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 WRITE_ONCE(sk->sk_err, err);
495 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
496
497 tcp_done(sk);
498 } else {
499 WRITE_ONCE(sk->sk_err_soft, err);
500 }
501 goto out;
502 case TCP_LISTEN:
503 break;
504 default:
505 /* check if this ICMP message allows revert of backoff.
506 * (see RFC 6069)
507 */
508 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
509 code == ICMPV6_NOROUTE)
510 tcp_ld_RTO_revert(sk, seq);
511 }
512
513 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
514 WRITE_ONCE(sk->sk_err, err);
515 sk_error_report(sk);
516 } else {
517 WRITE_ONCE(sk->sk_err_soft, err);
518 }
519 out:
520 bh_unlock_sock(sk);
521 sock_put(sk);
522 return 0;
523 }
524
525
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)526 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
527 struct flowi *fl,
528 struct request_sock *req,
529 struct tcp_fastopen_cookie *foc,
530 enum tcp_synack_type synack_type,
531 struct sk_buff *syn_skb)
532 {
533 struct inet_request_sock *ireq = inet_rsk(req);
534 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
535 struct ipv6_txoptions *opt;
536 struct flowi6 *fl6 = &fl->u.ip6;
537 struct sk_buff *skb;
538 int err = -ENOMEM;
539 u8 tclass;
540
541 /* First, grab a route. */
542 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
543 IPPROTO_TCP)) == NULL)
544 goto done;
545
546 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
547
548 if (skb) {
549 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
550 &ireq->ir_v6_rmt_addr);
551
552 fl6->daddr = ireq->ir_v6_rmt_addr;
553 if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts)
554 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
555
556 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
557 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
558 (np->tclass & INET_ECN_MASK) :
559 np->tclass;
560
561 if (!INET_ECN_is_capable(tclass) &&
562 tcp_bpf_ca_needs_ecn((struct sock *)req))
563 tclass |= INET_ECN_ECT_0;
564
565 rcu_read_lock();
566 opt = ireq->ipv6_opt;
567 if (!opt)
568 opt = rcu_dereference(np->opt);
569 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
570 opt, tclass, READ_ONCE(sk->sk_priority));
571 rcu_read_unlock();
572 err = net_xmit_eval(err);
573 }
574
575 done:
576 return err;
577 }
578
579
tcp_v6_reqsk_destructor(struct request_sock * req)580 static void tcp_v6_reqsk_destructor(struct request_sock *req)
581 {
582 kfree(inet_rsk(req)->ipv6_opt);
583 consume_skb(inet_rsk(req)->pktopts);
584 }
585
586 #ifdef CONFIG_TCP_MD5SIG
tcp_v6_md5_do_lookup(const struct sock * sk,const struct in6_addr * addr,int l3index)587 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
588 const struct in6_addr *addr,
589 int l3index)
590 {
591 return tcp_md5_do_lookup(sk, l3index,
592 (union tcp_md5_addr *)addr, AF_INET6);
593 }
594
tcp_v6_md5_lookup(const struct sock * sk,const struct sock * addr_sk)595 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
596 const struct sock *addr_sk)
597 {
598 int l3index;
599
600 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
601 addr_sk->sk_bound_dev_if);
602 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
603 l3index);
604 }
605
tcp_v6_parse_md5_keys(struct sock * sk,int optname,sockptr_t optval,int optlen)606 static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
607 sockptr_t optval, int optlen)
608 {
609 struct tcp_md5sig cmd;
610 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
611 union tcp_ao_addr *addr;
612 int l3index = 0;
613 u8 prefixlen;
614 bool l3flag;
615 u8 flags;
616
617 if (optlen < sizeof(cmd))
618 return -EINVAL;
619
620 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
621 return -EFAULT;
622
623 if (sin6->sin6_family != AF_INET6)
624 return -EINVAL;
625
626 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
627 l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
628
629 if (optname == TCP_MD5SIG_EXT &&
630 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
631 prefixlen = cmd.tcpm_prefixlen;
632 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
633 prefixlen > 32))
634 return -EINVAL;
635 } else {
636 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
637 }
638
639 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
640 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
641 struct net_device *dev;
642
643 rcu_read_lock();
644 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
645 if (dev && netif_is_l3_master(dev))
646 l3index = dev->ifindex;
647 rcu_read_unlock();
648
649 /* ok to reference set/not set outside of rcu;
650 * right now device MUST be an L3 master
651 */
652 if (!dev || !l3index)
653 return -EINVAL;
654 }
655
656 if (!cmd.tcpm_keylen) {
657 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
658 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
659 AF_INET, prefixlen,
660 l3index, flags);
661 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
662 AF_INET6, prefixlen, l3index, flags);
663 }
664
665 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
666 return -EINVAL;
667
668 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
669 addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
670
671 /* Don't allow keys for peers that have a matching TCP-AO key.
672 * See the comment in tcp_ao_add_cmd()
673 */
674 if (tcp_ao_required(sk, addr, AF_INET,
675 l3flag ? l3index : -1, false))
676 return -EKEYREJECTED;
677 return tcp_md5_do_add(sk, addr,
678 AF_INET, prefixlen, l3index, flags,
679 cmd.tcpm_key, cmd.tcpm_keylen);
680 }
681
682 addr = (union tcp_md5_addr *)&sin6->sin6_addr;
683
684 /* Don't allow keys for peers that have a matching TCP-AO key.
685 * See the comment in tcp_ao_add_cmd()
686 */
687 if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false))
688 return -EKEYREJECTED;
689
690 return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
691 cmd.tcpm_key, cmd.tcpm_keylen);
692 }
693
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)694 static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp,
695 const struct in6_addr *daddr,
696 const struct in6_addr *saddr,
697 const struct tcphdr *th, int nbytes)
698 {
699 struct tcp6_pseudohdr *bp;
700 struct scatterlist sg;
701 struct tcphdr *_th;
702
703 bp = hp->scratch;
704 /* 1. TCP pseudo-header (RFC2460) */
705 bp->saddr = *saddr;
706 bp->daddr = *daddr;
707 bp->protocol = cpu_to_be32(IPPROTO_TCP);
708 bp->len = cpu_to_be32(nbytes);
709
710 _th = (struct tcphdr *)(bp + 1);
711 memcpy(_th, th, sizeof(*th));
712 _th->check = 0;
713
714 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
715 ahash_request_set_crypt(hp->req, &sg, NULL,
716 sizeof(*bp) + sizeof(*th));
717 return crypto_ahash_update(hp->req);
718 }
719
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)720 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
721 const struct in6_addr *daddr, struct in6_addr *saddr,
722 const struct tcphdr *th)
723 {
724 struct tcp_sigpool hp;
725
726 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
727 goto clear_hash_nostart;
728
729 if (crypto_ahash_init(hp.req))
730 goto clear_hash;
731 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
732 goto clear_hash;
733 if (tcp_md5_hash_key(&hp, key))
734 goto clear_hash;
735 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
736 if (crypto_ahash_final(hp.req))
737 goto clear_hash;
738
739 tcp_sigpool_end(&hp);
740 return 0;
741
742 clear_hash:
743 tcp_sigpool_end(&hp);
744 clear_hash_nostart:
745 memset(md5_hash, 0, 16);
746 return 1;
747 }
748
tcp_v6_md5_hash_skb(char * md5_hash,const struct tcp_md5sig_key * key,const struct sock * sk,const struct sk_buff * skb)749 static int tcp_v6_md5_hash_skb(char *md5_hash,
750 const struct tcp_md5sig_key *key,
751 const struct sock *sk,
752 const struct sk_buff *skb)
753 {
754 const struct tcphdr *th = tcp_hdr(skb);
755 const struct in6_addr *saddr, *daddr;
756 struct tcp_sigpool hp;
757
758 if (sk) { /* valid for establish/request sockets */
759 saddr = &sk->sk_v6_rcv_saddr;
760 daddr = &sk->sk_v6_daddr;
761 } else {
762 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
763 saddr = &ip6h->saddr;
764 daddr = &ip6h->daddr;
765 }
766
767 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
768 goto clear_hash_nostart;
769
770 if (crypto_ahash_init(hp.req))
771 goto clear_hash;
772
773 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
774 goto clear_hash;
775 if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
776 goto clear_hash;
777 if (tcp_md5_hash_key(&hp, key))
778 goto clear_hash;
779 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
780 if (crypto_ahash_final(hp.req))
781 goto clear_hash;
782
783 tcp_sigpool_end(&hp);
784 return 0;
785
786 clear_hash:
787 tcp_sigpool_end(&hp);
788 clear_hash_nostart:
789 memset(md5_hash, 0, 16);
790 return 1;
791 }
792 #endif
793
tcp_v6_init_req(struct request_sock * req,const struct sock * sk_listener,struct sk_buff * skb,u32 tw_isn)794 static void tcp_v6_init_req(struct request_sock *req,
795 const struct sock *sk_listener,
796 struct sk_buff *skb,
797 u32 tw_isn)
798 {
799 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
800 struct inet_request_sock *ireq = inet_rsk(req);
801 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
802
803 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
804 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
805
806 /* So that link locals have meaning */
807 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
808 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
809 ireq->ir_iif = tcp_v6_iif(skb);
810
811 if (!tw_isn &&
812 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
813 np->rxopt.bits.rxinfo ||
814 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
815 np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) {
816 refcount_inc(&skb->users);
817 ireq->pktopts = skb;
818 }
819 }
820
tcp_v6_route_req(const struct sock * sk,struct sk_buff * skb,struct flowi * fl,struct request_sock * req,u32 tw_isn)821 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
822 struct sk_buff *skb,
823 struct flowi *fl,
824 struct request_sock *req,
825 u32 tw_isn)
826 {
827 tcp_v6_init_req(req, sk, skb, tw_isn);
828
829 if (security_inet_conn_request(sk, skb, req))
830 return NULL;
831
832 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
833 }
834
835 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
836 .family = AF_INET6,
837 .obj_size = sizeof(struct tcp6_request_sock),
838 .rtx_syn_ack = tcp_rtx_synack,
839 .send_ack = tcp_v6_reqsk_send_ack,
840 .destructor = tcp_v6_reqsk_destructor,
841 .send_reset = tcp_v6_send_reset,
842 .syn_ack_timeout = tcp_syn_ack_timeout,
843 };
844
845 const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
846 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
847 sizeof(struct ipv6hdr),
848 #ifdef CONFIG_TCP_MD5SIG
849 .req_md5_lookup = tcp_v6_md5_lookup,
850 .calc_md5_hash = tcp_v6_md5_hash_skb,
851 #endif
852 #ifdef CONFIG_TCP_AO
853 .ao_lookup = tcp_v6_ao_lookup_rsk,
854 .ao_calc_key = tcp_v6_ao_calc_key_rsk,
855 .ao_synack_hash = tcp_v6_ao_synack_hash,
856 #endif
857 #ifdef CONFIG_SYN_COOKIES
858 .cookie_init_seq = cookie_v6_init_sequence,
859 #endif
860 .route_req = tcp_v6_route_req,
861 .init_seq = tcp_v6_init_seq,
862 .init_ts_off = tcp_v6_init_ts_off,
863 .send_synack = tcp_v6_send_synack,
864 };
865
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)866 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
867 u32 ack, u32 win, u32 tsval, u32 tsecr,
868 int oif, int rst, u8 tclass, __be32 label,
869 u32 priority, u32 txhash, struct tcp_key *key)
870 {
871 const struct tcphdr *th = tcp_hdr(skb);
872 struct tcphdr *t1;
873 struct sk_buff *buff;
874 struct flowi6 fl6;
875 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
876 struct sock *ctl_sk = net->ipv6.tcp_sk;
877 unsigned int tot_len = sizeof(struct tcphdr);
878 __be32 mrst = 0, *topt;
879 struct dst_entry *dst;
880 __u32 mark = 0;
881
882 if (tsecr)
883 tot_len += TCPOLEN_TSTAMP_ALIGNED;
884 if (tcp_key_is_md5(key))
885 tot_len += TCPOLEN_MD5SIG_ALIGNED;
886 if (tcp_key_is_ao(key))
887 tot_len += tcp_ao_len_aligned(key->ao_key);
888
889 #ifdef CONFIG_MPTCP
890 if (rst && !tcp_key_is_md5(key)) {
891 mrst = mptcp_reset_option(skb);
892
893 if (mrst)
894 tot_len += sizeof(__be32);
895 }
896 #endif
897
898 buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
899 if (!buff)
900 return;
901
902 skb_reserve(buff, MAX_TCP_HEADER);
903
904 t1 = skb_push(buff, tot_len);
905 skb_reset_transport_header(buff);
906
907 /* Swap the send and the receive. */
908 memset(t1, 0, sizeof(*t1));
909 t1->dest = th->source;
910 t1->source = th->dest;
911 t1->doff = tot_len / 4;
912 t1->seq = htonl(seq);
913 t1->ack_seq = htonl(ack);
914 t1->ack = !rst || !th->ack;
915 t1->rst = rst;
916 t1->window = htons(win);
917
918 topt = (__be32 *)(t1 + 1);
919
920 if (tsecr) {
921 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
922 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
923 *topt++ = htonl(tsval);
924 *topt++ = htonl(tsecr);
925 }
926
927 if (mrst)
928 *topt++ = mrst;
929
930 #ifdef CONFIG_TCP_MD5SIG
931 if (tcp_key_is_md5(key)) {
932 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
933 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
934 tcp_v6_md5_hash_hdr((__u8 *)topt, key->md5_key,
935 &ipv6_hdr(skb)->saddr,
936 &ipv6_hdr(skb)->daddr, t1);
937 }
938 #endif
939 #ifdef CONFIG_TCP_AO
940 if (tcp_key_is_ao(key)) {
941 *topt++ = htonl((TCPOPT_AO << 24) |
942 (tcp_ao_len(key->ao_key) << 16) |
943 (key->ao_key->sndid << 8) |
944 (key->rcv_next));
945
946 tcp_ao_hash_hdr(AF_INET6, (char *)topt, key->ao_key,
947 key->traffic_key,
948 (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr,
949 (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr,
950 t1, key->sne);
951 }
952 #endif
953
954 memset(&fl6, 0, sizeof(fl6));
955 fl6.daddr = ipv6_hdr(skb)->saddr;
956 fl6.saddr = ipv6_hdr(skb)->daddr;
957 fl6.flowlabel = label;
958
959 buff->ip_summed = CHECKSUM_PARTIAL;
960
961 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
962
963 fl6.flowi6_proto = IPPROTO_TCP;
964 if (rt6_need_strict(&fl6.daddr) && !oif)
965 fl6.flowi6_oif = tcp_v6_iif(skb);
966 else {
967 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
968 oif = skb->skb_iif;
969
970 fl6.flowi6_oif = oif;
971 }
972
973 if (sk) {
974 if (sk->sk_state == TCP_TIME_WAIT)
975 mark = inet_twsk(sk)->tw_mark;
976 else
977 mark = READ_ONCE(sk->sk_mark);
978 skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
979 }
980 if (txhash) {
981 /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
982 skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
983 }
984 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
985 fl6.fl6_dport = t1->dest;
986 fl6.fl6_sport = t1->source;
987 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
988 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
989
990 /* Pass a socket to ip6_dst_lookup either it is for RST
991 * Underlying function will use this to retrieve the network
992 * namespace
993 */
994 if (sk && sk->sk_state != TCP_TIME_WAIT)
995 dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
996 else
997 dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
998 if (!IS_ERR(dst)) {
999 skb_dst_set(buff, dst);
1000 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
1001 tclass & ~INET_ECN_MASK, priority);
1002 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
1003 if (rst)
1004 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
1005 return;
1006 }
1007
1008 kfree_skb(buff);
1009 }
1010
tcp_v6_send_reset(const struct sock * sk,struct sk_buff * skb,enum sk_rst_reason reason)1011 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb,
1012 enum sk_rst_reason reason)
1013 {
1014 const struct tcphdr *th = tcp_hdr(skb);
1015 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1016 const __u8 *md5_hash_location = NULL;
1017 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1018 bool allocated_traffic_key = false;
1019 #endif
1020 const struct tcp_ao_hdr *aoh;
1021 struct tcp_key key = {};
1022 u32 seq = 0, ack_seq = 0;
1023 __be32 label = 0;
1024 u32 priority = 0;
1025 struct net *net;
1026 u32 txhash = 0;
1027 int oif = 0;
1028 #ifdef CONFIG_TCP_MD5SIG
1029 unsigned char newhash[16];
1030 int genhash;
1031 struct sock *sk1 = NULL;
1032 #endif
1033
1034 if (th->rst)
1035 return;
1036
1037 /* If sk not NULL, it means we did a successful lookup and incoming
1038 * route had to be correct. prequeue might have dropped our dst.
1039 */
1040 if (!sk && !ipv6_unicast_destination(skb))
1041 return;
1042
1043 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1044 /* Invalid TCP option size or twice included auth */
1045 if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
1046 return;
1047 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1048 rcu_read_lock();
1049 #endif
1050 #ifdef CONFIG_TCP_MD5SIG
1051 if (sk && sk_fullsock(sk)) {
1052 int l3index;
1053
1054 /* sdif set, means packet ingressed via a device
1055 * in an L3 domain and inet_iif is set to it.
1056 */
1057 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1058 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1059 if (key.md5_key)
1060 key.type = TCP_KEY_MD5;
1061 } else if (md5_hash_location) {
1062 int dif = tcp_v6_iif_l3_slave(skb);
1063 int sdif = tcp_v6_sdif(skb);
1064 int l3index;
1065
1066 /*
1067 * active side is lost. Try to find listening socket through
1068 * source port, and then find md5 key through listening socket.
1069 * we are not loose security here:
1070 * Incoming packet is checked with md5 hash with finding key,
1071 * no RST generated if md5 hash doesn't match.
1072 */
1073 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1074 NULL, 0, &ipv6h->saddr, th->source,
1075 &ipv6h->daddr, ntohs(th->source),
1076 dif, sdif);
1077 if (!sk1)
1078 goto out;
1079
1080 /* sdif set, means packet ingressed via a device
1081 * in an L3 domain and dif is set to it.
1082 */
1083 l3index = tcp_v6_sdif(skb) ? dif : 0;
1084
1085 key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1086 if (!key.md5_key)
1087 goto out;
1088 key.type = TCP_KEY_MD5;
1089
1090 genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb);
1091 if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
1092 goto out;
1093 }
1094 #endif
1095
1096 if (th->ack)
1097 seq = ntohl(th->ack_seq);
1098 else
1099 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1100 (th->doff << 2);
1101
1102 #ifdef CONFIG_TCP_AO
1103 if (aoh) {
1104 int l3index;
1105
1106 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1107 if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq,
1108 &key.ao_key, &key.traffic_key,
1109 &allocated_traffic_key,
1110 &key.rcv_next, &key.sne))
1111 goto out;
1112 key.type = TCP_KEY_AO;
1113 }
1114 #endif
1115
1116 if (sk) {
1117 oif = sk->sk_bound_dev_if;
1118 if (sk_fullsock(sk)) {
1119 if (inet6_test_bit(REPFLOW, sk))
1120 label = ip6_flowlabel(ipv6h);
1121 priority = READ_ONCE(sk->sk_priority);
1122 txhash = sk->sk_txhash;
1123 }
1124 if (sk->sk_state == TCP_TIME_WAIT) {
1125 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1126 priority = inet_twsk(sk)->tw_priority;
1127 txhash = inet_twsk(sk)->tw_txhash;
1128 }
1129 } else {
1130 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1131 label = ip6_flowlabel(ipv6h);
1132 }
1133
1134 trace_tcp_send_reset(sk, skb, reason);
1135
1136 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
1137 ipv6_get_dsfield(ipv6h), label, priority, txhash,
1138 &key);
1139
1140 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1141 out:
1142 if (allocated_traffic_key)
1143 kfree(key.traffic_key);
1144 rcu_read_unlock();
1145 #endif
1146 }
1147
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)1148 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1149 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1150 struct tcp_key *key, u8 tclass,
1151 __be32 label, u32 priority, u32 txhash)
1152 {
1153 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0,
1154 tclass, label, priority, txhash, key);
1155 }
1156
tcp_v6_timewait_ack(struct sock * sk,struct sk_buff * skb)1157 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1158 {
1159 struct inet_timewait_sock *tw = inet_twsk(sk);
1160 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1161 struct tcp_key key = {};
1162 #ifdef CONFIG_TCP_AO
1163 struct tcp_ao_info *ao_info;
1164
1165 if (static_branch_unlikely(&tcp_ao_needed.key)) {
1166
1167 /* FIXME: the segment to-be-acked is not verified yet */
1168 ao_info = rcu_dereference(tcptw->ao_info);
1169 if (ao_info) {
1170 const struct tcp_ao_hdr *aoh;
1171
1172 /* Invalid TCP option size or twice included auth */
1173 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1174 goto out;
1175 if (aoh)
1176 key.ao_key = tcp_ao_established_key(ao_info,
1177 aoh->rnext_keyid, -1);
1178 }
1179 }
1180 if (key.ao_key) {
1181 struct tcp_ao_key *rnext_key;
1182
1183 key.traffic_key = snd_other_key(key.ao_key);
1184 /* rcv_next switches to our rcv_next */
1185 rnext_key = READ_ONCE(ao_info->rnext_key);
1186 key.rcv_next = rnext_key->rcvid;
1187 key.sne = READ_ONCE(ao_info->snd_sne);
1188 key.type = TCP_KEY_AO;
1189 #else
1190 if (0) {
1191 #endif
1192 #ifdef CONFIG_TCP_MD5SIG
1193 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1194 key.md5_key = tcp_twsk_md5_key(tcptw);
1195 if (key.md5_key)
1196 key.type = TCP_KEY_MD5;
1197 #endif
1198 }
1199
1200 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1201 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1202 tcp_tw_tsval(tcptw),
1203 tcptw->tw_ts_recent, tw->tw_bound_dev_if, &key,
1204 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
1205 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)
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 if (opt_skb)
1663 __kfree_skb(opt_skb);
1664 return 0;
1665 }
1666 } else
1667 sock_rps_save_rxhash(sk, skb);
1668
1669 reason = tcp_rcv_state_process(sk, skb);
1670 if (reason)
1671 goto reset;
1672 if (opt_skb)
1673 goto ipv6_pktoptions;
1674 return 0;
1675
1676 reset:
1677 tcp_v6_send_reset(sk, skb, sk_rst_convert_drop_reason(reason));
1678 discard:
1679 if (opt_skb)
1680 __kfree_skb(opt_skb);
1681 kfree_skb_reason(skb, reason);
1682 return 0;
1683 csum_err:
1684 reason = SKB_DROP_REASON_TCP_CSUM;
1685 trace_tcp_bad_csum(skb);
1686 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1687 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1688 goto discard;
1689
1690
1691 ipv6_pktoptions:
1692 /* Do you ask, what is it?
1693
1694 1. skb was enqueued by tcp.
1695 2. skb is added to tail of read queue, rather than out of order.
1696 3. socket is not in passive state.
1697 4. Finally, it really contains options, which user wants to receive.
1698 */
1699 tp = tcp_sk(sk);
1700 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1701 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1702 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1703 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb));
1704 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1705 WRITE_ONCE(np->mcast_hops,
1706 ipv6_hdr(opt_skb)->hop_limit);
1707 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1708 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1709 if (inet6_test_bit(REPFLOW, sk))
1710 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1711 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1712 tcp_v6_restore_cb(opt_skb);
1713 opt_skb = xchg(&np->pktoptions, opt_skb);
1714 } else {
1715 __kfree_skb(opt_skb);
1716 opt_skb = xchg(&np->pktoptions, NULL);
1717 }
1718 }
1719
1720 consume_skb(opt_skb);
1721 return 0;
1722 }
1723
1724 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1725 const struct tcphdr *th)
1726 {
1727 /* This is tricky: we move IP6CB at its correct location into
1728 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1729 * _decode_session6() uses IP6CB().
1730 * barrier() makes sure compiler won't play aliasing games.
1731 */
1732 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1733 sizeof(struct inet6_skb_parm));
1734 barrier();
1735
1736 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1737 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1738 skb->len - th->doff*4);
1739 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1740 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1741 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1742 TCP_SKB_CB(skb)->sacked = 0;
1743 TCP_SKB_CB(skb)->has_rxtstamp =
1744 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1745 }
1746
1747 INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1748 {
1749 enum skb_drop_reason drop_reason;
1750 int sdif = inet6_sdif(skb);
1751 int dif = inet6_iif(skb);
1752 const struct tcphdr *th;
1753 const struct ipv6hdr *hdr;
1754 bool refcounted;
1755 struct sock *sk;
1756 int ret;
1757 u32 isn;
1758 struct net *net = dev_net(skb->dev);
1759
1760 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1761 if (skb->pkt_type != PACKET_HOST)
1762 goto discard_it;
1763
1764 /*
1765 * Count it even if it's bad.
1766 */
1767 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1768
1769 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1770 goto discard_it;
1771
1772 th = (const struct tcphdr *)skb->data;
1773
1774 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1775 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1776 goto bad_packet;
1777 }
1778 if (!pskb_may_pull(skb, th->doff*4))
1779 goto discard_it;
1780
1781 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1782 goto csum_error;
1783
1784 th = (const struct tcphdr *)skb->data;
1785 hdr = ipv6_hdr(skb);
1786
1787 lookup:
1788 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1789 th->source, th->dest, inet6_iif(skb), sdif,
1790 &refcounted);
1791 if (!sk)
1792 goto no_tcp_socket;
1793
1794 if (sk->sk_state == TCP_TIME_WAIT)
1795 goto do_time_wait;
1796
1797 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1798 struct request_sock *req = inet_reqsk(sk);
1799 bool req_stolen = false;
1800 struct sock *nsk;
1801
1802 sk = req->rsk_listener;
1803 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1804 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1805 else
1806 drop_reason = tcp_inbound_hash(sk, req, skb,
1807 &hdr->saddr, &hdr->daddr,
1808 AF_INET6, dif, sdif);
1809 if (drop_reason) {
1810 sk_drops_add(sk, skb);
1811 reqsk_put(req);
1812 goto discard_it;
1813 }
1814 if (tcp_checksum_complete(skb)) {
1815 reqsk_put(req);
1816 goto csum_error;
1817 }
1818 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1819 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1820 if (!nsk) {
1821 inet_csk_reqsk_queue_drop_and_put(sk, req);
1822 goto lookup;
1823 }
1824 sk = nsk;
1825 /* reuseport_migrate_sock() has already held one sk_refcnt
1826 * before returning.
1827 */
1828 } else {
1829 sock_hold(sk);
1830 }
1831 refcounted = true;
1832 nsk = NULL;
1833 if (!tcp_filter(sk, skb)) {
1834 th = (const struct tcphdr *)skb->data;
1835 hdr = ipv6_hdr(skb);
1836 tcp_v6_fill_cb(skb, hdr, th);
1837 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1838 } else {
1839 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1840 }
1841 if (!nsk) {
1842 reqsk_put(req);
1843 if (req_stolen) {
1844 /* Another cpu got exclusive access to req
1845 * and created a full blown socket.
1846 * Try to feed this packet to this socket
1847 * instead of discarding it.
1848 */
1849 tcp_v6_restore_cb(skb);
1850 sock_put(sk);
1851 goto lookup;
1852 }
1853 goto discard_and_relse;
1854 }
1855 nf_reset_ct(skb);
1856 if (nsk == sk) {
1857 reqsk_put(req);
1858 tcp_v6_restore_cb(skb);
1859 } else {
1860 drop_reason = tcp_child_process(sk, nsk, skb);
1861 if (drop_reason) {
1862 enum sk_rst_reason rst_reason;
1863
1864 rst_reason = sk_rst_convert_drop_reason(drop_reason);
1865 tcp_v6_send_reset(nsk, skb, rst_reason);
1866 goto discard_and_relse;
1867 }
1868 sock_put(sk);
1869 return 0;
1870 }
1871 }
1872
1873 process:
1874 if (static_branch_unlikely(&ip6_min_hopcount)) {
1875 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1876 if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) {
1877 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1878 drop_reason = SKB_DROP_REASON_TCP_MINTTL;
1879 goto discard_and_relse;
1880 }
1881 }
1882
1883 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1884 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1885 goto discard_and_relse;
1886 }
1887
1888 drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr,
1889 AF_INET6, dif, sdif);
1890 if (drop_reason)
1891 goto discard_and_relse;
1892
1893 nf_reset_ct(skb);
1894
1895 if (tcp_filter(sk, skb)) {
1896 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1897 goto discard_and_relse;
1898 }
1899 th = (const struct tcphdr *)skb->data;
1900 hdr = ipv6_hdr(skb);
1901 tcp_v6_fill_cb(skb, hdr, th);
1902
1903 skb->dev = NULL;
1904
1905 if (sk->sk_state == TCP_LISTEN) {
1906 ret = tcp_v6_do_rcv(sk, skb);
1907 goto put_and_return;
1908 }
1909
1910 sk_incoming_cpu_update(sk);
1911
1912 bh_lock_sock_nested(sk);
1913 tcp_segs_in(tcp_sk(sk), skb);
1914 ret = 0;
1915 if (!sock_owned_by_user(sk)) {
1916 ret = tcp_v6_do_rcv(sk, skb);
1917 } else {
1918 if (tcp_add_backlog(sk, skb, &drop_reason))
1919 goto discard_and_relse;
1920 }
1921 bh_unlock_sock(sk);
1922 put_and_return:
1923 if (refcounted)
1924 sock_put(sk);
1925 return ret ? -1 : 0;
1926
1927 no_tcp_socket:
1928 drop_reason = SKB_DROP_REASON_NO_SOCKET;
1929 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1930 goto discard_it;
1931
1932 tcp_v6_fill_cb(skb, hdr, th);
1933
1934 if (tcp_checksum_complete(skb)) {
1935 csum_error:
1936 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1937 trace_tcp_bad_csum(skb);
1938 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1939 bad_packet:
1940 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1941 } else {
1942 tcp_v6_send_reset(NULL, skb, sk_rst_convert_drop_reason(drop_reason));
1943 }
1944
1945 discard_it:
1946 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1947 kfree_skb_reason(skb, drop_reason);
1948 return 0;
1949
1950 discard_and_relse:
1951 sk_drops_add(sk, skb);
1952 if (refcounted)
1953 sock_put(sk);
1954 goto discard_it;
1955
1956 do_time_wait:
1957 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1958 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1959 inet_twsk_put(inet_twsk(sk));
1960 goto discard_it;
1961 }
1962
1963 tcp_v6_fill_cb(skb, hdr, th);
1964
1965 if (tcp_checksum_complete(skb)) {
1966 inet_twsk_put(inet_twsk(sk));
1967 goto csum_error;
1968 }
1969
1970 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th, &isn)) {
1971 case TCP_TW_SYN:
1972 {
1973 struct sock *sk2;
1974
1975 sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1976 skb, __tcp_hdrlen(th),
1977 &ipv6_hdr(skb)->saddr, th->source,
1978 &ipv6_hdr(skb)->daddr,
1979 ntohs(th->dest),
1980 tcp_v6_iif_l3_slave(skb),
1981 sdif);
1982 if (sk2) {
1983 struct inet_timewait_sock *tw = inet_twsk(sk);
1984 inet_twsk_deschedule_put(tw);
1985 sk = sk2;
1986 tcp_v6_restore_cb(skb);
1987 refcounted = false;
1988 __this_cpu_write(tcp_tw_isn, isn);
1989 goto process;
1990 }
1991 }
1992 /* to ACK */
1993 fallthrough;
1994 case TCP_TW_ACK:
1995 tcp_v6_timewait_ack(sk, skb);
1996 break;
1997 case TCP_TW_RST:
1998 tcp_v6_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET);
1999 inet_twsk_deschedule_put(inet_twsk(sk));
2000 goto discard_it;
2001 case TCP_TW_SUCCESS:
2002 ;
2003 }
2004 goto discard_it;
2005 }
2006
2007 void tcp_v6_early_demux(struct sk_buff *skb)
2008 {
2009 struct net *net = dev_net(skb->dev);
2010 const struct ipv6hdr *hdr;
2011 const struct tcphdr *th;
2012 struct sock *sk;
2013
2014 if (skb->pkt_type != PACKET_HOST)
2015 return;
2016
2017 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
2018 return;
2019
2020 hdr = ipv6_hdr(skb);
2021 th = tcp_hdr(skb);
2022
2023 if (th->doff < sizeof(struct tcphdr) / 4)
2024 return;
2025
2026 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
2027 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
2028 &hdr->saddr, th->source,
2029 &hdr->daddr, ntohs(th->dest),
2030 inet6_iif(skb), inet6_sdif(skb));
2031 if (sk) {
2032 skb->sk = sk;
2033 skb->destructor = sock_edemux;
2034 if (sk_fullsock(sk)) {
2035 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
2036
2037 if (dst)
2038 dst = dst_check(dst, sk->sk_rx_dst_cookie);
2039 if (dst &&
2040 sk->sk_rx_dst_ifindex == skb->skb_iif)
2041 skb_dst_set_noref(skb, dst);
2042 }
2043 }
2044 }
2045
2046 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
2047 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
2048 .twsk_destructor = tcp_twsk_destructor,
2049 };
2050
2051 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
2052 {
2053 __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
2054 }
2055
2056 const struct inet_connection_sock_af_ops ipv6_specific = {
2057 .queue_xmit = inet6_csk_xmit,
2058 .send_check = tcp_v6_send_check,
2059 .rebuild_header = inet6_sk_rebuild_header,
2060 .sk_rx_dst_set = inet6_sk_rx_dst_set,
2061 .conn_request = tcp_v6_conn_request,
2062 .syn_recv_sock = tcp_v6_syn_recv_sock,
2063 .net_header_len = sizeof(struct ipv6hdr),
2064 .setsockopt = ipv6_setsockopt,
2065 .getsockopt = ipv6_getsockopt,
2066 .addr2sockaddr = inet6_csk_addr2sockaddr,
2067 .sockaddr_len = sizeof(struct sockaddr_in6),
2068 .mtu_reduced = tcp_v6_mtu_reduced,
2069 };
2070
2071 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2072 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
2073 #ifdef CONFIG_TCP_MD5SIG
2074 .md5_lookup = tcp_v6_md5_lookup,
2075 .calc_md5_hash = tcp_v6_md5_hash_skb,
2076 .md5_parse = tcp_v6_parse_md5_keys,
2077 #endif
2078 #ifdef CONFIG_TCP_AO
2079 .ao_lookup = tcp_v6_ao_lookup,
2080 .calc_ao_hash = tcp_v6_ao_hash_skb,
2081 .ao_parse = tcp_v6_parse_ao,
2082 .ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
2083 #endif
2084 };
2085 #endif
2086
2087 /*
2088 * TCP over IPv4 via INET6 API
2089 */
2090 static const struct inet_connection_sock_af_ops ipv6_mapped = {
2091 .queue_xmit = ip_queue_xmit,
2092 .send_check = tcp_v4_send_check,
2093 .rebuild_header = inet_sk_rebuild_header,
2094 .sk_rx_dst_set = inet_sk_rx_dst_set,
2095 .conn_request = tcp_v6_conn_request,
2096 .syn_recv_sock = tcp_v6_syn_recv_sock,
2097 .net_header_len = sizeof(struct iphdr),
2098 .setsockopt = ipv6_setsockopt,
2099 .getsockopt = ipv6_getsockopt,
2100 .addr2sockaddr = inet6_csk_addr2sockaddr,
2101 .sockaddr_len = sizeof(struct sockaddr_in6),
2102 .mtu_reduced = tcp_v4_mtu_reduced,
2103 };
2104
2105 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2106 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
2107 #ifdef CONFIG_TCP_MD5SIG
2108 .md5_lookup = tcp_v4_md5_lookup,
2109 .calc_md5_hash = tcp_v4_md5_hash_skb,
2110 .md5_parse = tcp_v6_parse_md5_keys,
2111 #endif
2112 #ifdef CONFIG_TCP_AO
2113 .ao_lookup = tcp_v6_ao_lookup,
2114 .calc_ao_hash = tcp_v4_ao_hash_skb,
2115 .ao_parse = tcp_v6_parse_ao,
2116 .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
2117 #endif
2118 };
2119 #endif
2120
2121 /* NOTE: A lot of things set to zero explicitly by call to
2122 * sk_alloc() so need not be done here.
2123 */
2124 static int tcp_v6_init_sock(struct sock *sk)
2125 {
2126 struct inet_connection_sock *icsk = inet_csk(sk);
2127
2128 tcp_init_sock(sk);
2129
2130 icsk->icsk_af_ops = &ipv6_specific;
2131
2132 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2133 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
2134 #endif
2135
2136 return 0;
2137 }
2138
2139 #ifdef CONFIG_PROC_FS
2140 /* Proc filesystem TCPv6 sock list dumping. */
2141 static void get_openreq6(struct seq_file *seq,
2142 const struct request_sock *req, int i)
2143 {
2144 long ttd = req->rsk_timer.expires - jiffies;
2145 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
2146 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
2147
2148 if (ttd < 0)
2149 ttd = 0;
2150
2151 seq_printf(seq,
2152 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2153 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
2154 i,
2155 src->s6_addr32[0], src->s6_addr32[1],
2156 src->s6_addr32[2], src->s6_addr32[3],
2157 inet_rsk(req)->ir_num,
2158 dest->s6_addr32[0], dest->s6_addr32[1],
2159 dest->s6_addr32[2], dest->s6_addr32[3],
2160 ntohs(inet_rsk(req)->ir_rmt_port),
2161 TCP_SYN_RECV,
2162 0, 0, /* could print option size, but that is af dependent. */
2163 1, /* timers active (only the expire timer) */
2164 jiffies_to_clock_t(ttd),
2165 req->num_timeout,
2166 from_kuid_munged(seq_user_ns(seq),
2167 sock_i_uid(req->rsk_listener)),
2168 0, /* non standard timer */
2169 0, /* open_requests have no inode */
2170 0, req);
2171 }
2172
2173 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2174 {
2175 const struct in6_addr *dest, *src;
2176 __u16 destp, srcp;
2177 int timer_active;
2178 unsigned long timer_expires;
2179 const struct inet_sock *inet = inet_sk(sp);
2180 const struct tcp_sock *tp = tcp_sk(sp);
2181 const struct inet_connection_sock *icsk = inet_csk(sp);
2182 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
2183 int rx_queue;
2184 int state;
2185
2186 dest = &sp->sk_v6_daddr;
2187 src = &sp->sk_v6_rcv_saddr;
2188 destp = ntohs(inet->inet_dport);
2189 srcp = ntohs(inet->inet_sport);
2190
2191 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2192 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2193 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2194 timer_active = 1;
2195 timer_expires = icsk->icsk_timeout;
2196 } else if (icsk->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 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 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2387 SOCK_RAW, IPPROTO_TCP, net);
2388 }
2389
2390 static void __net_exit tcpv6_net_exit(struct net *net)
2391 {
2392 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2393 }
2394
2395 static struct pernet_operations tcpv6_net_ops = {
2396 .init = tcpv6_net_init,
2397 .exit = tcpv6_net_exit,
2398 };
2399
2400 int __init tcpv6_init(void)
2401 {
2402 int ret;
2403
2404 net_hotdata.tcpv6_protocol = (struct inet6_protocol) {
2405 .handler = tcp_v6_rcv,
2406 .err_handler = tcp_v6_err,
2407 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
2408 };
2409 ret = inet6_add_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2410 if (ret)
2411 goto out;
2412
2413 /* register inet6 protocol */
2414 ret = inet6_register_protosw(&tcpv6_protosw);
2415 if (ret)
2416 goto out_tcpv6_protocol;
2417
2418 ret = register_pernet_subsys(&tcpv6_net_ops);
2419 if (ret)
2420 goto out_tcpv6_protosw;
2421
2422 ret = mptcpv6_init();
2423 if (ret)
2424 goto out_tcpv6_pernet_subsys;
2425
2426 out:
2427 return ret;
2428
2429 out_tcpv6_pernet_subsys:
2430 unregister_pernet_subsys(&tcpv6_net_ops);
2431 out_tcpv6_protosw:
2432 inet6_unregister_protosw(&tcpv6_protosw);
2433 out_tcpv6_protocol:
2434 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2435 goto out;
2436 }
2437
2438 void tcpv6_exit(void)
2439 {
2440 unregister_pernet_subsys(&tcpv6_net_ops);
2441 inet6_unregister_protosw(&tcpv6_protosw);
2442 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2443 }
2444