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>
18 #include <asm/unaligned.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>
28 #include <net/netfilter/nf_log.h>
29 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
30 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
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
,
82 [TCP_CONNTRACK_SYN_SENT2
] = 2 MINS
,
85 #define sNO TCP_CONNTRACK_NONE
86 #define sSS TCP_CONNTRACK_SYN_SENT
87 #define sSR TCP_CONNTRACK_SYN_RECV
88 #define sES TCP_CONNTRACK_ESTABLISHED
89 #define sFW TCP_CONNTRACK_FIN_WAIT
90 #define sCW TCP_CONNTRACK_CLOSE_WAIT
91 #define sLA TCP_CONNTRACK_LAST_ACK
92 #define sTW TCP_CONNTRACK_TIME_WAIT
93 #define sCL TCP_CONNTRACK_CLOSE
94 #define sS2 TCP_CONNTRACK_SYN_SENT2
95 #define sIV TCP_CONNTRACK_MAX
96 #define sIG TCP_CONNTRACK_IGNORE
98 /* What TCP flags are set from RST/SYN/FIN/ACK. */
109 * The TCP state transition table needs a few words...
111 * We are the man in the middle. All the packets go through us
112 * but might get lost in transit to the destination.
113 * It is assumed that the destinations can't receive segments
116 * The checked segment is in window, but our windows are *not*
117 * equivalent with the ones of the sender/receiver. We always
118 * try to guess the state of the current sender.
120 * The meaning of the states are:
122 * NONE: initial state
123 * SYN_SENT: SYN-only packet seen
124 * SYN_SENT2: SYN-only packet seen from reply dir, simultaneous open
125 * SYN_RECV: SYN-ACK packet seen
126 * ESTABLISHED: ACK packet seen
127 * FIN_WAIT: FIN packet seen
128 * CLOSE_WAIT: ACK seen (after FIN)
129 * LAST_ACK: FIN seen (after FIN)
130 * TIME_WAIT: last ACK seen
131 * CLOSE: closed connection (RST)
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 we regard them as truly invalid packets
141 static const u8 tcp_conntracks
[2][6][TCP_CONNTRACK_MAX
] = {
144 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
145 /*syn*/ { sSS
, sSS
, sIG
, sIG
, sIG
, sIG
, sIG
, sSS
, sSS
, sS2
},
147 * sNO -> sSS Initialize a new connection
148 * sSS -> sSS Retransmitted SYN
149 * sS2 -> sS2 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, sS2 */
162 /*synack*/ { sIV
, sIV
, sIG
, sIG
, sIG
, sIG
, sIG
, sIG
, sIG
, sSR
},
164 * sNO -> sIV Too late and no reason to do anything
165 * sSS -> sIV Client can't send SYN and then SYN/ACK
166 * sS2 -> sSR SYN/ACK sent to SYN2 in simultaneous open
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.
178 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
179 /*fin*/ { sIV
, sIV
, sFW
, sFW
, sLA
, sLA
, sLA
, sTW
, sCL
, sIV
},
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.
185 * sSR -> sFW Close started.
187 * sFW -> sLA FIN seen in both directions, waiting for
189 * Migth be a retransmitted FIN as well...
191 * sLA -> sLA Retransmitted FIN. Remain in the same state.
195 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
196 /*ack*/ { sES
, sIV
, sES
, sES
, sCW
, sCW
, sTW
, sTW
, sCL
, sIV
},
198 * sNO -> sES Assumed.
199 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
201 * sSR -> sES Established state is reached.
203 * sFW -> sCW Normal close request answered by ACK.
205 * sLA -> sTW Last ACK detected.
206 * sTW -> sTW Retransmitted last ACK. Remain in the same state.
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
}
215 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
216 /*syn*/ { sIV
, sS2
, sIV
, sIV
, sIV
, sIV
, sIV
, sIV
, sIV
, sS2
},
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
226 * sTW -> sIV Reopened connection, but server may not do it.
229 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
230 /*synack*/ { sIV
, sSR
, sSR
, sIG
, sIG
, sIG
, sIG
, sIG
, sIG
, sSR
},
232 * sSS -> sSR Standard open.
233 * sS2 -> sSR Simultaneous open
234 * sSR -> sSR Retransmitted SYN/ACK.
235 * sES -> sIG Late retransmitted SYN/ACK?
236 * sFW -> sIG Might be SYN/ACK answering ignored SYN
242 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
243 /*fin*/ { sIV
, sIV
, sFW
, sFW
, sLA
, sLA
, sLA
, sTW
, sCL
, sIV
},
245 * sSS -> sIV Server might not send FIN in this state.
247 * sSR -> sFW Close started.
249 * sFW -> sLA FIN seen in both directions.
251 * sLA -> sLA Retransmitted FIN.
255 /* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
256 /*ack*/ { sIV
, sIG
, sSR
, sES
, sCW
, sCW
, sTW
, sTW
, sCL
, sIG
},
258 * sSS -> sIG Might be a half-open connection.
260 * sSR -> sSR Might answer late resent SYN.
262 * sFW -> sCW Normal close request answered by ACK.
264 * sLA -> sTW Last ACK detected.
265 * sTW -> sTW Retransmitted last ACK.
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
}
274 static bool tcp_pkt_to_tuple(const struct sk_buff
*skb
, unsigned int dataoff
,
275 struct nf_conntrack_tuple
*tuple
)
277 const struct tcphdr
*hp
;
280 /* Actually only need first 8 bytes. */
281 hp
= skb_header_pointer(skb
, dataoff
, 8, &_hdr
);
285 tuple
->src
.u
.tcp
.port
= hp
->source
;
286 tuple
->dst
.u
.tcp
.port
= hp
->dest
;
291 static bool tcp_invert_tuple(struct nf_conntrack_tuple
*tuple
,
292 const struct nf_conntrack_tuple
*orig
)
294 tuple
->src
.u
.tcp
.port
= orig
->dst
.u
.tcp
.port
;
295 tuple
->dst
.u
.tcp
.port
= orig
->src
.u
.tcp
.port
;
299 /* Print out the per-protocol part of the tuple. */
300 static int tcp_print_tuple(struct seq_file
*s
,
301 const struct nf_conntrack_tuple
*tuple
)
303 return seq_printf(s
, "sport=%hu dport=%hu ",
304 ntohs(tuple
->src
.u
.tcp
.port
),
305 ntohs(tuple
->dst
.u
.tcp
.port
));
308 /* Print out the private part of the conntrack. */
309 static int tcp_print_conntrack(struct seq_file
*s
, struct nf_conn
*ct
)
311 enum tcp_conntrack state
;
313 spin_lock_bh(&ct
->lock
);
314 state
= ct
->proto
.tcp
.state
;
315 spin_unlock_bh(&ct
->lock
);
317 return seq_printf(s
, "%s ", tcp_conntrack_names
[state
]);
320 static unsigned int get_conntrack_index(const struct tcphdr
*tcph
)
322 if (tcph
->rst
) return TCP_RST_SET
;
323 else if (tcph
->syn
) return (tcph
->ack
? TCP_SYNACK_SET
: TCP_SYN_SET
);
324 else if (tcph
->fin
) return TCP_FIN_SET
;
325 else if (tcph
->ack
) return TCP_ACK_SET
;
326 else return TCP_NONE_SET
;
329 /* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
330 in IP Filter' by Guido van Rooij.
332 http://www.nluug.nl/events/sane2000/papers.html
333 http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
335 The boundaries and the conditions are changed according to RFC793:
336 the packet must intersect the window (i.e. segments may be
337 after the right or before the left edge) and thus receivers may ACK
338 segments after the right edge of the window.
340 td_maxend = max(sack + max(win,1)) seen in reply packets
341 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
342 td_maxwin += seq + len - sender.td_maxend
343 if seq + len > sender.td_maxend
344 td_end = max(seq + len) seen in sent packets
346 I. Upper bound for valid data: seq <= sender.td_maxend
347 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin
348 III. Upper bound for valid (s)ack: sack <= receiver.td_end
349 IV. Lower bound for valid (s)ack: sack >= receiver.td_end - MAXACKWINDOW
351 where sack is the highest right edge of sack block found in the packet
352 or ack in the case of packet without SACK option.
354 The upper bound limit for a valid (s)ack is not ignored -
355 we doesn't have to deal with fragments.
358 static inline __u32
segment_seq_plus_len(__u32 seq
,
360 unsigned int dataoff
,
361 const struct tcphdr
*tcph
)
363 /* XXX Should I use payload length field in IP/IPv6 header ?
365 return (seq
+ len
- dataoff
- tcph
->doff
*4
366 + (tcph
->syn
? 1 : 0) + (tcph
->fin
? 1 : 0));
369 /* Fixme: what about big packets? */
370 #define MAXACKWINCONST 66000
371 #define MAXACKWINDOW(sender) \
372 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
376 * Simplified tcp_parse_options routine from tcp_input.c
378 static void tcp_options(const struct sk_buff
*skb
,
379 unsigned int dataoff
,
380 const struct tcphdr
*tcph
,
381 struct ip_ct_tcp_state
*state
)
383 unsigned char buff
[(15 * 4) - sizeof(struct tcphdr
)];
384 const unsigned char *ptr
;
385 int length
= (tcph
->doff
*4) - sizeof(struct tcphdr
);
390 ptr
= skb_header_pointer(skb
, dataoff
+ sizeof(struct tcphdr
),
404 case TCPOPT_NOP
: /* Ref: RFC 793 section 3.1 */
409 if (opsize
< 2) /* "silly options" */
412 break; /* don't parse partial options */
414 if (opcode
== TCPOPT_SACK_PERM
415 && opsize
== TCPOLEN_SACK_PERM
)
416 state
->flags
|= IP_CT_TCP_FLAG_SACK_PERM
;
417 else if (opcode
== TCPOPT_WINDOW
418 && opsize
== TCPOLEN_WINDOW
) {
419 state
->td_scale
= *(u_int8_t
*)ptr
;
421 if (state
->td_scale
> 14) {
423 state
->td_scale
= 14;
426 IP_CT_TCP_FLAG_WINDOW_SCALE
;
434 static void tcp_sack(const struct sk_buff
*skb
, unsigned int dataoff
,
435 const struct tcphdr
*tcph
, __u32
*sack
)
437 unsigned char buff
[(15 * 4) - sizeof(struct tcphdr
)];
438 const unsigned char *ptr
;
439 int length
= (tcph
->doff
*4) - sizeof(struct tcphdr
);
445 ptr
= skb_header_pointer(skb
, dataoff
+ sizeof(struct tcphdr
),
449 /* Fast path for timestamp-only option */
450 if (length
== TCPOLEN_TSTAMP_ALIGNED
*4
451 && *(__be32
*)ptr
== htonl((TCPOPT_NOP
<< 24)
453 | (TCPOPT_TIMESTAMP
<< 8)
454 | TCPOLEN_TIMESTAMP
))
464 case TCPOPT_NOP
: /* Ref: RFC 793 section 3.1 */
469 if (opsize
< 2) /* "silly options" */
472 break; /* don't parse partial options */
474 if (opcode
== TCPOPT_SACK
475 && opsize
>= (TCPOLEN_SACK_BASE
476 + TCPOLEN_SACK_PERBLOCK
)
477 && !((opsize
- TCPOLEN_SACK_BASE
)
478 % TCPOLEN_SACK_PERBLOCK
)) {
480 i
< (opsize
- TCPOLEN_SACK_BASE
);
481 i
+= TCPOLEN_SACK_PERBLOCK
) {
482 tmp
= get_unaligned_be32((__be32
*)(ptr
+i
)+1);
484 if (after(tmp
, *sack
))
495 #ifdef CONFIG_NF_NAT_NEEDED
496 static inline s16
nat_offset(const struct nf_conn
*ct
,
497 enum ip_conntrack_dir dir
,
500 typeof(nf_ct_nat_offset
) get_offset
= rcu_dereference(nf_ct_nat_offset
);
502 return get_offset
!= NULL
? get_offset(ct
, dir
, seq
) : 0;
504 #define NAT_OFFSET(pf, ct, dir, seq) \
505 (pf == NFPROTO_IPV4 ? nat_offset(ct, dir, seq) : 0)
507 #define NAT_OFFSET(pf, ct, dir, seq) 0
510 static bool tcp_in_window(const struct nf_conn
*ct
,
511 struct ip_ct_tcp
*state
,
512 enum ip_conntrack_dir dir
,
514 const struct sk_buff
*skb
,
515 unsigned int dataoff
,
516 const struct tcphdr
*tcph
,
519 struct net
*net
= nf_ct_net(ct
);
520 struct ip_ct_tcp_state
*sender
= &state
->seen
[dir
];
521 struct ip_ct_tcp_state
*receiver
= &state
->seen
[!dir
];
522 const struct nf_conntrack_tuple
*tuple
= &ct
->tuplehash
[dir
].tuple
;
523 __u32 seq
, ack
, sack
, end
, win
, swin
;
528 * Get the required data from the packet.
530 seq
= ntohl(tcph
->seq
);
531 ack
= sack
= ntohl(tcph
->ack_seq
);
532 win
= ntohs(tcph
->window
);
533 end
= segment_seq_plus_len(seq
, skb
->len
, dataoff
, tcph
);
535 if (receiver
->flags
& IP_CT_TCP_FLAG_SACK_PERM
)
536 tcp_sack(skb
, dataoff
, tcph
, &sack
);
538 /* Take into account NAT sequence number mangling */
539 receiver_offset
= NAT_OFFSET(pf
, ct
, !dir
, ack
- 1);
540 ack
-= receiver_offset
;
541 sack
-= receiver_offset
;
543 pr_debug("tcp_in_window: START\n");
544 pr_debug("tcp_in_window: ");
545 nf_ct_dump_tuple(tuple
);
546 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
547 seq
, ack
, receiver_offset
, sack
, receiver_offset
, win
, end
);
548 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
549 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
550 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
552 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
555 if (sender
->td_maxwin
== 0) {
557 * Initialize sender data.
561 * SYN-ACK in reply to a SYN
562 * or SYN from reply direction in simultaneous open.
565 sender
->td_maxend
= end
;
566 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
568 tcp_options(skb
, dataoff
, tcph
, sender
);
571 * Both sides must send the Window Scale option
572 * to enable window scaling in either direction.
574 if (!(sender
->flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
575 && receiver
->flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
))
577 receiver
->td_scale
= 0;
579 /* Simultaneous open */
583 * We are in the middle of a connection,
584 * its history is lost for us.
585 * Let's try to use the data from the packet.
587 sender
->td_end
= end
;
588 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
589 sender
->td_maxend
= end
+ sender
->td_maxwin
;
591 } else if (((state
->state
== TCP_CONNTRACK_SYN_SENT
592 && dir
== IP_CT_DIR_ORIGINAL
)
593 || (state
->state
== TCP_CONNTRACK_SYN_RECV
594 && dir
== IP_CT_DIR_REPLY
))
595 && after(end
, sender
->td_end
)) {
597 * RFC 793: "if a TCP is reinitialized ... then it need
598 * not wait at all; it must only be sure to use sequence
599 * numbers larger than those recently used."
602 sender
->td_maxend
= end
;
603 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
605 tcp_options(skb
, dataoff
, tcph
, sender
);
610 * If there is no ACK, just pretend it was set and OK.
612 ack
= sack
= receiver
->td_end
;
613 } else if (((tcp_flag_word(tcph
) & (TCP_FLAG_ACK
|TCP_FLAG_RST
)) ==
614 (TCP_FLAG_ACK
|TCP_FLAG_RST
))
617 * Broken TCP stacks, that set ACK in RST packets as well
618 * with zero ack value.
620 ack
= sack
= receiver
->td_end
;
625 || (seq
== 0 && state
->state
== TCP_CONNTRACK_SYN_SENT
)))
627 * Packets contains no data: we assume it is valid
628 * and check the ack value only.
629 * However RST segments are always validated by their
630 * SEQ number, except when seq == 0 (reset sent answering
633 seq
= end
= sender
->td_end
;
635 pr_debug("tcp_in_window: ");
636 nf_ct_dump_tuple(tuple
);
637 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n",
638 seq
, ack
, receiver_offset
, sack
, receiver_offset
, win
, end
);
639 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
640 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
641 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
643 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
646 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
647 before(seq
, sender
->td_maxend
+ 1),
648 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1),
649 before(sack
, receiver
->td_end
+ 1),
650 after(sack
, receiver
->td_end
- MAXACKWINDOW(sender
) - 1));
652 if (before(seq
, sender
->td_maxend
+ 1) &&
653 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1) &&
654 before(sack
, receiver
->td_end
+ 1) &&
655 after(sack
, receiver
->td_end
- MAXACKWINDOW(sender
) - 1)) {
657 * Take into account window scaling (RFC 1323).
660 win
<<= sender
->td_scale
;
663 * Update sender data.
665 swin
= win
+ (sack
- ack
);
666 if (sender
->td_maxwin
< swin
)
667 sender
->td_maxwin
= swin
;
668 if (after(end
, sender
->td_end
)) {
669 sender
->td_end
= end
;
670 sender
->flags
|= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
;
673 if (!(sender
->flags
& IP_CT_TCP_FLAG_MAXACK_SET
)) {
674 sender
->td_maxack
= ack
;
675 sender
->flags
|= IP_CT_TCP_FLAG_MAXACK_SET
;
676 } else if (after(ack
, sender
->td_maxack
))
677 sender
->td_maxack
= ack
;
681 * Update receiver data.
683 if (after(end
, sender
->td_maxend
))
684 receiver
->td_maxwin
+= end
- sender
->td_maxend
;
685 if (after(sack
+ win
, receiver
->td_maxend
- 1)) {
686 receiver
->td_maxend
= sack
+ win
;
688 receiver
->td_maxend
++;
690 if (ack
== receiver
->td_end
)
691 receiver
->flags
&= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
;
694 * Check retransmissions.
696 if (index
== TCP_ACK_SET
) {
697 if (state
->last_dir
== dir
698 && state
->last_seq
== seq
699 && state
->last_ack
== ack
700 && state
->last_end
== end
701 && state
->last_win
== win
)
704 state
->last_dir
= dir
;
705 state
->last_seq
= seq
;
706 state
->last_ack
= ack
;
707 state
->last_end
= end
;
708 state
->last_win
= win
;
715 if (sender
->flags
& IP_CT_TCP_FLAG_BE_LIBERAL
||
716 nf_ct_tcp_be_liberal
)
718 if (!res
&& LOG_INVALID(net
, IPPROTO_TCP
))
719 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
721 before(seq
, sender
->td_maxend
+ 1) ?
722 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1) ?
723 before(sack
, receiver
->td_end
+ 1) ?
724 after(sack
, receiver
->td_end
- MAXACKWINDOW(sender
) - 1) ? "BUG"
725 : "ACK is under the lower bound (possible overly delayed ACK)"
726 : "ACK is over the upper bound (ACKed data not seen yet)"
727 : "SEQ is under the lower bound (already ACKed data retransmitted)"
728 : "SEQ is over the upper bound (over the window of the receiver)");
731 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u "
732 "receiver end=%u maxend=%u maxwin=%u\n",
733 res
, sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
734 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
);
748 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
749 static const u8 tcp_valid_flags
[(TH_FIN
|TH_SYN
|TH_RST
|TH_ACK
|TH_URG
) + 1] =
757 [TH_FIN
|TH_ACK
|TH_URG
] = 1,
762 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
763 static int tcp_error(struct net
*net
,
765 unsigned int dataoff
,
766 enum ip_conntrack_info
*ctinfo
,
768 unsigned int hooknum
)
770 const struct tcphdr
*th
;
772 unsigned int tcplen
= skb
->len
- dataoff
;
775 /* Smaller that minimal TCP header? */
776 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
778 if (LOG_INVALID(net
, IPPROTO_TCP
))
779 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
780 "nf_ct_tcp: short packet ");
784 /* Not whole TCP header or malformed packet */
785 if (th
->doff
*4 < sizeof(struct tcphdr
) || tcplen
< th
->doff
*4) {
786 if (LOG_INVALID(net
, IPPROTO_TCP
))
787 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
788 "nf_ct_tcp: truncated/malformed packet ");
792 /* Checksum invalid? Ignore.
793 * We skip checking packets on the outgoing path
794 * because the checksum is assumed to be correct.
796 /* FIXME: Source route IP option packets --RR */
797 if (net
->ct
.sysctl_checksum
&& hooknum
== NF_INET_PRE_ROUTING
&&
798 nf_checksum(skb
, hooknum
, dataoff
, IPPROTO_TCP
, pf
)) {
799 if (LOG_INVALID(net
, IPPROTO_TCP
))
800 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
801 "nf_ct_tcp: bad TCP checksum ");
805 /* Check TCP flags. */
806 tcpflags
= (((u_int8_t
*)th
)[13] & ~(TH_ECE
|TH_CWR
|TH_PUSH
));
807 if (!tcp_valid_flags
[tcpflags
]) {
808 if (LOG_INVALID(net
, IPPROTO_TCP
))
809 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
810 "nf_ct_tcp: invalid TCP flag combination ");
817 /* Returns verdict for packet, or -1 for invalid. */
818 static int tcp_packet(struct nf_conn
*ct
,
819 const struct sk_buff
*skb
,
820 unsigned int dataoff
,
821 enum ip_conntrack_info ctinfo
,
823 unsigned int hooknum
)
825 struct net
*net
= nf_ct_net(ct
);
826 struct nf_conntrack_tuple
*tuple
;
827 enum tcp_conntrack new_state
, old_state
;
828 enum ip_conntrack_dir dir
;
829 const struct tcphdr
*th
;
831 unsigned long timeout
;
834 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
837 spin_lock_bh(&ct
->lock
);
838 old_state
= ct
->proto
.tcp
.state
;
839 dir
= CTINFO2DIR(ctinfo
);
840 index
= get_conntrack_index(th
);
841 new_state
= tcp_conntracks
[dir
][index
][old_state
];
842 tuple
= &ct
->tuplehash
[dir
].tuple
;
845 case TCP_CONNTRACK_SYN_SENT
:
846 if (old_state
< TCP_CONNTRACK_TIME_WAIT
)
848 /* RFC 1122: "When a connection is closed actively,
849 * it MUST linger in TIME-WAIT state for a time 2xMSL
850 * (Maximum Segment Lifetime). However, it MAY accept
851 * a new SYN from the remote TCP to reopen the connection
852 * directly from TIME-WAIT state, if..."
853 * We ignore the conditions because we are in the
854 * TIME-WAIT state anyway.
856 * Handle aborted connections: we and the server
857 * think there is an existing connection but the client
858 * aborts it and starts a new one.
860 if (((ct
->proto
.tcp
.seen
[dir
].flags
861 | ct
->proto
.tcp
.seen
[!dir
].flags
)
862 & IP_CT_TCP_FLAG_CLOSE_INIT
)
863 || (ct
->proto
.tcp
.last_dir
== dir
864 && ct
->proto
.tcp
.last_index
== TCP_RST_SET
)) {
865 /* Attempt to reopen a closed/aborted connection.
866 * Delete this connection and look up again. */
867 spin_unlock_bh(&ct
->lock
);
869 /* Only repeat if we can actually remove the timer.
870 * Destruction may already be in progress in process
871 * context and we must give it a chance to terminate.
878 case TCP_CONNTRACK_IGNORE
:
881 * Our connection entry may be out of sync, so ignore
882 * packets which may signal the real connection between
883 * the client and the server.
886 * b) SYN/ACK in REPLY
887 * c) ACK in reply direction after initial SYN in original.
889 * If the ignored packet is invalid, the receiver will send
890 * a RST we'll catch below.
892 if (index
== TCP_SYNACK_SET
893 && ct
->proto
.tcp
.last_index
== TCP_SYN_SET
894 && ct
->proto
.tcp
.last_dir
!= dir
895 && ntohl(th
->ack_seq
) == ct
->proto
.tcp
.last_end
) {
896 /* b) This SYN/ACK acknowledges a SYN that we earlier
897 * ignored as invalid. This means that the client and
898 * the server are both in sync, while the firewall is
899 * not. We kill this session and block the SYN/ACK so
900 * that the client cannot but retransmit its SYN and
901 * thus initiate a clean new session.
903 spin_unlock_bh(&ct
->lock
);
904 if (LOG_INVALID(net
, IPPROTO_TCP
))
905 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
906 "nf_ct_tcp: killing out of sync session ");
910 ct
->proto
.tcp
.last_index
= index
;
911 ct
->proto
.tcp
.last_dir
= dir
;
912 ct
->proto
.tcp
.last_seq
= ntohl(th
->seq
);
913 ct
->proto
.tcp
.last_end
=
914 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
, dataoff
, th
);
916 spin_unlock_bh(&ct
->lock
);
917 if (LOG_INVALID(net
, IPPROTO_TCP
))
918 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
919 "nf_ct_tcp: invalid packet ignored ");
921 case TCP_CONNTRACK_MAX
:
923 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
924 dir
, get_conntrack_index(th
), old_state
);
925 spin_unlock_bh(&ct
->lock
);
926 if (LOG_INVALID(net
, IPPROTO_TCP
))
927 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
928 "nf_ct_tcp: invalid state ");
930 case TCP_CONNTRACK_CLOSE
:
931 if (index
== TCP_RST_SET
932 && (ct
->proto
.tcp
.seen
[!dir
].flags
& IP_CT_TCP_FLAG_MAXACK_SET
)
933 && before(ntohl(th
->seq
), ct
->proto
.tcp
.seen
[!dir
].td_maxack
)) {
935 spin_unlock_bh(&ct
->lock
);
936 if (LOG_INVALID(net
, IPPROTO_TCP
))
937 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
938 "nf_ct_tcp: invalid RST ");
941 if (index
== TCP_RST_SET
942 && ((test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)
943 && ct
->proto
.tcp
.last_index
== TCP_SYN_SET
)
944 || (!test_bit(IPS_ASSURED_BIT
, &ct
->status
)
945 && ct
->proto
.tcp
.last_index
== TCP_ACK_SET
))
946 && ntohl(th
->ack_seq
) == ct
->proto
.tcp
.last_end
) {
947 /* RST sent to invalid SYN or ACK we had let through
948 * at a) and c) above:
950 * a) SYN was in window then
951 * c) we hold a half-open connection.
953 * Delete our connection entry.
954 * We skip window checking, because packet might ACK
955 * segments we ignored. */
958 /* Just fall through */
960 /* Keep compilers happy. */
964 if (!tcp_in_window(ct
, &ct
->proto
.tcp
, dir
, index
,
965 skb
, dataoff
, th
, pf
)) {
966 spin_unlock_bh(&ct
->lock
);
970 /* From now on we have got in-window packets */
971 ct
->proto
.tcp
.last_index
= index
;
972 ct
->proto
.tcp
.last_dir
= dir
;
974 pr_debug("tcp_conntracks: ");
975 nf_ct_dump_tuple(tuple
);
976 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
977 (th
->syn
? 1 : 0), (th
->ack
? 1 : 0),
978 (th
->fin
? 1 : 0), (th
->rst
? 1 : 0),
979 old_state
, new_state
);
981 ct
->proto
.tcp
.state
= new_state
;
982 if (old_state
!= new_state
983 && new_state
== TCP_CONNTRACK_FIN_WAIT
)
984 ct
->proto
.tcp
.seen
[dir
].flags
|= IP_CT_TCP_FLAG_CLOSE_INIT
;
986 if (ct
->proto
.tcp
.retrans
>= nf_ct_tcp_max_retrans
&&
987 tcp_timeouts
[new_state
] > nf_ct_tcp_timeout_max_retrans
)
988 timeout
= nf_ct_tcp_timeout_max_retrans
;
989 else if ((ct
->proto
.tcp
.seen
[0].flags
| ct
->proto
.tcp
.seen
[1].flags
) &
990 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
&&
991 tcp_timeouts
[new_state
] > nf_ct_tcp_timeout_unacknowledged
)
992 timeout
= nf_ct_tcp_timeout_unacknowledged
;
994 timeout
= tcp_timeouts
[new_state
];
995 spin_unlock_bh(&ct
->lock
);
997 if (new_state
!= old_state
)
998 nf_conntrack_event_cache(IPCT_PROTOINFO
, ct
);
1000 if (!test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
1001 /* If only reply is a RST, we can consider ourselves not to
1002 have an established connection: this is a fairly common
1003 problem case, so we can delete the conntrack
1004 immediately. --RR */
1006 nf_ct_kill_acct(ct
, ctinfo
, skb
);
1009 } else if (!test_bit(IPS_ASSURED_BIT
, &ct
->status
)
1010 && (old_state
== TCP_CONNTRACK_SYN_RECV
1011 || old_state
== TCP_CONNTRACK_ESTABLISHED
)
1012 && new_state
== TCP_CONNTRACK_ESTABLISHED
) {
1013 /* Set ASSURED if we see see valid ack in ESTABLISHED
1014 after SYN_RECV or a valid answer for a picked up
1016 set_bit(IPS_ASSURED_BIT
, &ct
->status
);
1017 nf_conntrack_event_cache(IPCT_STATUS
, ct
);
1019 nf_ct_refresh_acct(ct
, ctinfo
, skb
, timeout
);
1024 /* Called when a new connection for this protocol found. */
1025 static bool tcp_new(struct nf_conn
*ct
, const struct sk_buff
*skb
,
1026 unsigned int dataoff
)
1028 enum tcp_conntrack new_state
;
1029 const struct tcphdr
*th
;
1030 struct tcphdr _tcph
;
1031 const struct ip_ct_tcp_state
*sender
= &ct
->proto
.tcp
.seen
[0];
1032 const struct ip_ct_tcp_state
*receiver
= &ct
->proto
.tcp
.seen
[1];
1034 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
1037 /* Don't need lock here: this conntrack not in circulation yet */
1039 = tcp_conntracks
[0][get_conntrack_index(th
)]
1040 [TCP_CONNTRACK_NONE
];
1042 /* Invalid: delete conntrack */
1043 if (new_state
>= TCP_CONNTRACK_MAX
) {
1044 pr_debug("nf_ct_tcp: invalid new deleting.\n");
1048 if (new_state
== TCP_CONNTRACK_SYN_SENT
) {
1050 ct
->proto
.tcp
.seen
[0].td_end
=
1051 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
,
1053 ct
->proto
.tcp
.seen
[0].td_maxwin
= ntohs(th
->window
);
1054 if (ct
->proto
.tcp
.seen
[0].td_maxwin
== 0)
1055 ct
->proto
.tcp
.seen
[0].td_maxwin
= 1;
1056 ct
->proto
.tcp
.seen
[0].td_maxend
=
1057 ct
->proto
.tcp
.seen
[0].td_end
;
1059 tcp_options(skb
, dataoff
, th
, &ct
->proto
.tcp
.seen
[0]);
1060 ct
->proto
.tcp
.seen
[1].flags
= 0;
1061 } else if (nf_ct_tcp_loose
== 0) {
1062 /* Don't try to pick up connections. */
1066 * We are in the middle of a connection,
1067 * its history is lost for us.
1068 * Let's try to use the data from the packet.
1070 ct
->proto
.tcp
.seen
[0].td_end
=
1071 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
,
1073 ct
->proto
.tcp
.seen
[0].td_maxwin
= ntohs(th
->window
);
1074 if (ct
->proto
.tcp
.seen
[0].td_maxwin
== 0)
1075 ct
->proto
.tcp
.seen
[0].td_maxwin
= 1;
1076 ct
->proto
.tcp
.seen
[0].td_maxend
=
1077 ct
->proto
.tcp
.seen
[0].td_end
+
1078 ct
->proto
.tcp
.seen
[0].td_maxwin
;
1079 ct
->proto
.tcp
.seen
[0].td_scale
= 0;
1081 /* We assume SACK and liberal window checking to handle
1083 ct
->proto
.tcp
.seen
[0].flags
=
1084 ct
->proto
.tcp
.seen
[1].flags
= IP_CT_TCP_FLAG_SACK_PERM
|
1085 IP_CT_TCP_FLAG_BE_LIBERAL
;
1088 ct
->proto
.tcp
.seen
[1].td_end
= 0;
1089 ct
->proto
.tcp
.seen
[1].td_maxend
= 0;
1090 ct
->proto
.tcp
.seen
[1].td_maxwin
= 0;
1091 ct
->proto
.tcp
.seen
[1].td_scale
= 0;
1093 /* tcp_packet will set them */
1094 ct
->proto
.tcp
.state
= TCP_CONNTRACK_NONE
;
1095 ct
->proto
.tcp
.last_index
= TCP_NONE_SET
;
1097 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1098 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1099 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
1101 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
1102 receiver
->td_scale
);
1106 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1108 #include <linux/netfilter/nfnetlink.h>
1109 #include <linux/netfilter/nfnetlink_conntrack.h>
1111 static int tcp_to_nlattr(struct sk_buff
*skb
, struct nlattr
*nla
,
1114 struct nlattr
*nest_parms
;
1115 struct nf_ct_tcp_flags tmp
= {};
1117 spin_lock_bh(&ct
->lock
);
1118 nest_parms
= nla_nest_start(skb
, CTA_PROTOINFO_TCP
| NLA_F_NESTED
);
1120 goto nla_put_failure
;
1122 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_STATE
, ct
->proto
.tcp
.state
);
1124 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
,
1125 ct
->proto
.tcp
.seen
[0].td_scale
);
1127 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_WSCALE_REPLY
,
1128 ct
->proto
.tcp
.seen
[1].td_scale
);
1130 tmp
.flags
= ct
->proto
.tcp
.seen
[0].flags
;
1131 NLA_PUT(skb
, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
,
1132 sizeof(struct nf_ct_tcp_flags
), &tmp
);
1134 tmp
.flags
= ct
->proto
.tcp
.seen
[1].flags
;
1135 NLA_PUT(skb
, CTA_PROTOINFO_TCP_FLAGS_REPLY
,
1136 sizeof(struct nf_ct_tcp_flags
), &tmp
);
1137 spin_unlock_bh(&ct
->lock
);
1139 nla_nest_end(skb
, nest_parms
);
1144 spin_unlock_bh(&ct
->lock
);
1148 static const struct nla_policy tcp_nla_policy
[CTA_PROTOINFO_TCP_MAX
+1] = {
1149 [CTA_PROTOINFO_TCP_STATE
] = { .type
= NLA_U8
},
1150 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
] = { .type
= NLA_U8
},
1151 [CTA_PROTOINFO_TCP_WSCALE_REPLY
] = { .type
= NLA_U8
},
1152 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
] = { .len
= sizeof(struct nf_ct_tcp_flags
) },
1153 [CTA_PROTOINFO_TCP_FLAGS_REPLY
] = { .len
= sizeof(struct nf_ct_tcp_flags
) },
1156 static int nlattr_to_tcp(struct nlattr
*cda
[], struct nf_conn
*ct
)
1158 struct nlattr
*pattr
= cda
[CTA_PROTOINFO_TCP
];
1159 struct nlattr
*tb
[CTA_PROTOINFO_TCP_MAX
+1];
1162 /* updates could not contain anything about the private
1163 * protocol info, in that case skip the parsing */
1167 err
= nla_parse_nested(tb
, CTA_PROTOINFO_TCP_MAX
, pattr
, tcp_nla_policy
);
1171 if (tb
[CTA_PROTOINFO_TCP_STATE
] &&
1172 nla_get_u8(tb
[CTA_PROTOINFO_TCP_STATE
]) >= TCP_CONNTRACK_MAX
)
1175 spin_lock_bh(&ct
->lock
);
1176 if (tb
[CTA_PROTOINFO_TCP_STATE
])
1177 ct
->proto
.tcp
.state
= nla_get_u8(tb
[CTA_PROTOINFO_TCP_STATE
]);
1179 if (tb
[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
]) {
1180 struct nf_ct_tcp_flags
*attr
=
1181 nla_data(tb
[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
]);
1182 ct
->proto
.tcp
.seen
[0].flags
&= ~attr
->mask
;
1183 ct
->proto
.tcp
.seen
[0].flags
|= attr
->flags
& attr
->mask
;
1186 if (tb
[CTA_PROTOINFO_TCP_FLAGS_REPLY
]) {
1187 struct nf_ct_tcp_flags
*attr
=
1188 nla_data(tb
[CTA_PROTOINFO_TCP_FLAGS_REPLY
]);
1189 ct
->proto
.tcp
.seen
[1].flags
&= ~attr
->mask
;
1190 ct
->proto
.tcp
.seen
[1].flags
|= attr
->flags
& attr
->mask
;
1193 if (tb
[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
] &&
1194 tb
[CTA_PROTOINFO_TCP_WSCALE_REPLY
] &&
1195 ct
->proto
.tcp
.seen
[0].flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
&&
1196 ct
->proto
.tcp
.seen
[1].flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
) {
1197 ct
->proto
.tcp
.seen
[0].td_scale
=
1198 nla_get_u8(tb
[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
]);
1199 ct
->proto
.tcp
.seen
[1].td_scale
=
1200 nla_get_u8(tb
[CTA_PROTOINFO_TCP_WSCALE_REPLY
]);
1202 spin_unlock_bh(&ct
->lock
);
1207 static int tcp_nlattr_size(void)
1209 return nla_total_size(0) /* CTA_PROTOINFO_TCP */
1210 + nla_policy_len(tcp_nla_policy
, CTA_PROTOINFO_TCP_MAX
+ 1);
1213 static int tcp_nlattr_tuple_size(void)
1215 return nla_policy_len(nf_ct_port_nla_policy
, CTA_PROTO_MAX
+ 1);
1219 #ifdef CONFIG_SYSCTL
1220 static unsigned int tcp_sysctl_table_users
;
1221 static struct ctl_table_header
*tcp_sysctl_header
;
1222 static struct ctl_table tcp_sysctl_table
[] = {
1224 .procname
= "nf_conntrack_tcp_timeout_syn_sent",
1225 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_SENT
],
1226 .maxlen
= sizeof(unsigned int),
1228 .proc_handler
= proc_dointvec_jiffies
,
1231 .procname
= "nf_conntrack_tcp_timeout_syn_recv",
1232 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_RECV
],
1233 .maxlen
= sizeof(unsigned int),
1235 .proc_handler
= proc_dointvec_jiffies
,
1238 .procname
= "nf_conntrack_tcp_timeout_established",
1239 .data
= &tcp_timeouts
[TCP_CONNTRACK_ESTABLISHED
],
1240 .maxlen
= sizeof(unsigned int),
1242 .proc_handler
= proc_dointvec_jiffies
,
1245 .procname
= "nf_conntrack_tcp_timeout_fin_wait",
1246 .data
= &tcp_timeouts
[TCP_CONNTRACK_FIN_WAIT
],
1247 .maxlen
= sizeof(unsigned int),
1249 .proc_handler
= proc_dointvec_jiffies
,
1252 .procname
= "nf_conntrack_tcp_timeout_close_wait",
1253 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE_WAIT
],
1254 .maxlen
= sizeof(unsigned int),
1256 .proc_handler
= proc_dointvec_jiffies
,
1259 .procname
= "nf_conntrack_tcp_timeout_last_ack",
1260 .data
= &tcp_timeouts
[TCP_CONNTRACK_LAST_ACK
],
1261 .maxlen
= sizeof(unsigned int),
1263 .proc_handler
= proc_dointvec_jiffies
,
1266 .procname
= "nf_conntrack_tcp_timeout_time_wait",
1267 .data
= &tcp_timeouts
[TCP_CONNTRACK_TIME_WAIT
],
1268 .maxlen
= sizeof(unsigned int),
1270 .proc_handler
= proc_dointvec_jiffies
,
1273 .procname
= "nf_conntrack_tcp_timeout_close",
1274 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE
],
1275 .maxlen
= sizeof(unsigned int),
1277 .proc_handler
= proc_dointvec_jiffies
,
1280 .procname
= "nf_conntrack_tcp_timeout_max_retrans",
1281 .data
= &nf_ct_tcp_timeout_max_retrans
,
1282 .maxlen
= sizeof(unsigned int),
1284 .proc_handler
= proc_dointvec_jiffies
,
1287 .procname
= "nf_conntrack_tcp_timeout_unacknowledged",
1288 .data
= &nf_ct_tcp_timeout_unacknowledged
,
1289 .maxlen
= sizeof(unsigned int),
1291 .proc_handler
= proc_dointvec_jiffies
,
1294 .ctl_name
= NET_NF_CONNTRACK_TCP_LOOSE
,
1295 .procname
= "nf_conntrack_tcp_loose",
1296 .data
= &nf_ct_tcp_loose
,
1297 .maxlen
= sizeof(unsigned int),
1299 .proc_handler
= proc_dointvec
,
1302 .ctl_name
= NET_NF_CONNTRACK_TCP_BE_LIBERAL
,
1303 .procname
= "nf_conntrack_tcp_be_liberal",
1304 .data
= &nf_ct_tcp_be_liberal
,
1305 .maxlen
= sizeof(unsigned int),
1307 .proc_handler
= proc_dointvec
,
1310 .ctl_name
= NET_NF_CONNTRACK_TCP_MAX_RETRANS
,
1311 .procname
= "nf_conntrack_tcp_max_retrans",
1312 .data
= &nf_ct_tcp_max_retrans
,
1313 .maxlen
= sizeof(unsigned int),
1315 .proc_handler
= proc_dointvec
,
1322 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1323 static struct ctl_table tcp_compat_sysctl_table
[] = {
1325 .procname
= "ip_conntrack_tcp_timeout_syn_sent",
1326 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_SENT
],
1327 .maxlen
= sizeof(unsigned int),
1329 .proc_handler
= proc_dointvec_jiffies
,
1332 .procname
= "ip_conntrack_tcp_timeout_syn_sent2",
1333 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_SENT2
],
1334 .maxlen
= sizeof(unsigned int),
1336 .proc_handler
= proc_dointvec_jiffies
,
1339 .procname
= "ip_conntrack_tcp_timeout_syn_recv",
1340 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_RECV
],
1341 .maxlen
= sizeof(unsigned int),
1343 .proc_handler
= proc_dointvec_jiffies
,
1346 .procname
= "ip_conntrack_tcp_timeout_established",
1347 .data
= &tcp_timeouts
[TCP_CONNTRACK_ESTABLISHED
],
1348 .maxlen
= sizeof(unsigned int),
1350 .proc_handler
= proc_dointvec_jiffies
,
1353 .procname
= "ip_conntrack_tcp_timeout_fin_wait",
1354 .data
= &tcp_timeouts
[TCP_CONNTRACK_FIN_WAIT
],
1355 .maxlen
= sizeof(unsigned int),
1357 .proc_handler
= proc_dointvec_jiffies
,
1360 .procname
= "ip_conntrack_tcp_timeout_close_wait",
1361 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE_WAIT
],
1362 .maxlen
= sizeof(unsigned int),
1364 .proc_handler
= proc_dointvec_jiffies
,
1367 .procname
= "ip_conntrack_tcp_timeout_last_ack",
1368 .data
= &tcp_timeouts
[TCP_CONNTRACK_LAST_ACK
],
1369 .maxlen
= sizeof(unsigned int),
1371 .proc_handler
= proc_dointvec_jiffies
,
1374 .procname
= "ip_conntrack_tcp_timeout_time_wait",
1375 .data
= &tcp_timeouts
[TCP_CONNTRACK_TIME_WAIT
],
1376 .maxlen
= sizeof(unsigned int),
1378 .proc_handler
= proc_dointvec_jiffies
,
1381 .procname
= "ip_conntrack_tcp_timeout_close",
1382 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE
],
1383 .maxlen
= sizeof(unsigned int),
1385 .proc_handler
= proc_dointvec_jiffies
,
1388 .procname
= "ip_conntrack_tcp_timeout_max_retrans",
1389 .data
= &nf_ct_tcp_timeout_max_retrans
,
1390 .maxlen
= sizeof(unsigned int),
1392 .proc_handler
= proc_dointvec_jiffies
,
1395 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_LOOSE
,
1396 .procname
= "ip_conntrack_tcp_loose",
1397 .data
= &nf_ct_tcp_loose
,
1398 .maxlen
= sizeof(unsigned int),
1400 .proc_handler
= proc_dointvec
,
1403 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL
,
1404 .procname
= "ip_conntrack_tcp_be_liberal",
1405 .data
= &nf_ct_tcp_be_liberal
,
1406 .maxlen
= sizeof(unsigned int),
1408 .proc_handler
= proc_dointvec
,
1411 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS
,
1412 .procname
= "ip_conntrack_tcp_max_retrans",
1413 .data
= &nf_ct_tcp_max_retrans
,
1414 .maxlen
= sizeof(unsigned int),
1416 .proc_handler
= proc_dointvec
,
1422 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
1423 #endif /* CONFIG_SYSCTL */
1425 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly
=
1428 .l4proto
= IPPROTO_TCP
,
1430 .pkt_to_tuple
= tcp_pkt_to_tuple
,
1431 .invert_tuple
= tcp_invert_tuple
,
1432 .print_tuple
= tcp_print_tuple
,
1433 .print_conntrack
= tcp_print_conntrack
,
1434 .packet
= tcp_packet
,
1437 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1438 .to_nlattr
= tcp_to_nlattr
,
1439 .nlattr_size
= tcp_nlattr_size
,
1440 .from_nlattr
= nlattr_to_tcp
,
1441 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
1442 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
1443 .nlattr_tuple_size
= tcp_nlattr_tuple_size
,
1444 .nla_policy
= nf_ct_port_nla_policy
,
1446 #ifdef CONFIG_SYSCTL
1447 .ctl_table_users
= &tcp_sysctl_table_users
,
1448 .ctl_table_header
= &tcp_sysctl_header
,
1449 .ctl_table
= tcp_sysctl_table
,
1450 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1451 .ctl_compat_table
= tcp_compat_sysctl_table
,
1455 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4
);
1457 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly
=
1459 .l3proto
= PF_INET6
,
1460 .l4proto
= IPPROTO_TCP
,
1462 .pkt_to_tuple
= tcp_pkt_to_tuple
,
1463 .invert_tuple
= tcp_invert_tuple
,
1464 .print_tuple
= tcp_print_tuple
,
1465 .print_conntrack
= tcp_print_conntrack
,
1466 .packet
= tcp_packet
,
1469 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1470 .to_nlattr
= tcp_to_nlattr
,
1471 .nlattr_size
= tcp_nlattr_size
,
1472 .from_nlattr
= nlattr_to_tcp
,
1473 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
1474 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
1475 .nlattr_tuple_size
= tcp_nlattr_tuple_size
,
1476 .nla_policy
= nf_ct_port_nla_policy
,
1478 #ifdef CONFIG_SYSCTL
1479 .ctl_table_users
= &tcp_sysctl_table_users
,
1480 .ctl_table_header
= &tcp_sysctl_header
,
1481 .ctl_table
= tcp_sysctl_table
,
1484 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6
);