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net: Convert printks to pr_<level>
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / tcp_ipv4.c
blob257dba66eacac58f1fb4b79a836f6534f24e9fe5
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
8 * IPv4 specific functions
9 *
10 *
11 * code split from:
12 * linux/ipv4/tcp.c
13 * linux/ipv4/tcp_input.c
14 * linux/ipv4/tcp_output.c
15 *
16 * See tcp.c for author information
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24 /*
25 * Changes:
26 * David S. Miller : New socket lookup architecture.
27 * This code is dedicated to John Dyson.
28 * David S. Miller : Change semantics of established hash,
29 * half is devoted to TIME_WAIT sockets
30 * and the rest go in the other half.
31 * Andi Kleen : Add support for syncookies and fixed
32 * some bugs: ip options weren't passed to
33 * the TCP layer, missed a check for an
34 * ACK bit.
35 * Andi Kleen : Implemented fast path mtu discovery.
36 * Fixed many serious bugs in the
37 * request_sock handling and moved
38 * most of it into the af independent code.
39 * Added tail drop and some other bugfixes.
40 * Added new listen semantics.
41 * Mike McLagan : Routing by source
42 * Juan Jose Ciarlante: ip_dynaddr bits
43 * Andi Kleen: various fixes.
44 * Vitaly E. Lavrov : Transparent proxy revived after year
45 * coma.
46 * Andi Kleen : Fix new listen.
47 * Andi Kleen : Fix accept error reporting.
48 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
49 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
50 * a single port at the same time.
51 */
52
53
54 #include <linux/bottom_half.h>
55 #include <linux/types.h>
56 #include <linux/fcntl.h>
57 #include <linux/module.h>
58 #include <linux/random.h>
59 #include <linux/cache.h>
60 #include <linux/jhash.h>
61 #include <linux/init.h>
62 #include <linux/times.h>
63 #include <linux/slab.h>
64
65 #include <net/net_namespace.h>
66 #include <net/icmp.h>
67 #include <net/inet_hashtables.h>
68 #include <net/tcp.h>
69 #include <net/transp_v6.h>
70 #include <net/ipv6.h>
71 #include <net/inet_common.h>
72 #include <net/timewait_sock.h>
73 #include <net/xfrm.h>
74 #include <net/netdma.h>
75 #include <net/secure_seq.h>
76 #include <net/tcp_memcontrol.h>
77
78 #include <linux/inet.h>
79 #include <linux/ipv6.h>
80 #include <linux/stddef.h>
81 #include <linux/proc_fs.h>
82 #include <linux/seq_file.h>
83
84 #include <linux/crypto.h>
85 #include <linux/scatterlist.h>
86
87 int sysctl_tcp_tw_reuse __read_mostly;
88 int sysctl_tcp_low_latency __read_mostly;
89 EXPORT_SYMBOL(sysctl_tcp_low_latency);
90
91
92 #ifdef CONFIG_TCP_MD5SIG
93 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
94 __be32 daddr, __be32 saddr, const struct tcphdr *th);
95 #endif
96
97 struct inet_hashinfo tcp_hashinfo;
98 EXPORT_SYMBOL(tcp_hashinfo);
99
100 static inline __u32 tcp_v4_init_sequence(const struct sk_buff *skb)
101 {
102 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
103 ip_hdr(skb)->saddr,
104 tcp_hdr(skb)->dest,
105 tcp_hdr(skb)->source);
106 }
107
108 int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
109 {
110 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
111 struct tcp_sock *tp = tcp_sk(sk);
112
113 /* With PAWS, it is safe from the viewpoint
114 of data integrity. Even without PAWS it is safe provided sequence
115 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
116
117 Actually, the idea is close to VJ's one, only timestamp cache is
118 held not per host, but per port pair and TW bucket is used as state
119 holder.
120
121 If TW bucket has been already destroyed we fall back to VJ's scheme
122 and use initial timestamp retrieved from peer table.
123 */
124 if (tcptw->tw_ts_recent_stamp &&
125 (twp == NULL || (sysctl_tcp_tw_reuse &&
126 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
127 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
128 if (tp->write_seq == 0)
129 tp->write_seq = 1;
130 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
131 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
132 sock_hold(sktw);
133 return 1;
134 }
135
136 return 0;
137 }
138 EXPORT_SYMBOL_GPL(tcp_twsk_unique);
139
140 /* This will initiate an outgoing connection. */
141 int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
142 {
143 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
144 struct inet_sock *inet = inet_sk(sk);
145 struct tcp_sock *tp = tcp_sk(sk);
146 __be16 orig_sport, orig_dport;
147 __be32 daddr, nexthop;
148 struct flowi4 *fl4;
149 struct rtable *rt;
150 int err;
151 struct ip_options_rcu *inet_opt;
152
153 if (addr_len < sizeof(struct sockaddr_in))
154 return -EINVAL;
155
156 if (usin->sin_family != AF_INET)
157 return -EAFNOSUPPORT;
158
159 nexthop = daddr = usin->sin_addr.s_addr;
160 inet_opt = rcu_dereference_protected(inet->inet_opt,
161 sock_owned_by_user(sk));
162 if (inet_opt && inet_opt->opt.srr) {
163 if (!daddr)
164 return -EINVAL;
165 nexthop = inet_opt->opt.faddr;
166 }
167
168 orig_sport = inet->inet_sport;
169 orig_dport = usin->sin_port;
170 fl4 = &inet->cork.fl.u.ip4;
171 rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
172 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
173 IPPROTO_TCP,
174 orig_sport, orig_dport, sk, true);
175 if (IS_ERR(rt)) {
176 err = PTR_ERR(rt);
177 if (err == -ENETUNREACH)
178 IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
179 return err;
180 }
181
182 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
183 ip_rt_put(rt);
184 return -ENETUNREACH;
185 }
186
187 if (!inet_opt || !inet_opt->opt.srr)
188 daddr = fl4->daddr;
189
190 if (!inet->inet_saddr)
191 inet->inet_saddr = fl4->saddr;
192 inet->inet_rcv_saddr = inet->inet_saddr;
193
194 if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) {
195 /* Reset inherited state */
196 tp->rx_opt.ts_recent = 0;
197 tp->rx_opt.ts_recent_stamp = 0;
198 tp->write_seq = 0;
199 }
200
201 if (tcp_death_row.sysctl_tw_recycle &&
202 !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr) {
203 struct inet_peer *peer = rt_get_peer(rt, fl4->daddr);
204 /*
205 * VJ's idea. We save last timestamp seen from
206 * the destination in peer table, when entering state
207 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
208 * when trying new connection.
209 */
210 if (peer) {
211 inet_peer_refcheck(peer);
212 if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
213 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
214 tp->rx_opt.ts_recent = peer->tcp_ts;
215 }
216 }
217 }
218
219 inet->inet_dport = usin->sin_port;
220 inet->inet_daddr = daddr;
221
222 inet_csk(sk)->icsk_ext_hdr_len = 0;
223 if (inet_opt)
224 inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
225
226 tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
227
228 /* Socket identity is still unknown (sport may be zero).
229 * However we set state to SYN-SENT and not releasing socket
230 * lock select source port, enter ourselves into the hash tables and
231 * complete initialization after this.
232 */
233 tcp_set_state(sk, TCP_SYN_SENT);
234 err = inet_hash_connect(&tcp_death_row, sk);
235 if (err)
236 goto failure;
237
238 rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
239 inet->inet_sport, inet->inet_dport, sk);
240 if (IS_ERR(rt)) {
241 err = PTR_ERR(rt);
242 rt = NULL;
243 goto failure;
244 }
245 /* OK, now commit destination to socket. */
246 sk->sk_gso_type = SKB_GSO_TCPV4;
247 sk_setup_caps(sk, &rt->dst);
248
249 if (!tp->write_seq)
250 tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr,
251 inet->inet_daddr,
252 inet->inet_sport,
253 usin->sin_port);
254
255 inet->inet_id = tp->write_seq ^ jiffies;
256
257 err = tcp_connect(sk);
258 rt = NULL;
259 if (err)
260 goto failure;
261
262 return 0;
263
264 failure:
265 /*
266 * This unhashes the socket and releases the local port,
267 * if necessary.
268 */
269 tcp_set_state(sk, TCP_CLOSE);
270 ip_rt_put(rt);
271 sk->sk_route_caps = 0;
272 inet->inet_dport = 0;
273 return err;
274 }
275 EXPORT_SYMBOL(tcp_v4_connect);
276
277 /*
278 * This routine does path mtu discovery as defined in RFC1191.
279 */
280 static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu)
281 {
282 struct dst_entry *dst;
283 struct inet_sock *inet = inet_sk(sk);
284
285 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
286 * send out by Linux are always <576bytes so they should go through
287 * unfragmented).
288 */
289 if (sk->sk_state == TCP_LISTEN)
290 return;
291
292 /* We don't check in the destentry if pmtu discovery is forbidden
293 * on this route. We just assume that no packet_to_big packets
294 * are send back when pmtu discovery is not active.
295 * There is a small race when the user changes this flag in the
296 * route, but I think that's acceptable.
297 */
298 if ((dst = __sk_dst_check(sk, 0)) == NULL)
299 return;
300
301 dst->ops->update_pmtu(dst, mtu);
302
303 /* Something is about to be wrong... Remember soft error
304 * for the case, if this connection will not able to recover.
305 */
306 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
307 sk->sk_err_soft = EMSGSIZE;
308
309 mtu = dst_mtu(dst);
310
311 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
312 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
313 tcp_sync_mss(sk, mtu);
314
315 /* Resend the TCP packet because it's
316 * clear that the old packet has been
317 * dropped. This is the new "fast" path mtu
318 * discovery.
319 */
320 tcp_simple_retransmit(sk);
321 } /* else let the usual retransmit timer handle it */
322 }
323
324 /*
325 * This routine is called by the ICMP module when it gets some
326 * sort of error condition. If err < 0 then the socket should
327 * be closed and the error returned to the user. If err > 0
328 * it's just the icmp type << 8 | icmp code. After adjustment
329 * header points to the first 8 bytes of the tcp header. We need
330 * to find the appropriate port.
331 *
332 * The locking strategy used here is very "optimistic". When
333 * someone else accesses the socket the ICMP is just dropped
334 * and for some paths there is no check at all.
335 * A more general error queue to queue errors for later handling
336 * is probably better.
337 *
338 */
339
340 void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
341 {
342 const struct iphdr *iph = (const struct iphdr *)icmp_skb->data;
343 struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));
344 struct inet_connection_sock *icsk;
345 struct tcp_sock *tp;
346 struct inet_sock *inet;
347 const int type = icmp_hdr(icmp_skb)->type;
348 const int code = icmp_hdr(icmp_skb)->code;
349 struct sock *sk;
350 struct sk_buff *skb;
351 __u32 seq;
352 __u32 remaining;
353 int err;
354 struct net *net = dev_net(icmp_skb->dev);
355
356 if (icmp_skb->len < (iph->ihl << 2) + 8) {
357 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
358 return;
359 }
360
361 sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
362 iph->saddr, th->source, inet_iif(icmp_skb));
363 if (!sk) {
364 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
365 return;
366 }
367 if (sk->sk_state == TCP_TIME_WAIT) {
368 inet_twsk_put(inet_twsk(sk));
369 return;
370 }
371
372 bh_lock_sock(sk);
373 /* If too many ICMPs get dropped on busy
374 * servers this needs to be solved differently.
375 */
376 if (sock_owned_by_user(sk))
377 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
378
379 if (sk->sk_state == TCP_CLOSE)
380 goto out;
381
382 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
383 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
384 goto out;
385 }
386
387 icsk = inet_csk(sk);
388 tp = tcp_sk(sk);
389 seq = ntohl(th->seq);
390 if (sk->sk_state != TCP_LISTEN &&
391 !between(seq, tp->snd_una, tp->snd_nxt)) {
392 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
393 goto out;
394 }
395
396 switch (type) {
397 case ICMP_SOURCE_QUENCH:
398 /* Just silently ignore these. */
399 goto out;
400 case ICMP_PARAMETERPROB:
401 err = EPROTO;
402 break;
403 case ICMP_DEST_UNREACH:
404 if (code > NR_ICMP_UNREACH)
405 goto out;
406
407 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
408 if (!sock_owned_by_user(sk))
409 do_pmtu_discovery(sk, iph, info);
410 goto out;
411 }
412
413 err = icmp_err_convert[code].errno;
414 /* check if icmp_skb allows revert of backoff
415 * (see draft-zimmermann-tcp-lcd) */
416 if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
417 break;
418 if (seq != tp->snd_una || !icsk->icsk_retransmits ||
419 !icsk->icsk_backoff)
420 break;
421
422 if (sock_owned_by_user(sk))
423 break;
424
425 icsk->icsk_backoff--;
426 inet_csk(sk)->icsk_rto = (tp->srtt ? __tcp_set_rto(tp) :
427 TCP_TIMEOUT_INIT) << icsk->icsk_backoff;
428 tcp_bound_rto(sk);
429
430 skb = tcp_write_queue_head(sk);
431 BUG_ON(!skb);
432
433 remaining = icsk->icsk_rto - min(icsk->icsk_rto,
434 tcp_time_stamp - TCP_SKB_CB(skb)->when);
435
436 if (remaining) {
437 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
438 remaining, TCP_RTO_MAX);
439 } else {
440 /* RTO revert clocked out retransmission.
441 * Will retransmit now */
442 tcp_retransmit_timer(sk);
443 }
444
445 break;
446 case ICMP_TIME_EXCEEDED:
447 err = EHOSTUNREACH;
448 break;
449 default:
450 goto out;
451 }
452
453 switch (sk->sk_state) {
454 struct request_sock *req, **prev;
455 case TCP_LISTEN:
456 if (sock_owned_by_user(sk))
457 goto out;
458
459 req = inet_csk_search_req(sk, &prev, th->dest,
460 iph->daddr, iph->saddr);
461 if (!req)
462 goto out;
463
464 /* ICMPs are not backlogged, hence we cannot get
465 an established socket here.
466 */
467 WARN_ON(req->sk);
468
469 if (seq != tcp_rsk(req)->snt_isn) {
470 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
471 goto out;
472 }
473
474 /*
475 * Still in SYN_RECV, just remove it silently.
476 * There is no good way to pass the error to the newly
477 * created socket, and POSIX does not want network
478 * errors returned from accept().
479 */
480 inet_csk_reqsk_queue_drop(sk, req, prev);
481 goto out;
482
483 case TCP_SYN_SENT:
484 case TCP_SYN_RECV: /* Cannot happen.
485 It can f.e. if SYNs crossed.
486 */
487 if (!sock_owned_by_user(sk)) {
488 sk->sk_err = err;
489
490 sk->sk_error_report(sk);
491
492 tcp_done(sk);
493 } else {
494 sk->sk_err_soft = err;
495 }
496 goto out;
497 }
498
499 /* If we've already connected we will keep trying
500 * until we time out, or the user gives up.
501 *
502 * rfc1122 4.2.3.9 allows to consider as hard errors
503 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
504 * but it is obsoleted by pmtu discovery).
505 *
506 * Note, that in modern internet, where routing is unreliable
507 * and in each dark corner broken firewalls sit, sending random
508 * errors ordered by their masters even this two messages finally lose
509 * their original sense (even Linux sends invalid PORT_UNREACHs)
510 *
511 * Now we are in compliance with RFCs.
512 * --ANK (980905)
513 */
514
515 inet = inet_sk(sk);
516 if (!sock_owned_by_user(sk) && inet->recverr) {
517 sk->sk_err = err;
518 sk->sk_error_report(sk);
519 } else { /* Only an error on timeout */
520 sk->sk_err_soft = err;
521 }
522
523 out:
524 bh_unlock_sock(sk);
525 sock_put(sk);
526 }
527
528 static void __tcp_v4_send_check(struct sk_buff *skb,
529 __be32 saddr, __be32 daddr)
530 {
531 struct tcphdr *th = tcp_hdr(skb);
532
533 if (skb->ip_summed == CHECKSUM_PARTIAL) {
534 th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0);
535 skb->csum_start = skb_transport_header(skb) - skb->head;
536 skb->csum_offset = offsetof(struct tcphdr, check);
537 } else {
538 th->check = tcp_v4_check(skb->len, saddr, daddr,
539 csum_partial(th,
540 th->doff << 2,
541 skb->csum));
542 }
543 }
544
545 /* This routine computes an IPv4 TCP checksum. */
546 void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
547 {
548 const struct inet_sock *inet = inet_sk(sk);
549
550 __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
551 }
552 EXPORT_SYMBOL(tcp_v4_send_check);
553
554 int tcp_v4_gso_send_check(struct sk_buff *skb)
555 {
556 const struct iphdr *iph;
557 struct tcphdr *th;
558
559 if (!pskb_may_pull(skb, sizeof(*th)))
560 return -EINVAL;
561
562 iph = ip_hdr(skb);
563 th = tcp_hdr(skb);
564
565 th->check = 0;
566 skb->ip_summed = CHECKSUM_PARTIAL;
567 __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
568 return 0;
569 }
570
571 /*
572 * This routine will send an RST to the other tcp.
573 *
574 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
575 * for reset.
576 * Answer: if a packet caused RST, it is not for a socket
577 * existing in our system, if it is matched to a socket,
578 * it is just duplicate segment or bug in other side's TCP.
579 * So that we build reply only basing on parameters
580 * arrived with segment.
581 * Exception: precedence violation. We do not implement it in any case.
582 */
583
584 static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
585 {
586 const struct tcphdr *th = tcp_hdr(skb);
587 struct {
588 struct tcphdr th;
589 #ifdef CONFIG_TCP_MD5SIG
590 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
591 #endif
592 } rep;
593 struct ip_reply_arg arg;
594 #ifdef CONFIG_TCP_MD5SIG
595 struct tcp_md5sig_key *key;
596 const __u8 *hash_location = NULL;
597 unsigned char newhash[16];
598 int genhash;
599 struct sock *sk1 = NULL;
600 #endif
601 struct net *net;
602
603 /* Never send a reset in response to a reset. */
604 if (th->rst)
605 return;
606
607 if (skb_rtable(skb)->rt_type != RTN_LOCAL)
608 return;
609
610 /* Swap the send and the receive. */
611 memset(&rep, 0, sizeof(rep));
612 rep.th.dest = th->source;
613 rep.th.source = th->dest;
614 rep.th.doff = sizeof(struct tcphdr) / 4;
615 rep.th.rst = 1;
616
617 if (th->ack) {
618 rep.th.seq = th->ack_seq;
619 } else {
620 rep.th.ack = 1;
621 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
622 skb->len - (th->doff << 2));
623 }
624
625 memset(&arg, 0, sizeof(arg));
626 arg.iov[0].iov_base = (unsigned char *)&rep;
627 arg.iov[0].iov_len = sizeof(rep.th);
628
629 #ifdef CONFIG_TCP_MD5SIG
630 hash_location = tcp_parse_md5sig_option(th);
631 if (!sk && hash_location) {
632 /*
633 * active side is lost. Try to find listening socket through
634 * source port, and then find md5 key through listening socket.
635 * we are not loose security here:
636 * Incoming packet is checked with md5 hash with finding key,
637 * no RST generated if md5 hash doesn't match.
638 */
639 sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev),
640 &tcp_hashinfo, ip_hdr(skb)->daddr,
641 ntohs(th->source), inet_iif(skb));
642 /* don't send rst if it can't find key */
643 if (!sk1)
644 return;
645 rcu_read_lock();
646 key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *)
647 &ip_hdr(skb)->saddr, AF_INET);
648 if (!key)
649 goto release_sk1;
650
651 genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb);
652 if (genhash || memcmp(hash_location, newhash, 16) != 0)
653 goto release_sk1;
654 } else {
655 key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *)
656 &ip_hdr(skb)->saddr,
657 AF_INET) : NULL;
658 }
659
660 if (key) {
661 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
662 (TCPOPT_NOP << 16) |
663 (TCPOPT_MD5SIG << 8) |
664 TCPOLEN_MD5SIG);
665 /* Update length and the length the header thinks exists */
666 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
667 rep.th.doff = arg.iov[0].iov_len / 4;
668
669 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
670 key, ip_hdr(skb)->saddr,
671 ip_hdr(skb)->daddr, &rep.th);
672 }
673 #endif
674 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
675 ip_hdr(skb)->saddr, /* XXX */
676 arg.iov[0].iov_len, IPPROTO_TCP, 0);
677 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
678 arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
679 /* When socket is gone, all binding information is lost.
680 * routing might fail in this case. using iif for oif to
681 * make sure we can deliver it
682 */
683 arg.bound_dev_if = sk ? sk->sk_bound_dev_if : inet_iif(skb);
684
685 net = dev_net(skb_dst(skb)->dev);
686 arg.tos = ip_hdr(skb)->tos;
687 ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
688 &arg, arg.iov[0].iov_len);
689
690 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
691 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
692
693 #ifdef CONFIG_TCP_MD5SIG
694 release_sk1:
695 if (sk1) {
696 rcu_read_unlock();
697 sock_put(sk1);
698 }
699 #endif
700 }
701
702 /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
703 outside socket context is ugly, certainly. What can I do?
704 */
705
706 static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
707 u32 win, u32 ts, int oif,
708 struct tcp_md5sig_key *key,
709 int reply_flags, u8 tos)
710 {
711 const struct tcphdr *th = tcp_hdr(skb);
712 struct {
713 struct tcphdr th;
714 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
715 #ifdef CONFIG_TCP_MD5SIG
716 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
717 #endif
718 ];
719 } rep;
720 struct ip_reply_arg arg;
721 struct net *net = dev_net(skb_dst(skb)->dev);
722
723 memset(&rep.th, 0, sizeof(struct tcphdr));
724 memset(&arg, 0, sizeof(arg));
725
726 arg.iov[0].iov_base = (unsigned char *)&rep;
727 arg.iov[0].iov_len = sizeof(rep.th);
728 if (ts) {
729 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
730 (TCPOPT_TIMESTAMP << 8) |
731 TCPOLEN_TIMESTAMP);
732 rep.opt[1] = htonl(tcp_time_stamp);
733 rep.opt[2] = htonl(ts);
734 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
735 }
736
737 /* Swap the send and the receive. */
738 rep.th.dest = th->source;
739 rep.th.source = th->dest;
740 rep.th.doff = arg.iov[0].iov_len / 4;
741 rep.th.seq = htonl(seq);
742 rep.th.ack_seq = htonl(ack);
743 rep.th.ack = 1;
744 rep.th.window = htons(win);
745
746 #ifdef CONFIG_TCP_MD5SIG
747 if (key) {
748 int offset = (ts) ? 3 : 0;
749
750 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
751 (TCPOPT_NOP << 16) |
752 (TCPOPT_MD5SIG << 8) |
753 TCPOLEN_MD5SIG);
754 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
755 rep.th.doff = arg.iov[0].iov_len/4;
756
757 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
758 key, ip_hdr(skb)->saddr,
759 ip_hdr(skb)->daddr, &rep.th);
760 }
761 #endif
762 arg.flags = reply_flags;
763 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
764 ip_hdr(skb)->saddr, /* XXX */
765 arg.iov[0].iov_len, IPPROTO_TCP, 0);
766 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
767 if (oif)
768 arg.bound_dev_if = oif;
769 arg.tos = tos;
770 ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr,
771 &arg, arg.iov[0].iov_len);
772
773 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
774 }
775
776 static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
777 {
778 struct inet_timewait_sock *tw = inet_twsk(sk);
779 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
780
781 tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
782 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
783 tcptw->tw_ts_recent,
784 tw->tw_bound_dev_if,
785 tcp_twsk_md5_key(tcptw),
786 tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
787 tw->tw_tos
788 );
789
790 inet_twsk_put(tw);
791 }
792
793 static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
794 struct request_sock *req)
795 {
796 tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
797 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
798 req->ts_recent,
799 0,
800 tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr,
801 AF_INET),
802 inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
803 ip_hdr(skb)->tos);
804 }
805
806 /*
807 * Send a SYN-ACK after having received a SYN.
808 * This still operates on a request_sock only, not on a big
809 * socket.
810 */
811 static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
812 struct request_sock *req,
813 struct request_values *rvp)
814 {
815 const struct inet_request_sock *ireq = inet_rsk(req);
816 struct flowi4 fl4;
817 int err = -1;
818 struct sk_buff * skb;
819
820 /* First, grab a route. */
821 if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL)
822 return -1;
823
824 skb = tcp_make_synack(sk, dst, req, rvp);
825
826 if (skb) {
827 __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);
828
829 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
830 ireq->rmt_addr,
831 ireq->opt);
832 err = net_xmit_eval(err);
833 }
834
835 dst_release(dst);
836 return err;
837 }
838
839 static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req,
840 struct request_values *rvp)
841 {
842 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
843 return tcp_v4_send_synack(sk, NULL, req, rvp);
844 }
845
846 /*
847 * IPv4 request_sock destructor.
848 */
849 static void tcp_v4_reqsk_destructor(struct request_sock *req)
850 {
851 kfree(inet_rsk(req)->opt);
852 }
853
854 /*
855 * Return 1 if a syncookie should be sent
856 */
857 int tcp_syn_flood_action(struct sock *sk,
858 const struct sk_buff *skb,
859 const char *proto)
860 {
861 const char *msg = "Dropping request";
862 int want_cookie = 0;
863 struct listen_sock *lopt;
864
865
866
867 #ifdef CONFIG_SYN_COOKIES
868 if (sysctl_tcp_syncookies) {
869 msg = "Sending cookies";
870 want_cookie = 1;
871 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES);
872 } else
873 #endif
874 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP);
875
876 lopt = inet_csk(sk)->icsk_accept_queue.listen_opt;
877 if (!lopt->synflood_warned) {
878 lopt->synflood_warned = 1;
879 pr_info("%s: Possible SYN flooding on port %d. %s. "
880 " Check SNMP counters.\n",
881 proto, ntohs(tcp_hdr(skb)->dest), msg);
882 }
883 return want_cookie;
884 }
885 EXPORT_SYMBOL(tcp_syn_flood_action);
886
887 /*
888 * Save and compile IPv4 options into the request_sock if needed.
889 */
890 static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
891 struct sk_buff *skb)
892 {
893 const struct ip_options *opt = &(IPCB(skb)->opt);
894 struct ip_options_rcu *dopt = NULL;
895
896 if (opt && opt->optlen) {
897 int opt_size = sizeof(*dopt) + opt->optlen;
898
899 dopt = kmalloc(opt_size, GFP_ATOMIC);
900 if (dopt) {
901 if (ip_options_echo(&dopt->opt, skb)) {
902 kfree(dopt);
903 dopt = NULL;
904 }
905 }
906 }
907 return dopt;
908 }
909
910 #ifdef CONFIG_TCP_MD5SIG
911 /*
912 * RFC2385 MD5 checksumming requires a mapping of
913 * IP address->MD5 Key.
914 * We need to maintain these in the sk structure.
915 */
916
917 /* Find the Key structure for an address. */
918 struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
919 const union tcp_md5_addr *addr,
920 int family)
921 {
922 struct tcp_sock *tp = tcp_sk(sk);
923 struct tcp_md5sig_key *key;
924 struct hlist_node *pos;
925 unsigned int size = sizeof(struct in_addr);
926 struct tcp_md5sig_info *md5sig;
927
928 /* caller either holds rcu_read_lock() or socket lock */
929 md5sig = rcu_dereference_check(tp->md5sig_info,
930 sock_owned_by_user(sk) ||
931 lockdep_is_held(&sk->sk_lock.slock));
932 if (!md5sig)
933 return NULL;
934 #if IS_ENABLED(CONFIG_IPV6)
935 if (family == AF_INET6)
936 size = sizeof(struct in6_addr);
937 #endif
938 hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) {
939 if (key->family != family)
940 continue;
941 if (!memcmp(&key->addr, addr, size))
942 return key;
943 }
944 return NULL;
945 }
946 EXPORT_SYMBOL(tcp_md5_do_lookup);
947
948 struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
949 struct sock *addr_sk)
950 {
951 union tcp_md5_addr *addr;
952
953 addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_daddr;
954 return tcp_md5_do_lookup(sk, addr, AF_INET);
955 }
956 EXPORT_SYMBOL(tcp_v4_md5_lookup);
957
958 static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
959 struct request_sock *req)
960 {
961 union tcp_md5_addr *addr;
962
963 addr = (union tcp_md5_addr *)&inet_rsk(req)->rmt_addr;
964 return tcp_md5_do_lookup(sk, addr, AF_INET);
965 }
966
967 /* This can be called on a newly created socket, from other files */
968 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
969 int family, const u8 *newkey, u8 newkeylen, gfp_t gfp)
970 {
971 /* Add Key to the list */
972 struct tcp_md5sig_key *key;
973 struct tcp_sock *tp = tcp_sk(sk);
974 struct tcp_md5sig_info *md5sig;
975
976 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
977 if (key) {
978 /* Pre-existing entry - just update that one. */
979 memcpy(key->key, newkey, newkeylen);
980 key->keylen = newkeylen;
981 return 0;
982 }
983
984 md5sig = rcu_dereference_protected(tp->md5sig_info,
985 sock_owned_by_user(sk));
986 if (!md5sig) {
987 md5sig = kmalloc(sizeof(*md5sig), gfp);
988 if (!md5sig)
989 return -ENOMEM;
990
991 sk_nocaps_add(sk, NETIF_F_GSO_MASK);
992 INIT_HLIST_HEAD(&md5sig->head);
993 rcu_assign_pointer(tp->md5sig_info, md5sig);
994 }
995
996 key = sock_kmalloc(sk, sizeof(*key), gfp);
997 if (!key)
998 return -ENOMEM;
999 if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) {
1000 sock_kfree_s(sk, key, sizeof(*key));
1001 return -ENOMEM;
1002 }
1003
1004 memcpy(key->key, newkey, newkeylen);
1005 key->keylen = newkeylen;
1006 key->family = family;
1007 memcpy(&key->addr, addr,
1008 (family == AF_INET6) ? sizeof(struct in6_addr) :
1009 sizeof(struct in_addr));
1010 hlist_add_head_rcu(&key->node, &md5sig->head);
1011 return 0;
1012 }
1013 EXPORT_SYMBOL(tcp_md5_do_add);
1014
1015 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family)
1016 {
1017 struct tcp_sock *tp = tcp_sk(sk);
1018 struct tcp_md5sig_key *key;
1019 struct tcp_md5sig_info *md5sig;
1020
1021 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET);
1022 if (!key)
1023 return -ENOENT;
1024 hlist_del_rcu(&key->node);
1025 atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
1026 kfree_rcu(key, rcu);
1027 md5sig = rcu_dereference_protected(tp->md5sig_info,
1028 sock_owned_by_user(sk));
1029 if (hlist_empty(&md5sig->head))
1030 tcp_free_md5sig_pool();
1031 return 0;
1032 }
1033 EXPORT_SYMBOL(tcp_md5_do_del);
1034
1035 void tcp_clear_md5_list(struct sock *sk)
1036 {
1037 struct tcp_sock *tp = tcp_sk(sk);
1038 struct tcp_md5sig_key *key;
1039 struct hlist_node *pos, *n;
1040 struct tcp_md5sig_info *md5sig;
1041
1042 md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
1043
1044 if (!hlist_empty(&md5sig->head))
1045 tcp_free_md5sig_pool();
1046 hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) {
1047 hlist_del_rcu(&key->node);
1048 atomic_sub(sizeof(*key), &sk->sk_omem_alloc);
1049 kfree_rcu(key, rcu);
1050 }
1051 }
1052
1053 static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
1054 int optlen)
1055 {
1056 struct tcp_md5sig cmd;
1057 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
1058
1059 if (optlen < sizeof(cmd))
1060 return -EINVAL;
1061
1062 if (copy_from_user(&cmd, optval, sizeof(cmd)))
1063 return -EFAULT;
1064
1065 if (sin->sin_family != AF_INET)
1066 return -EINVAL;
1067
1068 if (!cmd.tcpm_key || !cmd.tcpm_keylen)
1069 return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
1070 AF_INET);
1071
1072 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
1073 return -EINVAL;
1074
1075 return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr,
1076 AF_INET, cmd.tcpm_key, cmd.tcpm_keylen,
1077 GFP_KERNEL);
1078 }
1079
1080 static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
1081 __be32 daddr, __be32 saddr, int nbytes)
1082 {
1083 struct tcp4_pseudohdr *bp;
1084 struct scatterlist sg;
1085
1086 bp = &hp->md5_blk.ip4;
1087
1088 /*
1089 * 1. the TCP pseudo-header (in the order: source IP address,
1090 * destination IP address, zero-padded protocol number, and
1091 * segment length)
1092 */
1093 bp->saddr = saddr;
1094 bp->daddr = daddr;
1095 bp->pad = 0;
1096 bp->protocol = IPPROTO_TCP;
1097 bp->len = cpu_to_be16(nbytes);
1098
1099 sg_init_one(&sg, bp, sizeof(*bp));
1100 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
1101 }
1102
1103 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
1104 __be32 daddr, __be32 saddr, const struct tcphdr *th)
1105 {
1106 struct tcp_md5sig_pool *hp;
1107 struct hash_desc *desc;
1108
1109 hp = tcp_get_md5sig_pool();
1110 if (!hp)
1111 goto clear_hash_noput;
1112 desc = &hp->md5_desc;
1113
1114 if (crypto_hash_init(desc))
1115 goto clear_hash;
1116 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
1117 goto clear_hash;
1118 if (tcp_md5_hash_header(hp, th))
1119 goto clear_hash;
1120 if (tcp_md5_hash_key(hp, key))
1121 goto clear_hash;
1122 if (crypto_hash_final(desc, md5_hash))
1123 goto clear_hash;
1124
1125 tcp_put_md5sig_pool();
1126 return 0;
1127
1128 clear_hash:
1129 tcp_put_md5sig_pool();
1130 clear_hash_noput:
1131 memset(md5_hash, 0, 16);
1132 return 1;
1133 }
1134
1135 int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
1136 const struct sock *sk, const struct request_sock *req,
1137 const struct sk_buff *skb)
1138 {
1139 struct tcp_md5sig_pool *hp;
1140 struct hash_desc *desc;
1141 const struct tcphdr *th = tcp_hdr(skb);
1142 __be32 saddr, daddr;
1143
1144 if (sk) {
1145 saddr = inet_sk(sk)->inet_saddr;
1146 daddr = inet_sk(sk)->inet_daddr;
1147 } else if (req) {
1148 saddr = inet_rsk(req)->loc_addr;
1149 daddr = inet_rsk(req)->rmt_addr;
1150 } else {
1151 const struct iphdr *iph = ip_hdr(skb);
1152 saddr = iph->saddr;
1153 daddr = iph->daddr;
1154 }
1155
1156 hp = tcp_get_md5sig_pool();
1157 if (!hp)
1158 goto clear_hash_noput;
1159 desc = &hp->md5_desc;
1160
1161 if (crypto_hash_init(desc))
1162 goto clear_hash;
1163
1164 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
1165 goto clear_hash;
1166 if (tcp_md5_hash_header(hp, th))
1167 goto clear_hash;
1168 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
1169 goto clear_hash;
1170 if (tcp_md5_hash_key(hp, key))
1171 goto clear_hash;
1172 if (crypto_hash_final(desc, md5_hash))
1173 goto clear_hash;
1174
1175 tcp_put_md5sig_pool();
1176 return 0;
1177
1178 clear_hash:
1179 tcp_put_md5sig_pool();
1180 clear_hash_noput:
1181 memset(md5_hash, 0, 16);
1182 return 1;
1183 }
1184 EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
1185
1186 static int tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
1187 {
1188 /*
1189 * This gets called for each TCP segment that arrives
1190 * so we want to be efficient.
1191 * We have 3 drop cases:
1192 * o No MD5 hash and one expected.
1193 * o MD5 hash and we're not expecting one.
1194 * o MD5 hash and its wrong.
1195 */
1196 const __u8 *hash_location = NULL;
1197 struct tcp_md5sig_key *hash_expected;
1198 const struct iphdr *iph = ip_hdr(skb);
1199 const struct tcphdr *th = tcp_hdr(skb);
1200 int genhash;
1201 unsigned char newhash[16];
1202
1203 hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr,
1204 AF_INET);
1205 hash_location = tcp_parse_md5sig_option(th);
1206
1207 /* We've parsed the options - do we have a hash? */
1208 if (!hash_expected && !hash_location)
1209 return 0;
1210
1211 if (hash_expected && !hash_location) {
1212 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
1213 return 1;
1214 }
1215
1216 if (!hash_expected && hash_location) {
1217 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
1218 return 1;
1219 }
1220
1221 /* Okay, so this is hash_expected and hash_location -
1222 * so we need to calculate the checksum.
1223 */
1224 genhash = tcp_v4_md5_hash_skb(newhash,
1225 hash_expected,
1226 NULL, NULL, skb);
1227
1228 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1229 if (net_ratelimit()) {
1230 pr_info("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1231 &iph->saddr, ntohs(th->source),
1232 &iph->daddr, ntohs(th->dest),
1233 genhash ? " tcp_v4_calc_md5_hash failed" : "");
1234 }
1235 return 1;
1236 }
1237 return 0;
1238 }
1239
1240 #endif
1241
1242 struct request_sock_ops tcp_request_sock_ops __read_mostly = {
1243 .family = PF_INET,
1244 .obj_size = sizeof(struct tcp_request_sock),
1245 .rtx_syn_ack = tcp_v4_rtx_synack,
1246 .send_ack = tcp_v4_reqsk_send_ack,
1247 .destructor = tcp_v4_reqsk_destructor,
1248 .send_reset = tcp_v4_send_reset,
1249 .syn_ack_timeout = tcp_syn_ack_timeout,
1250 };
1251
1252 #ifdef CONFIG_TCP_MD5SIG
1253 static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
1254 .md5_lookup = tcp_v4_reqsk_md5_lookup,
1255 .calc_md5_hash = tcp_v4_md5_hash_skb,
1256 };
1257 #endif
1258
1259 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1260 {
1261 struct tcp_extend_values tmp_ext;
1262 struct tcp_options_received tmp_opt;
1263 const u8 *hash_location;
1264 struct request_sock *req;
1265 struct inet_request_sock *ireq;
1266 struct tcp_sock *tp = tcp_sk(sk);
1267 struct dst_entry *dst = NULL;
1268 __be32 saddr = ip_hdr(skb)->saddr;
1269 __be32 daddr = ip_hdr(skb)->daddr;
1270 __u32 isn = TCP_SKB_CB(skb)->when;
1271 int want_cookie = 0;
1272
1273 /* Never answer to SYNs send to broadcast or multicast */
1274 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
1275 goto drop;
1276
1277 /* TW buckets are converted to open requests without
1278 * limitations, they conserve resources and peer is
1279 * evidently real one.
1280 */
1281 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
1282 want_cookie = tcp_syn_flood_action(sk, skb, "TCP");
1283 if (!want_cookie)
1284 goto drop;
1285 }
1286
1287 /* Accept backlog is full. If we have already queued enough
1288 * of warm entries in syn queue, drop request. It is better than
1289 * clogging syn queue with openreqs with exponentially increasing
1290 * timeout.
1291 */
1292 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
1293 goto drop;
1294
1295 req = inet_reqsk_alloc(&tcp_request_sock_ops);
1296 if (!req)
1297 goto drop;
1298
1299 #ifdef CONFIG_TCP_MD5SIG
1300 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1301 #endif
1302
1303 tcp_clear_options(&tmp_opt);
1304 tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
1305 tmp_opt.user_mss = tp->rx_opt.user_mss;
1306 tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
1307
1308 if (tmp_opt.cookie_plus > 0 &&
1309 tmp_opt.saw_tstamp &&
1310 !tp->rx_opt.cookie_out_never &&
1311 (sysctl_tcp_cookie_size > 0 ||
1312 (tp->cookie_values != NULL &&
1313 tp->cookie_values->cookie_desired > 0))) {
1314 u8 *c;
1315 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1316 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1317
1318 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1319 goto drop_and_release;
1320
1321 /* Secret recipe starts with IP addresses */
1322 *mess++ ^= (__force u32)daddr;
1323 *mess++ ^= (__force u32)saddr;
1324
1325 /* plus variable length Initiator Cookie */
1326 c = (u8 *)mess;
1327 while (l-- > 0)
1328 *c++ ^= *hash_location++;
1329
1330 want_cookie = 0; /* not our kind of cookie */
1331 tmp_ext.cookie_out_never = 0; /* false */
1332 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1333 } else if (!tp->rx_opt.cookie_in_always) {
1334 /* redundant indications, but ensure initialization. */
1335 tmp_ext.cookie_out_never = 1; /* true */
1336 tmp_ext.cookie_plus = 0;
1337 } else {
1338 goto drop_and_release;
1339 }
1340 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
1341
1342 if (want_cookie && !tmp_opt.saw_tstamp)
1343 tcp_clear_options(&tmp_opt);
1344
1345 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1346 tcp_openreq_init(req, &tmp_opt, skb);
1347
1348 ireq = inet_rsk(req);
1349 ireq->loc_addr = daddr;
1350 ireq->rmt_addr = saddr;
1351 ireq->no_srccheck = inet_sk(sk)->transparent;
1352 ireq->opt = tcp_v4_save_options(sk, skb);
1353
1354 if (security_inet_conn_request(sk, skb, req))
1355 goto drop_and_free;
1356
1357 if (!want_cookie || tmp_opt.tstamp_ok)
1358 TCP_ECN_create_request(req, tcp_hdr(skb));
1359
1360 if (want_cookie) {
1361 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1362 req->cookie_ts = tmp_opt.tstamp_ok;
1363 } else if (!isn) {
1364 struct inet_peer *peer = NULL;
1365 struct flowi4 fl4;
1366
1367 /* VJ's idea. We save last timestamp seen
1368 * from the destination in peer table, when entering
1369 * state TIME-WAIT, and check against it before
1370 * accepting new connection request.
1371 *
1372 * If "isn" is not zero, this request hit alive
1373 * timewait bucket, so that all the necessary checks
1374 * are made in the function processing timewait state.
1375 */
1376 if (tmp_opt.saw_tstamp &&
1377 tcp_death_row.sysctl_tw_recycle &&
1378 (dst = inet_csk_route_req(sk, &fl4, req)) != NULL &&
1379 fl4.daddr == saddr &&
1380 (peer = rt_get_peer((struct rtable *)dst, fl4.daddr)) != NULL) {
1381 inet_peer_refcheck(peer);
1382 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
1383 (s32)(peer->tcp_ts - req->ts_recent) >
1384 TCP_PAWS_WINDOW) {
1385 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
1386 goto drop_and_release;
1387 }
1388 }
1389 /* Kill the following clause, if you dislike this way. */
1390 else if (!sysctl_tcp_syncookies &&
1391 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
1392 (sysctl_max_syn_backlog >> 2)) &&
1393 (!peer || !peer->tcp_ts_stamp) &&
1394 (!dst || !dst_metric(dst, RTAX_RTT))) {
1395 /* Without syncookies last quarter of
1396 * backlog is filled with destinations,
1397 * proven to be alive.
1398 * It means that we continue to communicate
1399 * to destinations, already remembered
1400 * to the moment of synflood.
1401 */
1402 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n",
1403 &saddr, ntohs(tcp_hdr(skb)->source));
1404 goto drop_and_release;
1405 }
1406
1407 isn = tcp_v4_init_sequence(skb);
1408 }
1409 tcp_rsk(req)->snt_isn = isn;
1410 tcp_rsk(req)->snt_synack = tcp_time_stamp;
1411
1412 if (tcp_v4_send_synack(sk, dst, req,
1413 (struct request_values *)&tmp_ext) ||
1414 want_cookie)
1415 goto drop_and_free;
1416
1417 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
1418 return 0;
1419
1420 drop_and_release:
1421 dst_release(dst);
1422 drop_and_free:
1423 reqsk_free(req);
1424 drop:
1425 return 0;
1426 }
1427 EXPORT_SYMBOL(tcp_v4_conn_request);
1428
1429
1430 /*
1431 * The three way handshake has completed - we got a valid synack -
1432 * now create the new socket.
1433 */
1434 struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
1435 struct request_sock *req,
1436 struct dst_entry *dst)
1437 {
1438 struct inet_request_sock *ireq;
1439 struct inet_sock *newinet;
1440 struct tcp_sock *newtp;
1441 struct sock *newsk;
1442 #ifdef CONFIG_TCP_MD5SIG
1443 struct tcp_md5sig_key *key;
1444 #endif
1445 struct ip_options_rcu *inet_opt;
1446
1447 if (sk_acceptq_is_full(sk))
1448 goto exit_overflow;
1449
1450 newsk = tcp_create_openreq_child(sk, req, skb);
1451 if (!newsk)
1452 goto exit_nonewsk;
1453
1454 newsk->sk_gso_type = SKB_GSO_TCPV4;
1455
1456 newtp = tcp_sk(newsk);
1457 newinet = inet_sk(newsk);
1458 ireq = inet_rsk(req);
1459 newinet->inet_daddr = ireq->rmt_addr;
1460 newinet->inet_rcv_saddr = ireq->loc_addr;
1461 newinet->inet_saddr = ireq->loc_addr;
1462 inet_opt = ireq->opt;
1463 rcu_assign_pointer(newinet->inet_opt, inet_opt);
1464 ireq->opt = NULL;
1465 newinet->mc_index = inet_iif(skb);
1466 newinet->mc_ttl = ip_hdr(skb)->ttl;
1467 newinet->rcv_tos = ip_hdr(skb)->tos;
1468 inet_csk(newsk)->icsk_ext_hdr_len = 0;
1469 if (inet_opt)
1470 inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
1471 newinet->inet_id = newtp->write_seq ^ jiffies;
1472
1473 if (!dst && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
1474 goto put_and_exit;
1475
1476 sk_setup_caps(newsk, dst);
1477
1478 tcp_mtup_init(newsk);
1479 tcp_sync_mss(newsk, dst_mtu(dst));
1480 newtp->advmss = dst_metric_advmss(dst);
1481 if (tcp_sk(sk)->rx_opt.user_mss &&
1482 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1483 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1484
1485 tcp_initialize_rcv_mss(newsk);
1486 if (tcp_rsk(req)->snt_synack)
1487 tcp_valid_rtt_meas(newsk,
1488 tcp_time_stamp - tcp_rsk(req)->snt_synack);
1489 newtp->total_retrans = req->retrans;
1490
1491 #ifdef CONFIG_TCP_MD5SIG
1492 /* Copy over the MD5 key from the original socket */
1493 key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr,
1494 AF_INET);
1495 if (key != NULL) {
1496 /*
1497 * We're using one, so create a matching key
1498 * on the newsk structure. If we fail to get
1499 * memory, then we end up not copying the key
1500 * across. Shucks.
1501 */
1502 tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr,
1503 AF_INET, key->key, key->keylen, GFP_ATOMIC);
1504 sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
1505 }
1506 #endif
1507
1508 if (__inet_inherit_port(sk, newsk) < 0)
1509 goto put_and_exit;
1510 __inet_hash_nolisten(newsk, NULL);
1511
1512 return newsk;
1513
1514 exit_overflow:
1515 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1516 exit_nonewsk:
1517 dst_release(dst);
1518 exit:
1519 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
1520 return NULL;
1521 put_and_exit:
1522 tcp_clear_xmit_timers(newsk);
1523 tcp_cleanup_congestion_control(newsk);
1524 bh_unlock_sock(newsk);
1525 sock_put(newsk);
1526 goto exit;
1527 }
1528 EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
1529
1530 static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1531 {
1532 struct tcphdr *th = tcp_hdr(skb);
1533 const struct iphdr *iph = ip_hdr(skb);
1534 struct sock *nsk;
1535 struct request_sock **prev;
1536 /* Find possible connection requests. */
1537 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1538 iph->saddr, iph->daddr);
1539 if (req)
1540 return tcp_check_req(sk, skb, req, prev);
1541
1542 nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
1543 th->source, iph->daddr, th->dest, inet_iif(skb));
1544
1545 if (nsk) {
1546 if (nsk->sk_state != TCP_TIME_WAIT) {
1547 bh_lock_sock(nsk);
1548 return nsk;
1549 }
1550 inet_twsk_put(inet_twsk(nsk));
1551 return NULL;
1552 }
1553
1554 #ifdef CONFIG_SYN_COOKIES
1555 if (!th->syn)
1556 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1557 #endif
1558 return sk;
1559 }
1560
1561 static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
1562 {
1563 const struct iphdr *iph = ip_hdr(skb);
1564
1565 if (skb->ip_summed == CHECKSUM_COMPLETE) {
1566 if (!tcp_v4_check(skb->len, iph->saddr,
1567 iph->daddr, skb->csum)) {
1568 skb->ip_summed = CHECKSUM_UNNECESSARY;
1569 return 0;
1570 }
1571 }
1572
1573 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
1574 skb->len, IPPROTO_TCP, 0);
1575
1576 if (skb->len <= 76) {
1577 return __skb_checksum_complete(skb);
1578 }
1579 return 0;
1580 }
1581
1582
1583 /* The socket must have it's spinlock held when we get
1584 * here.
1585 *
1586 * We have a potential double-lock case here, so even when
1587 * doing backlog processing we use the BH locking scheme.
1588 * This is because we cannot sleep with the original spinlock
1589 * held.
1590 */
1591 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1592 {
1593 struct sock *rsk;
1594 #ifdef CONFIG_TCP_MD5SIG
1595 /*
1596 * We really want to reject the packet as early as possible
1597 * if:
1598 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1599 * o There is an MD5 option and we're not expecting one
1600 */
1601 if (tcp_v4_inbound_md5_hash(sk, skb))
1602 goto discard;
1603 #endif
1604
1605 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1606 sock_rps_save_rxhash(sk, skb);
1607 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
1608 rsk = sk;
1609 goto reset;
1610 }
1611 return 0;
1612 }
1613
1614 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
1615 goto csum_err;
1616
1617 if (sk->sk_state == TCP_LISTEN) {
1618 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1619 if (!nsk)
1620 goto discard;
1621
1622 if (nsk != sk) {
1623 sock_rps_save_rxhash(nsk, skb);
1624 if (tcp_child_process(sk, nsk, skb)) {
1625 rsk = nsk;
1626 goto reset;
1627 }
1628 return 0;
1629 }
1630 } else
1631 sock_rps_save_rxhash(sk, skb);
1632
1633 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
1634 rsk = sk;
1635 goto reset;
1636 }
1637 return 0;
1638
1639 reset:
1640 tcp_v4_send_reset(rsk, skb);
1641 discard:
1642 kfree_skb(skb);
1643 /* Be careful here. If this function gets more complicated and
1644 * gcc suffers from register pressure on the x86, sk (in %ebx)
1645 * might be destroyed here. This current version compiles correctly,
1646 * but you have been warned.
1647 */
1648 return 0;
1649
1650 csum_err:
1651 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
1652 goto discard;
1653 }
1654 EXPORT_SYMBOL(tcp_v4_do_rcv);
1655
1656 /*
1657 * From tcp_input.c
1658 */
1659
1660 int tcp_v4_rcv(struct sk_buff *skb)
1661 {
1662 const struct iphdr *iph;
1663 const struct tcphdr *th;
1664 struct sock *sk;
1665 int ret;
1666 struct net *net = dev_net(skb->dev);
1667
1668 if (skb->pkt_type != PACKET_HOST)
1669 goto discard_it;
1670
1671 /* Count it even if it's bad */
1672 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
1673
1674 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1675 goto discard_it;
1676
1677 th = tcp_hdr(skb);
1678
1679 if (th->doff < sizeof(struct tcphdr) / 4)
1680 goto bad_packet;
1681 if (!pskb_may_pull(skb, th->doff * 4))
1682 goto discard_it;
1683
1684 /* An explanation is required here, I think.
1685 * Packet length and doff are validated by header prediction,
1686 * provided case of th->doff==0 is eliminated.
1687 * So, we defer the checks. */
1688 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
1689 goto bad_packet;
1690
1691 th = tcp_hdr(skb);
1692 iph = ip_hdr(skb);
1693 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1694 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1695 skb->len - th->doff * 4);
1696 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1697 TCP_SKB_CB(skb)->when = 0;
1698 TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
1699 TCP_SKB_CB(skb)->sacked = 0;
1700
1701 sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
1702 if (!sk)
1703 goto no_tcp_socket;
1704
1705 process:
1706 if (sk->sk_state == TCP_TIME_WAIT)
1707 goto do_time_wait;
1708
1709 if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
1710 NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
1711 goto discard_and_relse;
1712 }
1713
1714 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1715 goto discard_and_relse;
1716 nf_reset(skb);
1717
1718 if (sk_filter(sk, skb))
1719 goto discard_and_relse;
1720
1721 skb->dev = NULL;
1722
1723 bh_lock_sock_nested(sk);
1724 ret = 0;
1725 if (!sock_owned_by_user(sk)) {
1726 #ifdef CONFIG_NET_DMA
1727 struct tcp_sock *tp = tcp_sk(sk);
1728 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1729 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
1730 if (tp->ucopy.dma_chan)
1731 ret = tcp_v4_do_rcv(sk, skb);
1732 else
1733 #endif
1734 {
1735 if (!tcp_prequeue(sk, skb))
1736 ret = tcp_v4_do_rcv(sk, skb);
1737 }
1738 } else if (unlikely(sk_add_backlog(sk, skb))) {
1739 bh_unlock_sock(sk);
1740 NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
1741 goto discard_and_relse;
1742 }
1743 bh_unlock_sock(sk);
1744
1745 sock_put(sk);
1746
1747 return ret;
1748
1749 no_tcp_socket:
1750 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1751 goto discard_it;
1752
1753 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1754 bad_packet:
1755 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1756 } else {
1757 tcp_v4_send_reset(NULL, skb);
1758 }
1759
1760 discard_it:
1761 /* Discard frame. */
1762 kfree_skb(skb);
1763 return 0;
1764
1765 discard_and_relse:
1766 sock_put(sk);
1767 goto discard_it;
1768
1769 do_time_wait:
1770 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1771 inet_twsk_put(inet_twsk(sk));
1772 goto discard_it;
1773 }
1774
1775 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1776 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
1777 inet_twsk_put(inet_twsk(sk));
1778 goto discard_it;
1779 }
1780 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1781 case TCP_TW_SYN: {
1782 struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
1783 &tcp_hashinfo,
1784 iph->daddr, th->dest,
1785 inet_iif(skb));
1786 if (sk2) {
1787 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1788 inet_twsk_put(inet_twsk(sk));
1789 sk = sk2;
1790 goto process;
1791 }
1792 /* Fall through to ACK */
1793 }
1794 case TCP_TW_ACK:
1795 tcp_v4_timewait_ack(sk, skb);
1796 break;
1797 case TCP_TW_RST:
1798 goto no_tcp_socket;
1799 case TCP_TW_SUCCESS:;
1800 }
1801 goto discard_it;
1802 }
1803
1804 struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it)
1805 {
1806 struct rtable *rt = (struct rtable *) __sk_dst_get(sk);
1807 struct inet_sock *inet = inet_sk(sk);
1808 struct inet_peer *peer;
1809
1810 if (!rt ||
1811 inet->cork.fl.u.ip4.daddr != inet->inet_daddr) {
1812 peer = inet_getpeer_v4(inet->inet_daddr, 1);
1813 *release_it = true;
1814 } else {
1815 if (!rt->peer)
1816 rt_bind_peer(rt, inet->inet_daddr, 1);
1817 peer = rt->peer;
1818 *release_it = false;
1819 }
1820
1821 return peer;
1822 }
1823 EXPORT_SYMBOL(tcp_v4_get_peer);
1824
1825 void *tcp_v4_tw_get_peer(struct sock *sk)
1826 {
1827 const struct inet_timewait_sock *tw = inet_twsk(sk);
1828
1829 return inet_getpeer_v4(tw->tw_daddr, 1);
1830 }
1831 EXPORT_SYMBOL(tcp_v4_tw_get_peer);
1832
1833 static struct timewait_sock_ops tcp_timewait_sock_ops = {
1834 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1835 .twsk_unique = tcp_twsk_unique,
1836 .twsk_destructor= tcp_twsk_destructor,
1837 .twsk_getpeer = tcp_v4_tw_get_peer,
1838 };
1839
1840 const struct inet_connection_sock_af_ops ipv4_specific = {
1841 .queue_xmit = ip_queue_xmit,
1842 .send_check = tcp_v4_send_check,
1843 .rebuild_header = inet_sk_rebuild_header,
1844 .conn_request = tcp_v4_conn_request,
1845 .syn_recv_sock = tcp_v4_syn_recv_sock,
1846 .get_peer = tcp_v4_get_peer,
1847 .net_header_len = sizeof(struct iphdr),
1848 .setsockopt = ip_setsockopt,
1849 .getsockopt = ip_getsockopt,
1850 .addr2sockaddr = inet_csk_addr2sockaddr,
1851 .sockaddr_len = sizeof(struct sockaddr_in),
1852 .bind_conflict = inet_csk_bind_conflict,
1853 #ifdef CONFIG_COMPAT
1854 .compat_setsockopt = compat_ip_setsockopt,
1855 .compat_getsockopt = compat_ip_getsockopt,
1856 #endif
1857 };
1858 EXPORT_SYMBOL(ipv4_specific);
1859
1860 #ifdef CONFIG_TCP_MD5SIG
1861 static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
1862 .md5_lookup = tcp_v4_md5_lookup,
1863 .calc_md5_hash = tcp_v4_md5_hash_skb,
1864 .md5_parse = tcp_v4_parse_md5_keys,
1865 };
1866 #endif
1867
1868 /* NOTE: A lot of things set to zero explicitly by call to
1869 * sk_alloc() so need not be done here.
1870 */
1871 static int tcp_v4_init_sock(struct sock *sk)
1872 {
1873 struct inet_connection_sock *icsk = inet_csk(sk);
1874 struct tcp_sock *tp = tcp_sk(sk);
1875
1876 skb_queue_head_init(&tp->out_of_order_queue);
1877 tcp_init_xmit_timers(sk);
1878 tcp_prequeue_init(tp);
1879
1880 icsk->icsk_rto = TCP_TIMEOUT_INIT;
1881 tp->mdev = TCP_TIMEOUT_INIT;
1882
1883 /* So many TCP implementations out there (incorrectly) count the
1884 * initial SYN frame in their delayed-ACK and congestion control
1885 * algorithms that we must have the following bandaid to talk
1886 * efficiently to them. -DaveM
1887 */
1888 tp->snd_cwnd = TCP_INIT_CWND;
1889
1890 /* See draft-stevens-tcpca-spec-01 for discussion of the
1891 * initialization of these values.
1892 */
1893 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
1894 tp->snd_cwnd_clamp = ~0;
1895 tp->mss_cache = TCP_MSS_DEFAULT;
1896
1897 tp->reordering = sysctl_tcp_reordering;
1898 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
1899
1900 sk->sk_state = TCP_CLOSE;
1901
1902 sk->sk_write_space = sk_stream_write_space;
1903 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1904
1905 icsk->icsk_af_ops = &ipv4_specific;
1906 icsk->icsk_sync_mss = tcp_sync_mss;
1907 #ifdef CONFIG_TCP_MD5SIG
1908 tp->af_specific = &tcp_sock_ipv4_specific;
1909 #endif
1910
1911 /* TCP Cookie Transactions */
1912 if (sysctl_tcp_cookie_size > 0) {
1913 /* Default, cookies without s_data_payload. */
1914 tp->cookie_values =
1915 kzalloc(sizeof(*tp->cookie_values),
1916 sk->sk_allocation);
1917 if (tp->cookie_values != NULL)
1918 kref_init(&tp->cookie_values->kref);
1919 }
1920 /* Presumed zeroed, in order of appearance:
1921 * cookie_in_always, cookie_out_never,
1922 * s_data_constant, s_data_in, s_data_out
1923 */
1924 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1925 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1926
1927 local_bh_disable();
1928 sock_update_memcg(sk);
1929 sk_sockets_allocated_inc(sk);
1930 local_bh_enable();
1931
1932 return 0;
1933 }
1934
1935 void tcp_v4_destroy_sock(struct sock *sk)
1936 {
1937 struct tcp_sock *tp = tcp_sk(sk);
1938
1939 tcp_clear_xmit_timers(sk);
1940
1941 tcp_cleanup_congestion_control(sk);
1942
1943 /* Cleanup up the write buffer. */
1944 tcp_write_queue_purge(sk);
1945
1946 /* Cleans up our, hopefully empty, out_of_order_queue. */
1947 __skb_queue_purge(&tp->out_of_order_queue);
1948
1949 #ifdef CONFIG_TCP_MD5SIG
1950 /* Clean up the MD5 key list, if any */
1951 if (tp->md5sig_info) {
1952 tcp_clear_md5_list(sk);
1953 kfree_rcu(tp->md5sig_info, rcu);
1954 tp->md5sig_info = NULL;
1955 }
1956 #endif
1957
1958 #ifdef CONFIG_NET_DMA
1959 /* Cleans up our sk_async_wait_queue */
1960 __skb_queue_purge(&sk->sk_async_wait_queue);
1961 #endif
1962
1963 /* Clean prequeue, it must be empty really */
1964 __skb_queue_purge(&tp->ucopy.prequeue);
1965
1966 /* Clean up a referenced TCP bind bucket. */
1967 if (inet_csk(sk)->icsk_bind_hash)
1968 inet_put_port(sk);
1969
1970 /*
1971 * If sendmsg cached page exists, toss it.
1972 */
1973 if (sk->sk_sndmsg_page) {
1974 __free_page(sk->sk_sndmsg_page);
1975 sk->sk_sndmsg_page = NULL;
1976 }
1977
1978 /* TCP Cookie Transactions */
1979 if (tp->cookie_values != NULL) {
1980 kref_put(&tp->cookie_values->kref,
1981 tcp_cookie_values_release);
1982 tp->cookie_values = NULL;
1983 }
1984
1985 sk_sockets_allocated_dec(sk);
1986 sock_release_memcg(sk);
1987 }
1988 EXPORT_SYMBOL(tcp_v4_destroy_sock);
1989
1990 #ifdef CONFIG_PROC_FS
1991 /* Proc filesystem TCP sock list dumping. */
1992
1993 static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
1994 {
1995 return hlist_nulls_empty(head) ? NULL :
1996 list_entry(head->first, struct inet_timewait_sock, tw_node);
1997 }
1998
1999 static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
2000 {
2001 return !is_a_nulls(tw->tw_node.next) ?
2002 hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
2003 }
2004
2005 /*
2006 * Get next listener socket follow cur. If cur is NULL, get first socket
2007 * starting from bucket given in st->bucket; when st->bucket is zero the
2008 * very first socket in the hash table is returned.
2009 */
2010 static void *listening_get_next(struct seq_file *seq, void *cur)
2011 {
2012 struct inet_connection_sock *icsk;
2013 struct hlist_nulls_node *node;
2014 struct sock *sk = cur;
2015 struct inet_listen_hashbucket *ilb;
2016 struct tcp_iter_state *st = seq->private;
2017 struct net *net = seq_file_net(seq);
2018
2019 if (!sk) {
2020 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2021 spin_lock_bh(&ilb->lock);
2022 sk = sk_nulls_head(&ilb->head);
2023 st->offset = 0;
2024 goto get_sk;
2025 }
2026 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2027 ++st->num;
2028 ++st->offset;
2029
2030 if (st->state == TCP_SEQ_STATE_OPENREQ) {
2031 struct request_sock *req = cur;
2032
2033 icsk = inet_csk(st->syn_wait_sk);
2034 req = req->dl_next;
2035 while (1) {
2036 while (req) {
2037 if (req->rsk_ops->family == st->family) {
2038 cur = req;
2039 goto out;
2040 }
2041 req = req->dl_next;
2042 }
2043 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
2044 break;
2045 get_req:
2046 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
2047 }
2048 sk = sk_nulls_next(st->syn_wait_sk);
2049 st->state = TCP_SEQ_STATE_LISTENING;
2050 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2051 } else {
2052 icsk = inet_csk(sk);
2053 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2054 if (reqsk_queue_len(&icsk->icsk_accept_queue))
2055 goto start_req;
2056 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2057 sk = sk_nulls_next(sk);
2058 }
2059 get_sk:
2060 sk_nulls_for_each_from(sk, node) {
2061 if (!net_eq(sock_net(sk), net))
2062 continue;
2063 if (sk->sk_family == st->family) {
2064 cur = sk;
2065 goto out;
2066 }
2067 icsk = inet_csk(sk);
2068 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2069 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
2070 start_req:
2071 st->uid = sock_i_uid(sk);
2072 st->syn_wait_sk = sk;
2073 st->state = TCP_SEQ_STATE_OPENREQ;
2074 st->sbucket = 0;
2075 goto get_req;
2076 }
2077 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2078 }
2079 spin_unlock_bh(&ilb->lock);
2080 st->offset = 0;
2081 if (++st->bucket < INET_LHTABLE_SIZE) {
2082 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2083 spin_lock_bh(&ilb->lock);
2084 sk = sk_nulls_head(&ilb->head);
2085 goto get_sk;
2086 }
2087 cur = NULL;
2088 out:
2089 return cur;
2090 }
2091
2092 static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
2093 {
2094 struct tcp_iter_state *st = seq->private;
2095 void *rc;
2096
2097 st->bucket = 0;
2098 st->offset = 0;
2099 rc = listening_get_next(seq, NULL);
2100
2101 while (rc && *pos) {
2102 rc = listening_get_next(seq, rc);
2103 --*pos;
2104 }
2105 return rc;
2106 }
2107
2108 static inline int empty_bucket(struct tcp_iter_state *st)
2109 {
2110 return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
2111 hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
2112 }
2113
2114 /*
2115 * Get first established socket starting from bucket given in st->bucket.
2116 * If st->bucket is zero, the very first socket in the hash is returned.
2117 */
2118 static void *established_get_first(struct seq_file *seq)
2119 {
2120 struct tcp_iter_state *st = seq->private;
2121 struct net *net = seq_file_net(seq);
2122 void *rc = NULL;
2123
2124 st->offset = 0;
2125 for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
2126 struct sock *sk;
2127 struct hlist_nulls_node *node;
2128 struct inet_timewait_sock *tw;
2129 spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
2130
2131 /* Lockless fast path for the common case of empty buckets */
2132 if (empty_bucket(st))
2133 continue;
2134
2135 spin_lock_bh(lock);
2136 sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
2137 if (sk->sk_family != st->family ||
2138 !net_eq(sock_net(sk), net)) {
2139 continue;
2140 }
2141 rc = sk;
2142 goto out;
2143 }
2144 st->state = TCP_SEQ_STATE_TIME_WAIT;
2145 inet_twsk_for_each(tw, node,
2146 &tcp_hashinfo.ehash[st->bucket].twchain) {
2147 if (tw->tw_family != st->family ||
2148 !net_eq(twsk_net(tw), net)) {
2149 continue;
2150 }
2151 rc = tw;
2152 goto out;
2153 }
2154 spin_unlock_bh(lock);
2155 st->state = TCP_SEQ_STATE_ESTABLISHED;
2156 }
2157 out:
2158 return rc;
2159 }
2160
2161 static void *established_get_next(struct seq_file *seq, void *cur)
2162 {
2163 struct sock *sk = cur;
2164 struct inet_timewait_sock *tw;
2165 struct hlist_nulls_node *node;
2166 struct tcp_iter_state *st = seq->private;
2167 struct net *net = seq_file_net(seq);
2168
2169 ++st->num;
2170 ++st->offset;
2171
2172 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2173 tw = cur;
2174 tw = tw_next(tw);
2175 get_tw:
2176 while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
2177 tw = tw_next(tw);
2178 }
2179 if (tw) {
2180 cur = tw;
2181 goto out;
2182 }
2183 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2184 st->state = TCP_SEQ_STATE_ESTABLISHED;
2185
2186 /* Look for next non empty bucket */
2187 st->offset = 0;
2188 while (++st->bucket <= tcp_hashinfo.ehash_mask &&
2189 empty_bucket(st))
2190 ;
2191 if (st->bucket > tcp_hashinfo.ehash_mask)
2192 return NULL;
2193
2194 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2195 sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
2196 } else
2197 sk = sk_nulls_next(sk);
2198
2199 sk_nulls_for_each_from(sk, node) {
2200 if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
2201 goto found;
2202 }
2203
2204 st->state = TCP_SEQ_STATE_TIME_WAIT;
2205 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
2206 goto get_tw;
2207 found:
2208 cur = sk;
2209 out:
2210 return cur;
2211 }
2212
2213 static void *established_get_idx(struct seq_file *seq, loff_t pos)
2214 {
2215 struct tcp_iter_state *st = seq->private;
2216 void *rc;
2217
2218 st->bucket = 0;
2219 rc = established_get_first(seq);
2220
2221 while (rc && pos) {
2222 rc = established_get_next(seq, rc);
2223 --pos;
2224 }
2225 return rc;
2226 }
2227
2228 static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2229 {
2230 void *rc;
2231 struct tcp_iter_state *st = seq->private;
2232
2233 st->state = TCP_SEQ_STATE_LISTENING;
2234 rc = listening_get_idx(seq, &pos);
2235
2236 if (!rc) {
2237 st->state = TCP_SEQ_STATE_ESTABLISHED;
2238 rc = established_get_idx(seq, pos);
2239 }
2240
2241 return rc;
2242 }
2243
2244 static void *tcp_seek_last_pos(struct seq_file *seq)
2245 {
2246 struct tcp_iter_state *st = seq->private;
2247 int offset = st->offset;
2248 int orig_num = st->num;
2249 void *rc = NULL;
2250
2251 switch (st->state) {
2252 case TCP_SEQ_STATE_OPENREQ:
2253 case TCP_SEQ_STATE_LISTENING:
2254 if (st->bucket >= INET_LHTABLE_SIZE)
2255 break;
2256 st->state = TCP_SEQ_STATE_LISTENING;
2257 rc = listening_get_next(seq, NULL);
2258 while (offset-- && rc)
2259 rc = listening_get_next(seq, rc);
2260 if (rc)
2261 break;
2262 st->bucket = 0;
2263 /* Fallthrough */
2264 case TCP_SEQ_STATE_ESTABLISHED:
2265 case TCP_SEQ_STATE_TIME_WAIT:
2266 st->state = TCP_SEQ_STATE_ESTABLISHED;
2267 if (st->bucket > tcp_hashinfo.ehash_mask)
2268 break;
2269 rc = established_get_first(seq);
2270 while (offset-- && rc)
2271 rc = established_get_next(seq, rc);
2272 }
2273
2274 st->num = orig_num;
2275
2276 return rc;
2277 }
2278
2279 static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2280 {
2281 struct tcp_iter_state *st = seq->private;
2282 void *rc;
2283
2284 if (*pos && *pos == st->last_pos) {
2285 rc = tcp_seek_last_pos(seq);
2286 if (rc)
2287 goto out;
2288 }
2289
2290 st->state = TCP_SEQ_STATE_LISTENING;
2291 st->num = 0;
2292 st->bucket = 0;
2293 st->offset = 0;
2294 rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2295
2296 out:
2297 st->last_pos = *pos;
2298 return rc;
2299 }
2300
2301 static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2302 {
2303 struct tcp_iter_state *st = seq->private;
2304 void *rc = NULL;
2305
2306 if (v == SEQ_START_TOKEN) {
2307 rc = tcp_get_idx(seq, 0);
2308 goto out;
2309 }
2310
2311 switch (st->state) {
2312 case TCP_SEQ_STATE_OPENREQ:
2313 case TCP_SEQ_STATE_LISTENING:
2314 rc = listening_get_next(seq, v);
2315 if (!rc) {
2316 st->state = TCP_SEQ_STATE_ESTABLISHED;
2317 st->bucket = 0;
2318 st->offset = 0;
2319 rc = established_get_first(seq);
2320 }
2321 break;
2322 case TCP_SEQ_STATE_ESTABLISHED:
2323 case TCP_SEQ_STATE_TIME_WAIT:
2324 rc = established_get_next(seq, v);
2325 break;
2326 }
2327 out:
2328 ++*pos;
2329 st->last_pos = *pos;
2330 return rc;
2331 }
2332
2333 static void tcp_seq_stop(struct seq_file *seq, void *v)
2334 {
2335 struct tcp_iter_state *st = seq->private;
2336
2337 switch (st->state) {
2338 case TCP_SEQ_STATE_OPENREQ:
2339 if (v) {
2340 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2341 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2342 }
2343 case TCP_SEQ_STATE_LISTENING:
2344 if (v != SEQ_START_TOKEN)
2345 spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
2346 break;
2347 case TCP_SEQ_STATE_TIME_WAIT:
2348 case TCP_SEQ_STATE_ESTABLISHED:
2349 if (v)
2350 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
2351 break;
2352 }
2353 }
2354
2355 int tcp_seq_open(struct inode *inode, struct file *file)
2356 {
2357 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
2358 struct tcp_iter_state *s;
2359 int err;
2360
2361 err = seq_open_net(inode, file, &afinfo->seq_ops,
2362 sizeof(struct tcp_iter_state));
2363 if (err < 0)
2364 return err;
2365
2366 s = ((struct seq_file *)file->private_data)->private;
2367 s->family = afinfo->family;
2368 s->last_pos = 0;
2369 return 0;
2370 }
2371 EXPORT_SYMBOL(tcp_seq_open);
2372
2373 int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
2374 {
2375 int rc = 0;
2376 struct proc_dir_entry *p;
2377
2378 afinfo->seq_ops.start = tcp_seq_start;
2379 afinfo->seq_ops.next = tcp_seq_next;
2380 afinfo->seq_ops.stop = tcp_seq_stop;
2381
2382 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2383 afinfo->seq_fops, afinfo);
2384 if (!p)
2385 rc = -ENOMEM;
2386 return rc;
2387 }
2388 EXPORT_SYMBOL(tcp_proc_register);
2389
2390 void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
2391 {
2392 proc_net_remove(net, afinfo->name);
2393 }
2394 EXPORT_SYMBOL(tcp_proc_unregister);
2395
2396 static void get_openreq4(const struct sock *sk, const struct request_sock *req,
2397 struct seq_file *f, int i, int uid, int *len)
2398 {
2399 const struct inet_request_sock *ireq = inet_rsk(req);
2400 int ttd = req->expires - jiffies;
2401
2402 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2403 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n",
2404 i,
2405 ireq->loc_addr,
2406 ntohs(inet_sk(sk)->inet_sport),
2407 ireq->rmt_addr,
2408 ntohs(ireq->rmt_port),
2409 TCP_SYN_RECV,
2410 0, 0, /* could print option size, but that is af dependent. */
2411 1, /* timers active (only the expire timer) */
2412 jiffies_to_clock_t(ttd),
2413 req->retrans,
2414 uid,
2415 0, /* non standard timer */
2416 0, /* open_requests have no inode */
2417 atomic_read(&sk->sk_refcnt),
2418 req,
2419 len);
2420 }
2421
2422 static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
2423 {
2424 int timer_active;
2425 unsigned long timer_expires;
2426 const struct tcp_sock *tp = tcp_sk(sk);
2427 const struct inet_connection_sock *icsk = inet_csk(sk);
2428 const struct inet_sock *inet = inet_sk(sk);
2429 __be32 dest = inet->inet_daddr;
2430 __be32 src = inet->inet_rcv_saddr;
2431 __u16 destp = ntohs(inet->inet_dport);
2432 __u16 srcp = ntohs(inet->inet_sport);
2433 int rx_queue;
2434
2435 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
2436 timer_active = 1;
2437 timer_expires = icsk->icsk_timeout;
2438 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2439 timer_active = 4;
2440 timer_expires = icsk->icsk_timeout;
2441 } else if (timer_pending(&sk->sk_timer)) {
2442 timer_active = 2;
2443 timer_expires = sk->sk_timer.expires;
2444 } else {
2445 timer_active = 0;
2446 timer_expires = jiffies;
2447 }
2448
2449 if (sk->sk_state == TCP_LISTEN)
2450 rx_queue = sk->sk_ack_backlog;
2451 else
2452 /*
2453 * because we dont lock socket, we might find a transient negative value
2454 */
2455 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
2456
2457 seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2458 "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n",
2459 i, src, srcp, dest, destp, sk->sk_state,
2460 tp->write_seq - tp->snd_una,
2461 rx_queue,
2462 timer_active,
2463 jiffies_to_clock_t(timer_expires - jiffies),
2464 icsk->icsk_retransmits,
2465 sock_i_uid(sk),
2466 icsk->icsk_probes_out,
2467 sock_i_ino(sk),
2468 atomic_read(&sk->sk_refcnt), sk,
2469 jiffies_to_clock_t(icsk->icsk_rto),
2470 jiffies_to_clock_t(icsk->icsk_ack.ato),
2471 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
2472 tp->snd_cwnd,
2473 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
2474 len);
2475 }
2476
2477 static void get_timewait4_sock(const struct inet_timewait_sock *tw,
2478 struct seq_file *f, int i, int *len)
2479 {
2480 __be32 dest, src;
2481 __u16 destp, srcp;
2482 int ttd = tw->tw_ttd - jiffies;
2483
2484 if (ttd < 0)
2485 ttd = 0;
2486
2487 dest = tw->tw_daddr;
2488 src = tw->tw_rcv_saddr;
2489 destp = ntohs(tw->tw_dport);
2490 srcp = ntohs(tw->tw_sport);
2491
2492 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2493 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n",
2494 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2495 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2496 atomic_read(&tw->tw_refcnt), tw, len);
2497 }
2498
2499 #define TMPSZ 150
2500
2501 static int tcp4_seq_show(struct seq_file *seq, void *v)
2502 {
2503 struct tcp_iter_state *st;
2504 int len;
2505
2506 if (v == SEQ_START_TOKEN) {
2507 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2508 " sl local_address rem_address st tx_queue "
2509 "rx_queue tr tm->when retrnsmt uid timeout "
2510 "inode");
2511 goto out;
2512 }
2513 st = seq->private;
2514
2515 switch (st->state) {
2516 case TCP_SEQ_STATE_LISTENING:
2517 case TCP_SEQ_STATE_ESTABLISHED:
2518 get_tcp4_sock(v, seq, st->num, &len);
2519 break;
2520 case TCP_SEQ_STATE_OPENREQ:
2521 get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
2522 break;
2523 case TCP_SEQ_STATE_TIME_WAIT:
2524 get_timewait4_sock(v, seq, st->num, &len);
2525 break;
2526 }
2527 seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
2528 out:
2529 return 0;
2530 }
2531
2532 static const struct file_operations tcp_afinfo_seq_fops = {
2533 .owner = THIS_MODULE,
2534 .open = tcp_seq_open,
2535 .read = seq_read,
2536 .llseek = seq_lseek,
2537 .release = seq_release_net
2538 };
2539
2540 static struct tcp_seq_afinfo tcp4_seq_afinfo = {
2541 .name = "tcp",
2542 .family = AF_INET,
2543 .seq_fops = &tcp_afinfo_seq_fops,
2544 .seq_ops = {
2545 .show = tcp4_seq_show,
2546 },
2547 };
2548
2549 static int __net_init tcp4_proc_init_net(struct net *net)
2550 {
2551 return tcp_proc_register(net, &tcp4_seq_afinfo);
2552 }
2553
2554 static void __net_exit tcp4_proc_exit_net(struct net *net)
2555 {
2556 tcp_proc_unregister(net, &tcp4_seq_afinfo);
2557 }
2558
2559 static struct pernet_operations tcp4_net_ops = {
2560 .init = tcp4_proc_init_net,
2561 .exit = tcp4_proc_exit_net,
2562 };
2563
2564 int __init tcp4_proc_init(void)
2565 {
2566 return register_pernet_subsys(&tcp4_net_ops);
2567 }
2568
2569 void tcp4_proc_exit(void)
2570 {
2571 unregister_pernet_subsys(&tcp4_net_ops);
2572 }
2573 #endif /* CONFIG_PROC_FS */
2574
2575 struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2576 {
2577 const struct iphdr *iph = skb_gro_network_header(skb);
2578
2579 switch (skb->ip_summed) {
2580 case CHECKSUM_COMPLETE:
2581 if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
2582 skb->csum)) {
2583 skb->ip_summed = CHECKSUM_UNNECESSARY;
2584 break;
2585 }
2586
2587 /* fall through */
2588 case CHECKSUM_NONE:
2589 NAPI_GRO_CB(skb)->flush = 1;
2590 return NULL;
2591 }
2592
2593 return tcp_gro_receive(head, skb);
2594 }
2595
2596 int tcp4_gro_complete(struct sk_buff *skb)
2597 {
2598 const struct iphdr *iph = ip_hdr(skb);
2599 struct tcphdr *th = tcp_hdr(skb);
2600
2601 th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
2602 iph->saddr, iph->daddr, 0);
2603 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
2604
2605 return tcp_gro_complete(skb);
2606 }
2607
2608 struct proto tcp_prot = {
2609 .name = "TCP",
2610 .owner = THIS_MODULE,
2611 .close = tcp_close,
2612 .connect = tcp_v4_connect,
2613 .disconnect = tcp_disconnect,
2614 .accept = inet_csk_accept,
2615 .ioctl = tcp_ioctl,
2616 .init = tcp_v4_init_sock,
2617 .destroy = tcp_v4_destroy_sock,
2618 .shutdown = tcp_shutdown,
2619 .setsockopt = tcp_setsockopt,
2620 .getsockopt = tcp_getsockopt,
2621 .recvmsg = tcp_recvmsg,
2622 .sendmsg = tcp_sendmsg,
2623 .sendpage = tcp_sendpage,
2624 .backlog_rcv = tcp_v4_do_rcv,
2625 .hash = inet_hash,
2626 .unhash = inet_unhash,
2627 .get_port = inet_csk_get_port,
2628 .enter_memory_pressure = tcp_enter_memory_pressure,
2629 .sockets_allocated = &tcp_sockets_allocated,
2630 .orphan_count = &tcp_orphan_count,
2631 .memory_allocated = &tcp_memory_allocated,
2632 .memory_pressure = &tcp_memory_pressure,
2633 .sysctl_wmem = sysctl_tcp_wmem,
2634 .sysctl_rmem = sysctl_tcp_rmem,
2635 .max_header = MAX_TCP_HEADER,
2636 .obj_size = sizeof(struct tcp_sock),
2637 .slab_flags = SLAB_DESTROY_BY_RCU,
2638 .twsk_prot = &tcp_timewait_sock_ops,
2639 .rsk_prot = &tcp_request_sock_ops,
2640 .h.hashinfo = &tcp_hashinfo,
2641 .no_autobind = true,
2642 #ifdef CONFIG_COMPAT
2643 .compat_setsockopt = compat_tcp_setsockopt,
2644 .compat_getsockopt = compat_tcp_getsockopt,
2645 #endif
2646 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
2647 .init_cgroup = tcp_init_cgroup,
2648 .destroy_cgroup = tcp_destroy_cgroup,
2649 .proto_cgroup = tcp_proto_cgroup,
2650 #endif
2651 };
2652 EXPORT_SYMBOL(tcp_prot);
2653
2654 static int __net_init tcp_sk_init(struct net *net)
2655 {
2656 return inet_ctl_sock_create(&net->ipv4.tcp_sock,
2657 PF_INET, SOCK_RAW, IPPROTO_TCP, net);
2658 }
2659
2660 static void __net_exit tcp_sk_exit(struct net *net)
2661 {
2662 inet_ctl_sock_destroy(net->ipv4.tcp_sock);
2663 }
2664
2665 static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
2666 {
2667 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
2668 }
2669
2670 static struct pernet_operations __net_initdata tcp_sk_ops = {
2671 .init = tcp_sk_init,
2672 .exit = tcp_sk_exit,
2673 .exit_batch = tcp_sk_exit_batch,
2674 };
2675
2676 void __init tcp_v4_init(void)
2677 {
2678 inet_hashinfo_init(&tcp_hashinfo);
2679 if (register_pernet_subsys(&tcp_sk_ops))
2680 panic("Failed to create the TCP control socket.\n");
2681 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree