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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
66#include <asm/uaccess.h>
67
68#include <linux/proc_fs.h>
69#include <linux/seq_file.h>
70
71#include <linux/crypto.h>
72#include <linux/scatterlist.h>
73
74static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
75static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
76 struct request_sock *req);
77
78static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79static void __tcp_v6_send_check(struct sk_buff *skb,
80 const struct in6_addr *saddr,
81 const struct in6_addr *daddr);
82
83static const struct inet_connection_sock_af_ops ipv6_mapped;
84static const struct inet_connection_sock_af_ops ipv6_specific;
85#ifdef CONFIG_TCP_MD5SIG
86static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
87static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
88#else
89static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
90 const struct in6_addr *addr)
91{
92 return NULL;
93}
94#endif
95
96static void tcp_v6_hash(struct sock *sk)
97{
98 if (sk->sk_state != TCP_CLOSE) {
99 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
100 tcp_prot.hash(sk);
101 return;
102 }
103 local_bh_disable();
104 __inet6_hash(sk, NULL);
105 local_bh_enable();
106 }
107}
108
109static __inline__ __sum16 tcp_v6_check(int len,
110 const struct in6_addr *saddr,
111 const struct in6_addr *daddr,
112 __wsum base)
113{
114 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
115}
116
117static __u32 tcp_v6_init_sequence(struct sk_buff *skb)
118{
119 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
120 ipv6_hdr(skb)->saddr.s6_addr32,
121 tcp_hdr(skb)->dest,
122 tcp_hdr(skb)->source);
123}
124
125static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
126 int addr_len)
127{
128 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
129 struct inet_sock *inet = inet_sk(sk);
130 struct inet_connection_sock *icsk = inet_csk(sk);
131 struct ipv6_pinfo *np = inet6_sk(sk);
132 struct tcp_sock *tp = tcp_sk(sk);
133 struct in6_addr *saddr = NULL, *final_p, final;
134 struct rt6_info *rt;
135 struct flowi6 fl6;
136 struct dst_entry *dst;
137 int addr_type;
138 int err;
139
140 if (addr_len < SIN6_LEN_RFC2133)
141 return -EINVAL;
142
143 if (usin->sin6_family != AF_INET6)
144 return -EAFNOSUPPORT;
145
146 memset(&fl6, 0, sizeof(fl6));
147
148 if (np->sndflow) {
149 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
150 IP6_ECN_flow_init(fl6.flowlabel);
151 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
152 struct ip6_flowlabel *flowlabel;
153 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
154 if (flowlabel == NULL)
155 return -EINVAL;
156 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
157 fl6_sock_release(flowlabel);
158 }
159 }
160
161 /*
162 * connect() to INADDR_ANY means loopback (BSD'ism).
163 */
164
165 if(ipv6_addr_any(&usin->sin6_addr))
166 usin->sin6_addr.s6_addr[15] = 0x1;
167
168 addr_type = ipv6_addr_type(&usin->sin6_addr);
169
170 if(addr_type & IPV6_ADDR_MULTICAST)
171 return -ENETUNREACH;
172
173 if (addr_type&IPV6_ADDR_LINKLOCAL) {
174 if (addr_len >= sizeof(struct sockaddr_in6) &&
175 usin->sin6_scope_id) {
176 /* If interface is set while binding, indices
177 * must coincide.
178 */
179 if (sk->sk_bound_dev_if &&
180 sk->sk_bound_dev_if != usin->sin6_scope_id)
181 return -EINVAL;
182
183 sk->sk_bound_dev_if = usin->sin6_scope_id;
184 }
185
186 /* Connect to link-local address requires an interface */
187 if (!sk->sk_bound_dev_if)
188 return -EINVAL;
189 }
190
191 if (tp->rx_opt.ts_recent_stamp &&
192 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
193 tp->rx_opt.ts_recent = 0;
194 tp->rx_opt.ts_recent_stamp = 0;
195 tp->write_seq = 0;
196 }
197
198 ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
199 np->flow_label = fl6.flowlabel;
200
201 /*
202 * TCP over IPv4
203 */
204
205 if (addr_type == IPV6_ADDR_MAPPED) {
206 u32 exthdrlen = icsk->icsk_ext_hdr_len;
207 struct sockaddr_in sin;
208
209 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
210
211 if (__ipv6_only_sock(sk))
212 return -ENETUNREACH;
213
214 sin.sin_family = AF_INET;
215 sin.sin_port = usin->sin6_port;
216 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
217
218 icsk->icsk_af_ops = &ipv6_mapped;
219 sk->sk_backlog_rcv = tcp_v4_do_rcv;
220#ifdef CONFIG_TCP_MD5SIG
221 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
222#endif
223
224 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
225
226 if (err) {
227 icsk->icsk_ext_hdr_len = exthdrlen;
228 icsk->icsk_af_ops = &ipv6_specific;
229 sk->sk_backlog_rcv = tcp_v6_do_rcv;
230#ifdef CONFIG_TCP_MD5SIG
231 tp->af_specific = &tcp_sock_ipv6_specific;
232#endif
233 goto failure;
234 } else {
235 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
236 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
237 &np->rcv_saddr);
238 }
239
240 return err;
241 }
242
243 if (!ipv6_addr_any(&np->rcv_saddr))
244 saddr = &np->rcv_saddr;
245
246 fl6.flowi6_proto = IPPROTO_TCP;
247 ipv6_addr_copy(&fl6.daddr, &np->daddr);
248 ipv6_addr_copy(&fl6.saddr,
249 (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 ipv6_addr_copy(&np->rcv_saddr, saddr);
268 }
269
270 /* set the source address */
271 ipv6_addr_copy(&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 ipv6_addr_copy(&fl6.daddr, &np->daddr);
402 ipv6_addr_copy(&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{
481 struct inet6_request_sock *treq = inet6_rsk(req);
482 struct ipv6_pinfo *np = inet6_sk(sk);
483 struct sk_buff * skb;
484 struct ipv6_txoptions *opt = NULL;
485 struct in6_addr * final_p, final;
486 struct flowi6 fl6;
487 struct dst_entry *dst;
488 int err;
489
490 memset(&fl6, 0, sizeof(fl6));
491 fl6.flowi6_proto = IPPROTO_TCP;
492 ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
493 ipv6_addr_copy(&fl6.saddr, &treq->loc_addr);
494 fl6.flowlabel = 0;
495 fl6.flowi6_oif = treq->iif;
496 fl6.flowi6_mark = sk->sk_mark;
497 fl6.fl6_dport = inet_rsk(req)->rmt_port;
498 fl6.fl6_sport = inet_rsk(req)->loc_port;
499 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
500
501 opt = np->opt;
502 final_p = fl6_update_dst(&fl6, opt, &final);
503
504 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
505 if (IS_ERR(dst)) {
506 err = PTR_ERR(dst);
507 dst = NULL;
508 goto done;
509 }
510 skb = tcp_make_synack(sk, dst, req, rvp);
511 err = -ENOMEM;
512 if (skb) {
513 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
514
515 ipv6_addr_copy(&fl6.daddr, &treq->rmt_addr);
516 err = ip6_xmit(sk, skb, &fl6, opt);
517 err = net_xmit_eval(err);
518 }
519
520done:
521 if (opt && opt != np->opt)
522 sock_kfree_s(sk, opt, opt->tot_len);
523 dst_release(dst);
524 return err;
525}
526
527static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
528 struct request_values *rvp)
529{
530 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
531 return tcp_v6_send_synack(sk, req, rvp);
532}
533
534static void tcp_v6_reqsk_destructor(struct request_sock *req)
535{
536 kfree_skb(inet6_rsk(req)->pktopts);
537}
538
539#ifdef CONFIG_TCP_MD5SIG
540static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
541 const struct in6_addr *addr)
542{
543 struct tcp_sock *tp = tcp_sk(sk);
544 int i;
545
546 BUG_ON(tp == NULL);
547
548 if (!tp->md5sig_info || !tp->md5sig_info->entries6)
549 return NULL;
550
551 for (i = 0; i < tp->md5sig_info->entries6; i++) {
552 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, addr))
553 return &tp->md5sig_info->keys6[i].base;
554 }
555 return NULL;
556}
557
558static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
559 struct sock *addr_sk)
560{
561 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
562}
563
564static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
565 struct request_sock *req)
566{
567 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
568}
569
570static int tcp_v6_md5_do_add(struct sock *sk, const struct in6_addr *peer,
571 char *newkey, u8 newkeylen)
572{
573 /* Add key to the list */
574 struct tcp_md5sig_key *key;
575 struct tcp_sock *tp = tcp_sk(sk);
576 struct tcp6_md5sig_key *keys;
577
578 key = tcp_v6_md5_do_lookup(sk, peer);
579 if (key) {
580 /* modify existing entry - just update that one */
581 kfree(key->key);
582 key->key = newkey;
583 key->keylen = newkeylen;
584 } else {
585 /* reallocate new list if current one is full. */
586 if (!tp->md5sig_info) {
587 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), GFP_ATOMIC);
588 if (!tp->md5sig_info) {
589 kfree(newkey);
590 return -ENOMEM;
591 }
592 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
593 }
594 if (tp->md5sig_info->entries6 == 0 &&
595 tcp_alloc_md5sig_pool(sk) == NULL) {
596 kfree(newkey);
597 return -ENOMEM;
598 }
599 if (tp->md5sig_info->alloced6 == tp->md5sig_info->entries6) {
600 keys = kmalloc((sizeof (tp->md5sig_info->keys6[0]) *
601 (tp->md5sig_info->entries6 + 1)), GFP_ATOMIC);
602
603 if (!keys) {
604 kfree(newkey);
605 if (tp->md5sig_info->entries6 == 0)
606 tcp_free_md5sig_pool();
607 return -ENOMEM;
608 }
609
610 if (tp->md5sig_info->entries6)
611 memmove(keys, tp->md5sig_info->keys6,
612 (sizeof (tp->md5sig_info->keys6[0]) *
613 tp->md5sig_info->entries6));
614
615 kfree(tp->md5sig_info->keys6);
616 tp->md5sig_info->keys6 = keys;
617 tp->md5sig_info->alloced6++;
618 }
619
620 ipv6_addr_copy(&tp->md5sig_info->keys6[tp->md5sig_info->entries6].addr,
621 peer);
622 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.key = newkey;
623 tp->md5sig_info->keys6[tp->md5sig_info->entries6].base.keylen = newkeylen;
624
625 tp->md5sig_info->entries6++;
626 }
627 return 0;
628}
629
630static int tcp_v6_md5_add_func(struct sock *sk, struct sock *addr_sk,
631 u8 *newkey, __u8 newkeylen)
632{
633 return tcp_v6_md5_do_add(sk, &inet6_sk(addr_sk)->daddr,
634 newkey, newkeylen);
635}
636
637static int tcp_v6_md5_do_del(struct sock *sk, const struct in6_addr *peer)
638{
639 struct tcp_sock *tp = tcp_sk(sk);
640 int i;
641
642 for (i = 0; i < tp->md5sig_info->entries6; i++) {
643 if (ipv6_addr_equal(&tp->md5sig_info->keys6[i].addr, peer)) {
644 /* Free the key */
645 kfree(tp->md5sig_info->keys6[i].base.key);
646 tp->md5sig_info->entries6--;
647
648 if (tp->md5sig_info->entries6 == 0) {
649 kfree(tp->md5sig_info->keys6);
650 tp->md5sig_info->keys6 = NULL;
651 tp->md5sig_info->alloced6 = 0;
652 tcp_free_md5sig_pool();
653 } else {
654 /* shrink the database */
655 if (tp->md5sig_info->entries6 != i)
656 memmove(&tp->md5sig_info->keys6[i],
657 &tp->md5sig_info->keys6[i+1],
658 (tp->md5sig_info->entries6 - i)
659 * sizeof (tp->md5sig_info->keys6[0]));
660 }
661 return 0;
662 }
663 }
664 return -ENOENT;
665}
666
667static void tcp_v6_clear_md5_list (struct sock *sk)
668{
669 struct tcp_sock *tp = tcp_sk(sk);
670 int i;
671
672 if (tp->md5sig_info->entries6) {
673 for (i = 0; i < tp->md5sig_info->entries6; i++)
674 kfree(tp->md5sig_info->keys6[i].base.key);
675 tp->md5sig_info->entries6 = 0;
676 tcp_free_md5sig_pool();
677 }
678
679 kfree(tp->md5sig_info->keys6);
680 tp->md5sig_info->keys6 = NULL;
681 tp->md5sig_info->alloced6 = 0;
682
683 if (tp->md5sig_info->entries4) {
684 for (i = 0; i < tp->md5sig_info->entries4; i++)
685 kfree(tp->md5sig_info->keys4[i].base.key);
686 tp->md5sig_info->entries4 = 0;
687 tcp_free_md5sig_pool();
688 }
689
690 kfree(tp->md5sig_info->keys4);
691 tp->md5sig_info->keys4 = NULL;
692 tp->md5sig_info->alloced4 = 0;
693}
694
695static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
696 int optlen)
697{
698 struct tcp_md5sig cmd;
699 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
700 u8 *newkey;
701
702 if (optlen < sizeof(cmd))
703 return -EINVAL;
704
705 if (copy_from_user(&cmd, optval, sizeof(cmd)))
706 return -EFAULT;
707
708 if (sin6->sin6_family != AF_INET6)
709 return -EINVAL;
710
711 if (!cmd.tcpm_keylen) {
712 if (!tcp_sk(sk)->md5sig_info)
713 return -ENOENT;
714 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
715 return tcp_v4_md5_do_del(sk, sin6->sin6_addr.s6_addr32[3]);
716 return tcp_v6_md5_do_del(sk, &sin6->sin6_addr);
717 }
718
719 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
720 return -EINVAL;
721
722 if (!tcp_sk(sk)->md5sig_info) {
723 struct tcp_sock *tp = tcp_sk(sk);
724 struct tcp_md5sig_info *p;
725
726 p = kzalloc(sizeof(struct tcp_md5sig_info), GFP_KERNEL);
727 if (!p)
728 return -ENOMEM;
729
730 tp->md5sig_info = p;
731 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
732 }
733
734 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
735 if (!newkey)
736 return -ENOMEM;
737 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
738 return tcp_v4_md5_do_add(sk, sin6->sin6_addr.s6_addr32[3],
739 newkey, cmd.tcpm_keylen);
740 }
741 return tcp_v6_md5_do_add(sk, &sin6->sin6_addr, newkey, cmd.tcpm_keylen);
742}
743
744static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
745 const struct in6_addr *daddr,
746 const struct in6_addr *saddr, int nbytes)
747{
748 struct tcp6_pseudohdr *bp;
749 struct scatterlist sg;
750
751 bp = &hp->md5_blk.ip6;
752 /* 1. TCP pseudo-header (RFC2460) */
753 ipv6_addr_copy(&bp->saddr, saddr);
754 ipv6_addr_copy(&bp->daddr, daddr);
755 bp->protocol = cpu_to_be32(IPPROTO_TCP);
756 bp->len = cpu_to_be32(nbytes);
757
758 sg_init_one(&sg, bp, sizeof(*bp));
759 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
760}
761
762static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
763 const struct in6_addr *daddr, struct in6_addr *saddr,
764 struct tcphdr *th)
765{
766 struct tcp_md5sig_pool *hp;
767 struct hash_desc *desc;
768
769 hp = tcp_get_md5sig_pool();
770 if (!hp)
771 goto clear_hash_noput;
772 desc = &hp->md5_desc;
773
774 if (crypto_hash_init(desc))
775 goto clear_hash;
776 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
777 goto clear_hash;
778 if (tcp_md5_hash_header(hp, th))
779 goto clear_hash;
780 if (tcp_md5_hash_key(hp, key))
781 goto clear_hash;
782 if (crypto_hash_final(desc, md5_hash))
783 goto clear_hash;
784
785 tcp_put_md5sig_pool();
786 return 0;
787
788clear_hash:
789 tcp_put_md5sig_pool();
790clear_hash_noput:
791 memset(md5_hash, 0, 16);
792 return 1;
793}
794
795static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
796 struct sock *sk, struct request_sock *req,
797 struct sk_buff *skb)
798{
799 const struct in6_addr *saddr, *daddr;
800 struct tcp_md5sig_pool *hp;
801 struct hash_desc *desc;
802 struct tcphdr *th = tcp_hdr(skb);
803
804 if (sk) {
805 saddr = &inet6_sk(sk)->saddr;
806 daddr = &inet6_sk(sk)->daddr;
807 } else if (req) {
808 saddr = &inet6_rsk(req)->loc_addr;
809 daddr = &inet6_rsk(req)->rmt_addr;
810 } else {
811 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
812 saddr = &ip6h->saddr;
813 daddr = &ip6h->daddr;
814 }
815
816 hp = tcp_get_md5sig_pool();
817 if (!hp)
818 goto clear_hash_noput;
819 desc = &hp->md5_desc;
820
821 if (crypto_hash_init(desc))
822 goto clear_hash;
823
824 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
825 goto clear_hash;
826 if (tcp_md5_hash_header(hp, th))
827 goto clear_hash;
828 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
829 goto clear_hash;
830 if (tcp_md5_hash_key(hp, key))
831 goto clear_hash;
832 if (crypto_hash_final(desc, md5_hash))
833 goto clear_hash;
834
835 tcp_put_md5sig_pool();
836 return 0;
837
838clear_hash:
839 tcp_put_md5sig_pool();
840clear_hash_noput:
841 memset(md5_hash, 0, 16);
842 return 1;
843}
844
845static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
846{
847 __u8 *hash_location = NULL;
848 struct tcp_md5sig_key *hash_expected;
849 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
850 struct tcphdr *th = tcp_hdr(skb);
851 int genhash;
852 u8 newhash[16];
853
854 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
855 hash_location = tcp_parse_md5sig_option(th);
856
857 /* We've parsed the options - do we have a hash? */
858 if (!hash_expected && !hash_location)
859 return 0;
860
861 if (hash_expected && !hash_location) {
862 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
863 return 1;
864 }
865
866 if (!hash_expected && hash_location) {
867 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
868 return 1;
869 }
870
871 /* check the signature */
872 genhash = tcp_v6_md5_hash_skb(newhash,
873 hash_expected,
874 NULL, NULL, skb);
875
876 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
877 if (net_ratelimit()) {
878 printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
879 genhash ? "failed" : "mismatch",
880 &ip6h->saddr, ntohs(th->source),
881 &ip6h->daddr, ntohs(th->dest));
882 }
883 return 1;
884 }
885 return 0;
886}
887#endif
888
889struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
890 .family = AF_INET6,
891 .obj_size = sizeof(struct tcp6_request_sock),
892 .rtx_syn_ack = tcp_v6_rtx_synack,
893 .send_ack = tcp_v6_reqsk_send_ack,
894 .destructor = tcp_v6_reqsk_destructor,
895 .send_reset = tcp_v6_send_reset,
896 .syn_ack_timeout = tcp_syn_ack_timeout,
897};
898
899#ifdef CONFIG_TCP_MD5SIG
900static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
901 .md5_lookup = tcp_v6_reqsk_md5_lookup,
902 .calc_md5_hash = tcp_v6_md5_hash_skb,
903};
904#endif
905
906static void __tcp_v6_send_check(struct sk_buff *skb,
907 const struct in6_addr *saddr, const struct in6_addr *daddr)
908{
909 struct tcphdr *th = tcp_hdr(skb);
910
911 if (skb->ip_summed == CHECKSUM_PARTIAL) {
912 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
913 skb->csum_start = skb_transport_header(skb) - skb->head;
914 skb->csum_offset = offsetof(struct tcphdr, check);
915 } else {
916 th->check = tcp_v6_check(skb->len, saddr, daddr,
917 csum_partial(th, th->doff << 2,
918 skb->csum));
919 }
920}
921
922static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
923{
924 struct ipv6_pinfo *np = inet6_sk(sk);
925
926 __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
927}
928
929static int tcp_v6_gso_send_check(struct sk_buff *skb)
930{
931 const struct ipv6hdr *ipv6h;
932 struct tcphdr *th;
933
934 if (!pskb_may_pull(skb, sizeof(*th)))
935 return -EINVAL;
936
937 ipv6h = ipv6_hdr(skb);
938 th = tcp_hdr(skb);
939
940 th->check = 0;
941 skb->ip_summed = CHECKSUM_PARTIAL;
942 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
943 return 0;
944}
945
946static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
947 struct sk_buff *skb)
948{
949 const struct ipv6hdr *iph = skb_gro_network_header(skb);
950
951 switch (skb->ip_summed) {
952 case CHECKSUM_COMPLETE:
953 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
954 skb->csum)) {
955 skb->ip_summed = CHECKSUM_UNNECESSARY;
956 break;
957 }
958
959 /* fall through */
960 case CHECKSUM_NONE:
961 NAPI_GRO_CB(skb)->flush = 1;
962 return NULL;
963 }
964
965 return tcp_gro_receive(head, skb);
966}
967
968static int tcp6_gro_complete(struct sk_buff *skb)
969{
970 const struct ipv6hdr *iph = ipv6_hdr(skb);
971 struct tcphdr *th = tcp_hdr(skb);
972
973 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
974 &iph->saddr, &iph->daddr, 0);
975 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
976
977 return tcp_gro_complete(skb);
978}
979
980static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
981 u32 ts, struct tcp_md5sig_key *key, int rst)
982{
983 struct tcphdr *th = tcp_hdr(skb), *t1;
984 struct sk_buff *buff;
985 struct flowi6 fl6;
986 struct net *net = dev_net(skb_dst(skb)->dev);
987 struct sock *ctl_sk = net->ipv6.tcp_sk;
988 unsigned int tot_len = sizeof(struct tcphdr);
989 struct dst_entry *dst;
990 __be32 *topt;
991
992 if (ts)
993 tot_len += TCPOLEN_TSTAMP_ALIGNED;
994#ifdef CONFIG_TCP_MD5SIG
995 if (key)
996 tot_len += TCPOLEN_MD5SIG_ALIGNED;
997#endif
998
999 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
1000 GFP_ATOMIC);
1001 if (buff == NULL)
1002 return;
1003
1004 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
1005
1006 t1 = (struct tcphdr *) skb_push(buff, tot_len);
1007 skb_reset_transport_header(buff);
1008
1009 /* Swap the send and the receive. */
1010 memset(t1, 0, sizeof(*t1));
1011 t1->dest = th->source;
1012 t1->source = th->dest;
1013 t1->doff = tot_len / 4;
1014 t1->seq = htonl(seq);
1015 t1->ack_seq = htonl(ack);
1016 t1->ack = !rst || !th->ack;
1017 t1->rst = rst;
1018 t1->window = htons(win);
1019
1020 topt = (__be32 *)(t1 + 1);
1021
1022 if (ts) {
1023 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1024 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1025 *topt++ = htonl(tcp_time_stamp);
1026 *topt++ = htonl(ts);
1027 }
1028
1029#ifdef CONFIG_TCP_MD5SIG
1030 if (key) {
1031 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1032 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
1033 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
1034 &ipv6_hdr(skb)->saddr,
1035 &ipv6_hdr(skb)->daddr, t1);
1036 }
1037#endif
1038
1039 memset(&fl6, 0, sizeof(fl6));
1040 ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
1041 ipv6_addr_copy(&fl6.saddr, &ipv6_hdr(skb)->daddr);
1042
1043 buff->ip_summed = CHECKSUM_PARTIAL;
1044 buff->csum = 0;
1045
1046 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
1047
1048 fl6.flowi6_proto = IPPROTO_TCP;
1049 fl6.flowi6_oif = inet6_iif(skb);
1050 fl6.fl6_dport = t1->dest;
1051 fl6.fl6_sport = t1->source;
1052 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
1053
1054 /* Pass a socket to ip6_dst_lookup either it is for RST
1055 * Underlying function will use this to retrieve the network
1056 * namespace
1057 */
1058 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
1059 if (!IS_ERR(dst)) {
1060 skb_dst_set(buff, dst);
1061 ip6_xmit(ctl_sk, buff, &fl6, NULL);
1062 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
1063 if (rst)
1064 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
1065 return;
1066 }
1067
1068 kfree_skb(buff);
1069}
1070
1071static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
1072{
1073 struct tcphdr *th = tcp_hdr(skb);
1074 u32 seq = 0, ack_seq = 0;
1075 struct tcp_md5sig_key *key = NULL;
1076
1077 if (th->rst)
1078 return;
1079
1080 if (!ipv6_unicast_destination(skb))
1081 return;
1082
1083#ifdef CONFIG_TCP_MD5SIG
1084 if (sk)
1085 key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr);
1086#endif
1087
1088 if (th->ack)
1089 seq = ntohl(th->ack_seq);
1090 else
1091 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1092 (th->doff << 2);
1093
1094 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1);
1095}
1096
1097static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
1098 struct tcp_md5sig_key *key)
1099{
1100 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0);
1101}
1102
1103static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1104{
1105 struct inet_timewait_sock *tw = inet_twsk(sk);
1106 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1107
1108 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1109 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1110 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw));
1111
1112 inet_twsk_put(tw);
1113}
1114
1115static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1116 struct request_sock *req)
1117{
1118 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1119 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr));
1120}
1121
1122
1123static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1124{
1125 struct request_sock *req, **prev;
1126 const struct tcphdr *th = tcp_hdr(skb);
1127 struct sock *nsk;
1128
1129 /* Find possible connection requests. */
1130 req = inet6_csk_search_req(sk, &prev, th->source,
1131 &ipv6_hdr(skb)->saddr,
1132 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1133 if (req)
1134 return tcp_check_req(sk, skb, req, prev);
1135
1136 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1137 &ipv6_hdr(skb)->saddr, th->source,
1138 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1139
1140 if (nsk) {
1141 if (nsk->sk_state != TCP_TIME_WAIT) {
1142 bh_lock_sock(nsk);
1143 return nsk;
1144 }
1145 inet_twsk_put(inet_twsk(nsk));
1146 return NULL;
1147 }
1148
1149#ifdef CONFIG_SYN_COOKIES
1150 if (!th->syn)
1151 sk = cookie_v6_check(sk, skb);
1152#endif
1153 return sk;
1154}
1155
1156/* FIXME: this is substantially similar to the ipv4 code.
1157 * Can some kind of merge be done? -- erics
1158 */
1159static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1160{
1161 struct tcp_extend_values tmp_ext;
1162 struct tcp_options_received tmp_opt;
1163 u8 *hash_location;
1164 struct request_sock *req;
1165 struct inet6_request_sock *treq;
1166 struct ipv6_pinfo *np = inet6_sk(sk);
1167 struct tcp_sock *tp = tcp_sk(sk);
1168 __u32 isn = TCP_SKB_CB(skb)->when;
1169 struct dst_entry *dst = NULL;
1170 int want_cookie = 0;
1171
1172 if (skb->protocol == htons(ETH_P_IP))
1173 return tcp_v4_conn_request(sk, skb);
1174
1175 if (!ipv6_unicast_destination(skb))
1176 goto drop;
1177
1178 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1179 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
1180 if (!want_cookie)
1181 goto drop;
1182 }
1183
1184 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1185 goto drop;
1186
1187 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1188 if (req == NULL)
1189 goto drop;
1190
1191#ifdef CONFIG_TCP_MD5SIG
1192 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1193#endif
1194
1195 tcp_clear_options(&tmp_opt);
1196 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1197 tmp_opt.user_mss = tp->rx_opt.user_mss;
1198 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1199
1200 if (tmp_opt.cookie_plus > 0 &&
1201 tmp_opt.saw_tstamp &&
1202 !tp->rx_opt.cookie_out_never &&
1203 (sysctl_tcp_cookie_size > 0 ||
1204 (tp->cookie_values != NULL &&
1205 tp->cookie_values->cookie_desired > 0))) {
1206 u8 *c;
1207 u32 *d;
1208 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1209 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1210
1211 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1212 goto drop_and_free;
1213
1214 /* Secret recipe starts with IP addresses */
1215 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1216 *mess++ ^= *d++;
1217 *mess++ ^= *d++;
1218 *mess++ ^= *d++;
1219 *mess++ ^= *d++;
1220 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1221 *mess++ ^= *d++;
1222 *mess++ ^= *d++;
1223 *mess++ ^= *d++;
1224 *mess++ ^= *d++;
1225
1226 /* plus variable length Initiator Cookie */
1227 c = (u8 *)mess;
1228 while (l-- > 0)
1229 *c++ ^= *hash_location++;
1230
1231 want_cookie = 0; /* not our kind of cookie */
1232 tmp_ext.cookie_out_never = 0; /* false */
1233 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1234 } else if (!tp->rx_opt.cookie_in_always) {
1235 /* redundant indications, but ensure initialization. */
1236 tmp_ext.cookie_out_never = 1; /* true */
1237 tmp_ext.cookie_plus = 0;
1238 } else {
1239 goto drop_and_free;
1240 }
1241 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1242
1243 if (want_cookie && !tmp_opt.saw_tstamp)
1244 tcp_clear_options(&tmp_opt);
1245
1246 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1247 tcp_openreq_init(req, &tmp_opt, skb);
1248
1249 treq = inet6_rsk(req);
1250 ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
1251 ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
1252 if (!want_cookie || tmp_opt.tstamp_ok)
1253 TCP_ECN_create_request(req, tcp_hdr(skb));
1254
1255 if (!isn) {
1256 struct inet_peer *peer = NULL;
1257
1258 if (ipv6_opt_accepted(sk, skb) ||
1259 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1260 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1261 atomic_inc(&skb->users);
1262 treq->pktopts = skb;
1263 }
1264 treq->iif = sk->sk_bound_dev_if;
1265
1266 /* So that link locals have meaning */
1267 if (!sk->sk_bound_dev_if &&
1268 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1269 treq->iif = inet6_iif(skb);
1270
1271 if (want_cookie) {
1272 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1273 req->cookie_ts = tmp_opt.tstamp_ok;
1274 goto have_isn;
1275 }
1276
1277 /* VJ's idea. We save last timestamp seen
1278 * from the destination in peer table, when entering
1279 * state TIME-WAIT, and check against it before
1280 * accepting new connection request.
1281 *
1282 * If "isn" is not zero, this request hit alive
1283 * timewait bucket, so that all the necessary checks
1284 * are made in the function processing timewait state.
1285 */
1286 if (tmp_opt.saw_tstamp &&
1287 tcp_death_row.sysctl_tw_recycle &&
1288 (dst = inet6_csk_route_req(sk, req)) != NULL &&
1289 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1290 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1291 &treq->rmt_addr)) {
1292 inet_peer_refcheck(peer);
1293 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1294 (s32)(peer->tcp_ts - req->ts_recent) >
1295 TCP_PAWS_WINDOW) {
1296 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1297 goto drop_and_release;
1298 }
1299 }
1300 /* Kill the following clause, if you dislike this way. */
1301 else if (!sysctl_tcp_syncookies &&
1302 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1303 (sysctl_max_syn_backlog >> 2)) &&
1304 (!peer || !peer->tcp_ts_stamp) &&
1305 (!dst || !dst_metric(dst, RTAX_RTT))) {
1306 /* Without syncookies last quarter of
1307 * backlog is filled with destinations,
1308 * proven to be alive.
1309 * It means that we continue to communicate
1310 * to destinations, already remembered
1311 * to the moment of synflood.
1312 */
1313 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1314 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1315 goto drop_and_release;
1316 }
1317
1318 isn = tcp_v6_init_sequence(skb);
1319 }
1320have_isn:
1321 tcp_rsk(req)->snt_isn = isn;
1322 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1323
1324 security_inet_conn_request(sk, skb, req);
1325
1326 if (tcp_v6_send_synack(sk, req,
1327 (struct request_values *)&tmp_ext) ||
1328 want_cookie)
1329 goto drop_and_free;
1330
1331 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1332 return 0;
1333
1334drop_and_release:
1335 dst_release(dst);
1336drop_and_free:
1337 reqsk_free(req);
1338drop:
1339 return 0; /* don't send reset */
1340}
1341
1342static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1343 struct request_sock *req,
1344 struct dst_entry *dst)
1345{
1346 struct inet6_request_sock *treq;
1347 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1348 struct tcp6_sock *newtcp6sk;
1349 struct inet_sock *newinet;
1350 struct tcp_sock *newtp;
1351 struct sock *newsk;
1352 struct ipv6_txoptions *opt;
1353#ifdef CONFIG_TCP_MD5SIG
1354 struct tcp_md5sig_key *key;
1355#endif
1356
1357 if (skb->protocol == htons(ETH_P_IP)) {
1358 /*
1359 * v6 mapped
1360 */
1361
1362 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1363
1364 if (newsk == NULL)
1365 return NULL;
1366
1367 newtcp6sk = (struct tcp6_sock *)newsk;
1368 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1369
1370 newinet = inet_sk(newsk);
1371 newnp = inet6_sk(newsk);
1372 newtp = tcp_sk(newsk);
1373
1374 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1375
1376 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1377
1378 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1379
1380 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
1381
1382 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1383 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1384#ifdef CONFIG_TCP_MD5SIG
1385 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1386#endif
1387
1388 newnp->ipv6_ac_list = NULL;
1389 newnp->ipv6_fl_list = NULL;
1390 newnp->pktoptions = NULL;
1391 newnp->opt = NULL;
1392 newnp->mcast_oif = inet6_iif(skb);
1393 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1394
1395 /*
1396 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1397 * here, tcp_create_openreq_child now does this for us, see the comment in
1398 * that function for the gory details. -acme
1399 */
1400
1401 /* It is tricky place. Until this moment IPv4 tcp
1402 worked with IPv6 icsk.icsk_af_ops.
1403 Sync it now.
1404 */
1405 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1406
1407 return newsk;
1408 }
1409
1410 treq = inet6_rsk(req);
1411 opt = np->opt;
1412
1413 if (sk_acceptq_is_full(sk))
1414 goto out_overflow;
1415
1416 if (!dst) {
1417 dst = inet6_csk_route_req(sk, req);
1418 if (!dst)
1419 goto out;
1420 }
1421
1422 newsk = tcp_create_openreq_child(sk, req, skb);
1423 if (newsk == NULL)
1424 goto out_nonewsk;
1425
1426 /*
1427 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1428 * count here, tcp_create_openreq_child now does this for us, see the
1429 * comment in that function for the gory details. -acme
1430 */
1431
1432 newsk->sk_gso_type = SKB_GSO_TCPV6;
1433 __ip6_dst_store(newsk, dst, NULL, NULL);
1434
1435 newtcp6sk = (struct tcp6_sock *)newsk;
1436 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1437
1438 newtp = tcp_sk(newsk);
1439 newinet = inet_sk(newsk);
1440 newnp = inet6_sk(newsk);
1441
1442 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1443
1444 ipv6_addr_copy(&newnp->daddr, &treq->rmt_addr);
1445 ipv6_addr_copy(&newnp->saddr, &treq->loc_addr);
1446 ipv6_addr_copy(&newnp->rcv_saddr, &treq->loc_addr);
1447 newsk->sk_bound_dev_if = treq->iif;
1448
1449 /* Now IPv6 options...
1450
1451 First: no IPv4 options.
1452 */
1453 newinet->inet_opt = NULL;
1454 newnp->ipv6_ac_list = NULL;
1455 newnp->ipv6_fl_list = NULL;
1456
1457 /* Clone RX bits */
1458 newnp->rxopt.all = np->rxopt.all;
1459
1460 /* Clone pktoptions received with SYN */
1461 newnp->pktoptions = NULL;
1462 if (treq->pktopts != NULL) {
1463 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1464 kfree_skb(treq->pktopts);
1465 treq->pktopts = NULL;
1466 if (newnp->pktoptions)
1467 skb_set_owner_r(newnp->pktoptions, newsk);
1468 }
1469 newnp->opt = NULL;
1470 newnp->mcast_oif = inet6_iif(skb);
1471 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1472
1473 /* Clone native IPv6 options from listening socket (if any)
1474
1475 Yes, keeping reference count would be much more clever,
1476 but we make one more one thing there: reattach optmem
1477 to newsk.
1478 */
1479 if (opt) {
1480 newnp->opt = ipv6_dup_options(newsk, opt);
1481 if (opt != np->opt)
1482 sock_kfree_s(sk, opt, opt->tot_len);
1483 }
1484
1485 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1486 if (newnp->opt)
1487 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1488 newnp->opt->opt_flen);
1489
1490 tcp_mtup_init(newsk);
1491 tcp_sync_mss(newsk, dst_mtu(dst));
1492 newtp->advmss = dst_metric_advmss(dst);
1493 tcp_initialize_rcv_mss(newsk);
1494 if (tcp_rsk(req)->snt_synack)
1495 tcp_valid_rtt_meas(newsk,
1496 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1497 newtp->total_retrans = req->retrans;
1498
1499 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1500 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1501
1502#ifdef CONFIG_TCP_MD5SIG
1503 /* Copy over the MD5 key from the original socket */
1504 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1505 /* We're using one, so create a matching key
1506 * on the newsk structure. If we fail to get
1507 * memory, then we end up not copying the key
1508 * across. Shucks.
1509 */
1510 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1511 if (newkey != NULL)
1512 tcp_v6_md5_do_add(newsk, &newnp->daddr,
1513 newkey, key->keylen);
1514 }
1515#endif
1516
1517 if (__inet_inherit_port(sk, newsk) < 0) {
1518 sock_put(newsk);
1519 goto out;
1520 }
1521 __inet6_hash(newsk, NULL);
1522
1523 return newsk;
1524
1525out_overflow:
1526 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1527out_nonewsk:
1528 if (opt && opt != np->opt)
1529 sock_kfree_s(sk, opt, opt->tot_len);
1530 dst_release(dst);
1531out:
1532 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1533 return NULL;
1534}
1535
1536static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1537{
1538 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1539 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1540 &ipv6_hdr(skb)->daddr, skb->csum)) {
1541 skb->ip_summed = CHECKSUM_UNNECESSARY;
1542 return 0;
1543 }
1544 }
1545
1546 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1547 &ipv6_hdr(skb)->saddr,
1548 &ipv6_hdr(skb)->daddr, 0));
1549
1550 if (skb->len <= 76) {
1551 return __skb_checksum_complete(skb);
1552 }
1553 return 0;
1554}
1555
1556/* The socket must have it's spinlock held when we get
1557 * here.
1558 *
1559 * We have a potential double-lock case here, so even when
1560 * doing backlog processing we use the BH locking scheme.
1561 * This is because we cannot sleep with the original spinlock
1562 * held.
1563 */
1564static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1565{
1566 struct ipv6_pinfo *np = inet6_sk(sk);
1567 struct tcp_sock *tp;
1568 struct sk_buff *opt_skb = NULL;
1569
1570 /* Imagine: socket is IPv6. IPv4 packet arrives,
1571 goes to IPv4 receive handler and backlogged.
1572 From backlog it always goes here. Kerboom...
1573 Fortunately, tcp_rcv_established and rcv_established
1574 handle them correctly, but it is not case with
1575 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1576 */
1577
1578 if (skb->protocol == htons(ETH_P_IP))
1579 return tcp_v4_do_rcv(sk, skb);
1580
1581#ifdef CONFIG_TCP_MD5SIG
1582 if (tcp_v6_inbound_md5_hash (sk, skb))
1583 goto discard;
1584#endif
1585
1586 if (sk_filter(sk, skb))
1587 goto discard;
1588
1589 /*
1590 * socket locking is here for SMP purposes as backlog rcv
1591 * is currently called with bh processing disabled.
1592 */
1593
1594 /* Do Stevens' IPV6_PKTOPTIONS.
1595
1596 Yes, guys, it is the only place in our code, where we
1597 may make it not affecting IPv4.
1598 The rest of code is protocol independent,
1599 and I do not like idea to uglify IPv4.
1600
1601 Actually, all the idea behind IPV6_PKTOPTIONS
1602 looks not very well thought. For now we latch
1603 options, received in the last packet, enqueued
1604 by tcp. Feel free to propose better solution.
1605 --ANK (980728)
1606 */
1607 if (np->rxopt.all)
1608 opt_skb = skb_clone(skb, GFP_ATOMIC);
1609
1610 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1611 sock_rps_save_rxhash(sk, skb->rxhash);
1612 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1613 goto reset;
1614 if (opt_skb)
1615 goto ipv6_pktoptions;
1616 return 0;
1617 }
1618
1619 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1620 goto csum_err;
1621
1622 if (sk->sk_state == TCP_LISTEN) {
1623 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1624 if (!nsk)
1625 goto discard;
1626
1627 /*
1628 * Queue it on the new socket if the new socket is active,
1629 * otherwise we just shortcircuit this and continue with
1630 * the new socket..
1631 */
1632 if(nsk != sk) {
1633 sock_rps_save_rxhash(nsk, skb->rxhash);
1634 if (tcp_child_process(sk, nsk, skb))
1635 goto reset;
1636 if (opt_skb)
1637 __kfree_skb(opt_skb);
1638 return 0;
1639 }
1640 } else
1641 sock_rps_save_rxhash(sk, skb->rxhash);
1642
1643 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1644 goto reset;
1645 if (opt_skb)
1646 goto ipv6_pktoptions;
1647 return 0;
1648
1649reset:
1650 tcp_v6_send_reset(sk, skb);
1651discard:
1652 if (opt_skb)
1653 __kfree_skb(opt_skb);
1654 kfree_skb(skb);
1655 return 0;
1656csum_err:
1657 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1658 goto discard;
1659
1660
1661ipv6_pktoptions:
1662 /* Do you ask, what is it?
1663
1664 1. skb was enqueued by tcp.
1665 2. skb is added to tail of read queue, rather than out of order.
1666 3. socket is not in passive state.
1667 4. Finally, it really contains options, which user wants to receive.
1668 */
1669 tp = tcp_sk(sk);
1670 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1671 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1672 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1673 np->mcast_oif = inet6_iif(opt_skb);
1674 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1675 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1676 if (ipv6_opt_accepted(sk, opt_skb)) {
1677 skb_set_owner_r(opt_skb, sk);
1678 opt_skb = xchg(&np->pktoptions, opt_skb);
1679 } else {
1680 __kfree_skb(opt_skb);
1681 opt_skb = xchg(&np->pktoptions, NULL);
1682 }
1683 }
1684
1685 kfree_skb(opt_skb);
1686 return 0;
1687}
1688
1689static int tcp_v6_rcv(struct sk_buff *skb)
1690{
1691 struct tcphdr *th;
1692 const struct ipv6hdr *hdr;
1693 struct sock *sk;
1694 int ret;
1695 struct net *net = dev_net(skb->dev);
1696
1697 if (skb->pkt_type != PACKET_HOST)
1698 goto discard_it;
1699
1700 /*
1701 * Count it even if it's bad.
1702 */
1703 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1704
1705 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1706 goto discard_it;
1707
1708 th = tcp_hdr(skb);
1709
1710 if (th->doff < sizeof(struct tcphdr)/4)
1711 goto bad_packet;
1712 if (!pskb_may_pull(skb, th->doff*4))
1713 goto discard_it;
1714
1715 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1716 goto bad_packet;
1717
1718 th = tcp_hdr(skb);
1719 hdr = ipv6_hdr(skb);
1720 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1721 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1722 skb->len - th->doff*4);
1723 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1724 TCP_SKB_CB(skb)->when = 0;
1725 TCP_SKB_CB(skb)->flags = ipv6_get_dsfield(hdr);
1726 TCP_SKB_CB(skb)->sacked = 0;
1727
1728 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1729 if (!sk)
1730 goto no_tcp_socket;
1731
1732process:
1733 if (sk->sk_state == TCP_TIME_WAIT)
1734 goto do_time_wait;
1735
1736 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1737 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1738 goto discard_and_relse;
1739 }
1740
1741 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1742 goto discard_and_relse;
1743
1744 if (sk_filter(sk, skb))
1745 goto discard_and_relse;
1746
1747 skb->dev = NULL;
1748
1749 bh_lock_sock_nested(sk);
1750 ret = 0;
1751 if (!sock_owned_by_user(sk)) {
1752#ifdef CONFIG_NET_DMA
1753 struct tcp_sock *tp = tcp_sk(sk);
1754 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1755 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1756 if (tp->ucopy.dma_chan)
1757 ret = tcp_v6_do_rcv(sk, skb);
1758 else
1759#endif
1760 {
1761 if (!tcp_prequeue(sk, skb))
1762 ret = tcp_v6_do_rcv(sk, skb);
1763 }
1764 } else if (unlikely(sk_add_backlog(sk, skb))) {
1765 bh_unlock_sock(sk);
1766 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1767 goto discard_and_relse;
1768 }
1769 bh_unlock_sock(sk);
1770
1771 sock_put(sk);
1772 return ret ? -1 : 0;
1773
1774no_tcp_socket:
1775 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1776 goto discard_it;
1777
1778 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1779bad_packet:
1780 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1781 } else {
1782 tcp_v6_send_reset(NULL, skb);
1783 }
1784
1785discard_it:
1786
1787 /*
1788 * Discard frame
1789 */
1790
1791 kfree_skb(skb);
1792 return 0;
1793
1794discard_and_relse:
1795 sock_put(sk);
1796 goto discard_it;
1797
1798do_time_wait:
1799 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1800 inet_twsk_put(inet_twsk(sk));
1801 goto discard_it;
1802 }
1803
1804 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1805 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1806 inet_twsk_put(inet_twsk(sk));
1807 goto discard_it;
1808 }
1809
1810 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1811 case TCP_TW_SYN:
1812 {
1813 struct sock *sk2;
1814
1815 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1816 &ipv6_hdr(skb)->daddr,
1817 ntohs(th->dest), inet6_iif(skb));
1818 if (sk2 != NULL) {
1819 struct inet_timewait_sock *tw = inet_twsk(sk);
1820 inet_twsk_deschedule(tw, &tcp_death_row);
1821 inet_twsk_put(tw);
1822 sk = sk2;
1823 goto process;
1824 }
1825 /* Fall through to ACK */
1826 }
1827 case TCP_TW_ACK:
1828 tcp_v6_timewait_ack(sk, skb);
1829 break;
1830 case TCP_TW_RST:
1831 goto no_tcp_socket;
1832 case TCP_TW_SUCCESS:;
1833 }
1834 goto discard_it;
1835}
1836
1837static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1838{
1839 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1840 struct ipv6_pinfo *np = inet6_sk(sk);
1841 struct inet_peer *peer;
1842
1843 if (!rt ||
1844 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1845 peer = inet_getpeer_v6(&np->daddr, 1);
1846 *release_it = true;
1847 } else {
1848 if (!rt->rt6i_peer)
1849 rt6_bind_peer(rt, 1);
1850 peer = rt->rt6i_peer;
1851 *release_it = false;
1852 }
1853
1854 return peer;
1855}
1856
1857static void *tcp_v6_tw_get_peer(struct sock *sk)
1858{
1859 struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1860 struct inet_timewait_sock *tw = inet_twsk(sk);
1861
1862 if (tw->tw_family == AF_INET)
1863 return tcp_v4_tw_get_peer(sk);
1864
1865 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1866}
1867
1868static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1869 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1870 .twsk_unique = tcp_twsk_unique,
1871 .twsk_destructor= tcp_twsk_destructor,
1872 .twsk_getpeer = tcp_v6_tw_get_peer,
1873};
1874
1875static const struct inet_connection_sock_af_ops ipv6_specific = {
1876 .queue_xmit = inet6_csk_xmit,
1877 .send_check = tcp_v6_send_check,
1878 .rebuild_header = inet6_sk_rebuild_header,
1879 .conn_request = tcp_v6_conn_request,
1880 .syn_recv_sock = tcp_v6_syn_recv_sock,
1881 .get_peer = tcp_v6_get_peer,
1882 .net_header_len = sizeof(struct ipv6hdr),
1883 .setsockopt = ipv6_setsockopt,
1884 .getsockopt = ipv6_getsockopt,
1885 .addr2sockaddr = inet6_csk_addr2sockaddr,
1886 .sockaddr_len = sizeof(struct sockaddr_in6),
1887 .bind_conflict = inet6_csk_bind_conflict,
1888#ifdef CONFIG_COMPAT
1889 .compat_setsockopt = compat_ipv6_setsockopt,
1890 .compat_getsockopt = compat_ipv6_getsockopt,
1891#endif
1892};
1893
1894#ifdef CONFIG_TCP_MD5SIG
1895static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1896 .md5_lookup = tcp_v6_md5_lookup,
1897 .calc_md5_hash = tcp_v6_md5_hash_skb,
1898 .md5_add = tcp_v6_md5_add_func,
1899 .md5_parse = tcp_v6_parse_md5_keys,
1900};
1901#endif
1902
1903/*
1904 * TCP over IPv4 via INET6 API
1905 */
1906
1907static const struct inet_connection_sock_af_ops ipv6_mapped = {
1908 .queue_xmit = ip_queue_xmit,
1909 .send_check = tcp_v4_send_check,
1910 .rebuild_header = inet_sk_rebuild_header,
1911 .conn_request = tcp_v6_conn_request,
1912 .syn_recv_sock = tcp_v6_syn_recv_sock,
1913 .get_peer = tcp_v4_get_peer,
1914 .net_header_len = sizeof(struct iphdr),
1915 .setsockopt = ipv6_setsockopt,
1916 .getsockopt = ipv6_getsockopt,
1917 .addr2sockaddr = inet6_csk_addr2sockaddr,
1918 .sockaddr_len = sizeof(struct sockaddr_in6),
1919 .bind_conflict = inet6_csk_bind_conflict,
1920#ifdef CONFIG_COMPAT
1921 .compat_setsockopt = compat_ipv6_setsockopt,
1922 .compat_getsockopt = compat_ipv6_getsockopt,
1923#endif
1924};
1925
1926#ifdef CONFIG_TCP_MD5SIG
1927static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1928 .md5_lookup = tcp_v4_md5_lookup,
1929 .calc_md5_hash = tcp_v4_md5_hash_skb,
1930 .md5_add = tcp_v6_md5_add_func,
1931 .md5_parse = tcp_v6_parse_md5_keys,
1932};
1933#endif
1934
1935/* NOTE: A lot of things set to zero explicitly by call to
1936 * sk_alloc() so need not be done here.
1937 */
1938static int tcp_v6_init_sock(struct sock *sk)
1939{
1940 struct inet_connection_sock *icsk = inet_csk(sk);
1941 struct tcp_sock *tp = tcp_sk(sk);
1942
1943 skb_queue_head_init(&tp->out_of_order_queue);
1944 tcp_init_xmit_timers(sk);
1945 tcp_prequeue_init(tp);
1946
1947 icsk->icsk_rto = TCP_TIMEOUT_INIT;
1948 tp->mdev = TCP_TIMEOUT_INIT;
1949
1950 /* So many TCP implementations out there (incorrectly) count the
1951 * initial SYN frame in their delayed-ACK and congestion control
1952 * algorithms that we must have the following bandaid to talk
1953 * efficiently to them. -DaveM
1954 */
1955 tp->snd_cwnd = 2;
1956
1957 /* See draft-stevens-tcpca-spec-01 for discussion of the
1958 * initialization of these values.
1959 */
1960 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1961 tp->snd_cwnd_clamp = ~0;
1962 tp->mss_cache = TCP_MSS_DEFAULT;
1963
1964 tp->reordering = sysctl_tcp_reordering;
1965
1966 sk->sk_state = TCP_CLOSE;
1967
1968 icsk->icsk_af_ops = &ipv6_specific;
1969 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1970 icsk->icsk_sync_mss = tcp_sync_mss;
1971 sk->sk_write_space = sk_stream_write_space;
1972 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1973
1974#ifdef CONFIG_TCP_MD5SIG
1975 tp->af_specific = &tcp_sock_ipv6_specific;
1976#endif
1977
1978 /* TCP Cookie Transactions */
1979 if (sysctl_tcp_cookie_size > 0) {
1980 /* Default, cookies without s_data_payload. */
1981 tp->cookie_values =
1982 kzalloc(sizeof(*tp->cookie_values),
1983 sk->sk_allocation);
1984 if (tp->cookie_values != NULL)
1985 kref_init(&tp->cookie_values->kref);
1986 }
1987 /* Presumed zeroed, in order of appearance:
1988 * cookie_in_always, cookie_out_never,
1989 * s_data_constant, s_data_in, s_data_out
1990 */
1991 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1992 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1993
1994 local_bh_disable();
1995 percpu_counter_inc(&tcp_sockets_allocated);
1996 local_bh_enable();
1997
1998 return 0;
1999}
2000
2001static void tcp_v6_destroy_sock(struct sock *sk)
2002{
2003#ifdef CONFIG_TCP_MD5SIG
2004 /* Clean up the MD5 key list */
2005 if (tcp_sk(sk)->md5sig_info)
2006 tcp_v6_clear_md5_list(sk);
2007#endif
2008 tcp_v4_destroy_sock(sk);
2009 inet6_destroy_sock(sk);
2010}
2011
2012#ifdef CONFIG_PROC_FS
2013/* Proc filesystem TCPv6 sock list dumping. */
2014static void get_openreq6(struct seq_file *seq,
2015 struct sock *sk, struct request_sock *req, int i, int uid)
2016{
2017 int ttd = req->expires - jiffies;
2018 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
2019 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
2020
2021 if (ttd < 0)
2022 ttd = 0;
2023
2024 seq_printf(seq,
2025 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2026 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2027 i,
2028 src->s6_addr32[0], src->s6_addr32[1],
2029 src->s6_addr32[2], src->s6_addr32[3],
2030 ntohs(inet_rsk(req)->loc_port),
2031 dest->s6_addr32[0], dest->s6_addr32[1],
2032 dest->s6_addr32[2], dest->s6_addr32[3],
2033 ntohs(inet_rsk(req)->rmt_port),
2034 TCP_SYN_RECV,
2035 0,0, /* could print option size, but that is af dependent. */
2036 1, /* timers active (only the expire timer) */
2037 jiffies_to_clock_t(ttd),
2038 req->retrans,
2039 uid,
2040 0, /* non standard timer */
2041 0, /* open_requests have no inode */
2042 0, req);
2043}
2044
2045static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2046{
2047 const struct in6_addr *dest, *src;
2048 __u16 destp, srcp;
2049 int timer_active;
2050 unsigned long timer_expires;
2051 struct inet_sock *inet = inet_sk(sp);
2052 struct tcp_sock *tp = tcp_sk(sp);
2053 const struct inet_connection_sock *icsk = inet_csk(sp);
2054 struct ipv6_pinfo *np = inet6_sk(sp);
2055
2056 dest = &np->daddr;
2057 src = &np->rcv_saddr;
2058 destp = ntohs(inet->inet_dport);
2059 srcp = ntohs(inet->inet_sport);
2060
2061 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2062 timer_active = 1;
2063 timer_expires = icsk->icsk_timeout;
2064 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2065 timer_active = 4;
2066 timer_expires = icsk->icsk_timeout;
2067 } else if (timer_pending(&sp->sk_timer)) {
2068 timer_active = 2;
2069 timer_expires = sp->sk_timer.expires;
2070 } else {
2071 timer_active = 0;
2072 timer_expires = jiffies;
2073 }
2074
2075 seq_printf(seq,
2076 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2077 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
2078 i,
2079 src->s6_addr32[0], src->s6_addr32[1],
2080 src->s6_addr32[2], src->s6_addr32[3], srcp,
2081 dest->s6_addr32[0], dest->s6_addr32[1],
2082 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2083 sp->sk_state,
2084 tp->write_seq-tp->snd_una,
2085 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
2086 timer_active,
2087 jiffies_to_clock_t(timer_expires - jiffies),
2088 icsk->icsk_retransmits,
2089 sock_i_uid(sp),
2090 icsk->icsk_probes_out,
2091 sock_i_ino(sp),
2092 atomic_read(&sp->sk_refcnt), sp,
2093 jiffies_to_clock_t(icsk->icsk_rto),
2094 jiffies_to_clock_t(icsk->icsk_ack.ato),
2095 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
2096 tp->snd_cwnd,
2097 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
2098 );
2099}
2100
2101static void get_timewait6_sock(struct seq_file *seq,
2102 struct inet_timewait_sock *tw, int i)
2103{
2104 const struct in6_addr *dest, *src;
2105 __u16 destp, srcp;
2106 struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
2107 int ttd = tw->tw_ttd - jiffies;
2108
2109 if (ttd < 0)
2110 ttd = 0;
2111
2112 dest = &tw6->tw_v6_daddr;
2113 src = &tw6->tw_v6_rcv_saddr;
2114 destp = ntohs(tw->tw_dport);
2115 srcp = ntohs(tw->tw_sport);
2116
2117 seq_printf(seq,
2118 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2119 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2120 i,
2121 src->s6_addr32[0], src->s6_addr32[1],
2122 src->s6_addr32[2], src->s6_addr32[3], srcp,
2123 dest->s6_addr32[0], dest->s6_addr32[1],
2124 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2125 tw->tw_substate, 0, 0,
2126 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2127 atomic_read(&tw->tw_refcnt), tw);
2128}
2129
2130static int tcp6_seq_show(struct seq_file *seq, void *v)
2131{
2132 struct tcp_iter_state *st;
2133
2134 if (v == SEQ_START_TOKEN) {
2135 seq_puts(seq,
2136 " sl "
2137 "local_address "
2138 "remote_address "
2139 "st tx_queue rx_queue tr tm->when retrnsmt"
2140 " uid timeout inode\n");
2141 goto out;
2142 }
2143 st = seq->private;
2144
2145 switch (st->state) {
2146 case TCP_SEQ_STATE_LISTENING:
2147 case TCP_SEQ_STATE_ESTABLISHED:
2148 get_tcp6_sock(seq, v, st->num);
2149 break;
2150 case TCP_SEQ_STATE_OPENREQ:
2151 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2152 break;
2153 case TCP_SEQ_STATE_TIME_WAIT:
2154 get_timewait6_sock(seq, v, st->num);
2155 break;
2156 }
2157out:
2158 return 0;
2159}
2160
2161static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2162 .name = "tcp6",
2163 .family = AF_INET6,
2164 .seq_fops = {
2165 .owner = THIS_MODULE,
2166 },
2167 .seq_ops = {
2168 .show = tcp6_seq_show,
2169 },
2170};
2171
2172int __net_init tcp6_proc_init(struct net *net)
2173{
2174 return tcp_proc_register(net, &tcp6_seq_afinfo);
2175}
2176
2177void tcp6_proc_exit(struct net *net)
2178{
2179 tcp_proc_unregister(net, &tcp6_seq_afinfo);
2180}
2181#endif
2182
2183struct proto tcpv6_prot = {
2184 .name = "TCPv6",
2185 .owner = THIS_MODULE,
2186 .close = tcp_close,
2187 .connect = tcp_v6_connect,
2188 .disconnect = tcp_disconnect,
2189 .accept = inet_csk_accept,
2190 .ioctl = tcp_ioctl,
2191 .init = tcp_v6_init_sock,
2192 .destroy = tcp_v6_destroy_sock,
2193 .shutdown = tcp_shutdown,
2194 .setsockopt = tcp_setsockopt,
2195 .getsockopt = tcp_getsockopt,
2196 .recvmsg = tcp_recvmsg,
2197 .sendmsg = tcp_sendmsg,
2198 .sendpage = tcp_sendpage,
2199 .backlog_rcv = tcp_v6_do_rcv,
2200 .hash = tcp_v6_hash,
2201 .unhash = inet_unhash,
2202 .get_port = inet_csk_get_port,
2203 .enter_memory_pressure = tcp_enter_memory_pressure,
2204 .sockets_allocated = &tcp_sockets_allocated,
2205 .memory_allocated = &tcp_memory_allocated,
2206 .memory_pressure = &tcp_memory_pressure,
2207 .orphan_count = &tcp_orphan_count,
2208 .sysctl_mem = sysctl_tcp_mem,
2209 .sysctl_wmem = sysctl_tcp_wmem,
2210 .sysctl_rmem = sysctl_tcp_rmem,
2211 .max_header = MAX_TCP_HEADER,
2212 .obj_size = sizeof(struct tcp6_sock),
2213 .slab_flags = SLAB_DESTROY_BY_RCU,
2214 .twsk_prot = &tcp6_timewait_sock_ops,
2215 .rsk_prot = &tcp6_request_sock_ops,
2216 .h.hashinfo = &tcp_hashinfo,
2217 .no_autobind = true,
2218#ifdef CONFIG_COMPAT
2219 .compat_setsockopt = compat_tcp_setsockopt,
2220 .compat_getsockopt = compat_tcp_getsockopt,
2221#endif
2222};
2223
2224static const struct inet6_protocol tcpv6_protocol = {
2225 .handler = tcp_v6_rcv,
2226 .err_handler = tcp_v6_err,
2227 .gso_send_check = tcp_v6_gso_send_check,
2228 .gso_segment = tcp_tso_segment,
2229 .gro_receive = tcp6_gro_receive,
2230 .gro_complete = tcp6_gro_complete,
2231 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2232};
2233
2234static struct inet_protosw tcpv6_protosw = {
2235 .type = SOCK_STREAM,
2236 .protocol = IPPROTO_TCP,
2237 .prot = &tcpv6_prot,
2238 .ops = &inet6_stream_ops,
2239 .no_check = 0,
2240 .flags = INET_PROTOSW_PERMANENT |
2241 INET_PROTOSW_ICSK,
2242};
2243
2244static int __net_init tcpv6_net_init(struct net *net)
2245{
2246 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2247 SOCK_RAW, IPPROTO_TCP, net);
2248}
2249
2250static void __net_exit tcpv6_net_exit(struct net *net)
2251{
2252 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2253}
2254
2255static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2256{
2257 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2258}
2259
2260static struct pernet_operations tcpv6_net_ops = {
2261 .init = tcpv6_net_init,
2262 .exit = tcpv6_net_exit,
2263 .exit_batch = tcpv6_net_exit_batch,
2264};
2265
2266int __init tcpv6_init(void)
2267{
2268 int ret;
2269
2270 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2271 if (ret)
2272 goto out;
2273
2274 /* register inet6 protocol */
2275 ret = inet6_register_protosw(&tcpv6_protosw);
2276 if (ret)
2277 goto out_tcpv6_protocol;
2278
2279 ret = register_pernet_subsys(&tcpv6_net_ops);
2280 if (ret)
2281 goto out_tcpv6_protosw;
2282out:
2283 return ret;
2284
2285out_tcpv6_protocol:
2286 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2287out_tcpv6_protosw:
2288 inet6_unregister_protosw(&tcpv6_protosw);
2289 goto out;
2290}
2291
2292void tcpv6_exit(void)
2293{
2294 unregister_pernet_subsys(&tcpv6_net_ops);
2295 inet6_unregister_protosw(&tcpv6_protosw);
2296 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2297}