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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Implementation of the Transmission Control Protocol(TCP). | |
7 | * | |
8 | * Version: $Id: tcp_ipv4.c,v 1.240 2002/02/01 22:01:04 davem Exp $ | |
9 | * | |
10 | * IPv4 specific functions | |
11 | * | |
12 | * | |
13 | * code split from: | |
14 | * linux/ipv4/tcp.c | |
15 | * linux/ipv4/tcp_input.c | |
16 | * linux/ipv4/tcp_output.c | |
17 | * | |
18 | * See tcp.c for author information | |
19 | * | |
20 | * This program is free software; you can redistribute it and/or | |
21 | * modify it under the terms of the GNU General Public License | |
22 | * as published by the Free Software Foundation; either version | |
23 | * 2 of the License, or (at your option) any later version. | |
24 | */ | |
25 | ||
26 | /* | |
27 | * Changes: | |
28 | * David S. Miller : New socket lookup architecture. | |
29 | * This code is dedicated to John Dyson. | |
30 | * David S. Miller : Change semantics of established hash, | |
31 | * half is devoted to TIME_WAIT sockets | |
32 | * and the rest go in the other half. | |
33 | * Andi Kleen : Add support for syncookies and fixed | |
34 | * some bugs: ip options weren't passed to | |
35 | * the TCP layer, missed a check for an | |
36 | * ACK bit. | |
37 | * Andi Kleen : Implemented fast path mtu discovery. | |
38 | * Fixed many serious bugs in the | |
60236fdd | 39 | * request_sock handling and moved |
1da177e4 LT |
40 | * most of it into the af independent code. |
41 | * Added tail drop and some other bugfixes. | |
42 | * Added new listen sematics. | |
43 | * Mike McLagan : Routing by source | |
44 | * Juan Jose Ciarlante: ip_dynaddr bits | |
45 | * Andi Kleen: various fixes. | |
46 | * Vitaly E. Lavrov : Transparent proxy revived after year | |
47 | * coma. | |
48 | * Andi Kleen : Fix new listen. | |
49 | * Andi Kleen : Fix accept error reporting. | |
50 | * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which | |
51 | * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind | |
52 | * a single port at the same time. | |
53 | */ | |
54 | ||
55 | #include <linux/config.h> | |
56 | ||
57 | #include <linux/types.h> | |
58 | #include <linux/fcntl.h> | |
59 | #include <linux/module.h> | |
60 | #include <linux/random.h> | |
61 | #include <linux/cache.h> | |
62 | #include <linux/jhash.h> | |
63 | #include <linux/init.h> | |
64 | #include <linux/times.h> | |
65 | ||
66 | #include <net/icmp.h> | |
304a1618 | 67 | #include <net/inet_hashtables.h> |
1da177e4 LT |
68 | #include <net/tcp.h> |
69 | #include <net/ipv6.h> | |
70 | #include <net/inet_common.h> | |
71 | #include <net/xfrm.h> | |
72 | ||
73 | #include <linux/inet.h> | |
74 | #include <linux/ipv6.h> | |
75 | #include <linux/stddef.h> | |
76 | #include <linux/proc_fs.h> | |
77 | #include <linux/seq_file.h> | |
78 | ||
79 | extern int sysctl_ip_dynaddr; | |
80 | int sysctl_tcp_tw_reuse; | |
81 | int sysctl_tcp_low_latency; | |
82 | ||
83 | /* Check TCP sequence numbers in ICMP packets. */ | |
84 | #define ICMP_MIN_LENGTH 8 | |
85 | ||
86 | /* Socket used for sending RSTs */ | |
87 | static struct socket *tcp_socket; | |
88 | ||
89 | void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, | |
90 | struct sk_buff *skb); | |
91 | ||
0f7ff927 ACM |
92 | struct inet_hashinfo __cacheline_aligned tcp_hashinfo = { |
93 | .lhash_lock = RW_LOCK_UNLOCKED, | |
94 | .lhash_users = ATOMIC_INIT(0), | |
95 | .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait), | |
96 | .portalloc_lock = SPIN_LOCK_UNLOCKED, | |
6e04e021 | 97 | .port_rover = 1024 - 1, |
1da177e4 LT |
98 | }; |
99 | ||
100 | /* | |
101 | * This array holds the first and last local port number. | |
102 | * For high-usage systems, use sysctl to change this to | |
103 | * 32768-61000 | |
104 | */ | |
105 | int sysctl_local_port_range[2] = { 1024, 4999 }; | |
1da177e4 | 106 | |
0f7ff927 | 107 | static inline int tcp_bind_conflict(struct sock *sk, struct inet_bind_bucket *tb) |
1da177e4 | 108 | { |
8feaf0c0 | 109 | const u32 sk_rcv_saddr = inet_rcv_saddr(sk); |
1da177e4 LT |
110 | struct sock *sk2; |
111 | struct hlist_node *node; | |
112 | int reuse = sk->sk_reuse; | |
113 | ||
114 | sk_for_each_bound(sk2, node, &tb->owners) { | |
115 | if (sk != sk2 && | |
116 | !tcp_v6_ipv6only(sk2) && | |
117 | (!sk->sk_bound_dev_if || | |
118 | !sk2->sk_bound_dev_if || | |
119 | sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { | |
120 | if (!reuse || !sk2->sk_reuse || | |
121 | sk2->sk_state == TCP_LISTEN) { | |
8feaf0c0 | 122 | const u32 sk2_rcv_saddr = inet_rcv_saddr(sk2); |
1da177e4 LT |
123 | if (!sk2_rcv_saddr || !sk_rcv_saddr || |
124 | sk2_rcv_saddr == sk_rcv_saddr) | |
125 | break; | |
126 | } | |
127 | } | |
128 | } | |
129 | return node != NULL; | |
130 | } | |
131 | ||
132 | /* Obtain a reference to a local port for the given sock, | |
133 | * if snum is zero it means select any available local port. | |
134 | */ | |
135 | static int tcp_v4_get_port(struct sock *sk, unsigned short snum) | |
136 | { | |
0f7ff927 | 137 | struct inet_bind_hashbucket *head; |
1da177e4 | 138 | struct hlist_node *node; |
0f7ff927 | 139 | struct inet_bind_bucket *tb; |
1da177e4 LT |
140 | int ret; |
141 | ||
142 | local_bh_disable(); | |
143 | if (!snum) { | |
144 | int low = sysctl_local_port_range[0]; | |
145 | int high = sysctl_local_port_range[1]; | |
146 | int remaining = (high - low) + 1; | |
147 | int rover; | |
148 | ||
6e04e021 ACM |
149 | spin_lock(&tcp_hashinfo.portalloc_lock); |
150 | if (tcp_hashinfo.port_rover < low) | |
0b2531bd FH |
151 | rover = low; |
152 | else | |
6e04e021 | 153 | rover = tcp_hashinfo.port_rover; |
1da177e4 LT |
154 | do { |
155 | rover++; | |
0b2531bd | 156 | if (rover > high) |
1da177e4 | 157 | rover = low; |
6e04e021 | 158 | head = &tcp_hashinfo.bhash[inet_bhashfn(rover, tcp_hashinfo.bhash_size)]; |
1da177e4 | 159 | spin_lock(&head->lock); |
0f7ff927 | 160 | inet_bind_bucket_for_each(tb, node, &head->chain) |
1da177e4 LT |
161 | if (tb->port == rover) |
162 | goto next; | |
163 | break; | |
164 | next: | |
165 | spin_unlock(&head->lock); | |
166 | } while (--remaining > 0); | |
6e04e021 ACM |
167 | tcp_hashinfo.port_rover = rover; |
168 | spin_unlock(&tcp_hashinfo.portalloc_lock); | |
1da177e4 | 169 | |
d5d28375 DM |
170 | /* Exhausted local port range during search? It is not |
171 | * possible for us to be holding one of the bind hash | |
172 | * locks if this test triggers, because if 'remaining' | |
173 | * drops to zero, we broke out of the do/while loop at | |
174 | * the top level, not from the 'break;' statement. | |
175 | */ | |
1da177e4 | 176 | ret = 1; |
d5d28375 | 177 | if (unlikely(remaining <= 0)) |
1da177e4 LT |
178 | goto fail; |
179 | ||
180 | /* OK, here is the one we will use. HEAD is | |
181 | * non-NULL and we hold it's mutex. | |
182 | */ | |
183 | snum = rover; | |
184 | } else { | |
6e04e021 | 185 | head = &tcp_hashinfo.bhash[inet_bhashfn(snum, tcp_hashinfo.bhash_size)]; |
1da177e4 | 186 | spin_lock(&head->lock); |
0f7ff927 | 187 | inet_bind_bucket_for_each(tb, node, &head->chain) |
1da177e4 LT |
188 | if (tb->port == snum) |
189 | goto tb_found; | |
190 | } | |
191 | tb = NULL; | |
192 | goto tb_not_found; | |
193 | tb_found: | |
194 | if (!hlist_empty(&tb->owners)) { | |
195 | if (sk->sk_reuse > 1) | |
196 | goto success; | |
197 | if (tb->fastreuse > 0 && | |
198 | sk->sk_reuse && sk->sk_state != TCP_LISTEN) { | |
199 | goto success; | |
200 | } else { | |
201 | ret = 1; | |
202 | if (tcp_bind_conflict(sk, tb)) | |
203 | goto fail_unlock; | |
204 | } | |
205 | } | |
206 | tb_not_found: | |
207 | ret = 1; | |
6e04e021 | 208 | if (!tb && (tb = inet_bind_bucket_create(tcp_hashinfo.bind_bucket_cachep, head, snum)) == NULL) |
1da177e4 LT |
209 | goto fail_unlock; |
210 | if (hlist_empty(&tb->owners)) { | |
211 | if (sk->sk_reuse && sk->sk_state != TCP_LISTEN) | |
212 | tb->fastreuse = 1; | |
213 | else | |
214 | tb->fastreuse = 0; | |
215 | } else if (tb->fastreuse && | |
216 | (!sk->sk_reuse || sk->sk_state == TCP_LISTEN)) | |
217 | tb->fastreuse = 0; | |
218 | success: | |
a55ebcc4 | 219 | if (!inet_sk(sk)->bind_hash) |
2d8c4ce5 | 220 | inet_bind_hash(sk, tb, snum); |
a55ebcc4 | 221 | BUG_TRAP(inet_sk(sk)->bind_hash == tb); |
1da177e4 LT |
222 | ret = 0; |
223 | ||
224 | fail_unlock: | |
225 | spin_unlock(&head->lock); | |
226 | fail: | |
227 | local_bh_enable(); | |
228 | return ret; | |
229 | } | |
230 | ||
1da177e4 LT |
231 | static void tcp_v4_hash(struct sock *sk) |
232 | { | |
81849d10 | 233 | inet_hash(&tcp_hashinfo, sk); |
1da177e4 LT |
234 | } |
235 | ||
236 | void tcp_unhash(struct sock *sk) | |
237 | { | |
81849d10 | 238 | inet_unhash(&tcp_hashinfo, sk); |
1da177e4 LT |
239 | } |
240 | ||
1da177e4 LT |
241 | /* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so |
242 | * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM | |
243 | * | |
244 | * Local BH must be disabled here. | |
245 | */ | |
246 | ||
0f7ff927 ACM |
247 | static inline struct sock *__tcp_v4_lookup_established(const u32 saddr, |
248 | const u16 sport, | |
249 | const u32 daddr, | |
250 | const u16 hnum, | |
251 | const int dif) | |
1da177e4 | 252 | { |
0f7ff927 | 253 | struct inet_ehash_bucket *head; |
8feaf0c0 ACM |
254 | INET_ADDR_COOKIE(acookie, saddr, daddr) |
255 | const __u32 ports = INET_COMBINED_PORTS(sport, hnum); | |
1da177e4 | 256 | struct sock *sk; |
8feaf0c0 | 257 | const struct hlist_node *node; |
1da177e4 LT |
258 | /* Optimize here for direct hit, only listening connections can |
259 | * have wildcards anyways. | |
260 | */ | |
6e04e021 ACM |
261 | const int hash = inet_ehashfn(daddr, hnum, saddr, sport, tcp_hashinfo.ehash_size); |
262 | head = &tcp_hashinfo.ehash[hash]; | |
1da177e4 LT |
263 | read_lock(&head->lock); |
264 | sk_for_each(sk, node, &head->chain) { | |
8feaf0c0 | 265 | if (INET_MATCH(sk, acookie, saddr, daddr, ports, dif)) |
1da177e4 LT |
266 | goto hit; /* You sunk my battleship! */ |
267 | } | |
268 | ||
269 | /* Must check for a TIME_WAIT'er before going to listener hash. */ | |
6e04e021 | 270 | sk_for_each(sk, node, &(head + tcp_hashinfo.ehash_size)->chain) { |
8feaf0c0 | 271 | if (INET_TW_MATCH(sk, acookie, saddr, daddr, ports, dif)) |
1da177e4 LT |
272 | goto hit; |
273 | } | |
274 | sk = NULL; | |
275 | out: | |
276 | read_unlock(&head->lock); | |
277 | return sk; | |
278 | hit: | |
279 | sock_hold(sk); | |
280 | goto out; | |
281 | } | |
282 | ||
283 | static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport, | |
284 | u32 daddr, u16 hnum, int dif) | |
285 | { | |
286 | struct sock *sk = __tcp_v4_lookup_established(saddr, sport, | |
287 | daddr, hnum, dif); | |
288 | ||
33b62231 | 289 | return sk ? : inet_lookup_listener(&tcp_hashinfo, daddr, hnum, dif); |
1da177e4 LT |
290 | } |
291 | ||
292 | inline struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, | |
293 | u16 dport, int dif) | |
294 | { | |
295 | struct sock *sk; | |
296 | ||
297 | local_bh_disable(); | |
298 | sk = __tcp_v4_lookup(saddr, sport, daddr, ntohs(dport), dif); | |
299 | local_bh_enable(); | |
300 | ||
301 | return sk; | |
302 | } | |
303 | ||
304 | EXPORT_SYMBOL_GPL(tcp_v4_lookup); | |
305 | ||
306 | static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb) | |
307 | { | |
308 | return secure_tcp_sequence_number(skb->nh.iph->daddr, | |
309 | skb->nh.iph->saddr, | |
310 | skb->h.th->dest, | |
311 | skb->h.th->source); | |
312 | } | |
313 | ||
314 | /* called with local bh disabled */ | |
315 | static int __tcp_v4_check_established(struct sock *sk, __u16 lport, | |
8feaf0c0 | 316 | struct inet_timewait_sock **twp) |
1da177e4 LT |
317 | { |
318 | struct inet_sock *inet = inet_sk(sk); | |
319 | u32 daddr = inet->rcv_saddr; | |
320 | u32 saddr = inet->daddr; | |
321 | int dif = sk->sk_bound_dev_if; | |
8feaf0c0 ACM |
322 | INET_ADDR_COOKIE(acookie, saddr, daddr) |
323 | const __u32 ports = INET_COMBINED_PORTS(inet->dport, lport); | |
6e04e021 ACM |
324 | const int hash = inet_ehashfn(daddr, lport, saddr, inet->dport, tcp_hashinfo.ehash_size); |
325 | struct inet_ehash_bucket *head = &tcp_hashinfo.ehash[hash]; | |
1da177e4 | 326 | struct sock *sk2; |
8feaf0c0 ACM |
327 | const struct hlist_node *node; |
328 | struct inet_timewait_sock *tw; | |
1da177e4 LT |
329 | |
330 | write_lock(&head->lock); | |
331 | ||
332 | /* Check TIME-WAIT sockets first. */ | |
6e04e021 | 333 | sk_for_each(sk2, node, &(head + tcp_hashinfo.ehash_size)->chain) { |
8feaf0c0 | 334 | tw = inet_twsk(sk2); |
1da177e4 | 335 | |
8feaf0c0 ACM |
336 | if (INET_TW_MATCH(sk2, acookie, saddr, daddr, ports, dif)) { |
337 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sk2); | |
1da177e4 LT |
338 | struct tcp_sock *tp = tcp_sk(sk); |
339 | ||
340 | /* With PAWS, it is safe from the viewpoint | |
341 | of data integrity. Even without PAWS it | |
342 | is safe provided sequence spaces do not | |
343 | overlap i.e. at data rates <= 80Mbit/sec. | |
344 | ||
345 | Actually, the idea is close to VJ's one, | |
346 | only timestamp cache is held not per host, | |
347 | but per port pair and TW bucket is used | |
348 | as state holder. | |
349 | ||
350 | If TW bucket has been already destroyed we | |
351 | fall back to VJ's scheme and use initial | |
352 | timestamp retrieved from peer table. | |
353 | */ | |
8feaf0c0 | 354 | if (tcptw->tw_ts_recent_stamp && |
1da177e4 LT |
355 | (!twp || (sysctl_tcp_tw_reuse && |
356 | xtime.tv_sec - | |
8feaf0c0 ACM |
357 | tcptw->tw_ts_recent_stamp > 1))) { |
358 | tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; | |
359 | if (tp->write_seq == 0) | |
1da177e4 | 360 | tp->write_seq = 1; |
8feaf0c0 ACM |
361 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; |
362 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; | |
1da177e4 LT |
363 | sock_hold(sk2); |
364 | goto unique; | |
365 | } else | |
366 | goto not_unique; | |
367 | } | |
368 | } | |
369 | tw = NULL; | |
370 | ||
371 | /* And established part... */ | |
372 | sk_for_each(sk2, node, &head->chain) { | |
8feaf0c0 | 373 | if (INET_MATCH(sk2, acookie, saddr, daddr, ports, dif)) |
1da177e4 LT |
374 | goto not_unique; |
375 | } | |
376 | ||
377 | unique: | |
378 | /* Must record num and sport now. Otherwise we will see | |
379 | * in hash table socket with a funny identity. */ | |
380 | inet->num = lport; | |
381 | inet->sport = htons(lport); | |
382 | sk->sk_hashent = hash; | |
383 | BUG_TRAP(sk_unhashed(sk)); | |
384 | __sk_add_node(sk, &head->chain); | |
385 | sock_prot_inc_use(sk->sk_prot); | |
386 | write_unlock(&head->lock); | |
387 | ||
388 | if (twp) { | |
389 | *twp = tw; | |
390 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); | |
391 | } else if (tw) { | |
392 | /* Silly. Should hash-dance instead... */ | |
393 | tcp_tw_deschedule(tw); | |
394 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); | |
395 | ||
8feaf0c0 | 396 | inet_twsk_put(tw); |
1da177e4 LT |
397 | } |
398 | ||
399 | return 0; | |
400 | ||
401 | not_unique: | |
402 | write_unlock(&head->lock); | |
403 | return -EADDRNOTAVAIL; | |
404 | } | |
405 | ||
406 | static inline u32 connect_port_offset(const struct sock *sk) | |
407 | { | |
408 | const struct inet_sock *inet = inet_sk(sk); | |
409 | ||
410 | return secure_tcp_port_ephemeral(inet->rcv_saddr, inet->daddr, | |
411 | inet->dport); | |
412 | } | |
413 | ||
414 | /* | |
415 | * Bind a port for a connect operation and hash it. | |
416 | */ | |
417 | static inline int tcp_v4_hash_connect(struct sock *sk) | |
418 | { | |
0f7ff927 ACM |
419 | const unsigned short snum = inet_sk(sk)->num; |
420 | struct inet_bind_hashbucket *head; | |
421 | struct inet_bind_bucket *tb; | |
1da177e4 LT |
422 | int ret; |
423 | ||
424 | if (!snum) { | |
425 | int low = sysctl_local_port_range[0]; | |
426 | int high = sysctl_local_port_range[1]; | |
427 | int range = high - low; | |
428 | int i; | |
429 | int port; | |
430 | static u32 hint; | |
431 | u32 offset = hint + connect_port_offset(sk); | |
432 | struct hlist_node *node; | |
8feaf0c0 | 433 | struct inet_timewait_sock *tw = NULL; |
1da177e4 LT |
434 | |
435 | local_bh_disable(); | |
436 | for (i = 1; i <= range; i++) { | |
437 | port = low + (i + offset) % range; | |
6e04e021 | 438 | head = &tcp_hashinfo.bhash[inet_bhashfn(port, tcp_hashinfo.bhash_size)]; |
1da177e4 LT |
439 | spin_lock(&head->lock); |
440 | ||
441 | /* Does not bother with rcv_saddr checks, | |
442 | * because the established check is already | |
443 | * unique enough. | |
444 | */ | |
0f7ff927 | 445 | inet_bind_bucket_for_each(tb, node, &head->chain) { |
1da177e4 LT |
446 | if (tb->port == port) { |
447 | BUG_TRAP(!hlist_empty(&tb->owners)); | |
448 | if (tb->fastreuse >= 0) | |
449 | goto next_port; | |
450 | if (!__tcp_v4_check_established(sk, | |
451 | port, | |
452 | &tw)) | |
453 | goto ok; | |
454 | goto next_port; | |
455 | } | |
456 | } | |
457 | ||
6e04e021 | 458 | tb = inet_bind_bucket_create(tcp_hashinfo.bind_bucket_cachep, head, port); |
1da177e4 LT |
459 | if (!tb) { |
460 | spin_unlock(&head->lock); | |
461 | break; | |
462 | } | |
463 | tb->fastreuse = -1; | |
464 | goto ok; | |
465 | ||
466 | next_port: | |
467 | spin_unlock(&head->lock); | |
468 | } | |
469 | local_bh_enable(); | |
470 | ||
471 | return -EADDRNOTAVAIL; | |
472 | ||
473 | ok: | |
474 | hint += i; | |
475 | ||
476 | /* Head lock still held and bh's disabled */ | |
2d8c4ce5 | 477 | inet_bind_hash(sk, tb, port); |
1da177e4 LT |
478 | if (sk_unhashed(sk)) { |
479 | inet_sk(sk)->sport = htons(port); | |
f3f05f70 | 480 | __inet_hash(&tcp_hashinfo, sk, 0); |
1da177e4 LT |
481 | } |
482 | spin_unlock(&head->lock); | |
483 | ||
484 | if (tw) { | |
485 | tcp_tw_deschedule(tw); | |
8feaf0c0 | 486 | inet_twsk_put(tw); |
1da177e4 LT |
487 | } |
488 | ||
489 | ret = 0; | |
490 | goto out; | |
491 | } | |
492 | ||
6e04e021 | 493 | head = &tcp_hashinfo.bhash[inet_bhashfn(snum, tcp_hashinfo.bhash_size)]; |
a55ebcc4 | 494 | tb = inet_sk(sk)->bind_hash; |
1da177e4 LT |
495 | spin_lock_bh(&head->lock); |
496 | if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) { | |
f3f05f70 | 497 | __inet_hash(&tcp_hashinfo, sk, 0); |
1da177e4 LT |
498 | spin_unlock_bh(&head->lock); |
499 | return 0; | |
500 | } else { | |
501 | spin_unlock(&head->lock); | |
502 | /* No definite answer... Walk to established hash table */ | |
503 | ret = __tcp_v4_check_established(sk, snum, NULL); | |
504 | out: | |
505 | local_bh_enable(); | |
506 | return ret; | |
507 | } | |
508 | } | |
509 | ||
510 | /* This will initiate an outgoing connection. */ | |
511 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
512 | { | |
513 | struct inet_sock *inet = inet_sk(sk); | |
514 | struct tcp_sock *tp = tcp_sk(sk); | |
515 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; | |
516 | struct rtable *rt; | |
517 | u32 daddr, nexthop; | |
518 | int tmp; | |
519 | int err; | |
520 | ||
521 | if (addr_len < sizeof(struct sockaddr_in)) | |
522 | return -EINVAL; | |
523 | ||
524 | if (usin->sin_family != AF_INET) | |
525 | return -EAFNOSUPPORT; | |
526 | ||
527 | nexthop = daddr = usin->sin_addr.s_addr; | |
528 | if (inet->opt && inet->opt->srr) { | |
529 | if (!daddr) | |
530 | return -EINVAL; | |
531 | nexthop = inet->opt->faddr; | |
532 | } | |
533 | ||
534 | tmp = ip_route_connect(&rt, nexthop, inet->saddr, | |
535 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, | |
536 | IPPROTO_TCP, | |
537 | inet->sport, usin->sin_port, sk); | |
538 | if (tmp < 0) | |
539 | return tmp; | |
540 | ||
541 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
542 | ip_rt_put(rt); | |
543 | return -ENETUNREACH; | |
544 | } | |
545 | ||
546 | if (!inet->opt || !inet->opt->srr) | |
547 | daddr = rt->rt_dst; | |
548 | ||
549 | if (!inet->saddr) | |
550 | inet->saddr = rt->rt_src; | |
551 | inet->rcv_saddr = inet->saddr; | |
552 | ||
553 | if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) { | |
554 | /* Reset inherited state */ | |
555 | tp->rx_opt.ts_recent = 0; | |
556 | tp->rx_opt.ts_recent_stamp = 0; | |
557 | tp->write_seq = 0; | |
558 | } | |
559 | ||
560 | if (sysctl_tcp_tw_recycle && | |
561 | !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) { | |
562 | struct inet_peer *peer = rt_get_peer(rt); | |
563 | ||
564 | /* VJ's idea. We save last timestamp seen from | |
565 | * the destination in peer table, when entering state TIME-WAIT | |
566 | * and initialize rx_opt.ts_recent from it, when trying new connection. | |
567 | */ | |
568 | ||
569 | if (peer && peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) { | |
570 | tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp; | |
571 | tp->rx_opt.ts_recent = peer->tcp_ts; | |
572 | } | |
573 | } | |
574 | ||
575 | inet->dport = usin->sin_port; | |
576 | inet->daddr = daddr; | |
577 | ||
578 | tp->ext_header_len = 0; | |
579 | if (inet->opt) | |
580 | tp->ext_header_len = inet->opt->optlen; | |
581 | ||
582 | tp->rx_opt.mss_clamp = 536; | |
583 | ||
584 | /* Socket identity is still unknown (sport may be zero). | |
585 | * However we set state to SYN-SENT and not releasing socket | |
586 | * lock select source port, enter ourselves into the hash tables and | |
587 | * complete initialization after this. | |
588 | */ | |
589 | tcp_set_state(sk, TCP_SYN_SENT); | |
590 | err = tcp_v4_hash_connect(sk); | |
591 | if (err) | |
592 | goto failure; | |
593 | ||
594 | err = ip_route_newports(&rt, inet->sport, inet->dport, sk); | |
595 | if (err) | |
596 | goto failure; | |
597 | ||
598 | /* OK, now commit destination to socket. */ | |
6cbb0df7 | 599 | sk_setup_caps(sk, &rt->u.dst); |
1da177e4 LT |
600 | |
601 | if (!tp->write_seq) | |
602 | tp->write_seq = secure_tcp_sequence_number(inet->saddr, | |
603 | inet->daddr, | |
604 | inet->sport, | |
605 | usin->sin_port); | |
606 | ||
607 | inet->id = tp->write_seq ^ jiffies; | |
608 | ||
609 | err = tcp_connect(sk); | |
610 | rt = NULL; | |
611 | if (err) | |
612 | goto failure; | |
613 | ||
614 | return 0; | |
615 | ||
616 | failure: | |
617 | /* This unhashes the socket and releases the local port, if necessary. */ | |
618 | tcp_set_state(sk, TCP_CLOSE); | |
619 | ip_rt_put(rt); | |
620 | sk->sk_route_caps = 0; | |
621 | inet->dport = 0; | |
622 | return err; | |
623 | } | |
624 | ||
625 | static __inline__ int tcp_v4_iif(struct sk_buff *skb) | |
626 | { | |
627 | return ((struct rtable *)skb->dst)->rt_iif; | |
628 | } | |
629 | ||
630 | static __inline__ u32 tcp_v4_synq_hash(u32 raddr, u16 rport, u32 rnd) | |
631 | { | |
632 | return (jhash_2words(raddr, (u32) rport, rnd) & (TCP_SYNQ_HSIZE - 1)); | |
633 | } | |
634 | ||
60236fdd ACM |
635 | static struct request_sock *tcp_v4_search_req(struct tcp_sock *tp, |
636 | struct request_sock ***prevp, | |
1da177e4 LT |
637 | __u16 rport, |
638 | __u32 raddr, __u32 laddr) | |
639 | { | |
2ad69c55 | 640 | struct listen_sock *lopt = tp->accept_queue.listen_opt; |
60236fdd | 641 | struct request_sock *req, **prev; |
1da177e4 LT |
642 | |
643 | for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport, lopt->hash_rnd)]; | |
644 | (req = *prev) != NULL; | |
645 | prev = &req->dl_next) { | |
2e6599cb ACM |
646 | const struct inet_request_sock *ireq = inet_rsk(req); |
647 | ||
648 | if (ireq->rmt_port == rport && | |
649 | ireq->rmt_addr == raddr && | |
650 | ireq->loc_addr == laddr && | |
60236fdd | 651 | TCP_INET_FAMILY(req->rsk_ops->family)) { |
1da177e4 LT |
652 | BUG_TRAP(!req->sk); |
653 | *prevp = prev; | |
654 | break; | |
655 | } | |
656 | } | |
657 | ||
658 | return req; | |
659 | } | |
660 | ||
60236fdd | 661 | static void tcp_v4_synq_add(struct sock *sk, struct request_sock *req) |
1da177e4 LT |
662 | { |
663 | struct tcp_sock *tp = tcp_sk(sk); | |
2ad69c55 | 664 | struct listen_sock *lopt = tp->accept_queue.listen_opt; |
2e6599cb | 665 | u32 h = tcp_v4_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, lopt->hash_rnd); |
1da177e4 | 666 | |
0e87506f | 667 | reqsk_queue_hash_req(&tp->accept_queue, h, req, TCP_TIMEOUT_INIT); |
1da177e4 LT |
668 | tcp_synq_added(sk); |
669 | } | |
670 | ||
671 | ||
672 | /* | |
673 | * This routine does path mtu discovery as defined in RFC1191. | |
674 | */ | |
675 | static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, | |
676 | u32 mtu) | |
677 | { | |
678 | struct dst_entry *dst; | |
679 | struct inet_sock *inet = inet_sk(sk); | |
680 | struct tcp_sock *tp = tcp_sk(sk); | |
681 | ||
682 | /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs | |
683 | * send out by Linux are always <576bytes so they should go through | |
684 | * unfragmented). | |
685 | */ | |
686 | if (sk->sk_state == TCP_LISTEN) | |
687 | return; | |
688 | ||
689 | /* We don't check in the destentry if pmtu discovery is forbidden | |
690 | * on this route. We just assume that no packet_to_big packets | |
691 | * are send back when pmtu discovery is not active. | |
692 | * There is a small race when the user changes this flag in the | |
693 | * route, but I think that's acceptable. | |
694 | */ | |
695 | if ((dst = __sk_dst_check(sk, 0)) == NULL) | |
696 | return; | |
697 | ||
698 | dst->ops->update_pmtu(dst, mtu); | |
699 | ||
700 | /* Something is about to be wrong... Remember soft error | |
701 | * for the case, if this connection will not able to recover. | |
702 | */ | |
703 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
704 | sk->sk_err_soft = EMSGSIZE; | |
705 | ||
706 | mtu = dst_mtu(dst); | |
707 | ||
708 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
709 | tp->pmtu_cookie > mtu) { | |
710 | tcp_sync_mss(sk, mtu); | |
711 | ||
712 | /* Resend the TCP packet because it's | |
713 | * clear that the old packet has been | |
714 | * dropped. This is the new "fast" path mtu | |
715 | * discovery. | |
716 | */ | |
717 | tcp_simple_retransmit(sk); | |
718 | } /* else let the usual retransmit timer handle it */ | |
719 | } | |
720 | ||
721 | /* | |
722 | * This routine is called by the ICMP module when it gets some | |
723 | * sort of error condition. If err < 0 then the socket should | |
724 | * be closed and the error returned to the user. If err > 0 | |
725 | * it's just the icmp type << 8 | icmp code. After adjustment | |
726 | * header points to the first 8 bytes of the tcp header. We need | |
727 | * to find the appropriate port. | |
728 | * | |
729 | * The locking strategy used here is very "optimistic". When | |
730 | * someone else accesses the socket the ICMP is just dropped | |
731 | * and for some paths there is no check at all. | |
732 | * A more general error queue to queue errors for later handling | |
733 | * is probably better. | |
734 | * | |
735 | */ | |
736 | ||
737 | void tcp_v4_err(struct sk_buff *skb, u32 info) | |
738 | { | |
739 | struct iphdr *iph = (struct iphdr *)skb->data; | |
740 | struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); | |
741 | struct tcp_sock *tp; | |
742 | struct inet_sock *inet; | |
743 | int type = skb->h.icmph->type; | |
744 | int code = skb->h.icmph->code; | |
745 | struct sock *sk; | |
746 | __u32 seq; | |
747 | int err; | |
748 | ||
749 | if (skb->len < (iph->ihl << 2) + 8) { | |
750 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
751 | return; | |
752 | } | |
753 | ||
754 | sk = tcp_v4_lookup(iph->daddr, th->dest, iph->saddr, | |
755 | th->source, tcp_v4_iif(skb)); | |
756 | if (!sk) { | |
757 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
758 | return; | |
759 | } | |
760 | if (sk->sk_state == TCP_TIME_WAIT) { | |
8feaf0c0 | 761 | inet_twsk_put((struct inet_timewait_sock *)sk); |
1da177e4 LT |
762 | return; |
763 | } | |
764 | ||
765 | bh_lock_sock(sk); | |
766 | /* If too many ICMPs get dropped on busy | |
767 | * servers this needs to be solved differently. | |
768 | */ | |
769 | if (sock_owned_by_user(sk)) | |
770 | NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); | |
771 | ||
772 | if (sk->sk_state == TCP_CLOSE) | |
773 | goto out; | |
774 | ||
775 | tp = tcp_sk(sk); | |
776 | seq = ntohl(th->seq); | |
777 | if (sk->sk_state != TCP_LISTEN && | |
778 | !between(seq, tp->snd_una, tp->snd_nxt)) { | |
779 | NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS); | |
780 | goto out; | |
781 | } | |
782 | ||
783 | switch (type) { | |
784 | case ICMP_SOURCE_QUENCH: | |
785 | /* Just silently ignore these. */ | |
786 | goto out; | |
787 | case ICMP_PARAMETERPROB: | |
788 | err = EPROTO; | |
789 | break; | |
790 | case ICMP_DEST_UNREACH: | |
791 | if (code > NR_ICMP_UNREACH) | |
792 | goto out; | |
793 | ||
794 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
795 | if (!sock_owned_by_user(sk)) | |
796 | do_pmtu_discovery(sk, iph, info); | |
797 | goto out; | |
798 | } | |
799 | ||
800 | err = icmp_err_convert[code].errno; | |
801 | break; | |
802 | case ICMP_TIME_EXCEEDED: | |
803 | err = EHOSTUNREACH; | |
804 | break; | |
805 | default: | |
806 | goto out; | |
807 | } | |
808 | ||
809 | switch (sk->sk_state) { | |
60236fdd | 810 | struct request_sock *req, **prev; |
1da177e4 LT |
811 | case TCP_LISTEN: |
812 | if (sock_owned_by_user(sk)) | |
813 | goto out; | |
814 | ||
815 | req = tcp_v4_search_req(tp, &prev, th->dest, | |
816 | iph->daddr, iph->saddr); | |
817 | if (!req) | |
818 | goto out; | |
819 | ||
820 | /* ICMPs are not backlogged, hence we cannot get | |
821 | an established socket here. | |
822 | */ | |
823 | BUG_TRAP(!req->sk); | |
824 | ||
2e6599cb | 825 | if (seq != tcp_rsk(req)->snt_isn) { |
1da177e4 LT |
826 | NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS); |
827 | goto out; | |
828 | } | |
829 | ||
830 | /* | |
831 | * Still in SYN_RECV, just remove it silently. | |
832 | * There is no good way to pass the error to the newly | |
833 | * created socket, and POSIX does not want network | |
834 | * errors returned from accept(). | |
835 | */ | |
836 | tcp_synq_drop(sk, req, prev); | |
837 | goto out; | |
838 | ||
839 | case TCP_SYN_SENT: | |
840 | case TCP_SYN_RECV: /* Cannot happen. | |
841 | It can f.e. if SYNs crossed. | |
842 | */ | |
843 | if (!sock_owned_by_user(sk)) { | |
844 | TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); | |
845 | sk->sk_err = err; | |
846 | ||
847 | sk->sk_error_report(sk); | |
848 | ||
849 | tcp_done(sk); | |
850 | } else { | |
851 | sk->sk_err_soft = err; | |
852 | } | |
853 | goto out; | |
854 | } | |
855 | ||
856 | /* If we've already connected we will keep trying | |
857 | * until we time out, or the user gives up. | |
858 | * | |
859 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
860 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
861 | * but it is obsoleted by pmtu discovery). | |
862 | * | |
863 | * Note, that in modern internet, where routing is unreliable | |
864 | * and in each dark corner broken firewalls sit, sending random | |
865 | * errors ordered by their masters even this two messages finally lose | |
866 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
867 | * | |
868 | * Now we are in compliance with RFCs. | |
869 | * --ANK (980905) | |
870 | */ | |
871 | ||
872 | inet = inet_sk(sk); | |
873 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
874 | sk->sk_err = err; | |
875 | sk->sk_error_report(sk); | |
876 | } else { /* Only an error on timeout */ | |
877 | sk->sk_err_soft = err; | |
878 | } | |
879 | ||
880 | out: | |
881 | bh_unlock_sock(sk); | |
882 | sock_put(sk); | |
883 | } | |
884 | ||
885 | /* This routine computes an IPv4 TCP checksum. */ | |
886 | void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, | |
887 | struct sk_buff *skb) | |
888 | { | |
889 | struct inet_sock *inet = inet_sk(sk); | |
890 | ||
891 | if (skb->ip_summed == CHECKSUM_HW) { | |
892 | th->check = ~tcp_v4_check(th, len, inet->saddr, inet->daddr, 0); | |
893 | skb->csum = offsetof(struct tcphdr, check); | |
894 | } else { | |
895 | th->check = tcp_v4_check(th, len, inet->saddr, inet->daddr, | |
896 | csum_partial((char *)th, | |
897 | th->doff << 2, | |
898 | skb->csum)); | |
899 | } | |
900 | } | |
901 | ||
902 | /* | |
903 | * This routine will send an RST to the other tcp. | |
904 | * | |
905 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
906 | * for reset. | |
907 | * Answer: if a packet caused RST, it is not for a socket | |
908 | * existing in our system, if it is matched to a socket, | |
909 | * it is just duplicate segment or bug in other side's TCP. | |
910 | * So that we build reply only basing on parameters | |
911 | * arrived with segment. | |
912 | * Exception: precedence violation. We do not implement it in any case. | |
913 | */ | |
914 | ||
915 | static void tcp_v4_send_reset(struct sk_buff *skb) | |
916 | { | |
917 | struct tcphdr *th = skb->h.th; | |
918 | struct tcphdr rth; | |
919 | struct ip_reply_arg arg; | |
920 | ||
921 | /* Never send a reset in response to a reset. */ | |
922 | if (th->rst) | |
923 | return; | |
924 | ||
925 | if (((struct rtable *)skb->dst)->rt_type != RTN_LOCAL) | |
926 | return; | |
927 | ||
928 | /* Swap the send and the receive. */ | |
929 | memset(&rth, 0, sizeof(struct tcphdr)); | |
930 | rth.dest = th->source; | |
931 | rth.source = th->dest; | |
932 | rth.doff = sizeof(struct tcphdr) / 4; | |
933 | rth.rst = 1; | |
934 | ||
935 | if (th->ack) { | |
936 | rth.seq = th->ack_seq; | |
937 | } else { | |
938 | rth.ack = 1; | |
939 | rth.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
940 | skb->len - (th->doff << 2)); | |
941 | } | |
942 | ||
943 | memset(&arg, 0, sizeof arg); | |
944 | arg.iov[0].iov_base = (unsigned char *)&rth; | |
945 | arg.iov[0].iov_len = sizeof rth; | |
946 | arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, | |
947 | skb->nh.iph->saddr, /*XXX*/ | |
948 | sizeof(struct tcphdr), IPPROTO_TCP, 0); | |
949 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
950 | ||
951 | ip_send_reply(tcp_socket->sk, skb, &arg, sizeof rth); | |
952 | ||
953 | TCP_INC_STATS_BH(TCP_MIB_OUTSEGS); | |
954 | TCP_INC_STATS_BH(TCP_MIB_OUTRSTS); | |
955 | } | |
956 | ||
957 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
958 | outside socket context is ugly, certainly. What can I do? | |
959 | */ | |
960 | ||
961 | static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, | |
962 | u32 win, u32 ts) | |
963 | { | |
964 | struct tcphdr *th = skb->h.th; | |
965 | struct { | |
966 | struct tcphdr th; | |
967 | u32 tsopt[3]; | |
968 | } rep; | |
969 | struct ip_reply_arg arg; | |
970 | ||
971 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
972 | memset(&arg, 0, sizeof arg); | |
973 | ||
974 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
975 | arg.iov[0].iov_len = sizeof(rep.th); | |
976 | if (ts) { | |
977 | rep.tsopt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | | |
978 | (TCPOPT_TIMESTAMP << 8) | | |
979 | TCPOLEN_TIMESTAMP); | |
980 | rep.tsopt[1] = htonl(tcp_time_stamp); | |
981 | rep.tsopt[2] = htonl(ts); | |
982 | arg.iov[0].iov_len = sizeof(rep); | |
983 | } | |
984 | ||
985 | /* Swap the send and the receive. */ | |
986 | rep.th.dest = th->source; | |
987 | rep.th.source = th->dest; | |
988 | rep.th.doff = arg.iov[0].iov_len / 4; | |
989 | rep.th.seq = htonl(seq); | |
990 | rep.th.ack_seq = htonl(ack); | |
991 | rep.th.ack = 1; | |
992 | rep.th.window = htons(win); | |
993 | ||
994 | arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, | |
995 | skb->nh.iph->saddr, /*XXX*/ | |
996 | arg.iov[0].iov_len, IPPROTO_TCP, 0); | |
997 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
998 | ||
999 | ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len); | |
1000 | ||
1001 | TCP_INC_STATS_BH(TCP_MIB_OUTSEGS); | |
1002 | } | |
1003 | ||
1004 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
1005 | { | |
8feaf0c0 ACM |
1006 | struct inet_timewait_sock *tw = inet_twsk(sk); |
1007 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sk); | |
1da177e4 | 1008 | |
8feaf0c0 ACM |
1009 | tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
1010 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, tcptw->tw_ts_recent); | |
1da177e4 | 1011 | |
8feaf0c0 | 1012 | inet_twsk_put(tw); |
1da177e4 LT |
1013 | } |
1014 | ||
60236fdd | 1015 | static void tcp_v4_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req) |
1da177e4 | 1016 | { |
2e6599cb | 1017 | tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, |
1da177e4 LT |
1018 | req->ts_recent); |
1019 | } | |
1020 | ||
1021 | static struct dst_entry* tcp_v4_route_req(struct sock *sk, | |
60236fdd | 1022 | struct request_sock *req) |
1da177e4 LT |
1023 | { |
1024 | struct rtable *rt; | |
2e6599cb ACM |
1025 | const struct inet_request_sock *ireq = inet_rsk(req); |
1026 | struct ip_options *opt = inet_rsk(req)->opt; | |
1da177e4 LT |
1027 | struct flowi fl = { .oif = sk->sk_bound_dev_if, |
1028 | .nl_u = { .ip4_u = | |
1029 | { .daddr = ((opt && opt->srr) ? | |
1030 | opt->faddr : | |
2e6599cb ACM |
1031 | ireq->rmt_addr), |
1032 | .saddr = ireq->loc_addr, | |
1da177e4 LT |
1033 | .tos = RT_CONN_FLAGS(sk) } }, |
1034 | .proto = IPPROTO_TCP, | |
1035 | .uli_u = { .ports = | |
1036 | { .sport = inet_sk(sk)->sport, | |
2e6599cb | 1037 | .dport = ireq->rmt_port } } }; |
1da177e4 LT |
1038 | |
1039 | if (ip_route_output_flow(&rt, &fl, sk, 0)) { | |
1040 | IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES); | |
1041 | return NULL; | |
1042 | } | |
1043 | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) { | |
1044 | ip_rt_put(rt); | |
1045 | IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES); | |
1046 | return NULL; | |
1047 | } | |
1048 | return &rt->u.dst; | |
1049 | } | |
1050 | ||
1051 | /* | |
1052 | * Send a SYN-ACK after having received an ACK. | |
60236fdd | 1053 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
1054 | * socket. |
1055 | */ | |
60236fdd | 1056 | static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req, |
1da177e4 LT |
1057 | struct dst_entry *dst) |
1058 | { | |
2e6599cb | 1059 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
1060 | int err = -1; |
1061 | struct sk_buff * skb; | |
1062 | ||
1063 | /* First, grab a route. */ | |
1064 | if (!dst && (dst = tcp_v4_route_req(sk, req)) == NULL) | |
1065 | goto out; | |
1066 | ||
1067 | skb = tcp_make_synack(sk, dst, req); | |
1068 | ||
1069 | if (skb) { | |
1070 | struct tcphdr *th = skb->h.th; | |
1071 | ||
1072 | th->check = tcp_v4_check(th, skb->len, | |
2e6599cb ACM |
1073 | ireq->loc_addr, |
1074 | ireq->rmt_addr, | |
1da177e4 LT |
1075 | csum_partial((char *)th, skb->len, |
1076 | skb->csum)); | |
1077 | ||
2e6599cb ACM |
1078 | err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, |
1079 | ireq->rmt_addr, | |
1080 | ireq->opt); | |
1da177e4 LT |
1081 | if (err == NET_XMIT_CN) |
1082 | err = 0; | |
1083 | } | |
1084 | ||
1085 | out: | |
1086 | dst_release(dst); | |
1087 | return err; | |
1088 | } | |
1089 | ||
1090 | /* | |
60236fdd | 1091 | * IPv4 request_sock destructor. |
1da177e4 | 1092 | */ |
60236fdd | 1093 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 1094 | { |
2e6599cb ACM |
1095 | if (inet_rsk(req)->opt) |
1096 | kfree(inet_rsk(req)->opt); | |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | static inline void syn_flood_warning(struct sk_buff *skb) | |
1100 | { | |
1101 | static unsigned long warntime; | |
1102 | ||
1103 | if (time_after(jiffies, (warntime + HZ * 60))) { | |
1104 | warntime = jiffies; | |
1105 | printk(KERN_INFO | |
1106 | "possible SYN flooding on port %d. Sending cookies.\n", | |
1107 | ntohs(skb->h.th->dest)); | |
1108 | } | |
1109 | } | |
1110 | ||
1111 | /* | |
60236fdd | 1112 | * Save and compile IPv4 options into the request_sock if needed. |
1da177e4 LT |
1113 | */ |
1114 | static inline struct ip_options *tcp_v4_save_options(struct sock *sk, | |
1115 | struct sk_buff *skb) | |
1116 | { | |
1117 | struct ip_options *opt = &(IPCB(skb)->opt); | |
1118 | struct ip_options *dopt = NULL; | |
1119 | ||
1120 | if (opt && opt->optlen) { | |
1121 | int opt_size = optlength(opt); | |
1122 | dopt = kmalloc(opt_size, GFP_ATOMIC); | |
1123 | if (dopt) { | |
1124 | if (ip_options_echo(dopt, skb)) { | |
1125 | kfree(dopt); | |
1126 | dopt = NULL; | |
1127 | } | |
1128 | } | |
1129 | } | |
1130 | return dopt; | |
1131 | } | |
1132 | ||
60236fdd | 1133 | struct request_sock_ops tcp_request_sock_ops = { |
1da177e4 | 1134 | .family = PF_INET, |
2e6599cb | 1135 | .obj_size = sizeof(struct tcp_request_sock), |
1da177e4 | 1136 | .rtx_syn_ack = tcp_v4_send_synack, |
60236fdd ACM |
1137 | .send_ack = tcp_v4_reqsk_send_ack, |
1138 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 LT |
1139 | .send_reset = tcp_v4_send_reset, |
1140 | }; | |
1141 | ||
1142 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) | |
1143 | { | |
2e6599cb | 1144 | struct inet_request_sock *ireq; |
1da177e4 | 1145 | struct tcp_options_received tmp_opt; |
60236fdd | 1146 | struct request_sock *req; |
1da177e4 LT |
1147 | __u32 saddr = skb->nh.iph->saddr; |
1148 | __u32 daddr = skb->nh.iph->daddr; | |
1149 | __u32 isn = TCP_SKB_CB(skb)->when; | |
1150 | struct dst_entry *dst = NULL; | |
1151 | #ifdef CONFIG_SYN_COOKIES | |
1152 | int want_cookie = 0; | |
1153 | #else | |
1154 | #define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */ | |
1155 | #endif | |
1156 | ||
1157 | /* Never answer to SYNs send to broadcast or multicast */ | |
1158 | if (((struct rtable *)skb->dst)->rt_flags & | |
1159 | (RTCF_BROADCAST | RTCF_MULTICAST)) | |
1160 | goto drop; | |
1161 | ||
1162 | /* TW buckets are converted to open requests without | |
1163 | * limitations, they conserve resources and peer is | |
1164 | * evidently real one. | |
1165 | */ | |
1166 | if (tcp_synq_is_full(sk) && !isn) { | |
1167 | #ifdef CONFIG_SYN_COOKIES | |
1168 | if (sysctl_tcp_syncookies) { | |
1169 | want_cookie = 1; | |
1170 | } else | |
1171 | #endif | |
1172 | goto drop; | |
1173 | } | |
1174 | ||
1175 | /* Accept backlog is full. If we have already queued enough | |
1176 | * of warm entries in syn queue, drop request. It is better than | |
1177 | * clogging syn queue with openreqs with exponentially increasing | |
1178 | * timeout. | |
1179 | */ | |
1180 | if (sk_acceptq_is_full(sk) && tcp_synq_young(sk) > 1) | |
1181 | goto drop; | |
1182 | ||
60236fdd | 1183 | req = reqsk_alloc(&tcp_request_sock_ops); |
1da177e4 LT |
1184 | if (!req) |
1185 | goto drop; | |
1186 | ||
1187 | tcp_clear_options(&tmp_opt); | |
1188 | tmp_opt.mss_clamp = 536; | |
1189 | tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss; | |
1190 | ||
1191 | tcp_parse_options(skb, &tmp_opt, 0); | |
1192 | ||
1193 | if (want_cookie) { | |
1194 | tcp_clear_options(&tmp_opt); | |
1195 | tmp_opt.saw_tstamp = 0; | |
1196 | } | |
1197 | ||
1198 | if (tmp_opt.saw_tstamp && !tmp_opt.rcv_tsval) { | |
1199 | /* Some OSes (unknown ones, but I see them on web server, which | |
1200 | * contains information interesting only for windows' | |
1201 | * users) do not send their stamp in SYN. It is easy case. | |
1202 | * We simply do not advertise TS support. | |
1203 | */ | |
1204 | tmp_opt.saw_tstamp = 0; | |
1205 | tmp_opt.tstamp_ok = 0; | |
1206 | } | |
1207 | tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; | |
1208 | ||
1209 | tcp_openreq_init(req, &tmp_opt, skb); | |
1210 | ||
2e6599cb ACM |
1211 | ireq = inet_rsk(req); |
1212 | ireq->loc_addr = daddr; | |
1213 | ireq->rmt_addr = saddr; | |
1214 | ireq->opt = tcp_v4_save_options(sk, skb); | |
1da177e4 LT |
1215 | if (!want_cookie) |
1216 | TCP_ECN_create_request(req, skb->h.th); | |
1217 | ||
1218 | if (want_cookie) { | |
1219 | #ifdef CONFIG_SYN_COOKIES | |
1220 | syn_flood_warning(skb); | |
1221 | #endif | |
1222 | isn = cookie_v4_init_sequence(sk, skb, &req->mss); | |
1223 | } else if (!isn) { | |
1224 | struct inet_peer *peer = NULL; | |
1225 | ||
1226 | /* VJ's idea. We save last timestamp seen | |
1227 | * from the destination in peer table, when entering | |
1228 | * state TIME-WAIT, and check against it before | |
1229 | * accepting new connection request. | |
1230 | * | |
1231 | * If "isn" is not zero, this request hit alive | |
1232 | * timewait bucket, so that all the necessary checks | |
1233 | * are made in the function processing timewait state. | |
1234 | */ | |
1235 | if (tmp_opt.saw_tstamp && | |
1236 | sysctl_tcp_tw_recycle && | |
1237 | (dst = tcp_v4_route_req(sk, req)) != NULL && | |
1238 | (peer = rt_get_peer((struct rtable *)dst)) != NULL && | |
1239 | peer->v4daddr == saddr) { | |
1240 | if (xtime.tv_sec < peer->tcp_ts_stamp + TCP_PAWS_MSL && | |
1241 | (s32)(peer->tcp_ts - req->ts_recent) > | |
1242 | TCP_PAWS_WINDOW) { | |
1243 | NET_INC_STATS_BH(LINUX_MIB_PAWSPASSIVEREJECTED); | |
1244 | dst_release(dst); | |
1245 | goto drop_and_free; | |
1246 | } | |
1247 | } | |
1248 | /* Kill the following clause, if you dislike this way. */ | |
1249 | else if (!sysctl_tcp_syncookies && | |
1250 | (sysctl_max_syn_backlog - tcp_synq_len(sk) < | |
1251 | (sysctl_max_syn_backlog >> 2)) && | |
1252 | (!peer || !peer->tcp_ts_stamp) && | |
1253 | (!dst || !dst_metric(dst, RTAX_RTT))) { | |
1254 | /* Without syncookies last quarter of | |
1255 | * backlog is filled with destinations, | |
1256 | * proven to be alive. | |
1257 | * It means that we continue to communicate | |
1258 | * to destinations, already remembered | |
1259 | * to the moment of synflood. | |
1260 | */ | |
ca933452 HO |
1261 | LIMIT_NETDEBUG(printk(KERN_DEBUG "TCP: drop open " |
1262 | "request from %u.%u." | |
1263 | "%u.%u/%u\n", | |
1264 | NIPQUAD(saddr), | |
1265 | ntohs(skb->h.th->source))); | |
1da177e4 LT |
1266 | dst_release(dst); |
1267 | goto drop_and_free; | |
1268 | } | |
1269 | ||
1270 | isn = tcp_v4_init_sequence(sk, skb); | |
1271 | } | |
2e6599cb | 1272 | tcp_rsk(req)->snt_isn = isn; |
1da177e4 LT |
1273 | |
1274 | if (tcp_v4_send_synack(sk, req, dst)) | |
1275 | goto drop_and_free; | |
1276 | ||
1277 | if (want_cookie) { | |
60236fdd | 1278 | reqsk_free(req); |
1da177e4 LT |
1279 | } else { |
1280 | tcp_v4_synq_add(sk, req); | |
1281 | } | |
1282 | return 0; | |
1283 | ||
1284 | drop_and_free: | |
60236fdd | 1285 | reqsk_free(req); |
1da177e4 LT |
1286 | drop: |
1287 | TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); | |
1288 | return 0; | |
1289 | } | |
1290 | ||
1291 | ||
1292 | /* | |
1293 | * The three way handshake has completed - we got a valid synack - | |
1294 | * now create the new socket. | |
1295 | */ | |
1296 | struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, | |
60236fdd | 1297 | struct request_sock *req, |
1da177e4 LT |
1298 | struct dst_entry *dst) |
1299 | { | |
2e6599cb | 1300 | struct inet_request_sock *ireq; |
1da177e4 LT |
1301 | struct inet_sock *newinet; |
1302 | struct tcp_sock *newtp; | |
1303 | struct sock *newsk; | |
1304 | ||
1305 | if (sk_acceptq_is_full(sk)) | |
1306 | goto exit_overflow; | |
1307 | ||
1308 | if (!dst && (dst = tcp_v4_route_req(sk, req)) == NULL) | |
1309 | goto exit; | |
1310 | ||
1311 | newsk = tcp_create_openreq_child(sk, req, skb); | |
1312 | if (!newsk) | |
1313 | goto exit; | |
1314 | ||
6cbb0df7 | 1315 | sk_setup_caps(newsk, dst); |
1da177e4 LT |
1316 | |
1317 | newtp = tcp_sk(newsk); | |
1318 | newinet = inet_sk(newsk); | |
2e6599cb ACM |
1319 | ireq = inet_rsk(req); |
1320 | newinet->daddr = ireq->rmt_addr; | |
1321 | newinet->rcv_saddr = ireq->loc_addr; | |
1322 | newinet->saddr = ireq->loc_addr; | |
1323 | newinet->opt = ireq->opt; | |
1324 | ireq->opt = NULL; | |
1da177e4 LT |
1325 | newinet->mc_index = tcp_v4_iif(skb); |
1326 | newinet->mc_ttl = skb->nh.iph->ttl; | |
1327 | newtp->ext_header_len = 0; | |
1328 | if (newinet->opt) | |
1329 | newtp->ext_header_len = newinet->opt->optlen; | |
1330 | newinet->id = newtp->write_seq ^ jiffies; | |
1331 | ||
1332 | tcp_sync_mss(newsk, dst_mtu(dst)); | |
1333 | newtp->advmss = dst_metric(dst, RTAX_ADVMSS); | |
1334 | tcp_initialize_rcv_mss(newsk); | |
1335 | ||
f3f05f70 | 1336 | __inet_hash(&tcp_hashinfo, newsk, 0); |
2d8c4ce5 | 1337 | __inet_inherit_port(&tcp_hashinfo, sk, newsk); |
1da177e4 LT |
1338 | |
1339 | return newsk; | |
1340 | ||
1341 | exit_overflow: | |
1342 | NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS); | |
1343 | exit: | |
1344 | NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS); | |
1345 | dst_release(dst); | |
1346 | return NULL; | |
1347 | } | |
1348 | ||
1349 | static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) | |
1350 | { | |
1351 | struct tcphdr *th = skb->h.th; | |
1352 | struct iphdr *iph = skb->nh.iph; | |
1353 | struct tcp_sock *tp = tcp_sk(sk); | |
1354 | struct sock *nsk; | |
60236fdd | 1355 | struct request_sock **prev; |
1da177e4 | 1356 | /* Find possible connection requests. */ |
60236fdd | 1357 | struct request_sock *req = tcp_v4_search_req(tp, &prev, th->source, |
1da177e4 LT |
1358 | iph->saddr, iph->daddr); |
1359 | if (req) | |
1360 | return tcp_check_req(sk, skb, req, prev); | |
1361 | ||
1362 | nsk = __tcp_v4_lookup_established(skb->nh.iph->saddr, | |
1363 | th->source, | |
1364 | skb->nh.iph->daddr, | |
1365 | ntohs(th->dest), | |
1366 | tcp_v4_iif(skb)); | |
1367 | ||
1368 | if (nsk) { | |
1369 | if (nsk->sk_state != TCP_TIME_WAIT) { | |
1370 | bh_lock_sock(nsk); | |
1371 | return nsk; | |
1372 | } | |
8feaf0c0 | 1373 | inet_twsk_put((struct inet_timewait_sock *)nsk); |
1da177e4 LT |
1374 | return NULL; |
1375 | } | |
1376 | ||
1377 | #ifdef CONFIG_SYN_COOKIES | |
1378 | if (!th->rst && !th->syn && th->ack) | |
1379 | sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); | |
1380 | #endif | |
1381 | return sk; | |
1382 | } | |
1383 | ||
1384 | static int tcp_v4_checksum_init(struct sk_buff *skb) | |
1385 | { | |
1386 | if (skb->ip_summed == CHECKSUM_HW) { | |
1387 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
1388 | if (!tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr, | |
1389 | skb->nh.iph->daddr, skb->csum)) | |
1390 | return 0; | |
1391 | ||
ca933452 | 1392 | LIMIT_NETDEBUG(printk(KERN_DEBUG "hw tcp v4 csum failed\n")); |
1da177e4 LT |
1393 | skb->ip_summed = CHECKSUM_NONE; |
1394 | } | |
1395 | if (skb->len <= 76) { | |
1396 | if (tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr, | |
1397 | skb->nh.iph->daddr, | |
1398 | skb_checksum(skb, 0, skb->len, 0))) | |
1399 | return -1; | |
1400 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
1401 | } else { | |
1402 | skb->csum = ~tcp_v4_check(skb->h.th, skb->len, | |
1403 | skb->nh.iph->saddr, | |
1404 | skb->nh.iph->daddr, 0); | |
1405 | } | |
1406 | return 0; | |
1407 | } | |
1408 | ||
1409 | ||
1410 | /* The socket must have it's spinlock held when we get | |
1411 | * here. | |
1412 | * | |
1413 | * We have a potential double-lock case here, so even when | |
1414 | * doing backlog processing we use the BH locking scheme. | |
1415 | * This is because we cannot sleep with the original spinlock | |
1416 | * held. | |
1417 | */ | |
1418 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1419 | { | |
1420 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ | |
1421 | TCP_CHECK_TIMER(sk); | |
1422 | if (tcp_rcv_established(sk, skb, skb->h.th, skb->len)) | |
1423 | goto reset; | |
1424 | TCP_CHECK_TIMER(sk); | |
1425 | return 0; | |
1426 | } | |
1427 | ||
1428 | if (skb->len < (skb->h.th->doff << 2) || tcp_checksum_complete(skb)) | |
1429 | goto csum_err; | |
1430 | ||
1431 | if (sk->sk_state == TCP_LISTEN) { | |
1432 | struct sock *nsk = tcp_v4_hnd_req(sk, skb); | |
1433 | if (!nsk) | |
1434 | goto discard; | |
1435 | ||
1436 | if (nsk != sk) { | |
1437 | if (tcp_child_process(sk, nsk, skb)) | |
1438 | goto reset; | |
1439 | return 0; | |
1440 | } | |
1441 | } | |
1442 | ||
1443 | TCP_CHECK_TIMER(sk); | |
1444 | if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len)) | |
1445 | goto reset; | |
1446 | TCP_CHECK_TIMER(sk); | |
1447 | return 0; | |
1448 | ||
1449 | reset: | |
1450 | tcp_v4_send_reset(skb); | |
1451 | discard: | |
1452 | kfree_skb(skb); | |
1453 | /* Be careful here. If this function gets more complicated and | |
1454 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1455 | * might be destroyed here. This current version compiles correctly, | |
1456 | * but you have been warned. | |
1457 | */ | |
1458 | return 0; | |
1459 | ||
1460 | csum_err: | |
1461 | TCP_INC_STATS_BH(TCP_MIB_INERRS); | |
1462 | goto discard; | |
1463 | } | |
1464 | ||
1465 | /* | |
1466 | * From tcp_input.c | |
1467 | */ | |
1468 | ||
1469 | int tcp_v4_rcv(struct sk_buff *skb) | |
1470 | { | |
1471 | struct tcphdr *th; | |
1472 | struct sock *sk; | |
1473 | int ret; | |
1474 | ||
1475 | if (skb->pkt_type != PACKET_HOST) | |
1476 | goto discard_it; | |
1477 | ||
1478 | /* Count it even if it's bad */ | |
1479 | TCP_INC_STATS_BH(TCP_MIB_INSEGS); | |
1480 | ||
1481 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1482 | goto discard_it; | |
1483 | ||
1484 | th = skb->h.th; | |
1485 | ||
1486 | if (th->doff < sizeof(struct tcphdr) / 4) | |
1487 | goto bad_packet; | |
1488 | if (!pskb_may_pull(skb, th->doff * 4)) | |
1489 | goto discard_it; | |
1490 | ||
1491 | /* An explanation is required here, I think. | |
1492 | * Packet length and doff are validated by header prediction, | |
1493 | * provided case of th->doff==0 is elimineted. | |
1494 | * So, we defer the checks. */ | |
1495 | if ((skb->ip_summed != CHECKSUM_UNNECESSARY && | |
1496 | tcp_v4_checksum_init(skb) < 0)) | |
1497 | goto bad_packet; | |
1498 | ||
1499 | th = skb->h.th; | |
1500 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); | |
1501 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1502 | skb->len - th->doff * 4); | |
1503 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
1504 | TCP_SKB_CB(skb)->when = 0; | |
1505 | TCP_SKB_CB(skb)->flags = skb->nh.iph->tos; | |
1506 | TCP_SKB_CB(skb)->sacked = 0; | |
1507 | ||
1508 | sk = __tcp_v4_lookup(skb->nh.iph->saddr, th->source, | |
1509 | skb->nh.iph->daddr, ntohs(th->dest), | |
1510 | tcp_v4_iif(skb)); | |
1511 | ||
1512 | if (!sk) | |
1513 | goto no_tcp_socket; | |
1514 | ||
1515 | process: | |
1516 | if (sk->sk_state == TCP_TIME_WAIT) | |
1517 | goto do_time_wait; | |
1518 | ||
1519 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) | |
1520 | goto discard_and_relse; | |
1521 | ||
1522 | if (sk_filter(sk, skb, 0)) | |
1523 | goto discard_and_relse; | |
1524 | ||
1525 | skb->dev = NULL; | |
1526 | ||
1527 | bh_lock_sock(sk); | |
1528 | ret = 0; | |
1529 | if (!sock_owned_by_user(sk)) { | |
1530 | if (!tcp_prequeue(sk, skb)) | |
1531 | ret = tcp_v4_do_rcv(sk, skb); | |
1532 | } else | |
1533 | sk_add_backlog(sk, skb); | |
1534 | bh_unlock_sock(sk); | |
1535 | ||
1536 | sock_put(sk); | |
1537 | ||
1538 | return ret; | |
1539 | ||
1540 | no_tcp_socket: | |
1541 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1542 | goto discard_it; | |
1543 | ||
1544 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
1545 | bad_packet: | |
1546 | TCP_INC_STATS_BH(TCP_MIB_INERRS); | |
1547 | } else { | |
1548 | tcp_v4_send_reset(skb); | |
1549 | } | |
1550 | ||
1551 | discard_it: | |
1552 | /* Discard frame. */ | |
1553 | kfree_skb(skb); | |
1554 | return 0; | |
1555 | ||
1556 | discard_and_relse: | |
1557 | sock_put(sk); | |
1558 | goto discard_it; | |
1559 | ||
1560 | do_time_wait: | |
1561 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
8feaf0c0 | 1562 | inet_twsk_put((struct inet_timewait_sock *) sk); |
1da177e4 LT |
1563 | goto discard_it; |
1564 | } | |
1565 | ||
1566 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
1567 | TCP_INC_STATS_BH(TCP_MIB_INERRS); | |
8feaf0c0 | 1568 | inet_twsk_put((struct inet_timewait_sock *) sk); |
1da177e4 LT |
1569 | goto discard_it; |
1570 | } | |
8feaf0c0 ACM |
1571 | switch (tcp_timewait_state_process((struct inet_timewait_sock *)sk, |
1572 | skb, th)) { | |
1da177e4 | 1573 | case TCP_TW_SYN: { |
33b62231 ACM |
1574 | struct sock *sk2 = inet_lookup_listener(&tcp_hashinfo, |
1575 | skb->nh.iph->daddr, | |
1576 | ntohs(th->dest), | |
1577 | tcp_v4_iif(skb)); | |
1da177e4 | 1578 | if (sk2) { |
8feaf0c0 ACM |
1579 | tcp_tw_deschedule((struct inet_timewait_sock *)sk); |
1580 | inet_twsk_put((struct inet_timewait_sock *)sk); | |
1da177e4 LT |
1581 | sk = sk2; |
1582 | goto process; | |
1583 | } | |
1584 | /* Fall through to ACK */ | |
1585 | } | |
1586 | case TCP_TW_ACK: | |
1587 | tcp_v4_timewait_ack(sk, skb); | |
1588 | break; | |
1589 | case TCP_TW_RST: | |
1590 | goto no_tcp_socket; | |
1591 | case TCP_TW_SUCCESS:; | |
1592 | } | |
1593 | goto discard_it; | |
1594 | } | |
1595 | ||
1da177e4 LT |
1596 | static void v4_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr) |
1597 | { | |
1598 | struct sockaddr_in *sin = (struct sockaddr_in *) uaddr; | |
1599 | struct inet_sock *inet = inet_sk(sk); | |
1600 | ||
1601 | sin->sin_family = AF_INET; | |
1602 | sin->sin_addr.s_addr = inet->daddr; | |
1603 | sin->sin_port = inet->dport; | |
1604 | } | |
1605 | ||
1606 | /* VJ's idea. Save last timestamp seen from this destination | |
1607 | * and hold it at least for normal timewait interval to use for duplicate | |
1608 | * segment detection in subsequent connections, before they enter synchronized | |
1609 | * state. | |
1610 | */ | |
1611 | ||
1612 | int tcp_v4_remember_stamp(struct sock *sk) | |
1613 | { | |
1614 | struct inet_sock *inet = inet_sk(sk); | |
1615 | struct tcp_sock *tp = tcp_sk(sk); | |
1616 | struct rtable *rt = (struct rtable *)__sk_dst_get(sk); | |
1617 | struct inet_peer *peer = NULL; | |
1618 | int release_it = 0; | |
1619 | ||
1620 | if (!rt || rt->rt_dst != inet->daddr) { | |
1621 | peer = inet_getpeer(inet->daddr, 1); | |
1622 | release_it = 1; | |
1623 | } else { | |
1624 | if (!rt->peer) | |
1625 | rt_bind_peer(rt, 1); | |
1626 | peer = rt->peer; | |
1627 | } | |
1628 | ||
1629 | if (peer) { | |
1630 | if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 || | |
1631 | (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec && | |
1632 | peer->tcp_ts_stamp <= tp->rx_opt.ts_recent_stamp)) { | |
1633 | peer->tcp_ts_stamp = tp->rx_opt.ts_recent_stamp; | |
1634 | peer->tcp_ts = tp->rx_opt.ts_recent; | |
1635 | } | |
1636 | if (release_it) | |
1637 | inet_putpeer(peer); | |
1638 | return 1; | |
1639 | } | |
1640 | ||
1641 | return 0; | |
1642 | } | |
1643 | ||
8feaf0c0 | 1644 | int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw) |
1da177e4 | 1645 | { |
8feaf0c0 | 1646 | struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1); |
1da177e4 LT |
1647 | |
1648 | if (peer) { | |
8feaf0c0 ACM |
1649 | const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw); |
1650 | ||
1651 | if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 || | |
1da177e4 | 1652 | (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec && |
8feaf0c0 ACM |
1653 | peer->tcp_ts_stamp <= tcptw->tw_ts_recent_stamp)) { |
1654 | peer->tcp_ts_stamp = tcptw->tw_ts_recent_stamp; | |
1655 | peer->tcp_ts = tcptw->tw_ts_recent; | |
1da177e4 LT |
1656 | } |
1657 | inet_putpeer(peer); | |
1658 | return 1; | |
1659 | } | |
1660 | ||
1661 | return 0; | |
1662 | } | |
1663 | ||
1664 | struct tcp_func ipv4_specific = { | |
1665 | .queue_xmit = ip_queue_xmit, | |
1666 | .send_check = tcp_v4_send_check, | |
32519f11 | 1667 | .rebuild_header = inet_sk_rebuild_header, |
1da177e4 LT |
1668 | .conn_request = tcp_v4_conn_request, |
1669 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
1670 | .remember_stamp = tcp_v4_remember_stamp, | |
1671 | .net_header_len = sizeof(struct iphdr), | |
1672 | .setsockopt = ip_setsockopt, | |
1673 | .getsockopt = ip_getsockopt, | |
1674 | .addr2sockaddr = v4_addr2sockaddr, | |
1675 | .sockaddr_len = sizeof(struct sockaddr_in), | |
1676 | }; | |
1677 | ||
1678 | /* NOTE: A lot of things set to zero explicitly by call to | |
1679 | * sk_alloc() so need not be done here. | |
1680 | */ | |
1681 | static int tcp_v4_init_sock(struct sock *sk) | |
1682 | { | |
1683 | struct tcp_sock *tp = tcp_sk(sk); | |
1684 | ||
1685 | skb_queue_head_init(&tp->out_of_order_queue); | |
1686 | tcp_init_xmit_timers(sk); | |
1687 | tcp_prequeue_init(tp); | |
1688 | ||
1689 | tp->rto = TCP_TIMEOUT_INIT; | |
1690 | tp->mdev = TCP_TIMEOUT_INIT; | |
1691 | ||
1692 | /* So many TCP implementations out there (incorrectly) count the | |
1693 | * initial SYN frame in their delayed-ACK and congestion control | |
1694 | * algorithms that we must have the following bandaid to talk | |
1695 | * efficiently to them. -DaveM | |
1696 | */ | |
1697 | tp->snd_cwnd = 2; | |
1698 | ||
1699 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
1700 | * initialization of these values. | |
1701 | */ | |
1702 | tp->snd_ssthresh = 0x7fffffff; /* Infinity */ | |
1703 | tp->snd_cwnd_clamp = ~0; | |
c1b4a7e6 | 1704 | tp->mss_cache = 536; |
1da177e4 LT |
1705 | |
1706 | tp->reordering = sysctl_tcp_reordering; | |
5f8ef48d | 1707 | tp->ca_ops = &tcp_init_congestion_ops; |
1da177e4 LT |
1708 | |
1709 | sk->sk_state = TCP_CLOSE; | |
1710 | ||
1711 | sk->sk_write_space = sk_stream_write_space; | |
1712 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
1713 | ||
1714 | tp->af_specific = &ipv4_specific; | |
1715 | ||
1716 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; | |
1717 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
1718 | ||
1719 | atomic_inc(&tcp_sockets_allocated); | |
1720 | ||
1721 | return 0; | |
1722 | } | |
1723 | ||
1724 | int tcp_v4_destroy_sock(struct sock *sk) | |
1725 | { | |
1726 | struct tcp_sock *tp = tcp_sk(sk); | |
1727 | ||
1728 | tcp_clear_xmit_timers(sk); | |
1729 | ||
317a76f9 SH |
1730 | tcp_cleanup_congestion_control(tp); |
1731 | ||
1da177e4 LT |
1732 | /* Cleanup up the write buffer. */ |
1733 | sk_stream_writequeue_purge(sk); | |
1734 | ||
1735 | /* Cleans up our, hopefully empty, out_of_order_queue. */ | |
1736 | __skb_queue_purge(&tp->out_of_order_queue); | |
1737 | ||
1738 | /* Clean prequeue, it must be empty really */ | |
1739 | __skb_queue_purge(&tp->ucopy.prequeue); | |
1740 | ||
1741 | /* Clean up a referenced TCP bind bucket. */ | |
a55ebcc4 | 1742 | if (inet_sk(sk)->bind_hash) |
2d8c4ce5 | 1743 | inet_put_port(&tcp_hashinfo, sk); |
1da177e4 LT |
1744 | |
1745 | /* | |
1746 | * If sendmsg cached page exists, toss it. | |
1747 | */ | |
1748 | if (sk->sk_sndmsg_page) { | |
1749 | __free_page(sk->sk_sndmsg_page); | |
1750 | sk->sk_sndmsg_page = NULL; | |
1751 | } | |
1752 | ||
1753 | atomic_dec(&tcp_sockets_allocated); | |
1754 | ||
1755 | return 0; | |
1756 | } | |
1757 | ||
1758 | EXPORT_SYMBOL(tcp_v4_destroy_sock); | |
1759 | ||
1760 | #ifdef CONFIG_PROC_FS | |
1761 | /* Proc filesystem TCP sock list dumping. */ | |
1762 | ||
8feaf0c0 | 1763 | static inline struct inet_timewait_sock *tw_head(struct hlist_head *head) |
1da177e4 LT |
1764 | { |
1765 | return hlist_empty(head) ? NULL : | |
8feaf0c0 | 1766 | list_entry(head->first, struct inet_timewait_sock, tw_node); |
1da177e4 LT |
1767 | } |
1768 | ||
8feaf0c0 | 1769 | static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw) |
1da177e4 LT |
1770 | { |
1771 | return tw->tw_node.next ? | |
1772 | hlist_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL; | |
1773 | } | |
1774 | ||
1775 | static void *listening_get_next(struct seq_file *seq, void *cur) | |
1776 | { | |
1777 | struct tcp_sock *tp; | |
1778 | struct hlist_node *node; | |
1779 | struct sock *sk = cur; | |
1780 | struct tcp_iter_state* st = seq->private; | |
1781 | ||
1782 | if (!sk) { | |
1783 | st->bucket = 0; | |
6e04e021 | 1784 | sk = sk_head(&tcp_hashinfo.listening_hash[0]); |
1da177e4 LT |
1785 | goto get_sk; |
1786 | } | |
1787 | ||
1788 | ++st->num; | |
1789 | ||
1790 | if (st->state == TCP_SEQ_STATE_OPENREQ) { | |
60236fdd | 1791 | struct request_sock *req = cur; |
1da177e4 LT |
1792 | |
1793 | tp = tcp_sk(st->syn_wait_sk); | |
1794 | req = req->dl_next; | |
1795 | while (1) { | |
1796 | while (req) { | |
60236fdd | 1797 | if (req->rsk_ops->family == st->family) { |
1da177e4 LT |
1798 | cur = req; |
1799 | goto out; | |
1800 | } | |
1801 | req = req->dl_next; | |
1802 | } | |
1803 | if (++st->sbucket >= TCP_SYNQ_HSIZE) | |
1804 | break; | |
1805 | get_req: | |
0e87506f | 1806 | req = tp->accept_queue.listen_opt->syn_table[st->sbucket]; |
1da177e4 LT |
1807 | } |
1808 | sk = sk_next(st->syn_wait_sk); | |
1809 | st->state = TCP_SEQ_STATE_LISTENING; | |
0e87506f | 1810 | read_unlock_bh(&tp->accept_queue.syn_wait_lock); |
1da177e4 LT |
1811 | } else { |
1812 | tp = tcp_sk(sk); | |
0e87506f ACM |
1813 | read_lock_bh(&tp->accept_queue.syn_wait_lock); |
1814 | if (reqsk_queue_len(&tp->accept_queue)) | |
1da177e4 | 1815 | goto start_req; |
0e87506f | 1816 | read_unlock_bh(&tp->accept_queue.syn_wait_lock); |
1da177e4 LT |
1817 | sk = sk_next(sk); |
1818 | } | |
1819 | get_sk: | |
1820 | sk_for_each_from(sk, node) { | |
1821 | if (sk->sk_family == st->family) { | |
1822 | cur = sk; | |
1823 | goto out; | |
1824 | } | |
1825 | tp = tcp_sk(sk); | |
0e87506f ACM |
1826 | read_lock_bh(&tp->accept_queue.syn_wait_lock); |
1827 | if (reqsk_queue_len(&tp->accept_queue)) { | |
1da177e4 LT |
1828 | start_req: |
1829 | st->uid = sock_i_uid(sk); | |
1830 | st->syn_wait_sk = sk; | |
1831 | st->state = TCP_SEQ_STATE_OPENREQ; | |
1832 | st->sbucket = 0; | |
1833 | goto get_req; | |
1834 | } | |
0e87506f | 1835 | read_unlock_bh(&tp->accept_queue.syn_wait_lock); |
1da177e4 | 1836 | } |
0f7ff927 | 1837 | if (++st->bucket < INET_LHTABLE_SIZE) { |
6e04e021 | 1838 | sk = sk_head(&tcp_hashinfo.listening_hash[st->bucket]); |
1da177e4 LT |
1839 | goto get_sk; |
1840 | } | |
1841 | cur = NULL; | |
1842 | out: | |
1843 | return cur; | |
1844 | } | |
1845 | ||
1846 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
1847 | { | |
1848 | void *rc = listening_get_next(seq, NULL); | |
1849 | ||
1850 | while (rc && *pos) { | |
1851 | rc = listening_get_next(seq, rc); | |
1852 | --*pos; | |
1853 | } | |
1854 | return rc; | |
1855 | } | |
1856 | ||
1857 | static void *established_get_first(struct seq_file *seq) | |
1858 | { | |
1859 | struct tcp_iter_state* st = seq->private; | |
1860 | void *rc = NULL; | |
1861 | ||
6e04e021 | 1862 | for (st->bucket = 0; st->bucket < tcp_hashinfo.ehash_size; ++st->bucket) { |
1da177e4 LT |
1863 | struct sock *sk; |
1864 | struct hlist_node *node; | |
8feaf0c0 | 1865 | struct inet_timewait_sock *tw; |
1da177e4 LT |
1866 | |
1867 | /* We can reschedule _before_ having picked the target: */ | |
1868 | cond_resched_softirq(); | |
1869 | ||
6e04e021 ACM |
1870 | read_lock(&tcp_hashinfo.ehash[st->bucket].lock); |
1871 | sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { | |
1da177e4 LT |
1872 | if (sk->sk_family != st->family) { |
1873 | continue; | |
1874 | } | |
1875 | rc = sk; | |
1876 | goto out; | |
1877 | } | |
1878 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
8feaf0c0 ACM |
1879 | inet_twsk_for_each(tw, node, |
1880 | &tcp_hashinfo.ehash[st->bucket + tcp_hashinfo.ehash_size].chain) { | |
1da177e4 LT |
1881 | if (tw->tw_family != st->family) { |
1882 | continue; | |
1883 | } | |
1884 | rc = tw; | |
1885 | goto out; | |
1886 | } | |
6e04e021 | 1887 | read_unlock(&tcp_hashinfo.ehash[st->bucket].lock); |
1da177e4 LT |
1888 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
1889 | } | |
1890 | out: | |
1891 | return rc; | |
1892 | } | |
1893 | ||
1894 | static void *established_get_next(struct seq_file *seq, void *cur) | |
1895 | { | |
1896 | struct sock *sk = cur; | |
8feaf0c0 | 1897 | struct inet_timewait_sock *tw; |
1da177e4 LT |
1898 | struct hlist_node *node; |
1899 | struct tcp_iter_state* st = seq->private; | |
1900 | ||
1901 | ++st->num; | |
1902 | ||
1903 | if (st->state == TCP_SEQ_STATE_TIME_WAIT) { | |
1904 | tw = cur; | |
1905 | tw = tw_next(tw); | |
1906 | get_tw: | |
1907 | while (tw && tw->tw_family != st->family) { | |
1908 | tw = tw_next(tw); | |
1909 | } | |
1910 | if (tw) { | |
1911 | cur = tw; | |
1912 | goto out; | |
1913 | } | |
6e04e021 | 1914 | read_unlock(&tcp_hashinfo.ehash[st->bucket].lock); |
1da177e4 LT |
1915 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
1916 | ||
1917 | /* We can reschedule between buckets: */ | |
1918 | cond_resched_softirq(); | |
1919 | ||
6e04e021 ACM |
1920 | if (++st->bucket < tcp_hashinfo.ehash_size) { |
1921 | read_lock(&tcp_hashinfo.ehash[st->bucket].lock); | |
1922 | sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain); | |
1da177e4 LT |
1923 | } else { |
1924 | cur = NULL; | |
1925 | goto out; | |
1926 | } | |
1927 | } else | |
1928 | sk = sk_next(sk); | |
1929 | ||
1930 | sk_for_each_from(sk, node) { | |
1931 | if (sk->sk_family == st->family) | |
1932 | goto found; | |
1933 | } | |
1934 | ||
1935 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
6e04e021 | 1936 | tw = tw_head(&tcp_hashinfo.ehash[st->bucket + tcp_hashinfo.ehash_size].chain); |
1da177e4 LT |
1937 | goto get_tw; |
1938 | found: | |
1939 | cur = sk; | |
1940 | out: | |
1941 | return cur; | |
1942 | } | |
1943 | ||
1944 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
1945 | { | |
1946 | void *rc = established_get_first(seq); | |
1947 | ||
1948 | while (rc && pos) { | |
1949 | rc = established_get_next(seq, rc); | |
1950 | --pos; | |
1951 | } | |
1952 | return rc; | |
1953 | } | |
1954 | ||
1955 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
1956 | { | |
1957 | void *rc; | |
1958 | struct tcp_iter_state* st = seq->private; | |
1959 | ||
f3f05f70 | 1960 | inet_listen_lock(&tcp_hashinfo); |
1da177e4 LT |
1961 | st->state = TCP_SEQ_STATE_LISTENING; |
1962 | rc = listening_get_idx(seq, &pos); | |
1963 | ||
1964 | if (!rc) { | |
f3f05f70 | 1965 | inet_listen_unlock(&tcp_hashinfo); |
1da177e4 LT |
1966 | local_bh_disable(); |
1967 | st->state = TCP_SEQ_STATE_ESTABLISHED; | |
1968 | rc = established_get_idx(seq, pos); | |
1969 | } | |
1970 | ||
1971 | return rc; | |
1972 | } | |
1973 | ||
1974 | static void *tcp_seq_start(struct seq_file *seq, loff_t *pos) | |
1975 | { | |
1976 | struct tcp_iter_state* st = seq->private; | |
1977 | st->state = TCP_SEQ_STATE_LISTENING; | |
1978 | st->num = 0; | |
1979 | return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1980 | } | |
1981 | ||
1982 | static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1983 | { | |
1984 | void *rc = NULL; | |
1985 | struct tcp_iter_state* st; | |
1986 | ||
1987 | if (v == SEQ_START_TOKEN) { | |
1988 | rc = tcp_get_idx(seq, 0); | |
1989 | goto out; | |
1990 | } | |
1991 | st = seq->private; | |
1992 | ||
1993 | switch (st->state) { | |
1994 | case TCP_SEQ_STATE_OPENREQ: | |
1995 | case TCP_SEQ_STATE_LISTENING: | |
1996 | rc = listening_get_next(seq, v); | |
1997 | if (!rc) { | |
f3f05f70 | 1998 | inet_listen_unlock(&tcp_hashinfo); |
1da177e4 LT |
1999 | local_bh_disable(); |
2000 | st->state = TCP_SEQ_STATE_ESTABLISHED; | |
2001 | rc = established_get_first(seq); | |
2002 | } | |
2003 | break; | |
2004 | case TCP_SEQ_STATE_ESTABLISHED: | |
2005 | case TCP_SEQ_STATE_TIME_WAIT: | |
2006 | rc = established_get_next(seq, v); | |
2007 | break; | |
2008 | } | |
2009 | out: | |
2010 | ++*pos; | |
2011 | return rc; | |
2012 | } | |
2013 | ||
2014 | static void tcp_seq_stop(struct seq_file *seq, void *v) | |
2015 | { | |
2016 | struct tcp_iter_state* st = seq->private; | |
2017 | ||
2018 | switch (st->state) { | |
2019 | case TCP_SEQ_STATE_OPENREQ: | |
2020 | if (v) { | |
2021 | struct tcp_sock *tp = tcp_sk(st->syn_wait_sk); | |
0e87506f | 2022 | read_unlock_bh(&tp->accept_queue.syn_wait_lock); |
1da177e4 LT |
2023 | } |
2024 | case TCP_SEQ_STATE_LISTENING: | |
2025 | if (v != SEQ_START_TOKEN) | |
f3f05f70 | 2026 | inet_listen_unlock(&tcp_hashinfo); |
1da177e4 LT |
2027 | break; |
2028 | case TCP_SEQ_STATE_TIME_WAIT: | |
2029 | case TCP_SEQ_STATE_ESTABLISHED: | |
2030 | if (v) | |
6e04e021 | 2031 | read_unlock(&tcp_hashinfo.ehash[st->bucket].lock); |
1da177e4 LT |
2032 | local_bh_enable(); |
2033 | break; | |
2034 | } | |
2035 | } | |
2036 | ||
2037 | static int tcp_seq_open(struct inode *inode, struct file *file) | |
2038 | { | |
2039 | struct tcp_seq_afinfo *afinfo = PDE(inode)->data; | |
2040 | struct seq_file *seq; | |
2041 | struct tcp_iter_state *s; | |
2042 | int rc; | |
2043 | ||
2044 | if (unlikely(afinfo == NULL)) | |
2045 | return -EINVAL; | |
2046 | ||
2047 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
2048 | if (!s) | |
2049 | return -ENOMEM; | |
2050 | memset(s, 0, sizeof(*s)); | |
2051 | s->family = afinfo->family; | |
2052 | s->seq_ops.start = tcp_seq_start; | |
2053 | s->seq_ops.next = tcp_seq_next; | |
2054 | s->seq_ops.show = afinfo->seq_show; | |
2055 | s->seq_ops.stop = tcp_seq_stop; | |
2056 | ||
2057 | rc = seq_open(file, &s->seq_ops); | |
2058 | if (rc) | |
2059 | goto out_kfree; | |
2060 | seq = file->private_data; | |
2061 | seq->private = s; | |
2062 | out: | |
2063 | return rc; | |
2064 | out_kfree: | |
2065 | kfree(s); | |
2066 | goto out; | |
2067 | } | |
2068 | ||
2069 | int tcp_proc_register(struct tcp_seq_afinfo *afinfo) | |
2070 | { | |
2071 | int rc = 0; | |
2072 | struct proc_dir_entry *p; | |
2073 | ||
2074 | if (!afinfo) | |
2075 | return -EINVAL; | |
2076 | afinfo->seq_fops->owner = afinfo->owner; | |
2077 | afinfo->seq_fops->open = tcp_seq_open; | |
2078 | afinfo->seq_fops->read = seq_read; | |
2079 | afinfo->seq_fops->llseek = seq_lseek; | |
2080 | afinfo->seq_fops->release = seq_release_private; | |
2081 | ||
2082 | p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops); | |
2083 | if (p) | |
2084 | p->data = afinfo; | |
2085 | else | |
2086 | rc = -ENOMEM; | |
2087 | return rc; | |
2088 | } | |
2089 | ||
2090 | void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo) | |
2091 | { | |
2092 | if (!afinfo) | |
2093 | return; | |
2094 | proc_net_remove(afinfo->name); | |
2095 | memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops)); | |
2096 | } | |
2097 | ||
60236fdd | 2098 | static void get_openreq4(struct sock *sk, struct request_sock *req, |
1da177e4 LT |
2099 | char *tmpbuf, int i, int uid) |
2100 | { | |
2e6599cb | 2101 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
2102 | int ttd = req->expires - jiffies; |
2103 | ||
2104 | sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" | |
2105 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p", | |
2106 | i, | |
2e6599cb | 2107 | ireq->loc_addr, |
1da177e4 | 2108 | ntohs(inet_sk(sk)->sport), |
2e6599cb ACM |
2109 | ireq->rmt_addr, |
2110 | ntohs(ireq->rmt_port), | |
1da177e4 LT |
2111 | TCP_SYN_RECV, |
2112 | 0, 0, /* could print option size, but that is af dependent. */ | |
2113 | 1, /* timers active (only the expire timer) */ | |
2114 | jiffies_to_clock_t(ttd), | |
2115 | req->retrans, | |
2116 | uid, | |
2117 | 0, /* non standard timer */ | |
2118 | 0, /* open_requests have no inode */ | |
2119 | atomic_read(&sk->sk_refcnt), | |
2120 | req); | |
2121 | } | |
2122 | ||
2123 | static void get_tcp4_sock(struct sock *sp, char *tmpbuf, int i) | |
2124 | { | |
2125 | int timer_active; | |
2126 | unsigned long timer_expires; | |
2127 | struct tcp_sock *tp = tcp_sk(sp); | |
2128 | struct inet_sock *inet = inet_sk(sp); | |
2129 | unsigned int dest = inet->daddr; | |
2130 | unsigned int src = inet->rcv_saddr; | |
2131 | __u16 destp = ntohs(inet->dport); | |
2132 | __u16 srcp = ntohs(inet->sport); | |
2133 | ||
2134 | if (tp->pending == TCP_TIME_RETRANS) { | |
2135 | timer_active = 1; | |
2136 | timer_expires = tp->timeout; | |
2137 | } else if (tp->pending == TCP_TIME_PROBE0) { | |
2138 | timer_active = 4; | |
2139 | timer_expires = tp->timeout; | |
2140 | } else if (timer_pending(&sp->sk_timer)) { | |
2141 | timer_active = 2; | |
2142 | timer_expires = sp->sk_timer.expires; | |
2143 | } else { | |
2144 | timer_active = 0; | |
2145 | timer_expires = jiffies; | |
2146 | } | |
2147 | ||
2148 | sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " | |
2149 | "%08X %5d %8d %lu %d %p %u %u %u %u %d", | |
2150 | i, src, srcp, dest, destp, sp->sk_state, | |
2151 | tp->write_seq - tp->snd_una, tp->rcv_nxt - tp->copied_seq, | |
2152 | timer_active, | |
2153 | jiffies_to_clock_t(timer_expires - jiffies), | |
2154 | tp->retransmits, | |
2155 | sock_i_uid(sp), | |
2156 | tp->probes_out, | |
2157 | sock_i_ino(sp), | |
2158 | atomic_read(&sp->sk_refcnt), sp, | |
2159 | tp->rto, tp->ack.ato, (tp->ack.quick << 1) | tp->ack.pingpong, | |
2160 | tp->snd_cwnd, | |
2161 | tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh); | |
2162 | } | |
2163 | ||
8feaf0c0 | 2164 | static void get_timewait4_sock(struct inet_timewait_sock *tw, char *tmpbuf, int i) |
1da177e4 LT |
2165 | { |
2166 | unsigned int dest, src; | |
2167 | __u16 destp, srcp; | |
2168 | int ttd = tw->tw_ttd - jiffies; | |
2169 | ||
2170 | if (ttd < 0) | |
2171 | ttd = 0; | |
2172 | ||
2173 | dest = tw->tw_daddr; | |
2174 | src = tw->tw_rcv_saddr; | |
2175 | destp = ntohs(tw->tw_dport); | |
2176 | srcp = ntohs(tw->tw_sport); | |
2177 | ||
2178 | sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" | |
2179 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p", | |
2180 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, | |
2181 | 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, | |
2182 | atomic_read(&tw->tw_refcnt), tw); | |
2183 | } | |
2184 | ||
2185 | #define TMPSZ 150 | |
2186 | ||
2187 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2188 | { | |
2189 | struct tcp_iter_state* st; | |
2190 | char tmpbuf[TMPSZ + 1]; | |
2191 | ||
2192 | if (v == SEQ_START_TOKEN) { | |
2193 | seq_printf(seq, "%-*s\n", TMPSZ - 1, | |
2194 | " sl local_address rem_address st tx_queue " | |
2195 | "rx_queue tr tm->when retrnsmt uid timeout " | |
2196 | "inode"); | |
2197 | goto out; | |
2198 | } | |
2199 | st = seq->private; | |
2200 | ||
2201 | switch (st->state) { | |
2202 | case TCP_SEQ_STATE_LISTENING: | |
2203 | case TCP_SEQ_STATE_ESTABLISHED: | |
2204 | get_tcp4_sock(v, tmpbuf, st->num); | |
2205 | break; | |
2206 | case TCP_SEQ_STATE_OPENREQ: | |
2207 | get_openreq4(st->syn_wait_sk, v, tmpbuf, st->num, st->uid); | |
2208 | break; | |
2209 | case TCP_SEQ_STATE_TIME_WAIT: | |
2210 | get_timewait4_sock(v, tmpbuf, st->num); | |
2211 | break; | |
2212 | } | |
2213 | seq_printf(seq, "%-*s\n", TMPSZ - 1, tmpbuf); | |
2214 | out: | |
2215 | return 0; | |
2216 | } | |
2217 | ||
2218 | static struct file_operations tcp4_seq_fops; | |
2219 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { | |
2220 | .owner = THIS_MODULE, | |
2221 | .name = "tcp", | |
2222 | .family = AF_INET, | |
2223 | .seq_show = tcp4_seq_show, | |
2224 | .seq_fops = &tcp4_seq_fops, | |
2225 | }; | |
2226 | ||
2227 | int __init tcp4_proc_init(void) | |
2228 | { | |
2229 | return tcp_proc_register(&tcp4_seq_afinfo); | |
2230 | } | |
2231 | ||
2232 | void tcp4_proc_exit(void) | |
2233 | { | |
2234 | tcp_proc_unregister(&tcp4_seq_afinfo); | |
2235 | } | |
2236 | #endif /* CONFIG_PROC_FS */ | |
2237 | ||
2238 | struct proto tcp_prot = { | |
2239 | .name = "TCP", | |
2240 | .owner = THIS_MODULE, | |
2241 | .close = tcp_close, | |
2242 | .connect = tcp_v4_connect, | |
2243 | .disconnect = tcp_disconnect, | |
2244 | .accept = tcp_accept, | |
2245 | .ioctl = tcp_ioctl, | |
2246 | .init = tcp_v4_init_sock, | |
2247 | .destroy = tcp_v4_destroy_sock, | |
2248 | .shutdown = tcp_shutdown, | |
2249 | .setsockopt = tcp_setsockopt, | |
2250 | .getsockopt = tcp_getsockopt, | |
2251 | .sendmsg = tcp_sendmsg, | |
2252 | .recvmsg = tcp_recvmsg, | |
2253 | .backlog_rcv = tcp_v4_do_rcv, | |
2254 | .hash = tcp_v4_hash, | |
2255 | .unhash = tcp_unhash, | |
2256 | .get_port = tcp_v4_get_port, | |
2257 | .enter_memory_pressure = tcp_enter_memory_pressure, | |
2258 | .sockets_allocated = &tcp_sockets_allocated, | |
2259 | .memory_allocated = &tcp_memory_allocated, | |
2260 | .memory_pressure = &tcp_memory_pressure, | |
2261 | .sysctl_mem = sysctl_tcp_mem, | |
2262 | .sysctl_wmem = sysctl_tcp_wmem, | |
2263 | .sysctl_rmem = sysctl_tcp_rmem, | |
2264 | .max_header = MAX_TCP_HEADER, | |
2265 | .obj_size = sizeof(struct tcp_sock), | |
8feaf0c0 | 2266 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), |
60236fdd | 2267 | .rsk_prot = &tcp_request_sock_ops, |
1da177e4 LT |
2268 | }; |
2269 | ||
2270 | ||
2271 | ||
2272 | void __init tcp_v4_init(struct net_proto_family *ops) | |
2273 | { | |
2274 | int err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_TCP, &tcp_socket); | |
2275 | if (err < 0) | |
2276 | panic("Failed to create the TCP control socket.\n"); | |
2277 | tcp_socket->sk->sk_allocation = GFP_ATOMIC; | |
2278 | inet_sk(tcp_socket->sk)->uc_ttl = -1; | |
2279 | ||
2280 | /* Unhash it so that IP input processing does not even | |
2281 | * see it, we do not wish this socket to see incoming | |
2282 | * packets. | |
2283 | */ | |
2284 | tcp_socket->sk->sk_prot->unhash(tcp_socket->sk); | |
2285 | } | |
2286 | ||
2287 | EXPORT_SYMBOL(ipv4_specific); | |
0f7ff927 | 2288 | EXPORT_SYMBOL(inet_bind_bucket_create); |
1da177e4 | 2289 | EXPORT_SYMBOL(tcp_hashinfo); |
1da177e4 | 2290 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 LT |
2291 | EXPORT_SYMBOL(tcp_unhash); |
2292 | EXPORT_SYMBOL(tcp_v4_conn_request); | |
2293 | EXPORT_SYMBOL(tcp_v4_connect); | |
2294 | EXPORT_SYMBOL(tcp_v4_do_rcv); | |
1da177e4 LT |
2295 | EXPORT_SYMBOL(tcp_v4_remember_stamp); |
2296 | EXPORT_SYMBOL(tcp_v4_send_check); | |
2297 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); | |
2298 | ||
2299 | #ifdef CONFIG_PROC_FS | |
2300 | EXPORT_SYMBOL(tcp_proc_register); | |
2301 | EXPORT_SYMBOL(tcp_proc_unregister); | |
2302 | #endif | |
2303 | EXPORT_SYMBOL(sysctl_local_port_range); | |
1da177e4 LT |
2304 | EXPORT_SYMBOL(sysctl_tcp_low_latency); |
2305 | EXPORT_SYMBOL(sysctl_tcp_tw_reuse); | |
2306 |