projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/dtor/input
[deliverable/linux.git] / net / ipv4 / netfilter / ip_conntrack_proto_tcp.c
1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>:
9 * - Real stateful connection tracking
10 * - Modified state transitions table
11 * - Window scaling support added
12 * - SACK support added
13 *
14 * Willy Tarreau:
15 * - State table bugfixes
16 * - More robust state changes
17 * - Tuning timer parameters
18 *
19 * version 2.2
20 */
21
22 #include <linux/types.h>
23 #include <linux/timer.h>
24 #include <linux/netfilter.h>
25 #include <linux/module.h>
26 #include <linux/in.h>
27 #include <linux/ip.h>
28 #include <linux/tcp.h>
29 #include <linux/spinlock.h>
30
31 #include <net/tcp.h>
32
33 #include <linux/netfilter_ipv4.h>
34 #include <linux/netfilter_ipv4/ip_conntrack.h>
35 #include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
36
37 #if 0
38 #define DEBUGP printk
39 #define DEBUGP_VARS
40 #else
41 #define DEBUGP(format, args...)
42 #endif
43
44 /* Protects conntrack->proto.tcp */
45 static DEFINE_RWLOCK(tcp_lock);
46
47 /* "Be conservative in what you do,
48 be liberal in what you accept from others."
49 If it's non-zero, we mark only out of window RST segments as INVALID. */
50 int ip_ct_tcp_be_liberal __read_mostly = 0;
51
52 /* If it is set to zero, we disable picking up already established
53 connections. */
54 int ip_ct_tcp_loose __read_mostly = 1;
55
56 /* Max number of the retransmitted packets without receiving an (acceptable)
57 ACK from the destination. If this number is reached, a shorter timer
58 will be started. */
59 int ip_ct_tcp_max_retrans __read_mostly = 3;
60
61 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
62 closely. They're more complex. --RR */
63
64 static const char *tcp_conntrack_names[] = {
65 "NONE",
66 "SYN_SENT",
67 "SYN_RECV",
68 "ESTABLISHED",
69 "FIN_WAIT",
70 "CLOSE_WAIT",
71 "LAST_ACK",
72 "TIME_WAIT",
73 "CLOSE",
74 "LISTEN"
75 };
76
77 #define SECS * HZ
78 #define MINS * 60 SECS
79 #define HOURS * 60 MINS
80 #define DAYS * 24 HOURS
81
82 unsigned int ip_ct_tcp_timeout_syn_sent __read_mostly = 2 MINS;
83 unsigned int ip_ct_tcp_timeout_syn_recv __read_mostly = 60 SECS;
84 unsigned int ip_ct_tcp_timeout_established __read_mostly = 5 DAYS;
85 unsigned int ip_ct_tcp_timeout_fin_wait __read_mostly = 2 MINS;
86 unsigned int ip_ct_tcp_timeout_close_wait __read_mostly = 60 SECS;
87 unsigned int ip_ct_tcp_timeout_last_ack __read_mostly = 30 SECS;
88 unsigned int ip_ct_tcp_timeout_time_wait __read_mostly = 2 MINS;
89 unsigned int ip_ct_tcp_timeout_close __read_mostly = 10 SECS;
90
91 /* RFC1122 says the R2 limit should be at least 100 seconds.
92 Linux uses 15 packets as limit, which corresponds
93 to ~13-30min depending on RTO. */
94 unsigned int ip_ct_tcp_timeout_max_retrans __read_mostly = 5 MINS;
95
96 static const unsigned int * tcp_timeouts[]
97 = { NULL, /* TCP_CONNTRACK_NONE */
98 &ip_ct_tcp_timeout_syn_sent, /* TCP_CONNTRACK_SYN_SENT, */
99 &ip_ct_tcp_timeout_syn_recv, /* TCP_CONNTRACK_SYN_RECV, */
100 &ip_ct_tcp_timeout_established, /* TCP_CONNTRACK_ESTABLISHED, */
101 &ip_ct_tcp_timeout_fin_wait, /* TCP_CONNTRACK_FIN_WAIT, */
102 &ip_ct_tcp_timeout_close_wait, /* TCP_CONNTRACK_CLOSE_WAIT, */
103 &ip_ct_tcp_timeout_last_ack, /* TCP_CONNTRACK_LAST_ACK, */
104 &ip_ct_tcp_timeout_time_wait, /* TCP_CONNTRACK_TIME_WAIT, */
105 &ip_ct_tcp_timeout_close, /* TCP_CONNTRACK_CLOSE, */
106 NULL, /* TCP_CONNTRACK_LISTEN */
107 };
108
109 #define sNO TCP_CONNTRACK_NONE
110 #define sSS TCP_CONNTRACK_SYN_SENT
111 #define sSR TCP_CONNTRACK_SYN_RECV
112 #define sES TCP_CONNTRACK_ESTABLISHED
113 #define sFW TCP_CONNTRACK_FIN_WAIT
114 #define sCW TCP_CONNTRACK_CLOSE_WAIT
115 #define sLA TCP_CONNTRACK_LAST_ACK
116 #define sTW TCP_CONNTRACK_TIME_WAIT
117 #define sCL TCP_CONNTRACK_CLOSE
118 #define sLI TCP_CONNTRACK_LISTEN
119 #define sIV TCP_CONNTRACK_MAX
120 #define sIG TCP_CONNTRACK_IGNORE
121
122 /* What TCP flags are set from RST/SYN/FIN/ACK. */
123 enum tcp_bit_set {
124 TCP_SYN_SET,
125 TCP_SYNACK_SET,
126 TCP_FIN_SET,
127 TCP_ACK_SET,
128 TCP_RST_SET,
129 TCP_NONE_SET,
130 };
131
132 /*
133 * The TCP state transition table needs a few words...
134 *
135 * We are the man in the middle. All the packets go through us
136 * but might get lost in transit to the destination.
137 * It is assumed that the destinations can't receive segments
138 * we haven't seen.
139 *
140 * The checked segment is in window, but our windows are *not*
141 * equivalent with the ones of the sender/receiver. We always
142 * try to guess the state of the current sender.
143 *
144 * The meaning of the states are:
145 *
146 * NONE: initial state
147 * SYN_SENT: SYN-only packet seen
148 * SYN_RECV: SYN-ACK packet seen
149 * ESTABLISHED: ACK packet seen
150 * FIN_WAIT: FIN packet seen
151 * CLOSE_WAIT: ACK seen (after FIN)
152 * LAST_ACK: FIN seen (after FIN)
153 * TIME_WAIT: last ACK seen
154 * CLOSE: closed connection
155 *
156 * LISTEN state is not used.
157 *
158 * Packets marked as IGNORED (sIG):
159 * if they may be either invalid or valid
160 * and the receiver may send back a connection
161 * closing RST or a SYN/ACK.
162 *
163 * Packets marked as INVALID (sIV):
164 * if they are invalid
165 * or we do not support the request (simultaneous open)
166 */
167 static const enum tcp_conntrack tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
168 {
169 /* ORIGINAL */
170 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
171 /*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
172 /*
173 * sNO -> sSS Initialize a new connection
174 * sSS -> sSS Retransmitted SYN
175 * sSR -> sIG Late retransmitted SYN?
176 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
177 * are errors. Receiver will reply with RST
178 * and close the connection.
179 * Or we are not in sync and hold a dead connection.
180 * sFW -> sIG
181 * sCW -> sIG
182 * sLA -> sIG
183 * sTW -> sSS Reopened connection (RFC 1122).
184 * sCL -> sSS
185 */
186 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
187 /*synack*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
188 /*
189 * A SYN/ACK from the client is always invalid:
190 * - either it tries to set up a simultaneous open, which is
191 * not supported;
192 * - or the firewall has just been inserted between the two hosts
193 * during the session set-up. The SYN will be retransmitted
194 * by the true client (or it'll time out).
195 */
196 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
197 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
198 /*
199 * sNO -> sIV Too late and no reason to do anything...
200 * sSS -> sIV Client migth not send FIN in this state:
201 * we enforce waiting for a SYN/ACK reply first.
202 * sSR -> sFW Close started.
203 * sES -> sFW
204 * sFW -> sLA FIN seen in both directions, waiting for
205 * the last ACK.
206 * Migth be a retransmitted FIN as well...
207 * sCW -> sLA
208 * sLA -> sLA Retransmitted FIN. Remain in the same state.
209 * sTW -> sTW
210 * sCL -> sCL
211 */
212 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
213 /*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
214 /*
215 * sNO -> sES Assumed.
216 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
217 * sSR -> sES Established state is reached.
218 * sES -> sES :-)
219 * sFW -> sCW Normal close request answered by ACK.
220 * sCW -> sCW
221 * sLA -> sTW Last ACK detected.
222 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
223 * sCL -> sCL
224 */
225 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
226 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
227 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
228 },
229 {
230 /* REPLY */
231 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
232 /*syn*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
233 /*
234 * sNO -> sIV Never reached.
235 * sSS -> sIV Simultaneous open, not supported
236 * sSR -> sIV Simultaneous open, not supported.
237 * sES -> sIV Server may not initiate a connection.
238 * sFW -> sIV
239 * sCW -> sIV
240 * sLA -> sIV
241 * sTW -> sIV Reopened connection, but server may not do it.
242 * sCL -> sIV
243 */
244 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
245 /*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIV },
246 /*
247 * sSS -> sSR Standard open.
248 * sSR -> sSR Retransmitted SYN/ACK.
249 * sES -> sIG Late retransmitted SYN/ACK?
250 * sFW -> sIG Might be SYN/ACK answering ignored SYN
251 * sCW -> sIG
252 * sLA -> sIG
253 * sTW -> sIG
254 * sCL -> sIG
255 */
256 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
257 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
258 /*
259 * sSS -> sIV Server might not send FIN in this state.
260 * sSR -> sFW Close started.
261 * sES -> sFW
262 * sFW -> sLA FIN seen in both directions.
263 * sCW -> sLA
264 * sLA -> sLA Retransmitted FIN.
265 * sTW -> sTW
266 * sCL -> sCL
267 */
268 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
269 /*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
270 /*
271 * sSS -> sIG Might be a half-open connection.
272 * sSR -> sSR Might answer late resent SYN.
273 * sES -> sES :-)
274 * sFW -> sCW Normal close request answered by ACK.
275 * sCW -> sCW
276 * sLA -> sTW Last ACK detected.
277 * sTW -> sTW Retransmitted last ACK.
278 * sCL -> sCL
279 */
280 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
281 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
282 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
283 }
284 };
285
286 static int tcp_pkt_to_tuple(const struct sk_buff *skb,
287 unsigned int dataoff,
288 struct ip_conntrack_tuple *tuple)
289 {
290 struct tcphdr _hdr, *hp;
291
292 /* Actually only need first 8 bytes. */
293 hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
294 if (hp == NULL)
295 return 0;
296
297 tuple->src.u.tcp.port = hp->source;
298 tuple->dst.u.tcp.port = hp->dest;
299
300 return 1;
301 }
302
303 static int tcp_invert_tuple(struct ip_conntrack_tuple *tuple,
304 const struct ip_conntrack_tuple *orig)
305 {
306 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
307 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
308 return 1;
309 }
310
311 /* Print out the per-protocol part of the tuple. */
312 static int tcp_print_tuple(struct seq_file *s,
313 const struct ip_conntrack_tuple *tuple)
314 {
315 return seq_printf(s, "sport=%hu dport=%hu ",
316 ntohs(tuple->src.u.tcp.port),
317 ntohs(tuple->dst.u.tcp.port));
318 }
319
320 /* Print out the private part of the conntrack. */
321 static int tcp_print_conntrack(struct seq_file *s,
322 const struct ip_conntrack *conntrack)
323 {
324 enum tcp_conntrack state;
325
326 read_lock_bh(&tcp_lock);
327 state = conntrack->proto.tcp.state;
328 read_unlock_bh(&tcp_lock);
329
330 return seq_printf(s, "%s ", tcp_conntrack_names[state]);
331 }
332
333 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
334 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
335 static int tcp_to_nfattr(struct sk_buff *skb, struct nfattr *nfa,
336 const struct ip_conntrack *ct)
337 {
338 struct nfattr *nest_parms;
339
340 read_lock_bh(&tcp_lock);
341 nest_parms = NFA_NEST(skb, CTA_PROTOINFO_TCP);
342 NFA_PUT(skb, CTA_PROTOINFO_TCP_STATE, sizeof(u_int8_t),
343 &ct->proto.tcp.state);
344 read_unlock_bh(&tcp_lock);
345
346 NFA_NEST_END(skb, nest_parms);
347
348 return 0;
349
350 nfattr_failure:
351 read_unlock_bh(&tcp_lock);
352 return -1;
353 }
354
355 static const size_t cta_min_tcp[CTA_PROTOINFO_TCP_MAX] = {
356 [CTA_PROTOINFO_TCP_STATE-1] = sizeof(u_int8_t),
357 };
358
359 static int nfattr_to_tcp(struct nfattr *cda[], struct ip_conntrack *ct)
360 {
361 struct nfattr *attr = cda[CTA_PROTOINFO_TCP-1];
362 struct nfattr *tb[CTA_PROTOINFO_TCP_MAX];
363
364 /* updates could not contain anything about the private
365 * protocol info, in that case skip the parsing */
366 if (!attr)
367 return 0;
368
369 nfattr_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr);
370
371 if (nfattr_bad_size(tb, CTA_PROTOINFO_TCP_MAX, cta_min_tcp))
372 return -EINVAL;
373
374 if (!tb[CTA_PROTOINFO_TCP_STATE-1])
375 return -EINVAL;
376
377 write_lock_bh(&tcp_lock);
378 ct->proto.tcp.state =
379 *(u_int8_t *)NFA_DATA(tb[CTA_PROTOINFO_TCP_STATE-1]);
380 write_unlock_bh(&tcp_lock);
381
382 return 0;
383 }
384 #endif
385
386 static unsigned int get_conntrack_index(const struct tcphdr *tcph)
387 {
388 if (tcph->rst) return TCP_RST_SET;
389 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
390 else if (tcph->fin) return TCP_FIN_SET;
391 else if (tcph->ack) return TCP_ACK_SET;
392 else return TCP_NONE_SET;
393 }
394
395 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
396 in IP Filter' by Guido van Rooij.
397
398 http://www.nluug.nl/events/sane2000/papers.html
399 http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
400
401 The boundaries and the conditions are changed according to RFC793:
402 the packet must intersect the window (i.e. segments may be
403 after the right or before the left edge) and thus receivers may ACK
404 segments after the right edge of the window.
405
406 td_maxend = max(sack + max(win,1)) seen in reply packets
407 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
408 td_maxwin += seq + len - sender.td_maxend
409 if seq + len > sender.td_maxend
410 td_end = max(seq + len) seen in sent packets
411
412 I. Upper bound for valid data: seq <= sender.td_maxend
413 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
414 III. Upper bound for valid ack: sack <= receiver.td_end
415 IV. Lower bound for valid ack: ack >= receiver.td_end - MAXACKWINDOW
416
417 where sack is the highest right edge of sack block found in the packet.
418
419 The upper bound limit for a valid ack is not ignored -
420 we doesn't have to deal with fragments.
421 */
422
423 static inline __u32 segment_seq_plus_len(__u32 seq,
424 size_t len,
425 struct iphdr *iph,
426 struct tcphdr *tcph)
427 {
428 return (seq + len - (iph->ihl + tcph->doff)*4
429 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
430 }
431
432 /* Fixme: what about big packets? */
433 #define MAXACKWINCONST 66000
434 #define MAXACKWINDOW(sender) \
435 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
436 : MAXACKWINCONST)
437
438 /*
439 * Simplified tcp_parse_options routine from tcp_input.c
440 */
441 static void tcp_options(const struct sk_buff *skb,
442 struct iphdr *iph,
443 struct tcphdr *tcph,
444 struct ip_ct_tcp_state *state)
445 {
446 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
447 unsigned char *ptr;
448 int length = (tcph->doff*4) - sizeof(struct tcphdr);
449
450 if (!length)
451 return;
452
453 ptr = skb_header_pointer(skb,
454 (iph->ihl * 4) + sizeof(struct tcphdr),
455 length, buff);
456 BUG_ON(ptr == NULL);
457
458 state->td_scale =
459 state->flags = 0;
460
461 while (length > 0) {
462 int opcode=*ptr++;
463 int opsize;
464
465 switch (opcode) {
466 case TCPOPT_EOL:
467 return;
468 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
469 length--;
470 continue;
471 default:
472 opsize=*ptr++;
473 if (opsize < 2) /* "silly options" */
474 return;
475 if (opsize > length)
476 break; /* don't parse partial options */
477
478 if (opcode == TCPOPT_SACK_PERM
479 && opsize == TCPOLEN_SACK_PERM)
480 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
481 else if (opcode == TCPOPT_WINDOW
482 && opsize == TCPOLEN_WINDOW) {
483 state->td_scale = *(u_int8_t *)ptr;
484
485 if (state->td_scale > 14) {
486 /* See RFC1323 */
487 state->td_scale = 14;
488 }
489 state->flags |=
490 IP_CT_TCP_FLAG_WINDOW_SCALE;
491 }
492 ptr += opsize - 2;
493 length -= opsize;
494 }
495 }
496 }
497
498 static void tcp_sack(const struct sk_buff *skb,
499 struct iphdr *iph,
500 struct tcphdr *tcph,
501 __u32 *sack)
502 {
503 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
504 unsigned char *ptr;
505 int length = (tcph->doff*4) - sizeof(struct tcphdr);
506 __u32 tmp;
507
508 if (!length)
509 return;
510
511 ptr = skb_header_pointer(skb,
512 (iph->ihl * 4) + sizeof(struct tcphdr),
513 length, buff);
514 BUG_ON(ptr == NULL);
515
516 /* Fast path for timestamp-only option */
517 if (length == TCPOLEN_TSTAMP_ALIGNED*4
518 && *(__be32 *)ptr ==
519 __constant_htonl((TCPOPT_NOP << 24)
520 | (TCPOPT_NOP << 16)
521 | (TCPOPT_TIMESTAMP << 8)
522 | TCPOLEN_TIMESTAMP))
523 return;
524
525 while (length > 0) {
526 int opcode=*ptr++;
527 int opsize, i;
528
529 switch (opcode) {
530 case TCPOPT_EOL:
531 return;
532 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
533 length--;
534 continue;
535 default:
536 opsize=*ptr++;
537 if (opsize < 2) /* "silly options" */
538 return;
539 if (opsize > length)
540 break; /* don't parse partial options */
541
542 if (opcode == TCPOPT_SACK
543 && opsize >= (TCPOLEN_SACK_BASE
544 + TCPOLEN_SACK_PERBLOCK)
545 && !((opsize - TCPOLEN_SACK_BASE)
546 % TCPOLEN_SACK_PERBLOCK)) {
547 for (i = 0;
548 i < (opsize - TCPOLEN_SACK_BASE);
549 i += TCPOLEN_SACK_PERBLOCK) {
550 tmp = ntohl(*((__be32 *)(ptr+i)+1));
551
552 if (after(tmp, *sack))
553 *sack = tmp;
554 }
555 return;
556 }
557 ptr += opsize - 2;
558 length -= opsize;
559 }
560 }
561 }
562
563 static int tcp_in_window(struct ip_ct_tcp *state,
564 enum ip_conntrack_dir dir,
565 unsigned int index,
566 const struct sk_buff *skb,
567 struct iphdr *iph,
568 struct tcphdr *tcph)
569 {
570 struct ip_ct_tcp_state *sender = &state->seen[dir];
571 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
572 __u32 seq, ack, sack, end, win, swin;
573 int res;
574
575 /*
576 * Get the required data from the packet.
577 */
578 seq = ntohl(tcph->seq);
579 ack = sack = ntohl(tcph->ack_seq);
580 win = ntohs(tcph->window);
581 end = segment_seq_plus_len(seq, skb->len, iph, tcph);
582
583 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
584 tcp_sack(skb, iph, tcph, &sack);
585
586 DEBUGP("tcp_in_window: START\n");
587 DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
588 "seq=%u ack=%u sack=%u win=%u end=%u\n",
589 NIPQUAD(iph->saddr), ntohs(tcph->source),
590 NIPQUAD(iph->daddr), ntohs(tcph->dest),
591 seq, ack, sack, win, end);
592 DEBUGP("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
593 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
594 sender->td_end, sender->td_maxend, sender->td_maxwin,
595 sender->td_scale,
596 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
597 receiver->td_scale);
598
599 if (sender->td_end == 0) {
600 /*
601 * Initialize sender data.
602 */
603 if (tcph->syn && tcph->ack) {
604 /*
605 * Outgoing SYN-ACK in reply to a SYN.
606 */
607 sender->td_end =
608 sender->td_maxend = end;
609 sender->td_maxwin = (win == 0 ? 1 : win);
610
611 tcp_options(skb, iph, tcph, sender);
612 /*
613 * RFC 1323:
614 * Both sides must send the Window Scale option
615 * to enable window scaling in either direction.
616 */
617 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
618 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
619 sender->td_scale =
620 receiver->td_scale = 0;
621 } else {
622 /*
623 * We are in the middle of a connection,
624 * its history is lost for us.
625 * Let's try to use the data from the packet.
626 */
627 sender->td_end = end;
628 sender->td_maxwin = (win == 0 ? 1 : win);
629 sender->td_maxend = end + sender->td_maxwin;
630 }
631 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
632 && dir == IP_CT_DIR_ORIGINAL)
633 || (state->state == TCP_CONNTRACK_SYN_RECV
634 && dir == IP_CT_DIR_REPLY))
635 && after(end, sender->td_end)) {
636 /*
637 * RFC 793: "if a TCP is reinitialized ... then it need
638 * not wait at all; it must only be sure to use sequence
639 * numbers larger than those recently used."
640 */
641 sender->td_end =
642 sender->td_maxend = end;
643 sender->td_maxwin = (win == 0 ? 1 : win);
644
645 tcp_options(skb, iph, tcph, sender);
646 }
647
648 if (!(tcph->ack)) {
649 /*
650 * If there is no ACK, just pretend it was set and OK.
651 */
652 ack = sack = receiver->td_end;
653 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
654 (TCP_FLAG_ACK|TCP_FLAG_RST))
655 && (ack == 0)) {
656 /*
657 * Broken TCP stacks, that set ACK in RST packets as well
658 * with zero ack value.
659 */
660 ack = sack = receiver->td_end;
661 }
662
663 if (seq == end
664 && (!tcph->rst
665 || (seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)))
666 /*
667 * Packets contains no data: we assume it is valid
668 * and check the ack value only.
669 * However RST segments are always validated by their
670 * SEQ number, except when seq == 0 (reset sent answering
671 * SYN.
672 */
673 seq = end = sender->td_end;
674
675 DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
676 "seq=%u ack=%u sack =%u win=%u end=%u\n",
677 NIPQUAD(iph->saddr), ntohs(tcph->source),
678 NIPQUAD(iph->daddr), ntohs(tcph->dest),
679 seq, ack, sack, win, end);
680 DEBUGP("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
681 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
682 sender->td_end, sender->td_maxend, sender->td_maxwin,
683 sender->td_scale,
684 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
685 receiver->td_scale);
686
687 DEBUGP("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
688 before(seq, sender->td_maxend + 1),
689 after(end, sender->td_end - receiver->td_maxwin - 1),
690 before(sack, receiver->td_end + 1),
691 after(ack, receiver->td_end - MAXACKWINDOW(sender)));
692
693 if (before(seq, sender->td_maxend + 1) &&
694 after(end, sender->td_end - receiver->td_maxwin - 1) &&
695 before(sack, receiver->td_end + 1) &&
696 after(ack, receiver->td_end - MAXACKWINDOW(sender))) {
697 /*
698 * Take into account window scaling (RFC 1323).
699 */
700 if (!tcph->syn)
701 win <<= sender->td_scale;
702
703 /*
704 * Update sender data.
705 */
706 swin = win + (sack - ack);
707 if (sender->td_maxwin < swin)
708 sender->td_maxwin = swin;
709 if (after(end, sender->td_end))
710 sender->td_end = end;
711 /*
712 * Update receiver data.
713 */
714 if (after(end, sender->td_maxend))
715 receiver->td_maxwin += end - sender->td_maxend;
716 if (after(sack + win, receiver->td_maxend - 1)) {
717 receiver->td_maxend = sack + win;
718 if (win == 0)
719 receiver->td_maxend++;
720 }
721
722 /*
723 * Check retransmissions.
724 */
725 if (index == TCP_ACK_SET) {
726 if (state->last_dir == dir
727 && state->last_seq == seq
728 && state->last_ack == ack
729 && state->last_end == end
730 && state->last_win == win)
731 state->retrans++;
732 else {
733 state->last_dir = dir;
734 state->last_seq = seq;
735 state->last_ack = ack;
736 state->last_end = end;
737 state->last_win = win;
738 state->retrans = 0;
739 }
740 }
741 res = 1;
742 } else {
743 res = 0;
744 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
745 ip_ct_tcp_be_liberal)
746 res = 1;
747 if (!res && LOG_INVALID(IPPROTO_TCP))
748 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
749 "ip_ct_tcp: %s ",
750 before(seq, sender->td_maxend + 1) ?
751 after(end, sender->td_end - receiver->td_maxwin - 1) ?
752 before(sack, receiver->td_end + 1) ?
753 after(ack, receiver->td_end - MAXACKWINDOW(sender)) ? "BUG"
754 : "ACK is under the lower bound (possible overly delayed ACK)"
755 : "ACK is over the upper bound (ACKed data not seen yet)"
756 : "SEQ is under the lower bound (already ACKed data retransmitted)"
757 : "SEQ is over the upper bound (over the window of the receiver)");
758 }
759
760 DEBUGP("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
761 "receiver end=%u maxend=%u maxwin=%u\n",
762 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
763 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
764
765 return res;
766 }
767
768 #ifdef CONFIG_IP_NF_NAT_NEEDED
769 /* Update sender->td_end after NAT successfully mangled the packet */
770 void ip_conntrack_tcp_update(struct sk_buff *skb,
771 struct ip_conntrack *conntrack,
772 enum ip_conntrack_dir dir)
773 {
774 struct iphdr *iph = skb->nh.iph;
775 struct tcphdr *tcph = (void *)skb->nh.iph + skb->nh.iph->ihl*4;
776 __u32 end;
777 #ifdef DEBUGP_VARS
778 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[dir];
779 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[!dir];
780 #endif
781
782 end = segment_seq_plus_len(ntohl(tcph->seq), skb->len, iph, tcph);
783
784 write_lock_bh(&tcp_lock);
785 /*
786 * We have to worry for the ack in the reply packet only...
787 */
788 if (after(end, conntrack->proto.tcp.seen[dir].td_end))
789 conntrack->proto.tcp.seen[dir].td_end = end;
790 conntrack->proto.tcp.last_end = end;
791 write_unlock_bh(&tcp_lock);
792 DEBUGP("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
793 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
794 sender->td_end, sender->td_maxend, sender->td_maxwin,
795 sender->td_scale,
796 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
797 receiver->td_scale);
798 }
799
800 #endif
801
802 #define TH_FIN 0x01
803 #define TH_SYN 0x02
804 #define TH_RST 0x04
805 #define TH_PUSH 0x08
806 #define TH_ACK 0x10
807 #define TH_URG 0x20
808 #define TH_ECE 0x40
809 #define TH_CWR 0x80
810
811 /* table of valid flag combinations - ECE and CWR are always valid */
812 static const u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] =
813 {
814 [TH_SYN] = 1,
815 [TH_SYN|TH_PUSH] = 1,
816 [TH_SYN|TH_URG] = 1,
817 [TH_SYN|TH_PUSH|TH_URG] = 1,
818 [TH_SYN|TH_ACK] = 1,
819 [TH_SYN|TH_ACK|TH_PUSH] = 1,
820 [TH_RST] = 1,
821 [TH_RST|TH_ACK] = 1,
822 [TH_RST|TH_ACK|TH_PUSH] = 1,
823 [TH_FIN|TH_ACK] = 1,
824 [TH_ACK] = 1,
825 [TH_ACK|TH_PUSH] = 1,
826 [TH_ACK|TH_URG] = 1,
827 [TH_ACK|TH_URG|TH_PUSH] = 1,
828 [TH_FIN|TH_ACK|TH_PUSH] = 1,
829 [TH_FIN|TH_ACK|TH_URG] = 1,
830 [TH_FIN|TH_ACK|TH_URG|TH_PUSH] = 1,
831 };
832
833 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
834 static int tcp_error(struct sk_buff *skb,
835 enum ip_conntrack_info *ctinfo,
836 unsigned int hooknum)
837 {
838 struct iphdr *iph = skb->nh.iph;
839 struct tcphdr _tcph, *th;
840 unsigned int tcplen = skb->len - iph->ihl * 4;
841 u_int8_t tcpflags;
842
843 /* Smaller that minimal TCP header? */
844 th = skb_header_pointer(skb, iph->ihl * 4,
845 sizeof(_tcph), &_tcph);
846 if (th == NULL) {
847 if (LOG_INVALID(IPPROTO_TCP))
848 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
849 "ip_ct_tcp: short packet ");
850 return -NF_ACCEPT;
851 }
852
853 /* Not whole TCP header or malformed packet */
854 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
855 if (LOG_INVALID(IPPROTO_TCP))
856 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
857 "ip_ct_tcp: truncated/malformed packet ");
858 return -NF_ACCEPT;
859 }
860
861 /* Checksum invalid? Ignore.
862 * We skip checking packets on the outgoing path
863 * because it is assumed to be correct.
864 */
865 /* FIXME: Source route IP option packets --RR */
866 if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
867 nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_TCP)) {
868 if (LOG_INVALID(IPPROTO_TCP))
869 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
870 "ip_ct_tcp: bad TCP checksum ");
871 return -NF_ACCEPT;
872 }
873
874 /* Check TCP flags. */
875 tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR));
876 if (!tcp_valid_flags[tcpflags]) {
877 if (LOG_INVALID(IPPROTO_TCP))
878 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
879 "ip_ct_tcp: invalid TCP flag combination ");
880 return -NF_ACCEPT;
881 }
882
883 return NF_ACCEPT;
884 }
885
886 /* Returns verdict for packet, or -1 for invalid. */
887 static int tcp_packet(struct ip_conntrack *conntrack,
888 const struct sk_buff *skb,
889 enum ip_conntrack_info ctinfo)
890 {
891 enum tcp_conntrack new_state, old_state;
892 enum ip_conntrack_dir dir;
893 struct iphdr *iph = skb->nh.iph;
894 struct tcphdr *th, _tcph;
895 unsigned long timeout;
896 unsigned int index;
897
898 th = skb_header_pointer(skb, iph->ihl * 4,
899 sizeof(_tcph), &_tcph);
900 BUG_ON(th == NULL);
901
902 write_lock_bh(&tcp_lock);
903 old_state = conntrack->proto.tcp.state;
904 dir = CTINFO2DIR(ctinfo);
905 index = get_conntrack_index(th);
906 new_state = tcp_conntracks[dir][index][old_state];
907
908 switch (new_state) {
909 case TCP_CONNTRACK_IGNORE:
910 /* Ignored packets:
911 *
912 * a) SYN in ORIGINAL
913 * b) SYN/ACK in REPLY
914 * c) ACK in reply direction after initial SYN in original.
915 */
916 if (index == TCP_SYNACK_SET
917 && conntrack->proto.tcp.last_index == TCP_SYN_SET
918 && conntrack->proto.tcp.last_dir != dir
919 && ntohl(th->ack_seq) ==
920 conntrack->proto.tcp.last_end) {
921 /* This SYN/ACK acknowledges a SYN that we earlier
922 * ignored as invalid. This means that the client and
923 * the server are both in sync, while the firewall is
924 * not. We kill this session and block the SYN/ACK so
925 * that the client cannot but retransmit its SYN and
926 * thus initiate a clean new session.
927 */
928 write_unlock_bh(&tcp_lock);
929 if (LOG_INVALID(IPPROTO_TCP))
930 nf_log_packet(PF_INET, 0, skb, NULL, NULL,
931 NULL, "ip_ct_tcp: "
932 "killing out of sync session ");
933 if (del_timer(&conntrack->timeout))
934 conntrack->timeout.function((unsigned long)
935 conntrack);
936 return -NF_DROP;
937 }
938 conntrack->proto.tcp.last_index = index;
939 conntrack->proto.tcp.last_dir = dir;
940 conntrack->proto.tcp.last_seq = ntohl(th->seq);
941 conntrack->proto.tcp.last_end =
942 segment_seq_plus_len(ntohl(th->seq), skb->len, iph, th);
943
944 write_unlock_bh(&tcp_lock);
945 if (LOG_INVALID(IPPROTO_TCP))
946 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
947 "ip_ct_tcp: invalid packet ignored ");
948 return NF_ACCEPT;
949 case TCP_CONNTRACK_MAX:
950 /* Invalid packet */
951 DEBUGP("ip_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
952 dir, get_conntrack_index(th),
953 old_state);
954 write_unlock_bh(&tcp_lock);
955 if (LOG_INVALID(IPPROTO_TCP))
956 nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
957 "ip_ct_tcp: invalid state ");
958 return -NF_ACCEPT;
959 case TCP_CONNTRACK_SYN_SENT:
960 if (old_state < TCP_CONNTRACK_TIME_WAIT)
961 break;
962 if ((conntrack->proto.tcp.seen[dir].flags &
963 IP_CT_TCP_FLAG_CLOSE_INIT)
964 || after(ntohl(th->seq),
965 conntrack->proto.tcp.seen[dir].td_end)) {
966 /* Attempt to reopen a closed connection.
967 * Delete this connection and look up again. */
968 write_unlock_bh(&tcp_lock);
969 if (del_timer(&conntrack->timeout))
970 conntrack->timeout.function((unsigned long)
971 conntrack);
972 return -NF_REPEAT;
973 } else {
974 write_unlock_bh(&tcp_lock);
975 if (LOG_INVALID(IPPROTO_TCP))
976 nf_log_packet(PF_INET, 0, skb, NULL, NULL,
977 NULL, "ip_ct_tcp: invalid SYN");
978 return -NF_ACCEPT;
979 }
980 case TCP_CONNTRACK_CLOSE:
981 if (index == TCP_RST_SET
982 && ((test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
983 && conntrack->proto.tcp.last_index == TCP_SYN_SET)
984 || (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
985 && conntrack->proto.tcp.last_index == TCP_ACK_SET))
986 && ntohl(th->ack_seq) == conntrack->proto.tcp.last_end) {
987 /* RST sent to invalid SYN or ACK we had let through
988 * at a) and c) above:
989 *
990 * a) SYN was in window then
991 * c) we hold a half-open connection.
992 *
993 * Delete our connection entry.
994 * We skip window checking, because packet might ACK
995 * segments we ignored. */
996 goto in_window;
997 }
998 /* Just fall through */
999 default:
1000 /* Keep compilers happy. */
1001 break;
1002 }
1003
1004 if (!tcp_in_window(&conntrack->proto.tcp, dir, index,
1005 skb, iph, th)) {
1006 write_unlock_bh(&tcp_lock);
1007 return -NF_ACCEPT;
1008 }
1009 in_window:
1010 /* From now on we have got in-window packets */
1011 conntrack->proto.tcp.last_index = index;
1012
1013 DEBUGP("tcp_conntracks: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
1014 "syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
1015 NIPQUAD(iph->saddr), ntohs(th->source),
1016 NIPQUAD(iph->daddr), ntohs(th->dest),
1017 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
1018 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
1019 old_state, new_state);
1020
1021 conntrack->proto.tcp.state = new_state;
1022 if (old_state != new_state
1023 && (new_state == TCP_CONNTRACK_FIN_WAIT
1024 || new_state == TCP_CONNTRACK_CLOSE))
1025 conntrack->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
1026 timeout = conntrack->proto.tcp.retrans >= ip_ct_tcp_max_retrans
1027 && *tcp_timeouts[new_state] > ip_ct_tcp_timeout_max_retrans
1028 ? ip_ct_tcp_timeout_max_retrans : *tcp_timeouts[new_state];
1029 write_unlock_bh(&tcp_lock);
1030
1031 ip_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
1032 if (new_state != old_state)
1033 ip_conntrack_event_cache(IPCT_PROTOINFO, skb);
1034
1035 if (!test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
1036 /* If only reply is a RST, we can consider ourselves not to
1037 have an established connection: this is a fairly common
1038 problem case, so we can delete the conntrack
1039 immediately. --RR */
1040 if (th->rst) {
1041 if (del_timer(&conntrack->timeout))
1042 conntrack->timeout.function((unsigned long)
1043 conntrack);
1044 return NF_ACCEPT;
1045 }
1046 } else if (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
1047 && (old_state == TCP_CONNTRACK_SYN_RECV
1048 || old_state == TCP_CONNTRACK_ESTABLISHED)
1049 && new_state == TCP_CONNTRACK_ESTABLISHED) {
1050 /* Set ASSURED if we see see valid ack in ESTABLISHED
1051 after SYN_RECV or a valid answer for a picked up
1052 connection. */
1053 set_bit(IPS_ASSURED_BIT, &conntrack->status);
1054 ip_conntrack_event_cache(IPCT_STATUS, skb);
1055 }
1056 ip_ct_refresh_acct(conntrack, ctinfo, skb, timeout);
1057
1058 return NF_ACCEPT;
1059 }
1060
1061 /* Called when a new connection for this protocol found. */
1062 static int tcp_new(struct ip_conntrack *conntrack,
1063 const struct sk_buff *skb)
1064 {
1065 enum tcp_conntrack new_state;
1066 struct iphdr *iph = skb->nh.iph;
1067 struct tcphdr *th, _tcph;
1068 #ifdef DEBUGP_VARS
1069 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[0];
1070 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[1];
1071 #endif
1072
1073 th = skb_header_pointer(skb, iph->ihl * 4,
1074 sizeof(_tcph), &_tcph);
1075 BUG_ON(th == NULL);
1076
1077 /* Don't need lock here: this conntrack not in circulation yet */
1078 new_state
1079 = tcp_conntracks[0][get_conntrack_index(th)]
1080 [TCP_CONNTRACK_NONE];
1081
1082 /* Invalid: delete conntrack */
1083 if (new_state >= TCP_CONNTRACK_MAX) {
1084 DEBUGP("ip_ct_tcp: invalid new deleting.\n");
1085 return 0;
1086 }
1087
1088 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1089 /* SYN packet */
1090 conntrack->proto.tcp.seen[0].td_end =
1091 segment_seq_plus_len(ntohl(th->seq), skb->len,
1092 iph, th);
1093 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1094 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1095 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1096 conntrack->proto.tcp.seen[0].td_maxend =
1097 conntrack->proto.tcp.seen[0].td_end;
1098
1099 tcp_options(skb, iph, th, &conntrack->proto.tcp.seen[0]);
1100 conntrack->proto.tcp.seen[1].flags = 0;
1101 } else if (ip_ct_tcp_loose == 0) {
1102 /* Don't try to pick up connections. */
1103 return 0;
1104 } else {
1105 /*
1106 * We are in the middle of a connection,
1107 * its history is lost for us.
1108 * Let's try to use the data from the packet.
1109 */
1110 conntrack->proto.tcp.seen[0].td_end =
1111 segment_seq_plus_len(ntohl(th->seq), skb->len,
1112 iph, th);
1113 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1114 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1115 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1116 conntrack->proto.tcp.seen[0].td_maxend =
1117 conntrack->proto.tcp.seen[0].td_end +
1118 conntrack->proto.tcp.seen[0].td_maxwin;
1119 conntrack->proto.tcp.seen[0].td_scale = 0;
1120
1121 /* We assume SACK and liberal window checking to handle
1122 * window scaling */
1123 conntrack->proto.tcp.seen[0].flags =
1124 conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1125 IP_CT_TCP_FLAG_BE_LIBERAL;
1126 }
1127
1128 conntrack->proto.tcp.seen[1].td_end = 0;
1129 conntrack->proto.tcp.seen[1].td_maxend = 0;
1130 conntrack->proto.tcp.seen[1].td_maxwin = 1;
1131 conntrack->proto.tcp.seen[1].td_scale = 0;
1132
1133 /* tcp_packet will set them */
1134 conntrack->proto.tcp.state = TCP_CONNTRACK_NONE;
1135 conntrack->proto.tcp.last_index = TCP_NONE_SET;
1136
1137 DEBUGP("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1138 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1139 sender->td_end, sender->td_maxend, sender->td_maxwin,
1140 sender->td_scale,
1141 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1142 receiver->td_scale);
1143 return 1;
1144 }
1145
1146 struct ip_conntrack_protocol ip_conntrack_protocol_tcp =
1147 {
1148 .proto = IPPROTO_TCP,
1149 .name = "tcp",
1150 .pkt_to_tuple = tcp_pkt_to_tuple,
1151 .invert_tuple = tcp_invert_tuple,
1152 .print_tuple = tcp_print_tuple,
1153 .print_conntrack = tcp_print_conntrack,
1154 .packet = tcp_packet,
1155 .new = tcp_new,
1156 .error = tcp_error,
1157 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
1158 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
1159 .to_nfattr = tcp_to_nfattr,
1160 .from_nfattr = nfattr_to_tcp,
1161 .tuple_to_nfattr = ip_ct_port_tuple_to_nfattr,
1162 .nfattr_to_tuple = ip_ct_port_nfattr_to_tuple,
1163 #endif
1164 };
Linux kernel - Deliverables
This page took 0.057062 seconds and 6 git commands to generate.