xref: /openbmc/linux/net/ipv6/tcp_ipv6.c (revision a36954f5)
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/inet_common.h>
63 #include <net/secure_seq.h>
64 #include <net/busy_poll.h>
65 
66 #include <linux/proc_fs.h>
67 #include <linux/seq_file.h>
68 
69 #include <crypto/hash.h>
70 #include <linux/scatterlist.h>
71 
72 static void	tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
73 static void	tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
74 				      struct request_sock *req);
75 
76 static int	tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
77 
78 static const struct inet_connection_sock_af_ops ipv6_mapped;
79 static const struct inet_connection_sock_af_ops ipv6_specific;
80 #ifdef CONFIG_TCP_MD5SIG
81 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
82 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
83 #else
84 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
85 						   const struct in6_addr *addr)
86 {
87 	return NULL;
88 }
89 #endif
90 
91 static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
92 {
93 	struct dst_entry *dst = skb_dst(skb);
94 
95 	if (dst && dst_hold_safe(dst)) {
96 		const struct rt6_info *rt = (const struct rt6_info *)dst;
97 
98 		sk->sk_rx_dst = dst;
99 		inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
100 		inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
101 	}
102 }
103 
104 static u32 tcp_v6_init_seq(const struct sk_buff *skb)
105 {
106 	return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
107 				ipv6_hdr(skb)->saddr.s6_addr32,
108 				tcp_hdr(skb)->dest,
109 				tcp_hdr(skb)->source);
110 }
111 
112 static u32 tcp_v6_init_ts_off(const struct sk_buff *skb)
113 {
114 	return secure_tcpv6_ts_off(ipv6_hdr(skb)->daddr.s6_addr32,
115 				   ipv6_hdr(skb)->saddr.s6_addr32);
116 }
117 
118 static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
119 			  int addr_len)
120 {
121 	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
122 	struct inet_sock *inet = inet_sk(sk);
123 	struct inet_connection_sock *icsk = inet_csk(sk);
124 	struct ipv6_pinfo *np = inet6_sk(sk);
125 	struct tcp_sock *tp = tcp_sk(sk);
126 	struct in6_addr *saddr = NULL, *final_p, final;
127 	struct ipv6_txoptions *opt;
128 	struct flowi6 fl6;
129 	struct dst_entry *dst;
130 	int addr_type;
131 	int err;
132 	struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
133 
134 	if (addr_len < SIN6_LEN_RFC2133)
135 		return -EINVAL;
136 
137 	if (usin->sin6_family != AF_INET6)
138 		return -EAFNOSUPPORT;
139 
140 	memset(&fl6, 0, sizeof(fl6));
141 
142 	if (np->sndflow) {
143 		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
144 		IP6_ECN_flow_init(fl6.flowlabel);
145 		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
146 			struct ip6_flowlabel *flowlabel;
147 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
148 			if (!flowlabel)
149 				return -EINVAL;
150 			fl6_sock_release(flowlabel);
151 		}
152 	}
153 
154 	/*
155 	 *	connect() to INADDR_ANY means loopback (BSD'ism).
156 	 */
157 
158 	if (ipv6_addr_any(&usin->sin6_addr)) {
159 		if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
160 			ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
161 					       &usin->sin6_addr);
162 		else
163 			usin->sin6_addr = in6addr_loopback;
164 	}
165 
166 	addr_type = ipv6_addr_type(&usin->sin6_addr);
167 
168 	if (addr_type & IPV6_ADDR_MULTICAST)
169 		return -ENETUNREACH;
170 
171 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
172 		if (addr_len >= sizeof(struct sockaddr_in6) &&
173 		    usin->sin6_scope_id) {
174 			/* If interface is set while binding, indices
175 			 * must coincide.
176 			 */
177 			if (sk->sk_bound_dev_if &&
178 			    sk->sk_bound_dev_if != usin->sin6_scope_id)
179 				return -EINVAL;
180 
181 			sk->sk_bound_dev_if = usin->sin6_scope_id;
182 		}
183 
184 		/* Connect to link-local address requires an interface */
185 		if (!sk->sk_bound_dev_if)
186 			return -EINVAL;
187 	}
188 
189 	if (tp->rx_opt.ts_recent_stamp &&
190 	    !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
191 		tp->rx_opt.ts_recent = 0;
192 		tp->rx_opt.ts_recent_stamp = 0;
193 		tp->write_seq = 0;
194 	}
195 
196 	sk->sk_v6_daddr = usin->sin6_addr;
197 	np->flow_label = fl6.flowlabel;
198 
199 	/*
200 	 *	TCP over IPv4
201 	 */
202 
203 	if (addr_type & IPV6_ADDR_MAPPED) {
204 		u32 exthdrlen = icsk->icsk_ext_hdr_len;
205 		struct sockaddr_in sin;
206 
207 		SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
208 
209 		if (__ipv6_only_sock(sk))
210 			return -ENETUNREACH;
211 
212 		sin.sin_family = AF_INET;
213 		sin.sin_port = usin->sin6_port;
214 		sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
215 
216 		icsk->icsk_af_ops = &ipv6_mapped;
217 		sk->sk_backlog_rcv = tcp_v4_do_rcv;
218 #ifdef CONFIG_TCP_MD5SIG
219 		tp->af_specific = &tcp_sock_ipv6_mapped_specific;
220 #endif
221 
222 		err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
223 
224 		if (err) {
225 			icsk->icsk_ext_hdr_len = exthdrlen;
226 			icsk->icsk_af_ops = &ipv6_specific;
227 			sk->sk_backlog_rcv = tcp_v6_do_rcv;
228 #ifdef CONFIG_TCP_MD5SIG
229 			tp->af_specific = &tcp_sock_ipv6_specific;
230 #endif
231 			goto failure;
232 		}
233 		np->saddr = sk->sk_v6_rcv_saddr;
234 
235 		return err;
236 	}
237 
238 	if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
239 		saddr = &sk->sk_v6_rcv_saddr;
240 
241 	fl6.flowi6_proto = IPPROTO_TCP;
242 	fl6.daddr = sk->sk_v6_daddr;
243 	fl6.saddr = saddr ? *saddr : np->saddr;
244 	fl6.flowi6_oif = sk->sk_bound_dev_if;
245 	fl6.flowi6_mark = sk->sk_mark;
246 	fl6.fl6_dport = usin->sin6_port;
247 	fl6.fl6_sport = inet->inet_sport;
248 	fl6.flowi6_uid = sk->sk_uid;
249 
250 	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
251 	final_p = fl6_update_dst(&fl6, opt, &final);
252 
253 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
254 
255 	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
256 	if (IS_ERR(dst)) {
257 		err = PTR_ERR(dst);
258 		goto failure;
259 	}
260 
261 	if (!saddr) {
262 		saddr = &fl6.saddr;
263 		sk->sk_v6_rcv_saddr = *saddr;
264 	}
265 
266 	/* set the source address */
267 	np->saddr = *saddr;
268 	inet->inet_rcv_saddr = LOOPBACK4_IPV6;
269 
270 	sk->sk_gso_type = SKB_GSO_TCPV6;
271 	ip6_dst_store(sk, dst, NULL, NULL);
272 
273 	icsk->icsk_ext_hdr_len = 0;
274 	if (opt)
275 		icsk->icsk_ext_hdr_len = opt->opt_flen +
276 					 opt->opt_nflen;
277 
278 	tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
279 
280 	inet->inet_dport = usin->sin6_port;
281 
282 	tcp_set_state(sk, TCP_SYN_SENT);
283 	err = inet6_hash_connect(tcp_death_row, sk);
284 	if (err)
285 		goto late_failure;
286 
287 	sk_set_txhash(sk);
288 
289 	if (likely(!tp->repair)) {
290 		if (!tp->write_seq)
291 			tp->write_seq = secure_tcpv6_seq(np->saddr.s6_addr32,
292 							 sk->sk_v6_daddr.s6_addr32,
293 							 inet->inet_sport,
294 							 inet->inet_dport);
295 		tp->tsoffset = secure_tcpv6_ts_off(np->saddr.s6_addr32,
296 						   sk->sk_v6_daddr.s6_addr32);
297 	}
298 
299 	if (tcp_fastopen_defer_connect(sk, &err))
300 		return err;
301 	if (err)
302 		goto late_failure;
303 
304 	err = tcp_connect(sk);
305 	if (err)
306 		goto late_failure;
307 
308 	return 0;
309 
310 late_failure:
311 	tcp_set_state(sk, TCP_CLOSE);
312 failure:
313 	inet->inet_dport = 0;
314 	sk->sk_route_caps = 0;
315 	return err;
316 }
317 
318 static void tcp_v6_mtu_reduced(struct sock *sk)
319 {
320 	struct dst_entry *dst;
321 
322 	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
323 		return;
324 
325 	dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info);
326 	if (!dst)
327 		return;
328 
329 	if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
330 		tcp_sync_mss(sk, dst_mtu(dst));
331 		tcp_simple_retransmit(sk);
332 	}
333 }
334 
335 static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
336 		u8 type, u8 code, int offset, __be32 info)
337 {
338 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
339 	const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
340 	struct net *net = dev_net(skb->dev);
341 	struct request_sock *fastopen;
342 	struct ipv6_pinfo *np;
343 	struct tcp_sock *tp;
344 	__u32 seq, snd_una;
345 	struct sock *sk;
346 	bool fatal;
347 	int err;
348 
349 	sk = __inet6_lookup_established(net, &tcp_hashinfo,
350 					&hdr->daddr, th->dest,
351 					&hdr->saddr, ntohs(th->source),
352 					skb->dev->ifindex);
353 
354 	if (!sk) {
355 		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
356 				  ICMP6_MIB_INERRORS);
357 		return;
358 	}
359 
360 	if (sk->sk_state == TCP_TIME_WAIT) {
361 		inet_twsk_put(inet_twsk(sk));
362 		return;
363 	}
364 	seq = ntohl(th->seq);
365 	fatal = icmpv6_err_convert(type, code, &err);
366 	if (sk->sk_state == TCP_NEW_SYN_RECV)
367 		return tcp_req_err(sk, seq, fatal);
368 
369 	bh_lock_sock(sk);
370 	if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
371 		__NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
372 
373 	if (sk->sk_state == TCP_CLOSE)
374 		goto out;
375 
376 	if (ipv6_hdr(skb)->hop_limit < inet6_sk(sk)->min_hopcount) {
377 		__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
378 		goto out;
379 	}
380 
381 	tp = tcp_sk(sk);
382 	/* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
383 	fastopen = tp->fastopen_rsk;
384 	snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
385 	if (sk->sk_state != TCP_LISTEN &&
386 	    !between(seq, snd_una, tp->snd_nxt)) {
387 		__NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
388 		goto out;
389 	}
390 
391 	np = inet6_sk(sk);
392 
393 	if (type == NDISC_REDIRECT) {
394 		if (!sock_owned_by_user(sk)) {
395 			struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
396 
397 			if (dst)
398 				dst->ops->redirect(dst, sk, skb);
399 		}
400 		goto out;
401 	}
402 
403 	if (type == ICMPV6_PKT_TOOBIG) {
404 		/* We are not interested in TCP_LISTEN and open_requests
405 		 * (SYN-ACKs send out by Linux are always <576bytes so
406 		 * they should go through unfragmented).
407 		 */
408 		if (sk->sk_state == TCP_LISTEN)
409 			goto out;
410 
411 		if (!ip6_sk_accept_pmtu(sk))
412 			goto out;
413 
414 		tp->mtu_info = ntohl(info);
415 		if (!sock_owned_by_user(sk))
416 			tcp_v6_mtu_reduced(sk);
417 		else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
418 					   &sk->sk_tsq_flags))
419 			sock_hold(sk);
420 		goto out;
421 	}
422 
423 
424 	/* Might be for an request_sock */
425 	switch (sk->sk_state) {
426 	case TCP_SYN_SENT:
427 	case TCP_SYN_RECV:
428 		/* Only in fast or simultaneous open. If a fast open socket is
429 		 * is already accepted it is treated as a connected one below.
430 		 */
431 		if (fastopen && !fastopen->sk)
432 			break;
433 
434 		if (!sock_owned_by_user(sk)) {
435 			sk->sk_err = err;
436 			sk->sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */
437 
438 			tcp_done(sk);
439 		} else
440 			sk->sk_err_soft = err;
441 		goto out;
442 	}
443 
444 	if (!sock_owned_by_user(sk) && np->recverr) {
445 		sk->sk_err = err;
446 		sk->sk_error_report(sk);
447 	} else
448 		sk->sk_err_soft = err;
449 
450 out:
451 	bh_unlock_sock(sk);
452 	sock_put(sk);
453 }
454 
455 
456 static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
457 			      struct flowi *fl,
458 			      struct request_sock *req,
459 			      struct tcp_fastopen_cookie *foc,
460 			      enum tcp_synack_type synack_type)
461 {
462 	struct inet_request_sock *ireq = inet_rsk(req);
463 	struct ipv6_pinfo *np = inet6_sk(sk);
464 	struct ipv6_txoptions *opt;
465 	struct flowi6 *fl6 = &fl->u.ip6;
466 	struct sk_buff *skb;
467 	int err = -ENOMEM;
468 
469 	/* First, grab a route. */
470 	if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
471 					       IPPROTO_TCP)) == NULL)
472 		goto done;
473 
474 	skb = tcp_make_synack(sk, dst, req, foc, synack_type);
475 
476 	if (skb) {
477 		__tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
478 				    &ireq->ir_v6_rmt_addr);
479 
480 		fl6->daddr = ireq->ir_v6_rmt_addr;
481 		if (np->repflow && ireq->pktopts)
482 			fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
483 
484 		rcu_read_lock();
485 		opt = ireq->ipv6_opt;
486 		if (!opt)
487 			opt = rcu_dereference(np->opt);
488 		err = ip6_xmit(sk, skb, fl6, sk->sk_mark, opt, np->tclass);
489 		rcu_read_unlock();
490 		err = net_xmit_eval(err);
491 	}
492 
493 done:
494 	return err;
495 }
496 
497 
498 static void tcp_v6_reqsk_destructor(struct request_sock *req)
499 {
500 	kfree(inet_rsk(req)->ipv6_opt);
501 	kfree_skb(inet_rsk(req)->pktopts);
502 }
503 
504 #ifdef CONFIG_TCP_MD5SIG
505 static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
506 						   const struct in6_addr *addr)
507 {
508 	return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6);
509 }
510 
511 static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
512 						const struct sock *addr_sk)
513 {
514 	return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
515 }
516 
517 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
518 				 int optlen)
519 {
520 	struct tcp_md5sig cmd;
521 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
522 
523 	if (optlen < sizeof(cmd))
524 		return -EINVAL;
525 
526 	if (copy_from_user(&cmd, optval, sizeof(cmd)))
527 		return -EFAULT;
528 
529 	if (sin6->sin6_family != AF_INET6)
530 		return -EINVAL;
531 
532 	if (!cmd.tcpm_keylen) {
533 		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
534 			return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
535 					      AF_INET);
536 		return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
537 				      AF_INET6);
538 	}
539 
540 	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
541 		return -EINVAL;
542 
543 	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
544 		return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
545 				      AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
546 
547 	return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
548 			      AF_INET6, cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
549 }
550 
551 static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
552 				   const struct in6_addr *daddr,
553 				   const struct in6_addr *saddr,
554 				   const struct tcphdr *th, int nbytes)
555 {
556 	struct tcp6_pseudohdr *bp;
557 	struct scatterlist sg;
558 	struct tcphdr *_th;
559 
560 	bp = hp->scratch;
561 	/* 1. TCP pseudo-header (RFC2460) */
562 	bp->saddr = *saddr;
563 	bp->daddr = *daddr;
564 	bp->protocol = cpu_to_be32(IPPROTO_TCP);
565 	bp->len = cpu_to_be32(nbytes);
566 
567 	_th = (struct tcphdr *)(bp + 1);
568 	memcpy(_th, th, sizeof(*th));
569 	_th->check = 0;
570 
571 	sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
572 	ahash_request_set_crypt(hp->md5_req, &sg, NULL,
573 				sizeof(*bp) + sizeof(*th));
574 	return crypto_ahash_update(hp->md5_req);
575 }
576 
577 static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
578 			       const struct in6_addr *daddr, struct in6_addr *saddr,
579 			       const struct tcphdr *th)
580 {
581 	struct tcp_md5sig_pool *hp;
582 	struct ahash_request *req;
583 
584 	hp = tcp_get_md5sig_pool();
585 	if (!hp)
586 		goto clear_hash_noput;
587 	req = hp->md5_req;
588 
589 	if (crypto_ahash_init(req))
590 		goto clear_hash;
591 	if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
592 		goto clear_hash;
593 	if (tcp_md5_hash_key(hp, key))
594 		goto clear_hash;
595 	ahash_request_set_crypt(req, NULL, md5_hash, 0);
596 	if (crypto_ahash_final(req))
597 		goto clear_hash;
598 
599 	tcp_put_md5sig_pool();
600 	return 0;
601 
602 clear_hash:
603 	tcp_put_md5sig_pool();
604 clear_hash_noput:
605 	memset(md5_hash, 0, 16);
606 	return 1;
607 }
608 
609 static int tcp_v6_md5_hash_skb(char *md5_hash,
610 			       const struct tcp_md5sig_key *key,
611 			       const struct sock *sk,
612 			       const struct sk_buff *skb)
613 {
614 	const struct in6_addr *saddr, *daddr;
615 	struct tcp_md5sig_pool *hp;
616 	struct ahash_request *req;
617 	const struct tcphdr *th = tcp_hdr(skb);
618 
619 	if (sk) { /* valid for establish/request sockets */
620 		saddr = &sk->sk_v6_rcv_saddr;
621 		daddr = &sk->sk_v6_daddr;
622 	} else {
623 		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
624 		saddr = &ip6h->saddr;
625 		daddr = &ip6h->daddr;
626 	}
627 
628 	hp = tcp_get_md5sig_pool();
629 	if (!hp)
630 		goto clear_hash_noput;
631 	req = hp->md5_req;
632 
633 	if (crypto_ahash_init(req))
634 		goto clear_hash;
635 
636 	if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
637 		goto clear_hash;
638 	if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
639 		goto clear_hash;
640 	if (tcp_md5_hash_key(hp, key))
641 		goto clear_hash;
642 	ahash_request_set_crypt(req, NULL, md5_hash, 0);
643 	if (crypto_ahash_final(req))
644 		goto clear_hash;
645 
646 	tcp_put_md5sig_pool();
647 	return 0;
648 
649 clear_hash:
650 	tcp_put_md5sig_pool();
651 clear_hash_noput:
652 	memset(md5_hash, 0, 16);
653 	return 1;
654 }
655 
656 #endif
657 
658 static bool tcp_v6_inbound_md5_hash(const struct sock *sk,
659 				    const struct sk_buff *skb)
660 {
661 #ifdef CONFIG_TCP_MD5SIG
662 	const __u8 *hash_location = NULL;
663 	struct tcp_md5sig_key *hash_expected;
664 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
665 	const struct tcphdr *th = tcp_hdr(skb);
666 	int genhash;
667 	u8 newhash[16];
668 
669 	hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
670 	hash_location = tcp_parse_md5sig_option(th);
671 
672 	/* We've parsed the options - do we have a hash? */
673 	if (!hash_expected && !hash_location)
674 		return false;
675 
676 	if (hash_expected && !hash_location) {
677 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
678 		return true;
679 	}
680 
681 	if (!hash_expected && hash_location) {
682 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
683 		return true;
684 	}
685 
686 	/* check the signature */
687 	genhash = tcp_v6_md5_hash_skb(newhash,
688 				      hash_expected,
689 				      NULL, skb);
690 
691 	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
692 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
693 		net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
694 				     genhash ? "failed" : "mismatch",
695 				     &ip6h->saddr, ntohs(th->source),
696 				     &ip6h->daddr, ntohs(th->dest));
697 		return true;
698 	}
699 #endif
700 	return false;
701 }
702 
703 static void tcp_v6_init_req(struct request_sock *req,
704 			    const struct sock *sk_listener,
705 			    struct sk_buff *skb)
706 {
707 	struct inet_request_sock *ireq = inet_rsk(req);
708 	const struct ipv6_pinfo *np = inet6_sk(sk_listener);
709 
710 	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
711 	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
712 
713 	/* So that link locals have meaning */
714 	if (!sk_listener->sk_bound_dev_if &&
715 	    ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
716 		ireq->ir_iif = tcp_v6_iif(skb);
717 
718 	if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
719 	    (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
720 	     np->rxopt.bits.rxinfo ||
721 	     np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
722 	     np->rxopt.bits.rxohlim || np->repflow)) {
723 		atomic_inc(&skb->users);
724 		ireq->pktopts = skb;
725 	}
726 }
727 
728 static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
729 					  struct flowi *fl,
730 					  const struct request_sock *req)
731 {
732 	return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
733 }
734 
735 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
736 	.family		=	AF_INET6,
737 	.obj_size	=	sizeof(struct tcp6_request_sock),
738 	.rtx_syn_ack	=	tcp_rtx_synack,
739 	.send_ack	=	tcp_v6_reqsk_send_ack,
740 	.destructor	=	tcp_v6_reqsk_destructor,
741 	.send_reset	=	tcp_v6_send_reset,
742 	.syn_ack_timeout =	tcp_syn_ack_timeout,
743 };
744 
745 static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
746 	.mss_clamp	=	IPV6_MIN_MTU - sizeof(struct tcphdr) -
747 				sizeof(struct ipv6hdr),
748 #ifdef CONFIG_TCP_MD5SIG
749 	.req_md5_lookup	=	tcp_v6_md5_lookup,
750 	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
751 #endif
752 	.init_req	=	tcp_v6_init_req,
753 #ifdef CONFIG_SYN_COOKIES
754 	.cookie_init_seq =	cookie_v6_init_sequence,
755 #endif
756 	.route_req	=	tcp_v6_route_req,
757 	.init_seq	=	tcp_v6_init_seq,
758 	.init_ts_off	=	tcp_v6_init_ts_off,
759 	.send_synack	=	tcp_v6_send_synack,
760 };
761 
762 static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
763 				 u32 ack, u32 win, u32 tsval, u32 tsecr,
764 				 int oif, struct tcp_md5sig_key *key, int rst,
765 				 u8 tclass, __be32 label)
766 {
767 	const struct tcphdr *th = tcp_hdr(skb);
768 	struct tcphdr *t1;
769 	struct sk_buff *buff;
770 	struct flowi6 fl6;
771 	struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
772 	struct sock *ctl_sk = net->ipv6.tcp_sk;
773 	unsigned int tot_len = sizeof(struct tcphdr);
774 	struct dst_entry *dst;
775 	__be32 *topt;
776 
777 	if (tsecr)
778 		tot_len += TCPOLEN_TSTAMP_ALIGNED;
779 #ifdef CONFIG_TCP_MD5SIG
780 	if (key)
781 		tot_len += TCPOLEN_MD5SIG_ALIGNED;
782 #endif
783 
784 	buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len,
785 			 GFP_ATOMIC);
786 	if (!buff)
787 		return;
788 
789 	skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len);
790 
791 	t1 = (struct tcphdr *) skb_push(buff, tot_len);
792 	skb_reset_transport_header(buff);
793 
794 	/* Swap the send and the receive. */
795 	memset(t1, 0, sizeof(*t1));
796 	t1->dest = th->source;
797 	t1->source = th->dest;
798 	t1->doff = tot_len / 4;
799 	t1->seq = htonl(seq);
800 	t1->ack_seq = htonl(ack);
801 	t1->ack = !rst || !th->ack;
802 	t1->rst = rst;
803 	t1->window = htons(win);
804 
805 	topt = (__be32 *)(t1 + 1);
806 
807 	if (tsecr) {
808 		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
809 				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
810 		*topt++ = htonl(tsval);
811 		*topt++ = htonl(tsecr);
812 	}
813 
814 #ifdef CONFIG_TCP_MD5SIG
815 	if (key) {
816 		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
817 				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
818 		tcp_v6_md5_hash_hdr((__u8 *)topt, key,
819 				    &ipv6_hdr(skb)->saddr,
820 				    &ipv6_hdr(skb)->daddr, t1);
821 	}
822 #endif
823 
824 	memset(&fl6, 0, sizeof(fl6));
825 	fl6.daddr = ipv6_hdr(skb)->saddr;
826 	fl6.saddr = ipv6_hdr(skb)->daddr;
827 	fl6.flowlabel = label;
828 
829 	buff->ip_summed = CHECKSUM_PARTIAL;
830 	buff->csum = 0;
831 
832 	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
833 
834 	fl6.flowi6_proto = IPPROTO_TCP;
835 	if (rt6_need_strict(&fl6.daddr) && !oif)
836 		fl6.flowi6_oif = tcp_v6_iif(skb);
837 	else {
838 		if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
839 			oif = skb->skb_iif;
840 
841 		fl6.flowi6_oif = oif;
842 	}
843 
844 	fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark);
845 	fl6.fl6_dport = t1->dest;
846 	fl6.fl6_sport = t1->source;
847 	fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
848 	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
849 
850 	/* Pass a socket to ip6_dst_lookup either it is for RST
851 	 * Underlying function will use this to retrieve the network
852 	 * namespace
853 	 */
854 	dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL);
855 	if (!IS_ERR(dst)) {
856 		skb_dst_set(buff, dst);
857 		ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass);
858 		TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
859 		if (rst)
860 			TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
861 		return;
862 	}
863 
864 	kfree_skb(buff);
865 }
866 
867 static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
868 {
869 	const struct tcphdr *th = tcp_hdr(skb);
870 	u32 seq = 0, ack_seq = 0;
871 	struct tcp_md5sig_key *key = NULL;
872 #ifdef CONFIG_TCP_MD5SIG
873 	const __u8 *hash_location = NULL;
874 	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
875 	unsigned char newhash[16];
876 	int genhash;
877 	struct sock *sk1 = NULL;
878 #endif
879 	int oif;
880 
881 	if (th->rst)
882 		return;
883 
884 	/* If sk not NULL, it means we did a successful lookup and incoming
885 	 * route had to be correct. prequeue might have dropped our dst.
886 	 */
887 	if (!sk && !ipv6_unicast_destination(skb))
888 		return;
889 
890 #ifdef CONFIG_TCP_MD5SIG
891 	rcu_read_lock();
892 	hash_location = tcp_parse_md5sig_option(th);
893 	if (sk && sk_fullsock(sk)) {
894 		key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr);
895 	} else if (hash_location) {
896 		/*
897 		 * active side is lost. Try to find listening socket through
898 		 * source port, and then find md5 key through listening socket.
899 		 * we are not loose security here:
900 		 * Incoming packet is checked with md5 hash with finding key,
901 		 * no RST generated if md5 hash doesn't match.
902 		 */
903 		sk1 = inet6_lookup_listener(dev_net(skb_dst(skb)->dev),
904 					   &tcp_hashinfo, NULL, 0,
905 					   &ipv6h->saddr,
906 					   th->source, &ipv6h->daddr,
907 					   ntohs(th->source), tcp_v6_iif(skb));
908 		if (!sk1)
909 			goto out;
910 
911 		key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr);
912 		if (!key)
913 			goto out;
914 
915 		genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
916 		if (genhash || memcmp(hash_location, newhash, 16) != 0)
917 			goto out;
918 	}
919 #endif
920 
921 	if (th->ack)
922 		seq = ntohl(th->ack_seq);
923 	else
924 		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
925 			  (th->doff << 2);
926 
927 	oif = sk ? sk->sk_bound_dev_if : 0;
928 	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);
929 
930 #ifdef CONFIG_TCP_MD5SIG
931 out:
932 	rcu_read_unlock();
933 #endif
934 }
935 
936 static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
937 			    u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
938 			    struct tcp_md5sig_key *key, u8 tclass,
939 			    __be32 label)
940 {
941 	tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
942 			     tclass, label);
943 }
944 
945 static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
946 {
947 	struct inet_timewait_sock *tw = inet_twsk(sk);
948 	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
949 
950 	tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
951 			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
952 			tcp_time_stamp + tcptw->tw_ts_offset,
953 			tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
954 			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel));
955 
956 	inet_twsk_put(tw);
957 }
958 
959 static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
960 				  struct request_sock *req)
961 {
962 	/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
963 	 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
964 	 */
965 	/* RFC 7323 2.3
966 	 * The window field (SEG.WND) of every outgoing segment, with the
967 	 * exception of <SYN> segments, MUST be right-shifted by
968 	 * Rcv.Wind.Shift bits:
969 	 */
970 	tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
971 			tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
972 			tcp_rsk(req)->rcv_nxt,
973 			req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
974 			tcp_time_stamp + tcp_rsk(req)->ts_off,
975 			req->ts_recent, sk->sk_bound_dev_if,
976 			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->daddr),
977 			0, 0);
978 }
979 
980 
981 static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
982 {
983 #ifdef CONFIG_SYN_COOKIES
984 	const struct tcphdr *th = tcp_hdr(skb);
985 
986 	if (!th->syn)
987 		sk = cookie_v6_check(sk, skb);
988 #endif
989 	return sk;
990 }
991 
992 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
993 {
994 	if (skb->protocol == htons(ETH_P_IP))
995 		return tcp_v4_conn_request(sk, skb);
996 
997 	if (!ipv6_unicast_destination(skb))
998 		goto drop;
999 
1000 	return tcp_conn_request(&tcp6_request_sock_ops,
1001 				&tcp_request_sock_ipv6_ops, sk, skb);
1002 
1003 drop:
1004 	tcp_listendrop(sk);
1005 	return 0; /* don't send reset */
1006 }
1007 
1008 static void tcp_v6_restore_cb(struct sk_buff *skb)
1009 {
1010 	/* We need to move header back to the beginning if xfrm6_policy_check()
1011 	 * and tcp_v6_fill_cb() are going to be called again.
1012 	 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1013 	 */
1014 	memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1015 		sizeof(struct inet6_skb_parm));
1016 }
1017 
1018 static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1019 					 struct request_sock *req,
1020 					 struct dst_entry *dst,
1021 					 struct request_sock *req_unhash,
1022 					 bool *own_req)
1023 {
1024 	struct inet_request_sock *ireq;
1025 	struct ipv6_pinfo *newnp;
1026 	const struct ipv6_pinfo *np = inet6_sk(sk);
1027 	struct ipv6_txoptions *opt;
1028 	struct tcp6_sock *newtcp6sk;
1029 	struct inet_sock *newinet;
1030 	struct tcp_sock *newtp;
1031 	struct sock *newsk;
1032 #ifdef CONFIG_TCP_MD5SIG
1033 	struct tcp_md5sig_key *key;
1034 #endif
1035 	struct flowi6 fl6;
1036 
1037 	if (skb->protocol == htons(ETH_P_IP)) {
1038 		/*
1039 		 *	v6 mapped
1040 		 */
1041 
1042 		newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1043 					     req_unhash, own_req);
1044 
1045 		if (!newsk)
1046 			return NULL;
1047 
1048 		newtcp6sk = (struct tcp6_sock *)newsk;
1049 		inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1050 
1051 		newinet = inet_sk(newsk);
1052 		newnp = inet6_sk(newsk);
1053 		newtp = tcp_sk(newsk);
1054 
1055 		memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1056 
1057 		newnp->saddr = newsk->sk_v6_rcv_saddr;
1058 
1059 		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1060 		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1061 #ifdef CONFIG_TCP_MD5SIG
1062 		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1063 #endif
1064 
1065 		newnp->ipv6_mc_list = NULL;
1066 		newnp->ipv6_ac_list = NULL;
1067 		newnp->ipv6_fl_list = NULL;
1068 		newnp->pktoptions  = NULL;
1069 		newnp->opt	   = NULL;
1070 		newnp->mcast_oif   = tcp_v6_iif(skb);
1071 		newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
1072 		newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1073 		if (np->repflow)
1074 			newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1075 
1076 		/*
1077 		 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1078 		 * here, tcp_create_openreq_child now does this for us, see the comment in
1079 		 * that function for the gory details. -acme
1080 		 */
1081 
1082 		/* It is tricky place. Until this moment IPv4 tcp
1083 		   worked with IPv6 icsk.icsk_af_ops.
1084 		   Sync it now.
1085 		 */
1086 		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1087 
1088 		return newsk;
1089 	}
1090 
1091 	ireq = inet_rsk(req);
1092 
1093 	if (sk_acceptq_is_full(sk))
1094 		goto out_overflow;
1095 
1096 	if (!dst) {
1097 		dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1098 		if (!dst)
1099 			goto out;
1100 	}
1101 
1102 	newsk = tcp_create_openreq_child(sk, req, skb);
1103 	if (!newsk)
1104 		goto out_nonewsk;
1105 
1106 	/*
1107 	 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1108 	 * count here, tcp_create_openreq_child now does this for us, see the
1109 	 * comment in that function for the gory details. -acme
1110 	 */
1111 
1112 	newsk->sk_gso_type = SKB_GSO_TCPV6;
1113 	ip6_dst_store(newsk, dst, NULL, NULL);
1114 	inet6_sk_rx_dst_set(newsk, skb);
1115 
1116 	newtcp6sk = (struct tcp6_sock *)newsk;
1117 	inet_sk(newsk)->pinet6 = &newtcp6sk->inet6;
1118 
1119 	newtp = tcp_sk(newsk);
1120 	newinet = inet_sk(newsk);
1121 	newnp = inet6_sk(newsk);
1122 
1123 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1124 
1125 	newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1126 	newnp->saddr = ireq->ir_v6_loc_addr;
1127 	newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1128 	newsk->sk_bound_dev_if = ireq->ir_iif;
1129 
1130 	/* Now IPv6 options...
1131 
1132 	   First: no IPv4 options.
1133 	 */
1134 	newinet->inet_opt = NULL;
1135 	newnp->ipv6_mc_list = NULL;
1136 	newnp->ipv6_ac_list = NULL;
1137 	newnp->ipv6_fl_list = NULL;
1138 
1139 	/* Clone RX bits */
1140 	newnp->rxopt.all = np->rxopt.all;
1141 
1142 	newnp->pktoptions = NULL;
1143 	newnp->opt	  = NULL;
1144 	newnp->mcast_oif  = tcp_v6_iif(skb);
1145 	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1146 	newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1147 	if (np->repflow)
1148 		newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1149 
1150 	/* Clone native IPv6 options from listening socket (if any)
1151 
1152 	   Yes, keeping reference count would be much more clever,
1153 	   but we make one more one thing there: reattach optmem
1154 	   to newsk.
1155 	 */
1156 	opt = ireq->ipv6_opt;
1157 	if (!opt)
1158 		opt = rcu_dereference(np->opt);
1159 	if (opt) {
1160 		opt = ipv6_dup_options(newsk, opt);
1161 		RCU_INIT_POINTER(newnp->opt, opt);
1162 	}
1163 	inet_csk(newsk)->icsk_ext_hdr_len = 0;
1164 	if (opt)
1165 		inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1166 						    opt->opt_flen;
1167 
1168 	tcp_ca_openreq_child(newsk, dst);
1169 
1170 	tcp_sync_mss(newsk, dst_mtu(dst));
1171 	newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1172 
1173 	tcp_initialize_rcv_mss(newsk);
1174 
1175 	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1176 	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1177 
1178 #ifdef CONFIG_TCP_MD5SIG
1179 	/* Copy over the MD5 key from the original socket */
1180 	key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr);
1181 	if (key) {
1182 		/* We're using one, so create a matching key
1183 		 * on the newsk structure. If we fail to get
1184 		 * memory, then we end up not copying the key
1185 		 * across. Shucks.
1186 		 */
1187 		tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
1188 			       AF_INET6, key->key, key->keylen,
1189 			       sk_gfp_mask(sk, GFP_ATOMIC));
1190 	}
1191 #endif
1192 
1193 	if (__inet_inherit_port(sk, newsk) < 0) {
1194 		inet_csk_prepare_forced_close(newsk);
1195 		tcp_done(newsk);
1196 		goto out;
1197 	}
1198 	*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
1199 	if (*own_req) {
1200 		tcp_move_syn(newtp, req);
1201 
1202 		/* Clone pktoptions received with SYN, if we own the req */
1203 		if (ireq->pktopts) {
1204 			newnp->pktoptions = skb_clone(ireq->pktopts,
1205 						      sk_gfp_mask(sk, GFP_ATOMIC));
1206 			consume_skb(ireq->pktopts);
1207 			ireq->pktopts = NULL;
1208 			if (newnp->pktoptions) {
1209 				tcp_v6_restore_cb(newnp->pktoptions);
1210 				skb_set_owner_r(newnp->pktoptions, newsk);
1211 			}
1212 		}
1213 	}
1214 
1215 	return newsk;
1216 
1217 out_overflow:
1218 	__NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1219 out_nonewsk:
1220 	dst_release(dst);
1221 out:
1222 	tcp_listendrop(sk);
1223 	return NULL;
1224 }
1225 
1226 /* The socket must have it's spinlock held when we get
1227  * here, unless it is a TCP_LISTEN socket.
1228  *
1229  * We have a potential double-lock case here, so even when
1230  * doing backlog processing we use the BH locking scheme.
1231  * This is because we cannot sleep with the original spinlock
1232  * held.
1233  */
1234 static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1235 {
1236 	struct ipv6_pinfo *np = inet6_sk(sk);
1237 	struct tcp_sock *tp;
1238 	struct sk_buff *opt_skb = NULL;
1239 
1240 	/* Imagine: socket is IPv6. IPv4 packet arrives,
1241 	   goes to IPv4 receive handler and backlogged.
1242 	   From backlog it always goes here. Kerboom...
1243 	   Fortunately, tcp_rcv_established and rcv_established
1244 	   handle them correctly, but it is not case with
1245 	   tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1246 	 */
1247 
1248 	if (skb->protocol == htons(ETH_P_IP))
1249 		return tcp_v4_do_rcv(sk, skb);
1250 
1251 	if (tcp_filter(sk, skb))
1252 		goto discard;
1253 
1254 	/*
1255 	 *	socket locking is here for SMP purposes as backlog rcv
1256 	 *	is currently called with bh processing disabled.
1257 	 */
1258 
1259 	/* Do Stevens' IPV6_PKTOPTIONS.
1260 
1261 	   Yes, guys, it is the only place in our code, where we
1262 	   may make it not affecting IPv4.
1263 	   The rest of code is protocol independent,
1264 	   and I do not like idea to uglify IPv4.
1265 
1266 	   Actually, all the idea behind IPV6_PKTOPTIONS
1267 	   looks not very well thought. For now we latch
1268 	   options, received in the last packet, enqueued
1269 	   by tcp. Feel free to propose better solution.
1270 					       --ANK (980728)
1271 	 */
1272 	if (np->rxopt.all)
1273 		opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
1274 
1275 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1276 		struct dst_entry *dst = sk->sk_rx_dst;
1277 
1278 		sock_rps_save_rxhash(sk, skb);
1279 		sk_mark_napi_id(sk, skb);
1280 		if (dst) {
1281 			if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
1282 			    dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
1283 				dst_release(dst);
1284 				sk->sk_rx_dst = NULL;
1285 			}
1286 		}
1287 
1288 		tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
1289 		if (opt_skb)
1290 			goto ipv6_pktoptions;
1291 		return 0;
1292 	}
1293 
1294 	if (tcp_checksum_complete(skb))
1295 		goto csum_err;
1296 
1297 	if (sk->sk_state == TCP_LISTEN) {
1298 		struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1299 
1300 		if (!nsk)
1301 			goto discard;
1302 
1303 		if (nsk != sk) {
1304 			if (tcp_child_process(sk, nsk, skb))
1305 				goto reset;
1306 			if (opt_skb)
1307 				__kfree_skb(opt_skb);
1308 			return 0;
1309 		}
1310 	} else
1311 		sock_rps_save_rxhash(sk, skb);
1312 
1313 	if (tcp_rcv_state_process(sk, skb))
1314 		goto reset;
1315 	if (opt_skb)
1316 		goto ipv6_pktoptions;
1317 	return 0;
1318 
1319 reset:
1320 	tcp_v6_send_reset(sk, skb);
1321 discard:
1322 	if (opt_skb)
1323 		__kfree_skb(opt_skb);
1324 	kfree_skb(skb);
1325 	return 0;
1326 csum_err:
1327 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1328 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1329 	goto discard;
1330 
1331 
1332 ipv6_pktoptions:
1333 	/* Do you ask, what is it?
1334 
1335 	   1. skb was enqueued by tcp.
1336 	   2. skb is added to tail of read queue, rather than out of order.
1337 	   3. socket is not in passive state.
1338 	   4. Finally, it really contains options, which user wants to receive.
1339 	 */
1340 	tp = tcp_sk(sk);
1341 	if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1342 	    !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1343 		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1344 			np->mcast_oif = tcp_v6_iif(opt_skb);
1345 		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1346 			np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
1347 		if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1348 			np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1349 		if (np->repflow)
1350 			np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1351 		if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1352 			skb_set_owner_r(opt_skb, sk);
1353 			tcp_v6_restore_cb(opt_skb);
1354 			opt_skb = xchg(&np->pktoptions, opt_skb);
1355 		} else {
1356 			__kfree_skb(opt_skb);
1357 			opt_skb = xchg(&np->pktoptions, NULL);
1358 		}
1359 	}
1360 
1361 	kfree_skb(opt_skb);
1362 	return 0;
1363 }
1364 
1365 static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1366 			   const struct tcphdr *th)
1367 {
1368 	/* This is tricky: we move IP6CB at its correct location into
1369 	 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1370 	 * _decode_session6() uses IP6CB().
1371 	 * barrier() makes sure compiler won't play aliasing games.
1372 	 */
1373 	memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1374 		sizeof(struct inet6_skb_parm));
1375 	barrier();
1376 
1377 	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1378 	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1379 				    skb->len - th->doff*4);
1380 	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1381 	TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1382 	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1383 	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1384 	TCP_SKB_CB(skb)->sacked = 0;
1385 }
1386 
1387 static int tcp_v6_rcv(struct sk_buff *skb)
1388 {
1389 	const struct tcphdr *th;
1390 	const struct ipv6hdr *hdr;
1391 	bool refcounted;
1392 	struct sock *sk;
1393 	int ret;
1394 	struct net *net = dev_net(skb->dev);
1395 
1396 	if (skb->pkt_type != PACKET_HOST)
1397 		goto discard_it;
1398 
1399 	/*
1400 	 *	Count it even if it's bad.
1401 	 */
1402 	__TCP_INC_STATS(net, TCP_MIB_INSEGS);
1403 
1404 	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1405 		goto discard_it;
1406 
1407 	th = (const struct tcphdr *)skb->data;
1408 
1409 	if (unlikely(th->doff < sizeof(struct tcphdr)/4))
1410 		goto bad_packet;
1411 	if (!pskb_may_pull(skb, th->doff*4))
1412 		goto discard_it;
1413 
1414 	if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1415 		goto csum_error;
1416 
1417 	th = (const struct tcphdr *)skb->data;
1418 	hdr = ipv6_hdr(skb);
1419 
1420 lookup:
1421 	sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
1422 				th->source, th->dest, inet6_iif(skb),
1423 				&refcounted);
1424 	if (!sk)
1425 		goto no_tcp_socket;
1426 
1427 process:
1428 	if (sk->sk_state == TCP_TIME_WAIT)
1429 		goto do_time_wait;
1430 
1431 	if (sk->sk_state == TCP_NEW_SYN_RECV) {
1432 		struct request_sock *req = inet_reqsk(sk);
1433 		struct sock *nsk;
1434 
1435 		sk = req->rsk_listener;
1436 		tcp_v6_fill_cb(skb, hdr, th);
1437 		if (tcp_v6_inbound_md5_hash(sk, skb)) {
1438 			sk_drops_add(sk, skb);
1439 			reqsk_put(req);
1440 			goto discard_it;
1441 		}
1442 		if (unlikely(sk->sk_state != TCP_LISTEN)) {
1443 			inet_csk_reqsk_queue_drop_and_put(sk, req);
1444 			goto lookup;
1445 		}
1446 		sock_hold(sk);
1447 		refcounted = true;
1448 		nsk = tcp_check_req(sk, skb, req, false);
1449 		if (!nsk) {
1450 			reqsk_put(req);
1451 			goto discard_and_relse;
1452 		}
1453 		if (nsk == sk) {
1454 			reqsk_put(req);
1455 			tcp_v6_restore_cb(skb);
1456 		} else if (tcp_child_process(sk, nsk, skb)) {
1457 			tcp_v6_send_reset(nsk, skb);
1458 			goto discard_and_relse;
1459 		} else {
1460 			sock_put(sk);
1461 			return 0;
1462 		}
1463 	}
1464 	if (hdr->hop_limit < inet6_sk(sk)->min_hopcount) {
1465 		__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1466 		goto discard_and_relse;
1467 	}
1468 
1469 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1470 		goto discard_and_relse;
1471 
1472 	tcp_v6_fill_cb(skb, hdr, th);
1473 
1474 	if (tcp_v6_inbound_md5_hash(sk, skb))
1475 		goto discard_and_relse;
1476 
1477 	if (tcp_filter(sk, skb))
1478 		goto discard_and_relse;
1479 	th = (const struct tcphdr *)skb->data;
1480 	hdr = ipv6_hdr(skb);
1481 
1482 	skb->dev = NULL;
1483 
1484 	if (sk->sk_state == TCP_LISTEN) {
1485 		ret = tcp_v6_do_rcv(sk, skb);
1486 		goto put_and_return;
1487 	}
1488 
1489 	sk_incoming_cpu_update(sk);
1490 
1491 	bh_lock_sock_nested(sk);
1492 	tcp_segs_in(tcp_sk(sk), skb);
1493 	ret = 0;
1494 	if (!sock_owned_by_user(sk)) {
1495 		if (!tcp_prequeue(sk, skb))
1496 			ret = tcp_v6_do_rcv(sk, skb);
1497 	} else if (tcp_add_backlog(sk, skb)) {
1498 		goto discard_and_relse;
1499 	}
1500 	bh_unlock_sock(sk);
1501 
1502 put_and_return:
1503 	if (refcounted)
1504 		sock_put(sk);
1505 	return ret ? -1 : 0;
1506 
1507 no_tcp_socket:
1508 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1509 		goto discard_it;
1510 
1511 	tcp_v6_fill_cb(skb, hdr, th);
1512 
1513 	if (tcp_checksum_complete(skb)) {
1514 csum_error:
1515 		__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1516 bad_packet:
1517 		__TCP_INC_STATS(net, TCP_MIB_INERRS);
1518 	} else {
1519 		tcp_v6_send_reset(NULL, skb);
1520 	}
1521 
1522 discard_it:
1523 	kfree_skb(skb);
1524 	return 0;
1525 
1526 discard_and_relse:
1527 	sk_drops_add(sk, skb);
1528 	if (refcounted)
1529 		sock_put(sk);
1530 	goto discard_it;
1531 
1532 do_time_wait:
1533 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1534 		inet_twsk_put(inet_twsk(sk));
1535 		goto discard_it;
1536 	}
1537 
1538 	tcp_v6_fill_cb(skb, hdr, th);
1539 
1540 	if (tcp_checksum_complete(skb)) {
1541 		inet_twsk_put(inet_twsk(sk));
1542 		goto csum_error;
1543 	}
1544 
1545 	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1546 	case TCP_TW_SYN:
1547 	{
1548 		struct sock *sk2;
1549 
1550 		sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo,
1551 					    skb, __tcp_hdrlen(th),
1552 					    &ipv6_hdr(skb)->saddr, th->source,
1553 					    &ipv6_hdr(skb)->daddr,
1554 					    ntohs(th->dest), tcp_v6_iif(skb));
1555 		if (sk2) {
1556 			struct inet_timewait_sock *tw = inet_twsk(sk);
1557 			inet_twsk_deschedule_put(tw);
1558 			sk = sk2;
1559 			tcp_v6_restore_cb(skb);
1560 			refcounted = false;
1561 			goto process;
1562 		}
1563 		/* Fall through to ACK */
1564 	}
1565 	case TCP_TW_ACK:
1566 		tcp_v6_timewait_ack(sk, skb);
1567 		break;
1568 	case TCP_TW_RST:
1569 		tcp_v6_restore_cb(skb);
1570 		tcp_v6_send_reset(sk, skb);
1571 		inet_twsk_deschedule_put(inet_twsk(sk));
1572 		goto discard_it;
1573 	case TCP_TW_SUCCESS:
1574 		;
1575 	}
1576 	goto discard_it;
1577 }
1578 
1579 static void tcp_v6_early_demux(struct sk_buff *skb)
1580 {
1581 	const struct ipv6hdr *hdr;
1582 	const struct tcphdr *th;
1583 	struct sock *sk;
1584 
1585 	if (skb->pkt_type != PACKET_HOST)
1586 		return;
1587 
1588 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
1589 		return;
1590 
1591 	hdr = ipv6_hdr(skb);
1592 	th = tcp_hdr(skb);
1593 
1594 	if (th->doff < sizeof(struct tcphdr) / 4)
1595 		return;
1596 
1597 	/* Note : We use inet6_iif() here, not tcp_v6_iif() */
1598 	sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo,
1599 					&hdr->saddr, th->source,
1600 					&hdr->daddr, ntohs(th->dest),
1601 					inet6_iif(skb));
1602 	if (sk) {
1603 		skb->sk = sk;
1604 		skb->destructor = sock_edemux;
1605 		if (sk_fullsock(sk)) {
1606 			struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
1607 
1608 			if (dst)
1609 				dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1610 			if (dst &&
1611 			    inet_sk(sk)->rx_dst_ifindex == skb->skb_iif)
1612 				skb_dst_set_noref(skb, dst);
1613 		}
1614 	}
1615 }
1616 
1617 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
1618 	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
1619 	.twsk_unique	= tcp_twsk_unique,
1620 	.twsk_destructor = tcp_twsk_destructor,
1621 };
1622 
1623 static const struct inet_connection_sock_af_ops ipv6_specific = {
1624 	.queue_xmit	   = inet6_csk_xmit,
1625 	.send_check	   = tcp_v6_send_check,
1626 	.rebuild_header	   = inet6_sk_rebuild_header,
1627 	.sk_rx_dst_set	   = inet6_sk_rx_dst_set,
1628 	.conn_request	   = tcp_v6_conn_request,
1629 	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
1630 	.net_header_len	   = sizeof(struct ipv6hdr),
1631 	.net_frag_header_len = sizeof(struct frag_hdr),
1632 	.setsockopt	   = ipv6_setsockopt,
1633 	.getsockopt	   = ipv6_getsockopt,
1634 	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
1635 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1636 #ifdef CONFIG_COMPAT
1637 	.compat_setsockopt = compat_ipv6_setsockopt,
1638 	.compat_getsockopt = compat_ipv6_getsockopt,
1639 #endif
1640 	.mtu_reduced	   = tcp_v6_mtu_reduced,
1641 };
1642 
1643 #ifdef CONFIG_TCP_MD5SIG
1644 static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
1645 	.md5_lookup	=	tcp_v6_md5_lookup,
1646 	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
1647 	.md5_parse	=	tcp_v6_parse_md5_keys,
1648 };
1649 #endif
1650 
1651 /*
1652  *	TCP over IPv4 via INET6 API
1653  */
1654 static const struct inet_connection_sock_af_ops ipv6_mapped = {
1655 	.queue_xmit	   = ip_queue_xmit,
1656 	.send_check	   = tcp_v4_send_check,
1657 	.rebuild_header	   = inet_sk_rebuild_header,
1658 	.sk_rx_dst_set	   = inet_sk_rx_dst_set,
1659 	.conn_request	   = tcp_v6_conn_request,
1660 	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
1661 	.net_header_len	   = sizeof(struct iphdr),
1662 	.setsockopt	   = ipv6_setsockopt,
1663 	.getsockopt	   = ipv6_getsockopt,
1664 	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
1665 	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1666 #ifdef CONFIG_COMPAT
1667 	.compat_setsockopt = compat_ipv6_setsockopt,
1668 	.compat_getsockopt = compat_ipv6_getsockopt,
1669 #endif
1670 	.mtu_reduced	   = tcp_v4_mtu_reduced,
1671 };
1672 
1673 #ifdef CONFIG_TCP_MD5SIG
1674 static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
1675 	.md5_lookup	=	tcp_v4_md5_lookup,
1676 	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
1677 	.md5_parse	=	tcp_v6_parse_md5_keys,
1678 };
1679 #endif
1680 
1681 /* NOTE: A lot of things set to zero explicitly by call to
1682  *       sk_alloc() so need not be done here.
1683  */
1684 static int tcp_v6_init_sock(struct sock *sk)
1685 {
1686 	struct inet_connection_sock *icsk = inet_csk(sk);
1687 
1688 	tcp_init_sock(sk);
1689 
1690 	icsk->icsk_af_ops = &ipv6_specific;
1691 
1692 #ifdef CONFIG_TCP_MD5SIG
1693 	tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
1694 #endif
1695 
1696 	return 0;
1697 }
1698 
1699 static void tcp_v6_destroy_sock(struct sock *sk)
1700 {
1701 	tcp_v4_destroy_sock(sk);
1702 	inet6_destroy_sock(sk);
1703 }
1704 
1705 #ifdef CONFIG_PROC_FS
1706 /* Proc filesystem TCPv6 sock list dumping. */
1707 static void get_openreq6(struct seq_file *seq,
1708 			 const struct request_sock *req, int i)
1709 {
1710 	long ttd = req->rsk_timer.expires - jiffies;
1711 	const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
1712 	const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
1713 
1714 	if (ttd < 0)
1715 		ttd = 0;
1716 
1717 	seq_printf(seq,
1718 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1719 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
1720 		   i,
1721 		   src->s6_addr32[0], src->s6_addr32[1],
1722 		   src->s6_addr32[2], src->s6_addr32[3],
1723 		   inet_rsk(req)->ir_num,
1724 		   dest->s6_addr32[0], dest->s6_addr32[1],
1725 		   dest->s6_addr32[2], dest->s6_addr32[3],
1726 		   ntohs(inet_rsk(req)->ir_rmt_port),
1727 		   TCP_SYN_RECV,
1728 		   0, 0, /* could print option size, but that is af dependent. */
1729 		   1,   /* timers active (only the expire timer) */
1730 		   jiffies_to_clock_t(ttd),
1731 		   req->num_timeout,
1732 		   from_kuid_munged(seq_user_ns(seq),
1733 				    sock_i_uid(req->rsk_listener)),
1734 		   0,  /* non standard timer */
1735 		   0, /* open_requests have no inode */
1736 		   0, req);
1737 }
1738 
1739 static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
1740 {
1741 	const struct in6_addr *dest, *src;
1742 	__u16 destp, srcp;
1743 	int timer_active;
1744 	unsigned long timer_expires;
1745 	const struct inet_sock *inet = inet_sk(sp);
1746 	const struct tcp_sock *tp = tcp_sk(sp);
1747 	const struct inet_connection_sock *icsk = inet_csk(sp);
1748 	const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
1749 	int rx_queue;
1750 	int state;
1751 
1752 	dest  = &sp->sk_v6_daddr;
1753 	src   = &sp->sk_v6_rcv_saddr;
1754 	destp = ntohs(inet->inet_dport);
1755 	srcp  = ntohs(inet->inet_sport);
1756 
1757 	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
1758 	    icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
1759 	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
1760 		timer_active	= 1;
1761 		timer_expires	= icsk->icsk_timeout;
1762 	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
1763 		timer_active	= 4;
1764 		timer_expires	= icsk->icsk_timeout;
1765 	} else if (timer_pending(&sp->sk_timer)) {
1766 		timer_active	= 2;
1767 		timer_expires	= sp->sk_timer.expires;
1768 	} else {
1769 		timer_active	= 0;
1770 		timer_expires = jiffies;
1771 	}
1772 
1773 	state = sk_state_load(sp);
1774 	if (state == TCP_LISTEN)
1775 		rx_queue = sp->sk_ack_backlog;
1776 	else
1777 		/* Because we don't lock the socket,
1778 		 * we might find a transient negative value.
1779 		 */
1780 		rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
1781 
1782 	seq_printf(seq,
1783 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1784 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
1785 		   i,
1786 		   src->s6_addr32[0], src->s6_addr32[1],
1787 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1788 		   dest->s6_addr32[0], dest->s6_addr32[1],
1789 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1790 		   state,
1791 		   tp->write_seq - tp->snd_una,
1792 		   rx_queue,
1793 		   timer_active,
1794 		   jiffies_delta_to_clock_t(timer_expires - jiffies),
1795 		   icsk->icsk_retransmits,
1796 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1797 		   icsk->icsk_probes_out,
1798 		   sock_i_ino(sp),
1799 		   atomic_read(&sp->sk_refcnt), sp,
1800 		   jiffies_to_clock_t(icsk->icsk_rto),
1801 		   jiffies_to_clock_t(icsk->icsk_ack.ato),
1802 		   (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
1803 		   tp->snd_cwnd,
1804 		   state == TCP_LISTEN ?
1805 			fastopenq->max_qlen :
1806 			(tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
1807 		   );
1808 }
1809 
1810 static void get_timewait6_sock(struct seq_file *seq,
1811 			       struct inet_timewait_sock *tw, int i)
1812 {
1813 	long delta = tw->tw_timer.expires - jiffies;
1814 	const struct in6_addr *dest, *src;
1815 	__u16 destp, srcp;
1816 
1817 	dest = &tw->tw_v6_daddr;
1818 	src  = &tw->tw_v6_rcv_saddr;
1819 	destp = ntohs(tw->tw_dport);
1820 	srcp  = ntohs(tw->tw_sport);
1821 
1822 	seq_printf(seq,
1823 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1824 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
1825 		   i,
1826 		   src->s6_addr32[0], src->s6_addr32[1],
1827 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1828 		   dest->s6_addr32[0], dest->s6_addr32[1],
1829 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1830 		   tw->tw_substate, 0, 0,
1831 		   3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
1832 		   atomic_read(&tw->tw_refcnt), tw);
1833 }
1834 
1835 static int tcp6_seq_show(struct seq_file *seq, void *v)
1836 {
1837 	struct tcp_iter_state *st;
1838 	struct sock *sk = v;
1839 
1840 	if (v == SEQ_START_TOKEN) {
1841 		seq_puts(seq,
1842 			 "  sl  "
1843 			 "local_address                         "
1844 			 "remote_address                        "
1845 			 "st tx_queue rx_queue tr tm->when retrnsmt"
1846 			 "   uid  timeout inode\n");
1847 		goto out;
1848 	}
1849 	st = seq->private;
1850 
1851 	if (sk->sk_state == TCP_TIME_WAIT)
1852 		get_timewait6_sock(seq, v, st->num);
1853 	else if (sk->sk_state == TCP_NEW_SYN_RECV)
1854 		get_openreq6(seq, v, st->num);
1855 	else
1856 		get_tcp6_sock(seq, v, st->num);
1857 out:
1858 	return 0;
1859 }
1860 
1861 static const struct file_operations tcp6_afinfo_seq_fops = {
1862 	.owner   = THIS_MODULE,
1863 	.open    = tcp_seq_open,
1864 	.read    = seq_read,
1865 	.llseek  = seq_lseek,
1866 	.release = seq_release_net
1867 };
1868 
1869 static struct tcp_seq_afinfo tcp6_seq_afinfo = {
1870 	.name		= "tcp6",
1871 	.family		= AF_INET6,
1872 	.seq_fops	= &tcp6_afinfo_seq_fops,
1873 	.seq_ops	= {
1874 		.show		= tcp6_seq_show,
1875 	},
1876 };
1877 
1878 int __net_init tcp6_proc_init(struct net *net)
1879 {
1880 	return tcp_proc_register(net, &tcp6_seq_afinfo);
1881 }
1882 
1883 void tcp6_proc_exit(struct net *net)
1884 {
1885 	tcp_proc_unregister(net, &tcp6_seq_afinfo);
1886 }
1887 #endif
1888 
1889 struct proto tcpv6_prot = {
1890 	.name			= "TCPv6",
1891 	.owner			= THIS_MODULE,
1892 	.close			= tcp_close,
1893 	.connect		= tcp_v6_connect,
1894 	.disconnect		= tcp_disconnect,
1895 	.accept			= inet_csk_accept,
1896 	.ioctl			= tcp_ioctl,
1897 	.init			= tcp_v6_init_sock,
1898 	.destroy		= tcp_v6_destroy_sock,
1899 	.shutdown		= tcp_shutdown,
1900 	.setsockopt		= tcp_setsockopt,
1901 	.getsockopt		= tcp_getsockopt,
1902 	.keepalive		= tcp_set_keepalive,
1903 	.recvmsg		= tcp_recvmsg,
1904 	.sendmsg		= tcp_sendmsg,
1905 	.sendpage		= tcp_sendpage,
1906 	.backlog_rcv		= tcp_v6_do_rcv,
1907 	.release_cb		= tcp_release_cb,
1908 	.hash			= inet6_hash,
1909 	.unhash			= inet_unhash,
1910 	.get_port		= inet_csk_get_port,
1911 	.enter_memory_pressure	= tcp_enter_memory_pressure,
1912 	.stream_memory_free	= tcp_stream_memory_free,
1913 	.sockets_allocated	= &tcp_sockets_allocated,
1914 	.memory_allocated	= &tcp_memory_allocated,
1915 	.memory_pressure	= &tcp_memory_pressure,
1916 	.orphan_count		= &tcp_orphan_count,
1917 	.sysctl_mem		= sysctl_tcp_mem,
1918 	.sysctl_wmem		= sysctl_tcp_wmem,
1919 	.sysctl_rmem		= sysctl_tcp_rmem,
1920 	.max_header		= MAX_TCP_HEADER,
1921 	.obj_size		= sizeof(struct tcp6_sock),
1922 	.slab_flags		= SLAB_TYPESAFE_BY_RCU,
1923 	.twsk_prot		= &tcp6_timewait_sock_ops,
1924 	.rsk_prot		= &tcp6_request_sock_ops,
1925 	.h.hashinfo		= &tcp_hashinfo,
1926 	.no_autobind		= true,
1927 #ifdef CONFIG_COMPAT
1928 	.compat_setsockopt	= compat_tcp_setsockopt,
1929 	.compat_getsockopt	= compat_tcp_getsockopt,
1930 #endif
1931 	.diag_destroy		= tcp_abort,
1932 };
1933 
1934 static struct inet6_protocol tcpv6_protocol = {
1935 	.early_demux	=	tcp_v6_early_demux,
1936 	.early_demux_handler =  tcp_v6_early_demux,
1937 	.handler	=	tcp_v6_rcv,
1938 	.err_handler	=	tcp_v6_err,
1939 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1940 };
1941 
1942 static struct inet_protosw tcpv6_protosw = {
1943 	.type		=	SOCK_STREAM,
1944 	.protocol	=	IPPROTO_TCP,
1945 	.prot		=	&tcpv6_prot,
1946 	.ops		=	&inet6_stream_ops,
1947 	.flags		=	INET_PROTOSW_PERMANENT |
1948 				INET_PROTOSW_ICSK,
1949 };
1950 
1951 static int __net_init tcpv6_net_init(struct net *net)
1952 {
1953 	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
1954 				    SOCK_RAW, IPPROTO_TCP, net);
1955 }
1956 
1957 static void __net_exit tcpv6_net_exit(struct net *net)
1958 {
1959 	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
1960 }
1961 
1962 static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
1963 {
1964 	inet_twsk_purge(&tcp_hashinfo, AF_INET6);
1965 }
1966 
1967 static struct pernet_operations tcpv6_net_ops = {
1968 	.init	    = tcpv6_net_init,
1969 	.exit	    = tcpv6_net_exit,
1970 	.exit_batch = tcpv6_net_exit_batch,
1971 };
1972 
1973 int __init tcpv6_init(void)
1974 {
1975 	int ret;
1976 
1977 	ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
1978 	if (ret)
1979 		goto out;
1980 
1981 	/* register inet6 protocol */
1982 	ret = inet6_register_protosw(&tcpv6_protosw);
1983 	if (ret)
1984 		goto out_tcpv6_protocol;
1985 
1986 	ret = register_pernet_subsys(&tcpv6_net_ops);
1987 	if (ret)
1988 		goto out_tcpv6_protosw;
1989 out:
1990 	return ret;
1991 
1992 out_tcpv6_protosw:
1993 	inet6_unregister_protosw(&tcpv6_protosw);
1994 out_tcpv6_protocol:
1995 	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
1996 	goto out;
1997 }
1998 
1999 void tcpv6_exit(void)
2000 {
2001 	unregister_pernet_subsys(&tcpv6_net_ops);
2002 	inet6_unregister_protosw(&tcpv6_protosw);
2003 	inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
2004 }
2005