blob: 15e96030ce47d16fdd1095807d7b8283a02d1215 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Implementation of the Transmission Control Protocol(TCP).
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * IPv4 specific functions
9 *
10 *
11 * code split from:
12 * linux/ipv4/tcp.c
13 * linux/ipv4/tcp_input.c
14 * linux/ipv4/tcp_output.c
15 *
16 * See tcp.c for author information
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24/*
25 * Changes:
26 * David S. Miller : New socket lookup architecture.
27 * This code is dedicated to John Dyson.
28 * David S. Miller : Change semantics of established hash,
29 * half is devoted to TIME_WAIT sockets
30 * and the rest go in the other half.
31 * Andi Kleen : Add support for syncookies and fixed
32 * some bugs: ip options weren't passed to
33 * the TCP layer, missed a check for an
34 * ACK bit.
35 * Andi Kleen : Implemented fast path mtu discovery.
36 * Fixed many serious bugs in the
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -070037 * request_sock handling and moved
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 * most of it into the af independent code.
39 * Added tail drop and some other bugfixes.
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -080040 * Added new listen semantics.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 * Mike McLagan : Routing by source
42 * Juan Jose Ciarlante: ip_dynaddr bits
43 * Andi Kleen: various fixes.
44 * Vitaly E. Lavrov : Transparent proxy revived after year
45 * coma.
46 * Andi Kleen : Fix new listen.
47 * Andi Kleen : Fix accept error reporting.
48 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
49 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
50 * a single port at the same time.
51 */
52
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Herbert Xueb4dea52008-12-29 23:04:08 -080054#include <linux/bottom_half.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#include <linux/types.h>
56#include <linux/fcntl.h>
57#include <linux/module.h>
58#include <linux/random.h>
59#include <linux/cache.h>
60#include <linux/jhash.h>
61#include <linux/init.h>
62#include <linux/times.h>
63
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020064#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#include <net/icmp.h>
Arnaldo Carvalho de Melo304a1612005-08-09 19:59:20 -070066#include <net/inet_hashtables.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070067#include <net/tcp.h>
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -030068#include <net/transp_v6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070069#include <net/ipv6.h>
70#include <net/inet_common.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080071#include <net/timewait_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072#include <net/xfrm.h>
Chris Leech1a2449a2006-05-23 18:05:53 -070073#include <net/netdma.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75#include <linux/inet.h>
76#include <linux/ipv6.h>
77#include <linux/stddef.h>
78#include <linux/proc_fs.h>
79#include <linux/seq_file.h>
80
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080081#include <linux/crypto.h>
82#include <linux/scatterlist.h>
83
Brian Haleyab32ea52006-09-22 14:15:41 -070084int sysctl_tcp_tw_reuse __read_mostly;
85int sysctl_tcp_low_latency __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080088#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -020089static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
90 __be32 addr);
Adam Langley49a72df2008-07-19 00:01:42 -070091static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
92 __be32 daddr, __be32 saddr, struct tcphdr *th);
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +090093#else
94static inline
95struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
96{
97 return NULL;
98}
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080099#endif
100
Eric Dumazet5caea4e2008-11-20 00:40:07 -0800101struct inet_hashinfo tcp_hashinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
Gerrit Renkera94f7232006-11-10 14:06:49 -0800103static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700105 return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
106 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700107 tcp_hdr(skb)->dest,
108 tcp_hdr(skb)->source);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109}
110
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800111int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
112{
113 const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
114 struct tcp_sock *tp = tcp_sk(sk);
115
116 /* With PAWS, it is safe from the viewpoint
117 of data integrity. Even without PAWS it is safe provided sequence
118 spaces do not overlap i.e. at data rates <= 80Mbit/sec.
119
120 Actually, the idea is close to VJ's one, only timestamp cache is
121 held not per host, but per port pair and TW bucket is used as state
122 holder.
123
124 If TW bucket has been already destroyed we fall back to VJ's scheme
125 and use initial timestamp retrieved from peer table.
126 */
127 if (tcptw->tw_ts_recent_stamp &&
128 (twp == NULL || (sysctl_tcp_tw_reuse &&
James Morris9d729f72007-03-04 16:12:44 -0800129 get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800130 tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
131 if (tp->write_seq == 0)
132 tp->write_seq = 1;
133 tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
134 tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
135 sock_hold(sktw);
136 return 1;
137 }
138
139 return 0;
140}
141
142EXPORT_SYMBOL_GPL(tcp_twsk_unique);
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144/* This will initiate an outgoing connection. */
145int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
146{
147 struct inet_sock *inet = inet_sk(sk);
148 struct tcp_sock *tp = tcp_sk(sk);
149 struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
150 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -0700151 __be32 daddr, nexthop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 int tmp;
153 int err;
154
155 if (addr_len < sizeof(struct sockaddr_in))
156 return -EINVAL;
157
158 if (usin->sin_family != AF_INET)
159 return -EAFNOSUPPORT;
160
161 nexthop = daddr = usin->sin_addr.s_addr;
162 if (inet->opt && inet->opt->srr) {
163 if (!daddr)
164 return -EINVAL;
165 nexthop = inet->opt->faddr;
166 }
167
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000168 tmp = ip_route_connect(&rt, nexthop, inet->inet_saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
170 IPPROTO_TCP,
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000171 inet->inet_sport, usin->sin_port, sk, 1);
Wei Dong584bdf82007-05-31 22:49:28 -0700172 if (tmp < 0) {
173 if (tmp == -ENETUNREACH)
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700174 IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return tmp;
Wei Dong584bdf82007-05-31 22:49:28 -0700176 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
178 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
179 ip_rt_put(rt);
180 return -ENETUNREACH;
181 }
182
183 if (!inet->opt || !inet->opt->srr)
184 daddr = rt->rt_dst;
185
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000186 if (!inet->inet_saddr)
187 inet->inet_saddr = rt->rt_src;
188 inet->inet_rcv_saddr = inet->inet_saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000190 if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 /* Reset inherited state */
192 tp->rx_opt.ts_recent = 0;
193 tp->rx_opt.ts_recent_stamp = 0;
194 tp->write_seq = 0;
195 }
196
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -0700197 if (tcp_death_row.sysctl_tw_recycle &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
199 struct inet_peer *peer = rt_get_peer(rt);
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200200 /*
201 * VJ's idea. We save last timestamp seen from
202 * the destination in peer table, when entering state
203 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
204 * when trying new connection.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200206 if (peer != NULL &&
Eric Dumazet2c1409a2009-11-12 09:33:09 +0000207 (u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
209 tp->rx_opt.ts_recent = peer->tcp_ts;
210 }
211 }
212
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000213 inet->inet_dport = usin->sin_port;
214 inet->inet_daddr = daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800216 inet_csk(sk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 if (inet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800218 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
William Allen Simpsonbee7ca92009-11-10 09:51:18 +0000220 tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 /* Socket identity is still unknown (sport may be zero).
223 * However we set state to SYN-SENT and not releasing socket
224 * lock select source port, enter ourselves into the hash tables and
225 * complete initialization after this.
226 */
227 tcp_set_state(sk, TCP_SYN_SENT);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800228 err = inet_hash_connect(&tcp_death_row, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (err)
230 goto failure;
231
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200232 err = ip_route_newports(&rt, IPPROTO_TCP,
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000233 inet->inet_sport, inet->inet_dport, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (err)
235 goto failure;
236
237 /* OK, now commit destination to socket. */
Herbert Xubcd76112006-06-30 13:36:35 -0700238 sk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -0700239 sk_setup_caps(sk, &rt->u.dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241 if (!tp->write_seq)
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000242 tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr,
243 inet->inet_daddr,
244 inet->inet_sport,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 usin->sin_port);
246
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000247 inet->inet_id = tp->write_seq ^ jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 err = tcp_connect(sk);
250 rt = NULL;
251 if (err)
252 goto failure;
253
254 return 0;
255
256failure:
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200257 /*
258 * This unhashes the socket and releases the local port,
259 * if necessary.
260 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 tcp_set_state(sk, TCP_CLOSE);
262 ip_rt_put(rt);
263 sk->sk_route_caps = 0;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000264 inet->inet_dport = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return err;
266}
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/*
269 * This routine does path mtu discovery as defined in RFC1191.
270 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800271static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
273 struct dst_entry *dst;
274 struct inet_sock *inet = inet_sk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276 /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
277 * send out by Linux are always <576bytes so they should go through
278 * unfragmented).
279 */
280 if (sk->sk_state == TCP_LISTEN)
281 return;
282
283 /* We don't check in the destentry if pmtu discovery is forbidden
284 * on this route. We just assume that no packet_to_big packets
285 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900286 * There is a small race when the user changes this flag in the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 * route, but I think that's acceptable.
288 */
289 if ((dst = __sk_dst_check(sk, 0)) == NULL)
290 return;
291
292 dst->ops->update_pmtu(dst, mtu);
293
294 /* Something is about to be wrong... Remember soft error
295 * for the case, if this connection will not able to recover.
296 */
297 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
298 sk->sk_err_soft = EMSGSIZE;
299
300 mtu = dst_mtu(dst);
301
302 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800303 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 tcp_sync_mss(sk, mtu);
305
306 /* Resend the TCP packet because it's
307 * clear that the old packet has been
308 * dropped. This is the new "fast" path mtu
309 * discovery.
310 */
311 tcp_simple_retransmit(sk);
312 } /* else let the usual retransmit timer handle it */
313}
314
315/*
316 * This routine is called by the ICMP module when it gets some
317 * sort of error condition. If err < 0 then the socket should
318 * be closed and the error returned to the user. If err > 0
319 * it's just the icmp type << 8 | icmp code. After adjustment
320 * header points to the first 8 bytes of the tcp header. We need
321 * to find the appropriate port.
322 *
323 * The locking strategy used here is very "optimistic". When
324 * someone else accesses the socket the ICMP is just dropped
325 * and for some paths there is no check at all.
326 * A more general error queue to queue errors for later handling
327 * is probably better.
328 *
329 */
330
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000331void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000333 struct iphdr *iph = (struct iphdr *)icmp_skb->data;
334 struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));
Damian Lukowskif1ecd5d2009-08-26 00:16:31 +0000335 struct inet_connection_sock *icsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 struct tcp_sock *tp;
337 struct inet_sock *inet;
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000338 const int type = icmp_hdr(icmp_skb)->type;
339 const int code = icmp_hdr(icmp_skb)->code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 struct sock *sk;
Damian Lukowskif1ecd5d2009-08-26 00:16:31 +0000341 struct sk_buff *skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 __u32 seq;
Damian Lukowskif1ecd5d2009-08-26 00:16:31 +0000343 __u32 remaining;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 int err;
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000345 struct net *net = dev_net(icmp_skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000347 if (icmp_skb->len < (iph->ihl << 2) + 8) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700348 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 return;
350 }
351
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700352 sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
Damian Lukowski4d1a2d92009-08-26 00:16:27 +0000353 iph->saddr, th->source, inet_iif(icmp_skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 if (!sk) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700355 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 return;
357 }
358 if (sk->sk_state == TCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700359 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 return;
361 }
362
363 bh_lock_sock(sk);
364 /* If too many ICMPs get dropped on busy
365 * servers this needs to be solved differently.
366 */
367 if (sock_owned_by_user(sk))
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700368 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370 if (sk->sk_state == TCP_CLOSE)
371 goto out;
372
Damian Lukowskif1ecd5d2009-08-26 00:16:31 +0000373 icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 tp = tcp_sk(sk);
375 seq = ntohl(th->seq);
376 if (sk->sk_state != TCP_LISTEN &&
377 !between(seq, tp->snd_una, tp->snd_nxt)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700378 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 goto out;
380 }
381
382 switch (type) {
383 case ICMP_SOURCE_QUENCH:
384 /* Just silently ignore these. */
385 goto out;
386 case ICMP_PARAMETERPROB:
387 err = EPROTO;
388 break;
389 case ICMP_DEST_UNREACH:
390 if (code > NR_ICMP_UNREACH)
391 goto out;
392
393 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
394 if (!sock_owned_by_user(sk))
395 do_pmtu_discovery(sk, iph, info);
396 goto out;
397 }
398
399 err = icmp_err_convert[code].errno;
Damian Lukowskif1ecd5d2009-08-26 00:16:31 +0000400 /* check if icmp_skb allows revert of backoff
401 * (see draft-zimmermann-tcp-lcd) */
402 if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
403 break;
404 if (seq != tp->snd_una || !icsk->icsk_retransmits ||
405 !icsk->icsk_backoff)
406 break;
407
408 icsk->icsk_backoff--;
409 inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) <<
410 icsk->icsk_backoff;
411 tcp_bound_rto(sk);
412
413 skb = tcp_write_queue_head(sk);
414 BUG_ON(!skb);
415
416 remaining = icsk->icsk_rto - min(icsk->icsk_rto,
417 tcp_time_stamp - TCP_SKB_CB(skb)->when);
418
419 if (remaining) {
420 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
421 remaining, TCP_RTO_MAX);
422 } else if (sock_owned_by_user(sk)) {
423 /* RTO revert clocked out retransmission,
424 * but socket is locked. Will defer. */
425 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
426 HZ/20, TCP_RTO_MAX);
427 } else {
428 /* RTO revert clocked out retransmission.
429 * Will retransmit now */
430 tcp_retransmit_timer(sk);
431 }
432
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 break;
434 case ICMP_TIME_EXCEEDED:
435 err = EHOSTUNREACH;
436 break;
437 default:
438 goto out;
439 }
440
441 switch (sk->sk_state) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700442 struct request_sock *req, **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 case TCP_LISTEN:
444 if (sock_owned_by_user(sk))
445 goto out;
446
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700447 req = inet_csk_search_req(sk, &prev, th->dest,
448 iph->daddr, iph->saddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 if (!req)
450 goto out;
451
452 /* ICMPs are not backlogged, hence we cannot get
453 an established socket here.
454 */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700455 WARN_ON(req->sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700457 if (seq != tcp_rsk(req)->snt_isn) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700458 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 goto out;
460 }
461
462 /*
463 * Still in SYN_RECV, just remove it silently.
464 * There is no good way to pass the error to the newly
465 * created socket, and POSIX does not want network
466 * errors returned from accept().
467 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700468 inet_csk_reqsk_queue_drop(sk, req, prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 goto out;
470
471 case TCP_SYN_SENT:
472 case TCP_SYN_RECV: /* Cannot happen.
473 It can f.e. if SYNs crossed.
474 */
475 if (!sock_owned_by_user(sk)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 sk->sk_err = err;
477
478 sk->sk_error_report(sk);
479
480 tcp_done(sk);
481 } else {
482 sk->sk_err_soft = err;
483 }
484 goto out;
485 }
486
487 /* If we've already connected we will keep trying
488 * until we time out, or the user gives up.
489 *
490 * rfc1122 4.2.3.9 allows to consider as hard errors
491 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
492 * but it is obsoleted by pmtu discovery).
493 *
494 * Note, that in modern internet, where routing is unreliable
495 * and in each dark corner broken firewalls sit, sending random
496 * errors ordered by their masters even this two messages finally lose
497 * their original sense (even Linux sends invalid PORT_UNREACHs)
498 *
499 * Now we are in compliance with RFCs.
500 * --ANK (980905)
501 */
502
503 inet = inet_sk(sk);
504 if (!sock_owned_by_user(sk) && inet->recverr) {
505 sk->sk_err = err;
506 sk->sk_error_report(sk);
507 } else { /* Only an error on timeout */
508 sk->sk_err_soft = err;
509 }
510
511out:
512 bh_unlock_sock(sk);
513 sock_put(sk);
514}
515
516/* This routine computes an IPv4 TCP checksum. */
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -0800517void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
519 struct inet_sock *inet = inet_sk(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700520 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Patrick McHardy84fa7932006-08-29 16:44:56 -0700522 if (skb->ip_summed == CHECKSUM_PARTIAL) {
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000523 th->check = ~tcp_v4_check(len, inet->inet_saddr,
524 inet->inet_daddr, 0);
Herbert Xu663ead32007-04-09 11:59:07 -0700525 skb->csum_start = skb_transport_header(skb) - skb->head;
Al Viroff1dcad2006-11-20 18:07:29 -0800526 skb->csum_offset = offsetof(struct tcphdr, check);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 } else {
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000528 th->check = tcp_v4_check(len, inet->inet_saddr,
529 inet->inet_daddr,
Joe Perches07f07572008-11-19 15:44:53 -0800530 csum_partial(th,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 th->doff << 2,
532 skb->csum));
533 }
534}
535
Herbert Xua430a432006-07-08 13:34:56 -0700536int tcp_v4_gso_send_check(struct sk_buff *skb)
537{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700538 const struct iphdr *iph;
Herbert Xua430a432006-07-08 13:34:56 -0700539 struct tcphdr *th;
540
541 if (!pskb_may_pull(skb, sizeof(*th)))
542 return -EINVAL;
543
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700544 iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700545 th = tcp_hdr(skb);
Herbert Xua430a432006-07-08 13:34:56 -0700546
547 th->check = 0;
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800548 th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
Herbert Xu663ead32007-04-09 11:59:07 -0700549 skb->csum_start = skb_transport_header(skb) - skb->head;
Al Viroff1dcad2006-11-20 18:07:29 -0800550 skb->csum_offset = offsetof(struct tcphdr, check);
Patrick McHardy84fa7932006-08-29 16:44:56 -0700551 skb->ip_summed = CHECKSUM_PARTIAL;
Herbert Xua430a432006-07-08 13:34:56 -0700552 return 0;
553}
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555/*
556 * This routine will send an RST to the other tcp.
557 *
558 * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
559 * for reset.
560 * Answer: if a packet caused RST, it is not for a socket
561 * existing in our system, if it is matched to a socket,
562 * it is just duplicate segment or bug in other side's TCP.
563 * So that we build reply only basing on parameters
564 * arrived with segment.
565 * Exception: precedence violation. We do not implement it in any case.
566 */
567
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800568static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700570 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800571 struct {
572 struct tcphdr th;
573#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800574 __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800575#endif
576 } rep;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 struct ip_reply_arg arg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800578#ifdef CONFIG_TCP_MD5SIG
579 struct tcp_md5sig_key *key;
580#endif
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700581 struct net *net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
583 /* Never send a reset in response to a reset. */
584 if (th->rst)
585 return;
586
Eric Dumazet511c3f92009-06-02 05:14:27 +0000587 if (skb_rtable(skb)->rt_type != RTN_LOCAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 return;
589
590 /* Swap the send and the receive. */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800591 memset(&rep, 0, sizeof(rep));
592 rep.th.dest = th->source;
593 rep.th.source = th->dest;
594 rep.th.doff = sizeof(struct tcphdr) / 4;
595 rep.th.rst = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596
597 if (th->ack) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800598 rep.th.seq = th->ack_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800600 rep.th.ack = 1;
601 rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
602 skb->len - (th->doff << 2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 }
604
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200605 memset(&arg, 0, sizeof(arg));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800606 arg.iov[0].iov_base = (unsigned char *)&rep;
607 arg.iov[0].iov_len = sizeof(rep.th);
608
609#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700610 key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800611 if (key) {
612 rep.opt[0] = htonl((TCPOPT_NOP << 24) |
613 (TCPOPT_NOP << 16) |
614 (TCPOPT_MD5SIG << 8) |
615 TCPOLEN_MD5SIG);
616 /* Update length and the length the header thinks exists */
617 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
618 rep.th.doff = arg.iov[0].iov_len / 4;
619
Adam Langley49a72df2008-07-19 00:01:42 -0700620 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
Ilpo Järvinen78e645cb2008-10-09 14:37:47 -0700621 key, ip_hdr(skb)->saddr,
622 ip_hdr(skb)->daddr, &rep.th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800623 }
624#endif
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700625 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
626 ip_hdr(skb)->saddr, /* XXX */
Ilpo Järvinen52cd5752008-10-08 11:34:06 -0700627 arg.iov[0].iov_len, IPPROTO_TCP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700629 arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
Eric Dumazetadf30902009-06-02 05:19:30 +0000631 net = dev_net(skb_dst(skb)->dev);
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700632 ip_send_reply(net->ipv4.tcp_sock, skb,
Denis V. Lunev7feb49c2008-04-03 14:32:00 -0700633 &arg, arg.iov[0].iov_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634
Pavel Emelyanov63231bd2008-07-16 20:22:25 -0700635 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
636 TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637}
638
639/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
640 outside socket context is ugly, certainly. What can I do?
641 */
642
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900643static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
644 u32 win, u32 ts, int oif,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700645 struct tcp_md5sig_key *key,
646 int reply_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700648 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 struct {
650 struct tcphdr th;
Al Viro714e85b2006-11-14 20:51:49 -0800651 __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800652#ifdef CONFIG_TCP_MD5SIG
Al Viro714e85b2006-11-14 20:51:49 -0800653 + (TCPOLEN_MD5SIG_ALIGNED >> 2)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800654#endif
655 ];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 } rep;
657 struct ip_reply_arg arg;
Eric Dumazetadf30902009-06-02 05:19:30 +0000658 struct net *net = dev_net(skb_dst(skb)->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
660 memset(&rep.th, 0, sizeof(struct tcphdr));
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200661 memset(&arg, 0, sizeof(arg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
663 arg.iov[0].iov_base = (unsigned char *)&rep;
664 arg.iov[0].iov_len = sizeof(rep.th);
665 if (ts) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800666 rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
667 (TCPOPT_TIMESTAMP << 8) |
668 TCPOLEN_TIMESTAMP);
669 rep.opt[1] = htonl(tcp_time_stamp);
670 rep.opt[2] = htonl(ts);
Craig Schlentercb48cfe2007-01-09 00:11:15 -0800671 arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 }
673
674 /* Swap the send and the receive. */
675 rep.th.dest = th->source;
676 rep.th.source = th->dest;
677 rep.th.doff = arg.iov[0].iov_len / 4;
678 rep.th.seq = htonl(seq);
679 rep.th.ack_seq = htonl(ack);
680 rep.th.ack = 1;
681 rep.th.window = htons(win);
682
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800683#ifdef CONFIG_TCP_MD5SIG
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800684 if (key) {
685 int offset = (ts) ? 3 : 0;
686
687 rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
688 (TCPOPT_NOP << 16) |
689 (TCPOPT_MD5SIG << 8) |
690 TCPOLEN_MD5SIG);
691 arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
692 rep.th.doff = arg.iov[0].iov_len/4;
693
Adam Langley49a72df2008-07-19 00:01:42 -0700694 tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
Adam Langley90b7e112008-07-31 20:49:48 -0700695 key, ip_hdr(skb)->saddr,
696 ip_hdr(skb)->daddr, &rep.th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800697 }
698#endif
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700699 arg.flags = reply_flags;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700700 arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
701 ip_hdr(skb)->saddr, /* XXX */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 arg.iov[0].iov_len, IPPROTO_TCP, 0);
703 arg.csumoffset = offsetof(struct tcphdr, check) / 2;
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900704 if (oif)
705 arg.bound_dev_if = oif;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
Pavel Emelyanova86b1e32008-07-16 20:20:58 -0700707 ip_send_reply(net->ipv4.tcp_sock, skb,
Denis V. Lunev7feb49c2008-04-03 14:32:00 -0700708 &arg, arg.iov[0].iov_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Pavel Emelyanov63231bd2008-07-16 20:22:25 -0700710 TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711}
712
713static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
714{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700715 struct inet_timewait_sock *tw = inet_twsk(sk);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800716 struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900718 tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200719 tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900720 tcptw->tw_ts_recent,
721 tw->tw_bound_dev_if,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700722 tcp_twsk_md5_key(tcptw),
723 tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900724 );
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
Gui Jianfeng6edafaa2008-08-06 23:50:04 -0700729static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200730 struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731{
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900732 tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800733 tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +0900734 req->ts_recent,
735 0,
KOVACS Krisztian88ef4a52008-10-01 07:41:00 -0700736 tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
737 inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738}
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740/*
Kris Katterjohn9bf1d832008-02-17 22:29:19 -0800741 * Send a SYN-ACK after having received a SYN.
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700742 * This still operates on a request_sock only, not on a big
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 * socket.
744 */
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000745static int __tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
746 struct request_sock *req,
747 struct request_values *rvp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700749 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 int err = -1;
751 struct sk_buff * skb;
752
753 /* First, grab a route. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700754 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800755 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000757 skb = tcp_make_synack(sk, dst, req, rvp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
759 if (skb) {
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700760 struct tcphdr *th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800762 th->check = tcp_v4_check(skb->len,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700763 ireq->loc_addr,
764 ireq->rmt_addr,
Joe Perches07f07572008-11-19 15:44:53 -0800765 csum_partial(th, skb->len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 skb->csum));
767
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700768 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
769 ireq->rmt_addr,
770 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200771 err = net_xmit_eval(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 }
773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 dst_release(dst);
775 return err;
776}
777
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000778static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
779 struct request_values *rvp)
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800780{
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000781 return __tcp_v4_send_synack(sk, NULL, req, rvp);
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800782}
783
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700785 * IPv4 request_sock destructor.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 */
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700787static void tcp_v4_reqsk_destructor(struct request_sock *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788{
Jesper Juhla51482b2005-11-08 09:41:34 -0800789 kfree(inet_rsk(req)->opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790}
791
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200792#ifdef CONFIG_SYN_COOKIES
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800793static void syn_flood_warning(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794{
795 static unsigned long warntime;
796
797 if (time_after(jiffies, (warntime + HZ * 60))) {
798 warntime = jiffies;
799 printk(KERN_INFO
800 "possible SYN flooding on port %d. Sending cookies.\n",
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700801 ntohs(tcp_hdr(skb)->dest));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 }
803}
Arnaldo Carvalho de Melo80e40da2006-01-04 01:58:06 -0200804#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
806/*
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700807 * Save and compile IPv4 options into the request_sock if needed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800809static struct ip_options *tcp_v4_save_options(struct sock *sk,
810 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811{
812 struct ip_options *opt = &(IPCB(skb)->opt);
813 struct ip_options *dopt = NULL;
814
815 if (opt && opt->optlen) {
816 int opt_size = optlength(opt);
817 dopt = kmalloc(opt_size, GFP_ATOMIC);
818 if (dopt) {
819 if (ip_options_echo(dopt, skb)) {
820 kfree(dopt);
821 dopt = NULL;
822 }
823 }
824 }
825 return dopt;
826}
827
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800828#ifdef CONFIG_TCP_MD5SIG
829/*
830 * RFC2385 MD5 checksumming requires a mapping of
831 * IP address->MD5 Key.
832 * We need to maintain these in the sk structure.
833 */
834
835/* Find the Key structure for an address. */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200836static struct tcp_md5sig_key *
837 tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800838{
839 struct tcp_sock *tp = tcp_sk(sk);
840 int i;
841
842 if (!tp->md5sig_info || !tp->md5sig_info->entries4)
843 return NULL;
844 for (i = 0; i < tp->md5sig_info->entries4; i++) {
845 if (tp->md5sig_info->keys4[i].addr == addr)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700846 return &tp->md5sig_info->keys4[i].base;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800847 }
848 return NULL;
849}
850
851struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
852 struct sock *addr_sk)
853{
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000854 return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->inet_daddr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800855}
856
857EXPORT_SYMBOL(tcp_v4_md5_lookup);
858
Adrian Bunkf5b99bc2006-11-30 17:22:29 -0800859static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
860 struct request_sock *req)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800861{
862 return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
863}
864
865/* This can be called on a newly created socket, from other files */
866int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
867 u8 *newkey, u8 newkeylen)
868{
869 /* Add Key to the list */
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700870 struct tcp_md5sig_key *key;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800871 struct tcp_sock *tp = tcp_sk(sk);
872 struct tcp4_md5sig_key *keys;
873
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700874 key = tcp_v4_md5_do_lookup(sk, addr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800875 if (key) {
876 /* Pre-existing entry - just update that one. */
Matthias M. Dellwegb0a713e2007-10-29 20:55:27 -0700877 kfree(key->key);
878 key->key = newkey;
879 key->keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800880 } else {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200881 struct tcp_md5sig_info *md5sig;
882
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800883 if (!tp->md5sig_info) {
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200884 tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
885 GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800886 if (!tp->md5sig_info) {
887 kfree(newkey);
888 return -ENOMEM;
889 }
David S. Miller3d7dbea2007-06-12 14:36:42 -0700890 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800891 }
Wu Fengguangaa133072009-09-02 23:45:45 -0700892 if (tcp_alloc_md5sig_pool(sk) == NULL) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800893 kfree(newkey);
894 return -ENOMEM;
895 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200896 md5sig = tp->md5sig_info;
897
898 if (md5sig->alloced4 == md5sig->entries4) {
899 keys = kmalloc((sizeof(*keys) *
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900900 (md5sig->entries4 + 1)), GFP_ATOMIC);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800901 if (!keys) {
902 kfree(newkey);
903 tcp_free_md5sig_pool();
904 return -ENOMEM;
905 }
906
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200907 if (md5sig->entries4)
908 memcpy(keys, md5sig->keys4,
909 sizeof(*keys) * md5sig->entries4);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800910
911 /* Free old key list, and reference new one */
YOSHIFUJI Hideakia80cc202007-11-20 17:30:06 -0800912 kfree(md5sig->keys4);
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200913 md5sig->keys4 = keys;
914 md5sig->alloced4++;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800915 }
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -0200916 md5sig->entries4++;
David S. Millerf8ab18d2007-09-28 15:18:35 -0700917 md5sig->keys4[md5sig->entries4 - 1].addr = addr;
918 md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
919 md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800920 }
921 return 0;
922}
923
924EXPORT_SYMBOL(tcp_v4_md5_do_add);
925
926static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
927 u8 *newkey, u8 newkeylen)
928{
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000929 return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->inet_daddr,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800930 newkey, newkeylen);
931}
932
933int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
934{
935 struct tcp_sock *tp = tcp_sk(sk);
936 int i;
937
938 for (i = 0; i < tp->md5sig_info->entries4; i++) {
939 if (tp->md5sig_info->keys4[i].addr == addr) {
940 /* Free the key */
David S. Millerf8ab18d2007-09-28 15:18:35 -0700941 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800942 tp->md5sig_info->entries4--;
943
944 if (tp->md5sig_info->entries4 == 0) {
945 kfree(tp->md5sig_info->keys4);
946 tp->md5sig_info->keys4 = NULL;
Leigh Brown8228a18d2006-12-17 17:12:30 -0800947 tp->md5sig_info->alloced4 = 0;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200948 } else if (tp->md5sig_info->entries4 != i) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800949 /* Need to do some manipulation */
YOSHIFUJI Hideaki354faf02007-11-20 17:30:31 -0800950 memmove(&tp->md5sig_info->keys4[i],
951 &tp->md5sig_info->keys4[i+1],
952 (tp->md5sig_info->entries4 - i) *
953 sizeof(struct tcp4_md5sig_key));
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800954 }
955 tcp_free_md5sig_pool();
956 return 0;
957 }
958 }
959 return -ENOENT;
960}
961
962EXPORT_SYMBOL(tcp_v4_md5_do_del);
963
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200964static void tcp_v4_clear_md5_list(struct sock *sk)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800965{
966 struct tcp_sock *tp = tcp_sk(sk);
967
968 /* Free each key, then the set of key keys,
969 * the crypto element, and then decrement our
970 * hold on the last resort crypto.
971 */
972 if (tp->md5sig_info->entries4) {
973 int i;
974 for (i = 0; i < tp->md5sig_info->entries4; i++)
David S. Millerf8ab18d2007-09-28 15:18:35 -0700975 kfree(tp->md5sig_info->keys4[i].base.key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800976 tp->md5sig_info->entries4 = 0;
977 tcp_free_md5sig_pool();
978 }
979 if (tp->md5sig_info->keys4) {
980 kfree(tp->md5sig_info->keys4);
981 tp->md5sig_info->keys4 = NULL;
982 tp->md5sig_info->alloced4 = 0;
983 }
984}
985
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200986static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
987 int optlen)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800988{
989 struct tcp_md5sig cmd;
990 struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
991 u8 *newkey;
992
993 if (optlen < sizeof(cmd))
994 return -EINVAL;
995
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -0200996 if (copy_from_user(&cmd, optval, sizeof(cmd)))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800997 return -EFAULT;
998
999 if (sin->sin_family != AF_INET)
1000 return -EINVAL;
1001
1002 if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
1003 if (!tcp_sk(sk)->md5sig_info)
1004 return -ENOENT;
1005 return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
1006 }
1007
1008 if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
1009 return -EINVAL;
1010
1011 if (!tcp_sk(sk)->md5sig_info) {
1012 struct tcp_sock *tp = tcp_sk(sk);
Wu Fengguangaa133072009-09-02 23:45:45 -07001013 struct tcp_md5sig_info *p;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001014
Wu Fengguangaa133072009-09-02 23:45:45 -07001015 p = kzalloc(sizeof(*p), sk->sk_allocation);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001016 if (!p)
1017 return -EINVAL;
1018
1019 tp->md5sig_info = p;
David S. Miller3d7dbea2007-06-12 14:36:42 -07001020 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001021 }
1022
Wu Fengguangaa133072009-09-02 23:45:45 -07001023 newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001024 if (!newkey)
1025 return -ENOMEM;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001026 return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
1027 newkey, cmd.tcpm_keylen);
1028}
1029
Adam Langley49a72df2008-07-19 00:01:42 -07001030static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
1031 __be32 daddr, __be32 saddr, int nbytes)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001032{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001033 struct tcp4_pseudohdr *bp;
Adam Langley49a72df2008-07-19 00:01:42 -07001034 struct scatterlist sg;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001035
1036 bp = &hp->md5_blk.ip4;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001037
1038 /*
Adam Langley49a72df2008-07-19 00:01:42 -07001039 * 1. the TCP pseudo-header (in the order: source IP address,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001040 * destination IP address, zero-padded protocol number, and
1041 * segment length)
1042 */
1043 bp->saddr = saddr;
1044 bp->daddr = daddr;
1045 bp->pad = 0;
YOSHIFUJI Hideaki076fb722008-04-17 12:48:12 +09001046 bp->protocol = IPPROTO_TCP;
Adam Langley49a72df2008-07-19 00:01:42 -07001047 bp->len = cpu_to_be16(nbytes);
David S. Millerc7da57a2007-10-26 00:41:21 -07001048
Adam Langley49a72df2008-07-19 00:01:42 -07001049 sg_init_one(&sg, bp, sizeof(*bp));
1050 return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
1051}
1052
1053static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
1054 __be32 daddr, __be32 saddr, struct tcphdr *th)
1055{
1056 struct tcp_md5sig_pool *hp;
1057 struct hash_desc *desc;
1058
1059 hp = tcp_get_md5sig_pool();
1060 if (!hp)
1061 goto clear_hash_noput;
1062 desc = &hp->md5_desc;
1063
1064 if (crypto_hash_init(desc))
1065 goto clear_hash;
1066 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
1067 goto clear_hash;
1068 if (tcp_md5_hash_header(hp, th))
1069 goto clear_hash;
1070 if (tcp_md5_hash_key(hp, key))
1071 goto clear_hash;
1072 if (crypto_hash_final(desc, md5_hash))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001073 goto clear_hash;
1074
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001075 tcp_put_md5sig_pool();
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001076 return 0;
Adam Langley49a72df2008-07-19 00:01:42 -07001077
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001078clear_hash:
1079 tcp_put_md5sig_pool();
1080clear_hash_noput:
1081 memset(md5_hash, 0, 16);
Adam Langley49a72df2008-07-19 00:01:42 -07001082 return 1;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001083}
1084
Adam Langley49a72df2008-07-19 00:01:42 -07001085int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
1086 struct sock *sk, struct request_sock *req,
1087 struct sk_buff *skb)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001088{
Adam Langley49a72df2008-07-19 00:01:42 -07001089 struct tcp_md5sig_pool *hp;
1090 struct hash_desc *desc;
1091 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001092 __be32 saddr, daddr;
1093
1094 if (sk) {
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001095 saddr = inet_sk(sk)->inet_saddr;
1096 daddr = inet_sk(sk)->inet_daddr;
Adam Langley49a72df2008-07-19 00:01:42 -07001097 } else if (req) {
1098 saddr = inet_rsk(req)->loc_addr;
1099 daddr = inet_rsk(req)->rmt_addr;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001100 } else {
Adam Langley49a72df2008-07-19 00:01:42 -07001101 const struct iphdr *iph = ip_hdr(skb);
1102 saddr = iph->saddr;
1103 daddr = iph->daddr;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001104 }
Adam Langley49a72df2008-07-19 00:01:42 -07001105
1106 hp = tcp_get_md5sig_pool();
1107 if (!hp)
1108 goto clear_hash_noput;
1109 desc = &hp->md5_desc;
1110
1111 if (crypto_hash_init(desc))
1112 goto clear_hash;
1113
1114 if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
1115 goto clear_hash;
1116 if (tcp_md5_hash_header(hp, th))
1117 goto clear_hash;
1118 if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
1119 goto clear_hash;
1120 if (tcp_md5_hash_key(hp, key))
1121 goto clear_hash;
1122 if (crypto_hash_final(desc, md5_hash))
1123 goto clear_hash;
1124
1125 tcp_put_md5sig_pool();
1126 return 0;
1127
1128clear_hash:
1129 tcp_put_md5sig_pool();
1130clear_hash_noput:
1131 memset(md5_hash, 0, 16);
1132 return 1;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001133}
1134
Adam Langley49a72df2008-07-19 00:01:42 -07001135EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001136
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001137static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001138{
1139 /*
1140 * This gets called for each TCP segment that arrives
1141 * so we want to be efficient.
1142 * We have 3 drop cases:
1143 * o No MD5 hash and one expected.
1144 * o MD5 hash and we're not expecting one.
1145 * o MD5 hash and its wrong.
1146 */
1147 __u8 *hash_location = NULL;
1148 struct tcp_md5sig_key *hash_expected;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001149 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001150 struct tcphdr *th = tcp_hdr(skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001151 int genhash;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001152 unsigned char newhash[16];
1153
1154 hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
YOSHIFUJI Hideaki7d5d5522008-04-17 12:29:53 +09001155 hash_location = tcp_parse_md5sig_option(th);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001156
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001157 /* We've parsed the options - do we have a hash? */
1158 if (!hash_expected && !hash_location)
1159 return 0;
1160
1161 if (hash_expected && !hash_location) {
David S. Miller785957d2008-07-30 03:03:15 -07001162 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001163 return 1;
1164 }
1165
1166 if (!hash_expected && hash_location) {
David S. Miller785957d2008-07-30 03:03:15 -07001167 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001168 return 1;
1169 }
1170
1171 /* Okay, so this is hash_expected and hash_location -
1172 * so we need to calculate the checksum.
1173 */
Adam Langley49a72df2008-07-19 00:01:42 -07001174 genhash = tcp_v4_md5_hash_skb(newhash,
1175 hash_expected,
1176 NULL, NULL, skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001177
1178 if (genhash || memcmp(hash_location, newhash, 16) != 0) {
1179 if (net_ratelimit()) {
Harvey Harrison673d57e2008-10-31 00:53:57 -07001180 printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
1181 &iph->saddr, ntohs(th->source),
1182 &iph->daddr, ntohs(th->dest),
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001183 genhash ? " tcp_v4_calc_md5_hash failed" : "");
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001184 }
1185 return 1;
1186 }
1187 return 0;
1188}
1189
1190#endif
1191
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001192struct request_sock_ops tcp_request_sock_ops __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193 .family = PF_INET,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001194 .obj_size = sizeof(struct tcp_request_sock),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 .rtx_syn_ack = tcp_v4_send_synack,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001196 .send_ack = tcp_v4_reqsk_send_ack,
1197 .destructor = tcp_v4_reqsk_destructor,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 .send_reset = tcp_v4_send_reset,
1199};
1200
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001201#ifdef CONFIG_TCP_MD5SIG
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +00001202static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001203 .md5_lookup = tcp_v4_reqsk_md5_lookup,
John Dykstrae3afe7b2009-07-16 05:04:51 +00001204 .calc_md5_hash = tcp_v4_md5_hash_skb,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001205};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001206#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001207
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001208static struct timewait_sock_ops tcp_timewait_sock_ops = {
1209 .twsk_obj_size = sizeof(struct tcp_timewait_sock),
1210 .twsk_unique = tcp_twsk_unique,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001211 .twsk_destructor= tcp_twsk_destructor,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001212};
1213
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
1215{
William Allen Simpson4957faade2009-12-02 18:25:27 +00001216 struct tcp_extend_values tmp_ext;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 struct tcp_options_received tmp_opt;
William Allen Simpson4957faade2009-12-02 18:25:27 +00001218 u8 *hash_location;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001219 struct request_sock *req;
William Allen Simpsone6b4d112009-12-02 18:07:39 +00001220 struct inet_request_sock *ireq;
William Allen Simpson4957faade2009-12-02 18:25:27 +00001221 struct tcp_sock *tp = tcp_sk(sk);
William Allen Simpsone6b4d112009-12-02 18:07:39 +00001222 struct dst_entry *dst = NULL;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001223 __be32 saddr = ip_hdr(skb)->saddr;
1224 __be32 daddr = ip_hdr(skb)->daddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 __u32 isn = TCP_SKB_CB(skb)->when;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226#ifdef CONFIG_SYN_COOKIES
1227 int want_cookie = 0;
1228#else
1229#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
1230#endif
1231
1232 /* Never answer to SYNs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +00001233 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 goto drop;
1235
1236 /* TW buckets are converted to open requests without
1237 * limitations, they conserve resources and peer is
1238 * evidently real one.
1239 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001240 if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241#ifdef CONFIG_SYN_COOKIES
1242 if (sysctl_tcp_syncookies) {
1243 want_cookie = 1;
1244 } else
1245#endif
1246 goto drop;
1247 }
1248
1249 /* Accept backlog is full. If we have already queued enough
1250 * of warm entries in syn queue, drop request. It is better than
1251 * clogging syn queue with openreqs with exponentially increasing
1252 * timeout.
1253 */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001254 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 goto drop;
1256
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -07001257 req = inet_reqsk_alloc(&tcp_request_sock_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258 if (!req)
1259 goto drop;
1260
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001261#ifdef CONFIG_TCP_MD5SIG
1262 tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
1263#endif
1264
Gilad Ben-Yossef022c3f72009-10-28 04:15:22 +00001265 ireq = inet_rsk(req);
1266 ireq->loc_addr = daddr;
1267 ireq->rmt_addr = saddr;
1268 ireq->no_srccheck = inet_sk(sk)->transparent;
1269 ireq->opt = tcp_v4_save_options(sk, skb);
1270
1271 dst = inet_csk_route_req(sk, req);
1272 if(!dst)
1273 goto drop_and_free;
1274
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 tcp_clear_options(&tmp_opt);
William Allen Simpsonbee7ca92009-11-10 09:51:18 +00001276 tmp_opt.mss_clamp = TCP_MSS_DEFAULT;
William Allen Simpson4957faade2009-12-02 18:25:27 +00001277 tmp_opt.user_mss = tp->rx_opt.user_mss;
1278 tcp_parse_options(skb, &tmp_opt, &hash_location, 0, dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279
William Allen Simpson4957faade2009-12-02 18:25:27 +00001280 if (tmp_opt.cookie_plus > 0 &&
1281 tmp_opt.saw_tstamp &&
1282 !tp->rx_opt.cookie_out_never &&
1283 (sysctl_tcp_cookie_size > 0 ||
1284 (tp->cookie_values != NULL &&
1285 tp->cookie_values->cookie_desired > 0))) {
1286 u8 *c;
1287 u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
1288 int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
1289
1290 if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
1291 goto drop_and_release;
1292
1293 /* Secret recipe starts with IP addresses */
1294 *mess++ ^= daddr;
1295 *mess++ ^= saddr;
1296
1297 /* plus variable length Initiator Cookie */
1298 c = (u8 *)mess;
1299 while (l-- > 0)
1300 *c++ ^= *hash_location++;
1301
1302#ifdef CONFIG_SYN_COOKIES
1303 want_cookie = 0; /* not our kind of cookie */
1304#endif
1305 tmp_ext.cookie_out_never = 0; /* false */
1306 tmp_ext.cookie_plus = tmp_opt.cookie_plus;
1307 } else if (!tp->rx_opt.cookie_in_always) {
1308 /* redundant indications, but ensure initialization. */
1309 tmp_ext.cookie_out_never = 1; /* true */
1310 tmp_ext.cookie_plus = 0;
1311 } else {
1312 goto drop_and_release;
1313 }
1314 tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315
Florian Westphal4dfc2812008-04-10 03:12:40 -07001316 if (want_cookie && !tmp_opt.saw_tstamp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 tcp_clear_options(&tmp_opt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 tcp_openreq_init(req, &tmp_opt, skb);
1321
Paul Moore284904a2009-03-27 17:10:28 -04001322 if (security_inet_conn_request(sk, skb, req))
Gilad Ben-Yossef022c3f72009-10-28 04:15:22 +00001323 goto drop_and_release;
Paul Moore284904a2009-03-27 17:10:28 -04001324
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 if (!want_cookie)
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001326 TCP_ECN_create_request(req, tcp_hdr(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327
1328 if (want_cookie) {
1329#ifdef CONFIG_SYN_COOKIES
1330 syn_flood_warning(skb);
Florian Westphal4dfc2812008-04-10 03:12:40 -07001331 req->cookie_ts = tmp_opt.tstamp_ok;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332#endif
1333 isn = cookie_v4_init_sequence(sk, skb, &req->mss);
1334 } else if (!isn) {
1335 struct inet_peer *peer = NULL;
1336
1337 /* VJ's idea. We save last timestamp seen
1338 * from the destination in peer table, when entering
1339 * state TIME-WAIT, and check against it before
1340 * accepting new connection request.
1341 *
1342 * If "isn" is not zero, this request hit alive
1343 * timewait bucket, so that all the necessary checks
1344 * are made in the function processing timewait state.
1345 */
1346 if (tmp_opt.saw_tstamp &&
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -07001347 tcp_death_row.sysctl_tw_recycle &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
1349 peer->v4daddr == saddr) {
Eric Dumazet2c1409a2009-11-12 09:33:09 +00001350 if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 (s32)(peer->tcp_ts - req->ts_recent) >
1352 TCP_PAWS_WINDOW) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001353 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001354 goto drop_and_release;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 }
1356 }
1357 /* Kill the following clause, if you dislike this way. */
1358 else if (!sysctl_tcp_syncookies &&
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001359 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 (sysctl_max_syn_backlog >> 2)) &&
1361 (!peer || !peer->tcp_ts_stamp) &&
1362 (!dst || !dst_metric(dst, RTAX_RTT))) {
1363 /* Without syncookies last quarter of
1364 * backlog is filled with destinations,
1365 * proven to be alive.
1366 * It means that we continue to communicate
1367 * to destinations, already remembered
1368 * to the moment of synflood.
1369 */
Harvey Harrison673d57e2008-10-31 00:53:57 -07001370 LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n",
1371 &saddr, ntohs(tcp_hdr(skb)->source));
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001372 goto drop_and_release;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 }
1374
Gerrit Renkera94f7232006-11-10 14:06:49 -08001375 isn = tcp_v4_init_sequence(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 }
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001377 tcp_rsk(req)->snt_isn = isn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378
William Allen Simpson4957faade2009-12-02 18:25:27 +00001379 if (__tcp_v4_send_synack(sk, dst, req,
1380 (struct request_values *)&tmp_ext) ||
1381 want_cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 goto drop_and_free;
1383
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001384 inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 return 0;
1386
Denis V. Lunev7cd04fa2008-03-03 11:59:32 -08001387drop_and_release:
1388 dst_release(dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389drop_and_free:
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001390 reqsk_free(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391drop:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 return 0;
1393}
1394
1395
1396/*
1397 * The three way handshake has completed - we got a valid synack -
1398 * now create the new socket.
1399 */
1400struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001401 struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 struct dst_entry *dst)
1403{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001404 struct inet_request_sock *ireq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 struct inet_sock *newinet;
1406 struct tcp_sock *newtp;
1407 struct sock *newsk;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001408#ifdef CONFIG_TCP_MD5SIG
1409 struct tcp_md5sig_key *key;
1410#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411
1412 if (sk_acceptq_is_full(sk))
1413 goto exit_overflow;
1414
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001415 if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 goto exit;
1417
1418 newsk = tcp_create_openreq_child(sk, req, skb);
1419 if (!newsk)
1420 goto exit;
1421
Herbert Xubcd76112006-06-30 13:36:35 -07001422 newsk->sk_gso_type = SKB_GSO_TCPV4;
Arnaldo Carvalho de Melo6cbb0df2005-08-09 19:49:02 -07001423 sk_setup_caps(newsk, dst);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424
1425 newtp = tcp_sk(newsk);
1426 newinet = inet_sk(newsk);
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001427 ireq = inet_rsk(req);
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001428 newinet->inet_daddr = ireq->rmt_addr;
1429 newinet->inet_rcv_saddr = ireq->loc_addr;
1430 newinet->inet_saddr = ireq->loc_addr;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07001431 newinet->opt = ireq->opt;
1432 ireq->opt = NULL;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001433 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001434 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001435 inet_csk(newsk)->icsk_ext_hdr_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 if (newinet->opt)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001437 inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001438 newinet->inet_id = newtp->write_seq ^ jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439
John Heffner5d424d52006-03-20 17:53:41 -08001440 tcp_mtup_init(newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 tcp_sync_mss(newsk, dst_mtu(dst));
1442 newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
Tom Quetchenbachf5fff5d2008-09-21 00:21:51 -07001443 if (tcp_sk(sk)->rx_opt.user_mss &&
1444 tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
1445 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
1446
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 tcp_initialize_rcv_mss(newsk);
1448
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001449#ifdef CONFIG_TCP_MD5SIG
1450 /* Copy over the MD5 key from the original socket */
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001451 key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr);
1452 if (key != NULL) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001453 /*
1454 * We're using one, so create a matching key
1455 * on the newsk structure. If we fail to get
1456 * memory, then we end up not copying the key
1457 * across. Shucks.
1458 */
Arnaldo Carvalho de Melof6685932006-11-17 11:06:01 -02001459 char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
1460 if (newkey != NULL)
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001461 tcp_v4_md5_do_add(newsk, newinet->inet_daddr,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001462 newkey, key->keylen);
Adam Langley49a72df2008-07-19 00:01:42 -07001463 newsk->sk_route_caps &= ~NETIF_F_GSO_MASK;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001464 }
1465#endif
1466
Eric Dumazet9327f702009-12-04 03:46:54 +00001467 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001468 __inet_inherit_port(sk, newsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001469
1470 return newsk;
1471
1472exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001473 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -07001475 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476 dst_release(dst);
1477 return NULL;
1478}
1479
1480static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
1481{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001482 struct tcphdr *th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001483 const struct iphdr *iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 struct sock *nsk;
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001485 struct request_sock **prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 /* Find possible connection requests. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001487 struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
1488 iph->saddr, iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489 if (req)
1490 return tcp_check_req(sk, skb, req, prev);
1491
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001492 nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
Pavel Emelyanovc67499c2008-01-31 05:06:40 -08001493 th->source, iph->daddr, th->dest, inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001494
1495 if (nsk) {
1496 if (nsk->sk_state != TCP_TIME_WAIT) {
1497 bh_lock_sock(nsk);
1498 return nsk;
1499 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001500 inet_twsk_put(inet_twsk(nsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001501 return NULL;
1502 }
1503
1504#ifdef CONFIG_SYN_COOKIES
1505 if (!th->rst && !th->syn && th->ack)
1506 sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
1507#endif
1508 return sk;
1509}
1510
Al Virob51655b2006-11-14 21:40:42 -08001511static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001513 const struct iphdr *iph = ip_hdr(skb);
1514
Patrick McHardy84fa7932006-08-29 16:44:56 -07001515 if (skb->ip_summed == CHECKSUM_COMPLETE) {
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001516 if (!tcp_v4_check(skb->len, iph->saddr,
1517 iph->daddr, skb->csum)) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001518 skb->ip_summed = CHECKSUM_UNNECESSARY;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519 return 0;
Herbert Xufb286bb2005-11-10 13:01:24 -08001520 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001521 }
Herbert Xufb286bb2005-11-10 13:01:24 -08001522
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001523 skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
Herbert Xufb286bb2005-11-10 13:01:24 -08001524 skb->len, IPPROTO_TCP, 0);
1525
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 if (skb->len <= 76) {
Herbert Xufb286bb2005-11-10 13:01:24 -08001527 return __skb_checksum_complete(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 }
1529 return 0;
1530}
1531
1532
1533/* The socket must have it's spinlock held when we get
1534 * here.
1535 *
1536 * We have a potential double-lock case here, so even when
1537 * doing backlog processing we use the BH locking scheme.
1538 * This is because we cannot sleep with the original spinlock
1539 * held.
1540 */
1541int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
1542{
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001543 struct sock *rsk;
1544#ifdef CONFIG_TCP_MD5SIG
1545 /*
1546 * We really want to reject the packet as early as possible
1547 * if:
1548 * o We're expecting an MD5'd packet and this is no MD5 tcp option
1549 * o There is an MD5 option and we're not expecting one
1550 */
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02001551 if (tcp_v4_inbound_md5_hash(sk, skb))
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001552 goto discard;
1553#endif
1554
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1556 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001557 if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001558 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001560 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001561 TCP_CHECK_TIMER(sk);
1562 return 0;
1563 }
1564
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -07001565 if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566 goto csum_err;
1567
1568 if (sk->sk_state == TCP_LISTEN) {
1569 struct sock *nsk = tcp_v4_hnd_req(sk, skb);
1570 if (!nsk)
1571 goto discard;
1572
1573 if (nsk != sk) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001574 if (tcp_child_process(sk, nsk, skb)) {
1575 rsk = nsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001577 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 return 0;
1579 }
1580 }
1581
1582 TCP_CHECK_TIMER(sk);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001583 if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001584 rsk = sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 goto reset;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001586 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 TCP_CHECK_TIMER(sk);
1588 return 0;
1589
1590reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001591 tcp_v4_send_reset(rsk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592discard:
1593 kfree_skb(skb);
1594 /* Be careful here. If this function gets more complicated and
1595 * gcc suffers from register pressure on the x86, sk (in %ebx)
1596 * might be destroyed here. This current version compiles correctly,
1597 * but you have been warned.
1598 */
1599 return 0;
1600
1601csum_err:
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001602 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 goto discard;
1604}
1605
1606/*
1607 * From tcp_input.c
1608 */
1609
1610int tcp_v4_rcv(struct sk_buff *skb)
1611{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001612 const struct iphdr *iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 struct tcphdr *th;
1614 struct sock *sk;
1615 int ret;
Pavel Emelyanova86b1e32008-07-16 20:20:58 -07001616 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617
1618 if (skb->pkt_type != PACKET_HOST)
1619 goto discard_it;
1620
1621 /* Count it even if it's bad */
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001622 TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623
1624 if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1625 goto discard_it;
1626
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001627 th = tcp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628
1629 if (th->doff < sizeof(struct tcphdr) / 4)
1630 goto bad_packet;
1631 if (!pskb_may_pull(skb, th->doff * 4))
1632 goto discard_it;
1633
1634 /* An explanation is required here, I think.
1635 * Packet length and doff are validated by header prediction,
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -08001636 * provided case of th->doff==0 is eliminated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 * So, we defer the checks. */
Herbert Xu60476372007-04-09 11:59:39 -07001638 if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639 goto bad_packet;
1640
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -07001641 th = tcp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001642 iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1644 TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1645 skb->len - th->doff * 4);
1646 TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1647 TCP_SKB_CB(skb)->when = 0;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001648 TCP_SKB_CB(skb)->flags = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001649 TCP_SKB_CB(skb)->sacked = 0;
1650
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -07001651 sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 if (!sk)
1653 goto no_tcp_socket;
1654
1655process:
1656 if (sk->sk_state == TCP_TIME_WAIT)
1657 goto do_time_wait;
1658
1659 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
1660 goto discard_and_relse;
Patrick McHardyb59c2702006-01-06 23:06:10 -08001661 nf_reset(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662
Dmitry Mishinfda9ef52006-08-31 15:28:39 -07001663 if (sk_filter(sk, skb))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 goto discard_and_relse;
1665
1666 skb->dev = NULL;
1667
Ingo Molnarc6366182006-07-03 00:25:13 -07001668 bh_lock_sock_nested(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669 ret = 0;
1670 if (!sock_owned_by_user(sk)) {
Chris Leech1a2449a2006-05-23 18:05:53 -07001671#ifdef CONFIG_NET_DMA
1672 struct tcp_sock *tp = tcp_sk(sk);
1673 if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
Dan Williamsf67b4592009-01-06 11:38:15 -07001674 tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
Chris Leech1a2449a2006-05-23 18:05:53 -07001675 if (tp->ucopy.dma_chan)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 ret = tcp_v4_do_rcv(sk, skb);
Chris Leech1a2449a2006-05-23 18:05:53 -07001677 else
1678#endif
1679 {
1680 if (!tcp_prequeue(sk, skb))
Shan Weiae8d7f82009-05-05 01:01:29 +00001681 ret = tcp_v4_do_rcv(sk, skb);
Chris Leech1a2449a2006-05-23 18:05:53 -07001682 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 } else
1684 sk_add_backlog(sk, skb);
1685 bh_unlock_sock(sk);
1686
1687 sock_put(sk);
1688
1689 return ret;
1690
1691no_tcp_socket:
1692 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
1693 goto discard_it;
1694
1695 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
1696bad_packet:
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001697 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 } else {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001699 tcp_v4_send_reset(NULL, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 }
1701
1702discard_it:
1703 /* Discard frame. */
1704 kfree_skb(skb);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001705 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
1707discard_and_relse:
1708 sock_put(sk);
1709 goto discard_it;
1710
1711do_time_wait:
1712 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001713 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 goto discard_it;
1715 }
1716
1717 if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
Pavel Emelyanov63231bd2008-07-16 20:22:25 -07001718 TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001719 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 goto discard_it;
1721 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001722 switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 case TCP_TW_SYN: {
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +09001724 struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
Pavel Emelyanovc67499c2008-01-31 05:06:40 -08001725 &tcp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07001726 iph->daddr, th->dest,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001727 inet_iif(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 if (sk2) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -07001729 inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
1730 inet_twsk_put(inet_twsk(sk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 sk = sk2;
1732 goto process;
1733 }
1734 /* Fall through to ACK */
1735 }
1736 case TCP_TW_ACK:
1737 tcp_v4_timewait_ack(sk, skb);
1738 break;
1739 case TCP_TW_RST:
1740 goto no_tcp_socket;
1741 case TCP_TW_SUCCESS:;
1742 }
1743 goto discard_it;
1744}
1745
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746/* VJ's idea. Save last timestamp seen from this destination
1747 * and hold it at least for normal timewait interval to use for duplicate
1748 * segment detection in subsequent connections, before they enter synchronized
1749 * state.
1750 */
1751
1752int tcp_v4_remember_stamp(struct sock *sk)
1753{
1754 struct inet_sock *inet = inet_sk(sk);
1755 struct tcp_sock *tp = tcp_sk(sk);
1756 struct rtable *rt = (struct rtable *)__sk_dst_get(sk);
1757 struct inet_peer *peer = NULL;
1758 int release_it = 0;
1759
Eric Dumazetc720c7e2009-10-15 06:30:45 +00001760 if (!rt || rt->rt_dst != inet->inet_daddr) {
1761 peer = inet_getpeer(inet->inet_daddr, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762 release_it = 1;
1763 } else {
1764 if (!rt->peer)
1765 rt_bind_peer(rt, 1);
1766 peer = rt->peer;
1767 }
1768
1769 if (peer) {
1770 if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
Eric Dumazet2c1409a2009-11-12 09:33:09 +00001771 ((u32)get_seconds() - peer->tcp_ts_stamp > TCP_PAWS_MSL &&
1772 peer->tcp_ts_stamp <= (u32)tp->rx_opt.ts_recent_stamp)) {
1773 peer->tcp_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001774 peer->tcp_ts = tp->rx_opt.ts_recent;
1775 }
1776 if (release_it)
1777 inet_putpeer(peer);
1778 return 1;
1779 }
1780
1781 return 0;
1782}
1783
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001784int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785{
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001786 struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787
1788 if (peer) {
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001789 const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
1790
1791 if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 ||
Eric Dumazet2c1409a2009-11-12 09:33:09 +00001792 ((u32)get_seconds() - peer->tcp_ts_stamp > TCP_PAWS_MSL &&
1793 peer->tcp_ts_stamp <= (u32)tcptw->tw_ts_recent_stamp)) {
1794 peer->tcp_ts_stamp = (u32)tcptw->tw_ts_recent_stamp;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001795 peer->tcp_ts = tcptw->tw_ts_recent;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796 }
1797 inet_putpeer(peer);
1798 return 1;
1799 }
1800
1801 return 0;
1802}
1803
Stephen Hemminger3b401a82009-09-01 19:25:04 +00001804const struct inet_connection_sock_af_ops ipv4_specific = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001805 .queue_xmit = ip_queue_xmit,
1806 .send_check = tcp_v4_send_check,
1807 .rebuild_header = inet_sk_rebuild_header,
1808 .conn_request = tcp_v4_conn_request,
1809 .syn_recv_sock = tcp_v4_syn_recv_sock,
1810 .remember_stamp = tcp_v4_remember_stamp,
1811 .net_header_len = sizeof(struct iphdr),
1812 .setsockopt = ip_setsockopt,
1813 .getsockopt = ip_getsockopt,
1814 .addr2sockaddr = inet_csk_addr2sockaddr,
1815 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001816 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001817#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001818 .compat_setsockopt = compat_ip_setsockopt,
1819 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001820#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821};
1822
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001823#ifdef CONFIG_TCP_MD5SIG
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +00001824static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001825 .md5_lookup = tcp_v4_md5_lookup,
Adam Langley49a72df2008-07-19 00:01:42 -07001826 .calc_md5_hash = tcp_v4_md5_hash_skb,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001827 .md5_add = tcp_v4_md5_add_func,
1828 .md5_parse = tcp_v4_parse_md5_keys,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001829};
Andrew Mortonb6332e62006-11-30 19:16:28 -08001830#endif
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001831
Linus Torvalds1da177e2005-04-16 15:20:36 -07001832/* NOTE: A lot of things set to zero explicitly by call to
1833 * sk_alloc() so need not be done here.
1834 */
1835static int tcp_v4_init_sock(struct sock *sk)
1836{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001837 struct inet_connection_sock *icsk = inet_csk(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 struct tcp_sock *tp = tcp_sk(sk);
1839
1840 skb_queue_head_init(&tp->out_of_order_queue);
1841 tcp_init_xmit_timers(sk);
1842 tcp_prequeue_init(tp);
1843
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001844 icsk->icsk_rto = TCP_TIMEOUT_INIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001845 tp->mdev = TCP_TIMEOUT_INIT;
1846
1847 /* So many TCP implementations out there (incorrectly) count the
1848 * initial SYN frame in their delayed-ACK and congestion control
1849 * algorithms that we must have the following bandaid to talk
1850 * efficiently to them. -DaveM
1851 */
1852 tp->snd_cwnd = 2;
1853
1854 /* See draft-stevens-tcpca-spec-01 for discussion of the
1855 * initialization of these values.
1856 */
Ilpo Järvinen0b6a05c2009-09-15 01:30:10 -07001857 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858 tp->snd_cwnd_clamp = ~0;
William Allen Simpsonbee7ca92009-11-10 09:51:18 +00001859 tp->mss_cache = TCP_MSS_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860
1861 tp->reordering = sysctl_tcp_reordering;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001862 icsk->icsk_ca_ops = &tcp_init_congestion_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001863
1864 sk->sk_state = TCP_CLOSE;
1865
1866 sk->sk_write_space = sk_stream_write_space;
1867 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1868
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -08001869 icsk->icsk_af_ops = &ipv4_specific;
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001870 icsk->icsk_sync_mss = tcp_sync_mss;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001871#ifdef CONFIG_TCP_MD5SIG
1872 tp->af_specific = &tcp_sock_ipv4_specific;
1873#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874
William Allen Simpson435cf552009-12-02 18:17:05 +00001875 /* TCP Cookie Transactions */
1876 if (sysctl_tcp_cookie_size > 0) {
1877 /* Default, cookies without s_data_payload. */
1878 tp->cookie_values =
1879 kzalloc(sizeof(*tp->cookie_values),
1880 sk->sk_allocation);
1881 if (tp->cookie_values != NULL)
1882 kref_init(&tp->cookie_values->kref);
1883 }
1884 /* Presumed zeroed, in order of appearance:
1885 * cookie_in_always, cookie_out_never,
1886 * s_data_constant, s_data_in, s_data_out
1887 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 sk->sk_sndbuf = sysctl_tcp_wmem[1];
1889 sk->sk_rcvbuf = sysctl_tcp_rmem[1];
1890
Herbert Xueb4dea52008-12-29 23:04:08 -08001891 local_bh_disable();
Eric Dumazet17483762008-11-25 21:16:35 -08001892 percpu_counter_inc(&tcp_sockets_allocated);
Herbert Xueb4dea52008-12-29 23:04:08 -08001893 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894
1895 return 0;
1896}
1897
Brian Haley7d06b2e2008-06-14 17:04:49 -07001898void tcp_v4_destroy_sock(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899{
1900 struct tcp_sock *tp = tcp_sk(sk);
1901
1902 tcp_clear_xmit_timers(sk);
1903
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03001904 tcp_cleanup_congestion_control(sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -07001905
Linus Torvalds1da177e2005-04-16 15:20:36 -07001906 /* Cleanup up the write buffer. */
David S. Millerfe067e82007-03-07 12:12:44 -08001907 tcp_write_queue_purge(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001908
1909 /* Cleans up our, hopefully empty, out_of_order_queue. */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001910 __skb_queue_purge(&tp->out_of_order_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001912#ifdef CONFIG_TCP_MD5SIG
1913 /* Clean up the MD5 key list, if any */
1914 if (tp->md5sig_info) {
1915 tcp_v4_clear_md5_list(sk);
1916 kfree(tp->md5sig_info);
1917 tp->md5sig_info = NULL;
1918 }
1919#endif
1920
Chris Leech1a2449a2006-05-23 18:05:53 -07001921#ifdef CONFIG_NET_DMA
1922 /* Cleans up our sk_async_wait_queue */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001923 __skb_queue_purge(&sk->sk_async_wait_queue);
Chris Leech1a2449a2006-05-23 18:05:53 -07001924#endif
1925
Linus Torvalds1da177e2005-04-16 15:20:36 -07001926 /* Clean prequeue, it must be empty really */
1927 __skb_queue_purge(&tp->ucopy.prequeue);
1928
1929 /* Clean up a referenced TCP bind bucket. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001930 if (inet_csk(sk)->icsk_bind_hash)
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08001931 inet_put_port(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932
1933 /*
1934 * If sendmsg cached page exists, toss it.
1935 */
1936 if (sk->sk_sndmsg_page) {
1937 __free_page(sk->sk_sndmsg_page);
1938 sk->sk_sndmsg_page = NULL;
1939 }
1940
William Allen Simpson435cf552009-12-02 18:17:05 +00001941 /* TCP Cookie Transactions */
1942 if (tp->cookie_values != NULL) {
1943 kref_put(&tp->cookie_values->kref,
1944 tcp_cookie_values_release);
1945 tp->cookie_values = NULL;
1946 }
1947
Eric Dumazet17483762008-11-25 21:16:35 -08001948 percpu_counter_dec(&tcp_sockets_allocated);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001949}
1950
1951EXPORT_SYMBOL(tcp_v4_destroy_sock);
1952
1953#ifdef CONFIG_PROC_FS
1954/* Proc filesystem TCP sock list dumping. */
1955
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001956static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001957{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001958 return hlist_nulls_empty(head) ? NULL :
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001959 list_entry(head->first, struct inet_timewait_sock, tw_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001960}
1961
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07001962static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001963{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08001964 return !is_a_nulls(tw->tw_node.next) ?
1965 hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001966}
1967
1968static void *listening_get_next(struct seq_file *seq, void *cur)
1969{
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07001970 struct inet_connection_sock *icsk;
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001971 struct hlist_nulls_node *node;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001972 struct sock *sk = cur;
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001973 struct inet_listen_hashbucket *ilb;
Jianjun Kong5799de02008-11-03 02:49:10 -08001974 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07001975 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976
1977 if (!sk) {
1978 st->bucket = 0;
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001979 ilb = &tcp_hashinfo.listening_hash[0];
1980 spin_lock_bh(&ilb->lock);
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08001981 sk = sk_nulls_head(&ilb->head);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 goto get_sk;
1983 }
Eric Dumazet5caea4e2008-11-20 00:40:07 -08001984 ilb = &tcp_hashinfo.listening_hash[st->bucket];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 ++st->num;
1986
1987 if (st->state == TCP_SEQ_STATE_OPENREQ) {
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07001988 struct request_sock *req = cur;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989
Eric Dumazet72a3eff2006-11-16 02:30:37 -08001990 icsk = inet_csk(st->syn_wait_sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 req = req->dl_next;
1992 while (1) {
1993 while (req) {
Daniel Lezcanobdccc4c2008-07-19 00:15:13 -07001994 if (req->rsk_ops->family == st->family) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995 cur = req;
1996 goto out;
1997 }
1998 req = req->dl_next;
1999 }
Eric Dumazet72a3eff2006-11-16 02:30:37 -08002000 if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002001 break;
2002get_req:
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002003 req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004 }
2005 sk = sk_next(st->syn_wait_sk);
2006 st->state = TCP_SEQ_STATE_LISTENING;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002007 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002008 } else {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002009 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002010 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2011 if (reqsk_queue_len(&icsk->icsk_accept_queue))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002012 goto start_req;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002013 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014 sk = sk_next(sk);
2015 }
2016get_sk:
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08002017 sk_nulls_for_each_from(sk, node) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002018 if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019 cur = sk;
2020 goto out;
2021 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09002022 icsk = inet_csk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002023 read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
2024 if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025start_req:
2026 st->uid = sock_i_uid(sk);
2027 st->syn_wait_sk = sk;
2028 st->state = TCP_SEQ_STATE_OPENREQ;
2029 st->sbucket = 0;
2030 goto get_req;
2031 }
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002032 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033 }
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002034 spin_unlock_bh(&ilb->lock);
Arnaldo Carvalho de Melo0f7ff922005-08-09 19:59:44 -07002035 if (++st->bucket < INET_LHTABLE_SIZE) {
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002036 ilb = &tcp_hashinfo.listening_hash[st->bucket];
2037 spin_lock_bh(&ilb->lock);
Eric Dumazetc25eb3b2008-11-23 17:22:55 -08002038 sk = sk_nulls_head(&ilb->head);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002039 goto get_sk;
2040 }
2041 cur = NULL;
2042out:
2043 return cur;
2044}
2045
2046static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
2047{
2048 void *rc = listening_get_next(seq, NULL);
2049
2050 while (rc && *pos) {
2051 rc = listening_get_next(seq, rc);
2052 --*pos;
2053 }
2054 return rc;
2055}
2056
Andi Kleen6eac5602008-08-28 01:08:02 -07002057static inline int empty_bucket(struct tcp_iter_state *st)
2058{
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002059 return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
2060 hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
Andi Kleen6eac5602008-08-28 01:08:02 -07002061}
2062
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063static void *established_get_first(struct seq_file *seq)
2064{
Jianjun Kong5799de02008-11-03 02:49:10 -08002065 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07002066 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002067 void *rc = NULL;
2068
Eric Dumazetf373b532009-10-09 00:16:19 +00002069 for (st->bucket = 0; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 struct sock *sk;
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002071 struct hlist_nulls_node *node;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002072 struct inet_timewait_sock *tw;
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002073 spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074
Andi Kleen6eac5602008-08-28 01:08:02 -07002075 /* Lockless fast path for the common case of empty buckets */
2076 if (empty_bucket(st))
2077 continue;
2078
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002079 spin_lock_bh(lock);
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002080 sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
Daniel Lezcanof40c8172008-03-21 04:13:54 -07002081 if (sk->sk_family != st->family ||
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002082 !net_eq(sock_net(sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002083 continue;
2084 }
2085 rc = sk;
2086 goto out;
2087 }
2088 st->state = TCP_SEQ_STATE_TIME_WAIT;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002089 inet_twsk_for_each(tw, node,
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002090 &tcp_hashinfo.ehash[st->bucket].twchain) {
Pavel Emelyanov28518fc2008-03-21 15:52:00 -07002091 if (tw->tw_family != st->family ||
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002092 !net_eq(twsk_net(tw), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002093 continue;
2094 }
2095 rc = tw;
2096 goto out;
2097 }
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002098 spin_unlock_bh(lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099 st->state = TCP_SEQ_STATE_ESTABLISHED;
2100 }
2101out:
2102 return rc;
2103}
2104
2105static void *established_get_next(struct seq_file *seq, void *cur)
2106{
2107 struct sock *sk = cur;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -07002108 struct inet_timewait_sock *tw;
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002109 struct hlist_nulls_node *node;
Jianjun Kong5799de02008-11-03 02:49:10 -08002110 struct tcp_iter_state *st = seq->private;
Denis V. Luneva4146b12008-04-13 22:11:14 -07002111 struct net *net = seq_file_net(seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112
2113 ++st->num;
2114
2115 if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
2116 tw = cur;
2117 tw = tw_next(tw);
2118get_tw:
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002119 while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120 tw = tw_next(tw);
2121 }
2122 if (tw) {
2123 cur = tw;
2124 goto out;
2125 }
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002126 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127 st->state = TCP_SEQ_STATE_ESTABLISHED;
2128
Andi Kleen6eac5602008-08-28 01:08:02 -07002129 /* Look for next non empty bucket */
Eric Dumazetf373b532009-10-09 00:16:19 +00002130 while (++st->bucket <= tcp_hashinfo.ehash_mask &&
Andi Kleen6eac5602008-08-28 01:08:02 -07002131 empty_bucket(st))
2132 ;
Eric Dumazetf373b532009-10-09 00:16:19 +00002133 if (st->bucket > tcp_hashinfo.ehash_mask)
Andi Kleen6eac5602008-08-28 01:08:02 -07002134 return NULL;
2135
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002136 spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002137 sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138 } else
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002139 sk = sk_nulls_next(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002141 sk_nulls_for_each_from(sk, node) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +09002142 if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002143 goto found;
2144 }
2145
2146 st->state = TCP_SEQ_STATE_TIME_WAIT;
Eric Dumazetdbca9b2752007-02-08 14:16:46 -08002147 tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148 goto get_tw;
2149found:
2150 cur = sk;
2151out:
2152 return cur;
2153}
2154
2155static void *established_get_idx(struct seq_file *seq, loff_t pos)
2156{
2157 void *rc = established_get_first(seq);
2158
2159 while (rc && pos) {
2160 rc = established_get_next(seq, rc);
2161 --pos;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002162 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163 return rc;
2164}
2165
2166static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
2167{
2168 void *rc;
Jianjun Kong5799de02008-11-03 02:49:10 -08002169 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002170
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 st->state = TCP_SEQ_STATE_LISTENING;
2172 rc = listening_get_idx(seq, &pos);
2173
2174 if (!rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002175 st->state = TCP_SEQ_STATE_ESTABLISHED;
2176 rc = established_get_idx(seq, pos);
2177 }
2178
2179 return rc;
2180}
2181
2182static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
2183{
Jianjun Kong5799de02008-11-03 02:49:10 -08002184 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185 st->state = TCP_SEQ_STATE_LISTENING;
2186 st->num = 0;
2187 return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2188}
2189
2190static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2191{
2192 void *rc = NULL;
Jianjun Kong5799de02008-11-03 02:49:10 -08002193 struct tcp_iter_state *st;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002194
2195 if (v == SEQ_START_TOKEN) {
2196 rc = tcp_get_idx(seq, 0);
2197 goto out;
2198 }
2199 st = seq->private;
2200
2201 switch (st->state) {
2202 case TCP_SEQ_STATE_OPENREQ:
2203 case TCP_SEQ_STATE_LISTENING:
2204 rc = listening_get_next(seq, v);
2205 if (!rc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002206 st->state = TCP_SEQ_STATE_ESTABLISHED;
2207 rc = established_get_first(seq);
2208 }
2209 break;
2210 case TCP_SEQ_STATE_ESTABLISHED:
2211 case TCP_SEQ_STATE_TIME_WAIT:
2212 rc = established_get_next(seq, v);
2213 break;
2214 }
2215out:
2216 ++*pos;
2217 return rc;
2218}
2219
2220static void tcp_seq_stop(struct seq_file *seq, void *v)
2221{
Jianjun Kong5799de02008-11-03 02:49:10 -08002222 struct tcp_iter_state *st = seq->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002223
2224 switch (st->state) {
2225 case TCP_SEQ_STATE_OPENREQ:
2226 if (v) {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002227 struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
2228 read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002229 }
2230 case TCP_SEQ_STATE_LISTENING:
2231 if (v != SEQ_START_TOKEN)
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002232 spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233 break;
2234 case TCP_SEQ_STATE_TIME_WAIT:
2235 case TCP_SEQ_STATE_ESTABLISHED:
2236 if (v)
Eric Dumazet9db66bd2008-11-20 20:39:09 -08002237 spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002238 break;
2239 }
2240}
2241
2242static int tcp_seq_open(struct inode *inode, struct file *file)
2243{
2244 struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 struct tcp_iter_state *s;
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002246 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002247
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002248 err = seq_open_net(inode, file, &afinfo->seq_ops,
2249 sizeof(struct tcp_iter_state));
2250 if (err < 0)
2251 return err;
Daniel Lezcanof40c8172008-03-21 04:13:54 -07002252
Denis V. Lunev52d6f3f2008-04-13 22:12:41 -07002253 s = ((struct seq_file *)file->private_data)->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002254 s->family = afinfo->family;
Daniel Lezcanof40c8172008-03-21 04:13:54 -07002255 return 0;
2256}
2257
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002258int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002259{
2260 int rc = 0;
2261 struct proc_dir_entry *p;
2262
Denis V. Lunev68fcadd2008-04-13 22:13:30 -07002263 afinfo->seq_fops.open = tcp_seq_open;
2264 afinfo->seq_fops.read = seq_read;
2265 afinfo->seq_fops.llseek = seq_lseek;
2266 afinfo->seq_fops.release = seq_release_net;
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002267
Denis V. Lunev9427c4b2008-04-13 22:12:13 -07002268 afinfo->seq_ops.start = tcp_seq_start;
2269 afinfo->seq_ops.next = tcp_seq_next;
2270 afinfo->seq_ops.stop = tcp_seq_stop;
2271
Denis V. Lunev84841c32008-05-02 04:10:08 -07002272 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
2273 &afinfo->seq_fops, afinfo);
2274 if (!p)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002275 rc = -ENOMEM;
2276 return rc;
2277}
2278
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002279void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002280{
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07002281 proc_net_remove(net, afinfo->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002282}
2283
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002284static void get_openreq4(struct sock *sk, struct request_sock *req,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002285 struct seq_file *f, int i, int uid, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002286{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002287 const struct inet_request_sock *ireq = inet_rsk(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002288 int ttd = req->expires - jiffies;
2289
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002290 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2291 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292 i,
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002293 ireq->loc_addr,
Eric Dumazetc720c7e2009-10-15 06:30:45 +00002294 ntohs(inet_sk(sk)->inet_sport),
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -07002295 ireq->rmt_addr,
2296 ntohs(ireq->rmt_port),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002297 TCP_SYN_RECV,
2298 0, 0, /* could print option size, but that is af dependent. */
2299 1, /* timers active (only the expire timer) */
2300 jiffies_to_clock_t(ttd),
2301 req->retrans,
2302 uid,
2303 0, /* non standard timer */
2304 0, /* open_requests have no inode */
2305 atomic_read(&sk->sk_refcnt),
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002306 req,
2307 len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002308}
2309
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002310static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002311{
2312 int timer_active;
2313 unsigned long timer_expires;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002314 struct tcp_sock *tp = tcp_sk(sk);
2315 const struct inet_connection_sock *icsk = inet_csk(sk);
2316 struct inet_sock *inet = inet_sk(sk);
Eric Dumazetc720c7e2009-10-15 06:30:45 +00002317 __be32 dest = inet->inet_daddr;
2318 __be32 src = inet->inet_rcv_saddr;
2319 __u16 destp = ntohs(inet->inet_dport);
2320 __u16 srcp = ntohs(inet->inet_sport);
Eric Dumazet49d09002009-12-03 16:06:13 -08002321 int rx_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002322
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002323 if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002324 timer_active = 1;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002325 timer_expires = icsk->icsk_timeout;
2326 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002327 timer_active = 4;
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002328 timer_expires = icsk->icsk_timeout;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002329 } else if (timer_pending(&sk->sk_timer)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002330 timer_active = 2;
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002331 timer_expires = sk->sk_timer.expires;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002332 } else {
2333 timer_active = 0;
2334 timer_expires = jiffies;
2335 }
2336
Eric Dumazet49d09002009-12-03 16:06:13 -08002337 if (sk->sk_state == TCP_LISTEN)
2338 rx_queue = sk->sk_ack_backlog;
2339 else
2340 /*
2341 * because we dont lock socket, we might find a transient negative value
2342 */
2343 rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
2344
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002345 seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
Stephen Hemminger7be87352008-06-27 20:00:19 -07002346 "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002347 i, src, srcp, dest, destp, sk->sk_state,
Sridhar Samudrala47da8ee2006-06-27 13:29:00 -07002348 tp->write_seq - tp->snd_una,
Eric Dumazet49d09002009-12-03 16:06:13 -08002349 rx_queue,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002350 timer_active,
2351 jiffies_to_clock_t(timer_expires - jiffies),
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002352 icsk->icsk_retransmits,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002353 sock_i_uid(sk),
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -03002354 icsk->icsk_probes_out,
Ilpo Järvinencf4c6bf2007-02-22 01:13:58 -08002355 sock_i_ino(sk),
2356 atomic_read(&sk->sk_refcnt), sk,
Stephen Hemminger7be87352008-06-27 20:00:19 -07002357 jiffies_to_clock_t(icsk->icsk_rto),
2358 jiffies_to_clock_t(icsk->icsk_ack.ato),
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002359 (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002360 tp->snd_cwnd,
Ilpo Järvinen0b6a05c2009-09-15 01:30:10 -07002361 tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002362 len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002363}
2364
Arnaldo Carvalho de Melo71742592006-11-17 10:57:30 -02002365static void get_timewait4_sock(struct inet_timewait_sock *tw,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002366 struct seq_file *f, int i, int *len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367{
Al Viro23f33c22006-09-27 18:43:50 -07002368 __be32 dest, src;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002369 __u16 destp, srcp;
2370 int ttd = tw->tw_ttd - jiffies;
2371
2372 if (ttd < 0)
2373 ttd = 0;
2374
2375 dest = tw->tw_daddr;
2376 src = tw->tw_rcv_saddr;
2377 destp = ntohs(tw->tw_dport);
2378 srcp = ntohs(tw->tw_sport);
2379
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002380 seq_printf(f, "%4d: %08X:%04X %08X:%04X"
2381 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382 i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
2383 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002384 atomic_read(&tw->tw_refcnt), tw, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002385}
2386
2387#define TMPSZ 150
2388
2389static int tcp4_seq_show(struct seq_file *seq, void *v)
2390{
Jianjun Kong5799de02008-11-03 02:49:10 -08002391 struct tcp_iter_state *st;
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002392 int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002393
2394 if (v == SEQ_START_TOKEN) {
2395 seq_printf(seq, "%-*s\n", TMPSZ - 1,
2396 " sl local_address rem_address st tx_queue "
2397 "rx_queue tr tm->when retrnsmt uid timeout "
2398 "inode");
2399 goto out;
2400 }
2401 st = seq->private;
2402
2403 switch (st->state) {
2404 case TCP_SEQ_STATE_LISTENING:
2405 case TCP_SEQ_STATE_ESTABLISHED:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002406 get_tcp4_sock(v, seq, st->num, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002407 break;
2408 case TCP_SEQ_STATE_OPENREQ:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002409 get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002410 break;
2411 case TCP_SEQ_STATE_TIME_WAIT:
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002412 get_timewait4_sock(v, seq, st->num, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002413 break;
2414 }
Pavel Emelyanov5e659e42008-04-24 01:02:16 -07002415 seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002416out:
2417 return 0;
2418}
2419
Linus Torvalds1da177e2005-04-16 15:20:36 -07002420static struct tcp_seq_afinfo tcp4_seq_afinfo = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002421 .name = "tcp",
2422 .family = AF_INET,
Denis V. Lunev5f4472c2008-04-13 22:13:53 -07002423 .seq_fops = {
2424 .owner = THIS_MODULE,
2425 },
Denis V. Lunev9427c4b2008-04-13 22:12:13 -07002426 .seq_ops = {
2427 .show = tcp4_seq_show,
2428 },
Linus Torvalds1da177e2005-04-16 15:20:36 -07002429};
2430
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002431static int tcp4_proc_init_net(struct net *net)
2432{
2433 return tcp_proc_register(net, &tcp4_seq_afinfo);
2434}
2435
2436static void tcp4_proc_exit_net(struct net *net)
2437{
2438 tcp_proc_unregister(net, &tcp4_seq_afinfo);
2439}
2440
2441static struct pernet_operations tcp4_net_ops = {
2442 .init = tcp4_proc_init_net,
2443 .exit = tcp4_proc_exit_net,
2444};
2445
Linus Torvalds1da177e2005-04-16 15:20:36 -07002446int __init tcp4_proc_init(void)
2447{
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002448 return register_pernet_subsys(&tcp4_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449}
2450
2451void tcp4_proc_exit(void)
2452{
Pavel Emelyanov757764f2008-03-24 14:56:02 -07002453 unregister_pernet_subsys(&tcp4_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002454}
2455#endif /* CONFIG_PROC_FS */
2456
Herbert Xubf296b12008-12-15 23:43:36 -08002457struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
2458{
Herbert Xu36e7b1b2009-04-27 05:44:45 -07002459 struct iphdr *iph = skb_gro_network_header(skb);
Herbert Xubf296b12008-12-15 23:43:36 -08002460
2461 switch (skb->ip_summed) {
2462 case CHECKSUM_COMPLETE:
Herbert Xu86911732009-01-29 14:19:50 +00002463 if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
Herbert Xubf296b12008-12-15 23:43:36 -08002464 skb->csum)) {
2465 skb->ip_summed = CHECKSUM_UNNECESSARY;
2466 break;
2467 }
2468
2469 /* fall through */
2470 case CHECKSUM_NONE:
2471 NAPI_GRO_CB(skb)->flush = 1;
2472 return NULL;
2473 }
2474
2475 return tcp_gro_receive(head, skb);
2476}
2477EXPORT_SYMBOL(tcp4_gro_receive);
2478
2479int tcp4_gro_complete(struct sk_buff *skb)
2480{
2481 struct iphdr *iph = ip_hdr(skb);
2482 struct tcphdr *th = tcp_hdr(skb);
2483
2484 th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
2485 iph->saddr, iph->daddr, 0);
2486 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
2487
2488 return tcp_gro_complete(skb);
2489}
2490EXPORT_SYMBOL(tcp4_gro_complete);
2491
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492struct proto tcp_prot = {
2493 .name = "TCP",
2494 .owner = THIS_MODULE,
2495 .close = tcp_close,
2496 .connect = tcp_v4_connect,
2497 .disconnect = tcp_disconnect,
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -07002498 .accept = inet_csk_accept,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002499 .ioctl = tcp_ioctl,
2500 .init = tcp_v4_init_sock,
2501 .destroy = tcp_v4_destroy_sock,
2502 .shutdown = tcp_shutdown,
2503 .setsockopt = tcp_setsockopt,
2504 .getsockopt = tcp_getsockopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002505 .recvmsg = tcp_recvmsg,
2506 .backlog_rcv = tcp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -08002507 .hash = inet_hash,
2508 .unhash = inet_unhash,
2509 .get_port = inet_csk_get_port,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002510 .enter_memory_pressure = tcp_enter_memory_pressure,
2511 .sockets_allocated = &tcp_sockets_allocated,
Arnaldo Carvalho de Melo0a5578c2005-08-09 20:11:41 -07002512 .orphan_count = &tcp_orphan_count,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002513 .memory_allocated = &tcp_memory_allocated,
2514 .memory_pressure = &tcp_memory_pressure,
2515 .sysctl_mem = sysctl_tcp_mem,
2516 .sysctl_wmem = sysctl_tcp_wmem,
2517 .sysctl_rmem = sysctl_tcp_rmem,
2518 .max_header = MAX_TCP_HEADER,
2519 .obj_size = sizeof(struct tcp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -08002520 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08002521 .twsk_prot = &tcp_timewait_sock_ops,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -07002522 .rsk_prot = &tcp_request_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -07002523 .h.hashinfo = &tcp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08002524#ifdef CONFIG_COMPAT
2525 .compat_setsockopt = compat_tcp_setsockopt,
2526 .compat_getsockopt = compat_tcp_getsockopt,
2527#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002528};
2529
Denis V. Lunev046ee902008-04-03 14:31:33 -07002530
2531static int __net_init tcp_sk_init(struct net *net)
2532{
2533 return inet_ctl_sock_create(&net->ipv4.tcp_sock,
2534 PF_INET, SOCK_RAW, IPPROTO_TCP, net);
2535}
2536
2537static void __net_exit tcp_sk_exit(struct net *net)
2538{
2539 inet_ctl_sock_destroy(net->ipv4.tcp_sock);
Eric W. Biedermanb099ce22009-12-03 02:29:09 +00002540}
2541
2542static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
2543{
2544 inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
Denis V. Lunev046ee902008-04-03 14:31:33 -07002545}
2546
2547static struct pernet_operations __net_initdata tcp_sk_ops = {
Eric W. Biedermanb099ce22009-12-03 02:29:09 +00002548 .init = tcp_sk_init,
2549 .exit = tcp_sk_exit,
2550 .exit_batch = tcp_sk_exit_batch,
Denis V. Lunev046ee902008-04-03 14:31:33 -07002551};
2552
Denis V. Lunev9b0f9762008-02-29 11:13:15 -08002553void __init tcp_v4_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002554{
Eric Dumazet5caea4e2008-11-20 00:40:07 -08002555 inet_hashinfo_init(&tcp_hashinfo);
Eric W. Biederman6a1b3052009-02-22 00:10:18 -08002556 if (register_pernet_subsys(&tcp_sk_ops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002557 panic("Failed to create the TCP control socket.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002558}
2559
2560EXPORT_SYMBOL(ipv4_specific);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002561EXPORT_SYMBOL(tcp_hashinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002562EXPORT_SYMBOL(tcp_prot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002563EXPORT_SYMBOL(tcp_v4_conn_request);
2564EXPORT_SYMBOL(tcp_v4_connect);
2565EXPORT_SYMBOL(tcp_v4_do_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002566EXPORT_SYMBOL(tcp_v4_remember_stamp);
2567EXPORT_SYMBOL(tcp_v4_send_check);
2568EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
2569
2570#ifdef CONFIG_PROC_FS
2571EXPORT_SYMBOL(tcp_proc_register);
2572EXPORT_SYMBOL(tcp_proc_unregister);
2573#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07002574EXPORT_SYMBOL(sysctl_tcp_low_latency);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002575