blob: 9d839fa9331e5845c39b22d07d9d3a93f39634d3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * 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
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070037 * request_sock handling and moved
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 * most of it into the af independent code.
39 * Added tail drop and some other bugfixes.
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -080040 * Added new listen semantics.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Herbert Xueb4dea52008-12-29 23:04:08 -080054#include <linux/bottom_half.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#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
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020064#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#include <net/icmp.h>
Arnaldo Carvalho de Melo304a1612005-08-09 19:59:20 -070066#include <net/inet_hashtables.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070067#include <net/tcp.h>
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -030068#include <net/transp_v6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#include <net/ipv6.h>
70#include <net/inet_common.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080071#include <net/timewait_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <net/xfrm.h>
Chris Leech1a2449a2006-05-23 18:05:53 -070073#include <net/netdma.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75#include <linux/inet.h>
76#include <linux/ipv6.h>
77#include <linux/stddef.h>
78#include <linux/proc_fs.h>
79#include <linux/seq_file.h>
80
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080081#include <linux/crypto.h>
82#include <linux/scatterlist.h>
83
Brian Haleyab32ea52006-09-22 14:15:41 -070084int sysctl_tcp_tw_reuse __read_mostly;
85int sysctl_tcp_low_latency __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080088#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -020089static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
90 __be32 addr);
Adam Langley49a72df2008-07-19 00:01:42 -070091static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
92 __be32 daddr, __be32 saddr, struct tcphdr *th);
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +090093#else
94static inline
95struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
96{
97 return NULL;
98}
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080099#endif
100
Eric Dumazet5caea4e2008-11-20 00:40:07 -0800101struct inet_hashinfo tcp_hashinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Gerrit Renkera94f7232006-11-10 14:06:49 -0800103static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700105 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
106 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700107 tcp_hdr(skb)->dest,
108 tcp_hdr(skb)->source);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109}
110
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800111int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
112{
113 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
114 struct tcp_sock *tp = tcp_sk(sk);
115
116 /* With PAWS, it is safe from the viewpoint
117 of data integrity. Even without PAWS it is safe provided sequence
118 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
119
120 Actually, the idea is close to VJ's one, only timestamp cache is
121 held not per host, but per port pair and TW bucket is used as state
122 holder.
123
124 If TW bucket has been already destroyed we fall back to VJ's scheme
125 and use initial timestamp retrieved from peer table.
126 */
127 if (tcptw->tw_ts_recent_stamp &&
128 (twp == NULL || (sysctl_tcp_tw_reuse &&
James Morris9d729f72007-03-04 16:12:44 -0800129 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800130 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
131 if (tp->write_seq == 0)
132 tp->write_seq = 1;
133 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
134 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
135 sock_hold(sktw);
136 return 1;
137 }
138
139 return 0;
140}
141
142EXPORT_SYMBOL_GPL(tcp_twsk_unique);
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144/* This will initiate an outgoing connection. */
145int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
146{
147 struct inet_sock *inet = inet_sk(sk);
148 struct tcp_sock *tp = tcp_sk(sk);
149 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
150 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -0700151 __be32 daddr, nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 int tmp;
153 int err;
154
155 if (addr_len < sizeof(struct sockaddr_in))
156 return -EINVAL;
157
158 if (usin->sin_family != AF_INET)
159 return -EAFNOSUPPORT;
160
161 nexthop = daddr = usin->sin_addr.s_addr;
162 if (inet->opt && inet->opt->srr) {
163 if (!daddr)
164 return -EINVAL;
165 nexthop = inet->opt->faddr;
166 }
167
168 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
169 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
170 IPPROTO_TCP,
David S. Miller8eb90862007-02-08 02:09:21 -0800171 inet->sport, usin->sin_port, sk, 1);
Wei Dong584bdf82007-05-31 22:49:28 -0700172 if (tmp < 0) {
173 if (tmp == -ENETUNREACH)
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700174 IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return tmp;
Wei Dong584bdf82007-05-31 22:49:28 -0700176 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
178 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
179 ip_rt_put(rt);
180 return -ENETUNREACH;
181 }
182
183 if (!inet->opt || !inet->opt->srr)
184 daddr = rt->rt_dst;
185
186 if (!inet->saddr)
187 inet->saddr = rt->rt_src;
188 inet->rcv_saddr = inet->saddr;
189
190 if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
191 /* Reset inherited state */
192 tp->rx_opt.ts_recent = 0;
193 tp->rx_opt.ts_recent_stamp = 0;
194 tp->write_seq = 0;
195 }
196
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -0700197 if (tcp_death_row.sysctl_tw_recycle &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
199 struct inet_peer *peer = rt_get_peer(rt);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200200 /*
201 * VJ's idea. We save last timestamp seen from
202 * the destination in peer table, when entering state
203 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
204 * when trying new connection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200206 if (peer != NULL &&
James Morris9d729f72007-03-04 16:12:44 -0800207 peer->tcp_ts_stamp + TCP_PAWS_MSL >= get_seconds()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
209 tp->rx_opt.ts_recent = peer->tcp_ts;
210 }
211 }
212
213 inet->dport = usin->sin_port;
214 inet->daddr = daddr;
215
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800216 inet_csk(sk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 if (inet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800218 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 tp->rx_opt.mss_clamp = 536;
221
222 /* Socket identity is still unknown (sport may be zero).
223 * However we set state to SYN-SENT and not releasing socket
224 * lock select source port, enter ourselves into the hash tables and
225 * complete initialization after this.
226 */
227 tcp_set_state(sk, TCP_SYN_SENT);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800228 err = inet_hash_connect(&tcp_death_row, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (err)
230 goto failure;
231
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200232 err = ip_route_newports(&rt, IPPROTO_TCP,
233 inet->sport, inet->dport, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (err)
235 goto failure;
236
237 /* OK, now commit destination to socket. */
Herbert Xubcd76112006-06-30 13:36:35 -0700238 sk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -0700239 sk_setup_caps(sk, &rt->u.dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241 if (!tp->write_seq)
242 tp->write_seq = secure_tcp_sequence_number(inet->saddr,
243 inet->daddr,
244 inet->sport,
245 usin->sin_port);
246
247 inet->id = tp->write_seq ^ jiffies;
248
249 err = tcp_connect(sk);
250 rt = NULL;
251 if (err)
252 goto failure;
253
254 return 0;
255
256failure:
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200257 /*
258 * This unhashes the socket and releases the local port,
259 * if necessary.
260 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 tcp_set_state(sk, TCP_CLOSE);
262 ip_rt_put(rt);
263 sk->sk_route_caps = 0;
264 inet->dport = 0;
265 return err;
266}
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/*
269 * This routine does path mtu discovery as defined in RFC1191.
270 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800271static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
273 struct dst_entry *dst;
274 struct inet_sock *inet = inet_sk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
277 * send out by Linux are always <576bytes so they should go through
278 * unfragmented).
279 */
280 if (sk->sk_state == TCP_LISTEN)
281 return;
282
283 /* We don't check in the destentry if pmtu discovery is forbidden
284 * on this route. We just assume that no packet_to_big packets
285 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900286 * There is a small race when the user changes this flag in the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 * route, but I think that's acceptable.
288 */
289 if ((dst = __sk_dst_check(sk, 0)) == NULL)
290 return;
291
292 dst->ops->update_pmtu(dst, mtu);
293
294 /* Something is about to be wrong... Remember soft error
295 * for the case, if this connection will not able to recover.
296 */
297 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
298 sk->sk_err_soft = EMSGSIZE;
299
300 mtu = dst_mtu(dst);
301
302 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800303 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 tcp_sync_mss(sk, mtu);
305
306 /* Resend the TCP packet because it's
307 * clear that the old packet has been
308 * dropped. This is the new "fast" path mtu
309 * discovery.
310 */
311 tcp_simple_retransmit(sk);
312 } /* else let the usual retransmit timer handle it */
313}
314
315/*
316 * This routine is called by the ICMP module when it gets some
317 * sort of error condition. If err < 0 then the socket should
318 * be closed and the error returned to the user. If err > 0
319 * it's just the icmp type << 8 | icmp code. After adjustment
320 * header points to the first 8 bytes of the tcp header. We need
321 * to find the appropriate port.
322 *
323 * The locking strategy used here is very "optimistic". When
324 * someone else accesses the socket the ICMP is just dropped
325 * and for some paths there is no check at all.
326 * A more general error queue to queue errors for later handling
327 * is probably better.
328 *
329 */
330
331void tcp_v4_err(struct sk_buff *skb, u32 info)
332{
333 struct iphdr *iph = (struct iphdr *)skb->data;
334 struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
335 struct tcp_sock *tp;
336 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300337 const int type = icmp_hdr(skb)->type;
338 const int code = icmp_hdr(skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 struct sock *sk;
340 __u32 seq;
341 int err;
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700342 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
344 if (skb->len < (iph->ihl << 2) + 8) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700345 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 return;
347 }
348
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700349 sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
Pavel Emelyanovc67499c2008-01-31 05:06:40 -0800350 iph->saddr, th->source, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 if (!sk) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700352 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 return;
354 }
355 if (sk->sk_state == TCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700356 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 return;
358 }
359
360 bh_lock_sock(sk);
361 /* If too many ICMPs get dropped on busy
362 * servers this needs to be solved differently.
363 */
364 if (sock_owned_by_user(sk))
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700365 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
367 if (sk->sk_state == TCP_CLOSE)
368 goto out;
369
370 tp = tcp_sk(sk);
371 seq = ntohl(th->seq);
372 if (sk->sk_state != TCP_LISTEN &&
373 !between(seq, tp->snd_una, tp->snd_nxt)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700374 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 goto out;
376 }
377
378 switch (type) {
379 case ICMP_SOURCE_QUENCH:
380 /* Just silently ignore these. */
381 goto out;
382 case ICMP_PARAMETERPROB:
383 err = EPROTO;
384 break;
385 case ICMP_DEST_UNREACH:
386 if (code > NR_ICMP_UNREACH)
387 goto out;
388
389 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
390 if (!sock_owned_by_user(sk))
391 do_pmtu_discovery(sk, iph, info);
392 goto out;
393 }
394
395 err = icmp_err_convert[code].errno;
396 break;
397 case ICMP_TIME_EXCEEDED:
398 err = EHOSTUNREACH;
399 break;
400 default:
401 goto out;
402 }
403
404 switch (sk->sk_state) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700405 struct request_sock *req, **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 case TCP_LISTEN:
407 if (sock_owned_by_user(sk))
408 goto out;
409
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700410 req = inet_csk_search_req(sk, &prev, th->dest,
411 iph->daddr, iph->saddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 if (!req)
413 goto out;
414
415 /* ICMPs are not backlogged, hence we cannot get
416 an established socket here.
417 */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700418 WARN_ON(req->sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700420 if (seq != tcp_rsk(req)->snt_isn) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700421 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 goto out;
423 }
424
425 /*
426 * Still in SYN_RECV, just remove it silently.
427 * There is no good way to pass the error to the newly
428 * created socket, and POSIX does not want network
429 * errors returned from accept().
430 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700431 inet_csk_reqsk_queue_drop(sk, req, prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 goto out;
433
434 case TCP_SYN_SENT:
435 case TCP_SYN_RECV: /* Cannot happen.
436 It can f.e. if SYNs crossed.
437 */
438 if (!sock_owned_by_user(sk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 sk->sk_err = err;
440
441 sk->sk_error_report(sk);
442
443 tcp_done(sk);
444 } else {
445 sk->sk_err_soft = err;
446 }
447 goto out;
448 }
449
450 /* If we've already connected we will keep trying
451 * until we time out, or the user gives up.
452 *
453 * rfc1122 4.2.3.9 allows to consider as hard errors
454 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
455 * but it is obsoleted by pmtu discovery).
456 *
457 * Note, that in modern internet, where routing is unreliable
458 * and in each dark corner broken firewalls sit, sending random
459 * errors ordered by their masters even this two messages finally lose
460 * their original sense (even Linux sends invalid PORT_UNREACHs)
461 *
462 * Now we are in compliance with RFCs.
463 * --ANK (980905)
464 */
465
466 inet = inet_sk(sk);
467 if (!sock_owned_by_user(sk) && inet->recverr) {
468 sk->sk_err = err;
469 sk->sk_error_report(sk);
470 } else { /* Only an error on timeout */
471 sk->sk_err_soft = err;
472 }
473
474out:
475 bh_unlock_sock(sk);
476 sock_put(sk);
477}
478
479/* This routine computes an IPv4 TCP checksum. */
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -0800480void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481{
482 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700483 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Patrick McHardy84fa7932006-08-29 16:44:56 -0700485 if (skb->ip_summed == CHECKSUM_PARTIAL) {
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800486 th->check = ~tcp_v4_check(len, inet->saddr,
487 inet->daddr, 0);
Herbert Xu663ead32007-04-09 11:59:07 -0700488 skb->csum_start = skb_transport_header(skb) - skb->head;
Al Viroff1dcad2006-11-20 18:07:29 -0800489 skb->csum_offset = offsetof(struct tcphdr, check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 } else {
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800491 th->check = tcp_v4_check(len, inet->saddr, inet->daddr,
Joe Perches07f07572008-11-19 15:44:53 -0800492 csum_partial(th,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 th->doff << 2,
494 skb->csum));
495 }
496}
497
Herbert Xua430a432006-07-08 13:34:56 -0700498int tcp_v4_gso_send_check(struct sk_buff *skb)
499{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700500 const struct iphdr *iph;
Herbert Xua430a432006-07-08 13:34:56 -0700501 struct tcphdr *th;
502
503 if (!pskb_may_pull(skb, sizeof(*th)))
504 return -EINVAL;
505
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700506 iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700507 th = tcp_hdr(skb);
Herbert Xua430a432006-07-08 13:34:56 -0700508
509 th->check = 0;
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800510 th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
Herbert Xu663ead32007-04-09 11:59:07 -0700511 skb->csum_start = skb_transport_header(skb) - skb->head;
Al Viroff1dcad2006-11-20 18:07:29 -0800512 skb->csum_offset = offsetof(struct tcphdr, check);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700513 skb->ip_summed = CHECKSUM_PARTIAL;
Herbert Xua430a432006-07-08 13:34:56 -0700514 return 0;
515}
516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517/*
518 * This routine will send an RST to the other tcp.
519 *
520 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
521 * for reset.
522 * Answer: if a packet caused RST, it is not for a socket
523 * existing in our system, if it is matched to a socket,
524 * it is just duplicate segment or bug in other side's TCP.
525 * So that we build reply only basing on parameters
526 * arrived with segment.
527 * Exception: precedence violation. We do not implement it in any case.
528 */
529
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800530static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700532 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800533 struct {
534 struct tcphdr th;
535#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800536 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800537#endif
538 } rep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 struct ip_reply_arg arg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800540#ifdef CONFIG_TCP_MD5SIG
541 struct tcp_md5sig_key *key;
542#endif
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700543 struct net *net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544
545 /* Never send a reset in response to a reset. */
546 if (th->rst)
547 return;
548
Eric Dumazetee6b9672008-03-05 18:30:47 -0800549 if (skb->rtable->rt_type != RTN_LOCAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 return;
551
552 /* Swap the send and the receive. */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800553 memset(&rep, 0, sizeof(rep));
554 rep.th.dest = th->source;
555 rep.th.source = th->dest;
556 rep.th.doff = sizeof(struct tcphdr) / 4;
557 rep.th.rst = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 if (th->ack) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800560 rep.th.seq = th->ack_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800562 rep.th.ack = 1;
563 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
564 skb->len - (th->doff << 2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 }
566
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200567 memset(&arg, 0, sizeof(arg));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800568 arg.iov[0].iov_base = (unsigned char *)&rep;
569 arg.iov[0].iov_len = sizeof(rep.th);
570
571#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700572 key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800573 if (key) {
574 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
575 (TCPOPT_NOP << 16) |
576 (TCPOPT_MD5SIG << 8) |
577 TCPOLEN_MD5SIG);
578 /* Update length and the length the header thinks exists */
579 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
580 rep.th.doff = arg.iov[0].iov_len / 4;
581
Adam Langley49a72df2008-07-19 00:01:42 -0700582 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
Ilpo Järvinen78e645cb2008-10-09 14:37:47 -0700583 key, ip_hdr(skb)->saddr,
584 ip_hdr(skb)->daddr, &rep.th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800585 }
586#endif
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700587 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
588 ip_hdr(skb)->saddr, /* XXX */
Ilpo Järvinen52cd5752008-10-08 11:34:06 -0700589 arg.iov[0].iov_len, IPPROTO_TCP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700591 arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700593 net = dev_net(skb->dst->dev);
594 ip_send_reply(net->ipv4.tcp_sock, skb,
Denis V. Lunev7feb49c2008-04-03 14:32:00 -0700595 &arg, arg.iov[0].iov_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596
Pavel Emelyanov63231bd2008-07-16 20:22:25 -0700597 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
598 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599}
600
601/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
602 outside socket context is ugly, certainly. What can I do?
603 */
604
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900605static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
606 u32 win, u32 ts, int oif,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700607 struct tcp_md5sig_key *key,
608 int reply_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700610 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 struct {
612 struct tcphdr th;
Al Viro714e85b2006-11-14 20:51:49 -0800613 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800614#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800615 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800616#endif
617 ];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 } rep;
619 struct ip_reply_arg arg;
Vitaliy Gusev4dd79722008-10-01 01:51:39 -0700620 struct net *net = dev_net(skb->dst->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
622 memset(&rep.th, 0, sizeof(struct tcphdr));
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200623 memset(&arg, 0, sizeof(arg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
625 arg.iov[0].iov_base = (unsigned char *)&rep;
626 arg.iov[0].iov_len = sizeof(rep.th);
627 if (ts) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800628 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
629 (TCPOPT_TIMESTAMP << 8) |
630 TCPOLEN_TIMESTAMP);
631 rep.opt[1] = htonl(tcp_time_stamp);
632 rep.opt[2] = htonl(ts);
Craig Schlentercb48cfe2007-01-09 00:11:15 -0800633 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 }
635
636 /* Swap the send and the receive. */
637 rep.th.dest = th->source;
638 rep.th.source = th->dest;
639 rep.th.doff = arg.iov[0].iov_len / 4;
640 rep.th.seq = htonl(seq);
641 rep.th.ack_seq = htonl(ack);
642 rep.th.ack = 1;
643 rep.th.window = htons(win);
644
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800645#ifdef CONFIG_TCP_MD5SIG
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800646 if (key) {
647 int offset = (ts) ? 3 : 0;
648
649 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
650 (TCPOPT_NOP << 16) |
651 (TCPOPT_MD5SIG << 8) |
652 TCPOLEN_MD5SIG);
653 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
654 rep.th.doff = arg.iov[0].iov_len/4;
655
Adam Langley49a72df2008-07-19 00:01:42 -0700656 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
Adam Langley90b7e112008-07-31 20:49:48 -0700657 key, ip_hdr(skb)->saddr,
658 ip_hdr(skb)->daddr, &rep.th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800659 }
660#endif
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700661 arg.flags = reply_flags;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700662 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
663 ip_hdr(skb)->saddr, /* XXX */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 arg.iov[0].iov_len, IPPROTO_TCP, 0);
665 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900666 if (oif)
667 arg.bound_dev_if = oif;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700669 ip_send_reply(net->ipv4.tcp_sock, skb,
Denis V. Lunev7feb49c2008-04-03 14:32:00 -0700670 &arg, arg.iov[0].iov_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
Pavel Emelyanov63231bd2008-07-16 20:22:25 -0700672 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673}
674
675static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
676{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700677 struct inet_timewait_sock *tw = inet_twsk(sk);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800678 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900680 tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200681 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900682 tcptw->tw_ts_recent,
683 tw->tw_bound_dev_if,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700684 tcp_twsk_md5_key(tcptw),
685 tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900686 );
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700688 inet_twsk_put(tw);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689}
690
Gui Jianfeng6edafaa2008-08-06 23:50:04 -0700691static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200692 struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693{
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900694 tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800695 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900696 req->ts_recent,
697 0,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700698 tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
699 inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700}
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702/*
Kris Katterjohn9bf1d832008-02-17 22:29:19 -0800703 * Send a SYN-ACK after having received a SYN.
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700704 * This still operates on a request_sock only, not on a big
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 * socket.
706 */
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800707static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
708 struct dst_entry *dst)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700710 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 int err = -1;
712 struct sk_buff * skb;
713
714 /* First, grab a route. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700715 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800716 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
718 skb = tcp_make_synack(sk, dst, req);
719
720 if (skb) {
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700721 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800723 th->check = tcp_v4_check(skb->len,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700724 ireq->loc_addr,
725 ireq->rmt_addr,
Joe Perches07f07572008-11-19 15:44:53 -0800726 csum_partial(th, skb->len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 skb->csum));
728
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700729 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
730 ireq->rmt_addr,
731 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200732 err = net_xmit_eval(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 }
734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 dst_release(dst);
736 return err;
737}
738
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800739static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req)
740{
741 return __tcp_v4_send_synack(sk, req, NULL);
742}
743
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700745 * IPv4 request_sock destructor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700747static void tcp_v4_reqsk_destructor(struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748{
Jesper Juhla51482b2005-11-08 09:41:34 -0800749 kfree(inet_rsk(req)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750}
751
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200752#ifdef CONFIG_SYN_COOKIES
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800753static void syn_flood_warning(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754{
755 static unsigned long warntime;
756
757 if (time_after(jiffies, (warntime + HZ * 60))) {
758 warntime = jiffies;
759 printk(KERN_INFO
760 "possible SYN flooding on port %d. Sending cookies.\n",
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700761 ntohs(tcp_hdr(skb)->dest));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 }
763}
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200764#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
766/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700767 * Save and compile IPv4 options into the request_sock if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800769static struct ip_options *tcp_v4_save_options(struct sock *sk,
770 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771{
772 struct ip_options *opt = &(IPCB(skb)->opt);
773 struct ip_options *dopt = NULL;
774
775 if (opt && opt->optlen) {
776 int opt_size = optlength(opt);
777 dopt = kmalloc(opt_size, GFP_ATOMIC);
778 if (dopt) {
779 if (ip_options_echo(dopt, skb)) {
780 kfree(dopt);
781 dopt = NULL;
782 }
783 }
784 }
785 return dopt;
786}
787
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800788#ifdef CONFIG_TCP_MD5SIG
789/*
790 * RFC2385 MD5 checksumming requires a mapping of
791 * IP address->MD5 Key.
792 * We need to maintain these in the sk structure.
793 */
794
795/* Find the Key structure for an address. */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200796static struct tcp_md5sig_key *
797 tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800798{
799 struct tcp_sock *tp = tcp_sk(sk);
800 int i;
801
802 if (!tp->md5sig_info || !tp->md5sig_info->entries4)
803 return NULL;
804 for (i = 0; i < tp->md5sig_info->entries4; i++) {
805 if (tp->md5sig_info->keys4[i].addr == addr)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700806 return &tp->md5sig_info->keys4[i].base;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800807 }
808 return NULL;
809}
810
811struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
812 struct sock *addr_sk)
813{
814 return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->daddr);
815}
816
817EXPORT_SYMBOL(tcp_v4_md5_lookup);
818
Adrian Bunkf5b99bc2006-11-30 17:22:29 -0800819static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
820 struct request_sock *req)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800821{
822 return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
823}
824
825/* This can be called on a newly created socket, from other files */
826int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
827 u8 *newkey, u8 newkeylen)
828{
829 /* Add Key to the list */
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700830 struct tcp_md5sig_key *key;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800831 struct tcp_sock *tp = tcp_sk(sk);
832 struct tcp4_md5sig_key *keys;
833
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700834 key = tcp_v4_md5_do_lookup(sk, addr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800835 if (key) {
836 /* Pre-existing entry - just update that one. */
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700837 kfree(key->key);
838 key->key = newkey;
839 key->keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800840 } else {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200841 struct tcp_md5sig_info *md5sig;
842
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800843 if (!tp->md5sig_info) {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200844 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
845 GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800846 if (!tp->md5sig_info) {
847 kfree(newkey);
848 return -ENOMEM;
849 }
David S. Miller3d7dbea2007-06-12 14:36:42 -0700850 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800851 }
852 if (tcp_alloc_md5sig_pool() == NULL) {
853 kfree(newkey);
854 return -ENOMEM;
855 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200856 md5sig = tp->md5sig_info;
857
858 if (md5sig->alloced4 == md5sig->entries4) {
859 keys = kmalloc((sizeof(*keys) *
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900860 (md5sig->entries4 + 1)), GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800861 if (!keys) {
862 kfree(newkey);
863 tcp_free_md5sig_pool();
864 return -ENOMEM;
865 }
866
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200867 if (md5sig->entries4)
868 memcpy(keys, md5sig->keys4,
869 sizeof(*keys) * md5sig->entries4);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800870
871 /* Free old key list, and reference new one */
YOSHIFUJI Hideakia80cc202007-11-20 17:30:06 -0800872 kfree(md5sig->keys4);
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200873 md5sig->keys4 = keys;
874 md5sig->alloced4++;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800875 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200876 md5sig->entries4++;
David S. Millerf8ab18d2007-09-28 15:18:35 -0700877 md5sig->keys4[md5sig->entries4 - 1].addr = addr;
878 md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
879 md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800880 }
881 return 0;
882}
883
884EXPORT_SYMBOL(tcp_v4_md5_do_add);
885
886static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
887 u8 *newkey, u8 newkeylen)
888{
889 return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->daddr,
890 newkey, newkeylen);
891}
892
893int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
894{
895 struct tcp_sock *tp = tcp_sk(sk);
896 int i;
897
898 for (i = 0; i < tp->md5sig_info->entries4; i++) {
899 if (tp->md5sig_info->keys4[i].addr == addr) {
900 /* Free the key */
David S. Millerf8ab18d2007-09-28 15:18:35 -0700901 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800902 tp->md5sig_info->entries4--;
903
904 if (tp->md5sig_info->entries4 == 0) {
905 kfree(tp->md5sig_info->keys4);
906 tp->md5sig_info->keys4 = NULL;
Leigh Brown8228a18d2006-12-17 17:12:30 -0800907 tp->md5sig_info->alloced4 = 0;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200908 } else if (tp->md5sig_info->entries4 != i) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800909 /* Need to do some manipulation */
YOSHIFUJI Hideaki354faf02007-11-20 17:30:31 -0800910 memmove(&tp->md5sig_info->keys4[i],
911 &tp->md5sig_info->keys4[i+1],
912 (tp->md5sig_info->entries4 - i) *
913 sizeof(struct tcp4_md5sig_key));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800914 }
915 tcp_free_md5sig_pool();
916 return 0;
917 }
918 }
919 return -ENOENT;
920}
921
922EXPORT_SYMBOL(tcp_v4_md5_do_del);
923
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200924static void tcp_v4_clear_md5_list(struct sock *sk)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800925{
926 struct tcp_sock *tp = tcp_sk(sk);
927
928 /* Free each key, then the set of key keys,
929 * the crypto element, and then decrement our
930 * hold on the last resort crypto.
931 */
932 if (tp->md5sig_info->entries4) {
933 int i;
934 for (i = 0; i < tp->md5sig_info->entries4; i++)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700935 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800936 tp->md5sig_info->entries4 = 0;
937 tcp_free_md5sig_pool();
938 }
939 if (tp->md5sig_info->keys4) {
940 kfree(tp->md5sig_info->keys4);
941 tp->md5sig_info->keys4 = NULL;
942 tp->md5sig_info->alloced4 = 0;
943 }
944}
945
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200946static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
947 int optlen)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800948{
949 struct tcp_md5sig cmd;
950 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
951 u8 *newkey;
952
953 if (optlen < sizeof(cmd))
954 return -EINVAL;
955
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200956 if (copy_from_user(&cmd, optval, sizeof(cmd)))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800957 return -EFAULT;
958
959 if (sin->sin_family != AF_INET)
960 return -EINVAL;
961
962 if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
963 if (!tcp_sk(sk)->md5sig_info)
964 return -ENOENT;
965 return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
966 }
967
968 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
969 return -EINVAL;
970
971 if (!tcp_sk(sk)->md5sig_info) {
972 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200973 struct tcp_md5sig_info *p = kzalloc(sizeof(*p), GFP_KERNEL);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800974
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800975 if (!p)
976 return -EINVAL;
977
978 tp->md5sig_info = p;
David S. Miller3d7dbea2007-06-12 14:36:42 -0700979 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800980 }
981
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200982 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800983 if (!newkey)
984 return -ENOMEM;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800985 return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
986 newkey, cmd.tcpm_keylen);
987}
988
Adam Langley49a72df2008-07-19 00:01:42 -0700989static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
990 __be32 daddr, __be32 saddr, int nbytes)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800991{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800992 struct tcp4_pseudohdr *bp;
Adam Langley49a72df2008-07-19 00:01:42 -0700993 struct scatterlist sg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800994
995 bp = &hp->md5_blk.ip4;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800996
997 /*
Adam Langley49a72df2008-07-19 00:01:42 -0700998 * 1. the TCP pseudo-header (in the order: source IP address,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800999 * destination IP address, zero-padded protocol number, and
1000 * segment length)
1001 */
1002 bp->saddr = saddr;
1003 bp->daddr = daddr;
1004 bp->pad = 0;
YOSHIFUJI Hideaki076fb722008-04-17 12:48:12 +09001005 bp->protocol = IPPROTO_TCP;
Adam Langley49a72df2008-07-19 00:01:42 -07001006 bp->len = cpu_to_be16(nbytes);
David S. Millerc7da57a2007-10-26 00:41:21 -07001007
Adam Langley49a72df2008-07-19 00:01:42 -07001008 sg_init_one(&sg, bp, sizeof(*bp));
1009 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
1010}
1011
1012static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
1013 __be32 daddr, __be32 saddr, struct tcphdr *th)
1014{
1015 struct tcp_md5sig_pool *hp;
1016 struct hash_desc *desc;
1017
1018 hp = tcp_get_md5sig_pool();
1019 if (!hp)
1020 goto clear_hash_noput;
1021 desc = &hp->md5_desc;
1022
1023 if (crypto_hash_init(desc))
1024 goto clear_hash;
1025 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
1026 goto clear_hash;
1027 if (tcp_md5_hash_header(hp, th))
1028 goto clear_hash;
1029 if (tcp_md5_hash_key(hp, key))
1030 goto clear_hash;
1031 if (crypto_hash_final(desc, md5_hash))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001032 goto clear_hash;
1033
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001034 tcp_put_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001035 return 0;
Adam Langley49a72df2008-07-19 00:01:42 -07001036
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001037clear_hash:
1038 tcp_put_md5sig_pool();
1039clear_hash_noput:
1040 memset(md5_hash, 0, 16);
Adam Langley49a72df2008-07-19 00:01:42 -07001041 return 1;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001042}
1043
Adam Langley49a72df2008-07-19 00:01:42 -07001044int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
1045 struct sock *sk, struct request_sock *req,
1046 struct sk_buff *skb)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001047{
Adam Langley49a72df2008-07-19 00:01:42 -07001048 struct tcp_md5sig_pool *hp;
1049 struct hash_desc *desc;
1050 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001051 __be32 saddr, daddr;
1052
1053 if (sk) {
1054 saddr = inet_sk(sk)->saddr;
1055 daddr = inet_sk(sk)->daddr;
Adam Langley49a72df2008-07-19 00:01:42 -07001056 } else if (req) {
1057 saddr = inet_rsk(req)->loc_addr;
1058 daddr = inet_rsk(req)->rmt_addr;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001059 } else {
Adam Langley49a72df2008-07-19 00:01:42 -07001060 const struct iphdr *iph = ip_hdr(skb);
1061 saddr = iph->saddr;
1062 daddr = iph->daddr;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001063 }
Adam Langley49a72df2008-07-19 00:01:42 -07001064
1065 hp = tcp_get_md5sig_pool();
1066 if (!hp)
1067 goto clear_hash_noput;
1068 desc = &hp->md5_desc;
1069
1070 if (crypto_hash_init(desc))
1071 goto clear_hash;
1072
1073 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
1074 goto clear_hash;
1075 if (tcp_md5_hash_header(hp, th))
1076 goto clear_hash;
1077 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
1078 goto clear_hash;
1079 if (tcp_md5_hash_key(hp, key))
1080 goto clear_hash;
1081 if (crypto_hash_final(desc, md5_hash))
1082 goto clear_hash;
1083
1084 tcp_put_md5sig_pool();
1085 return 0;
1086
1087clear_hash:
1088 tcp_put_md5sig_pool();
1089clear_hash_noput:
1090 memset(md5_hash, 0, 16);
1091 return 1;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001092}
1093
Adam Langley49a72df2008-07-19 00:01:42 -07001094EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001095
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001096static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001097{
1098 /*
1099 * This gets called for each TCP segment that arrives
1100 * so we want to be efficient.
1101 * We have 3 drop cases:
1102 * o No MD5 hash and one expected.
1103 * o MD5 hash and we're not expecting one.
1104 * o MD5 hash and its wrong.
1105 */
1106 __u8 *hash_location = NULL;
1107 struct tcp_md5sig_key *hash_expected;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001108 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001109 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001110 int genhash;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001111 unsigned char newhash[16];
1112
1113 hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
YOSHIFUJI Hideaki7d5d5522008-04-17 12:29:53 +09001114 hash_location = tcp_parse_md5sig_option(th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001115
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001116 /* We've parsed the options - do we have a hash? */
1117 if (!hash_expected && !hash_location)
1118 return 0;
1119
1120 if (hash_expected && !hash_location) {
David S. Miller785957d2008-07-30 03:03:15 -07001121 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001122 return 1;
1123 }
1124
1125 if (!hash_expected && hash_location) {
David S. Miller785957d2008-07-30 03:03:15 -07001126 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001127 return 1;
1128 }
1129
1130 /* Okay, so this is hash_expected and hash_location -
1131 * so we need to calculate the checksum.
1132 */
Adam Langley49a72df2008-07-19 00:01:42 -07001133 genhash = tcp_v4_md5_hash_skb(newhash,
1134 hash_expected,
1135 NULL, NULL, skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001136
1137 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1138 if (net_ratelimit()) {
Harvey Harrison673d57e2008-10-31 00:53:57 -07001139 printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1140 &iph->saddr, ntohs(th->source),
1141 &iph->daddr, ntohs(th->dest),
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001142 genhash ? " tcp_v4_calc_md5_hash failed" : "");
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001143 }
1144 return 1;
1145 }
1146 return 0;
1147}
1148
1149#endif
1150
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001151struct request_sock_ops tcp_request_sock_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 .family = PF_INET,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001153 .obj_size = sizeof(struct tcp_request_sock),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 .rtx_syn_ack = tcp_v4_send_synack,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001155 .send_ack = tcp_v4_reqsk_send_ack,
1156 .destructor = tcp_v4_reqsk_destructor,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157 .send_reset = tcp_v4_send_reset,
1158};
1159
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001160#ifdef CONFIG_TCP_MD5SIG
Andrew Mortonb6332e62006-11-30 19:16:28 -08001161static struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001162 .md5_lookup = tcp_v4_reqsk_md5_lookup,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001163};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001164#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001165
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001166static struct timewait_sock_ops tcp_timewait_sock_ops = {
1167 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1168 .twsk_unique = tcp_twsk_unique,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001169 .twsk_destructor= tcp_twsk_destructor,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001170};
1171
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1173{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001174 struct inet_request_sock *ireq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 struct tcp_options_received tmp_opt;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001176 struct request_sock *req;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001177 __be32 saddr = ip_hdr(skb)->saddr;
1178 __be32 daddr = ip_hdr(skb)->daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 __u32 isn = TCP_SKB_CB(skb)->when;
1180 struct dst_entry *dst = NULL;
1181#ifdef CONFIG_SYN_COOKIES
1182 int want_cookie = 0;
1183#else
1184#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
1185#endif
1186
1187 /* Never answer to SYNs send to broadcast or multicast */
Eric Dumazetee6b9672008-03-05 18:30:47 -08001188 if (skb->rtable->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 goto drop;
1190
1191 /* TW buckets are converted to open requests without
1192 * limitations, they conserve resources and peer is
1193 * evidently real one.
1194 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001195 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196#ifdef CONFIG_SYN_COOKIES
1197 if (sysctl_tcp_syncookies) {
1198 want_cookie = 1;
1199 } else
1200#endif
1201 goto drop;
1202 }
1203
1204 /* Accept backlog is full. If we have already queued enough
1205 * of warm entries in syn queue, drop request. It is better than
1206 * clogging syn queue with openreqs with exponentially increasing
1207 * timeout.
1208 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001209 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 goto drop;
1211
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -07001212 req = inet_reqsk_alloc(&tcp_request_sock_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 if (!req)
1214 goto drop;
1215
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001216#ifdef CONFIG_TCP_MD5SIG
1217 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1218#endif
1219
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 tcp_clear_options(&tmp_opt);
1221 tmp_opt.mss_clamp = 536;
1222 tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss;
1223
1224 tcp_parse_options(skb, &tmp_opt, 0);
1225
Florian Westphal4dfc2812008-04-10 03:12:40 -07001226 if (want_cookie && !tmp_opt.saw_tstamp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 tcp_clear_options(&tmp_opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228
1229 if (tmp_opt.saw_tstamp && !tmp_opt.rcv_tsval) {
1230 /* Some OSes (unknown ones, but I see them on web server, which
1231 * contains information interesting only for windows'
1232 * users) do not send their stamp in SYN. It is easy case.
1233 * We simply do not advertise TS support.
1234 */
1235 tmp_opt.saw_tstamp = 0;
1236 tmp_opt.tstamp_ok = 0;
1237 }
1238 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1239
1240 tcp_openreq_init(req, &tmp_opt, skb);
1241
Venkat Yekkirala4237c752006-07-24 23:32:50 -07001242 if (security_inet_conn_request(sk, skb, req))
1243 goto drop_and_free;
1244
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001245 ireq = inet_rsk(req);
1246 ireq->loc_addr = daddr;
1247 ireq->rmt_addr = saddr;
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -07001248 ireq->no_srccheck = inet_sk(sk)->transparent;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001249 ireq->opt = tcp_v4_save_options(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 if (!want_cookie)
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001251 TCP_ECN_create_request(req, tcp_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252
1253 if (want_cookie) {
1254#ifdef CONFIG_SYN_COOKIES
1255 syn_flood_warning(skb);
Florian Westphal4dfc2812008-04-10 03:12:40 -07001256 req->cookie_ts = tmp_opt.tstamp_ok;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257#endif
1258 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1259 } else if (!isn) {
1260 struct inet_peer *peer = NULL;
1261
1262 /* VJ's idea. We save last timestamp seen
1263 * from the destination in peer table, when entering
1264 * state TIME-WAIT, and check against it before
1265 * accepting new connection request.
1266 *
1267 * If "isn" is not zero, this request hit alive
1268 * timewait bucket, so that all the necessary checks
1269 * are made in the function processing timewait state.
1270 */
1271 if (tmp_opt.saw_tstamp &&
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07001272 tcp_death_row.sysctl_tw_recycle &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001273 (dst = inet_csk_route_req(sk, req)) != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
1275 peer->v4daddr == saddr) {
James Morris9d729f72007-03-04 16:12:44 -08001276 if (get_seconds() < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 (s32)(peer->tcp_ts - req->ts_recent) >
1278 TCP_PAWS_WINDOW) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001279 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001280 goto drop_and_release;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001281 }
1282 }
1283 /* Kill the following clause, if you dislike this way. */
1284 else if (!sysctl_tcp_syncookies &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001285 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 (sysctl_max_syn_backlog >> 2)) &&
1287 (!peer || !peer->tcp_ts_stamp) &&
1288 (!dst || !dst_metric(dst, RTAX_RTT))) {
1289 /* Without syncookies last quarter of
1290 * backlog is filled with destinations,
1291 * proven to be alive.
1292 * It means that we continue to communicate
1293 * to destinations, already remembered
1294 * to the moment of synflood.
1295 */
Harvey Harrison673d57e2008-10-31 00:53:57 -07001296 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n",
1297 &saddr, ntohs(tcp_hdr(skb)->source));
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001298 goto drop_and_release;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 }
1300
Gerrit Renkera94f7232006-11-10 14:06:49 -08001301 isn = tcp_v4_init_sequence(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 }
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001303 tcp_rsk(req)->snt_isn = isn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001305 if (__tcp_v4_send_synack(sk, req, dst) || want_cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 goto drop_and_free;
1307
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001308 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 return 0;
1310
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001311drop_and_release:
1312 dst_release(dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313drop_and_free:
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001314 reqsk_free(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315drop:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 return 0;
1317}
1318
1319
1320/*
1321 * The three way handshake has completed - we got a valid synack -
1322 * now create the new socket.
1323 */
1324struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001325 struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 struct dst_entry *dst)
1327{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001328 struct inet_request_sock *ireq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 struct inet_sock *newinet;
1330 struct tcp_sock *newtp;
1331 struct sock *newsk;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001332#ifdef CONFIG_TCP_MD5SIG
1333 struct tcp_md5sig_key *key;
1334#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335
1336 if (sk_acceptq_is_full(sk))
1337 goto exit_overflow;
1338
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001339 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 goto exit;
1341
1342 newsk = tcp_create_openreq_child(sk, req, skb);
1343 if (!newsk)
1344 goto exit;
1345
Herbert Xubcd76112006-06-30 13:36:35 -07001346 newsk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -07001347 sk_setup_caps(newsk, dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348
1349 newtp = tcp_sk(newsk);
1350 newinet = inet_sk(newsk);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001351 ireq = inet_rsk(req);
1352 newinet->daddr = ireq->rmt_addr;
1353 newinet->rcv_saddr = ireq->loc_addr;
1354 newinet->saddr = ireq->loc_addr;
1355 newinet->opt = ireq->opt;
1356 ireq->opt = NULL;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001357 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001358 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001359 inet_csk(newsk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 if (newinet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001361 inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 newinet->id = newtp->write_seq ^ jiffies;
1363
John Heffner5d424d52006-03-20 17:53:41 -08001364 tcp_mtup_init(newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 tcp_sync_mss(newsk, dst_mtu(dst));
1366 newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
Tom Quetchenbachf5fff5d2008-09-21 00:21:51 -07001367 if (tcp_sk(sk)->rx_opt.user_mss &&
1368 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1369 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1370
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 tcp_initialize_rcv_mss(newsk);
1372
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001373#ifdef CONFIG_TCP_MD5SIG
1374 /* Copy over the MD5 key from the original socket */
1375 if ((key = tcp_v4_md5_do_lookup(sk, newinet->daddr)) != NULL) {
1376 /*
1377 * We're using one, so create a matching key
1378 * on the newsk structure. If we fail to get
1379 * memory, then we end up not copying the key
1380 * across. Shucks.
1381 */
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -02001382 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1383 if (newkey != NULL)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001384 tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
1385 newkey, key->keylen);
Adam Langley49a72df2008-07-19 00:01:42 -07001386 newsk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001387 }
1388#endif
1389
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001390 __inet_hash_nolisten(newsk);
1391 __inet_inherit_port(sk, newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392
1393 return newsk;
1394
1395exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001396 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001398 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399 dst_release(dst);
1400 return NULL;
1401}
1402
1403static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1404{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001405 struct tcphdr *th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001406 const struct iphdr *iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 struct sock *nsk;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001408 struct request_sock **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 /* Find possible connection requests. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001410 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1411 iph->saddr, iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 if (req)
1413 return tcp_check_req(sk, skb, req, prev);
1414
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001415 nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
Pavel Emelyanovc67499c2008-01-31 05:06:40 -08001416 th->source, iph->daddr, th->dest, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417
1418 if (nsk) {
1419 if (nsk->sk_state != TCP_TIME_WAIT) {
1420 bh_lock_sock(nsk);
1421 return nsk;
1422 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001423 inet_twsk_put(inet_twsk(nsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 return NULL;
1425 }
1426
1427#ifdef CONFIG_SYN_COOKIES
1428 if (!th->rst && !th->syn && th->ack)
1429 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1430#endif
1431 return sk;
1432}
1433
Al Virob51655b2006-11-14 21:40:42 -08001434static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001436 const struct iphdr *iph = ip_hdr(skb);
1437
Patrick McHardy84fa7932006-08-29 16:44:56 -07001438 if (skb->ip_summed == CHECKSUM_COMPLETE) {
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001439 if (!tcp_v4_check(skb->len, iph->saddr,
1440 iph->daddr, skb->csum)) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001441 skb->ip_summed = CHECKSUM_UNNECESSARY;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 return 0;
Herbert Xufb286bb2005-11-10 13:01:24 -08001443 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 }
Herbert Xufb286bb2005-11-10 13:01:24 -08001445
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001446 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
Herbert Xufb286bb2005-11-10 13:01:24 -08001447 skb->len, IPPROTO_TCP, 0);
1448
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 if (skb->len <= 76) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001450 return __skb_checksum_complete(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 }
1452 return 0;
1453}
1454
1455
1456/* The socket must have it's spinlock held when we get
1457 * here.
1458 *
1459 * We have a potential double-lock case here, so even when
1460 * doing backlog processing we use the BH locking scheme.
1461 * This is because we cannot sleep with the original spinlock
1462 * held.
1463 */
1464int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1465{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001466 struct sock *rsk;
1467#ifdef CONFIG_TCP_MD5SIG
1468 /*
1469 * We really want to reject the packet as early as possible
1470 * if:
1471 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1472 * o There is an MD5 option and we're not expecting one
1473 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001474 if (tcp_v4_inbound_md5_hash(sk, skb))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001475 goto discard;
1476#endif
1477
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1479 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001480 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001481 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001482 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001483 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 TCP_CHECK_TIMER(sk);
1485 return 0;
1486 }
1487
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -07001488 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489 goto csum_err;
1490
1491 if (sk->sk_state == TCP_LISTEN) {
1492 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1493 if (!nsk)
1494 goto discard;
1495
1496 if (nsk != sk) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001497 if (tcp_child_process(sk, nsk, skb)) {
1498 rsk = nsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001500 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001501 return 0;
1502 }
1503 }
1504
1505 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001506 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001507 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001509 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 TCP_CHECK_TIMER(sk);
1511 return 0;
1512
1513reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001514 tcp_v4_send_reset(rsk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515discard:
1516 kfree_skb(skb);
1517 /* Be careful here. If this function gets more complicated and
1518 * gcc suffers from register pressure on the x86, sk (in %ebx)
1519 * might be destroyed here. This current version compiles correctly,
1520 * but you have been warned.
1521 */
1522 return 0;
1523
1524csum_err:
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001525 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 goto discard;
1527}
1528
1529/*
1530 * From tcp_input.c
1531 */
1532
1533int tcp_v4_rcv(struct sk_buff *skb)
1534{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001535 const struct iphdr *iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 struct tcphdr *th;
1537 struct sock *sk;
1538 int ret;
Pavel Emelyanova86b1e32008-07-16 20:20:58 -07001539 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540
1541 if (skb->pkt_type != PACKET_HOST)
1542 goto discard_it;
1543
1544 /* Count it even if it's bad */
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001545 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546
1547 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1548 goto discard_it;
1549
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001550 th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551
1552 if (th->doff < sizeof(struct tcphdr) / 4)
1553 goto bad_packet;
1554 if (!pskb_may_pull(skb, th->doff * 4))
1555 goto discard_it;
1556
1557 /* An explanation is required here, I think.
1558 * Packet length and doff are validated by header prediction,
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001559 * provided case of th->doff==0 is eliminated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560 * So, we defer the checks. */
Herbert Xu60476372007-04-09 11:59:39 -07001561 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 goto bad_packet;
1563
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001564 th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001565 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1567 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1568 skb->len - th->doff * 4);
1569 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1570 TCP_SKB_CB(skb)->when = 0;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001571 TCP_SKB_CB(skb)->flags = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572 TCP_SKB_CB(skb)->sacked = 0;
1573
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -07001574 sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001575 if (!sk)
1576 goto no_tcp_socket;
1577
1578process:
1579 if (sk->sk_state == TCP_TIME_WAIT)
1580 goto do_time_wait;
1581
1582 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1583 goto discard_and_relse;
Patrick McHardyb59c2702006-01-06 23:06:10 -08001584 nf_reset(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585
Dmitry Mishinfda9ef52006-08-31 15:28:39 -07001586 if (sk_filter(sk, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 goto discard_and_relse;
1588
1589 skb->dev = NULL;
1590
Ingo Molnarc6366182006-07-03 00:25:13 -07001591 bh_lock_sock_nested(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592 ret = 0;
1593 if (!sock_owned_by_user(sk)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001594#ifdef CONFIG_NET_DMA
1595 struct tcp_sock *tp = tcp_sk(sk);
1596 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1597 tp->ucopy.dma_chan = get_softnet_dma();
1598 if (tp->ucopy.dma_chan)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599 ret = tcp_v4_do_rcv(sk, skb);
Chris Leech1a2449a2006-05-23 18:05:53 -07001600 else
1601#endif
1602 {
1603 if (!tcp_prequeue(sk, skb))
1604 ret = tcp_v4_do_rcv(sk, skb);
1605 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606 } else
1607 sk_add_backlog(sk, skb);
1608 bh_unlock_sock(sk);
1609
1610 sock_put(sk);
1611
1612 return ret;
1613
1614no_tcp_socket:
1615 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1616 goto discard_it;
1617
1618 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1619bad_packet:
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001620 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001621 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001622 tcp_v4_send_reset(NULL, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 }
1624
1625discard_it:
1626 /* Discard frame. */
1627 kfree_skb(skb);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001628 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629
1630discard_and_relse:
1631 sock_put(sk);
1632 goto discard_it;
1633
1634do_time_wait:
1635 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001636 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 goto discard_it;
1638 }
1639
1640 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001641 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001642 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 goto discard_it;
1644 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001645 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646 case TCP_TW_SYN: {
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +09001647 struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
Pavel Emelyanovc67499c2008-01-31 05:06:40 -08001648 &tcp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001649 iph->daddr, th->dest,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001650 inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 if (sk2) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001652 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1653 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654 sk = sk2;
1655 goto process;
1656 }
1657 /* Fall through to ACK */
1658 }
1659 case TCP_TW_ACK:
1660 tcp_v4_timewait_ack(sk, skb);
1661 break;
1662 case TCP_TW_RST:
1663 goto no_tcp_socket;
1664 case TCP_TW_SUCCESS:;
1665 }
1666 goto discard_it;
1667}
1668
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669/* VJ's idea. Save last timestamp seen from this destination
1670 * and hold it at least for normal timewait interval to use for duplicate
1671 * segment detection in subsequent connections, before they enter synchronized
1672 * state.
1673 */
1674
1675int tcp_v4_remember_stamp(struct sock *sk)
1676{
1677 struct inet_sock *inet = inet_sk(sk);
1678 struct tcp_sock *tp = tcp_sk(sk);
1679 struct rtable *rt = (struct rtable *)__sk_dst_get(sk);
1680 struct inet_peer *peer = NULL;
1681 int release_it = 0;
1682
1683 if (!rt || rt->rt_dst != inet->daddr) {
1684 peer = inet_getpeer(inet->daddr, 1);
1685 release_it = 1;
1686 } else {
1687 if (!rt->peer)
1688 rt_bind_peer(rt, 1);
1689 peer = rt->peer;
1690 }
1691
1692 if (peer) {
1693 if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
James Morris9d729f72007-03-04 16:12:44 -08001694 (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695 peer->tcp_ts_stamp <= tp->rx_opt.ts_recent_stamp)) {
1696 peer->tcp_ts_stamp = tp->rx_opt.ts_recent_stamp;
1697 peer->tcp_ts = tp->rx_opt.ts_recent;
1698 }
1699 if (release_it)
1700 inet_putpeer(peer);
1701 return 1;
1702 }
1703
1704 return 0;
1705}
1706
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001707int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001709 struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001710
1711 if (peer) {
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001712 const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
1713
1714 if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 ||
James Morris9d729f72007-03-04 16:12:44 -08001715 (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001716 peer->tcp_ts_stamp <= tcptw->tw_ts_recent_stamp)) {
1717 peer->tcp_ts_stamp = tcptw->tw_ts_recent_stamp;
1718 peer->tcp_ts = tcptw->tw_ts_recent;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 }
1720 inet_putpeer(peer);
1721 return 1;
1722 }
1723
1724 return 0;
1725}
1726
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -08001727struct inet_connection_sock_af_ops ipv4_specific = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001728 .queue_xmit = ip_queue_xmit,
1729 .send_check = tcp_v4_send_check,
1730 .rebuild_header = inet_sk_rebuild_header,
1731 .conn_request = tcp_v4_conn_request,
1732 .syn_recv_sock = tcp_v4_syn_recv_sock,
1733 .remember_stamp = tcp_v4_remember_stamp,
1734 .net_header_len = sizeof(struct iphdr),
1735 .setsockopt = ip_setsockopt,
1736 .getsockopt = ip_getsockopt,
1737 .addr2sockaddr = inet_csk_addr2sockaddr,
1738 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001739 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001740#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001741 .compat_setsockopt = compat_ip_setsockopt,
1742 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001743#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744};
1745
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001746#ifdef CONFIG_TCP_MD5SIG
Andrew Mortonb6332e62006-11-30 19:16:28 -08001747static struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001748 .md5_lookup = tcp_v4_md5_lookup,
Adam Langley49a72df2008-07-19 00:01:42 -07001749 .calc_md5_hash = tcp_v4_md5_hash_skb,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001750 .md5_add = tcp_v4_md5_add_func,
1751 .md5_parse = tcp_v4_parse_md5_keys,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001752};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001753#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001754
Linus Torvalds1da177e2005-04-16 15:20:36 -07001755/* NOTE: A lot of things set to zero explicitly by call to
1756 * sk_alloc() so need not be done here.
1757 */
1758static int tcp_v4_init_sock(struct sock *sk)
1759{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001760 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761 struct tcp_sock *tp = tcp_sk(sk);
1762
1763 skb_queue_head_init(&tp->out_of_order_queue);
1764 tcp_init_xmit_timers(sk);
1765 tcp_prequeue_init(tp);
1766
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001767 icsk->icsk_rto = TCP_TIMEOUT_INIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 tp->mdev = TCP_TIMEOUT_INIT;
1769
1770 /* So many TCP implementations out there (incorrectly) count the
1771 * initial SYN frame in their delayed-ACK and congestion control
1772 * algorithms that we must have the following bandaid to talk
1773 * efficiently to them. -DaveM
1774 */
1775 tp->snd_cwnd = 2;
1776
1777 /* See draft-stevens-tcpca-spec-01 for discussion of the
1778 * initialization of these values.
1779 */
1780 tp->snd_ssthresh = 0x7fffffff; /* Infinity */
1781 tp->snd_cwnd_clamp = ~0;
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001782 tp->mss_cache = 536;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783
1784 tp->reordering = sysctl_tcp_reordering;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001785 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786
1787 sk->sk_state = TCP_CLOSE;
1788
1789 sk->sk_write_space = sk_stream_write_space;
1790 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1791
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -08001792 icsk->icsk_af_ops = &ipv4_specific;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001793 icsk->icsk_sync_mss = tcp_sync_mss;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001794#ifdef CONFIG_TCP_MD5SIG
1795 tp->af_specific = &tcp_sock_ipv4_specific;
1796#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797
1798 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1799 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1800
Herbert Xueb4dea52008-12-29 23:04:08 -08001801 local_bh_disable();
Eric Dumazet17483762008-11-25 21:16:35 -08001802 percpu_counter_inc(&tcp_sockets_allocated);
Herbert Xueb4dea52008-12-29 23:04:08 -08001803 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804
1805 return 0;
1806}
1807
Brian Haley7d06b2e2008-06-14 17:04:49 -07001808void tcp_v4_destroy_sock(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001809{
1810 struct tcp_sock *tp = tcp_sk(sk);
1811
1812 tcp_clear_xmit_timers(sk);
1813
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001814 tcp_cleanup_congestion_control(sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07001815
Linus Torvalds1da177e2005-04-16 15:20:36 -07001816 /* Cleanup up the write buffer. */
David S. Millerfe067e82007-03-07 12:12:44 -08001817 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818
1819 /* Cleans up our, hopefully empty, out_of_order_queue. */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001820 __skb_queue_purge(&tp->out_of_order_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001822#ifdef CONFIG_TCP_MD5SIG
1823 /* Clean up the MD5 key list, if any */
1824 if (tp->md5sig_info) {
1825 tcp_v4_clear_md5_list(sk);
1826 kfree(tp->md5sig_info);
1827 tp->md5sig_info = NULL;
1828 }
1829#endif
1830
Chris Leech1a2449a2006-05-23 18:05:53 -07001831#ifdef CONFIG_NET_DMA
1832 /* Cleans up our sk_async_wait_queue */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001833 __skb_queue_purge(&sk->sk_async_wait_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001834#endif
1835
Linus Torvalds1da177e2005-04-16 15:20:36 -07001836 /* Clean prequeue, it must be empty really */
1837 __skb_queue_purge(&tp->ucopy.prequeue);
1838
1839 /* Clean up a referenced TCP bind bucket. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001840 if (inet_csk(sk)->icsk_bind_hash)
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001841 inet_put_port(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001842
1843 /*
1844 * If sendmsg cached page exists, toss it.
1845 */
1846 if (sk->sk_sndmsg_page) {
1847 __free_page(sk->sk_sndmsg_page);
1848 sk->sk_sndmsg_page = NULL;
1849 }
1850
Eric Dumazet17483762008-11-25 21:16:35 -08001851 percpu_counter_dec(&tcp_sockets_allocated);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852}
1853
1854EXPORT_SYMBOL(tcp_v4_destroy_sock);
1855
1856#ifdef CONFIG_PROC_FS
1857/* Proc filesystem TCP sock list dumping. */
1858
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001859static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001861 return hlist_nulls_empty(head) ? NULL :
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001862 list_entry(head->first, struct inet_timewait_sock, tw_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001863}
1864
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001865static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001866{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001867 return !is_a_nulls(tw->tw_node.next) ?
1868 hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869}
1870
1871static void *listening_get_next(struct seq_file *seq, void *cur)
1872{
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001873 struct inet_connection_sock *icsk;
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001874 struct hlist_nulls_node *node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875 struct sock *sk = cur;
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001876 struct inet_listen_hashbucket *ilb;
Jianjun Kong5799de02008-11-03 02:49:10 -08001877 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07001878 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879
1880 if (!sk) {
1881 st->bucket = 0;
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001882 ilb = &tcp_hashinfo.listening_hash[0];
1883 spin_lock_bh(&ilb->lock);
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001884 sk = sk_nulls_head(&ilb->head);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 goto get_sk;
1886 }
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001887 ilb = &tcp_hashinfo.listening_hash[st->bucket];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 ++st->num;
1889
1890 if (st->state == TCP_SEQ_STATE_OPENREQ) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001891 struct request_sock *req = cur;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001893 icsk = inet_csk(st->syn_wait_sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894 req = req->dl_next;
1895 while (1) {
1896 while (req) {
Daniel Lezcanobdccc4c2008-07-19 00:15:13 -07001897 if (req->rsk_ops->family == st->family) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898 cur = req;
1899 goto out;
1900 }
1901 req = req->dl_next;
1902 }
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001903 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001904 break;
1905get_req:
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001906 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 }
1908 sk = sk_next(st->syn_wait_sk);
1909 st->state = TCP_SEQ_STATE_LISTENING;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001910 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 } else {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001912 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001913 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
1914 if (reqsk_queue_len(&icsk->icsk_accept_queue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001915 goto start_req;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001916 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917 sk = sk_next(sk);
1918 }
1919get_sk:
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001920 sk_nulls_for_each_from(sk, node) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09001921 if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001922 cur = sk;
1923 goto out;
1924 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001925 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001926 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
1927 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001928start_req:
1929 st->uid = sock_i_uid(sk);
1930 st->syn_wait_sk = sk;
1931 st->state = TCP_SEQ_STATE_OPENREQ;
1932 st->sbucket = 0;
1933 goto get_req;
1934 }
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001935 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 }
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001937 spin_unlock_bh(&ilb->lock);
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07001938 if (++st->bucket < INET_LHTABLE_SIZE) {
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001939 ilb = &tcp_hashinfo.listening_hash[st->bucket];
1940 spin_lock_bh(&ilb->lock);
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001941 sk = sk_nulls_head(&ilb->head);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942 goto get_sk;
1943 }
1944 cur = NULL;
1945out:
1946 return cur;
1947}
1948
1949static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
1950{
1951 void *rc = listening_get_next(seq, NULL);
1952
1953 while (rc && *pos) {
1954 rc = listening_get_next(seq, rc);
1955 --*pos;
1956 }
1957 return rc;
1958}
1959
Andi Kleen6eac5602008-08-28 01:08:02 -07001960static inline int empty_bucket(struct tcp_iter_state *st)
1961{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001962 return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
1963 hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
Andi Kleen6eac5602008-08-28 01:08:02 -07001964}
1965
Linus Torvalds1da177e2005-04-16 15:20:36 -07001966static void *established_get_first(struct seq_file *seq)
1967{
Jianjun Kong5799de02008-11-03 02:49:10 -08001968 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07001969 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970 void *rc = NULL;
1971
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07001972 for (st->bucket = 0; st->bucket < tcp_hashinfo.ehash_size; ++st->bucket) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973 struct sock *sk;
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001974 struct hlist_nulls_node *node;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001975 struct inet_timewait_sock *tw;
Eric Dumazet9db66bd2008-11-20 20:39:09 -08001976 spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977
Andi Kleen6eac5602008-08-28 01:08:02 -07001978 /* Lockless fast path for the common case of empty buckets */
1979 if (empty_bucket(st))
1980 continue;
1981
Eric Dumazet9db66bd2008-11-20 20:39:09 -08001982 spin_lock_bh(lock);
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001983 sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
Daniel Lezcanof40c8172008-03-21 04:13:54 -07001984 if (sk->sk_family != st->family ||
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09001985 !net_eq(sock_net(sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 continue;
1987 }
1988 rc = sk;
1989 goto out;
1990 }
1991 st->state = TCP_SEQ_STATE_TIME_WAIT;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001992 inet_twsk_for_each(tw, node,
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08001993 &tcp_hashinfo.ehash[st->bucket].twchain) {
Pavel Emelyanov28518fc2008-03-21 15:52:00 -07001994 if (tw->tw_family != st->family ||
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09001995 !net_eq(twsk_net(tw), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996 continue;
1997 }
1998 rc = tw;
1999 goto out;
2000 }
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002001 spin_unlock_bh(lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002 st->state = TCP_SEQ_STATE_ESTABLISHED;
2003 }
2004out:
2005 return rc;
2006}
2007
2008static void *established_get_next(struct seq_file *seq, void *cur)
2009{
2010 struct sock *sk = cur;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002011 struct inet_timewait_sock *tw;
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002012 struct hlist_nulls_node *node;
Jianjun Kong5799de02008-11-03 02:49:10 -08002013 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07002014 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015
2016 ++st->num;
2017
2018 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2019 tw = cur;
2020 tw = tw_next(tw);
2021get_tw:
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002022 while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023 tw = tw_next(tw);
2024 }
2025 if (tw) {
2026 cur = tw;
2027 goto out;
2028 }
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002029 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030 st->state = TCP_SEQ_STATE_ESTABLISHED;
2031
Andi Kleen6eac5602008-08-28 01:08:02 -07002032 /* Look for next non empty bucket */
2033 while (++st->bucket < tcp_hashinfo.ehash_size &&
2034 empty_bucket(st))
2035 ;
2036 if (st->bucket >= tcp_hashinfo.ehash_size)
2037 return NULL;
2038
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002039 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002040 sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002041 } else
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002042 sk = sk_nulls_next(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002043
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002044 sk_nulls_for_each_from(sk, node) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002045 if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 goto found;
2047 }
2048
2049 st->state = TCP_SEQ_STATE_TIME_WAIT;
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002050 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002051 goto get_tw;
2052found:
2053 cur = sk;
2054out:
2055 return cur;
2056}
2057
2058static void *established_get_idx(struct seq_file *seq, loff_t pos)
2059{
2060 void *rc = established_get_first(seq);
2061
2062 while (rc && pos) {
2063 rc = established_get_next(seq, rc);
2064 --pos;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002065 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066 return rc;
2067}
2068
2069static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2070{
2071 void *rc;
Jianjun Kong5799de02008-11-03 02:49:10 -08002072 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074 st->state = TCP_SEQ_STATE_LISTENING;
2075 rc = listening_get_idx(seq, &pos);
2076
2077 if (!rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002078 st->state = TCP_SEQ_STATE_ESTABLISHED;
2079 rc = established_get_idx(seq, pos);
2080 }
2081
2082 return rc;
2083}
2084
2085static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2086{
Jianjun Kong5799de02008-11-03 02:49:10 -08002087 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088 st->state = TCP_SEQ_STATE_LISTENING;
2089 st->num = 0;
2090 return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2091}
2092
2093static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2094{
2095 void *rc = NULL;
Jianjun Kong5799de02008-11-03 02:49:10 -08002096 struct tcp_iter_state *st;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002097
2098 if (v == SEQ_START_TOKEN) {
2099 rc = tcp_get_idx(seq, 0);
2100 goto out;
2101 }
2102 st = seq->private;
2103
2104 switch (st->state) {
2105 case TCP_SEQ_STATE_OPENREQ:
2106 case TCP_SEQ_STATE_LISTENING:
2107 rc = listening_get_next(seq, v);
2108 if (!rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 st->state = TCP_SEQ_STATE_ESTABLISHED;
2110 rc = established_get_first(seq);
2111 }
2112 break;
2113 case TCP_SEQ_STATE_ESTABLISHED:
2114 case TCP_SEQ_STATE_TIME_WAIT:
2115 rc = established_get_next(seq, v);
2116 break;
2117 }
2118out:
2119 ++*pos;
2120 return rc;
2121}
2122
2123static void tcp_seq_stop(struct seq_file *seq, void *v)
2124{
Jianjun Kong5799de02008-11-03 02:49:10 -08002125 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002126
2127 switch (st->state) {
2128 case TCP_SEQ_STATE_OPENREQ:
2129 if (v) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002130 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2131 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002132 }
2133 case TCP_SEQ_STATE_LISTENING:
2134 if (v != SEQ_START_TOKEN)
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002135 spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136 break;
2137 case TCP_SEQ_STATE_TIME_WAIT:
2138 case TCP_SEQ_STATE_ESTABLISHED:
2139 if (v)
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002140 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002141 break;
2142 }
2143}
2144
2145static int tcp_seq_open(struct inode *inode, struct file *file)
2146{
2147 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148 struct tcp_iter_state *s;
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002149 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002150
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002151 err = seq_open_net(inode, file, &afinfo->seq_ops,
2152 sizeof(struct tcp_iter_state));
2153 if (err < 0)
2154 return err;
Daniel Lezcanof40c8172008-03-21 04:13:54 -07002155
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002156 s = ((struct seq_file *)file->private_data)->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002157 s->family = afinfo->family;
Daniel Lezcanof40c8172008-03-21 04:13:54 -07002158 return 0;
2159}
2160
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002161int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162{
2163 int rc = 0;
2164 struct proc_dir_entry *p;
2165
Denis V. Lunev68fcadd2008-04-13 22:13:30 -07002166 afinfo->seq_fops.open = tcp_seq_open;
2167 afinfo->seq_fops.read = seq_read;
2168 afinfo->seq_fops.llseek = seq_lseek;
2169 afinfo->seq_fops.release = seq_release_net;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002170
Denis V. Lunev9427c4b2008-04-13 22:12:13 -07002171 afinfo->seq_ops.start = tcp_seq_start;
2172 afinfo->seq_ops.next = tcp_seq_next;
2173 afinfo->seq_ops.stop = tcp_seq_stop;
2174
Denis V. Lunev84841c32008-05-02 04:10:08 -07002175 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2176 &afinfo->seq_fops, afinfo);
2177 if (!p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002178 rc = -ENOMEM;
2179 return rc;
2180}
2181
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002182void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183{
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002184 proc_net_remove(net, afinfo->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185}
2186
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002187static void get_openreq4(struct sock *sk, struct request_sock *req,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002188 struct seq_file *f, int i, int uid, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002189{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002190 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191 int ttd = req->expires - jiffies;
2192
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002193 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2194 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002195 i,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002196 ireq->loc_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197 ntohs(inet_sk(sk)->sport),
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002198 ireq->rmt_addr,
2199 ntohs(ireq->rmt_port),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 TCP_SYN_RECV,
2201 0, 0, /* could print option size, but that is af dependent. */
2202 1, /* timers active (only the expire timer) */
2203 jiffies_to_clock_t(ttd),
2204 req->retrans,
2205 uid,
2206 0, /* non standard timer */
2207 0, /* open_requests have no inode */
2208 atomic_read(&sk->sk_refcnt),
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002209 req,
2210 len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002211}
2212
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002213static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002214{
2215 int timer_active;
2216 unsigned long timer_expires;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002217 struct tcp_sock *tp = tcp_sk(sk);
2218 const struct inet_connection_sock *icsk = inet_csk(sk);
2219 struct inet_sock *inet = inet_sk(sk);
Al Viro714e85b2006-11-14 20:51:49 -08002220 __be32 dest = inet->daddr;
2221 __be32 src = inet->rcv_saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222 __u16 destp = ntohs(inet->dport);
2223 __u16 srcp = ntohs(inet->sport);
2224
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002225 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002226 timer_active = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002227 timer_expires = icsk->icsk_timeout;
2228 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002229 timer_active = 4;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002230 timer_expires = icsk->icsk_timeout;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002231 } else if (timer_pending(&sk->sk_timer)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002232 timer_active = 2;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002233 timer_expires = sk->sk_timer.expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002234 } else {
2235 timer_active = 0;
2236 timer_expires = jiffies;
2237 }
2238
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002239 seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
Stephen Hemminger7be87352008-06-27 20:00:19 -07002240 "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002241 i, src, srcp, dest, destp, sk->sk_state,
Sridhar Samudrala47da8ee2006-06-27 13:29:00 -07002242 tp->write_seq - tp->snd_una,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002243 sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog :
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002244 (tp->rcv_nxt - tp->copied_seq),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 timer_active,
2246 jiffies_to_clock_t(timer_expires - jiffies),
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002247 icsk->icsk_retransmits,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002248 sock_i_uid(sk),
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002249 icsk->icsk_probes_out,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002250 sock_i_ino(sk),
2251 atomic_read(&sk->sk_refcnt), sk,
Stephen Hemminger7be87352008-06-27 20:00:19 -07002252 jiffies_to_clock_t(icsk->icsk_rto),
2253 jiffies_to_clock_t(icsk->icsk_ack.ato),
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002254 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002255 tp->snd_cwnd,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002256 tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh,
2257 len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258}
2259
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002260static void get_timewait4_sock(struct inet_timewait_sock *tw,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002261 struct seq_file *f, int i, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002262{
Al Viro23f33c22006-09-27 18:43:50 -07002263 __be32 dest, src;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264 __u16 destp, srcp;
2265 int ttd = tw->tw_ttd - jiffies;
2266
2267 if (ttd < 0)
2268 ttd = 0;
2269
2270 dest = tw->tw_daddr;
2271 src = tw->tw_rcv_saddr;
2272 destp = ntohs(tw->tw_dport);
2273 srcp = ntohs(tw->tw_sport);
2274
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002275 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2276 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002277 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2278 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002279 atomic_read(&tw->tw_refcnt), tw, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280}
2281
2282#define TMPSZ 150
2283
2284static int tcp4_seq_show(struct seq_file *seq, void *v)
2285{
Jianjun Kong5799de02008-11-03 02:49:10 -08002286 struct tcp_iter_state *st;
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002287 int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002288
2289 if (v == SEQ_START_TOKEN) {
2290 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2291 " sl local_address rem_address st tx_queue "
2292 "rx_queue tr tm->when retrnsmt uid timeout "
2293 "inode");
2294 goto out;
2295 }
2296 st = seq->private;
2297
2298 switch (st->state) {
2299 case TCP_SEQ_STATE_LISTENING:
2300 case TCP_SEQ_STATE_ESTABLISHED:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002301 get_tcp4_sock(v, seq, st->num, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002302 break;
2303 case TCP_SEQ_STATE_OPENREQ:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002304 get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 break;
2306 case TCP_SEQ_STATE_TIME_WAIT:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002307 get_timewait4_sock(v, seq, st->num, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308 break;
2309 }
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002310 seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002311out:
2312 return 0;
2313}
2314
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315static struct tcp_seq_afinfo tcp4_seq_afinfo = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316 .name = "tcp",
2317 .family = AF_INET,
Denis V. Lunev5f4472c2008-04-13 22:13:53 -07002318 .seq_fops = {
2319 .owner = THIS_MODULE,
2320 },
Denis V. Lunev9427c4b2008-04-13 22:12:13 -07002321 .seq_ops = {
2322 .show = tcp4_seq_show,
2323 },
Linus Torvalds1da177e2005-04-16 15:20:36 -07002324};
2325
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002326static int tcp4_proc_init_net(struct net *net)
2327{
2328 return tcp_proc_register(net, &tcp4_seq_afinfo);
2329}
2330
2331static void tcp4_proc_exit_net(struct net *net)
2332{
2333 tcp_proc_unregister(net, &tcp4_seq_afinfo);
2334}
2335
2336static struct pernet_operations tcp4_net_ops = {
2337 .init = tcp4_proc_init_net,
2338 .exit = tcp4_proc_exit_net,
2339};
2340
Linus Torvalds1da177e2005-04-16 15:20:36 -07002341int __init tcp4_proc_init(void)
2342{
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002343 return register_pernet_subsys(&tcp4_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344}
2345
2346void tcp4_proc_exit(void)
2347{
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002348 unregister_pernet_subsys(&tcp4_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002349}
2350#endif /* CONFIG_PROC_FS */
2351
Herbert Xubf296b12008-12-15 23:43:36 -08002352struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2353{
2354 struct iphdr *iph = ip_hdr(skb);
2355
2356 switch (skb->ip_summed) {
2357 case CHECKSUM_COMPLETE:
2358 if (!tcp_v4_check(skb->len, iph->saddr, iph->daddr,
2359 skb->csum)) {
2360 skb->ip_summed = CHECKSUM_UNNECESSARY;
2361 break;
2362 }
2363
2364 /* fall through */
2365 case CHECKSUM_NONE:
2366 NAPI_GRO_CB(skb)->flush = 1;
2367 return NULL;
2368 }
2369
2370 return tcp_gro_receive(head, skb);
2371}
2372EXPORT_SYMBOL(tcp4_gro_receive);
2373
2374int tcp4_gro_complete(struct sk_buff *skb)
2375{
2376 struct iphdr *iph = ip_hdr(skb);
2377 struct tcphdr *th = tcp_hdr(skb);
2378
2379 th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
2380 iph->saddr, iph->daddr, 0);
2381 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
2382
2383 return tcp_gro_complete(skb);
2384}
2385EXPORT_SYMBOL(tcp4_gro_complete);
2386
Linus Torvalds1da177e2005-04-16 15:20:36 -07002387struct proto tcp_prot = {
2388 .name = "TCP",
2389 .owner = THIS_MODULE,
2390 .close = tcp_close,
2391 .connect = tcp_v4_connect,
2392 .disconnect = tcp_disconnect,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002393 .accept = inet_csk_accept,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002394 .ioctl = tcp_ioctl,
2395 .init = tcp_v4_init_sock,
2396 .destroy = tcp_v4_destroy_sock,
2397 .shutdown = tcp_shutdown,
2398 .setsockopt = tcp_setsockopt,
2399 .getsockopt = tcp_getsockopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002400 .recvmsg = tcp_recvmsg,
2401 .backlog_rcv = tcp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08002402 .hash = inet_hash,
2403 .unhash = inet_unhash,
2404 .get_port = inet_csk_get_port,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002405 .enter_memory_pressure = tcp_enter_memory_pressure,
2406 .sockets_allocated = &tcp_sockets_allocated,
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002407 .orphan_count = &tcp_orphan_count,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408 .memory_allocated = &tcp_memory_allocated,
2409 .memory_pressure = &tcp_memory_pressure,
2410 .sysctl_mem = sysctl_tcp_mem,
2411 .sysctl_wmem = sysctl_tcp_wmem,
2412 .sysctl_rmem = sysctl_tcp_rmem,
2413 .max_header = MAX_TCP_HEADER,
2414 .obj_size = sizeof(struct tcp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002415 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08002416 .twsk_prot = &tcp_timewait_sock_ops,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002417 .rsk_prot = &tcp_request_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -07002418 .h.hashinfo = &tcp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002419#ifdef CONFIG_COMPAT
2420 .compat_setsockopt = compat_tcp_setsockopt,
2421 .compat_getsockopt = compat_tcp_getsockopt,
2422#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002423};
2424
Denis V. Lunev046ee902008-04-03 14:31:33 -07002425
2426static int __net_init tcp_sk_init(struct net *net)
2427{
2428 return inet_ctl_sock_create(&net->ipv4.tcp_sock,
2429 PF_INET, SOCK_RAW, IPPROTO_TCP, net);
2430}
2431
2432static void __net_exit tcp_sk_exit(struct net *net)
2433{
2434 inet_ctl_sock_destroy(net->ipv4.tcp_sock);
Daniel Lezcanod3154922008-09-08 13:17:27 -07002435 inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET);
Denis V. Lunev046ee902008-04-03 14:31:33 -07002436}
2437
2438static struct pernet_operations __net_initdata tcp_sk_ops = {
2439 .init = tcp_sk_init,
2440 .exit = tcp_sk_exit,
2441};
2442
Denis V. Lunev9b0f9762008-02-29 11:13:15 -08002443void __init tcp_v4_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002444{
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002445 inet_hashinfo_init(&tcp_hashinfo);
Denis V. Lunev046ee902008-04-03 14:31:33 -07002446 if (register_pernet_device(&tcp_sk_ops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002447 panic("Failed to create the TCP control socket.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002448}
2449
2450EXPORT_SYMBOL(ipv4_specific);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002451EXPORT_SYMBOL(tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002452EXPORT_SYMBOL(tcp_prot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002453EXPORT_SYMBOL(tcp_v4_conn_request);
2454EXPORT_SYMBOL(tcp_v4_connect);
2455EXPORT_SYMBOL(tcp_v4_do_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002456EXPORT_SYMBOL(tcp_v4_remember_stamp);
2457EXPORT_SYMBOL(tcp_v4_send_check);
2458EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
2459
2460#ifdef CONFIG_PROC_FS
2461EXPORT_SYMBOL(tcp_proc_register);
2462EXPORT_SYMBOL(tcp_proc_unregister);
2463#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002464EXPORT_SYMBOL(sysctl_tcp_low_latency);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465