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Merge tag 'sound-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / tcp_ipv6.c
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
75 static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
76 static void tcp_v6_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
77 struct request_sock *req);
78
79 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
80 static void __tcp_v6_send_check(struct sk_buff *skb,
81 const struct in6_addr *saddr,
82 const struct in6_addr *daddr);
83
84 static const struct inet_connection_sock_af_ops ipv6_mapped;
85 static const struct inet_connection_sock_af_ops ipv6_specific;
86 #ifdef CONFIG_TCP_MD5SIG
87 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
88 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
89 #else
90 static 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
97 static 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
110 static __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
118 static __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
126 static 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
323 late_failure:
324 tcp_set_state(sk, TCP_CLOSE);
325 __sk_dst_reset(sk);
326 failure:
327 inet->inet_dport = 0;
328 sk->sk_route_caps = 0;
329 return err;
330 }
331
332 static 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
472 out:
473 bh_unlock_sock(sk);
474 sock_put(sk);
475 }
476
477
478 static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
479 struct request_values *rvp)
480 {
481 struct inet6_request_sock *treq = inet6_rsk(req);
482 struct ipv6_pinfo *np = inet6_sk(sk);
483 struct sk_buff * skb;
484 struct ipv6_txoptions *opt = NULL;
485 struct in6_addr * final_p, final;
486 struct flowi6 fl6;
487 struct dst_entry *dst;
488 int err;
489
490 memset(&fl6, 0, sizeof(fl6));
491 fl6.flowi6_proto = IPPROTO_TCP;
492 fl6.daddr = treq->rmt_addr;
493 fl6.saddr = treq->loc_addr;
494 fl6.flowlabel = 0;
495 fl6.flowi6_oif = treq->iif;
496 fl6.flowi6_mark = sk->sk_mark;
497 fl6.fl6_dport = inet_rsk(req)->rmt_port;
498 fl6.fl6_sport = inet_rsk(req)->loc_port;
499 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
500
501 opt = np->opt;
502 final_p = fl6_update_dst(&fl6, opt, &final);
503
504 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
505 if (IS_ERR(dst)) {
506 err = PTR_ERR(dst);
507 dst = NULL;
508 goto done;
509 }
510 skb = tcp_make_synack(sk, dst, req, rvp);
511 err = -ENOMEM;
512 if (skb) {
513 __tcp_v6_send_check(skb, &treq->loc_addr, &treq->rmt_addr);
514
515 fl6.daddr = treq->rmt_addr;
516 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass);
517 err = net_xmit_eval(err);
518 }
519
520 done:
521 if (opt && opt != np->opt)
522 sock_kfree_s(sk, opt, opt->tot_len);
523 dst_release(dst);
524 return err;
525 }
526
527 static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
528 struct request_values *rvp)
529 {
530 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
531 return tcp_v6_send_synack(sk, req, rvp);
532 }
533
534 static void tcp_v6_reqsk_destructor(struct request_sock *req)
535 {
536 kfree_skb(inet6_rsk(req)->pktopts);
537 }
538
539 #ifdef CONFIG_TCP_MD5SIG
540 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
541 const struct in6_addr *addr)
542 {
543 return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
544 }
545
546 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
547 struct sock *addr_sk)
548 {
549 return tcp_v6_md5_do_lookup(sk, &inet6_sk(addr_sk)->daddr);
550 }
551
552 static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
553 struct request_sock *req)
554 {
555 return tcp_v6_md5_do_lookup(sk, &inet6_rsk(req)->rmt_addr);
556 }
557
558 static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval,
559 int optlen)
560 {
561 struct tcp_md5sig cmd;
562 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
563
564 if (optlen < sizeof(cmd))
565 return -EINVAL;
566
567 if (copy_from_user(&cmd, optval, sizeof(cmd)))
568 return -EFAULT;
569
570 if (sin6->sin6_family != AF_INET6)
571 return -EINVAL;
572
573 if (!cmd.tcpm_keylen) {
574 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
575 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
576 AF_INET);
577 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
578 AF_INET6);
579 }
580
581 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
582 return -EINVAL;
583
584 if (ipv6_addr_v4mapped(&sin6->sin6_addr))
585 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
586 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
587
588 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
589 AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
590 }
591
592 static int tcp_v6_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
593 const struct in6_addr *daddr,
594 const struct in6_addr *saddr, int nbytes)
595 {
596 struct tcp6_pseudohdr *bp;
597 struct scatterlist sg;
598
599 bp = &hp->md5_blk.ip6;
600 /* 1. TCP pseudo-header (RFC2460) */
601 bp->saddr = *saddr;
602 bp->daddr = *daddr;
603 bp->protocol = cpu_to_be32(IPPROTO_TCP);
604 bp->len = cpu_to_be32(nbytes);
605
606 sg_init_one(&sg, bp, sizeof(*bp));
607 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
608 }
609
610 static int tcp_v6_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
611 const struct in6_addr *daddr, struct in6_addr *saddr,
612 const struct tcphdr *th)
613 {
614 struct tcp_md5sig_pool *hp;
615 struct hash_desc *desc;
616
617 hp = tcp_get_md5sig_pool();
618 if (!hp)
619 goto clear_hash_noput;
620 desc = &hp->md5_desc;
621
622 if (crypto_hash_init(desc))
623 goto clear_hash;
624 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
625 goto clear_hash;
626 if (tcp_md5_hash_header(hp, th))
627 goto clear_hash;
628 if (tcp_md5_hash_key(hp, key))
629 goto clear_hash;
630 if (crypto_hash_final(desc, md5_hash))
631 goto clear_hash;
632
633 tcp_put_md5sig_pool();
634 return 0;
635
636 clear_hash:
637 tcp_put_md5sig_pool();
638 clear_hash_noput:
639 memset(md5_hash, 0, 16);
640 return 1;
641 }
642
643 static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
644 const struct sock *sk,
645 const struct request_sock *req,
646 const struct sk_buff *skb)
647 {
648 const struct in6_addr *saddr, *daddr;
649 struct tcp_md5sig_pool *hp;
650 struct hash_desc *desc;
651 const struct tcphdr *th = tcp_hdr(skb);
652
653 if (sk) {
654 saddr = &inet6_sk(sk)->saddr;
655 daddr = &inet6_sk(sk)->daddr;
656 } else if (req) {
657 saddr = &inet6_rsk(req)->loc_addr;
658 daddr = &inet6_rsk(req)->rmt_addr;
659 } else {
660 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
661 saddr = &ip6h->saddr;
662 daddr = &ip6h->daddr;
663 }
664
665 hp = tcp_get_md5sig_pool();
666 if (!hp)
667 goto clear_hash_noput;
668 desc = &hp->md5_desc;
669
670 if (crypto_hash_init(desc))
671 goto clear_hash;
672
673 if (tcp_v6_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
674 goto clear_hash;
675 if (tcp_md5_hash_header(hp, th))
676 goto clear_hash;
677 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
678 goto clear_hash;
679 if (tcp_md5_hash_key(hp, key))
680 goto clear_hash;
681 if (crypto_hash_final(desc, md5_hash))
682 goto clear_hash;
683
684 tcp_put_md5sig_pool();
685 return 0;
686
687 clear_hash:
688 tcp_put_md5sig_pool();
689 clear_hash_noput:
690 memset(md5_hash, 0, 16);
691 return 1;
692 }
693
694 static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
695 {
696 const __u8 *hash_location = NULL;
697 struct tcp_md5sig_key *hash_expected;
698 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
699 const struct tcphdr *th = tcp_hdr(skb);
700 int genhash;
701 u8 newhash[16];
702
703 hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
704 hash_location = tcp_parse_md5sig_option(th);
705
706 /* We've parsed the options - do we have a hash? */
707 if (!hash_expected && !hash_location)
708 return 0;
709
710 if (hash_expected && !hash_location) {
711 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
712 return 1;
713 }
714
715 if (!hash_expected && hash_location) {
716 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
717 return 1;
718 }
719
720 /* check the signature */
721 genhash = tcp_v6_md5_hash_skb(newhash,
722 hash_expected,
723 NULL, NULL, skb);
724
725 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
726 if (net_ratelimit()) {
727 printk(KERN_INFO "MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
728 genhash ? "failed" : "mismatch",
729 &ip6h->saddr, ntohs(th->source),
730 &ip6h->daddr, ntohs(th->dest));
731 }
732 return 1;
733 }
734 return 0;
735 }
736 #endif
737
738 struct 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
749 static 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
755 static 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
771 static 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
778 static 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
795 static 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
817 static 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
829 static 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
921 static 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
978 release_sk1:
979 if (sk1) {
980 rcu_read_unlock();
981 sock_put(sk1);
982 }
983 #endif
984 }
985
986 static 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
992 static 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
1005 static 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
1013 static 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 */
1049 static 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 int want_cookie = 0;
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 = 0; /* 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, tcp_hdr(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 }
1211 have_isn:
1212 tcp_rsk(req)->snt_isn = isn;
1213 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1214
1215 security_inet_conn_request(sk, skb, req);
1216
1217 if (tcp_v6_send_synack(sk, req,
1218 (struct request_values *)&tmp_ext) ||
1219 want_cookie)
1220 goto drop_and_free;
1221
1222 inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1223 return 0;
1224
1225 drop_and_release:
1226 dst_release(dst);
1227 drop_and_free:
1228 reqsk_free(req);
1229 drop:
1230 return 0; /* don't send reset */
1231 }
1232
1233 static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1234 struct request_sock *req,
1235 struct dst_entry *dst)
1236 {
1237 struct inet6_request_sock *treq;
1238 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
1239 struct tcp6_sock *newtcp6sk;
1240 struct inet_sock *newinet;
1241 struct tcp_sock *newtp;
1242 struct sock *newsk;
1243 struct ipv6_txoptions *opt;
1244 #ifdef CONFIG_TCP_MD5SIG
1245 struct tcp_md5sig_key *key;
1246 #endif
1247
1248 if (skb->protocol == htons(ETH_P_IP)) {
1249 /*
1250 * v6 mapped
1251 */
1252
1253 newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst);
1254
1255 if (newsk == NULL)
1256 return NULL;
1257
1258 newtcp6sk = (struct tcp6_sock *)newsk;
1259 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1260
1261 newinet = inet_sk(newsk);
1262 newnp = inet6_sk(newsk);
1263 newtp = tcp_sk(newsk);
1264
1265 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1266
1267 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
1268
1269 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
1270
1271 newnp->rcv_saddr = newnp->saddr;
1272
1273 inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1274 newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1275 #ifdef CONFIG_TCP_MD5SIG
1276 newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1277 #endif
1278
1279 newnp->ipv6_ac_list = NULL;
1280 newnp->ipv6_fl_list = NULL;
1281 newnp->pktoptions = NULL;
1282 newnp->opt = NULL;
1283 newnp->mcast_oif = inet6_iif(skb);
1284 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1285 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1286
1287 /*
1288 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1289 * here, tcp_create_openreq_child now does this for us, see the comment in
1290 * that function for the gory details. -acme
1291 */
1292
1293 /* It is tricky place. Until this moment IPv4 tcp
1294 worked with IPv6 icsk.icsk_af_ops.
1295 Sync it now.
1296 */
1297 tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1298
1299 return newsk;
1300 }
1301
1302 treq = inet6_rsk(req);
1303 opt = np->opt;
1304
1305 if (sk_acceptq_is_full(sk))
1306 goto out_overflow;
1307
1308 if (!dst) {
1309 dst = inet6_csk_route_req(sk, req);
1310 if (!dst)
1311 goto out;
1312 }
1313
1314 newsk = tcp_create_openreq_child(sk, req, skb);
1315 if (newsk == NULL)
1316 goto out_nonewsk;
1317
1318 /*
1319 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1320 * count here, tcp_create_openreq_child now does this for us, see the
1321 * comment in that function for the gory details. -acme
1322 */
1323
1324 newsk->sk_gso_type = SKB_GSO_TCPV6;
1325 __ip6_dst_store(newsk, dst, NULL, NULL);
1326
1327 newtcp6sk = (struct tcp6_sock *)newsk;
1328 inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1329
1330 newtp = tcp_sk(newsk);
1331 newinet = inet_sk(newsk);
1332 newnp = inet6_sk(newsk);
1333
1334 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1335
1336 newnp->daddr = treq->rmt_addr;
1337 newnp->saddr = treq->loc_addr;
1338 newnp->rcv_saddr = treq->loc_addr;
1339 newsk->sk_bound_dev_if = treq->iif;
1340
1341 /* Now IPv6 options...
1342
1343 First: no IPv4 options.
1344 */
1345 newinet->inet_opt = NULL;
1346 newnp->ipv6_ac_list = NULL;
1347 newnp->ipv6_fl_list = NULL;
1348
1349 /* Clone RX bits */
1350 newnp->rxopt.all = np->rxopt.all;
1351
1352 /* Clone pktoptions received with SYN */
1353 newnp->pktoptions = NULL;
1354 if (treq->pktopts != NULL) {
1355 newnp->pktoptions = skb_clone(treq->pktopts, GFP_ATOMIC);
1356 kfree_skb(treq->pktopts);
1357 treq->pktopts = NULL;
1358 if (newnp->pktoptions)
1359 skb_set_owner_r(newnp->pktoptions, newsk);
1360 }
1361 newnp->opt = NULL;
1362 newnp->mcast_oif = inet6_iif(skb);
1363 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1364 newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1365
1366 /* Clone native IPv6 options from listening socket (if any)
1367
1368 Yes, keeping reference count would be much more clever,
1369 but we make one more one thing there: reattach optmem
1370 to newsk.
1371 */
1372 if (opt) {
1373 newnp->opt = ipv6_dup_options(newsk, opt);
1374 if (opt != np->opt)
1375 sock_kfree_s(sk, opt, opt->tot_len);
1376 }
1377
1378 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1379 if (newnp->opt)
1380 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
1381 newnp->opt->opt_flen);
1382
1383 tcp_mtup_init(newsk);
1384 tcp_sync_mss(newsk, dst_mtu(dst));
1385 newtp->advmss = dst_metric_advmss(dst);
1386 tcp_initialize_rcv_mss(newsk);
1387 if (tcp_rsk(req)->snt_synack)
1388 tcp_valid_rtt_meas(newsk,
1389 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1390 newtp->total_retrans = req->retrans;
1391
1392 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1393 newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1394
1395 #ifdef CONFIG_TCP_MD5SIG
1396 /* Copy over the MD5 key from the original socket */
1397 if ((key = tcp_v6_md5_do_lookup(sk, &newnp->daddr)) != NULL) {
1398 /* We're using one, so create a matching key
1399 * on the newsk structure. If we fail to get
1400 * memory, then we end up not copying the key
1401 * across. Shucks.
1402 */
1403 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newnp->daddr,
1404 AF_INET6, key->key, key->keylen, GFP_ATOMIC);
1405 }
1406 #endif
1407
1408 if (__inet_inherit_port(sk, newsk) < 0) {
1409 sock_put(newsk);
1410 goto out;
1411 }
1412 __inet6_hash(newsk, NULL);
1413
1414 return newsk;
1415
1416 out_overflow:
1417 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1418 out_nonewsk:
1419 if (opt && opt != np->opt)
1420 sock_kfree_s(sk, opt, opt->tot_len);
1421 dst_release(dst);
1422 out:
1423 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1424 return NULL;
1425 }
1426
1427 static __sum16 tcp_v6_checksum_init(struct sk_buff *skb)
1428 {
1429 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1430 if (!tcp_v6_check(skb->len, &ipv6_hdr(skb)->saddr,
1431 &ipv6_hdr(skb)->daddr, skb->csum)) {
1432 skb->ip_summed = CHECKSUM_UNNECESSARY;
1433 return 0;
1434 }
1435 }
1436
1437 skb->csum = ~csum_unfold(tcp_v6_check(skb->len,
1438 &ipv6_hdr(skb)->saddr,
1439 &ipv6_hdr(skb)->daddr, 0));
1440
1441 if (skb->len <= 76) {
1442 return __skb_checksum_complete(skb);
1443 }
1444 return 0;
1445 }
1446
1447 /* The socket must have it's spinlock held when we get
1448 * here.
1449 *
1450 * We have a potential double-lock case here, so even when
1451 * doing backlog processing we use the BH locking scheme.
1452 * This is because we cannot sleep with the original spinlock
1453 * held.
1454 */
1455 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1456 {
1457 struct ipv6_pinfo *np = inet6_sk(sk);
1458 struct tcp_sock *tp;
1459 struct sk_buff *opt_skb = NULL;
1460
1461 /* Imagine: socket is IPv6. IPv4 packet arrives,
1462 goes to IPv4 receive handler and backlogged.
1463 From backlog it always goes here. Kerboom...
1464 Fortunately, tcp_rcv_established and rcv_established
1465 handle them correctly, but it is not case with
1466 tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
1467 */
1468
1469 if (skb->protocol == htons(ETH_P_IP))
1470 return tcp_v4_do_rcv(sk, skb);
1471
1472 #ifdef CONFIG_TCP_MD5SIG
1473 if (tcp_v6_inbound_md5_hash (sk, skb))
1474 goto discard;
1475 #endif
1476
1477 if (sk_filter(sk, skb))
1478 goto discard;
1479
1480 /*
1481 * socket locking is here for SMP purposes as backlog rcv
1482 * is currently called with bh processing disabled.
1483 */
1484
1485 /* Do Stevens' IPV6_PKTOPTIONS.
1486
1487 Yes, guys, it is the only place in our code, where we
1488 may make it not affecting IPv4.
1489 The rest of code is protocol independent,
1490 and I do not like idea to uglify IPv4.
1491
1492 Actually, all the idea behind IPV6_PKTOPTIONS
1493 looks not very well thought. For now we latch
1494 options, received in the last packet, enqueued
1495 by tcp. Feel free to propose better solution.
1496 --ANK (980728)
1497 */
1498 if (np->rxopt.all)
1499 opt_skb = skb_clone(skb, GFP_ATOMIC);
1500
1501 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1502 sock_rps_save_rxhash(sk, skb);
1503 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
1504 goto reset;
1505 if (opt_skb)
1506 goto ipv6_pktoptions;
1507 return 0;
1508 }
1509
1510 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1511 goto csum_err;
1512
1513 if (sk->sk_state == TCP_LISTEN) {
1514 struct sock *nsk = tcp_v6_hnd_req(sk, skb);
1515 if (!nsk)
1516 goto discard;
1517
1518 /*
1519 * Queue it on the new socket if the new socket is active,
1520 * otherwise we just shortcircuit this and continue with
1521 * the new socket..
1522 */
1523 if(nsk != sk) {
1524 sock_rps_save_rxhash(nsk, skb);
1525 if (tcp_child_process(sk, nsk, skb))
1526 goto reset;
1527 if (opt_skb)
1528 __kfree_skb(opt_skb);
1529 return 0;
1530 }
1531 } else
1532 sock_rps_save_rxhash(sk, skb);
1533
1534 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len))
1535 goto reset;
1536 if (opt_skb)
1537 goto ipv6_pktoptions;
1538 return 0;
1539
1540 reset:
1541 tcp_v6_send_reset(sk, skb);
1542 discard:
1543 if (opt_skb)
1544 __kfree_skb(opt_skb);
1545 kfree_skb(skb);
1546 return 0;
1547 csum_err:
1548 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1549 goto discard;
1550
1551
1552 ipv6_pktoptions:
1553 /* Do you ask, what is it?
1554
1555 1. skb was enqueued by tcp.
1556 2. skb is added to tail of read queue, rather than out of order.
1557 3. socket is not in passive state.
1558 4. Finally, it really contains options, which user wants to receive.
1559 */
1560 tp = tcp_sk(sk);
1561 if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1562 !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1563 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1564 np->mcast_oif = inet6_iif(opt_skb);
1565 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1566 np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1567 if (np->rxopt.bits.rxtclass)
1568 np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
1569 if (ipv6_opt_accepted(sk, opt_skb)) {
1570 skb_set_owner_r(opt_skb, sk);
1571 opt_skb = xchg(&np->pktoptions, opt_skb);
1572 } else {
1573 __kfree_skb(opt_skb);
1574 opt_skb = xchg(&np->pktoptions, NULL);
1575 }
1576 }
1577
1578 kfree_skb(opt_skb);
1579 return 0;
1580 }
1581
1582 static int tcp_v6_rcv(struct sk_buff *skb)
1583 {
1584 const struct tcphdr *th;
1585 const struct ipv6hdr *hdr;
1586 struct sock *sk;
1587 int ret;
1588 struct net *net = dev_net(skb->dev);
1589
1590 if (skb->pkt_type != PACKET_HOST)
1591 goto discard_it;
1592
1593 /*
1594 * Count it even if it's bad.
1595 */
1596 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1597
1598 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1599 goto discard_it;
1600
1601 th = tcp_hdr(skb);
1602
1603 if (th->doff < sizeof(struct tcphdr)/4)
1604 goto bad_packet;
1605 if (!pskb_may_pull(skb, th->doff*4))
1606 goto discard_it;
1607
1608 if (!skb_csum_unnecessary(skb) && tcp_v6_checksum_init(skb))
1609 goto bad_packet;
1610
1611 th = tcp_hdr(skb);
1612 hdr = ipv6_hdr(skb);
1613 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1614 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1615 skb->len - th->doff*4);
1616 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1617 TCP_SKB_CB(skb)->when = 0;
1618 TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1619 TCP_SKB_CB(skb)->sacked = 0;
1620
1621 sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1622 if (!sk)
1623 goto no_tcp_socket;
1624
1625 process:
1626 if (sk->sk_state == TCP_TIME_WAIT)
1627 goto do_time_wait;
1628
1629 if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1630 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1631 goto discard_and_relse;
1632 }
1633
1634 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1635 goto discard_and_relse;
1636
1637 if (sk_filter(sk, skb))
1638 goto discard_and_relse;
1639
1640 skb->dev = NULL;
1641
1642 bh_lock_sock_nested(sk);
1643 ret = 0;
1644 if (!sock_owned_by_user(sk)) {
1645 #ifdef CONFIG_NET_DMA
1646 struct tcp_sock *tp = tcp_sk(sk);
1647 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1648 tp->ucopy.dma_chan = net_dma_find_channel();
1649 if (tp->ucopy.dma_chan)
1650 ret = tcp_v6_do_rcv(sk, skb);
1651 else
1652 #endif
1653 {
1654 if (!tcp_prequeue(sk, skb))
1655 ret = tcp_v6_do_rcv(sk, skb);
1656 }
1657 } else if (unlikely(sk_add_backlog(sk, skb))) {
1658 bh_unlock_sock(sk);
1659 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1660 goto discard_and_relse;
1661 }
1662 bh_unlock_sock(sk);
1663
1664 sock_put(sk);
1665 return ret ? -1 : 0;
1666
1667 no_tcp_socket:
1668 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1669 goto discard_it;
1670
1671 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1672 bad_packet:
1673 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1674 } else {
1675 tcp_v6_send_reset(NULL, skb);
1676 }
1677
1678 discard_it:
1679
1680 /*
1681 * Discard frame
1682 */
1683
1684 kfree_skb(skb);
1685 return 0;
1686
1687 discard_and_relse:
1688 sock_put(sk);
1689 goto discard_it;
1690
1691 do_time_wait:
1692 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1693 inet_twsk_put(inet_twsk(sk));
1694 goto discard_it;
1695 }
1696
1697 if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
1698 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1699 inet_twsk_put(inet_twsk(sk));
1700 goto discard_it;
1701 }
1702
1703 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1704 case TCP_TW_SYN:
1705 {
1706 struct sock *sk2;
1707
1708 sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1709 &ipv6_hdr(skb)->daddr,
1710 ntohs(th->dest), inet6_iif(skb));
1711 if (sk2 != NULL) {
1712 struct inet_timewait_sock *tw = inet_twsk(sk);
1713 inet_twsk_deschedule(tw, &tcp_death_row);
1714 inet_twsk_put(tw);
1715 sk = sk2;
1716 goto process;
1717 }
1718 /* Fall through to ACK */
1719 }
1720 case TCP_TW_ACK:
1721 tcp_v6_timewait_ack(sk, skb);
1722 break;
1723 case TCP_TW_RST:
1724 goto no_tcp_socket;
1725 case TCP_TW_SUCCESS:;
1726 }
1727 goto discard_it;
1728 }
1729
1730 static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
1731 {
1732 struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
1733 struct ipv6_pinfo *np = inet6_sk(sk);
1734 struct inet_peer *peer;
1735
1736 if (!rt ||
1737 !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
1738 peer = inet_getpeer_v6(&np->daddr, 1);
1739 *release_it = true;
1740 } else {
1741 if (!rt->rt6i_peer)
1742 rt6_bind_peer(rt, 1);
1743 peer = rt->rt6i_peer;
1744 *release_it = false;
1745 }
1746
1747 return peer;
1748 }
1749
1750 static void *tcp_v6_tw_get_peer(struct sock *sk)
1751 {
1752 const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
1753 const struct inet_timewait_sock *tw = inet_twsk(sk);
1754
1755 if (tw->tw_family == AF_INET)
1756 return tcp_v4_tw_get_peer(sk);
1757
1758 return inet_getpeer_v6(&tw6->tw_v6_daddr, 1);
1759 }
1760
1761 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1762 .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
1763 .twsk_unique = tcp_twsk_unique,
1764 .twsk_destructor= tcp_twsk_destructor,
1765 .twsk_getpeer = tcp_v6_tw_get_peer,
1766 };
1767
1768 static const struct inet_connection_sock_af_ops ipv6_specific = {
1769 .queue_xmit = inet6_csk_xmit,
1770 .send_check = tcp_v6_send_check,
1771 .rebuild_header = inet6_sk_rebuild_header,
1772 .conn_request = tcp_v6_conn_request,
1773 .syn_recv_sock = tcp_v6_syn_recv_sock,
1774 .get_peer = tcp_v6_get_peer,
1775 .net_header_len = sizeof(struct ipv6hdr),
1776 .setsockopt = ipv6_setsockopt,
1777 .getsockopt = ipv6_getsockopt,
1778 .addr2sockaddr = inet6_csk_addr2sockaddr,
1779 .sockaddr_len = sizeof(struct sockaddr_in6),
1780 .bind_conflict = inet6_csk_bind_conflict,
1781 #ifdef CONFIG_COMPAT
1782 .compat_setsockopt = compat_ipv6_setsockopt,
1783 .compat_getsockopt = compat_ipv6_getsockopt,
1784 #endif
1785 };
1786
1787 #ifdef CONFIG_TCP_MD5SIG
1788 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1789 .md5_lookup = tcp_v6_md5_lookup,
1790 .calc_md5_hash = tcp_v6_md5_hash_skb,
1791 .md5_parse = tcp_v6_parse_md5_keys,
1792 };
1793 #endif
1794
1795 /*
1796 * TCP over IPv4 via INET6 API
1797 */
1798
1799 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1800 .queue_xmit = ip_queue_xmit,
1801 .send_check = tcp_v4_send_check,
1802 .rebuild_header = inet_sk_rebuild_header,
1803 .conn_request = tcp_v6_conn_request,
1804 .syn_recv_sock = tcp_v6_syn_recv_sock,
1805 .get_peer = tcp_v4_get_peer,
1806 .net_header_len = sizeof(struct iphdr),
1807 .setsockopt = ipv6_setsockopt,
1808 .getsockopt = ipv6_getsockopt,
1809 .addr2sockaddr = inet6_csk_addr2sockaddr,
1810 .sockaddr_len = sizeof(struct sockaddr_in6),
1811 .bind_conflict = inet6_csk_bind_conflict,
1812 #ifdef CONFIG_COMPAT
1813 .compat_setsockopt = compat_ipv6_setsockopt,
1814 .compat_getsockopt = compat_ipv6_getsockopt,
1815 #endif
1816 };
1817
1818 #ifdef CONFIG_TCP_MD5SIG
1819 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1820 .md5_lookup = tcp_v4_md5_lookup,
1821 .calc_md5_hash = tcp_v4_md5_hash_skb,
1822 .md5_parse = tcp_v6_parse_md5_keys,
1823 };
1824 #endif
1825
1826 /* NOTE: A lot of things set to zero explicitly by call to
1827 * sk_alloc() so need not be done here.
1828 */
1829 static int tcp_v6_init_sock(struct sock *sk)
1830 {
1831 struct inet_connection_sock *icsk = inet_csk(sk);
1832 struct tcp_sock *tp = tcp_sk(sk);
1833
1834 skb_queue_head_init(&tp->out_of_order_queue);
1835 tcp_init_xmit_timers(sk);
1836 tcp_prequeue_init(tp);
1837
1838 icsk->icsk_rto = TCP_TIMEOUT_INIT;
1839 tp->mdev = TCP_TIMEOUT_INIT;
1840
1841 /* So many TCP implementations out there (incorrectly) count the
1842 * initial SYN frame in their delayed-ACK and congestion control
1843 * algorithms that we must have the following bandaid to talk
1844 * efficiently to them. -DaveM
1845 */
1846 tp->snd_cwnd = 2;
1847
1848 /* See draft-stevens-tcpca-spec-01 for discussion of the
1849 * initialization of these values.
1850 */
1851 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1852 tp->snd_cwnd_clamp = ~0;
1853 tp->mss_cache = TCP_MSS_DEFAULT;
1854
1855 tp->reordering = sysctl_tcp_reordering;
1856
1857 sk->sk_state = TCP_CLOSE;
1858
1859 icsk->icsk_af_ops = &ipv6_specific;
1860 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1861 icsk->icsk_sync_mss = tcp_sync_mss;
1862 sk->sk_write_space = sk_stream_write_space;
1863 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1864
1865 #ifdef CONFIG_TCP_MD5SIG
1866 tp->af_specific = &tcp_sock_ipv6_specific;
1867 #endif
1868
1869 /* TCP Cookie Transactions */
1870 if (sysctl_tcp_cookie_size > 0) {
1871 /* Default, cookies without s_data_payload. */
1872 tp->cookie_values =
1873 kzalloc(sizeof(*tp->cookie_values),
1874 sk->sk_allocation);
1875 if (tp->cookie_values != NULL)
1876 kref_init(&tp->cookie_values->kref);
1877 }
1878 /* Presumed zeroed, in order of appearance:
1879 * cookie_in_always, cookie_out_never,
1880 * s_data_constant, s_data_in, s_data_out
1881 */
1882 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1883 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1884
1885 local_bh_disable();
1886 sock_update_memcg(sk);
1887 sk_sockets_allocated_inc(sk);
1888 local_bh_enable();
1889
1890 return 0;
1891 }
1892
1893 static void tcp_v6_destroy_sock(struct sock *sk)
1894 {
1895 tcp_v4_destroy_sock(sk);
1896 inet6_destroy_sock(sk);
1897 }
1898
1899 #ifdef CONFIG_PROC_FS
1900 /* Proc filesystem TCPv6 sock list dumping. */
1901 static void get_openreq6(struct seq_file *seq,
1902 const struct sock *sk, struct request_sock *req, int i, int uid)
1903 {
1904 int ttd = req->expires - jiffies;
1905 const struct in6_addr *src = &inet6_rsk(req)->loc_addr;
1906 const struct in6_addr *dest = &inet6_rsk(req)->rmt_addr;
1907
1908 if (ttd < 0)
1909 ttd = 0;
1910
1911 seq_printf(seq,
1912 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1913 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1914 i,
1915 src->s6_addr32[0], src->s6_addr32[1],
1916 src->s6_addr32[2], src->s6_addr32[3],
1917 ntohs(inet_rsk(req)->loc_port),
1918 dest->s6_addr32[0], dest->s6_addr32[1],
1919 dest->s6_addr32[2], dest->s6_addr32[3],
1920 ntohs(inet_rsk(req)->rmt_port),
1921 TCP_SYN_RECV,
1922 0,0, /* could print option size, but that is af dependent. */
1923 1, /* timers active (only the expire timer) */
1924 jiffies_to_clock_t(ttd),
1925 req->retrans,
1926 uid,
1927 0, /* non standard timer */
1928 0, /* open_requests have no inode */
1929 0, req);
1930 }
1931
1932 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1933 {
1934 const struct in6_addr *dest, *src;
1935 __u16 destp, srcp;
1936 int timer_active;
1937 unsigned long timer_expires;
1938 const struct inet_sock *inet = inet_sk(sp);
1939 const struct tcp_sock *tp = tcp_sk(sp);
1940 const struct inet_connection_sock *icsk = inet_csk(sp);
1941 const struct ipv6_pinfo *np = inet6_sk(sp);
1942
1943 dest = &np->daddr;
1944 src = &np->rcv_saddr;
1945 destp = ntohs(inet->inet_dport);
1946 srcp = ntohs(inet->inet_sport);
1947
1948 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
1949 timer_active = 1;
1950 timer_expires = icsk->icsk_timeout;
1951 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1952 timer_active = 4;
1953 timer_expires = icsk->icsk_timeout;
1954 } else if (timer_pending(&sp->sk_timer)) {
1955 timer_active = 2;
1956 timer_expires = sp->sk_timer.expires;
1957 } else {
1958 timer_active = 0;
1959 timer_expires = jiffies;
1960 }
1961
1962 seq_printf(seq,
1963 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1964 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %lu %lu %u %u %d\n",
1965 i,
1966 src->s6_addr32[0], src->s6_addr32[1],
1967 src->s6_addr32[2], src->s6_addr32[3], srcp,
1968 dest->s6_addr32[0], dest->s6_addr32[1],
1969 dest->s6_addr32[2], dest->s6_addr32[3], destp,
1970 sp->sk_state,
1971 tp->write_seq-tp->snd_una,
1972 (sp->sk_state == TCP_LISTEN) ? sp->sk_ack_backlog : (tp->rcv_nxt - tp->copied_seq),
1973 timer_active,
1974 jiffies_to_clock_t(timer_expires - jiffies),
1975 icsk->icsk_retransmits,
1976 sock_i_uid(sp),
1977 icsk->icsk_probes_out,
1978 sock_i_ino(sp),
1979 atomic_read(&sp->sk_refcnt), sp,
1980 jiffies_to_clock_t(icsk->icsk_rto),
1981 jiffies_to_clock_t(icsk->icsk_ack.ato),
1982 (icsk->icsk_ack.quick << 1 ) | icsk->icsk_ack.pingpong,
1983 tp->snd_cwnd,
1984 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
1985 );
1986 }
1987
1988 static void get_timewait6_sock(struct seq_file *seq,
1989 struct inet_timewait_sock *tw, int i)
1990 {
1991 const struct in6_addr *dest, *src;
1992 __u16 destp, srcp;
1993 const struct inet6_timewait_sock *tw6 = inet6_twsk((struct sock *)tw);
1994 int ttd = tw->tw_ttd - jiffies;
1995
1996 if (ttd < 0)
1997 ttd = 0;
1998
1999 dest = &tw6->tw_v6_daddr;
2000 src = &tw6->tw_v6_rcv_saddr;
2001 destp = ntohs(tw->tw_dport);
2002 srcp = ntohs(tw->tw_sport);
2003
2004 seq_printf(seq,
2005 "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2006 "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2007 i,
2008 src->s6_addr32[0], src->s6_addr32[1],
2009 src->s6_addr32[2], src->s6_addr32[3], srcp,
2010 dest->s6_addr32[0], dest->s6_addr32[1],
2011 dest->s6_addr32[2], dest->s6_addr32[3], destp,
2012 tw->tw_substate, 0, 0,
2013 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2014 atomic_read(&tw->tw_refcnt), tw);
2015 }
2016
2017 static int tcp6_seq_show(struct seq_file *seq, void *v)
2018 {
2019 struct tcp_iter_state *st;
2020
2021 if (v == SEQ_START_TOKEN) {
2022 seq_puts(seq,
2023 " sl "
2024 "local_address "
2025 "remote_address "
2026 "st tx_queue rx_queue tr tm->when retrnsmt"
2027 " uid timeout inode\n");
2028 goto out;
2029 }
2030 st = seq->private;
2031
2032 switch (st->state) {
2033 case TCP_SEQ_STATE_LISTENING:
2034 case TCP_SEQ_STATE_ESTABLISHED:
2035 get_tcp6_sock(seq, v, st->num);
2036 break;
2037 case TCP_SEQ_STATE_OPENREQ:
2038 get_openreq6(seq, st->syn_wait_sk, v, st->num, st->uid);
2039 break;
2040 case TCP_SEQ_STATE_TIME_WAIT:
2041 get_timewait6_sock(seq, v, st->num);
2042 break;
2043 }
2044 out:
2045 return 0;
2046 }
2047
2048 static const struct file_operations tcp6_afinfo_seq_fops = {
2049 .owner = THIS_MODULE,
2050 .open = tcp_seq_open,
2051 .read = seq_read,
2052 .llseek = seq_lseek,
2053 .release = seq_release_net
2054 };
2055
2056 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2057 .name = "tcp6",
2058 .family = AF_INET6,
2059 .seq_fops = &tcp6_afinfo_seq_fops,
2060 .seq_ops = {
2061 .show = tcp6_seq_show,
2062 },
2063 };
2064
2065 int __net_init tcp6_proc_init(struct net *net)
2066 {
2067 return tcp_proc_register(net, &tcp6_seq_afinfo);
2068 }
2069
2070 void tcp6_proc_exit(struct net *net)
2071 {
2072 tcp_proc_unregister(net, &tcp6_seq_afinfo);
2073 }
2074 #endif
2075
2076 struct proto tcpv6_prot = {
2077 .name = "TCPv6",
2078 .owner = THIS_MODULE,
2079 .close = tcp_close,
2080 .connect = tcp_v6_connect,
2081 .disconnect = tcp_disconnect,
2082 .accept = inet_csk_accept,
2083 .ioctl = tcp_ioctl,
2084 .init = tcp_v6_init_sock,
2085 .destroy = tcp_v6_destroy_sock,
2086 .shutdown = tcp_shutdown,
2087 .setsockopt = tcp_setsockopt,
2088 .getsockopt = tcp_getsockopt,
2089 .recvmsg = tcp_recvmsg,
2090 .sendmsg = tcp_sendmsg,
2091 .sendpage = tcp_sendpage,
2092 .backlog_rcv = tcp_v6_do_rcv,
2093 .hash = tcp_v6_hash,
2094 .unhash = inet_unhash,
2095 .get_port = inet_csk_get_port,
2096 .enter_memory_pressure = tcp_enter_memory_pressure,
2097 .sockets_allocated = &tcp_sockets_allocated,
2098 .memory_allocated = &tcp_memory_allocated,
2099 .memory_pressure = &tcp_memory_pressure,
2100 .orphan_count = &tcp_orphan_count,
2101 .sysctl_wmem = sysctl_tcp_wmem,
2102 .sysctl_rmem = sysctl_tcp_rmem,
2103 .max_header = MAX_TCP_HEADER,
2104 .obj_size = sizeof(struct tcp6_sock),
2105 .slab_flags = SLAB_DESTROY_BY_RCU,
2106 .twsk_prot = &tcp6_timewait_sock_ops,
2107 .rsk_prot = &tcp6_request_sock_ops,
2108 .h.hashinfo = &tcp_hashinfo,
2109 .no_autobind = true,
2110 #ifdef CONFIG_COMPAT
2111 .compat_setsockopt = compat_tcp_setsockopt,
2112 .compat_getsockopt = compat_tcp_getsockopt,
2113 #endif
2114 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
2115 .proto_cgroup = tcp_proto_cgroup,
2116 #endif
2117 };
2118
2119 static const struct inet6_protocol tcpv6_protocol = {
2120 .handler = tcp_v6_rcv,
2121 .err_handler = tcp_v6_err,
2122 .gso_send_check = tcp_v6_gso_send_check,
2123 .gso_segment = tcp_tso_segment,
2124 .gro_receive = tcp6_gro_receive,
2125 .gro_complete = tcp6_gro_complete,
2126 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
2127 };
2128
2129 static struct inet_protosw tcpv6_protosw = {
2130 .type = SOCK_STREAM,
2131 .protocol = IPPROTO_TCP,
2132 .prot = &tcpv6_prot,
2133 .ops = &inet6_stream_ops,
2134 .no_check = 0,
2135 .flags = INET_PROTOSW_PERMANENT |
2136 INET_PROTOSW_ICSK,
2137 };
2138
2139 static int __net_init tcpv6_net_init(struct net *net)
2140 {
2141 return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2142 SOCK_RAW, IPPROTO_TCP, net);
2143 }
2144
2145 static void __net_exit tcpv6_net_exit(struct net *net)
2146 {
2147 inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2148 }
2149
2150 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2151 {
2152 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);
2153 }
2154
2155 static struct pernet_operations tcpv6_net_ops = {
2156 .init = tcpv6_net_init,
2157 .exit = tcpv6_net_exit,
2158 .exit_batch = tcpv6_net_exit_batch,
2159 };
2160
2161 int __init tcpv6_init(void)
2162 {
2163 int ret;
2164
2165 ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
2166 if (ret)
2167 goto out;
2168
2169 /* register inet6 protocol */
2170 ret = inet6_register_protosw(&tcpv6_protosw);
2171 if (ret)
2172 goto out_tcpv6_protocol;
2173
2174 ret = register_pernet_subsys(&tcpv6_net_ops);
2175 if (ret)
2176 goto out_tcpv6_protosw;
2177 out:
2178 return ret;
2179
2180 out_tcpv6_protocol:
2181 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2182 out_tcpv6_protosw:
2183 inet6_unregister_protosw(&tcpv6_protosw);
2184 goto out;
2185 }
2186
2187 void tcpv6_exit(void)
2188 {
2189 unregister_pernet_subsys(&tcpv6_net_ops);
2190 inet6_unregister_protosw(&tcpv6_protosw);
2191 inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2192 }
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