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 if (sk->sk_state == TCP_TIME_WAIT)
971 mark = inet_twsk(sk)->tw_mark;
972 else
973 mark = READ_ONCE(sk->sk_mark);
974 skb_set_delivery_time(buff, tcp_transmit_time(sk), SKB_CLOCK_MONOTONIC);
975 }
976 if (txhash) {
977 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
978 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
979 }
980 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
981 fl6.fl6_dport = t1->dest;
982 fl6.fl6_sport = t1->source;
983 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
984 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
985
986 /* Pass a socket to ip6_dst_lookup either it is for RST
987 * Underlying function will use this to retrieve the network
988 * namespace
989 */
990 if (sk && sk->sk_state != TCP_TIME_WAIT)
991 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
992 else
993 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
994 if (!IS_ERR(dst)) {
995 skb_dst_set(buff, dst);
996 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
997 tclass & ~INET_ECN_MASK, priority);
998 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
999 if (rst)
1000 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
1001 return;
1002 }
1003
1004 kfree_skb(buff);
1005 }
1006
tcp_v6_send_reset(const struct sock * sk,struct sk_buff * skb,enum sk_rst_reason reason)1007 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb,
1008 enum sk_rst_reason reason)
1009 {
1010 const struct tcphdr *th = tcp_hdr(skb);
1011 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1012 const __u8 *md5_hash_location = NULL;
1013 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1014 bool allocated_traffic_key = false;
1015 #endif
1016 const struct tcp_ao_hdr *aoh;
1017 struct tcp_key key = {};
1018 u32 seq = 0, ack_seq = 0;
1019 __be32 label = 0;
1020 u32 priority = 0;
1021 struct net *net;
1022 u32 txhash = 0;
1023 int oif = 0;
1024 #ifdef CONFIG_TCP_MD5SIG
1025 unsigned char newhash[16];
1026 int genhash;
1027 struct sock *sk1 = NULL;
1028 #endif
1029
1030 if (th->rst)
1031 return;
1032
1033 /* If sk not NULL, it means we did a successful lookup and incoming
1034 * route had to be correct. prequeue might have dropped our dst.
1035 */
1036 if (!sk && !ipv6_unicast_destination(skb))
1037 return;
1038
1039 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1040 /* Invalid TCP option size or twice included auth */
1041 if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
1042 return;
1043 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1044 rcu_read_lock();
1045 #endif
1046 #ifdef CONFIG_TCP_MD5SIG
1047 if (sk && sk_fullsock(sk)) {
1048 int l3index;
1049
1050 /* sdif set, means packet ingressed via a device
1051 * in an L3 domain and inet_iif is set to it.
1052 */
1053 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1054 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1055 if (key.md5_key)
1056 key.type = TCP_KEY_MD5;
1057 } else if (md5_hash_location) {
1058 int dif = tcp_v6_iif_l3_slave(skb);
1059 int sdif = tcp_v6_sdif(skb);
1060 int l3index;
1061
1062 /*
1063 * active side is lost. Try to find listening socket through
1064 * source port, and then find md5 key through listening socket.
1065 * we are not loose security here:
1066 * Incoming packet is checked with md5 hash with finding key,
1067 * no RST generated if md5 hash doesn't match.
1068 */
1069 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1070 NULL, 0, &ipv6h->saddr, th->source,
1071 &ipv6h->daddr, ntohs(th->source),
1072 dif, sdif);
1073 if (!sk1)
1074 goto out;
1075
1076 /* sdif set, means packet ingressed via a device
1077 * in an L3 domain and dif is set to it.
1078 */
1079 l3index = tcp_v6_sdif(skb) ? dif : 0;
1080
1081 key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1082 if (!key.md5_key)
1083 goto out;
1084 key.type = TCP_KEY_MD5;
1085
1086 genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb);
1087 if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
1088 goto out;
1089 }
1090 #endif
1091
1092 if (th->ack)
1093 seq = ntohl(th->ack_seq);
1094 else
1095 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1096 (th->doff << 2);
1097
1098 #ifdef CONFIG_TCP_AO
1099 if (aoh) {
1100 int l3index;
1101
1102 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1103 if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq,
1104 &key.ao_key, &key.traffic_key,
1105 &allocated_traffic_key,
1106 &key.rcv_next, &key.sne))
1107 goto out;
1108 key.type = TCP_KEY_AO;
1109 }
1110 #endif
1111
1112 if (sk) {
1113 oif = sk->sk_bound_dev_if;
1114 if (sk_fullsock(sk)) {
1115 if (inet6_test_bit(REPFLOW, sk))
1116 label = ip6_flowlabel(ipv6h);
1117 priority = READ_ONCE(sk->sk_priority);
1118 txhash = sk->sk_txhash;
1119 }
1120 if (sk->sk_state == TCP_TIME_WAIT) {
1121 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1122 priority = inet_twsk(sk)->tw_priority;
1123 txhash = inet_twsk(sk)->tw_txhash;
1124 }
1125 } else {
1126 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1127 label = ip6_flowlabel(ipv6h);
1128 }
1129
1130 trace_tcp_send_reset(sk, skb, reason);
1131
1132 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
1133 ipv6_get_dsfield(ipv6h), label, priority, txhash,
1134 &key);
1135
1136 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1137 out:
1138 if (allocated_traffic_key)
1139 kfree(key.traffic_key);
1140 rcu_read_unlock();
1141 #endif
1142 }
1143
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)1144 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1145 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1146 struct tcp_key *key, u8 tclass,
1147 __be32 label, u32 priority, u32 txhash)
1148 {
1149 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0,
1150 tclass, label, priority, txhash, key);
1151 }
1152
tcp_v6_timewait_ack(struct sock * sk,struct sk_buff * skb)1153 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1154 {
1155 struct inet_timewait_sock *tw = inet_twsk(sk);
1156 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1157 struct tcp_key key = {};
1158 #ifdef CONFIG_TCP_AO
1159 struct tcp_ao_info *ao_info;
1160
1161 if (static_branch_unlikely(&tcp_ao_needed.key)) {
1162
1163 /* FIXME: the segment to-be-acked is not verified yet */
1164 ao_info = rcu_dereference(tcptw->ao_info);
1165 if (ao_info) {
1166 const struct tcp_ao_hdr *aoh;
1167
1168 /* Invalid TCP option size or twice included auth */
1169 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1170 goto out;
1171 if (aoh)
1172 key.ao_key = tcp_ao_established_key(ao_info,
1173 aoh->rnext_keyid, -1);
1174 }
1175 }
1176 if (key.ao_key) {
1177 struct tcp_ao_key *rnext_key;
1178
1179 key.traffic_key = snd_other_key(key.ao_key);
1180 /* rcv_next switches to our rcv_next */
1181 rnext_key = READ_ONCE(ao_info->rnext_key);
1182 key.rcv_next = rnext_key->rcvid;
1183 key.sne = READ_ONCE(ao_info->snd_sne);
1184 key.type = TCP_KEY_AO;
1185 #else
1186 if (0) {
1187 #endif
1188 #ifdef CONFIG_TCP_MD5SIG
1189 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1190 key.md5_key = tcp_twsk_md5_key(tcptw);
1191 if (key.md5_key)
1192 key.type = TCP_KEY_MD5;
1193 #endif
1194 }
1195
1196 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt,
1197 READ_ONCE(tcptw->tw_rcv_nxt),
1198 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1199 tcp_tw_tsval(tcptw),
1200 READ_ONCE(tcptw->tw_ts_recent), tw->tw_bound_dev_if,
1201 &key, tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel),
1202 tw->tw_priority, tw->tw_txhash);
1203
1204 #ifdef CONFIG_TCP_AO
1205 out:
1206 #endif
1207 inet_twsk_put(tw);
1208 }
1209
1210 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1211 struct request_sock *req)
1212 {
1213 struct tcp_key key = {};
1214
1215 #ifdef CONFIG_TCP_AO
1216 if (static_branch_unlikely(&tcp_ao_needed.key) &&
1217 tcp_rsk_used_ao(req)) {
1218 const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
1219 const struct tcp_ao_hdr *aoh;
1220 int l3index;
1221
1222 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1223 /* Invalid TCP option size or twice included auth */
1224 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1225 return;
1226 if (!aoh)
1227 return;
1228 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1229 (union tcp_ao_addr *)addr,
1230 AF_INET6, aoh->rnext_keyid, -1);
1231 if (unlikely(!key.ao_key)) {
1232 /* Send ACK with any matching MKT for the peer */
1233 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1234 (union tcp_ao_addr *)addr,
1235 AF_INET6, -1, -1);
1236 /* Matching key disappeared (user removed the key?)
1237 * let the handshake timeout.
1238 */
1239 if (!key.ao_key) {
1240 net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
1241 addr,
1242 ntohs(tcp_hdr(skb)->source),
1243 &ipv6_hdr(skb)->daddr,
1244 ntohs(tcp_hdr(skb)->dest));
1245 return;
1246 }
1247 }
1248 key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
1249 if (!key.traffic_key)
1250 return;
1251
1252 key.type = TCP_KEY_AO;
1253 key.rcv_next = aoh->keyid;
1254 tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
1255 #else
1256 if (0) {
1257 #endif
1258 #ifdef CONFIG_TCP_MD5SIG
1259 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1260 int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1261
1262 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
1263 l3index);
1264 if (key.md5_key)
1265 key.type = TCP_KEY_MD5;
1266 #endif
1267 }
1268
1269 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1270 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1271 */
1272 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1273 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1274 tcp_rsk(req)->rcv_nxt,
1275 tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale,
1276 tcp_rsk_tsval(tcp_rsk(req)),
1277 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
1278 &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
1279 READ_ONCE(sk->sk_priority),
1280 READ_ONCE(tcp_rsk(req)->txhash));
1281 if (tcp_key_is_ao(&key))
1282 kfree(key.traffic_key);
1283 }
1284
1285
1286 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1287 {
1288 #ifdef CONFIG_SYN_COOKIES
1289 const struct tcphdr *th = tcp_hdr(skb);
1290
1291 if (!th->syn)
1292 sk = cookie_v6_check(sk, skb);
1293 #endif
1294 return sk;
1295 }
1296
1297 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1298 struct tcphdr *th, u32 *cookie)
1299 {
1300 u16 mss = 0;
1301 #ifdef CONFIG_SYN_COOKIES
1302 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1303 &tcp_request_sock_ipv6_ops, sk, th);
1304 if (mss) {
1305 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1306 tcp_synq_overflow(sk);
1307 }
1308 #endif
1309 return mss;
1310 }
1311
1312 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1313 {
1314 if (skb->protocol == htons(ETH_P_IP))
1315 return tcp_v4_conn_request(sk, skb);
1316
1317 if (!ipv6_unicast_destination(skb))
1318 goto drop;
1319
1320 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1321 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1322 return 0;
1323 }
1324
1325 return tcp_conn_request(&tcp6_request_sock_ops,
1326 &tcp_request_sock_ipv6_ops, sk, skb);
1327
1328 drop:
1329 tcp_listendrop(sk);
1330 return 0; /* don't send reset */
1331 }
1332
1333 static void tcp_v6_restore_cb(struct sk_buff *skb)
1334 {
1335 /* We need to move header back to the beginning if xfrm6_policy_check()
1336 * and tcp_v6_fill_cb() are going to be called again.
1337 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1338 */
1339 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1340 sizeof(struct inet6_skb_parm));
1341 }
1342
1343 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1344 struct request_sock *req,
1345 struct dst_entry *dst,
1346 struct request_sock *req_unhash,
1347 bool *own_req)
1348 {
1349 struct inet_request_sock *ireq;
1350 struct ipv6_pinfo *newnp;
1351 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1352 struct ipv6_txoptions *opt;
1353 struct inet_sock *newinet;
1354 bool found_dup_sk = false;
1355 struct tcp_sock *newtp;
1356 struct sock *newsk;
1357 #ifdef CONFIG_TCP_MD5SIG
1358 struct tcp_md5sig_key *key;
1359 int l3index;
1360 #endif
1361 struct flowi6 fl6;
1362
1363 if (skb->protocol == htons(ETH_P_IP)) {
1364 /*
1365 * v6 mapped
1366 */
1367
1368 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1369 req_unhash, own_req);
1370
1371 if (!newsk)
1372 return NULL;
1373
1374 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1375
1376 newnp = tcp_inet6_sk(newsk);
1377 newtp = tcp_sk(newsk);
1378
1379 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1380
1381 newnp->saddr = newsk->sk_v6_rcv_saddr;
1382
1383 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1384 if (sk_is_mptcp(newsk))
1385 mptcpv6_handle_mapped(newsk, true);
1386 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1387 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1388 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1389 #endif
1390
1391 newnp->ipv6_mc_list = NULL;
1392 newnp->ipv6_ac_list = NULL;
1393 newnp->ipv6_fl_list = NULL;
1394 newnp->pktoptions = NULL;
1395 newnp->opt = NULL;
1396 newnp->mcast_oif = inet_iif(skb);
1397 newnp->mcast_hops = ip_hdr(skb)->ttl;
1398 newnp->rcv_flowinfo = 0;
1399 if (inet6_test_bit(REPFLOW, sk))
1400 newnp->flow_label = 0;
1401
1402 /*
1403 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1404 * here, tcp_create_openreq_child now does this for us, see the comment in
1405 * that function for the gory details. -acme
1406 */
1407
1408 /* It is tricky place. Until this moment IPv4 tcp
1409 worked with IPv6 icsk.icsk_af_ops.
1410 Sync it now.
1411 */
1412 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1413
1414 return newsk;
1415 }
1416
1417 ireq = inet_rsk(req);
1418
1419 if (sk_acceptq_is_full(sk))
1420 goto out_overflow;
1421
1422 if (!dst) {
1423 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1424 if (!dst)
1425 goto out;
1426 }
1427
1428 newsk = tcp_create_openreq_child(sk, req, skb);
1429 if (!newsk)
1430 goto out_nonewsk;
1431
1432 /*
1433 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1434 * count here, tcp_create_openreq_child now does this for us, see the
1435 * comment in that function for the gory details. -acme
1436 */
1437
1438 newsk->sk_gso_type = SKB_GSO_TCPV6;
1439 inet6_sk_rx_dst_set(newsk, skb);
1440
1441 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1442
1443 newtp = tcp_sk(newsk);
1444 newinet = inet_sk(newsk);
1445 newnp = tcp_inet6_sk(newsk);
1446
1447 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1448
1449 ip6_dst_store(newsk, dst, NULL, NULL);
1450
1451 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1452 newnp->saddr = ireq->ir_v6_loc_addr;
1453 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1454 newsk->sk_bound_dev_if = ireq->ir_iif;
1455
1456 /* Now IPv6 options...
1457
1458 First: no IPv4 options.
1459 */
1460 newinet->inet_opt = NULL;
1461 newnp->ipv6_mc_list = NULL;
1462 newnp->ipv6_ac_list = NULL;
1463 newnp->ipv6_fl_list = NULL;
1464
1465 /* Clone RX bits */
1466 newnp->rxopt.all = np->rxopt.all;
1467
1468 newnp->pktoptions = NULL;
1469 newnp->opt = NULL;
1470 newnp->mcast_oif = tcp_v6_iif(skb);
1471 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1472 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1473 if (inet6_test_bit(REPFLOW, sk))
1474 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1475
1476 /* Set ToS of the new socket based upon the value of incoming SYN.
1477 * ECT bits are set later in tcp_init_transfer().
1478 */
1479 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1480 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1481
1482 /* Clone native IPv6 options from listening socket (if any)
1483
1484 Yes, keeping reference count would be much more clever,
1485 but we make one more one thing there: reattach optmem
1486 to newsk.
1487 */
1488 opt = ireq->ipv6_opt;
1489 if (!opt)
1490 opt = rcu_dereference(np->opt);
1491 if (opt) {
1492 opt = ipv6_dup_options(newsk, opt);
1493 RCU_INIT_POINTER(newnp->opt, opt);
1494 }
1495 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1496 if (opt)
1497 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1498 opt->opt_flen;
1499
1500 tcp_ca_openreq_child(newsk, dst);
1501
1502 tcp_sync_mss(newsk, dst_mtu(dst));
1503 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1504
1505 tcp_initialize_rcv_mss(newsk);
1506
1507 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1508 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1509
1510 #ifdef CONFIG_TCP_MD5SIG
1511 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1512
1513 if (!tcp_rsk_used_ao(req)) {
1514 /* Copy over the MD5 key from the original socket */
1515 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1516 if (key) {
1517 const union tcp_md5_addr *addr;
1518
1519 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1520 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1521 inet_csk_prepare_forced_close(newsk);
1522 tcp_done(newsk);
1523 goto out;
1524 }
1525 }
1526 }
1527 #endif
1528 #ifdef CONFIG_TCP_AO
1529 /* Copy over tcp_ao_info if any */
1530 if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
1531 goto out; /* OOM */
1532 #endif
1533
1534 if (__inet_inherit_port(sk, newsk) < 0) {
1535 inet_csk_prepare_forced_close(newsk);
1536 tcp_done(newsk);
1537 goto out;
1538 }
1539 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1540 &found_dup_sk);
1541 if (*own_req) {
1542 tcp_move_syn(newtp, req);
1543
1544 /* Clone pktoptions received with SYN, if we own the req */
1545 if (ireq->pktopts) {
1546 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1547 consume_skb(ireq->pktopts);
1548 ireq->pktopts = NULL;
1549 if (newnp->pktoptions)
1550 tcp_v6_restore_cb(newnp->pktoptions);
1551 }
1552 } else {
1553 if (!req_unhash && found_dup_sk) {
1554 /* This code path should only be executed in the
1555 * syncookie case only
1556 */
1557 bh_unlock_sock(newsk);
1558 sock_put(newsk);
1559 newsk = NULL;
1560 }
1561 }
1562
1563 return newsk;
1564
1565 out_overflow:
1566 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1567 out_nonewsk:
1568 dst_release(dst);
1569 out:
1570 tcp_listendrop(sk);
1571 return NULL;
1572 }
1573
1574 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1575 u32));
1576 /* The socket must have it's spinlock held when we get
1577 * here, unless it is a TCP_LISTEN socket.
1578 *
1579 * We have a potential double-lock case here, so even when
1580 * doing backlog processing we use the BH locking scheme.
1581 * This is because we cannot sleep with the original spinlock
1582 * held.
1583 */
1584 INDIRECT_CALLABLE_SCOPE
1585 int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1586 {
1587 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1588 struct sk_buff *opt_skb = NULL;
1589 enum skb_drop_reason reason;
1590 struct tcp_sock *tp;
1591
1592 /* Imagine: socket is IPv6. IPv4 packet arrives,
1593 goes to IPv4 receive handler and backlogged.
1594 From backlog it always goes here. Kerboom...
1595 Fortunately, tcp_rcv_established and rcv_established
1596 handle them correctly, but it is not case with
1597 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1598 */
1599
1600 if (skb->protocol == htons(ETH_P_IP))
1601 return tcp_v4_do_rcv(sk, skb);
1602
1603 /*
1604 * socket locking is here for SMP purposes as backlog rcv
1605 * is currently called with bh processing disabled.
1606 */
1607
1608 /* Do Stevens' IPV6_PKTOPTIONS.
1609
1610 Yes, guys, it is the only place in our code, where we
1611 may make it not affecting IPv4.
1612 The rest of code is protocol independent,
1613 and I do not like idea to uglify IPv4.
1614
1615 Actually, all the idea behind IPV6_PKTOPTIONS
1616 looks not very well thought. For now we latch
1617 options, received in the last packet, enqueued
1618 by tcp. Feel free to propose better solution.
1619 --ANK (980728)
1620 */
1621 if (np->rxopt.all && sk->sk_state != TCP_LISTEN)
1622 opt_skb = skb_clone_and_charge_r(skb, sk);
1623
1624 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1625 struct dst_entry *dst;
1626
1627 dst = rcu_dereference_protected(sk->sk_rx_dst,
1628 lockdep_sock_is_held(sk));
1629
1630 sock_rps_save_rxhash(sk, skb);
1631 sk_mark_napi_id(sk, skb);
1632 if (dst) {
1633 if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1634 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1635 dst, sk->sk_rx_dst_cookie) == NULL) {
1636 RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1637 dst_release(dst);
1638 }
1639 }
1640
1641 tcp_rcv_established(sk, skb);
1642 if (opt_skb)
1643 goto ipv6_pktoptions;
1644 return 0;
1645 }
1646
1647 if (tcp_checksum_complete(skb))
1648 goto csum_err;
1649
1650 if (sk->sk_state == TCP_LISTEN) {
1651 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1652
1653 if (nsk != sk) {
1654 if (nsk) {
1655 reason = tcp_child_process(sk, nsk, skb);
1656 if (reason)
1657 goto reset;
1658 }
1659 return 0;
1660 }
1661 } else
1662 sock_rps_save_rxhash(sk, skb);
1663
1664 reason = tcp_rcv_state_process(sk, skb);
1665 if (reason)
1666 goto reset;
1667 if (opt_skb)
1668 goto ipv6_pktoptions;
1669 return 0;
1670
1671 reset:
1672 tcp_v6_send_reset(sk, skb, sk_rst_convert_drop_reason(reason));
1673 discard:
1674 if (opt_skb)
1675 __kfree_skb(opt_skb);
1676 sk_skb_reason_drop(sk, skb, reason);
1677 return 0;
1678 csum_err:
1679 reason = SKB_DROP_REASON_TCP_CSUM;
1680 trace_tcp_bad_csum(skb);
1681 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1682 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1683 goto discard;
1684
1685
1686 ipv6_pktoptions:
1687 /* Do you ask, what is it?
1688
1689 1. skb was enqueued by tcp.
1690 2. skb is added to tail of read queue, rather than out of order.
1691 3. socket is not in passive state.
1692 4. Finally, it really contains options, which user wants to receive.
1693 */
1694 tp = tcp_sk(sk);
1695 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1696 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1697 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1698 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb));
1699 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1700 WRITE_ONCE(np->mcast_hops,
1701 ipv6_hdr(opt_skb)->hop_limit);
1702 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1703 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1704 if (inet6_test_bit(REPFLOW, sk))
1705 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1706 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1707 tcp_v6_restore_cb(opt_skb);
1708 opt_skb = xchg(&np->pktoptions, opt_skb);
1709 } else {
1710 __kfree_skb(opt_skb);
1711 opt_skb = xchg(&np->pktoptions, NULL);
1712 }
1713 }
1714
1715 consume_skb(opt_skb);
1716 return 0;
1717 }
1718
1719 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1720 const struct tcphdr *th)
1721 {
1722 /* This is tricky: we move IP6CB at its correct location into
1723 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1724 * _decode_session6() uses IP6CB().
1725 * barrier() makes sure compiler won't play aliasing games.
1726 */
1727 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1728 sizeof(struct inet6_skb_parm));
1729 barrier();
1730
1731 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1732 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1733 skb->len - th->doff*4);
1734 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1735 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1736 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1737 TCP_SKB_CB(skb)->sacked = 0;
1738 TCP_SKB_CB(skb)->has_rxtstamp =
1739 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1740 }
1741
1742 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1743 {
1744 enum skb_drop_reason drop_reason;
1745 int sdif = inet6_sdif(skb);
1746 int dif = inet6_iif(skb);
1747 const struct tcphdr *th;
1748 const struct ipv6hdr *hdr;
1749 struct sock *sk = NULL;
1750 bool refcounted;
1751 int ret;
1752 u32 isn;
1753 struct net *net = dev_net(skb->dev);
1754
1755 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1756 if (skb->pkt_type != PACKET_HOST)
1757 goto discard_it;
1758
1759 /*
1760 * Count it even if it's bad.
1761 */
1762 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1763
1764 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1765 goto discard_it;
1766
1767 th = (const struct tcphdr *)skb->data;
1768
1769 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1770 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1771 goto bad_packet;
1772 }
1773 if (!pskb_may_pull(skb, th->doff*4))
1774 goto discard_it;
1775
1776 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1777 goto csum_error;
1778
1779 th = (const struct tcphdr *)skb->data;
1780 hdr = ipv6_hdr(skb);
1781
1782 lookup:
1783 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1784 th->source, th->dest, inet6_iif(skb), sdif,
1785 &refcounted);
1786 if (!sk)
1787 goto no_tcp_socket;
1788
1789 if (sk->sk_state == TCP_TIME_WAIT)
1790 goto do_time_wait;
1791
1792 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1793 struct request_sock *req = inet_reqsk(sk);
1794 bool req_stolen = false;
1795 struct sock *nsk;
1796
1797 sk = req->rsk_listener;
1798 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1799 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1800 else
1801 drop_reason = tcp_inbound_hash(sk, req, skb,
1802 &hdr->saddr, &hdr->daddr,
1803 AF_INET6, dif, sdif);
1804 if (drop_reason) {
1805 sk_drops_add(sk, skb);
1806 reqsk_put(req);
1807 goto discard_it;
1808 }
1809 if (tcp_checksum_complete(skb)) {
1810 reqsk_put(req);
1811 goto csum_error;
1812 }
1813 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1814 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1815 if (!nsk) {
1816 inet_csk_reqsk_queue_drop_and_put(sk, req);
1817 goto lookup;
1818 }
1819 sk = nsk;
1820 /* reuseport_migrate_sock() has already held one sk_refcnt
1821 * before returning.
1822 */
1823 } else {
1824 sock_hold(sk);
1825 }
1826 refcounted = true;
1827 nsk = NULL;
1828 if (!tcp_filter(sk, skb)) {
1829 th = (const struct tcphdr *)skb->data;
1830 hdr = ipv6_hdr(skb);
1831 tcp_v6_fill_cb(skb, hdr, th);
1832 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1833 } else {
1834 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1835 }
1836 if (!nsk) {
1837 reqsk_put(req);
1838 if (req_stolen) {
1839 /* Another cpu got exclusive access to req
1840 * and created a full blown socket.
1841 * Try to feed this packet to this socket
1842 * instead of discarding it.
1843 */
1844 tcp_v6_restore_cb(skb);
1845 sock_put(sk);
1846 goto lookup;
1847 }
1848 goto discard_and_relse;
1849 }
1850 nf_reset_ct(skb);
1851 if (nsk == sk) {
1852 reqsk_put(req);
1853 tcp_v6_restore_cb(skb);
1854 } else {
1855 drop_reason = tcp_child_process(sk, nsk, skb);
1856 if (drop_reason) {
1857 enum sk_rst_reason rst_reason;
1858
1859 rst_reason = sk_rst_convert_drop_reason(drop_reason);
1860 tcp_v6_send_reset(nsk, skb, rst_reason);
1861 goto discard_and_relse;
1862 }
1863 sock_put(sk);
1864 return 0;
1865 }
1866 }
1867
1868 process:
1869 if (static_branch_unlikely(&ip6_min_hopcount)) {
1870 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1871 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) {
1872 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1873 drop_reason = SKB_DROP_REASON_TCP_MINTTL;
1874 goto discard_and_relse;
1875 }
1876 }
1877
1878 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1879 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1880 goto discard_and_relse;
1881 }
1882
1883 drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr,
1884 AF_INET6, dif, sdif);
1885 if (drop_reason)
1886 goto discard_and_relse;
1887
1888 nf_reset_ct(skb);
1889
1890 if (tcp_filter(sk, skb)) {
1891 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1892 goto discard_and_relse;
1893 }
1894 th = (const struct tcphdr *)skb->data;
1895 hdr = ipv6_hdr(skb);
1896 tcp_v6_fill_cb(skb, hdr, th);
1897
1898 skb->dev = NULL;
1899
1900 if (sk->sk_state == TCP_LISTEN) {
1901 ret = tcp_v6_do_rcv(sk, skb);
1902 goto put_and_return;
1903 }
1904
1905 sk_incoming_cpu_update(sk);
1906
1907 bh_lock_sock_nested(sk);
1908 tcp_segs_in(tcp_sk(sk), skb);
1909 ret = 0;
1910 if (!sock_owned_by_user(sk)) {
1911 ret = tcp_v6_do_rcv(sk, skb);
1912 } else {
1913 if (tcp_add_backlog(sk, skb, &drop_reason))
1914 goto discard_and_relse;
1915 }
1916 bh_unlock_sock(sk);
1917 put_and_return:
1918 if (refcounted)
1919 sock_put(sk);
1920 return ret ? -1 : 0;
1921
1922 no_tcp_socket:
1923 drop_reason = SKB_DROP_REASON_NO_SOCKET;
1924 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1925 goto discard_it;
1926
1927 tcp_v6_fill_cb(skb, hdr, th);
1928
1929 if (tcp_checksum_complete(skb)) {
1930 csum_error:
1931 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1932 trace_tcp_bad_csum(skb);
1933 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1934 bad_packet:
1935 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1936 } else {
1937 tcp_v6_send_reset(NULL, skb, sk_rst_convert_drop_reason(drop_reason));
1938 }
1939
1940 discard_it:
1941 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1942 sk_skb_reason_drop(sk, skb, drop_reason);
1943 return 0;
1944
1945 discard_and_relse:
1946 sk_drops_add(sk, skb);
1947 if (refcounted)
1948 sock_put(sk);
1949 goto discard_it;
1950
1951 do_time_wait:
1952 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1953 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1954 inet_twsk_put(inet_twsk(sk));
1955 goto discard_it;
1956 }
1957
1958 tcp_v6_fill_cb(skb, hdr, th);
1959
1960 if (tcp_checksum_complete(skb)) {
1961 inet_twsk_put(inet_twsk(sk));
1962 goto csum_error;
1963 }
1964
1965 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, &isn)) {
1966 case TCP_TW_SYN:
1967 {
1968 struct sock *sk2;
1969
1970 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1971 skb, __tcp_hdrlen(th),
1972 &ipv6_hdr(skb)->saddr, th->source,
1973 &ipv6_hdr(skb)->daddr,
1974 ntohs(th->dest),
1975 tcp_v6_iif_l3_slave(skb),
1976 sdif);
1977 if (sk2) {
1978 struct inet_timewait_sock *tw = inet_twsk(sk);
1979 inet_twsk_deschedule_put(tw);
1980 sk = sk2;
1981 tcp_v6_restore_cb(skb);
1982 refcounted = false;
1983 __this_cpu_write(tcp_tw_isn, isn);
1984 goto process;
1985 }
1986 }
1987 /* to ACK */
1988 fallthrough;
1989 case TCP_TW_ACK:
1990 tcp_v6_timewait_ack(sk, skb);
1991 break;
1992 case TCP_TW_RST:
1993 tcp_v6_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET);
1994 inet_twsk_deschedule_put(inet_twsk(sk));
1995 goto discard_it;
1996 case TCP_TW_SUCCESS:
1997 ;
1998 }
1999 goto discard_it;
2000 }
2001
2002 void tcp_v6_early_demux(struct sk_buff *skb)
2003 {
2004 struct net *net = dev_net(skb->dev);
2005 const struct ipv6hdr *hdr;
2006 const struct tcphdr *th;
2007 struct sock *sk;
2008
2009 if (skb->pkt_type != PACKET_HOST)
2010 return;
2011
2012 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
2013 return;
2014
2015 hdr = ipv6_hdr(skb);
2016 th = tcp_hdr(skb);
2017
2018 if (th->doff < sizeof(struct tcphdr) / 4)
2019 return;
2020
2021 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
2022 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
2023 &hdr->saddr, th->source,
2024 &hdr->daddr, ntohs(th->dest),
2025 inet6_iif(skb), inet6_sdif(skb));
2026 if (sk) {
2027 skb->sk = sk;
2028 skb->destructor = sock_edemux;
2029 if (sk_fullsock(sk)) {
2030 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
2031
2032 if (dst)
2033 dst = dst_check(dst, sk->sk_rx_dst_cookie);
2034 if (dst &&
2035 sk->sk_rx_dst_ifindex == skb->skb_iif)
2036 skb_dst_set_noref(skb, dst);
2037 }
2038 }
2039 }
2040
2041 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
2042 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
2043 .twsk_destructor = tcp_twsk_destructor,
2044 };
2045
2046 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
2047 {
2048 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
2049 }
2050
2051 const struct inet_connection_sock_af_ops ipv6_specific = {
2052 .queue_xmit = inet6_csk_xmit,
2053 .send_check = tcp_v6_send_check,
2054 .rebuild_header = inet6_sk_rebuild_header,
2055 .sk_rx_dst_set = inet6_sk_rx_dst_set,
2056 .conn_request = tcp_v6_conn_request,
2057 .syn_recv_sock = tcp_v6_syn_recv_sock,
2058 .net_header_len = sizeof(struct ipv6hdr),
2059 .setsockopt = ipv6_setsockopt,
2060 .getsockopt = ipv6_getsockopt,
2061 .addr2sockaddr = inet6_csk_addr2sockaddr,
2062 .sockaddr_len = sizeof(struct sockaddr_in6),
2063 .mtu_reduced = tcp_v6_mtu_reduced,
2064 };
2065
2066 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2067 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
2068 #ifdef CONFIG_TCP_MD5SIG
2069 .md5_lookup = tcp_v6_md5_lookup,
2070 .calc_md5_hash = tcp_v6_md5_hash_skb,
2071 .md5_parse = tcp_v6_parse_md5_keys,
2072 #endif
2073 #ifdef CONFIG_TCP_AO
2074 .ao_lookup = tcp_v6_ao_lookup,
2075 .calc_ao_hash = tcp_v6_ao_hash_skb,
2076 .ao_parse = tcp_v6_parse_ao,
2077 .ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
2078 #endif
2079 };
2080 #endif
2081
2082 /*
2083 * TCP over IPv4 via INET6 API
2084 */
2085 static const struct inet_connection_sock_af_ops ipv6_mapped = {
2086 .queue_xmit = ip_queue_xmit,
2087 .send_check = tcp_v4_send_check,
2088 .rebuild_header = inet_sk_rebuild_header,
2089 .sk_rx_dst_set = inet_sk_rx_dst_set,
2090 .conn_request = tcp_v6_conn_request,
2091 .syn_recv_sock = tcp_v6_syn_recv_sock,
2092 .net_header_len = sizeof(struct iphdr),
2093 .setsockopt = ipv6_setsockopt,
2094 .getsockopt = ipv6_getsockopt,
2095 .addr2sockaddr = inet6_csk_addr2sockaddr,
2096 .sockaddr_len = sizeof(struct sockaddr_in6),
2097 .mtu_reduced = tcp_v4_mtu_reduced,
2098 };
2099
2100 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2101 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
2102 #ifdef CONFIG_TCP_MD5SIG
2103 .md5_lookup = tcp_v4_md5_lookup,
2104 .calc_md5_hash = tcp_v4_md5_hash_skb,
2105 .md5_parse = tcp_v6_parse_md5_keys,
2106 #endif
2107 #ifdef CONFIG_TCP_AO
2108 .ao_lookup = tcp_v6_ao_lookup,
2109 .calc_ao_hash = tcp_v4_ao_hash_skb,
2110 .ao_parse = tcp_v6_parse_ao,
2111 .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
2112 #endif
2113 };
2114 #endif
2115
2116 /* NOTE: A lot of things set to zero explicitly by call to
2117 * sk_alloc() so need not be done here.
2118 */
2119 static int tcp_v6_init_sock(struct sock *sk)
2120 {
2121 struct inet_connection_sock *icsk = inet_csk(sk);
2122
2123 tcp_init_sock(sk);
2124
2125 icsk->icsk_af_ops = &ipv6_specific;
2126
2127 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2128 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
2129 #endif
2130
2131 return 0;
2132 }
2133
2134 #ifdef CONFIG_PROC_FS
2135 /* Proc filesystem TCPv6 sock list dumping. */
2136 static void get_openreq6(struct seq_file *seq,
2137 const struct request_sock *req, int i)
2138 {
2139 long ttd = req->rsk_timer.expires - jiffies;
2140 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
2141 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
2142
2143 if (ttd < 0)
2144 ttd = 0;
2145
2146 seq_printf(seq,
2147 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2148 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
2149 i,
2150 src->s6_addr32[0], src->s6_addr32[1],
2151 src->s6_addr32[2], src->s6_addr32[3],
2152 inet_rsk(req)->ir_num,
2153 dest->s6_addr32[0], dest->s6_addr32[1],
2154 dest->s6_addr32[2], dest->s6_addr32[3],
2155 ntohs(inet_rsk(req)->ir_rmt_port),
2156 TCP_SYN_RECV,
2157 0, 0, /* could print option size, but that is af dependent. */
2158 1, /* timers active (only the expire timer) */
2159 jiffies_to_clock_t(ttd),
2160 req->num_timeout,
2161 from_kuid_munged(seq_user_ns(seq),
2162 sock_i_uid(req->rsk_listener)),
2163 0, /* non standard timer */
2164 0, /* open_requests have no inode */
2165 0, req);
2166 }
2167
2168 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2169 {
2170 const struct in6_addr *dest, *src;
2171 __u16 destp, srcp;
2172 int timer_active;
2173 unsigned long timer_expires;
2174 const struct inet_sock *inet = inet_sk(sp);
2175 const struct tcp_sock *tp = tcp_sk(sp);
2176 const struct inet_connection_sock *icsk = inet_csk(sp);
2177 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
2178 int rx_queue;
2179 int state;
2180
2181 dest = &sp->sk_v6_daddr;
2182 src = &sp->sk_v6_rcv_saddr;
2183 destp = ntohs(inet->inet_dport);
2184 srcp = ntohs(inet->inet_sport);
2185
2186 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2187 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2188 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2189 timer_active = 1;
2190 timer_expires = icsk->icsk_timeout;
2191 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2192 timer_active = 4;
2193 timer_expires = icsk->icsk_timeout;
2194 } else if (timer_pending(&sp->sk_timer)) {
2195 timer_active = 2;
2196 timer_expires = sp->sk_timer.expires;
2197 } else {
2198 timer_active = 0;
2199 timer_expires = jiffies;
2200 }
2201
2202 state = inet_sk_state_load(sp);
2203 if (state == TCP_LISTEN)
2204 rx_queue = READ_ONCE(sp->sk_ack_backlog);
2205 else
2206 /* Because we don't lock the socket,
2207 * we might find a transient negative value.
2208 */
2209 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2210 READ_ONCE(tp->copied_seq), 0);
2211
2212 seq_printf(seq,
2213 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2214 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2215 i,
2216 src->s6_addr32[0], src->s6_addr32[1],
2217 src->s6_addr32[2], src->s6_addr32[3], srcp,
2218 dest->s6_addr32[0], dest->s6_addr32[1],
2219 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2220 state,
2221 READ_ONCE(tp->write_seq) - tp->snd_una,
2222 rx_queue,
2223 timer_active,
2224 jiffies_delta_to_clock_t(timer_expires - jiffies),
2225 icsk->icsk_retransmits,
2226 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2227 icsk->icsk_probes_out,
2228 sock_i_ino(sp),
2229 refcount_read(&sp->sk_refcnt), sp,
2230 jiffies_to_clock_t(icsk->icsk_rto),
2231 jiffies_to_clock_t(icsk->icsk_ack.ato),
2232 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2233 tcp_snd_cwnd(tp),
2234 state == TCP_LISTEN ?
2235 fastopenq->max_qlen :
2236 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2237 );
2238 }
2239
2240 static void get_timewait6_sock(struct seq_file *seq,
2241 struct inet_timewait_sock *tw, int i)
2242 {
2243 long delta = tw->tw_timer.expires - jiffies;
2244 const struct in6_addr *dest, *src;
2245 __u16 destp, srcp;
2246
2247 dest = &tw->tw_v6_daddr;
2248 src = &tw->tw_v6_rcv_saddr;
2249 destp = ntohs(tw->tw_dport);
2250 srcp = ntohs(tw->tw_sport);
2251
2252 seq_printf(seq,
2253 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2254 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2255 i,
2256 src->s6_addr32[0], src->s6_addr32[1],
2257 src->s6_addr32[2], src->s6_addr32[3], srcp,
2258 dest->s6_addr32[0], dest->s6_addr32[1],
2259 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2260 READ_ONCE(tw->tw_substate), 0, 0,
2261 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2262 refcount_read(&tw->tw_refcnt), tw);
2263 }
2264
2265 static int tcp6_seq_show(struct seq_file *seq, void *v)
2266 {
2267 struct tcp_iter_state *st;
2268 struct sock *sk = v;
2269
2270 if (v == SEQ_START_TOKEN) {
2271 seq_puts(seq,
2272 " sl "
2273 "local_address "
2274 "remote_address "
2275 "st tx_queue rx_queue tr tm->when retrnsmt"
2276 " uid timeout inode\n");
2277 goto out;
2278 }
2279 st = seq->private;
2280
2281 if (sk->sk_state == TCP_TIME_WAIT)
2282 get_timewait6_sock(seq, v, st->num);
2283 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2284 get_openreq6(seq, v, st->num);
2285 else
2286 get_tcp6_sock(seq, v, st->num);
2287 out:
2288 return 0;
2289 }
2290
2291 static const struct seq_operations tcp6_seq_ops = {
2292 .show = tcp6_seq_show,
2293 .start = tcp_seq_start,
2294 .next = tcp_seq_next,
2295 .stop = tcp_seq_stop,
2296 };
2297
2298 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2299 .family = AF_INET6,
2300 };
2301
2302 int __net_init tcp6_proc_init(struct net *net)
2303 {
2304 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2305 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2306 return -ENOMEM;
2307 return 0;
2308 }
2309
2310 void tcp6_proc_exit(struct net *net)
2311 {
2312 remove_proc_entry("tcp6", net->proc_net);
2313 }
2314 #endif
2315
2316 struct proto tcpv6_prot = {
2317 .name = "TCPv6",
2318 .owner = THIS_MODULE,
2319 .close = tcp_close,
2320 .pre_connect = tcp_v6_pre_connect,
2321 .connect = tcp_v6_connect,
2322 .disconnect = tcp_disconnect,
2323 .accept = inet_csk_accept,
2324 .ioctl = tcp_ioctl,
2325 .init = tcp_v6_init_sock,
2326 .destroy = tcp_v4_destroy_sock,
2327 .shutdown = tcp_shutdown,
2328 .setsockopt = tcp_setsockopt,
2329 .getsockopt = tcp_getsockopt,
2330 .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
2331 .keepalive = tcp_set_keepalive,
2332 .recvmsg = tcp_recvmsg,
2333 .sendmsg = tcp_sendmsg,
2334 .splice_eof = tcp_splice_eof,
2335 .backlog_rcv = tcp_v6_do_rcv,
2336 .release_cb = tcp_release_cb,
2337 .hash = inet6_hash,
2338 .unhash = inet_unhash,
2339 .get_port = inet_csk_get_port,
2340 .put_port = inet_put_port,
2341 #ifdef CONFIG_BPF_SYSCALL
2342 .psock_update_sk_prot = tcp_bpf_update_proto,
2343 #endif
2344 .enter_memory_pressure = tcp_enter_memory_pressure,
2345 .leave_memory_pressure = tcp_leave_memory_pressure,
2346 .stream_memory_free = tcp_stream_memory_free,
2347 .sockets_allocated = &tcp_sockets_allocated,
2348
2349 .memory_allocated = &tcp_memory_allocated,
2350 .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
2351
2352 .memory_pressure = &tcp_memory_pressure,
2353 .orphan_count = &tcp_orphan_count,
2354 .sysctl_mem = sysctl_tcp_mem,
2355 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2356 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2357 .max_header = MAX_TCP_HEADER,
2358 .obj_size = sizeof(struct tcp6_sock),
2359 .ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6),
2360 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2361 .twsk_prot = &tcp6_timewait_sock_ops,
2362 .rsk_prot = &tcp6_request_sock_ops,
2363 .h.hashinfo = NULL,
2364 .no_autobind = true,
2365 .diag_destroy = tcp_abort,
2366 };
2367 EXPORT_SYMBOL_GPL(tcpv6_prot);
2368
2369
2370 static struct inet_protosw tcpv6_protosw = {
2371 .type = SOCK_STREAM,
2372 .protocol = IPPROTO_TCP,
2373 .prot = &tcpv6_prot,
2374 .ops = &inet6_stream_ops,
2375 .flags = INET_PROTOSW_PERMANENT |
2376 INET_PROTOSW_ICSK,
2377 };
2378
2379 static int __net_init tcpv6_net_init(struct net *net)
2380 {
2381 int res;
2382
2383 res = inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2384 SOCK_RAW, IPPROTO_TCP, net);
2385 if (!res)
2386 net->ipv6.tcp_sk->sk_clockid = CLOCK_MONOTONIC;
2387
2388 return res;
2389 }
2390
2391 static void __net_exit tcpv6_net_exit(struct net *net)
2392 {
2393 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2394 }
2395
2396 static struct pernet_operations tcpv6_net_ops = {
2397 .init = tcpv6_net_init,
2398 .exit = tcpv6_net_exit,
2399 };
2400
2401 int __init tcpv6_init(void)
2402 {
2403 int ret;
2404
2405 net_hotdata.tcpv6_protocol = (struct inet6_protocol) {
2406 .handler = tcp_v6_rcv,
2407 .err_handler = tcp_v6_err,
2408 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
2409 };
2410 ret = inet6_add_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2411 if (ret)
2412 goto out;
2413
2414 /* register inet6 protocol */
2415 ret = inet6_register_protosw(&tcpv6_protosw);
2416 if (ret)
2417 goto out_tcpv6_protocol;
2418
2419 ret = register_pernet_subsys(&tcpv6_net_ops);
2420 if (ret)
2421 goto out_tcpv6_protosw;
2422
2423 ret = mptcpv6_init();
2424 if (ret)
2425 goto out_tcpv6_pernet_subsys;
2426
2427 out:
2428 return ret;
2429
2430 out_tcpv6_pernet_subsys:
2431 unregister_pernet_subsys(&tcpv6_net_ops);
2432 out_tcpv6_protosw:
2433 inet6_unregister_protosw(&tcpv6_protosw);
2434 out_tcpv6_protocol:
2435 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2436 goto out;
2437 }
2438
2439 void tcpv6_exit(void)
2440 {
2441 unregister_pernet_subsys(&tcpv6_net_ops);
2442 inet6_unregister_protosw(&tcpv6_protosw);
2443 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2444 }
2445