_and_relse;
1715 }
1716 if (nsk == sk) {
1717 reqsk_put(req);
1718 tcp_v6_restore_cb(skb);
1719 } else if (tcp_child_process(sk, nsk, skb)) {
1720 tcp_v6_send_reset(nsk, skb);
1721 goto discard_and_relse;
1722 } else {
1723 sock_put(sk);
1724 return 0;
1725 }
1726 }
1727 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
1728 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1729 goto discard_and_relse;
1730 }
1731
1732 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1733 goto discard_and_relse;
1734
1735 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
1736 goto discard_and_relse;
1737
1738 if (tcp_filter(sk, skb))
1739 goto discard_and_relse;
1740 th = (const struct tcphdr *)skb->data;
1741 hdr = ipv6_hdr(skb);
1742 tcp_v6_fill_cb(skb, hdr, th);
1743
1744 skb->dev = NULL;
1745
1746 if (sk->sk_state == TCP_LISTEN) {
1747 ret = tcp_v6_do_rcv(sk, skb);
1748 goto put_and_return;
1749 }
1750
1751 sk_incoming_cpu_update(sk);
1752
1753 bh_lock_sock_nested(sk);
1754 tcp_segs_in(tcp_sk(sk), skb);
1755 ret = 0;
1756 if (!sock_owned_by_user(sk)) {
1757 skb_to_free = sk->sk_rx_skb_cache;
1758 sk->sk_rx_skb_cache = NULL;
1759 ret = tcp_v6_do_rcv(sk, skb);
1760 } else {
1761 if (tcp_add_backlog(sk, skb))
1762 goto discard_and_relse;
1763 skb_to_free = NULL;
1764 }
1765 bh_unlock_sock(sk);
1766 if (skb_to_free)
1767 __kfree_skb(skb_to_free);
1768put_and_return:
1769 if (refcounted)
1770 sock_put(sk);
1771 return ret ? -1 : 0;
1772
1773no_tcp_socket:
1774 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1775 goto discard_it;
1776
1777 tcp_v6_fill_cb(skb, hdr, th);
1778
1779 if (tcp_checksum_complete(skb)) {
1780csum_error:
1781 trace_tcp_bad_csum(skb);
1782 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1783bad_packet:
1784 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1785 } else {
1786 tcp_v6_send_reset(NULL, skb);
1787 }
1788
1789discard_it:
1790 kfree_skb(skb);
1791 return 0;
1792
1793discard_and_relse:
1794 sk_drops_add(sk, skb);
1795 if (refcounted)
1796 sock_put(sk);
1797 goto discard_it;
1798
1799do_time_wait:
1800 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1801 inet_twsk_put(inet_twsk(sk));
1802 goto discard_it;
1803 }
1804
1805 tcp_v6_fill_cb(skb, hdr, th);
1806
1807 if (tcp_checksum_complete(skb)) {
1808 inet_twsk_put(inet_twsk(sk));
1809 goto csum_error;
1810 }
1811
1812 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1813 case TCP_TW_SYN:
1814 {
1815 struct sock *sk2;
1816
1817 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1818 skb, __tcp_hdrlen(th),
1819 &ipv6_hdr(skb)->saddr, th->source,
1820 &ipv6_hdr(skb)->daddr,
1821 ntohs(th->dest),
1822 tcp_v6_iif_l3_slave(skb),
1823 sdif);
1824 if (sk2) {
1825 struct inet_timewait_sock *tw = inet_twsk(sk);
1826 inet_twsk_deschedule_put(tw);
1827 sk = sk2;
1828 tcp_v6_restore_cb(skb);
1829 refcounted = false;
1830 goto process;
1831 }
1832 }
1833 /* to ACK */
1834 fallthrough;
1835 case TCP_TW_ACK:
1836 tcp_v6_timewait_ack(sk, skb);
1837 break;
1838 case TCP_TW_RST:
1839 tcp_v6_send_reset(sk, skb);
1840 inet_twsk_deschedule_put(inet_twsk(sk));
1841 goto discard_it;
1842 case TCP_TW_SUCCESS:
1843 ;
1844 }
1845 goto discard_it;
1846}
1847
1848INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
1849{
1850 const struct ipv6hdr *hdr;
1851 const struct tcphdr *th;
1852 struct sock *sk;
1853
1854 if (skb->pkt_type != PACKET_HOST)
1855 return;
1856
1857 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1858 return;
1859
1860 hdr = ipv6_hdr(skb);
1861 th = tcp_hdr(skb);
1862
1863 if (th->doff < sizeof(struct tcphdr) / 4)
1864 return;
1865
1866 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1867 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1868 &hdr->saddr, th->source,
1869 &hdr->daddr, ntohs(th->dest),
1870 inet6_iif(skb), inet6_sdif(skb));
1871 if (sk) {
1872 skb->sk = sk;
1873 skb->destructor = sock_edemux;
1874 if (sk_fullsock(sk)) {
1875 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1876
1877 if (dst)
1878 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
1879 if (dst &&
1880 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1881 skb_dst_set_noref(skb, dst);
1882 }
1883 }
1884}
1885
1886static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1887 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1888 .twsk_unique = tcp_twsk_unique,
1889 .twsk_destructor = tcp_twsk_destructor,
1890};
1891
1892INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1893{
1894 struct ipv6_pinfo *np = inet6_sk(sk);
1895
1896 __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
1897}
1898
1899const struct inet_connection_sock_af_ops ipv6_specific = {
1900 .queue_xmit = inet6_csk_xmit,
1901 .send_check = tcp_v6_send_check,
1902 .rebuild_header = inet6_sk_rebuild_header,
1903 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1904 .conn_request = tcp_v6_conn_request,
1905 .syn_recv_sock = tcp_v6_syn_recv_sock,
1906 .net_header_len = sizeof(struct ipv6hdr),
1907 .net_frag_header_len = sizeof(struct frag_hdr),
1908 .setsockopt = ipv6_setsockopt,
1909 .getsockopt = ipv6_getsockopt,
1910 .addr2sockaddr = inet6_csk_addr2sockaddr,
1911 .sockaddr_len = sizeof(struct sockaddr_in6),
1912 .mtu_reduced = tcp_v6_mtu_reduced,
1913};
1914
1915#ifdef CONFIG_TCP_MD5SIG
1916static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1917 .md5_lookup = tcp_v6_md5_lookup,
1918 .calc_md5_hash = tcp_v6_md5_hash_skb,
1919 .md5_parse = tcp_v6_parse_md5_keys,
1920};
1921#endif
1922
1923/*
1924 * TCP over IPv4 via INET6 API
1925 */
1926static const struct inet_connection_sock_af_ops ipv6_mapped = {
1927 .queue_xmit = ip_queue_xmit,
1928 .send_check = tcp_v4_send_check,
1929 .rebuild_header = inet_sk_rebuild_header,
1930 .sk_rx_dst_set = inet_sk_rx_dst_set,
1931 .conn_request = tcp_v6_conn_request,
1932 .syn_recv_sock = tcp_v6_syn_recv_sock,
1933 .net_header_len = sizeof(struct iphdr),
1934 .setsockopt = ipv6_setsockopt,
1935 .getsockopt = ipv6_getsockopt,
1936 .addr2sockaddr = inet6_csk_addr2sockaddr,
1937 .sockaddr_len = sizeof(struct sockaddr_in6),
1938 .mtu_reduced = tcp_v4_mtu_reduced,
1939};
1940
1941#ifdef CONFIG_TCP_MD5SIG
1942static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1943 .md5_lookup = tcp_v4_md5_lookup,
1944 .calc_md5_hash = tcp_v4_md5_hash_skb,
1945 .md5_parse = tcp_v6_parse_md5_keys,
1946};
1947#endif
1948
1949/* NOTE: A lot of things set to zero explicitly by call to
1950 * sk_alloc() so need not be done here.
1951 */
1952static int tcp_v6_init_sock(struct sock *sk)
1953{
1954 struct inet_connection_sock *icsk = inet_csk(sk);
1955
1956 tcp_init_sock(sk);
1957
1958 icsk->icsk_af_ops = &ipv6_specific;
1959
1960#ifdef CONFIG_TCP_MD5SIG
1961 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1962#endif
1963
1964 return 0;
1965}
1966
1967static void tcp_v6_destroy_sock(struct sock *sk)
1968{
1969 tcp_v4_destroy_sock(sk);
1970 inet6_destroy_sock(sk);
1971}
1972
1973#ifdef CONFIG_PROC_FS
1974/* Proc filesystem TCPv6 sock list dumping. */
1975static void get_openreq6(struct seq_file *seq,
1976 const struct request_sock *req, int i)
1977{
1978 long ttd = req->rsk_timer.expires - jiffies;
1979 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1980 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1981
1982 if (ttd < 0)
1983 ttd = 0;
1984
1985 seq_printf(seq,
1986 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1987 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1988 i,
1989 src->s6_addr32[0], src->s6_addr32[1],
1990 src->s6_addr32[2], src->s6_addr32[3],
1991 inet_rsk(req)->ir_num,
1992 dest->s6_addr32[0], dest->s6_addr32[1],
1993 dest->s6_addr32[2], dest->s6_addr32[3],
1994 ntohs(inet_rsk(req)->ir_rmt_port),
1995 TCP_SYN_RECV,
1996 0, 0, /* could print option size, but that is af dependent. */
1997 1, /* timers active (only the expire timer) */
1998 jiffies_to_clock_t(ttd),
1999 req->num_timeout,
2000 from_kuid_munged(seq_user_ns(seq),
2001 sock_i_uid(req->rsk_listener)),
2002 0, /* non standard timer */
2003 0, /* open_requests have no inode */
2004 0, req);
2005}
2006
2007static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2008{
2009 const struct in6_addr *dest, *src;
2010 __u16 destp, srcp;
2011 int timer_active;
2012 unsigned long timer_expires;
2013 const struct inet_sock *inet = inet_sk(sp);
2014 const struct tcp_sock *tp = tcp_sk(sp);
2015 const struct inet_connection_sock *icsk = inet_csk(sp);
2016 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
2017 int rx_queue;
2018 int state;
2019
2020 dest = &sp->sk_v6_daddr;
2021 src = &sp->sk_v6_rcv_saddr;
2022 destp = ntohs(inet->inet_dport);
2023 srcp = ntohs(inet->inet_sport);
2024
2025 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2026 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2027 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2028 timer_active = 1;
2029 timer_expires = icsk->icsk_timeout;
2030 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2031 timer_active = 4;
2032 timer_expires = icsk->icsk_timeout;
2033 } else if (timer_pending(&sp->sk_timer)) {
2034 timer_active = 2;
2035 timer_expires = sp->sk_timer.expires;
2036 } else {
2037 timer_active = 0;
2038 timer_expires = jiffies;
2039 }
2040
2041 state = inet_sk_state_load(sp);
2042 if (state == TCP_LISTEN)
2043 rx_queue = READ_ONCE(sp->sk_ack_backlog);
2044 else
2045 /* Because we don't lock the socket,
2046 * we might find a transient negative value.
2047 */
2048 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2049 READ_ONCE(tp->copied_seq), 0);
2050
2051 seq_printf(seq,
2052 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2053 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2054 i,
2055 src->s6_addr32[0], src->s6_addr32[1],
2056 src->s6_addr32[2], src->s6_addr32[3], srcp,
2057 dest->s6_addr32[0], dest->s6_addr32[1],
2058 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2059 state,
2060 READ_ONCE(tp->write_seq) - tp->snd_una,
2061 rx_queue,
2062 timer_active,
2063 jiffies_delta_to_clock_t(timer_expires - jiffies),
2064 icsk->icsk_retransmits,
2065 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2066 icsk->icsk_probes_out,
2067 sock_i_ino(sp),
2068 refcount_read(&sp->sk_refcnt), sp,
2069 jiffies_to_clock_t(icsk->icsk_rto),
2070 jiffies_to_clock_t(icsk->icsk_ack.ato),
2071 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2072 tp->snd_cwnd,
2073 state == TCP_LISTEN ?
2074 fastopenq->max_qlen :
2075 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2076 );
2077}
2078
2079static void get_timewait6_sock(struct seq_file *seq,
2080 struct inet_timewait_sock *tw, int i)
2081{
2082 long delta = tw->tw_timer.expires - jiffies;
2083 const struct in6_addr *dest, *src;
2084 __u16 destp, srcp;
2085
2086 dest = &tw->tw_v6_daddr;
2087 src = &tw->tw_v6_rcv_saddr;
2088 destp = ntohs(tw->tw_dport);
2089 srcp = ntohs(tw->tw_sport);
2090
2091 seq_printf(seq,
2092 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2093 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2094 i,
2095 src->s6_addr32[0], src->s6_addr32[1],
2096 src->s6_addr32[2], src->s6_addr32[3], srcp,
2097 dest->s6_addr32[0], dest->s6_addr32[1],
2098 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2099 tw->tw_substate, 0, 0,
2100 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2101 refcount_read(&tw->tw_refcnt), tw);
2102}
2103
2104static int tcp6_seq_show(struct seq_file *seq, void *v)
2105{
2106 struct tcp_iter_state *st;
2107 struct sock *sk = v;
2108
2109 if (v == SEQ_START_TOKEN) {
2110 seq_puts(seq,
2111 " sl "
2112 "local_address "
2113 "remote_address "
2114 "st tx_queue rx_queue tr tm->when retrnsmt"
2115 " uid timeout inode\n");
2116 goto out;
2117 }
2118 st = seq->private;
2119
2120 if (sk->sk_state == TCP_TIME_WAIT)
2121 get_timewait6_sock(seq, v, st->num);
2122 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2123 get_openreq6(seq, v, st->num);
2124 else
2125 get_tcp6_sock(seq, v, st->num);
2126out:
2127 return 0;
2128}
2129
2130static const struct seq_operations tcp6_seq_ops = {
2131 .show = tcp6_seq_show,
2132 .start = tcp_seq_start,
2133 .next = tcp_seq_next,
2134 .stop = tcp_seq_stop,
2135};
2136
2137static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2138 .family = AF_INET6,
2139};
2140
2141int __net_init tcp6_proc_init(struct net *net)
2142{
2143 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2144 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2145 return -ENOMEM;
2146 return 0;
2147}
2148
2149void tcp6_proc_exit(struct net *net)
2150{
2151 remove_proc_entry("tcp6", net->proc_net);
2152}
2153#endif
2154
2155struct proto tcpv6_prot = {
2156 .name = "TCPv6",
2157 .owner = THIS_MODULE,
2158 .close = tcp_close,
2159 .pre_connect = tcp_v6_pre_connect,
2160 .connect = tcp_v6_connect,
2161 .disconnect = tcp_disconnect,
2162 .accept = inet_csk_accept,
2163 .ioctl = tcp_ioctl,
2164 .init = tcp_v6_init_sock,
2165 .destroy = tcp_v6_destroy_sock,
2166 .shutdown = tcp_shutdown,
2167 .setsockopt = tcp_setsockopt,
2168 .getsockopt = tcp_getsockopt,
2169 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
2170 .keepalive = tcp_set_keepalive,
2171 .recvmsg = tcp_recvmsg,
2172 .sendmsg = tcp_sendmsg,
2173 .sendpage = tcp_sendpage,
2174 .backlog_rcv = tcp_v6_do_rcv,
2175 .release_cb = tcp_release_cb,
2176 .hash = inet6_hash,
2177 .unhash = inet_unhash,
2178 .get_port = inet_csk_get_port,
2179#ifdef CONFIG_BPF_SYSCALL
2180 .psock_update_sk_prot = tcp_bpf_update_proto,
2181#endif
2182 .enter_memory_pressure = tcp_enter_memory_pressure,
2183 .leave_memory_pressure = tcp_leave_memory_pressure,
2184 .stream_memory_free = tcp_stream_memory_free,
2185 .sockets_allocated = &tcp_sockets_allocated,
2186 .memory_allocated = &tcp_memory_allocated,
2187 .memory_pressure = &tcp_memory_pressure,
2188 .orphan_count = &tcp_orphan_count,
2189 .sysctl_mem = sysctl_tcp_mem,
2190 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2191 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2192 .max_header = MAX_TCP_HEADER,
2193 .obj_size = sizeof(struct tcp6_sock),
2194 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2195 .twsk_prot = &tcp6_timewait_sock_ops,
2196 .rsk_prot = &tcp6_request_sock_ops,
2197 .h.hashinfo = &tcp_hashinfo,
2198 .no_autobind = true,
2199 .diag_destroy = tcp_abort,
2200};
2201EXPORT_SYMBOL_GPL(tcpv6_prot);
2202
2203/* thinking of making this const? Don't.
2204 * early_demux can change based on sysctl.
2205 */
2206static struct inet6_protocol tcpv6_protocol = {
2207 .early_demux = tcp_v6_early_demux,
2208 .early_demux_handler = tcp_v6_early_demux,
2209 .handler = tcp_v6_rcv,
2210 .err_handler = tcp_v6_err,
2211 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2212};
2213
2214static struct inet_protosw tcpv6_protosw = {
2215 .type = SOCK_STREAM,
2216 .protocol = IPPROTO_TCP,
2217 .prot = &tcpv6_prot,
2218 .ops = &inet6_stream_ops,
2219 .flags = INET_PROTOSW_PERMANENT |
2220 INET_PROTOSW_ICSK,
2221};
2222
2223static int __net_init tcpv6_net_init(struct net *net)
2224{
2225 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2226 SOCK_RAW, IPPROTO_TCP, net);
2227}
2228
2229static void __net_exit tcpv6_net_exit(struct net *net)
2230{
2231 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2232}
2233
2234static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2235{
2236 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2237}
2238
2239static struct pernet_operations tcpv6_net_ops = {
2240 .init = tcpv6_net_init,
2241 .exit = tcpv6_net_exit,
2242 .exit_batch = tcpv6_net_exit_batch,
2243};
2244
2245int __init tcpv6_init(void)
2246{
2247 int ret;
2248
2249 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2250 if (ret)
2251 goto out;
2252
2253 /* register inet6 protocol */
2254 ret = inet6_register_protosw(&tcpv6_protosw);
2255 if (ret)
2256 goto out_tcpv6_protocol;
2257
2258 ret = register_pernet_subsys(&tcpv6_net_ops);
2259 if (ret)
2260 goto out_tcpv6_protosw;
2261
2262 ret = mptcpv6_init();
2263 if (ret)
2264 goto out_tcpv6_pernet_subsys;
2265
2266out:
2267 return ret;
2268
2269out_tcpv6_pernet_subsys:
2270 unregister_pernet_subsys(&tcpv6_net_ops);
2271out_tcpv6_protosw:
2272 inet6_unregister_protosw(&tcpv6_protosw);
2273out_tcpv6_protocol:
2274 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2275 goto out;
2276}
2277
2278void tcpv6_exit(void)
2279{
2280 unregister_pernet_subsys(&tcpv6_net_ops);
2281 inet6_unregister_protosw(&tcpv6_protosw);
2282 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2283}