blob: 8855e640e95845d260f4e572d1ca6d35d4d706aa [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 *
8 * Version: $Id: tcp_ipv4.c,v 1.240 2002/02/01 22:01:04 davem Exp $
9 *
10 * IPv4 specific functions
11 *
12 *
13 * code split from:
14 * linux/ipv4/tcp.c
15 * linux/ipv4/tcp_input.c
16 * linux/ipv4/tcp_output.c
17 *
18 * See tcp.c for author information
19 *
20 * This program is free software; you can redistribute it and/or
21 * modify it under the terms of the GNU General Public License
22 * as published by the Free Software Foundation; either version
23 * 2 of the License, or (at your option) any later version.
24 */
25
26/*
27 * Changes:
28 * David S. Miller : New socket lookup architecture.
29 * This code is dedicated to John Dyson.
30 * David S. Miller : Change semantics of established hash,
31 * half is devoted to TIME_WAIT sockets
32 * and the rest go in the other half.
33 * Andi Kleen : Add support for syncookies and fixed
34 * some bugs: ip options weren't passed to
35 * the TCP layer, missed a check for an
36 * ACK bit.
37 * Andi Kleen : Implemented fast path mtu discovery.
38 * Fixed many serious bugs in the
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070039 * request_sock handling and moved
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 * most of it into the af independent code.
41 * Added tail drop and some other bugfixes.
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -080042 * Added new listen semantics.
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 * Mike McLagan : Routing by source
44 * Juan Jose Ciarlante: ip_dynaddr bits
45 * Andi Kleen: various fixes.
46 * Vitaly E. Lavrov : Transparent proxy revived after year
47 * coma.
48 * Andi Kleen : Fix new listen.
49 * Andi Kleen : Fix accept error reporting.
50 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
51 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
52 * a single port at the same time.
53 */
54
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56#include <linux/types.h>
57#include <linux/fcntl.h>
58#include <linux/module.h>
59#include <linux/random.h>
60#include <linux/cache.h>
61#include <linux/jhash.h>
62#include <linux/init.h>
63#include <linux/times.h>
64
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020065#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#include <net/icmp.h>
Arnaldo Carvalho de Melo304a1612005-08-09 19:59:20 -070067#include <net/inet_hashtables.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#include <net/tcp.h>
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -030069#include <net/transp_v6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#include <net/ipv6.h>
71#include <net/inet_common.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080072#include <net/timewait_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#include <net/xfrm.h>
Chris Leech1a2449a2006-05-23 18:05:53 -070074#include <net/netdma.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76#include <linux/inet.h>
77#include <linux/ipv6.h>
78#include <linux/stddef.h>
79#include <linux/proc_fs.h>
80#include <linux/seq_file.h>
81
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080082#include <linux/crypto.h>
83#include <linux/scatterlist.h>
84
Brian Haleyab32ea52006-09-22 14:15:41 -070085int sysctl_tcp_tw_reuse __read_mostly;
86int sysctl_tcp_low_latency __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88/* Check TCP sequence numbers in ICMP packets. */
89#define ICMP_MIN_LENGTH 8
90
91/* Socket used for sending RSTs */
Eric Dumazet4103f8c2007-03-27 13:58:31 -070092static struct socket *tcp_socket __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -080094void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080096#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -020097static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
98 __be32 addr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080099static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200100 __be32 saddr, __be32 daddr,
101 struct tcphdr *th, int protocol,
102 int tcplen);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800103#endif
104
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -0700105struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200106 .lhash_lock = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
107 .lhash_users = ATOMIC_INIT(0),
108 .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109};
110
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700111static int tcp_v4_get_port(struct sock *sk, unsigned short snum)
112{
Arnaldo Carvalho de Melo971af182005-12-13 23:14:47 -0800113 return inet_csk_get_port(&tcp_hashinfo, sk, snum,
114 inet_csk_bind_conflict);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700115}
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117static void tcp_v4_hash(struct sock *sk)
118{
Arnaldo Carvalho de Melo81849d12005-08-09 20:08:50 -0700119 inet_hash(&tcp_hashinfo, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120}
121
122void tcp_unhash(struct sock *sk)
123{
Arnaldo Carvalho de Melo81849d12005-08-09 20:08:50 -0700124 inet_unhash(&tcp_hashinfo, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125}
126
Gerrit Renkera94f7232006-11-10 14:06:49 -0800127static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700129 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
130 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700131 tcp_hdr(skb)->dest,
132 tcp_hdr(skb)->source);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133}
134
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800135int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
136{
137 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
138 struct tcp_sock *tp = tcp_sk(sk);
139
140 /* With PAWS, it is safe from the viewpoint
141 of data integrity. Even without PAWS it is safe provided sequence
142 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
143
144 Actually, the idea is close to VJ's one, only timestamp cache is
145 held not per host, but per port pair and TW bucket is used as state
146 holder.
147
148 If TW bucket has been already destroyed we fall back to VJ's scheme
149 and use initial timestamp retrieved from peer table.
150 */
151 if (tcptw->tw_ts_recent_stamp &&
152 (twp == NULL || (sysctl_tcp_tw_reuse &&
James Morris9d729f72007-03-04 16:12:44 -0800153 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800154 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
155 if (tp->write_seq == 0)
156 tp->write_seq = 1;
157 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
158 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
159 sock_hold(sktw);
160 return 1;
161 }
162
163 return 0;
164}
165
166EXPORT_SYMBOL_GPL(tcp_twsk_unique);
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168/* This will initiate an outgoing connection. */
169int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
170{
171 struct inet_sock *inet = inet_sk(sk);
172 struct tcp_sock *tp = tcp_sk(sk);
173 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
174 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -0700175 __be32 daddr, nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 int tmp;
177 int err;
178
179 if (addr_len < sizeof(struct sockaddr_in))
180 return -EINVAL;
181
182 if (usin->sin_family != AF_INET)
183 return -EAFNOSUPPORT;
184
185 nexthop = daddr = usin->sin_addr.s_addr;
186 if (inet->opt && inet->opt->srr) {
187 if (!daddr)
188 return -EINVAL;
189 nexthop = inet->opt->faddr;
190 }
191
192 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
193 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
194 IPPROTO_TCP,
David S. Miller8eb90862007-02-08 02:09:21 -0800195 inet->sport, usin->sin_port, sk, 1);
Wei Dong584bdf82007-05-31 22:49:28 -0700196 if (tmp < 0) {
197 if (tmp == -ENETUNREACH)
198 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 return tmp;
Wei Dong584bdf82007-05-31 22:49:28 -0700200 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
203 ip_rt_put(rt);
204 return -ENETUNREACH;
205 }
206
207 if (!inet->opt || !inet->opt->srr)
208 daddr = rt->rt_dst;
209
210 if (!inet->saddr)
211 inet->saddr = rt->rt_src;
212 inet->rcv_saddr = inet->saddr;
213
214 if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
215 /* Reset inherited state */
216 tp->rx_opt.ts_recent = 0;
217 tp->rx_opt.ts_recent_stamp = 0;
218 tp->write_seq = 0;
219 }
220
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -0700221 if (tcp_death_row.sysctl_tw_recycle &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
223 struct inet_peer *peer = rt_get_peer(rt);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200224 /*
225 * VJ's idea. We save last timestamp seen from
226 * the destination in peer table, when entering state
227 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
228 * when trying new connection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200230 if (peer != NULL &&
James Morris9d729f72007-03-04 16:12:44 -0800231 peer->tcp_ts_stamp + TCP_PAWS_MSL >= get_seconds()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
233 tp->rx_opt.ts_recent = peer->tcp_ts;
234 }
235 }
236
237 inet->dport = usin->sin_port;
238 inet->daddr = daddr;
239
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800240 inet_csk(sk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 if (inet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800242 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 tp->rx_opt.mss_clamp = 536;
245
246 /* Socket identity is still unknown (sport may be zero).
247 * However we set state to SYN-SENT and not releasing socket
248 * lock select source port, enter ourselves into the hash tables and
249 * complete initialization after this.
250 */
251 tcp_set_state(sk, TCP_SYN_SENT);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800252 err = inet_hash_connect(&tcp_death_row, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 if (err)
254 goto failure;
255
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200256 err = ip_route_newports(&rt, IPPROTO_TCP,
257 inet->sport, inet->dport, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 if (err)
259 goto failure;
260
261 /* OK, now commit destination to socket. */
Herbert Xubcd76112006-06-30 13:36:35 -0700262 sk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -0700263 sk_setup_caps(sk, &rt->u.dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265 if (!tp->write_seq)
266 tp->write_seq = secure_tcp_sequence_number(inet->saddr,
267 inet->daddr,
268 inet->sport,
269 usin->sin_port);
270
271 inet->id = tp->write_seq ^ jiffies;
272
273 err = tcp_connect(sk);
274 rt = NULL;
275 if (err)
276 goto failure;
277
278 return 0;
279
280failure:
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200281 /*
282 * This unhashes the socket and releases the local port,
283 * if necessary.
284 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 tcp_set_state(sk, TCP_CLOSE);
286 ip_rt_put(rt);
287 sk->sk_route_caps = 0;
288 inet->dport = 0;
289 return err;
290}
291
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292/*
293 * This routine does path mtu discovery as defined in RFC1191.
294 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800295static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296{
297 struct dst_entry *dst;
298 struct inet_sock *inet = inet_sk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
300 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
301 * send out by Linux are always <576bytes so they should go through
302 * unfragmented).
303 */
304 if (sk->sk_state == TCP_LISTEN)
305 return;
306
307 /* We don't check in the destentry if pmtu discovery is forbidden
308 * on this route. We just assume that no packet_to_big packets
309 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900310 * There is a small race when the user changes this flag in the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 * route, but I think that's acceptable.
312 */
313 if ((dst = __sk_dst_check(sk, 0)) == NULL)
314 return;
315
316 dst->ops->update_pmtu(dst, mtu);
317
318 /* Something is about to be wrong... Remember soft error
319 * for the case, if this connection will not able to recover.
320 */
321 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
322 sk->sk_err_soft = EMSGSIZE;
323
324 mtu = dst_mtu(dst);
325
326 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800327 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 tcp_sync_mss(sk, mtu);
329
330 /* Resend the TCP packet because it's
331 * clear that the old packet has been
332 * dropped. This is the new "fast" path mtu
333 * discovery.
334 */
335 tcp_simple_retransmit(sk);
336 } /* else let the usual retransmit timer handle it */
337}
338
339/*
340 * This routine is called by the ICMP module when it gets some
341 * sort of error condition. If err < 0 then the socket should
342 * be closed and the error returned to the user. If err > 0
343 * it's just the icmp type << 8 | icmp code. After adjustment
344 * header points to the first 8 bytes of the tcp header. We need
345 * to find the appropriate port.
346 *
347 * The locking strategy used here is very "optimistic". When
348 * someone else accesses the socket the ICMP is just dropped
349 * and for some paths there is no check at all.
350 * A more general error queue to queue errors for later handling
351 * is probably better.
352 *
353 */
354
355void tcp_v4_err(struct sk_buff *skb, u32 info)
356{
357 struct iphdr *iph = (struct iphdr *)skb->data;
358 struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
359 struct tcp_sock *tp;
360 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300361 const int type = icmp_hdr(skb)->type;
362 const int code = icmp_hdr(skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 struct sock *sk;
364 __u32 seq;
365 int err;
366
367 if (skb->len < (iph->ihl << 2) + 8) {
368 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
369 return;
370 }
371
Arnaldo Carvalho de Meloe48c4142005-08-09 20:09:46 -0700372 sk = inet_lookup(&tcp_hashinfo, iph->daddr, th->dest, iph->saddr,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700373 th->source, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 if (!sk) {
375 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
376 return;
377 }
378 if (sk->sk_state == TCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700379 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 return;
381 }
382
383 bh_lock_sock(sk);
384 /* If too many ICMPs get dropped on busy
385 * servers this needs to be solved differently.
386 */
387 if (sock_owned_by_user(sk))
388 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
389
390 if (sk->sk_state == TCP_CLOSE)
391 goto out;
392
393 tp = tcp_sk(sk);
394 seq = ntohl(th->seq);
395 if (sk->sk_state != TCP_LISTEN &&
396 !between(seq, tp->snd_una, tp->snd_nxt)) {
Eric Dumazet06ca7192006-10-20 00:22:25 -0700397 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 goto out;
399 }
400
401 switch (type) {
402 case ICMP_SOURCE_QUENCH:
403 /* Just silently ignore these. */
404 goto out;
405 case ICMP_PARAMETERPROB:
406 err = EPROTO;
407 break;
408 case ICMP_DEST_UNREACH:
409 if (code > NR_ICMP_UNREACH)
410 goto out;
411
412 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
413 if (!sock_owned_by_user(sk))
414 do_pmtu_discovery(sk, iph, info);
415 goto out;
416 }
417
418 err = icmp_err_convert[code].errno;
419 break;
420 case ICMP_TIME_EXCEEDED:
421 err = EHOSTUNREACH;
422 break;
423 default:
424 goto out;
425 }
426
427 switch (sk->sk_state) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700428 struct request_sock *req, **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 case TCP_LISTEN:
430 if (sock_owned_by_user(sk))
431 goto out;
432
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700433 req = inet_csk_search_req(sk, &prev, th->dest,
434 iph->daddr, iph->saddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 if (!req)
436 goto out;
437
438 /* ICMPs are not backlogged, hence we cannot get
439 an established socket here.
440 */
441 BUG_TRAP(!req->sk);
442
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700443 if (seq != tcp_rsk(req)->snt_isn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
445 goto out;
446 }
447
448 /*
449 * Still in SYN_RECV, just remove it silently.
450 * There is no good way to pass the error to the newly
451 * created socket, and POSIX does not want network
452 * errors returned from accept().
453 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700454 inet_csk_reqsk_queue_drop(sk, req, prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 goto out;
456
457 case TCP_SYN_SENT:
458 case TCP_SYN_RECV: /* Cannot happen.
459 It can f.e. if SYNs crossed.
460 */
461 if (!sock_owned_by_user(sk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 sk->sk_err = err;
463
464 sk->sk_error_report(sk);
465
466 tcp_done(sk);
467 } else {
468 sk->sk_err_soft = err;
469 }
470 goto out;
471 }
472
473 /* If we've already connected we will keep trying
474 * until we time out, or the user gives up.
475 *
476 * rfc1122 4.2.3.9 allows to consider as hard errors
477 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
478 * but it is obsoleted by pmtu discovery).
479 *
480 * Note, that in modern internet, where routing is unreliable
481 * and in each dark corner broken firewalls sit, sending random
482 * errors ordered by their masters even this two messages finally lose
483 * their original sense (even Linux sends invalid PORT_UNREACHs)
484 *
485 * Now we are in compliance with RFCs.
486 * --ANK (980905)
487 */
488
489 inet = inet_sk(sk);
490 if (!sock_owned_by_user(sk) && inet->recverr) {
491 sk->sk_err = err;
492 sk->sk_error_report(sk);
493 } else { /* Only an error on timeout */
494 sk->sk_err_soft = err;
495 }
496
497out:
498 bh_unlock_sock(sk);
499 sock_put(sk);
500}
501
502/* This routine computes an IPv4 TCP checksum. */
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -0800503void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
505 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700506 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507
Patrick McHardy84fa7932006-08-29 16:44:56 -0700508 if (skb->ip_summed == CHECKSUM_PARTIAL) {
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800509 th->check = ~tcp_v4_check(len, inet->saddr,
510 inet->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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 } else {
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800514 th->check = tcp_v4_check(len, inet->saddr, inet->daddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 csum_partial((char *)th,
516 th->doff << 2,
517 skb->csum));
518 }
519}
520
Herbert Xua430a432006-07-08 13:34:56 -0700521int tcp_v4_gso_send_check(struct sk_buff *skb)
522{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700523 const struct iphdr *iph;
Herbert Xua430a432006-07-08 13:34:56 -0700524 struct tcphdr *th;
525
526 if (!pskb_may_pull(skb, sizeof(*th)))
527 return -EINVAL;
528
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700529 iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700530 th = tcp_hdr(skb);
Herbert Xua430a432006-07-08 13:34:56 -0700531
532 th->check = 0;
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800533 th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
Herbert Xu663ead32007-04-09 11:59:07 -0700534 skb->csum_start = skb_transport_header(skb) - skb->head;
Al Viroff1dcad2006-11-20 18:07:29 -0800535 skb->csum_offset = offsetof(struct tcphdr, check);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700536 skb->ip_summed = CHECKSUM_PARTIAL;
Herbert Xua430a432006-07-08 13:34:56 -0700537 return 0;
538}
539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540/*
541 * This routine will send an RST to the other tcp.
542 *
543 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
544 * for reset.
545 * Answer: if a packet caused RST, it is not for a socket
546 * existing in our system, if it is matched to a socket,
547 * it is just duplicate segment or bug in other side's TCP.
548 * So that we build reply only basing on parameters
549 * arrived with segment.
550 * Exception: precedence violation. We do not implement it in any case.
551 */
552
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800553static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700555 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800556 struct {
557 struct tcphdr th;
558#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800559 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800560#endif
561 } rep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 struct ip_reply_arg arg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800563#ifdef CONFIG_TCP_MD5SIG
564 struct tcp_md5sig_key *key;
565#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
567 /* Never send a reset in response to a reset. */
568 if (th->rst)
569 return;
570
571 if (((struct rtable *)skb->dst)->rt_type != RTN_LOCAL)
572 return;
573
574 /* Swap the send and the receive. */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800575 memset(&rep, 0, sizeof(rep));
576 rep.th.dest = th->source;
577 rep.th.source = th->dest;
578 rep.th.doff = sizeof(struct tcphdr) / 4;
579 rep.th.rst = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581 if (th->ack) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800582 rep.th.seq = th->ack_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800584 rep.th.ack = 1;
585 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
586 skb->len - (th->doff << 2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 }
588
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200589 memset(&arg, 0, sizeof(arg));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800590 arg.iov[0].iov_base = (unsigned char *)&rep;
591 arg.iov[0].iov_len = sizeof(rep.th);
592
593#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700594 key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800595 if (key) {
596 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
597 (TCPOPT_NOP << 16) |
598 (TCPOPT_MD5SIG << 8) |
599 TCPOLEN_MD5SIG);
600 /* Update length and the length the header thinks exists */
601 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
602 rep.th.doff = arg.iov[0].iov_len / 4;
603
604 tcp_v4_do_calc_md5_hash((__u8 *)&rep.opt[1],
605 key,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700606 ip_hdr(skb)->daddr,
607 ip_hdr(skb)->saddr,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800608 &rep.th, IPPROTO_TCP,
609 arg.iov[0].iov_len);
610 }
611#endif
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700612 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
613 ip_hdr(skb)->saddr, /* XXX */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 sizeof(struct tcphdr), IPPROTO_TCP, 0);
615 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
616
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800617 ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619 TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
620 TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
621}
622
623/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
624 outside socket context is ugly, certainly. What can I do?
625 */
626
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800627static void tcp_v4_send_ack(struct tcp_timewait_sock *twsk,
628 struct sk_buff *skb, u32 seq, u32 ack,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 u32 win, u32 ts)
630{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700631 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 struct {
633 struct tcphdr th;
Al Viro714e85b2006-11-14 20:51:49 -0800634 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800635#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800636 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800637#endif
638 ];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 } rep;
640 struct ip_reply_arg arg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800641#ifdef CONFIG_TCP_MD5SIG
642 struct tcp_md5sig_key *key;
643 struct tcp_md5sig_key tw_key;
644#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
646 memset(&rep.th, 0, sizeof(struct tcphdr));
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200647 memset(&arg, 0, sizeof(arg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649 arg.iov[0].iov_base = (unsigned char *)&rep;
650 arg.iov[0].iov_len = sizeof(rep.th);
651 if (ts) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800652 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
653 (TCPOPT_TIMESTAMP << 8) |
654 TCPOLEN_TIMESTAMP);
655 rep.opt[1] = htonl(tcp_time_stamp);
656 rep.opt[2] = htonl(ts);
Craig Schlentercb48cfe2007-01-09 00:11:15 -0800657 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 }
659
660 /* Swap the send and the receive. */
661 rep.th.dest = th->source;
662 rep.th.source = th->dest;
663 rep.th.doff = arg.iov[0].iov_len / 4;
664 rep.th.seq = htonl(seq);
665 rep.th.ack_seq = htonl(ack);
666 rep.th.ack = 1;
667 rep.th.window = htons(win);
668
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800669#ifdef CONFIG_TCP_MD5SIG
670 /*
671 * The SKB holds an imcoming packet, but may not have a valid ->sk
672 * pointer. This is especially the case when we're dealing with a
673 * TIME_WAIT ack, because the sk structure is long gone, and only
674 * the tcp_timewait_sock remains. So the md5 key is stashed in that
675 * structure, and we use it in preference. I believe that (twsk ||
676 * skb->sk) holds true, but we program defensively.
677 */
678 if (!twsk && skb->sk) {
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700679 key = tcp_v4_md5_do_lookup(skb->sk, ip_hdr(skb)->daddr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800680 } else if (twsk && twsk->tw_md5_keylen) {
681 tw_key.key = twsk->tw_md5_key;
682 tw_key.keylen = twsk->tw_md5_keylen;
683 key = &tw_key;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200684 } else
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800685 key = NULL;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800686
687 if (key) {
688 int offset = (ts) ? 3 : 0;
689
690 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
691 (TCPOPT_NOP << 16) |
692 (TCPOPT_MD5SIG << 8) |
693 TCPOLEN_MD5SIG);
694 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
695 rep.th.doff = arg.iov[0].iov_len/4;
696
697 tcp_v4_do_calc_md5_hash((__u8 *)&rep.opt[offset],
698 key,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700699 ip_hdr(skb)->daddr,
700 ip_hdr(skb)->saddr,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800701 &rep.th, IPPROTO_TCP,
702 arg.iov[0].iov_len);
703 }
704#endif
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700705 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
706 ip_hdr(skb)->saddr, /* XXX */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 arg.iov[0].iov_len, IPPROTO_TCP, 0);
708 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
Patrick McHardyf0e48db2007-06-04 21:32:46 -0700709 if (twsk)
710 arg.bound_dev_if = twsk->tw_sk.tw_bound_dev_if;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
712 ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
713
714 TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
715}
716
717static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
718{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700719 struct inet_timewait_sock *tw = inet_twsk(sk);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800720 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800722 tcp_v4_send_ack(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200723 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
724 tcptw->tw_ts_recent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700726 inet_twsk_put(tw);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727}
728
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200729static void tcp_v4_reqsk_send_ack(struct sk_buff *skb,
730 struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800732 tcp_v4_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1,
733 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 req->ts_recent);
735}
736
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737/*
738 * Send a SYN-ACK after having received an ACK.
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700739 * This still operates on a request_sock only, not on a big
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 * socket.
741 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700742static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 struct dst_entry *dst)
744{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700745 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 int err = -1;
747 struct sk_buff * skb;
748
749 /* First, grab a route. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700750 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 goto out;
752
753 skb = tcp_make_synack(sk, dst, req);
754
755 if (skb) {
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700756 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800758 th->check = tcp_v4_check(skb->len,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700759 ireq->loc_addr,
760 ireq->rmt_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 csum_partial((char *)th, skb->len,
762 skb->csum));
763
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700764 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
765 ireq->rmt_addr,
766 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200767 err = net_xmit_eval(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 }
769
770out:
771 dst_release(dst);
772 return err;
773}
774
775/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700776 * IPv4 request_sock destructor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700778static void tcp_v4_reqsk_destructor(struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779{
Jesper Juhla51482b2005-11-08 09:41:34 -0800780 kfree(inet_rsk(req)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781}
782
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200783#ifdef CONFIG_SYN_COOKIES
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800784static void syn_flood_warning(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785{
786 static unsigned long warntime;
787
788 if (time_after(jiffies, (warntime + HZ * 60))) {
789 warntime = jiffies;
790 printk(KERN_INFO
791 "possible SYN flooding on port %d. Sending cookies.\n",
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700792 ntohs(tcp_hdr(skb)->dest));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 }
794}
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200795#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796
797/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700798 * Save and compile IPv4 options into the request_sock if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800800static struct ip_options *tcp_v4_save_options(struct sock *sk,
801 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802{
803 struct ip_options *opt = &(IPCB(skb)->opt);
804 struct ip_options *dopt = NULL;
805
806 if (opt && opt->optlen) {
807 int opt_size = optlength(opt);
808 dopt = kmalloc(opt_size, GFP_ATOMIC);
809 if (dopt) {
810 if (ip_options_echo(dopt, skb)) {
811 kfree(dopt);
812 dopt = NULL;
813 }
814 }
815 }
816 return dopt;
817}
818
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800819#ifdef CONFIG_TCP_MD5SIG
820/*
821 * RFC2385 MD5 checksumming requires a mapping of
822 * IP address->MD5 Key.
823 * We need to maintain these in the sk structure.
824 */
825
826/* Find the Key structure for an address. */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200827static struct tcp_md5sig_key *
828 tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800829{
830 struct tcp_sock *tp = tcp_sk(sk);
831 int i;
832
833 if (!tp->md5sig_info || !tp->md5sig_info->entries4)
834 return NULL;
835 for (i = 0; i < tp->md5sig_info->entries4; i++) {
836 if (tp->md5sig_info->keys4[i].addr == addr)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700837 return &tp->md5sig_info->keys4[i].base;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800838 }
839 return NULL;
840}
841
842struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
843 struct sock *addr_sk)
844{
845 return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->daddr);
846}
847
848EXPORT_SYMBOL(tcp_v4_md5_lookup);
849
Adrian Bunkf5b99bc2006-11-30 17:22:29 -0800850static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
851 struct request_sock *req)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800852{
853 return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
854}
855
856/* This can be called on a newly created socket, from other files */
857int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
858 u8 *newkey, u8 newkeylen)
859{
860 /* Add Key to the list */
861 struct tcp4_md5sig_key *key;
862 struct tcp_sock *tp = tcp_sk(sk);
863 struct tcp4_md5sig_key *keys;
864
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200865 key = (struct tcp4_md5sig_key *)tcp_v4_md5_do_lookup(sk, addr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800866 if (key) {
867 /* Pre-existing entry - just update that one. */
David S. Millerf8ab18d2007-09-28 15:18:35 -0700868 kfree(key->base.key);
869 key->base.key = newkey;
870 key->base.keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800871 } else {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200872 struct tcp_md5sig_info *md5sig;
873
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800874 if (!tp->md5sig_info) {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200875 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
876 GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800877 if (!tp->md5sig_info) {
878 kfree(newkey);
879 return -ENOMEM;
880 }
David S. Miller3d7dbea2007-06-12 14:36:42 -0700881 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800882 }
883 if (tcp_alloc_md5sig_pool() == NULL) {
884 kfree(newkey);
885 return -ENOMEM;
886 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200887 md5sig = tp->md5sig_info;
888
889 if (md5sig->alloced4 == md5sig->entries4) {
890 keys = kmalloc((sizeof(*keys) *
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900891 (md5sig->entries4 + 1)), GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800892 if (!keys) {
893 kfree(newkey);
894 tcp_free_md5sig_pool();
895 return -ENOMEM;
896 }
897
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200898 if (md5sig->entries4)
899 memcpy(keys, md5sig->keys4,
900 sizeof(*keys) * md5sig->entries4);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800901
902 /* Free old key list, and reference new one */
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200903 if (md5sig->keys4)
904 kfree(md5sig->keys4);
905 md5sig->keys4 = keys;
906 md5sig->alloced4++;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800907 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200908 md5sig->entries4++;
David S. Millerf8ab18d2007-09-28 15:18:35 -0700909 md5sig->keys4[md5sig->entries4 - 1].addr = addr;
910 md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
911 md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800912 }
913 return 0;
914}
915
916EXPORT_SYMBOL(tcp_v4_md5_do_add);
917
918static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
919 u8 *newkey, u8 newkeylen)
920{
921 return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->daddr,
922 newkey, newkeylen);
923}
924
925int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
926{
927 struct tcp_sock *tp = tcp_sk(sk);
928 int i;
929
930 for (i = 0; i < tp->md5sig_info->entries4; i++) {
931 if (tp->md5sig_info->keys4[i].addr == addr) {
932 /* Free the key */
David S. Millerf8ab18d2007-09-28 15:18:35 -0700933 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800934 tp->md5sig_info->entries4--;
935
936 if (tp->md5sig_info->entries4 == 0) {
937 kfree(tp->md5sig_info->keys4);
938 tp->md5sig_info->keys4 = NULL;
Leigh Brown8228a18d2006-12-17 17:12:30 -0800939 tp->md5sig_info->alloced4 = 0;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200940 } else if (tp->md5sig_info->entries4 != i) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800941 /* Need to do some manipulation */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200942 memcpy(&tp->md5sig_info->keys4[i],
943 &tp->md5sig_info->keys4[i+1],
944 (tp->md5sig_info->entries4 - i) *
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900945 sizeof(struct tcp4_md5sig_key));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800946 }
947 tcp_free_md5sig_pool();
948 return 0;
949 }
950 }
951 return -ENOENT;
952}
953
954EXPORT_SYMBOL(tcp_v4_md5_do_del);
955
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200956static void tcp_v4_clear_md5_list(struct sock *sk)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800957{
958 struct tcp_sock *tp = tcp_sk(sk);
959
960 /* Free each key, then the set of key keys,
961 * the crypto element, and then decrement our
962 * hold on the last resort crypto.
963 */
964 if (tp->md5sig_info->entries4) {
965 int i;
966 for (i = 0; i < tp->md5sig_info->entries4; i++)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700967 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800968 tp->md5sig_info->entries4 = 0;
969 tcp_free_md5sig_pool();
970 }
971 if (tp->md5sig_info->keys4) {
972 kfree(tp->md5sig_info->keys4);
973 tp->md5sig_info->keys4 = NULL;
974 tp->md5sig_info->alloced4 = 0;
975 }
976}
977
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200978static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
979 int optlen)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800980{
981 struct tcp_md5sig cmd;
982 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
983 u8 *newkey;
984
985 if (optlen < sizeof(cmd))
986 return -EINVAL;
987
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200988 if (copy_from_user(&cmd, optval, sizeof(cmd)))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800989 return -EFAULT;
990
991 if (sin->sin_family != AF_INET)
992 return -EINVAL;
993
994 if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
995 if (!tcp_sk(sk)->md5sig_info)
996 return -ENOENT;
997 return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
998 }
999
1000 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
1001 return -EINVAL;
1002
1003 if (!tcp_sk(sk)->md5sig_info) {
1004 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001005 struct tcp_md5sig_info *p = kzalloc(sizeof(*p), GFP_KERNEL);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001006
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001007 if (!p)
1008 return -EINVAL;
1009
1010 tp->md5sig_info = p;
David S. Miller3d7dbea2007-06-12 14:36:42 -07001011 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001012 }
1013
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -02001014 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001015 if (!newkey)
1016 return -ENOMEM;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001017 return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
1018 newkey, cmd.tcpm_keylen);
1019}
1020
1021static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
1022 __be32 saddr, __be32 daddr,
1023 struct tcphdr *th, int protocol,
1024 int tcplen)
1025{
1026 struct scatterlist sg[4];
1027 __u16 data_len;
1028 int block = 0;
Al Viro8e5200f2006-11-20 18:06:37 -08001029 __sum16 old_checksum;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001030 struct tcp_md5sig_pool *hp;
1031 struct tcp4_pseudohdr *bp;
1032 struct hash_desc *desc;
1033 int err;
1034 unsigned int nbytes = 0;
1035
1036 /*
1037 * Okay, so RFC2385 is turned on for this connection,
1038 * so we need to generate the MD5 hash for the packet now.
1039 */
1040
1041 hp = tcp_get_md5sig_pool();
1042 if (!hp)
1043 goto clear_hash_noput;
1044
1045 bp = &hp->md5_blk.ip4;
1046 desc = &hp->md5_desc;
1047
1048 /*
1049 * 1. the TCP pseudo-header (in the order: source IP address,
1050 * destination IP address, zero-padded protocol number, and
1051 * segment length)
1052 */
1053 bp->saddr = saddr;
1054 bp->daddr = daddr;
1055 bp->pad = 0;
1056 bp->protocol = protocol;
1057 bp->len = htons(tcplen);
1058 sg_set_buf(&sg[block++], bp, sizeof(*bp));
1059 nbytes += sizeof(*bp);
1060
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001061 /* 2. the TCP header, excluding options, and assuming a
1062 * checksum of zero/
1063 */
1064 old_checksum = th->check;
1065 th->check = 0;
1066 sg_set_buf(&sg[block++], th, sizeof(struct tcphdr));
1067 nbytes += sizeof(struct tcphdr);
David S. Miller08dd1a52006-11-30 16:35:01 -08001068
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001069 /* 3. the TCP segment data (if any) */
1070 data_len = tcplen - (th->doff << 2);
1071 if (data_len > 0) {
1072 unsigned char *data = (unsigned char *)th + (th->doff << 2);
1073 sg_set_buf(&sg[block++], data, data_len);
1074 nbytes += data_len;
1075 }
1076
1077 /* 4. an independently-specified key or password, known to both
1078 * TCPs and presumably connection-specific
1079 */
1080 sg_set_buf(&sg[block++], key->key, key->keylen);
1081 nbytes += key->keylen;
1082
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001083 /* Now store the Hash into the packet */
1084 err = crypto_hash_init(desc);
1085 if (err)
1086 goto clear_hash;
1087 err = crypto_hash_update(desc, sg, nbytes);
1088 if (err)
1089 goto clear_hash;
1090 err = crypto_hash_final(desc, md5_hash);
1091 if (err)
1092 goto clear_hash;
1093
1094 /* Reset header, and free up the crypto */
1095 tcp_put_md5sig_pool();
1096 th->check = old_checksum;
1097
1098out:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001099 return 0;
1100clear_hash:
1101 tcp_put_md5sig_pool();
1102clear_hash_noput:
1103 memset(md5_hash, 0, 16);
1104 goto out;
1105}
1106
1107int tcp_v4_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
1108 struct sock *sk,
1109 struct dst_entry *dst,
1110 struct request_sock *req,
1111 struct tcphdr *th, int protocol,
1112 int tcplen)
1113{
1114 __be32 saddr, daddr;
1115
1116 if (sk) {
1117 saddr = inet_sk(sk)->saddr;
1118 daddr = inet_sk(sk)->daddr;
1119 } else {
1120 struct rtable *rt = (struct rtable *)dst;
1121 BUG_ON(!rt);
1122 saddr = rt->rt_src;
1123 daddr = rt->rt_dst;
1124 }
1125 return tcp_v4_do_calc_md5_hash(md5_hash, key,
1126 saddr, daddr,
1127 th, protocol, tcplen);
1128}
1129
1130EXPORT_SYMBOL(tcp_v4_calc_md5_hash);
1131
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001132static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001133{
1134 /*
1135 * This gets called for each TCP segment that arrives
1136 * so we want to be efficient.
1137 * We have 3 drop cases:
1138 * o No MD5 hash and one expected.
1139 * o MD5 hash and we're not expecting one.
1140 * o MD5 hash and its wrong.
1141 */
1142 __u8 *hash_location = NULL;
1143 struct tcp_md5sig_key *hash_expected;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001144 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001145 struct tcphdr *th = tcp_hdr(skb);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001146 int length = (th->doff << 2) - sizeof(struct tcphdr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001147 int genhash;
1148 unsigned char *ptr;
1149 unsigned char newhash[16];
1150
1151 hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
1152
1153 /*
1154 * If the TCP option length is less than the TCP_MD5SIG
1155 * option length, then we can shortcut
1156 */
1157 if (length < TCPOLEN_MD5SIG) {
1158 if (hash_expected)
1159 return 1;
1160 else
1161 return 0;
1162 }
1163
1164 /* Okay, we can't shortcut - we have to grub through the options */
1165 ptr = (unsigned char *)(th + 1);
1166 while (length > 0) {
1167 int opcode = *ptr++;
1168 int opsize;
1169
1170 switch (opcode) {
1171 case TCPOPT_EOL:
1172 goto done_opts;
1173 case TCPOPT_NOP:
1174 length--;
1175 continue;
1176 default:
1177 opsize = *ptr++;
1178 if (opsize < 2)
1179 goto done_opts;
1180 if (opsize > length)
1181 goto done_opts;
1182
1183 if (opcode == TCPOPT_MD5SIG) {
1184 hash_location = ptr;
1185 goto done_opts;
1186 }
1187 }
1188 ptr += opsize-2;
1189 length -= opsize;
1190 }
1191done_opts:
1192 /* We've parsed the options - do we have a hash? */
1193 if (!hash_expected && !hash_location)
1194 return 0;
1195
1196 if (hash_expected && !hash_location) {
Leigh Browna9fc00c2006-12-17 17:13:10 -08001197 LIMIT_NETDEBUG(KERN_INFO "MD5 Hash expected but NOT found "
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001198 "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001199 NIPQUAD(iph->saddr), ntohs(th->source),
1200 NIPQUAD(iph->daddr), ntohs(th->dest));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001201 return 1;
1202 }
1203
1204 if (!hash_expected && hash_location) {
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001205 LIMIT_NETDEBUG(KERN_INFO "MD5 Hash NOT expected but found "
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001206 "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001207 NIPQUAD(iph->saddr), ntohs(th->source),
1208 NIPQUAD(iph->daddr), ntohs(th->dest));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001209 return 1;
1210 }
1211
1212 /* Okay, so this is hash_expected and hash_location -
1213 * so we need to calculate the checksum.
1214 */
1215 genhash = tcp_v4_do_calc_md5_hash(newhash,
1216 hash_expected,
1217 iph->saddr, iph->daddr,
1218 th, sk->sk_protocol,
1219 skb->len);
1220
1221 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1222 if (net_ratelimit()) {
1223 printk(KERN_INFO "MD5 Hash failed for "
1224 "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)%s\n",
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001225 NIPQUAD(iph->saddr), ntohs(th->source),
1226 NIPQUAD(iph->daddr), ntohs(th->dest),
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001227 genhash ? " tcp_v4_calc_md5_hash failed" : "");
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001228 }
1229 return 1;
1230 }
1231 return 0;
1232}
1233
1234#endif
1235
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001236struct request_sock_ops tcp_request_sock_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 .family = PF_INET,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001238 .obj_size = sizeof(struct tcp_request_sock),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 .rtx_syn_ack = tcp_v4_send_synack,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001240 .send_ack = tcp_v4_reqsk_send_ack,
1241 .destructor = tcp_v4_reqsk_destructor,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 .send_reset = tcp_v4_send_reset,
1243};
1244
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001245#ifdef CONFIG_TCP_MD5SIG
Andrew Mortonb6332e62006-11-30 19:16:28 -08001246static struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001247 .md5_lookup = tcp_v4_reqsk_md5_lookup,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001248};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001249#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001250
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001251static struct timewait_sock_ops tcp_timewait_sock_ops = {
1252 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1253 .twsk_unique = tcp_twsk_unique,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001254 .twsk_destructor= tcp_twsk_destructor,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001255};
1256
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1258{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001259 struct inet_request_sock *ireq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001260 struct tcp_options_received tmp_opt;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001261 struct request_sock *req;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001262 __be32 saddr = ip_hdr(skb)->saddr;
1263 __be32 daddr = ip_hdr(skb)->daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264 __u32 isn = TCP_SKB_CB(skb)->when;
1265 struct dst_entry *dst = NULL;
1266#ifdef CONFIG_SYN_COOKIES
1267 int want_cookie = 0;
1268#else
1269#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
1270#endif
1271
1272 /* Never answer to SYNs send to broadcast or multicast */
1273 if (((struct rtable *)skb->dst)->rt_flags &
1274 (RTCF_BROADCAST | RTCF_MULTICAST))
1275 goto drop;
1276
1277 /* TW buckets are converted to open requests without
1278 * limitations, they conserve resources and peer is
1279 * evidently real one.
1280 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001281 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282#ifdef CONFIG_SYN_COOKIES
1283 if (sysctl_tcp_syncookies) {
1284 want_cookie = 1;
1285 } else
1286#endif
1287 goto drop;
1288 }
1289
1290 /* Accept backlog is full. If we have already queued enough
1291 * of warm entries in syn queue, drop request. It is better than
1292 * clogging syn queue with openreqs with exponentially increasing
1293 * timeout.
1294 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001295 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 goto drop;
1297
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001298 req = reqsk_alloc(&tcp_request_sock_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 if (!req)
1300 goto drop;
1301
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001302#ifdef CONFIG_TCP_MD5SIG
1303 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1304#endif
1305
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306 tcp_clear_options(&tmp_opt);
1307 tmp_opt.mss_clamp = 536;
1308 tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss;
1309
1310 tcp_parse_options(skb, &tmp_opt, 0);
1311
1312 if (want_cookie) {
1313 tcp_clear_options(&tmp_opt);
1314 tmp_opt.saw_tstamp = 0;
1315 }
1316
1317 if (tmp_opt.saw_tstamp && !tmp_opt.rcv_tsval) {
1318 /* Some OSes (unknown ones, but I see them on web server, which
1319 * contains information interesting only for windows'
1320 * users) do not send their stamp in SYN. It is easy case.
1321 * We simply do not advertise TS support.
1322 */
1323 tmp_opt.saw_tstamp = 0;
1324 tmp_opt.tstamp_ok = 0;
1325 }
1326 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
1327
1328 tcp_openreq_init(req, &tmp_opt, skb);
1329
Venkat Yekkirala4237c752006-07-24 23:32:50 -07001330 if (security_inet_conn_request(sk, skb, req))
1331 goto drop_and_free;
1332
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001333 ireq = inet_rsk(req);
1334 ireq->loc_addr = daddr;
1335 ireq->rmt_addr = saddr;
1336 ireq->opt = tcp_v4_save_options(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 if (!want_cookie)
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001338 TCP_ECN_create_request(req, tcp_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339
1340 if (want_cookie) {
1341#ifdef CONFIG_SYN_COOKIES
1342 syn_flood_warning(skb);
1343#endif
1344 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1345 } else if (!isn) {
1346 struct inet_peer *peer = NULL;
1347
1348 /* VJ's idea. We save last timestamp seen
1349 * from the destination in peer table, when entering
1350 * state TIME-WAIT, and check against it before
1351 * accepting new connection request.
1352 *
1353 * If "isn" is not zero, this request hit alive
1354 * timewait bucket, so that all the necessary checks
1355 * are made in the function processing timewait state.
1356 */
1357 if (tmp_opt.saw_tstamp &&
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07001358 tcp_death_row.sysctl_tw_recycle &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001359 (dst = inet_csk_route_req(sk, req)) != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
1361 peer->v4daddr == saddr) {
James Morris9d729f72007-03-04 16:12:44 -08001362 if (get_seconds() < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 (s32)(peer->tcp_ts - req->ts_recent) >
1364 TCP_PAWS_WINDOW) {
1365 NET_INC_STATS_BH(LINUX_MIB_PAWSPASSIVEREJECTED);
1366 dst_release(dst);
1367 goto drop_and_free;
1368 }
1369 }
1370 /* Kill the following clause, if you dislike this way. */
1371 else if (!sysctl_tcp_syncookies &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001372 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 (sysctl_max_syn_backlog >> 2)) &&
1374 (!peer || !peer->tcp_ts_stamp) &&
1375 (!dst || !dst_metric(dst, RTAX_RTT))) {
1376 /* Without syncookies last quarter of
1377 * backlog is filled with destinations,
1378 * proven to be alive.
1379 * It means that we continue to communicate
1380 * to destinations, already remembered
1381 * to the moment of synflood.
1382 */
Patrick McHardy64ce2072005-08-09 20:50:53 -07001383 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open "
1384 "request from %u.%u.%u.%u/%u\n",
1385 NIPQUAD(saddr),
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001386 ntohs(tcp_hdr(skb)->source));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 dst_release(dst);
1388 goto drop_and_free;
1389 }
1390
Gerrit Renkera94f7232006-11-10 14:06:49 -08001391 isn = tcp_v4_init_sequence(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 }
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001393 tcp_rsk(req)->snt_isn = isn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394
1395 if (tcp_v4_send_synack(sk, req, dst))
1396 goto drop_and_free;
1397
1398 if (want_cookie) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001399 reqsk_free(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 } else {
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -07001401 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 }
1403 return 0;
1404
1405drop_and_free:
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001406 reqsk_free(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407drop:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408 return 0;
1409}
1410
1411
1412/*
1413 * The three way handshake has completed - we got a valid synack -
1414 * now create the new socket.
1415 */
1416struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001417 struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 struct dst_entry *dst)
1419{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001420 struct inet_request_sock *ireq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 struct inet_sock *newinet;
1422 struct tcp_sock *newtp;
1423 struct sock *newsk;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001424#ifdef CONFIG_TCP_MD5SIG
1425 struct tcp_md5sig_key *key;
1426#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427
1428 if (sk_acceptq_is_full(sk))
1429 goto exit_overflow;
1430
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001431 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432 goto exit;
1433
1434 newsk = tcp_create_openreq_child(sk, req, skb);
1435 if (!newsk)
1436 goto exit;
1437
Herbert Xubcd76112006-06-30 13:36:35 -07001438 newsk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -07001439 sk_setup_caps(newsk, dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440
1441 newtp = tcp_sk(newsk);
1442 newinet = inet_sk(newsk);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001443 ireq = inet_rsk(req);
1444 newinet->daddr = ireq->rmt_addr;
1445 newinet->rcv_saddr = ireq->loc_addr;
1446 newinet->saddr = ireq->loc_addr;
1447 newinet->opt = ireq->opt;
1448 ireq->opt = NULL;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001449 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001450 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001451 inet_csk(newsk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452 if (newinet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001453 inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 newinet->id = newtp->write_seq ^ jiffies;
1455
John Heffner5d424d52006-03-20 17:53:41 -08001456 tcp_mtup_init(newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 tcp_sync_mss(newsk, dst_mtu(dst));
1458 newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
1459 tcp_initialize_rcv_mss(newsk);
1460
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001461#ifdef CONFIG_TCP_MD5SIG
1462 /* Copy over the MD5 key from the original socket */
1463 if ((key = tcp_v4_md5_do_lookup(sk, newinet->daddr)) != NULL) {
1464 /*
1465 * We're using one, so create a matching key
1466 * on the newsk structure. If we fail to get
1467 * memory, then we end up not copying the key
1468 * across. Shucks.
1469 */
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -02001470 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1471 if (newkey != NULL)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001472 tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
1473 newkey, key->keylen);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001474 }
1475#endif
1476
Arnaldo Carvalho de Melof3f05f72005-08-09 20:08:09 -07001477 __inet_hash(&tcp_hashinfo, newsk, 0);
Arnaldo Carvalho de Melo2d8c4ce2005-08-09 20:07:13 -07001478 __inet_inherit_port(&tcp_hashinfo, sk, newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479
1480 return newsk;
1481
1482exit_overflow:
1483 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
1484exit:
1485 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
1486 dst_release(dst);
1487 return NULL;
1488}
1489
1490static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1491{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001492 struct tcphdr *th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001493 const struct iphdr *iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494 struct sock *nsk;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001495 struct request_sock **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496 /* Find possible connection requests. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001497 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1498 iph->saddr, iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 if (req)
1500 return tcp_check_req(sk, skb, req, prev);
1501
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001502 nsk = inet_lookup_established(&tcp_hashinfo, iph->saddr, th->source,
1503 iph->daddr, th->dest, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504
1505 if (nsk) {
1506 if (nsk->sk_state != TCP_TIME_WAIT) {
1507 bh_lock_sock(nsk);
1508 return nsk;
1509 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001510 inet_twsk_put(inet_twsk(nsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 return NULL;
1512 }
1513
1514#ifdef CONFIG_SYN_COOKIES
1515 if (!th->rst && !th->syn && th->ack)
1516 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1517#endif
1518 return sk;
1519}
1520
Al Virob51655b2006-11-14 21:40:42 -08001521static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001523 const struct iphdr *iph = ip_hdr(skb);
1524
Patrick McHardy84fa7932006-08-29 16:44:56 -07001525 if (skb->ip_summed == CHECKSUM_COMPLETE) {
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001526 if (!tcp_v4_check(skb->len, iph->saddr,
1527 iph->daddr, skb->csum)) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001528 skb->ip_summed = CHECKSUM_UNNECESSARY;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529 return 0;
Herbert Xufb286bb2005-11-10 13:01:24 -08001530 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531 }
Herbert Xufb286bb2005-11-10 13:01:24 -08001532
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001533 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
Herbert Xufb286bb2005-11-10 13:01:24 -08001534 skb->len, IPPROTO_TCP, 0);
1535
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536 if (skb->len <= 76) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001537 return __skb_checksum_complete(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538 }
1539 return 0;
1540}
1541
1542
1543/* The socket must have it's spinlock held when we get
1544 * here.
1545 *
1546 * We have a potential double-lock case here, so even when
1547 * doing backlog processing we use the BH locking scheme.
1548 * This is because we cannot sleep with the original spinlock
1549 * held.
1550 */
1551int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1552{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001553 struct sock *rsk;
1554#ifdef CONFIG_TCP_MD5SIG
1555 /*
1556 * We really want to reject the packet as early as possible
1557 * if:
1558 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1559 * o There is an MD5 option and we're not expecting one
1560 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001561 if (tcp_v4_inbound_md5_hash(sk, skb))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001562 goto discard;
1563#endif
1564
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1566 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001567 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001568 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001570 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 TCP_CHECK_TIMER(sk);
1572 return 0;
1573 }
1574
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -07001575 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 goto csum_err;
1577
1578 if (sk->sk_state == TCP_LISTEN) {
1579 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1580 if (!nsk)
1581 goto discard;
1582
1583 if (nsk != sk) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001584 if (tcp_child_process(sk, nsk, skb)) {
1585 rsk = nsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001587 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588 return 0;
1589 }
1590 }
1591
1592 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001593 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001594 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001596 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 TCP_CHECK_TIMER(sk);
1598 return 0;
1599
1600reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001601 tcp_v4_send_reset(rsk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602discard:
1603 kfree_skb(skb);
1604 /* Be careful here. If this function gets more complicated and
1605 * gcc suffers from register pressure on the x86, sk (in %ebx)
1606 * might be destroyed here. This current version compiles correctly,
1607 * but you have been warned.
1608 */
1609 return 0;
1610
1611csum_err:
1612 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1613 goto discard;
1614}
1615
1616/*
1617 * From tcp_input.c
1618 */
1619
1620int tcp_v4_rcv(struct sk_buff *skb)
1621{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001622 const struct iphdr *iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623 struct tcphdr *th;
1624 struct sock *sk;
1625 int ret;
1626
1627 if (skb->pkt_type != PACKET_HOST)
1628 goto discard_it;
1629
1630 /* Count it even if it's bad */
1631 TCP_INC_STATS_BH(TCP_MIB_INSEGS);
1632
1633 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1634 goto discard_it;
1635
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001636 th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637
1638 if (th->doff < sizeof(struct tcphdr) / 4)
1639 goto bad_packet;
1640 if (!pskb_may_pull(skb, th->doff * 4))
1641 goto discard_it;
1642
1643 /* An explanation is required here, I think.
1644 * Packet length and doff are validated by header prediction,
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001645 * provided case of th->doff==0 is eliminated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646 * So, we defer the checks. */
Herbert Xu60476372007-04-09 11:59:39 -07001647 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 goto bad_packet;
1649
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001650 th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001651 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1653 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1654 skb->len - th->doff * 4);
1655 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1656 TCP_SKB_CB(skb)->when = 0;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001657 TCP_SKB_CB(skb)->flags = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001658 TCP_SKB_CB(skb)->sacked = 0;
1659
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001660 sk = __inet_lookup(&tcp_hashinfo, iph->saddr, th->source,
1661 iph->daddr, th->dest, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 if (!sk)
1663 goto no_tcp_socket;
1664
1665process:
1666 if (sk->sk_state == TCP_TIME_WAIT)
1667 goto do_time_wait;
1668
1669 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1670 goto discard_and_relse;
Patrick McHardyb59c2702006-01-06 23:06:10 -08001671 nf_reset(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672
Dmitry Mishinfda9ef52006-08-31 15:28:39 -07001673 if (sk_filter(sk, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674 goto discard_and_relse;
1675
1676 skb->dev = NULL;
1677
Ingo Molnarc6366182006-07-03 00:25:13 -07001678 bh_lock_sock_nested(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679 ret = 0;
1680 if (!sock_owned_by_user(sk)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001681#ifdef CONFIG_NET_DMA
1682 struct tcp_sock *tp = tcp_sk(sk);
1683 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
1684 tp->ucopy.dma_chan = get_softnet_dma();
1685 if (tp->ucopy.dma_chan)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001686 ret = tcp_v4_do_rcv(sk, skb);
Chris Leech1a2449a2006-05-23 18:05:53 -07001687 else
1688#endif
1689 {
1690 if (!tcp_prequeue(sk, skb))
1691 ret = tcp_v4_do_rcv(sk, skb);
1692 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001693 } else
1694 sk_add_backlog(sk, skb);
1695 bh_unlock_sock(sk);
1696
1697 sock_put(sk);
1698
1699 return ret;
1700
1701no_tcp_socket:
1702 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1703 goto discard_it;
1704
1705 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1706bad_packet:
1707 TCP_INC_STATS_BH(TCP_MIB_INERRS);
1708 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001709 tcp_v4_send_reset(NULL, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001710 }
1711
1712discard_it:
1713 /* Discard frame. */
1714 kfree_skb(skb);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001715 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716
1717discard_and_relse:
1718 sock_put(sk);
1719 goto discard_it;
1720
1721do_time_wait:
1722 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001723 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 goto discard_it;
1725 }
1726
1727 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1728 TCP_INC_STATS_BH(TCP_MIB_INERRS);
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001729 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 goto discard_it;
1731 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001732 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 case TCP_TW_SYN: {
Arnaldo Carvalho de Melo33b62232005-08-09 20:09:06 -07001734 struct sock *sk2 = inet_lookup_listener(&tcp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001735 iph->daddr, th->dest,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001736 inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 if (sk2) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001738 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1739 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001740 sk = sk2;
1741 goto process;
1742 }
1743 /* Fall through to ACK */
1744 }
1745 case TCP_TW_ACK:
1746 tcp_v4_timewait_ack(sk, skb);
1747 break;
1748 case TCP_TW_RST:
1749 goto no_tcp_socket;
1750 case TCP_TW_SUCCESS:;
1751 }
1752 goto discard_it;
1753}
1754
Linus Torvalds1da177e2005-04-16 15:20:36 -07001755/* VJ's idea. Save last timestamp seen from this destination
1756 * and hold it at least for normal timewait interval to use for duplicate
1757 * segment detection in subsequent connections, before they enter synchronized
1758 * state.
1759 */
1760
1761int tcp_v4_remember_stamp(struct sock *sk)
1762{
1763 struct inet_sock *inet = inet_sk(sk);
1764 struct tcp_sock *tp = tcp_sk(sk);
1765 struct rtable *rt = (struct rtable *)__sk_dst_get(sk);
1766 struct inet_peer *peer = NULL;
1767 int release_it = 0;
1768
1769 if (!rt || rt->rt_dst != inet->daddr) {
1770 peer = inet_getpeer(inet->daddr, 1);
1771 release_it = 1;
1772 } else {
1773 if (!rt->peer)
1774 rt_bind_peer(rt, 1);
1775 peer = rt->peer;
1776 }
1777
1778 if (peer) {
1779 if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
James Morris9d729f72007-03-04 16:12:44 -08001780 (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 peer->tcp_ts_stamp <= tp->rx_opt.ts_recent_stamp)) {
1782 peer->tcp_ts_stamp = tp->rx_opt.ts_recent_stamp;
1783 peer->tcp_ts = tp->rx_opt.ts_recent;
1784 }
1785 if (release_it)
1786 inet_putpeer(peer);
1787 return 1;
1788 }
1789
1790 return 0;
1791}
1792
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001793int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001795 struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796
1797 if (peer) {
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001798 const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
1799
1800 if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 ||
James Morris9d729f72007-03-04 16:12:44 -08001801 (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001802 peer->tcp_ts_stamp <= tcptw->tw_ts_recent_stamp)) {
1803 peer->tcp_ts_stamp = tcptw->tw_ts_recent_stamp;
1804 peer->tcp_ts = tcptw->tw_ts_recent;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805 }
1806 inet_putpeer(peer);
1807 return 1;
1808 }
1809
1810 return 0;
1811}
1812
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -08001813struct inet_connection_sock_af_ops ipv4_specific = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001814 .queue_xmit = ip_queue_xmit,
1815 .send_check = tcp_v4_send_check,
1816 .rebuild_header = inet_sk_rebuild_header,
1817 .conn_request = tcp_v4_conn_request,
1818 .syn_recv_sock = tcp_v4_syn_recv_sock,
1819 .remember_stamp = tcp_v4_remember_stamp,
1820 .net_header_len = sizeof(struct iphdr),
1821 .setsockopt = ip_setsockopt,
1822 .getsockopt = ip_getsockopt,
1823 .addr2sockaddr = inet_csk_addr2sockaddr,
1824 .sockaddr_len = sizeof(struct sockaddr_in),
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001825#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001826 .compat_setsockopt = compat_ip_setsockopt,
1827 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001828#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001829};
1830
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001831#ifdef CONFIG_TCP_MD5SIG
Andrew Mortonb6332e62006-11-30 19:16:28 -08001832static struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001833 .md5_lookup = tcp_v4_md5_lookup,
1834 .calc_md5_hash = tcp_v4_calc_md5_hash,
1835 .md5_add = tcp_v4_md5_add_func,
1836 .md5_parse = tcp_v4_parse_md5_keys,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001837};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001838#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001839
Linus Torvalds1da177e2005-04-16 15:20:36 -07001840/* NOTE: A lot of things set to zero explicitly by call to
1841 * sk_alloc() so need not be done here.
1842 */
1843static int tcp_v4_init_sock(struct sock *sk)
1844{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001845 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846 struct tcp_sock *tp = tcp_sk(sk);
1847
1848 skb_queue_head_init(&tp->out_of_order_queue);
1849 tcp_init_xmit_timers(sk);
1850 tcp_prequeue_init(tp);
1851
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001852 icsk->icsk_rto = TCP_TIMEOUT_INIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001853 tp->mdev = TCP_TIMEOUT_INIT;
1854
1855 /* So many TCP implementations out there (incorrectly) count the
1856 * initial SYN frame in their delayed-ACK and congestion control
1857 * algorithms that we must have the following bandaid to talk
1858 * efficiently to them. -DaveM
1859 */
1860 tp->snd_cwnd = 2;
1861
1862 /* See draft-stevens-tcpca-spec-01 for discussion of the
1863 * initialization of these values.
1864 */
1865 tp->snd_ssthresh = 0x7fffffff; /* Infinity */
1866 tp->snd_cwnd_clamp = ~0;
David S. Millerc1b4a7e2005-07-05 15:24:38 -07001867 tp->mss_cache = 536;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868
1869 tp->reordering = sysctl_tcp_reordering;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001870 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871
1872 sk->sk_state = TCP_CLOSE;
1873
1874 sk->sk_write_space = sk_stream_write_space;
1875 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1876
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -08001877 icsk->icsk_af_ops = &ipv4_specific;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001878 icsk->icsk_sync_mss = tcp_sync_mss;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001879#ifdef CONFIG_TCP_MD5SIG
1880 tp->af_specific = &tcp_sock_ipv4_specific;
1881#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001882
1883 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1884 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1885
1886 atomic_inc(&tcp_sockets_allocated);
1887
1888 return 0;
1889}
1890
1891int tcp_v4_destroy_sock(struct sock *sk)
1892{
1893 struct tcp_sock *tp = tcp_sk(sk);
1894
1895 tcp_clear_xmit_timers(sk);
1896
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001897 tcp_cleanup_congestion_control(sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07001898
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 /* Cleanup up the write buffer. */
David S. Millerfe067e82007-03-07 12:12:44 -08001900 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001901
1902 /* Cleans up our, hopefully empty, out_of_order_queue. */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001903 __skb_queue_purge(&tp->out_of_order_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001904
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001905#ifdef CONFIG_TCP_MD5SIG
1906 /* Clean up the MD5 key list, if any */
1907 if (tp->md5sig_info) {
1908 tcp_v4_clear_md5_list(sk);
1909 kfree(tp->md5sig_info);
1910 tp->md5sig_info = NULL;
1911 }
1912#endif
1913
Chris Leech1a2449a2006-05-23 18:05:53 -07001914#ifdef CONFIG_NET_DMA
1915 /* Cleans up our sk_async_wait_queue */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001916 __skb_queue_purge(&sk->sk_async_wait_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001917#endif
1918
Linus Torvalds1da177e2005-04-16 15:20:36 -07001919 /* Clean prequeue, it must be empty really */
1920 __skb_queue_purge(&tp->ucopy.prequeue);
1921
1922 /* Clean up a referenced TCP bind bucket. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001923 if (inet_csk(sk)->icsk_bind_hash)
Arnaldo Carvalho de Melo2d8c4ce2005-08-09 20:07:13 -07001924 inet_put_port(&tcp_hashinfo, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925
1926 /*
1927 * If sendmsg cached page exists, toss it.
1928 */
1929 if (sk->sk_sndmsg_page) {
1930 __free_page(sk->sk_sndmsg_page);
1931 sk->sk_sndmsg_page = NULL;
1932 }
1933
1934 atomic_dec(&tcp_sockets_allocated);
1935
1936 return 0;
1937}
1938
1939EXPORT_SYMBOL(tcp_v4_destroy_sock);
1940
1941#ifdef CONFIG_PROC_FS
1942/* Proc filesystem TCP sock list dumping. */
1943
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001944static inline struct inet_timewait_sock *tw_head(struct hlist_head *head)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945{
1946 return hlist_empty(head) ? NULL :
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001947 list_entry(head->first, struct inet_timewait_sock, tw_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001948}
1949
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001950static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951{
1952 return tw->tw_node.next ?
1953 hlist_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
1954}
1955
1956static void *listening_get_next(struct seq_file *seq, void *cur)
1957{
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001958 struct inet_connection_sock *icsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 struct hlist_node *node;
1960 struct sock *sk = cur;
1961 struct tcp_iter_state* st = seq->private;
1962
1963 if (!sk) {
1964 st->bucket = 0;
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07001965 sk = sk_head(&tcp_hashinfo.listening_hash[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001966 goto get_sk;
1967 }
1968
1969 ++st->num;
1970
1971 if (st->state == TCP_SEQ_STATE_OPENREQ) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001972 struct request_sock *req = cur;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001974 icsk = inet_csk(st->syn_wait_sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001975 req = req->dl_next;
1976 while (1) {
1977 while (req) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001978 if (req->rsk_ops->family == st->family) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001979 cur = req;
1980 goto out;
1981 }
1982 req = req->dl_next;
1983 }
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001984 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 break;
1986get_req:
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001987 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 }
1989 sk = sk_next(st->syn_wait_sk);
1990 st->state = TCP_SEQ_STATE_LISTENING;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001991 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992 } else {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001993 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001994 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
1995 if (reqsk_queue_len(&icsk->icsk_accept_queue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996 goto start_req;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001997 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001998 sk = sk_next(sk);
1999 }
2000get_sk:
2001 sk_for_each_from(sk, node) {
2002 if (sk->sk_family == st->family) {
2003 cur = sk;
2004 goto out;
2005 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002006 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002007 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2008 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002009start_req:
2010 st->uid = sock_i_uid(sk);
2011 st->syn_wait_sk = sk;
2012 st->state = TCP_SEQ_STATE_OPENREQ;
2013 st->sbucket = 0;
2014 goto get_req;
2015 }
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002016 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002017 }
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002018 if (++st->bucket < INET_LHTABLE_SIZE) {
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002019 sk = sk_head(&tcp_hashinfo.listening_hash[st->bucket]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002020 goto get_sk;
2021 }
2022 cur = NULL;
2023out:
2024 return cur;
2025}
2026
2027static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
2028{
2029 void *rc = listening_get_next(seq, NULL);
2030
2031 while (rc && *pos) {
2032 rc = listening_get_next(seq, rc);
2033 --*pos;
2034 }
2035 return rc;
2036}
2037
2038static void *established_get_first(struct seq_file *seq)
2039{
2040 struct tcp_iter_state* st = seq->private;
2041 void *rc = NULL;
2042
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002043 for (st->bucket = 0; st->bucket < tcp_hashinfo.ehash_size; ++st->bucket) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002044 struct sock *sk;
2045 struct hlist_node *node;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002046 struct inet_timewait_sock *tw;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002047
Herbert Xua7ab4b52007-06-10 17:33:08 -07002048 read_lock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002049 sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 if (sk->sk_family != st->family) {
2051 continue;
2052 }
2053 rc = sk;
2054 goto out;
2055 }
2056 st->state = TCP_SEQ_STATE_TIME_WAIT;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002057 inet_twsk_for_each(tw, node,
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002058 &tcp_hashinfo.ehash[st->bucket].twchain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002059 if (tw->tw_family != st->family) {
2060 continue;
2061 }
2062 rc = tw;
2063 goto out;
2064 }
Herbert Xua7ab4b52007-06-10 17:33:08 -07002065 read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066 st->state = TCP_SEQ_STATE_ESTABLISHED;
2067 }
2068out:
2069 return rc;
2070}
2071
2072static void *established_get_next(struct seq_file *seq, void *cur)
2073{
2074 struct sock *sk = cur;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002075 struct inet_timewait_sock *tw;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076 struct hlist_node *node;
2077 struct tcp_iter_state* st = seq->private;
2078
2079 ++st->num;
2080
2081 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2082 tw = cur;
2083 tw = tw_next(tw);
2084get_tw:
2085 while (tw && tw->tw_family != st->family) {
2086 tw = tw_next(tw);
2087 }
2088 if (tw) {
2089 cur = tw;
2090 goto out;
2091 }
Herbert Xua7ab4b52007-06-10 17:33:08 -07002092 read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002093 st->state = TCP_SEQ_STATE_ESTABLISHED;
2094
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002095 if (++st->bucket < tcp_hashinfo.ehash_size) {
Herbert Xua7ab4b52007-06-10 17:33:08 -07002096 read_lock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -07002097 sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002098 } else {
2099 cur = NULL;
2100 goto out;
2101 }
2102 } else
2103 sk = sk_next(sk);
2104
2105 sk_for_each_from(sk, node) {
2106 if (sk->sk_family == st->family)
2107 goto found;
2108 }
2109
2110 st->state = TCP_SEQ_STATE_TIME_WAIT;
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002111 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112 goto get_tw;
2113found:
2114 cur = sk;
2115out:
2116 return cur;
2117}
2118
2119static void *established_get_idx(struct seq_file *seq, loff_t pos)
2120{
2121 void *rc = established_get_first(seq);
2122
2123 while (rc && pos) {
2124 rc = established_get_next(seq, rc);
2125 --pos;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002126 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127 return rc;
2128}
2129
2130static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2131{
2132 void *rc;
2133 struct tcp_iter_state* st = seq->private;
2134
Arnaldo Carvalho de Melof3f05f72005-08-09 20:08:09 -07002135 inet_listen_lock(&tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136 st->state = TCP_SEQ_STATE_LISTENING;
2137 rc = listening_get_idx(seq, &pos);
2138
2139 if (!rc) {
Arnaldo Carvalho de Melof3f05f72005-08-09 20:08:09 -07002140 inet_listen_unlock(&tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002141 st->state = TCP_SEQ_STATE_ESTABLISHED;
2142 rc = established_get_idx(seq, pos);
2143 }
2144
2145 return rc;
2146}
2147
2148static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2149{
2150 struct tcp_iter_state* st = seq->private;
2151 st->state = TCP_SEQ_STATE_LISTENING;
2152 st->num = 0;
2153 return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2154}
2155
2156static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2157{
2158 void *rc = NULL;
2159 struct tcp_iter_state* st;
2160
2161 if (v == SEQ_START_TOKEN) {
2162 rc = tcp_get_idx(seq, 0);
2163 goto out;
2164 }
2165 st = seq->private;
2166
2167 switch (st->state) {
2168 case TCP_SEQ_STATE_OPENREQ:
2169 case TCP_SEQ_STATE_LISTENING:
2170 rc = listening_get_next(seq, v);
2171 if (!rc) {
Arnaldo Carvalho de Melof3f05f72005-08-09 20:08:09 -07002172 inet_listen_unlock(&tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002173 st->state = TCP_SEQ_STATE_ESTABLISHED;
2174 rc = established_get_first(seq);
2175 }
2176 break;
2177 case TCP_SEQ_STATE_ESTABLISHED:
2178 case TCP_SEQ_STATE_TIME_WAIT:
2179 rc = established_get_next(seq, v);
2180 break;
2181 }
2182out:
2183 ++*pos;
2184 return rc;
2185}
2186
2187static void tcp_seq_stop(struct seq_file *seq, void *v)
2188{
2189 struct tcp_iter_state* st = seq->private;
2190
2191 switch (st->state) {
2192 case TCP_SEQ_STATE_OPENREQ:
2193 if (v) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002194 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2195 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002196 }
2197 case TCP_SEQ_STATE_LISTENING:
2198 if (v != SEQ_START_TOKEN)
Arnaldo Carvalho de Melof3f05f72005-08-09 20:08:09 -07002199 inet_listen_unlock(&tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 break;
2201 case TCP_SEQ_STATE_TIME_WAIT:
2202 case TCP_SEQ_STATE_ESTABLISHED:
2203 if (v)
Herbert Xua7ab4b52007-06-10 17:33:08 -07002204 read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002205 break;
2206 }
2207}
2208
2209static int tcp_seq_open(struct inode *inode, struct file *file)
2210{
2211 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
2212 struct seq_file *seq;
2213 struct tcp_iter_state *s;
2214 int rc;
2215
2216 if (unlikely(afinfo == NULL))
2217 return -EINVAL;
2218
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07002219 s = kzalloc(sizeof(*s), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002220 if (!s)
2221 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002222 s->family = afinfo->family;
2223 s->seq_ops.start = tcp_seq_start;
2224 s->seq_ops.next = tcp_seq_next;
2225 s->seq_ops.show = afinfo->seq_show;
2226 s->seq_ops.stop = tcp_seq_stop;
2227
2228 rc = seq_open(file, &s->seq_ops);
2229 if (rc)
2230 goto out_kfree;
2231 seq = file->private_data;
2232 seq->private = s;
2233out:
2234 return rc;
2235out_kfree:
2236 kfree(s);
2237 goto out;
2238}
2239
2240int tcp_proc_register(struct tcp_seq_afinfo *afinfo)
2241{
2242 int rc = 0;
2243 struct proc_dir_entry *p;
2244
2245 if (!afinfo)
2246 return -EINVAL;
2247 afinfo->seq_fops->owner = afinfo->owner;
2248 afinfo->seq_fops->open = tcp_seq_open;
2249 afinfo->seq_fops->read = seq_read;
2250 afinfo->seq_fops->llseek = seq_lseek;
2251 afinfo->seq_fops->release = seq_release_private;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002252
Eric W. Biederman457c4cb2007-09-12 12:01:34 +02002253 p = proc_net_fops_create(&init_net, afinfo->name, S_IRUGO, afinfo->seq_fops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002254 if (p)
2255 p->data = afinfo;
2256 else
2257 rc = -ENOMEM;
2258 return rc;
2259}
2260
2261void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo)
2262{
2263 if (!afinfo)
2264 return;
Eric W. Biederman457c4cb2007-09-12 12:01:34 +02002265 proc_net_remove(&init_net, afinfo->name);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002266 memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002267}
2268
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002269static void get_openreq4(struct sock *sk, struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002270 char *tmpbuf, int i, int uid)
2271{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002272 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002273 int ttd = req->expires - jiffies;
2274
2275 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
2276 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p",
2277 i,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002278 ireq->loc_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 ntohs(inet_sk(sk)->sport),
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002280 ireq->rmt_addr,
2281 ntohs(ireq->rmt_port),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282 TCP_SYN_RECV,
2283 0, 0, /* could print option size, but that is af dependent. */
2284 1, /* timers active (only the expire timer) */
2285 jiffies_to_clock_t(ttd),
2286 req->retrans,
2287 uid,
2288 0, /* non standard timer */
2289 0, /* open_requests have no inode */
2290 atomic_read(&sk->sk_refcnt),
2291 req);
2292}
2293
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002294static void get_tcp4_sock(struct sock *sk, char *tmpbuf, int i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295{
2296 int timer_active;
2297 unsigned long timer_expires;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002298 struct tcp_sock *tp = tcp_sk(sk);
2299 const struct inet_connection_sock *icsk = inet_csk(sk);
2300 struct inet_sock *inet = inet_sk(sk);
Al Viro714e85b2006-11-14 20:51:49 -08002301 __be32 dest = inet->daddr;
2302 __be32 src = inet->rcv_saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002303 __u16 destp = ntohs(inet->dport);
2304 __u16 srcp = ntohs(inet->sport);
2305
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002306 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002307 timer_active = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002308 timer_expires = icsk->icsk_timeout;
2309 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002310 timer_active = 4;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002311 timer_expires = icsk->icsk_timeout;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002312 } else if (timer_pending(&sk->sk_timer)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002313 timer_active = 2;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002314 timer_expires = sk->sk_timer.expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315 } else {
2316 timer_active = 0;
2317 timer_expires = jiffies;
2318 }
2319
2320 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
2321 "%08X %5d %8d %lu %d %p %u %u %u %u %d",
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002322 i, src, srcp, dest, destp, sk->sk_state,
Sridhar Samudrala47da8ee2006-06-27 13:29:00 -07002323 tp->write_seq - tp->snd_una,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002324 sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog :
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002325 (tp->rcv_nxt - tp->copied_seq),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002326 timer_active,
2327 jiffies_to_clock_t(timer_expires - jiffies),
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002328 icsk->icsk_retransmits,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002329 sock_i_uid(sk),
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002330 icsk->icsk_probes_out,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002331 sock_i_ino(sk),
2332 atomic_read(&sk->sk_refcnt), sk,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002333 icsk->icsk_rto,
2334 icsk->icsk_ack.ato,
2335 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002336 tp->snd_cwnd,
2337 tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh);
2338}
2339
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002340static void get_timewait4_sock(struct inet_timewait_sock *tw,
2341 char *tmpbuf, int i)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002342{
Al Viro23f33c22006-09-27 18:43:50 -07002343 __be32 dest, src;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 __u16 destp, srcp;
2345 int ttd = tw->tw_ttd - jiffies;
2346
2347 if (ttd < 0)
2348 ttd = 0;
2349
2350 dest = tw->tw_daddr;
2351 src = tw->tw_rcv_saddr;
2352 destp = ntohs(tw->tw_dport);
2353 srcp = ntohs(tw->tw_sport);
2354
2355 sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
2356 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p",
2357 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2358 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
2359 atomic_read(&tw->tw_refcnt), tw);
2360}
2361
2362#define TMPSZ 150
2363
2364static int tcp4_seq_show(struct seq_file *seq, void *v)
2365{
2366 struct tcp_iter_state* st;
2367 char tmpbuf[TMPSZ + 1];
2368
2369 if (v == SEQ_START_TOKEN) {
2370 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2371 " sl local_address rem_address st tx_queue "
2372 "rx_queue tr tm->when retrnsmt uid timeout "
2373 "inode");
2374 goto out;
2375 }
2376 st = seq->private;
2377
2378 switch (st->state) {
2379 case TCP_SEQ_STATE_LISTENING:
2380 case TCP_SEQ_STATE_ESTABLISHED:
2381 get_tcp4_sock(v, tmpbuf, st->num);
2382 break;
2383 case TCP_SEQ_STATE_OPENREQ:
2384 get_openreq4(st->syn_wait_sk, v, tmpbuf, st->num, st->uid);
2385 break;
2386 case TCP_SEQ_STATE_TIME_WAIT:
2387 get_timewait4_sock(v, tmpbuf, st->num);
2388 break;
2389 }
2390 seq_printf(seq, "%-*s\n", TMPSZ - 1, tmpbuf);
2391out:
2392 return 0;
2393}
2394
2395static struct file_operations tcp4_seq_fops;
2396static struct tcp_seq_afinfo tcp4_seq_afinfo = {
2397 .owner = THIS_MODULE,
2398 .name = "tcp",
2399 .family = AF_INET,
2400 .seq_show = tcp4_seq_show,
2401 .seq_fops = &tcp4_seq_fops,
2402};
2403
2404int __init tcp4_proc_init(void)
2405{
2406 return tcp_proc_register(&tcp4_seq_afinfo);
2407}
2408
2409void tcp4_proc_exit(void)
2410{
2411 tcp_proc_unregister(&tcp4_seq_afinfo);
2412}
2413#endif /* CONFIG_PROC_FS */
2414
2415struct proto tcp_prot = {
2416 .name = "TCP",
2417 .owner = THIS_MODULE,
2418 .close = tcp_close,
2419 .connect = tcp_v4_connect,
2420 .disconnect = tcp_disconnect,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002421 .accept = inet_csk_accept,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002422 .ioctl = tcp_ioctl,
2423 .init = tcp_v4_init_sock,
2424 .destroy = tcp_v4_destroy_sock,
2425 .shutdown = tcp_shutdown,
2426 .setsockopt = tcp_setsockopt,
2427 .getsockopt = tcp_getsockopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002428 .recvmsg = tcp_recvmsg,
2429 .backlog_rcv = tcp_v4_do_rcv,
2430 .hash = tcp_v4_hash,
2431 .unhash = tcp_unhash,
2432 .get_port = tcp_v4_get_port,
2433 .enter_memory_pressure = tcp_enter_memory_pressure,
2434 .sockets_allocated = &tcp_sockets_allocated,
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002435 .orphan_count = &tcp_orphan_count,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002436 .memory_allocated = &tcp_memory_allocated,
2437 .memory_pressure = &tcp_memory_pressure,
2438 .sysctl_mem = sysctl_tcp_mem,
2439 .sysctl_wmem = sysctl_tcp_wmem,
2440 .sysctl_rmem = sysctl_tcp_rmem,
2441 .max_header = MAX_TCP_HEADER,
2442 .obj_size = sizeof(struct tcp_sock),
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08002443 .twsk_prot = &tcp_timewait_sock_ops,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002444 .rsk_prot = &tcp_request_sock_ops,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002445#ifdef CONFIG_COMPAT
2446 .compat_setsockopt = compat_tcp_setsockopt,
2447 .compat_getsockopt = compat_tcp_getsockopt,
2448#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449};
2450
Linus Torvalds1da177e2005-04-16 15:20:36 -07002451void __init tcp_v4_init(struct net_proto_family *ops)
2452{
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002453 if (inet_csk_ctl_sock_create(&tcp_socket, PF_INET, SOCK_RAW,
2454 IPPROTO_TCP) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002455 panic("Failed to create the TCP control socket.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002456}
2457
2458EXPORT_SYMBOL(ipv4_specific);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002459EXPORT_SYMBOL(tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002460EXPORT_SYMBOL(tcp_prot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002461EXPORT_SYMBOL(tcp_unhash);
2462EXPORT_SYMBOL(tcp_v4_conn_request);
2463EXPORT_SYMBOL(tcp_v4_connect);
2464EXPORT_SYMBOL(tcp_v4_do_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465EXPORT_SYMBOL(tcp_v4_remember_stamp);
2466EXPORT_SYMBOL(tcp_v4_send_check);
2467EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
2468
2469#ifdef CONFIG_PROC_FS
2470EXPORT_SYMBOL(tcp_proc_register);
2471EXPORT_SYMBOL(tcp_proc_unregister);
2472#endif
2473EXPORT_SYMBOL(sysctl_local_port_range);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002474EXPORT_SYMBOL(sysctl_tcp_low_latency);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002475