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[NETFILTER]: nf_conntrack_{tcp,sctp}: shrink state table
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / nf_conntrack_proto_tcp.c
CommitLineData
9fb9cbb1
YK		 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.
9fb9cbb1
YK		 7 */
8
9fb9cbb1 9#include <linux/types.h>
9fb9cbb1 10#include <linux/timer.h>
9fb9cbb1
YK		 11#include <linux/module.h>
12#include <linux/in.h>
13#include <linux/tcp.h>
14#include <linux/spinlock.h>
15#include <linux/skbuff.h>
16#include <linux/ipv6.h>
17#include <net/ip6_checksum.h>
18
19#include <net/tcp.h>
20
21#include <linux/netfilter.h>
22#include <linux/netfilter_ipv4.h>
23#include <linux/netfilter_ipv6.h>
24#include <net/netfilter/nf_conntrack.h>
605dcad6 25#include <net/netfilter/nf_conntrack_l4proto.h>
f6180121 26#include <net/netfilter/nf_conntrack_ecache.h>
f01ffbd6 27#include <net/netfilter/nf_log.h>
9fb9cbb1 28
9fb9cbb1
YK		 29/* Protects conntrack->proto.tcp */
30static DEFINE_RWLOCK(tcp_lock);
31
601e68e1
YH		 32/* "Be conservative in what you do,
33 be liberal in what you accept from others."
9fb9cbb1 34 If it's non-zero, we mark only out of window RST segments as INVALID. */
3aef0fd9 35static int nf_ct_tcp_be_liberal __read_mostly = 0;
9fb9cbb1 36
a09113c2 37/* If it is set to zero, we disable picking up already established
9fb9cbb1 38 connections. */
3aef0fd9 39static int nf_ct_tcp_loose __read_mostly = 1;
9fb9cbb1 40
601e68e1
YH		 41/* Max number of the retransmitted packets without receiving an (acceptable)
42 ACK from the destination. If this number is reached, a shorter timer
9fb9cbb1 43 will be started. */
3aef0fd9 44static int nf_ct_tcp_max_retrans __read_mostly = 3;
9fb9cbb1
YK		 45
46 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
47 closely. They're more complex. --RR */
48
49static const char *tcp_conntrack_names[] = {
50 "NONE",
51 "SYN_SENT",
52 "SYN_RECV",
53 "ESTABLISHED",
54 "FIN_WAIT",
55 "CLOSE_WAIT",
56 "LAST_ACK",
57 "TIME_WAIT",
58 "CLOSE",
59 "LISTEN"
60};
601e68e1 61
9fb9cbb1
YK		 62#define SECS * HZ
63#define MINS * 60 SECS
64#define HOURS * 60 MINS
65#define DAYS * 24 HOURS
66
933a41e7
PM		 67static unsigned int nf_ct_tcp_timeout_syn_sent __read_mostly = 2 MINS;
68static unsigned int nf_ct_tcp_timeout_syn_recv __read_mostly = 60 SECS;
69static unsigned int nf_ct_tcp_timeout_established __read_mostly = 5 DAYS;
70static unsigned int nf_ct_tcp_timeout_fin_wait __read_mostly = 2 MINS;
71static unsigned int nf_ct_tcp_timeout_close_wait __read_mostly = 60 SECS;
72static unsigned int nf_ct_tcp_timeout_last_ack __read_mostly = 30 SECS;
73static unsigned int nf_ct_tcp_timeout_time_wait __read_mostly = 2 MINS;
74static unsigned int nf_ct_tcp_timeout_close __read_mostly = 10 SECS;
9fb9cbb1
YK		 75
76/* RFC1122 says the R2 limit should be at least 100 seconds.
601e68e1 77 Linux uses 15 packets as limit, which corresponds
9fb9cbb1 78 to ~13-30min depending on RTO. */
933a41e7 79static unsigned int nf_ct_tcp_timeout_max_retrans __read_mostly = 5 MINS;
601e68e1 80
933a41e7
PM		 81static unsigned int * tcp_timeouts[] = {
82 NULL, /* TCP_CONNTRACK_NONE */
9fb9cbb1
YK		 83 &nf_ct_tcp_timeout_syn_sent, /* TCP_CONNTRACK_SYN_SENT, */
84 &nf_ct_tcp_timeout_syn_recv, /* TCP_CONNTRACK_SYN_RECV, */
85 &nf_ct_tcp_timeout_established, /* TCP_CONNTRACK_ESTABLISHED, */
86 &nf_ct_tcp_timeout_fin_wait, /* TCP_CONNTRACK_FIN_WAIT, */
87 &nf_ct_tcp_timeout_close_wait, /* TCP_CONNTRACK_CLOSE_WAIT, */
88 &nf_ct_tcp_timeout_last_ack, /* TCP_CONNTRACK_LAST_ACK, */
89 &nf_ct_tcp_timeout_time_wait, /* TCP_CONNTRACK_TIME_WAIT, */
90 &nf_ct_tcp_timeout_close, /* TCP_CONNTRACK_CLOSE, */
91 NULL, /* TCP_CONNTRACK_LISTEN */
92 };
601e68e1 93
9fb9cbb1
YK		 94#define sNO TCP_CONNTRACK_NONE
95#define sSS TCP_CONNTRACK_SYN_SENT
96#define sSR TCP_CONNTRACK_SYN_RECV
97#define sES TCP_CONNTRACK_ESTABLISHED
98#define sFW TCP_CONNTRACK_FIN_WAIT
99#define sCW TCP_CONNTRACK_CLOSE_WAIT
100#define sLA TCP_CONNTRACK_LAST_ACK
101#define sTW TCP_CONNTRACK_TIME_WAIT
102#define sCL TCP_CONNTRACK_CLOSE
103#define sLI TCP_CONNTRACK_LISTEN
104#define sIV TCP_CONNTRACK_MAX
105#define sIG TCP_CONNTRACK_IGNORE
106
107/* What TCP flags are set from RST/SYN/FIN/ACK. */
108enum tcp_bit_set {
109 TCP_SYN_SET,
110 TCP_SYNACK_SET,
111 TCP_FIN_SET,
112 TCP_ACK_SET,
113 TCP_RST_SET,
114 TCP_NONE_SET,
115};
601e68e1 116
9fb9cbb1
YK		 117/*
118 * The TCP state transition table needs a few words...
119 *
120 * We are the man in the middle. All the packets go through us
121 * but might get lost in transit to the destination.
601e68e1 122 * It is assumed that the destinations can't receive segments
9fb9cbb1
YK		 123 * we haven't seen.
124 *
125 * The checked segment is in window, but our windows are *not*
126 * equivalent with the ones of the sender/receiver. We always
127 * try to guess the state of the current sender.
128 *
129 * The meaning of the states are:
130 *
131 * NONE: initial state
601e68e1 132 * SYN_SENT: SYN-only packet seen
9fb9cbb1
YK		 133 * SYN_RECV: SYN-ACK packet seen
134 * ESTABLISHED: ACK packet seen
135 * FIN_WAIT: FIN packet seen
601e68e1 136 * CLOSE_WAIT: ACK seen (after FIN)
9fb9cbb1
YK		 137 * LAST_ACK: FIN seen (after FIN)
138 * TIME_WAIT: last ACK seen
139 * CLOSE: closed connection
140 *
141 * LISTEN state is not used.
142 *
143 * Packets marked as IGNORED (sIG):
601e68e1
YH		 144 * if they may be either invalid or valid
145 * and the receiver may send back a connection
9fb9cbb1
YK		 146 * closing RST or a SYN/ACK.
147 *
148 * Packets marked as INVALID (sIV):
149 * if they are invalid
150 * or we do not support the request (simultaneous open)
151 */
a5e73c29 152static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
9fb9cbb1
YK		 153 {
154/* ORIGINAL */
155/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
156/*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
157/*
158 * sNO -> sSS Initialize a new connection
159 * sSS -> sSS Retransmitted SYN
160 * sSR -> sIG Late retransmitted SYN?
161 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
601e68e1 162 * are errors. Receiver will reply with RST
9fb9cbb1
YK		 163 * and close the connection.
164 * Or we are not in sync and hold a dead connection.
165 * sFW -> sIG
166 * sCW -> sIG
167 * sLA -> sIG
168 * sTW -> sSS Reopened connection (RFC 1122).
169 * sCL -> sSS
170 */
171/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
172/*synack*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
173/*
174 * A SYN/ACK from the client is always invalid:
601e68e1 175 * - either it tries to set up a simultaneous open, which is
9fb9cbb1
YK		 176 * not supported;
177 * - or the firewall has just been inserted between the two hosts
601e68e1 178 * during the session set-up. The SYN will be retransmitted
9fb9cbb1
YK		 179 * by the true client (or it'll time out).
180 */
181/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
182/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
183/*
184 * sNO -> sIV Too late and no reason to do anything...
185 * sSS -> sIV Client migth not send FIN in this state:
186 * we enforce waiting for a SYN/ACK reply first.
187 * sSR -> sFW Close started.
188 * sES -> sFW
189 * sFW -> sLA FIN seen in both directions, waiting for
601e68e1 190 * the last ACK.
9fb9cbb1
YK		 191 * Migth be a retransmitted FIN as well...
192 * sCW -> sLA
193 * sLA -> sLA Retransmitted FIN. Remain in the same state.
194 * sTW -> sTW
195 * sCL -> sCL
196 */
197/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
198/*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
199/*
200 * sNO -> sES Assumed.
201 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
202 * sSR -> sES Established state is reached.
203 * sES -> sES :-)
204 * sFW -> sCW Normal close request answered by ACK.
205 * sCW -> sCW
206 * sLA -> sTW Last ACK detected.
207 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
208 * sCL -> sCL
209 */
210/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
211/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
212/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
213 },
214 {
215/* REPLY */
216/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
217/*syn*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
218/*
219 * sNO -> sIV Never reached.
220 * sSS -> sIV Simultaneous open, not supported
221 * sSR -> sIV Simultaneous open, not supported.
222 * sES -> sIV Server may not initiate a connection.
223 * sFW -> sIV
224 * sCW -> sIV
225 * sLA -> sIV
226 * sTW -> sIV Reopened connection, but server may not do it.
227 * sCL -> sIV
228 */
229/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
230/*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIV },
231/*
232 * sSS -> sSR Standard open.
233 * sSR -> sSR Retransmitted SYN/ACK.
234 * sES -> sIG Late retransmitted SYN/ACK?
235 * sFW -> sIG Might be SYN/ACK answering ignored SYN
236 * sCW -> sIG
237 * sLA -> sIG
238 * sTW -> sIG
239 * sCL -> sIG
240 */
241/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
242/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
243/*
244 * sSS -> sIV Server might not send FIN in this state.
245 * sSR -> sFW Close started.
246 * sES -> sFW
247 * sFW -> sLA FIN seen in both directions.
248 * sCW -> sLA
249 * sLA -> sLA Retransmitted FIN.
250 * sTW -> sTW
251 * sCL -> sCL
252 */
253/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
73f30602 254/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
9fb9cbb1 255/*
73f30602 256 * sSS -> sIG Might be a half-open connection.
9fb9cbb1
YK		 257 * sSR -> sSR Might answer late resent SYN.
258 * sES -> sES :-)
259 * sFW -> sCW Normal close request answered by ACK.
260 * sCW -> sCW
261 * sLA -> sTW Last ACK detected.
262 * sTW -> sTW Retransmitted last ACK.
263 * sCL -> sCL
264 */
265/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
266/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
267/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
601e68e1 268 }
9fb9cbb1
YK		 269};
270
271static int tcp_pkt_to_tuple(const struct sk_buff *skb,
272 unsigned int dataoff,
273 struct nf_conntrack_tuple *tuple)
274{
275 struct tcphdr _hdr, *hp;
276
277 /* Actually only need first 8 bytes. */
278 hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
279 if (hp == NULL)
280 return 0;
281
282 tuple->src.u.tcp.port = hp->source;
283 tuple->dst.u.tcp.port = hp->dest;
284
285 return 1;
286}
287
288static int tcp_invert_tuple(struct nf_conntrack_tuple *tuple,
289 const struct nf_conntrack_tuple *orig)
290{
291 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
292 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
293 return 1;
294}
295
296/* Print out the per-protocol part of the tuple. */
297static int tcp_print_tuple(struct seq_file *s,
298 const struct nf_conntrack_tuple *tuple)
299{
300 return seq_printf(s, "sport=%hu dport=%hu ",
301 ntohs(tuple->src.u.tcp.port),
302 ntohs(tuple->dst.u.tcp.port));
303}
304
305/* Print out the private part of the conntrack. */
306static int tcp_print_conntrack(struct seq_file *s,
307 const struct nf_conn *conntrack)
308{
309 enum tcp_conntrack state;
310
311 read_lock_bh(&tcp_lock);
312 state = conntrack->proto.tcp.state;
313 read_unlock_bh(&tcp_lock);
314
315 return seq_printf(s, "%s ", tcp_conntrack_names[state]);
316}
317
318static unsigned int get_conntrack_index(const struct tcphdr *tcph)
319{
320 if (tcph->rst) return TCP_RST_SET;
321 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
322 else if (tcph->fin) return TCP_FIN_SET;
323 else if (tcph->ack) return TCP_ACK_SET;
324 else return TCP_NONE_SET;
325}
326
327/* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
328 in IP Filter' by Guido van Rooij.
601e68e1 329
9fb9cbb1
YK		 330 http://www.nluug.nl/events/sane2000/papers.html
331 http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
601e68e1 332
9fb9cbb1
YK		 333 The boundaries and the conditions are changed according to RFC793:
334 the packet must intersect the window (i.e. segments may be
335 after the right or before the left edge) and thus receivers may ACK
336 segments after the right edge of the window.
337
601e68e1 338 td_maxend = max(sack + max(win,1)) seen in reply packets
9fb9cbb1
YK		 339 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
340 td_maxwin += seq + len - sender.td_maxend
341 if seq + len > sender.td_maxend
342 td_end = max(seq + len) seen in sent packets
601e68e1 343
9fb9cbb1
YK		 344 I. Upper bound for valid data: seq <= sender.td_maxend
345 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
346 III. Upper bound for valid ack: sack <= receiver.td_end
347 IV. Lower bound for valid ack: ack >= receiver.td_end - MAXACKWINDOW
348
349 where sack is the highest right edge of sack block found in the packet.
350
601e68e1
YH		 351 The upper bound limit for a valid ack is not ignored -
352 we doesn't have to deal with fragments.
9fb9cbb1
YK		 353*/
354
355static inline __u32 segment_seq_plus_len(__u32 seq,
356 size_t len,
357 unsigned int dataoff,
358 struct tcphdr *tcph)
359{
360 /* XXX Should I use payload length field in IP/IPv6 header ?
361 * - YK */
362 return (seq + len - dataoff - tcph->doff*4
363 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
364}
601e68e1 365
9fb9cbb1
YK		 366/* Fixme: what about big packets? */
367#define MAXACKWINCONST 66000
368#define MAXACKWINDOW(sender) \
369 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
370 : MAXACKWINCONST)
601e68e1 371
9fb9cbb1
YK		 372/*
373 * Simplified tcp_parse_options routine from tcp_input.c
374 */
375static void tcp_options(const struct sk_buff *skb,
376 unsigned int dataoff,
601e68e1 377 struct tcphdr *tcph,
9fb9cbb1
YK		 378 struct ip_ct_tcp_state *state)
379{
380 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
381 unsigned char *ptr;
382 int length = (tcph->doff*4) - sizeof(struct tcphdr);
383
384 if (!length)
385 return;
386
387 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
388 length, buff);
389 BUG_ON(ptr == NULL);
390
601e68e1 391 state->td_scale =
9fb9cbb1
YK		 392 state->flags = 0;
393
394 while (length > 0) {
395 int opcode=*ptr++;
396 int opsize;
397
398 switch (opcode) {
399 case TCPOPT_EOL:
400 return;
401 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
402 length--;
403 continue;
404 default:
405 opsize=*ptr++;
406 if (opsize < 2) /* "silly options" */
407 return;
408 if (opsize > length)
409 break; /* don't parse partial options */
410
601e68e1 411 if (opcode == TCPOPT_SACK_PERM
9fb9cbb1
YK		 412 && opsize == TCPOLEN_SACK_PERM)
413 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
414 else if (opcode == TCPOPT_WINDOW
415 && opsize == TCPOLEN_WINDOW) {
416 state->td_scale = *(u_int8_t *)ptr;
417
418 if (state->td_scale > 14) {
419 /* See RFC1323 */
420 state->td_scale = 14;
421 }
422 state->flags |=
423 IP_CT_TCP_FLAG_WINDOW_SCALE;
424 }
425 ptr += opsize - 2;
426 length -= opsize;
427 }
428 }
429}
430
431static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
432 struct tcphdr *tcph, __u32 *sack)
433{
601e68e1 434 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
9fb9cbb1
YK		 435 unsigned char *ptr;
436 int length = (tcph->doff*4) - sizeof(struct tcphdr);
437 __u32 tmp;
438
439 if (!length)
440 return;
441
442 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
443 length, buff);
444 BUG_ON(ptr == NULL);
445
446 /* Fast path for timestamp-only option */
447 if (length == TCPOLEN_TSTAMP_ALIGNED*4
8f05ce91
YH		 448 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24)
449 | (TCPOPT_NOP << 16)
450 | (TCPOPT_TIMESTAMP << 8)
451 | TCPOLEN_TIMESTAMP))
9fb9cbb1
YK		 452 return;
453
454 while (length > 0) {
455 int opcode = *ptr++;
456 int opsize, i;
457
458 switch (opcode) {
459 case TCPOPT_EOL:
460 return;
461 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
462 length--;
463 continue;
464 default:
465 opsize = *ptr++;
466 if (opsize < 2) /* "silly options" */
467 return;
468 if (opsize > length)
469 break; /* don't parse partial options */
470
601e68e1
YH		 471 if (opcode == TCPOPT_SACK
472 && opsize >= (TCPOLEN_SACK_BASE
473 + TCPOLEN_SACK_PERBLOCK)
474 && !((opsize - TCPOLEN_SACK_BASE)
475 % TCPOLEN_SACK_PERBLOCK)) {
476 for (i = 0;
477 i < (opsize - TCPOLEN_SACK_BASE);
478 i += TCPOLEN_SACK_PERBLOCK) {
479 tmp = ntohl(*((__be32 *)(ptr+i)+1));
9fb9cbb1
YK		 480
481 if (after(tmp, *sack))
482 *sack = tmp;
483 }
484 return;
485 }
486 ptr += opsize - 2;
487 length -= opsize;
488 }
489 }
490}
491
0d53778e
PM		 492static int tcp_in_window(struct nf_conn *ct,
493 struct ip_ct_tcp *state,
601e68e1
YH		 494 enum ip_conntrack_dir dir,
495 unsigned int index,
496 const struct sk_buff *skb,
9fb9cbb1 497 unsigned int dataoff,
601e68e1 498 struct tcphdr *tcph,
9fb9cbb1
YK		 499 int pf)
500{
501 struct ip_ct_tcp_state *sender = &state->seen[dir];
502 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
0d53778e 503 struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
9fb9cbb1
YK		 504 __u32 seq, ack, sack, end, win, swin;
505 int res;
506
507 /*
508 * Get the required data from the packet.
509 */
510 seq = ntohl(tcph->seq);
511 ack = sack = ntohl(tcph->ack_seq);
512 win = ntohs(tcph->window);
513 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph);
514
515 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
516 tcp_sack(skb, dataoff, tcph, &sack);
517
0d53778e
PM		 518 pr_debug("tcp_in_window: START\n");
519 pr_debug("tcp_in_window: ");
520 NF_CT_DUMP_TUPLE(tuple);
521 pr_debug("seq=%u ack=%u sack=%u win=%u end=%u\n",
522 seq, ack, sack, win, end);
523 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
524 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
525 sender->td_end, sender->td_maxend, sender->td_maxwin,
526 sender->td_scale,
527 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
528 receiver->td_scale);
9fb9cbb1
YK		 529
530 if (sender->td_end == 0) {
531 /*
532 * Initialize sender data.
533 */
534 if (tcph->syn && tcph->ack) {
535 /*
536 * Outgoing SYN-ACK in reply to a SYN.
537 */
601e68e1 538 sender->td_end =
9fb9cbb1
YK		 539 sender->td_maxend = end;
540 sender->td_maxwin = (win == 0 ? 1 : win);
541
542 tcp_options(skb, dataoff, tcph, sender);
601e68e1 543 /*
9fb9cbb1
YK		 544 * RFC 1323:
545 * Both sides must send the Window Scale option
546 * to enable window scaling in either direction.
547 */
548 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
549 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
601e68e1 550 sender->td_scale =
9fb9cbb1
YK		 551 receiver->td_scale = 0;
552 } else {
553 /*
554 * We are in the middle of a connection,
555 * its history is lost for us.
556 * Let's try to use the data from the packet.
601e68e1 557 */
9fb9cbb1
YK		 558 sender->td_end = end;
559 sender->td_maxwin = (win == 0 ? 1 : win);
560 sender->td_maxend = end + sender->td_maxwin;
561 }
562 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
563 && dir == IP_CT_DIR_ORIGINAL)
564 || (state->state == TCP_CONNTRACK_SYN_RECV
565 && dir == IP_CT_DIR_REPLY))
566 && after(end, sender->td_end)) {
567 /*
568 * RFC 793: "if a TCP is reinitialized ... then it need
601e68e1 569 * not wait at all; it must only be sure to use sequence
9fb9cbb1
YK		 570 * numbers larger than those recently used."
571 */
572 sender->td_end =
573 sender->td_maxend = end;
574 sender->td_maxwin = (win == 0 ? 1 : win);
575
576 tcp_options(skb, dataoff, tcph, sender);
577 }
578
579 if (!(tcph->ack)) {
580 /*
581 * If there is no ACK, just pretend it was set and OK.
582 */
583 ack = sack = receiver->td_end;
601e68e1
YH		 584 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
585 (TCP_FLAG_ACK|TCP_FLAG_RST))
9fb9cbb1
YK		 586 && (ack == 0)) {
587 /*
588 * Broken TCP stacks, that set ACK in RST packets as well
589 * with zero ack value.
590 */
591 ack = sack = receiver->td_end;
592 }
593
594 if (seq == end
595 && (!tcph->rst
596 || (seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)))
597 /*
598 * Packets contains no data: we assume it is valid
599 * and check the ack value only.
600 * However RST segments are always validated by their
601 * SEQ number, except when seq == 0 (reset sent answering
602 * SYN.
603 */
604 seq = end = sender->td_end;
605
0d53778e
PM		 606 pr_debug("tcp_in_window: ");
607 NF_CT_DUMP_TUPLE(tuple);
608 pr_debug("seq=%u ack=%u sack =%u win=%u end=%u\n",
609 seq, ack, sack, win, end);
610 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
611 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
612 sender->td_end, sender->td_maxend, sender->td_maxwin,
613 sender->td_scale,
614 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
615 receiver->td_scale);
616
617 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
618 before(seq, sender->td_maxend + 1),
619 after(end, sender->td_end - receiver->td_maxwin - 1),
620 before(sack, receiver->td_end + 1),
621 after(ack, receiver->td_end - MAXACKWINDOW(sender)));
9fb9cbb1 622
a09113c2
PM		 623 if (before(seq, sender->td_maxend + 1) &&
624 after(end, sender->td_end - receiver->td_maxwin - 1) &&
625 before(sack, receiver->td_end + 1) &&
626 after(ack, receiver->td_end - MAXACKWINDOW(sender))) {
601e68e1 627 /*
9fb9cbb1
YK		 628 * Take into account window scaling (RFC 1323).
629 */
630 if (!tcph->syn)
631 win <<= sender->td_scale;
632
633 /*
634 * Update sender data.
635 */
636 swin = win + (sack - ack);
637 if (sender->td_maxwin < swin)
638 sender->td_maxwin = swin;
639 if (after(end, sender->td_end))
640 sender->td_end = end;
641 /*
642 * Update receiver data.
643 */
644 if (after(end, sender->td_maxend))
645 receiver->td_maxwin += end - sender->td_maxend;
646 if (after(sack + win, receiver->td_maxend - 1)) {
647 receiver->td_maxend = sack + win;
648 if (win == 0)
649 receiver->td_maxend++;
650 }
651
601e68e1 652 /*
9fb9cbb1
YK		 653 * Check retransmissions.
654 */
655 if (index == TCP_ACK_SET) {
656 if (state->last_dir == dir
657 && state->last_seq == seq
658 && state->last_ack == ack
c1fe3ca5
GH		 659 && state->last_end == end
660 && state->last_win == win)
9fb9cbb1
YK		 661 state->retrans++;
662 else {
663 state->last_dir = dir;
664 state->last_seq = seq;
665 state->last_ack = ack;
666 state->last_end = end;
c1fe3ca5 667 state->last_win = win;
9fb9cbb1
YK		 668 state->retrans = 0;
669 }
670 }
9fb9cbb1
YK		 671 res = 1;
672 } else {
a09113c2
PM		 673 res = 0;
674 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
675 nf_ct_tcp_be_liberal)
676 res = 1;
677 if (!res && LOG_INVALID(IPPROTO_TCP))
9fb9cbb1
YK		 678 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
679 "nf_ct_tcp: %s ",
680 before(seq, sender->td_maxend + 1) ?
681 after(end, sender->td_end - receiver->td_maxwin - 1) ?
682 before(sack, receiver->td_end + 1) ?
683 after(ack, receiver->td_end - MAXACKWINDOW(sender)) ? "BUG"
684 : "ACK is under the lower bound (possible overly delayed ACK)"
685 : "ACK is over the upper bound (ACKed data not seen yet)"
686 : "SEQ is under the lower bound (already ACKed data retransmitted)"
687 : "SEQ is over the upper bound (over the window of the receiver)");
601e68e1
YH		 688 }
689
0d53778e
PM		 690 pr_debug("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
691 "receiver end=%u maxend=%u maxwin=%u\n",
692 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
693 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
9fb9cbb1
YK		 694
695 return res;
696}
697
5b1158e9 698#ifdef CONFIG_NF_NAT_NEEDED
9fb9cbb1
YK		 699/* Update sender->td_end after NAT successfully mangled the packet */
700/* Caller must linearize skb at tcp header. */
701void nf_conntrack_tcp_update(struct sk_buff *skb,
702 unsigned int dataoff,
601e68e1 703 struct nf_conn *conntrack,
9fb9cbb1
YK		 704 int dir)
705{
706 struct tcphdr *tcph = (void *)skb->data + dataoff;
9fb9cbb1
YK		 707 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[dir];
708 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[!dir];
0d53778e 709 __u32 end;
9fb9cbb1
YK		 710
711 end = segment_seq_plus_len(ntohl(tcph->seq), skb->len, dataoff, tcph);
712
713 write_lock_bh(&tcp_lock);
714 /*
715 * We have to worry for the ack in the reply packet only...
716 */
717 if (after(end, conntrack->proto.tcp.seen[dir].td_end))
718 conntrack->proto.tcp.seen[dir].td_end = end;
719 conntrack->proto.tcp.last_end = end;
720 write_unlock_bh(&tcp_lock);
0d53778e
PM		 721 pr_debug("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
722 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
723 sender->td_end, sender->td_maxend, sender->td_maxwin,
724 sender->td_scale,
725 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
726 receiver->td_scale);
9fb9cbb1 727}
13b18339 728EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
9fb9cbb1
YK		 729#endif
730
731#define TH_FIN 0x01
732#define TH_SYN 0x02
733#define TH_RST 0x04
734#define TH_PUSH 0x08
735#define TH_ACK 0x10
736#define TH_URG 0x20
737#define TH_ECE 0x40
738#define TH_CWR 0x80
739
5c8ce7c9
WT		 740/* table of valid flag combinations - PUSH, ECE and CWR are always valid */
741static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG) + 1] =
9fb9cbb1
YK		 742{
743 [TH_SYN] = 1,
d3ab4298 744 [TH_SYN|TH_URG] = 1,
d3ab4298 745 [TH_SYN|TH_ACK] = 1,
9fb9cbb1
YK		 746 [TH_RST] = 1,
747 [TH_RST|TH_ACK] = 1,
9fb9cbb1 748 [TH_FIN|TH_ACK] = 1,
5c8ce7c9 749 [TH_FIN|TH_ACK|TH_URG] = 1,
9fb9cbb1 750 [TH_ACK] = 1,
9fb9cbb1 751 [TH_ACK|TH_URG] = 1,
9fb9cbb1
YK		 752};
753
754/* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
755static int tcp_error(struct sk_buff *skb,
756 unsigned int dataoff,
757 enum ip_conntrack_info *ctinfo,
758 int pf,
96f6bf82 759 unsigned int hooknum)
9fb9cbb1
YK		 760{
761 struct tcphdr _tcph, *th;
762 unsigned int tcplen = skb->len - dataoff;
763 u_int8_t tcpflags;
764
765 /* Smaller that minimal TCP header? */
766 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
767 if (th == NULL) {
768 if (LOG_INVALID(IPPROTO_TCP))
769 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
770 "nf_ct_tcp: short packet ");
771 return -NF_ACCEPT;
601e68e1
YH		 772 }
773
9fb9cbb1
YK		 774 /* Not whole TCP header or malformed packet */
775 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
776 if (LOG_INVALID(IPPROTO_TCP))
777 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
778 "nf_ct_tcp: truncated/malformed packet ");
779 return -NF_ACCEPT;
780 }
601e68e1 781
9fb9cbb1
YK		 782 /* Checksum invalid? Ignore.
783 * We skip checking packets on the outgoing path
84fa7933 784 * because the checksum is assumed to be correct.
9fb9cbb1
YK		 785 */
786 /* FIXME: Source route IP option packets --RR */
6e23ae2a 787 if (nf_conntrack_checksum && hooknum == NF_INET_PRE_ROUTING &&
96f6bf82 788 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
9fb9cbb1
YK		 789 if (LOG_INVALID(IPPROTO_TCP))
790 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
791 "nf_ct_tcp: bad TCP checksum ");
792 return -NF_ACCEPT;
793 }
794
795 /* Check TCP flags. */
5c8ce7c9 796 tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR|TH_PUSH));
9fb9cbb1
YK		 797 if (!tcp_valid_flags[tcpflags]) {
798 if (LOG_INVALID(IPPROTO_TCP))
799 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
800 "nf_ct_tcp: invalid TCP flag combination ");
801 return -NF_ACCEPT;
802 }
803
804 return NF_ACCEPT;
805}
806
9fb9cbb1
YK		 807/* Returns verdict for packet, or -1 for invalid. */
808static int tcp_packet(struct nf_conn *conntrack,
809 const struct sk_buff *skb,
810 unsigned int dataoff,
811 enum ip_conntrack_info ctinfo,
812 int pf,
813 unsigned int hooknum)
814{
0d53778e 815 struct nf_conntrack_tuple *tuple;
9fb9cbb1
YK		 816 enum tcp_conntrack new_state, old_state;
817 enum ip_conntrack_dir dir;
818 struct tcphdr *th, _tcph;
819 unsigned long timeout;
820 unsigned int index;
821
822 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
823 BUG_ON(th == NULL);
824
825 write_lock_bh(&tcp_lock);
826 old_state = conntrack->proto.tcp.state;
827 dir = CTINFO2DIR(ctinfo);
828 index = get_conntrack_index(th);
829 new_state = tcp_conntracks[dir][index][old_state];
0d53778e 830 tuple = &conntrack->tuplehash[dir].tuple;
9fb9cbb1
YK		 831
832 switch (new_state) {
17311393
JK		 833 case TCP_CONNTRACK_SYN_SENT:
834 if (old_state < TCP_CONNTRACK_TIME_WAIT)
835 break;
bc34b841
JK		 836 if ((conntrack->proto.tcp.seen[!dir].flags &
837 IP_CT_TCP_FLAG_CLOSE_INIT)
838 || (conntrack->proto.tcp.last_dir == dir
839 && conntrack->proto.tcp.last_index == TCP_RST_SET)) {
840 /* Attempt to reopen a closed/aborted connection.
841 * Delete this connection and look up again. */
17311393
JK		 842 write_unlock_bh(&tcp_lock);
843 if (del_timer(&conntrack->timeout))
844 conntrack->timeout.function((unsigned long)
845 conntrack);
846 return -NF_REPEAT;
847 }
848 /* Fall through */
9fb9cbb1 849 case TCP_CONNTRACK_IGNORE:
73f30602
JK		 850 /* Ignored packets:
851 *
852 * a) SYN in ORIGINAL
853 * b) SYN/ACK in REPLY
601e68e1 854 * c) ACK in reply direction after initial SYN in original.
73f30602 855 */
9fb9cbb1
YK		 856 if (index == TCP_SYNACK_SET
857 && conntrack->proto.tcp.last_index == TCP_SYN_SET
858 && conntrack->proto.tcp.last_dir != dir
859 && ntohl(th->ack_seq) ==
601e68e1
YH		 860 conntrack->proto.tcp.last_end) {
861 /* This SYN/ACK acknowledges a SYN that we earlier
9fb9cbb1
YK		 862 * ignored as invalid. This means that the client and
863 * the server are both in sync, while the firewall is
864 * not. We kill this session and block the SYN/ACK so
601e68e1 865 * that the client cannot but retransmit its SYN and
9fb9cbb1
YK		 866 * thus initiate a clean new session.
867 */
601e68e1 868 write_unlock_bh(&tcp_lock);
9fb9cbb1
YK		 869 if (LOG_INVALID(IPPROTO_TCP))
870 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
871 "nf_ct_tcp: killing out of sync session ");
601e68e1
YH		 872 if (del_timer(&conntrack->timeout))
873 conntrack->timeout.function((unsigned long)
874 conntrack);
875 return -NF_DROP;
9fb9cbb1
YK		 876 }
877 conntrack->proto.tcp.last_index = index;
878 conntrack->proto.tcp.last_dir = dir;
879 conntrack->proto.tcp.last_seq = ntohl(th->seq);
880 conntrack->proto.tcp.last_end =
881 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th);
882
883 write_unlock_bh(&tcp_lock);
884 if (LOG_INVALID(IPPROTO_TCP))
885 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
886 "nf_ct_tcp: invalid packed ignored ");
887 return NF_ACCEPT;
888 case TCP_CONNTRACK_MAX:
889 /* Invalid packet */
0d53778e
PM		 890 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
891 dir, get_conntrack_index(th), old_state);
9fb9cbb1
YK		 892 write_unlock_bh(&tcp_lock);
893 if (LOG_INVALID(IPPROTO_TCP))
894 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
895 "nf_ct_tcp: invalid state ");
896 return -NF_ACCEPT;
9fb9cbb1
YK		 897 case TCP_CONNTRACK_CLOSE:
898 if (index == TCP_RST_SET
73f30602 899 && ((test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
601e68e1
YH		 900 && conntrack->proto.tcp.last_index == TCP_SYN_SET)
901 || (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
902 && conntrack->proto.tcp.last_index == TCP_ACK_SET))
9fb9cbb1 903 && ntohl(th->ack_seq) == conntrack->proto.tcp.last_end) {
93b1fae4 904 /* RST sent to invalid SYN or ACK we had let through
73f30602
JK		 905 * at a) and c) above:
906 *
907 * a) SYN was in window then
908 * c) we hold a half-open connection.
909 *
910 * Delete our connection entry.
9fb9cbb1 911 * We skip window checking, because packet might ACK
73f30602 912 * segments we ignored. */
9fb9cbb1
YK		 913 goto in_window;
914 }
93b1fae4 915 /* Just fall through */
9fb9cbb1
YK		 916 default:
917 /* Keep compilers happy. */
918 break;
919 }
920
0d53778e 921 if (!tcp_in_window(conntrack, &conntrack->proto.tcp, dir, index,
9fb9cbb1
YK		 922 skb, dataoff, th, pf)) {
923 write_unlock_bh(&tcp_lock);
924 return -NF_ACCEPT;
925 }
926 in_window:
927 /* From now on we have got in-window packets */
928 conntrack->proto.tcp.last_index = index;
bc34b841 929 conntrack->proto.tcp.last_dir = dir;
9fb9cbb1 930
0d53778e
PM		 931 pr_debug("tcp_conntracks: ");
932 NF_CT_DUMP_TUPLE(tuple);
933 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
934 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
935 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
936 old_state, new_state);
9fb9cbb1
YK		 937
938 conntrack->proto.tcp.state = new_state;
939 if (old_state != new_state
940 && (new_state == TCP_CONNTRACK_FIN_WAIT
941 || new_state == TCP_CONNTRACK_CLOSE))
942 conntrack->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
943 timeout = conntrack->proto.tcp.retrans >= nf_ct_tcp_max_retrans
944 && *tcp_timeouts[new_state] > nf_ct_tcp_timeout_max_retrans
945 ? nf_ct_tcp_timeout_max_retrans : *tcp_timeouts[new_state];
946 write_unlock_bh(&tcp_lock);
947
948 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
949 if (new_state != old_state)
950 nf_conntrack_event_cache(IPCT_PROTOINFO, skb);
951
952 if (!test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
953 /* If only reply is a RST, we can consider ourselves not to
954 have an established connection: this is a fairly common
955 problem case, so we can delete the conntrack
956 immediately. --RR */
957 if (th->rst) {
958 if (del_timer(&conntrack->timeout))
959 conntrack->timeout.function((unsigned long)
960 conntrack);
961 return NF_ACCEPT;
962 }
963 } else if (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
964 && (old_state == TCP_CONNTRACK_SYN_RECV
965 || old_state == TCP_CONNTRACK_ESTABLISHED)
966 && new_state == TCP_CONNTRACK_ESTABLISHED) {
601e68e1
YH		 967 /* Set ASSURED if we see see valid ack in ESTABLISHED
968 after SYN_RECV or a valid answer for a picked up
9fb9cbb1
YK		 969 connection. */
970 set_bit(IPS_ASSURED_BIT, &conntrack->status);
971 nf_conntrack_event_cache(IPCT_STATUS, skb);
972 }
973 nf_ct_refresh_acct(conntrack, ctinfo, skb, timeout);
974
975 return NF_ACCEPT;
976}
601e68e1 977
9fb9cbb1
YK		 978/* Called when a new connection for this protocol found. */
979static int tcp_new(struct nf_conn *conntrack,
980 const struct sk_buff *skb,
981 unsigned int dataoff)
982{
983 enum tcp_conntrack new_state;
984 struct tcphdr *th, _tcph;
9fb9cbb1
YK		 985 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[0];
986 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[1];
9fb9cbb1
YK		 987
988 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
989 BUG_ON(th == NULL);
990
991 /* Don't need lock here: this conntrack not in circulation yet */
992 new_state
993 = tcp_conntracks[0][get_conntrack_index(th)]
994 [TCP_CONNTRACK_NONE];
995
996 /* Invalid: delete conntrack */
997 if (new_state >= TCP_CONNTRACK_MAX) {
0d53778e 998 pr_debug("nf_ct_tcp: invalid new deleting.\n");
9fb9cbb1
YK		 999 return 0;
1000 }
1001
1002 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1003 /* SYN packet */
1004 conntrack->proto.tcp.seen[0].td_end =
1005 segment_seq_plus_len(ntohl(th->seq), skb->len,
1006 dataoff, th);
1007 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1008 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1009 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1010 conntrack->proto.tcp.seen[0].td_maxend =
1011 conntrack->proto.tcp.seen[0].td_end;
1012
1013 tcp_options(skb, dataoff, th, &conntrack->proto.tcp.seen[0]);
1014 conntrack->proto.tcp.seen[1].flags = 0;
9fb9cbb1
YK		 1015 } else if (nf_ct_tcp_loose == 0) {
1016 /* Don't try to pick up connections. */
1017 return 0;
1018 } else {
1019 /*
1020 * We are in the middle of a connection,
1021 * its history is lost for us.
1022 * Let's try to use the data from the packet.
1023 */
1024 conntrack->proto.tcp.seen[0].td_end =
1025 segment_seq_plus_len(ntohl(th->seq), skb->len,
1026 dataoff, th);
1027 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1028 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1029 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1030 conntrack->proto.tcp.seen[0].td_maxend =
601e68e1 1031 conntrack->proto.tcp.seen[0].td_end +
9fb9cbb1
YK		 1032 conntrack->proto.tcp.seen[0].td_maxwin;
1033 conntrack->proto.tcp.seen[0].td_scale = 0;
1034
a09113c2
PM		 1035 /* We assume SACK and liberal window checking to handle
1036 * window scaling */
9fb9cbb1 1037 conntrack->proto.tcp.seen[0].flags =
a09113c2
PM		 1038 conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1039 IP_CT_TCP_FLAG_BE_LIBERAL;
9fb9cbb1 1040 }
601e68e1 1041
9fb9cbb1
YK		 1042 conntrack->proto.tcp.seen[1].td_end = 0;
1043 conntrack->proto.tcp.seen[1].td_maxend = 0;
1044 conntrack->proto.tcp.seen[1].td_maxwin = 1;
601e68e1 1045 conntrack->proto.tcp.seen[1].td_scale = 0;
9fb9cbb1
YK		 1046
1047 /* tcp_packet will set them */
1048 conntrack->proto.tcp.state = TCP_CONNTRACK_NONE;
1049 conntrack->proto.tcp.last_index = TCP_NONE_SET;
601e68e1 1050
0d53778e
PM		 1051 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1052 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1053 sender->td_end, sender->td_maxend, sender->td_maxwin,
1054 sender->td_scale,
1055 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1056 receiver->td_scale);
9fb9cbb1
YK		 1057 return 1;
1058}
c1d10adb 1059
e281db5c 1060#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
c1d10adb
PNA		 1061
1062#include <linux/netfilter/nfnetlink.h>
1063#include <linux/netfilter/nfnetlink_conntrack.h>
1064
fdf70832 1065static int tcp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
c1d10adb
PNA		 1066 const struct nf_conn *ct)
1067{
df6fb868 1068 struct nlattr *nest_parms;
c8e2078c 1069 struct nf_ct_tcp_flags tmp = {};
601e68e1 1070
c1d10adb 1071 read_lock_bh(&tcp_lock);
df6fb868
PM		 1072 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_TCP | NLA_F_NESTED);
1073 if (!nest_parms)
1074 goto nla_put_failure;
1075
77236b6e 1076 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_STATE, ct->proto.tcp.state);
c8e2078c 1077
77236b6e
PM		 1078 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL,
1079 ct->proto.tcp.seen[0].td_scale);
c8e2078c 1080
77236b6e
PM		 1081 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY,
1082 ct->proto.tcp.seen[1].td_scale);
c8e2078c
PNA		 1083
1084 tmp.flags = ct->proto.tcp.seen[0].flags;
df6fb868 1085 NLA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL,
c8e2078c
PNA		 1086 sizeof(struct nf_ct_tcp_flags), &tmp);
1087
1088 tmp.flags = ct->proto.tcp.seen[1].flags;
df6fb868 1089 NLA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY,
c8e2078c 1090 sizeof(struct nf_ct_tcp_flags), &tmp);
c1d10adb
PNA		 1091 read_unlock_bh(&tcp_lock);
1092
df6fb868 1093 nla_nest_end(skb, nest_parms);
c1d10adb
PNA		 1094
1095 return 0;
1096
df6fb868 1097nla_put_failure:
c1d10adb
PNA		 1098 read_unlock_bh(&tcp_lock);
1099 return -1;
1100}
1101
f73e924c
PM		 1102static const struct nla_policy tcp_nla_policy[CTA_PROTOINFO_TCP_MAX+1] = {
1103 [CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 },
1104 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 },
1105 [CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 },
1106 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .len = sizeof(struct nf_ct_tcp_flags) },
1107 [CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .len = sizeof(struct nf_ct_tcp_flags) },
c1d10adb
PNA		 1108};
1109
fdf70832 1110static int nlattr_to_tcp(struct nlattr *cda[], struct nf_conn *ct)
c1d10adb 1111{
df6fb868
PM		 1112 struct nlattr *attr = cda[CTA_PROTOINFO_TCP];
1113 struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1];
f73e924c 1114 int err;
c1d10adb
PNA		 1115
1116 /* updates could not contain anything about the private
1117 * protocol info, in that case skip the parsing */
1118 if (!attr)
1119 return 0;
1120
f73e924c
PM		 1121 err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr, tcp_nla_policy);
1122 if (err < 0)
1123 return err;
c1d10adb 1124
df6fb868 1125 if (!tb[CTA_PROTOINFO_TCP_STATE])
c1d10adb
PNA		 1126 return -EINVAL;
1127
1128 write_lock_bh(&tcp_lock);
77236b6e 1129 ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
c8e2078c 1130
df6fb868 1131 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) {
c8e2078c 1132 struct nf_ct_tcp_flags *attr =
df6fb868 1133 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]);
c8e2078c
PNA		 1134 ct->proto.tcp.seen[0].flags &= ~attr->mask;
1135 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask;
1136 }
1137
df6fb868 1138 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]) {
c8e2078c 1139 struct nf_ct_tcp_flags *attr =
df6fb868 1140 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]);
c8e2078c
PNA		 1141 ct->proto.tcp.seen[1].flags &= ~attr->mask;
1142 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask;
1143 }
1144
df6fb868
PM		 1145 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] &&
1146 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY] &&
c8e2078c
PNA		 1147 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
1148 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
77236b6e
PM		 1149 ct->proto.tcp.seen[0].td_scale =
1150 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL]);
1151 ct->proto.tcp.seen[1].td_scale =
1152 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY]);
c8e2078c 1153 }
c1d10adb
PNA		 1154 write_unlock_bh(&tcp_lock);
1155
1156 return 0;
1157}
1158#endif
933a41e7
PM		 1159
1160#ifdef CONFIG_SYSCTL
1161static unsigned int tcp_sysctl_table_users;
1162static struct ctl_table_header *tcp_sysctl_header;
1163static struct ctl_table tcp_sysctl_table[] = {
1164 {
933a41e7
PM		 1165 .procname = "nf_conntrack_tcp_timeout_syn_sent",
1166 .data = &nf_ct_tcp_timeout_syn_sent,
1167 .maxlen = sizeof(unsigned int),
1168 .mode = 0644,
1169 .proc_handler = &proc_dointvec_jiffies,
1170 },
1171 {
933a41e7
PM		 1172 .procname = "nf_conntrack_tcp_timeout_syn_recv",
1173 .data = &nf_ct_tcp_timeout_syn_recv,
1174 .maxlen = sizeof(unsigned int),
1175 .mode = 0644,
1176 .proc_handler = &proc_dointvec_jiffies,
1177 },
1178 {
933a41e7
PM		 1179 .procname = "nf_conntrack_tcp_timeout_established",
1180 .data = &nf_ct_tcp_timeout_established,
1181 .maxlen = sizeof(unsigned int),
1182 .mode = 0644,
1183 .proc_handler = &proc_dointvec_jiffies,
1184 },
1185 {
933a41e7
PM		 1186 .procname = "nf_conntrack_tcp_timeout_fin_wait",
1187 .data = &nf_ct_tcp_timeout_fin_wait,
1188 .maxlen = sizeof(unsigned int),
1189 .mode = 0644,
1190 .proc_handler = &proc_dointvec_jiffies,
1191 },
1192 {
933a41e7
PM		 1193 .procname = "nf_conntrack_tcp_timeout_close_wait",
1194 .data = &nf_ct_tcp_timeout_close_wait,
1195 .maxlen = sizeof(unsigned int),
1196 .mode = 0644,
1197 .proc_handler = &proc_dointvec_jiffies,
1198 },
1199 {
933a41e7
PM		 1200 .procname = "nf_conntrack_tcp_timeout_last_ack",
1201 .data = &nf_ct_tcp_timeout_last_ack,
1202 .maxlen = sizeof(unsigned int),
1203 .mode = 0644,
1204 .proc_handler = &proc_dointvec_jiffies,
1205 },
1206 {
933a41e7
PM		 1207 .procname = "nf_conntrack_tcp_timeout_time_wait",
1208 .data = &nf_ct_tcp_timeout_time_wait,
1209 .maxlen = sizeof(unsigned int),
1210 .mode = 0644,
1211 .proc_handler = &proc_dointvec_jiffies,
1212 },
1213 {
933a41e7
PM		 1214 .procname = "nf_conntrack_tcp_timeout_close",
1215 .data = &nf_ct_tcp_timeout_close,
1216 .maxlen = sizeof(unsigned int),
1217 .mode = 0644,
1218 .proc_handler = &proc_dointvec_jiffies,
1219 },
1220 {
933a41e7
PM		 1221 .procname = "nf_conntrack_tcp_timeout_max_retrans",
1222 .data = &nf_ct_tcp_timeout_max_retrans,
1223 .maxlen = sizeof(unsigned int),
1224 .mode = 0644,
1225 .proc_handler = &proc_dointvec_jiffies,
1226 },
1227 {
1228 .ctl_name = NET_NF_CONNTRACK_TCP_LOOSE,
1229 .procname = "nf_conntrack_tcp_loose",
1230 .data = &nf_ct_tcp_loose,
1231 .maxlen = sizeof(unsigned int),
1232 .mode = 0644,
1233 .proc_handler = &proc_dointvec,
1234 },
1235 {
1236 .ctl_name = NET_NF_CONNTRACK_TCP_BE_LIBERAL,
1237 .procname = "nf_conntrack_tcp_be_liberal",
1238 .data = &nf_ct_tcp_be_liberal,
1239 .maxlen = sizeof(unsigned int),
1240 .mode = 0644,
1241 .proc_handler = &proc_dointvec,
1242 },
1243 {
1244 .ctl_name = NET_NF_CONNTRACK_TCP_MAX_RETRANS,
1245 .procname = "nf_conntrack_tcp_max_retrans",
1246 .data = &nf_ct_tcp_max_retrans,
1247 .maxlen = sizeof(unsigned int),
1248 .mode = 0644,
1249 .proc_handler = &proc_dointvec,
1250 },
1251 {
1252 .ctl_name = 0
1253 }
1254};
a999e683
PM		 1255
1256#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1257static struct ctl_table tcp_compat_sysctl_table[] = {
1258 {
a999e683
PM		 1259 .procname = "ip_conntrack_tcp_timeout_syn_sent",
1260 .data = &nf_ct_tcp_timeout_syn_sent,
1261 .maxlen = sizeof(unsigned int),
1262 .mode = 0644,
1263 .proc_handler = &proc_dointvec_jiffies,
1264 },
1265 {
a999e683
PM		 1266 .procname = "ip_conntrack_tcp_timeout_syn_recv",
1267 .data = &nf_ct_tcp_timeout_syn_recv,
1268 .maxlen = sizeof(unsigned int),
1269 .mode = 0644,
1270 .proc_handler = &proc_dointvec_jiffies,
1271 },
1272 {
a999e683
PM		 1273 .procname = "ip_conntrack_tcp_timeout_established",
1274 .data = &nf_ct_tcp_timeout_established,
1275 .maxlen = sizeof(unsigned int),
1276 .mode = 0644,
1277 .proc_handler = &proc_dointvec_jiffies,
1278 },
1279 {
a999e683
PM		 1280 .procname = "ip_conntrack_tcp_timeout_fin_wait",
1281 .data = &nf_ct_tcp_timeout_fin_wait,
1282 .maxlen = sizeof(unsigned int),
1283 .mode = 0644,
1284 .proc_handler = &proc_dointvec_jiffies,
1285 },
1286 {
a999e683
PM		 1287 .procname = "ip_conntrack_tcp_timeout_close_wait",
1288 .data = &nf_ct_tcp_timeout_close_wait,
1289 .maxlen = sizeof(unsigned int),
1290 .mode = 0644,
1291 .proc_handler = &proc_dointvec_jiffies,
1292 },
1293 {
a999e683
PM		 1294 .procname = "ip_conntrack_tcp_timeout_last_ack",
1295 .data = &nf_ct_tcp_timeout_last_ack,
1296 .maxlen = sizeof(unsigned int),
1297 .mode = 0644,
1298 .proc_handler = &proc_dointvec_jiffies,
1299 },
1300 {
a999e683
PM		 1301 .procname = "ip_conntrack_tcp_timeout_time_wait",
1302 .data = &nf_ct_tcp_timeout_time_wait,
1303 .maxlen = sizeof(unsigned int),
1304 .mode = 0644,
1305 .proc_handler = &proc_dointvec_jiffies,
1306 },
1307 {
a999e683
PM		 1308 .procname = "ip_conntrack_tcp_timeout_close",
1309 .data = &nf_ct_tcp_timeout_close,
1310 .maxlen = sizeof(unsigned int),
1311 .mode = 0644,
1312 .proc_handler = &proc_dointvec_jiffies,
1313 },
1314 {
a999e683
PM		 1315 .procname = "ip_conntrack_tcp_timeout_max_retrans",
1316 .data = &nf_ct_tcp_timeout_max_retrans,
1317 .maxlen = sizeof(unsigned int),
1318 .mode = 0644,
1319 .proc_handler = &proc_dointvec_jiffies,
1320 },
1321 {
1322 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_LOOSE,
1323 .procname = "ip_conntrack_tcp_loose",
1324 .data = &nf_ct_tcp_loose,
1325 .maxlen = sizeof(unsigned int),
1326 .mode = 0644,
1327 .proc_handler = &proc_dointvec,
1328 },
1329 {
1330 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,
1331 .procname = "ip_conntrack_tcp_be_liberal",
1332 .data = &nf_ct_tcp_be_liberal,
1333 .maxlen = sizeof(unsigned int),
1334 .mode = 0644,
1335 .proc_handler = &proc_dointvec,
1336 },
1337 {
1338 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,
1339 .procname = "ip_conntrack_tcp_max_retrans",
1340 .data = &nf_ct_tcp_max_retrans,
1341 .maxlen = sizeof(unsigned int),
1342 .mode = 0644,
1343 .proc_handler = &proc_dointvec,
1344 },
1345 {
1346 .ctl_name = 0
1347 }
1348};
1349#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
933a41e7
PM		 1350#endif /* CONFIG_SYSCTL */
1351
61075af5 1352struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
9fb9cbb1
YK		 1353{
1354 .l3proto = PF_INET,
605dcad6 1355 .l4proto = IPPROTO_TCP,
9fb9cbb1
YK		 1356 .name = "tcp",
1357 .pkt_to_tuple = tcp_pkt_to_tuple,
1358 .invert_tuple = tcp_invert_tuple,
1359 .print_tuple = tcp_print_tuple,
1360 .print_conntrack = tcp_print_conntrack,
1361 .packet = tcp_packet,
1362 .new = tcp_new,
96f6bf82 1363 .error = tcp_error,
e281db5c 1364#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832
PM		 1365 .to_nlattr = tcp_to_nlattr,
1366 .from_nlattr = nlattr_to_tcp,
1367 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1368 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c 1369 .nla_policy = nf_ct_port_nla_policy,
c1d10adb 1370#endif
933a41e7
PM		 1371#ifdef CONFIG_SYSCTL
1372 .ctl_table_users = &tcp_sysctl_table_users,
1373 .ctl_table_header = &tcp_sysctl_header,
1374 .ctl_table = tcp_sysctl_table,
a999e683
PM		 1375#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1376 .ctl_compat_table = tcp_compat_sysctl_table,
1377#endif
933a41e7 1378#endif
9fb9cbb1 1379};
13b18339 1380EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
9fb9cbb1 1381
61075af5 1382struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly =
9fb9cbb1
YK		 1383{
1384 .l3proto = PF_INET6,
605dcad6 1385 .l4proto = IPPROTO_TCP,
9fb9cbb1
YK		 1386 .name = "tcp",
1387 .pkt_to_tuple = tcp_pkt_to_tuple,
1388 .invert_tuple = tcp_invert_tuple,
1389 .print_tuple = tcp_print_tuple,
1390 .print_conntrack = tcp_print_conntrack,
1391 .packet = tcp_packet,
1392 .new = tcp_new,
96f6bf82 1393 .error = tcp_error,
e281db5c 1394#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832
PM		 1395 .to_nlattr = tcp_to_nlattr,
1396 .from_nlattr = nlattr_to_tcp,
1397 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1398 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c 1399 .nla_policy = nf_ct_port_nla_policy,
c1d10adb 1400#endif
933a41e7
PM		 1401#ifdef CONFIG_SYSCTL
1402 .ctl_table_users = &tcp_sysctl_table_users,
1403 .ctl_table_header = &tcp_sysctl_header,
1404 .ctl_table = tcp_sysctl_table,
1405#endif
9fb9cbb1 1406};
13b18339 1407EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);
kernel source for telekom puls (alcatel/mediatek)