1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/types.h>
10 #include <linux/timer.h>
11 #include <linux/module.h>
13 #include <linux/tcp.h>
14 #include <linux/spinlock.h>
15 #include <linux/skbuff.h>
16 #include <linux/ipv6.h>
17 #include <net/ip6_checksum.h>
21 #include <linux/netfilter.h>
22 #include <linux/netfilter_ipv4.h>
23 #include <linux/netfilter_ipv6.h>
24 #include <net/netfilter/nf_conntrack.h>
25 #include <net/netfilter/nf_conntrack_l4proto.h>
26 #include <net/netfilter/nf_conntrack_ecache.h>
27 #include <net/netfilter/nf_log.h>
29 /* Protects ct->proto.tcp */
30 static DEFINE_RWLOCK(tcp_lock);
32 /* "Be conservative in what you do,
33 be liberal in what you accept from others."
34 If it's non-zero, we mark only out of window RST segments as INVALID. */
35 static int nf_ct_tcp_be_liberal __read_mostly = 0;
37 /* If it is set to zero, we disable picking up already established
39 static int nf_ct_tcp_loose __read_mostly = 1;
41 /* Max number of the retransmitted packets without receiving an (acceptable)
42 ACK from the destination. If this number is reached, a shorter timer
44 static int nf_ct_tcp_max_retrans __read_mostly = 3;
46 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
47 closely. They're more complex. --RR */
49 static const char *const tcp_conntrack_names[] = {
63 #define MINS * 60 SECS
64 #define HOURS * 60 MINS
65 #define DAYS * 24 HOURS
67 /* RFC1122 says the R2 limit should be at least 100 seconds.
68 Linux uses 15 packets as limit, which corresponds
69 to ~13-30min depending on RTO. */
70 static unsigned int nf_ct_tcp_timeout_max_retrans __read_mostly = 5 MINS;
71 static unsigned int nf_ct_tcp_timeout_unacknowledged __read_mostly = 5 MINS;
73 static unsigned int tcp_timeouts[TCP_CONNTRACK_MAX] __read_mostly = {
74 [TCP_CONNTRACK_SYN_SENT] = 2 MINS,
75 [TCP_CONNTRACK_SYN_RECV] = 60 SECS,
76 [TCP_CONNTRACK_ESTABLISHED] = 5 DAYS,
77 [TCP_CONNTRACK_FIN_WAIT] = 2 MINS,
78 [TCP_CONNTRACK_CLOSE_WAIT] = 60 SECS,
79 [TCP_CONNTRACK_LAST_ACK] = 30 SECS,
80 [TCP_CONNTRACK_TIME_WAIT] = 2 MINS,
81 [TCP_CONNTRACK_CLOSE] = 10 SECS,
84 #define sNO TCP_CONNTRACK_NONE
85 #define sSS TCP_CONNTRACK_SYN_SENT
86 #define sSR TCP_CONNTRACK_SYN_RECV
87 #define sES TCP_CONNTRACK_ESTABLISHED
88 #define sFW TCP_CONNTRACK_FIN_WAIT
89 #define sCW TCP_CONNTRACK_CLOSE_WAIT
90 #define sLA TCP_CONNTRACK_LAST_ACK
91 #define sTW TCP_CONNTRACK_TIME_WAIT
92 #define sCL TCP_CONNTRACK_CLOSE
93 #define sLI TCP_CONNTRACK_LISTEN
94 #define sIV TCP_CONNTRACK_MAX
95 #define sIG TCP_CONNTRACK_IGNORE
97 /* What TCP flags are set from RST/SYN/FIN/ACK. */
108 * The TCP state transition table needs a few words...
110 * We are the man in the middle. All the packets go through us
111 * but might get lost in transit to the destination.
112 * It is assumed that the destinations can't receive segments
115 * The checked segment is in window, but our windows are *not*
116 * equivalent with the ones of the sender/receiver. We always
117 * try to guess the state of the current sender.
119 * The meaning of the states are:
121 * NONE: initial state
122 * SYN_SENT: SYN-only packet seen
123 * SYN_RECV: SYN-ACK packet seen
124 * ESTABLISHED: ACK packet seen
125 * FIN_WAIT: FIN packet seen
126 * CLOSE_WAIT: ACK seen (after FIN)
127 * LAST_ACK: FIN seen (after FIN)
128 * TIME_WAIT: last ACK seen
129 * CLOSE: closed connection (RST)
131 * LISTEN state is not used.
133 * Packets marked as IGNORED (sIG):
134 * if they may be either invalid or valid
135 * and the receiver may send back a connection
136 * closing RST or a SYN/ACK.
138 * Packets marked as INVALID (sIV):
139 * if they are invalid
140 * or we do not support the request (simultaneous open)
142 static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
145 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
146 /*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
148 * sNO -> sSS Initialize a new connection
149 * sSS -> sSS Retransmitted SYN
150 * sSR -> sIG Late retransmitted SYN?
151 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
152 * are errors. Receiver will reply with RST
153 * and close the connection.
154 * Or we are not in sync and hold a dead connection.
158 * sTW -> sSS Reopened connection (RFC 1122).
161 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
162 /*synack*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
164 * A SYN/ACK from the client is always invalid:
165 * - either it tries to set up a simultaneous open, which is
167 * - or the firewall has just been inserted between the two hosts
168 * during the session set-up. The SYN will be retransmitted
169 * by the true client (or it'll time out).
171 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
172 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
174 * sNO -> sIV Too late and no reason to do anything...
175 * sSS -> sIV Client migth not send FIN in this state:
176 * we enforce waiting for a SYN/ACK reply first.
177 * sSR -> sFW Close started.
179 * sFW -> sLA FIN seen in both directions, waiting for
181 * Migth be a retransmitted FIN as well...
183 * sLA -> sLA Retransmitted FIN. Remain in the same state.
187 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
188 /*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
190 * sNO -> sES Assumed.
191 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
192 * sSR -> sES Established state is reached.
194 * sFW -> sCW Normal close request answered by ACK.
196 * sLA -> sTW Last ACK detected.
197 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
200 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
201 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
202 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
206 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
207 /*syn*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
209 * sNO -> sIV Never reached.
210 * sSS -> sIV Simultaneous open, not supported
211 * sSR -> sIV Simultaneous open, not supported.
212 * sES -> sIV Server may not initiate a connection.
216 * sTW -> sIV Reopened connection, but server may not do it.
219 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
220 /*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIV },
222 * sSS -> sSR Standard open.
223 * sSR -> sSR Retransmitted SYN/ACK.
224 * sES -> sIG Late retransmitted SYN/ACK?
225 * sFW -> sIG Might be SYN/ACK answering ignored SYN
231 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
232 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
234 * sSS -> sIV Server might not send FIN in this state.
235 * sSR -> sFW Close started.
237 * sFW -> sLA FIN seen in both directions.
239 * sLA -> sLA Retransmitted FIN.
243 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
244 /*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
246 * sSS -> sIG Might be a half-open connection.
247 * sSR -> sSR Might answer late resent SYN.
249 * sFW -> sCW Normal close request answered by ACK.
251 * sLA -> sTW Last ACK detected.
252 * sTW -> sTW Retransmitted last ACK.
255 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
256 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
257 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
261 static bool tcp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
262 struct nf_conntrack_tuple *tuple)
264 const struct tcphdr *hp;
267 /* Actually only need first 8 bytes. */
268 hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
272 tuple->src.u.tcp.port = hp->source;
273 tuple->dst.u.tcp.port = hp->dest;
278 static bool tcp_invert_tuple(struct nf_conntrack_tuple *tuple,
279 const struct nf_conntrack_tuple *orig)
281 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
282 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
286 /* Print out the per-protocol part of the tuple. */
287 static int tcp_print_tuple(struct seq_file *s,
288 const struct nf_conntrack_tuple *tuple)
290 return seq_printf(s, "sport=%hu dport=%hu ",
291 ntohs(tuple->src.u.tcp.port),
292 ntohs(tuple->dst.u.tcp.port));
295 /* Print out the private part of the conntrack. */
296 static int tcp_print_conntrack(struct seq_file *s, const struct nf_conn *ct)
298 enum tcp_conntrack state;
300 read_lock_bh(&tcp_lock);
301 state = ct->proto.tcp.state;
302 read_unlock_bh(&tcp_lock);
304 return seq_printf(s, "%s ", tcp_conntrack_names[state]);
307 static unsigned int get_conntrack_index(const struct tcphdr *tcph)
309 if (tcph->rst) return TCP_RST_SET;
310 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
311 else if (tcph->fin) return TCP_FIN_SET;
312 else if (tcph->ack) return TCP_ACK_SET;
313 else return TCP_NONE_SET;
316 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
317 in IP Filter' by Guido van Rooij.
319 http://www.nluug.nl/events/sane2000/papers.html
320 http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
322 The boundaries and the conditions are changed according to RFC793:
323 the packet must intersect the window (i.e. segments may be
324 after the right or before the left edge) and thus receivers may ACK
325 segments after the right edge of the window.
327 td_maxend = max(sack + max(win,1)) seen in reply packets
328 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
329 td_maxwin += seq + len - sender.td_maxend
330 if seq + len > sender.td_maxend
331 td_end = max(seq + len) seen in sent packets
333 I. Upper bound for valid data: seq <= sender.td_maxend
334 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
335 III. Upper bound for valid (s)ack: sack <= receiver.td_end
336 IV. Lower bound for valid (s)ack: sack >= receiver.td_end - MAXACKWINDOW
338 where sack is the highest right edge of sack block found in the packet
339 or ack in the case of packet without SACK option.
341 The upper bound limit for a valid (s)ack is not ignored -
342 we doesn't have to deal with fragments.
345 static inline __u32 segment_seq_plus_len(__u32 seq,
347 unsigned int dataoff,
348 const struct tcphdr *tcph)
350 /* XXX Should I use payload length field in IP/IPv6 header ?
352 return (seq + len - dataoff - tcph->doff*4
353 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
356 /* Fixme: what about big packets? */
357 #define MAXACKWINCONST 66000
358 #define MAXACKWINDOW(sender) \
359 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
363 * Simplified tcp_parse_options routine from tcp_input.c
365 static void tcp_options(const struct sk_buff *skb,
366 unsigned int dataoff,
367 const struct tcphdr *tcph,
368 struct ip_ct_tcp_state *state)
370 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
371 const unsigned char *ptr;
372 int length = (tcph->doff*4) - sizeof(struct tcphdr);
377 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
391 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
396 if (opsize < 2) /* "silly options" */
399 break; /* don't parse partial options */
401 if (opcode == TCPOPT_SACK_PERM
402 && opsize == TCPOLEN_SACK_PERM)
403 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
404 else if (opcode == TCPOPT_WINDOW
405 && opsize == TCPOLEN_WINDOW) {
406 state->td_scale = *(u_int8_t *)ptr;
408 if (state->td_scale > 14) {
410 state->td_scale = 14;
413 IP_CT_TCP_FLAG_WINDOW_SCALE;
421 static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
422 const struct tcphdr *tcph, __u32 *sack)
424 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
425 const unsigned char *ptr;
426 int length = (tcph->doff*4) - sizeof(struct tcphdr);
432 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
436 /* Fast path for timestamp-only option */
437 if (length == TCPOLEN_TSTAMP_ALIGNED*4
438 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24)
440 | (TCPOPT_TIMESTAMP << 8)
441 | TCPOLEN_TIMESTAMP))
451 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
456 if (opsize < 2) /* "silly options" */
459 break; /* don't parse partial options */
461 if (opcode == TCPOPT_SACK
462 && opsize >= (TCPOLEN_SACK_BASE
463 + TCPOLEN_SACK_PERBLOCK)
464 && !((opsize - TCPOLEN_SACK_BASE)
465 % TCPOLEN_SACK_PERBLOCK)) {
467 i < (opsize - TCPOLEN_SACK_BASE);
468 i += TCPOLEN_SACK_PERBLOCK) {
469 tmp = ntohl(*((__be32 *)(ptr+i)+1));
471 if (after(tmp, *sack))
482 static bool tcp_in_window(const struct nf_conn *ct,
483 struct ip_ct_tcp *state,
484 enum ip_conntrack_dir dir,
486 const struct sk_buff *skb,
487 unsigned int dataoff,
488 const struct tcphdr *tcph,
491 struct net *net = nf_ct_net(ct);
492 struct ip_ct_tcp_state *sender = &state->seen[dir];
493 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
494 const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
495 __u32 seq, ack, sack, end, win, swin;
499 * Get the required data from the packet.
501 seq = ntohl(tcph->seq);
502 ack = sack = ntohl(tcph->ack_seq);
503 win = ntohs(tcph->window);
504 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph);
506 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
507 tcp_sack(skb, dataoff, tcph, &sack);
509 pr_debug("tcp_in_window: START\n");
510 pr_debug("tcp_in_window: ");
511 nf_ct_dump_tuple(tuple);
512 pr_debug("seq=%u ack=%u sack=%u win=%u end=%u\n",
513 seq, ack, sack, win, end);
514 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
515 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
516 sender->td_end, sender->td_maxend, sender->td_maxwin,
518 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
521 if (sender->td_end == 0) {
523 * Initialize sender data.
525 if (tcph->syn && tcph->ack) {
527 * Outgoing SYN-ACK in reply to a SYN.
530 sender->td_maxend = end;
531 sender->td_maxwin = (win == 0 ? 1 : win);
533 tcp_options(skb, dataoff, tcph, sender);
536 * Both sides must send the Window Scale option
537 * to enable window scaling in either direction.
539 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
540 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
542 receiver->td_scale = 0;
545 * We are in the middle of a connection,
546 * its history is lost for us.
547 * Let's try to use the data from the packet.
549 sender->td_end = end;
550 sender->td_maxwin = (win == 0 ? 1 : win);
551 sender->td_maxend = end + sender->td_maxwin;
553 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
554 && dir == IP_CT_DIR_ORIGINAL)
555 || (state->state == TCP_CONNTRACK_SYN_RECV
556 && dir == IP_CT_DIR_REPLY))
557 && after(end, sender->td_end)) {
559 * RFC 793: "if a TCP is reinitialized ... then it need
560 * not wait at all; it must only be sure to use sequence
561 * numbers larger than those recently used."
564 sender->td_maxend = end;
565 sender->td_maxwin = (win == 0 ? 1 : win);
567 tcp_options(skb, dataoff, tcph, sender);
572 * If there is no ACK, just pretend it was set and OK.
574 ack = sack = receiver->td_end;
575 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
576 (TCP_FLAG_ACK|TCP_FLAG_RST))
579 * Broken TCP stacks, that set ACK in RST packets as well
580 * with zero ack value.
582 ack = sack = receiver->td_end;
587 || (seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)))
589 * Packets contains no data: we assume it is valid
590 * and check the ack value only.
591 * However RST segments are always validated by their
592 * SEQ number, except when seq == 0 (reset sent answering
595 seq = end = sender->td_end;
597 pr_debug("tcp_in_window: ");
598 nf_ct_dump_tuple(tuple);
599 pr_debug("seq=%u ack=%u sack =%u win=%u end=%u\n",
600 seq, ack, sack, win, end);
601 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
602 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
603 sender->td_end, sender->td_maxend, sender->td_maxwin,
605 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
608 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
609 before(seq, sender->td_maxend + 1),
610 after(end, sender->td_end - receiver->td_maxwin - 1),
611 before(sack, receiver->td_end + 1),
612 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1));
614 if (before(seq, sender->td_maxend + 1) &&
615 after(end, sender->td_end - receiver->td_maxwin - 1) &&
616 before(sack, receiver->td_end + 1) &&
617 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)) {
619 * Take into account window scaling (RFC 1323).
622 win <<= sender->td_scale;
625 * Update sender data.
627 swin = win + (sack - ack);
628 if (sender->td_maxwin < swin)
629 sender->td_maxwin = swin;
630 if (after(end, sender->td_end)) {
631 sender->td_end = end;
632 sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
635 * Update receiver data.
637 if (after(end, sender->td_maxend))
638 receiver->td_maxwin += end - sender->td_maxend;
639 if (after(sack + win, receiver->td_maxend - 1)) {
640 receiver->td_maxend = sack + win;
642 receiver->td_maxend++;
644 if (ack == receiver->td_end)
645 receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
648 * Check retransmissions.
650 if (index == TCP_ACK_SET) {
651 if (state->last_dir == dir
652 && state->last_seq == seq
653 && state->last_ack == ack
654 && state->last_end == end
655 && state->last_win == win)
658 state->last_dir = dir;
659 state->last_seq = seq;
660 state->last_ack = ack;
661 state->last_end = end;
662 state->last_win = win;
669 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
670 nf_ct_tcp_be_liberal)
672 if (!res && LOG_INVALID(net, IPPROTO_TCP))
673 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
675 before(seq, sender->td_maxend + 1) ?
676 after(end, sender->td_end - receiver->td_maxwin - 1) ?
677 before(sack, receiver->td_end + 1) ?
678 after(ack, receiver->td_end - MAXACKWINDOW(sender)) ? "BUG"
679 : "ACK is under the lower bound (possible overly delayed ACK)"
680 : "ACK is over the upper bound (ACKed data not seen yet)"
681 : "SEQ is under the lower bound (already ACKed data retransmitted)"
682 : "SEQ is over the upper bound (over the window of the receiver)");
685 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u "
686 "receiver end=%u maxend=%u maxwin=%u\n",
687 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
688 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
693 #ifdef CONFIG_NF_NAT_NEEDED
694 /* Update sender->td_end after NAT successfully mangled the packet */
695 /* Caller must linearize skb at tcp header. */
696 void nf_conntrack_tcp_update(const struct sk_buff *skb,
697 unsigned int dataoff,
701 const struct tcphdr *tcph = (const void *)skb->data + dataoff;
702 const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[dir];
703 const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[!dir];
706 end = segment_seq_plus_len(ntohl(tcph->seq), skb->len, dataoff, tcph);
708 write_lock_bh(&tcp_lock);
710 * We have to worry for the ack in the reply packet only...
712 if (after(end, ct->proto.tcp.seen[dir].td_end))
713 ct->proto.tcp.seen[dir].td_end = end;
714 ct->proto.tcp.last_end = end;
715 write_unlock_bh(&tcp_lock);
716 pr_debug("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
717 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
718 sender->td_end, sender->td_maxend, sender->td_maxwin,
720 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
723 EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
735 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
736 static const u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG) + 1] =
744 [TH_FIN|TH_ACK|TH_URG] = 1,
749 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
750 static int tcp_error(struct net *net,
752 unsigned int dataoff,
753 enum ip_conntrack_info *ctinfo,
755 unsigned int hooknum)
757 const struct tcphdr *th;
759 unsigned int tcplen = skb->len - dataoff;
762 /* Smaller that minimal TCP header? */
763 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
765 if (LOG_INVALID(net, IPPROTO_TCP))
766 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
767 "nf_ct_tcp: short packet ");
771 /* Not whole TCP header or malformed packet */
772 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
773 if (LOG_INVALID(net, IPPROTO_TCP))
774 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
775 "nf_ct_tcp: truncated/malformed packet ");
779 /* Checksum invalid? Ignore.
780 * We skip checking packets on the outgoing path
781 * because the checksum is assumed to be correct.
783 /* FIXME: Source route IP option packets --RR */
784 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
785 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
786 if (LOG_INVALID(net, IPPROTO_TCP))
787 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
788 "nf_ct_tcp: bad TCP checksum ");
792 /* Check TCP flags. */
793 tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR|TH_PUSH));
794 if (!tcp_valid_flags[tcpflags]) {
795 if (LOG_INVALID(net, IPPROTO_TCP))
796 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
797 "nf_ct_tcp: invalid TCP flag combination ");
804 /* Returns verdict for packet, or -1 for invalid. */
805 static int tcp_packet(struct nf_conn *ct,
806 const struct sk_buff *skb,
807 unsigned int dataoff,
808 enum ip_conntrack_info ctinfo,
810 unsigned int hooknum)
812 struct net *net = nf_ct_net(ct);
813 struct nf_conntrack_tuple *tuple;
814 enum tcp_conntrack new_state, old_state;
815 enum ip_conntrack_dir dir;
816 const struct tcphdr *th;
818 unsigned long timeout;
821 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
824 write_lock_bh(&tcp_lock);
825 old_state = ct->proto.tcp.state;
826 dir = CTINFO2DIR(ctinfo);
827 index = get_conntrack_index(th);
828 new_state = tcp_conntracks[dir][index][old_state];
829 tuple = &ct->tuplehash[dir].tuple;
832 case TCP_CONNTRACK_SYN_SENT:
833 if (old_state < TCP_CONNTRACK_TIME_WAIT)
835 /* RFC 1122: "When a connection is closed actively,
836 * it MUST linger in TIME-WAIT state for a time 2xMSL
837 * (Maximum Segment Lifetime). However, it MAY accept
838 * a new SYN from the remote TCP to reopen the connection
839 * directly from TIME-WAIT state, if..."
840 * We ignore the conditions because we are in the
841 * TIME-WAIT state anyway.
843 * Handle aborted connections: we and the server
844 * think there is an existing connection but the client
845 * aborts it and starts a new one.
847 if (((ct->proto.tcp.seen[dir].flags
848 | ct->proto.tcp.seen[!dir].flags)
849 & IP_CT_TCP_FLAG_CLOSE_INIT)
850 || (ct->proto.tcp.last_dir == dir
851 && ct->proto.tcp.last_index == TCP_RST_SET)) {
852 /* Attempt to reopen a closed/aborted connection.
853 * Delete this connection and look up again. */
854 write_unlock_bh(&tcp_lock);
856 /* Only repeat if we can actually remove the timer.
857 * Destruction may already be in progress in process
858 * context and we must give it a chance to terminate.
865 case TCP_CONNTRACK_IGNORE:
868 * Our connection entry may be out of sync, so ignore
869 * packets which may signal the real connection between
870 * the client and the server.
873 * b) SYN/ACK in REPLY
874 * c) ACK in reply direction after initial SYN in original.
876 * If the ignored packet is invalid, the receiver will send
877 * a RST we'll catch below.
879 if (index == TCP_SYNACK_SET
880 && ct->proto.tcp.last_index == TCP_SYN_SET
881 && ct->proto.tcp.last_dir != dir
882 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
883 /* b) This SYN/ACK acknowledges a SYN that we earlier
884 * ignored as invalid. This means that the client and
885 * the server are both in sync, while the firewall is
886 * not. We kill this session and block the SYN/ACK so
887 * that the client cannot but retransmit its SYN and
888 * thus initiate a clean new session.
890 write_unlock_bh(&tcp_lock);
891 if (LOG_INVALID(net, IPPROTO_TCP))
892 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
893 "nf_ct_tcp: killing out of sync session ");
897 ct->proto.tcp.last_index = index;
898 ct->proto.tcp.last_dir = dir;
899 ct->proto.tcp.last_seq = ntohl(th->seq);
900 ct->proto.tcp.last_end =
901 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th);
903 write_unlock_bh(&tcp_lock);
904 if (LOG_INVALID(net, IPPROTO_TCP))
905 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
906 "nf_ct_tcp: invalid packet ignored ");
908 case TCP_CONNTRACK_MAX:
910 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
911 dir, get_conntrack_index(th), old_state);
912 write_unlock_bh(&tcp_lock);
913 if (LOG_INVALID(net, IPPROTO_TCP))
914 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
915 "nf_ct_tcp: invalid state ");
917 case TCP_CONNTRACK_CLOSE:
918 if (index == TCP_RST_SET
919 && ((test_bit(IPS_SEEN_REPLY_BIT, &ct->status)
920 && ct->proto.tcp.last_index == TCP_SYN_SET)
921 || (!test_bit(IPS_ASSURED_BIT, &ct->status)
922 && ct->proto.tcp.last_index == TCP_ACK_SET))
923 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) {
924 /* RST sent to invalid SYN or ACK we had let through
925 * at a) and c) above:
927 * a) SYN was in window then
928 * c) we hold a half-open connection.
930 * Delete our connection entry.
931 * We skip window checking, because packet might ACK
932 * segments we ignored. */
935 /* Just fall through */
937 /* Keep compilers happy. */
941 if (!tcp_in_window(ct, &ct->proto.tcp, dir, index,
942 skb, dataoff, th, pf)) {
943 write_unlock_bh(&tcp_lock);
947 /* From now on we have got in-window packets */
948 ct->proto.tcp.last_index = index;
949 ct->proto.tcp.last_dir = dir;
951 pr_debug("tcp_conntracks: ");
952 nf_ct_dump_tuple(tuple);
953 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
954 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
955 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
956 old_state, new_state);
958 ct->proto.tcp.state = new_state;
959 if (old_state != new_state
960 && new_state == TCP_CONNTRACK_FIN_WAIT)
961 ct->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
963 if (ct->proto.tcp.retrans >= nf_ct_tcp_max_retrans &&
964 tcp_timeouts[new_state] > nf_ct_tcp_timeout_max_retrans)
965 timeout = nf_ct_tcp_timeout_max_retrans;
966 else if ((ct->proto.tcp.seen[0].flags | ct->proto.tcp.seen[1].flags) &
967 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED &&
968 tcp_timeouts[new_state] > nf_ct_tcp_timeout_unacknowledged)
969 timeout = nf_ct_tcp_timeout_unacknowledged;
971 timeout = tcp_timeouts[new_state];
972 write_unlock_bh(&tcp_lock);
974 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct);
975 if (new_state != old_state)
976 nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
978 if (!test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
979 /* If only reply is a RST, we can consider ourselves not to
980 have an established connection: this is a fairly common
981 problem case, so we can delete the conntrack
984 nf_ct_kill_acct(ct, ctinfo, skb);
987 } else if (!test_bit(IPS_ASSURED_BIT, &ct->status)
988 && (old_state == TCP_CONNTRACK_SYN_RECV
989 || old_state == TCP_CONNTRACK_ESTABLISHED)
990 && new_state == TCP_CONNTRACK_ESTABLISHED) {
991 /* Set ASSURED if we see see valid ack in ESTABLISHED
992 after SYN_RECV or a valid answer for a picked up
994 set_bit(IPS_ASSURED_BIT, &ct->status);
995 nf_conntrack_event_cache(IPCT_STATUS, ct);
997 nf_ct_refresh_acct(ct, ctinfo, skb, timeout);
1002 /* Called when a new connection for this protocol found. */
1003 static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb,
1004 unsigned int dataoff)
1006 enum tcp_conntrack new_state;
1007 const struct tcphdr *th;
1008 struct tcphdr _tcph;
1009 const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0];
1010 const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1];
1012 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
1015 /* Don't need lock here: this conntrack not in circulation yet */
1017 = tcp_conntracks[0][get_conntrack_index(th)]
1018 [TCP_CONNTRACK_NONE];
1020 /* Invalid: delete conntrack */
1021 if (new_state >= TCP_CONNTRACK_MAX) {
1022 pr_debug("nf_ct_tcp: invalid new deleting.\n");
1026 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1028 ct->proto.tcp.seen[0].td_end =
1029 segment_seq_plus_len(ntohl(th->seq), skb->len,
1031 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1032 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1033 ct->proto.tcp.seen[0].td_maxwin = 1;
1034 ct->proto.tcp.seen[0].td_maxend =
1035 ct->proto.tcp.seen[0].td_end;
1037 tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]);
1038 ct->proto.tcp.seen[1].flags = 0;
1039 } else if (nf_ct_tcp_loose == 0) {
1040 /* Don't try to pick up connections. */
1044 * We are in the middle of a connection,
1045 * its history is lost for us.
1046 * Let's try to use the data from the packet.
1048 ct->proto.tcp.seen[0].td_end =
1049 segment_seq_plus_len(ntohl(th->seq), skb->len,
1051 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1052 if (ct->proto.tcp.seen[0].td_maxwin == 0)
1053 ct->proto.tcp.seen[0].td_maxwin = 1;
1054 ct->proto.tcp.seen[0].td_maxend =
1055 ct->proto.tcp.seen[0].td_end +
1056 ct->proto.tcp.seen[0].td_maxwin;
1057 ct->proto.tcp.seen[0].td_scale = 0;
1059 /* We assume SACK and liberal window checking to handle
1061 ct->proto.tcp.seen[0].flags =
1062 ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1063 IP_CT_TCP_FLAG_BE_LIBERAL;
1066 ct->proto.tcp.seen[1].td_end = 0;
1067 ct->proto.tcp.seen[1].td_maxend = 0;
1068 ct->proto.tcp.seen[1].td_maxwin = 1;
1069 ct->proto.tcp.seen[1].td_scale = 0;
1071 /* tcp_packet will set them */
1072 ct->proto.tcp.state = TCP_CONNTRACK_NONE;
1073 ct->proto.tcp.last_index = TCP_NONE_SET;
1075 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1076 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1077 sender->td_end, sender->td_maxend, sender->td_maxwin,
1079 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1080 receiver->td_scale);
1084 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1086 #include <linux/netfilter/nfnetlink.h>
1087 #include <linux/netfilter/nfnetlink_conntrack.h>
1089 static int tcp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
1090 const struct nf_conn *ct)
1092 struct nlattr *nest_parms;
1093 struct nf_ct_tcp_flags tmp = {};
1095 read_lock_bh(&tcp_lock);
1096 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_TCP | NLA_F_NESTED);
1098 goto nla_put_failure;
1100 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_STATE, ct->proto.tcp.state);
1102 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL,
1103 ct->proto.tcp.seen[0].td_scale);
1105 NLA_PUT_U8(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY,
1106 ct->proto.tcp.seen[1].td_scale);
1108 tmp.flags = ct->proto.tcp.seen[0].flags;
1109 NLA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL,
1110 sizeof(struct nf_ct_tcp_flags), &tmp);
1112 tmp.flags = ct->proto.tcp.seen[1].flags;
1113 NLA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY,
1114 sizeof(struct nf_ct_tcp_flags), &tmp);
1115 read_unlock_bh(&tcp_lock);
1117 nla_nest_end(skb, nest_parms);
1122 read_unlock_bh(&tcp_lock);
1126 static const struct nla_policy tcp_nla_policy[CTA_PROTOINFO_TCP_MAX+1] = {
1127 [CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 },
1128 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 },
1129 [CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 },
1130 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .len = sizeof(struct nf_ct_tcp_flags) },
1131 [CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .len = sizeof(struct nf_ct_tcp_flags) },
1134 static int nlattr_to_tcp(struct nlattr *cda[], struct nf_conn *ct)
1136 struct nlattr *pattr = cda[CTA_PROTOINFO_TCP];
1137 struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1];
1140 /* updates could not contain anything about the private
1141 * protocol info, in that case skip the parsing */
1145 err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, pattr, tcp_nla_policy);
1149 if (tb[CTA_PROTOINFO_TCP_STATE] &&
1150 nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]) >= TCP_CONNTRACK_MAX)
1153 write_lock_bh(&tcp_lock);
1154 if (tb[CTA_PROTOINFO_TCP_STATE])
1155 ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]);
1157 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) {
1158 struct nf_ct_tcp_flags *attr =
1159 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]);
1160 ct->proto.tcp.seen[0].flags &= ~attr->mask;
1161 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask;
1164 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]) {
1165 struct nf_ct_tcp_flags *attr =
1166 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]);
1167 ct->proto.tcp.seen[1].flags &= ~attr->mask;
1168 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask;
1171 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] &&
1172 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY] &&
1173 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
1174 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
1175 ct->proto.tcp.seen[0].td_scale =
1176 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL]);
1177 ct->proto.tcp.seen[1].td_scale =
1178 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY]);
1180 write_unlock_bh(&tcp_lock);
1186 #ifdef CONFIG_SYSCTL
1187 static unsigned int tcp_sysctl_table_users;
1188 static struct ctl_table_header *tcp_sysctl_header;
1189 static struct ctl_table tcp_sysctl_table[] = {
1191 .procname = "nf_conntrack_tcp_timeout_syn_sent",
1192 .data = &tcp_timeouts[TCP_CONNTRACK_SYN_SENT],
1193 .maxlen = sizeof(unsigned int),
1195 .proc_handler = &proc_dointvec_jiffies,
1198 .procname = "nf_conntrack_tcp_timeout_syn_recv",
1199 .data = &tcp_timeouts[TCP_CONNTRACK_SYN_RECV],
1200 .maxlen = sizeof(unsigned int),
1202 .proc_handler = &proc_dointvec_jiffies,
1205 .procname = "nf_conntrack_tcp_timeout_established",
1206 .data = &tcp_timeouts[TCP_CONNTRACK_ESTABLISHED],
1207 .maxlen = sizeof(unsigned int),
1209 .proc_handler = &proc_dointvec_jiffies,
1212 .procname = "nf_conntrack_tcp_timeout_fin_wait",
1213 .data = &tcp_timeouts[TCP_CONNTRACK_FIN_WAIT],
1214 .maxlen = sizeof(unsigned int),
1216 .proc_handler = &proc_dointvec_jiffies,
1219 .procname = "nf_conntrack_tcp_timeout_close_wait",
1220 .data = &tcp_timeouts[TCP_CONNTRACK_CLOSE_WAIT],
1221 .maxlen = sizeof(unsigned int),
1223 .proc_handler = &proc_dointvec_jiffies,
1226 .procname = "nf_conntrack_tcp_timeout_last_ack",
1227 .data = &tcp_timeouts[TCP_CONNTRACK_LAST_ACK],
1228 .maxlen = sizeof(unsigned int),
1230 .proc_handler = &proc_dointvec_jiffies,
1233 .procname = "nf_conntrack_tcp_timeout_time_wait",
1234 .data = &tcp_timeouts[TCP_CONNTRACK_TIME_WAIT],
1235 .maxlen = sizeof(unsigned int),
1237 .proc_handler = &proc_dointvec_jiffies,
1240 .procname = "nf_conntrack_tcp_timeout_close",
1241 .data = &tcp_timeouts[TCP_CONNTRACK_CLOSE],
1242 .maxlen = sizeof(unsigned int),
1244 .proc_handler = &proc_dointvec_jiffies,
1247 .procname = "nf_conntrack_tcp_timeout_max_retrans",
1248 .data = &nf_ct_tcp_timeout_max_retrans,
1249 .maxlen = sizeof(unsigned int),
1251 .proc_handler = &proc_dointvec_jiffies,
1254 .procname = "nf_conntrack_tcp_timeout_unacknowledged",
1255 .data = &nf_ct_tcp_timeout_unacknowledged,
1256 .maxlen = sizeof(unsigned int),
1258 .proc_handler = &proc_dointvec_jiffies,
1261 .ctl_name = NET_NF_CONNTRACK_TCP_LOOSE,
1262 .procname = "nf_conntrack_tcp_loose",
1263 .data = &nf_ct_tcp_loose,
1264 .maxlen = sizeof(unsigned int),
1266 .proc_handler = &proc_dointvec,
1269 .ctl_name = NET_NF_CONNTRACK_TCP_BE_LIBERAL,
1270 .procname = "nf_conntrack_tcp_be_liberal",
1271 .data = &nf_ct_tcp_be_liberal,
1272 .maxlen = sizeof(unsigned int),
1274 .proc_handler = &proc_dointvec,
1277 .ctl_name = NET_NF_CONNTRACK_TCP_MAX_RETRANS,
1278 .procname = "nf_conntrack_tcp_max_retrans",
1279 .data = &nf_ct_tcp_max_retrans,
1280 .maxlen = sizeof(unsigned int),
1282 .proc_handler = &proc_dointvec,
1289 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1290 static struct ctl_table tcp_compat_sysctl_table[] = {
1292 .procname = "ip_conntrack_tcp_timeout_syn_sent",
1293 .data = &tcp_timeouts[TCP_CONNTRACK_SYN_SENT],
1294 .maxlen = sizeof(unsigned int),
1296 .proc_handler = &proc_dointvec_jiffies,
1299 .procname = "ip_conntrack_tcp_timeout_syn_recv",
1300 .data = &tcp_timeouts[TCP_CONNTRACK_SYN_RECV],
1301 .maxlen = sizeof(unsigned int),
1303 .proc_handler = &proc_dointvec_jiffies,
1306 .procname = "ip_conntrack_tcp_timeout_established",
1307 .data = &tcp_timeouts[TCP_CONNTRACK_ESTABLISHED],
1308 .maxlen = sizeof(unsigned int),
1310 .proc_handler = &proc_dointvec_jiffies,
1313 .procname = "ip_conntrack_tcp_timeout_fin_wait",
1314 .data = &tcp_timeouts[TCP_CONNTRACK_FIN_WAIT],
1315 .maxlen = sizeof(unsigned int),
1317 .proc_handler = &proc_dointvec_jiffies,
1320 .procname = "ip_conntrack_tcp_timeout_close_wait",
1321 .data = &tcp_timeouts[TCP_CONNTRACK_CLOSE_WAIT],
1322 .maxlen = sizeof(unsigned int),
1324 .proc_handler = &proc_dointvec_jiffies,
1327 .procname = "ip_conntrack_tcp_timeout_last_ack",
1328 .data = &tcp_timeouts[TCP_CONNTRACK_LAST_ACK],
1329 .maxlen = sizeof(unsigned int),
1331 .proc_handler = &proc_dointvec_jiffies,
1334 .procname = "ip_conntrack_tcp_timeout_time_wait",
1335 .data = &tcp_timeouts[TCP_CONNTRACK_TIME_WAIT],
1336 .maxlen = sizeof(unsigned int),
1338 .proc_handler = &proc_dointvec_jiffies,
1341 .procname = "ip_conntrack_tcp_timeout_close",
1342 .data = &tcp_timeouts[TCP_CONNTRACK_CLOSE],
1343 .maxlen = sizeof(unsigned int),
1345 .proc_handler = &proc_dointvec_jiffies,
1348 .procname = "ip_conntrack_tcp_timeout_max_retrans",
1349 .data = &nf_ct_tcp_timeout_max_retrans,
1350 .maxlen = sizeof(unsigned int),
1352 .proc_handler = &proc_dointvec_jiffies,
1355 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_LOOSE,
1356 .procname = "ip_conntrack_tcp_loose",
1357 .data = &nf_ct_tcp_loose,
1358 .maxlen = sizeof(unsigned int),
1360 .proc_handler = &proc_dointvec,
1363 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,
1364 .procname = "ip_conntrack_tcp_be_liberal",
1365 .data = &nf_ct_tcp_be_liberal,
1366 .maxlen = sizeof(unsigned int),
1368 .proc_handler = &proc_dointvec,
1371 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,
1372 .procname = "ip_conntrack_tcp_max_retrans",
1373 .data = &nf_ct_tcp_max_retrans,
1374 .maxlen = sizeof(unsigned int),
1376 .proc_handler = &proc_dointvec,
1382 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
1383 #endif /* CONFIG_SYSCTL */
1385 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly =
1388 .l4proto = IPPROTO_TCP,
1390 .pkt_to_tuple = tcp_pkt_to_tuple,
1391 .invert_tuple = tcp_invert_tuple,
1392 .print_tuple = tcp_print_tuple,
1393 .print_conntrack = tcp_print_conntrack,
1394 .packet = tcp_packet,
1397 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1398 .to_nlattr = tcp_to_nlattr,
1399 .from_nlattr = nlattr_to_tcp,
1400 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1401 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1402 .nla_policy = nf_ct_port_nla_policy,
1404 #ifdef CONFIG_SYSCTL
1405 .ctl_table_users = &tcp_sysctl_table_users,
1406 .ctl_table_header = &tcp_sysctl_header,
1407 .ctl_table = tcp_sysctl_table,
1408 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1409 .ctl_compat_table = tcp_compat_sysctl_table,
1413 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
1415 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly =
1417 .l3proto = PF_INET6,
1418 .l4proto = IPPROTO_TCP,
1420 .pkt_to_tuple = tcp_pkt_to_tuple,
1421 .invert_tuple = tcp_invert_tuple,
1422 .print_tuple = tcp_print_tuple,
1423 .print_conntrack = tcp_print_conntrack,
1424 .packet = tcp_packet,
1427 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1428 .to_nlattr = tcp_to_nlattr,
1429 .from_nlattr = nlattr_to_tcp,
1430 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
1431 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
1432 .nla_policy = nf_ct_port_nla_policy,
1434 #ifdef CONFIG_SYSCTL
1435 .ctl_table_users = &tcp_sysctl_table_users,
1436 .ctl_table_header = &tcp_sysctl_header,
1437 .ctl_table = tcp_sysctl_table,
1440 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);