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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * TCP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on:
10 * linux/net/ipv4/tcp.c
11 * linux/net/ipv4/tcp_input.c
12 * linux/net/ipv4/tcp_output.c
13 *
14 * Fixes:
15 * Hideaki YOSHIFUJI : sin6_scope_id support
16 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
17 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
18 * a single port at the same time.
19 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
20 */
21
22#include <linux/bottom_half.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/types.h>
26#include <linux/socket.h>
27#include <linux/sockios.h>
28#include <linux/net.h>
29#include <linux/jiffies.h>
30#include <linux/in.h>
31#include <linux/in6.h>
32#include <linux/netdevice.h>
33#include <linux/init.h>
34#include <linux/jhash.h>
35#include <linux/ipsec.h>
36#include <linux/times.h>
37#include <linux/slab.h>
38#include <linux/uaccess.h>
39#include <linux/ipv6.h>
40#include <linux/icmpv6.h>
41#include <linux/random.h>
42#include <linux/indirect_call_wrapper.h>
43
44#include <net/tcp.h>
45#include <net/ndisc.h>
46#include <net/inet6_hashtables.h>
47#include <net/inet6_connection_sock.h>
48#include <net/ipv6.h>
49#include <net/transp_v6.h>
50#include <net/addrconf.h>
51#include <net/ip6_route.h>
52#include <net/ip6_checksum.h>
53#include <net/inet_ecn.h>
54#include <net/protocol.h>
55#include <net/xfrm.h>
56#include <net/snmp.h>
57#include <net/dsfield.h>
58#include <net/timewait_sock.h>
59#include <net/inet_common.h>
60#include <net/secure_seq.h>
61#include <net/busy_poll.h>
62
63#include <linux/proc_fs.h>
64#include <linux/seq_file.h>
65
66#include <crypto/hash.h>
67#include <linux/scatterlist.h>
68
69#include <trace/events/tcp.h>
70
71static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
72static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
73 struct request_sock *req);
74
75static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
76
77static const struct inet_connection_sock_af_ops ipv6_mapped;
78const struct inet_connection_sock_af_ops ipv6_specific;
79#ifdef CONFIG_TCP_MD5SIG
80static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
81static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
82#else
83static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
84 const struct in6_addr *addr,
85 int l3index)
86{
87 return NULL;
88}
89#endif
90
91/* Helper returning the inet6 address from a given tcp socket.
92 * It can be used in TCP stack instead of inet6_sk(sk).
93 * This avoids a dereference and allow compiler optimizations.
94 * It is a specialized version of inet6_sk_generic().
95 */
96static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
97{
98 unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
99
100 return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
101}
102
103static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
104{
105 struct dst_entry *dst = skb_dst(skb);
106
107 if (dst && dst_hold_safe(dst)) {
108 const struct rt6_info *rt = (const struct rt6_info *)dst;
109
110 sk->sk_rx_dst = dst;
111 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
112 tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
113 }
114}
115
116static u32 tcp_v6_init_seq(const struct sk_buff *skb)
117{
118 return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
119 ipv6_hdr(skb)->saddr.s6_addr32,
120 tcp_hdr(skb)->dest,
121 tcp_hdr(skb)->source);
122}
123
124static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
125{
126 return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
127 ipv6_hdr(skb)->saddr.s6_addr32);
128}
129
130static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
131 int addr_len)
132{
133 /* This check is replicated from tcp_v6_connect() and intended to
134 * prevent BPF program called below from accessing bytes that are out
135 * of the bound specified by user in addr_len.
136 */
137 if (addr_len < SIN6_LEN_RFC2133)
138 return -EINVAL;
139
140 sock_owned_by_me(sk);
141
142 return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
143}
144
145static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
146 int addr_len)
147{
148 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
149 struct inet_sock *inet = inet_sk(sk);
150 struct inet_connection_sock *icsk = inet_csk(sk);
151 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
152 struct tcp_sock *tp = tcp_sk(sk);
153 struct in6_addr *saddr = NULL, *final_p, final;
154 struct ipv6_txoptions *opt;
155 struct flowi6 fl6;
156 struct dst_entry *dst;
157 int addr_type;
158 int err;
159 struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
160
161 if (addr_len < SIN6_LEN_RFC2133)
162 return -EINVAL;
163
164 if (usin->sin6_family != AF_INET6)
165 return -EAFNOSUPPORT;
166
167 memset(&fl6, 0, sizeof(fl6));
168
169 if (np->sndflow) {
170 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
171 IP6_ECN_flow_init(fl6.flowlabel);
172 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
173 struct ip6_flowlabel *flowlabel;
174 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
175 if (IS_ERR(flowlabel))
176 return -EINVAL;
177 fl6_sock_release(flowlabel);
178 }
179 }
180
181 /*
182 * connect() to INADDR_ANY means loopback (BSD'ism).
183 */
184
185 if (ipv6_addr_any(&usin->sin6_addr)) {
186 if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
187 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
188 &usin->sin6_addr);
189 else
190 usin->sin6_addr = in6addr_loopback;
191 }
192
193 addr_type = ipv6_addr_type(&usin->sin6_addr);
194
195 if (addr_type & IPV6_ADDR_MULTICAST)
196 return -ENETUNREACH;
197
198 if (addr_type&IPV6_ADDR_LINKLOCAL) {
199 if (addr_len >= sizeof(struct sockaddr_in6) &&
200 usin->sin6_scope_id) {
201 /* If interface is set while binding, indices
202 * must coincide.
203 */
204 if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
205 return -EINVAL;
206
207 sk->sk_bound_dev_if = usin->sin6_scope_id;
208 }
209
210 /* Connect to link-local address requires an interface */
211 if (!sk->sk_bound_dev_if)
212 return -EINVAL;
213 }
214
215 if (tp->rx_opt.ts_recent_stamp &&
216 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
217 tp->rx_opt.ts_recent = 0;
218 tp->rx_opt.ts_recent_stamp = 0;
219 WRITE_ONCE(tp->write_seq, 0);
220 }
221
222 sk->sk_v6_daddr = usin->sin6_addr;
223 np->flow_label = fl6.flowlabel;
224
225 /*
226 * TCP over IPv4
227 */
228
229 if (addr_type & IPV6_ADDR_MAPPED) {
230 u32 exthdrlen = icsk->icsk_ext_hdr_len;
231 struct sockaddr_in sin;
232
233 if (__ipv6_only_sock(sk))
234 return -ENETUNREACH;
235
236 sin.sin_family = AF_INET;
237 sin.sin_port = usin->sin6_port;
238 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
239
240 icsk->icsk_af_ops = &ipv6_mapped;
241 if (sk_is_mptcp(sk))
242 mptcpv6_handle_mapped(sk, true);
243 sk->sk_backlog_rcv = tcp_v4_do_rcv;
244#ifdef CONFIG_TCP_MD5SIG
245 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
246#endif
247
248 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
249
250 if (err) {
251 icsk->icsk_ext_hdr_len = exthdrlen;
252 icsk->icsk_af_ops = &ipv6_specific;
253 if (sk_is_mptcp(sk))
254 mptcpv6_handle_mapped(sk, false);
255 sk->sk_backlog_rcv = tcp_v6_do_rcv;
256#ifdef CONFIG_TCP_MD5SIG
257 tp->af_specific = &tcp_sock_ipv6_specific;
258#endif
259 goto failure;
260 }
261 np->saddr = sk->sk_v6_rcv_saddr;
262
263 return err;
264 }
265
266 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
267 saddr = &sk->sk_v6_rcv_saddr;
268
269 fl6.flowi6_proto = IPPROTO_TCP;
270 fl6.daddr = sk->sk_v6_daddr;
271 fl6.saddr = saddr ? *saddr : np->saddr;
272 fl6.flowi6_oif = sk->sk_bound_dev_if;
273 fl6.flowi6_mark = sk->sk_mark;
274 fl6.fl6_dport = usin->sin6_port;
275 fl6.fl6_sport = inet->inet_sport;
276 fl6.flowi6_uid = sk->sk_uid;
277
278 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
279 final_p = fl6_update_dst(&fl6, opt, &final);
280
281 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
282
283 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
284 if (IS_ERR(dst)) {
285 err = PTR_ERR(dst);
286 goto failure;
287 }
288
289 if (!saddr) {
290 saddr = &fl6.saddr;
291 sk->sk_v6_rcv_saddr = *saddr;
292 }
293
294 /* set the source address */
295 np->saddr = *saddr;
296 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
297
298 sk->sk_gso_type = SKB_GSO_TCPV6;
299 ip6_dst_store(sk, dst, NULL, NULL);
300
301 icsk->icsk_ext_hdr_len = 0;
302 if (opt)
303 icsk->icsk_ext_hdr_len = opt->opt_flen +
304 opt->opt_nflen;
305
306 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
307
308 inet->inet_dport = usin->sin6_port;
309
310 tcp_set_state(sk, TCP_SYN_SENT);
311 err = inet6_hash_connect(tcp_death_row, sk);
312 if (err)
313 goto late_failure;
314
315 sk_set_txhash(sk);
316
317 if (likely(!tp->repair)) {
318 if (!tp->write_seq)
319 WRITE_ONCE(tp->write_seq,
320 secure_tcpv6_seq(np->saddr.s6_addr32,
321 sk->sk_v6_daddr.s6_addr32,
322 inet->inet_sport,
323 inet->inet_dport));
324 tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk),
325 np->saddr.s6_addr32,
326 sk->sk_v6_daddr.s6_addr32);
327 }
328
329 if (tcp_fastopen_defer_connect(sk, &err))
330 return err;
331 if (err)
332 goto late_failure;
333
334 err = tcp_connect(sk);
335 if (err)
336 goto late_failure;
337
338 return 0;
339
340late_failure:
341 tcp_set_state(sk, TCP_CLOSE);
342failure:
343 inet->inet_dport = 0;
344 sk->sk_route_caps = 0;
345 return err;
346}
347
348static void tcp_v6_mtu_reduced(struct sock *sk)
349{
350 struct dst_entry *dst;
351
352 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
353 return;
354
355 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
356 if (!dst)
357 return;
358
359 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
360 tcp_sync_mss(sk, dst_mtu(dst));
361 tcp_simple_retransmit(sk);
362 }
363}
364
365static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
366 u8 type, u8 code, int offset, __be32 info)
367{
368 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
369 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
370 struct net *net = dev_net(skb->dev);
371 struct request_sock *fastopen;
372 struct ipv6_pinfo *np;
373 struct tcp_sock *tp;
374 __u32 seq, snd_una;
375 struct sock *sk;
376 bool fatal;
377 int err;
378
379 sk = __inet6_lookup_established(net, &tcp_hashinfo,
380 &hdr->daddr, th->dest,
381 &hdr->saddr, ntohs(th->source),
382 skb->dev->ifindex, inet6_sdif(skb));
383
384 if (!sk) {
385 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
386 ICMP6_MIB_INERRORS);
387 return -ENOENT;
388 }
389
390 if (sk->sk_state == TCP_TIME_WAIT) {
391 inet_twsk_put(inet_twsk(sk));
392 return 0;
393 }
394 seq = ntohl(th->seq);
395 fatal = icmpv6_err_convert(type, code, &err);
396 if (sk->sk_state == TCP_NEW_SYN_RECV) {
397 tcp_req_err(sk, seq, fatal);
398 return 0;
399 }
400
401 bh_lock_sock(sk);
402 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
403 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
404
405 if (sk->sk_state == TCP_CLOSE)
406 goto out;
407
408 if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
409 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
410 goto out;
411 }
412
413 tp = tcp_sk(sk);
414 /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
415 fastopen = rcu_dereference(tp->fastopen_rsk);
416 snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
417 if (sk->sk_state != TCP_LISTEN &&
418 !between(seq, snd_una, tp->snd_nxt)) {
419 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
420 goto out;
421 }
422
423 np = tcp_inet6_sk(sk);
424
425 if (type == NDISC_REDIRECT) {
426 if (!sock_owned_by_user(sk)) {
427 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
428
429 if (dst)
430 dst->ops->redirect(dst, sk, skb);
431 }
432 goto out;
433 }
434
435 if (type == ICMPV6_PKT_TOOBIG) {
436 /* We are not interested in TCP_LISTEN and open_requests
437 * (SYN-ACKs send out by Linux are always <576bytes so
438 * they should go through unfragmented).
439 */
440 if (sk->sk_state == TCP_LISTEN)
441 goto out;
442
443 if (!ip6_sk_accept_pmtu(sk))
444 goto out;
445
446 tp->mtu_info = ntohl(info);
447 if (!sock_owned_by_user(sk))
448 tcp_v6_mtu_reduced(sk);
449 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
450 &sk->sk_tsq_flags))
451 sock_hold(sk);
452 goto out;
453 }
454
455
456 /* Might be for an request_sock */
457 switch (sk->sk_state) {
458 case TCP_SYN_SENT:
459 case TCP_SYN_RECV:
460 /* Only in fast or simultaneous open. If a fast open socket is
461 * is already accepted it is treated as a connected one below.
462 */
463 if (fastopen && !fastopen->sk)
464 break;
465
466 ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
467
468 if (!sock_owned_by_user(sk)) {
469 sk->sk_err = err;
470 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
471
472 tcp_done(sk);
473 } else
474 sk->sk_err_soft = err;
475 goto out;
476 case TCP_LISTEN:
477 break;
478 default:
479 /* check if this ICMP message allows revert of backoff.
480 * (see RFC 6069)
481 */
482 if (!fastopen && type == ICMPV6_DEST_UNREACH &&
483 code == ICMPV6_NOROUTE)
484 tcp_ld_RTO_revert(sk, seq);
485 }
486
487 if (!sock_owned_by_user(sk) && np->recverr) {
488 sk->sk_err = err;
489 sk->sk_error_report(sk);
490 } else
491 sk->sk_err_soft = err;
492
493out:
494 bh_unlock_sock(sk);
495 sock_put(sk);
496 return 0;
497}
498
499
500static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
501 struct flowi *fl,
502 struct request_sock *req,
503 struct tcp_fastopen_cookie *foc,
504 enum tcp_synack_type synack_type)
505{
506 struct inet_request_sock *ireq = inet_rsk(req);
507 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
508 struct ipv6_txoptions *opt;
509 struct flowi6 *fl6 = &fl->u.ip6;
510 struct sk_buff *skb;
511 int err = -ENOMEM;
512
513 /* First, grab a route. */
514 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
515 IPPROTO_TCP)) == NULL)
516 goto done;
517
518 skb = tcp_make_synack(sk, dst, req, foc, synack_type);
519
520 if (skb) {
521 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
522 &ireq->ir_v6_rmt_addr);
523
524 fl6->daddr = ireq->ir_v6_rmt_addr;
525 if (np->repflow && ireq->pktopts)
526 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
527
528 rcu_read_lock();
529 opt = ireq->ipv6_opt;
530 if (!opt)
531 opt = rcu_dereference(np->opt);
532 err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass,
533 sk->sk_priority);
534 rcu_read_unlock();
535 err = net_xmit_eval(err);
536 }
537
538done:
539 return err;
540}
541
542
543static void tcp_v6_reqsk_destructor(struct request_sock *req)
544{
545 kfree(inet_rsk(req)->ipv6_opt);
546 kfree_skb(inet_rsk(req)->pktopts);
547}
548
549#ifdef CONFIG_TCP_MD5SIG
550static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
551 const struct in6_addr *addr,
552 int l3index)
553{
554 return tcp_md5_do_lookup(sk, l3index,
555 (union tcp_md5_addr *)addr, AF_INET6);
556}
557
558static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
559 const struct sock *addr_sk)
560{
561 int l3index;
562
563 l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
564 addr_sk->sk_bound_dev_if);
565 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
566 l3index);
567}
568
569static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
570 sockptr_t optval, int optlen)
571{
572 struct tcp_md5sig cmd;
573 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
574 int l3index = 0;
575 u8 prefixlen;
576
577 if (optlen < sizeof(cmd))
578 return -EINVAL;
579
580 if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
581 return -EFAULT;
582
583 if (sin6->sin6_family != AF_INET6)
584 return -EINVAL;
585
586 if (optname == TCP_MD5SIG_EXT &&
587 cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
588 prefixlen = cmd.tcpm_prefixlen;
589 if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
590 prefixlen > 32))
591 return -EINVAL;
592 } else {
593 prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
594 }
595
596 if (optname == TCP_MD5SIG_EXT &&
597 cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
598 struct net_device *dev;
599
600 rcu_read_lock();
601 dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
602 if (dev && netif_is_l3_master(dev))
603 l3index = dev->ifindex;
604 rcu_read_unlock();
605
606 /* ok to reference set/not set outside of rcu;
607 * right now device MUST be an L3 master
608 */
609 if (!dev || !l3index)
610 return -EINVAL;
611 }
612
613 if (!cmd.tcpm_keylen) {
614 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
615 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
616 AF_INET, prefixlen,
617 l3index);
618 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
619 AF_INET6, prefixlen, l3index);
620 }
621
622 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
623 return -EINVAL;
624
625 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
626 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
627 AF_INET, prefixlen, l3index,
628 cmd.tcpm_key, cmd.tcpm_keylen,
629 GFP_KERNEL);
630
631 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
632 AF_INET6, prefixlen, l3index,
633 cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
634}
635
636static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
637 const struct in6_addr *daddr,
638 const struct in6_addr *saddr,
639 const struct tcphdr *th, int nbytes)
640{
641 struct tcp6_pseudohdr *bp;
642 struct scatterlist sg;
643 struct tcphdr *_th;
644
645 bp = hp->scratch;
646 /* 1. TCP pseudo-header (RFC2460) */
647 bp->saddr = *saddr;
648 bp->daddr = *daddr;
649 bp->protocol = cpu_to_be32(IPPROTO_TCP);
650 bp->len = cpu_to_be32(nbytes);
651
652 _th = (struct tcphdr *)(bp + 1);
653 memcpy(_th, th, sizeof(*th));
654 _th->check = 0;
655
656 sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
657 ahash_request_set_crypt(hp->md5_req, &sg, NULL,
658 sizeof(*bp) + sizeof(*th));
659 return crypto_ahash_update(hp->md5_req);
660}
661
662static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
663 const struct in6_addr *daddr, struct in6_addr *saddr,
664 const struct tcphdr *th)
665{
666 struct tcp_md5sig_pool *hp;
667 struct ahash_request *req;
668
669 hp = tcp_get_md5sig_pool();
670 if (!hp)
671 goto clear_hash_noput;
672 req = hp->md5_req;
673
674 if (crypto_ahash_init(req))
675 goto clear_hash;
676 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
677 goto clear_hash;
678 if (tcp_md5_hash_key(hp, key))
679 goto clear_hash;
680 ahash_request_set_crypt(req, NULL, md5_hash, 0);
681 if (crypto_ahash_final(req))
682 goto clear_hash;
683
684 tcp_put_md5sig_pool();
685 return 0;
686
687clear_hash:
688 tcp_put_md5sig_pool();
689clear_hash_noput:
690 memset(md5_hash, 0, 16);
691 return 1;
692}
693
694static int tcp_v6_md5_hash_skb(char *md5_hash,
695 const struct tcp_md5sig_key *key,
696 const struct sock *sk,
697 const struct sk_buff *skb)
698{
699 const struct in6_addr *saddr, *daddr;
700 struct tcp_md5sig_pool *hp;
701 struct ahash_request *req;
702 const struct tcphdr *th = tcp_hdr(skb);
703
704 if (sk) { /* valid for establish/request sockets */
705 saddr = &sk->sk_v6_rcv_saddr;
706 daddr = &sk->sk_v6_daddr;
707 } else {
708 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
709 saddr = &ip6h->saddr;
710 daddr = &ip6h->daddr;
711 }
712
713 hp = tcp_get_md5sig_pool();
714 if (!hp)
715 goto clear_hash_noput;
716 req = hp->md5_req;
717
718 if (crypto_ahash_init(req))
719 goto clear_hash;
720
721 if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
722 goto clear_hash;
723 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
724 goto clear_hash;
725 if (tcp_md5_hash_key(hp, key))
726 goto clear_hash;
727 ahash_request_set_crypt(req, NULL, md5_hash, 0);
728 if (crypto_ahash_final(req))
729 goto clear_hash;
730
731 tcp_put_md5sig_pool();
732 return 0;
733
734clear_hash:
735 tcp_put_md5sig_pool();
736clear_hash_noput:
737 memset(md5_hash, 0, 16);
738 return 1;
739}
740
741#endif
742
743static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
744 const struct sk_buff *skb,
745 int dif, int sdif)
746{
747#ifdef CONFIG_TCP_MD5SIG
748 const __u8 *hash_location = NULL;
749 struct tcp_md5sig_key *hash_expected;
750 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
751 const struct tcphdr *th = tcp_hdr(skb);
752 int genhash, l3index;
753 u8 newhash[16];
754
755 /* sdif set, means packet ingressed via a device
756 * in an L3 domain and dif is set to the l3mdev
757 */
758 l3index = sdif ? dif : 0;
759
760 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr, l3index);
761 hash_location = tcp_parse_md5sig_option(th);
762
763 /* We've parsed the options - do we have a hash? */
764 if (!hash_expected && !hash_location)
765 return false;
766
767 if (hash_expected && !hash_location) {
768 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
769 return true;
770 }
771
772 if (!hash_expected && hash_location) {
773 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
774 return true;
775 }
776
777 /* check the signature */
778 genhash = tcp_v6_md5_hash_skb(newhash,
779 hash_expected,
780 NULL, skb);
781
782 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
783 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
784 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
785 genhash ? "failed" : "mismatch",
786 &ip6h->saddr, ntohs(th->source),
787 &ip6h->daddr, ntohs(th->dest), l3index);
788 return true;
789 }
790#endif
791 return false;
792}
793
794static void tcp_v6_init_req(struct request_sock *req,
795 const struct sock *sk_listener,
796 struct sk_buff *skb)
797{
798 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
799 struct inet_request_sock *ireq = inet_rsk(req);
800 const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
801
802 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
803 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
804
805 /* So that link locals have meaning */
806 if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
807 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
808 ireq->ir_iif = tcp_v6_iif(skb);
809
810 if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
811 (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
812 np->rxopt.bits.rxinfo ||
813 np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
814 np->rxopt.bits.rxohlim || np->repflow)) {
815 refcount_inc(&skb->users);
816 ireq->pktopts = skb;
817 }
818}
819
820static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
821 struct flowi *fl,
822 const struct request_sock *req)
823{
824 return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
825}
826
827struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
828 .family = AF_INET6,
829 .obj_size = sizeof(struct tcp6_request_sock),
830 .rtx_syn_ack = tcp_rtx_synack,
831 .send_ack = tcp_v6_reqsk_send_ack,
832 .destructor = tcp_v6_reqsk_destructor,
833 .send_reset = tcp_v6_send_reset,
834 .syn_ack_timeout = tcp_syn_ack_timeout,
835};
836
837const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
838 .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
839 sizeof(struct ipv6hdr),
840#ifdef CONFIG_TCP_MD5SIG
841 .req_md5_lookup = tcp_v6_md5_lookup,
842 .calc_md5_hash = tcp_v6_md5_hash_skb,
843#endif
844 .init_req = tcp_v6_init_req,
845#ifdef CONFIG_SYN_COOKIES
846 .cookie_init_seq = cookie_v6_init_sequence,
847#endif
848 .route_req = tcp_v6_route_req,
849 .init_seq = tcp_v6_init_seq,
850 .init_ts_off = tcp_v6_init_ts_off,
851 .send_synack = tcp_v6_send_synack,
852};
853
854static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
855 u32 ack, u32 win, u32 tsval, u32 tsecr,
856 int oif, struct tcp_md5sig_key *key, int rst,
857 u8 tclass, __be32 label, u32 priority)
858{
859 const struct tcphdr *th = tcp_hdr(skb);
860 struct tcphdr *t1;
861 struct sk_buff *buff;
862 struct flowi6 fl6;
863 struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
864 struct sock *ctl_sk = net->ipv6.tcp_sk;
865 unsigned int tot_len = sizeof(struct tcphdr);
866 struct dst_entry *dst;
867 __be32 *topt;
868 __u32 mark = 0;
869
870 if (tsecr)
871 tot_len += TCPOLEN_TSTAMP_ALIGNED;
872#ifdef CONFIG_TCP_MD5SIG
873 if (key)
874 tot_len += TCPOLEN_MD5SIG_ALIGNED;
875#endif
876
877 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
878 GFP_ATOMIC);
879 if (!buff)
880 return;
881
882 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
883
884 t1 = skb_push(buff, tot_len);
885 skb_reset_transport_header(buff);
886
887 /* Swap the send and the receive. */
888 memset(t1, 0, sizeof(*t1));
889 t1->dest = th->source;
890 t1->source = th->dest;
891 t1->doff = tot_len / 4;
892 t1->seq = htonl(seq);
893 t1->ack_seq = htonl(ack);
894 t1->ack = !rst || !th->ack;
895 t1->rst = rst;
896 t1->window = htons(win);
897
898 topt = (__be32 *)(t1 + 1);
899
900 if (tsecr) {
901 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
902 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
903 *topt++ = htonl(tsval);
904 *topt++ = htonl(tsecr);
905 }
906
907#ifdef CONFIG_TCP_MD5SIG
908 if (key) {
909 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
910 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
911 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
912 &ipv6_hdr(skb)->saddr,
913 &ipv6_hdr(skb)->daddr, t1);
914 }
915#endif
916
917 memset(&fl6, 0, sizeof(fl6));
918 fl6.daddr = ipv6_hdr(skb)->saddr;
919 fl6.saddr = ipv6_hdr(skb)->daddr;
920 fl6.flowlabel = label;
921
922 buff->ip_summed = CHECKSUM_PARTIAL;
923 buff->csum = 0;
924
925 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
926
927 fl6.flowi6_proto = IPPROTO_TCP;
928 if (rt6_need_strict(&fl6.daddr) && !oif)
929 fl6.flowi6_oif = tcp_v6_iif(skb);
930 else {
931 if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
932 oif = skb->skb_iif;
933
934 fl6.flowi6_oif = oif;
935 }
936
937 if (sk) {
938 if (sk->sk_state == TCP_TIME_WAIT) {
939 mark = inet_twsk(sk)->tw_mark;
940 /* autoflowlabel relies on buff->hash */
941 skb_set_hash(buff, inet_twsk(sk)->tw_txhash,
942 PKT_HASH_TYPE_L4);
943 } else {
944 mark = sk->sk_mark;
945 }
946 buff->tstamp = tcp_transmit_time(sk);
947 }
948 fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
949 fl6.fl6_dport = t1->dest;
950 fl6.fl6_sport = t1->source;
951 fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
952 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
953
954 /* Pass a socket to ip6_dst_lookup either it is for RST
955 * Underlying function will use this to retrieve the network
956 * namespace
957 */
958 dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
959 if (!IS_ERR(dst)) {
960 skb_dst_set(buff, dst);
961 ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass,
962 priority);
963 TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
964 if (rst)
965 TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
966 return;
967 }
968
969 kfree_skb(buff);
970}
971
972static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
973{
974 const struct tcphdr *th = tcp_hdr(skb);
975 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
976 u32 seq = 0, ack_seq = 0;
977 struct tcp_md5sig_key *key = NULL;
978#ifdef CONFIG_TCP_MD5SIG
979 const __u8 *hash_location = NULL;
980 unsigned char newhash[16];
981 int genhash;
982 struct sock *sk1 = NULL;
983#endif
984 __be32 label = 0;
985 u32 priority = 0;
986 struct net *net;
987 int oif = 0;
988
989 if (th->rst)
990 return;
991
992 /* If sk not NULL, it means we did a successful lookup and incoming
993 * route had to be correct. prequeue might have dropped our dst.
994 */
995 if (!sk && !ipv6_unicast_destination(skb))
996 return;
997
998 net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
999#ifdef CONFIG_TCP_MD5SIG
1000 rcu_read_lock();
1001 hash_location = tcp_parse_md5sig_option(th);
1002 if (sk && sk_fullsock(sk)) {
1003 int l3index;
1004
1005 /* sdif set, means packet ingressed via a device
1006 * in an L3 domain and inet_iif is set to it.
1007 */
1008 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1009 key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1010 } else if (hash_location) {
1011 int dif = tcp_v6_iif_l3_slave(skb);
1012 int sdif = tcp_v6_sdif(skb);
1013 int l3index;
1014
1015 /*
1016 * active side is lost. Try to find listening socket through
1017 * source port, and then find md5 key through listening socket.
1018 * we are not loose security here:
1019 * Incoming packet is checked with md5 hash with finding key,
1020 * no RST generated if md5 hash doesn't match.
1021 */
1022 sk1 = inet6_lookup_listener(net,
1023 &tcp_hashinfo, NULL, 0,
1024 &ipv6h->saddr,
1025 th->source, &ipv6h->daddr,
1026 ntohs(th->source), dif, sdif);
1027 if (!sk1)
1028 goto out;
1029
1030 /* sdif set, means packet ingressed via a device
1031 * in an L3 domain and dif is set to it.
1032 */
1033 l3index = tcp_v6_sdif(skb) ? dif : 0;
1034
1035 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1036 if (!key)
1037 goto out;
1038
1039 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
1040 if (genhash || memcmp(hash_location, newhash, 16) != 0)
1041 goto out;
1042 }
1043#endif
1044
1045 if (th->ack)
1046 seq = ntohl(th->ack_seq);
1047 else
1048 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1049 (th->doff << 2);
1050
1051 if (sk) {
1052 oif = sk->sk_bound_dev_if;
1053 if (sk_fullsock(sk)) {
1054 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1055
1056 trace_tcp_send_reset(sk, skb);
1057 if (np->repflow)
1058 label = ip6_flowlabel(ipv6h);
1059 priority = sk->sk_priority;
1060 }
1061 if (sk->sk_state == TCP_TIME_WAIT) {
1062 label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1063 priority = inet_twsk(sk)->tw_priority;
1064 }
1065 } else {
1066 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1067 label = ip6_flowlabel(ipv6h);
1068 }
1069
1070 tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0,
1071 label, priority);
1072
1073#ifdef CONFIG_TCP_MD5SIG
1074out:
1075 rcu_read_unlock();
1076#endif
1077}
1078
1079static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1080 u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1081 struct tcp_md5sig_key *key, u8 tclass,
1082 __be32 label, u32 priority)
1083{
1084 tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
1085 tclass, label, priority);
1086}
1087
1088static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1089{
1090 struct inet_timewait_sock *tw = inet_twsk(sk);
1091 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1092
1093 tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1094 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1095 tcp_time_stamp_raw() + tcptw->tw_ts_offset,
1096 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
1097 tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority);
1098
1099 inet_twsk_put(tw);
1100}
1101
1102static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1103 struct request_sock *req)
1104{
1105 int l3index;
1106
1107 l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1108
1109 /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1110 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1111 */
1112 /* RFC 7323 2.3
1113 * The window field (SEG.WND) of every outgoing segment, with the
1114 * exception of <SYN> segments, MUST be right-shifted by
1115 * Rcv.Wind.Shift bits:
1116 */
1117 tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1118 tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1119 tcp_rsk(req)->rcv_nxt,
1120 req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1121 tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
1122 req->ts_recent, sk->sk_bound_dev_if,
1123 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
1124 0, 0, sk->sk_priority);
1125}
1126
1127
1128static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1129{
1130#ifdef CONFIG_SYN_COOKIES
1131 const struct tcphdr *th = tcp_hdr(skb);
1132
1133 if (!th->syn)
1134 sk = cookie_v6_check(sk, skb);
1135#endif
1136 return sk;
1137}
1138
1139u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1140 struct tcphdr *th, u32 *cookie)
1141{
1142 u16 mss = 0;
1143#ifdef CONFIG_SYN_COOKIES
1144 mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1145 &tcp_request_sock_ipv6_ops, sk, th);
1146 if (mss) {
1147 *cookie = __cookie_v6_init_sequence(iph, th, &mss);
1148 tcp_synq_overflow(sk);
1149 }
1150#endif
1151 return mss;
1152}
1153
1154static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1155{
1156 if (skb->protocol == htons(ETH_P_IP))
1157 return tcp_v4_conn_request(sk, skb);
1158
1159 if (!ipv6_unicast_destination(skb))
1160 goto drop;
1161
1162 return tcp_conn_request(&tcp6_request_sock_ops,
1163 &tcp_request_sock_ipv6_ops, sk, skb);
1164
1165drop:
1166 tcp_listendrop(sk);
1167 return 0; /* don't send reset */
1168}
1169
1170static void tcp_v6_restore_cb(struct sk_buff *skb)
1171{
1172 /* We need to move header back to the beginning if xfrm6_policy_check()
1173 * and tcp_v6_fill_cb() are going to be called again.
1174 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1175 */
1176 memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1177 sizeof(struct inet6_skb_parm));
1178}
1179
1180static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1181 struct request_sock *req,
1182 struct dst_entry *dst,
1183 struct request_sock *req_unhash,
1184 bool *own_req)
1185{
1186 struct inet_request_sock *ireq;
1187 struct ipv6_pinfo *newnp;
1188 const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1189 struct ipv6_txoptions *opt;
1190 struct inet_sock *newinet;
1191 struct tcp_sock *newtp;
1192 struct sock *newsk;
1193#ifdef CONFIG_TCP_MD5SIG
1194 struct tcp_md5sig_key *key;
1195 int l3index;
1196#endif
1197 struct flowi6 fl6;
1198
1199 if (skb->protocol == htons(ETH_P_IP)) {
1200 /*
1201 * v6 mapped
1202 */
1203
1204 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1205 req_unhash, own_req);
1206
1207 if (!newsk)
1208 return NULL;
1209
1210 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1211
1212 newinet = inet_sk(newsk);
1213 newnp = tcp_inet6_sk(newsk);
1214 newtp = tcp_sk(newsk);
1215
1216 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1217
1218 newnp->saddr = newsk->sk_v6_rcv_saddr;
1219
1220 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1221 if (sk_is_mptcp(newsk))
1222 mptcpv6_handle_mapped(newsk, true);
1223 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1224#ifdef CONFIG_TCP_MD5SIG
1225 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1226#endif
1227
1228 newnp->ipv6_mc_list = NULL;
1229 newnp->ipv6_ac_list = NULL;
1230 newnp->ipv6_fl_list = NULL;
1231 newnp->pktoptions = NULL;
1232 newnp->opt = NULL;
1233 newnp->mcast_oif = inet_iif(skb);
1234 newnp->mcast_hops = ip_hdr(skb)->ttl;
1235 newnp->rcv_flowinfo = 0;
1236 if (np->repflow)
1237 newnp->flow_label = 0;
1238
1239 /*
1240 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1241 * here, tcp_create_openreq_child now does this for us, see the comment in
1242 * that function for the gory details. -acme
1243 */
1244
1245 /* It is tricky place. Until this moment IPv4 tcp
1246 worked with IPv6 icsk.icsk_af_ops.
1247 Sync it now.
1248 */
1249 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1250
1251 return newsk;
1252 }
1253
1254 ireq = inet_rsk(req);
1255
1256 if (sk_acceptq_is_full(sk))
1257 goto out_overflow;
1258
1259 if (!dst) {
1260 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1261 if (!dst)
1262 goto out;
1263 }
1264
1265 newsk = tcp_create_openreq_child(sk, req, skb);
1266 if (!newsk)
1267 goto out_nonewsk;
1268
1269 /*
1270 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1271 * count here, tcp_create_openreq_child now does this for us, see the
1272 * comment in that function for the gory details. -acme
1273 */
1274
1275 newsk->sk_gso_type = SKB_GSO_TCPV6;
1276 ip6_dst_store(newsk, dst, NULL, NULL);
1277 inet6_sk_rx_dst_set(newsk, skb);
1278
1279 inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1280
1281 newtp = tcp_sk(newsk);
1282 newinet = inet_sk(newsk);
1283 newnp = tcp_inet6_sk(newsk);
1284
1285 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1286
1287 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1288 newnp->saddr = ireq->ir_v6_loc_addr;
1289 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1290 newsk->sk_bound_dev_if = ireq->ir_iif;
1291
1292 /* Now IPv6 options...
1293
1294 First: no IPv4 options.
1295 */
1296 newinet->inet_opt = NULL;
1297 newnp->ipv6_mc_list = NULL;
1298 newnp->ipv6_ac_list = NULL;
1299 newnp->ipv6_fl_list = NULL;
1300
1301 /* Clone RX bits */
1302 newnp->rxopt.all = np->rxopt.all;
1303
1304 newnp->pktoptions = NULL;
1305 newnp->opt = NULL;
1306 newnp->mcast_oif = tcp_v6_iif(skb);
1307 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1308 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1309 if (np->repflow)
1310 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1311
1312 /* Clone native IPv6 options from listening socket (if any)
1313
1314 Yes, keeping reference count would be much more clever,
1315 but we make one more one thing there: reattach optmem
1316 to newsk.
1317 */
1318 opt = ireq->ipv6_opt;
1319 if (!opt)
1320 opt = rcu_dereference(np->opt);
1321 if (opt) {
1322 opt = ipv6_dup_options(newsk, opt);
1323 RCU_INIT_POINTER(newnp->opt, opt);
1324 }
1325 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1326 if (opt)
1327 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1328 opt->opt_flen;
1329
1330 tcp_ca_openreq_child(newsk, dst);
1331
1332 tcp_sync_mss(newsk, dst_mtu(dst));
1333 newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1334
1335 tcp_initialize_rcv_mss(newsk);
1336
1337 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1338 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1339
1340#ifdef CONFIG_TCP_MD5SIG
1341 l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1342
1343 /* Copy over the MD5 key from the original socket */
1344 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1345 if (key) {
1346 /* We're using one, so create a matching key
1347 * on the newsk structure. If we fail to get
1348 * memory, then we end up not copying the key
1349 * across. Shucks.
1350 */
1351 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1352 AF_INET6, 128, l3index, key->key, key->keylen,
1353 sk_gfp_mask(sk, GFP_ATOMIC));
1354 }
1355#endif
1356
1357 if (__inet_inherit_port(sk, newsk) < 0) {
1358 inet_csk_prepare_forced_close(newsk);
1359 tcp_done(newsk);
1360 goto out;
1361 }
1362 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1363 if (*own_req) {
1364 tcp_move_syn(newtp, req);
1365
1366 /* Clone pktoptions received with SYN, if we own the req */
1367 if (ireq->pktopts) {
1368 newnp->pktoptions = skb_clone(ireq->pktopts,
1369 sk_gfp_mask(sk, GFP_ATOMIC));
1370 consume_skb(ireq->pktopts);
1371 ireq->pktopts = NULL;
1372 if (newnp->pktoptions) {
1373 tcp_v6_restore_cb(newnp->pktoptions);
1374 skb_set_owner_r(newnp->pktoptions, newsk);
1375 }
1376 }
1377 }
1378
1379 return newsk;
1380
1381out_overflow:
1382 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1383out_nonewsk:
1384 dst_release(dst);
1385out:
1386 tcp_listendrop(sk);
1387 return NULL;
1388}
1389
1390/* The socket must have it's spinlock held when we get
1391 * here, unless it is a TCP_LISTEN socket.
1392 *
1393 * We have a potential double-lock case here, so even when
1394 * doing backlog processing we use the BH locking scheme.
1395 * This is because we cannot sleep with the original spinlock
1396 * held.
1397 */
1398static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1399{
1400 struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1401 struct sk_buff *opt_skb = NULL;
1402 struct tcp_sock *tp;
1403
1404 /* Imagine: socket is IPv6. IPv4 packet arrives,
1405 goes to IPv4 receive handler and backlogged.
1406 From backlog it always goes here. Kerboom...
1407 Fortunately, tcp_rcv_established and rcv_established
1408 handle them correctly, but it is not case with
1409 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1410 */
1411
1412 if (skb->protocol == htons(ETH_P_IP))
1413 return tcp_v4_do_rcv(sk, skb);
1414
1415 /*
1416 * socket locking is here for SMP purposes as backlog rcv
1417 * is currently called with bh processing disabled.
1418 */
1419
1420 /* Do Stevens' IPV6_PKTOPTIONS.
1421
1422 Yes, guys, it is the only place in our code, where we
1423 may make it not affecting IPv4.
1424 The rest of code is protocol independent,
1425 and I do not like idea to uglify IPv4.
1426
1427 Actually, all the idea behind IPV6_PKTOPTIONS
1428 looks not very well thought. For now we latch
1429 options, received in the last packet, enqueued
1430 by tcp. Feel free to propose better solution.
1431 --ANK (980728)
1432 */
1433 if (np->rxopt.all)
1434 opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1435
1436 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1437 struct dst_entry *dst = sk->sk_rx_dst;
1438
1439 sock_rps_save_rxhash(sk, skb);
1440 sk_mark_napi_id(sk, skb);
1441 if (dst) {
1442 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1443 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1444 dst_release(dst);
1445 sk->sk_rx_dst = NULL;
1446 }
1447 }
1448
1449 tcp_rcv_established(sk, skb);
1450 if (opt_skb)
1451 goto ipv6_pktoptions;
1452 return 0;
1453 }
1454
1455 if (tcp_checksum_complete(skb))
1456 goto csum_err;
1457
1458 if (sk->sk_state == TCP_LISTEN) {
1459 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1460
1461 if (!nsk)
1462 goto discard;
1463
1464 if (nsk != sk) {
1465 if (tcp_child_process(sk, nsk, skb))
1466 goto reset;
1467 if (opt_skb)
1468 __kfree_skb(opt_skb);
1469 return 0;
1470 }
1471 } else
1472 sock_rps_save_rxhash(sk, skb);
1473
1474 if (tcp_rcv_state_process(sk, skb))
1475 goto reset;
1476 if (opt_skb)
1477 goto ipv6_pktoptions;
1478 return 0;
1479
1480reset:
1481 tcp_v6_send_reset(sk, skb);
1482discard:
1483 if (opt_skb)
1484 __kfree_skb(opt_skb);
1485 kfree_skb(skb);
1486 return 0;
1487csum_err:
1488 TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1489 TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1490 goto discard;
1491
1492
1493ipv6_pktoptions:
1494 /* Do you ask, what is it?
1495
1496 1. skb was enqueued by tcp.
1497 2. skb is added to tail of read queue, rather than out of order.
1498 3. socket is not in passive state.
1499 4. Finally, it really contains options, which user wants to receive.
1500 */
1501 tp = tcp_sk(sk);
1502 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1503 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1504 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1505 np->mcast_oif = tcp_v6_iif(opt_skb);
1506 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1507 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1508 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1509 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1510 if (np->repflow)
1511 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1512 if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1513 skb_set_owner_r(opt_skb, sk);
1514 tcp_v6_restore_cb(opt_skb);
1515 opt_skb = xchg(&np->pktoptions, opt_skb);
1516 } else {
1517 __kfree_skb(opt_skb);
1518 opt_skb = xchg(&np->pktoptions, NULL);
1519 }
1520 }
1521
1522 kfree_skb(opt_skb);
1523 return 0;
1524}
1525
1526static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1527 const struct tcphdr *th)
1528{
1529 /* This is tricky: we move IP6CB at its correct location into
1530 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1531 * _decode_session6() uses IP6CB().
1532 * barrier() makes sure compiler won't play aliasing games.
1533 */
1534 memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1535 sizeof(struct inet6_skb_parm));
1536 barrier();
1537
1538 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1539 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1540 skb->len - th->doff*4);
1541 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1542 TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1543 TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1544 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1545 TCP_SKB_CB(skb)->sacked = 0;
1546 TCP_SKB_CB(skb)->has_rxtstamp =
1547 skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1548}
1549
1550INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1551{
1552 struct sk_buff *skb_to_free;
1553 int sdif = inet6_sdif(skb);
1554 int dif = inet6_iif(skb);
1555 const struct tcphdr *th;
1556 const struct ipv6hdr *hdr;
1557 bool refcounted;
1558 struct sock *sk;
1559 int ret;
1560 struct net *net = dev_net(skb->dev);
1561
1562 if (skb->pkt_type != PACKET_HOST)
1563 goto discard_it;
1564
1565 /*
1566 * Count it even if it's bad.
1567 */
1568 __TCP_INC_STATS(net, TCP_MIB_INSEGS);
1569
1570 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1571 goto discard_it;
1572
1573 th = (const struct tcphdr *)skb->data;
1574
1575 if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1576 goto bad_packet;
1577 if (!pskb_may_pull(skb, th->doff*4))
1578 goto discard_it;
1579
1580 if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1581 goto csum_error;
1582
1583 th = (const struct tcphdr *)skb->data;
1584 hdr = ipv6_hdr(skb);
1585
1586lookup:
1587 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1588 th->source, th->dest, inet6_iif(skb), sdif,
1589 &refcounted);
1590 if (!sk)
1591 goto no_tcp_socket;
1592
1593process:
1594 if (sk->sk_state == TCP_TIME_WAIT)
1595 goto do_time_wait;
1596
1597 if (sk->sk_state == TCP_NEW_SYN_RECV) {
1598 struct request_sock *req = inet_reqsk(sk);
1599 bool req_stolen = false;
1600 struct sock *nsk;
1601
1602 sk = req->rsk_listener;
1603 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif)) {
1604 sk_drops_add(sk, skb);
1605 reqsk_put(req);
1606 goto discard_it;
1607 }
1608 if (tcp_checksum_complete(skb)) {
1609 reqsk_put(req);
1610 goto csum_error;
1611 }
1612 if (unlikely(sk->sk_state != TCP_LISTEN)) {
1613 inet_csk_reqsk_queue_drop_and_put(sk, req);
1614 goto lookup;
1615 }
1616 sock_hold(sk);
1617 refcounted = true;
1618 nsk = NULL;
1619 if (!tcp_filter(sk, skb)) {
1620 th = (const struct tcphdr *)skb->data;
1621 hdr = ipv6_hdr(skb);
1622 tcp_v6_fill_cb(skb, hdr, th);
1623 nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1624 }
1625 if (!nsk) {
1626 reqsk_put(req);
1627 if (req_stolen) {
1628 /* Another cpu got exclusive access to req
1629 * and created a full blown socket.
1630 * Try to feed this packet to this socket
1631 * instead of discarding it.
1632 */
1633 tcp_v6_restore_cb(skb);
1634 sock_put(sk);
1635 goto lookup;
1636 }
1637 goto discard_and_relse;
1638 }
1639 if (nsk == sk) {
1640 reqsk_put(req);
1641 tcp_v6_restore_cb(skb);
1642 } else if (tcp_child_process(sk, nsk, skb)) {
1643 tcp_v6_send_reset(nsk, skb);
1644 goto discard_and_relse;
1645 } else {
1646 sock_put(sk);
1647 return 0;
1648 }
1649 }
1650 if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) {
1651 __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1652 goto discard_and_relse;
1653 }
1654
1655 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1656 goto discard_and_relse;
1657
1658 if (tcp_v6_inbound_md5_hash(sk, skb, dif, sdif))
1659 goto discard_and_relse;
1660
1661 if (tcp_filter(sk, skb))
1662 goto discard_and_relse;
1663 th = (const struct tcphdr *)skb->data;
1664 hdr = ipv6_hdr(skb);
1665 tcp_v6_fill_cb(skb, hdr, th);
1666
1667 skb->dev = NULL;
1668
1669 if (sk->sk_state == TCP_LISTEN) {
1670 ret = tcp_v6_do_rcv(sk, skb);
1671 goto put_and_return;
1672 }
1673
1674 sk_incoming_cpu_update(sk);
1675
1676 bh_lock_sock_nested(sk);
1677 tcp_segs_in(tcp_sk(sk), skb);
1678 ret = 0;
1679 if (!sock_owned_by_user(sk)) {
1680 skb_to_free = sk->sk_rx_skb_cache;
1681 sk->sk_rx_skb_cache = NULL;
1682 ret = tcp_v6_do_rcv(sk, skb);
1683 } else {
1684 if (tcp_add_backlog(sk, skb))
1685 goto discard_and_relse;
1686 skb_to_free = NULL;
1687 }
1688 bh_unlock_sock(sk);
1689 if (skb_to_free)
1690 __kfree_skb(skb_to_free);
1691put_and_return:
1692 if (refcounted)
1693 sock_put(sk);
1694 return ret ? -1 : 0;
1695
1696no_tcp_socket:
1697 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1698 goto discard_it;
1699
1700 tcp_v6_fill_cb(skb, hdr, th);
1701
1702 if (tcp_checksum_complete(skb)) {
1703csum_error:
1704 __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1705bad_packet:
1706 __TCP_INC_STATS(net, TCP_MIB_INERRS);
1707 } else {
1708 tcp_v6_send_reset(NULL, skb);
1709 }
1710
1711discard_it:
1712 kfree_skb(skb);
1713 return 0;
1714
1715discard_and_relse:
1716 sk_drops_add(sk, skb);
1717 if (refcounted)
1718 sock_put(sk);
1719 goto discard_it;
1720
1721do_time_wait:
1722 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1723 inet_twsk_put(inet_twsk(sk));
1724 goto discard_it;
1725 }
1726
1727 tcp_v6_fill_cb(skb, hdr, th);
1728
1729 if (tcp_checksum_complete(skb)) {
1730 inet_twsk_put(inet_twsk(sk));
1731 goto csum_error;
1732 }
1733
1734 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1735 case TCP_TW_SYN:
1736 {
1737 struct sock *sk2;
1738
1739 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1740 skb, __tcp_hdrlen(th),
1741 &ipv6_hdr(skb)->saddr, th->source,
1742 &ipv6_hdr(skb)->daddr,
1743 ntohs(th->dest),
1744 tcp_v6_iif_l3_slave(skb),
1745 sdif);
1746 if (sk2) {
1747 struct inet_timewait_sock *tw = inet_twsk(sk);
1748 inet_twsk_deschedule_put(tw);
1749 sk = sk2;
1750 tcp_v6_restore_cb(skb);
1751 refcounted = false;
1752 goto process;
1753 }
1754 }
1755 /* to ACK */
1756 fallthrough;
1757 case TCP_TW_ACK:
1758 tcp_v6_timewait_ack(sk, skb);
1759 break;
1760 case TCP_TW_RST:
1761 tcp_v6_send_reset(sk, skb);
1762 inet_twsk_deschedule_put(inet_twsk(sk));
1763 goto discard_it;
1764 case TCP_TW_SUCCESS:
1765 ;
1766 }
1767 goto discard_it;
1768}
1769
1770INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb)
1771{
1772 const struct ipv6hdr *hdr;
1773 const struct tcphdr *th;
1774 struct sock *sk;
1775
1776 if (skb->pkt_type != PACKET_HOST)
1777 return;
1778
1779 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1780 return;
1781
1782 hdr = ipv6_hdr(skb);
1783 th = tcp_hdr(skb);
1784
1785 if (th->doff < sizeof(struct tcphdr) / 4)
1786 return;
1787
1788 /* Note : We use inet6_iif() here, not tcp_v6_iif() */
1789 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1790 &hdr->saddr, th->source,
1791 &hdr->daddr, ntohs(th->dest),
1792 inet6_iif(skb), inet6_sdif(skb));
1793 if (sk) {
1794 skb->sk = sk;
1795 skb->destructor = sock_edemux;
1796 if (sk_fullsock(sk)) {
1797 struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1798
1799 if (dst)
1800 dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
1801 if (dst &&
1802 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1803 skb_dst_set_noref(skb, dst);
1804 }
1805 }
1806}
1807
1808static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1809 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1810 .twsk_unique = tcp_twsk_unique,
1811 .twsk_destructor = tcp_twsk_destructor,
1812};
1813
1814INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
1815{
1816 struct ipv6_pinfo *np = inet6_sk(sk);
1817
1818 __tcp_v6_send_check(skb, &np->saddr, &sk->sk_v6_daddr);
1819}
1820
1821const struct inet_connection_sock_af_ops ipv6_specific = {
1822 .queue_xmit = inet6_csk_xmit,
1823 .send_check = tcp_v6_send_check,
1824 .rebuild_header = inet6_sk_rebuild_header,
1825 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1826 .conn_request = tcp_v6_conn_request,
1827 .syn_recv_sock = tcp_v6_syn_recv_sock,
1828 .net_header_len = sizeof(struct ipv6hdr),
1829 .net_frag_header_len = sizeof(struct frag_hdr),
1830 .setsockopt = ipv6_setsockopt,
1831 .getsockopt = ipv6_getsockopt,
1832 .addr2sockaddr = inet6_csk_addr2sockaddr,
1833 .sockaddr_len = sizeof(struct sockaddr_in6),
1834 .mtu_reduced = tcp_v6_mtu_reduced,
1835};
1836
1837#ifdef CONFIG_TCP_MD5SIG
1838static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1839 .md5_lookup = tcp_v6_md5_lookup,
1840 .calc_md5_hash = tcp_v6_md5_hash_skb,
1841 .md5_parse = tcp_v6_parse_md5_keys,
1842};
1843#endif
1844
1845/*
1846 * TCP over IPv4 via INET6 API
1847 */
1848static const struct inet_connection_sock_af_ops ipv6_mapped = {
1849 .queue_xmit = ip_queue_xmit,
1850 .send_check = tcp_v4_send_check,
1851 .rebuild_header = inet_sk_rebuild_header,
1852 .sk_rx_dst_set = inet_sk_rx_dst_set,
1853 .conn_request = tcp_v6_conn_request,
1854 .syn_recv_sock = tcp_v6_syn_recv_sock,
1855 .net_header_len = sizeof(struct iphdr),
1856 .setsockopt = ipv6_setsockopt,
1857 .getsockopt = ipv6_getsockopt,
1858 .addr2sockaddr = inet6_csk_addr2sockaddr,
1859 .sockaddr_len = sizeof(struct sockaddr_in6),
1860 .mtu_reduced = tcp_v4_mtu_reduced,
1861};
1862
1863#ifdef CONFIG_TCP_MD5SIG
1864static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1865 .md5_lookup = tcp_v4_md5_lookup,
1866 .calc_md5_hash = tcp_v4_md5_hash_skb,
1867 .md5_parse = tcp_v6_parse_md5_keys,
1868};
1869#endif
1870
1871/* NOTE: A lot of things set to zero explicitly by call to
1872 * sk_alloc() so need not be done here.
1873 */
1874static int tcp_v6_init_sock(struct sock *sk)
1875{
1876 struct inet_connection_sock *icsk = inet_csk(sk);
1877
1878 tcp_init_sock(sk);
1879
1880 icsk->icsk_af_ops = &ipv6_specific;
1881
1882#ifdef CONFIG_TCP_MD5SIG
1883 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1884#endif
1885
1886 return 0;
1887}
1888
1889static void tcp_v6_destroy_sock(struct sock *sk)
1890{
1891 tcp_v4_destroy_sock(sk);
1892 inet6_destroy_sock(sk);
1893}
1894
1895#ifdef CONFIG_PROC_FS
1896/* Proc filesystem TCPv6 sock list dumping. */
1897static void get_openreq6(struct seq_file *seq,
1898 const struct request_sock *req, int i)
1899{
1900 long ttd = req->rsk_timer.expires - jiffies;
1901 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1902 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1903
1904 if (ttd < 0)
1905 ttd = 0;
1906
1907 seq_printf(seq,
1908 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1909 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1910 i,
1911 src->s6_addr32[0], src->s6_addr32[1],
1912 src->s6_addr32[2], src->s6_addr32[3],
1913 inet_rsk(req)->ir_num,
1914 dest->s6_addr32[0], dest->s6_addr32[1],
1915 dest->s6_addr32[2], dest->s6_addr32[3],
1916 ntohs(inet_rsk(req)->ir_rmt_port),
1917 TCP_SYN_RECV,
1918 0, 0, /* could print option size, but that is af dependent. */
1919 1, /* timers active (only the expire timer) */
1920 jiffies_to_clock_t(ttd),
1921 req->num_timeout,
1922 from_kuid_munged(seq_user_ns(seq),
1923 sock_i_uid(req->rsk_listener)),
1924 0, /* non standard timer */
1925 0, /* open_requests have no inode */
1926 0, req);
1927}
1928
1929static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1930{
1931 const struct in6_addr *dest, *src;
1932 __u16 destp, srcp;
1933 int timer_active;
1934 unsigned long timer_expires;
1935 const struct inet_sock *inet = inet_sk(sp);
1936 const struct tcp_sock *tp = tcp_sk(sp);
1937 const struct inet_connection_sock *icsk = inet_csk(sp);
1938 const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1939 int rx_queue;
1940 int state;
1941
1942 dest = &sp->sk_v6_daddr;
1943 src = &sp->sk_v6_rcv_saddr;
1944 destp = ntohs(inet->inet_dport);
1945 srcp = ntohs(inet->inet_sport);
1946
1947 if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1948 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1949 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1950 timer_active = 1;
1951 timer_expires = icsk->icsk_timeout;
1952 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1953 timer_active = 4;
1954 timer_expires = icsk->icsk_timeout;
1955 } else if (timer_pending(&sp->sk_timer)) {
1956 timer_active = 2;
1957 timer_expires = sp->sk_timer.expires;
1958 } else {
1959 timer_active = 0;
1960 timer_expires = jiffies;
1961 }
1962
1963 state = inet_sk_state_load(sp);
1964 if (state == TCP_LISTEN)
1965 rx_queue = READ_ONCE(sp->sk_ack_backlog);
1966 else
1967 /* Because we don't lock the socket,
1968 * we might find a transient negative value.
1969 */
1970 rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
1971 READ_ONCE(tp->copied_seq), 0);
1972
1973 seq_printf(seq,
1974 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1975 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1976 i,
1977 src->s6_addr32[0], src->s6_addr32[1],
1978 src->s6_addr32[2], src->s6_addr32[3], srcp,
1979 dest->s6_addr32[0], dest->s6_addr32[1],
1980 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1981 state,
1982 READ_ONCE(tp->write_seq) - tp->snd_una,
1983 rx_queue,
1984 timer_active,
1985 jiffies_delta_to_clock_t(timer_expires - jiffies),
1986 icsk->icsk_retransmits,
1987 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1988 icsk->icsk_probes_out,
1989 sock_i_ino(sp),
1990 refcount_read(&sp->sk_refcnt), sp,
1991 jiffies_to_clock_t(icsk->icsk_rto),
1992 jiffies_to_clock_t(icsk->icsk_ack.ato),
1993 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
1994 tp->snd_cwnd,
1995 state == TCP_LISTEN ?
1996 fastopenq->max_qlen :
1997 (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1998 );
1999}
2000
2001static void get_timewait6_sock(struct seq_file *seq,
2002 struct inet_timewait_sock *tw, int i)
2003{
2004 long delta = tw->tw_timer.expires - jiffies;
2005 const struct in6_addr *dest, *src;
2006 __u16 destp, srcp;
2007
2008 dest = &tw->tw_v6_daddr;
2009 src = &tw->tw_v6_rcv_saddr;
2010 destp = ntohs(tw->tw_dport);
2011 srcp = ntohs(tw->tw_sport);
2012
2013 seq_printf(seq,
2014 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2015 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2016 i,
2017 src->s6_addr32[0], src->s6_addr32[1],
2018 src->s6_addr32[2], src->s6_addr32[3], srcp,
2019 dest->s6_addr32[0], dest->s6_addr32[1],
2020 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2021 tw->tw_substate, 0, 0,
2022 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2023 refcount_read(&tw->tw_refcnt), tw);
2024}
2025
2026static int tcp6_seq_show(struct seq_file *seq, void *v)
2027{
2028 struct tcp_iter_state *st;
2029 struct sock *sk = v;
2030
2031 if (v == SEQ_START_TOKEN) {
2032 seq_puts(seq,
2033 " sl "
2034 "local_address "
2035 "remote_address "
2036 "st tx_queue rx_queue tr tm->when retrnsmt"
2037 " uid timeout inode\n");
2038 goto out;
2039 }
2040 st = seq->private;
2041
2042 if (sk->sk_state == TCP_TIME_WAIT)
2043 get_timewait6_sock(seq, v, st->num);
2044 else if (sk->sk_state == TCP_NEW_SYN_RECV)
2045 get_openreq6(seq, v, st->num);
2046 else
2047 get_tcp6_sock(seq, v, st->num);
2048out:
2049 return 0;
2050}
2051
2052static const struct seq_operations tcp6_seq_ops = {
2053 .show = tcp6_seq_show,
2054 .start = tcp_seq_start,
2055 .next = tcp_seq_next,
2056 .stop = tcp_seq_stop,
2057};
2058
2059static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2060 .family = AF_INET6,
2061};
2062
2063int __net_init tcp6_proc_init(struct net *net)
2064{
2065 if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2066 sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2067 return -ENOMEM;
2068 return 0;
2069}
2070
2071void tcp6_proc_exit(struct net *net)
2072{
2073 remove_proc_entry("tcp6", net->proc_net);
2074}
2075#endif
2076
2077struct proto tcpv6_prot = {
2078 .name = "TCPv6",
2079 .owner = THIS_MODULE,
2080 .close = tcp_close,
2081 .pre_connect = tcp_v6_pre_connect,
2082 .connect = tcp_v6_connect,
2083 .disconnect = tcp_disconnect,
2084 .accept = inet_csk_accept,
2085 .ioctl = tcp_ioctl,
2086 .init = tcp_v6_init_sock,
2087 .destroy = tcp_v6_destroy_sock,
2088 .shutdown = tcp_shutdown,
2089 .setsockopt = tcp_setsockopt,
2090 .getsockopt = tcp_getsockopt,
2091 .keepalive = tcp_set_keepalive,
2092 .recvmsg = tcp_recvmsg,
2093 .sendmsg = tcp_sendmsg,
2094 .sendpage = tcp_sendpage,
2095 .backlog_rcv = tcp_v6_do_rcv,
2096 .release_cb = tcp_release_cb,
2097 .hash = inet6_hash,
2098 .unhash = inet_unhash,
2099 .get_port = inet_csk_get_port,
2100 .enter_memory_pressure = tcp_enter_memory_pressure,
2101 .leave_memory_pressure = tcp_leave_memory_pressure,
2102 .stream_memory_free = tcp_stream_memory_free,
2103 .sockets_allocated = &tcp_sockets_allocated,
2104 .memory_allocated = &tcp_memory_allocated,
2105 .memory_pressure = &tcp_memory_pressure,
2106 .orphan_count = &tcp_orphan_count,
2107 .sysctl_mem = sysctl_tcp_mem,
2108 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
2109 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
2110 .max_header = MAX_TCP_HEADER,
2111 .obj_size = sizeof(struct tcp6_sock),
2112 .slab_flags = SLAB_TYPESAFE_BY_RCU,
2113 .twsk_prot = &tcp6_timewait_sock_ops,
2114 .rsk_prot = &tcp6_request_sock_ops,
2115 .h.hashinfo = &tcp_hashinfo,
2116 .no_autobind = true,
2117 .diag_destroy = tcp_abort,
2118};
2119EXPORT_SYMBOL_GPL(tcpv6_prot);
2120
2121/* thinking of making this const? Don't.
2122 * early_demux can change based on sysctl.
2123 */
2124static struct inet6_protocol tcpv6_protocol = {
2125 .early_demux = tcp_v6_early_demux,
2126 .early_demux_handler = tcp_v6_early_demux,
2127 .handler = tcp_v6_rcv,
2128 .err_handler = tcp_v6_err,
2129 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2130};
2131
2132static struct inet_protosw tcpv6_protosw = {
2133 .type = SOCK_STREAM,
2134 .protocol = IPPROTO_TCP,
2135 .prot = &tcpv6_prot,
2136 .ops = &inet6_stream_ops,
2137 .flags = INET_PROTOSW_PERMANENT |
2138 INET_PROTOSW_ICSK,
2139};
2140
2141static int __net_init tcpv6_net_init(struct net *net)
2142{
2143 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2144 SOCK_RAW, IPPROTO_TCP, net);
2145}
2146
2147static void __net_exit tcpv6_net_exit(struct net *net)
2148{
2149 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2150}
2151
2152static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2153{
2154 inet_twsk_purge(&tcp_hashinfo, AF_INET6);
2155}
2156
2157static struct pernet_operations tcpv6_net_ops = {
2158 .init = tcpv6_net_init,
2159 .exit = tcpv6_net_exit,
2160 .exit_batch = tcpv6_net_exit_batch,
2161};
2162
2163int __init tcpv6_init(void)
2164{
2165 int ret;
2166
2167 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2168 if (ret)
2169 goto out;
2170
2171 /* register inet6 protocol */
2172 ret = inet6_register_protosw(&tcpv6_protosw);
2173 if (ret)
2174 goto out_tcpv6_protocol;
2175
2176 ret = register_pernet_subsys(&tcpv6_net_ops);
2177 if (ret)
2178 goto out_tcpv6_protosw;
2179
2180 ret = mptcpv6_init();
2181 if (ret)
2182 goto out_tcpv6_pernet_subsys;
2183
2184out:
2185 return ret;
2186
2187out_tcpv6_pernet_subsys:
2188 unregister_pernet_subsys(&tcpv6_net_ops);
2189out_tcpv6_protosw:
2190 inet6_unregister_protosw(&tcpv6_protosw);
2191out_tcpv6_protocol:
2192 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2193 goto out;
2194}
2195
2196void tcpv6_exit(void)
2197{
2198 unregister_pernet_subsys(&tcpv6_net_ops);
2199 inet6_unregister_protosw(&tcpv6_protosw);
2200 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2201}
1/*
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
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
67#include <asm/uaccess.h>
68
69#include <linux/proc_fs.h>
70#include <linux/seq_file.h>
71
72#include <linux/crypto.h>
73#include <linux/scatterlist.h>
74
75static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
76static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
77 struct request_sock *req);
78
79static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
80static void __tcp_v6_send_check(struct sk_buff *skb,
81 const struct in6_addr *saddr,
82 const struct in6_addr *daddr);
83
84static const struct inet_connection_sock_af_ops ipv6_mapped;
85static const struct inet_connection_sock_af_ops ipv6_specific;
86#ifdef CONFIG_TCP_MD5SIG
87static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
88static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
89#else
90static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
91 const struct in6_addr *addr)
92{
93 return NULL;
94}
95#endif
96
97static void tcp_v6_hash(struct sock *sk)
98{
99 if (sk->sk_state != TCP_CLOSE) {
100 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
101 tcp_prot.hash(sk);
102 return;
103 }
104 local_bh_disable();
105 __inet6_hash(sk, NULL);
106 local_bh_enable();
107 }
108}
109
110static __inline__ __sum16 tcp_v6_check(int len,
111 const struct in6_addr *saddr,
112 const struct in6_addr *daddr,
113 __wsum base)
114{
115 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
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 usin->sin6_addr = flowlabel->dst;
158 fl6_sock_release(flowlabel);
159 }
160 }
161
162 /*
163 * connect() to INADDR_ANY means loopback (BSD'ism).
164 */
165
166 if(ipv6_addr_any(&usin->sin6_addr))
167 usin->sin6_addr.s6_addr[15] = 0x1;
168
169 addr_type = ipv6_addr_type(&usin->sin6_addr);
170
171 if(addr_type & IPV6_ADDR_MULTICAST)
172 return -ENETUNREACH;
173
174 if (addr_type&IPV6_ADDR_LINKLOCAL) {
175 if (addr_len >= sizeof(struct sockaddr_in6) &&
176 usin->sin6_scope_id) {
177 /* If interface is set while binding, indices
178 * must coincide.
179 */
180 if (sk->sk_bound_dev_if &&
181 sk->sk_bound_dev_if != usin->sin6_scope_id)
182 return -EINVAL;
183
184 sk->sk_bound_dev_if = usin->sin6_scope_id;
185 }
186
187 /* Connect to link-local address requires an interface */
188 if (!sk->sk_bound_dev_if)
189 return -EINVAL;
190 }
191
192 if (tp->rx_opt.ts_recent_stamp &&
193 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
194 tp->rx_opt.ts_recent = 0;
195 tp->rx_opt.ts_recent_stamp = 0;
196 tp->write_seq = 0;
197 }
198
199 np->daddr = usin->sin6_addr;
200 np->flow_label = fl6.flowlabel;
201
202 /*
203 * TCP over IPv4
204 */
205
206 if (addr_type == IPV6_ADDR_MAPPED) {
207 u32 exthdrlen = icsk->icsk_ext_hdr_len;
208 struct sockaddr_in sin;
209
210 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
211
212 if (__ipv6_only_sock(sk))
213 return -ENETUNREACH;
214
215 sin.sin_family = AF_INET;
216 sin.sin_port = usin->sin6_port;
217 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
218
219 icsk->icsk_af_ops = &ipv6_mapped;
220 sk->sk_backlog_rcv = tcp_v4_do_rcv;
221#ifdef CONFIG_TCP_MD5SIG
222 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
223#endif
224
225 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
226
227 if (err) {
228 icsk->icsk_ext_hdr_len = exthdrlen;
229 icsk->icsk_af_ops = &ipv6_specific;
230 sk->sk_backlog_rcv = tcp_v6_do_rcv;
231#ifdef CONFIG_TCP_MD5SIG
232 tp->af_specific = &tcp_sock_ipv6_specific;
233#endif
234 goto failure;
235 } else {
236 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
237 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
238 &np->rcv_saddr);
239 }
240
241 return err;
242 }
243
244 if (!ipv6_addr_any(&np->rcv_saddr))
245 saddr = &np->rcv_saddr;
246
247 fl6.flowi6_proto = IPPROTO_TCP;
248 fl6.daddr = np->daddr;
249 fl6.saddr = saddr ? *saddr : np->saddr;
250 fl6.flowi6_oif = sk->sk_bound_dev_if;
251 fl6.flowi6_mark = sk->sk_mark;
252 fl6.fl6_dport = usin->sin6_port;
253 fl6.fl6_sport = inet->inet_sport;
254
255 final_p = fl6_update_dst(&fl6, np->opt, &final);
256
257 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
258
259 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
260 if (IS_ERR(dst)) {
261 err = PTR_ERR(dst);
262 goto failure;
263 }
264
265 if (saddr == NULL) {
266 saddr = &fl6.saddr;
267 np->rcv_saddr = *saddr;
268 }
269
270 /* set the source address */
271 np->saddr = *saddr;
272 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
273
274 sk->sk_gso_type = SKB_GSO_TCPV6;
275 __ip6_dst_store(sk, dst, NULL, NULL);
276
277 rt = (struct rt6_info *) dst;
278 if (tcp_death_row.sysctl_tw_recycle &&
279 !tp->rx_opt.ts_recent_stamp &&
280 ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
281 struct inet_peer *peer = rt6_get_peer(rt);
282 /*
283 * VJ's idea. We save last timestamp seen from
284 * the destination in peer table, when entering state
285 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
286 * when trying new connection.
287 */
288 if (peer) {
289 inet_peer_refcheck(peer);
290 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
291 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
292 tp->rx_opt.ts_recent = peer->tcp_ts;
293 }
294 }
295 }
296
297 icsk->icsk_ext_hdr_len = 0;
298 if (np->opt)
299 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
300 np->opt->opt_nflen);
301
302 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
303
304 inet->inet_dport = usin->sin6_port;
305
306 tcp_set_state(sk, TCP_SYN_SENT);
307 err = inet6_hash_connect(&tcp_death_row, sk);
308 if (err)
309 goto late_failure;
310
311 if (!tp->write_seq)
312 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
313 np->daddr.s6_addr32,
314 inet->inet_sport,
315 inet->inet_dport);
316
317 err = tcp_connect(sk);
318 if (err)
319 goto late_failure;
320
321 return 0;
322
323late_failure:
324 tcp_set_state(sk, TCP_CLOSE);
325 __sk_dst_reset(sk);
326failure:
327 inet->inet_dport = 0;
328 sk->sk_route_caps = 0;
329 return err;
330}
331
332static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
333 u8 type, u8 code, int offset, __be32 info)
334{
335 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
336 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
337 struct ipv6_pinfo *np;
338 struct sock *sk;
339 int err;
340 struct tcp_sock *tp;
341 __u32 seq;
342 struct net *net = dev_net(skb->dev);
343
344 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
345 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
346
347 if (sk == NULL) {
348 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
349 ICMP6_MIB_INERRORS);
350 return;
351 }
352
353 if (sk->sk_state == TCP_TIME_WAIT) {
354 inet_twsk_put(inet_twsk(sk));
355 return;
356 }
357
358 bh_lock_sock(sk);
359 if (sock_owned_by_user(sk))
360 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
361
362 if (sk->sk_state == TCP_CLOSE)
363 goto out;
364
365 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
366 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
367 goto out;
368 }
369
370 tp = tcp_sk(sk);
371 seq = ntohl(th->seq);
372 if (sk->sk_state != TCP_LISTEN &&
373 !between(seq, tp->snd_una, tp->snd_nxt)) {
374 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
375 goto out;
376 }
377
378 np = inet6_sk(sk);
379
380 if (type == ICMPV6_PKT_TOOBIG) {
381 struct dst_entry *dst;
382
383 if (sock_owned_by_user(sk))
384 goto out;
385 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
386 goto out;
387
388 /* icmp should have updated the destination cache entry */
389 dst = __sk_dst_check(sk, np->dst_cookie);
390
391 if (dst == NULL) {
392 struct inet_sock *inet = inet_sk(sk);
393 struct flowi6 fl6;
394
395 /* BUGGG_FUTURE: Again, it is not clear how
396 to handle rthdr case. Ignore this complexity
397 for now.
398 */
399 memset(&fl6, 0, sizeof(fl6));
400 fl6.flowi6_proto = IPPROTO_TCP;
401 fl6.daddr = np->daddr;
402 fl6.saddr = np->saddr;
403 fl6.flowi6_oif = sk->sk_bound_dev_if;
404 fl6.flowi6_mark = sk->sk_mark;
405 fl6.fl6_dport = inet->inet_dport;
406 fl6.fl6_sport = inet->inet_sport;
407 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
408
409 dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
410 if (IS_ERR(dst)) {
411 sk->sk_err_soft = -PTR_ERR(dst);
412 goto out;
413 }
414
415 } else
416 dst_hold(dst);
417
418 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
419 tcp_sync_mss(sk, dst_mtu(dst));
420 tcp_simple_retransmit(sk);
421 } /* else let the usual retransmit timer handle it */
422 dst_release(dst);
423 goto out;
424 }
425
426 icmpv6_err_convert(type, code, &err);
427
428 /* Might be for an request_sock */
429 switch (sk->sk_state) {
430 struct request_sock *req, **prev;
431 case TCP_LISTEN:
432 if (sock_owned_by_user(sk))
433 goto out;
434
435 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
436 &hdr->saddr, inet6_iif(skb));
437 if (!req)
438 goto out;
439
440 /* ICMPs are not backlogged, hence we cannot get
441 * an established socket here.
442 */
443 WARN_ON(req->sk != NULL);
444
445 if (seq != tcp_rsk(req)->snt_isn) {
446 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
447 goto out;
448 }
449
450 inet_csk_reqsk_queue_drop(sk, req, prev);
451 goto out;
452
453 case TCP_SYN_SENT:
454 case TCP_SYN_RECV: /* Cannot happen.
455 It can, it SYNs are crossed. --ANK */
456 if (!sock_owned_by_user(sk)) {
457 sk->sk_err = err;
458 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
459
460 tcp_done(sk);
461 } else
462 sk->sk_err_soft = err;
463 goto out;
464 }
465
466 if (!sock_owned_by_user(sk) && np->recverr) {
467 sk->sk_err = err;
468 sk->sk_error_report(sk);
469 } else
470 sk->sk_err_soft = err;
471
472out:
473 bh_unlock_sock(sk);
474 sock_put(sk);
475}
476
477
478static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
479 struct request_values *rvp,
480 u16 queue_mapping)
481{
482 struct inet6_request_sock *treq = inet6_rsk(req);
483 struct ipv6_pinfo *np = inet6_sk(sk);
484 struct sk_buff * skb;
485 struct ipv6_txoptions *opt = NULL;
486 struct in6_addr * final_p, final;
487 struct flowi6 fl6;
488 struct dst_entry *dst;
489 int err;
490
491 memset(&fl6, 0, sizeof(fl6));
492 fl6.flowi6_proto = IPPROTO_TCP;
493 fl6.daddr = treq->rmt_addr;
494 fl6.saddr = treq->loc_addr;
495 fl6.flowlabel = 0;
496 fl6.flowi6_oif = treq->iif;
497 fl6.flowi6_mark = sk->sk_mark;
498 fl6.fl6_dport = inet_rsk(req)->rmt_port;
499 fl6.fl6_sport = inet_rsk(req)->loc_port;
500 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
501
502 opt = np->opt;
503 final_p = fl6_update_dst(&fl6, opt, &final);
504
505 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
506 if (IS_ERR(dst)) {
507 err = PTR_ERR(dst);
508 dst = NULL;
509 goto done;
510 }
511 skb = tcp_make_synack(sk, dst, req, rvp);
512 err = -ENOMEM;
513 if (skb) {
514 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
515
516 fl6.daddr = treq->rmt_addr;
517 skb_set_queue_mapping(skb, queue_mapping);
518 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
519 err = net_xmit_eval(err);
520 }
521
522done:
523 if (opt && opt != np->opt)
524 sock_kfree_s(sk, opt, opt->tot_len);
525 dst_release(dst);
526 return err;
527}
528
529static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
530 struct request_values *rvp)
531{
532 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
533 return tcp_v6_send_synack(sk, req, rvp, 0);
534}
535
536static void tcp_v6_reqsk_destructor(struct request_sock *req)
537{
538 kfree_skb(inet6_rsk(req)->pktopts);
539}
540
541#ifdef CONFIG_TCP_MD5SIG
542static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
543 const struct in6_addr *addr)
544{
545 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
546}
547
548static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
549 struct sock *addr_sk)
550{
551 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
552}
553
554static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
555 struct request_sock *req)
556{
557 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
558}
559
560static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
561 int optlen)
562{
563 struct tcp_md5sig cmd;
564 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
565
566 if (optlen < sizeof(cmd))
567 return -EINVAL;
568
569 if (copy_from_user(&cmd, optval, sizeof(cmd)))
570 return -EFAULT;
571
572 if (sin6->sin6_family != AF_INET6)
573 return -EINVAL;
574
575 if (!cmd.tcpm_keylen) {
576 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
577 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
578 AF_INET);
579 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
580 AF_INET6);
581 }
582
583 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
584 return -EINVAL;
585
586 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
587 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
588 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
589
590 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
591 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
592}
593
594static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
595 const struct in6_addr *daddr,
596 const struct in6_addr *saddr, int nbytes)
597{
598 struct tcp6_pseudohdr *bp;
599 struct scatterlist sg;
600
601 bp = &hp->md5_blk.ip6;
602 /* 1. TCP pseudo-header (RFC2460) */
603 bp->saddr = *saddr;
604 bp->daddr = *daddr;
605 bp->protocol = cpu_to_be32(IPPROTO_TCP);
606 bp->len = cpu_to_be32(nbytes);
607
608 sg_init_one(&sg, bp, sizeof(*bp));
609 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
610}
611
612static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
613 const struct in6_addr *daddr, struct in6_addr *saddr,
614 const struct tcphdr *th)
615{
616 struct tcp_md5sig_pool *hp;
617 struct hash_desc *desc;
618
619 hp = tcp_get_md5sig_pool();
620 if (!hp)
621 goto clear_hash_noput;
622 desc = &hp->md5_desc;
623
624 if (crypto_hash_init(desc))
625 goto clear_hash;
626 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
627 goto clear_hash;
628 if (tcp_md5_hash_header(hp, th))
629 goto clear_hash;
630 if (tcp_md5_hash_key(hp, key))
631 goto clear_hash;
632 if (crypto_hash_final(desc, md5_hash))
633 goto clear_hash;
634
635 tcp_put_md5sig_pool();
636 return 0;
637
638clear_hash:
639 tcp_put_md5sig_pool();
640clear_hash_noput:
641 memset(md5_hash, 0, 16);
642 return 1;
643}
644
645static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
646 const struct sock *sk,
647 const struct request_sock *req,
648 const struct sk_buff *skb)
649{
650 const struct in6_addr *saddr, *daddr;
651 struct tcp_md5sig_pool *hp;
652 struct hash_desc *desc;
653 const struct tcphdr *th = tcp_hdr(skb);
654
655 if (sk) {
656 saddr = &inet6_sk(sk)->saddr;
657 daddr = &inet6_sk(sk)->daddr;
658 } else if (req) {
659 saddr = &inet6_rsk(req)->loc_addr;
660 daddr = &inet6_rsk(req)->rmt_addr;
661 } else {
662 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
663 saddr = &ip6h->saddr;
664 daddr = &ip6h->daddr;
665 }
666
667 hp = tcp_get_md5sig_pool();
668 if (!hp)
669 goto clear_hash_noput;
670 desc = &hp->md5_desc;
671
672 if (crypto_hash_init(desc))
673 goto clear_hash;
674
675 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
676 goto clear_hash;
677 if (tcp_md5_hash_header(hp, th))
678 goto clear_hash;
679 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
680 goto clear_hash;
681 if (tcp_md5_hash_key(hp, key))
682 goto clear_hash;
683 if (crypto_hash_final(desc, md5_hash))
684 goto clear_hash;
685
686 tcp_put_md5sig_pool();
687 return 0;
688
689clear_hash:
690 tcp_put_md5sig_pool();
691clear_hash_noput:
692 memset(md5_hash, 0, 16);
693 return 1;
694}
695
696static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
697{
698 const __u8 *hash_location = NULL;
699 struct tcp_md5sig_key *hash_expected;
700 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
701 const struct tcphdr *th = tcp_hdr(skb);
702 int genhash;
703 u8 newhash[16];
704
705 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
706 hash_location = tcp_parse_md5sig_option(th);
707
708 /* We've parsed the options - do we have a hash? */
709 if (!hash_expected && !hash_location)
710 return 0;
711
712 if (hash_expected && !hash_location) {
713 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
714 return 1;
715 }
716
717 if (!hash_expected && hash_location) {
718 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
719 return 1;
720 }
721
722 /* check the signature */
723 genhash = tcp_v6_md5_hash_skb(newhash,
724 hash_expected,
725 NULL, NULL, skb);
726
727 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
728 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
729 genhash ? "failed" : "mismatch",
730 &ip6h->saddr, ntohs(th->source),
731 &ip6h->daddr, ntohs(th->dest));
732 return 1;
733 }
734 return 0;
735}
736#endif
737
738struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
739 .family = AF_INET6,
740 .obj_size = sizeof(struct tcp6_request_sock),
741 .rtx_syn_ack = tcp_v6_rtx_synack,
742 .send_ack = tcp_v6_reqsk_send_ack,
743 .destructor = tcp_v6_reqsk_destructor,
744 .send_reset = tcp_v6_send_reset,
745 .syn_ack_timeout = tcp_syn_ack_timeout,
746};
747
748#ifdef CONFIG_TCP_MD5SIG
749static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
750 .md5_lookup = tcp_v6_reqsk_md5_lookup,
751 .calc_md5_hash = tcp_v6_md5_hash_skb,
752};
753#endif
754
755static void __tcp_v6_send_check(struct sk_buff *skb,
756 const struct in6_addr *saddr, const struct in6_addr *daddr)
757{
758 struct tcphdr *th = tcp_hdr(skb);
759
760 if (skb->ip_summed == CHECKSUM_PARTIAL) {
761 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
762 skb->csum_start = skb_transport_header(skb) - skb->head;
763 skb->csum_offset = offsetof(struct tcphdr, check);
764 } else {
765 th->check = tcp_v6_check(skb->len, saddr, daddr,
766 csum_partial(th, th->doff << 2,
767 skb->csum));
768 }
769}
770
771static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
772{
773 struct ipv6_pinfo *np = inet6_sk(sk);
774
775 __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
776}
777
778static int tcp_v6_gso_send_check(struct sk_buff *skb)
779{
780 const struct ipv6hdr *ipv6h;
781 struct tcphdr *th;
782
783 if (!pskb_may_pull(skb, sizeof(*th)))
784 return -EINVAL;
785
786 ipv6h = ipv6_hdr(skb);
787 th = tcp_hdr(skb);
788
789 th->check = 0;
790 skb->ip_summed = CHECKSUM_PARTIAL;
791 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
792 return 0;
793}
794
795static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
796 struct sk_buff *skb)
797{
798 const struct ipv6hdr *iph = skb_gro_network_header(skb);
799
800 switch (skb->ip_summed) {
801 case CHECKSUM_COMPLETE:
802 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
803 skb->csum)) {
804 skb->ip_summed = CHECKSUM_UNNECESSARY;
805 break;
806 }
807
808 /* fall through */
809 case CHECKSUM_NONE:
810 NAPI_GRO_CB(skb)->flush = 1;
811 return NULL;
812 }
813
814 return tcp_gro_receive(head, skb);
815}
816
817static int tcp6_gro_complete(struct sk_buff *skb)
818{
819 const struct ipv6hdr *iph = ipv6_hdr(skb);
820 struct tcphdr *th = tcp_hdr(skb);
821
822 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
823 &iph->saddr, &iph->daddr, 0);
824 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
825
826 return tcp_gro_complete(skb);
827}
828
829static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
830 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
831{
832 const struct tcphdr *th = tcp_hdr(skb);
833 struct tcphdr *t1;
834 struct sk_buff *buff;
835 struct flowi6 fl6;
836 struct net *net = dev_net(skb_dst(skb)->dev);
837 struct sock *ctl_sk = net->ipv6.tcp_sk;
838 unsigned int tot_len = sizeof(struct tcphdr);
839 struct dst_entry *dst;
840 __be32 *topt;
841
842 if (ts)
843 tot_len += TCPOLEN_TSTAMP_ALIGNED;
844#ifdef CONFIG_TCP_MD5SIG
845 if (key)
846 tot_len += TCPOLEN_MD5SIG_ALIGNED;
847#endif
848
849 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
850 GFP_ATOMIC);
851 if (buff == NULL)
852 return;
853
854 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
855
856 t1 = (struct tcphdr *) skb_push(buff, tot_len);
857 skb_reset_transport_header(buff);
858
859 /* Swap the send and the receive. */
860 memset(t1, 0, sizeof(*t1));
861 t1->dest = th->source;
862 t1->source = th->dest;
863 t1->doff = tot_len / 4;
864 t1->seq = htonl(seq);
865 t1->ack_seq = htonl(ack);
866 t1->ack = !rst || !th->ack;
867 t1->rst = rst;
868 t1->window = htons(win);
869
870 topt = (__be32 *)(t1 + 1);
871
872 if (ts) {
873 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
874 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
875 *topt++ = htonl(tcp_time_stamp);
876 *topt++ = htonl(ts);
877 }
878
879#ifdef CONFIG_TCP_MD5SIG
880 if (key) {
881 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
882 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
883 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
884 &ipv6_hdr(skb)->saddr,
885 &ipv6_hdr(skb)->daddr, t1);
886 }
887#endif
888
889 memset(&fl6, 0, sizeof(fl6));
890 fl6.daddr = ipv6_hdr(skb)->saddr;
891 fl6.saddr = ipv6_hdr(skb)->daddr;
892
893 buff->ip_summed = CHECKSUM_PARTIAL;
894 buff->csum = 0;
895
896 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
897
898 fl6.flowi6_proto = IPPROTO_TCP;
899 fl6.flowi6_oif = inet6_iif(skb);
900 fl6.fl6_dport = t1->dest;
901 fl6.fl6_sport = t1->source;
902 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
903
904 /* Pass a socket to ip6_dst_lookup either it is for RST
905 * Underlying function will use this to retrieve the network
906 * namespace
907 */
908 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
909 if (!IS_ERR(dst)) {
910 skb_dst_set(buff, dst);
911 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
912 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
913 if (rst)
914 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
915 return;
916 }
917
918 kfree_skb(buff);
919}
920
921static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
922{
923 const struct tcphdr *th = tcp_hdr(skb);
924 u32 seq = 0, ack_seq = 0;
925 struct tcp_md5sig_key *key = NULL;
926#ifdef CONFIG_TCP_MD5SIG
927 const __u8 *hash_location = NULL;
928 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
929 unsigned char newhash[16];
930 int genhash;
931 struct sock *sk1 = NULL;
932#endif
933
934 if (th->rst)
935 return;
936
937 if (!ipv6_unicast_destination(skb))
938 return;
939
940#ifdef CONFIG_TCP_MD5SIG
941 hash_location = tcp_parse_md5sig_option(th);
942 if (!sk && hash_location) {
943 /*
944 * active side is lost. Try to find listening socket through
945 * source port, and then find md5 key through listening socket.
946 * we are not loose security here:
947 * Incoming packet is checked with md5 hash with finding key,
948 * no RST generated if md5 hash doesn't match.
949 */
950 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
951 &tcp_hashinfo, &ipv6h->daddr,
952 ntohs(th->source), inet6_iif(skb));
953 if (!sk1)
954 return;
955
956 rcu_read_lock();
957 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
958 if (!key)
959 goto release_sk1;
960
961 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
962 if (genhash || memcmp(hash_location, newhash, 16) != 0)
963 goto release_sk1;
964 } else {
965 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
966 }
967#endif
968
969 if (th->ack)
970 seq = ntohl(th->ack_seq);
971 else
972 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
973 (th->doff << 2);
974
975 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
976
977#ifdef CONFIG_TCP_MD5SIG
978release_sk1:
979 if (sk1) {
980 rcu_read_unlock();
981 sock_put(sk1);
982 }
983#endif
984}
985
986static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
987 struct tcp_md5sig_key *key, u8 tclass)
988{
989 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
990}
991
992static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
993{
994 struct inet_timewait_sock *tw = inet_twsk(sk);
995 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
996
997 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
998 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
999 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
1000 tw->tw_tclass);
1001
1002 inet_twsk_put(tw);
1003}
1004
1005static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1006 struct request_sock *req)
1007{
1008 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1009 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
1010}
1011
1012
1013static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1014{
1015 struct request_sock *req, **prev;
1016 const struct tcphdr *th = tcp_hdr(skb);
1017 struct sock *nsk;
1018
1019 /* Find possible connection requests. */
1020 req = inet6_csk_search_req(sk, &prev, th->source,
1021 &ipv6_hdr(skb)->saddr,
1022 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1023 if (req)
1024 return tcp_check_req(sk, skb, req, prev);
1025
1026 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1027 &ipv6_hdr(skb)->saddr, th->source,
1028 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1029
1030 if (nsk) {
1031 if (nsk->sk_state != TCP_TIME_WAIT) {
1032 bh_lock_sock(nsk);
1033 return nsk;
1034 }
1035 inet_twsk_put(inet_twsk(nsk));
1036 return NULL;
1037 }
1038
1039#ifdef CONFIG_SYN_COOKIES
1040 if (!th->syn)
1041 sk = cookie_v6_check(sk, skb);
1042#endif
1043 return sk;
1044}
1045
1046/* FIXME: this is substantially similar to the ipv4 code.
1047 * Can some kind of merge be done? -- erics
1048 */
1049static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1050{
1051 struct tcp_extend_values tmp_ext;
1052 struct tcp_options_received tmp_opt;
1053 const u8 *hash_location;
1054 struct request_sock *req;
1055 struct inet6_request_sock *treq;
1056 struct ipv6_pinfo *np = inet6_sk(sk);
1057 struct tcp_sock *tp = tcp_sk(sk);
1058 __u32 isn = TCP_SKB_CB(skb)->when;
1059 struct dst_entry *dst = NULL;
1060 bool want_cookie = false;
1061
1062 if (skb->protocol == htons(ETH_P_IP))
1063 return tcp_v4_conn_request(sk, skb);
1064
1065 if (!ipv6_unicast_destination(skb))
1066 goto drop;
1067
1068 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1069 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
1070 if (!want_cookie)
1071 goto drop;
1072 }
1073
1074 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1075 goto drop;
1076
1077 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1078 if (req == NULL)
1079 goto drop;
1080
1081#ifdef CONFIG_TCP_MD5SIG
1082 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1083#endif
1084
1085 tcp_clear_options(&tmp_opt);
1086 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1087 tmp_opt.user_mss = tp->rx_opt.user_mss;
1088 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1089
1090 if (tmp_opt.cookie_plus > 0 &&
1091 tmp_opt.saw_tstamp &&
1092 !tp->rx_opt.cookie_out_never &&
1093 (sysctl_tcp_cookie_size > 0 ||
1094 (tp->cookie_values != NULL &&
1095 tp->cookie_values->cookie_desired > 0))) {
1096 u8 *c;
1097 u32 *d;
1098 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1099 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1100
1101 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1102 goto drop_and_free;
1103
1104 /* Secret recipe starts with IP addresses */
1105 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1106 *mess++ ^= *d++;
1107 *mess++ ^= *d++;
1108 *mess++ ^= *d++;
1109 *mess++ ^= *d++;
1110 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1111 *mess++ ^= *d++;
1112 *mess++ ^= *d++;
1113 *mess++ ^= *d++;
1114 *mess++ ^= *d++;
1115
1116 /* plus variable length Initiator Cookie */
1117 c = (u8 *)mess;
1118 while (l-- > 0)
1119 *c++ ^= *hash_location++;
1120
1121 want_cookie = false; /* not our kind of cookie */
1122 tmp_ext.cookie_out_never = 0; /* false */
1123 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1124 } else if (!tp->rx_opt.cookie_in_always) {
1125 /* redundant indications, but ensure initialization. */
1126 tmp_ext.cookie_out_never = 1; /* true */
1127 tmp_ext.cookie_plus = 0;
1128 } else {
1129 goto drop_and_free;
1130 }
1131 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1132
1133 if (want_cookie && !tmp_opt.saw_tstamp)
1134 tcp_clear_options(&tmp_opt);
1135
1136 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1137 tcp_openreq_init(req, &tmp_opt, skb);
1138
1139 treq = inet6_rsk(req);
1140 treq->rmt_addr = ipv6_hdr(skb)->saddr;
1141 treq->loc_addr = ipv6_hdr(skb)->daddr;
1142 if (!want_cookie || tmp_opt.tstamp_ok)
1143 TCP_ECN_create_request(req, skb);
1144
1145 treq->iif = sk->sk_bound_dev_if;
1146
1147 /* So that link locals have meaning */
1148 if (!sk->sk_bound_dev_if &&
1149 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1150 treq->iif = inet6_iif(skb);
1151
1152 if (!isn) {
1153 struct inet_peer *peer = NULL;
1154
1155 if (ipv6_opt_accepted(sk, skb) ||
1156 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1157 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1158 atomic_inc(&skb->users);
1159 treq->pktopts = skb;
1160 }
1161
1162 if (want_cookie) {
1163 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1164 req->cookie_ts = tmp_opt.tstamp_ok;
1165 goto have_isn;
1166 }
1167
1168 /* VJ's idea. We save last timestamp seen
1169 * from the destination in peer table, when entering
1170 * state TIME-WAIT, and check against it before
1171 * accepting new connection request.
1172 *
1173 * If "isn" is not zero, this request hit alive
1174 * timewait bucket, so that all the necessary checks
1175 * are made in the function processing timewait state.
1176 */
1177 if (tmp_opt.saw_tstamp &&
1178 tcp_death_row.sysctl_tw_recycle &&
1179 (dst = inet6_csk_route_req(sk, req)) != NULL &&
1180 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1181 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1182 &treq->rmt_addr)) {
1183 inet_peer_refcheck(peer);
1184 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1185 (s32)(peer->tcp_ts - req->ts_recent) >
1186 TCP_PAWS_WINDOW) {
1187 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1188 goto drop_and_release;
1189 }
1190 }
1191 /* Kill the following clause, if you dislike this way. */
1192 else if (!sysctl_tcp_syncookies &&
1193 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1194 (sysctl_max_syn_backlog >> 2)) &&
1195 (!peer || !peer->tcp_ts_stamp) &&
1196 (!dst || !dst_metric(dst, RTAX_RTT))) {
1197 /* Without syncookies last quarter of
1198 * backlog is filled with destinations,
1199 * proven to be alive.
1200 * It means that we continue to communicate
1201 * to destinations, already remembered
1202 * to the moment of synflood.
1203 */
1204 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1205 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1206 goto drop_and_release;
1207 }
1208
1209 isn = tcp_v6_init_sequence(skb);
1210 }
1211have_isn:
1212 tcp_rsk(req)->snt_isn = isn;
1213 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1214
1215 if (security_inet_conn_request(sk, skb, req))
1216 goto drop_and_release;
1217
1218 if (tcp_v6_send_synack(sk, req,
1219 (struct request_values *)&tmp_ext,
1220 skb_get_queue_mapping(skb)) ||
1221 want_cookie)
1222 goto drop_and_free;
1223
1224 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1225 return 0;
1226
1227drop_and_release:
1228 dst_release(dst);
1229drop_and_free:
1230 reqsk_free(req);
1231drop:
1232 return 0; /* don't send reset */
1233}
1234
1235static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1236 struct request_sock *req,
1237 struct dst_entry *dst)
1238{
1239 struct inet6_request_sock *treq;
1240 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1241 struct tcp6_sock *newtcp6sk;
1242 struct inet_sock *newinet;
1243 struct tcp_sock *newtp;
1244 struct sock *newsk;
1245 struct ipv6_txoptions *opt;
1246#ifdef CONFIG_TCP_MD5SIG
1247 struct tcp_md5sig_key *key;
1248#endif
1249
1250 if (skb->protocol == htons(ETH_P_IP)) {
1251 /*
1252 * v6 mapped
1253 */
1254
1255 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1256
1257 if (newsk == NULL)
1258 return NULL;
1259
1260 newtcp6sk = (struct tcp6_sock *)newsk;
1261 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1262
1263 newinet = inet_sk(newsk);
1264 newnp = inet6_sk(newsk);
1265 newtp = tcp_sk(newsk);
1266
1267 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1268
1269 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1270
1271 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1272
1273 newnp->rcv_saddr = newnp->saddr;
1274
1275 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1276 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1277#ifdef CONFIG_TCP_MD5SIG
1278 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1279#endif
1280
1281 newnp->ipv6_ac_list = NULL;
1282 newnp->ipv6_fl_list = NULL;
1283 newnp->pktoptions = NULL;
1284 newnp->opt = NULL;
1285 newnp->mcast_oif = inet6_iif(skb);
1286 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1287 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1288
1289 /*
1290 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1291 * here, tcp_create_openreq_child now does this for us, see the comment in
1292 * that function for the gory details. -acme
1293 */
1294
1295 /* It is tricky place. Until this moment IPv4 tcp
1296 worked with IPv6 icsk.icsk_af_ops.
1297 Sync it now.
1298 */
1299 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1300
1301 return newsk;
1302 }
1303
1304 treq = inet6_rsk(req);
1305 opt = np->opt;
1306
1307 if (sk_acceptq_is_full(sk))
1308 goto out_overflow;
1309
1310 if (!dst) {
1311 dst = inet6_csk_route_req(sk, req);
1312 if (!dst)
1313 goto out;
1314 }
1315
1316 newsk = tcp_create_openreq_child(sk, req, skb);
1317 if (newsk == NULL)
1318 goto out_nonewsk;
1319
1320 /*
1321 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1322 * count here, tcp_create_openreq_child now does this for us, see the
1323 * comment in that function for the gory details. -acme
1324 */
1325
1326 newsk->sk_gso_type = SKB_GSO_TCPV6;
1327 __ip6_dst_store(newsk, dst, NULL, NULL);
1328
1329 newtcp6sk = (struct tcp6_sock *)newsk;
1330 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1331
1332 newtp = tcp_sk(newsk);
1333 newinet = inet_sk(newsk);
1334 newnp = inet6_sk(newsk);
1335
1336 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1337
1338 newnp->daddr = treq->rmt_addr;
1339 newnp->saddr = treq->loc_addr;
1340 newnp->rcv_saddr = treq->loc_addr;
1341 newsk->sk_bound_dev_if = treq->iif;
1342
1343 /* Now IPv6 options...
1344
1345 First: no IPv4 options.
1346 */
1347 newinet->inet_opt = NULL;
1348 newnp->ipv6_ac_list = NULL;
1349 newnp->ipv6_fl_list = NULL;
1350
1351 /* Clone RX bits */
1352 newnp->rxopt.all = np->rxopt.all;
1353
1354 /* Clone pktoptions received with SYN */
1355 newnp->pktoptions = NULL;
1356 if (treq->pktopts != NULL) {
1357 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1358 consume_skb(treq->pktopts);
1359 treq->pktopts = NULL;
1360 if (newnp->pktoptions)
1361 skb_set_owner_r(newnp->pktoptions, newsk);
1362 }
1363 newnp->opt = NULL;
1364 newnp->mcast_oif = inet6_iif(skb);
1365 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1366 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1367
1368 /* Clone native IPv6 options from listening socket (if any)
1369
1370 Yes, keeping reference count would be much more clever,
1371 but we make one more one thing there: reattach optmem
1372 to newsk.
1373 */
1374 if (opt) {
1375 newnp->opt = ipv6_dup_options(newsk, opt);
1376 if (opt != np->opt)
1377 sock_kfree_s(sk, opt, opt->tot_len);
1378 }
1379
1380 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1381 if (newnp->opt)
1382 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1383 newnp->opt->opt_flen);
1384
1385 tcp_mtup_init(newsk);
1386 tcp_sync_mss(newsk, dst_mtu(dst));
1387 newtp->advmss = dst_metric_advmss(dst);
1388 if (tcp_sk(sk)->rx_opt.user_mss &&
1389 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1390 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1391
1392 tcp_initialize_rcv_mss(newsk);
1393 if (tcp_rsk(req)->snt_synack)
1394 tcp_valid_rtt_meas(newsk,
1395 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1396 newtp->total_retrans = req->retrans;
1397
1398 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1399 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1400
1401#ifdef CONFIG_TCP_MD5SIG
1402 /* Copy over the MD5 key from the original socket */
1403 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1404 /* We're using one, so create a matching key
1405 * on the newsk structure. If we fail to get
1406 * memory, then we end up not copying the key
1407 * across. Shucks.
1408 */
1409 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1410 AF_INET6, key->key, key->keylen, GFP_ATOMIC);
1411 }
1412#endif
1413
1414 if (__inet_inherit_port(sk, newsk) < 0) {
1415 sock_put(newsk);
1416 goto out;
1417 }
1418 __inet6_hash(newsk, NULL);
1419
1420 return newsk;
1421
1422out_overflow:
1423 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1424out_nonewsk:
1425 if (opt && opt != np->opt)
1426 sock_kfree_s(sk, opt, opt->tot_len);
1427 dst_release(dst);
1428out:
1429 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1430 return NULL;
1431}
1432
1433static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1434{
1435 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1436 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1437 &ipv6_hdr(skb)->daddr, skb->csum)) {
1438 skb->ip_summed = CHECKSUM_UNNECESSARY;
1439 return 0;
1440 }
1441 }
1442
1443 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1444 &ipv6_hdr(skb)->saddr,
1445 &ipv6_hdr(skb)->daddr, 0));
1446
1447 if (skb->len <= 76) {
1448 return __skb_checksum_complete(skb);
1449 }
1450 return 0;
1451}
1452
1453/* The socket must have it's spinlock held when we get
1454 * here.
1455 *
1456 * We have a potential double-lock case here, so even when
1457 * doing backlog processing we use the BH locking scheme.
1458 * This is because we cannot sleep with the original spinlock
1459 * held.
1460 */
1461static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1462{
1463 struct ipv6_pinfo *np = inet6_sk(sk);
1464 struct tcp_sock *tp;
1465 struct sk_buff *opt_skb = NULL;
1466
1467 /* Imagine: socket is IPv6. IPv4 packet arrives,
1468 goes to IPv4 receive handler and backlogged.
1469 From backlog it always goes here. Kerboom...
1470 Fortunately, tcp_rcv_established and rcv_established
1471 handle them correctly, but it is not case with
1472 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1473 */
1474
1475 if (skb->protocol == htons(ETH_P_IP))
1476 return tcp_v4_do_rcv(sk, skb);
1477
1478#ifdef CONFIG_TCP_MD5SIG
1479 if (tcp_v6_inbound_md5_hash (sk, skb))
1480 goto discard;
1481#endif
1482
1483 if (sk_filter(sk, skb))
1484 goto discard;
1485
1486 /*
1487 * socket locking is here for SMP purposes as backlog rcv
1488 * is currently called with bh processing disabled.
1489 */
1490
1491 /* Do Stevens' IPV6_PKTOPTIONS.
1492
1493 Yes, guys, it is the only place in our code, where we
1494 may make it not affecting IPv4.
1495 The rest of code is protocol independent,
1496 and I do not like idea to uglify IPv4.
1497
1498 Actually, all the idea behind IPV6_PKTOPTIONS
1499 looks not very well thought. For now we latch
1500 options, received in the last packet, enqueued
1501 by tcp. Feel free to propose better solution.
1502 --ANK (980728)
1503 */
1504 if (np->rxopt.all)
1505 opt_skb = skb_clone(skb, GFP_ATOMIC);
1506
1507 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1508 sock_rps_save_rxhash(sk, skb);
1509 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1510 goto reset;
1511 if (opt_skb)
1512 goto ipv6_pktoptions;
1513 return 0;
1514 }
1515
1516 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1517 goto csum_err;
1518
1519 if (sk->sk_state == TCP_LISTEN) {
1520 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1521 if (!nsk)
1522 goto discard;
1523
1524 /*
1525 * Queue it on the new socket if the new socket is active,
1526 * otherwise we just shortcircuit this and continue with
1527 * the new socket..
1528 */
1529 if(nsk != sk) {
1530 sock_rps_save_rxhash(nsk, skb);
1531 if (tcp_child_process(sk, nsk, skb))
1532 goto reset;
1533 if (opt_skb)
1534 __kfree_skb(opt_skb);
1535 return 0;
1536 }
1537 } else
1538 sock_rps_save_rxhash(sk, skb);
1539
1540 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1541 goto reset;
1542 if (opt_skb)
1543 goto ipv6_pktoptions;
1544 return 0;
1545
1546reset:
1547 tcp_v6_send_reset(sk, skb);
1548discard:
1549 if (opt_skb)
1550 __kfree_skb(opt_skb);
1551 kfree_skb(skb);
1552 return 0;
1553csum_err:
1554 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1555 goto discard;
1556
1557
1558ipv6_pktoptions:
1559 /* Do you ask, what is it?
1560
1561 1. skb was enqueued by tcp.
1562 2. skb is added to tail of read queue, rather than out of order.
1563 3. socket is not in passive state.
1564 4. Finally, it really contains options, which user wants to receive.
1565 */
1566 tp = tcp_sk(sk);
1567 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1568 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1569 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1570 np->mcast_oif = inet6_iif(opt_skb);
1571 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1572 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1573 if (np->rxopt.bits.rxtclass)
1574 np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1575 if (ipv6_opt_accepted(sk, opt_skb)) {
1576 skb_set_owner_r(opt_skb, sk);
1577 opt_skb = xchg(&np->pktoptions, opt_skb);
1578 } else {
1579 __kfree_skb(opt_skb);
1580 opt_skb = xchg(&np->pktoptions, NULL);
1581 }
1582 }
1583
1584 kfree_skb(opt_skb);
1585 return 0;
1586}
1587
1588static int tcp_v6_rcv(struct sk_buff *skb)
1589{
1590 const struct tcphdr *th;
1591 const struct ipv6hdr *hdr;
1592 struct sock *sk;
1593 int ret;
1594 struct net *net = dev_net(skb->dev);
1595
1596 if (skb->pkt_type != PACKET_HOST)
1597 goto discard_it;
1598
1599 /*
1600 * Count it even if it's bad.
1601 */
1602 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1603
1604 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1605 goto discard_it;
1606
1607 th = tcp_hdr(skb);
1608
1609 if (th->doff < sizeof(struct tcphdr)/4)
1610 goto bad_packet;
1611 if (!pskb_may_pull(skb, th->doff*4))
1612 goto discard_it;
1613
1614 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1615 goto bad_packet;
1616
1617 th = tcp_hdr(skb);
1618 hdr = ipv6_hdr(skb);
1619 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1620 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1621 skb->len - th->doff*4);
1622 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1623 TCP_SKB_CB(skb)->when = 0;
1624 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1625 TCP_SKB_CB(skb)->sacked = 0;
1626
1627 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1628 if (!sk)
1629 goto no_tcp_socket;
1630
1631process:
1632 if (sk->sk_state == TCP_TIME_WAIT)
1633 goto do_time_wait;
1634
1635 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1636 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1637 goto discard_and_relse;
1638 }
1639
1640 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1641 goto discard_and_relse;
1642
1643 if (sk_filter(sk, skb))
1644 goto discard_and_relse;
1645
1646 skb->dev = NULL;
1647
1648 bh_lock_sock_nested(sk);
1649 ret = 0;
1650 if (!sock_owned_by_user(sk)) {
1651#ifdef CONFIG_NET_DMA
1652 struct tcp_sock *tp = tcp_sk(sk);
1653 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1654 tp->ucopy.dma_chan = net_dma_find_channel();
1655 if (tp->ucopy.dma_chan)
1656 ret = tcp_v6_do_rcv(sk, skb);
1657 else
1658#endif
1659 {
1660 if (!tcp_prequeue(sk, skb))
1661 ret = tcp_v6_do_rcv(sk, skb);
1662 }
1663 } else if (unlikely(sk_add_backlog(sk, skb,
1664 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1665 bh_unlock_sock(sk);
1666 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1667 goto discard_and_relse;
1668 }
1669 bh_unlock_sock(sk);
1670
1671 sock_put(sk);
1672 return ret ? -1 : 0;
1673
1674no_tcp_socket:
1675 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1676 goto discard_it;
1677
1678 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1679bad_packet:
1680 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1681 } else {
1682 tcp_v6_send_reset(NULL, skb);
1683 }
1684
1685discard_it:
1686
1687 /*
1688 * Discard frame
1689 */
1690
1691 kfree_skb(skb);
1692 return 0;
1693
1694discard_and_relse:
1695 sock_put(sk);
1696 goto discard_it;
1697
1698do_time_wait:
1699 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1700 inet_twsk_put(inet_twsk(sk));
1701 goto discard_it;
1702 }
1703
1704 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1705 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1706 inet_twsk_put(inet_twsk(sk));
1707 goto discard_it;
1708 }
1709
1710 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1711 case TCP_TW_SYN:
1712 {
1713 struct sock *sk2;
1714
1715 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1716 &ipv6_hdr(skb)->daddr,
1717 ntohs(th->dest), inet6_iif(skb));
1718 if (sk2 != NULL) {
1719 struct inet_timewait_sock *tw = inet_twsk(sk);
1720 inet_twsk_deschedule(tw, &tcp_death_row);
1721 inet_twsk_put(tw);
1722 sk = sk2;
1723 goto process;
1724 }
1725 /* Fall through to ACK */
1726 }
1727 case TCP_TW_ACK:
1728 tcp_v6_timewait_ack(sk, skb);
1729 break;
1730 case TCP_TW_RST:
1731 goto no_tcp_socket;
1732 case TCP_TW_SUCCESS:;
1733 }
1734 goto discard_it;
1735}
1736
1737static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1738{
1739 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1740 struct ipv6_pinfo *np = inet6_sk(sk);
1741 struct inet_peer *peer;
1742
1743 if (!rt ||
1744 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1745 peer = inet_getpeer_v6(&np->daddr, 1);
1746 *release_it = true;
1747 } else {
1748 if (!rt->rt6i_peer)
1749 rt6_bind_peer(rt, 1);
1750 peer = rt->rt6i_peer;
1751 *release_it = false;
1752 }
1753
1754 return peer;
1755}
1756
1757static void *tcp_v6_tw_get_peer(struct sock *sk)
1758{
1759 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1760 const struct inet_timewait_sock *tw = inet_twsk(sk);
1761
1762 if (tw->tw_family == AF_INET)
1763 return tcp_v4_tw_get_peer(sk);
1764
1765 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1766}
1767
1768static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1769 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1770 .twsk_unique = tcp_twsk_unique,
1771 .twsk_destructor= tcp_twsk_destructor,
1772 .twsk_getpeer = tcp_v6_tw_get_peer,
1773};
1774
1775static const struct inet_connection_sock_af_ops ipv6_specific = {
1776 .queue_xmit = inet6_csk_xmit,
1777 .send_check = tcp_v6_send_check,
1778 .rebuild_header = inet6_sk_rebuild_header,
1779 .conn_request = tcp_v6_conn_request,
1780 .syn_recv_sock = tcp_v6_syn_recv_sock,
1781 .get_peer = tcp_v6_get_peer,
1782 .net_header_len = sizeof(struct ipv6hdr),
1783 .net_frag_header_len = sizeof(struct frag_hdr),
1784 .setsockopt = ipv6_setsockopt,
1785 .getsockopt = ipv6_getsockopt,
1786 .addr2sockaddr = inet6_csk_addr2sockaddr,
1787 .sockaddr_len = sizeof(struct sockaddr_in6),
1788 .bind_conflict = inet6_csk_bind_conflict,
1789#ifdef CONFIG_COMPAT
1790 .compat_setsockopt = compat_ipv6_setsockopt,
1791 .compat_getsockopt = compat_ipv6_getsockopt,
1792#endif
1793};
1794
1795#ifdef CONFIG_TCP_MD5SIG
1796static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1797 .md5_lookup = tcp_v6_md5_lookup,
1798 .calc_md5_hash = tcp_v6_md5_hash_skb,
1799 .md5_parse = tcp_v6_parse_md5_keys,
1800};
1801#endif
1802
1803/*
1804 * TCP over IPv4 via INET6 API
1805 */
1806
1807static const struct inet_connection_sock_af_ops ipv6_mapped = {
1808 .queue_xmit = ip_queue_xmit,
1809 .send_check = tcp_v4_send_check,
1810 .rebuild_header = inet_sk_rebuild_header,
1811 .conn_request = tcp_v6_conn_request,
1812 .syn_recv_sock = tcp_v6_syn_recv_sock,
1813 .get_peer = tcp_v4_get_peer,
1814 .net_header_len = sizeof(struct iphdr),
1815 .setsockopt = ipv6_setsockopt,
1816 .getsockopt = ipv6_getsockopt,
1817 .addr2sockaddr = inet6_csk_addr2sockaddr,
1818 .sockaddr_len = sizeof(struct sockaddr_in6),
1819 .bind_conflict = inet6_csk_bind_conflict,
1820#ifdef CONFIG_COMPAT
1821 .compat_setsockopt = compat_ipv6_setsockopt,
1822 .compat_getsockopt = compat_ipv6_getsockopt,
1823#endif
1824};
1825
1826#ifdef CONFIG_TCP_MD5SIG
1827static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1828 .md5_lookup = tcp_v4_md5_lookup,
1829 .calc_md5_hash = tcp_v4_md5_hash_skb,
1830 .md5_parse = tcp_v6_parse_md5_keys,
1831};
1832#endif
1833
1834/* NOTE: A lot of things set to zero explicitly by call to
1835 * sk_alloc() so need not be done here.
1836 */
1837static int tcp_v6_init_sock(struct sock *sk)
1838{
1839 struct inet_connection_sock *icsk = inet_csk(sk);
1840
1841 tcp_init_sock(sk);
1842
1843 icsk->icsk_af_ops = &ipv6_specific;
1844
1845#ifdef CONFIG_TCP_MD5SIG
1846 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1847#endif
1848
1849 return 0;
1850}
1851
1852static void tcp_v6_destroy_sock(struct sock *sk)
1853{
1854 tcp_v4_destroy_sock(sk);
1855 inet6_destroy_sock(sk);
1856}
1857
1858#ifdef CONFIG_PROC_FS
1859/* Proc filesystem TCPv6 sock list dumping. */
1860static void get_openreq6(struct seq_file *seq,
1861 const struct sock *sk, struct request_sock *req, int i, int uid)
1862{
1863 int ttd = req->expires - jiffies;
1864 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1865 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1866
1867 if (ttd < 0)
1868 ttd = 0;
1869
1870 seq_printf(seq,
1871 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1872 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1873 i,
1874 src->s6_addr32[0], src->s6_addr32[1],
1875 src->s6_addr32[2], src->s6_addr32[3],
1876 ntohs(inet_rsk(req)->loc_port),
1877 dest->s6_addr32[0], dest->s6_addr32[1],
1878 dest->s6_addr32[2], dest->s6_addr32[3],
1879 ntohs(inet_rsk(req)->rmt_port),
1880 TCP_SYN_RECV,
1881 0,0, /* could print option size, but that is af dependent. */
1882 1, /* timers active (only the expire timer) */
1883 jiffies_to_clock_t(ttd),
1884 req->retrans,
1885 uid,
1886 0, /* non standard timer */
1887 0, /* open_requests have no inode */
1888 0, req);
1889}
1890
1891static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1892{
1893 const struct in6_addr *dest, *src;
1894 __u16 destp, srcp;
1895 int timer_active;
1896 unsigned long timer_expires;
1897 const struct inet_sock *inet = inet_sk(sp);
1898 const struct tcp_sock *tp = tcp_sk(sp);
1899 const struct inet_connection_sock *icsk = inet_csk(sp);
1900 const struct ipv6_pinfo *np = inet6_sk(sp);
1901
1902 dest = &np->daddr;
1903 src = &np->rcv_saddr;
1904 destp = ntohs(inet->inet_dport);
1905 srcp = ntohs(inet->inet_sport);
1906
1907 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1908 timer_active = 1;
1909 timer_expires = icsk->icsk_timeout;
1910 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1911 timer_active = 4;
1912 timer_expires = icsk->icsk_timeout;
1913 } else if (timer_pending(&sp->sk_timer)) {
1914 timer_active = 2;
1915 timer_expires = sp->sk_timer.expires;
1916 } else {
1917 timer_active = 0;
1918 timer_expires = jiffies;
1919 }
1920
1921 seq_printf(seq,
1922 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1923 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1924 i,
1925 src->s6_addr32[0], src->s6_addr32[1],
1926 src->s6_addr32[2], src->s6_addr32[3], srcp,
1927 dest->s6_addr32[0], dest->s6_addr32[1],
1928 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1929 sp->sk_state,
1930 tp->write_seq-tp->snd_una,
1931 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1932 timer_active,
1933 jiffies_to_clock_t(timer_expires - jiffies),
1934 icsk->icsk_retransmits,
1935 sock_i_uid(sp),
1936 icsk->icsk_probes_out,
1937 sock_i_ino(sp),
1938 atomic_read(&sp->sk_refcnt), sp,
1939 jiffies_to_clock_t(icsk->icsk_rto),
1940 jiffies_to_clock_t(icsk->icsk_ack.ato),
1941 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1942 tp->snd_cwnd,
1943 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1944 );
1945}
1946
1947static void get_timewait6_sock(struct seq_file *seq,
1948 struct inet_timewait_sock *tw, int i)
1949{
1950 const struct in6_addr *dest, *src;
1951 __u16 destp, srcp;
1952 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1953 int ttd = tw->tw_ttd - jiffies;
1954
1955 if (ttd < 0)
1956 ttd = 0;
1957
1958 dest = &tw6->tw_v6_daddr;
1959 src = &tw6->tw_v6_rcv_saddr;
1960 destp = ntohs(tw->tw_dport);
1961 srcp = ntohs(tw->tw_sport);
1962
1963 seq_printf(seq,
1964 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1965 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1966 i,
1967 src->s6_addr32[0], src->s6_addr32[1],
1968 src->s6_addr32[2], src->s6_addr32[3], srcp,
1969 dest->s6_addr32[0], dest->s6_addr32[1],
1970 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1971 tw->tw_substate, 0, 0,
1972 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
1973 atomic_read(&tw->tw_refcnt), tw);
1974}
1975
1976static int tcp6_seq_show(struct seq_file *seq, void *v)
1977{
1978 struct tcp_iter_state *st;
1979
1980 if (v == SEQ_START_TOKEN) {
1981 seq_puts(seq,
1982 " sl "
1983 "local_address "
1984 "remote_address "
1985 "st tx_queue rx_queue tr tm->when retrnsmt"
1986 " uid timeout inode\n");
1987 goto out;
1988 }
1989 st = seq->private;
1990
1991 switch (st->state) {
1992 case TCP_SEQ_STATE_LISTENING:
1993 case TCP_SEQ_STATE_ESTABLISHED:
1994 get_tcp6_sock(seq, v, st->num);
1995 break;
1996 case TCP_SEQ_STATE_OPENREQ:
1997 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1998 break;
1999 case TCP_SEQ_STATE_TIME_WAIT:
2000 get_timewait6_sock(seq, v, st->num);
2001 break;
2002 }
2003out:
2004 return 0;
2005}
2006
2007static const struct file_operations tcp6_afinfo_seq_fops = {
2008 .owner = THIS_MODULE,
2009 .open = tcp_seq_open,
2010 .read = seq_read,
2011 .llseek = seq_lseek,
2012 .release = seq_release_net
2013};
2014
2015static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2016 .name = "tcp6",
2017 .family = AF_INET6,
2018 .seq_fops = &tcp6_afinfo_seq_fops,
2019 .seq_ops = {
2020 .show = tcp6_seq_show,
2021 },
2022};
2023
2024int __net_init tcp6_proc_init(struct net *net)
2025{
2026 return tcp_proc_register(net, &tcp6_seq_afinfo);
2027}
2028
2029void tcp6_proc_exit(struct net *net)
2030{
2031 tcp_proc_unregister(net, &tcp6_seq_afinfo);
2032}
2033#endif
2034
2035struct proto tcpv6_prot = {
2036 .name = "TCPv6",
2037 .owner = THIS_MODULE,
2038 .close = tcp_close,
2039 .connect = tcp_v6_connect,
2040 .disconnect = tcp_disconnect,
2041 .accept = inet_csk_accept,
2042 .ioctl = tcp_ioctl,
2043 .init = tcp_v6_init_sock,
2044 .destroy = tcp_v6_destroy_sock,
2045 .shutdown = tcp_shutdown,
2046 .setsockopt = tcp_setsockopt,
2047 .getsockopt = tcp_getsockopt,
2048 .recvmsg = tcp_recvmsg,
2049 .sendmsg = tcp_sendmsg,
2050 .sendpage = tcp_sendpage,
2051 .backlog_rcv = tcp_v6_do_rcv,
2052 .hash = tcp_v6_hash,
2053 .unhash = inet_unhash,
2054 .get_port = inet_csk_get_port,
2055 .enter_memory_pressure = tcp_enter_memory_pressure,
2056 .sockets_allocated = &tcp_sockets_allocated,
2057 .memory_allocated = &tcp_memory_allocated,
2058 .memory_pressure = &tcp_memory_pressure,
2059 .orphan_count = &tcp_orphan_count,
2060 .sysctl_wmem = sysctl_tcp_wmem,
2061 .sysctl_rmem = sysctl_tcp_rmem,
2062 .max_header = MAX_TCP_HEADER,
2063 .obj_size = sizeof(struct tcp6_sock),
2064 .slab_flags = SLAB_DESTROY_BY_RCU,
2065 .twsk_prot = &tcp6_timewait_sock_ops,
2066 .rsk_prot = &tcp6_request_sock_ops,
2067 .h.hashinfo = &tcp_hashinfo,
2068 .no_autobind = true,
2069#ifdef CONFIG_COMPAT
2070 .compat_setsockopt = compat_tcp_setsockopt,
2071 .compat_getsockopt = compat_tcp_getsockopt,
2072#endif
2073#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
2074 .proto_cgroup = tcp_proto_cgroup,
2075#endif
2076};
2077
2078static const struct inet6_protocol tcpv6_protocol = {
2079 .handler = tcp_v6_rcv,
2080 .err_handler = tcp_v6_err,
2081 .gso_send_check = tcp_v6_gso_send_check,
2082 .gso_segment = tcp_tso_segment,
2083 .gro_receive = tcp6_gro_receive,
2084 .gro_complete = tcp6_gro_complete,
2085 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2086};
2087
2088static struct inet_protosw tcpv6_protosw = {
2089 .type = SOCK_STREAM,
2090 .protocol = IPPROTO_TCP,
2091 .prot = &tcpv6_prot,
2092 .ops = &inet6_stream_ops,
2093 .no_check = 0,
2094 .flags = INET_PROTOSW_PERMANENT |
2095 INET_PROTOSW_ICSK,
2096};
2097
2098static int __net_init tcpv6_net_init(struct net *net)
2099{
2100 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2101 SOCK_RAW, IPPROTO_TCP, net);
2102}
2103
2104static void __net_exit tcpv6_net_exit(struct net *net)
2105{
2106 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2107}
2108
2109static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2110{
2111 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2112}
2113
2114static struct pernet_operations tcpv6_net_ops = {
2115 .init = tcpv6_net_init,
2116 .exit = tcpv6_net_exit,
2117 .exit_batch = tcpv6_net_exit_batch,
2118};
2119
2120int __init tcpv6_init(void)
2121{
2122 int ret;
2123
2124 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2125 if (ret)
2126 goto out;
2127
2128 /* register inet6 protocol */
2129 ret = inet6_register_protosw(&tcpv6_protosw);
2130 if (ret)
2131 goto out_tcpv6_protocol;
2132
2133 ret = register_pernet_subsys(&tcpv6_net_ops);
2134 if (ret)
2135 goto out_tcpv6_protosw;
2136out:
2137 return ret;
2138
2139out_tcpv6_protocol:
2140 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2141out_tcpv6_protosw:
2142 inet6_unregister_protosw(&tcpv6_protosw);
2143 goto out;
2144}
2145
2146void tcpv6_exit(void)
2147{
2148 unregister_pernet_subsys(&tcpv6_net_ops);
2149 inet6_unregister_protosw(&tcpv6_protosw);
2150 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2151}