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1/*
2 * TCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on:
9 * linux/net/ipv4/tcp.c
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
12 *
13 * Fixes:
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26#include <linux/bottom_half.h>
27#include <linux/module.h>
28#include <linux/errno.h>
29#include <linux/types.h>
30#include <linux/socket.h>
31#include <linux/sockios.h>
32#include <linux/net.h>
33#include <linux/jiffies.h>
34#include <linux/in.h>
35#include <linux/in6.h>
36#include <linux/netdevice.h>
37#include <linux/init.h>
38#include <linux/jhash.h>
39#include <linux/ipsec.h>
40#include <linux/times.h>
41#include <linux/slab.h>
42#include <linux/uaccess.h>
43#include <linux/ipv6.h>
44#include <linux/icmpv6.h>
45#include <linux/random.h>
46
47#include <net/tcp.h>
48#include <net/ndisc.h>
49#include <net/inet6_hashtables.h>
50#include <net/inet6_connection_sock.h>
51#include <net/ipv6.h>
52#include <net/transp_v6.h>
53#include <net/addrconf.h>
54#include <net/ip6_route.h>
55#include <net/ip6_checksum.h>
56#include <net/inet_ecn.h>
57#include <net/protocol.h>
58#include <net/xfrm.h>
59#include <net/snmp.h>
60#include <net/dsfield.h>
61#include <net/timewait_sock.h>
62#include <net/netdma.h>
63#include <net/inet_common.h>
64#include <net/secure_seq.h>
65#include <net/tcp_memcontrol.h>
66#include <net/busy_poll.h>
67
68#include <linux/proc_fs.h>
69#include <linux/seq_file.h>
70
71#include <linux/crypto.h>
72#include <linux/scatterlist.h>
73
74static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
75static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
76 struct request_sock *req);
77
78static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
79
80static const struct inet_connection_sock_af_ops ipv6_mapped;
81static const struct inet_connection_sock_af_ops ipv6_specific;
82#ifdef CONFIG_TCP_MD5SIG
83static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
84static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
85#else
86static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
87 const struct in6_addr *addr)
88{
89 return NULL;
90}
91#endif
92
93static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
94{
95 struct dst_entry *dst = skb_dst(skb);
96 const struct rt6_info *rt = (const struct rt6_info *)dst;
97
98 dst_hold(dst);
99 sk->sk_rx_dst = dst;
100 inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
101 if (rt->rt6i_node)
102 inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum;
103}
104
105static void tcp_v6_hash(struct sock *sk)
106{
107 if (sk->sk_state != TCP_CLOSE) {
108 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
109 tcp_prot.hash(sk);
110 return;
111 }
112 local_bh_disable();
113 __inet6_hash(sk, NULL);
114 local_bh_enable();
115 }
116}
117
118static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
119{
120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
121 ipv6_hdr(skb)->saddr.s6_addr32,
122 tcp_hdr(skb)->dest,
123 tcp_hdr(skb)->source);
124}
125
126static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128{
129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
130 struct inet_sock *inet = inet_sk(sk);
131 struct inet_connection_sock *icsk = inet_csk(sk);
132 struct ipv6_pinfo *np = inet6_sk(sk);
133 struct tcp_sock *tp = tcp_sk(sk);
134 struct in6_addr *saddr = NULL, *final_p, final;
135 struct rt6_info *rt;
136 struct flowi6 fl6;
137 struct dst_entry *dst;
138 int addr_type;
139 int err;
140
141 if (addr_len < SIN6_LEN_RFC2133)
142 return -EINVAL;
143
144 if (usin->sin6_family != AF_INET6)
145 return -EAFNOSUPPORT;
146
147 memset(&fl6, 0, sizeof(fl6));
148
149 if (np->sndflow) {
150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
151 IP6_ECN_flow_init(fl6.flowlabel);
152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
153 struct ip6_flowlabel *flowlabel;
154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
155 if (flowlabel == NULL)
156 return -EINVAL;
157 fl6_sock_release(flowlabel);
158 }
159 }
160
161 /*
162 * connect() to INADDR_ANY means loopback (BSD'ism).
163 */
164
165 if (ipv6_addr_any(&usin->sin6_addr))
166 usin->sin6_addr.s6_addr[15] = 0x1;
167
168 addr_type = ipv6_addr_type(&usin->sin6_addr);
169
170 if (addr_type & IPV6_ADDR_MULTICAST)
171 return -ENETUNREACH;
172
173 if (addr_type&IPV6_ADDR_LINKLOCAL) {
174 if (addr_len >= sizeof(struct sockaddr_in6) &&
175 usin->sin6_scope_id) {
176 /* If interface is set while binding, indices
177 * must coincide.
178 */
179 if (sk->sk_bound_dev_if &&
180 sk->sk_bound_dev_if != usin->sin6_scope_id)
181 return -EINVAL;
182
183 sk->sk_bound_dev_if = usin->sin6_scope_id;
184 }
185
186 /* Connect to link-local address requires an interface */
187 if (!sk->sk_bound_dev_if)
188 return -EINVAL;
189 }
190
191 if (tp->rx_opt.ts_recent_stamp &&
192 !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
193 tp->rx_opt.ts_recent = 0;
194 tp->rx_opt.ts_recent_stamp = 0;
195 tp->write_seq = 0;
196 }
197
198 sk->sk_v6_daddr = usin->sin6_addr;
199 np->flow_label = fl6.flowlabel;
200
201 /*
202 * TCP over IPv4
203 */
204
205 if (addr_type == IPV6_ADDR_MAPPED) {
206 u32 exthdrlen = icsk->icsk_ext_hdr_len;
207 struct sockaddr_in sin;
208
209 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
210
211 if (__ipv6_only_sock(sk))
212 return -ENETUNREACH;
213
214 sin.sin_family = AF_INET;
215 sin.sin_port = usin->sin6_port;
216 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
217
218 icsk->icsk_af_ops = &ipv6_mapped;
219 sk->sk_backlog_rcv = tcp_v4_do_rcv;
220#ifdef CONFIG_TCP_MD5SIG
221 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
222#endif
223
224 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
225
226 if (err) {
227 icsk->icsk_ext_hdr_len = exthdrlen;
228 icsk->icsk_af_ops = &ipv6_specific;
229 sk->sk_backlog_rcv = tcp_v6_do_rcv;
230#ifdef CONFIG_TCP_MD5SIG
231 tp->af_specific = &tcp_sock_ipv6_specific;
232#endif
233 goto failure;
234 } else {
235 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
236 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
237 &sk->sk_v6_rcv_saddr);
238 }
239
240 return err;
241 }
242
243 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
244 saddr = &sk->sk_v6_rcv_saddr;
245
246 fl6.flowi6_proto = IPPROTO_TCP;
247 fl6.daddr = sk->sk_v6_daddr;
248 fl6.saddr = saddr ? *saddr : np->saddr;
249 fl6.flowi6_oif = sk->sk_bound_dev_if;
250 fl6.flowi6_mark = sk->sk_mark;
251 fl6.fl6_dport = usin->sin6_port;
252 fl6.fl6_sport = inet->inet_sport;
253
254 final_p = fl6_update_dst(&fl6, np->opt, &final);
255
256 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
257
258 dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
259 if (IS_ERR(dst)) {
260 err = PTR_ERR(dst);
261 goto failure;
262 }
263
264 if (saddr == NULL) {
265 saddr = &fl6.saddr;
266 sk->sk_v6_rcv_saddr = *saddr;
267 }
268
269 /* set the source address */
270 np->saddr = *saddr;
271 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
272
273 sk->sk_gso_type = SKB_GSO_TCPV6;
274 __ip6_dst_store(sk, dst, NULL, NULL);
275
276 rt = (struct rt6_info *) dst;
277 if (tcp_death_row.sysctl_tw_recycle &&
278 !tp->rx_opt.ts_recent_stamp &&
279 ipv6_addr_equal(&rt->rt6i_dst.addr, &sk->sk_v6_daddr))
280 tcp_fetch_timewait_stamp(sk, dst);
281
282 icsk->icsk_ext_hdr_len = 0;
283 if (np->opt)
284 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
285 np->opt->opt_nflen);
286
287 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
288
289 inet->inet_dport = usin->sin6_port;
290
291 tcp_set_state(sk, TCP_SYN_SENT);
292 err = inet6_hash_connect(&tcp_death_row, sk);
293 if (err)
294 goto late_failure;
295
296 if (!tp->write_seq && likely(!tp->repair))
297 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
298 sk->sk_v6_daddr.s6_addr32,
299 inet->inet_sport,
300 inet->inet_dport);
301
302 err = tcp_connect(sk);
303 if (err)
304 goto late_failure;
305
306 return 0;
307
308late_failure:
309 tcp_set_state(sk, TCP_CLOSE);
310 __sk_dst_reset(sk);
311failure:
312 inet->inet_dport = 0;
313 sk->sk_route_caps = 0;
314 return err;
315}
316
317static void tcp_v6_mtu_reduced(struct sock *sk)
318{
319 struct dst_entry *dst;
320
321 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
322 return;
323
324 dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
325 if (!dst)
326 return;
327
328 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
329 tcp_sync_mss(sk, dst_mtu(dst));
330 tcp_simple_retransmit(sk);
331 }
332}
333
334static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
335 u8 type, u8 code, int offset, __be32 info)
336{
337 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
338 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
339 struct ipv6_pinfo *np;
340 struct sock *sk;
341 int err;
342 struct tcp_sock *tp;
343 __u32 seq;
344 struct net *net = dev_net(skb->dev);
345
346 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
347 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
348
349 if (sk == NULL) {
350 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
351 ICMP6_MIB_INERRORS);
352 return;
353 }
354
355 if (sk->sk_state == TCP_TIME_WAIT) {
356 inet_twsk_put(inet_twsk(sk));
357 return;
358 }
359
360 bh_lock_sock(sk);
361 if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
362 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
363
364 if (sk->sk_state == TCP_CLOSE)
365 goto out;
366
367 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
368 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
369 goto out;
370 }
371
372 tp = tcp_sk(sk);
373 seq = ntohl(th->seq);
374 if (sk->sk_state != TCP_LISTEN &&
375 !between(seq, tp->snd_una, tp->snd_nxt)) {
376 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
377 goto out;
378 }
379
380 np = inet6_sk(sk);
381
382 if (type == NDISC_REDIRECT) {
383 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
384
385 if (dst)
386 dst->ops->redirect(dst, sk, skb);
387 goto out;
388 }
389
390 if (type == ICMPV6_PKT_TOOBIG) {
391 /* We are not interested in TCP_LISTEN and open_requests
392 * (SYN-ACKs send out by Linux are always <576bytes so
393 * they should go through unfragmented).
394 */
395 if (sk->sk_state == TCP_LISTEN)
396 goto out;
397
398 if (!ip6_sk_accept_pmtu(sk))
399 goto out;
400
401 tp->mtu_info = ntohl(info);
402 if (!sock_owned_by_user(sk))
403 tcp_v6_mtu_reduced(sk);
404 else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
405 &tp->tsq_flags))
406 sock_hold(sk);
407 goto out;
408 }
409
410 icmpv6_err_convert(type, code, &err);
411
412 /* Might be for an request_sock */
413 switch (sk->sk_state) {
414 struct request_sock *req, **prev;
415 case TCP_LISTEN:
416 if (sock_owned_by_user(sk))
417 goto out;
418
419 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
420 &hdr->saddr, inet6_iif(skb));
421 if (!req)
422 goto out;
423
424 /* ICMPs are not backlogged, hence we cannot get
425 * an established socket here.
426 */
427 WARN_ON(req->sk != NULL);
428
429 if (seq != tcp_rsk(req)->snt_isn) {
430 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
431 goto out;
432 }
433
434 inet_csk_reqsk_queue_drop(sk, req, prev);
435 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
436 goto out;
437
438 case TCP_SYN_SENT:
439 case TCP_SYN_RECV: /* Cannot happen.
440 It can, it SYNs are crossed. --ANK */
441 if (!sock_owned_by_user(sk)) {
442 sk->sk_err = err;
443 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
444
445 tcp_done(sk);
446 } else
447 sk->sk_err_soft = err;
448 goto out;
449 }
450
451 if (!sock_owned_by_user(sk) && np->recverr) {
452 sk->sk_err = err;
453 sk->sk_error_report(sk);
454 } else
455 sk->sk_err_soft = err;
456
457out:
458 bh_unlock_sock(sk);
459 sock_put(sk);
460}
461
462
463static int tcp_v6_send_synack(struct sock *sk, struct dst_entry *dst,
464 struct flowi6 *fl6,
465 struct request_sock *req,
466 u16 queue_mapping)
467{
468 struct inet_request_sock *ireq = inet_rsk(req);
469 struct ipv6_pinfo *np = inet6_sk(sk);
470 struct sk_buff *skb;
471 int err = -ENOMEM;
472
473 /* First, grab a route. */
474 if (!dst && (dst = inet6_csk_route_req(sk, fl6, req)) == NULL)
475 goto done;
476
477 skb = tcp_make_synack(sk, dst, req, NULL);
478
479 if (skb) {
480 __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
481 &ireq->ir_v6_rmt_addr);
482
483 fl6->daddr = ireq->ir_v6_rmt_addr;
484 if (np->repflow && (ireq->pktopts != NULL))
485 fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
486
487 skb_set_queue_mapping(skb, queue_mapping);
488 err = ip6_xmit(sk, skb, fl6, np->opt, np->tclass);
489 err = net_xmit_eval(err);
490 }
491
492done:
493 return err;
494}
495
496static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req)
497{
498 struct flowi6 fl6;
499 int res;
500
501 res = tcp_v6_send_synack(sk, NULL, &fl6, req, 0);
502 if (!res) {
503 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
504 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);
505 }
506 return res;
507}
508
509static void tcp_v6_reqsk_destructor(struct request_sock *req)
510{
511 kfree_skb(inet_rsk(req)->pktopts);
512}
513
514#ifdef CONFIG_TCP_MD5SIG
515static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
516 const struct in6_addr *addr)
517{
518 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
519}
520
521static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
522 struct sock *addr_sk)
523{
524 return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
525}
526
527static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
528 struct request_sock *req)
529{
530 return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
531}
532
533static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
534 int optlen)
535{
536 struct tcp_md5sig cmd;
537 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
538
539 if (optlen < sizeof(cmd))
540 return -EINVAL;
541
542 if (copy_from_user(&cmd, optval, sizeof(cmd)))
543 return -EFAULT;
544
545 if (sin6->sin6_family != AF_INET6)
546 return -EINVAL;
547
548 if (!cmd.tcpm_keylen) {
549 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
550 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
551 AF_INET);
552 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
553 AF_INET6);
554 }
555
556 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
557 return -EINVAL;
558
559 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
560 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
561 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
562
563 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
564 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
565}
566
567static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
568 const struct in6_addr *daddr,
569 const struct in6_addr *saddr, int nbytes)
570{
571 struct tcp6_pseudohdr *bp;
572 struct scatterlist sg;
573
574 bp = &hp->md5_blk.ip6;
575 /* 1. TCP pseudo-header (RFC2460) */
576 bp->saddr = *saddr;
577 bp->daddr = *daddr;
578 bp->protocol = cpu_to_be32(IPPROTO_TCP);
579 bp->len = cpu_to_be32(nbytes);
580
581 sg_init_one(&sg, bp, sizeof(*bp));
582 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
583}
584
585static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
586 const struct in6_addr *daddr, struct in6_addr *saddr,
587 const struct tcphdr *th)
588{
589 struct tcp_md5sig_pool *hp;
590 struct hash_desc *desc;
591
592 hp = tcp_get_md5sig_pool();
593 if (!hp)
594 goto clear_hash_noput;
595 desc = &hp->md5_desc;
596
597 if (crypto_hash_init(desc))
598 goto clear_hash;
599 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
600 goto clear_hash;
601 if (tcp_md5_hash_header(hp, th))
602 goto clear_hash;
603 if (tcp_md5_hash_key(hp, key))
604 goto clear_hash;
605 if (crypto_hash_final(desc, md5_hash))
606 goto clear_hash;
607
608 tcp_put_md5sig_pool();
609 return 0;
610
611clear_hash:
612 tcp_put_md5sig_pool();
613clear_hash_noput:
614 memset(md5_hash, 0, 16);
615 return 1;
616}
617
618static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
619 const struct sock *sk,
620 const struct request_sock *req,
621 const struct sk_buff *skb)
622{
623 const struct in6_addr *saddr, *daddr;
624 struct tcp_md5sig_pool *hp;
625 struct hash_desc *desc;
626 const struct tcphdr *th = tcp_hdr(skb);
627
628 if (sk) {
629 saddr = &inet6_sk(sk)->saddr;
630 daddr = &sk->sk_v6_daddr;
631 } else if (req) {
632 saddr = &inet_rsk(req)->ir_v6_loc_addr;
633 daddr = &inet_rsk(req)->ir_v6_rmt_addr;
634 } else {
635 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
636 saddr = &ip6h->saddr;
637 daddr = &ip6h->daddr;
638 }
639
640 hp = tcp_get_md5sig_pool();
641 if (!hp)
642 goto clear_hash_noput;
643 desc = &hp->md5_desc;
644
645 if (crypto_hash_init(desc))
646 goto clear_hash;
647
648 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
649 goto clear_hash;
650 if (tcp_md5_hash_header(hp, th))
651 goto clear_hash;
652 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
653 goto clear_hash;
654 if (tcp_md5_hash_key(hp, key))
655 goto clear_hash;
656 if (crypto_hash_final(desc, md5_hash))
657 goto clear_hash;
658
659 tcp_put_md5sig_pool();
660 return 0;
661
662clear_hash:
663 tcp_put_md5sig_pool();
664clear_hash_noput:
665 memset(md5_hash, 0, 16);
666 return 1;
667}
668
669static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
670{
671 const __u8 *hash_location = NULL;
672 struct tcp_md5sig_key *hash_expected;
673 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
674 const struct tcphdr *th = tcp_hdr(skb);
675 int genhash;
676 u8 newhash[16];
677
678 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
679 hash_location = tcp_parse_md5sig_option(th);
680
681 /* We've parsed the options - do we have a hash? */
682 if (!hash_expected && !hash_location)
683 return 0;
684
685 if (hash_expected && !hash_location) {
686 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
687 return 1;
688 }
689
690 if (!hash_expected && hash_location) {
691 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
692 return 1;
693 }
694
695 /* check the signature */
696 genhash = tcp_v6_md5_hash_skb(newhash,
697 hash_expected,
698 NULL, NULL, skb);
699
700 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
701 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
702 genhash ? "failed" : "mismatch",
703 &ip6h->saddr, ntohs(th->source),
704 &ip6h->daddr, ntohs(th->dest));
705 return 1;
706 }
707 return 0;
708}
709#endif
710
711struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
712 .family = AF_INET6,
713 .obj_size = sizeof(struct tcp6_request_sock),
714 .rtx_syn_ack = tcp_v6_rtx_synack,
715 .send_ack = tcp_v6_reqsk_send_ack,
716 .destructor = tcp_v6_reqsk_destructor,
717 .send_reset = tcp_v6_send_reset,
718 .syn_ack_timeout = tcp_syn_ack_timeout,
719};
720
721#ifdef CONFIG_TCP_MD5SIG
722static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
723 .md5_lookup = tcp_v6_reqsk_md5_lookup,
724 .calc_md5_hash = tcp_v6_md5_hash_skb,
725};
726#endif
727
728static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
729 u32 tsval, u32 tsecr, int oif,
730 struct tcp_md5sig_key *key, int rst, u8 tclass,
731 u32 label)
732{
733 const struct tcphdr *th = tcp_hdr(skb);
734 struct tcphdr *t1;
735 struct sk_buff *buff;
736 struct flowi6 fl6;
737 struct net *net = dev_net(skb_dst(skb)->dev);
738 struct sock *ctl_sk = net->ipv6.tcp_sk;
739 unsigned int tot_len = sizeof(struct tcphdr);
740 struct dst_entry *dst;
741 __be32 *topt;
742
743 if (tsecr)
744 tot_len += TCPOLEN_TSTAMP_ALIGNED;
745#ifdef CONFIG_TCP_MD5SIG
746 if (key)
747 tot_len += TCPOLEN_MD5SIG_ALIGNED;
748#endif
749
750 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
751 GFP_ATOMIC);
752 if (buff == NULL)
753 return;
754
755 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
756
757 t1 = (struct tcphdr *) skb_push(buff, tot_len);
758 skb_reset_transport_header(buff);
759
760 /* Swap the send and the receive. */
761 memset(t1, 0, sizeof(*t1));
762 t1->dest = th->source;
763 t1->source = th->dest;
764 t1->doff = tot_len / 4;
765 t1->seq = htonl(seq);
766 t1->ack_seq = htonl(ack);
767 t1->ack = !rst || !th->ack;
768 t1->rst = rst;
769 t1->window = htons(win);
770
771 topt = (__be32 *)(t1 + 1);
772
773 if (tsecr) {
774 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
775 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
776 *topt++ = htonl(tsval);
777 *topt++ = htonl(tsecr);
778 }
779
780#ifdef CONFIG_TCP_MD5SIG
781 if (key) {
782 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
783 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
784 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
785 &ipv6_hdr(skb)->saddr,
786 &ipv6_hdr(skb)->daddr, t1);
787 }
788#endif
789
790 memset(&fl6, 0, sizeof(fl6));
791 fl6.daddr = ipv6_hdr(skb)->saddr;
792 fl6.saddr = ipv6_hdr(skb)->daddr;
793 fl6.flowlabel = label;
794
795 buff->ip_summed = CHECKSUM_PARTIAL;
796 buff->csum = 0;
797
798 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
799
800 fl6.flowi6_proto = IPPROTO_TCP;
801 if (rt6_need_strict(&fl6.daddr) && !oif)
802 fl6.flowi6_oif = inet6_iif(skb);
803 else
804 fl6.flowi6_oif = oif;
805 fl6.fl6_dport = t1->dest;
806 fl6.fl6_sport = t1->source;
807 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
808
809 /* Pass a socket to ip6_dst_lookup either it is for RST
810 * Underlying function will use this to retrieve the network
811 * namespace
812 */
813 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
814 if (!IS_ERR(dst)) {
815 skb_dst_set(buff, dst);
816 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
817 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
818 if (rst)
819 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
820 return;
821 }
822
823 kfree_skb(buff);
824}
825
826static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
827{
828 const struct tcphdr *th = tcp_hdr(skb);
829 u32 seq = 0, ack_seq = 0;
830 struct tcp_md5sig_key *key = NULL;
831#ifdef CONFIG_TCP_MD5SIG
832 const __u8 *hash_location = NULL;
833 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
834 unsigned char newhash[16];
835 int genhash;
836 struct sock *sk1 = NULL;
837#endif
838 int oif;
839
840 if (th->rst)
841 return;
842
843 if (!ipv6_unicast_destination(skb))
844 return;
845
846#ifdef CONFIG_TCP_MD5SIG
847 hash_location = tcp_parse_md5sig_option(th);
848 if (!sk && hash_location) {
849 /*
850 * active side is lost. Try to find listening socket through
851 * source port, and then find md5 key through listening socket.
852 * we are not loose security here:
853 * Incoming packet is checked with md5 hash with finding key,
854 * no RST generated if md5 hash doesn't match.
855 */
856 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
857 &tcp_hashinfo, &ipv6h->saddr,
858 th->source, &ipv6h->daddr,
859 ntohs(th->source), inet6_iif(skb));
860 if (!sk1)
861 return;
862
863 rcu_read_lock();
864 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
865 if (!key)
866 goto release_sk1;
867
868 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
869 if (genhash || memcmp(hash_location, newhash, 16) != 0)
870 goto release_sk1;
871 } else {
872 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
873 }
874#endif
875
876 if (th->ack)
877 seq = ntohl(th->ack_seq);
878 else
879 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
880 (th->doff << 2);
881
882 oif = sk ? sk->sk_bound_dev_if : 0;
883 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
884
885#ifdef CONFIG_TCP_MD5SIG
886release_sk1:
887 if (sk1) {
888 rcu_read_unlock();
889 sock_put(sk1);
890 }
891#endif
892}
893
894static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
895 u32 win, u32 tsval, u32 tsecr, int oif,
896 struct tcp_md5sig_key *key, u8 tclass,
897 u32 label)
898{
899 tcp_v6_send_response(skb, seq, ack, win, tsval, tsecr, oif, key, 0, tclass,
900 label);
901}
902
903static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
904{
905 struct inet_timewait_sock *tw = inet_twsk(sk);
906 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
907
908 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
909 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
910 tcp_time_stamp + tcptw->tw_ts_offset,
911 tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
912 tw->tw_tclass, (tw->tw_flowlabel << 12));
913
914 inet_twsk_put(tw);
915}
916
917static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
918 struct request_sock *req)
919{
920 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1,
921 req->rcv_wnd, tcp_time_stamp, req->ts_recent, sk->sk_bound_dev_if,
922 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
923 0, 0);
924}
925
926
927static struct sock *tcp_v6_hnd_req(struct sock *sk, struct sk_buff *skb)
928{
929 struct request_sock *req, **prev;
930 const struct tcphdr *th = tcp_hdr(skb);
931 struct sock *nsk;
932
933 /* Find possible connection requests. */
934 req = inet6_csk_search_req(sk, &prev, th->source,
935 &ipv6_hdr(skb)->saddr,
936 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
937 if (req)
938 return tcp_check_req(sk, skb, req, prev, false);
939
940 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
941 &ipv6_hdr(skb)->saddr, th->source,
942 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
943
944 if (nsk) {
945 if (nsk->sk_state != TCP_TIME_WAIT) {
946 bh_lock_sock(nsk);
947 return nsk;
948 }
949 inet_twsk_put(inet_twsk(nsk));
950 return NULL;
951 }
952
953#ifdef CONFIG_SYN_COOKIES
954 if (!th->syn)
955 sk = cookie_v6_check(sk, skb);
956#endif
957 return sk;
958}
959
960/* FIXME: this is substantially similar to the ipv4 code.
961 * Can some kind of merge be done? -- erics
962 */
963static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
964{
965 struct tcp_options_received tmp_opt;
966 struct request_sock *req;
967 struct inet_request_sock *ireq;
968 struct ipv6_pinfo *np = inet6_sk(sk);
969 struct tcp_sock *tp = tcp_sk(sk);
970 __u32 isn = TCP_SKB_CB(skb)->when;
971 struct dst_entry *dst = NULL;
972 struct flowi6 fl6;
973 bool want_cookie = false;
974
975 if (skb->protocol == htons(ETH_P_IP))
976 return tcp_v4_conn_request(sk, skb);
977
978 if (!ipv6_unicast_destination(skb))
979 goto drop;
980
981 if ((sysctl_tcp_syncookies == 2 ||
982 inet_csk_reqsk_queue_is_full(sk)) && !isn) {
983 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
984 if (!want_cookie)
985 goto drop;
986 }
987
988 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) {
989 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
990 goto drop;
991 }
992
993 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
994 if (req == NULL)
995 goto drop;
996
997#ifdef CONFIG_TCP_MD5SIG
998 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
999#endif
1000
1001 tcp_clear_options(&tmp_opt);
1002 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1003 tmp_opt.user_mss = tp->rx_opt.user_mss;
1004 tcp_parse_options(skb, &tmp_opt, 0, NULL);
1005
1006 if (want_cookie && !tmp_opt.saw_tstamp)
1007 tcp_clear_options(&tmp_opt);
1008
1009 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1010 tcp_openreq_init(req, &tmp_opt, skb);
1011
1012 ireq = inet_rsk(req);
1013 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
1014 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
1015 if (!want_cookie || tmp_opt.tstamp_ok)
1016 TCP_ECN_create_request(req, skb, sock_net(sk));
1017
1018 ireq->ir_iif = sk->sk_bound_dev_if;
1019
1020 /* So that link locals have meaning */
1021 if (!sk->sk_bound_dev_if &&
1022 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
1023 ireq->ir_iif = inet6_iif(skb);
1024
1025 if (!isn) {
1026 if (ipv6_opt_accepted(sk, skb) ||
1027 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1028 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim ||
1029 np->repflow) {
1030 atomic_inc(&skb->users);
1031 ireq->pktopts = skb;
1032 }
1033
1034 if (want_cookie) {
1035 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1036 req->cookie_ts = tmp_opt.tstamp_ok;
1037 goto have_isn;
1038 }
1039
1040 /* VJ's idea. We save last timestamp seen
1041 * from the destination in peer table, when entering
1042 * state TIME-WAIT, and check against it before
1043 * accepting new connection request.
1044 *
1045 * If "isn" is not zero, this request hit alive
1046 * timewait bucket, so that all the necessary checks
1047 * are made in the function processing timewait state.
1048 */
1049 if (tmp_opt.saw_tstamp &&
1050 tcp_death_row.sysctl_tw_recycle &&
1051 (dst = inet6_csk_route_req(sk, &fl6, req)) != NULL) {
1052 if (!tcp_peer_is_proven(req, dst, true)) {
1053 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1054 goto drop_and_release;
1055 }
1056 }
1057 /* Kill the following clause, if you dislike this way. */
1058 else if (!sysctl_tcp_syncookies &&
1059 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1060 (sysctl_max_syn_backlog >> 2)) &&
1061 !tcp_peer_is_proven(req, dst, false)) {
1062 /* Without syncookies last quarter of
1063 * backlog is filled with destinations,
1064 * proven to be alive.
1065 * It means that we continue to communicate
1066 * to destinations, already remembered
1067 * to the moment of synflood.
1068 */
1069 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1070 &ireq->ir_v6_rmt_addr, ntohs(tcp_hdr(skb)->source));
1071 goto drop_and_release;
1072 }
1073
1074 isn = tcp_v6_init_sequence(skb);
1075 }
1076have_isn:
1077 tcp_rsk(req)->snt_isn = isn;
1078
1079 if (security_inet_conn_request(sk, skb, req))
1080 goto drop_and_release;
1081
1082 if (tcp_v6_send_synack(sk, dst, &fl6, req,
1083 skb_get_queue_mapping(skb)) ||
1084 want_cookie)
1085 goto drop_and_free;
1086
1087 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1088 tcp_rsk(req)->listener = NULL;
1089 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1090 return 0;
1091
1092drop_and_release:
1093 dst_release(dst);
1094drop_and_free:
1095 reqsk_free(req);
1096drop:
1097 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1098 return 0; /* don't send reset */
1099}
1100
1101static struct sock *tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1102 struct request_sock *req,
1103 struct dst_entry *dst)
1104{
1105 struct inet_request_sock *ireq;
1106 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1107 struct tcp6_sock *newtcp6sk;
1108 struct inet_sock *newinet;
1109 struct tcp_sock *newtp;
1110 struct sock *newsk;
1111#ifdef CONFIG_TCP_MD5SIG
1112 struct tcp_md5sig_key *key;
1113#endif
1114 struct flowi6 fl6;
1115
1116 if (skb->protocol == htons(ETH_P_IP)) {
1117 /*
1118 * v6 mapped
1119 */
1120
1121 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1122
1123 if (newsk == NULL)
1124 return NULL;
1125
1126 newtcp6sk = (struct tcp6_sock *)newsk;
1127 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1128
1129 newinet = inet_sk(newsk);
1130 newnp = inet6_sk(newsk);
1131 newtp = tcp_sk(newsk);
1132
1133 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1134
1135 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr);
1136
1137 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1138
1139 newsk->sk_v6_rcv_saddr = newnp->saddr;
1140
1141 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1142 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1143#ifdef CONFIG_TCP_MD5SIG
1144 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1145#endif
1146
1147 newnp->ipv6_ac_list = NULL;
1148 newnp->ipv6_fl_list = NULL;
1149 newnp->pktoptions = NULL;
1150 newnp->opt = NULL;
1151 newnp->mcast_oif = inet6_iif(skb);
1152 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1153 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1154 if (np->repflow)
1155 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1156
1157 /*
1158 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1159 * here, tcp_create_openreq_child now does this for us, see the comment in
1160 * that function for the gory details. -acme
1161 */
1162
1163 /* It is tricky place. Until this moment IPv4 tcp
1164 worked with IPv6 icsk.icsk_af_ops.
1165 Sync it now.
1166 */
1167 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1168
1169 return newsk;
1170 }
1171
1172 ireq = inet_rsk(req);
1173
1174 if (sk_acceptq_is_full(sk))
1175 goto out_overflow;
1176
1177 if (!dst) {
1178 dst = inet6_csk_route_req(sk, &fl6, req);
1179 if (!dst)
1180 goto out;
1181 }
1182
1183 newsk = tcp_create_openreq_child(sk, req, skb);
1184 if (newsk == NULL)
1185 goto out_nonewsk;
1186
1187 /*
1188 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1189 * count here, tcp_create_openreq_child now does this for us, see the
1190 * comment in that function for the gory details. -acme
1191 */
1192
1193 newsk->sk_gso_type = SKB_GSO_TCPV6;
1194 __ip6_dst_store(newsk, dst, NULL, NULL);
1195 inet6_sk_rx_dst_set(newsk, skb);
1196
1197 newtcp6sk = (struct tcp6_sock *)newsk;
1198 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1199
1200 newtp = tcp_sk(newsk);
1201 newinet = inet_sk(newsk);
1202 newnp = inet6_sk(newsk);
1203
1204 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1205
1206 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1207 newnp->saddr = ireq->ir_v6_loc_addr;
1208 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1209 newsk->sk_bound_dev_if = ireq->ir_iif;
1210
1211 /* Now IPv6 options...
1212
1213 First: no IPv4 options.
1214 */
1215 newinet->inet_opt = NULL;
1216 newnp->ipv6_ac_list = NULL;
1217 newnp->ipv6_fl_list = NULL;
1218
1219 /* Clone RX bits */
1220 newnp->rxopt.all = np->rxopt.all;
1221
1222 /* Clone pktoptions received with SYN */
1223 newnp->pktoptions = NULL;
1224 if (ireq->pktopts != NULL) {
1225 newnp->pktoptions = skb_clone(ireq->pktopts,
1226 sk_gfp_atomic(sk, GFP_ATOMIC));
1227 consume_skb(ireq->pktopts);
1228 ireq->pktopts = NULL;
1229 if (newnp->pktoptions)
1230 skb_set_owner_r(newnp->pktoptions, newsk);
1231 }
1232 newnp->opt = NULL;
1233 newnp->mcast_oif = inet6_iif(skb);
1234 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1235 newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1236 if (np->repflow)
1237 newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1238
1239 /* Clone native IPv6 options from listening socket (if any)
1240
1241 Yes, keeping reference count would be much more clever,
1242 but we make one more one thing there: reattach optmem
1243 to newsk.
1244 */
1245 if (np->opt)
1246 newnp->opt = ipv6_dup_options(newsk, np->opt);
1247
1248 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1249 if (newnp->opt)
1250 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1251 newnp->opt->opt_flen);
1252
1253 tcp_sync_mss(newsk, dst_mtu(dst));
1254 newtp->advmss = dst_metric_advmss(dst);
1255 if (tcp_sk(sk)->rx_opt.user_mss &&
1256 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1257 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1258
1259 tcp_initialize_rcv_mss(newsk);
1260
1261 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1262 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1263
1264#ifdef CONFIG_TCP_MD5SIG
1265 /* Copy over the MD5 key from the original socket */
1266 key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1267 if (key != NULL) {
1268 /* We're using one, so create a matching key
1269 * on the newsk structure. If we fail to get
1270 * memory, then we end up not copying the key
1271 * across. Shucks.
1272 */
1273 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1274 AF_INET6, key->key, key->keylen,
1275 sk_gfp_atomic(sk, GFP_ATOMIC));
1276 }
1277#endif
1278
1279 if (__inet_inherit_port(sk, newsk) < 0) {
1280 inet_csk_prepare_forced_close(newsk);
1281 tcp_done(newsk);
1282 goto out;
1283 }
1284 __inet6_hash(newsk, NULL);
1285
1286 return newsk;
1287
1288out_overflow:
1289 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1290out_nonewsk:
1291 dst_release(dst);
1292out:
1293 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1294 return NULL;
1295}
1296
1297static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1298{
1299 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1300 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1301 &ipv6_hdr(skb)->daddr, skb->csum)) {
1302 skb->ip_summed = CHECKSUM_UNNECESSARY;
1303 return 0;
1304 }
1305 }
1306
1307 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1308 &ipv6_hdr(skb)->saddr,
1309 &ipv6_hdr(skb)->daddr, 0));
1310
1311 if (skb->len <= 76)
1312 return __skb_checksum_complete(skb);
1313 return 0;
1314}
1315
1316/* The socket must have it's spinlock held when we get
1317 * here.
1318 *
1319 * We have a potential double-lock case here, so even when
1320 * doing backlog processing we use the BH locking scheme.
1321 * This is because we cannot sleep with the original spinlock
1322 * held.
1323 */
1324static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1325{
1326 struct ipv6_pinfo *np = inet6_sk(sk);
1327 struct tcp_sock *tp;
1328 struct sk_buff *opt_skb = NULL;
1329
1330 /* Imagine: socket is IPv6. IPv4 packet arrives,
1331 goes to IPv4 receive handler and backlogged.
1332 From backlog it always goes here. Kerboom...
1333 Fortunately, tcp_rcv_established and rcv_established
1334 handle them correctly, but it is not case with
1335 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1336 */
1337
1338 if (skb->protocol == htons(ETH_P_IP))
1339 return tcp_v4_do_rcv(sk, skb);
1340
1341#ifdef CONFIG_TCP_MD5SIG
1342 if (tcp_v6_inbound_md5_hash(sk, skb))
1343 goto discard;
1344#endif
1345
1346 if (sk_filter(sk, skb))
1347 goto discard;
1348
1349 /*
1350 * socket locking is here for SMP purposes as backlog rcv
1351 * is currently called with bh processing disabled.
1352 */
1353
1354 /* Do Stevens' IPV6_PKTOPTIONS.
1355
1356 Yes, guys, it is the only place in our code, where we
1357 may make it not affecting IPv4.
1358 The rest of code is protocol independent,
1359 and I do not like idea to uglify IPv4.
1360
1361 Actually, all the idea behind IPV6_PKTOPTIONS
1362 looks not very well thought. For now we latch
1363 options, received in the last packet, enqueued
1364 by tcp. Feel free to propose better solution.
1365 --ANK (980728)
1366 */
1367 if (np->rxopt.all)
1368 opt_skb = skb_clone(skb, sk_gfp_atomic(sk, GFP_ATOMIC));
1369
1370 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1371 struct dst_entry *dst = sk->sk_rx_dst;
1372
1373 sock_rps_save_rxhash(sk, skb);
1374 if (dst) {
1375 if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1376 dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1377 dst_release(dst);
1378 sk->sk_rx_dst = NULL;
1379 }
1380 }
1381
1382 tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1383 if (opt_skb)
1384 goto ipv6_pktoptions;
1385 return 0;
1386 }
1387
1388 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1389 goto csum_err;
1390
1391 if (sk->sk_state == TCP_LISTEN) {
1392 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1393 if (!nsk)
1394 goto discard;
1395
1396 /*
1397 * Queue it on the new socket if the new socket is active,
1398 * otherwise we just shortcircuit this and continue with
1399 * the new socket..
1400 */
1401 if (nsk != sk) {
1402 sock_rps_save_rxhash(nsk, skb);
1403 if (tcp_child_process(sk, nsk, skb))
1404 goto reset;
1405 if (opt_skb)
1406 __kfree_skb(opt_skb);
1407 return 0;
1408 }
1409 } else
1410 sock_rps_save_rxhash(sk, skb);
1411
1412 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1413 goto reset;
1414 if (opt_skb)
1415 goto ipv6_pktoptions;
1416 return 0;
1417
1418reset:
1419 tcp_v6_send_reset(sk, skb);
1420discard:
1421 if (opt_skb)
1422 __kfree_skb(opt_skb);
1423 kfree_skb(skb);
1424 return 0;
1425csum_err:
1426 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
1427 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1428 goto discard;
1429
1430
1431ipv6_pktoptions:
1432 /* Do you ask, what is it?
1433
1434 1. skb was enqueued by tcp.
1435 2. skb is added to tail of read queue, rather than out of order.
1436 3. socket is not in passive state.
1437 4. Finally, it really contains options, which user wants to receive.
1438 */
1439 tp = tcp_sk(sk);
1440 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1441 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1442 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1443 np->mcast_oif = inet6_iif(opt_skb);
1444 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1445 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1446 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1447 np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1448 if (np->repflow)
1449 np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1450 if (ipv6_opt_accepted(sk, opt_skb)) {
1451 skb_set_owner_r(opt_skb, sk);
1452 opt_skb = xchg(&np->pktoptions, opt_skb);
1453 } else {
1454 __kfree_skb(opt_skb);
1455 opt_skb = xchg(&np->pktoptions, NULL);
1456 }
1457 }
1458
1459 kfree_skb(opt_skb);
1460 return 0;
1461}
1462
1463static int tcp_v6_rcv(struct sk_buff *skb)
1464{
1465 const struct tcphdr *th;
1466 const struct ipv6hdr *hdr;
1467 struct sock *sk;
1468 int ret;
1469 struct net *net = dev_net(skb->dev);
1470
1471 if (skb->pkt_type != PACKET_HOST)
1472 goto discard_it;
1473
1474 /*
1475 * Count it even if it's bad.
1476 */
1477 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1478
1479 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1480 goto discard_it;
1481
1482 th = tcp_hdr(skb);
1483
1484 if (th->doff < sizeof(struct tcphdr)/4)
1485 goto bad_packet;
1486 if (!pskb_may_pull(skb, th->doff*4))
1487 goto discard_it;
1488
1489 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1490 goto csum_error;
1491
1492 th = tcp_hdr(skb);
1493 hdr = ipv6_hdr(skb);
1494 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1495 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1496 skb->len - th->doff*4);
1497 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1498 TCP_SKB_CB(skb)->when = 0;
1499 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1500 TCP_SKB_CB(skb)->sacked = 0;
1501
1502 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1503 if (!sk)
1504 goto no_tcp_socket;
1505
1506process:
1507 if (sk->sk_state == TCP_TIME_WAIT)
1508 goto do_time_wait;
1509
1510 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1511 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1512 goto discard_and_relse;
1513 }
1514
1515 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1516 goto discard_and_relse;
1517
1518 if (sk_filter(sk, skb))
1519 goto discard_and_relse;
1520
1521 sk_mark_napi_id(sk, skb);
1522 skb->dev = NULL;
1523
1524 bh_lock_sock_nested(sk);
1525 ret = 0;
1526 if (!sock_owned_by_user(sk)) {
1527#ifdef CONFIG_NET_DMA
1528 struct tcp_sock *tp = tcp_sk(sk);
1529 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1530 tp->ucopy.dma_chan = net_dma_find_channel();
1531 if (tp->ucopy.dma_chan)
1532 ret = tcp_v6_do_rcv(sk, skb);
1533 else
1534#endif
1535 {
1536 if (!tcp_prequeue(sk, skb))
1537 ret = tcp_v6_do_rcv(sk, skb);
1538 }
1539 } else if (unlikely(sk_add_backlog(sk, skb,
1540 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1541 bh_unlock_sock(sk);
1542 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1543 goto discard_and_relse;
1544 }
1545 bh_unlock_sock(sk);
1546
1547 sock_put(sk);
1548 return ret ? -1 : 0;
1549
1550no_tcp_socket:
1551 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1552 goto discard_it;
1553
1554 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1555csum_error:
1556 TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
1557bad_packet:
1558 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1559 } else {
1560 tcp_v6_send_reset(NULL, skb);
1561 }
1562
1563discard_it:
1564 kfree_skb(skb);
1565 return 0;
1566
1567discard_and_relse:
1568 sock_put(sk);
1569 goto discard_it;
1570
1571do_time_wait:
1572 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1573 inet_twsk_put(inet_twsk(sk));
1574 goto discard_it;
1575 }
1576
1577 if (skb->len < (th->doff<<2)) {
1578 inet_twsk_put(inet_twsk(sk));
1579 goto bad_packet;
1580 }
1581 if (tcp_checksum_complete(skb)) {
1582 inet_twsk_put(inet_twsk(sk));
1583 goto csum_error;
1584 }
1585
1586 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1587 case TCP_TW_SYN:
1588 {
1589 struct sock *sk2;
1590
1591 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1592 &ipv6_hdr(skb)->saddr, th->source,
1593 &ipv6_hdr(skb)->daddr,
1594 ntohs(th->dest), inet6_iif(skb));
1595 if (sk2 != NULL) {
1596 struct inet_timewait_sock *tw = inet_twsk(sk);
1597 inet_twsk_deschedule(tw, &tcp_death_row);
1598 inet_twsk_put(tw);
1599 sk = sk2;
1600 goto process;
1601 }
1602 /* Fall through to ACK */
1603 }
1604 case TCP_TW_ACK:
1605 tcp_v6_timewait_ack(sk, skb);
1606 break;
1607 case TCP_TW_RST:
1608 goto no_tcp_socket;
1609 case TCP_TW_SUCCESS:
1610 ;
1611 }
1612 goto discard_it;
1613}
1614
1615static void tcp_v6_early_demux(struct sk_buff *skb)
1616{
1617 const struct ipv6hdr *hdr;
1618 const struct tcphdr *th;
1619 struct sock *sk;
1620
1621 if (skb->pkt_type != PACKET_HOST)
1622 return;
1623
1624 if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1625 return;
1626
1627 hdr = ipv6_hdr(skb);
1628 th = tcp_hdr(skb);
1629
1630 if (th->doff < sizeof(struct tcphdr) / 4)
1631 return;
1632
1633 sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1634 &hdr->saddr, th->source,
1635 &hdr->daddr, ntohs(th->dest),
1636 inet6_iif(skb));
1637 if (sk) {
1638 skb->sk = sk;
1639 skb->destructor = sock_edemux;
1640 if (sk->sk_state != TCP_TIME_WAIT) {
1641 struct dst_entry *dst = sk->sk_rx_dst;
1642
1643 if (dst)
1644 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1645 if (dst &&
1646 inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1647 skb_dst_set_noref(skb, dst);
1648 }
1649 }
1650}
1651
1652static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1653 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1654 .twsk_unique = tcp_twsk_unique,
1655 .twsk_destructor = tcp_twsk_destructor,
1656};
1657
1658static const struct inet_connection_sock_af_ops ipv6_specific = {
1659 .queue_xmit = inet6_csk_xmit,
1660 .send_check = tcp_v6_send_check,
1661 .rebuild_header = inet6_sk_rebuild_header,
1662 .sk_rx_dst_set = inet6_sk_rx_dst_set,
1663 .conn_request = tcp_v6_conn_request,
1664 .syn_recv_sock = tcp_v6_syn_recv_sock,
1665 .net_header_len = sizeof(struct ipv6hdr),
1666 .net_frag_header_len = sizeof(struct frag_hdr),
1667 .setsockopt = ipv6_setsockopt,
1668 .getsockopt = ipv6_getsockopt,
1669 .addr2sockaddr = inet6_csk_addr2sockaddr,
1670 .sockaddr_len = sizeof(struct sockaddr_in6),
1671 .bind_conflict = inet6_csk_bind_conflict,
1672#ifdef CONFIG_COMPAT
1673 .compat_setsockopt = compat_ipv6_setsockopt,
1674 .compat_getsockopt = compat_ipv6_getsockopt,
1675#endif
1676};
1677
1678#ifdef CONFIG_TCP_MD5SIG
1679static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1680 .md5_lookup = tcp_v6_md5_lookup,
1681 .calc_md5_hash = tcp_v6_md5_hash_skb,
1682 .md5_parse = tcp_v6_parse_md5_keys,
1683};
1684#endif
1685
1686/*
1687 * TCP over IPv4 via INET6 API
1688 */
1689static const struct inet_connection_sock_af_ops ipv6_mapped = {
1690 .queue_xmit = ip_queue_xmit,
1691 .send_check = tcp_v4_send_check,
1692 .rebuild_header = inet_sk_rebuild_header,
1693 .sk_rx_dst_set = inet_sk_rx_dst_set,
1694 .conn_request = tcp_v6_conn_request,
1695 .syn_recv_sock = tcp_v6_syn_recv_sock,
1696 .net_header_len = sizeof(struct iphdr),
1697 .setsockopt = ipv6_setsockopt,
1698 .getsockopt = ipv6_getsockopt,
1699 .addr2sockaddr = inet6_csk_addr2sockaddr,
1700 .sockaddr_len = sizeof(struct sockaddr_in6),
1701 .bind_conflict = inet6_csk_bind_conflict,
1702#ifdef CONFIG_COMPAT
1703 .compat_setsockopt = compat_ipv6_setsockopt,
1704 .compat_getsockopt = compat_ipv6_getsockopt,
1705#endif
1706};
1707
1708#ifdef CONFIG_TCP_MD5SIG
1709static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1710 .md5_lookup = tcp_v4_md5_lookup,
1711 .calc_md5_hash = tcp_v4_md5_hash_skb,
1712 .md5_parse = tcp_v6_parse_md5_keys,
1713};
1714#endif
1715
1716/* NOTE: A lot of things set to zero explicitly by call to
1717 * sk_alloc() so need not be done here.
1718 */
1719static int tcp_v6_init_sock(struct sock *sk)
1720{
1721 struct inet_connection_sock *icsk = inet_csk(sk);
1722
1723 tcp_init_sock(sk);
1724
1725 icsk->icsk_af_ops = &ipv6_specific;
1726
1727#ifdef CONFIG_TCP_MD5SIG
1728 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1729#endif
1730
1731 return 0;
1732}
1733
1734static void tcp_v6_destroy_sock(struct sock *sk)
1735{
1736 tcp_v4_destroy_sock(sk);
1737 inet6_destroy_sock(sk);
1738}
1739
1740#ifdef CONFIG_PROC_FS
1741/* Proc filesystem TCPv6 sock list dumping. */
1742static void get_openreq6(struct seq_file *seq,
1743 const struct sock *sk, struct request_sock *req, int i, kuid_t uid)
1744{
1745 int ttd = req->expires - jiffies;
1746 const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1747 const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1748
1749 if (ttd < 0)
1750 ttd = 0;
1751
1752 seq_printf(seq,
1753 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1754 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1755 i,
1756 src->s6_addr32[0], src->s6_addr32[1],
1757 src->s6_addr32[2], src->s6_addr32[3],
1758 inet_rsk(req)->ir_num,
1759 dest->s6_addr32[0], dest->s6_addr32[1],
1760 dest->s6_addr32[2], dest->s6_addr32[3],
1761 ntohs(inet_rsk(req)->ir_rmt_port),
1762 TCP_SYN_RECV,
1763 0, 0, /* could print option size, but that is af dependent. */
1764 1, /* timers active (only the expire timer) */
1765 jiffies_to_clock_t(ttd),
1766 req->num_timeout,
1767 from_kuid_munged(seq_user_ns(seq), uid),
1768 0, /* non standard timer */
1769 0, /* open_requests have no inode */
1770 0, req);
1771}
1772
1773static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1774{
1775 const struct in6_addr *dest, *src;
1776 __u16 destp, srcp;
1777 int timer_active;
1778 unsigned long timer_expires;
1779 const struct inet_sock *inet = inet_sk(sp);
1780 const struct tcp_sock *tp = tcp_sk(sp);
1781 const struct inet_connection_sock *icsk = inet_csk(sp);
1782
1783 dest = &sp->sk_v6_daddr;
1784 src = &sp->sk_v6_rcv_saddr;
1785 destp = ntohs(inet->inet_dport);
1786 srcp = ntohs(inet->inet_sport);
1787
1788 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1789 timer_active = 1;
1790 timer_expires = icsk->icsk_timeout;
1791 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1792 timer_active = 4;
1793 timer_expires = icsk->icsk_timeout;
1794 } else if (timer_pending(&sp->sk_timer)) {
1795 timer_active = 2;
1796 timer_expires = sp->sk_timer.expires;
1797 } else {
1798 timer_active = 0;
1799 timer_expires = jiffies;
1800 }
1801
1802 seq_printf(seq,
1803 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1804 "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1805 i,
1806 src->s6_addr32[0], src->s6_addr32[1],
1807 src->s6_addr32[2], src->s6_addr32[3], srcp,
1808 dest->s6_addr32[0], dest->s6_addr32[1],
1809 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1810 sp->sk_state,
1811 tp->write_seq-tp->snd_una,
1812 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1813 timer_active,
1814 jiffies_delta_to_clock_t(timer_expires - jiffies),
1815 icsk->icsk_retransmits,
1816 from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1817 icsk->icsk_probes_out,
1818 sock_i_ino(sp),
1819 atomic_read(&sp->sk_refcnt), sp,
1820 jiffies_to_clock_t(icsk->icsk_rto),
1821 jiffies_to_clock_t(icsk->icsk_ack.ato),
1822 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1823 tp->snd_cwnd,
1824 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1825 );
1826}
1827
1828static void get_timewait6_sock(struct seq_file *seq,
1829 struct inet_timewait_sock *tw, int i)
1830{
1831 const struct in6_addr *dest, *src;
1832 __u16 destp, srcp;
1833 s32 delta = tw->tw_ttd - inet_tw_time_stamp();
1834
1835 dest = &tw->tw_v6_daddr;
1836 src = &tw->tw_v6_rcv_saddr;
1837 destp = ntohs(tw->tw_dport);
1838 srcp = ntohs(tw->tw_sport);
1839
1840 seq_printf(seq,
1841 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1842 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1843 i,
1844 src->s6_addr32[0], src->s6_addr32[1],
1845 src->s6_addr32[2], src->s6_addr32[3], srcp,
1846 dest->s6_addr32[0], dest->s6_addr32[1],
1847 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1848 tw->tw_substate, 0, 0,
1849 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1850 atomic_read(&tw->tw_refcnt), tw);
1851}
1852
1853static int tcp6_seq_show(struct seq_file *seq, void *v)
1854{
1855 struct tcp_iter_state *st;
1856 struct sock *sk = v;
1857
1858 if (v == SEQ_START_TOKEN) {
1859 seq_puts(seq,
1860 " sl "
1861 "local_address "
1862 "remote_address "
1863 "st tx_queue rx_queue tr tm->when retrnsmt"
1864 " uid timeout inode\n");
1865 goto out;
1866 }
1867 st = seq->private;
1868
1869 switch (st->state) {
1870 case TCP_SEQ_STATE_LISTENING:
1871 case TCP_SEQ_STATE_ESTABLISHED:
1872 if (sk->sk_state == TCP_TIME_WAIT)
1873 get_timewait6_sock(seq, v, st->num);
1874 else
1875 get_tcp6_sock(seq, v, st->num);
1876 break;
1877 case TCP_SEQ_STATE_OPENREQ:
1878 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1879 break;
1880 }
1881out:
1882 return 0;
1883}
1884
1885static const struct file_operations tcp6_afinfo_seq_fops = {
1886 .owner = THIS_MODULE,
1887 .open = tcp_seq_open,
1888 .read = seq_read,
1889 .llseek = seq_lseek,
1890 .release = seq_release_net
1891};
1892
1893static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1894 .name = "tcp6",
1895 .family = AF_INET6,
1896 .seq_fops = &tcp6_afinfo_seq_fops,
1897 .seq_ops = {
1898 .show = tcp6_seq_show,
1899 },
1900};
1901
1902int __net_init tcp6_proc_init(struct net *net)
1903{
1904 return tcp_proc_register(net, &tcp6_seq_afinfo);
1905}
1906
1907void tcp6_proc_exit(struct net *net)
1908{
1909 tcp_proc_unregister(net, &tcp6_seq_afinfo);
1910}
1911#endif
1912
1913static void tcp_v6_clear_sk(struct sock *sk, int size)
1914{
1915 struct inet_sock *inet = inet_sk(sk);
1916
1917 /* we do not want to clear pinet6 field, because of RCU lookups */
1918 sk_prot_clear_nulls(sk, offsetof(struct inet_sock, pinet6));
1919
1920 size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1921 memset(&inet->pinet6 + 1, 0, size);
1922}
1923
1924struct proto tcpv6_prot = {
1925 .name = "TCPv6",
1926 .owner = THIS_MODULE,
1927 .close = tcp_close,
1928 .connect = tcp_v6_connect,
1929 .disconnect = tcp_disconnect,
1930 .accept = inet_csk_accept,
1931 .ioctl = tcp_ioctl,
1932 .init = tcp_v6_init_sock,
1933 .destroy = tcp_v6_destroy_sock,
1934 .shutdown = tcp_shutdown,
1935 .setsockopt = tcp_setsockopt,
1936 .getsockopt = tcp_getsockopt,
1937 .recvmsg = tcp_recvmsg,
1938 .sendmsg = tcp_sendmsg,
1939 .sendpage = tcp_sendpage,
1940 .backlog_rcv = tcp_v6_do_rcv,
1941 .release_cb = tcp_release_cb,
1942 .mtu_reduced = tcp_v6_mtu_reduced,
1943 .hash = tcp_v6_hash,
1944 .unhash = inet_unhash,
1945 .get_port = inet_csk_get_port,
1946 .enter_memory_pressure = tcp_enter_memory_pressure,
1947 .stream_memory_free = tcp_stream_memory_free,
1948 .sockets_allocated = &tcp_sockets_allocated,
1949 .memory_allocated = &tcp_memory_allocated,
1950 .memory_pressure = &tcp_memory_pressure,
1951 .orphan_count = &tcp_orphan_count,
1952 .sysctl_mem = sysctl_tcp_mem,
1953 .sysctl_wmem = sysctl_tcp_wmem,
1954 .sysctl_rmem = sysctl_tcp_rmem,
1955 .max_header = MAX_TCP_HEADER,
1956 .obj_size = sizeof(struct tcp6_sock),
1957 .slab_flags = SLAB_DESTROY_BY_RCU,
1958 .twsk_prot = &tcp6_timewait_sock_ops,
1959 .rsk_prot = &tcp6_request_sock_ops,
1960 .h.hashinfo = &tcp_hashinfo,
1961 .no_autobind = true,
1962#ifdef CONFIG_COMPAT
1963 .compat_setsockopt = compat_tcp_setsockopt,
1964 .compat_getsockopt = compat_tcp_getsockopt,
1965#endif
1966#ifdef CONFIG_MEMCG_KMEM
1967 .proto_cgroup = tcp_proto_cgroup,
1968#endif
1969 .clear_sk = tcp_v6_clear_sk,
1970};
1971
1972static const struct inet6_protocol tcpv6_protocol = {
1973 .early_demux = tcp_v6_early_demux,
1974 .handler = tcp_v6_rcv,
1975 .err_handler = tcp_v6_err,
1976 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1977};
1978
1979static struct inet_protosw tcpv6_protosw = {
1980 .type = SOCK_STREAM,
1981 .protocol = IPPROTO_TCP,
1982 .prot = &tcpv6_prot,
1983 .ops = &inet6_stream_ops,
1984 .no_check = 0,
1985 .flags = INET_PROTOSW_PERMANENT |
1986 INET_PROTOSW_ICSK,
1987};
1988
1989static int __net_init tcpv6_net_init(struct net *net)
1990{
1991 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1992 SOCK_RAW, IPPROTO_TCP, net);
1993}
1994
1995static void __net_exit tcpv6_net_exit(struct net *net)
1996{
1997 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1998}
1999
2000static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2001{
2002 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2003}
2004
2005static struct pernet_operations tcpv6_net_ops = {
2006 .init = tcpv6_net_init,
2007 .exit = tcpv6_net_exit,
2008 .exit_batch = tcpv6_net_exit_batch,
2009};
2010
2011int __init tcpv6_init(void)
2012{
2013 int ret;
2014
2015 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2016 if (ret)
2017 goto out;
2018
2019 /* register inet6 protocol */
2020 ret = inet6_register_protosw(&tcpv6_protosw);
2021 if (ret)
2022 goto out_tcpv6_protocol;
2023
2024 ret = register_pernet_subsys(&tcpv6_net_ops);
2025 if (ret)
2026 goto out_tcpv6_protosw;
2027out:
2028 return ret;
2029
2030out_tcpv6_protosw:
2031 inet6_unregister_protosw(&tcpv6_protosw);
2032out_tcpv6_protocol:
2033 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2034 goto out;
2035}
2036
2037void tcpv6_exit(void)
2038{
2039 unregister_pernet_subsys(&tcpv6_net_ops);
2040 inet6_unregister_protosw(&tcpv6_protosw);
2041 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2042}
1/*
2 * TCP over IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on:
9 * linux/net/ipv4/tcp.c
10 * linux/net/ipv4/tcp_input.c
11 * linux/net/ipv4/tcp_output.c
12 *
13 * Fixes:
14 * Hideaki YOSHIFUJI : sin6_scope_id support
15 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
16 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
17 * a single port at the same time.
18 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26#include <linux/bottom_half.h>
27#include <linux/module.h>
28#include <linux/errno.h>
29#include <linux/types.h>
30#include <linux/socket.h>
31#include <linux/sockios.h>
32#include <linux/net.h>
33#include <linux/jiffies.h>
34#include <linux/in.h>
35#include <linux/in6.h>
36#include <linux/netdevice.h>
37#include <linux/init.h>
38#include <linux/jhash.h>
39#include <linux/ipsec.h>
40#include <linux/times.h>
41#include <linux/slab.h>
42
43#include <linux/ipv6.h>
44#include <linux/icmpv6.h>
45#include <linux/random.h>
46
47#include <net/tcp.h>
48#include <net/ndisc.h>
49#include <net/inet6_hashtables.h>
50#include <net/inet6_connection_sock.h>
51#include <net/ipv6.h>
52#include <net/transp_v6.h>
53#include <net/addrconf.h>
54#include <net/ip6_route.h>
55#include <net/ip6_checksum.h>
56#include <net/inet_ecn.h>
57#include <net/protocol.h>
58#include <net/xfrm.h>
59#include <net/snmp.h>
60#include <net/dsfield.h>
61#include <net/timewait_sock.h>
62#include <net/netdma.h>
63#include <net/inet_common.h>
64#include <net/secure_seq.h>
65#include <net/tcp_memcontrol.h>
66
67#include <asm/uaccess.h>
68
69#include <linux/proc_fs.h>
70#include <linux/seq_file.h>
71
72#include <linux/crypto.h>
73#include <linux/scatterlist.h>
74
75static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
76static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
77 struct request_sock *req);
78
79static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
80static void __tcp_v6_send_check(struct sk_buff *skb,
81 const struct in6_addr *saddr,
82 const struct in6_addr *daddr);
83
84static const struct inet_connection_sock_af_ops ipv6_mapped;
85static const struct inet_connection_sock_af_ops ipv6_specific;
86#ifdef CONFIG_TCP_MD5SIG
87static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
88static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
89#else
90static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
91 const struct in6_addr *addr)
92{
93 return NULL;
94}
95#endif
96
97static void tcp_v6_hash(struct sock *sk)
98{
99 if (sk->sk_state != TCP_CLOSE) {
100 if (inet_csk(sk)->icsk_af_ops == &ipv6_mapped) {
101 tcp_prot.hash(sk);
102 return;
103 }
104 local_bh_disable();
105 __inet6_hash(sk, NULL);
106 local_bh_enable();
107 }
108}
109
110static __inline__ __sum16 tcp_v6_check(int len,
111 const struct in6_addr *saddr,
112 const struct in6_addr *daddr,
113 __wsum base)
114{
115 return csum_ipv6_magic(saddr, daddr, len, IPPROTO_TCP, base);
116}
117
118static __u32 tcp_v6_init_sequence(const struct sk_buff *skb)
119{
120 return secure_tcpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
121 ipv6_hdr(skb)->saddr.s6_addr32,
122 tcp_hdr(skb)->dest,
123 tcp_hdr(skb)->source);
124}
125
126static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
127 int addr_len)
128{
129 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
130 struct inet_sock *inet = inet_sk(sk);
131 struct inet_connection_sock *icsk = inet_csk(sk);
132 struct ipv6_pinfo *np = inet6_sk(sk);
133 struct tcp_sock *tp = tcp_sk(sk);
134 struct in6_addr *saddr = NULL, *final_p, final;
135 struct rt6_info *rt;
136 struct flowi6 fl6;
137 struct dst_entry *dst;
138 int addr_type;
139 int err;
140
141 if (addr_len < SIN6_LEN_RFC2133)
142 return -EINVAL;
143
144 if (usin->sin6_family != AF_INET6)
145 return -EAFNOSUPPORT;
146
147 memset(&fl6, 0, sizeof(fl6));
148
149 if (np->sndflow) {
150 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
151 IP6_ECN_flow_init(fl6.flowlabel);
152 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
153 struct ip6_flowlabel *flowlabel;
154 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
155 if (flowlabel == NULL)
156 return -EINVAL;
157 usin->sin6_addr = flowlabel->dst;
158 fl6_sock_release(flowlabel);
159 }
160 }
161
162 /*
163 * connect() to INADDR_ANY means loopback (BSD'ism).
164 */
165
166 if(ipv6_addr_any(&usin->sin6_addr))
167 usin->sin6_addr.s6_addr[15] = 0x1;
168
169 addr_type = ipv6_addr_type(&usin->sin6_addr);
170
171 if(addr_type & IPV6_ADDR_MULTICAST)
172 return -ENETUNREACH;
173
174 if (addr_type&IPV6_ADDR_LINKLOCAL) {
175 if (addr_len >= sizeof(struct sockaddr_in6) &&
176 usin->sin6_scope_id) {
177 /* If interface is set while binding, indices
178 * must coincide.
179 */
180 if (sk->sk_bound_dev_if &&
181 sk->sk_bound_dev_if != usin->sin6_scope_id)
182 return -EINVAL;
183
184 sk->sk_bound_dev_if = usin->sin6_scope_id;
185 }
186
187 /* Connect to link-local address requires an interface */
188 if (!sk->sk_bound_dev_if)
189 return -EINVAL;
190 }
191
192 if (tp->rx_opt.ts_recent_stamp &&
193 !ipv6_addr_equal(&np->daddr, &usin->sin6_addr)) {
194 tp->rx_opt.ts_recent = 0;
195 tp->rx_opt.ts_recent_stamp = 0;
196 tp->write_seq = 0;
197 }
198
199 np->daddr = usin->sin6_addr;
200 np->flow_label = fl6.flowlabel;
201
202 /*
203 * TCP over IPv4
204 */
205
206 if (addr_type == IPV6_ADDR_MAPPED) {
207 u32 exthdrlen = icsk->icsk_ext_hdr_len;
208 struct sockaddr_in sin;
209
210 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
211
212 if (__ipv6_only_sock(sk))
213 return -ENETUNREACH;
214
215 sin.sin_family = AF_INET;
216 sin.sin_port = usin->sin6_port;
217 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
218
219 icsk->icsk_af_ops = &ipv6_mapped;
220 sk->sk_backlog_rcv = tcp_v4_do_rcv;
221#ifdef CONFIG_TCP_MD5SIG
222 tp->af_specific = &tcp_sock_ipv6_mapped_specific;
223#endif
224
225 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
226
227 if (err) {
228 icsk->icsk_ext_hdr_len = exthdrlen;
229 icsk->icsk_af_ops = &ipv6_specific;
230 sk->sk_backlog_rcv = tcp_v6_do_rcv;
231#ifdef CONFIG_TCP_MD5SIG
232 tp->af_specific = &tcp_sock_ipv6_specific;
233#endif
234 goto failure;
235 } else {
236 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
237 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
238 &np->rcv_saddr);
239 }
240
241 return err;
242 }
243
244 if (!ipv6_addr_any(&np->rcv_saddr))
245 saddr = &np->rcv_saddr;
246
247 fl6.flowi6_proto = IPPROTO_TCP;
248 fl6.daddr = np->daddr;
249 fl6.saddr = saddr ? *saddr : np->saddr;
250 fl6.flowi6_oif = sk->sk_bound_dev_if;
251 fl6.flowi6_mark = sk->sk_mark;
252 fl6.fl6_dport = usin->sin6_port;
253 fl6.fl6_sport = inet->inet_sport;
254
255 final_p = fl6_update_dst(&fl6, np->opt, &final);
256
257 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
258
259 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
260 if (IS_ERR(dst)) {
261 err = PTR_ERR(dst);
262 goto failure;
263 }
264
265 if (saddr == NULL) {
266 saddr = &fl6.saddr;
267 np->rcv_saddr = *saddr;
268 }
269
270 /* set the source address */
271 np->saddr = *saddr;
272 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
273
274 sk->sk_gso_type = SKB_GSO_TCPV6;
275 __ip6_dst_store(sk, dst, NULL, NULL);
276
277 rt = (struct rt6_info *) dst;
278 if (tcp_death_row.sysctl_tw_recycle &&
279 !tp->rx_opt.ts_recent_stamp &&
280 ipv6_addr_equal(&rt->rt6i_dst.addr, &np->daddr)) {
281 struct inet_peer *peer = rt6_get_peer(rt);
282 /*
283 * VJ's idea. We save last timestamp seen from
284 * the destination in peer table, when entering state
285 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
286 * when trying new connection.
287 */
288 if (peer) {
289 inet_peer_refcheck(peer);
290 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
291 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
292 tp->rx_opt.ts_recent = peer->tcp_ts;
293 }
294 }
295 }
296
297 icsk->icsk_ext_hdr_len = 0;
298 if (np->opt)
299 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
300 np->opt->opt_nflen);
301
302 tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
303
304 inet->inet_dport = usin->sin6_port;
305
306 tcp_set_state(sk, TCP_SYN_SENT);
307 err = inet6_hash_connect(&tcp_death_row, sk);
308 if (err)
309 goto late_failure;
310
311 if (!tp->write_seq)
312 tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
313 np->daddr.s6_addr32,
314 inet->inet_sport,
315 inet->inet_dport);
316
317 err = tcp_connect(sk);
318 if (err)
319 goto late_failure;
320
321 return 0;
322
323late_failure:
324 tcp_set_state(sk, TCP_CLOSE);
325 __sk_dst_reset(sk);
326failure:
327 inet->inet_dport = 0;
328 sk->sk_route_caps = 0;
329 return err;
330}
331
332static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
333 u8 type, u8 code, int offset, __be32 info)
334{
335 const struct ipv6hdr *hdr = (const struct ipv6hdr*)skb->data;
336 const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
337 struct ipv6_pinfo *np;
338 struct sock *sk;
339 int err;
340 struct tcp_sock *tp;
341 __u32 seq;
342 struct net *net = dev_net(skb->dev);
343
344 sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
345 th->dest, &hdr->saddr, th->source, skb->dev->ifindex);
346
347 if (sk == NULL) {
348 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
349 ICMP6_MIB_INERRORS);
350 return;
351 }
352
353 if (sk->sk_state == TCP_TIME_WAIT) {
354 inet_twsk_put(inet_twsk(sk));
355 return;
356 }
357
358 bh_lock_sock(sk);
359 if (sock_owned_by_user(sk))
360 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
361
362 if (sk->sk_state == TCP_CLOSE)
363 goto out;
364
365 if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
366 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
367 goto out;
368 }
369
370 tp = tcp_sk(sk);
371 seq = ntohl(th->seq);
372 if (sk->sk_state != TCP_LISTEN &&
373 !between(seq, tp->snd_una, tp->snd_nxt)) {
374 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
375 goto out;
376 }
377
378 np = inet6_sk(sk);
379
380 if (type == ICMPV6_PKT_TOOBIG) {
381 struct dst_entry *dst;
382
383 if (sock_owned_by_user(sk))
384 goto out;
385 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
386 goto out;
387
388 /* icmp should have updated the destination cache entry */
389 dst = __sk_dst_check(sk, np->dst_cookie);
390
391 if (dst == NULL) {
392 struct inet_sock *inet = inet_sk(sk);
393 struct flowi6 fl6;
394
395 /* BUGGG_FUTURE: Again, it is not clear how
396 to handle rthdr case. Ignore this complexity
397 for now.
398 */
399 memset(&fl6, 0, sizeof(fl6));
400 fl6.flowi6_proto = IPPROTO_TCP;
401 fl6.daddr = np->daddr;
402 fl6.saddr = np->saddr;
403 fl6.flowi6_oif = sk->sk_bound_dev_if;
404 fl6.flowi6_mark = sk->sk_mark;
405 fl6.fl6_dport = inet->inet_dport;
406 fl6.fl6_sport = inet->inet_sport;
407 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
408
409 dst = ip6_dst_lookup_flow(sk, &fl6, NULL, false);
410 if (IS_ERR(dst)) {
411 sk->sk_err_soft = -PTR_ERR(dst);
412 goto out;
413 }
414
415 } else
416 dst_hold(dst);
417
418 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
419 tcp_sync_mss(sk, dst_mtu(dst));
420 tcp_simple_retransmit(sk);
421 } /* else let the usual retransmit timer handle it */
422 dst_release(dst);
423 goto out;
424 }
425
426 icmpv6_err_convert(type, code, &err);
427
428 /* Might be for an request_sock */
429 switch (sk->sk_state) {
430 struct request_sock *req, **prev;
431 case TCP_LISTEN:
432 if (sock_owned_by_user(sk))
433 goto out;
434
435 req = inet6_csk_search_req(sk, &prev, th->dest, &hdr->daddr,
436 &hdr->saddr, inet6_iif(skb));
437 if (!req)
438 goto out;
439
440 /* ICMPs are not backlogged, hence we cannot get
441 * an established socket here.
442 */
443 WARN_ON(req->sk != NULL);
444
445 if (seq != tcp_rsk(req)->snt_isn) {
446 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
447 goto out;
448 }
449
450 inet_csk_reqsk_queue_drop(sk, req, prev);
451 goto out;
452
453 case TCP_SYN_SENT:
454 case TCP_SYN_RECV: /* Cannot happen.
455 It can, it SYNs are crossed. --ANK */
456 if (!sock_owned_by_user(sk)) {
457 sk->sk_err = err;
458 sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
459
460 tcp_done(sk);
461 } else
462 sk->sk_err_soft = err;
463 goto out;
464 }
465
466 if (!sock_owned_by_user(sk) && np->recverr) {
467 sk->sk_err = err;
468 sk->sk_error_report(sk);
469 } else
470 sk->sk_err_soft = err;
471
472out:
473 bh_unlock_sock(sk);
474 sock_put(sk);
475}
476
477
478static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
479 struct request_values *rvp,
480 u16 queue_mapping)
481{
482 struct inet6_request_sock *treq = inet6_rsk(req);
483 struct ipv6_pinfo *np = inet6_sk(sk);
484 struct sk_buff * skb;
485 struct ipv6_txoptions *opt = NULL;
486 struct in6_addr * final_p, final;
487 struct flowi6 fl6;
488 struct dst_entry *dst;
489 int err;
490
491 memset(&fl6, 0, sizeof(fl6));
492 fl6.flowi6_proto = IPPROTO_TCP;
493 fl6.daddr = treq->rmt_addr;
494 fl6.saddr = treq->loc_addr;
495 fl6.flowlabel = 0;
496 fl6.flowi6_oif = treq->iif;
497 fl6.flowi6_mark = sk->sk_mark;
498 fl6.fl6_dport = inet_rsk(req)->rmt_port;
499 fl6.fl6_sport = inet_rsk(req)->loc_port;
500 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
501
502 opt = np->opt;
503 final_p = fl6_update_dst(&fl6, opt, &final);
504
505 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
506 if (IS_ERR(dst)) {
507 err = PTR_ERR(dst);
508 dst = NULL;
509 goto done;
510 }
511 skb = tcp_make_synack(sk, dst, req, rvp);
512 err = -ENOMEM;
513 if (skb) {
514 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
515
516 fl6.daddr = treq->rmt_addr;
517 skb_set_queue_mapping(skb, queue_mapping);
518 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
519 err = net_xmit_eval(err);
520 }
521
522done:
523 if (opt && opt != np->opt)
524 sock_kfree_s(sk, opt, opt->tot_len);
525 dst_release(dst);
526 return err;
527}
528
529static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
530 struct request_values *rvp)
531{
532 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
533 return tcp_v6_send_synack(sk, req, rvp, 0);
534}
535
536static void tcp_v6_reqsk_destructor(struct request_sock *req)
537{
538 kfree_skb(inet6_rsk(req)->pktopts);
539}
540
541#ifdef CONFIG_TCP_MD5SIG
542static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
543 const struct in6_addr *addr)
544{
545 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
546}
547
548static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
549 struct sock *addr_sk)
550{
551 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
552}
553
554static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
555 struct request_sock *req)
556{
557 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
558}
559
560static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
561 int optlen)
562{
563 struct tcp_md5sig cmd;
564 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
565
566 if (optlen < sizeof(cmd))
567 return -EINVAL;
568
569 if (copy_from_user(&cmd, optval, sizeof(cmd)))
570 return -EFAULT;
571
572 if (sin6->sin6_family != AF_INET6)
573 return -EINVAL;
574
575 if (!cmd.tcpm_keylen) {
576 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
577 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
578 AF_INET);
579 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
580 AF_INET6);
581 }
582
583 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
584 return -EINVAL;
585
586 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
587 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
588 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
589
590 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
591 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
592}
593
594static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
595 const struct in6_addr *daddr,
596 const struct in6_addr *saddr, int nbytes)
597{
598 struct tcp6_pseudohdr *bp;
599 struct scatterlist sg;
600
601 bp = &hp->md5_blk.ip6;
602 /* 1. TCP pseudo-header (RFC2460) */
603 bp->saddr = *saddr;
604 bp->daddr = *daddr;
605 bp->protocol = cpu_to_be32(IPPROTO_TCP);
606 bp->len = cpu_to_be32(nbytes);
607
608 sg_init_one(&sg, bp, sizeof(*bp));
609 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
610}
611
612static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
613 const struct in6_addr *daddr, struct in6_addr *saddr,
614 const struct tcphdr *th)
615{
616 struct tcp_md5sig_pool *hp;
617 struct hash_desc *desc;
618
619 hp = tcp_get_md5sig_pool();
620 if (!hp)
621 goto clear_hash_noput;
622 desc = &hp->md5_desc;
623
624 if (crypto_hash_init(desc))
625 goto clear_hash;
626 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
627 goto clear_hash;
628 if (tcp_md5_hash_header(hp, th))
629 goto clear_hash;
630 if (tcp_md5_hash_key(hp, key))
631 goto clear_hash;
632 if (crypto_hash_final(desc, md5_hash))
633 goto clear_hash;
634
635 tcp_put_md5sig_pool();
636 return 0;
637
638clear_hash:
639 tcp_put_md5sig_pool();
640clear_hash_noput:
641 memset(md5_hash, 0, 16);
642 return 1;
643}
644
645static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
646 const struct sock *sk,
647 const struct request_sock *req,
648 const struct sk_buff *skb)
649{
650 const struct in6_addr *saddr, *daddr;
651 struct tcp_md5sig_pool *hp;
652 struct hash_desc *desc;
653 const struct tcphdr *th = tcp_hdr(skb);
654
655 if (sk) {
656 saddr = &inet6_sk(sk)->saddr;
657 daddr = &inet6_sk(sk)->daddr;
658 } else if (req) {
659 saddr = &inet6_rsk(req)->loc_addr;
660 daddr = &inet6_rsk(req)->rmt_addr;
661 } else {
662 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
663 saddr = &ip6h->saddr;
664 daddr = &ip6h->daddr;
665 }
666
667 hp = tcp_get_md5sig_pool();
668 if (!hp)
669 goto clear_hash_noput;
670 desc = &hp->md5_desc;
671
672 if (crypto_hash_init(desc))
673 goto clear_hash;
674
675 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
676 goto clear_hash;
677 if (tcp_md5_hash_header(hp, th))
678 goto clear_hash;
679 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
680 goto clear_hash;
681 if (tcp_md5_hash_key(hp, key))
682 goto clear_hash;
683 if (crypto_hash_final(desc, md5_hash))
684 goto clear_hash;
685
686 tcp_put_md5sig_pool();
687 return 0;
688
689clear_hash:
690 tcp_put_md5sig_pool();
691clear_hash_noput:
692 memset(md5_hash, 0, 16);
693 return 1;
694}
695
696static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
697{
698 const __u8 *hash_location = NULL;
699 struct tcp_md5sig_key *hash_expected;
700 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
701 const struct tcphdr *th = tcp_hdr(skb);
702 int genhash;
703 u8 newhash[16];
704
705 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
706 hash_location = tcp_parse_md5sig_option(th);
707
708 /* We've parsed the options - do we have a hash? */
709 if (!hash_expected && !hash_location)
710 return 0;
711
712 if (hash_expected && !hash_location) {
713 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
714 return 1;
715 }
716
717 if (!hash_expected && hash_location) {
718 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
719 return 1;
720 }
721
722 /* check the signature */
723 genhash = tcp_v6_md5_hash_skb(newhash,
724 hash_expected,
725 NULL, NULL, skb);
726
727 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
728 net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
729 genhash ? "failed" : "mismatch",
730 &ip6h->saddr, ntohs(th->source),
731 &ip6h->daddr, ntohs(th->dest));
732 return 1;
733 }
734 return 0;
735}
736#endif
737
738struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
739 .family = AF_INET6,
740 .obj_size = sizeof(struct tcp6_request_sock),
741 .rtx_syn_ack = tcp_v6_rtx_synack,
742 .send_ack = tcp_v6_reqsk_send_ack,
743 .destructor = tcp_v6_reqsk_destructor,
744 .send_reset = tcp_v6_send_reset,
745 .syn_ack_timeout = tcp_syn_ack_timeout,
746};
747
748#ifdef CONFIG_TCP_MD5SIG
749static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
750 .md5_lookup = tcp_v6_reqsk_md5_lookup,
751 .calc_md5_hash = tcp_v6_md5_hash_skb,
752};
753#endif
754
755static void __tcp_v6_send_check(struct sk_buff *skb,
756 const struct in6_addr *saddr, const struct in6_addr *daddr)
757{
758 struct tcphdr *th = tcp_hdr(skb);
759
760 if (skb->ip_summed == CHECKSUM_PARTIAL) {
761 th->check = ~tcp_v6_check(skb->len, saddr, daddr, 0);
762 skb->csum_start = skb_transport_header(skb) - skb->head;
763 skb->csum_offset = offsetof(struct tcphdr, check);
764 } else {
765 th->check = tcp_v6_check(skb->len, saddr, daddr,
766 csum_partial(th, th->doff << 2,
767 skb->csum));
768 }
769}
770
771static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
772{
773 struct ipv6_pinfo *np = inet6_sk(sk);
774
775 __tcp_v6_send_check(skb, &np->saddr, &np->daddr);
776}
777
778static int tcp_v6_gso_send_check(struct sk_buff *skb)
779{
780 const struct ipv6hdr *ipv6h;
781 struct tcphdr *th;
782
783 if (!pskb_may_pull(skb, sizeof(*th)))
784 return -EINVAL;
785
786 ipv6h = ipv6_hdr(skb);
787 th = tcp_hdr(skb);
788
789 th->check = 0;
790 skb->ip_summed = CHECKSUM_PARTIAL;
791 __tcp_v6_send_check(skb, &ipv6h->saddr, &ipv6h->daddr);
792 return 0;
793}
794
795static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
796 struct sk_buff *skb)
797{
798 const struct ipv6hdr *iph = skb_gro_network_header(skb);
799
800 switch (skb->ip_summed) {
801 case CHECKSUM_COMPLETE:
802 if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
803 skb->csum)) {
804 skb->ip_summed = CHECKSUM_UNNECESSARY;
805 break;
806 }
807
808 /* fall through */
809 case CHECKSUM_NONE:
810 NAPI_GRO_CB(skb)->flush = 1;
811 return NULL;
812 }
813
814 return tcp_gro_receive(head, skb);
815}
816
817static int tcp6_gro_complete(struct sk_buff *skb)
818{
819 const struct ipv6hdr *iph = ipv6_hdr(skb);
820 struct tcphdr *th = tcp_hdr(skb);
821
822 th->check = ~tcp_v6_check(skb->len - skb_transport_offset(skb),
823 &iph->saddr, &iph->daddr, 0);
824 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
825
826 return tcp_gro_complete(skb);
827}
828
829static void tcp_v6_send_response(struct sk_buff *skb, u32 seq, u32 ack, u32 win,
830 u32 ts, struct tcp_md5sig_key *key, int rst, u8 tclass)
831{
832 const struct tcphdr *th = tcp_hdr(skb);
833 struct tcphdr *t1;
834 struct sk_buff *buff;
835 struct flowi6 fl6;
836 struct net *net = dev_net(skb_dst(skb)->dev);
837 struct sock *ctl_sk = net->ipv6.tcp_sk;
838 unsigned int tot_len = sizeof(struct tcphdr);
839 struct dst_entry *dst;
840 __be32 *topt;
841
842 if (ts)
843 tot_len += TCPOLEN_TSTAMP_ALIGNED;
844#ifdef CONFIG_TCP_MD5SIG
845 if (key)
846 tot_len += TCPOLEN_MD5SIG_ALIGNED;
847#endif
848
849 buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
850 GFP_ATOMIC);
851 if (buff == NULL)
852 return;
853
854 skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
855
856 t1 = (struct tcphdr *) skb_push(buff, tot_len);
857 skb_reset_transport_header(buff);
858
859 /* Swap the send and the receive. */
860 memset(t1, 0, sizeof(*t1));
861 t1->dest = th->source;
862 t1->source = th->dest;
863 t1->doff = tot_len / 4;
864 t1->seq = htonl(seq);
865 t1->ack_seq = htonl(ack);
866 t1->ack = !rst || !th->ack;
867 t1->rst = rst;
868 t1->window = htons(win);
869
870 topt = (__be32 *)(t1 + 1);
871
872 if (ts) {
873 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
874 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
875 *topt++ = htonl(tcp_time_stamp);
876 *topt++ = htonl(ts);
877 }
878
879#ifdef CONFIG_TCP_MD5SIG
880 if (key) {
881 *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
882 (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
883 tcp_v6_md5_hash_hdr((__u8 *)topt, key,
884 &ipv6_hdr(skb)->saddr,
885 &ipv6_hdr(skb)->daddr, t1);
886 }
887#endif
888
889 memset(&fl6, 0, sizeof(fl6));
890 fl6.daddr = ipv6_hdr(skb)->saddr;
891 fl6.saddr = ipv6_hdr(skb)->daddr;
892
893 buff->ip_summed = CHECKSUM_PARTIAL;
894 buff->csum = 0;
895
896 __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
897
898 fl6.flowi6_proto = IPPROTO_TCP;
899 fl6.flowi6_oif = inet6_iif(skb);
900 fl6.fl6_dport = t1->dest;
901 fl6.fl6_sport = t1->source;
902 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
903
904 /* Pass a socket to ip6_dst_lookup either it is for RST
905 * Underlying function will use this to retrieve the network
906 * namespace
907 */
908 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
909 if (!IS_ERR(dst)) {
910 skb_dst_set(buff, dst);
911 ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass);
912 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
913 if (rst)
914 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
915 return;
916 }
917
918 kfree_skb(buff);
919}
920
921static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
922{
923 const struct tcphdr *th = tcp_hdr(skb);
924 u32 seq = 0, ack_seq = 0;
925 struct tcp_md5sig_key *key = NULL;
926#ifdef CONFIG_TCP_MD5SIG
927 const __u8 *hash_location = NULL;
928 struct ipv6hdr *ipv6h = ipv6_hdr(skb);
929 unsigned char newhash[16];
930 int genhash;
931 struct sock *sk1 = NULL;
932#endif
933
934 if (th->rst)
935 return;
936
937 if (!ipv6_unicast_destination(skb))
938 return;
939
940#ifdef CONFIG_TCP_MD5SIG
941 hash_location = tcp_parse_md5sig_option(th);
942 if (!sk && hash_location) {
943 /*
944 * active side is lost. Try to find listening socket through
945 * source port, and then find md5 key through listening socket.
946 * we are not loose security here:
947 * Incoming packet is checked with md5 hash with finding key,
948 * no RST generated if md5 hash doesn't match.
949 */
950 sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
951 &tcp_hashinfo, &ipv6h->daddr,
952 ntohs(th->source), inet6_iif(skb));
953 if (!sk1)
954 return;
955
956 rcu_read_lock();
957 key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
958 if (!key)
959 goto release_sk1;
960
961 genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
962 if (genhash || memcmp(hash_location, newhash, 16) != 0)
963 goto release_sk1;
964 } else {
965 key = sk ? tcp_v6_md5_do_lookup(sk, &ipv6h->saddr) : NULL;
966 }
967#endif
968
969 if (th->ack)
970 seq = ntohl(th->ack_seq);
971 else
972 ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
973 (th->doff << 2);
974
975 tcp_v6_send_response(skb, seq, ack_seq, 0, 0, key, 1, 0);
976
977#ifdef CONFIG_TCP_MD5SIG
978release_sk1:
979 if (sk1) {
980 rcu_read_unlock();
981 sock_put(sk1);
982 }
983#endif
984}
985
986static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts,
987 struct tcp_md5sig_key *key, u8 tclass)
988{
989 tcp_v6_send_response(skb, seq, ack, win, ts, key, 0, tclass);
990}
991
992static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
993{
994 struct inet_timewait_sock *tw = inet_twsk(sk);
995 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
996
997 tcp_v6_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
998 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
999 tcptw->tw_ts_recent, tcp_twsk_md5_key(tcptw),
1000 tw->tw_tclass);
1001
1002 inet_twsk_put(tw);
1003}
1004
1005static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
1006 struct request_sock *req)
1007{
1008 tcp_v6_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, req->ts_recent,
1009 tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr), 0);
1010}
1011
1012
1013static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
1014{
1015 struct request_sock *req, **prev;
1016 const struct tcphdr *th = tcp_hdr(skb);
1017 struct sock *nsk;
1018
1019 /* Find possible connection requests. */
1020 req = inet6_csk_search_req(sk, &prev, th->source,
1021 &ipv6_hdr(skb)->saddr,
1022 &ipv6_hdr(skb)->daddr, inet6_iif(skb));
1023 if (req)
1024 return tcp_check_req(sk, skb, req, prev);
1025
1026 nsk = __inet6_lookup_established(sock_net(sk), &tcp_hashinfo,
1027 &ipv6_hdr(skb)->saddr, th->source,
1028 &ipv6_hdr(skb)->daddr, ntohs(th->dest), inet6_iif(skb));
1029
1030 if (nsk) {
1031 if (nsk->sk_state != TCP_TIME_WAIT) {
1032 bh_lock_sock(nsk);
1033 return nsk;
1034 }
1035 inet_twsk_put(inet_twsk(nsk));
1036 return NULL;
1037 }
1038
1039#ifdef CONFIG_SYN_COOKIES
1040 if (!th->syn)
1041 sk = cookie_v6_check(sk, skb);
1042#endif
1043 return sk;
1044}
1045
1046/* FIXME: this is substantially similar to the ipv4 code.
1047 * Can some kind of merge be done? -- erics
1048 */
1049static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1050{
1051 struct tcp_extend_values tmp_ext;
1052 struct tcp_options_received tmp_opt;
1053 const u8 *hash_location;
1054 struct request_sock *req;
1055 struct inet6_request_sock *treq;
1056 struct ipv6_pinfo *np = inet6_sk(sk);
1057 struct tcp_sock *tp = tcp_sk(sk);
1058 __u32 isn = TCP_SKB_CB(skb)->when;
1059 struct dst_entry *dst = NULL;
1060 bool want_cookie = false;
1061
1062 if (skb->protocol == htons(ETH_P_IP))
1063 return tcp_v4_conn_request(sk, skb);
1064
1065 if (!ipv6_unicast_destination(skb))
1066 goto drop;
1067
1068 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1069 want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6");
1070 if (!want_cookie)
1071 goto drop;
1072 }
1073
1074 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1075 goto drop;
1076
1077 req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
1078 if (req == NULL)
1079 goto drop;
1080
1081#ifdef CONFIG_TCP_MD5SIG
1082 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv6_ops;
1083#endif
1084
1085 tcp_clear_options(&tmp_opt);
1086 tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
1087 tmp_opt.user_mss = tp->rx_opt.user_mss;
1088 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1089
1090 if (tmp_opt.cookie_plus > 0 &&
1091 tmp_opt.saw_tstamp &&
1092 !tp->rx_opt.cookie_out_never &&
1093 (sysctl_tcp_cookie_size > 0 ||
1094 (tp->cookie_values != NULL &&
1095 tp->cookie_values->cookie_desired > 0))) {
1096 u8 *c;
1097 u32 *d;
1098 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1099 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1100
1101 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1102 goto drop_and_free;
1103
1104 /* Secret recipe starts with IP addresses */
1105 d = (__force u32 *)&ipv6_hdr(skb)->daddr.s6_addr32[0];
1106 *mess++ ^= *d++;
1107 *mess++ ^= *d++;
1108 *mess++ ^= *d++;
1109 *mess++ ^= *d++;
1110 d = (__force u32 *)&ipv6_hdr(skb)->saddr.s6_addr32[0];
1111 *mess++ ^= *d++;
1112 *mess++ ^= *d++;
1113 *mess++ ^= *d++;
1114 *mess++ ^= *d++;
1115
1116 /* plus variable length Initiator Cookie */
1117 c = (u8 *)mess;
1118 while (l-- > 0)
1119 *c++ ^= *hash_location++;
1120
1121 want_cookie = false; /* not our kind of cookie */
1122 tmp_ext.cookie_out_never = 0; /* false */
1123 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1124 } else if (!tp->rx_opt.cookie_in_always) {
1125 /* redundant indications, but ensure initialization. */
1126 tmp_ext.cookie_out_never = 1; /* true */
1127 tmp_ext.cookie_plus = 0;
1128 } else {
1129 goto drop_and_free;
1130 }
1131 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1132
1133 if (want_cookie && !tmp_opt.saw_tstamp)
1134 tcp_clear_options(&tmp_opt);
1135
1136 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1137 tcp_openreq_init(req, &tmp_opt, skb);
1138
1139 treq = inet6_rsk(req);
1140 treq->rmt_addr = ipv6_hdr(skb)->saddr;
1141 treq->loc_addr = ipv6_hdr(skb)->daddr;
1142 if (!want_cookie || tmp_opt.tstamp_ok)
1143 TCP_ECN_create_request(req, skb);
1144
1145 treq->iif = sk->sk_bound_dev_if;
1146
1147 /* So that link locals have meaning */
1148 if (!sk->sk_bound_dev_if &&
1149 ipv6_addr_type(&treq->rmt_addr) & IPV6_ADDR_LINKLOCAL)
1150 treq->iif = inet6_iif(skb);
1151
1152 if (!isn) {
1153 struct inet_peer *peer = NULL;
1154
1155 if (ipv6_opt_accepted(sk, skb) ||
1156 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
1157 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
1158 atomic_inc(&skb->users);
1159 treq->pktopts = skb;
1160 }
1161
1162 if (want_cookie) {
1163 isn = cookie_v6_init_sequence(sk, skb, &req->mss);
1164 req->cookie_ts = tmp_opt.tstamp_ok;
1165 goto have_isn;
1166 }
1167
1168 /* VJ's idea. We save last timestamp seen
1169 * from the destination in peer table, when entering
1170 * state TIME-WAIT, and check against it before
1171 * accepting new connection request.
1172 *
1173 * If "isn" is not zero, this request hit alive
1174 * timewait bucket, so that all the necessary checks
1175 * are made in the function processing timewait state.
1176 */
1177 if (tmp_opt.saw_tstamp &&
1178 tcp_death_row.sysctl_tw_recycle &&
1179 (dst = inet6_csk_route_req(sk, req)) != NULL &&
1180 (peer = rt6_get_peer((struct rt6_info *)dst)) != NULL &&
1181 ipv6_addr_equal((struct in6_addr *)peer->daddr.addr.a6,
1182 &treq->rmt_addr)) {
1183 inet_peer_refcheck(peer);
1184 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1185 (s32)(peer->tcp_ts - req->ts_recent) >
1186 TCP_PAWS_WINDOW) {
1187 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1188 goto drop_and_release;
1189 }
1190 }
1191 /* Kill the following clause, if you dislike this way. */
1192 else if (!sysctl_tcp_syncookies &&
1193 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1194 (sysctl_max_syn_backlog >> 2)) &&
1195 (!peer || !peer->tcp_ts_stamp) &&
1196 (!dst || !dst_metric(dst, RTAX_RTT))) {
1197 /* Without syncookies last quarter of
1198 * backlog is filled with destinations,
1199 * proven to be alive.
1200 * It means that we continue to communicate
1201 * to destinations, already remembered
1202 * to the moment of synflood.
1203 */
1204 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI6/%u\n",
1205 &treq->rmt_addr, ntohs(tcp_hdr(skb)->source));
1206 goto drop_and_release;
1207 }
1208
1209 isn = tcp_v6_init_sequence(skb);
1210 }
1211have_isn:
1212 tcp_rsk(req)->snt_isn = isn;
1213 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1214
1215 if (security_inet_conn_request(sk, skb, req))
1216 goto drop_and_release;
1217
1218 if (tcp_v6_send_synack(sk, req,
1219 (struct request_values *)&tmp_ext,
1220 skb_get_queue_mapping(skb)) ||
1221 want_cookie)
1222 goto drop_and_free;
1223
1224 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1225 return 0;
1226
1227drop_and_release:
1228 dst_release(dst);
1229drop_and_free:
1230 reqsk_free(req);
1231drop:
1232 return 0; /* don't send reset */
1233}
1234
1235static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1236 struct request_sock *req,
1237 struct dst_entry *dst)
1238{
1239 struct inet6_request_sock *treq;
1240 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1241 struct tcp6_sock *newtcp6sk;
1242 struct inet_sock *newinet;
1243 struct tcp_sock *newtp;
1244 struct sock *newsk;
1245 struct ipv6_txoptions *opt;
1246#ifdef CONFIG_TCP_MD5SIG
1247 struct tcp_md5sig_key *key;
1248#endif
1249
1250 if (skb->protocol == htons(ETH_P_IP)) {
1251 /*
1252 * v6 mapped
1253 */
1254
1255 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1256
1257 if (newsk == NULL)
1258 return NULL;
1259
1260 newtcp6sk = (struct tcp6_sock *)newsk;
1261 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1262
1263 newinet = inet_sk(newsk);
1264 newnp = inet6_sk(newsk);
1265 newtp = tcp_sk(newsk);
1266
1267 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1268
1269 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1270
1271 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1272
1273 newnp->rcv_saddr = newnp->saddr;
1274
1275 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1276 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1277#ifdef CONFIG_TCP_MD5SIG
1278 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1279#endif
1280
1281 newnp->ipv6_ac_list = NULL;
1282 newnp->ipv6_fl_list = NULL;
1283 newnp->pktoptions = NULL;
1284 newnp->opt = NULL;
1285 newnp->mcast_oif = inet6_iif(skb);
1286 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1287 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1288
1289 /*
1290 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1291 * here, tcp_create_openreq_child now does this for us, see the comment in
1292 * that function for the gory details. -acme
1293 */
1294
1295 /* It is tricky place. Until this moment IPv4 tcp
1296 worked with IPv6 icsk.icsk_af_ops.
1297 Sync it now.
1298 */
1299 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1300
1301 return newsk;
1302 }
1303
1304 treq = inet6_rsk(req);
1305 opt = np->opt;
1306
1307 if (sk_acceptq_is_full(sk))
1308 goto out_overflow;
1309
1310 if (!dst) {
1311 dst = inet6_csk_route_req(sk, req);
1312 if (!dst)
1313 goto out;
1314 }
1315
1316 newsk = tcp_create_openreq_child(sk, req, skb);
1317 if (newsk == NULL)
1318 goto out_nonewsk;
1319
1320 /*
1321 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1322 * count here, tcp_create_openreq_child now does this for us, see the
1323 * comment in that function for the gory details. -acme
1324 */
1325
1326 newsk->sk_gso_type = SKB_GSO_TCPV6;
1327 __ip6_dst_store(newsk, dst, NULL, NULL);
1328
1329 newtcp6sk = (struct tcp6_sock *)newsk;
1330 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1331
1332 newtp = tcp_sk(newsk);
1333 newinet = inet_sk(newsk);
1334 newnp = inet6_sk(newsk);
1335
1336 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1337
1338 newnp->daddr = treq->rmt_addr;
1339 newnp->saddr = treq->loc_addr;
1340 newnp->rcv_saddr = treq->loc_addr;
1341 newsk->sk_bound_dev_if = treq->iif;
1342
1343 /* Now IPv6 options...
1344
1345 First: no IPv4 options.
1346 */
1347 newinet->inet_opt = NULL;
1348 newnp->ipv6_ac_list = NULL;
1349 newnp->ipv6_fl_list = NULL;
1350
1351 /* Clone RX bits */
1352 newnp->rxopt.all = np->rxopt.all;
1353
1354 /* Clone pktoptions received with SYN */
1355 newnp->pktoptions = NULL;
1356 if (treq->pktopts != NULL) {
1357 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1358 consume_skb(treq->pktopts);
1359 treq->pktopts = NULL;
1360 if (newnp->pktoptions)
1361 skb_set_owner_r(newnp->pktoptions, newsk);
1362 }
1363 newnp->opt = NULL;
1364 newnp->mcast_oif = inet6_iif(skb);
1365 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1366 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1367
1368 /* Clone native IPv6 options from listening socket (if any)
1369
1370 Yes, keeping reference count would be much more clever,
1371 but we make one more one thing there: reattach optmem
1372 to newsk.
1373 */
1374 if (opt) {
1375 newnp->opt = ipv6_dup_options(newsk, opt);
1376 if (opt != np->opt)
1377 sock_kfree_s(sk, opt, opt->tot_len);
1378 }
1379
1380 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1381 if (newnp->opt)
1382 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1383 newnp->opt->opt_flen);
1384
1385 tcp_mtup_init(newsk);
1386 tcp_sync_mss(newsk, dst_mtu(dst));
1387 newtp->advmss = dst_metric_advmss(dst);
1388 if (tcp_sk(sk)->rx_opt.user_mss &&
1389 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1390 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1391
1392 tcp_initialize_rcv_mss(newsk);
1393 if (tcp_rsk(req)->snt_synack)
1394 tcp_valid_rtt_meas(newsk,
1395 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1396 newtp->total_retrans = req->retrans;
1397
1398 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1399 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1400
1401#ifdef CONFIG_TCP_MD5SIG
1402 /* Copy over the MD5 key from the original socket */
1403 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1404 /* We're using one, so create a matching key
1405 * on the newsk structure. If we fail to get
1406 * memory, then we end up not copying the key
1407 * across. Shucks.
1408 */
1409 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1410 AF_INET6, key->key, key->keylen, GFP_ATOMIC);
1411 }
1412#endif
1413
1414 if (__inet_inherit_port(sk, newsk) < 0) {
1415 sock_put(newsk);
1416 goto out;
1417 }
1418 __inet6_hash(newsk, NULL);
1419
1420 return newsk;
1421
1422out_overflow:
1423 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1424out_nonewsk:
1425 if (opt && opt != np->opt)
1426 sock_kfree_s(sk, opt, opt->tot_len);
1427 dst_release(dst);
1428out:
1429 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1430 return NULL;
1431}
1432
1433static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1434{
1435 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1436 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1437 &ipv6_hdr(skb)->daddr, skb->csum)) {
1438 skb->ip_summed = CHECKSUM_UNNECESSARY;
1439 return 0;
1440 }
1441 }
1442
1443 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1444 &ipv6_hdr(skb)->saddr,
1445 &ipv6_hdr(skb)->daddr, 0));
1446
1447 if (skb->len <= 76) {
1448 return __skb_checksum_complete(skb);
1449 }
1450 return 0;
1451}
1452
1453/* The socket must have it's spinlock held when we get
1454 * here.
1455 *
1456 * We have a potential double-lock case here, so even when
1457 * doing backlog processing we use the BH locking scheme.
1458 * This is because we cannot sleep with the original spinlock
1459 * held.
1460 */
1461static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1462{
1463 struct ipv6_pinfo *np = inet6_sk(sk);
1464 struct tcp_sock *tp;
1465 struct sk_buff *opt_skb = NULL;
1466
1467 /* Imagine: socket is IPv6. IPv4 packet arrives,
1468 goes to IPv4 receive handler and backlogged.
1469 From backlog it always goes here. Kerboom...
1470 Fortunately, tcp_rcv_established and rcv_established
1471 handle them correctly, but it is not case with
1472 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1473 */
1474
1475 if (skb->protocol == htons(ETH_P_IP))
1476 return tcp_v4_do_rcv(sk, skb);
1477
1478#ifdef CONFIG_TCP_MD5SIG
1479 if (tcp_v6_inbound_md5_hash (sk, skb))
1480 goto discard;
1481#endif
1482
1483 if (sk_filter(sk, skb))
1484 goto discard;
1485
1486 /*
1487 * socket locking is here for SMP purposes as backlog rcv
1488 * is currently called with bh processing disabled.
1489 */
1490
1491 /* Do Stevens' IPV6_PKTOPTIONS.
1492
1493 Yes, guys, it is the only place in our code, where we
1494 may make it not affecting IPv4.
1495 The rest of code is protocol independent,
1496 and I do not like idea to uglify IPv4.
1497
1498 Actually, all the idea behind IPV6_PKTOPTIONS
1499 looks not very well thought. For now we latch
1500 options, received in the last packet, enqueued
1501 by tcp. Feel free to propose better solution.
1502 --ANK (980728)
1503 */
1504 if (np->rxopt.all)
1505 opt_skb = skb_clone(skb, GFP_ATOMIC);
1506
1507 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1508 sock_rps_save_rxhash(sk, skb);
1509 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1510 goto reset;
1511 if (opt_skb)
1512 goto ipv6_pktoptions;
1513 return 0;
1514 }
1515
1516 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1517 goto csum_err;
1518
1519 if (sk->sk_state == TCP_LISTEN) {
1520 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1521 if (!nsk)
1522 goto discard;
1523
1524 /*
1525 * Queue it on the new socket if the new socket is active,
1526 * otherwise we just shortcircuit this and continue with
1527 * the new socket..
1528 */
1529 if(nsk != sk) {
1530 sock_rps_save_rxhash(nsk, skb);
1531 if (tcp_child_process(sk, nsk, skb))
1532 goto reset;
1533 if (opt_skb)
1534 __kfree_skb(opt_skb);
1535 return 0;
1536 }
1537 } else
1538 sock_rps_save_rxhash(sk, skb);
1539
1540 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1541 goto reset;
1542 if (opt_skb)
1543 goto ipv6_pktoptions;
1544 return 0;
1545
1546reset:
1547 tcp_v6_send_reset(sk, skb);
1548discard:
1549 if (opt_skb)
1550 __kfree_skb(opt_skb);
1551 kfree_skb(skb);
1552 return 0;
1553csum_err:
1554 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1555 goto discard;
1556
1557
1558ipv6_pktoptions:
1559 /* Do you ask, what is it?
1560
1561 1. skb was enqueued by tcp.
1562 2. skb is added to tail of read queue, rather than out of order.
1563 3. socket is not in passive state.
1564 4. Finally, it really contains options, which user wants to receive.
1565 */
1566 tp = tcp_sk(sk);
1567 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1568 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1569 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1570 np->mcast_oif = inet6_iif(opt_skb);
1571 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1572 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1573 if (np->rxopt.bits.rxtclass)
1574 np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1575 if (ipv6_opt_accepted(sk, opt_skb)) {
1576 skb_set_owner_r(opt_skb, sk);
1577 opt_skb = xchg(&np->pktoptions, opt_skb);
1578 } else {
1579 __kfree_skb(opt_skb);
1580 opt_skb = xchg(&np->pktoptions, NULL);
1581 }
1582 }
1583
1584 kfree_skb(opt_skb);
1585 return 0;
1586}
1587
1588static int tcp_v6_rcv(struct sk_buff *skb)
1589{
1590 const struct tcphdr *th;
1591 const struct ipv6hdr *hdr;
1592 struct sock *sk;
1593 int ret;
1594 struct net *net = dev_net(skb->dev);
1595
1596 if (skb->pkt_type != PACKET_HOST)
1597 goto discard_it;
1598
1599 /*
1600 * Count it even if it's bad.
1601 */
1602 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1603
1604 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1605 goto discard_it;
1606
1607 th = tcp_hdr(skb);
1608
1609 if (th->doff < sizeof(struct tcphdr)/4)
1610 goto bad_packet;
1611 if (!pskb_may_pull(skb, th->doff*4))
1612 goto discard_it;
1613
1614 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1615 goto bad_packet;
1616
1617 th = tcp_hdr(skb);
1618 hdr = ipv6_hdr(skb);
1619 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1620 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1621 skb->len - th->doff*4);
1622 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1623 TCP_SKB_CB(skb)->when = 0;
1624 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1625 TCP_SKB_CB(skb)->sacked = 0;
1626
1627 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1628 if (!sk)
1629 goto no_tcp_socket;
1630
1631process:
1632 if (sk->sk_state == TCP_TIME_WAIT)
1633 goto do_time_wait;
1634
1635 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1636 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1637 goto discard_and_relse;
1638 }
1639
1640 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1641 goto discard_and_relse;
1642
1643 if (sk_filter(sk, skb))
1644 goto discard_and_relse;
1645
1646 skb->dev = NULL;
1647
1648 bh_lock_sock_nested(sk);
1649 ret = 0;
1650 if (!sock_owned_by_user(sk)) {
1651#ifdef CONFIG_NET_DMA
1652 struct tcp_sock *tp = tcp_sk(sk);
1653 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1654 tp->ucopy.dma_chan = net_dma_find_channel();
1655 if (tp->ucopy.dma_chan)
1656 ret = tcp_v6_do_rcv(sk, skb);
1657 else
1658#endif
1659 {
1660 if (!tcp_prequeue(sk, skb))
1661 ret = tcp_v6_do_rcv(sk, skb);
1662 }
1663 } else if (unlikely(sk_add_backlog(sk, skb,
1664 sk->sk_rcvbuf + sk->sk_sndbuf))) {
1665 bh_unlock_sock(sk);
1666 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1667 goto discard_and_relse;
1668 }
1669 bh_unlock_sock(sk);
1670
1671 sock_put(sk);
1672 return ret ? -1 : 0;
1673
1674no_tcp_socket:
1675 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1676 goto discard_it;
1677
1678 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1679bad_packet:
1680 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1681 } else {
1682 tcp_v6_send_reset(NULL, skb);
1683 }
1684
1685discard_it:
1686
1687 /*
1688 * Discard frame
1689 */
1690
1691 kfree_skb(skb);
1692 return 0;
1693
1694discard_and_relse:
1695 sock_put(sk);
1696 goto discard_it;
1697
1698do_time_wait:
1699 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1700 inet_twsk_put(inet_twsk(sk));
1701 goto discard_it;
1702 }
1703
1704 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1705 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1706 inet_twsk_put(inet_twsk(sk));
1707 goto discard_it;
1708 }
1709
1710 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1711 case TCP_TW_SYN:
1712 {
1713 struct sock *sk2;
1714
1715 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1716 &ipv6_hdr(skb)->daddr,
1717 ntohs(th->dest), inet6_iif(skb));
1718 if (sk2 != NULL) {
1719 struct inet_timewait_sock *tw = inet_twsk(sk);
1720 inet_twsk_deschedule(tw, &tcp_death_row);
1721 inet_twsk_put(tw);
1722 sk = sk2;
1723 goto process;
1724 }
1725 /* Fall through to ACK */
1726 }
1727 case TCP_TW_ACK:
1728 tcp_v6_timewait_ack(sk, skb);
1729 break;
1730 case TCP_TW_RST:
1731 goto no_tcp_socket;
1732 case TCP_TW_SUCCESS:;
1733 }
1734 goto discard_it;
1735}
1736
1737static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1738{
1739 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1740 struct ipv6_pinfo *np = inet6_sk(sk);
1741 struct inet_peer *peer;
1742
1743 if (!rt ||
1744 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1745 peer = inet_getpeer_v6(&np->daddr, 1);
1746 *release_it = true;
1747 } else {
1748 if (!rt->rt6i_peer)
1749 rt6_bind_peer(rt, 1);
1750 peer = rt->rt6i_peer;
1751 *release_it = false;
1752 }
1753
1754 return peer;
1755}
1756
1757static void *tcp_v6_tw_get_peer(struct sock *sk)
1758{
1759 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1760 const struct inet_timewait_sock *tw = inet_twsk(sk);
1761
1762 if (tw->tw_family == AF_INET)
1763 return tcp_v4_tw_get_peer(sk);
1764
1765 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1766}
1767
1768static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1769 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1770 .twsk_unique = tcp_twsk_unique,
1771 .twsk_destructor= tcp_twsk_destructor,
1772 .twsk_getpeer = tcp_v6_tw_get_peer,
1773};
1774
1775static const struct inet_connection_sock_af_ops ipv6_specific = {
1776 .queue_xmit = inet6_csk_xmit,
1777 .send_check = tcp_v6_send_check,
1778 .rebuild_header = inet6_sk_rebuild_header,
1779 .conn_request = tcp_v6_conn_request,
1780 .syn_recv_sock = tcp_v6_syn_recv_sock,
1781 .get_peer = tcp_v6_get_peer,
1782 .net_header_len = sizeof(struct ipv6hdr),
1783 .net_frag_header_len = sizeof(struct frag_hdr),
1784 .setsockopt = ipv6_setsockopt,
1785 .getsockopt = ipv6_getsockopt,
1786 .addr2sockaddr = inet6_csk_addr2sockaddr,
1787 .sockaddr_len = sizeof(struct sockaddr_in6),
1788 .bind_conflict = inet6_csk_bind_conflict,
1789#ifdef CONFIG_COMPAT
1790 .compat_setsockopt = compat_ipv6_setsockopt,
1791 .compat_getsockopt = compat_ipv6_getsockopt,
1792#endif
1793};
1794
1795#ifdef CONFIG_TCP_MD5SIG
1796static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1797 .md5_lookup = tcp_v6_md5_lookup,
1798 .calc_md5_hash = tcp_v6_md5_hash_skb,
1799 .md5_parse = tcp_v6_parse_md5_keys,
1800};
1801#endif
1802
1803/*
1804 * TCP over IPv4 via INET6 API
1805 */
1806
1807static const struct inet_connection_sock_af_ops ipv6_mapped = {
1808 .queue_xmit = ip_queue_xmit,
1809 .send_check = tcp_v4_send_check,
1810 .rebuild_header = inet_sk_rebuild_header,
1811 .conn_request = tcp_v6_conn_request,
1812 .syn_recv_sock = tcp_v6_syn_recv_sock,
1813 .get_peer = tcp_v4_get_peer,
1814 .net_header_len = sizeof(struct iphdr),
1815 .setsockopt = ipv6_setsockopt,
1816 .getsockopt = ipv6_getsockopt,
1817 .addr2sockaddr = inet6_csk_addr2sockaddr,
1818 .sockaddr_len = sizeof(struct sockaddr_in6),
1819 .bind_conflict = inet6_csk_bind_conflict,
1820#ifdef CONFIG_COMPAT
1821 .compat_setsockopt = compat_ipv6_setsockopt,
1822 .compat_getsockopt = compat_ipv6_getsockopt,
1823#endif
1824};
1825
1826#ifdef CONFIG_TCP_MD5SIG
1827static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1828 .md5_lookup = tcp_v4_md5_lookup,
1829 .calc_md5_hash = tcp_v4_md5_hash_skb,
1830 .md5_parse = tcp_v6_parse_md5_keys,
1831};
1832#endif
1833
1834/* NOTE: A lot of things set to zero explicitly by call to
1835 * sk_alloc() so need not be done here.
1836 */
1837static int tcp_v6_init_sock(struct sock *sk)
1838{
1839 struct inet_connection_sock *icsk = inet_csk(sk);
1840
1841 tcp_init_sock(sk);
1842
1843 icsk->icsk_af_ops = &ipv6_specific;
1844
1845#ifdef CONFIG_TCP_MD5SIG
1846 tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1847#endif
1848
1849 return 0;
1850}
1851
1852static void tcp_v6_destroy_sock(struct sock *sk)
1853{
1854 tcp_v4_destroy_sock(sk);
1855 inet6_destroy_sock(sk);
1856}
1857
1858#ifdef CONFIG_PROC_FS
1859/* Proc filesystem TCPv6 sock list dumping. */
1860static void get_openreq6(struct seq_file *seq,
1861 const struct sock *sk, struct request_sock *req, int i, int uid)
1862{
1863 int ttd = req->expires - jiffies;
1864 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1865 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1866
1867 if (ttd < 0)
1868 ttd = 0;
1869
1870 seq_printf(seq,
1871 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1872 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1873 i,
1874 src->s6_addr32[0], src->s6_addr32[1],
1875 src->s6_addr32[2], src->s6_addr32[3],
1876 ntohs(inet_rsk(req)->loc_port),
1877 dest->s6_addr32[0], dest->s6_addr32[1],
1878 dest->s6_addr32[2], dest->s6_addr32[3],
1879 ntohs(inet_rsk(req)->rmt_port),
1880 TCP_SYN_RECV,
1881 0,0, /* could print option size, but that is af dependent. */
1882 1, /* timers active (only the expire timer) */
1883 jiffies_to_clock_t(ttd),
1884 req->retrans,
1885 uid,
1886 0, /* non standard timer */
1887 0, /* open_requests have no inode */
1888 0, req);
1889}
1890
1891static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1892{
1893 const struct in6_addr *dest, *src;
1894 __u16 destp, srcp;
1895 int timer_active;
1896 unsigned long timer_expires;
1897 const struct inet_sock *inet = inet_sk(sp);
1898 const struct tcp_sock *tp = tcp_sk(sp);
1899 const struct inet_connection_sock *icsk = inet_csk(sp);
1900 const struct ipv6_pinfo *np = inet6_sk(sp);
1901
1902 dest = &np->daddr;
1903 src = &np->rcv_saddr;
1904 destp = ntohs(inet->inet_dport);
1905 srcp = ntohs(inet->inet_sport);
1906
1907 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1908 timer_active = 1;
1909 timer_expires = icsk->icsk_timeout;
1910 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1911 timer_active = 4;
1912 timer_expires = icsk->icsk_timeout;
1913 } else if (timer_pending(&sp->sk_timer)) {
1914 timer_active = 2;
1915 timer_expires = sp->sk_timer.expires;
1916 } else {
1917 timer_active = 0;
1918 timer_expires = jiffies;
1919 }
1920
1921 seq_printf(seq,
1922 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1923 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1924 i,
1925 src->s6_addr32[0], src->s6_addr32[1],
1926 src->s6_addr32[2], src->s6_addr32[3], srcp,
1927 dest->s6_addr32[0], dest->s6_addr32[1],
1928 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1929 sp->sk_state,
1930 tp->write_seq-tp->snd_una,
1931 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1932 timer_active,
1933 jiffies_to_clock_t(timer_expires - jiffies),
1934 icsk->icsk_retransmits,
1935 sock_i_uid(sp),
1936 icsk->icsk_probes_out,
1937 sock_i_ino(sp),
1938 atomic_read(&sp->sk_refcnt), sp,
1939 jiffies_to_clock_t(icsk->icsk_rto),
1940 jiffies_to_clock_t(icsk->icsk_ack.ato),
1941 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1942 tp->snd_cwnd,
1943 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1944 );
1945}
1946
1947static void get_timewait6_sock(struct seq_file *seq,
1948 struct inet_timewait_sock *tw, int i)
1949{
1950 const struct in6_addr *dest, *src;
1951 __u16 destp, srcp;
1952 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1953 int ttd = tw->tw_ttd - jiffies;
1954
1955 if (ttd < 0)
1956 ttd = 0;
1957
1958 dest = &tw6->tw_v6_daddr;
1959 src = &tw6->tw_v6_rcv_saddr;
1960 destp = ntohs(tw->tw_dport);
1961 srcp = ntohs(tw->tw_sport);
1962
1963 seq_printf(seq,
1964 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1965 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1966 i,
1967 src->s6_addr32[0], src->s6_addr32[1],
1968 src->s6_addr32[2], src->s6_addr32[3], srcp,
1969 dest->s6_addr32[0], dest->s6_addr32[1],
1970 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1971 tw->tw_substate, 0, 0,
1972 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
1973 atomic_read(&tw->tw_refcnt), tw);
1974}
1975
1976static int tcp6_seq_show(struct seq_file *seq, void *v)
1977{
1978 struct tcp_iter_state *st;
1979
1980 if (v == SEQ_START_TOKEN) {
1981 seq_puts(seq,
1982 " sl "
1983 "local_address "
1984 "remote_address "
1985 "st tx_queue rx_queue tr tm->when retrnsmt"
1986 " uid timeout inode\n");
1987 goto out;
1988 }
1989 st = seq->private;
1990
1991 switch (st->state) {
1992 case TCP_SEQ_STATE_LISTENING:
1993 case TCP_SEQ_STATE_ESTABLISHED:
1994 get_tcp6_sock(seq, v, st->num);
1995 break;
1996 case TCP_SEQ_STATE_OPENREQ:
1997 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
1998 break;
1999 case TCP_SEQ_STATE_TIME_WAIT:
2000 get_timewait6_sock(seq, v, st->num);
2001 break;
2002 }
2003out:
2004 return 0;
2005}
2006
2007static const struct file_operations tcp6_afinfo_seq_fops = {
2008 .owner = THIS_MODULE,
2009 .open = tcp_seq_open,
2010 .read = seq_read,
2011 .llseek = seq_lseek,
2012 .release = seq_release_net
2013};
2014
2015static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2016 .name = "tcp6",
2017 .family = AF_INET6,
2018 .seq_fops = &tcp6_afinfo_seq_fops,
2019 .seq_ops = {
2020 .show = tcp6_seq_show,
2021 },
2022};
2023
2024int __net_init tcp6_proc_init(struct net *net)
2025{
2026 return tcp_proc_register(net, &tcp6_seq_afinfo);
2027}
2028
2029void tcp6_proc_exit(struct net *net)
2030{
2031 tcp_proc_unregister(net, &tcp6_seq_afinfo);
2032}
2033#endif
2034
2035struct proto tcpv6_prot = {
2036 .name = "TCPv6",
2037 .owner = THIS_MODULE,
2038 .close = tcp_close,
2039 .connect = tcp_v6_connect,
2040 .disconnect = tcp_disconnect,
2041 .accept = inet_csk_accept,
2042 .ioctl = tcp_ioctl,
2043 .init = tcp_v6_init_sock,
2044 .destroy = tcp_v6_destroy_sock,
2045 .shutdown = tcp_shutdown,
2046 .setsockopt = tcp_setsockopt,
2047 .getsockopt = tcp_getsockopt,
2048 .recvmsg = tcp_recvmsg,
2049 .sendmsg = tcp_sendmsg,
2050 .sendpage = tcp_sendpage,
2051 .backlog_rcv = tcp_v6_do_rcv,
2052 .hash = tcp_v6_hash,
2053 .unhash = inet_unhash,
2054 .get_port = inet_csk_get_port,
2055 .enter_memory_pressure = tcp_enter_memory_pressure,
2056 .sockets_allocated = &tcp_sockets_allocated,
2057 .memory_allocated = &tcp_memory_allocated,
2058 .memory_pressure = &tcp_memory_pressure,
2059 .orphan_count = &tcp_orphan_count,
2060 .sysctl_wmem = sysctl_tcp_wmem,
2061 .sysctl_rmem = sysctl_tcp_rmem,
2062 .max_header = MAX_TCP_HEADER,
2063 .obj_size = sizeof(struct tcp6_sock),
2064 .slab_flags = SLAB_DESTROY_BY_RCU,
2065 .twsk_prot = &tcp6_timewait_sock_ops,
2066 .rsk_prot = &tcp6_request_sock_ops,
2067 .h.hashinfo = &tcp_hashinfo,
2068 .no_autobind = true,
2069#ifdef CONFIG_COMPAT
2070 .compat_setsockopt = compat_tcp_setsockopt,
2071 .compat_getsockopt = compat_tcp_getsockopt,
2072#endif
2073#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
2074 .proto_cgroup = tcp_proto_cgroup,
2075#endif
2076};
2077
2078static const struct inet6_protocol tcpv6_protocol = {
2079 .handler = tcp_v6_rcv,
2080 .err_handler = tcp_v6_err,
2081 .gso_send_check = tcp_v6_gso_send_check,
2082 .gso_segment = tcp_tso_segment,
2083 .gro_receive = tcp6_gro_receive,
2084 .gro_complete = tcp6_gro_complete,
2085 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2086};
2087
2088static struct inet_protosw tcpv6_protosw = {
2089 .type = SOCK_STREAM,
2090 .protocol = IPPROTO_TCP,
2091 .prot = &tcpv6_prot,
2092 .ops = &inet6_stream_ops,
2093 .no_check = 0,
2094 .flags = INET_PROTOSW_PERMANENT |
2095 INET_PROTOSW_ICSK,
2096};
2097
2098static int __net_init tcpv6_net_init(struct net *net)
2099{
2100 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2101 SOCK_RAW, IPPROTO_TCP, net);
2102}
2103
2104static void __net_exit tcpv6_net_exit(struct net *net)
2105{
2106 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2107}
2108
2109static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2110{
2111 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2112}
2113
2114static struct pernet_operations tcpv6_net_ops = {
2115 .init = tcpv6_net_init,
2116 .exit = tcpv6_net_exit,
2117 .exit_batch = tcpv6_net_exit_batch,
2118};
2119
2120int __init tcpv6_init(void)
2121{
2122 int ret;
2123
2124 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2125 if (ret)
2126 goto out;
2127
2128 /* register inet6 protocol */
2129 ret = inet6_register_protosw(&tcpv6_protosw);
2130 if (ret)
2131 goto out_tcpv6_protocol;
2132
2133 ret = register_pernet_subsys(&tcpv6_net_ops);
2134 if (ret)
2135 goto out_tcpv6_protosw;
2136out:
2137 return ret;
2138
2139out_tcpv6_protocol:
2140 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2141out_tcpv6_protosw:
2142 inet6_unregister_protosw(&tcpv6_protosw);
2143 goto out;
2144}
2145
2146void tcpv6_exit(void)
2147{
2148 unregister_pernet_subsys(&tcpv6_net_ops);
2149 inet6_unregister_protosw(&tcpv6_protosw);
2150 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2151}