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1/*
2 * TCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on:
9 * linux/net/ipv4/tcp.c
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
12 *
13 * Fixes:
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26#include <linux/bottom_half.h>
27#include <linux/module.h>
28#include <linux/errno.h>
29#include <linux/types.h>
30#include <linux/socket.h>
31#include <linux/sockios.h>
32#include <linux/net.h>
33#include <linux/jiffies.h>
34#include <linux/in.h>
35#include <linux/in6.h>
36#include <linux/netdevice.h>
37#include <linux/init.h>
38#include <linux/jhash.h>
39#include <linux/ipsec.h>
40#include <linux/times.h>
41#include <linux/slab.h>
42#include <linux/uaccess.h>
43#include <linux/ipv6.h>
44#include <linux/icmpv6.h>
45#include <linux/random.h>
46
47#include <net/tcp.h>
48#include <net/ndisc.h>
49#include <net/inet6_hashtables.h>
50#include <net/inet6_connection_sock.h>
51#include <net/ipv6.h>
52#include <net/transp_v6.h>
53#include <net/addrconf.h>
54#include <net/ip6_route.h>
55#include <net/ip6_checksum.h>
56#include <net/inet_ecn.h>
57#include <net/protocol.h>
58#include <net/xfrm.h>
59#include <net/snmp.h>
60#include <net/dsfield.h>
61#include <net/timewait_sock.h>
62#include <net/netdma.h>
63#include <net/inet_common.h>
64#include <net/secure_seq.h>
65#include <net/tcp_memcontrol.h>
66#include <net/busy_poll.h>
67
68#include <linux/proc_fs.h>
69#include <linux/seq_file.h>
70
71#include <linux/crypto.h>
72#include <linux/scatterlist.h>
73
74static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
75static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
76 struct request_sock *req);
77
78static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79
80static const struct inet_connection_sock_af_ops ipv6_mapped;
81static const struct inet_connection_sock_af_ops ipv6_specific;
82#ifdef CONFIG_TCP_MD5SIG
83static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
84static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
85#else
86static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
87 const struct in6_addr *addr)
88{
89 return NULL;
90}
91#endif
92
93static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
94{
95 struct dst_entry *dst = skb_dst(skb);
96 const struct rt6_info *rt = (const struct rt6_info *)dst;
97
98 dst_hold(dst);
99 sk->sk_rx_dst = dst;
100 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
101 if (rt->rt6i_node)
102 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
103}
104
105static void tcp_v6_hash(struct sock *sk)
106{
107 if (sk->sk_state != TCP_CLOSE) {
108 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
109 tcp_prot.hash(sk);
110 return;
111 }
112 local_bh_disable();
113 __inet6_hash(sk, NULL);
114 local_bh_enable();
115 }
116}
117
118static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
119{
120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
121 ipv6_hdr(skb)->saddr.s6_addr32,
122 tcp_hdr(skb)->dest,
123 tcp_hdr(skb)->source);
124}
125
126static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128{
129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
130 struct inet_sock *inet = inet_sk(sk);
131 struct inet_connection_sock *icsk = inet_csk(sk);
132 struct ipv6_pinfo *np = inet6_sk(sk);
133 struct tcp_sock *tp = tcp_sk(sk);
134 struct in6_addr *saddr = NULL, *final_p, final;
135 struct rt6_info *rt;
136 struct flowi6 fl6;
137 struct dst_entry *dst;
138 int addr_type;
139 int err;
140
141 if (addr_len < SIN6_LEN_RFC2133)
142 return -EINVAL;
143
144 if (usin->sin6_family != AF_INET6)
145 return -EAFNOSUPPORT;
146
147 memset(&fl6, 0, sizeof(fl6));
148
149 if (np->sndflow) {
150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
151 IP6_ECN_flow_init(fl6.flowlabel);
152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
153 struct ip6_flowlabel *flowlabel;
154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
155 if (flowlabel == NULL)
156 return -EINVAL;
157 fl6_sock_release(flowlabel);
158 }
159 }
160
161 /*
162 * connect() to INADDR_ANY means loopback (BSD'ism).
163 */
164
165 if (ipv6_addr_any(&usin->sin6_addr))
166 usin->sin6_addr.s6_addr[15] = 0x1;
167
168 addr_type = ipv6_addr_type(&usin->sin6_addr);
169
170 if (addr_type & IPV6_ADDR_MULTICAST)
171 return -ENETUNREACH;
172
173 if (addr_type&IPV6_ADDR_LINKLOCAL) {
174 if (addr_len >= sizeof(struct sockaddr_in6) &&
175 usin->sin6_scope_id) {
176 /* If interface is set while binding, indices
177 * must coincide.
178 */
179 if (sk->sk_bound_dev_if &&
180 sk->sk_bound_dev_if != usin->sin6_scope_id)
181 return -EINVAL;
182
183 sk->sk_bound_dev_if = usin->sin6_scope_id;
184 }
185
186 /* Connect to link-local address requires an interface */
187 if (!sk->sk_bound_dev_if)
188 return -EINVAL;
189 }
190
191 if (tp->rx_opt.ts_recent_stamp &&
192 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
193 tp->rx_opt.ts_recent = 0;
194 tp->rx_opt.ts_recent_stamp = 0;
195 tp->write_seq = 0;
196 }
197
198 sk->sk_v6_daddr = usin->sin6_addr;
199 np->flow_label = fl6.flowlabel;
200
201 /*
202 * TCP over IPv4
203 */
204
205 if (addr_type == IPV6_ADDR_MAPPED) {
206 u32 exthdrlen = icsk->icsk_ext_hdr_len;
207 struct sockaddr_in sin;
208
209 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
210
211 if (__ipv6_only_sock(sk))
212 return -ENETUNREACH;
213
214 sin.sin_family = AF_INET;
215 sin.sin_port = usin->sin6_port;
216 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
217
218 icsk->icsk_af_ops = &ipv6_mapped;
219 sk->sk_backlog_rcv = tcp_v4_do_rcv;
220#ifdef CONFIG_TCP_MD5SIG
221 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
222#endif
223
224 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
225
226 if (err) {
227 icsk->icsk_ext_hdr_len = exthdrlen;
228 icsk->icsk_af_ops = &ipv6_specific;
229 sk->sk_backlog_rcv = tcp_v6_do_rcv;
230#ifdef CONFIG_TCP_MD5SIG
231 tp->af_specific = &tcp_sock_ipv6_specific;
232#endif
233 goto failure;
234 } else {
235 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
236 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
237 &sk->sk_v6_rcv_saddr);
238 }
239
240 return err;
241 }
242
243 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
244 saddr = &sk->sk_v6_rcv_saddr;
245
246 fl6.flowi6_proto = IPPROTO_TCP;
247 fl6.daddr = sk->sk_v6_daddr;
248 fl6.saddr = saddr ? *saddr : np->saddr;
249 fl6.flowi6_oif = sk->sk_bound_dev_if;
250 fl6.flowi6_mark = sk->sk_mark;
251 fl6.fl6_dport = usin->sin6_port;
252 fl6.fl6_sport = inet->inet_sport;
253
254 final_p = fl6_update_dst(&fl6, np->opt, &final);
255
256 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
257
258 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
259 if (IS_ERR(dst)) {
260 err = PTR_ERR(dst);
261 goto failure;
262 }
263
264 if (saddr == NULL) {
265 saddr = &fl6.saddr;
266 sk->sk_v6_rcv_saddr = *saddr;
267 }
268
269 /* set the source address */
270 np->saddr = *saddr;
271 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
272
273 sk->sk_gso_type = SKB_GSO_TCPV6;
274 __ip6_dst_store(sk, dst, NULL, NULL);
275
276 rt = (struct rt6_info *) dst;
277 if (tcp_death_row.sysctl_tw_recycle &&
278 !tp->rx_opt.ts_recent_stamp &&
279 ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
280 tcp_fetch_timewait_stamp(sk, dst);
281
282 icsk->icsk_ext_hdr_len = 0;
283 if (np->opt)
284 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
285 np->opt->opt_nflen);
286
287 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
288
289 inet->inet_dport = usin->sin6_port;
290
291 tcp_set_state(sk, TCP_SYN_SENT);
292 err = inet6_hash_connect(&tcp_death_row, sk);
293 if (err)
294 goto late_failure;
295
296 if (!tp->write_seq && likely(!tp->repair))
297 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
298 sk->sk_v6_daddr.s6_addr32,
299 inet->inet_sport,
300 inet->inet_dport);
301
302 err = tcp_connect(sk);
303 if (err)
304 goto late_failure;
305
306 return 0;
307
308late_failure:
309 tcp_set_state(sk, TCP_CLOSE);
310 __sk_dst_reset(sk);
311failure:
312 inet->inet_dport = 0;
313 sk->sk_route_caps = 0;
314 return err;
315}
316
317static void tcp_v6_mtu_reduced(struct sock *sk)
318{
319 struct dst_entry *dst;
320
321 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
322 return;
323
324 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
325 if (!dst)
326 return;
327
328 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
329 tcp_sync_mss(sk, dst_mtu(dst));
330 tcp_simple_retransmit(sk);
331 }
332}
333
334static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
335 u8 type, u8 code, int offset, __be32 info)
336{
337 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
338 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
339 struct ipv6_pinfo *np;
340 struct sock *sk;
341 int err;
342 struct tcp_sock *tp;
343 __u32 seq;
344 struct net *net = dev_net(skb->dev);
345
346 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
347 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
348
349 if (sk == NULL) {
350 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
351 ICMP6_MIB_INERRORS);
352 return;
353 }
354
355 if (sk->sk_state == TCP_TIME_WAIT) {
356 inet_twsk_put(inet_twsk(sk));
357 return;
358 }
359
360 bh_lock_sock(sk);
361 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
362 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
363
364 if (sk->sk_state == TCP_CLOSE)
365 goto out;
366
367 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
368 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
369 goto out;
370 }
371
372 tp = tcp_sk(sk);
373 seq = ntohl(th->seq);
374 if (sk->sk_state != TCP_LISTEN &&
375 !between(seq, tp->snd_una, tp->snd_nxt)) {
376 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
377 goto out;
378 }
379
380 np = inet6_sk(sk);
381
382 if (type == NDISC_REDIRECT) {
383 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
384
385 if (dst)
386 dst->ops->redirect(dst, sk, skb);
387 goto out;
388 }
389
390 if (type == ICMPV6_PKT_TOOBIG) {
391 /* We are not interested in TCP_LISTEN and open_requests
392 * (SYN-ACKs send out by Linux are always <576bytes so
393 * they should go through unfragmented).
394 */
395 if (sk->sk_state == TCP_LISTEN)
396 goto out;
397
398 if (!ip6_sk_accept_pmtu(sk))
399 goto out;
400
401 tp->mtu_info = ntohl(info);
402 if (!sock_owned_by_user(sk))
403 tcp_v6_mtu_reduced(sk);
404 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
405 &tp->tsq_flags))
406 sock_hold(sk);
407 goto out;
408 }
409
410 icmpv6_err_convert(type, code, &err);
411
412 /* Might be for an request_sock */
413 switch (sk->sk_state) {
414 struct request_sock *req, **prev;
415 case TCP_LISTEN:
416 if (sock_owned_by_user(sk))
417 goto out;
418
419 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
420 &hdr->saddr, inet6_iif(skb));
421 if (!req)
422 goto out;
423
424 /* ICMPs are not backlogged, hence we cannot get
425 * an established socket here.
426 */
427 WARN_ON(req->sk != NULL);
428
429 if (seq != tcp_rsk(req)->snt_isn) {
430 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
431 goto out;
432 }
433
434 inet_csk_reqsk_queue_drop(sk, req, prev);
435 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
436 goto out;
437
438 case TCP_SYN_SENT:
439 case TCP_SYN_RECV: /* Cannot happen.
440 It can, it SYNs are crossed. --ANK */
441 if (!sock_owned_by_user(sk)) {
442 sk->sk_err = err;
443 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
444
445 tcp_done(sk);
446 } else
447 sk->sk_err_soft = err;
448 goto out;
449 }
450
451 if (!sock_owned_by_user(sk) && np->recverr) {
452 sk->sk_err = err;
453 sk->sk_error_report(sk);
454 } else
455 sk->sk_err_soft = err;
456
457out:
458 bh_unlock_sock(sk);
459 sock_put(sk);
460}
461
462
463static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
464 struct flowi6 *fl6,
465 struct request_sock *req,
466 u16 queue_mapping)
467{
468 struct inet_request_sock *ireq = inet_rsk(req);
469 struct ipv6_pinfo *np = inet6_sk(sk);
470 struct sk_buff *skb;
471 int err = -ENOMEM;
472
473 /* First, grab a route. */
474 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
475 goto done;
476
477 skb = tcp_make_synack(sk, dst, req, NULL);
478
479 if (skb) {
480 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
481 &ireq->ir_v6_rmt_addr);
482
483 fl6->daddr = ireq->ir_v6_rmt_addr;
484 if (np->repflow && (ireq->pktopts != NULL))
485 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
486
487 skb_set_queue_mapping(skb, queue_mapping);
488 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
489 err = net_xmit_eval(err);
490 }
491
492done:
493 return err;
494}
495
496static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
497{
498 struct flowi6 fl6;
499 int res;
500
501 res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
502 if (!res) {
503 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
504 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);
505 }
506 return res;
507}
508
509static void tcp_v6_reqsk_destructor(struct request_sock *req)
510{
511 kfree_skb(inet_rsk(req)->pktopts);
512}
513
514#ifdef CONFIG_TCP_MD5SIG
515static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
516 const struct in6_addr *addr)
517{
518 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
519}
520
521static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
522 struct sock *addr_sk)
523{
524 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
525}
526
527static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
528 struct request_sock *req)
529{
530 return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
531}
532
533static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
534 int optlen)
535{
536 struct tcp_md5sig cmd;
537 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
538
539 if (optlen < sizeof(cmd))
540 return -EINVAL;
541
542 if (copy_from_user(&cmd, optval, sizeof(cmd)))
543 return -EFAULT;
544
545 if (sin6->sin6_family != AF_INET6)
546 return -EINVAL;
547
548 if (!cmd.tcpm_keylen) {
549 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
550 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
551 AF_INET);
552 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
553 AF_INET6);
554 }
555
556 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
557 return -EINVAL;
558
559 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
560 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
561 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
562
563 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
564 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
565}
566
567static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
568 const struct in6_addr *daddr,
569 const struct in6_addr *saddr, int nbytes)
570{
571 struct tcp6_pseudohdr *bp;
572 struct scatterlist sg;
573
574 bp = &hp->md5_blk.ip6;
575 /* 1. TCP pseudo-header (RFC2460) */
576 bp->saddr = *saddr;
577 bp->daddr = *daddr;
578 bp->protocol = cpu_to_be32(IPPROTO_TCP);
579 bp->len = cpu_to_be32(nbytes);
580
581 sg_init_one(&sg, bp, sizeof(*bp));
582 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
583}
584
585static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
586 const struct in6_addr *daddr, struct in6_addr *saddr,
587 const struct tcphdr *th)
588{
589 struct tcp_md5sig_pool *hp;
590 struct hash_desc *desc;
591
592 hp = tcp_get_md5sig_pool();
593 if (!hp)
594 goto clear_hash_noput;
595 desc = &hp->md5_desc;
596
597 if (crypto_hash_init(desc))
598 goto clear_hash;
599 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
600 goto clear_hash;
601 if (tcp_md5_hash_header(hp, th))
602 goto clear_hash;
603 if (tcp_md5_hash_key(hp, key))
604 goto clear_hash;
605 if (crypto_hash_final(desc, md5_hash))
606 goto clear_hash;
607
608 tcp_put_md5sig_pool();
609 return 0;
610
611clear_hash:
612 tcp_put_md5sig_pool();
613clear_hash_noput:
614 memset(md5_hash, 0, 16);
615 return 1;
616}
617
618static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
619 const struct sock *sk,
620 const struct request_sock *req,
621 const struct sk_buff *skb)
622{
623 const struct in6_addr *saddr, *daddr;
624 struct tcp_md5sig_pool *hp;
625 struct hash_desc *desc;
626 const struct tcphdr *th = tcp_hdr(skb);
627
628 if (sk) {
629 saddr = &inet6_sk(sk)->saddr;
630 daddr = &sk->sk_v6_daddr;
631 } else if (req) {
632 saddr = &inet_rsk(req)->ir_v6_loc_addr;
633 daddr = &inet_rsk(req)->ir_v6_rmt_addr;
634 } else {
635 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
636 saddr = &ip6h->saddr;
637 daddr = &ip6h->daddr;
638 }
639
640 hp = tcp_get_md5sig_pool();
641 if (!hp)
642 goto clear_hash_noput;
643 desc = &hp->md5_desc;
644
645 if (crypto_hash_init(desc))
646 goto clear_hash;
647
648 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
649 goto clear_hash;
650 if (tcp_md5_hash_header(hp, th))
651 goto clear_hash;
652 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
653 goto clear_hash;
654 if (tcp_md5_hash_key(hp, key))
655 goto clear_hash;
656 if (crypto_hash_final(desc, md5_hash))
657 goto clear_hash;
658
659 tcp_put_md5sig_pool();
660 return 0;
661
662clear_hash:
663 tcp_put_md5sig_pool();
664clear_hash_noput:
665 memset(md5_hash, 0, 16);
666 return 1;
667}
668
669static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
670{
671 const __u8 *hash_location = NULL;
672 struct tcp_md5sig_key *hash_expected;
673 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
674 const struct tcphdr *th = tcp_hdr(skb);
675 int genhash;
676 u8 newhash[16];
677
678 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
679 hash_location = tcp_parse_md5sig_option(th);
680
681 /* We've parsed the options - do we have a hash? */
682 if (!hash_expected && !hash_location)
683 return 0;
684
685 if (hash_expected && !hash_location) {
686 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
687 return 1;
688 }
689
690 if (!hash_expected && hash_location) {
691 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
692 return 1;
693 }
694
695 /* check the signature */
696 genhash = tcp_v6_md5_hash_skb(newhash,
697 hash_expected,
698 NULL, NULL, skb);
699
700 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
701 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
702 genhash ? "failed" : "mismatch",
703 &ip6h->saddr, ntohs(th->source),
704 &ip6h->daddr, ntohs(th->dest));
705 return 1;
706 }
707 return 0;
708}
709#endif
710
711struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
712 .family = AF_INET6,
713 .obj_size = sizeof(struct tcp6_request_sock),
714 .rtx_syn_ack = tcp_v6_rtx_synack,
715 .send_ack = tcp_v6_reqsk_send_ack,
716 .destructor = tcp_v6_reqsk_destructor,
717 .send_reset = tcp_v6_send_reset,
718 .syn_ack_timeout = tcp_syn_ack_timeout,
719};
720
721#ifdef CONFIG_TCP_MD5SIG
722static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
723 .md5_lookup = tcp_v6_reqsk_md5_lookup,
724 .calc_md5_hash = tcp_v6_md5_hash_skb,
725};
726#endif
727
728static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
729 u32 tsval, u32 tsecr, int oif,
730 struct tcp_md5sig_key *key, int rst, u8 tclass,
731 u32 label)
732{
733 const struct tcphdr *th = tcp_hdr(skb);
734 struct tcphdr *t1;
735 struct sk_buff *buff;
736 struct flowi6 fl6;
737 struct net *net = dev_net(skb_dst(skb)->dev);
738 struct sock *ctl_sk = net->ipv6.tcp_sk;
739 unsigned int tot_len = sizeof(struct tcphdr);
740 struct dst_entry *dst;
741 __be32 *topt;
742
743 if (tsecr)
744 tot_len += TCPOLEN_TSTAMP_ALIGNED;
745#ifdef CONFIG_TCP_MD5SIG
746 if (key)
747 tot_len += TCPOLEN_MD5SIG_ALIGNED;
748#endif
749
750 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
751 GFP_ATOMIC);
752 if (buff == NULL)
753 return;
754
755 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
756
757 t1 = (struct tcphdr *) skb_push(buff, tot_len);
758 skb_reset_transport_header(buff);
759
760 /* Swap the send and the receive. */
761 memset(t1, 0, sizeof(*t1));
762 t1->dest = th->source;
763 t1->source = th->dest;
764 t1->doff = tot_len / 4;
765 t1->seq = htonl(seq);
766 t1->ack_seq = htonl(ack);
767 t1->ack = !rst || !th->ack;
768 t1->rst = rst;
769 t1->window = htons(win);
770
771 topt = (__be32 *)(t1 + 1);
772
773 if (tsecr) {
774 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
775 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
776 *topt++ = htonl(tsval);
777 *topt++ = htonl(tsecr);
778 }
779
780#ifdef CONFIG_TCP_MD5SIG
781 if (key) {
782 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
783 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
784 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
785 &ipv6_hdr(skb)->saddr,
786 &ipv6_hdr(skb)->daddr, t1);
787 }
788#endif
789
790 memset(&fl6, 0, sizeof(fl6));
791 fl6.daddr = ipv6_hdr(skb)->saddr;
792 fl6.saddr = ipv6_hdr(skb)->daddr;
793 fl6.flowlabel = label;
794
795 buff->ip_summed = CHECKSUM_PARTIAL;
796 buff->csum = 0;
797
798 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
799
800 fl6.flowi6_proto = IPPROTO_TCP;
801 if (rt6_need_strict(&fl6.daddr) && !oif)
802 fl6.flowi6_oif = inet6_iif(skb);
803 else
804 fl6.flowi6_oif = oif;
805 fl6.fl6_dport = t1->dest;
806 fl6.fl6_sport = t1->source;
807 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
808
809 /* Pass a socket to ip6_dst_lookup either it is for RST
810 * Underlying function will use this to retrieve the network
811 * namespace
812 */
813 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
814 if (!IS_ERR(dst)) {
815 skb_dst_set(buff, dst);
816 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
817 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
818 if (rst)
819 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
820 return;
821 }
822
823 kfree_skb(buff);
824}
825
826static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
827{
828 const struct tcphdr *th = tcp_hdr(skb);
829 u32 seq = 0, ack_seq = 0;
830 struct tcp_md5sig_key *key = NULL;
831#ifdef CONFIG_TCP_MD5SIG
832 const __u8 *hash_location = NULL;
833 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
834 unsigned char newhash[16];
835 int genhash;
836 struct sock *sk1 = NULL;
837#endif
838 int oif;
839
840 if (th->rst)
841 return;
842
843 if (!ipv6_unicast_destination(skb))
844 return;
845
846#ifdef CONFIG_TCP_MD5SIG
847 hash_location = tcp_parse_md5sig_option(th);
848 if (!sk && hash_location) {
849 /*
850 * active side is lost. Try to find listening socket through
851 * source port, and then find md5 key through listening socket.
852 * we are not loose security here:
853 * Incoming packet is checked with md5 hash with finding key,
854 * no RST generated if md5 hash doesn't match.
855 */
856 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
857 &tcp_hashinfo, &ipv6h->saddr,
858 th->source, &ipv6h->daddr,
859 ntohs(th->source), inet6_iif(skb));
860 if (!sk1)
861 return;
862
863 rcu_read_lock();
864 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
865 if (!key)
866 goto release_sk1;
867
868 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
869 if (genhash || memcmp(hash_location, newhash, 16) != 0)
870 goto release_sk1;
871 } else {
872 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
873 }
874#endif
875
876 if (th->ack)
877 seq = ntohl(th->ack_seq);
878 else
879 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
880 (th->doff << 2);
881
882 oif = sk ? sk->sk_bound_dev_if : 0;
883 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
884
885#ifdef CONFIG_TCP_MD5SIG
886release_sk1:
887 if (sk1) {
888 rcu_read_unlock();
889 sock_put(sk1);
890 }
891#endif
892}
893
894static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
895 u32 win, u32 tsval, u32 tsecr, int oif,
896 struct tcp_md5sig_key *key, u8 tclass,
897 u32 label)
898{
899 tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, oif, key, 0, tclass,
900 label);
901}
902
903static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
904{
905 struct inet_timewait_sock *tw = inet_twsk(sk);
906 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
907
908 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
909 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
910 tcp_time_stamp + tcptw->tw_ts_offset,
911 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
912 tw->tw_tclass, (tw->tw_flowlabel << 12));
913
914 inet_twsk_put(tw);
915}
916
917static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
918 struct request_sock *req)
919{
920 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
921 req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
922 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
923 0, 0);
924}
925
926
927static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
928{
929 struct request_sock *req, **prev;
930 const struct tcphdr *th = tcp_hdr(skb);
931 struct sock *nsk;
932
933 /* Find possible connection requests. */
934 req = inet6_csk_search_req(sk, &prev, th->source,
935 &ipv6_hdr(skb)->saddr,
936 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
937 if (req)
938 return tcp_check_req(sk, skb, req, prev, false);
939
940 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
941 &ipv6_hdr(skb)->saddr, th->source,
942 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
943
944 if (nsk) {
945 if (nsk->sk_state != TCP_TIME_WAIT) {
946 bh_lock_sock(nsk);
947 return nsk;
948 }
949 inet_twsk_put(inet_twsk(nsk));
950 return NULL;
951 }
952
953#ifdef CONFIG_SYN_COOKIES
954 if (!th->syn)
955 sk = cookie_v6_check(sk, skb);
956#endif
957 return sk;
958}
959
960/* FIXME: this is substantially similar to the ipv4 code.
961 * Can some kind of merge be done? -- erics
962 */
963static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
964{
965 struct tcp_options_received tmp_opt;
966 struct request_sock *req;
967 struct inet_request_sock *ireq;
968 struct ipv6_pinfo *np = inet6_sk(sk);
969 struct tcp_sock *tp = tcp_sk(sk);
970 __u32 isn = TCP_SKB_CB(skb)->when;
971 struct dst_entry *dst = NULL;
972 struct flowi6 fl6;
973 bool want_cookie = false;
974
975 if (skb->protocol == htons(ETH_P_IP))
976 return tcp_v4_conn_request(sk, skb);
977
978 if (!ipv6_unicast_destination(skb))
979 goto drop;
980
981 if ((sysctl_tcp_syncookies == 2 ||
982 inet_csk_reqsk_queue_is_full(sk)) && !isn) {
983 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
984 if (!want_cookie)
985 goto drop;
986 }
987
988 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
989 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
990 goto drop;
991 }
992
993 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
994 if (req == NULL)
995 goto drop;
996
997#ifdef CONFIG_TCP_MD5SIG
998 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
999#endif
1000
1001 tcp_clear_options(&tmp_opt);
1002 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1003 tmp_opt.user_mss = tp->rx_opt.user_mss;
1004 tcp_parse_options(skb, &tmp_opt, 0, NULL);
1005
1006 if (want_cookie && !tmp_opt.saw_tstamp)
1007 tcp_clear_options(&tmp_opt);
1008
1009 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1010 tcp_openreq_init(req, &tmp_opt, skb);
1011
1012 ireq = inet_rsk(req);
1013 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
1014 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
1015 if (!want_cookie || tmp_opt.tstamp_ok)
1016 TCP_ECN_create_request(req, skb, sock_net(sk));
1017
1018 ireq->ir_iif = sk->sk_bound_dev_if;
1019
1020 /* So that link locals have meaning */
1021 if (!sk->sk_bound_dev_if &&
1022 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
1023 ireq->ir_iif = inet6_iif(skb);
1024
1025 if (!isn) {
1026 if (ipv6_opt_accepted(sk, skb) ||
1027 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1028 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim ||
1029 np->repflow) {
1030 atomic_inc(&skb->users);
1031 ireq->pktopts = skb;
1032 }
1033
1034 if (want_cookie) {
1035 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1036 req->cookie_ts = tmp_opt.tstamp_ok;
1037 goto have_isn;
1038 }
1039
1040 /* VJ's idea. We save last timestamp seen
1041 * from the destination in peer table, when entering
1042 * state TIME-WAIT, and check against it before
1043 * accepting new connection request.
1044 *
1045 * If "isn" is not zero, this request hit alive
1046 * timewait bucket, so that all the necessary checks
1047 * are made in the function processing timewait state.
1048 */
1049 if (tmp_opt.saw_tstamp &&
1050 tcp_death_row.sysctl_tw_recycle &&
1051 (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1052 if (!tcp_peer_is_proven(req, dst, true)) {
1053 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1054 goto drop_and_release;
1055 }
1056 }
1057 /* Kill the following clause, if you dislike this way. */
1058 else if (!sysctl_tcp_syncookies &&
1059 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1060 (sysctl_max_syn_backlog >> 2)) &&
1061 !tcp_peer_is_proven(req, dst, false)) {
1062 /* Without syncookies last quarter of
1063 * backlog is filled with destinations,
1064 * proven to be alive.
1065 * It means that we continue to communicate
1066 * to destinations, already remembered
1067 * to the moment of synflood.
1068 */
1069 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1070 &ireq->ir_v6_rmt_addr, ntohs(tcp_hdr(skb)->source));
1071 goto drop_and_release;
1072 }
1073
1074 isn = tcp_v6_init_sequence(skb);
1075 }
1076have_isn:
1077 tcp_rsk(req)->snt_isn = isn;
1078
1079 if (security_inet_conn_request(sk, skb, req))
1080 goto drop_and_release;
1081
1082 if (tcp_v6_send_synack(sk, dst, &fl6, req,
1083 skb_get_queue_mapping(skb)) ||
1084 want_cookie)
1085 goto drop_and_free;
1086
1087 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1088 tcp_rsk(req)->listener = NULL;
1089 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1090 return 0;
1091
1092drop_and_release:
1093 dst_release(dst);
1094drop_and_free:
1095 reqsk_free(req);
1096drop:
1097 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1098 return 0; /* don't send reset */
1099}
1100
1101static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1102 struct request_sock *req,
1103 struct dst_entry *dst)
1104{
1105 struct inet_request_sock *ireq;
1106 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1107 struct tcp6_sock *newtcp6sk;
1108 struct inet_sock *newinet;
1109 struct tcp_sock *newtp;
1110 struct sock *newsk;
1111#ifdef CONFIG_TCP_MD5SIG
1112 struct tcp_md5sig_key *key;
1113#endif
1114 struct flowi6 fl6;
1115
1116 if (skb->protocol == htons(ETH_P_IP)) {
1117 /*
1118 * v6 mapped
1119 */
1120
1121 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1122
1123 if (newsk == NULL)
1124 return NULL;
1125
1126 newtcp6sk = (struct tcp6_sock *)newsk;
1127 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1128
1129 newinet = inet_sk(newsk);
1130 newnp = inet6_sk(newsk);
1131 newtp = tcp_sk(newsk);
1132
1133 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1134
1135 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
1136
1137 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1138
1139 newsk->sk_v6_rcv_saddr = newnp->saddr;
1140
1141 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1142 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1143#ifdef CONFIG_TCP_MD5SIG
1144 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1145#endif
1146
1147 newnp->ipv6_ac_list = NULL;
1148 newnp->ipv6_fl_list = NULL;
1149 newnp->pktoptions = NULL;
1150 newnp->opt = NULL;
1151 newnp->mcast_oif = inet6_iif(skb);
1152 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1153 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1154 if (np->repflow)
1155 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1156
1157 /*
1158 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1159 * here, tcp_create_openreq_child now does this for us, see the comment in
1160 * that function for the gory details. -acme
1161 */
1162
1163 /* It is tricky place. Until this moment IPv4 tcp
1164 worked with IPv6 icsk.icsk_af_ops.
1165 Sync it now.
1166 */
1167 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1168
1169 return newsk;
1170 }
1171
1172 ireq = inet_rsk(req);
1173
1174 if (sk_acceptq_is_full(sk))
1175 goto out_overflow;
1176
1177 if (!dst) {
1178 dst = inet6_csk_route_req(sk, &fl6, req);
1179 if (!dst)
1180 goto out;
1181 }
1182
1183 newsk = tcp_create_openreq_child(sk, req, skb);
1184 if (newsk == NULL)
1185 goto out_nonewsk;
1186
1187 /*
1188 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1189 * count here, tcp_create_openreq_child now does this for us, see the
1190 * comment in that function for the gory details. -acme
1191 */
1192
1193 newsk->sk_gso_type = SKB_GSO_TCPV6;
1194 __ip6_dst_store(newsk, dst, NULL, NULL);
1195 inet6_sk_rx_dst_set(newsk, skb);
1196
1197 newtcp6sk = (struct tcp6_sock *)newsk;
1198 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1199
1200 newtp = tcp_sk(newsk);
1201 newinet = inet_sk(newsk);
1202 newnp = inet6_sk(newsk);
1203
1204 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1205
1206 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1207 newnp->saddr = ireq->ir_v6_loc_addr;
1208 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1209 newsk->sk_bound_dev_if = ireq->ir_iif;
1210
1211 /* Now IPv6 options...
1212
1213 First: no IPv4 options.
1214 */
1215 newinet->inet_opt = NULL;
1216 newnp->ipv6_ac_list = NULL;
1217 newnp->ipv6_fl_list = NULL;
1218
1219 /* Clone RX bits */
1220 newnp->rxopt.all = np->rxopt.all;
1221
1222 /* Clone pktoptions received with SYN */
1223 newnp->pktoptions = NULL;
1224 if (ireq->pktopts != NULL) {
1225 newnp->pktoptions = skb_clone(ireq->pktopts,
1226 sk_gfp_atomic(sk, GFP_ATOMIC));
1227 consume_skb(ireq->pktopts);
1228 ireq->pktopts = NULL;
1229 if (newnp->pktoptions)
1230 skb_set_owner_r(newnp->pktoptions, newsk);
1231 }
1232 newnp->opt = NULL;
1233 newnp->mcast_oif = inet6_iif(skb);
1234 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1235 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1236 if (np->repflow)
1237 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1238
1239 /* Clone native IPv6 options from listening socket (if any)
1240
1241 Yes, keeping reference count would be much more clever,
1242 but we make one more one thing there: reattach optmem
1243 to newsk.
1244 */
1245 if (np->opt)
1246 newnp->opt = ipv6_dup_options(newsk, np->opt);
1247
1248 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1249 if (newnp->opt)
1250 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1251 newnp->opt->opt_flen);
1252
1253 tcp_sync_mss(newsk, dst_mtu(dst));
1254 newtp->advmss = dst_metric_advmss(dst);
1255 if (tcp_sk(sk)->rx_opt.user_mss &&
1256 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1257 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1258
1259 tcp_initialize_rcv_mss(newsk);
1260
1261 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1262 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1263
1264#ifdef CONFIG_TCP_MD5SIG
1265 /* Copy over the MD5 key from the original socket */
1266 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1267 if (key != NULL) {
1268 /* We're using one, so create a matching key
1269 * on the newsk structure. If we fail to get
1270 * memory, then we end up not copying the key
1271 * across. Shucks.
1272 */
1273 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1274 AF_INET6, key->key, key->keylen,
1275 sk_gfp_atomic(sk, GFP_ATOMIC));
1276 }
1277#endif
1278
1279 if (__inet_inherit_port(sk, newsk) < 0) {
1280 inet_csk_prepare_forced_close(newsk);
1281 tcp_done(newsk);
1282 goto out;
1283 }
1284 __inet6_hash(newsk, NULL);
1285
1286 return newsk;
1287
1288out_overflow:
1289 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1290out_nonewsk:
1291 dst_release(dst);
1292out:
1293 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1294 return NULL;
1295}
1296
1297static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1298{
1299 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1300 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1301 &ipv6_hdr(skb)->daddr, skb->csum)) {
1302 skb->ip_summed = CHECKSUM_UNNECESSARY;
1303 return 0;
1304 }
1305 }
1306
1307 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1308 &ipv6_hdr(skb)->saddr,
1309 &ipv6_hdr(skb)->daddr, 0));
1310
1311 if (skb->len <= 76)
1312 return __skb_checksum_complete(skb);
1313 return 0;
1314}
1315
1316/* The socket must have it's spinlock held when we get
1317 * here.
1318 *
1319 * We have a potential double-lock case here, so even when
1320 * doing backlog processing we use the BH locking scheme.
1321 * This is because we cannot sleep with the original spinlock
1322 * held.
1323 */
1324static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1325{
1326 struct ipv6_pinfo *np = inet6_sk(sk);
1327 struct tcp_sock *tp;
1328 struct sk_buff *opt_skb = NULL;
1329
1330 /* Imagine: socket is IPv6. IPv4 packet arrives,
1331 goes to IPv4 receive handler and backlogged.
1332 From backlog it always goes here. Kerboom...
1333 Fortunately, tcp_rcv_established and rcv_established
1334 handle them correctly, but it is not case with
1335 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1336 */
1337
1338 if (skb->protocol == htons(ETH_P_IP))
1339 return tcp_v4_do_rcv(sk, skb);
1340
1341#ifdef CONFIG_TCP_MD5SIG
1342 if (tcp_v6_inbound_md5_hash(sk, skb))
1343 goto discard;
1344#endif
1345
1346 if (sk_filter(sk, skb))
1347 goto discard;
1348
1349 /*
1350 * socket locking is here for SMP purposes as backlog rcv
1351 * is currently called with bh processing disabled.
1352 */
1353
1354 /* Do Stevens' IPV6_PKTOPTIONS.
1355
1356 Yes, guys, it is the only place in our code, where we
1357 may make it not affecting IPv4.
1358 The rest of code is protocol independent,
1359 and I do not like idea to uglify IPv4.
1360
1361 Actually, all the idea behind IPV6_PKTOPTIONS
1362 looks not very well thought. For now we latch
1363 options, received in the last packet, enqueued
1364 by tcp. Feel free to propose better solution.
1365 --ANK (980728)
1366 */
1367 if (np->rxopt.all)
1368 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1369
1370 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1371 struct dst_entry *dst = sk->sk_rx_dst;
1372
1373 sock_rps_save_rxhash(sk, skb);
1374 if (dst) {
1375 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1376 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1377 dst_release(dst);
1378 sk->sk_rx_dst = NULL;
1379 }
1380 }
1381
1382 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1383 if (opt_skb)
1384 goto ipv6_pktoptions;
1385 return 0;
1386 }
1387
1388 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1389 goto csum_err;
1390
1391 if (sk->sk_state == TCP_LISTEN) {
1392 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1393 if (!nsk)
1394 goto discard;
1395
1396 /*
1397 * Queue it on the new socket if the new socket is active,
1398 * otherwise we just shortcircuit this and continue with
1399 * the new socket..
1400 */
1401 if (nsk != sk) {
1402 sock_rps_save_rxhash(nsk, skb);
1403 if (tcp_child_process(sk, nsk, skb))
1404 goto reset;
1405 if (opt_skb)
1406 __kfree_skb(opt_skb);
1407 return 0;
1408 }
1409 } else
1410 sock_rps_save_rxhash(sk, skb);
1411
1412 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1413 goto reset;
1414 if (opt_skb)
1415 goto ipv6_pktoptions;
1416 return 0;
1417
1418reset:
1419 tcp_v6_send_reset(sk, skb);
1420discard:
1421 if (opt_skb)
1422 __kfree_skb(opt_skb);
1423 kfree_skb(skb);
1424 return 0;
1425csum_err:
1426 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1427 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1428 goto discard;
1429
1430
1431ipv6_pktoptions:
1432 /* Do you ask, what is it?
1433
1434 1. skb was enqueued by tcp.
1435 2. skb is added to tail of read queue, rather than out of order.
1436 3. socket is not in passive state.
1437 4. Finally, it really contains options, which user wants to receive.
1438 */
1439 tp = tcp_sk(sk);
1440 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1441 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1442 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1443 np->mcast_oif = inet6_iif(opt_skb);
1444 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1445 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1446 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1447 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1448 if (np->repflow)
1449 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1450 if (ipv6_opt_accepted(sk, opt_skb)) {
1451 skb_set_owner_r(opt_skb, sk);
1452 opt_skb = xchg(&np->pktoptions, opt_skb);
1453 } else {
1454 __kfree_skb(opt_skb);
1455 opt_skb = xchg(&np->pktoptions, NULL);
1456 }
1457 }
1458
1459 kfree_skb(opt_skb);
1460 return 0;
1461}
1462
1463static int tcp_v6_rcv(struct sk_buff *skb)
1464{
1465 const struct tcphdr *th;
1466 const struct ipv6hdr *hdr;
1467 struct sock *sk;
1468 int ret;
1469 struct net *net = dev_net(skb->dev);
1470
1471 if (skb->pkt_type != PACKET_HOST)
1472 goto discard_it;
1473
1474 /*
1475 * Count it even if it's bad.
1476 */
1477 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1478
1479 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1480 goto discard_it;
1481
1482 th = tcp_hdr(skb);
1483
1484 if (th->doff < sizeof(struct tcphdr)/4)
1485 goto bad_packet;
1486 if (!pskb_may_pull(skb, th->doff*4))
1487 goto discard_it;
1488
1489 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1490 goto csum_error;
1491
1492 th = tcp_hdr(skb);
1493 hdr = ipv6_hdr(skb);
1494 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1495 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1496 skb->len - th->doff*4);
1497 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1498 TCP_SKB_CB(skb)->when = 0;
1499 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1500 TCP_SKB_CB(skb)->sacked = 0;
1501
1502 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1503 if (!sk)
1504 goto no_tcp_socket;
1505
1506process:
1507 if (sk->sk_state == TCP_TIME_WAIT)
1508 goto do_time_wait;
1509
1510 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1511 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1512 goto discard_and_relse;
1513 }
1514
1515 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1516 goto discard_and_relse;
1517
1518 if (sk_filter(sk, skb))
1519 goto discard_and_relse;
1520
1521 sk_mark_napi_id(sk, skb);
1522 skb->dev = NULL;
1523
1524 bh_lock_sock_nested(sk);
1525 ret = 0;
1526 if (!sock_owned_by_user(sk)) {
1527#ifdef CONFIG_NET_DMA
1528 struct tcp_sock *tp = tcp_sk(sk);
1529 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1530 tp->ucopy.dma_chan = net_dma_find_channel();
1531 if (tp->ucopy.dma_chan)
1532 ret = tcp_v6_do_rcv(sk, skb);
1533 else
1534#endif
1535 {
1536 if (!tcp_prequeue(sk, skb))
1537 ret = tcp_v6_do_rcv(sk, skb);
1538 }
1539 } else if (unlikely(sk_add_backlog(sk, skb,
1540 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1541 bh_unlock_sock(sk);
1542 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1543 goto discard_and_relse;
1544 }
1545 bh_unlock_sock(sk);
1546
1547 sock_put(sk);
1548 return ret ? -1 : 0;
1549
1550no_tcp_socket:
1551 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1552 goto discard_it;
1553
1554 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1555csum_error:
1556 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1557bad_packet:
1558 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1559 } else {
1560 tcp_v6_send_reset(NULL, skb);
1561 }
1562
1563discard_it:
1564 kfree_skb(skb);
1565 return 0;
1566
1567discard_and_relse:
1568 sock_put(sk);
1569 goto discard_it;
1570
1571do_time_wait:
1572 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1573 inet_twsk_put(inet_twsk(sk));
1574 goto discard_it;
1575 }
1576
1577 if (skb->len < (th->doff<<2)) {
1578 inet_twsk_put(inet_twsk(sk));
1579 goto bad_packet;
1580 }
1581 if (tcp_checksum_complete(skb)) {
1582 inet_twsk_put(inet_twsk(sk));
1583 goto csum_error;
1584 }
1585
1586 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1587 case TCP_TW_SYN:
1588 {
1589 struct sock *sk2;
1590
1591 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1592 &ipv6_hdr(skb)->saddr, th->source,
1593 &ipv6_hdr(skb)->daddr,
1594 ntohs(th->dest), inet6_iif(skb));
1595 if (sk2 != NULL) {
1596 struct inet_timewait_sock *tw = inet_twsk(sk);
1597 inet_twsk_deschedule(tw, &tcp_death_row);
1598 inet_twsk_put(tw);
1599 sk = sk2;
1600 goto process;
1601 }
1602 /* Fall through to ACK */
1603 }
1604 case TCP_TW_ACK:
1605 tcp_v6_timewait_ack(sk, skb);
1606 break;
1607 case TCP_TW_RST:
1608 goto no_tcp_socket;
1609 case TCP_TW_SUCCESS:
1610 ;
1611 }
1612 goto discard_it;
1613}
1614
1615static void tcp_v6_early_demux(struct sk_buff *skb)
1616{
1617 const struct ipv6hdr *hdr;
1618 const struct tcphdr *th;
1619 struct sock *sk;
1620
1621 if (skb->pkt_type != PACKET_HOST)
1622 return;
1623
1624 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1625 return;
1626
1627 hdr = ipv6_hdr(skb);
1628 th = tcp_hdr(skb);
1629
1630 if (th->doff < sizeof(struct tcphdr) / 4)
1631 return;
1632
1633 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1634 &hdr->saddr, th->source,
1635 &hdr->daddr, ntohs(th->dest),
1636 inet6_iif(skb));
1637 if (sk) {
1638 skb->sk = sk;
1639 skb->destructor = sock_edemux;
1640 if (sk->sk_state != TCP_TIME_WAIT) {
1641 struct dst_entry *dst = sk->sk_rx_dst;
1642
1643 if (dst)
1644 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1645 if (dst &&
1646 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1647 skb_dst_set_noref(skb, dst);
1648 }
1649 }
1650}
1651
1652static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1653 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1654 .twsk_unique = tcp_twsk_unique,
1655 .twsk_destructor = tcp_twsk_destructor,
1656};
1657
1658static const struct inet_connection_sock_af_ops ipv6_specific = {
1659 .queue_xmit = inet6_csk_xmit,
1660 .send_check = tcp_v6_send_check,
1661 .rebuild_header = inet6_sk_rebuild_header,
1662 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1663 .conn_request = tcp_v6_conn_request,
1664 .syn_recv_sock = tcp_v6_syn_recv_sock,
1665 .net_header_len = sizeof(struct ipv6hdr),
1666 .net_frag_header_len = sizeof(struct frag_hdr),
1667 .setsockopt = ipv6_setsockopt,
1668 .getsockopt = ipv6_getsockopt,
1669 .addr2sockaddr = inet6_csk_addr2sockaddr,
1670 .sockaddr_len = sizeof(struct sockaddr_in6),
1671 .bind_conflict = inet6_csk_bind_conflict,
1672#ifdef CONFIG_COMPAT
1673 .compat_setsockopt = compat_ipv6_setsockopt,
1674 .compat_getsockopt = compat_ipv6_getsockopt,
1675#endif
1676};
1677
1678#ifdef CONFIG_TCP_MD5SIG
1679static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1680 .md5_lookup = tcp_v6_md5_lookup,
1681 .calc_md5_hash = tcp_v6_md5_hash_skb,
1682 .md5_parse = tcp_v6_parse_md5_keys,
1683};
1684#endif
1685
1686/*
1687 * TCP over IPv4 via INET6 API
1688 */
1689static const struct inet_connection_sock_af_ops ipv6_mapped = {
1690 .queue_xmit = ip_queue_xmit,
1691 .send_check = tcp_v4_send_check,
1692 .rebuild_header = inet_sk_rebuild_header,
1693 .sk_rx_dst_set = inet_sk_rx_dst_set,
1694 .conn_request = tcp_v6_conn_request,
1695 .syn_recv_sock = tcp_v6_syn_recv_sock,
1696 .net_header_len = sizeof(struct iphdr),
1697 .setsockopt = ipv6_setsockopt,
1698 .getsockopt = ipv6_getsockopt,
1699 .addr2sockaddr = inet6_csk_addr2sockaddr,
1700 .sockaddr_len = sizeof(struct sockaddr_in6),
1701 .bind_conflict = inet6_csk_bind_conflict,
1702#ifdef CONFIG_COMPAT
1703 .compat_setsockopt = compat_ipv6_setsockopt,
1704 .compat_getsockopt = compat_ipv6_getsockopt,
1705#endif
1706};
1707
1708#ifdef CONFIG_TCP_MD5SIG
1709static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1710 .md5_lookup = tcp_v4_md5_lookup,
1711 .calc_md5_hash = tcp_v4_md5_hash_skb,
1712 .md5_parse = tcp_v6_parse_md5_keys,
1713};
1714#endif
1715
1716/* NOTE: A lot of things set to zero explicitly by call to
1717 * sk_alloc() so need not be done here.
1718 */
1719static int tcp_v6_init_sock(struct sock *sk)
1720{
1721 struct inet_connection_sock *icsk = inet_csk(sk);
1722
1723 tcp_init_sock(sk);
1724
1725 icsk->icsk_af_ops = &ipv6_specific;
1726
1727#ifdef CONFIG_TCP_MD5SIG
1728 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1729#endif
1730
1731 return 0;
1732}
1733
1734static void tcp_v6_destroy_sock(struct sock *sk)
1735{
1736 tcp_v4_destroy_sock(sk);
1737 inet6_destroy_sock(sk);
1738}
1739
1740#ifdef CONFIG_PROC_FS
1741/* Proc filesystem TCPv6 sock list dumping. */
1742static void get_openreq6(struct seq_file *seq,
1743 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1744{
1745 int ttd = req->expires - jiffies;
1746 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1747 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1748
1749 if (ttd < 0)
1750 ttd = 0;
1751
1752 seq_printf(seq,
1753 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1754 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1755 i,
1756 src->s6_addr32[0], src->s6_addr32[1],
1757 src->s6_addr32[2], src->s6_addr32[3],
1758 inet_rsk(req)->ir_num,
1759 dest->s6_addr32[0], dest->s6_addr32[1],
1760 dest->s6_addr32[2], dest->s6_addr32[3],
1761 ntohs(inet_rsk(req)->ir_rmt_port),
1762 TCP_SYN_RECV,
1763 0, 0, /* could print option size, but that is af dependent. */
1764 1, /* timers active (only the expire timer) */
1765 jiffies_to_clock_t(ttd),
1766 req->num_timeout,
1767 from_kuid_munged(seq_user_ns(seq), uid),
1768 0, /* non standard timer */
1769 0, /* open_requests have no inode */
1770 0, req);
1771}
1772
1773static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1774{
1775 const struct in6_addr *dest, *src;
1776 __u16 destp, srcp;
1777 int timer_active;
1778 unsigned long timer_expires;
1779 const struct inet_sock *inet = inet_sk(sp);
1780 const struct tcp_sock *tp = tcp_sk(sp);
1781 const struct inet_connection_sock *icsk = inet_csk(sp);
1782
1783 dest = &sp->sk_v6_daddr;
1784 src = &sp->sk_v6_rcv_saddr;
1785 destp = ntohs(inet->inet_dport);
1786 srcp = ntohs(inet->inet_sport);
1787
1788 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1789 timer_active = 1;
1790 timer_expires = icsk->icsk_timeout;
1791 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1792 timer_active = 4;
1793 timer_expires = icsk->icsk_timeout;
1794 } else if (timer_pending(&sp->sk_timer)) {
1795 timer_active = 2;
1796 timer_expires = sp->sk_timer.expires;
1797 } else {
1798 timer_active = 0;
1799 timer_expires = jiffies;
1800 }
1801
1802 seq_printf(seq,
1803 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1804 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1805 i,
1806 src->s6_addr32[0], src->s6_addr32[1],
1807 src->s6_addr32[2], src->s6_addr32[3], srcp,
1808 dest->s6_addr32[0], dest->s6_addr32[1],
1809 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1810 sp->sk_state,
1811 tp->write_seq-tp->snd_una,
1812 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1813 timer_active,
1814 jiffies_delta_to_clock_t(timer_expires - jiffies),
1815 icsk->icsk_retransmits,
1816 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1817 icsk->icsk_probes_out,
1818 sock_i_ino(sp),
1819 atomic_read(&sp->sk_refcnt), sp,
1820 jiffies_to_clock_t(icsk->icsk_rto),
1821 jiffies_to_clock_t(icsk->icsk_ack.ato),
1822 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1823 tp->snd_cwnd,
1824 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1825 );
1826}
1827
1828static void get_timewait6_sock(struct seq_file *seq,
1829 struct inet_timewait_sock *tw, int i)
1830{
1831 const struct in6_addr *dest, *src;
1832 __u16 destp, srcp;
1833 s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1834
1835 dest = &tw->tw_v6_daddr;
1836 src = &tw->tw_v6_rcv_saddr;
1837 destp = ntohs(tw->tw_dport);
1838 srcp = ntohs(tw->tw_sport);
1839
1840 seq_printf(seq,
1841 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1842 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1843 i,
1844 src->s6_addr32[0], src->s6_addr32[1],
1845 src->s6_addr32[2], src->s6_addr32[3], srcp,
1846 dest->s6_addr32[0], dest->s6_addr32[1],
1847 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1848 tw->tw_substate, 0, 0,
1849 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1850 atomic_read(&tw->tw_refcnt), tw);
1851}
1852
1853static int tcp6_seq_show(struct seq_file *seq, void *v)
1854{
1855 struct tcp_iter_state *st;
1856 struct sock *sk = v;
1857
1858 if (v == SEQ_START_TOKEN) {
1859 seq_puts(seq,
1860 " sl "
1861 "local_address "
1862 "remote_address "
1863 "st tx_queue rx_queue tr tm->when retrnsmt"
1864 " uid timeout inode\n");
1865 goto out;
1866 }
1867 st = seq->private;
1868
1869 switch (st->state) {
1870 case TCP_SEQ_STATE_LISTENING:
1871 case TCP_SEQ_STATE_ESTABLISHED:
1872 if (sk->sk_state == TCP_TIME_WAIT)
1873 get_timewait6_sock(seq, v, st->num);
1874 else
1875 get_tcp6_sock(seq, v, st->num);
1876 break;
1877 case TCP_SEQ_STATE_OPENREQ:
1878 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1879 break;
1880 }
1881out:
1882 return 0;
1883}
1884
1885static const struct file_operations tcp6_afinfo_seq_fops = {
1886 .owner = THIS_MODULE,
1887 .open = tcp_seq_open,
1888 .read = seq_read,
1889 .llseek = seq_lseek,
1890 .release = seq_release_net
1891};
1892
1893static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1894 .name = "tcp6",
1895 .family = AF_INET6,
1896 .seq_fops = &tcp6_afinfo_seq_fops,
1897 .seq_ops = {
1898 .show = tcp6_seq_show,
1899 },
1900};
1901
1902int __net_init tcp6_proc_init(struct net *net)
1903{
1904 return tcp_proc_register(net, &tcp6_seq_afinfo);
1905}
1906
1907void tcp6_proc_exit(struct net *net)
1908{
1909 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1910}
1911#endif
1912
1913static void tcp_v6_clear_sk(struct sock *sk, int size)
1914{
1915 struct inet_sock *inet = inet_sk(sk);
1916
1917 /* we do not want to clear pinet6 field, because of RCU lookups */
1918 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1919
1920 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1921 memset(&inet->pinet6 + 1, 0, size);
1922}
1923
1924struct proto tcpv6_prot = {
1925 .name = "TCPv6",
1926 .owner = THIS_MODULE,
1927 .close = tcp_close,
1928 .connect = tcp_v6_connect,
1929 .disconnect = tcp_disconnect,
1930 .accept = inet_csk_accept,
1931 .ioctl = tcp_ioctl,
1932 .init = tcp_v6_init_sock,
1933 .destroy = tcp_v6_destroy_sock,
1934 .shutdown = tcp_shutdown,
1935 .setsockopt = tcp_setsockopt,
1936 .getsockopt = tcp_getsockopt,
1937 .recvmsg = tcp_recvmsg,
1938 .sendmsg = tcp_sendmsg,
1939 .sendpage = tcp_sendpage,
1940 .backlog_rcv = tcp_v6_do_rcv,
1941 .release_cb = tcp_release_cb,
1942 .mtu_reduced = tcp_v6_mtu_reduced,
1943 .hash = tcp_v6_hash,
1944 .unhash = inet_unhash,
1945 .get_port = inet_csk_get_port,
1946 .enter_memory_pressure = tcp_enter_memory_pressure,
1947 .stream_memory_free = tcp_stream_memory_free,
1948 .sockets_allocated = &tcp_sockets_allocated,
1949 .memory_allocated = &tcp_memory_allocated,
1950 .memory_pressure = &tcp_memory_pressure,
1951 .orphan_count = &tcp_orphan_count,
1952 .sysctl_mem = sysctl_tcp_mem,
1953 .sysctl_wmem = sysctl_tcp_wmem,
1954 .sysctl_rmem = sysctl_tcp_rmem,
1955 .max_header = MAX_TCP_HEADER,
1956 .obj_size = sizeof(struct tcp6_sock),
1957 .slab_flags = SLAB_DESTROY_BY_RCU,
1958 .twsk_prot = &tcp6_timewait_sock_ops,
1959 .rsk_prot = &tcp6_request_sock_ops,
1960 .h.hashinfo = &tcp_hashinfo,
1961 .no_autobind = true,
1962#ifdef CONFIG_COMPAT
1963 .compat_setsockopt = compat_tcp_setsockopt,
1964 .compat_getsockopt = compat_tcp_getsockopt,
1965#endif
1966#ifdef CONFIG_MEMCG_KMEM
1967 .proto_cgroup = tcp_proto_cgroup,
1968#endif
1969 .clear_sk = tcp_v6_clear_sk,
1970};
1971
1972static const struct inet6_protocol tcpv6_protocol = {
1973 .early_demux = tcp_v6_early_demux,
1974 .handler = tcp_v6_rcv,
1975 .err_handler = tcp_v6_err,
1976 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1977};
1978
1979static struct inet_protosw tcpv6_protosw = {
1980 .type = SOCK_STREAM,
1981 .protocol = IPPROTO_TCP,
1982 .prot = &tcpv6_prot,
1983 .ops = &inet6_stream_ops,
1984 .no_check = 0,
1985 .flags = INET_PROTOSW_PERMANENT |
1986 INET_PROTOSW_ICSK,
1987};
1988
1989static int __net_init tcpv6_net_init(struct net *net)
1990{
1991 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1992 SOCK_RAW, IPPROTO_TCP, net);
1993}
1994
1995static void __net_exit tcpv6_net_exit(struct net *net)
1996{
1997 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1998}
1999
2000static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2001{
2002 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2003}
2004
2005static struct pernet_operations tcpv6_net_ops = {
2006 .init = tcpv6_net_init,
2007 .exit = tcpv6_net_exit,
2008 .exit_batch = tcpv6_net_exit_batch,
2009};
2010
2011int __init tcpv6_init(void)
2012{
2013 int ret;
2014
2015 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2016 if (ret)
2017 goto out;
2018
2019 /* register inet6 protocol */
2020 ret = inet6_register_protosw(&tcpv6_protosw);
2021 if (ret)
2022 goto out_tcpv6_protocol;
2023
2024 ret = register_pernet_subsys(&tcpv6_net_ops);
2025 if (ret)
2026 goto out_tcpv6_protosw;
2027out:
2028 return ret;
2029
2030out_tcpv6_protosw:
2031 inet6_unregister_protosw(&tcpv6_protosw);
2032out_tcpv6_protocol:
2033 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2034 goto out;
2035}
2036
2037void tcpv6_exit(void)
2038{
2039 unregister_pernet_subsys(&tcpv6_net_ops);
2040 inet6_unregister_protosw(&tcpv6_protosw);
2041 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2042}
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
64#include <linux/proc_fs.h>
65#include <linux/seq_file.h>
66
67#include <crypto/hash.h>
68#include <linux/scatterlist.h>
69
70#include <trace/events/tcp.h>
71
72static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
73static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
74 struct request_sock *req);
75
76INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
77
78static const struct inet_connection_sock_af_ops ipv6_mapped;
79const struct inet_connection_sock_af_ops ipv6_specific;
80#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
81static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
82static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
83#endif
84
85/* Helper returning the inet6 address from a given tcp socket.
86 * It can be used in TCP stack instead of inet6_sk(sk).
87 * This avoids a dereference and allow compiler optimizations.
88 * It is a specialized version of inet6_sk_generic().
89 */
90#define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \
91 struct tcp6_sock, tcp)->inet6)
92
93static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
94{
95 struct dst_entry *dst = skb_dst(skb);
96
97 if (dst && dst_hold_safe(dst)) {
98 rcu_assign_pointer(sk->sk_rx_dst, dst);
99 sk->sk_rx_dst_ifindex = skb->skb_iif;
100 sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
101 }
102}
103
104static u32 tcp_v6_init_seq(const struct sk_buff *skb)
105{
106 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
107 ipv6_hdr(skb)->saddr.s6_addr32,
108 tcp_hdr(skb)->dest,
109 tcp_hdr(skb)->source);
110}
111
112static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
113{
114 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
115 ipv6_hdr(skb)->saddr.s6_addr32);
116}
117
118static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
119 int addr_len)
120{
121 /* This check is replicated from tcp_v6_connect() and intended to
122 * prevent BPF program called below from accessing bytes that are out
123 * of the bound specified by user in addr_len.
124 */
125 if (addr_len < SIN6_LEN_RFC2133)
126 return -EINVAL;
127
128 sock_owned_by_me(sk);
129
130 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len);
131}
132
133static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
134 int addr_len)
135{
136 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
137 struct inet_connection_sock *icsk = inet_csk(sk);
138 struct in6_addr *saddr = NULL, *final_p, final;
139 struct inet_timewait_death_row *tcp_death_row;
140 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
141 struct inet_sock *inet = inet_sk(sk);
142 struct tcp_sock *tp = tcp_sk(sk);
143 struct net *net = sock_net(sk);
144 struct ipv6_txoptions *opt;
145 struct dst_entry *dst;
146 struct flowi6 fl6;
147 int addr_type;
148 int err;
149
150 if (addr_len < SIN6_LEN_RFC2133)
151 return -EINVAL;
152
153 if (usin->sin6_family != AF_INET6)
154 return -EAFNOSUPPORT;
155
156 memset(&fl6, 0, sizeof(fl6));
157
158 if (inet6_test_bit(SNDFLOW, sk)) {
159 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
160 IP6_ECN_flow_init(fl6.flowlabel);
161 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
162 struct ip6_flowlabel *flowlabel;
163 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
164 if (IS_ERR(flowlabel))
165 return -EINVAL;
166 fl6_sock_release(flowlabel);
167 }
168 }
169
170 /*
171 * connect() to INADDR_ANY means loopback (BSD'ism).
172 */
173
174 if (ipv6_addr_any(&usin->sin6_addr)) {
175 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
176 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
177 &usin->sin6_addr);
178 else
179 usin->sin6_addr = in6addr_loopback;
180 }
181
182 addr_type = ipv6_addr_type(&usin->sin6_addr);
183
184 if (addr_type & IPV6_ADDR_MULTICAST)
185 return -ENETUNREACH;
186
187 if (addr_type&IPV6_ADDR_LINKLOCAL) {
188 if (addr_len >= sizeof(struct sockaddr_in6) &&
189 usin->sin6_scope_id) {
190 /* If interface is set while binding, indices
191 * must coincide.
192 */
193 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
194 return -EINVAL;
195
196 sk->sk_bound_dev_if = usin->sin6_scope_id;
197 }
198
199 /* Connect to link-local address requires an interface */
200 if (!sk->sk_bound_dev_if)
201 return -EINVAL;
202 }
203
204 if (tp->rx_opt.ts_recent_stamp &&
205 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
206 tp->rx_opt.ts_recent = 0;
207 tp->rx_opt.ts_recent_stamp = 0;
208 WRITE_ONCE(tp->write_seq, 0);
209 }
210
211 sk->sk_v6_daddr = usin->sin6_addr;
212 np->flow_label = fl6.flowlabel;
213
214 /*
215 * TCP over IPv4
216 */
217
218 if (addr_type & IPV6_ADDR_MAPPED) {
219 u32 exthdrlen = icsk->icsk_ext_hdr_len;
220 struct sockaddr_in sin;
221
222 if (ipv6_only_sock(sk))
223 return -ENETUNREACH;
224
225 sin.sin_family = AF_INET;
226 sin.sin_port = usin->sin6_port;
227 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
228
229 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
230 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
231 if (sk_is_mptcp(sk))
232 mptcpv6_handle_mapped(sk, true);
233 sk->sk_backlog_rcv = tcp_v4_do_rcv;
234#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
235 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
236#endif
237
238 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
239
240 if (err) {
241 icsk->icsk_ext_hdr_len = exthdrlen;
242 /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
243 WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
244 if (sk_is_mptcp(sk))
245 mptcpv6_handle_mapped(sk, false);
246 sk->sk_backlog_rcv = tcp_v6_do_rcv;
247#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
248 tp->af_specific = &tcp_sock_ipv6_specific;
249#endif
250 goto failure;
251 }
252 np->saddr = sk->sk_v6_rcv_saddr;
253
254 return err;
255 }
256
257 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
258 saddr = &sk->sk_v6_rcv_saddr;
259
260 fl6.flowi6_proto = IPPROTO_TCP;
261 fl6.daddr = sk->sk_v6_daddr;
262 fl6.saddr = saddr ? *saddr : np->saddr;
263 fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
264 fl6.flowi6_oif = sk->sk_bound_dev_if;
265 fl6.flowi6_mark = sk->sk_mark;
266 fl6.fl6_dport = usin->sin6_port;
267 fl6.fl6_sport = inet->inet_sport;
268 fl6.flowi6_uid = sk->sk_uid;
269
270 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
271 final_p = fl6_update_dst(&fl6, opt, &final);
272
273 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
274
275 dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
276 if (IS_ERR(dst)) {
277 err = PTR_ERR(dst);
278 goto failure;
279 }
280
281 tp->tcp_usec_ts = dst_tcp_usec_ts(dst);
282 tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
283
284 if (!saddr) {
285 saddr = &fl6.saddr;
286
287 err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
288 if (err)
289 goto failure;
290 }
291
292 /* set the source address */
293 np->saddr = *saddr;
294 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
295
296 sk->sk_gso_type = SKB_GSO_TCPV6;
297 ip6_dst_store(sk, dst, NULL, NULL);
298
299 icsk->icsk_ext_hdr_len = 0;
300 if (opt)
301 icsk->icsk_ext_hdr_len = opt->opt_flen +
302 opt->opt_nflen;
303
304 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
305
306 inet->inet_dport = usin->sin6_port;
307
308 tcp_set_state(sk, TCP_SYN_SENT);
309 err = inet6_hash_connect(tcp_death_row, sk);
310 if (err)
311 goto late_failure;
312
313 sk_set_txhash(sk);
314
315 if (likely(!tp->repair)) {
316 if (!tp->write_seq)
317 WRITE_ONCE(tp->write_seq,
318 secure_tcpv6_seq(np->saddr.s6_addr32,
319 sk->sk_v6_daddr.s6_addr32,
320 inet->inet_sport,
321 inet->inet_dport));
322 tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
323 sk->sk_v6_daddr.s6_addr32);
324 }
325
326 if (tcp_fastopen_defer_connect(sk, &err))
327 return err;
328 if (err)
329 goto late_failure;
330
331 err = tcp_connect(sk);
332 if (err)
333 goto late_failure;
334
335 return 0;
336
337late_failure:
338 tcp_set_state(sk, TCP_CLOSE);
339 inet_bhash2_reset_saddr(sk);
340failure:
341 inet->inet_dport = 0;
342 sk->sk_route_caps = 0;
343 return err;
344}
345
346static void tcp_v6_mtu_reduced(struct sock *sk)
347{
348 struct dst_entry *dst;
349 u32 mtu;
350
351 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
352 return;
353
354 mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
355
356 /* Drop requests trying to increase our current mss.
357 * Check done in __ip6_rt_update_pmtu() is too late.
358 */
359 if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
360 return;
361
362 dst = inet6_csk_update_pmtu(sk, mtu);
363 if (!dst)
364 return;
365
366 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
367 tcp_sync_mss(sk, dst_mtu(dst));
368 tcp_simple_retransmit(sk);
369 }
370}
371
372static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
373 u8 type, u8 code, int offset, __be32 info)
374{
375 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
376 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
377 struct net *net = dev_net(skb->dev);
378 struct request_sock *fastopen;
379 struct ipv6_pinfo *np;
380 struct tcp_sock *tp;
381 __u32 seq, snd_una;
382 struct sock *sk;
383 bool fatal;
384 int err;
385
386 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
387 &hdr->daddr, th->dest,
388 &hdr->saddr, ntohs(th->source),
389 skb->dev->ifindex, inet6_sdif(skb));
390
391 if (!sk) {
392 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
393 ICMP6_MIB_INERRORS);
394 return -ENOENT;
395 }
396
397 if (sk->sk_state == TCP_TIME_WAIT) {
398 /* To increase the counter of ignored icmps for TCP-AO */
399 tcp_ao_ignore_icmp(sk, AF_INET6, type, code);
400 inet_twsk_put(inet_twsk(sk));
401 return 0;
402 }
403 seq = ntohl(th->seq);
404 fatal = icmpv6_err_convert(type, code, &err);
405 if (sk->sk_state == TCP_NEW_SYN_RECV) {
406 tcp_req_err(sk, seq, fatal);
407 return 0;
408 }
409
410 if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) {
411 sock_put(sk);
412 return 0;
413 }
414
415 bh_lock_sock(sk);
416 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
417 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
418
419 if (sk->sk_state == TCP_CLOSE)
420 goto out;
421
422 if (static_branch_unlikely(&ip6_min_hopcount)) {
423 /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
424 if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
425 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
426 goto out;
427 }
428 }
429
430 tp = tcp_sk(sk);
431 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
432 fastopen = rcu_dereference(tp->fastopen_rsk);
433 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
434 if (sk->sk_state != TCP_LISTEN &&
435 !between(seq, snd_una, tp->snd_nxt)) {
436 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
437 goto out;
438 }
439
440 np = tcp_inet6_sk(sk);
441
442 if (type == NDISC_REDIRECT) {
443 if (!sock_owned_by_user(sk)) {
444 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
445
446 if (dst)
447 dst->ops->redirect(dst, sk, skb);
448 }
449 goto out;
450 }
451
452 if (type == ICMPV6_PKT_TOOBIG) {
453 u32 mtu = ntohl(info);
454
455 /* We are not interested in TCP_LISTEN and open_requests
456 * (SYN-ACKs send out by Linux are always <576bytes so
457 * they should go through unfragmented).
458 */
459 if (sk->sk_state == TCP_LISTEN)
460 goto out;
461
462 if (!ip6_sk_accept_pmtu(sk))
463 goto out;
464
465 if (mtu < IPV6_MIN_MTU)
466 goto out;
467
468 WRITE_ONCE(tp->mtu_info, mtu);
469
470 if (!sock_owned_by_user(sk))
471 tcp_v6_mtu_reduced(sk);
472 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
473 &sk->sk_tsq_flags))
474 sock_hold(sk);
475 goto out;
476 }
477
478
479 /* Might be for an request_sock */
480 switch (sk->sk_state) {
481 case TCP_SYN_SENT:
482 case TCP_SYN_RECV:
483 /* Only in fast or simultaneous open. If a fast open socket is
484 * already accepted it is treated as a connected one below.
485 */
486 if (fastopen && !fastopen->sk)
487 break;
488
489 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
490
491 if (!sock_owned_by_user(sk)) {
492 WRITE_ONCE(sk->sk_err, err);
493 sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
494
495 tcp_done(sk);
496 } else {
497 WRITE_ONCE(sk->sk_err_soft, err);
498 }
499 goto out;
500 case TCP_LISTEN:
501 break;
502 default:
503 /* check if this ICMP message allows revert of backoff.
504 * (see RFC 6069)
505 */
506 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
507 code == ICMPV6_NOROUTE)
508 tcp_ld_RTO_revert(sk, seq);
509 }
510
511 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
512 WRITE_ONCE(sk->sk_err, err);
513 sk_error_report(sk);
514 } else {
515 WRITE_ONCE(sk->sk_err_soft, err);
516 }
517out:
518 bh_unlock_sock(sk);
519 sock_put(sk);
520 return 0;
521}
522
523
524static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
525 struct flowi *fl,
526 struct request_sock *req,
527 struct tcp_fastopen_cookie *foc,
528 enum tcp_synack_type synack_type,
529 struct sk_buff *syn_skb)
530{
531 struct inet_request_sock *ireq = inet_rsk(req);
532 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
533 struct ipv6_txoptions *opt;
534 struct flowi6 *fl6 = &fl->u.ip6;
535 struct sk_buff *skb;
536 int err = -ENOMEM;
537 u8 tclass;
538
539 /* First, grab a route. */
540 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
541 IPPROTO_TCP)) == NULL)
542 goto done;
543
544 skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
545
546 if (skb) {
547 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
548 &ireq->ir_v6_rmt_addr);
549
550 fl6->daddr = ireq->ir_v6_rmt_addr;
551 if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts)
552 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
553
554 tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
555 (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
556 (np->tclass & INET_ECN_MASK) :
557 np->tclass;
558
559 if (!INET_ECN_is_capable(tclass) &&
560 tcp_bpf_ca_needs_ecn((struct sock *)req))
561 tclass |= INET_ECN_ECT_0;
562
563 rcu_read_lock();
564 opt = ireq->ipv6_opt;
565 if (!opt)
566 opt = rcu_dereference(np->opt);
567 err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
568 opt, tclass, READ_ONCE(sk->sk_priority));
569 rcu_read_unlock();
570 err = net_xmit_eval(err);
571 }
572
573done:
574 return err;
575}
576
577
578static void tcp_v6_reqsk_destructor(struct request_sock *req)
579{
580 kfree(inet_rsk(req)->ipv6_opt);
581 consume_skb(inet_rsk(req)->pktopts);
582}
583
584#ifdef CONFIG_TCP_MD5SIG
585static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
586 const struct in6_addr *addr,
587 int l3index)
588{
589 return tcp_md5_do_lookup(sk, l3index,
590 (union tcp_md5_addr *)addr, AF_INET6);
591}
592
593static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
594 const struct sock *addr_sk)
595{
596 int l3index;
597
598 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
599 addr_sk->sk_bound_dev_if);
600 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
601 l3index);
602}
603
604static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
605 sockptr_t optval, int optlen)
606{
607 struct tcp_md5sig cmd;
608 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
609 union tcp_ao_addr *addr;
610 int l3index = 0;
611 u8 prefixlen;
612 bool l3flag;
613 u8 flags;
614
615 if (optlen < sizeof(cmd))
616 return -EINVAL;
617
618 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
619 return -EFAULT;
620
621 if (sin6->sin6_family != AF_INET6)
622 return -EINVAL;
623
624 flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
625 l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
626
627 if (optname == TCP_MD5SIG_EXT &&
628 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
629 prefixlen = cmd.tcpm_prefixlen;
630 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
631 prefixlen > 32))
632 return -EINVAL;
633 } else {
634 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
635 }
636
637 if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
638 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
639 struct net_device *dev;
640
641 rcu_read_lock();
642 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
643 if (dev && netif_is_l3_master(dev))
644 l3index = dev->ifindex;
645 rcu_read_unlock();
646
647 /* ok to reference set/not set outside of rcu;
648 * right now device MUST be an L3 master
649 */
650 if (!dev || !l3index)
651 return -EINVAL;
652 }
653
654 if (!cmd.tcpm_keylen) {
655 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
656 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
657 AF_INET, prefixlen,
658 l3index, flags);
659 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
660 AF_INET6, prefixlen, l3index, flags);
661 }
662
663 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
664 return -EINVAL;
665
666 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
667 addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
668
669 /* Don't allow keys for peers that have a matching TCP-AO key.
670 * See the comment in tcp_ao_add_cmd()
671 */
672 if (tcp_ao_required(sk, addr, AF_INET,
673 l3flag ? l3index : -1, false))
674 return -EKEYREJECTED;
675 return tcp_md5_do_add(sk, addr,
676 AF_INET, prefixlen, l3index, flags,
677 cmd.tcpm_key, cmd.tcpm_keylen);
678 }
679
680 addr = (union tcp_md5_addr *)&sin6->sin6_addr;
681
682 /* Don't allow keys for peers that have a matching TCP-AO key.
683 * See the comment in tcp_ao_add_cmd()
684 */
685 if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false))
686 return -EKEYREJECTED;
687
688 return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
689 cmd.tcpm_key, cmd.tcpm_keylen);
690}
691
692static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp,
693 const struct in6_addr *daddr,
694 const struct in6_addr *saddr,
695 const struct tcphdr *th, int nbytes)
696{
697 struct tcp6_pseudohdr *bp;
698 struct scatterlist sg;
699 struct tcphdr *_th;
700
701 bp = hp->scratch;
702 /* 1. TCP pseudo-header (RFC2460) */
703 bp->saddr = *saddr;
704 bp->daddr = *daddr;
705 bp->protocol = cpu_to_be32(IPPROTO_TCP);
706 bp->len = cpu_to_be32(nbytes);
707
708 _th = (struct tcphdr *)(bp + 1);
709 memcpy(_th, th, sizeof(*th));
710 _th->check = 0;
711
712 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
713 ahash_request_set_crypt(hp->req, &sg, NULL,
714 sizeof(*bp) + sizeof(*th));
715 return crypto_ahash_update(hp->req);
716}
717
718static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
719 const struct in6_addr *daddr, struct in6_addr *saddr,
720 const struct tcphdr *th)
721{
722 struct tcp_sigpool hp;
723
724 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
725 goto clear_hash_nostart;
726
727 if (crypto_ahash_init(hp.req))
728 goto clear_hash;
729 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
730 goto clear_hash;
731 if (tcp_md5_hash_key(&hp, key))
732 goto clear_hash;
733 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
734 if (crypto_ahash_final(hp.req))
735 goto clear_hash;
736
737 tcp_sigpool_end(&hp);
738 return 0;
739
740clear_hash:
741 tcp_sigpool_end(&hp);
742clear_hash_nostart:
743 memset(md5_hash, 0, 16);
744 return 1;
745}
746
747static int tcp_v6_md5_hash_skb(char *md5_hash,
748 const struct tcp_md5sig_key *key,
749 const struct sock *sk,
750 const struct sk_buff *skb)
751{
752 const struct tcphdr *th = tcp_hdr(skb);
753 const struct in6_addr *saddr, *daddr;
754 struct tcp_sigpool hp;
755
756 if (sk) { /* valid for establish/request sockets */
757 saddr = &sk->sk_v6_rcv_saddr;
758 daddr = &sk->sk_v6_daddr;
759 } else {
760 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
761 saddr = &ip6h->saddr;
762 daddr = &ip6h->daddr;
763 }
764
765 if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
766 goto clear_hash_nostart;
767
768 if (crypto_ahash_init(hp.req))
769 goto clear_hash;
770
771 if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
772 goto clear_hash;
773 if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
774 goto clear_hash;
775 if (tcp_md5_hash_key(&hp, key))
776 goto clear_hash;
777 ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
778 if (crypto_ahash_final(hp.req))
779 goto clear_hash;
780
781 tcp_sigpool_end(&hp);
782 return 0;
783
784clear_hash:
785 tcp_sigpool_end(&hp);
786clear_hash_nostart:
787 memset(md5_hash, 0, 16);
788 return 1;
789}
790#endif
791
792static void tcp_v6_init_req(struct request_sock *req,
793 const struct sock *sk_listener,
794 struct sk_buff *skb)
795{
796 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
797 struct inet_request_sock *ireq = inet_rsk(req);
798 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
799
800 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
801 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
802
803 /* So that link locals have meaning */
804 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
805 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
806 ireq->ir_iif = tcp_v6_iif(skb);
807
808 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
809 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
810 np->rxopt.bits.rxinfo ||
811 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
812 np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) {
813 refcount_inc(&skb->users);
814 ireq->pktopts = skb;
815 }
816}
817
818static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
819 struct sk_buff *skb,
820 struct flowi *fl,
821 struct request_sock *req)
822{
823 tcp_v6_init_req(req, sk, skb);
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
831struct 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
841const 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
862static 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), true);
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
1007static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
1008{
1009 const struct tcphdr *th = tcp_hdr(skb);
1010 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1011 const __u8 *md5_hash_location = NULL;
1012#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1013 bool allocated_traffic_key = false;
1014#endif
1015 const struct tcp_ao_hdr *aoh;
1016 struct tcp_key key = {};
1017 u32 seq = 0, ack_seq = 0;
1018 __be32 label = 0;
1019 u32 priority = 0;
1020 struct net *net;
1021 u32 txhash = 0;
1022 int oif = 0;
1023#ifdef CONFIG_TCP_MD5SIG
1024 unsigned char newhash[16];
1025 int genhash;
1026 struct sock *sk1 = NULL;
1027#endif
1028
1029 if (th->rst)
1030 return;
1031
1032 /* If sk not NULL, it means we did a successful lookup and incoming
1033 * route had to be correct. prequeue might have dropped our dst.
1034 */
1035 if (!sk && !ipv6_unicast_destination(skb))
1036 return;
1037
1038 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1039 /* Invalid TCP option size or twice included auth */
1040 if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
1041 return;
1042#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1043 rcu_read_lock();
1044#endif
1045#ifdef CONFIG_TCP_MD5SIG
1046 if (sk && sk_fullsock(sk)) {
1047 int l3index;
1048
1049 /* sdif set, means packet ingressed via a device
1050 * in an L3 domain and inet_iif is set to it.
1051 */
1052 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1053 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1054 if (key.md5_key)
1055 key.type = TCP_KEY_MD5;
1056 } else if (md5_hash_location) {
1057 int dif = tcp_v6_iif_l3_slave(skb);
1058 int sdif = tcp_v6_sdif(skb);
1059 int l3index;
1060
1061 /*
1062 * active side is lost. Try to find listening socket through
1063 * source port, and then find md5 key through listening socket.
1064 * we are not loose security here:
1065 * Incoming packet is checked with md5 hash with finding key,
1066 * no RST generated if md5 hash doesn't match.
1067 */
1068 sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1069 NULL, 0, &ipv6h->saddr, th->source,
1070 &ipv6h->daddr, ntohs(th->source),
1071 dif, sdif);
1072 if (!sk1)
1073 goto out;
1074
1075 /* sdif set, means packet ingressed via a device
1076 * in an L3 domain and dif is set to it.
1077 */
1078 l3index = tcp_v6_sdif(skb) ? dif : 0;
1079
1080 key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1081 if (!key.md5_key)
1082 goto out;
1083 key.type = TCP_KEY_MD5;
1084
1085 genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb);
1086 if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
1087 goto out;
1088 }
1089#endif
1090
1091 if (th->ack)
1092 seq = ntohl(th->ack_seq);
1093 else
1094 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1095 (th->doff << 2);
1096
1097#ifdef CONFIG_TCP_AO
1098 if (aoh) {
1099 int l3index;
1100
1101 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1102 if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq,
1103 &key.ao_key, &key.traffic_key,
1104 &allocated_traffic_key,
1105 &key.rcv_next, &key.sne))
1106 goto out;
1107 key.type = TCP_KEY_AO;
1108 }
1109#endif
1110
1111 if (sk) {
1112 oif = sk->sk_bound_dev_if;
1113 if (sk_fullsock(sk)) {
1114 trace_tcp_send_reset(sk, skb);
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 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
1131 ipv6_get_dsfield(ipv6h), label, priority, txhash,
1132 &key);
1133
1134#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1135out:
1136 if (allocated_traffic_key)
1137 kfree(key.traffic_key);
1138 rcu_read_unlock();
1139#endif
1140}
1141
1142static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1143 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1144 struct tcp_key *key, u8 tclass,
1145 __be32 label, u32 priority, u32 txhash)
1146{
1147 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0,
1148 tclass, label, priority, txhash, key);
1149}
1150
1151static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1152{
1153 struct inet_timewait_sock *tw = inet_twsk(sk);
1154 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1155 struct tcp_key key = {};
1156#ifdef CONFIG_TCP_AO
1157 struct tcp_ao_info *ao_info;
1158
1159 if (static_branch_unlikely(&tcp_ao_needed.key)) {
1160
1161 /* FIXME: the segment to-be-acked is not verified yet */
1162 ao_info = rcu_dereference(tcptw->ao_info);
1163 if (ao_info) {
1164 const struct tcp_ao_hdr *aoh;
1165
1166 /* Invalid TCP option size or twice included auth */
1167 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1168 goto out;
1169 if (aoh)
1170 key.ao_key = tcp_ao_established_key(ao_info,
1171 aoh->rnext_keyid, -1);
1172 }
1173 }
1174 if (key.ao_key) {
1175 struct tcp_ao_key *rnext_key;
1176
1177 key.traffic_key = snd_other_key(key.ao_key);
1178 /* rcv_next switches to our rcv_next */
1179 rnext_key = READ_ONCE(ao_info->rnext_key);
1180 key.rcv_next = rnext_key->rcvid;
1181 key.sne = READ_ONCE(ao_info->snd_sne);
1182 key.type = TCP_KEY_AO;
1183#else
1184 if (0) {
1185#endif
1186#ifdef CONFIG_TCP_MD5SIG
1187 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1188 key.md5_key = tcp_twsk_md5_key(tcptw);
1189 if (key.md5_key)
1190 key.type = TCP_KEY_MD5;
1191#endif
1192 }
1193
1194 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1195 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1196 tcp_tw_tsval(tcptw),
1197 tcptw->tw_ts_recent, tw->tw_bound_dev_if, &key,
1198 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
1199 tw->tw_txhash);
1200
1201#ifdef CONFIG_TCP_AO
1202out:
1203#endif
1204 inet_twsk_put(tw);
1205}
1206
1207static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1208 struct request_sock *req)
1209{
1210 struct tcp_key key = {};
1211
1212#ifdef CONFIG_TCP_AO
1213 if (static_branch_unlikely(&tcp_ao_needed.key) &&
1214 tcp_rsk_used_ao(req)) {
1215 const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
1216 const struct tcp_ao_hdr *aoh;
1217 int l3index;
1218
1219 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1220 /* Invalid TCP option size or twice included auth */
1221 if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1222 return;
1223 if (!aoh)
1224 return;
1225 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1226 (union tcp_ao_addr *)addr,
1227 AF_INET6, aoh->rnext_keyid, -1);
1228 if (unlikely(!key.ao_key)) {
1229 /* Send ACK with any matching MKT for the peer */
1230 key.ao_key = tcp_ao_do_lookup(sk, l3index,
1231 (union tcp_ao_addr *)addr,
1232 AF_INET6, -1, -1);
1233 /* Matching key disappeared (user removed the key?)
1234 * let the handshake timeout.
1235 */
1236 if (!key.ao_key) {
1237 net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
1238 addr,
1239 ntohs(tcp_hdr(skb)->source),
1240 &ipv6_hdr(skb)->daddr,
1241 ntohs(tcp_hdr(skb)->dest));
1242 return;
1243 }
1244 }
1245 key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
1246 if (!key.traffic_key)
1247 return;
1248
1249 key.type = TCP_KEY_AO;
1250 key.rcv_next = aoh->keyid;
1251 tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
1252#else
1253 if (0) {
1254#endif
1255#ifdef CONFIG_TCP_MD5SIG
1256 } else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1257 int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1258
1259 key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
1260 l3index);
1261 if (key.md5_key)
1262 key.type = TCP_KEY_MD5;
1263#endif
1264 }
1265
1266 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1267 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1268 */
1269 /* RFC 7323 2.3
1270 * The window field (SEG.WND) of every outgoing segment, with the
1271 * exception of <SYN> segments, MUST be right-shifted by
1272 * Rcv.Wind.Shift bits:
1273 */
1274 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1275 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1276 tcp_rsk(req)->rcv_nxt,
1277 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1278 tcp_rsk_tsval(tcp_rsk(req)),
1279 READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
1280 &key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
1281 READ_ONCE(sk->sk_priority),
1282 READ_ONCE(tcp_rsk(req)->txhash));
1283 if (tcp_key_is_ao(&key))
1284 kfree(key.traffic_key);
1285}
1286
1287
1288static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1289{
1290#ifdef CONFIG_SYN_COOKIES
1291 const struct tcphdr *th = tcp_hdr(skb);
1292
1293 if (!th->syn)
1294 sk = cookie_v6_check(sk, skb);
1295#endif
1296 return sk;
1297}
1298
1299u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1300 struct tcphdr *th, u32 *cookie)
1301{
1302 u16 mss = 0;
1303#ifdef CONFIG_SYN_COOKIES
1304 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1305 &tcp_request_sock_ipv6_ops, sk, th);
1306 if (mss) {
1307 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1308 tcp_synq_overflow(sk);
1309 }
1310#endif
1311 return mss;
1312}
1313
1314static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1315{
1316 if (skb->protocol == htons(ETH_P_IP))
1317 return tcp_v4_conn_request(sk, skb);
1318
1319 if (!ipv6_unicast_destination(skb))
1320 goto drop;
1321
1322 if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1323 __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1324 return 0;
1325 }
1326
1327 return tcp_conn_request(&tcp6_request_sock_ops,
1328 &tcp_request_sock_ipv6_ops, sk, skb);
1329
1330drop:
1331 tcp_listendrop(sk);
1332 return 0; /* don't send reset */
1333}
1334
1335static void tcp_v6_restore_cb(struct sk_buff *skb)
1336{
1337 /* We need to move header back to the beginning if xfrm6_policy_check()
1338 * and tcp_v6_fill_cb() are going to be called again.
1339 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1340 */
1341 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1342 sizeof(struct inet6_skb_parm));
1343}
1344
1345static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1346 struct request_sock *req,
1347 struct dst_entry *dst,
1348 struct request_sock *req_unhash,
1349 bool *own_req)
1350{
1351 struct inet_request_sock *ireq;
1352 struct ipv6_pinfo *newnp;
1353 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1354 struct ipv6_txoptions *opt;
1355 struct inet_sock *newinet;
1356 bool found_dup_sk = false;
1357 struct tcp_sock *newtp;
1358 struct sock *newsk;
1359#ifdef CONFIG_TCP_MD5SIG
1360 struct tcp_md5sig_key *key;
1361 int l3index;
1362#endif
1363 struct flowi6 fl6;
1364
1365 if (skb->protocol == htons(ETH_P_IP)) {
1366 /*
1367 * v6 mapped
1368 */
1369
1370 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1371 req_unhash, own_req);
1372
1373 if (!newsk)
1374 return NULL;
1375
1376 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1377
1378 newnp = tcp_inet6_sk(newsk);
1379 newtp = tcp_sk(newsk);
1380
1381 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1382
1383 newnp->saddr = newsk->sk_v6_rcv_saddr;
1384
1385 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1386 if (sk_is_mptcp(newsk))
1387 mptcpv6_handle_mapped(newsk, true);
1388 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1389#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1390 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1391#endif
1392
1393 newnp->ipv6_mc_list = NULL;
1394 newnp->ipv6_ac_list = NULL;
1395 newnp->ipv6_fl_list = NULL;
1396 newnp->pktoptions = NULL;
1397 newnp->opt = NULL;
1398 newnp->mcast_oif = inet_iif(skb);
1399 newnp->mcast_hops = ip_hdr(skb)->ttl;
1400 newnp->rcv_flowinfo = 0;
1401 if (inet6_test_bit(REPFLOW, sk))
1402 newnp->flow_label = 0;
1403
1404 /*
1405 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1406 * here, tcp_create_openreq_child now does this for us, see the comment in
1407 * that function for the gory details. -acme
1408 */
1409
1410 /* It is tricky place. Until this moment IPv4 tcp
1411 worked with IPv6 icsk.icsk_af_ops.
1412 Sync it now.
1413 */
1414 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1415
1416 return newsk;
1417 }
1418
1419 ireq = inet_rsk(req);
1420
1421 if (sk_acceptq_is_full(sk))
1422 goto out_overflow;
1423
1424 if (!dst) {
1425 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1426 if (!dst)
1427 goto out;
1428 }
1429
1430 newsk = tcp_create_openreq_child(sk, req, skb);
1431 if (!newsk)
1432 goto out_nonewsk;
1433
1434 /*
1435 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1436 * count here, tcp_create_openreq_child now does this for us, see the
1437 * comment in that function for the gory details. -acme
1438 */
1439
1440 newsk->sk_gso_type = SKB_GSO_TCPV6;
1441 ip6_dst_store(newsk, dst, NULL, NULL);
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 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1453 newnp->saddr = ireq->ir_v6_loc_addr;
1454 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1455 newsk->sk_bound_dev_if = ireq->ir_iif;
1456
1457 /* Now IPv6 options...
1458
1459 First: no IPv4 options.
1460 */
1461 newinet->inet_opt = NULL;
1462 newnp->ipv6_mc_list = NULL;
1463 newnp->ipv6_ac_list = NULL;
1464 newnp->ipv6_fl_list = NULL;
1465
1466 /* Clone RX bits */
1467 newnp->rxopt.all = np->rxopt.all;
1468
1469 newnp->pktoptions = NULL;
1470 newnp->opt = NULL;
1471 newnp->mcast_oif = tcp_v6_iif(skb);
1472 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1473 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1474 if (inet6_test_bit(REPFLOW, sk))
1475 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1476
1477 /* Set ToS of the new socket based upon the value of incoming SYN.
1478 * ECT bits are set later in tcp_init_transfer().
1479 */
1480 if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1481 newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1482
1483 /* Clone native IPv6 options from listening socket (if any)
1484
1485 Yes, keeping reference count would be much more clever,
1486 but we make one more one thing there: reattach optmem
1487 to newsk.
1488 */
1489 opt = ireq->ipv6_opt;
1490 if (!opt)
1491 opt = rcu_dereference(np->opt);
1492 if (opt) {
1493 opt = ipv6_dup_options(newsk, opt);
1494 RCU_INIT_POINTER(newnp->opt, opt);
1495 }
1496 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1497 if (opt)
1498 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1499 opt->opt_flen;
1500
1501 tcp_ca_openreq_child(newsk, dst);
1502
1503 tcp_sync_mss(newsk, dst_mtu(dst));
1504 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1505
1506 tcp_initialize_rcv_mss(newsk);
1507
1508 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1509 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1510
1511#ifdef CONFIG_TCP_MD5SIG
1512 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1513
1514 if (!tcp_rsk_used_ao(req)) {
1515 /* Copy over the MD5 key from the original socket */
1516 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1517 if (key) {
1518 const union tcp_md5_addr *addr;
1519
1520 addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1521 if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1522 inet_csk_prepare_forced_close(newsk);
1523 tcp_done(newsk);
1524 goto out;
1525 }
1526 }
1527 }
1528#endif
1529#ifdef CONFIG_TCP_AO
1530 /* Copy over tcp_ao_info if any */
1531 if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
1532 goto out; /* OOM */
1533#endif
1534
1535 if (__inet_inherit_port(sk, newsk) < 0) {
1536 inet_csk_prepare_forced_close(newsk);
1537 tcp_done(newsk);
1538 goto out;
1539 }
1540 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1541 &found_dup_sk);
1542 if (*own_req) {
1543 tcp_move_syn(newtp, req);
1544
1545 /* Clone pktoptions received with SYN, if we own the req */
1546 if (ireq->pktopts) {
1547 newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1548 consume_skb(ireq->pktopts);
1549 ireq->pktopts = NULL;
1550 if (newnp->pktoptions)
1551 tcp_v6_restore_cb(newnp->pktoptions);
1552 }
1553 } else {
1554 if (!req_unhash && found_dup_sk) {
1555 /* This code path should only be executed in the
1556 * syncookie case only
1557 */
1558 bh_unlock_sock(newsk);
1559 sock_put(newsk);
1560 newsk = NULL;
1561 }
1562 }
1563
1564 return newsk;
1565
1566out_overflow:
1567 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1568out_nonewsk:
1569 dst_release(dst);
1570out:
1571 tcp_listendrop(sk);
1572 return NULL;
1573}
1574
1575INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1576 u32));
1577/* The socket must have it's spinlock held when we get
1578 * here, unless it is a TCP_LISTEN socket.
1579 *
1580 * We have a potential double-lock case here, so even when
1581 * doing backlog processing we use the BH locking scheme.
1582 * This is because we cannot sleep with the original spinlock
1583 * held.
1584 */
1585INDIRECT_CALLABLE_SCOPE
1586int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1587{
1588 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1589 struct sk_buff *opt_skb = NULL;
1590 enum skb_drop_reason reason;
1591 struct tcp_sock *tp;
1592
1593 /* Imagine: socket is IPv6. IPv4 packet arrives,
1594 goes to IPv4 receive handler and backlogged.
1595 From backlog it always goes here. Kerboom...
1596 Fortunately, tcp_rcv_established and rcv_established
1597 handle them correctly, but it is not case with
1598 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1599 */
1600
1601 if (skb->protocol == htons(ETH_P_IP))
1602 return tcp_v4_do_rcv(sk, skb);
1603
1604 /*
1605 * socket locking is here for SMP purposes as backlog rcv
1606 * is currently called with bh processing disabled.
1607 */
1608
1609 /* Do Stevens' IPV6_PKTOPTIONS.
1610
1611 Yes, guys, it is the only place in our code, where we
1612 may make it not affecting IPv4.
1613 The rest of code is protocol independent,
1614 and I do not like idea to uglify IPv4.
1615
1616 Actually, all the idea behind IPV6_PKTOPTIONS
1617 looks not very well thought. For now we latch
1618 options, received in the last packet, enqueued
1619 by tcp. Feel free to propose better solution.
1620 --ANK (980728)
1621 */
1622 if (np->rxopt.all)
1623 opt_skb = skb_clone_and_charge_r(skb, sk);
1624
1625 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1626 struct dst_entry *dst;
1627
1628 dst = rcu_dereference_protected(sk->sk_rx_dst,
1629 lockdep_sock_is_held(sk));
1630
1631 sock_rps_save_rxhash(sk, skb);
1632 sk_mark_napi_id(sk, skb);
1633 if (dst) {
1634 if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1635 INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1636 dst, sk->sk_rx_dst_cookie) == NULL) {
1637 RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1638 dst_release(dst);
1639 }
1640 }
1641
1642 tcp_rcv_established(sk, skb);
1643 if (opt_skb)
1644 goto ipv6_pktoptions;
1645 return 0;
1646 }
1647
1648 if (tcp_checksum_complete(skb))
1649 goto csum_err;
1650
1651 if (sk->sk_state == TCP_LISTEN) {
1652 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1653
1654 if (nsk != sk) {
1655 if (nsk) {
1656 reason = tcp_child_process(sk, nsk, skb);
1657 if (reason)
1658 goto reset;
1659 }
1660 if (opt_skb)
1661 __kfree_skb(opt_skb);
1662 return 0;
1663 }
1664 } else
1665 sock_rps_save_rxhash(sk, skb);
1666
1667 reason = tcp_rcv_state_process(sk, skb);
1668 if (reason)
1669 goto reset;
1670 if (opt_skb)
1671 goto ipv6_pktoptions;
1672 return 0;
1673
1674reset:
1675 tcp_v6_send_reset(sk, skb);
1676discard:
1677 if (opt_skb)
1678 __kfree_skb(opt_skb);
1679 kfree_skb_reason(skb, reason);
1680 return 0;
1681csum_err:
1682 reason = SKB_DROP_REASON_TCP_CSUM;
1683 trace_tcp_bad_csum(skb);
1684 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1685 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1686 goto discard;
1687
1688
1689ipv6_pktoptions:
1690 /* Do you ask, what is it?
1691
1692 1. skb was enqueued by tcp.
1693 2. skb is added to tail of read queue, rather than out of order.
1694 3. socket is not in passive state.
1695 4. Finally, it really contains options, which user wants to receive.
1696 */
1697 tp = tcp_sk(sk);
1698 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1699 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1700 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1701 WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb));
1702 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1703 WRITE_ONCE(np->mcast_hops,
1704 ipv6_hdr(opt_skb)->hop_limit);
1705 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1706 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1707 if (inet6_test_bit(REPFLOW, sk))
1708 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1709 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1710 tcp_v6_restore_cb(opt_skb);
1711 opt_skb = xchg(&np->pktoptions, opt_skb);
1712 } else {
1713 __kfree_skb(opt_skb);
1714 opt_skb = xchg(&np->pktoptions, NULL);
1715 }
1716 }
1717
1718 consume_skb(opt_skb);
1719 return 0;
1720}
1721
1722static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1723 const struct tcphdr *th)
1724{
1725 /* This is tricky: we move IP6CB at its correct location into
1726 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1727 * _decode_session6() uses IP6CB().
1728 * barrier() makes sure compiler won't play aliasing games.
1729 */
1730 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1731 sizeof(struct inet6_skb_parm));
1732 barrier();
1733
1734 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1735 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1736 skb->len - th->doff*4);
1737 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1738 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1739 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1740 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1741 TCP_SKB_CB(skb)->sacked = 0;
1742 TCP_SKB_CB(skb)->has_rxtstamp =
1743 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1744}
1745
1746INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1747{
1748 enum skb_drop_reason drop_reason;
1749 int sdif = inet6_sdif(skb);
1750 int dif = inet6_iif(skb);
1751 const struct tcphdr *th;
1752 const struct ipv6hdr *hdr;
1753 bool refcounted;
1754 struct sock *sk;
1755 int ret;
1756 struct net *net = dev_net(skb->dev);
1757
1758 drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1759 if (skb->pkt_type != PACKET_HOST)
1760 goto discard_it;
1761
1762 /*
1763 * Count it even if it's bad.
1764 */
1765 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1766
1767 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1768 goto discard_it;
1769
1770 th = (const struct tcphdr *)skb->data;
1771
1772 if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1773 drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1774 goto bad_packet;
1775 }
1776 if (!pskb_may_pull(skb, th->doff*4))
1777 goto discard_it;
1778
1779 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1780 goto csum_error;
1781
1782 th = (const struct tcphdr *)skb->data;
1783 hdr = ipv6_hdr(skb);
1784
1785lookup:
1786 sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1787 th->source, th->dest, inet6_iif(skb), sdif,
1788 &refcounted);
1789 if (!sk)
1790 goto no_tcp_socket;
1791
1792process:
1793 if (sk->sk_state == TCP_TIME_WAIT)
1794 goto do_time_wait;
1795
1796 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1797 struct request_sock *req = inet_reqsk(sk);
1798 bool req_stolen = false;
1799 struct sock *nsk;
1800
1801 sk = req->rsk_listener;
1802 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1803 drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1804 else
1805 drop_reason = tcp_inbound_hash(sk, req, skb,
1806 &hdr->saddr, &hdr->daddr,
1807 AF_INET6, dif, sdif);
1808 if (drop_reason) {
1809 sk_drops_add(sk, skb);
1810 reqsk_put(req);
1811 goto discard_it;
1812 }
1813 if (tcp_checksum_complete(skb)) {
1814 reqsk_put(req);
1815 goto csum_error;
1816 }
1817 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1818 nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1819 if (!nsk) {
1820 inet_csk_reqsk_queue_drop_and_put(sk, req);
1821 goto lookup;
1822 }
1823 sk = nsk;
1824 /* reuseport_migrate_sock() has already held one sk_refcnt
1825 * before returning.
1826 */
1827 } else {
1828 sock_hold(sk);
1829 }
1830 refcounted = true;
1831 nsk = NULL;
1832 if (!tcp_filter(sk, skb)) {
1833 th = (const struct tcphdr *)skb->data;
1834 hdr = ipv6_hdr(skb);
1835 tcp_v6_fill_cb(skb, hdr, th);
1836 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1837 } else {
1838 drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1839 }
1840 if (!nsk) {
1841 reqsk_put(req);
1842 if (req_stolen) {
1843 /* Another cpu got exclusive access to req
1844 * and created a full blown socket.
1845 * Try to feed this packet to this socket
1846 * instead of discarding it.
1847 */
1848 tcp_v6_restore_cb(skb);
1849 sock_put(sk);
1850 goto lookup;
1851 }
1852 goto discard_and_relse;
1853 }
1854 nf_reset_ct(skb);
1855 if (nsk == sk) {
1856 reqsk_put(req);
1857 tcp_v6_restore_cb(skb);
1858 } else {
1859 drop_reason = tcp_child_process(sk, nsk, skb);
1860 if (drop_reason) {
1861 tcp_v6_send_reset(nsk, skb);
1862 goto discard_and_relse;
1863 }
1864 sock_put(sk);
1865 return 0;
1866 }
1867 }
1868
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);
1917put_and_return:
1918 if (refcounted)
1919 sock_put(sk);
1920 return ret ? -1 : 0;
1921
1922no_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)) {
1930csum_error:
1931 drop_reason = SKB_DROP_REASON_TCP_CSUM;
1932 trace_tcp_bad_csum(skb);
1933 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1934bad_packet:
1935 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1936 } else {
1937 tcp_v6_send_reset(NULL, skb);
1938 }
1939
1940discard_it:
1941 SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1942 kfree_skb_reason(skb, drop_reason);
1943 return 0;
1944
1945discard_and_relse:
1946 sk_drops_add(sk, skb);
1947 if (refcounted)
1948 sock_put(sk);
1949 goto discard_it;
1950
1951do_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)) {
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 goto process;
1984 }
1985 }
1986 /* to ACK */
1987 fallthrough;
1988 case TCP_TW_ACK:
1989 tcp_v6_timewait_ack(sk, skb);
1990 break;
1991 case TCP_TW_RST:
1992 tcp_v6_send_reset(sk, skb);
1993 inet_twsk_deschedule_put(inet_twsk(sk));
1994 goto discard_it;
1995 case TCP_TW_SUCCESS:
1996 ;
1997 }
1998 goto discard_it;
1999}
2000
2001void tcp_v6_early_demux(struct sk_buff *skb)
2002{
2003 struct net *net = dev_net(skb->dev);
2004 const struct ipv6hdr *hdr;
2005 const struct tcphdr *th;
2006 struct sock *sk;
2007
2008 if (skb->pkt_type != PACKET_HOST)
2009 return;
2010
2011 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
2012 return;
2013
2014 hdr = ipv6_hdr(skb);
2015 th = tcp_hdr(skb);
2016
2017 if (th->doff < sizeof(struct tcphdr) / 4)
2018 return;
2019
2020 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
2021 sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
2022 &hdr->saddr, th->source,
2023 &hdr->daddr, ntohs(th->dest),
2024 inet6_iif(skb), inet6_sdif(skb));
2025 if (sk) {
2026 skb->sk = sk;
2027 skb->destructor = sock_edemux;
2028 if (sk_fullsock(sk)) {
2029 struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
2030
2031 if (dst)
2032 dst = dst_check(dst, sk->sk_rx_dst_cookie);
2033 if (dst &&
2034 sk->sk_rx_dst_ifindex == skb->skb_iif)
2035 skb_dst_set_noref(skb, dst);
2036 }
2037 }
2038}
2039
2040static struct timewait_sock_ops tcp6_timewait_sock_ops = {
2041 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
2042 .twsk_unique = tcp_twsk_unique,
2043 .twsk_destructor = tcp_twsk_destructor,
2044};
2045
2046INDIRECT_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
2051const 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)
2067static 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 */
2085static 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)
2101static 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 */
2119static 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. */
2136static 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
2168static 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
2240static 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 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
2265static 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);
2287out:
2288 return 0;
2289}
2290
2291static 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
2298static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2299 .family = AF_INET6,
2300};
2301
2302int __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
2310void tcp6_proc_exit(struct net *net)
2311{
2312 remove_proc_entry("tcp6", net->proc_net);
2313}
2314#endif
2315
2316struct 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};
2367EXPORT_SYMBOL_GPL(tcpv6_prot);
2368
2369
2370static 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
2379static int __net_init tcpv6_net_init(struct net *net)
2380{
2381 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2382 SOCK_RAW, IPPROTO_TCP, net);
2383}
2384
2385static void __net_exit tcpv6_net_exit(struct net *net)
2386{
2387 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2388}
2389
2390static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2391{
2392 tcp_twsk_purge(net_exit_list, AF_INET6);
2393}
2394
2395static struct pernet_operations tcpv6_net_ops = {
2396 .init = tcpv6_net_init,
2397 .exit = tcpv6_net_exit,
2398 .exit_batch = tcpv6_net_exit_batch,
2399};
2400
2401int __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
2427out:
2428 return ret;
2429
2430out_tcpv6_pernet_subsys:
2431 unregister_pernet_subsys(&tcpv6_net_ops);
2432out_tcpv6_protosw:
2433 inet6_unregister_protosw(&tcpv6_protosw);
2434out_tcpv6_protocol:
2435 inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2436 goto out;
2437}
2438
2439void 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}