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Merge git://git.infradead.org/users/eparis/selinux
[deliverable/linux.git] / net / netfilter / nf_conntrack_proto_tcp.c
1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2002-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
4 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/types.h>
12 #include <linux/timer.h>
13 #include <linux/module.h>
14 #include <linux/in.h>
15 #include <linux/tcp.h>
16 #include <linux/spinlock.h>
17 #include <linux/skbuff.h>
18 #include <linux/ipv6.h>
19 #include <net/ip6_checksum.h>
20 #include <asm/unaligned.h>
21
22 #include <net/tcp.h>
23
24 #include <linux/netfilter.h>
25 #include <linux/netfilter_ipv4.h>
26 #include <linux/netfilter_ipv6.h>
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_l4proto.h>
29 #include <net/netfilter/nf_conntrack_ecache.h>
30 #include <net/netfilter/nf_log.h>
31 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
32 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
33
34 /* "Be conservative in what you do,
35 be liberal in what you accept from others."
36 If it's non-zero, we mark only out of window RST segments as INVALID. */
37 static int nf_ct_tcp_be_liberal __read_mostly = 0;
38
39 /* If it is set to zero, we disable picking up already established
40 connections. */
41 static int nf_ct_tcp_loose __read_mostly = 1;
42
43 /* Max number of the retransmitted packets without receiving an (acceptable)
44 ACK from the destination. If this number is reached, a shorter timer
45 will be started. */
46 static int nf_ct_tcp_max_retrans __read_mostly = 3;
47
48 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
49 closely. They're more complex. --RR */
50
51 static const char *const tcp_conntrack_names[] = {
52 "NONE",
53 "SYN_SENT",
54 "SYN_RECV",
55 "ESTABLISHED",
56 "FIN_WAIT",
57 "CLOSE_WAIT",
58 "LAST_ACK",
59 "TIME_WAIT",
60 "CLOSE",
61 "SYN_SENT2",
62 };
63
64 #define SECS * HZ
65 #define MINS * 60 SECS
66 #define HOURS * 60 MINS
67 #define DAYS * 24 HOURS
68
69 static unsigned int tcp_timeouts[TCP_CONNTRACK_TIMEOUT_MAX] __read_mostly = {
70 [TCP_CONNTRACK_SYN_SENT] = 2 MINS,
71 [TCP_CONNTRACK_SYN_RECV] = 60 SECS,
72 [TCP_CONNTRACK_ESTABLISHED] = 5 DAYS,
73 [TCP_CONNTRACK_FIN_WAIT] = 2 MINS,
74 [TCP_CONNTRACK_CLOSE_WAIT] = 60 SECS,
75 [TCP_CONNTRACK_LAST_ACK] = 30 SECS,
76 [TCP_CONNTRACK_TIME_WAIT] = 2 MINS,
77 [TCP_CONNTRACK_CLOSE] = 10 SECS,
78 [TCP_CONNTRACK_SYN_SENT2] = 2 MINS,
79 /* RFC1122 says the R2 limit should be at least 100 seconds.
80 Linux uses 15 packets as limit, which corresponds
81 to ~13-30min depending on RTO. */
82 [TCP_CONNTRACK_RETRANS] = 5 MINS,
83 [TCP_CONNTRACK_UNACK] = 5 MINS,
84 };
85
86 #define sNO TCP_CONNTRACK_NONE
87 #define sSS TCP_CONNTRACK_SYN_SENT
88 #define sSR TCP_CONNTRACK_SYN_RECV
89 #define sES TCP_CONNTRACK_ESTABLISHED
90 #define sFW TCP_CONNTRACK_FIN_WAIT
91 #define sCW TCP_CONNTRACK_CLOSE_WAIT
92 #define sLA TCP_CONNTRACK_LAST_ACK
93 #define sTW TCP_CONNTRACK_TIME_WAIT
94 #define sCL TCP_CONNTRACK_CLOSE
95 #define sS2 TCP_CONNTRACK_SYN_SENT2
96 #define sIV TCP_CONNTRACK_MAX
97 #define sIG TCP_CONNTRACK_IGNORE
98
99 /* What TCP flags are set from RST/SYN/FIN/ACK. */
100 enum tcp_bit_set {
101 TCP_SYN_SET,
102 TCP_SYNACK_SET,
103 TCP_FIN_SET,
104 TCP_ACK_SET,
105 TCP_RST_SET,
106 TCP_NONE_SET,
107 };
108
109 /*
110 * The TCP state transition table needs a few words...
111 *
112 * We are the man in the middle. All the packets go through us
113 * but might get lost in transit to the destination.
114 * It is assumed that the destinations can't receive segments
115 * we haven't seen.
116 *
117 * The checked segment is in window, but our windows are *not*
118 * equivalent with the ones of the sender/receiver. We always
119 * try to guess the state of the current sender.
120 *
121 * The meaning of the states are:
122 *
123 * NONE: initial state
124 * SYN_SENT: SYN-only packet seen
125 * SYN_SENT2: SYN-only packet seen from reply dir, simultaneous open
126 * SYN_RECV: SYN-ACK packet seen
127 * ESTABLISHED: ACK packet seen
128 * FIN_WAIT: FIN packet seen
129 * CLOSE_WAIT: ACK seen (after FIN)
130 * LAST_ACK: FIN seen (after FIN)
131 * TIME_WAIT: last ACK seen
132 * CLOSE: closed connection (RST)
133 *
134 * Packets marked as IGNORED (sIG):
135 * if they may be either invalid or valid
136 * and the receiver may send back a connection
137 * closing RST or a SYN/ACK.
138 *
139 * Packets marked as INVALID (sIV):
140 * if we regard them as truly invalid packets
141 */
142 static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
143 {
144 /* ORIGINAL */
145 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
146 /*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sS2 },
147 /*
148 * sNO -> sSS Initialize a new connection
149 * sSS -> sSS Retransmitted SYN
150 * sS2 -> sS2 Late retransmitted SYN
151 * sSR -> sIG
152 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
153 * are errors. Receiver will reply with RST
154 * and close the connection.
155 * Or we are not in sync and hold a dead connection.
156 * sFW -> sIG
157 * sCW -> sIG
158 * sLA -> sIG
159 * sTW -> sSS Reopened connection (RFC 1122).
160 * sCL -> sSS
161 */
162 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
163 /*synack*/ { sIV, sIV, sSR, sIV, sIV, sIV, sIV, sIV, sIV, sSR },
164 /*
165 * sNO -> sIV Too late and no reason to do anything
166 * sSS -> sIV Client can't send SYN and then SYN/ACK
167 * sS2 -> sSR SYN/ACK sent to SYN2 in simultaneous open
168 * sSR -> sSR Late retransmitted SYN/ACK in simultaneous open
169 * sES -> sIV Invalid SYN/ACK packets sent by the client
170 * sFW -> sIV
171 * sCW -> sIV
172 * sLA -> sIV
173 * sTW -> sIV
174 * sCL -> sIV
175 */
176 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
177 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
178 /*
179 * sNO -> sIV Too late and no reason to do anything...
180 * sSS -> sIV Client migth not send FIN in this state:
181 * we enforce waiting for a SYN/ACK reply first.
182 * sS2 -> sIV
183 * sSR -> sFW Close started.
184 * sES -> sFW
185 * sFW -> sLA FIN seen in both directions, waiting for
186 * the last ACK.
187 * Migth be a retransmitted FIN as well...
188 * sCW -> sLA
189 * sLA -> sLA Retransmitted FIN. Remain in the same state.
190 * sTW -> sTW
191 * sCL -> sCL
192 */
193 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
194 /*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
195 /*
196 * sNO -> sES Assumed.
197 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
198 * sS2 -> sIV
199 * sSR -> sES Established state is reached.
200 * sES -> sES :-)
201 * sFW -> sCW Normal close request answered by ACK.
202 * sCW -> sCW
203 * sLA -> sTW Last ACK detected.
204 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
205 * sCL -> sCL
206 */
207 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
208 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
209 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
210 },
211 {
212 /* REPLY */
213 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
214 /*syn*/ { sIV, sS2, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sS2 },
215 /*
216 * sNO -> sIV Never reached.
217 * sSS -> sS2 Simultaneous open
218 * sS2 -> sS2 Retransmitted simultaneous SYN
219 * sSR -> sIV Invalid SYN packets sent by the server
220 * sES -> sIV
221 * sFW -> sIV
222 * sCW -> sIV
223 * sLA -> sIV
224 * sTW -> sIV Reopened connection, but server may not do it.
225 * sCL -> sIV
226 */
227 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
228 /*synack*/ { sIV, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIG, sSR },
229 /*
230 * sSS -> sSR Standard open.
231 * sS2 -> sSR Simultaneous open
232 * sSR -> sIG Retransmitted SYN/ACK, ignore it.
233 * sES -> sIG Late retransmitted SYN/ACK?
234 * sFW -> sIG Might be SYN/ACK answering ignored SYN
235 * sCW -> sIG
236 * sLA -> sIG
237 * sTW -> sIG
238 * sCL -> sIG
239 */
240 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
241 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
242 /*
243 * sSS -> sIV Server might not send FIN in this state.
244 * sS2 -> sIV
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, sS2 */
254 /*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIG },
255 /*
256 * sSS -> sIG Might be a half-open connection.
257 * sS2 -> sIG
258 * sSR -> sSR Might answer late resent SYN.
259 * sES -> sES :-)
260 * sFW -> sCW Normal close request answered by ACK.
261 * sCW -> sCW
262 * sLA -> sTW Last ACK detected.
263 * sTW -> sTW Retransmitted last ACK.
264 * sCL -> sCL
265 */
266 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
267 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
268 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
269 }
270 };
271
272 static inline struct nf_tcp_net *tcp_pernet(struct net *net)
273 {
274 return &net->ct.nf_ct_proto.tcp;
275 }
276
277 static bool tcp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
278 struct nf_conntrack_tuple *tuple)
279 {
280 const struct tcphdr *hp;
281 struct tcphdr _hdr;
282
283 /* Actually only need first 8 bytes. */
284 hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
285 if (hp == NULL)
286 return false;
287
288 tuple->src.u.tcp.port = hp->source;
289 tuple->dst.u.tcp.port = hp->dest;
290
291 return true;
292 }
293
294 static bool tcp_invert_tuple(struct nf_conntrack_tuple *tuple,
295 const struct nf_conntrack_tuple *orig)
296 {
297 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
298 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
299 return true;
300 }
301
302 /* Print out the per-protocol part of the tuple. */
303 static int tcp_print_tuple(struct seq_file *s,
304 const struct nf_conntrack_tuple *tuple)
305 {
306 return seq_printf(s, "sport=%hu dport=%hu ",
307 ntohs(tuple->src.u.tcp.port),
308 ntohs(tuple->dst.u.tcp.port));
309 }
310
311 /* Print out the private part of the conntrack. */
312 static int tcp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
313 {
314 enum tcp_conntrack state;
315
316 spin_lock_bh(&ct->lock);
317 state = ct->proto.tcp.state;
318 spin_unlock_bh(&ct->lock);
319
320 return seq_printf(s, "%s ", tcp_conntrack_names[state]);
321 }
322
323 static unsigned int get_conntrack_index(const struct tcphdr *tcph)
324 {
325 if (tcph->rst) return TCP_RST_SET;
326 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
327 else if (tcph->fin) return TCP_FIN_SET;
328 else if (tcph->ack) return TCP_ACK_SET;
329 else return TCP_NONE_SET;
330 }
331
332 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
333 in IP Filter' by Guido van Rooij.
334
335 http://www.sane.nl/events/sane2000/papers.html
336 http://www.darkart.com/mirrors/www.obfuscation.org/ipf/
337
338 The boundaries and the conditions are changed according to RFC793:
339 the packet must intersect the window (i.e. segments may be
340 after the right or before the left edge) and thus receivers may ACK
341 segments after the right edge of the window.
342
343 td_maxend = max(sack + max(win,1)) seen in reply packets
344 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
345 td_maxwin += seq + len - sender.td_maxend
346 if seq + len > sender.td_maxend
347 td_end = max(seq + len) seen in sent packets
348
349 I. Upper bound for valid data: seq <= sender.td_maxend
350 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
351 III. Upper bound for valid (s)ack: sack <= receiver.td_end
352 IV. Lower bound for valid (s)ack: sack >= receiver.td_end - MAXACKWINDOW
353
354 where sack is the highest right edge of sack block found in the packet
355 or ack in the case of packet without SACK option.
356
357 The upper bound limit for a valid (s)ack is not ignored -
358 we doesn't have to deal with fragments.
359 */
360
361 static inline __u32 segment_seq_plus_len(__u32 seq,
362 size_t len,
363 unsigned int dataoff,
364 const struct tcphdr *tcph)
365 {
366 /* XXX Should I use payload length field in IP/IPv6 header ?
367 * - YK */
368 return (seq + len - dataoff - tcph->doff*4
369 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
370 }
371
372 /* Fixme: what about big packets? */
373 #define MAXACKWINCONST 66000
374 #define MAXACKWINDOW(sender) \
375 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
376 : MAXACKWINCONST)
377
378 /*
379 * Simplified tcp_parse_options routine from tcp_input.c
380 */
381 static void tcp_options(const struct sk_buff *skb,
382 unsigned int dataoff,
383 const struct tcphdr *tcph,
384 struct ip_ct_tcp_state *state)
385 {
386 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
387 const unsigned char *ptr;
388 int length = (tcph->doff*4) - sizeof(struct tcphdr);
389
390 if (!length)
391 return;
392
393 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
394 length, buff);
395 BUG_ON(ptr == NULL);
396
397 state->td_scale =
398 state->flags = 0;
399
400 while (length > 0) {
401 int opcode=*ptr++;
402 int opsize;
403
404 switch (opcode) {
405 case TCPOPT_EOL:
406 return;
407 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
408 length--;
409 continue;
410 default:
411 opsize=*ptr++;
412 if (opsize < 2) /* "silly options" */
413 return;
414 if (opsize > length)
415 return; /* don't parse partial options */
416
417 if (opcode == TCPOPT_SACK_PERM
418 && opsize == TCPOLEN_SACK_PERM)
419 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
420 else if (opcode == TCPOPT_WINDOW
421 && opsize == TCPOLEN_WINDOW) {
422 state->td_scale = *(u_int8_t *)ptr;
423
424 if (state->td_scale > 14) {
425 /* See RFC1323 */
426 state->td_scale = 14;
427 }
428 state->flags |=
429 IP_CT_TCP_FLAG_WINDOW_SCALE;
430 }
431 ptr += opsize - 2;
432 length -= opsize;
433 }
434 }
435 }
436
437 static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
438 const struct tcphdr *tcph, __u32 *sack)
439 {
440 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
441 const unsigned char *ptr;
442 int length = (tcph->doff*4) - sizeof(struct tcphdr);
443 __u32 tmp;
444
445 if (!length)
446 return;
447
448 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
449 length, buff);
450 BUG_ON(ptr == NULL);
451
452 /* Fast path for timestamp-only option */
453 if (length == TCPOLEN_TSTAMP_ALIGNED
454 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24)
455 | (TCPOPT_NOP << 16)
456 | (TCPOPT_TIMESTAMP << 8)
457 | TCPOLEN_TIMESTAMP))
458 return;
459
460 while (length > 0) {
461 int opcode = *ptr++;
462 int opsize, i;
463
464 switch (opcode) {
465 case TCPOPT_EOL:
466 return;
467 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
468 length--;
469 continue;
470 default:
471 opsize = *ptr++;
472 if (opsize < 2) /* "silly options" */
473 return;
474 if (opsize > length)
475 return; /* don't parse partial options */
476
477 if (opcode == TCPOPT_SACK
478 && opsize >= (TCPOLEN_SACK_BASE
479 + TCPOLEN_SACK_PERBLOCK)
480 && !((opsize - TCPOLEN_SACK_BASE)
481 % TCPOLEN_SACK_PERBLOCK)) {
482 for (i = 0;
483 i < (opsize - TCPOLEN_SACK_BASE);
484 i += TCPOLEN_SACK_PERBLOCK) {
485 tmp = get_unaligned_be32((__be32 *)(ptr+i)+1);
486
487 if (after(tmp, *sack))
488 *sack = tmp;
489 }
490 return;
491 }
492 ptr += opsize - 2;
493 length -= opsize;
494 }
495 }
496 }
497
498 #ifdef CONFIG_NF_NAT_NEEDED
499 static inline s16 nat_offset(const struct nf_conn *ct,
500 enum ip_conntrack_dir dir,
501 u32 seq)
502 {
503 typeof(nf_ct_nat_offset) get_offset = rcu_dereference(nf_ct_nat_offset);
504
505 return get_offset != NULL ? get_offset(ct, dir, seq) : 0;
506 }
507 #define NAT_OFFSET(ct, dir, seq) \
508 (nat_offset(ct, dir, seq))
509 #else
510 #define NAT_OFFSET(ct, dir, seq) 0
511 #endif
512
513 static bool tcp_in_window(const struct nf_conn *ct,
514 struct ip_ct_tcp *state,
515 enum ip_conntrack_dir dir,
516 unsigned int index,
517 const struct sk_buff *skb,
518 unsigned int dataoff,
519 const struct tcphdr *tcph,
520 u_int8_t pf)
521 {
522 struct net *net = nf_ct_net(ct);
523 struct nf_tcp_net *tn = tcp_pernet(net);
524 struct ip_ct_tcp_state *sender = &state->seen[dir];
525 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
526 const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
527 __u32 seq, ack, sack, end, win, swin;
528 s16 receiver_offset;
529 bool res, in_recv_win;
530
531 /*
532 * Get the required data from the packet.
533 */
534 seq = ntohl(tcph->seq);
535 ack = sack = ntohl(tcph->ack_seq);
536 win = ntohs(tcph->window);
537 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph);
538
539 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
540 tcp_sack(skb, dataoff, tcph, &sack);
541
542 /* Take into account NAT sequence number mangling */
543 receiver_offset = NAT_OFFSET(ct, !dir, ack - 1);
544 ack -= receiver_offset;
545 sack -= receiver_offset;
546
547 pr_debug("tcp_in_window: START\n");
548 pr_debug("tcp_in_window: ");
549 nf_ct_dump_tuple(tuple);
550 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
551 seq, ack, receiver_offset, sack, receiver_offset, win, end);
552 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
553 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
554 sender->td_end, sender->td_maxend, sender->td_maxwin,
555 sender->td_scale,
556 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
557 receiver->td_scale);
558
559 if (sender->td_maxwin == 0) {
560 /*
561 * Initialize sender data.
562 */
563 if (tcph->syn) {
564 /*
565 * SYN-ACK in reply to a SYN
566 * or SYN from reply direction in simultaneous open.
567 */
568 sender->td_end =
569 sender->td_maxend = end;
570 sender->td_maxwin = (win == 0 ? 1 : win);
571
572 tcp_options(skb, dataoff, tcph, sender);
573 /*
574 * RFC 1323:
575 * Both sides must send the Window Scale option
576 * to enable window scaling in either direction.
577 */
578 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
579 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
580 sender->td_scale =
581 receiver->td_scale = 0;
582 if (!tcph->ack)
583 /* Simultaneous open */
584 return true;
585 } else {
586 /*
587 * We are in the middle of a connection,
588 * its history is lost for us.
589 * Let's try to use the data from the packet.
590 */
591 sender->td_end = end;
592 swin = win << sender->td_scale;
593 sender->td_maxwin = (swin == 0 ? 1 : swin);
594 sender->td_maxend = end + sender->td_maxwin;
595 /*
596 * We haven't seen traffic in the other direction yet
597 * but we have to tweak window tracking to pass III
598 * and IV until that happens.
599 */
600 if (receiver->td_maxwin == 0)
601 receiver->td_end = receiver->td_maxend = sack;
602 }
603 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
604 && dir == IP_CT_DIR_ORIGINAL)
605 || (state->state == TCP_CONNTRACK_SYN_RECV
606 && dir == IP_CT_DIR_REPLY))
607 && after(end, sender->td_end)) {
608 /*
609 * RFC 793: "if a TCP is reinitialized ... then it need
610 * not wait at all; it must only be sure to use sequence
611 * numbers larger than those recently used."
612 */
613 sender->td_end =
614 sender->td_maxend = end;
615 sender->td_maxwin = (win == 0 ? 1 : win);
616
617 tcp_options(skb, dataoff, tcph, sender);
618 }
619
620 if (!(tcph->ack)) {
621 /*
622 * If there is no ACK, just pretend it was set and OK.
623 */
624 ack = sack = receiver->td_end;
625 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
626 (TCP_FLAG_ACK|TCP_FLAG_RST))
627 && (ack == 0)) {
628 /*
629 * Broken TCP stacks, that set ACK in RST packets as well
630 * with zero ack value.
631 */
632 ack = sack = receiver->td_end;
633 }
634
635 if (tcph->rst && seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)
636 /*
637 * RST sent answering SYN.
638 */
639 seq = end = sender->td_end;
640
641 pr_debug("tcp_in_window: ");
642 nf_ct_dump_tuple(tuple);
643 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
644 seq, ack, receiver_offset, sack, receiver_offset, win, end);
645 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
646 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
647 sender->td_end, sender->td_maxend, sender->td_maxwin,
648 sender->td_scale,
649 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
650 receiver->td_scale);
651
652 /* Is the ending sequence in the receive window (if available)? */
653 in_recv_win = !receiver->td_maxwin ||
654 after(end, sender->td_end - receiver->td_maxwin - 1);
655
656 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
657 before(seq, sender->td_maxend + 1),
658 (in_recv_win ? 1 : 0),
659 before(sack, receiver->td_end + 1),
660 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1));
661
662 if (before(seq, sender->td_maxend + 1) &&
663 in_recv_win &&
664 before(sack, receiver->td_end + 1) &&
665 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)) {
666 /*
667 * Take into account window scaling (RFC 1323).
668 */
669 if (!tcph->syn)
670 win <<= sender->td_scale;
671
672 /*
673 * Update sender data.
674 */
675 swin = win + (sack - ack);
676 if (sender->td_maxwin < swin)
677 sender->td_maxwin = swin;
678 if (after(end, sender->td_end)) {
679 sender->td_end = end;
680 sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
681 }
682 if (tcph->ack) {
683 if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) {
684 sender->td_maxack = ack;
685 sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET;
686 } else if (after(ack, sender->td_maxack))
687 sender->td_maxack = ack;
688 }
689
690 /*
691 * Update receiver data.
692 */
693 if (receiver->td_maxwin != 0 && after(end, sender->td_maxend))
694 receiver->td_maxwin += end - sender->td_maxend;
695 if (after(sack + win, receiver->td_maxend - 1)) {
696 receiver->td_maxend = sack + win;
697 if (win == 0)
698 receiver->td_maxend++;
699 }
700 if (ack == receiver->td_end)
701 receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
702
703 /*
704 * Check retransmissions.
705 */
706 if (index == TCP_ACK_SET) {
707 if (state->last_dir == dir
708 && state->last_seq == seq
709 && state->last_ack == ack
710 && state->last_end == end
711 && state->last_win == win)
712 state->retrans++;
713 else {
714 state->last_dir = dir;
715 state->last_seq = seq;
716 state->last_ack = ack;
717 state->last_end = end;
718 state->last_win = win;
719 state->retrans = 0;
720 }
721 }
722 res = true;
723 } else {
724 res = false;
725 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
726 tn->tcp_be_liberal)
727 res = true;
728 if (!res && LOG_INVALID(net, IPPROTO_TCP))
729 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
730 "nf_ct_tcp: %s ",
731 before(seq, sender->td_maxend + 1) ?
732 in_recv_win ?
733 before(sack, receiver->td_end + 1) ?
734 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1) ? "BUG"
735 : "ACK is under the lower bound (possible overly delayed ACK)"
736 : "ACK is over the upper bound (ACKed data not seen yet)"
737 : "SEQ is under the lower bound (already ACKed data retransmitted)"
738 : "SEQ is over the upper bound (over the window of the receiver)");
739 }
740
741 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u "
742 "receiver end=%u maxend=%u maxwin=%u\n",
743 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
744 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
745
746 return res;
747 }
748
749 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
750 static const u8 tcp_valid_flags[(TCPHDR_FIN|TCPHDR_SYN|TCPHDR_RST|TCPHDR_ACK|
751 TCPHDR_URG) + 1] =
752 {
753 [TCPHDR_SYN] = 1,
754 [TCPHDR_SYN|TCPHDR_URG] = 1,
755 [TCPHDR_SYN|TCPHDR_ACK] = 1,
756 [TCPHDR_RST] = 1,
757 [TCPHDR_RST|TCPHDR_ACK] = 1,
758 [TCPHDR_FIN|TCPHDR_ACK] = 1,
759 [TCPHDR_FIN|TCPHDR_ACK|TCPHDR_URG] = 1,
760 [TCPHDR_ACK] = 1,
761 [TCPHDR_ACK|TCPHDR_URG] = 1,
762 };
763
764 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
765 static int tcp_error(struct net *net, struct nf_conn *tmpl,
766 struct sk_buff *skb,
767 unsigned int dataoff,
768 enum ip_conntrack_info *ctinfo,
769 u_int8_t pf,
770 unsigned int hooknum)
771 {
772 const struct tcphdr *th;
773 struct tcphdr _tcph;
774 unsigned int tcplen = skb->len - dataoff;
775 u_int8_t tcpflags;
776
777 /* Smaller that minimal TCP header? */
778 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
779 if (th == NULL) {
780 if (LOG_INVALID(net, IPPROTO_TCP))
781 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
782 "nf_ct_tcp: short packet ");
783 return -NF_ACCEPT;
784 }
785
786 /* Not whole TCP header or malformed packet */
787 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
788 if (LOG_INVALID(net, IPPROTO_TCP))
789 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
790 "nf_ct_tcp: truncated/malformed packet ");
791 return -NF_ACCEPT;
792 }
793
794 /* Checksum invalid? Ignore.
795 * We skip checking packets on the outgoing path
796 * because the checksum is assumed to be correct.
797 */
798 /* FIXME: Source route IP option packets --RR */
799 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
800 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
801 if (LOG_INVALID(net, IPPROTO_TCP))
802 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
803 "nf_ct_tcp: bad TCP checksum ");
804 return -NF_ACCEPT;
805 }
806
807 /* Check TCP flags. */
808 tcpflags = (tcp_flag_byte(th) & ~(TCPHDR_ECE|TCPHDR_CWR|TCPHDR_PSH));
809 if (!tcp_valid_flags[tcpflags]) {
810 if (LOG_INVALID(net, IPPROTO_TCP))
811 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
812 "nf_ct_tcp: invalid TCP flag combination ");
813 return -NF_ACCEPT;
814 }
815
816 return NF_ACCEPT;
817 }
818
819 static unsigned int *tcp_get_timeouts(struct net *net)
820 {
821 return tcp_pernet(net)->timeouts;
822 }
823
824 /* Returns verdict for packet, or -1 for invalid. */
825 static int tcp_packet(struct nf_conn *ct,
826 const struct sk_buff *skb,
827 unsigned int dataoff,
828 enum ip_conntrack_info ctinfo,
829 u_int8_t pf,
830 unsigned int hooknum,
831 unsigned int *timeouts)
832 {
833 struct net *net = nf_ct_net(ct);
834 struct nf_tcp_net *tn = tcp_pernet(net);
835 struct nf_conntrack_tuple *tuple;
836 enum tcp_conntrack new_state, old_state;
837 enum ip_conntrack_dir dir;
838 const struct tcphdr *th;
839 struct tcphdr _tcph;
840 unsigned long timeout;
841 unsigned int index;
842
843 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
844 BUG_ON(th == NULL);
845
846 spin_lock_bh(&ct->lock);
847 old_state = ct->proto.tcp.state;
848 dir = CTINFO2DIR(ctinfo);
849 index = get_conntrack_index(th);
850 new_state = tcp_conntracks[dir][index][old_state];
851 tuple = &ct->tuplehash[dir].tuple;
852
853 switch (new_state) {
854 case TCP_CONNTRACK_SYN_SENT:
855 if (old_state < TCP_CONNTRACK_TIME_WAIT)
856 break;
857 /* RFC 1122: "When a connection is closed actively,
858 * it MUST linger in TIME-WAIT state for a time 2xMSL
859 * (Maximum Segment Lifetime). However, it MAY accept
860 * a new SYN from the remote TCP to reopen the connection
861 * directly from TIME-WAIT state, if..."
862 * We ignore the conditions because we are in the
863 * TIME-WAIT state anyway.
864 *
865 * Handle aborted connections: we and the server
866 * think there is an existing connection but the client
867 * aborts it and starts a new one.
868 */
869 if (((ct->proto.tcp.seen[dir].flags
870 | ct->proto.tcp.seen[!dir].flags)
871 & IP_CT_TCP_FLAG_CLOSE_INIT)
872 || (ct->proto.tcp.last_dir == dir
873 && ct->proto.tcp.last_index == TCP_RST_SET)) {
874 /* Attempt to reopen a closed/aborted connection.
875 * Delete this connection and look up again. */
876 spin_unlock_bh(&ct->lock);
877
878 /* Only repeat if we can actually remove the timer.
879 * Destruction may already be in progress in process
880 * context and we must give it a chance to terminate.
881 */
882 if (nf_ct_kill(ct))
883 return -NF_REPEAT;
884 return NF_DROP;
885 }
886 /* Fall through */
887 case TCP_CONNTRACK_IGNORE:
888 /* Ignored packets:
889 *
890 * Our connection entry may be out of sync, so ignore
891 * packets which may signal the real connection between
892 * the client and the server.
893 *
894 * a) SYN in ORIGINAL
895 * b) SYN/ACK in REPLY
896 * c) ACK in reply direction after initial SYN in original.
897 *
898 * If the ignored packet is invalid, the receiver will send
899 * a RST we'll catch below.
900 */
901 if (index == TCP_SYNACK_SET
902 && ct->proto.tcp.last_index == TCP_SYN_SET
903 && ct->proto.tcp.last_dir != dir
904 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
905 /* b) This SYN/ACK acknowledges a SYN that we earlier
906 * ignored as invalid. This means that the client and
907 * the server are both in sync, while the firewall is
908 * not. We get in sync from the previously annotated
909 * values.
910 */
911 old_state = TCP_CONNTRACK_SYN_SENT;
912 new_state = TCP_CONNTRACK_SYN_RECV;
913 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_end =
914 ct->proto.tcp.last_end;
915 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxend =
916 ct->proto.tcp.last_end;
917 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxwin =
918 ct->proto.tcp.last_win == 0 ?
919 1 : ct->proto.tcp.last_win;
920 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_scale =
921 ct->proto.tcp.last_wscale;
922 ct->proto.tcp.seen[ct->proto.tcp.last_dir].flags =
923 ct->proto.tcp.last_flags;
924 memset(&ct->proto.tcp.seen[dir], 0,
925 sizeof(struct ip_ct_tcp_state));
926 break;
927 }
928 ct->proto.tcp.last_index = index;
929 ct->proto.tcp.last_dir = dir;
930 ct->proto.tcp.last_seq = ntohl(th->seq);
931 ct->proto.tcp.last_end =
932 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th);
933 ct->proto.tcp.last_win = ntohs(th->window);
934
935 /* a) This is a SYN in ORIGINAL. The client and the server
936 * may be in sync but we are not. In that case, we annotate
937 * the TCP options and let the packet go through. If it is a
938 * valid SYN packet, the server will reply with a SYN/ACK, and
939 * then we'll get in sync. Otherwise, the server ignores it. */
940 if (index == TCP_SYN_SET && dir == IP_CT_DIR_ORIGINAL) {
941 struct ip_ct_tcp_state seen = {};
942
943 ct->proto.tcp.last_flags =
944 ct->proto.tcp.last_wscale = 0;
945 tcp_options(skb, dataoff, th, &seen);
946 if (seen.flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
947 ct->proto.tcp.last_flags |=
948 IP_CT_TCP_FLAG_WINDOW_SCALE;
949 ct->proto.tcp.last_wscale = seen.td_scale;
950 }
951 if (seen.flags & IP_CT_TCP_FLAG_SACK_PERM) {
952 ct->proto.tcp.last_flags |=
953 IP_CT_TCP_FLAG_SACK_PERM;
954 }
955 }
956 spin_unlock_bh(&ct->lock);
957 if (LOG_INVALID(net, IPPROTO_TCP))
958 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
959 "nf_ct_tcp: invalid packet ignored in "
960 "state %s ", tcp_conntrack_names[old_state]);
961 return NF_ACCEPT;
962 case TCP_CONNTRACK_MAX:
963 /* Invalid packet */
964 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
965 dir, get_conntrack_index(th), old_state);
966 spin_unlock_bh(&ct->lock);
967 if (LOG_INVALID(net, IPPROTO_TCP))
968 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
969 "nf_ct_tcp: invalid state ");
970 return -NF_ACCEPT;
971 case TCP_CONNTRACK_CLOSE:
972 if (index == TCP_RST_SET
973 && (ct->proto.tcp.seen[!dir].flags & IP_CT_TCP_FLAG_MAXACK_SET)
974 && before(ntohl(th->seq), ct->proto.tcp.seen[!dir].td_maxack)) {
975 /* Invalid RST */
976 spin_unlock_bh(&ct->lock);
977 if (LOG_INVALID(net, IPPROTO_TCP))
978 nf_log_packet(net, pf, 0, skb, NULL, NULL,
979 NULL, "nf_ct_tcp: invalid RST ");
980 return -NF_ACCEPT;
981 }
982 if (index == TCP_RST_SET
983 && ((test_bit(IPS_SEEN_REPLY_BIT, &ct->status)
984 && ct->proto.tcp.last_index == TCP_SYN_SET)
985 || (!test_bit(IPS_ASSURED_BIT, &ct->status)
986 && ct->proto.tcp.last_index == TCP_ACK_SET))
987 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
988 /* RST sent to invalid SYN or ACK we had let through
989 * at a) and c) above:
990 *
991 * a) SYN was in window then
992 * c) we hold a half-open connection.
993 *
994 * Delete our connection entry.
995 * We skip window checking, because packet might ACK
996 * segments we ignored. */
997 goto in_window;
998 }
999 /* Just fall through */
1000 default:
1001 /* Keep compilers happy. */
1002 break;
1003 }
1004
1005 if (!tcp_in_window(ct, &ct->proto.tcp, dir, index,
1006 skb, dataoff, th, pf)) {
1007 spin_unlock_bh(&ct->lock);
1008 return -NF_ACCEPT;
1009 }
1010 in_window:
1011 /* From now on we have got in-window packets */
1012 ct->proto.tcp.last_index = index;
1013 ct->proto.tcp.last_dir = dir;
1014
1015 pr_debug("tcp_conntracks: ");
1016 nf_ct_dump_tuple(tuple);
1017 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
1018 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
1019 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
1020 old_state, new_state);
1021
1022 ct->proto.tcp.state = new_state;
1023 if (old_state != new_state
1024 && new_state == TCP_CONNTRACK_FIN_WAIT)
1025 ct->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
1026
1027 if (ct->proto.tcp.retrans >= tn->tcp_max_retrans &&
1028 timeouts[new_state] > timeouts[TCP_CONNTRACK_RETRANS])
1029 timeout = timeouts[TCP_CONNTRACK_RETRANS];
1030 else if ((ct->proto.tcp.seen[0].flags | ct->proto.tcp.seen[1].flags) &
1031 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED &&
1032 timeouts[new_state] > timeouts[TCP_CONNTRACK_UNACK])
1033 timeout = timeouts[TCP_CONNTRACK_UNACK];
1034 else
1035 timeout = timeouts[new_state];
1036 spin_unlock_bh(&ct->lock);
1037
1038 if (new_state != old_state)
1039 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
1040
1041 if (!test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1042 /* If only reply is a RST, we can consider ourselves not to
1043 have an established connection: this is a fairly common
1044 problem case, so we can delete the conntrack
1045 immediately. --RR */
1046 if (th->rst) {
1047 nf_ct_kill_acct(ct, ctinfo, skb);
1048 return NF_ACCEPT;
1049 }
1050 /* ESTABLISHED without SEEN_REPLY, i.e. mid-connection
1051 * pickup with loose=1. Avoid large ESTABLISHED timeout.
1052 */
1053 if (new_state == TCP_CONNTRACK_ESTABLISHED &&
1054 timeout > timeouts[TCP_CONNTRACK_UNACK])
1055 timeout = timeouts[TCP_CONNTRACK_UNACK];
1056 } else if (!test_bit(IPS_ASSURED_BIT, &ct->status)
1057 && (old_state == TCP_CONNTRACK_SYN_RECV
1058 || old_state == TCP_CONNTRACK_ESTABLISHED)
1059 && new_state == TCP_CONNTRACK_ESTABLISHED) {
1060 /* Set ASSURED if we see see valid ack in ESTABLISHED
1061 after SYN_RECV or a valid answer for a picked up
1062 connection. */
1063 set_bit(IPS_ASSURED_BIT, &ct->status);
1064 nf_conntrack_event_cache(IPCT_ASSURED, ct);
1065 }
1066 nf_ct_refresh_acct(ct, ctinfo, skb, timeout);
1067
1068 return NF_ACCEPT;
1069 }
1070
1071 /* Called when a new connection for this protocol found. */
1072 static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb,
1073 unsigned int dataoff, unsigned int *timeouts)
1074 {
1075 enum tcp_conntrack new_state;
1076 const struct tcphdr *th;
1077 struct tcphdr _tcph;
1078 struct net *net = nf_ct_net(ct);
1079 struct nf_tcp_net *tn = tcp_pernet(net);
1080 const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0];
1081 const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1];
1082
1083 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
1084 BUG_ON(th == NULL);
1085
1086 /* Don't need lock here: this conntrack not in circulation yet */
1087 new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE];
1088
1089 /* Invalid: delete conntrack */
1090 if (new_state >= TCP_CONNTRACK_MAX) {
1091 pr_debug("nf_ct_tcp: invalid new deleting.\n");
1092 return false;
1093 }
1094
1095 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1096 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
1097 /* SYN packet */
1098 ct->proto.tcp.seen[0].td_end =
1099 segment_seq_plus_len(ntohl(th->seq), skb->len,
1100 dataoff, th);
1101 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1102 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1103 ct->proto.tcp.seen[0].td_maxwin = 1;
1104 ct->proto.tcp.seen[0].td_maxend =
1105 ct->proto.tcp.seen[0].td_end;
1106
1107 tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]);
1108 } else if (tn->tcp_loose == 0) {
1109 /* Don't try to pick up connections. */
1110 return false;
1111 } else {
1112 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
1113 /*
1114 * We are in the middle of a connection,
1115 * its history is lost for us.
1116 * Let's try to use the data from the packet.
1117 */
1118 ct->proto.tcp.seen[0].td_end =
1119 segment_seq_plus_len(ntohl(th->seq), skb->len,
1120 dataoff, th);
1121 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1122 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1123 ct->proto.tcp.seen[0].td_maxwin = 1;
1124 ct->proto.tcp.seen[0].td_maxend =
1125 ct->proto.tcp.seen[0].td_end +
1126 ct->proto.tcp.seen[0].td_maxwin;
1127
1128 /* We assume SACK and liberal window checking to handle
1129 * window scaling */
1130 ct->proto.tcp.seen[0].flags =
1131 ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1132 IP_CT_TCP_FLAG_BE_LIBERAL;
1133 }
1134
1135 /* tcp_packet will set them */
1136 ct->proto.tcp.last_index = TCP_NONE_SET;
1137
1138 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1139 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1140 sender->td_end, sender->td_maxend, sender->td_maxwin,
1141 sender->td_scale,
1142 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1143 receiver->td_scale);
1144 return true;
1145 }
1146
1147 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1148
1149 #include <linux/netfilter/nfnetlink.h>
1150 #include <linux/netfilter/nfnetlink_conntrack.h>
1151
1152 static int tcp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
1153 struct nf_conn *ct)
1154 {
1155 struct nlattr *nest_parms;
1156 struct nf_ct_tcp_flags tmp = {};
1157
1158 spin_lock_bh(&ct->lock);
1159 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_TCP | NLA_F_NESTED);
1160 if (!nest_parms)
1161 goto nla_put_failure;
1162
1163 if (nla_put_u8(skb, CTA_PROTOINFO_TCP_STATE, ct->proto.tcp.state) ||
1164 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL,
1165 ct->proto.tcp.seen[0].td_scale) ||
1166 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY,
1167 ct->proto.tcp.seen[1].td_scale))
1168 goto nla_put_failure;
1169
1170 tmp.flags = ct->proto.tcp.seen[0].flags;
1171 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL,
1172 sizeof(struct nf_ct_tcp_flags), &tmp))
1173 goto nla_put_failure;
1174
1175 tmp.flags = ct->proto.tcp.seen[1].flags;
1176 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY,
1177 sizeof(struct nf_ct_tcp_flags), &tmp))
1178 goto nla_put_failure;
1179 spin_unlock_bh(&ct->lock);
1180
1181 nla_nest_end(skb, nest_parms);
1182
1183 return 0;
1184
1185 nla_put_failure:
1186 spin_unlock_bh(&ct->lock);
1187 return -1;
1188 }
1189
1190 static const struct nla_policy tcp_nla_policy[CTA_PROTOINFO_TCP_MAX+1] = {
1191 [CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 },
1192 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 },
1193 [CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 },
1194 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .len = sizeof(struct nf_ct_tcp_flags) },
1195 [CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .len = sizeof(struct nf_ct_tcp_flags) },
1196 };
1197
1198 static int nlattr_to_tcp(struct nlattr *cda[], struct nf_conn *ct)
1199 {
1200 struct nlattr *pattr = cda[CTA_PROTOINFO_TCP];
1201 struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1];
1202 int err;
1203
1204 /* updates could not contain anything about the private
1205 * protocol info, in that case skip the parsing */
1206 if (!pattr)
1207 return 0;
1208
1209 err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, pattr, tcp_nla_policy);
1210 if (err < 0)
1211 return err;
1212
1213 if (tb[CTA_PROTOINFO_TCP_STATE] &&
1214 nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]) >= TCP_CONNTRACK_MAX)
1215 return -EINVAL;
1216
1217 spin_lock_bh(&ct->lock);
1218 if (tb[CTA_PROTOINFO_TCP_STATE])
1219 ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
1220
1221 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) {
1222 struct nf_ct_tcp_flags *attr =
1223 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]);
1224 ct->proto.tcp.seen[0].flags &= ~attr->mask;
1225 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask;
1226 }
1227
1228 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]) {
1229 struct nf_ct_tcp_flags *attr =
1230 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]);
1231 ct->proto.tcp.seen[1].flags &= ~attr->mask;
1232 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask;
1233 }
1234
1235 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] &&
1236 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY] &&
1237 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
1238 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
1239 ct->proto.tcp.seen[0].td_scale =
1240 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL]);
1241 ct->proto.tcp.seen[1].td_scale =
1242 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY]);
1243 }
1244 spin_unlock_bh(&ct->lock);
1245
1246 return 0;
1247 }
1248
1249 static int tcp_nlattr_size(void)
1250 {
1251 return nla_total_size(0) /* CTA_PROTOINFO_TCP */
1252 + nla_policy_len(tcp_nla_policy, CTA_PROTOINFO_TCP_MAX + 1);
1253 }
1254
1255 static int tcp_nlattr_tuple_size(void)
1256 {
1257 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1258 }
1259 #endif
1260
1261 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1262
1263 #include <linux/netfilter/nfnetlink.h>
1264 #include <linux/netfilter/nfnetlink_cttimeout.h>
1265
1266 static int tcp_timeout_nlattr_to_obj(struct nlattr *tb[],
1267 struct net *net, void *data)
1268 {
1269 unsigned int *timeouts = data;
1270 struct nf_tcp_net *tn = tcp_pernet(net);
1271 int i;
1272
1273 /* set default TCP timeouts. */
1274 for (i=0; i<TCP_CONNTRACK_TIMEOUT_MAX; i++)
1275 timeouts[i] = tn->timeouts[i];
1276
1277 if (tb[CTA_TIMEOUT_TCP_SYN_SENT]) {
1278 timeouts[TCP_CONNTRACK_SYN_SENT] =
1279 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT]))*HZ;
1280 }
1281 if (tb[CTA_TIMEOUT_TCP_SYN_RECV]) {
1282 timeouts[TCP_CONNTRACK_SYN_RECV] =
1283 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_RECV]))*HZ;
1284 }
1285 if (tb[CTA_TIMEOUT_TCP_ESTABLISHED]) {
1286 timeouts[TCP_CONNTRACK_ESTABLISHED] =
1287 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_ESTABLISHED]))*HZ;
1288 }
1289 if (tb[CTA_TIMEOUT_TCP_FIN_WAIT]) {
1290 timeouts[TCP_CONNTRACK_FIN_WAIT] =
1291 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_FIN_WAIT]))*HZ;
1292 }
1293 if (tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]) {
1294 timeouts[TCP_CONNTRACK_CLOSE_WAIT] =
1295 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]))*HZ;
1296 }
1297 if (tb[CTA_TIMEOUT_TCP_LAST_ACK]) {
1298 timeouts[TCP_CONNTRACK_LAST_ACK] =
1299 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_LAST_ACK]))*HZ;
1300 }
1301 if (tb[CTA_TIMEOUT_TCP_TIME_WAIT]) {
1302 timeouts[TCP_CONNTRACK_TIME_WAIT] =
1303 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_TIME_WAIT]))*HZ;
1304 }
1305 if (tb[CTA_TIMEOUT_TCP_CLOSE]) {
1306 timeouts[TCP_CONNTRACK_CLOSE] =
1307 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE]))*HZ;
1308 }
1309 if (tb[CTA_TIMEOUT_TCP_SYN_SENT2]) {
1310 timeouts[TCP_CONNTRACK_SYN_SENT2] =
1311 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT2]))*HZ;
1312 }
1313 if (tb[CTA_TIMEOUT_TCP_RETRANS]) {
1314 timeouts[TCP_CONNTRACK_RETRANS] =
1315 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_RETRANS]))*HZ;
1316 }
1317 if (tb[CTA_TIMEOUT_TCP_UNACK]) {
1318 timeouts[TCP_CONNTRACK_UNACK] =
1319 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_UNACK]))*HZ;
1320 }
1321 return 0;
1322 }
1323
1324 static int
1325 tcp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
1326 {
1327 const unsigned int *timeouts = data;
1328
1329 if (nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT,
1330 htonl(timeouts[TCP_CONNTRACK_SYN_SENT] / HZ)) ||
1331 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_RECV,
1332 htonl(timeouts[TCP_CONNTRACK_SYN_RECV] / HZ)) ||
1333 nla_put_be32(skb, CTA_TIMEOUT_TCP_ESTABLISHED,
1334 htonl(timeouts[TCP_CONNTRACK_ESTABLISHED] / HZ)) ||
1335 nla_put_be32(skb, CTA_TIMEOUT_TCP_FIN_WAIT,
1336 htonl(timeouts[TCP_CONNTRACK_FIN_WAIT] / HZ)) ||
1337 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE_WAIT,
1338 htonl(timeouts[TCP_CONNTRACK_CLOSE_WAIT] / HZ)) ||
1339 nla_put_be32(skb, CTA_TIMEOUT_TCP_LAST_ACK,
1340 htonl(timeouts[TCP_CONNTRACK_LAST_ACK] / HZ)) ||
1341 nla_put_be32(skb, CTA_TIMEOUT_TCP_TIME_WAIT,
1342 htonl(timeouts[TCP_CONNTRACK_TIME_WAIT] / HZ)) ||
1343 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE,
1344 htonl(timeouts[TCP_CONNTRACK_CLOSE] / HZ)) ||
1345 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT2,
1346 htonl(timeouts[TCP_CONNTRACK_SYN_SENT2] / HZ)) ||
1347 nla_put_be32(skb, CTA_TIMEOUT_TCP_RETRANS,
1348 htonl(timeouts[TCP_CONNTRACK_RETRANS] / HZ)) ||
1349 nla_put_be32(skb, CTA_TIMEOUT_TCP_UNACK,
1350 htonl(timeouts[TCP_CONNTRACK_UNACK] / HZ)))
1351 goto nla_put_failure;
1352 return 0;
1353
1354 nla_put_failure:
1355 return -ENOSPC;
1356 }
1357
1358 static const struct nla_policy tcp_timeout_nla_policy[CTA_TIMEOUT_TCP_MAX+1] = {
1359 [CTA_TIMEOUT_TCP_SYN_SENT] = { .type = NLA_U32 },
1360 [CTA_TIMEOUT_TCP_SYN_RECV] = { .type = NLA_U32 },
1361 [CTA_TIMEOUT_TCP_ESTABLISHED] = { .type = NLA_U32 },
1362 [CTA_TIMEOUT_TCP_FIN_WAIT] = { .type = NLA_U32 },
1363 [CTA_TIMEOUT_TCP_CLOSE_WAIT] = { .type = NLA_U32 },
1364 [CTA_TIMEOUT_TCP_LAST_ACK] = { .type = NLA_U32 },
1365 [CTA_TIMEOUT_TCP_TIME_WAIT] = { .type = NLA_U32 },
1366 [CTA_TIMEOUT_TCP_CLOSE] = { .type = NLA_U32 },
1367 [CTA_TIMEOUT_TCP_SYN_SENT2] = { .type = NLA_U32 },
1368 [CTA_TIMEOUT_TCP_RETRANS] = { .type = NLA_U32 },
1369 [CTA_TIMEOUT_TCP_UNACK] = { .type = NLA_U32 },
1370 };
1371 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1372
1373 #ifdef CONFIG_SYSCTL
1374 static struct ctl_table tcp_sysctl_table[] = {
1375 {
1376 .procname = "nf_conntrack_tcp_timeout_syn_sent",
1377 .maxlen = sizeof(unsigned int),
1378 .mode = 0644,
1379 .proc_handler = proc_dointvec_jiffies,
1380 },
1381 {
1382 .procname = "nf_conntrack_tcp_timeout_syn_recv",
1383 .maxlen = sizeof(unsigned int),
1384 .mode = 0644,
1385 .proc_handler = proc_dointvec_jiffies,
1386 },
1387 {
1388 .procname = "nf_conntrack_tcp_timeout_established",
1389 .maxlen = sizeof(unsigned int),
1390 .mode = 0644,
1391 .proc_handler = proc_dointvec_jiffies,
1392 },
1393 {
1394 .procname = "nf_conntrack_tcp_timeout_fin_wait",
1395 .maxlen = sizeof(unsigned int),
1396 .mode = 0644,
1397 .proc_handler = proc_dointvec_jiffies,
1398 },
1399 {
1400 .procname = "nf_conntrack_tcp_timeout_close_wait",
1401 .maxlen = sizeof(unsigned int),
1402 .mode = 0644,
1403 .proc_handler = proc_dointvec_jiffies,
1404 },
1405 {
1406 .procname = "nf_conntrack_tcp_timeout_last_ack",
1407 .maxlen = sizeof(unsigned int),
1408 .mode = 0644,
1409 .proc_handler = proc_dointvec_jiffies,
1410 },
1411 {
1412 .procname = "nf_conntrack_tcp_timeout_time_wait",
1413 .maxlen = sizeof(unsigned int),
1414 .mode = 0644,
1415 .proc_handler = proc_dointvec_jiffies,
1416 },
1417 {
1418 .procname = "nf_conntrack_tcp_timeout_close",
1419 .maxlen = sizeof(unsigned int),
1420 .mode = 0644,
1421 .proc_handler = proc_dointvec_jiffies,
1422 },
1423 {
1424 .procname = "nf_conntrack_tcp_timeout_max_retrans",
1425 .maxlen = sizeof(unsigned int),
1426 .mode = 0644,
1427 .proc_handler = proc_dointvec_jiffies,
1428 },
1429 {
1430 .procname = "nf_conntrack_tcp_timeout_unacknowledged",
1431 .maxlen = sizeof(unsigned int),
1432 .mode = 0644,
1433 .proc_handler = proc_dointvec_jiffies,
1434 },
1435 {
1436 .procname = "nf_conntrack_tcp_loose",
1437 .maxlen = sizeof(unsigned int),
1438 .mode = 0644,
1439 .proc_handler = proc_dointvec,
1440 },
1441 {
1442 .procname = "nf_conntrack_tcp_be_liberal",
1443 .maxlen = sizeof(unsigned int),
1444 .mode = 0644,
1445 .proc_handler = proc_dointvec,
1446 },
1447 {
1448 .procname = "nf_conntrack_tcp_max_retrans",
1449 .maxlen = sizeof(unsigned int),
1450 .mode = 0644,
1451 .proc_handler = proc_dointvec,
1452 },
1453 { }
1454 };
1455
1456 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1457 static struct ctl_table tcp_compat_sysctl_table[] = {
1458 {
1459 .procname = "ip_conntrack_tcp_timeout_syn_sent",
1460 .maxlen = sizeof(unsigned int),
1461 .mode = 0644,
1462 .proc_handler = proc_dointvec_jiffies,
1463 },
1464 {
1465 .procname = "ip_conntrack_tcp_timeout_syn_sent2",
1466 .maxlen = sizeof(unsigned int),
1467 .mode = 0644,
1468 .proc_handler = proc_dointvec_jiffies,
1469 },
1470 {
1471 .procname = "ip_conntrack_tcp_timeout_syn_recv",
1472 .maxlen = sizeof(unsigned int),
1473 .mode = 0644,
1474 .proc_handler = proc_dointvec_jiffies,
1475 },
1476 {
1477 .procname = "ip_conntrack_tcp_timeout_established",
1478 .maxlen = sizeof(unsigned int),
1479 .mode = 0644,
1480 .proc_handler = proc_dointvec_jiffies,
1481 },
1482 {
1483 .procname = "ip_conntrack_tcp_timeout_fin_wait",
1484 .maxlen = sizeof(unsigned int),
1485 .mode = 0644,
1486 .proc_handler = proc_dointvec_jiffies,
1487 },
1488 {
1489 .procname = "ip_conntrack_tcp_timeout_close_wait",
1490 .maxlen = sizeof(unsigned int),
1491 .mode = 0644,
1492 .proc_handler = proc_dointvec_jiffies,
1493 },
1494 {
1495 .procname = "ip_conntrack_tcp_timeout_last_ack",
1496 .maxlen = sizeof(unsigned int),
1497 .mode = 0644,
1498 .proc_handler = proc_dointvec_jiffies,
1499 },
1500 {
1501 .procname = "ip_conntrack_tcp_timeout_time_wait",
1502 .maxlen = sizeof(unsigned int),
1503 .mode = 0644,
1504 .proc_handler = proc_dointvec_jiffies,
1505 },
1506 {
1507 .procname = "ip_conntrack_tcp_timeout_close",
1508 .maxlen = sizeof(unsigned int),
1509 .mode = 0644,
1510 .proc_handler = proc_dointvec_jiffies,
1511 },
1512 {
1513 .procname = "ip_conntrack_tcp_timeout_max_retrans",
1514 .maxlen = sizeof(unsigned int),
1515 .mode = 0644,
1516 .proc_handler = proc_dointvec_jiffies,
1517 },
1518 {
1519 .procname = "ip_conntrack_tcp_loose",
1520 .maxlen = sizeof(unsigned int),
1521 .mode = 0644,
1522 .proc_handler = proc_dointvec,
1523 },
1524 {
1525 .procname = "ip_conntrack_tcp_be_liberal",
1526 .maxlen = sizeof(unsigned int),
1527 .mode = 0644,
1528 .proc_handler = proc_dointvec,
1529 },
1530 {
1531 .procname = "ip_conntrack_tcp_max_retrans",
1532 .maxlen = sizeof(unsigned int),
1533 .mode = 0644,
1534 .proc_handler = proc_dointvec,
1535 },
1536 { }
1537 };
1538 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
1539 #endif /* CONFIG_SYSCTL */
1540
1541 static int tcp_kmemdup_sysctl_table(struct nf_proto_net *pn,
1542 struct nf_tcp_net *tn)
1543 {
1544 #ifdef CONFIG_SYSCTL
1545 if (pn->ctl_table)
1546 return 0;
1547
1548 pn->ctl_table = kmemdup(tcp_sysctl_table,
1549 sizeof(tcp_sysctl_table),
1550 GFP_KERNEL);
1551 if (!pn->ctl_table)
1552 return -ENOMEM;
1553
1554 pn->ctl_table[0].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT];
1555 pn->ctl_table[1].data = &tn->timeouts[TCP_CONNTRACK_SYN_RECV];
1556 pn->ctl_table[2].data = &tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
1557 pn->ctl_table[3].data = &tn->timeouts[TCP_CONNTRACK_FIN_WAIT];
1558 pn->ctl_table[4].data = &tn->timeouts[TCP_CONNTRACK_CLOSE_WAIT];
1559 pn->ctl_table[5].data = &tn->timeouts[TCP_CONNTRACK_LAST_ACK];
1560 pn->ctl_table[6].data = &tn->timeouts[TCP_CONNTRACK_TIME_WAIT];
1561 pn->ctl_table[7].data = &tn->timeouts[TCP_CONNTRACK_CLOSE];
1562 pn->ctl_table[8].data = &tn->timeouts[TCP_CONNTRACK_RETRANS];
1563 pn->ctl_table[9].data = &tn->timeouts[TCP_CONNTRACK_UNACK];
1564 pn->ctl_table[10].data = &tn->tcp_loose;
1565 pn->ctl_table[11].data = &tn->tcp_be_liberal;
1566 pn->ctl_table[12].data = &tn->tcp_max_retrans;
1567 #endif
1568 return 0;
1569 }
1570
1571 static int tcp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
1572 struct nf_tcp_net *tn)
1573 {
1574 #ifdef CONFIG_SYSCTL
1575 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1576 pn->ctl_compat_table = kmemdup(tcp_compat_sysctl_table,
1577 sizeof(tcp_compat_sysctl_table),
1578 GFP_KERNEL);
1579 if (!pn->ctl_compat_table)
1580 return -ENOMEM;
1581
1582 pn->ctl_compat_table[0].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT];
1583 pn->ctl_compat_table[1].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT2];
1584 pn->ctl_compat_table[2].data = &tn->timeouts[TCP_CONNTRACK_SYN_RECV];
1585 pn->ctl_compat_table[3].data = &tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
1586 pn->ctl_compat_table[4].data = &tn->timeouts[TCP_CONNTRACK_FIN_WAIT];
1587 pn->ctl_compat_table[5].data = &tn->timeouts[TCP_CONNTRACK_CLOSE_WAIT];
1588 pn->ctl_compat_table[6].data = &tn->timeouts[TCP_CONNTRACK_LAST_ACK];
1589 pn->ctl_compat_table[7].data = &tn->timeouts[TCP_CONNTRACK_TIME_WAIT];
1590 pn->ctl_compat_table[8].data = &tn->timeouts[TCP_CONNTRACK_CLOSE];
1591 pn->ctl_compat_table[9].data = &tn->timeouts[TCP_CONNTRACK_RETRANS];
1592 pn->ctl_compat_table[10].data = &tn->tcp_loose;
1593 pn->ctl_compat_table[11].data = &tn->tcp_be_liberal;
1594 pn->ctl_compat_table[12].data = &tn->tcp_max_retrans;
1595 #endif
1596 #endif
1597 return 0;
1598 }
1599
1600 static int tcp_init_net(struct net *net, u_int16_t proto)
1601 {
1602 int ret;
1603 struct nf_tcp_net *tn = tcp_pernet(net);
1604 struct nf_proto_net *pn = &tn->pn;
1605
1606 if (!pn->users) {
1607 int i;
1608
1609 for (i = 0; i < TCP_CONNTRACK_TIMEOUT_MAX; i++)
1610 tn->timeouts[i] = tcp_timeouts[i];
1611
1612 tn->tcp_loose = nf_ct_tcp_loose;
1613 tn->tcp_be_liberal = nf_ct_tcp_be_liberal;
1614 tn->tcp_max_retrans = nf_ct_tcp_max_retrans;
1615 }
1616
1617 if (proto == AF_INET) {
1618 ret = tcp_kmemdup_compat_sysctl_table(pn, tn);
1619 if (ret < 0)
1620 return ret;
1621
1622 ret = tcp_kmemdup_sysctl_table(pn, tn);
1623 if (ret < 0)
1624 nf_ct_kfree_compat_sysctl_table(pn);
1625 } else
1626 ret = tcp_kmemdup_sysctl_table(pn, tn);
1627
1628 return ret;
1629 }
1630
1631 static struct nf_proto_net *tcp_get_net_proto(struct net *net)
1632 {
1633 return &net->ct.nf_ct_proto.tcp.pn;
1634 }
1635
1636 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
1637 {
1638 .l3proto = PF_INET,
1639 .l4proto = IPPROTO_TCP,
1640 .name = "tcp",
1641 .pkt_to_tuple = tcp_pkt_to_tuple,
1642 .invert_tuple = tcp_invert_tuple,
1643 .print_tuple = tcp_print_tuple,
1644 .print_conntrack = tcp_print_conntrack,
1645 .packet = tcp_packet,
1646 .get_timeouts = tcp_get_timeouts,
1647 .new = tcp_new,
1648 .error = tcp_error,
1649 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1650 .to_nlattr = tcp_to_nlattr,
1651 .nlattr_size = tcp_nlattr_size,
1652 .from_nlattr = nlattr_to_tcp,
1653 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1654 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1655 .nlattr_tuple_size = tcp_nlattr_tuple_size,
1656 .nla_policy = nf_ct_port_nla_policy,
1657 #endif
1658 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1659 .ctnl_timeout = {
1660 .nlattr_to_obj = tcp_timeout_nlattr_to_obj,
1661 .obj_to_nlattr = tcp_timeout_obj_to_nlattr,
1662 .nlattr_max = CTA_TIMEOUT_TCP_MAX,
1663 .obj_size = sizeof(unsigned int) *
1664 TCP_CONNTRACK_TIMEOUT_MAX,
1665 .nla_policy = tcp_timeout_nla_policy,
1666 },
1667 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1668 .init_net = tcp_init_net,
1669 .get_net_proto = tcp_get_net_proto,
1670 };
1671 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
1672
1673 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly =
1674 {
1675 .l3proto = PF_INET6,
1676 .l4proto = IPPROTO_TCP,
1677 .name = "tcp",
1678 .pkt_to_tuple = tcp_pkt_to_tuple,
1679 .invert_tuple = tcp_invert_tuple,
1680 .print_tuple = tcp_print_tuple,
1681 .print_conntrack = tcp_print_conntrack,
1682 .packet = tcp_packet,
1683 .get_timeouts = tcp_get_timeouts,
1684 .new = tcp_new,
1685 .error = tcp_error,
1686 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1687 .to_nlattr = tcp_to_nlattr,
1688 .nlattr_size = tcp_nlattr_size,
1689 .from_nlattr = nlattr_to_tcp,
1690 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1691 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1692 .nlattr_tuple_size = tcp_nlattr_tuple_size,
1693 .nla_policy = nf_ct_port_nla_policy,
1694 #endif
1695 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1696 .ctnl_timeout = {
1697 .nlattr_to_obj = tcp_timeout_nlattr_to_obj,
1698 .obj_to_nlattr = tcp_timeout_obj_to_nlattr,
1699 .nlattr_max = CTA_TIMEOUT_TCP_MAX,
1700 .obj_size = sizeof(unsigned int) *
1701 TCP_CONNTRACK_TIMEOUT_MAX,
1702 .nla_policy = tcp_timeout_nla_policy,
1703 },
1704 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1705 .init_net = tcp_init_net,
1706 .get_net_proto = tcp_get_net_proto,
1707 };
1708 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);
Linux kernel - Deliverables
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