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/hotdata.h>
62 #include <net/busy_poll.h>
63 #include <net/rstreason.h>
64
65 #include <linux/proc_fs.h>
66 #include <linux/seq_file.h>
67
68 #include <crypto/hash.h>
69 #include <linux/scatterlist.h>
70
71 #include <trace/events/tcp.h>
72
73 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb,
74 enum sk_rst_reason reason);
75 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
76 struct request_sock *req);
77
78 INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79
80 static const struct inet_connection_sock_af_ops ipv6_mapped;
81 const struct inet_connection_sock_af_ops ipv6_specific;
82 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
83 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
84 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
85 #endif
86
87 /* Helper returning the inet6 address from a given tcp socket.
88 * It can be used in TCP stack instead of inet6_sk(sk).
89 * This avoids a dereference and allow compiler optimizations.
90 * It is a specialized version of inet6_sk_generic().
91 */
92 #define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \
93 struct tcp6_sock, tcp)->inet6)
94
inet6_sk_rx_dst_set(struct sock * sk,const struct sk_buff * skb)95 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
96 {
97 struct dst_entry *dst = skb_dst(skb);
98
99 if (dst && dst_hold_safe(dst)) {
100 rcu_assign_pointer(sk->sk_rx_dst, dst);
101 sk->sk_rx_dst_ifindex = skb->skb_iif;
102 sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
103 }
104 }
105
tcp_v6_init_seq(const struct sk_buff * skb)106 static u32 tcp_v6_init_seq(const struct sk_buff *skb)
107 {
108 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
109 ipv6_hdr(skb)->saddr.s6_addr32,
110 tcp_hdr(skb)->dest,
111 tcp_hdr(skb)->source);
112 }
113
tcp_v6_init_ts_off(const struct net * net,const struct sk_buff * skb)114 static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
115 {
116 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
117 ipv6_hdr(skb)->saddr.s6_addr32);
118 }
119
tcp_v6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)120 static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
121 int addr_len)
122 {
123 /* This check is replicated from tcp_v6_connect() and intended to
124 * prevent BPF program called below from accessing bytes that are out
125 * of the bound specified by user in addr_len.
126 */
127 if (addr_len < SIN6_LEN_RFC2133)
128 return -EINVAL;
129
130 sock_owned_by_me(sk);
131
132 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len);
133 }
134
tcp_v6_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)135 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
136 int addr_len)
137 {
138 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
139 struct inet_connection_sock *icsk = inet_csk(sk);
140 struct in6_addr *saddr = NULL, *final_p, final;
141 struct inet_timewait_death_row *tcp_death_row;
142 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
143 struct inet_sock *inet = inet_sk(sk);
144 struct tcp_sock *tp = tcp_sk(sk);
145 struct net *net = sock_net(sk);
146 struct ipv6_txoptions *opt;
147 struct dst_entry *dst;
148 struct flowi6 fl6;
149 int addr_type;
150 int err;
151
152 if (addr_len < SIN6_LEN_RFC2133)
153 return -EINVAL;
154
155 if (usin->sin6_family != AF_INET6)
156 return -EAFNOSUPPORT;
157
158 memset(&fl6, 0, sizeof(fl6));
159
160 if (inet6_test_bit(SNDFLOW, sk)) {
161 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
162 IP6_ECN_flow_init(fl6.flowlabel);
163 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
164 struct ip6_flowlabel *flowlabel;
165 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
166 if (IS_ERR(flowlabel))
167 return -EINVAL;
168 fl6_sock_release(flowlabel);
169 }
170 }
171
172 /*
173 * connect() to INADDR_ANY means loopback (BSD'ism).
174 */
175
176 if (ipv6_addr_any(&usin->sin6_addr)) {
177 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
178 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
179 &usin->sin6_addr);
180 else
181 usin->sin6_addr = in6addr_loopback;
182 }
183
184 addr_type = ipv6_addr_type(&usin->sin6_addr);
185
186 if (addr_type & IPV6_ADDR_MULTICAST)
187 return -ENETUNREACH;
188
189 if (addr_type&IPV6_ADDR_LINKLOCAL) {
190 if (addr_len >= sizeof(struct sockaddr_in6) &&
191 usin->sin6_scope_id) {
192 /* If interface is set while binding, indices
193 * must coincide.
194 */
195 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
196 return -EINVAL;
197
198 sk->sk_bound_dev_if = usin->sin6_scope_id;
199 }
200
201 /* Connect to link-local address requires an interface */
202 if (!sk->sk_bound_dev_if)
203 return -EINVAL;
204 }
205
206 if (tp->rx_opt.ts_recent_stamp &&
207 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
208 tp->rx_opt.ts_recent = 0;
209 tp->rx_opt.ts_recent_stamp = 0;
210 WRITE_ONCE(tp->write_seq, 0);
211 }
212
213 sk->sk_v6_daddr = usin->sin6_addr;
214 np->flow_label = fl6.flowlabel;
215
216 /*
217 * TCP over IPv4
218 */
219
220 if (addr_type & IPV6_ADDR_MAPPED) {
221 u32 exthdrlen = icsk->icsk_ext_hdr_len;
222 struct sockaddr_in sin;
223
224 if (ipv6_only_sock(sk))
225 return -ENETUNREACH;
226
227 sin.sin_family = AF_INET;
228 sin.sin_port = usin->sin6_port;
229 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
230
231 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
232 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
233 if (sk_is_mptcp(sk))
234 mptcpv6_handle_mapped(sk, true);
235 sk->sk_backlog_rcv = tcp_v4_do_rcv;
236 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
237 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
238 #endif
239
240 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
241
242 if (err) {
243 icsk->icsk_ext_hdr_len = exthdrlen;
244 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
245 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
246 if (sk_is_mptcp(sk))
247 mptcpv6_handle_mapped(sk, false);
248 sk->sk_backlog_rcv = tcp_v6_do_rcv;
249 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
250 tp->af_specific = &tcp_sock_ipv6_specific;
251 #endif
252 goto failure;
253 }
254 np->saddr = sk->sk_v6_rcv_saddr;
255
256 return err;
257 }
258
259 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
260 saddr = &sk->sk_v6_rcv_saddr;
261
262 fl6.flowi6_proto = IPPROTO_TCP;
263 fl6.daddr = sk->sk_v6_daddr;
264 fl6.saddr = saddr ? *saddr : np->saddr;
265 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
266 fl6.flowi6_oif = sk->sk_bound_dev_if;
267 fl6.flowi6_mark = sk->sk_mark;
268 fl6.fl6_dport = usin->sin6_port;
269 fl6.fl6_sport = inet->inet_sport;
270 fl6.flowi6_uid = sk->sk_uid;
271
272 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
273 final_p = fl6_update_dst(&fl6, opt, &final);
274
275 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
276
277 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
278 if (IS_ERR(dst)) {
279 err = PTR_ERR(dst);
280 goto failure;
281 }
282
283 tp->tcp_usec_ts = dst_tcp_usec_ts(dst);
284 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
285
286 if (!saddr) {
287 saddr = &fl6.saddr;
288
289 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
290 if (err)
291 goto failure;
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(net, np->saddr.s6_addr32,
325 sk->sk_v6_daddr.s6_addr32);
326 }
327
328 if (tcp_fastopen_defer_connect(sk, &err))
329 return err;
330 if (err)
331 goto late_failure;
332
333 err = tcp_connect(sk);
334 if (err)
335 goto late_failure;
336
337 return 0;
338
339 late_failure:
340 tcp_set_state(sk, TCP_CLOSE);
341 inet_bhash2_reset_saddr(sk);
342 failure:
343 inet->inet_dport = 0;
344 sk->sk_route_caps = 0;
345 return err;
346 }
347
tcp_v6_mtu_reduced(struct sock * sk)348 static 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
tcp_v6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)374 static 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, net->ipv4.tcp_death_row.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 /* To increase the counter of ignored icmps for TCP-AO */
401 tcp_ao_ignore_icmp(sk, AF_INET6, type, code);
402 inet_twsk_put(inet_twsk(sk));
403 return 0;
404 }
405 seq = ntohl(th->seq);
406 fatal = icmpv6_err_convert(type, code, &err);
407 if (sk->sk_state == TCP_NEW_SYN_RECV) {
408 tcp_req_err(sk, seq, fatal);
409 return 0;
410 }
411
412 if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) {
413 sock_put(sk);
414 return 0;
415 }
416
417 bh_lock_sock(sk);
418 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
419 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
420
421 if (sk->sk_state == TCP_CLOSE)
422 goto out;
423
424 if (static_branch_unlikely(&ip6_min_hopcount)) {
425 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
426 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
427 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
428 goto out;
429 }
430 }
431
432 tp = tcp_sk(sk);
433 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
434 fastopen = rcu_dereference(tp->fastopen_rsk);
435 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
436 if (sk->sk_state != TCP_LISTEN &&
437 !between(seq, snd_una, tp->snd_nxt)) {
438 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
439 goto out;
440 }
441
442 np = tcp_inet6_sk(sk);
443
444 if (type == NDISC_REDIRECT) {
445 if (!sock_owned_by_user(sk)) {
446 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
447
448 if (dst)
449 dst->ops->redirect(dst, sk, skb);
450 }
451 goto out;
452 }
453
454 if (type == ICMPV6_PKT_TOOBIG) {
455 u32 mtu = ntohl(info);
456
457 /* We are not interested in TCP_LISTEN and open_requests
458 * (SYN-ACKs send out by Linux are always <576bytes so
459 * they should go through unfragmented).
460 */
461 if (sk->sk_state == TCP_LISTEN)
462 goto out;
463
464 if (!ip6_sk_accept_pmtu(sk))
465 goto out;
466
467 if (mtu < IPV6_MIN_MTU)
468 goto out;
469
470 WRITE_ONCE(tp->mtu_info, mtu);
471
472 if (!sock_owned_by_user(sk))
473 tcp_v6_mtu_reduced(sk);
474 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
475 &sk->sk_tsq_flags))
476 sock_hold(sk);
477 goto out;
478 }
479
480
481 /* Might be for an request_sock */
482 switch (sk->sk_state) {
483 case TCP_SYN_SENT:
484 case TCP_SYN_RECV:
485 /* Only in fast or simultaneous open. If a fast open socket is
486 * already accepted it is treated as a connected one below.
487 */
488 if (fastopen && !fastopen->sk)
489 break;
490
491 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
492
493 if (!sock_owned_by_user(sk))
494 tcp_done_with_error(sk, err);
495 else
496 WRITE_ONCE(sk->sk_err_soft, err);
497 goto out;
498 case TCP_LISTEN:
499 break;
500 default:
501 /* check if this ICMP message allows revert of backoff.
502 * (see RFC 6069)
503 */
504 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
505 code == ICMPV6_NOROUTE)
506 tcp_ld_RTO_revert(sk, seq);
507 }
508
509 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
510 WRITE_ONCE(sk->sk_err, err);
511 sk_error_report(sk);
512 } else {
513 WRITE_ONCE(sk->sk_err_soft, err);
514 }
515 out:
516 bh_unlock_sock(sk);
517 sock_put(sk);
518 return 0;
519 }
520
521
tcp_v6_send_synack(const struct sock * sk,struct dst_entry * dst,struct flowi * fl,struct request_sock * req,struct tcp_fastopen_cookie * foc,enum tcp_synack_type synack_type,struct sk_buff * syn_skb)522 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
523 struct flowi *fl,
524 struct request_sock *req,
525 struct tcp_fastopen_cookie *foc,
526 enum tcp_synack_type synack_type,
527 struct sk_buff *syn_skb)
528 {
529 struct inet_request_sock *ireq = inet_rsk(req);
530 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
531 struct ipv6_txoptions *opt;
532 struct flowi6 *fl6 = &fl->u.ip6;
533 struct sk_buff *skb;
534 int err = -ENOMEM;
535 u8 tclass;
536
537 /* First, grab a route. */
538 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
539 IPPROTO_TCP)) == NULL)
540 goto done;
541
542 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
543
544 if (skb) {
545 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
546 &ireq->ir_v6_rmt_addr);
547
548 fl6->daddr = ireq->ir_v6_rmt_addr;
549 if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts)
550 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
551
552 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
553 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
554 (np->tclass & INET_ECN_MASK) :
555 np->tclass;
556
557 if (!INET_ECN_is_capable(tclass) &&
558 tcp_bpf_ca_needs_ecn((struct sock *)req))
559 tclass |= INET_ECN_ECT_0;
560
561 rcu_read_lock();
562 opt = ireq->ipv6_opt;
563 if (!opt)
564 opt = rcu_dereference(np->opt);
565 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
566 opt, tclass, READ_ONCE(sk->sk_priority));
567 rcu_read_unlock();
568 err = net_xmit_eval(err);
569 }
570
571 done:
572 return err;
573 }
574
575
tcp_v6_reqsk_destructor(struct request_sock * req)576 static void tcp_v6_reqsk_destructor(struct request_sock *req)
577 {
578 kfree(inet_rsk(req)->ipv6_opt);
579 consume_skb(inet_rsk(req)->pktopts);
580 }
581
582 #ifdef CONFIG_TCP_MD5SIG
tcp_v6_md5_do_lookup(const struct sock * sk,const struct in6_addr * addr,int l3index)583 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
584 const struct in6_addr *addr,
585 int l3index)
586 {
587 return tcp_md5_do_lookup(sk, l3index,
588 (union tcp_md5_addr *)addr, AF_INET6);
589 }
590
tcp_v6_md5_lookup(const struct sock * sk,const struct sock * addr_sk)591 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
592 const struct sock *addr_sk)
593 {
594 int l3index;
595
596 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
597 addr_sk->sk_bound_dev_if);
598 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
599 l3index);
600 }
601
tcp_v6_parse_md5_keys(struct sock * sk,int optname,sockptr_t optval,int optlen)602 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
603 sockptr_t optval, int optlen)
604 {
605 struct tcp_md5sig cmd;
606 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
607 union tcp_ao_addr *addr;
608 int l3index = 0;
609 u8 prefixlen;
610 bool l3flag;
611 u8 flags;
612
613 if (optlen < sizeof(cmd))
614 return -EINVAL;
615
616 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
617 return -EFAULT;
618
619 if (sin6->sin6_family != AF_INET6)
620 return -EINVAL;
621
622 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
623 l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
624
625 if (optname == TCP_MD5SIG_EXT &&
626 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
627 prefixlen = cmd.tcpm_prefixlen;
628 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
629 prefixlen > 32))
630 return -EINVAL;
631 } else {
632 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
633 }
634
635 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
636 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
637 struct net_device *dev;
638
639 rcu_read_lock();
640 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
641 if (dev && netif_is_l3_master(dev))
642 l3index = dev->ifindex;
643 rcu_read_unlock();
644
645 /* ok to reference set/not set outside of rcu;
646 * right now device MUST be an L3 master
647 */
648 if (!dev || !l3index)
649 return -EINVAL;
650 }
651
652 if (!cmd.tcpm_keylen) {
653 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
654 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
655 AF_INET, prefixlen,
656 l3index, flags);
657 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
658 AF_INET6, prefixlen, l3index, flags);
659 }
660
661 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
662 return -EINVAL;
663
664 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
665 addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
666
667 /* Don't allow keys for peers that have a matching TCP-AO key.
668 * See the comment in tcp_ao_add_cmd()
669 */
670 if (tcp_ao_required(sk, addr, AF_INET,
671 l3flag ? l3index : -1, false))
672 return -EKEYREJECTED;
673 return tcp_md5_do_add(sk, addr,
674 AF_INET, prefixlen, l3index, flags,
675 cmd.tcpm_key, cmd.tcpm_keylen);
676 }
677
678 addr = (union tcp_md5_addr *)&sin6->sin6_addr;
679
680 /* Don't allow keys for peers that have a matching TCP-AO key.
681 * See the comment in tcp_ao_add_cmd()
682 */
683 if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false))
684 return -EKEYREJECTED;
685
686 return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
687 cmd.tcpm_key, cmd.tcpm_keylen);
688 }
689
tcp_v6_md5_hash_headers(struct tcp_sigpool * hp,const struct in6_addr * daddr,const struct in6_addr * saddr,const struct tcphdr * th,int nbytes)690 static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp,
691 const struct in6_addr *daddr,
692 const struct in6_addr *saddr,
693 const struct tcphdr *th, int nbytes)
694 {
695 struct tcp6_pseudohdr *bp;
696 struct scatterlist sg;
697 struct tcphdr *_th;
698
699 bp = hp->scratch;
700 /* 1. TCP pseudo-header (RFC2460) */
701 bp->saddr = *saddr;
702 bp->daddr = *daddr;
703 bp->protocol = cpu_to_be32(IPPROTO_TCP);
704 bp->len = cpu_to_be32(nbytes);
705
706 _th = (struct tcphdr *)(bp + 1);
707 memcpy(_th, th, sizeof(*th));
708 _th->check = 0;
709
710 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
711 ahash_request_set_crypt(hp->req, &sg, NULL,
712 sizeof(*bp) + sizeof(*th));
713 return crypto_ahash_update(hp->req);
714 }
715
tcp_v6_md5_hash_hdr(char * md5_hash,const struct tcp_md5sig_key * key,const struct in6_addr * daddr,struct in6_addr * saddr,const struct tcphdr * th)716 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
717 const struct in6_addr *daddr, struct in6_addr *saddr,
718 const struct tcphdr *th)
719 {
720 struct tcp_sigpool hp;
721
722 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
723 goto clear_hash_nostart;
724
725 if (crypto_ahash_init(hp.req))
726 goto clear_hash;
727 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
728 goto clear_hash;
729 if (tcp_md5_hash_key(&hp, key))
730 goto clear_hash;
731 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
732 if (crypto_ahash_final(hp.req))
733 goto clear_hash;
734
735 tcp_sigpool_end(&hp);
736 return 0;
737
738 clear_hash:
739 tcp_sigpool_end(&hp);
740 clear_hash_nostart:
741 memset(md5_hash, 0, 16);
742 return 1;
743 }
744
tcp_v6_md5_hash_skb(char * md5_hash,const struct tcp_md5sig_key * key,const struct sock * sk,const struct sk_buff * skb)745 static int tcp_v6_md5_hash_skb(char *md5_hash,
746 const struct tcp_md5sig_key *key,
747 const struct sock *sk,
748 const struct sk_buff *skb)
749 {
750 const struct tcphdr *th = tcp_hdr(skb);
751 const struct in6_addr *saddr, *daddr;
752 struct tcp_sigpool hp;
753
754 if (sk) { /* valid for establish/request sockets */
755 saddr = &sk->sk_v6_rcv_saddr;
756 daddr = &sk->sk_v6_daddr;
757 } else {
758 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
759 saddr = &ip6h->saddr;
760 daddr = &ip6h->daddr;
761 }
762
763 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
764 goto clear_hash_nostart;
765
766 if (crypto_ahash_init(hp.req))
767 goto clear_hash;
768
769 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
770 goto clear_hash;
771 if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
772 goto clear_hash;
773 if (tcp_md5_hash_key(&hp, key))
774 goto clear_hash;
775 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
776 if (crypto_ahash_final(hp.req))
777 goto clear_hash;
778
779 tcp_sigpool_end(&hp);
780 return 0;
781
782 clear_hash:
783 tcp_sigpool_end(&hp);
784 clear_hash_nostart:
785 memset(md5_hash, 0, 16);
786 return 1;
787 }
788 #endif
789
tcp_v6_init_req(struct request_sock * req,const struct sock * sk_listener,struct sk_buff * skb,u32 tw_isn)790 static void tcp_v6_init_req(struct request_sock *req,
791 const struct sock *sk_listener,
792 struct sk_buff *skb,
793 u32 tw_isn)
794 {
795 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
796 struct inet_request_sock *ireq = inet_rsk(req);
797 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
798
799 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
800 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
801
802 /* So that link locals have meaning */
803 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
804 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
805 ireq->ir_iif = tcp_v6_iif(skb);
806
807 if (!tw_isn &&
808 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
809 np->rxopt.bits.rxinfo ||
810 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
811 np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) {
812 refcount_inc(&skb->users);
813 ireq->pktopts = skb;
814 }
815 }
816
tcp_v6_route_req(const struct sock * sk,struct sk_buff * skb,struct flowi * fl,struct request_sock * req,u32 tw_isn)817 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
818 struct sk_buff *skb,
819 struct flowi *fl,
820 struct request_sock *req,
821 u32 tw_isn)
822 {
823 tcp_v6_init_req(req, sk, skb, tw_isn);
824
825 if (security_inet_conn_request(sk, skb, req))
826 return NULL;
827
828 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
829 }
830
831 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
832 .family = AF_INET6,
833 .obj_size = sizeof(struct tcp6_request_sock),
834 .rtx_syn_ack = tcp_rtx_synack,
835 .send_ack = tcp_v6_reqsk_send_ack,
836 .destructor = tcp_v6_reqsk_destructor,
837 .send_reset = tcp_v6_send_reset,
838 .syn_ack_timeout = tcp_syn_ack_timeout,
839 };
840
841 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
842 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
843 sizeof(struct ipv6hdr),
844 #ifdef CONFIG_TCP_MD5SIG
845 .req_md5_lookup = tcp_v6_md5_lookup,
846 .calc_md5_hash = tcp_v6_md5_hash_skb,
847 #endif
848 #ifdef CONFIG_TCP_AO
849 .ao_lookup = tcp_v6_ao_lookup_rsk,
850 .ao_calc_key = tcp_v6_ao_calc_key_rsk,
851 .ao_synack_hash = tcp_v6_ao_synack_hash,
852 #endif
853 #ifdef CONFIG_SYN_COOKIES
854 .cookie_init_seq = cookie_v6_init_sequence,
855 #endif
856 .route_req = tcp_v6_route_req,
857 .init_seq = tcp_v6_init_seq,
858 .init_ts_off = tcp_v6_init_ts_off,
859 .send_synack = tcp_v6_send_synack,
860 };
861
tcp_v6_send_response(const struct sock * sk,struct sk_buff * skb,u32 seq,u32 ack,u32 win,u32 tsval,u32 tsecr,int oif,int rst,u8 tclass,__be32 label,u32 priority,u32 txhash,struct tcp_key * key)862 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
863 u32 ack, u32 win, u32 tsval, u32 tsecr,
864 int oif, int rst, u8 tclass, __be32 label,
865 u32 priority, u32 txhash, struct tcp_key *key)
866 {
867 const struct tcphdr *th = tcp_hdr(skb);
868 struct tcphdr *t1;
869 struct sk_buff *buff;
870 struct flowi6 fl6;
871 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
872 struct sock *ctl_sk = net->ipv6.tcp_sk;
873 unsigned int tot_len = sizeof(struct tcphdr);
874 __be32 mrst = 0, *topt;
875 struct dst_entry *dst;
876 __u32 mark = 0;
877
878 if (tsecr)
879 tot_len += TCPOLEN_TSTAMP_ALIGNED;
880 if (tcp_key_is_md5(key))
881 tot_len += TCPOLEN_MD5SIG_ALIGNED;
882 if (tcp_key_is_ao(key))
883 tot_len += tcp_ao_len_aligned(key->ao_key);
884
885 #ifdef CONFIG_MPTCP
886 if (rst && !tcp_key_is_md5(key)) {
887 mrst = mptcp_reset_option(skb);
888
889 if (mrst)
890 tot_len += sizeof(__be32);
891 }
892 #endif
893
894 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
895 if (!buff)
896 return;
897
898 skb_reserve(buff, MAX_TCP_HEADER);
899
900 t1 = skb_push(buff, tot_len);
901 skb_reset_transport_header(buff);
902
903 /* Swap the send and the receive. */
904 memset(t1, 0, sizeof(*t1));
905 t1->dest = th->source;
906 t1->source = th->dest;
907 t1->doff = tot_len / 4;
908 t1->seq = htonl(seq);
909 t1->ack_seq = htonl(ack);
910 t1->ack = !rst || !th->ack;
911 t1->rst = rst;
912 t1->window = htons(win);
913
914 topt = (__be32 *)(t1 + 1);
915
916 if (tsecr) {
917 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
918 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
919 *topt++ = htonl(tsval);
920 *topt++ = htonl(tsecr);
921 }
922
923 if (mrst)
924 *topt++ = mrst;
925
926 #ifdef CONFIG_TCP_MD5SIG
927 if (tcp_key_is_md5(key)) {
928 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
929 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
930 tcp_v6_md5_hash_hdr((__u8 *)topt, key->md5_key,
931 &ipv6_hdr(skb)->saddr,
932 &ipv6_hdr(skb)->daddr, t1);
933 }
934 #endif
935 #ifdef CONFIG_TCP_AO
936 if (tcp_key_is_ao(key)) {
937 *topt++ = htonl((TCPOPT_AO << 24) |
938 (tcp_ao_len(key->ao_key) << 16) |
939 (key->ao_key->sndid << 8) |
940 (key->rcv_next));
941
942 tcp_ao_hash_hdr(AF_INET6, (char *)topt, key->ao_key,
943 key->traffic_key,
944 (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr,
945 (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr,
946 t1, key->sne);
947 }
948 #endif
949
950 memset(&fl6, 0, sizeof(fl6));
951 fl6.daddr = ipv6_hdr(skb)->saddr;
952 fl6.saddr = ipv6_hdr(skb)->daddr;
953 fl6.flowlabel = label;
954
955 buff->ip_summed = CHECKSUM_PARTIAL;
956
957 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
958
959 fl6.flowi6_proto = IPPROTO_TCP;
960 if (rt6_need_strict(&fl6.daddr) && !oif)
961 fl6.flowi6_oif = tcp_v6_iif(skb);
962 else {
963 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
964 oif = skb->skb_iif;
965
966 fl6.flowi6_oif = oif;
967 }
968
969 if (sk) {
970 /* unconstify the socket only to attach it to buff with care. */
971 skb_set_owner_edemux(buff, (struct sock *)sk);
972
973 if (sk->sk_state == TCP_TIME_WAIT)
974 mark = inet_twsk(sk)->tw_mark;
975 else
976 mark = READ_ONCE(sk->sk_mark);
977 skb_set_delivery_time(buff, tcp_transmit_time(sk), SKB_CLOCK_MONOTONIC);
978 }
979 if (txhash) {
980 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
981 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
982 }
983 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
984 fl6.fl6_dport = t1->dest;
985 fl6.fl6_sport = t1->source;
986 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
987 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
988
989 /* Pass a socket to ip6_dst_lookup either it is for RST
990 * Underlying function will use this to retrieve the network
991 * namespace
992 */
993 if (sk && sk->sk_state != TCP_TIME_WAIT)
994 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
995 else
996 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
997 if (!IS_ERR(dst)) {
998 skb_dst_set(buff, dst);
999 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
1000 tclass & ~INET_ECN_MASK, priority);
1001 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
1002 if (rst)
1003 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
1004 return;
1005 }
1006
1007 kfree_skb(buff);
1008 }
1009
tcp_v6_send_reset(const struct sock * sk,struct sk_buff * skb,enum sk_rst_reason reason)1010 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb,
1011 enum sk_rst_reason reason)
1012 {
1013 const struct tcphdr *th = tcp_hdr(skb);
1014 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1015 const __u8 *md5_hash_location = NULL;
1016 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1017 bool allocated_traffic_key = false;
1018 #endif
1019 const struct tcp_ao_hdr *aoh;
1020 struct tcp_key key = {};
1021 u32 seq = 0, ack_seq = 0;
1022 __be32 label = 0;
1023 u32 priority = 0;
1024 struct net *net;
1025 u32 txhash = 0;
1026 int oif = 0;
1027 #ifdef CONFIG_TCP_MD5SIG
1028 unsigned char newhash[16];
1029 int genhash;
1030 struct sock *sk1 = NULL;
1031 #endif
1032
1033 if (th->rst)
1034 return;
1035
1036 /* If sk not NULL, it means we did a successful lookup and incoming
1037 * route had to be correct. prequeue might have dropped our dst.
1038 */
1039 if (!sk && !ipv6_unicast_destination(skb))
1040 return;
1041
1042 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1043 /* Invalid TCP option size or twice included auth */
1044 if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
1045 return;
1046 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1047 rcu_read_lock();
1048 #endif
1049 #ifdef CONFIG_TCP_MD5SIG
1050 if (sk && sk_fullsock(sk)) {
1051 int l3index;
1052
1053 /* sdif set, means packet ingressed via a device
1054 * in an L3 domain and inet_iif is set to it.
1055 */
1056 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1057 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1058 if (key.md5_key)
1059 key.type = TCP_KEY_MD5;
1060 } else if (md5_hash_location) {
1061 int dif = tcp_v6_iif_l3_slave(skb);
1062 int sdif = tcp_v6_sdif(skb);
1063 int l3index;
1064
1065 /*
1066 * active side is lost. Try to find listening socket through
1067 * source port, and then find md5 key through listening socket.
1068 * we are not loose security here:
1069 * Incoming packet is checked with md5 hash with finding key,
1070 * no RST generated if md5 hash doesn't match.
1071 */
1072 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1073 NULL, 0, &ipv6h->saddr, th->source,
1074 &ipv6h->daddr, ntohs(th->source),
1075 dif, sdif);
1076 if (!sk1)
1077 goto out;
1078
1079 /* sdif set, means packet ingressed via a device
1080 * in an L3 domain and dif is set to it.
1081 */
1082 l3index = tcp_v6_sdif(skb) ? dif : 0;
1083
1084 key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1085 if (!key.md5_key)
1086 goto out;
1087 key.type = TCP_KEY_MD5;
1088
1089 genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb);
1090 if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
1091 goto out;
1092 }
1093 #endif
1094
1095 if (th->ack)
1096 seq = ntohl(th->ack_seq);
1097 else
1098 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1099 (th->doff << 2);
1100
1101 #ifdef CONFIG_TCP_AO
1102 if (aoh) {
1103 int l3index;
1104
1105 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1106 if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq,
1107 &key.ao_key, &key.traffic_key,
1108 &allocated_traffic_key,
1109 &key.rcv_next, &key.sne))
1110 goto out;
1111 key.type = TCP_KEY_AO;
1112 }
1113 #endif
1114
1115 if (sk) {
1116 oif = sk->sk_bound_dev_if;
1117 if (sk_fullsock(sk)) {
1118 if (inet6_test_bit(REPFLOW, sk))
1119 label = ip6_flowlabel(ipv6h);
1120 priority = READ_ONCE(sk->sk_priority);
1121 txhash = sk->sk_txhash;
1122 }
1123 if (sk->sk_state == TCP_TIME_WAIT) {
1124 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1125 priority = inet_twsk(sk)->tw_priority;
1126 txhash = inet_twsk(sk)->tw_txhash;
1127 }
1128 } else {
1129 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1130 label = ip6_flowlabel(ipv6h);
1131 }
1132
1133 trace_tcp_send_reset(sk, skb, reason);
1134
1135 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
1136 ipv6_get_dsfield(ipv6h), label, priority, txhash,
1137 &key);
1138
1139 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1140 out:
1141 if (allocated_traffic_key)
1142 kfree(key.traffic_key);
1143 rcu_read_unlock();
1144 #endif
1145 }
1146
tcp_v6_send_ack(const struct sock * sk,struct sk_buff * skb,u32 seq,u32 ack,u32 win,u32 tsval,u32 tsecr,int oif,struct tcp_key * key,u8 tclass,__be32 label,u32 priority,u32 txhash)1147 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1148 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1149 struct tcp_key *key, u8 tclass,
1150 __be32 label, u32 priority, u32 txhash)
1151 {
1152 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0,
1153 tclass, label, priority, txhash, key);
1154 }
1155
tcp_v6_timewait_ack(struct sock * sk,struct sk_buff * skb)1156 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1157 {
1158 struct inet_timewait_sock *tw = inet_twsk(sk);
1159 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1160 struct tcp_key key = {};
1161 #ifdef CONFIG_TCP_AO
1162 struct tcp_ao_info *ao_info;
1163
1164 if (static_branch_unlikely(&tcp_ao_needed.key)) {
1165
1166 /* FIXME: the segment to-be-acked is not verified yet */
1167 ao_info = rcu_dereference(tcptw->ao_info);
1168 if (ao_info) {
1169 const struct tcp_ao_hdr *aoh;
1170
1171 /* Invalid TCP option size or twice included auth */
1172 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1173 goto out;
1174 if (aoh)
1175 key.ao_key = tcp_ao_established_key(sk, ao_info,
1176 aoh->rnext_keyid, -1);
1177 }
1178 }
1179 if (key.ao_key) {
1180 struct tcp_ao_key *rnext_key;
1181
1182 key.traffic_key = snd_other_key(key.ao_key);
1183 /* rcv_next switches to our rcv_next */
1184 rnext_key = READ_ONCE(ao_info->rnext_key);
1185 key.rcv_next = rnext_key->rcvid;
1186 key.sne = READ_ONCE(ao_info->snd_sne);
1187 key.type = TCP_KEY_AO;
1188 #else
1189 if (0) {
1190 #endif
1191 #ifdef CONFIG_TCP_MD5SIG
1192 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1193 key.md5_key = tcp_twsk_md5_key(tcptw);
1194 if (key.md5_key)
1195 key.type = TCP_KEY_MD5;
1196 #endif
1197 }
1198
1199 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt,
1200 READ_ONCE(tcptw->tw_rcv_nxt),
1201 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1202 tcp_tw_tsval(tcptw),
1203 READ_ONCE(tcptw->tw_ts_recent), tw->tw_bound_dev_if,
1204 &key, tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel),
1205 tw->tw_priority, tw->tw_txhash);
1206
1207 #ifdef CONFIG_TCP_AO
1208 out:
1209 #endif
1210 inet_twsk_put(tw);
1211 }
1212
1213 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1214 struct request_sock *req)
1215 {
1216 struct tcp_key key = {};
1217
1218 #ifdef CONFIG_TCP_AO
1219 if (static_branch_unlikely(&tcp_ao_needed.key) &&
1220 tcp_rsk_used_ao(req)) {
1221 const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
1222 const struct tcp_ao_hdr *aoh;
1223 int l3index;
1224
1225 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1226 /* Invalid TCP option size or twice included auth */
1227 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1228 return;
1229 if (!aoh)
1230 return;
1231 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1232 (union tcp_ao_addr *)addr,
1233 AF_INET6, aoh->rnext_keyid, -1);
1234 if (unlikely(!key.ao_key)) {
1235 /* Send ACK with any matching MKT for the peer */
1236 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1237 (union tcp_ao_addr *)addr,
1238 AF_INET6, -1, -1);
1239 /* Matching key disappeared (user removed the key?)
1240 * let the handshake timeout.
1241 */
1242 if (!key.ao_key) {
1243 net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
1244 addr,
1245 ntohs(tcp_hdr(skb)->source),
1246 &ipv6_hdr(skb)->daddr,
1247 ntohs(tcp_hdr(skb)->dest));
1248 return;
1249 }
1250 }
1251 key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
1252 if (!key.traffic_key)
1253 return;
1254
1255 key.type = TCP_KEY_AO;
1256 key.rcv_next = aoh->keyid;
1257 tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
1258 #else
1259 if (0) {
1260 #endif
1261 #ifdef CONFIG_TCP_MD5SIG
1262 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1263 int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1264
1265 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
1266 l3index);
1267 if (key.md5_key)
1268 key.type = TCP_KEY_MD5;
1269 #endif
1270 }
1271
1272 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1273 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1274 */
1275 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1276 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1277 tcp_rsk(req)->rcv_nxt,
1278 tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale,
1279 tcp_rsk_tsval(tcp_rsk(req)),
1280 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
1281 &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
1282 READ_ONCE(sk->sk_priority),
1283 READ_ONCE(tcp_rsk(req)->txhash));
1284 if (tcp_key_is_ao(&key))
1285 kfree(key.traffic_key);
1286 }
1287
1288
1289 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1290 {
1291 #ifdef CONFIG_SYN_COOKIES
1292 const struct tcphdr *th = tcp_hdr(skb);
1293
1294 if (!th->syn)
1295 sk = cookie_v6_check(sk, skb);
1296 #endif
1297 return sk;
1298 }
1299
1300 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1301 struct tcphdr *th, u32 *cookie)
1302 {
1303 u16 mss = 0;
1304 #ifdef CONFIG_SYN_COOKIES
1305 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1306 &tcp_request_sock_ipv6_ops, sk, th);
1307 if (mss) {
1308 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1309 tcp_synq_overflow(sk);
1310 }
1311 #endif
1312 return mss;
1313 }
1314
1315 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1316 {
1317 if (skb->protocol == htons(ETH_P_IP))
1318 return tcp_v4_conn_request(sk, skb);
1319
1320 if (!ipv6_unicast_destination(skb))
1321 goto drop;
1322
1323 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1324 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1325 return 0;
1326 }
1327
1328 return tcp_conn_request(&tcp6_request_sock_ops,
1329 &tcp_request_sock_ipv6_ops, sk, skb);
1330
1331 drop:
1332 tcp_listendrop(sk);
1333 return 0; /* don't send reset */
1334 }
1335
1336 static void tcp_v6_restore_cb(struct sk_buff *skb)
1337 {
1338 /* We need to move header back to the beginning if xfrm6_policy_check()
1339 * and tcp_v6_fill_cb() are going to be called again.
1340 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1341 */
1342 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1343 sizeof(struct inet6_skb_parm));
1344 }
1345
1346 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1347 struct request_sock *req,
1348 struct dst_entry *dst,
1349 struct request_sock *req_unhash,
1350 bool *own_req)
1351 {
1352 struct inet_request_sock *ireq;
1353 struct ipv6_pinfo *newnp;
1354 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1355 struct ipv6_txoptions *opt;
1356 struct inet_sock *newinet;
1357 bool found_dup_sk = false;
1358 struct tcp_sock *newtp;
1359 struct sock *newsk;
1360 #ifdef CONFIG_TCP_MD5SIG
1361 struct tcp_md5sig_key *key;
1362 int l3index;
1363 #endif
1364 struct flowi6 fl6;
1365
1366 if (skb->protocol == htons(ETH_P_IP)) {
1367 /*
1368 * v6 mapped
1369 */
1370
1371 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1372 req_unhash, own_req);
1373
1374 if (!newsk)
1375 return NULL;
1376
1377 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1378
1379 newnp = tcp_inet6_sk(newsk);
1380 newtp = tcp_sk(newsk);
1381
1382 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1383
1384 newnp->saddr = newsk->sk_v6_rcv_saddr;
1385
1386 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1387 if (sk_is_mptcp(newsk))
1388 mptcpv6_handle_mapped(newsk, true);
1389 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1390 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1391 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1392 #endif
1393
1394 newnp->ipv6_mc_list = NULL;
1395 newnp->ipv6_ac_list = NULL;
1396 newnp->ipv6_fl_list = NULL;
1397 newnp->pktoptions = NULL;
1398 newnp->opt = NULL;
1399 newnp->mcast_oif = inet_iif(skb);
1400 newnp->mcast_hops = ip_hdr(skb)->ttl;
1401 newnp->rcv_flowinfo = 0;
1402 if (inet6_test_bit(REPFLOW, sk))
1403 newnp->flow_label = 0;
1404
1405 /*
1406 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1407 * here, tcp_create_openreq_child now does this for us, see the comment in
1408 * that function for the gory details. -acme
1409 */
1410
1411 /* It is tricky place. Until this moment IPv4 tcp
1412 worked with IPv6 icsk.icsk_af_ops.
1413 Sync it now.
1414 */
1415 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1416
1417 return newsk;
1418 }
1419
1420 ireq = inet_rsk(req);
1421
1422 if (sk_acceptq_is_full(sk))
1423 goto out_overflow;
1424
1425 if (!dst) {
1426 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1427 if (!dst)
1428 goto out;
1429 }
1430
1431 newsk = tcp_create_openreq_child(sk, req, skb);
1432 if (!newsk)
1433 goto out_nonewsk;
1434
1435 /*
1436 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1437 * count here, tcp_create_openreq_child now does this for us, see the
1438 * comment in that function for the gory details. -acme
1439 */
1440
1441 newsk->sk_gso_type = SKB_GSO_TCPV6;
1442 inet6_sk_rx_dst_set(newsk, skb);
1443
1444 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1445
1446 newtp = tcp_sk(newsk);
1447 newinet = inet_sk(newsk);
1448 newnp = tcp_inet6_sk(newsk);
1449
1450 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1451
1452 ip6_dst_store(newsk, dst, NULL, NULL);
1453
1454 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1455 newnp->saddr = ireq->ir_v6_loc_addr;
1456 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1457 newsk->sk_bound_dev_if = ireq->ir_iif;
1458
1459 /* Now IPv6 options...
1460
1461 First: no IPv4 options.
1462 */
1463 newinet->inet_opt = NULL;
1464 newnp->ipv6_mc_list = NULL;
1465 newnp->ipv6_ac_list = NULL;
1466 newnp->ipv6_fl_list = NULL;
1467
1468 /* Clone RX bits */
1469 newnp->rxopt.all = np->rxopt.all;
1470
1471 newnp->pktoptions = NULL;
1472 newnp->opt = NULL;
1473 newnp->mcast_oif = tcp_v6_iif(skb);
1474 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1475 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1476 if (inet6_test_bit(REPFLOW, sk))
1477 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1478
1479 /* Set ToS of the new socket based upon the value of incoming SYN.
1480 * ECT bits are set later in tcp_init_transfer().
1481 */
1482 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1483 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1484
1485 /* Clone native IPv6 options from listening socket (if any)
1486
1487 Yes, keeping reference count would be much more clever,
1488 but we make one more one thing there: reattach optmem
1489 to newsk.
1490 */
1491 opt = ireq->ipv6_opt;
1492 if (!opt)
1493 opt = rcu_dereference(np->opt);
1494 if (opt) {
1495 opt = ipv6_dup_options(newsk, opt);
1496 RCU_INIT_POINTER(newnp->opt, opt);
1497 }
1498 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1499 if (opt)
1500 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1501 opt->opt_flen;
1502
1503 tcp_ca_openreq_child(newsk, dst);
1504
1505 tcp_sync_mss(newsk, dst_mtu(dst));
1506 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1507
1508 tcp_initialize_rcv_mss(newsk);
1509
1510 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1511 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1512
1513 #ifdef CONFIG_TCP_MD5SIG
1514 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1515
1516 if (!tcp_rsk_used_ao(req)) {
1517 /* Copy over the MD5 key from the original socket */
1518 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1519 if (key) {
1520 const union tcp_md5_addr *addr;
1521
1522 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1523 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1524 inet_csk_prepare_forced_close(newsk);
1525 tcp_done(newsk);
1526 goto out;
1527 }
1528 }
1529 }
1530 #endif
1531 #ifdef CONFIG_TCP_AO
1532 /* Copy over tcp_ao_info if any */
1533 if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
1534 goto out; /* OOM */
1535 #endif
1536
1537 if (__inet_inherit_port(sk, newsk) < 0) {
1538 inet_csk_prepare_forced_close(newsk);
1539 tcp_done(newsk);
1540 goto out;
1541 }
1542 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1543 &found_dup_sk);
1544 if (*own_req) {
1545 tcp_move_syn(newtp, req);
1546
1547 /* Clone pktoptions received with SYN, if we own the req */
1548 if (ireq->pktopts) {
1549 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1550 consume_skb(ireq->pktopts);
1551 ireq->pktopts = NULL;
1552 if (newnp->pktoptions)
1553 tcp_v6_restore_cb(newnp->pktoptions);
1554 }
1555 } else {
1556 if (!req_unhash && found_dup_sk) {
1557 /* This code path should only be executed in the
1558 * syncookie case only
1559 */
1560 bh_unlock_sock(newsk);
1561 sock_put(newsk);
1562 newsk = NULL;
1563 }
1564 }
1565
1566 return newsk;
1567
1568 out_overflow:
1569 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1570 out_nonewsk:
1571 dst_release(dst);
1572 out:
1573 tcp_listendrop(sk);
1574 return NULL;
1575 }
1576
1577 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1578 u32));
1579 /* The socket must have it's spinlock held when we get
1580 * here, unless it is a TCP_LISTEN socket.
1581 *
1582 * We have a potential double-lock case here, so even when
1583 * doing backlog processing we use the BH locking scheme.
1584 * This is because we cannot sleep with the original spinlock
1585 * held.
1586 */
1587 INDIRECT_CALLABLE_SCOPE
1588 int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1589 {
1590 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1591 struct sk_buff *opt_skb = NULL;
1592 enum skb_drop_reason reason;
1593 struct tcp_sock *tp;
1594
1595 /* Imagine: socket is IPv6. IPv4 packet arrives,
1596 goes to IPv4 receive handler and backlogged.
1597 From backlog it always goes here. Kerboom...
1598 Fortunately, tcp_rcv_established and rcv_established
1599 handle them correctly, but it is not case with
1600 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1601 */
1602
1603 if (skb->protocol == htons(ETH_P_IP))
1604 return tcp_v4_do_rcv(sk, skb);
1605
1606 /*
1607 * socket locking is here for SMP purposes as backlog rcv
1608 * is currently called with bh processing disabled.
1609 */
1610
1611 /* Do Stevens' IPV6_PKTOPTIONS.
1612
1613 Yes, guys, it is the only place in our code, where we
1614 may make it not affecting IPv4.
1615 The rest of code is protocol independent,
1616 and I do not like idea to uglify IPv4.
1617
1618 Actually, all the idea behind IPV6_PKTOPTIONS
1619 looks not very well thought. For now we latch
1620 options, received in the last packet, enqueued
1621 by tcp. Feel free to propose better solution.
1622 --ANK (980728)
1623 */
1624 if (np->rxopt.all && sk->sk_state != TCP_LISTEN)
1625 opt_skb = skb_clone_and_charge_r(skb, sk);
1626
1627 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1628 struct dst_entry *dst;
1629
1630 dst = rcu_dereference_protected(sk->sk_rx_dst,
1631 lockdep_sock_is_held(sk));
1632
1633 sock_rps_save_rxhash(sk, skb);
1634 sk_mark_napi_id(sk, skb);
1635 if (dst) {
1636 if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1637 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1638 dst, sk->sk_rx_dst_cookie) == NULL) {
1639 RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1640 dst_release(dst);
1641 }
1642 }
1643
1644 tcp_rcv_established(sk, skb);
1645 if (opt_skb)
1646 goto ipv6_pktoptions;
1647 return 0;
1648 }
1649
1650 if (tcp_checksum_complete(skb))
1651 goto csum_err;
1652
1653 if (sk->sk_state == TCP_LISTEN) {
1654 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1655
1656 if (nsk != sk) {
1657 if (nsk) {
1658 reason = tcp_child_process(sk, nsk, skb);
1659 if (reason)
1660 goto reset;
1661 }
1662 return 0;
1663 }
1664 } else
1665 sock_rps_save_rxhash(sk, skb);
1666
1667 reason = tcp_rcv_state_process(sk, skb);
1668 if (reason)
1669 goto reset;
1670 if (opt_skb)
1671 goto ipv6_pktoptions;
1672 return 0;
1673
1674 reset:
1675 tcp_v6_send_reset(sk, skb, sk_rst_convert_drop_reason(reason));
1676 discard:
1677 if (opt_skb)
1678 __kfree_skb(opt_skb);
1679 sk_skb_reason_drop(sk, skb, reason);
1680 return 0;
1681 csum_err:
1682 reason = SKB_DROP_REASON_TCP_CSUM;
1683 trace_tcp_bad_csum(skb);
1684 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1685 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1686 goto discard;
1687
1688
1689 ipv6_pktoptions:
1690 /* Do you ask, what is it?
1691
1692 1. skb was enqueued by tcp.
1693 2. skb is added to tail of read queue, rather than out of order.
1694 3. socket is not in passive state.
1695 4. Finally, it really contains options, which user wants to receive.
1696 */
1697 tp = tcp_sk(sk);
1698 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1699 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1700 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1701 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb));
1702 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1703 WRITE_ONCE(np->mcast_hops,
1704 ipv6_hdr(opt_skb)->hop_limit);
1705 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1706 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1707 if (inet6_test_bit(REPFLOW, sk))
1708 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1709 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1710 tcp_v6_restore_cb(opt_skb);
1711 opt_skb = xchg(&np->pktoptions, opt_skb);
1712 } else {
1713 __kfree_skb(opt_skb);
1714 opt_skb = xchg(&np->pktoptions, NULL);
1715 }
1716 }
1717
1718 consume_skb(opt_skb);
1719 return 0;
1720 }
1721
1722 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1723 const struct tcphdr *th)
1724 {
1725 /* This is tricky: we move IP6CB at its correct location into
1726 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1727 * _decode_session6() uses IP6CB().
1728 * barrier() makes sure compiler won't play aliasing games.
1729 */
1730 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1731 sizeof(struct inet6_skb_parm));
1732 barrier();
1733
1734 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1735 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1736 skb->len - th->doff*4);
1737 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1738 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1739 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1740 TCP_SKB_CB(skb)->sacked = 0;
1741 TCP_SKB_CB(skb)->has_rxtstamp =
1742 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1743 }
1744
1745 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1746 {
1747 enum skb_drop_reason drop_reason;
1748 int sdif = inet6_sdif(skb);
1749 int dif = inet6_iif(skb);
1750 const struct tcphdr *th;
1751 const struct ipv6hdr *hdr;
1752 struct sock *sk = NULL;
1753 bool refcounted;
1754 int ret;
1755 u32 isn;
1756 struct net *net = dev_net(skb->dev);
1757
1758 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1759 if (skb->pkt_type != PACKET_HOST)
1760 goto discard_it;
1761
1762 /*
1763 * Count it even if it's bad.
1764 */
1765 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1766
1767 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1768 goto discard_it;
1769
1770 th = (const struct tcphdr *)skb->data;
1771
1772 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1773 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1774 goto bad_packet;
1775 }
1776 if (!pskb_may_pull(skb, th->doff*4))
1777 goto discard_it;
1778
1779 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1780 goto csum_error;
1781
1782 th = (const struct tcphdr *)skb->data;
1783 hdr = ipv6_hdr(skb);
1784
1785 lookup:
1786 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1787 th->source, th->dest, inet6_iif(skb), sdif,
1788 &refcounted);
1789 if (!sk)
1790 goto no_tcp_socket;
1791
1792 if (sk->sk_state == TCP_TIME_WAIT)
1793 goto do_time_wait;
1794
1795 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1796 struct request_sock *req = inet_reqsk(sk);
1797 bool req_stolen = false;
1798 struct sock *nsk;
1799
1800 sk = req->rsk_listener;
1801 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1802 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1803 else
1804 drop_reason = tcp_inbound_hash(sk, req, skb,
1805 &hdr->saddr, &hdr->daddr,
1806 AF_INET6, dif, sdif);
1807 if (drop_reason) {
1808 sk_drops_add(sk, skb);
1809 reqsk_put(req);
1810 goto discard_it;
1811 }
1812 if (tcp_checksum_complete(skb)) {
1813 reqsk_put(req);
1814 goto csum_error;
1815 }
1816 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1817 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1818 if (!nsk) {
1819 inet_csk_reqsk_queue_drop_and_put(sk, req);
1820 goto lookup;
1821 }
1822 sk = nsk;
1823 /* reuseport_migrate_sock() has already held one sk_refcnt
1824 * before returning.
1825 */
1826 } else {
1827 sock_hold(sk);
1828 }
1829 refcounted = true;
1830 nsk = NULL;
1831 if (!tcp_filter(sk, skb)) {
1832 th = (const struct tcphdr *)skb->data;
1833 hdr = ipv6_hdr(skb);
1834 tcp_v6_fill_cb(skb, hdr, th);
1835 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1836 } else {
1837 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1838 }
1839 if (!nsk) {
1840 reqsk_put(req);
1841 if (req_stolen) {
1842 /* Another cpu got exclusive access to req
1843 * and created a full blown socket.
1844 * Try to feed this packet to this socket
1845 * instead of discarding it.
1846 */
1847 tcp_v6_restore_cb(skb);
1848 sock_put(sk);
1849 goto lookup;
1850 }
1851 goto discard_and_relse;
1852 }
1853 nf_reset_ct(skb);
1854 if (nsk == sk) {
1855 reqsk_put(req);
1856 tcp_v6_restore_cb(skb);
1857 } else {
1858 drop_reason = tcp_child_process(sk, nsk, skb);
1859 if (drop_reason) {
1860 enum sk_rst_reason rst_reason;
1861
1862 rst_reason = sk_rst_convert_drop_reason(drop_reason);
1863 tcp_v6_send_reset(nsk, skb, rst_reason);
1864 goto discard_and_relse;
1865 }
1866 sock_put(sk);
1867 return 0;
1868 }
1869 }
1870
1871 process:
1872 if (static_branch_unlikely(&ip6_min_hopcount)) {
1873 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1874 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) {
1875 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1876 drop_reason = SKB_DROP_REASON_TCP_MINTTL;
1877 goto discard_and_relse;
1878 }
1879 }
1880
1881 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1882 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1883 goto discard_and_relse;
1884 }
1885
1886 drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr,
1887 AF_INET6, dif, sdif);
1888 if (drop_reason)
1889 goto discard_and_relse;
1890
1891 nf_reset_ct(skb);
1892
1893 if (tcp_filter(sk, skb)) {
1894 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1895 goto discard_and_relse;
1896 }
1897 th = (const struct tcphdr *)skb->data;
1898 hdr = ipv6_hdr(skb);
1899 tcp_v6_fill_cb(skb, hdr, th);
1900
1901 skb->dev = NULL;
1902
1903 if (sk->sk_state == TCP_LISTEN) {
1904 ret = tcp_v6_do_rcv(sk, skb);
1905 goto put_and_return;
1906 }
1907
1908 sk_incoming_cpu_update(sk);
1909
1910 bh_lock_sock_nested(sk);
1911 tcp_segs_in(tcp_sk(sk), skb);
1912 ret = 0;
1913 if (!sock_owned_by_user(sk)) {
1914 ret = tcp_v6_do_rcv(sk, skb);
1915 } else {
1916 if (tcp_add_backlog(sk, skb, &drop_reason))
1917 goto discard_and_relse;
1918 }
1919 bh_unlock_sock(sk);
1920 put_and_return:
1921 if (refcounted)
1922 sock_put(sk);
1923 return ret ? -1 : 0;
1924
1925 no_tcp_socket:
1926 drop_reason = SKB_DROP_REASON_NO_SOCKET;
1927 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1928 goto discard_it;
1929
1930 tcp_v6_fill_cb(skb, hdr, th);
1931
1932 if (tcp_checksum_complete(skb)) {
1933 csum_error:
1934 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1935 trace_tcp_bad_csum(skb);
1936 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1937 bad_packet:
1938 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1939 } else {
1940 tcp_v6_send_reset(NULL, skb, sk_rst_convert_drop_reason(drop_reason));
1941 }
1942
1943 discard_it:
1944 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1945 sk_skb_reason_drop(sk, skb, drop_reason);
1946 return 0;
1947
1948 discard_and_relse:
1949 sk_drops_add(sk, skb);
1950 if (refcounted)
1951 sock_put(sk);
1952 goto discard_it;
1953
1954 do_time_wait:
1955 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1956 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1957 inet_twsk_put(inet_twsk(sk));
1958 goto discard_it;
1959 }
1960
1961 tcp_v6_fill_cb(skb, hdr, th);
1962
1963 if (tcp_checksum_complete(skb)) {
1964 inet_twsk_put(inet_twsk(sk));
1965 goto csum_error;
1966 }
1967
1968 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, &isn)) {
1969 case TCP_TW_SYN:
1970 {
1971 struct sock *sk2;
1972
1973 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1974 skb, __tcp_hdrlen(th),
1975 &ipv6_hdr(skb)->saddr, th->source,
1976 &ipv6_hdr(skb)->daddr,
1977 ntohs(th->dest),
1978 tcp_v6_iif_l3_slave(skb),
1979 sdif);
1980 if (sk2) {
1981 struct inet_timewait_sock *tw = inet_twsk(sk);
1982 inet_twsk_deschedule_put(tw);
1983 sk = sk2;
1984 tcp_v6_restore_cb(skb);
1985 refcounted = false;
1986 __this_cpu_write(tcp_tw_isn, isn);
1987 goto process;
1988 }
1989 }
1990 /* to ACK */
1991 fallthrough;
1992 case TCP_TW_ACK:
1993 tcp_v6_timewait_ack(sk, skb);
1994 break;
1995 case TCP_TW_RST:
1996 tcp_v6_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET);
1997 inet_twsk_deschedule_put(inet_twsk(sk));
1998 goto discard_it;
1999 case TCP_TW_SUCCESS:
2000 ;
2001 }
2002 goto discard_it;
2003 }
2004
2005 void tcp_v6_early_demux(struct sk_buff *skb)
2006 {
2007 struct net *net = dev_net(skb->dev);
2008 const struct ipv6hdr *hdr;
2009 const struct tcphdr *th;
2010 struct sock *sk;
2011
2012 if (skb->pkt_type != PACKET_HOST)
2013 return;
2014
2015 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
2016 return;
2017
2018 hdr = ipv6_hdr(skb);
2019 th = tcp_hdr(skb);
2020
2021 if (th->doff < sizeof(struct tcphdr) / 4)
2022 return;
2023
2024 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
2025 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
2026 &hdr->saddr, th->source,
2027 &hdr->daddr, ntohs(th->dest),
2028 inet6_iif(skb), inet6_sdif(skb));
2029 if (sk) {
2030 skb->sk = sk;
2031 skb->destructor = sock_edemux;
2032 if (sk_fullsock(sk)) {
2033 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
2034
2035 if (dst)
2036 dst = dst_check(dst, sk->sk_rx_dst_cookie);
2037 if (dst &&
2038 sk->sk_rx_dst_ifindex == skb->skb_iif)
2039 skb_dst_set_noref(skb, dst);
2040 }
2041 }
2042 }
2043
2044 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
2045 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
2046 .twsk_destructor = tcp_twsk_destructor,
2047 };
2048
2049 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
2050 {
2051 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
2052 }
2053
2054 const struct inet_connection_sock_af_ops ipv6_specific = {
2055 .queue_xmit = inet6_csk_xmit,
2056 .send_check = tcp_v6_send_check,
2057 .rebuild_header = inet6_sk_rebuild_header,
2058 .sk_rx_dst_set = inet6_sk_rx_dst_set,
2059 .conn_request = tcp_v6_conn_request,
2060 .syn_recv_sock = tcp_v6_syn_recv_sock,
2061 .net_header_len = sizeof(struct ipv6hdr),
2062 .setsockopt = ipv6_setsockopt,
2063 .getsockopt = ipv6_getsockopt,
2064 .addr2sockaddr = inet6_csk_addr2sockaddr,
2065 .sockaddr_len = sizeof(struct sockaddr_in6),
2066 .mtu_reduced = tcp_v6_mtu_reduced,
2067 };
2068
2069 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2070 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
2071 #ifdef CONFIG_TCP_MD5SIG
2072 .md5_lookup = tcp_v6_md5_lookup,
2073 .calc_md5_hash = tcp_v6_md5_hash_skb,
2074 .md5_parse = tcp_v6_parse_md5_keys,
2075 #endif
2076 #ifdef CONFIG_TCP_AO
2077 .ao_lookup = tcp_v6_ao_lookup,
2078 .calc_ao_hash = tcp_v6_ao_hash_skb,
2079 .ao_parse = tcp_v6_parse_ao,
2080 .ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
2081 #endif
2082 };
2083 #endif
2084
2085 /*
2086 * TCP over IPv4 via INET6 API
2087 */
2088 static const struct inet_connection_sock_af_ops ipv6_mapped = {
2089 .queue_xmit = ip_queue_xmit,
2090 .send_check = tcp_v4_send_check,
2091 .rebuild_header = inet_sk_rebuild_header,
2092 .sk_rx_dst_set = inet_sk_rx_dst_set,
2093 .conn_request = tcp_v6_conn_request,
2094 .syn_recv_sock = tcp_v6_syn_recv_sock,
2095 .net_header_len = sizeof(struct iphdr),
2096 .setsockopt = ipv6_setsockopt,
2097 .getsockopt = ipv6_getsockopt,
2098 .addr2sockaddr = inet6_csk_addr2sockaddr,
2099 .sockaddr_len = sizeof(struct sockaddr_in6),
2100 .mtu_reduced = tcp_v4_mtu_reduced,
2101 };
2102
2103 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2104 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
2105 #ifdef CONFIG_TCP_MD5SIG
2106 .md5_lookup = tcp_v4_md5_lookup,
2107 .calc_md5_hash = tcp_v4_md5_hash_skb,
2108 .md5_parse = tcp_v6_parse_md5_keys,
2109 #endif
2110 #ifdef CONFIG_TCP_AO
2111 .ao_lookup = tcp_v6_ao_lookup,
2112 .calc_ao_hash = tcp_v4_ao_hash_skb,
2113 .ao_parse = tcp_v6_parse_ao,
2114 .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
2115 #endif
2116 };
2117 #endif
2118
2119 /* NOTE: A lot of things set to zero explicitly by call to
2120 * sk_alloc() so need not be done here.
2121 */
2122 static int tcp_v6_init_sock(struct sock *sk)
2123 {
2124 struct inet_connection_sock *icsk = inet_csk(sk);
2125
2126 tcp_init_sock(sk);
2127
2128 icsk->icsk_af_ops = &ipv6_specific;
2129
2130 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2131 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
2132 #endif
2133
2134 return 0;
2135 }
2136
2137 #ifdef CONFIG_PROC_FS
2138 /* Proc filesystem TCPv6 sock list dumping. */
2139 static void get_openreq6(struct seq_file *seq,
2140 const struct request_sock *req, int i)
2141 {
2142 long ttd = req->rsk_timer.expires - jiffies;
2143 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
2144 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
2145
2146 if (ttd < 0)
2147 ttd = 0;
2148
2149 seq_printf(seq,
2150 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2151 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
2152 i,
2153 src->s6_addr32[0], src->s6_addr32[1],
2154 src->s6_addr32[2], src->s6_addr32[3],
2155 inet_rsk(req)->ir_num,
2156 dest->s6_addr32[0], dest->s6_addr32[1],
2157 dest->s6_addr32[2], dest->s6_addr32[3],
2158 ntohs(inet_rsk(req)->ir_rmt_port),
2159 TCP_SYN_RECV,
2160 0, 0, /* could print option size, but that is af dependent. */
2161 1, /* timers active (only the expire timer) */
2162 jiffies_to_clock_t(ttd),
2163 req->num_timeout,
2164 from_kuid_munged(seq_user_ns(seq),
2165 sock_i_uid(req->rsk_listener)),
2166 0, /* non standard timer */
2167 0, /* open_requests have no inode */
2168 0, req);
2169 }
2170
2171 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2172 {
2173 const struct in6_addr *dest, *src;
2174 __u16 destp, srcp;
2175 int timer_active;
2176 unsigned long timer_expires;
2177 const struct inet_sock *inet = inet_sk(sp);
2178 const struct tcp_sock *tp = tcp_sk(sp);
2179 const struct inet_connection_sock *icsk = inet_csk(sp);
2180 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
2181 u8 icsk_pending;
2182 int rx_queue;
2183 int state;
2184
2185 dest = &sp->sk_v6_daddr;
2186 src = &sp->sk_v6_rcv_saddr;
2187 destp = ntohs(inet->inet_dport);
2188 srcp = ntohs(inet->inet_sport);
2189
2190 icsk_pending = smp_load_acquire(&icsk->icsk_pending);
2191 if (icsk_pending == ICSK_TIME_RETRANS ||
2192 icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2193 icsk_pending == ICSK_TIME_LOSS_PROBE) {
2194 timer_active = 1;
2195 timer_expires = icsk->icsk_timeout;
2196 } else if (icsk_pending == ICSK_TIME_PROBE0) {
2197 timer_active = 4;
2198 timer_expires = icsk->icsk_timeout;
2199 } else if (timer_pending(&sp->sk_timer)) {
2200 timer_active = 2;
2201 timer_expires = sp->sk_timer.expires;
2202 } else {
2203 timer_active = 0;
2204 timer_expires = jiffies;
2205 }
2206
2207 state = inet_sk_state_load(sp);
2208 if (state == TCP_LISTEN)
2209 rx_queue = READ_ONCE(sp->sk_ack_backlog);
2210 else
2211 /* Because we don't lock the socket,
2212 * we might find a transient negative value.
2213 */
2214 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2215 READ_ONCE(tp->copied_seq), 0);
2216
2217 seq_printf(seq,
2218 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2219 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2220 i,
2221 src->s6_addr32[0], src->s6_addr32[1],
2222 src->s6_addr32[2], src->s6_addr32[3], srcp,
2223 dest->s6_addr32[0], dest->s6_addr32[1],
2224 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2225 state,
2226 READ_ONCE(tp->write_seq) - tp->snd_una,
2227 rx_queue,
2228 timer_active,
2229 jiffies_delta_to_clock_t(timer_expires - jiffies),
2230 icsk->icsk_retransmits,
2231 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2232 icsk->icsk_probes_out,
2233 sock_i_ino(sp),
2234 refcount_read(&sp->sk_refcnt), sp,
2235 jiffies_to_clock_t(icsk->icsk_rto),
2236 jiffies_to_clock_t(icsk->icsk_ack.ato),
2237 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2238 tcp_snd_cwnd(tp),
2239 state == TCP_LISTEN ?
2240 fastopenq->max_qlen :
2241 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2242 );
2243 }
2244
2245 static void get_timewait6_sock(struct seq_file *seq,
2246 struct inet_timewait_sock *tw, int i)
2247 {
2248 long delta = tw->tw_timer.expires - jiffies;
2249 const struct in6_addr *dest, *src;
2250 __u16 destp, srcp;
2251
2252 dest = &tw->tw_v6_daddr;
2253 src = &tw->tw_v6_rcv_saddr;
2254 destp = ntohs(tw->tw_dport);
2255 srcp = ntohs(tw->tw_sport);
2256
2257 seq_printf(seq,
2258 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2259 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2260 i,
2261 src->s6_addr32[0], src->s6_addr32[1],
2262 src->s6_addr32[2], src->s6_addr32[3], srcp,
2263 dest->s6_addr32[0], dest->s6_addr32[1],
2264 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2265 READ_ONCE(tw->tw_substate), 0, 0,
2266 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2267 refcount_read(&tw->tw_refcnt), tw);
2268 }
2269
2270 static int tcp6_seq_show(struct seq_file *seq, void *v)
2271 {
2272 struct tcp_iter_state *st;
2273 struct sock *sk = v;
2274
2275 if (v == SEQ_START_TOKEN) {
2276 seq_puts(seq,
2277 " sl "
2278 "local_address "
2279 "remote_address "
2280 "st tx_queue rx_queue tr tm->when retrnsmt"
2281 " uid timeout inode\n");
2282 goto out;
2283 }
2284 st = seq->private;
2285
2286 if (sk->sk_state == TCP_TIME_WAIT)
2287 get_timewait6_sock(seq, v, st->num);
2288 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2289 get_openreq6(seq, v, st->num);
2290 else
2291 get_tcp6_sock(seq, v, st->num);
2292 out:
2293 return 0;
2294 }
2295
2296 static const struct seq_operations tcp6_seq_ops = {
2297 .show = tcp6_seq_show,
2298 .start = tcp_seq_start,
2299 .next = tcp_seq_next,
2300 .stop = tcp_seq_stop,
2301 };
2302
2303 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2304 .family = AF_INET6,
2305 };
2306
2307 int __net_init tcp6_proc_init(struct net *net)
2308 {
2309 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2310 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2311 return -ENOMEM;
2312 return 0;
2313 }
2314
2315 void tcp6_proc_exit(struct net *net)
2316 {
2317 remove_proc_entry("tcp6", net->proc_net);
2318 }
2319 #endif
2320
2321 struct proto tcpv6_prot = {
2322 .name = "TCPv6",
2323 .owner = THIS_MODULE,
2324 .close = tcp_close,
2325 .pre_connect = tcp_v6_pre_connect,
2326 .connect = tcp_v6_connect,
2327 .disconnect = tcp_disconnect,
2328 .accept = inet_csk_accept,
2329 .ioctl = tcp_ioctl,
2330 .init = tcp_v6_init_sock,
2331 .destroy = tcp_v4_destroy_sock,
2332 .shutdown = tcp_shutdown,
2333 .setsockopt = tcp_setsockopt,
2334 .getsockopt = tcp_getsockopt,
2335 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
2336 .keepalive = tcp_set_keepalive,
2337 .recvmsg = tcp_recvmsg,
2338 .sendmsg = tcp_sendmsg,
2339 .splice_eof = tcp_splice_eof,
2340 .backlog_rcv = tcp_v6_do_rcv,
2341 .release_cb = tcp_release_cb,
2342 .hash = inet6_hash,
2343 .unhash = inet_unhash,
2344 .get_port = inet_csk_get_port,
2345 .put_port = inet_put_port,
2346 #ifdef CONFIG_BPF_SYSCALL
2347 .psock_update_sk_prot = tcp_bpf_update_proto,
2348 #endif
2349 .enter_memory_pressure = tcp_enter_memory_pressure,
2350 .leave_memory_pressure = tcp_leave_memory_pressure,
2351 .stream_memory_free = tcp_stream_memory_free,
2352 .sockets_allocated = &tcp_sockets_allocated,
2353
2354 .memory_allocated = &tcp_memory_allocated,
2355 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
2356
2357 .memory_pressure = &tcp_memory_pressure,
2358 .orphan_count = &tcp_orphan_count,
2359 .sysctl_mem = sysctl_tcp_mem,
2360 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2361 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2362 .max_header = MAX_TCP_HEADER,
2363 .obj_size = sizeof(struct tcp6_sock),
2364 .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6),
2365 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2366 .twsk_prot = &tcp6_timewait_sock_ops,
2367 .rsk_prot = &tcp6_request_sock_ops,
2368 .h.hashinfo = NULL,
2369 .no_autobind = true,
2370 .diag_destroy = tcp_abort,
2371 };
2372 EXPORT_SYMBOL_GPL(tcpv6_prot);
2373
2374
2375 static struct inet_protosw tcpv6_protosw = {
2376 .type = SOCK_STREAM,
2377 .protocol = IPPROTO_TCP,
2378 .prot = &tcpv6_prot,
2379 .ops = &inet6_stream_ops,
2380 .flags = INET_PROTOSW_PERMANENT |
2381 INET_PROTOSW_ICSK,
2382 };
2383
2384 static int __net_init tcpv6_net_init(struct net *net)
2385 {
2386 int res;
2387
2388 res = inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2389 SOCK_RAW, IPPROTO_TCP, net);
2390 if (!res)
2391 net->ipv6.tcp_sk->sk_clockid = CLOCK_MONOTONIC;
2392
2393 return res;
2394 }
2395
2396 static void __net_exit tcpv6_net_exit(struct net *net)
2397 {
2398 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2399 }
2400
2401 static struct pernet_operations tcpv6_net_ops = {
2402 .init = tcpv6_net_init,
2403 .exit = tcpv6_net_exit,
2404 };
2405
2406 int __init tcpv6_init(void)
2407 {
2408 int ret;
2409
2410 net_hotdata.tcpv6_protocol = (struct inet6_protocol) {
2411 .handler = tcp_v6_rcv,
2412 .err_handler = tcp_v6_err,
2413 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
2414 };
2415 ret = inet6_add_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2416 if (ret)
2417 goto out;
2418
2419 /* register inet6 protocol */
2420 ret = inet6_register_protosw(&tcpv6_protosw);
2421 if (ret)
2422 goto out_tcpv6_protocol;
2423
2424 ret = register_pernet_subsys(&tcpv6_net_ops);
2425 if (ret)
2426 goto out_tcpv6_protosw;
2427
2428 ret = mptcpv6_init();
2429 if (ret)
2430 goto out_tcpv6_pernet_subsys;
2431
2432 out:
2433 return ret;
2434
2435 out_tcpv6_pernet_subsys:
2436 unregister_pernet_subsys(&tcpv6_net_ops);
2437 out_tcpv6_protosw:
2438 inet6_unregister_protosw(&tcpv6_protosw);
2439 out_tcpv6_protocol:
2440 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2441 goto out;
2442 }
2443
2444 void tcpv6_exit(void)
2445 {
2446 unregister_pernet_subsys(&tcpv6_net_ops);
2447 inet6_unregister_protosw(&tcpv6_protosw);
2448 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2449 }
2450