?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
net: qcom/emac: enforce DMA address restrictions
[linux-2.6/btrfs-unstable.git] / net / netfilter / nf_conntrack_proto_tcp.c
blobcba1c6ffe51aff7bbdf3ef0ee0cff350881dbf7a
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_conntrack_seqadj.h>
31 #include <net/netfilter/nf_conntrack_synproxy.h>
32 #include <net/netfilter/nf_log.h>
33 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
34 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
35
36 /* "Be conservative in what you do,
37 be liberal in what you accept from others."
38 If it's non-zero, we mark only out of window RST segments as INVALID. */
39 static int nf_ct_tcp_be_liberal __read_mostly = 0;
40
41 /* If it is set to zero, we disable picking up already established
42 connections. */
43 static int nf_ct_tcp_loose __read_mostly = 1;
44
45 /* Max number of the retransmitted packets without receiving an (acceptable)
46 ACK from the destination. If this number is reached, a shorter timer
47 will be started. */
48 static int nf_ct_tcp_max_retrans __read_mostly = 3;
49
50 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
51 closely. They're more complex. --RR */
52
53 static const char *const tcp_conntrack_names[] = {
54 "NONE",
55 "SYN_SENT",
56 "SYN_RECV",
57 "ESTABLISHED",
58 "FIN_WAIT",
59 "CLOSE_WAIT",
60 "LAST_ACK",
61 "TIME_WAIT",
62 "CLOSE",
63 "SYN_SENT2",
64 };
65
66 #define SECS * HZ
67 #define MINS * 60 SECS
68 #define HOURS * 60 MINS
69 #define DAYS * 24 HOURS
70
71 static unsigned int tcp_timeouts[TCP_CONNTRACK_TIMEOUT_MAX] __read_mostly = {
72 [TCP_CONNTRACK_SYN_SENT] = 2 MINS,
73 [TCP_CONNTRACK_SYN_RECV] = 60 SECS,
74 [TCP_CONNTRACK_ESTABLISHED] = 5 DAYS,
75 [TCP_CONNTRACK_FIN_WAIT] = 2 MINS,
76 [TCP_CONNTRACK_CLOSE_WAIT] = 60 SECS,
77 [TCP_CONNTRACK_LAST_ACK] = 30 SECS,
78 [TCP_CONNTRACK_TIME_WAIT] = 2 MINS,
79 [TCP_CONNTRACK_CLOSE] = 10 SECS,
80 [TCP_CONNTRACK_SYN_SENT2] = 2 MINS,
81 /* RFC1122 says the R2 limit should be at least 100 seconds.
82 Linux uses 15 packets as limit, which corresponds
83 to ~13-30min depending on RTO. */
84 [TCP_CONNTRACK_RETRANS] = 5 MINS,
85 [TCP_CONNTRACK_UNACK] = 5 MINS,
86 };
87
88 #define sNO TCP_CONNTRACK_NONE
89 #define sSS TCP_CONNTRACK_SYN_SENT
90 #define sSR TCP_CONNTRACK_SYN_RECV
91 #define sES TCP_CONNTRACK_ESTABLISHED
92 #define sFW TCP_CONNTRACK_FIN_WAIT
93 #define sCW TCP_CONNTRACK_CLOSE_WAIT
94 #define sLA TCP_CONNTRACK_LAST_ACK
95 #define sTW TCP_CONNTRACK_TIME_WAIT
96 #define sCL TCP_CONNTRACK_CLOSE
97 #define sS2 TCP_CONNTRACK_SYN_SENT2
98 #define sIV TCP_CONNTRACK_MAX
99 #define sIG TCP_CONNTRACK_IGNORE
100
101 /* What TCP flags are set from RST/SYN/FIN/ACK. */
102 enum tcp_bit_set {
103 TCP_SYN_SET,
104 TCP_SYNACK_SET,
105 TCP_FIN_SET,
106 TCP_ACK_SET,
107 TCP_RST_SET,
108 TCP_NONE_SET,
109 };
110
111 /*
112 * The TCP state transition table needs a few words...
113 *
114 * We are the man in the middle. All the packets go through us
115 * but might get lost in transit to the destination.
116 * It is assumed that the destinations can't receive segments
117 * we haven't seen.
118 *
119 * The checked segment is in window, but our windows are *not*
120 * equivalent with the ones of the sender/receiver. We always
121 * try to guess the state of the current sender.
122 *
123 * The meaning of the states are:
124 *
125 * NONE: initial state
126 * SYN_SENT: SYN-only packet seen
127 * SYN_SENT2: SYN-only packet seen from reply dir, simultaneous open
128 * SYN_RECV: SYN-ACK packet seen
129 * ESTABLISHED: ACK packet seen
130 * FIN_WAIT: FIN packet seen
131 * CLOSE_WAIT: ACK seen (after FIN)
132 * LAST_ACK: FIN seen (after FIN)
133 * TIME_WAIT: last ACK seen
134 * CLOSE: closed connection (RST)
135 *
136 * Packets marked as IGNORED (sIG):
137 * if they may be either invalid or valid
138 * and the receiver may send back a connection
139 * closing RST or a SYN/ACK.
140 *
141 * Packets marked as INVALID (sIV):
142 * if we regard them as truly invalid packets
143 */
144 static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
145 {
146 /* ORIGINAL */
147 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
148 /*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sS2 },
149 /*
150 * sNO -> sSS Initialize a new connection
151 * sSS -> sSS Retransmitted SYN
152 * sS2 -> sS2 Late retransmitted SYN
153 * sSR -> sIG
154 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
155 * are errors. Receiver will reply with RST
156 * and close the connection.
157 * Or we are not in sync and hold a dead connection.
158 * sFW -> sIG
159 * sCW -> sIG
160 * sLA -> sIG
161 * sTW -> sSS Reopened connection (RFC 1122).
162 * sCL -> sSS
163 */
164 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
165 /*synack*/ { sIV, sIV, sSR, sIV, sIV, sIV, sIV, sIV, sIV, sSR },
166 /*
167 * sNO -> sIV Too late and no reason to do anything
168 * sSS -> sIV Client can't send SYN and then SYN/ACK
169 * sS2 -> sSR SYN/ACK sent to SYN2 in simultaneous open
170 * sSR -> sSR Late retransmitted SYN/ACK in simultaneous open
171 * sES -> sIV Invalid SYN/ACK packets sent by the client
172 * sFW -> sIV
173 * sCW -> sIV
174 * sLA -> sIV
175 * sTW -> sIV
176 * sCL -> sIV
177 */
178 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
179 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
180 /*
181 * sNO -> sIV Too late and no reason to do anything...
182 * sSS -> sIV Client migth not send FIN in this state:
183 * we enforce waiting for a SYN/ACK reply first.
184 * sS2 -> sIV
185 * sSR -> sFW Close started.
186 * sES -> sFW
187 * sFW -> sLA FIN seen in both directions, waiting for
188 * the last ACK.
189 * Migth be a retransmitted FIN as well...
190 * sCW -> sLA
191 * sLA -> sLA Retransmitted FIN. Remain in the same state.
192 * sTW -> sTW
193 * sCL -> sCL
194 */
195 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
196 /*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
197 /*
198 * sNO -> sES Assumed.
199 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
200 * sS2 -> sIV
201 * sSR -> sES Established state is reached.
202 * sES -> sES :-)
203 * sFW -> sCW Normal close request answered by ACK.
204 * sCW -> sCW
205 * sLA -> sTW Last ACK detected (RFC5961 challenged)
206 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
207 * sCL -> sCL
208 */
209 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
210 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
211 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
212 },
213 {
214 /* REPLY */
215 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
216 /*syn*/ { sIV, sS2, sIV, sIV, sIV, sIV, sIV, sSS, sIV, sS2 },
217 /*
218 * sNO -> sIV Never reached.
219 * sSS -> sS2 Simultaneous open
220 * sS2 -> sS2 Retransmitted simultaneous SYN
221 * sSR -> sIV Invalid SYN packets sent by the server
222 * sES -> sIV
223 * sFW -> sIV
224 * sCW -> sIV
225 * sLA -> sIV
226 * sTW -> sSS Reopened connection, but server may have switched role
227 * sCL -> sIV
228 */
229 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
230 /*synack*/ { sIV, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIG, sSR },
231 /*
232 * sSS -> sSR Standard open.
233 * sS2 -> sSR Simultaneous open
234 * sSR -> sIG Retransmitted SYN/ACK, ignore it.
235 * sES -> sIG Late retransmitted SYN/ACK?
236 * sFW -> sIG Might be SYN/ACK answering ignored SYN
237 * sCW -> sIG
238 * sLA -> sIG
239 * sTW -> sIG
240 * sCL -> sIG
241 */
242 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
243 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
244 /*
245 * sSS -> sIV Server might not send FIN in this state.
246 * sS2 -> sIV
247 * sSR -> sFW Close started.
248 * sES -> sFW
249 * sFW -> sLA FIN seen in both directions.
250 * sCW -> sLA
251 * sLA -> sLA Retransmitted FIN.
252 * sTW -> sTW
253 * sCL -> sCL
254 */
255 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
256 /*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIG },
257 /*
258 * sSS -> sIG Might be a half-open connection.
259 * sS2 -> sIG
260 * sSR -> sSR Might answer late resent SYN.
261 * sES -> sES :-)
262 * sFW -> sCW Normal close request answered by ACK.
263 * sCW -> sCW
264 * sLA -> sTW Last ACK detected (RFC5961 challenged)
265 * sTW -> sTW Retransmitted last ACK.
266 * sCL -> sCL
267 */
268 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
269 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
270 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
271 }
272 };
273
274 static inline struct nf_tcp_net *tcp_pernet(struct net *net)
275 {
276 return &net->ct.nf_ct_proto.tcp;
277 }
278
279 static bool tcp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
280 struct net *net, struct nf_conntrack_tuple *tuple)
281 {
282 const struct tcphdr *hp;
283 struct tcphdr _hdr;
284
285 /* Actually only need first 4 bytes to get ports. */
286 hp = skb_header_pointer(skb, dataoff, 4, &_hdr);
287 if (hp == NULL)
288 return false;
289
290 tuple->src.u.tcp.port = hp->source;
291 tuple->dst.u.tcp.port = hp->dest;
292
293 return true;
294 }
295
296 static bool tcp_invert_tuple(struct nf_conntrack_tuple *tuple,
297 const struct nf_conntrack_tuple *orig)
298 {
299 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
300 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
301 return true;
302 }
303
304 #ifdef CONFIG_NF_CONNTRACK_PROCFS
305 /* Print out the private part of the conntrack. */
306 static void tcp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
307 {
308 seq_printf(s, "%s ", tcp_conntrack_names[ct->proto.tcp.state]);
309 }
310 #endif
311
312 static unsigned int get_conntrack_index(const struct tcphdr *tcph)
313 {
314 if (tcph->rst) return TCP_RST_SET;
315 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
316 else if (tcph->fin) return TCP_FIN_SET;
317 else if (tcph->ack) return TCP_ACK_SET;
318 else return TCP_NONE_SET;
319 }
320
321 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
322 in IP Filter' by Guido van Rooij.
323
324 http://www.sane.nl/events/sane2000/papers.html
325 http://www.darkart.com/mirrors/www.obfuscation.org/ipf/
326
327 The boundaries and the conditions are changed according to RFC793:
328 the packet must intersect the window (i.e. segments may be
329 after the right or before the left edge) and thus receivers may ACK
330 segments after the right edge of the window.
331
332 td_maxend = max(sack + max(win,1)) seen in reply packets
333 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
334 td_maxwin += seq + len - sender.td_maxend
335 if seq + len > sender.td_maxend
336 td_end = max(seq + len) seen in sent packets
337
338 I. Upper bound for valid data: seq <= sender.td_maxend
339 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
340 III. Upper bound for valid (s)ack: sack <= receiver.td_end
341 IV. Lower bound for valid (s)ack: sack >= receiver.td_end - MAXACKWINDOW
342
343 where sack is the highest right edge of sack block found in the packet
344 or ack in the case of packet without SACK option.
345
346 The upper bound limit for a valid (s)ack is not ignored -
347 we doesn't have to deal with fragments.
348 */
349
350 static inline __u32 segment_seq_plus_len(__u32 seq,
351 size_t len,
352 unsigned int dataoff,
353 const struct tcphdr *tcph)
354 {
355 /* XXX Should I use payload length field in IP/IPv6 header ?
356 * - YK */
357 return (seq + len - dataoff - tcph->doff*4
358 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
359 }
360
361 /* Fixme: what about big packets? */
362 #define MAXACKWINCONST 66000
363 #define MAXACKWINDOW(sender) \
364 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
365 : MAXACKWINCONST)
366
367 /*
368 * Simplified tcp_parse_options routine from tcp_input.c
369 */
370 static void tcp_options(const struct sk_buff *skb,
371 unsigned int dataoff,
372 const struct tcphdr *tcph,
373 struct ip_ct_tcp_state *state)
374 {
375 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
376 const unsigned char *ptr;
377 int length = (tcph->doff*4) - sizeof(struct tcphdr);
378
379 if (!length)
380 return;
381
382 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
383 length, buff);
384 BUG_ON(ptr == NULL);
385
386 state->td_scale =
387 state->flags = 0;
388
389 while (length > 0) {
390 int opcode=*ptr++;
391 int opsize;
392
393 switch (opcode) {
394 case TCPOPT_EOL:
395 return;
396 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
397 length--;
398 continue;
399 default:
400 if (length < 2)
401 return;
402 opsize=*ptr++;
403 if (opsize < 2) /* "silly options" */
404 return;
405 if (opsize > length)
406 return; /* don't parse partial options */
407
408 if (opcode == TCPOPT_SACK_PERM
409 && opsize == TCPOLEN_SACK_PERM)
410 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
411 else if (opcode == TCPOPT_WINDOW
412 && opsize == TCPOLEN_WINDOW) {
413 state->td_scale = *(u_int8_t *)ptr;
414
415 if (state->td_scale > TCP_MAX_WSCALE)
416 state->td_scale = TCP_MAX_WSCALE;
417
418 state->flags |=
419 IP_CT_TCP_FLAG_WINDOW_SCALE;
420 }
421 ptr += opsize - 2;
422 length -= opsize;
423 }
424 }
425 }
426
427 static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
428 const struct tcphdr *tcph, __u32 *sack)
429 {
430 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
431 const unsigned char *ptr;
432 int length = (tcph->doff*4) - sizeof(struct tcphdr);
433 __u32 tmp;
434
435 if (!length)
436 return;
437
438 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
439 length, buff);
440 BUG_ON(ptr == NULL);
441
442 /* Fast path for timestamp-only option */
443 if (length == TCPOLEN_TSTAMP_ALIGNED
444 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24)
445 | (TCPOPT_NOP << 16)
446 | (TCPOPT_TIMESTAMP << 8)
447 | TCPOLEN_TIMESTAMP))
448 return;
449
450 while (length > 0) {
451 int opcode = *ptr++;
452 int opsize, i;
453
454 switch (opcode) {
455 case TCPOPT_EOL:
456 return;
457 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
458 length--;
459 continue;
460 default:
461 if (length < 2)
462 return;
463 opsize = *ptr++;
464 if (opsize < 2) /* "silly options" */
465 return;
466 if (opsize > length)
467 return; /* don't parse partial options */
468
469 if (opcode == TCPOPT_SACK
470 && opsize >= (TCPOLEN_SACK_BASE
471 + TCPOLEN_SACK_PERBLOCK)
472 && !((opsize - TCPOLEN_SACK_BASE)
473 % TCPOLEN_SACK_PERBLOCK)) {
474 for (i = 0;
475 i < (opsize - TCPOLEN_SACK_BASE);
476 i += TCPOLEN_SACK_PERBLOCK) {
477 tmp = get_unaligned_be32((__be32 *)(ptr+i)+1);
478
479 if (after(tmp, *sack))
480 *sack = tmp;
481 }
482 return;
483 }
484 ptr += opsize - 2;
485 length -= opsize;
486 }
487 }
488 }
489
490 static bool tcp_in_window(const struct nf_conn *ct,
491 struct ip_ct_tcp *state,
492 enum ip_conntrack_dir dir,
493 unsigned int index,
494 const struct sk_buff *skb,
495 unsigned int dataoff,
496 const struct tcphdr *tcph,
497 u_int8_t pf)
498 {
499 struct net *net = nf_ct_net(ct);
500 struct nf_tcp_net *tn = tcp_pernet(net);
501 struct ip_ct_tcp_state *sender = &state->seen[dir];
502 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
503 const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
504 __u32 seq, ack, sack, end, win, swin;
505 s32 receiver_offset;
506 bool res, in_recv_win;
507
508 /*
509 * Get the required data from the packet.
510 */
511 seq = ntohl(tcph->seq);
512 ack = sack = ntohl(tcph->ack_seq);
513 win = ntohs(tcph->window);
514 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph);
515
516 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
517 tcp_sack(skb, dataoff, tcph, &sack);
518
519 /* Take into account NAT sequence number mangling */
520 receiver_offset = nf_ct_seq_offset(ct, !dir, ack - 1);
521 ack -= receiver_offset;
522 sack -= receiver_offset;
523
524 pr_debug("tcp_in_window: START\n");
525 pr_debug("tcp_in_window: ");
526 nf_ct_dump_tuple(tuple);
527 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
528 seq, ack, receiver_offset, sack, receiver_offset, win, end);
529 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
530 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
531 sender->td_end, sender->td_maxend, sender->td_maxwin,
532 sender->td_scale,
533 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
534 receiver->td_scale);
535
536 if (sender->td_maxwin == 0) {
537 /*
538 * Initialize sender data.
539 */
540 if (tcph->syn) {
541 /*
542 * SYN-ACK in reply to a SYN
543 * or SYN from reply direction in simultaneous open.
544 */
545 sender->td_end =
546 sender->td_maxend = end;
547 sender->td_maxwin = (win == 0 ? 1 : win);
548
549 tcp_options(skb, dataoff, tcph, sender);
550 /*
551 * RFC 1323:
552 * Both sides must send the Window Scale option
553 * to enable window scaling in either direction.
554 */
555 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
556 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
557 sender->td_scale =
558 receiver->td_scale = 0;
559 if (!tcph->ack)
560 /* Simultaneous open */
561 return true;
562 } else {
563 /*
564 * We are in the middle of a connection,
565 * its history is lost for us.
566 * Let's try to use the data from the packet.
567 */
568 sender->td_end = end;
569 swin = win << sender->td_scale;
570 sender->td_maxwin = (swin == 0 ? 1 : swin);
571 sender->td_maxend = end + sender->td_maxwin;
572 /*
573 * We haven't seen traffic in the other direction yet
574 * but we have to tweak window tracking to pass III
575 * and IV until that happens.
576 */
577 if (receiver->td_maxwin == 0)
578 receiver->td_end = receiver->td_maxend = sack;
579 }
580 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
581 && dir == IP_CT_DIR_ORIGINAL)
582 || (state->state == TCP_CONNTRACK_SYN_RECV
583 && dir == IP_CT_DIR_REPLY))
584 && after(end, sender->td_end)) {
585 /*
586 * RFC 793: "if a TCP is reinitialized ... then it need
587 * not wait at all; it must only be sure to use sequence
588 * numbers larger than those recently used."
589 */
590 sender->td_end =
591 sender->td_maxend = end;
592 sender->td_maxwin = (win == 0 ? 1 : win);
593
594 tcp_options(skb, dataoff, tcph, sender);
595 }
596
597 if (!(tcph->ack)) {
598 /*
599 * If there is no ACK, just pretend it was set and OK.
600 */
601 ack = sack = receiver->td_end;
602 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
603 (TCP_FLAG_ACK|TCP_FLAG_RST))
604 && (ack == 0)) {
605 /*
606 * Broken TCP stacks, that set ACK in RST packets as well
607 * with zero ack value.
608 */
609 ack = sack = receiver->td_end;
610 }
611
612 if (tcph->rst && seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)
613 /*
614 * RST sent answering SYN.
615 */
616 seq = end = sender->td_end;
617
618 pr_debug("tcp_in_window: ");
619 nf_ct_dump_tuple(tuple);
620 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
621 seq, ack, receiver_offset, sack, receiver_offset, win, end);
622 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
623 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
624 sender->td_end, sender->td_maxend, sender->td_maxwin,
625 sender->td_scale,
626 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
627 receiver->td_scale);
628
629 /* Is the ending sequence in the receive window (if available)? */
630 in_recv_win = !receiver->td_maxwin ||
631 after(end, sender->td_end - receiver->td_maxwin - 1);
632
633 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
634 before(seq, sender->td_maxend + 1),
635 (in_recv_win ? 1 : 0),
636 before(sack, receiver->td_end + 1),
637 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1));
638
639 if (before(seq, sender->td_maxend + 1) &&
640 in_recv_win &&
641 before(sack, receiver->td_end + 1) &&
642 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)) {
643 /*
644 * Take into account window scaling (RFC 1323).
645 */
646 if (!tcph->syn)
647 win <<= sender->td_scale;
648
649 /*
650 * Update sender data.
651 */
652 swin = win + (sack - ack);
653 if (sender->td_maxwin < swin)
654 sender->td_maxwin = swin;
655 if (after(end, sender->td_end)) {
656 sender->td_end = end;
657 sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
658 }
659 if (tcph->ack) {
660 if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) {
661 sender->td_maxack = ack;
662 sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET;
663 } else if (after(ack, sender->td_maxack))
664 sender->td_maxack = ack;
665 }
666
667 /*
668 * Update receiver data.
669 */
670 if (receiver->td_maxwin != 0 && after(end, sender->td_maxend))
671 receiver->td_maxwin += end - sender->td_maxend;
672 if (after(sack + win, receiver->td_maxend - 1)) {
673 receiver->td_maxend = sack + win;
674 if (win == 0)
675 receiver->td_maxend++;
676 }
677 if (ack == receiver->td_end)
678 receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
679
680 /*
681 * Check retransmissions.
682 */
683 if (index == TCP_ACK_SET) {
684 if (state->last_dir == dir
685 && state->last_seq == seq
686 && state->last_ack == ack
687 && state->last_end == end
688 && state->last_win == win)
689 state->retrans++;
690 else {
691 state->last_dir = dir;
692 state->last_seq = seq;
693 state->last_ack = ack;
694 state->last_end = end;
695 state->last_win = win;
696 state->retrans = 0;
697 }
698 }
699 res = true;
700 } else {
701 res = false;
702 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
703 tn->tcp_be_liberal)
704 res = true;
705 if (!res && LOG_INVALID(net, IPPROTO_TCP))
706 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
707 "nf_ct_tcp: %s ",
708 before(seq, sender->td_maxend + 1) ?
709 in_recv_win ?
710 before(sack, receiver->td_end + 1) ?
711 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1) ? "BUG"
712 : "ACK is under the lower bound (possible overly delayed ACK)"
713 : "ACK is over the upper bound (ACKed data not seen yet)"
714 : "SEQ is under the lower bound (already ACKed data retransmitted)"
715 : "SEQ is over the upper bound (over the window of the receiver)");
716 }
717
718 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u "
719 "receiver end=%u maxend=%u maxwin=%u\n",
720 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
721 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
722
723 return res;
724 }
725
726 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
727 static const u8 tcp_valid_flags[(TCPHDR_FIN|TCPHDR_SYN|TCPHDR_RST|TCPHDR_ACK|
728 TCPHDR_URG) + 1] =
729 {
730 [TCPHDR_SYN] = 1,
731 [TCPHDR_SYN|TCPHDR_URG] = 1,
732 [TCPHDR_SYN|TCPHDR_ACK] = 1,
733 [TCPHDR_RST] = 1,
734 [TCPHDR_RST|TCPHDR_ACK] = 1,
735 [TCPHDR_FIN|TCPHDR_ACK] = 1,
736 [TCPHDR_FIN|TCPHDR_ACK|TCPHDR_URG] = 1,
737 [TCPHDR_ACK] = 1,
738 [TCPHDR_ACK|TCPHDR_URG] = 1,
739 };
740
741 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
742 static int tcp_error(struct net *net, struct nf_conn *tmpl,
743 struct sk_buff *skb,
744 unsigned int dataoff,
745 u_int8_t pf,
746 unsigned int hooknum)
747 {
748 const struct tcphdr *th;
749 struct tcphdr _tcph;
750 unsigned int tcplen = skb->len - dataoff;
751 u_int8_t tcpflags;
752
753 /* Smaller that minimal TCP header? */
754 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
755 if (th == NULL) {
756 if (LOG_INVALID(net, IPPROTO_TCP))
757 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
758 "nf_ct_tcp: short packet ");
759 return -NF_ACCEPT;
760 }
761
762 /* Not whole TCP header or malformed packet */
763 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
764 if (LOG_INVALID(net, IPPROTO_TCP))
765 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
766 "nf_ct_tcp: truncated/malformed packet ");
767 return -NF_ACCEPT;
768 }
769
770 /* Checksum invalid? Ignore.
771 * We skip checking packets on the outgoing path
772 * because the checksum is assumed to be correct.
773 */
774 /* FIXME: Source route IP option packets --RR */
775 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
776 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
777 if (LOG_INVALID(net, IPPROTO_TCP))
778 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
779 "nf_ct_tcp: bad TCP checksum ");
780 return -NF_ACCEPT;
781 }
782
783 /* Check TCP flags. */
784 tcpflags = (tcp_flag_byte(th) & ~(TCPHDR_ECE|TCPHDR_CWR|TCPHDR_PSH));
785 if (!tcp_valid_flags[tcpflags]) {
786 if (LOG_INVALID(net, IPPROTO_TCP))
787 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
788 "nf_ct_tcp: invalid TCP flag combination ");
789 return -NF_ACCEPT;
790 }
791
792 return NF_ACCEPT;
793 }
794
795 static unsigned int *tcp_get_timeouts(struct net *net)
796 {
797 return tcp_pernet(net)->timeouts;
798 }
799
800 /* Returns verdict for packet, or -1 for invalid. */
801 static int tcp_packet(struct nf_conn *ct,
802 const struct sk_buff *skb,
803 unsigned int dataoff,
804 enum ip_conntrack_info ctinfo,
805 u_int8_t pf,
806 unsigned int *timeouts)
807 {
808 struct net *net = nf_ct_net(ct);
809 struct nf_tcp_net *tn = tcp_pernet(net);
810 struct nf_conntrack_tuple *tuple;
811 enum tcp_conntrack new_state, old_state;
812 enum ip_conntrack_dir dir;
813 const struct tcphdr *th;
814 struct tcphdr _tcph;
815 unsigned long timeout;
816 unsigned int index;
817
818 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
819 BUG_ON(th == NULL);
820
821 spin_lock_bh(&ct->lock);
822 old_state = ct->proto.tcp.state;
823 dir = CTINFO2DIR(ctinfo);
824 index = get_conntrack_index(th);
825 new_state = tcp_conntracks[dir][index][old_state];
826 tuple = &ct->tuplehash[dir].tuple;
827
828 switch (new_state) {
829 case TCP_CONNTRACK_SYN_SENT:
830 if (old_state < TCP_CONNTRACK_TIME_WAIT)
831 break;
832 /* RFC 1122: "When a connection is closed actively,
833 * it MUST linger in TIME-WAIT state for a time 2xMSL
834 * (Maximum Segment Lifetime). However, it MAY accept
835 * a new SYN from the remote TCP to reopen the connection
836 * directly from TIME-WAIT state, if..."
837 * We ignore the conditions because we are in the
838 * TIME-WAIT state anyway.
839 *
840 * Handle aborted connections: we and the server
841 * think there is an existing connection but the client
842 * aborts it and starts a new one.
843 */
844 if (((ct->proto.tcp.seen[dir].flags
845 | ct->proto.tcp.seen[!dir].flags)
846 & IP_CT_TCP_FLAG_CLOSE_INIT)
847 || (ct->proto.tcp.last_dir == dir
848 && ct->proto.tcp.last_index == TCP_RST_SET)) {
849 /* Attempt to reopen a closed/aborted connection.
850 * Delete this connection and look up again. */
851 spin_unlock_bh(&ct->lock);
852
853 /* Only repeat if we can actually remove the timer.
854 * Destruction may already be in progress in process
855 * context and we must give it a chance to terminate.
856 */
857 if (nf_ct_kill(ct))
858 return -NF_REPEAT;
859 return NF_DROP;
860 }
861 /* Fall through */
862 case TCP_CONNTRACK_IGNORE:
863 /* Ignored packets:
864 *
865 * Our connection entry may be out of sync, so ignore
866 * packets which may signal the real connection between
867 * the client and the server.
868 *
869 * a) SYN in ORIGINAL
870 * b) SYN/ACK in REPLY
871 * c) ACK in reply direction after initial SYN in original.
872 *
873 * If the ignored packet is invalid, the receiver will send
874 * a RST we'll catch below.
875 */
876 if (index == TCP_SYNACK_SET
877 && ct->proto.tcp.last_index == TCP_SYN_SET
878 && ct->proto.tcp.last_dir != dir
879 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
880 /* b) This SYN/ACK acknowledges a SYN that we earlier
881 * ignored as invalid. This means that the client and
882 * the server are both in sync, while the firewall is
883 * not. We get in sync from the previously annotated
884 * values.
885 */
886 old_state = TCP_CONNTRACK_SYN_SENT;
887 new_state = TCP_CONNTRACK_SYN_RECV;
888 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_end =
889 ct->proto.tcp.last_end;
890 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxend =
891 ct->proto.tcp.last_end;
892 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxwin =
893 ct->proto.tcp.last_win == 0 ?
894 1 : ct->proto.tcp.last_win;
895 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_scale =
896 ct->proto.tcp.last_wscale;
897 ct->proto.tcp.last_flags &= ~IP_CT_EXP_CHALLENGE_ACK;
898 ct->proto.tcp.seen[ct->proto.tcp.last_dir].flags =
899 ct->proto.tcp.last_flags;
900 memset(&ct->proto.tcp.seen[dir], 0,
901 sizeof(struct ip_ct_tcp_state));
902 break;
903 }
904 ct->proto.tcp.last_index = index;
905 ct->proto.tcp.last_dir = dir;
906 ct->proto.tcp.last_seq = ntohl(th->seq);
907 ct->proto.tcp.last_end =
908 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th);
909 ct->proto.tcp.last_win = ntohs(th->window);
910
911 /* a) This is a SYN in ORIGINAL. The client and the server
912 * may be in sync but we are not. In that case, we annotate
913 * the TCP options and let the packet go through. If it is a
914 * valid SYN packet, the server will reply with a SYN/ACK, and
915 * then we'll get in sync. Otherwise, the server potentially
916 * responds with a challenge ACK if implementing RFC5961.
917 */
918 if (index == TCP_SYN_SET && dir == IP_CT_DIR_ORIGINAL) {
919 struct ip_ct_tcp_state seen = {};
920
921 ct->proto.tcp.last_flags =
922 ct->proto.tcp.last_wscale = 0;
923 tcp_options(skb, dataoff, th, &seen);
924 if (seen.flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
925 ct->proto.tcp.last_flags |=
926 IP_CT_TCP_FLAG_WINDOW_SCALE;
927 ct->proto.tcp.last_wscale = seen.td_scale;
928 }
929 if (seen.flags & IP_CT_TCP_FLAG_SACK_PERM) {
930 ct->proto.tcp.last_flags |=
931 IP_CT_TCP_FLAG_SACK_PERM;
932 }
933 /* Mark the potential for RFC5961 challenge ACK,
934 * this pose a special problem for LAST_ACK state
935 * as ACK is intrepretated as ACKing last FIN.
936 */
937 if (old_state == TCP_CONNTRACK_LAST_ACK)
938 ct->proto.tcp.last_flags |=
939 IP_CT_EXP_CHALLENGE_ACK;
940 }
941 spin_unlock_bh(&ct->lock);
942 if (LOG_INVALID(net, IPPROTO_TCP))
943 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
944 "nf_ct_tcp: invalid packet ignored in "
945 "state %s ", tcp_conntrack_names[old_state]);
946 return NF_ACCEPT;
947 case TCP_CONNTRACK_MAX:
948 /* Special case for SYN proxy: when the SYN to the server or
949 * the SYN/ACK from the server is lost, the client may transmit
950 * a keep-alive packet while in SYN_SENT state. This needs to
951 * be associated with the original conntrack entry in order to
952 * generate a new SYN with the correct sequence number.
953 */
954 if (nfct_synproxy(ct) && old_state == TCP_CONNTRACK_SYN_SENT &&
955 index == TCP_ACK_SET && dir == IP_CT_DIR_ORIGINAL &&
956 ct->proto.tcp.last_dir == IP_CT_DIR_ORIGINAL &&
957 ct->proto.tcp.seen[dir].td_end - 1 == ntohl(th->seq)) {
958 pr_debug("nf_ct_tcp: SYN proxy client keep alive\n");
959 spin_unlock_bh(&ct->lock);
960 return NF_ACCEPT;
961 }
962
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_TIME_WAIT:
972 /* RFC5961 compliance cause stack to send "challenge-ACK"
973 * e.g. in response to spurious SYNs. Conntrack MUST
974 * not believe this ACK is acking last FIN.
975 */
976 if (old_state == TCP_CONNTRACK_LAST_ACK &&
977 index == TCP_ACK_SET &&
978 ct->proto.tcp.last_dir != dir &&
979 ct->proto.tcp.last_index == TCP_SYN_SET &&
980 (ct->proto.tcp.last_flags & IP_CT_EXP_CHALLENGE_ACK)) {
981 /* Detected RFC5961 challenge ACK */
982 ct->proto.tcp.last_flags &= ~IP_CT_EXP_CHALLENGE_ACK;
983 spin_unlock_bh(&ct->lock);
984 if (LOG_INVALID(net, IPPROTO_TCP))
985 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL,
986 "nf_ct_tcp: challenge-ACK ignored ");
987 return NF_ACCEPT; /* Don't change state */
988 }
989 break;
990 case TCP_CONNTRACK_CLOSE:
991 if (index == TCP_RST_SET
992 && (ct->proto.tcp.seen[!dir].flags & IP_CT_TCP_FLAG_MAXACK_SET)
993 && before(ntohl(th->seq), ct->proto.tcp.seen[!dir].td_maxack)) {
994 /* Invalid RST */
995 spin_unlock_bh(&ct->lock);
996 if (LOG_INVALID(net, IPPROTO_TCP))
997 nf_log_packet(net, pf, 0, skb, NULL, NULL,
998 NULL, "nf_ct_tcp: invalid RST ");
999 return -NF_ACCEPT;
1000 }
1001 if (index == TCP_RST_SET
1002 && ((test_bit(IPS_SEEN_REPLY_BIT, &ct->status)
1003 && ct->proto.tcp.last_index == TCP_SYN_SET)
1004 || (!test_bit(IPS_ASSURED_BIT, &ct->status)
1005 && ct->proto.tcp.last_index == TCP_ACK_SET))
1006 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
1007 /* RST sent to invalid SYN or ACK we had let through
1008 * at a) and c) above:
1009 *
1010 * a) SYN was in window then
1011 * c) we hold a half-open connection.
1012 *
1013 * Delete our connection entry.
1014 * We skip window checking, because packet might ACK
1015 * segments we ignored. */
1016 goto in_window;
1017 }
1018 /* Just fall through */
1019 default:
1020 /* Keep compilers happy. */
1021 break;
1022 }
1023
1024 if (!tcp_in_window(ct, &ct->proto.tcp, dir, index,
1025 skb, dataoff, th, pf)) {
1026 spin_unlock_bh(&ct->lock);
1027 return -NF_ACCEPT;
1028 }
1029 in_window:
1030 /* From now on we have got in-window packets */
1031 ct->proto.tcp.last_index = index;
1032 ct->proto.tcp.last_dir = dir;
1033
1034 pr_debug("tcp_conntracks: ");
1035 nf_ct_dump_tuple(tuple);
1036 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
1037 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
1038 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
1039 old_state, new_state);
1040
1041 ct->proto.tcp.state = new_state;
1042 if (old_state != new_state
1043 && new_state == TCP_CONNTRACK_FIN_WAIT)
1044 ct->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
1045
1046 if (ct->proto.tcp.retrans >= tn->tcp_max_retrans &&
1047 timeouts[new_state] > timeouts[TCP_CONNTRACK_RETRANS])
1048 timeout = timeouts[TCP_CONNTRACK_RETRANS];
1049 else if ((ct->proto.tcp.seen[0].flags | ct->proto.tcp.seen[1].flags) &
1050 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED &&
1051 timeouts[new_state] > timeouts[TCP_CONNTRACK_UNACK])
1052 timeout = timeouts[TCP_CONNTRACK_UNACK];
1053 else
1054 timeout = timeouts[new_state];
1055 spin_unlock_bh(&ct->lock);
1056
1057 if (new_state != old_state)
1058 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
1059
1060 if (!test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
1061 /* If only reply is a RST, we can consider ourselves not to
1062 have an established connection: this is a fairly common
1063 problem case, so we can delete the conntrack
1064 immediately. --RR */
1065 if (th->rst) {
1066 nf_ct_kill_acct(ct, ctinfo, skb);
1067 return NF_ACCEPT;
1068 }
1069 /* ESTABLISHED without SEEN_REPLY, i.e. mid-connection
1070 * pickup with loose=1. Avoid large ESTABLISHED timeout.
1071 */
1072 if (new_state == TCP_CONNTRACK_ESTABLISHED &&
1073 timeout > timeouts[TCP_CONNTRACK_UNACK])
1074 timeout = timeouts[TCP_CONNTRACK_UNACK];
1075 } else if (!test_bit(IPS_ASSURED_BIT, &ct->status)
1076 && (old_state == TCP_CONNTRACK_SYN_RECV
1077 || old_state == TCP_CONNTRACK_ESTABLISHED)
1078 && new_state == TCP_CONNTRACK_ESTABLISHED) {
1079 /* Set ASSURED if we see see valid ack in ESTABLISHED
1080 after SYN_RECV or a valid answer for a picked up
1081 connection. */
1082 set_bit(IPS_ASSURED_BIT, &ct->status);
1083 nf_conntrack_event_cache(IPCT_ASSURED, ct);
1084 }
1085 nf_ct_refresh_acct(ct, ctinfo, skb, timeout);
1086
1087 return NF_ACCEPT;
1088 }
1089
1090 /* Called when a new connection for this protocol found. */
1091 static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb,
1092 unsigned int dataoff, unsigned int *timeouts)
1093 {
1094 enum tcp_conntrack new_state;
1095 const struct tcphdr *th;
1096 struct tcphdr _tcph;
1097 struct net *net = nf_ct_net(ct);
1098 struct nf_tcp_net *tn = tcp_pernet(net);
1099 const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0];
1100 const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1];
1101
1102 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
1103 BUG_ON(th == NULL);
1104
1105 /* Don't need lock here: this conntrack not in circulation yet */
1106 new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE];
1107
1108 /* Invalid: delete conntrack */
1109 if (new_state >= TCP_CONNTRACK_MAX) {
1110 pr_debug("nf_ct_tcp: invalid new deleting.\n");
1111 return false;
1112 }
1113
1114 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1115 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
1116 /* SYN packet */
1117 ct->proto.tcp.seen[0].td_end =
1118 segment_seq_plus_len(ntohl(th->seq), skb->len,
1119 dataoff, th);
1120 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1121 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1122 ct->proto.tcp.seen[0].td_maxwin = 1;
1123 ct->proto.tcp.seen[0].td_maxend =
1124 ct->proto.tcp.seen[0].td_end;
1125
1126 tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]);
1127 } else if (tn->tcp_loose == 0) {
1128 /* Don't try to pick up connections. */
1129 return false;
1130 } else {
1131 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
1132 /*
1133 * We are in the middle of a connection,
1134 * its history is lost for us.
1135 * Let's try to use the data from the packet.
1136 */
1137 ct->proto.tcp.seen[0].td_end =
1138 segment_seq_plus_len(ntohl(th->seq), skb->len,
1139 dataoff, th);
1140 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1141 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1142 ct->proto.tcp.seen[0].td_maxwin = 1;
1143 ct->proto.tcp.seen[0].td_maxend =
1144 ct->proto.tcp.seen[0].td_end +
1145 ct->proto.tcp.seen[0].td_maxwin;
1146
1147 /* We assume SACK and liberal window checking to handle
1148 * window scaling */
1149 ct->proto.tcp.seen[0].flags =
1150 ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1151 IP_CT_TCP_FLAG_BE_LIBERAL;
1152 }
1153
1154 /* tcp_packet will set them */
1155 ct->proto.tcp.last_index = TCP_NONE_SET;
1156
1157 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1158 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1159 sender->td_end, sender->td_maxend, sender->td_maxwin,
1160 sender->td_scale,
1161 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1162 receiver->td_scale);
1163 return true;
1164 }
1165
1166 static bool tcp_can_early_drop(const struct nf_conn *ct)
1167 {
1168 switch (ct->proto.tcp.state) {
1169 case TCP_CONNTRACK_FIN_WAIT:
1170 case TCP_CONNTRACK_LAST_ACK:
1171 case TCP_CONNTRACK_TIME_WAIT:
1172 case TCP_CONNTRACK_CLOSE:
1173 case TCP_CONNTRACK_CLOSE_WAIT:
1174 return true;
1175 default:
1176 break;
1177 }
1178
1179 return false;
1180 }
1181
1182 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1183
1184 #include <linux/netfilter/nfnetlink.h>
1185 #include <linux/netfilter/nfnetlink_conntrack.h>
1186
1187 static int tcp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
1188 struct nf_conn *ct)
1189 {
1190 struct nlattr *nest_parms;
1191 struct nf_ct_tcp_flags tmp = {};
1192
1193 spin_lock_bh(&ct->lock);
1194 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_TCP | NLA_F_NESTED);
1195 if (!nest_parms)
1196 goto nla_put_failure;
1197
1198 if (nla_put_u8(skb, CTA_PROTOINFO_TCP_STATE, ct->proto.tcp.state) ||
1199 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL,
1200 ct->proto.tcp.seen[0].td_scale) ||
1201 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY,
1202 ct->proto.tcp.seen[1].td_scale))
1203 goto nla_put_failure;
1204
1205 tmp.flags = ct->proto.tcp.seen[0].flags;
1206 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL,
1207 sizeof(struct nf_ct_tcp_flags), &tmp))
1208 goto nla_put_failure;
1209
1210 tmp.flags = ct->proto.tcp.seen[1].flags;
1211 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY,
1212 sizeof(struct nf_ct_tcp_flags), &tmp))
1213 goto nla_put_failure;
1214 spin_unlock_bh(&ct->lock);
1215
1216 nla_nest_end(skb, nest_parms);
1217
1218 return 0;
1219
1220 nla_put_failure:
1221 spin_unlock_bh(&ct->lock);
1222 return -1;
1223 }
1224
1225 static const struct nla_policy tcp_nla_policy[CTA_PROTOINFO_TCP_MAX+1] = {
1226 [CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 },
1227 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 },
1228 [CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 },
1229 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .len = sizeof(struct nf_ct_tcp_flags) },
1230 [CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .len = sizeof(struct nf_ct_tcp_flags) },
1231 };
1232
1233 static int nlattr_to_tcp(struct nlattr *cda[], struct nf_conn *ct)
1234 {
1235 struct nlattr *pattr = cda[CTA_PROTOINFO_TCP];
1236 struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1];
1237 int err;
1238
1239 /* updates could not contain anything about the private
1240 * protocol info, in that case skip the parsing */
1241 if (!pattr)
1242 return 0;
1243
1244 err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, pattr,
1245 tcp_nla_policy, NULL);
1246 if (err < 0)
1247 return err;
1248
1249 if (tb[CTA_PROTOINFO_TCP_STATE] &&
1250 nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]) >= TCP_CONNTRACK_MAX)
1251 return -EINVAL;
1252
1253 spin_lock_bh(&ct->lock);
1254 if (tb[CTA_PROTOINFO_TCP_STATE])
1255 ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
1256
1257 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) {
1258 struct nf_ct_tcp_flags *attr =
1259 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]);
1260 ct->proto.tcp.seen[0].flags &= ~attr->mask;
1261 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask;
1262 }
1263
1264 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]) {
1265 struct nf_ct_tcp_flags *attr =
1266 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]);
1267 ct->proto.tcp.seen[1].flags &= ~attr->mask;
1268 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask;
1269 }
1270
1271 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] &&
1272 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY] &&
1273 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
1274 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
1275 ct->proto.tcp.seen[0].td_scale =
1276 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL]);
1277 ct->proto.tcp.seen[1].td_scale =
1278 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY]);
1279 }
1280 spin_unlock_bh(&ct->lock);
1281
1282 return 0;
1283 }
1284
1285 static int tcp_nlattr_size(void)
1286 {
1287 return nla_total_size(0) /* CTA_PROTOINFO_TCP */
1288 + nla_policy_len(tcp_nla_policy, CTA_PROTOINFO_TCP_MAX + 1);
1289 }
1290
1291 static int tcp_nlattr_tuple_size(void)
1292 {
1293 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1);
1294 }
1295 #endif
1296
1297 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1298
1299 #include <linux/netfilter/nfnetlink.h>
1300 #include <linux/netfilter/nfnetlink_cttimeout.h>
1301
1302 static int tcp_timeout_nlattr_to_obj(struct nlattr *tb[],
1303 struct net *net, void *data)
1304 {
1305 unsigned int *timeouts = data;
1306 struct nf_tcp_net *tn = tcp_pernet(net);
1307 int i;
1308
1309 /* set default TCP timeouts. */
1310 for (i=0; i<TCP_CONNTRACK_TIMEOUT_MAX; i++)
1311 timeouts[i] = tn->timeouts[i];
1312
1313 if (tb[CTA_TIMEOUT_TCP_SYN_SENT]) {
1314 timeouts[TCP_CONNTRACK_SYN_SENT] =
1315 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT]))*HZ;
1316 }
1317 if (tb[CTA_TIMEOUT_TCP_SYN_RECV]) {
1318 timeouts[TCP_CONNTRACK_SYN_RECV] =
1319 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_RECV]))*HZ;
1320 }
1321 if (tb[CTA_TIMEOUT_TCP_ESTABLISHED]) {
1322 timeouts[TCP_CONNTRACK_ESTABLISHED] =
1323 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_ESTABLISHED]))*HZ;
1324 }
1325 if (tb[CTA_TIMEOUT_TCP_FIN_WAIT]) {
1326 timeouts[TCP_CONNTRACK_FIN_WAIT] =
1327 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_FIN_WAIT]))*HZ;
1328 }
1329 if (tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]) {
1330 timeouts[TCP_CONNTRACK_CLOSE_WAIT] =
1331 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]))*HZ;
1332 }
1333 if (tb[CTA_TIMEOUT_TCP_LAST_ACK]) {
1334 timeouts[TCP_CONNTRACK_LAST_ACK] =
1335 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_LAST_ACK]))*HZ;
1336 }
1337 if (tb[CTA_TIMEOUT_TCP_TIME_WAIT]) {
1338 timeouts[TCP_CONNTRACK_TIME_WAIT] =
1339 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_TIME_WAIT]))*HZ;
1340 }
1341 if (tb[CTA_TIMEOUT_TCP_CLOSE]) {
1342 timeouts[TCP_CONNTRACK_CLOSE] =
1343 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE]))*HZ;
1344 }
1345 if (tb[CTA_TIMEOUT_TCP_SYN_SENT2]) {
1346 timeouts[TCP_CONNTRACK_SYN_SENT2] =
1347 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT2]))*HZ;
1348 }
1349 if (tb[CTA_TIMEOUT_TCP_RETRANS]) {
1350 timeouts[TCP_CONNTRACK_RETRANS] =
1351 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_RETRANS]))*HZ;
1352 }
1353 if (tb[CTA_TIMEOUT_TCP_UNACK]) {
1354 timeouts[TCP_CONNTRACK_UNACK] =
1355 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_UNACK]))*HZ;
1356 }
1357 return 0;
1358 }
1359
1360 static int
1361 tcp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
1362 {
1363 const unsigned int *timeouts = data;
1364
1365 if (nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT,
1366 htonl(timeouts[TCP_CONNTRACK_SYN_SENT] / HZ)) ||
1367 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_RECV,
1368 htonl(timeouts[TCP_CONNTRACK_SYN_RECV] / HZ)) ||
1369 nla_put_be32(skb, CTA_TIMEOUT_TCP_ESTABLISHED,
1370 htonl(timeouts[TCP_CONNTRACK_ESTABLISHED] / HZ)) ||
1371 nla_put_be32(skb, CTA_TIMEOUT_TCP_FIN_WAIT,
1372 htonl(timeouts[TCP_CONNTRACK_FIN_WAIT] / HZ)) ||
1373 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE_WAIT,
1374 htonl(timeouts[TCP_CONNTRACK_CLOSE_WAIT] / HZ)) ||
1375 nla_put_be32(skb, CTA_TIMEOUT_TCP_LAST_ACK,
1376 htonl(timeouts[TCP_CONNTRACK_LAST_ACK] / HZ)) ||
1377 nla_put_be32(skb, CTA_TIMEOUT_TCP_TIME_WAIT,
1378 htonl(timeouts[TCP_CONNTRACK_TIME_WAIT] / HZ)) ||
1379 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE,
1380 htonl(timeouts[TCP_CONNTRACK_CLOSE] / HZ)) ||
1381 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT2,
1382 htonl(timeouts[TCP_CONNTRACK_SYN_SENT2] / HZ)) ||
1383 nla_put_be32(skb, CTA_TIMEOUT_TCP_RETRANS,
1384 htonl(timeouts[TCP_CONNTRACK_RETRANS] / HZ)) ||
1385 nla_put_be32(skb, CTA_TIMEOUT_TCP_UNACK,
1386 htonl(timeouts[TCP_CONNTRACK_UNACK] / HZ)))
1387 goto nla_put_failure;
1388 return 0;
1389
1390 nla_put_failure:
1391 return -ENOSPC;
1392 }
1393
1394 static const struct nla_policy tcp_timeout_nla_policy[CTA_TIMEOUT_TCP_MAX+1] = {
1395 [CTA_TIMEOUT_TCP_SYN_SENT] = { .type = NLA_U32 },
1396 [CTA_TIMEOUT_TCP_SYN_RECV] = { .type = NLA_U32 },
1397 [CTA_TIMEOUT_TCP_ESTABLISHED] = { .type = NLA_U32 },
1398 [CTA_TIMEOUT_TCP_FIN_WAIT] = { .type = NLA_U32 },
1399 [CTA_TIMEOUT_TCP_CLOSE_WAIT] = { .type = NLA_U32 },
1400 [CTA_TIMEOUT_TCP_LAST_ACK] = { .type = NLA_U32 },
1401 [CTA_TIMEOUT_TCP_TIME_WAIT] = { .type = NLA_U32 },
1402 [CTA_TIMEOUT_TCP_CLOSE] = { .type = NLA_U32 },
1403 [CTA_TIMEOUT_TCP_SYN_SENT2] = { .type = NLA_U32 },
1404 [CTA_TIMEOUT_TCP_RETRANS] = { .type = NLA_U32 },
1405 [CTA_TIMEOUT_TCP_UNACK] = { .type = NLA_U32 },
1406 };
1407 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1408
1409 #ifdef CONFIG_SYSCTL
1410 static struct ctl_table tcp_sysctl_table[] = {
1411 {
1412 .procname = "nf_conntrack_tcp_timeout_syn_sent",
1413 .maxlen = sizeof(unsigned int),
1414 .mode = 0644,
1415 .proc_handler = proc_dointvec_jiffies,
1416 },
1417 {
1418 .procname = "nf_conntrack_tcp_timeout_syn_recv",
1419 .maxlen = sizeof(unsigned int),
1420 .mode = 0644,
1421 .proc_handler = proc_dointvec_jiffies,
1422 },
1423 {
1424 .procname = "nf_conntrack_tcp_timeout_established",
1425 .maxlen = sizeof(unsigned int),
1426 .mode = 0644,
1427 .proc_handler = proc_dointvec_jiffies,
1428 },
1429 {
1430 .procname = "nf_conntrack_tcp_timeout_fin_wait",
1431 .maxlen = sizeof(unsigned int),
1432 .mode = 0644,
1433 .proc_handler = proc_dointvec_jiffies,
1434 },
1435 {
1436 .procname = "nf_conntrack_tcp_timeout_close_wait",
1437 .maxlen = sizeof(unsigned int),
1438 .mode = 0644,
1439 .proc_handler = proc_dointvec_jiffies,
1440 },
1441 {
1442 .procname = "nf_conntrack_tcp_timeout_last_ack",
1443 .maxlen = sizeof(unsigned int),
1444 .mode = 0644,
1445 .proc_handler = proc_dointvec_jiffies,
1446 },
1447 {
1448 .procname = "nf_conntrack_tcp_timeout_time_wait",
1449 .maxlen = sizeof(unsigned int),
1450 .mode = 0644,
1451 .proc_handler = proc_dointvec_jiffies,
1452 },
1453 {
1454 .procname = "nf_conntrack_tcp_timeout_close",
1455 .maxlen = sizeof(unsigned int),
1456 .mode = 0644,
1457 .proc_handler = proc_dointvec_jiffies,
1458 },
1459 {
1460 .procname = "nf_conntrack_tcp_timeout_max_retrans",
1461 .maxlen = sizeof(unsigned int),
1462 .mode = 0644,
1463 .proc_handler = proc_dointvec_jiffies,
1464 },
1465 {
1466 .procname = "nf_conntrack_tcp_timeout_unacknowledged",
1467 .maxlen = sizeof(unsigned int),
1468 .mode = 0644,
1469 .proc_handler = proc_dointvec_jiffies,
1470 },
1471 {
1472 .procname = "nf_conntrack_tcp_loose",
1473 .maxlen = sizeof(unsigned int),
1474 .mode = 0644,
1475 .proc_handler = proc_dointvec,
1476 },
1477 {
1478 .procname = "nf_conntrack_tcp_be_liberal",
1479 .maxlen = sizeof(unsigned int),
1480 .mode = 0644,
1481 .proc_handler = proc_dointvec,
1482 },
1483 {
1484 .procname = "nf_conntrack_tcp_max_retrans",
1485 .maxlen = sizeof(unsigned int),
1486 .mode = 0644,
1487 .proc_handler = proc_dointvec,
1488 },
1489 { }
1490 };
1491 #endif /* CONFIG_SYSCTL */
1492
1493 static int tcp_kmemdup_sysctl_table(struct nf_proto_net *pn,
1494 struct nf_tcp_net *tn)
1495 {
1496 #ifdef CONFIG_SYSCTL
1497 if (pn->ctl_table)
1498 return 0;
1499
1500 pn->ctl_table = kmemdup(tcp_sysctl_table,
1501 sizeof(tcp_sysctl_table),
1502 GFP_KERNEL);
1503 if (!pn->ctl_table)
1504 return -ENOMEM;
1505
1506 pn->ctl_table[0].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT];
1507 pn->ctl_table[1].data = &tn->timeouts[TCP_CONNTRACK_SYN_RECV];
1508 pn->ctl_table[2].data = &tn->timeouts[TCP_CONNTRACK_ESTABLISHED];
1509 pn->ctl_table[3].data = &tn->timeouts[TCP_CONNTRACK_FIN_WAIT];
1510 pn->ctl_table[4].data = &tn->timeouts[TCP_CONNTRACK_CLOSE_WAIT];
1511 pn->ctl_table[5].data = &tn->timeouts[TCP_CONNTRACK_LAST_ACK];
1512 pn->ctl_table[6].data = &tn->timeouts[TCP_CONNTRACK_TIME_WAIT];
1513 pn->ctl_table[7].data = &tn->timeouts[TCP_CONNTRACK_CLOSE];
1514 pn->ctl_table[8].data = &tn->timeouts[TCP_CONNTRACK_RETRANS];
1515 pn->ctl_table[9].data = &tn->timeouts[TCP_CONNTRACK_UNACK];
1516 pn->ctl_table[10].data = &tn->tcp_loose;
1517 pn->ctl_table[11].data = &tn->tcp_be_liberal;
1518 pn->ctl_table[12].data = &tn->tcp_max_retrans;
1519 #endif
1520 return 0;
1521 }
1522
1523 static int tcp_init_net(struct net *net, u_int16_t proto)
1524 {
1525 struct nf_tcp_net *tn = tcp_pernet(net);
1526 struct nf_proto_net *pn = &tn->pn;
1527
1528 if (!pn->users) {
1529 int i;
1530
1531 for (i = 0; i < TCP_CONNTRACK_TIMEOUT_MAX; i++)
1532 tn->timeouts[i] = tcp_timeouts[i];
1533
1534 tn->tcp_loose = nf_ct_tcp_loose;
1535 tn->tcp_be_liberal = nf_ct_tcp_be_liberal;
1536 tn->tcp_max_retrans = nf_ct_tcp_max_retrans;
1537 }
1538
1539 return tcp_kmemdup_sysctl_table(pn, tn);
1540 }
1541
1542 static struct nf_proto_net *tcp_get_net_proto(struct net *net)
1543 {
1544 return &net->ct.nf_ct_proto.tcp.pn;
1545 }
1546
1547 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
1548 {
1549 .l3proto = PF_INET,
1550 .l4proto = IPPROTO_TCP,
1551 .pkt_to_tuple = tcp_pkt_to_tuple,
1552 .invert_tuple = tcp_invert_tuple,
1553 #ifdef CONFIG_NF_CONNTRACK_PROCFS
1554 .print_conntrack = tcp_print_conntrack,
1555 #endif
1556 .packet = tcp_packet,
1557 .get_timeouts = tcp_get_timeouts,
1558 .new = tcp_new,
1559 .error = tcp_error,
1560 .can_early_drop = tcp_can_early_drop,
1561 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1562 .to_nlattr = tcp_to_nlattr,
1563 .nlattr_size = tcp_nlattr_size,
1564 .from_nlattr = nlattr_to_tcp,
1565 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1566 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1567 .nlattr_tuple_size = tcp_nlattr_tuple_size,
1568 .nla_policy = nf_ct_port_nla_policy,
1569 #endif
1570 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1571 .ctnl_timeout = {
1572 .nlattr_to_obj = tcp_timeout_nlattr_to_obj,
1573 .obj_to_nlattr = tcp_timeout_obj_to_nlattr,
1574 .nlattr_max = CTA_TIMEOUT_TCP_MAX,
1575 .obj_size = sizeof(unsigned int) *
1576 TCP_CONNTRACK_TIMEOUT_MAX,
1577 .nla_policy = tcp_timeout_nla_policy,
1578 },
1579 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1580 .init_net = tcp_init_net,
1581 .get_net_proto = tcp_get_net_proto,
1582 };
1583 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
1584
1585 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly =
1586 {
1587 .l3proto = PF_INET6,
1588 .l4proto = IPPROTO_TCP,
1589 .pkt_to_tuple = tcp_pkt_to_tuple,
1590 .invert_tuple = tcp_invert_tuple,
1591 #ifdef CONFIG_NF_CONNTRACK_PROCFS
1592 .print_conntrack = tcp_print_conntrack,
1593 #endif
1594 .packet = tcp_packet,
1595 .get_timeouts = tcp_get_timeouts,
1596 .new = tcp_new,
1597 .error = tcp_error,
1598 .can_early_drop = tcp_can_early_drop,
1599 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
1600 .to_nlattr = tcp_to_nlattr,
1601 .nlattr_size = tcp_nlattr_size,
1602 .from_nlattr = nlattr_to_tcp,
1603 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1604 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1605 .nlattr_tuple_size = tcp_nlattr_tuple_size,
1606 .nla_policy = nf_ct_port_nla_policy,
1607 #endif
1608 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
1609 .ctnl_timeout = {
1610 .nlattr_to_obj = tcp_timeout_nlattr_to_obj,
1611 .obj_to_nlattr = tcp_timeout_obj_to_nlattr,
1612 .nlattr_max = CTA_TIMEOUT_TCP_MAX,
1613 .obj_size = sizeof(unsigned int) *
1614 TCP_CONNTRACK_TIMEOUT_MAX,
1615 .nla_policy = tcp_timeout_nla_policy,
1616 },
1617 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
1618 .init_net = tcp_init_net,
1619 .get_net_proto = tcp_get_net_proto,
1620 };
1621 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);
(deprecated) Btrfs devel tree