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/netfilter.h>
12 #include <linux/module.h>
14 #include <linux/tcp.h>
15 #include <linux/spinlock.h>
16 #include <linux/skbuff.h>
17 #include <linux/ipv6.h>
18 #include <net/ip6_checksum.h>
22 #include <linux/netfilter.h>
23 #include <linux/netfilter_ipv4.h>
24 #include <linux/netfilter_ipv6.h>
25 #include <net/netfilter/nf_conntrack.h>
26 #include <net/netfilter/nf_conntrack_l4proto.h>
27 #include <net/netfilter/nf_conntrack_ecache.h>
33 #define DEBUGP(format, args...)
36 /* Protects conntrack->proto.tcp */
37 static DEFINE_RWLOCK(tcp_lock);
39 /* "Be conservative in what you do,
40 be liberal in what you accept from others."
41 If it's non-zero, we mark only out of window RST segments as INVALID. */
42 static int nf_ct_tcp_be_liberal __read_mostly = 0;
44 /* If it is set to zero, we disable picking up already established
46 static int nf_ct_tcp_loose __read_mostly = 1;
48 /* Max number of the retransmitted packets without receiving an (acceptable)
49 ACK from the destination. If this number is reached, a shorter timer
51 static int nf_ct_tcp_max_retrans __read_mostly = 3;
53 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
54 closely. They're more complex. --RR */
56 static const char *tcp_conntrack_names[] = {
70 #define MINS * 60 SECS
71 #define HOURS * 60 MINS
72 #define DAYS * 24 HOURS
74 static unsigned int nf_ct_tcp_timeout_syn_sent __read_mostly = 2 MINS;
75 static unsigned int nf_ct_tcp_timeout_syn_recv __read_mostly = 60 SECS;
76 static unsigned int nf_ct_tcp_timeout_established __read_mostly = 5 DAYS;
77 static unsigned int nf_ct_tcp_timeout_fin_wait __read_mostly = 2 MINS;
78 static unsigned int nf_ct_tcp_timeout_close_wait __read_mostly = 60 SECS;
79 static unsigned int nf_ct_tcp_timeout_last_ack __read_mostly = 30 SECS;
80 static unsigned int nf_ct_tcp_timeout_time_wait __read_mostly = 2 MINS;
81 static unsigned int nf_ct_tcp_timeout_close __read_mostly = 10 SECS;
83 /* RFC1122 says the R2 limit should be at least 100 seconds.
84 Linux uses 15 packets as limit, which corresponds
85 to ~13-30min depending on RTO. */
86 static unsigned int nf_ct_tcp_timeout_max_retrans __read_mostly = 5 MINS;
88 static unsigned int * tcp_timeouts[] = {
89 NULL, /* TCP_CONNTRACK_NONE */
90 &nf_ct_tcp_timeout_syn_sent, /* TCP_CONNTRACK_SYN_SENT, */
91 &nf_ct_tcp_timeout_syn_recv, /* TCP_CONNTRACK_SYN_RECV, */
92 &nf_ct_tcp_timeout_established, /* TCP_CONNTRACK_ESTABLISHED, */
93 &nf_ct_tcp_timeout_fin_wait, /* TCP_CONNTRACK_FIN_WAIT, */
94 &nf_ct_tcp_timeout_close_wait, /* TCP_CONNTRACK_CLOSE_WAIT, */
95 &nf_ct_tcp_timeout_last_ack, /* TCP_CONNTRACK_LAST_ACK, */
96 &nf_ct_tcp_timeout_time_wait, /* TCP_CONNTRACK_TIME_WAIT, */
97 &nf_ct_tcp_timeout_close, /* TCP_CONNTRACK_CLOSE, */
98 NULL, /* TCP_CONNTRACK_LISTEN */
101 #define sNO TCP_CONNTRACK_NONE
102 #define sSS TCP_CONNTRACK_SYN_SENT
103 #define sSR TCP_CONNTRACK_SYN_RECV
104 #define sES TCP_CONNTRACK_ESTABLISHED
105 #define sFW TCP_CONNTRACK_FIN_WAIT
106 #define sCW TCP_CONNTRACK_CLOSE_WAIT
107 #define sLA TCP_CONNTRACK_LAST_ACK
108 #define sTW TCP_CONNTRACK_TIME_WAIT
109 #define sCL TCP_CONNTRACK_CLOSE
110 #define sLI TCP_CONNTRACK_LISTEN
111 #define sIV TCP_CONNTRACK_MAX
112 #define sIG TCP_CONNTRACK_IGNORE
114 /* What TCP flags are set from RST/SYN/FIN/ACK. */
125 * The TCP state transition table needs a few words...
127 * We are the man in the middle. All the packets go through us
128 * but might get lost in transit to the destination.
129 * It is assumed that the destinations can't receive segments
132 * The checked segment is in window, but our windows are *not*
133 * equivalent with the ones of the sender/receiver. We always
134 * try to guess the state of the current sender.
136 * The meaning of the states are:
138 * NONE: initial state
139 * SYN_SENT: SYN-only packet seen
140 * SYN_RECV: SYN-ACK packet seen
141 * ESTABLISHED: ACK packet seen
142 * FIN_WAIT: FIN packet seen
143 * CLOSE_WAIT: ACK seen (after FIN)
144 * LAST_ACK: FIN seen (after FIN)
145 * TIME_WAIT: last ACK seen
146 * CLOSE: closed connection
148 * LISTEN state is not used.
150 * Packets marked as IGNORED (sIG):
151 * if they may be either invalid or valid
152 * and the receiver may send back a connection
153 * closing RST or a SYN/ACK.
155 * Packets marked as INVALID (sIV):
156 * if they are invalid
157 * or we do not support the request (simultaneous open)
159 static enum tcp_conntrack tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
162 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
163 /*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
165 * sNO -> sSS Initialize a new connection
166 * sSS -> sSS Retransmitted SYN
167 * sSR -> sIG Late retransmitted SYN?
168 * sES -> sIG Error: SYNs in window outside the SYN_SENT state
169 * are errors. Receiver will reply with RST
170 * and close the connection.
171 * Or we are not in sync and hold a dead connection.
175 * sTW -> sSS Reopened connection (RFC 1122).
178 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
179 /*synack*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
181 * A SYN/ACK from the client is always invalid:
182 * - either it tries to set up a simultaneous open, which is
184 * - or the firewall has just been inserted between the two hosts
185 * during the session set-up. The SYN will be retransmitted
186 * by the true client (or it'll time out).
188 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
189 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
191 * sNO -> sIV Too late and no reason to do anything...
192 * sSS -> sIV Client migth not send FIN in this state:
193 * we enforce waiting for a SYN/ACK reply first.
194 * sSR -> sFW Close started.
196 * sFW -> sLA FIN seen in both directions, waiting for
198 * Migth be a retransmitted FIN as well...
200 * sLA -> sLA Retransmitted FIN. Remain in the same state.
204 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
205 /*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
207 * sNO -> sES Assumed.
208 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
209 * sSR -> sES Established state is reached.
211 * sFW -> sCW Normal close request answered by ACK.
213 * sLA -> sTW Last ACK detected.
214 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
217 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
218 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
219 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
223 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
224 /*syn*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
226 * sNO -> sIV Never reached.
227 * sSS -> sIV Simultaneous open, not supported
228 * sSR -> sIV Simultaneous open, not supported.
229 * sES -> sIV Server may not initiate a connection.
233 * sTW -> sIV Reopened connection, but server may not do it.
236 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
237 /*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIV },
239 * sSS -> sSR Standard open.
240 * sSR -> sSR Retransmitted SYN/ACK.
241 * sES -> sIG Late retransmitted SYN/ACK?
242 * sFW -> sIG Might be SYN/ACK answering ignored SYN
248 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
249 /*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
251 * sSS -> sIV Server might not send FIN in this state.
252 * sSR -> sFW Close started.
254 * sFW -> sLA FIN seen in both directions.
256 * sLA -> sLA Retransmitted FIN.
260 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
261 /*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
263 * sSS -> sIG Might be a half-open connection.
264 * sSR -> sSR Might answer late resent SYN.
266 * sFW -> sCW Normal close request answered by ACK.
268 * sLA -> sTW Last ACK detected.
269 * sTW -> sTW Retransmitted last ACK.
272 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
273 /*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
274 /*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
278 static int tcp_pkt_to_tuple(const struct sk_buff *skb,
279 unsigned int dataoff,
280 struct nf_conntrack_tuple *tuple)
282 struct tcphdr _hdr, *hp;
284 /* Actually only need first 8 bytes. */
285 hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
289 tuple->src.u.tcp.port = hp->source;
290 tuple->dst.u.tcp.port = hp->dest;
295 static int tcp_invert_tuple(struct nf_conntrack_tuple *tuple,
296 const struct nf_conntrack_tuple *orig)
298 tuple->src.u.tcp.port = orig->dst.u.tcp.port;
299 tuple->dst.u.tcp.port = orig->src.u.tcp.port;
303 /* Print out the per-protocol part of the tuple. */
304 static int tcp_print_tuple(struct seq_file *s,
305 const struct nf_conntrack_tuple *tuple)
307 return seq_printf(s, "sport=%hu dport=%hu ",
308 ntohs(tuple->src.u.tcp.port),
309 ntohs(tuple->dst.u.tcp.port));
312 /* Print out the private part of the conntrack. */
313 static int tcp_print_conntrack(struct seq_file *s,
314 const struct nf_conn *conntrack)
316 enum tcp_conntrack state;
318 read_lock_bh(&tcp_lock);
319 state = conntrack->proto.tcp.state;
320 read_unlock_bh(&tcp_lock);
322 return seq_printf(s, "%s ", tcp_conntrack_names[state]);
325 static unsigned int get_conntrack_index(const struct tcphdr *tcph)
327 if (tcph->rst) return TCP_RST_SET;
328 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
329 else if (tcph->fin) return TCP_FIN_SET;
330 else if (tcph->ack) return TCP_ACK_SET;
331 else return TCP_NONE_SET;
334 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
335 in IP Filter' by Guido van Rooij.
337 http://www.nluug.nl/events/sane2000/papers.html
338 http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
340 The boundaries and the conditions are changed according to RFC793:
341 the packet must intersect the window (i.e. segments may be
342 after the right or before the left edge) and thus receivers may ACK
343 segments after the right edge of the window.
345 td_maxend = max(sack + max(win,1)) seen in reply packets
346 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
347 td_maxwin += seq + len - sender.td_maxend
348 if seq + len > sender.td_maxend
349 td_end = max(seq + len) seen in sent packets
351 I. Upper bound for valid data: seq <= sender.td_maxend
352 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
353 III. Upper bound for valid ack: sack <= receiver.td_end
354 IV. Lower bound for valid ack: ack >= receiver.td_end - MAXACKWINDOW
356 where sack is the highest right edge of sack block found in the packet.
358 The upper bound limit for a valid ack is not ignored -
359 we doesn't have to deal with fragments.
362 static inline __u32 segment_seq_plus_len(__u32 seq,
364 unsigned int dataoff,
367 /* XXX Should I use payload length field in IP/IPv6 header ?
369 return (seq + len - dataoff - tcph->doff*4
370 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
373 /* Fixme: what about big packets? */
374 #define MAXACKWINCONST 66000
375 #define MAXACKWINDOW(sender) \
376 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
380 * Simplified tcp_parse_options routine from tcp_input.c
382 static void tcp_options(const struct sk_buff *skb,
383 unsigned int dataoff,
385 struct ip_ct_tcp_state *state)
387 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
389 int length = (tcph->doff*4) - sizeof(struct tcphdr);
394 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
408 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
413 if (opsize < 2) /* "silly options" */
416 break; /* don't parse partial options */
418 if (opcode == TCPOPT_SACK_PERM
419 && opsize == TCPOLEN_SACK_PERM)
420 state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
421 else if (opcode == TCPOPT_WINDOW
422 && opsize == TCPOLEN_WINDOW) {
423 state->td_scale = *(u_int8_t *)ptr;
425 if (state->td_scale > 14) {
427 state->td_scale = 14;
430 IP_CT_TCP_FLAG_WINDOW_SCALE;
438 static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
439 struct tcphdr *tcph, __u32 *sack)
441 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)];
443 int length = (tcph->doff*4) - sizeof(struct tcphdr);
449 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr),
453 /* Fast path for timestamp-only option */
454 if (length == TCPOLEN_TSTAMP_ALIGNED*4
455 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24)
457 | (TCPOPT_TIMESTAMP << 8)
458 | TCPOLEN_TIMESTAMP))
468 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
473 if (opsize < 2) /* "silly options" */
476 break; /* don't parse partial options */
478 if (opcode == TCPOPT_SACK
479 && opsize >= (TCPOLEN_SACK_BASE
480 + TCPOLEN_SACK_PERBLOCK)
481 && !((opsize - TCPOLEN_SACK_BASE)
482 % TCPOLEN_SACK_PERBLOCK)) {
484 i < (opsize - TCPOLEN_SACK_BASE);
485 i += TCPOLEN_SACK_PERBLOCK) {
486 tmp = ntohl(*((__be32 *)(ptr+i)+1));
488 if (after(tmp, *sack))
499 static int tcp_in_window(struct ip_ct_tcp *state,
500 enum ip_conntrack_dir dir,
502 const struct sk_buff *skb,
503 unsigned int dataoff,
507 struct ip_ct_tcp_state *sender = &state->seen[dir];
508 struct ip_ct_tcp_state *receiver = &state->seen[!dir];
509 __u32 seq, ack, sack, end, win, swin;
513 * Get the required data from the packet.
515 seq = ntohl(tcph->seq);
516 ack = sack = ntohl(tcph->ack_seq);
517 win = ntohs(tcph->window);
518 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph);
520 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
521 tcp_sack(skb, dataoff, tcph, &sack);
523 DEBUGP("tcp_in_window: START\n");
524 DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
525 "seq=%u ack=%u sack=%u win=%u end=%u\n",
526 NIPQUAD(iph->saddr), ntohs(tcph->source),
527 NIPQUAD(iph->daddr), ntohs(tcph->dest),
528 seq, ack, sack, win, end);
529 DEBUGP("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,
533 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
536 if (sender->td_end == 0) {
538 * Initialize sender data.
540 if (tcph->syn && tcph->ack) {
542 * Outgoing SYN-ACK in reply to a SYN.
545 sender->td_maxend = end;
546 sender->td_maxwin = (win == 0 ? 1 : win);
548 tcp_options(skb, dataoff, tcph, sender);
551 * Both sides must send the Window Scale option
552 * to enable window scaling in either direction.
554 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE
555 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
557 receiver->td_scale = 0;
560 * We are in the middle of a connection,
561 * its history is lost for us.
562 * Let's try to use the data from the packet.
564 sender->td_end = end;
565 sender->td_maxwin = (win == 0 ? 1 : win);
566 sender->td_maxend = end + sender->td_maxwin;
568 } else if (((state->state == TCP_CONNTRACK_SYN_SENT
569 && dir == IP_CT_DIR_ORIGINAL)
570 || (state->state == TCP_CONNTRACK_SYN_RECV
571 && dir == IP_CT_DIR_REPLY))
572 && after(end, sender->td_end)) {
574 * RFC 793: "if a TCP is reinitialized ... then it need
575 * not wait at all; it must only be sure to use sequence
576 * numbers larger than those recently used."
579 sender->td_maxend = end;
580 sender->td_maxwin = (win == 0 ? 1 : win);
582 tcp_options(skb, dataoff, tcph, sender);
587 * If there is no ACK, just pretend it was set and OK.
589 ack = sack = receiver->td_end;
590 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
591 (TCP_FLAG_ACK|TCP_FLAG_RST))
594 * Broken TCP stacks, that set ACK in RST packets as well
595 * with zero ack value.
597 ack = sack = receiver->td_end;
602 || (seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT)))
604 * Packets contains no data: we assume it is valid
605 * and check the ack value only.
606 * However RST segments are always validated by their
607 * SEQ number, except when seq == 0 (reset sent answering
610 seq = end = sender->td_end;
612 DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
613 "seq=%u ack=%u sack =%u win=%u end=%u\n",
614 NIPQUAD(iph->saddr), ntohs(tcph->source),
615 NIPQUAD(iph->daddr), ntohs(tcph->dest),
616 seq, ack, sack, win, end);
617 DEBUGP("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
618 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
619 sender->td_end, sender->td_maxend, sender->td_maxwin,
621 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
624 DEBUGP("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
625 before(seq, sender->td_maxend + 1),
626 after(end, sender->td_end - receiver->td_maxwin - 1),
627 before(sack, receiver->td_end + 1),
628 after(ack, receiver->td_end - MAXACKWINDOW(sender)));
630 if (before(seq, sender->td_maxend + 1) &&
631 after(end, sender->td_end - receiver->td_maxwin - 1) &&
632 before(sack, receiver->td_end + 1) &&
633 after(ack, receiver->td_end - MAXACKWINDOW(sender))) {
635 * Take into account window scaling (RFC 1323).
638 win <<= sender->td_scale;
641 * Update sender data.
643 swin = win + (sack - ack);
644 if (sender->td_maxwin < swin)
645 sender->td_maxwin = swin;
646 if (after(end, sender->td_end))
647 sender->td_end = end;
649 * Update receiver data.
651 if (after(end, sender->td_maxend))
652 receiver->td_maxwin += end - sender->td_maxend;
653 if (after(sack + win, receiver->td_maxend - 1)) {
654 receiver->td_maxend = sack + win;
656 receiver->td_maxend++;
660 * Check retransmissions.
662 if (index == TCP_ACK_SET) {
663 if (state->last_dir == dir
664 && state->last_seq == seq
665 && state->last_ack == ack
666 && state->last_end == end
667 && state->last_win == win)
670 state->last_dir = dir;
671 state->last_seq = seq;
672 state->last_ack = ack;
673 state->last_end = end;
674 state->last_win = win;
681 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
682 nf_ct_tcp_be_liberal)
684 if (!res && LOG_INVALID(IPPROTO_TCP))
685 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
687 before(seq, sender->td_maxend + 1) ?
688 after(end, sender->td_end - receiver->td_maxwin - 1) ?
689 before(sack, receiver->td_end + 1) ?
690 after(ack, receiver->td_end - MAXACKWINDOW(sender)) ? "BUG"
691 : "ACK is under the lower bound (possible overly delayed ACK)"
692 : "ACK is over the upper bound (ACKed data not seen yet)"
693 : "SEQ is under the lower bound (already ACKed data retransmitted)"
694 : "SEQ is over the upper bound (over the window of the receiver)");
697 DEBUGP("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
698 "receiver end=%u maxend=%u maxwin=%u\n",
699 res, sender->td_end, sender->td_maxend, sender->td_maxwin,
700 receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
705 #ifdef CONFIG_NF_NAT_NEEDED
706 /* Update sender->td_end after NAT successfully mangled the packet */
707 /* Caller must linearize skb at tcp header. */
708 void nf_conntrack_tcp_update(struct sk_buff *skb,
709 unsigned int dataoff,
710 struct nf_conn *conntrack,
713 struct tcphdr *tcph = (void *)skb->data + dataoff;
716 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[dir];
717 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[!dir];
720 end = segment_seq_plus_len(ntohl(tcph->seq), skb->len, dataoff, tcph);
722 write_lock_bh(&tcp_lock);
724 * We have to worry for the ack in the reply packet only...
726 if (after(end, conntrack->proto.tcp.seen[dir].td_end))
727 conntrack->proto.tcp.seen[dir].td_end = end;
728 conntrack->proto.tcp.last_end = end;
729 write_unlock_bh(&tcp_lock);
730 DEBUGP("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
731 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
732 sender->td_end, sender->td_maxend, sender->td_maxwin,
734 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
737 EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
749 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
750 static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG) + 1] =
758 [TH_FIN|TH_ACK|TH_URG] = 1,
763 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
764 static int tcp_error(struct sk_buff *skb,
765 unsigned int dataoff,
766 enum ip_conntrack_info *ctinfo,
768 unsigned int hooknum)
770 struct tcphdr _tcph, *th;
771 unsigned int tcplen = skb->len - dataoff;
774 /* Smaller that minimal TCP header? */
775 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
777 if (LOG_INVALID(IPPROTO_TCP))
778 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
779 "nf_ct_tcp: short packet ");
783 /* Not whole TCP header or malformed packet */
784 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) {
785 if (LOG_INVALID(IPPROTO_TCP))
786 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
787 "nf_ct_tcp: truncated/malformed packet ");
791 /* Checksum invalid? Ignore.
792 * We skip checking packets on the outgoing path
793 * because the checksum is assumed to be correct.
795 /* FIXME: Source route IP option packets --RR */
796 if (nf_conntrack_checksum &&
797 ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
798 (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
799 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
800 if (LOG_INVALID(IPPROTO_TCP))
801 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
802 "nf_ct_tcp: bad TCP checksum ");
806 /* Check TCP flags. */
807 tcpflags = (((u_int8_t *)th)[13] & ~(TH_ECE|TH_CWR|TH_PUSH));
808 if (!tcp_valid_flags[tcpflags]) {
809 if (LOG_INVALID(IPPROTO_TCP))
810 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
811 "nf_ct_tcp: invalid TCP flag combination ");
818 /* Returns verdict for packet, or -1 for invalid. */
819 static int tcp_packet(struct nf_conn *conntrack,
820 const struct sk_buff *skb,
821 unsigned int dataoff,
822 enum ip_conntrack_info ctinfo,
824 unsigned int hooknum)
826 enum tcp_conntrack new_state, old_state;
827 enum ip_conntrack_dir dir;
828 struct tcphdr *th, _tcph;
829 unsigned long timeout;
832 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
835 write_lock_bh(&tcp_lock);
836 old_state = conntrack->proto.tcp.state;
837 dir = CTINFO2DIR(ctinfo);
838 index = get_conntrack_index(th);
839 new_state = tcp_conntracks[dir][index][old_state];
842 case TCP_CONNTRACK_IGNORE:
846 * b) SYN/ACK in REPLY
847 * c) ACK in reply direction after initial SYN in original.
849 if (index == TCP_SYNACK_SET
850 && conntrack->proto.tcp.last_index == TCP_SYN_SET
851 && conntrack->proto.tcp.last_dir != dir
852 && ntohl(th->ack_seq) ==
853 conntrack->proto.tcp.last_end) {
854 /* This SYN/ACK acknowledges a SYN that we earlier
855 * ignored as invalid. This means that the client and
856 * the server are both in sync, while the firewall is
857 * not. We kill this session and block the SYN/ACK so
858 * that the client cannot but retransmit its SYN and
859 * thus initiate a clean new session.
861 write_unlock_bh(&tcp_lock);
862 if (LOG_INVALID(IPPROTO_TCP))
863 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
864 "nf_ct_tcp: killing out of sync session ");
865 if (del_timer(&conntrack->timeout))
866 conntrack->timeout.function((unsigned long)
870 conntrack->proto.tcp.last_index = index;
871 conntrack->proto.tcp.last_dir = dir;
872 conntrack->proto.tcp.last_seq = ntohl(th->seq);
873 conntrack->proto.tcp.last_end =
874 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th);
876 write_unlock_bh(&tcp_lock);
877 if (LOG_INVALID(IPPROTO_TCP))
878 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
879 "nf_ct_tcp: invalid packed ignored ");
881 case TCP_CONNTRACK_MAX:
883 DEBUGP("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
884 dir, get_conntrack_index(th),
886 write_unlock_bh(&tcp_lock);
887 if (LOG_INVALID(IPPROTO_TCP))
888 nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
889 "nf_ct_tcp: invalid state ");
891 case TCP_CONNTRACK_SYN_SENT:
892 if (old_state < TCP_CONNTRACK_TIME_WAIT)
894 if ((conntrack->proto.tcp.seen[dir].flags &
895 IP_CT_TCP_FLAG_CLOSE_INIT)
896 || after(ntohl(th->seq),
897 conntrack->proto.tcp.seen[dir].td_end)) {
898 /* Attempt to reopen a closed connection.
899 * Delete this connection and look up again. */
900 write_unlock_bh(&tcp_lock);
901 if (del_timer(&conntrack->timeout))
902 conntrack->timeout.function((unsigned long)
906 write_unlock_bh(&tcp_lock);
907 if (LOG_INVALID(IPPROTO_TCP))
908 nf_log_packet(pf, 0, skb, NULL, NULL,
909 NULL, "nf_ct_tcp: invalid SYN");
912 case TCP_CONNTRACK_CLOSE:
913 if (index == TCP_RST_SET
914 && ((test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
915 && conntrack->proto.tcp.last_index == TCP_SYN_SET)
916 || (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
917 && conntrack->proto.tcp.last_index == TCP_ACK_SET))
918 && ntohl(th->ack_seq) == conntrack->proto.tcp.last_end) {
919 /* RST sent to invalid SYN or ACK we had let through
920 * at a) and c) above:
922 * a) SYN was in window then
923 * c) we hold a half-open connection.
925 * Delete our connection entry.
926 * We skip window checking, because packet might ACK
927 * segments we ignored. */
930 /* Just fall through */
932 /* Keep compilers happy. */
936 if (!tcp_in_window(&conntrack->proto.tcp, dir, index,
937 skb, dataoff, th, pf)) {
938 write_unlock_bh(&tcp_lock);
942 /* From now on we have got in-window packets */
943 conntrack->proto.tcp.last_index = index;
945 DEBUGP("tcp_conntracks: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
946 "syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
947 NIPQUAD(iph->saddr), ntohs(th->source),
948 NIPQUAD(iph->daddr), ntohs(th->dest),
949 (th->syn ? 1 : 0), (th->ack ? 1 : 0),
950 (th->fin ? 1 : 0), (th->rst ? 1 : 0),
951 old_state, new_state);
953 conntrack->proto.tcp.state = new_state;
954 if (old_state != new_state
955 && (new_state == TCP_CONNTRACK_FIN_WAIT
956 || new_state == TCP_CONNTRACK_CLOSE))
957 conntrack->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT;
958 timeout = conntrack->proto.tcp.retrans >= nf_ct_tcp_max_retrans
959 && *tcp_timeouts[new_state] > nf_ct_tcp_timeout_max_retrans
960 ? nf_ct_tcp_timeout_max_retrans : *tcp_timeouts[new_state];
961 write_unlock_bh(&tcp_lock);
963 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
964 if (new_state != old_state)
965 nf_conntrack_event_cache(IPCT_PROTOINFO, skb);
967 if (!test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
968 /* If only reply is a RST, we can consider ourselves not to
969 have an established connection: this is a fairly common
970 problem case, so we can delete the conntrack
973 if (del_timer(&conntrack->timeout))
974 conntrack->timeout.function((unsigned long)
978 } else if (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
979 && (old_state == TCP_CONNTRACK_SYN_RECV
980 || old_state == TCP_CONNTRACK_ESTABLISHED)
981 && new_state == TCP_CONNTRACK_ESTABLISHED) {
982 /* Set ASSURED if we see see valid ack in ESTABLISHED
983 after SYN_RECV or a valid answer for a picked up
985 set_bit(IPS_ASSURED_BIT, &conntrack->status);
986 nf_conntrack_event_cache(IPCT_STATUS, skb);
988 nf_ct_refresh_acct(conntrack, ctinfo, skb, timeout);
993 /* Called when a new connection for this protocol found. */
994 static int tcp_new(struct nf_conn *conntrack,
995 const struct sk_buff *skb,
996 unsigned int dataoff)
998 enum tcp_conntrack new_state;
999 struct tcphdr *th, _tcph;
1001 struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[0];
1002 struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[1];
1005 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
1008 /* Don't need lock here: this conntrack not in circulation yet */
1010 = tcp_conntracks[0][get_conntrack_index(th)]
1011 [TCP_CONNTRACK_NONE];
1013 /* Invalid: delete conntrack */
1014 if (new_state >= TCP_CONNTRACK_MAX) {
1015 DEBUGP("nf_ct_tcp: invalid new deleting.\n");
1019 if (new_state == TCP_CONNTRACK_SYN_SENT) {
1021 conntrack->proto.tcp.seen[0].td_end =
1022 segment_seq_plus_len(ntohl(th->seq), skb->len,
1024 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1025 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1026 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1027 conntrack->proto.tcp.seen[0].td_maxend =
1028 conntrack->proto.tcp.seen[0].td_end;
1030 tcp_options(skb, dataoff, th, &conntrack->proto.tcp.seen[0]);
1031 conntrack->proto.tcp.seen[1].flags = 0;
1032 } else if (nf_ct_tcp_loose == 0) {
1033 /* Don't try to pick up connections. */
1037 * We are in the middle of a connection,
1038 * its history is lost for us.
1039 * Let's try to use the data from the packet.
1041 conntrack->proto.tcp.seen[0].td_end =
1042 segment_seq_plus_len(ntohl(th->seq), skb->len,
1044 conntrack->proto.tcp.seen[0].td_maxwin = ntohs(th->window);
1045 if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
1046 conntrack->proto.tcp.seen[0].td_maxwin = 1;
1047 conntrack->proto.tcp.seen[0].td_maxend =
1048 conntrack->proto.tcp.seen[0].td_end +
1049 conntrack->proto.tcp.seen[0].td_maxwin;
1050 conntrack->proto.tcp.seen[0].td_scale = 0;
1052 /* We assume SACK and liberal window checking to handle
1054 conntrack->proto.tcp.seen[0].flags =
1055 conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM |
1056 IP_CT_TCP_FLAG_BE_LIBERAL;
1059 conntrack->proto.tcp.seen[1].td_end = 0;
1060 conntrack->proto.tcp.seen[1].td_maxend = 0;
1061 conntrack->proto.tcp.seen[1].td_maxwin = 1;
1062 conntrack->proto.tcp.seen[1].td_scale = 0;
1064 /* tcp_packet will set them */
1065 conntrack->proto.tcp.state = TCP_CONNTRACK_NONE;
1066 conntrack->proto.tcp.last_index = TCP_NONE_SET;
1068 DEBUGP("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1069 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1070 sender->td_end, sender->td_maxend, sender->td_maxwin,
1072 receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
1073 receiver->td_scale);
1077 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1079 #include <linux/netfilter/nfnetlink.h>
1080 #include <linux/netfilter/nfnetlink_conntrack.h>
1082 static int tcp_to_nfattr(struct sk_buff *skb, struct nfattr *nfa,
1083 const struct nf_conn *ct)
1085 struct nfattr *nest_parms;
1086 struct nf_ct_tcp_flags tmp = {};
1088 read_lock_bh(&tcp_lock);
1089 nest_parms = NFA_NEST(skb, CTA_PROTOINFO_TCP);
1090 NFA_PUT(skb, CTA_PROTOINFO_TCP_STATE, sizeof(u_int8_t),
1091 &ct->proto.tcp.state);
1093 NFA_PUT(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL, sizeof(u_int8_t),
1094 &ct->proto.tcp.seen[0].td_scale);
1096 NFA_PUT(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY, sizeof(u_int8_t),
1097 &ct->proto.tcp.seen[1].td_scale);
1099 tmp.flags = ct->proto.tcp.seen[0].flags;
1100 NFA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL,
1101 sizeof(struct nf_ct_tcp_flags), &tmp);
1103 tmp.flags = ct->proto.tcp.seen[1].flags;
1104 NFA_PUT(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY,
1105 sizeof(struct nf_ct_tcp_flags), &tmp);
1106 read_unlock_bh(&tcp_lock);
1108 NFA_NEST_END(skb, nest_parms);
1113 read_unlock_bh(&tcp_lock);
1117 static const size_t cta_min_tcp[CTA_PROTOINFO_TCP_MAX] = {
1118 [CTA_PROTOINFO_TCP_STATE-1] = sizeof(u_int8_t),
1119 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL-1] = sizeof(u_int8_t),
1120 [CTA_PROTOINFO_TCP_WSCALE_REPLY-1] = sizeof(u_int8_t),
1121 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL-1] = sizeof(struct nf_ct_tcp_flags),
1122 [CTA_PROTOINFO_TCP_FLAGS_REPLY-1] = sizeof(struct nf_ct_tcp_flags)
1125 static int nfattr_to_tcp(struct nfattr *cda[], struct nf_conn *ct)
1127 struct nfattr *attr = cda[CTA_PROTOINFO_TCP-1];
1128 struct nfattr *tb[CTA_PROTOINFO_TCP_MAX];
1130 /* updates could not contain anything about the private
1131 * protocol info, in that case skip the parsing */
1135 nfattr_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, attr);
1137 if (nfattr_bad_size(tb, CTA_PROTOINFO_TCP_MAX, cta_min_tcp))
1140 if (!tb[CTA_PROTOINFO_TCP_STATE-1])
1143 write_lock_bh(&tcp_lock);
1144 ct->proto.tcp.state =
1145 *(u_int8_t *)NFA_DATA(tb[CTA_PROTOINFO_TCP_STATE-1]);
1147 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL-1]) {
1148 struct nf_ct_tcp_flags *attr =
1149 NFA_DATA(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL-1]);
1150 ct->proto.tcp.seen[0].flags &= ~attr->mask;
1151 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask;
1154 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY-1]) {
1155 struct nf_ct_tcp_flags *attr =
1156 NFA_DATA(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY-1]);
1157 ct->proto.tcp.seen[1].flags &= ~attr->mask;
1158 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask;
1161 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL-1] &&
1162 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY-1] &&
1163 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE &&
1164 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) {
1165 ct->proto.tcp.seen[0].td_scale = *(u_int8_t *)
1166 NFA_DATA(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL-1]);
1167 ct->proto.tcp.seen[1].td_scale = *(u_int8_t *)
1168 NFA_DATA(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY-1]);
1170 write_unlock_bh(&tcp_lock);
1176 #ifdef CONFIG_SYSCTL
1177 static unsigned int tcp_sysctl_table_users;
1178 static struct ctl_table_header *tcp_sysctl_header;
1179 static struct ctl_table tcp_sysctl_table[] = {
1181 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
1182 .procname = "nf_conntrack_tcp_timeout_syn_sent",
1183 .data = &nf_ct_tcp_timeout_syn_sent,
1184 .maxlen = sizeof(unsigned int),
1186 .proc_handler = &proc_dointvec_jiffies,
1189 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV,
1190 .procname = "nf_conntrack_tcp_timeout_syn_recv",
1191 .data = &nf_ct_tcp_timeout_syn_recv,
1192 .maxlen = sizeof(unsigned int),
1194 .proc_handler = &proc_dointvec_jiffies,
1197 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED,
1198 .procname = "nf_conntrack_tcp_timeout_established",
1199 .data = &nf_ct_tcp_timeout_established,
1200 .maxlen = sizeof(unsigned int),
1202 .proc_handler = &proc_dointvec_jiffies,
1205 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT,
1206 .procname = "nf_conntrack_tcp_timeout_fin_wait",
1207 .data = &nf_ct_tcp_timeout_fin_wait,
1208 .maxlen = sizeof(unsigned int),
1210 .proc_handler = &proc_dointvec_jiffies,
1213 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT,
1214 .procname = "nf_conntrack_tcp_timeout_close_wait",
1215 .data = &nf_ct_tcp_timeout_close_wait,
1216 .maxlen = sizeof(unsigned int),
1218 .proc_handler = &proc_dointvec_jiffies,
1221 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK,
1222 .procname = "nf_conntrack_tcp_timeout_last_ack",
1223 .data = &nf_ct_tcp_timeout_last_ack,
1224 .maxlen = sizeof(unsigned int),
1226 .proc_handler = &proc_dointvec_jiffies,
1229 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT,
1230 .procname = "nf_conntrack_tcp_timeout_time_wait",
1231 .data = &nf_ct_tcp_timeout_time_wait,
1232 .maxlen = sizeof(unsigned int),
1234 .proc_handler = &proc_dointvec_jiffies,
1237 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE,
1238 .procname = "nf_conntrack_tcp_timeout_close",
1239 .data = &nf_ct_tcp_timeout_close,
1240 .maxlen = sizeof(unsigned int),
1242 .proc_handler = &proc_dointvec_jiffies,
1245 .ctl_name = NET_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS,
1246 .procname = "nf_conntrack_tcp_timeout_max_retrans",
1247 .data = &nf_ct_tcp_timeout_max_retrans,
1248 .maxlen = sizeof(unsigned int),
1250 .proc_handler = &proc_dointvec_jiffies,
1253 .ctl_name = NET_NF_CONNTRACK_TCP_LOOSE,
1254 .procname = "nf_conntrack_tcp_loose",
1255 .data = &nf_ct_tcp_loose,
1256 .maxlen = sizeof(unsigned int),
1258 .proc_handler = &proc_dointvec,
1261 .ctl_name = NET_NF_CONNTRACK_TCP_BE_LIBERAL,
1262 .procname = "nf_conntrack_tcp_be_liberal",
1263 .data = &nf_ct_tcp_be_liberal,
1264 .maxlen = sizeof(unsigned int),
1266 .proc_handler = &proc_dointvec,
1269 .ctl_name = NET_NF_CONNTRACK_TCP_MAX_RETRANS,
1270 .procname = "nf_conntrack_tcp_max_retrans",
1271 .data = &nf_ct_tcp_max_retrans,
1272 .maxlen = sizeof(unsigned int),
1274 .proc_handler = &proc_dointvec,
1281 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1282 static struct ctl_table tcp_compat_sysctl_table[] = {
1284 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
1285 .procname = "ip_conntrack_tcp_timeout_syn_sent",
1286 .data = &nf_ct_tcp_timeout_syn_sent,
1287 .maxlen = sizeof(unsigned int),
1289 .proc_handler = &proc_dointvec_jiffies,
1292 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV,
1293 .procname = "ip_conntrack_tcp_timeout_syn_recv",
1294 .data = &nf_ct_tcp_timeout_syn_recv,
1295 .maxlen = sizeof(unsigned int),
1297 .proc_handler = &proc_dointvec_jiffies,
1300 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED,
1301 .procname = "ip_conntrack_tcp_timeout_established",
1302 .data = &nf_ct_tcp_timeout_established,
1303 .maxlen = sizeof(unsigned int),
1305 .proc_handler = &proc_dointvec_jiffies,
1308 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT,
1309 .procname = "ip_conntrack_tcp_timeout_fin_wait",
1310 .data = &nf_ct_tcp_timeout_fin_wait,
1311 .maxlen = sizeof(unsigned int),
1313 .proc_handler = &proc_dointvec_jiffies,
1316 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT,
1317 .procname = "ip_conntrack_tcp_timeout_close_wait",
1318 .data = &nf_ct_tcp_timeout_close_wait,
1319 .maxlen = sizeof(unsigned int),
1321 .proc_handler = &proc_dointvec_jiffies,
1324 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK,
1325 .procname = "ip_conntrack_tcp_timeout_last_ack",
1326 .data = &nf_ct_tcp_timeout_last_ack,
1327 .maxlen = sizeof(unsigned int),
1329 .proc_handler = &proc_dointvec_jiffies,
1332 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT,
1333 .procname = "ip_conntrack_tcp_timeout_time_wait",
1334 .data = &nf_ct_tcp_timeout_time_wait,
1335 .maxlen = sizeof(unsigned int),
1337 .proc_handler = &proc_dointvec_jiffies,
1340 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE,
1341 .procname = "ip_conntrack_tcp_timeout_close",
1342 .data = &nf_ct_tcp_timeout_close,
1343 .maxlen = sizeof(unsigned int),
1345 .proc_handler = &proc_dointvec_jiffies,
1348 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS,
1349 .procname = "ip_conntrack_tcp_timeout_max_retrans",
1350 .data = &nf_ct_tcp_timeout_max_retrans,
1351 .maxlen = sizeof(unsigned int),
1353 .proc_handler = &proc_dointvec_jiffies,
1356 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_LOOSE,
1357 .procname = "ip_conntrack_tcp_loose",
1358 .data = &nf_ct_tcp_loose,
1359 .maxlen = sizeof(unsigned int),
1361 .proc_handler = &proc_dointvec,
1364 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,
1365 .procname = "ip_conntrack_tcp_be_liberal",
1366 .data = &nf_ct_tcp_be_liberal,
1367 .maxlen = sizeof(unsigned int),
1369 .proc_handler = &proc_dointvec,
1372 .ctl_name = NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,
1373 .procname = "ip_conntrack_tcp_max_retrans",
1374 .data = &nf_ct_tcp_max_retrans,
1375 .maxlen = sizeof(unsigned int),
1377 .proc_handler = &proc_dointvec,
1383 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
1384 #endif /* CONFIG_SYSCTL */
1386 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 =
1389 .l4proto = IPPROTO_TCP,
1391 .pkt_to_tuple = tcp_pkt_to_tuple,
1392 .invert_tuple = tcp_invert_tuple,
1393 .print_tuple = tcp_print_tuple,
1394 .print_conntrack = tcp_print_conntrack,
1395 .packet = tcp_packet,
1398 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1399 .to_nfattr = tcp_to_nfattr,
1400 .from_nfattr = nfattr_to_tcp,
1401 .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
1402 .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
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 =
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_nfattr = tcp_to_nfattr,
1429 .from_nfattr = nfattr_to_tcp,
1430 .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
1431 .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
1433 #ifdef CONFIG_SYSCTL
1434 .ctl_table_users = &tcp_sysctl_table_users,
1435 .ctl_table_header = &tcp_sysctl_header,
1436 .ctl_table = tcp_sysctl_table,
1439 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);