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 ip_ct_tcp_state
*sender
= &state
->seen
[dir
];
492 struct ip_ct_tcp_state
*receiver
= &state
->seen
[!dir
];
493 const struct nf_conntrack_tuple
*tuple
= &ct
->tuplehash
[dir
].tuple
;
494 __u32 seq
, ack
, sack
, end
, win
, swin
;
498 * Get the required data from the packet.
500 seq
= ntohl(tcph
->seq
);
501 ack
= sack
= ntohl(tcph
->ack_seq
);
502 win
= ntohs(tcph
->window
);
503 end
= segment_seq_plus_len(seq
, skb
->len
, dataoff
, tcph
);
505 if (receiver
->flags
& IP_CT_TCP_FLAG_SACK_PERM
)
506 tcp_sack(skb
, dataoff
, tcph
, &sack
);
508 pr_debug("tcp_in_window: START\n");
509 pr_debug("tcp_in_window: ");
510 nf_ct_dump_tuple(tuple
);
511 pr_debug("seq=%u ack=%u sack=%u win=%u end=%u\n",
512 seq
, ack
, sack
, win
, end
);
513 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
514 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
515 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
517 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
520 if (sender
->td_end
== 0) {
522 * Initialize sender data.
524 if (tcph
->syn
&& tcph
->ack
) {
526 * Outgoing SYN-ACK in reply to a SYN.
529 sender
->td_maxend
= end
;
530 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
532 tcp_options(skb
, dataoff
, tcph
, sender
);
535 * Both sides must send the Window Scale option
536 * to enable window scaling in either direction.
538 if (!(sender
->flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
539 && receiver
->flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
))
541 receiver
->td_scale
= 0;
544 * We are in the middle of a connection,
545 * its history is lost for us.
546 * Let's try to use the data from the packet.
548 sender
->td_end
= end
;
549 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
550 sender
->td_maxend
= end
+ sender
->td_maxwin
;
552 } else if (((state
->state
== TCP_CONNTRACK_SYN_SENT
553 && dir
== IP_CT_DIR_ORIGINAL
)
554 || (state
->state
== TCP_CONNTRACK_SYN_RECV
555 && dir
== IP_CT_DIR_REPLY
))
556 && after(end
, sender
->td_end
)) {
558 * RFC 793: "if a TCP is reinitialized ... then it need
559 * not wait at all; it must only be sure to use sequence
560 * numbers larger than those recently used."
563 sender
->td_maxend
= end
;
564 sender
->td_maxwin
= (win
== 0 ? 1 : win
);
566 tcp_options(skb
, dataoff
, tcph
, sender
);
571 * If there is no ACK, just pretend it was set and OK.
573 ack
= sack
= receiver
->td_end
;
574 } else if (((tcp_flag_word(tcph
) & (TCP_FLAG_ACK
|TCP_FLAG_RST
)) ==
575 (TCP_FLAG_ACK
|TCP_FLAG_RST
))
578 * Broken TCP stacks, that set ACK in RST packets as well
579 * with zero ack value.
581 ack
= sack
= receiver
->td_end
;
586 || (seq
== 0 && state
->state
== TCP_CONNTRACK_SYN_SENT
)))
588 * Packets contains no data: we assume it is valid
589 * and check the ack value only.
590 * However RST segments are always validated by their
591 * SEQ number, except when seq == 0 (reset sent answering
594 seq
= end
= sender
->td_end
;
596 pr_debug("tcp_in_window: ");
597 nf_ct_dump_tuple(tuple
);
598 pr_debug("seq=%u ack=%u sack =%u win=%u end=%u\n",
599 seq
, ack
, sack
, win
, end
);
600 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
601 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
602 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
604 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
607 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
608 before(seq
, sender
->td_maxend
+ 1),
609 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1),
610 before(sack
, receiver
->td_end
+ 1),
611 after(sack
, receiver
->td_end
- MAXACKWINDOW(sender
) - 1));
613 if (before(seq
, sender
->td_maxend
+ 1) &&
614 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1) &&
615 before(sack
, receiver
->td_end
+ 1) &&
616 after(sack
, receiver
->td_end
- MAXACKWINDOW(sender
) - 1)) {
618 * Take into account window scaling (RFC 1323).
621 win
<<= sender
->td_scale
;
624 * Update sender data.
626 swin
= win
+ (sack
- ack
);
627 if (sender
->td_maxwin
< swin
)
628 sender
->td_maxwin
= swin
;
629 if (after(end
, sender
->td_end
)) {
630 sender
->td_end
= end
;
631 sender
->flags
|= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
;
634 * Update receiver data.
636 if (after(end
, sender
->td_maxend
))
637 receiver
->td_maxwin
+= end
- sender
->td_maxend
;
638 if (after(sack
+ win
, receiver
->td_maxend
- 1)) {
639 receiver
->td_maxend
= sack
+ win
;
641 receiver
->td_maxend
++;
643 if (ack
== receiver
->td_end
)
644 receiver
->flags
&= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
;
647 * Check retransmissions.
649 if (index
== TCP_ACK_SET
) {
650 if (state
->last_dir
== dir
651 && state
->last_seq
== seq
652 && state
->last_ack
== ack
653 && state
->last_end
== end
654 && state
->last_win
== win
)
657 state
->last_dir
= dir
;
658 state
->last_seq
= seq
;
659 state
->last_ack
= ack
;
660 state
->last_end
= end
;
661 state
->last_win
= win
;
668 if (sender
->flags
& IP_CT_TCP_FLAG_BE_LIBERAL
||
669 nf_ct_tcp_be_liberal
)
671 if (!res
&& LOG_INVALID(IPPROTO_TCP
))
672 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
674 before(seq
, sender
->td_maxend
+ 1) ?
675 after(end
, sender
->td_end
- receiver
->td_maxwin
- 1) ?
676 before(sack
, receiver
->td_end
+ 1) ?
677 after(ack
, receiver
->td_end
- MAXACKWINDOW(sender
)) ? "BUG"
678 : "ACK is under the lower bound (possible overly delayed ACK)"
679 : "ACK is over the upper bound (ACKed data not seen yet)"
680 : "SEQ is under the lower bound (already ACKed data retransmitted)"
681 : "SEQ is over the upper bound (over the window of the receiver)");
684 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u "
685 "receiver end=%u maxend=%u maxwin=%u\n",
686 res
, sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
687 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
);
692 #ifdef CONFIG_NF_NAT_NEEDED
693 /* Update sender->td_end after NAT successfully mangled the packet */
694 /* Caller must linearize skb at tcp header. */
695 void nf_conntrack_tcp_update(const struct sk_buff
*skb
,
696 unsigned int dataoff
,
700 const struct tcphdr
*tcph
= (const void *)skb
->data
+ dataoff
;
701 const struct ip_ct_tcp_state
*sender
= &ct
->proto
.tcp
.seen
[dir
];
702 const struct ip_ct_tcp_state
*receiver
= &ct
->proto
.tcp
.seen
[!dir
];
705 end
= segment_seq_plus_len(ntohl(tcph
->seq
), skb
->len
, dataoff
, tcph
);
707 write_lock_bh(&tcp_lock
);
709 * We have to worry for the ack in the reply packet only...
711 if (after(end
, ct
->proto
.tcp
.seen
[dir
].td_end
))
712 ct
->proto
.tcp
.seen
[dir
].td_end
= end
;
713 ct
->proto
.tcp
.last_end
= end
;
714 write_unlock_bh(&tcp_lock
);
715 pr_debug("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
716 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
717 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
719 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
722 EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update
);
734 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
735 static const u8 tcp_valid_flags
[(TH_FIN
|TH_SYN
|TH_RST
|TH_ACK
|TH_URG
) + 1] =
743 [TH_FIN
|TH_ACK
|TH_URG
] = 1,
748 /* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
749 static int tcp_error(struct net
*net
,
751 unsigned int dataoff
,
752 enum ip_conntrack_info
*ctinfo
,
754 unsigned int hooknum
)
756 const struct tcphdr
*th
;
758 unsigned int tcplen
= skb
->len
- dataoff
;
761 /* Smaller that minimal TCP header? */
762 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
764 if (LOG_INVALID(IPPROTO_TCP
))
765 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
766 "nf_ct_tcp: short packet ");
770 /* Not whole TCP header or malformed packet */
771 if (th
->doff
*4 < sizeof(struct tcphdr
) || tcplen
< th
->doff
*4) {
772 if (LOG_INVALID(IPPROTO_TCP
))
773 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
774 "nf_ct_tcp: truncated/malformed packet ");
778 /* Checksum invalid? Ignore.
779 * We skip checking packets on the outgoing path
780 * because the checksum is assumed to be correct.
782 /* FIXME: Source route IP option packets --RR */
783 if (net
->ct
.sysctl_checksum
&& hooknum
== NF_INET_PRE_ROUTING
&&
784 nf_checksum(skb
, hooknum
, dataoff
, IPPROTO_TCP
, pf
)) {
785 if (LOG_INVALID(IPPROTO_TCP
))
786 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
787 "nf_ct_tcp: bad TCP checksum ");
791 /* Check TCP flags. */
792 tcpflags
= (((u_int8_t
*)th
)[13] & ~(TH_ECE
|TH_CWR
|TH_PUSH
));
793 if (!tcp_valid_flags
[tcpflags
]) {
794 if (LOG_INVALID(IPPROTO_TCP
))
795 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
796 "nf_ct_tcp: invalid TCP flag combination ");
803 /* Returns verdict for packet, or -1 for invalid. */
804 static int tcp_packet(struct nf_conn
*ct
,
805 const struct sk_buff
*skb
,
806 unsigned int dataoff
,
807 enum ip_conntrack_info ctinfo
,
809 unsigned int hooknum
)
811 struct nf_conntrack_tuple
*tuple
;
812 enum tcp_conntrack new_state
, old_state
;
813 enum ip_conntrack_dir dir
;
814 const struct tcphdr
*th
;
816 unsigned long timeout
;
819 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
822 write_lock_bh(&tcp_lock
);
823 old_state
= ct
->proto
.tcp
.state
;
824 dir
= CTINFO2DIR(ctinfo
);
825 index
= get_conntrack_index(th
);
826 new_state
= tcp_conntracks
[dir
][index
][old_state
];
827 tuple
= &ct
->tuplehash
[dir
].tuple
;
830 case TCP_CONNTRACK_SYN_SENT
:
831 if (old_state
< TCP_CONNTRACK_TIME_WAIT
)
833 /* RFC 1122: "When a connection is closed actively,
834 * it MUST linger in TIME-WAIT state for a time 2xMSL
835 * (Maximum Segment Lifetime). However, it MAY accept
836 * a new SYN from the remote TCP to reopen the connection
837 * directly from TIME-WAIT state, if..."
838 * We ignore the conditions because we are in the
839 * TIME-WAIT state anyway.
841 * Handle aborted connections: we and the server
842 * think there is an existing connection but the client
843 * aborts it and starts a new one.
845 if (((ct
->proto
.tcp
.seen
[dir
].flags
846 | ct
->proto
.tcp
.seen
[!dir
].flags
)
847 & IP_CT_TCP_FLAG_CLOSE_INIT
)
848 || (ct
->proto
.tcp
.last_dir
== dir
849 && ct
->proto
.tcp
.last_index
== TCP_RST_SET
)) {
850 /* Attempt to reopen a closed/aborted connection.
851 * Delete this connection and look up again. */
852 write_unlock_bh(&tcp_lock
);
854 /* Only repeat if we can actually remove the timer.
855 * Destruction may already be in progress in process
856 * context and we must give it a chance to terminate.
863 case TCP_CONNTRACK_IGNORE
:
866 * Our connection entry may be out of sync, so ignore
867 * packets which may signal the real connection between
868 * the client and the server.
871 * b) SYN/ACK in REPLY
872 * c) ACK in reply direction after initial SYN in original.
874 * If the ignored packet is invalid, the receiver will send
875 * a RST we'll catch below.
877 if (index
== TCP_SYNACK_SET
878 && ct
->proto
.tcp
.last_index
== TCP_SYN_SET
879 && ct
->proto
.tcp
.last_dir
!= dir
880 && ntohl(th
->ack_seq
) == ct
->proto
.tcp
.last_end
) {
881 /* b) This SYN/ACK acknowledges a SYN that we earlier
882 * ignored as invalid. This means that the client and
883 * the server are both in sync, while the firewall is
884 * not. We kill this session and block the SYN/ACK so
885 * that the client cannot but retransmit its SYN and
886 * thus initiate a clean new session.
888 write_unlock_bh(&tcp_lock
);
889 if (LOG_INVALID(IPPROTO_TCP
))
890 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
891 "nf_ct_tcp: killing out of sync session ");
895 ct
->proto
.tcp
.last_index
= index
;
896 ct
->proto
.tcp
.last_dir
= dir
;
897 ct
->proto
.tcp
.last_seq
= ntohl(th
->seq
);
898 ct
->proto
.tcp
.last_end
=
899 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
, dataoff
, th
);
901 write_unlock_bh(&tcp_lock
);
902 if (LOG_INVALID(IPPROTO_TCP
))
903 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
904 "nf_ct_tcp: invalid packet ignored ");
906 case TCP_CONNTRACK_MAX
:
908 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
909 dir
, get_conntrack_index(th
), old_state
);
910 write_unlock_bh(&tcp_lock
);
911 if (LOG_INVALID(IPPROTO_TCP
))
912 nf_log_packet(pf
, 0, skb
, NULL
, NULL
, NULL
,
913 "nf_ct_tcp: invalid state ");
915 case TCP_CONNTRACK_CLOSE
:
916 if (index
== TCP_RST_SET
917 && ((test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)
918 && ct
->proto
.tcp
.last_index
== TCP_SYN_SET
)
919 || (!test_bit(IPS_ASSURED_BIT
, &ct
->status
)
920 && ct
->proto
.tcp
.last_index
== TCP_ACK_SET
))
921 && ntohl(th
->ack_seq
) == ct
->proto
.tcp
.last_end
) {
922 /* RST sent to invalid SYN or ACK we had let through
923 * at a) and c) above:
925 * a) SYN was in window then
926 * c) we hold a half-open connection.
928 * Delete our connection entry.
929 * We skip window checking, because packet might ACK
930 * segments we ignored. */
933 /* Just fall through */
935 /* Keep compilers happy. */
939 if (!tcp_in_window(ct
, &ct
->proto
.tcp
, dir
, index
,
940 skb
, dataoff
, th
, pf
)) {
941 write_unlock_bh(&tcp_lock
);
945 /* From now on we have got in-window packets */
946 ct
->proto
.tcp
.last_index
= index
;
947 ct
->proto
.tcp
.last_dir
= dir
;
949 pr_debug("tcp_conntracks: ");
950 nf_ct_dump_tuple(tuple
);
951 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
952 (th
->syn
? 1 : 0), (th
->ack
? 1 : 0),
953 (th
->fin
? 1 : 0), (th
->rst
? 1 : 0),
954 old_state
, new_state
);
956 ct
->proto
.tcp
.state
= new_state
;
957 if (old_state
!= new_state
958 && new_state
== TCP_CONNTRACK_FIN_WAIT
)
959 ct
->proto
.tcp
.seen
[dir
].flags
|= IP_CT_TCP_FLAG_CLOSE_INIT
;
961 if (ct
->proto
.tcp
.retrans
>= nf_ct_tcp_max_retrans
&&
962 tcp_timeouts
[new_state
] > nf_ct_tcp_timeout_max_retrans
)
963 timeout
= nf_ct_tcp_timeout_max_retrans
;
964 else if ((ct
->proto
.tcp
.seen
[0].flags
| ct
->proto
.tcp
.seen
[1].flags
) &
965 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED
&&
966 tcp_timeouts
[new_state
] > nf_ct_tcp_timeout_unacknowledged
)
967 timeout
= nf_ct_tcp_timeout_unacknowledged
;
969 timeout
= tcp_timeouts
[new_state
];
970 write_unlock_bh(&tcp_lock
);
972 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE
, ct
);
973 if (new_state
!= old_state
)
974 nf_conntrack_event_cache(IPCT_PROTOINFO
, ct
);
976 if (!test_bit(IPS_SEEN_REPLY_BIT
, &ct
->status
)) {
977 /* If only reply is a RST, we can consider ourselves not to
978 have an established connection: this is a fairly common
979 problem case, so we can delete the conntrack
982 nf_ct_kill_acct(ct
, ctinfo
, skb
);
985 } else if (!test_bit(IPS_ASSURED_BIT
, &ct
->status
)
986 && (old_state
== TCP_CONNTRACK_SYN_RECV
987 || old_state
== TCP_CONNTRACK_ESTABLISHED
)
988 && new_state
== TCP_CONNTRACK_ESTABLISHED
) {
989 /* Set ASSURED if we see see valid ack in ESTABLISHED
990 after SYN_RECV or a valid answer for a picked up
992 set_bit(IPS_ASSURED_BIT
, &ct
->status
);
993 nf_conntrack_event_cache(IPCT_STATUS
, ct
);
995 nf_ct_refresh_acct(ct
, ctinfo
, skb
, timeout
);
1000 /* Called when a new connection for this protocol found. */
1001 static bool tcp_new(struct nf_conn
*ct
, const struct sk_buff
*skb
,
1002 unsigned int dataoff
)
1004 enum tcp_conntrack new_state
;
1005 const struct tcphdr
*th
;
1006 struct tcphdr _tcph
;
1007 const struct ip_ct_tcp_state
*sender
= &ct
->proto
.tcp
.seen
[0];
1008 const struct ip_ct_tcp_state
*receiver
= &ct
->proto
.tcp
.seen
[1];
1010 th
= skb_header_pointer(skb
, dataoff
, sizeof(_tcph
), &_tcph
);
1013 /* Don't need lock here: this conntrack not in circulation yet */
1015 = tcp_conntracks
[0][get_conntrack_index(th
)]
1016 [TCP_CONNTRACK_NONE
];
1018 /* Invalid: delete conntrack */
1019 if (new_state
>= TCP_CONNTRACK_MAX
) {
1020 pr_debug("nf_ct_tcp: invalid new deleting.\n");
1024 if (new_state
== TCP_CONNTRACK_SYN_SENT
) {
1026 ct
->proto
.tcp
.seen
[0].td_end
=
1027 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
,
1029 ct
->proto
.tcp
.seen
[0].td_maxwin
= ntohs(th
->window
);
1030 if (ct
->proto
.tcp
.seen
[0].td_maxwin
== 0)
1031 ct
->proto
.tcp
.seen
[0].td_maxwin
= 1;
1032 ct
->proto
.tcp
.seen
[0].td_maxend
=
1033 ct
->proto
.tcp
.seen
[0].td_end
;
1035 tcp_options(skb
, dataoff
, th
, &ct
->proto
.tcp
.seen
[0]);
1036 ct
->proto
.tcp
.seen
[1].flags
= 0;
1037 } else if (nf_ct_tcp_loose
== 0) {
1038 /* Don't try to pick up connections. */
1042 * We are in the middle of a connection,
1043 * its history is lost for us.
1044 * Let's try to use the data from the packet.
1046 ct
->proto
.tcp
.seen
[0].td_end
=
1047 segment_seq_plus_len(ntohl(th
->seq
), skb
->len
,
1049 ct
->proto
.tcp
.seen
[0].td_maxwin
= ntohs(th
->window
);
1050 if (ct
->proto
.tcp
.seen
[0].td_maxwin
== 0)
1051 ct
->proto
.tcp
.seen
[0].td_maxwin
= 1;
1052 ct
->proto
.tcp
.seen
[0].td_maxend
=
1053 ct
->proto
.tcp
.seen
[0].td_end
+
1054 ct
->proto
.tcp
.seen
[0].td_maxwin
;
1055 ct
->proto
.tcp
.seen
[0].td_scale
= 0;
1057 /* We assume SACK and liberal window checking to handle
1059 ct
->proto
.tcp
.seen
[0].flags
=
1060 ct
->proto
.tcp
.seen
[1].flags
= IP_CT_TCP_FLAG_SACK_PERM
|
1061 IP_CT_TCP_FLAG_BE_LIBERAL
;
1064 ct
->proto
.tcp
.seen
[1].td_end
= 0;
1065 ct
->proto
.tcp
.seen
[1].td_maxend
= 0;
1066 ct
->proto
.tcp
.seen
[1].td_maxwin
= 1;
1067 ct
->proto
.tcp
.seen
[1].td_scale
= 0;
1069 /* tcp_packet will set them */
1070 ct
->proto
.tcp
.state
= TCP_CONNTRACK_NONE
;
1071 ct
->proto
.tcp
.last_index
= TCP_NONE_SET
;
1073 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
1074 "receiver end=%u maxend=%u maxwin=%u scale=%i\n",
1075 sender
->td_end
, sender
->td_maxend
, sender
->td_maxwin
,
1077 receiver
->td_end
, receiver
->td_maxend
, receiver
->td_maxwin
,
1078 receiver
->td_scale
);
1082 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1084 #include <linux/netfilter/nfnetlink.h>
1085 #include <linux/netfilter/nfnetlink_conntrack.h>
1087 static int tcp_to_nlattr(struct sk_buff
*skb
, struct nlattr
*nla
,
1088 const struct nf_conn
*ct
)
1090 struct nlattr
*nest_parms
;
1091 struct nf_ct_tcp_flags tmp
= {};
1093 read_lock_bh(&tcp_lock
);
1094 nest_parms
= nla_nest_start(skb
, CTA_PROTOINFO_TCP
| NLA_F_NESTED
);
1096 goto nla_put_failure
;
1098 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_STATE
, ct
->proto
.tcp
.state
);
1100 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
,
1101 ct
->proto
.tcp
.seen
[0].td_scale
);
1103 NLA_PUT_U8(skb
, CTA_PROTOINFO_TCP_WSCALE_REPLY
,
1104 ct
->proto
.tcp
.seen
[1].td_scale
);
1106 tmp
.flags
= ct
->proto
.tcp
.seen
[0].flags
;
1107 NLA_PUT(skb
, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
,
1108 sizeof(struct nf_ct_tcp_flags
), &tmp
);
1110 tmp
.flags
= ct
->proto
.tcp
.seen
[1].flags
;
1111 NLA_PUT(skb
, CTA_PROTOINFO_TCP_FLAGS_REPLY
,
1112 sizeof(struct nf_ct_tcp_flags
), &tmp
);
1113 read_unlock_bh(&tcp_lock
);
1115 nla_nest_end(skb
, nest_parms
);
1120 read_unlock_bh(&tcp_lock
);
1124 static const struct nla_policy tcp_nla_policy
[CTA_PROTOINFO_TCP_MAX
+1] = {
1125 [CTA_PROTOINFO_TCP_STATE
] = { .type
= NLA_U8
},
1126 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
] = { .type
= NLA_U8
},
1127 [CTA_PROTOINFO_TCP_WSCALE_REPLY
] = { .type
= NLA_U8
},
1128 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
] = { .len
= sizeof(struct nf_ct_tcp_flags
) },
1129 [CTA_PROTOINFO_TCP_FLAGS_REPLY
] = { .len
= sizeof(struct nf_ct_tcp_flags
) },
1132 static int nlattr_to_tcp(struct nlattr
*cda
[], struct nf_conn
*ct
)
1134 struct nlattr
*pattr
= cda
[CTA_PROTOINFO_TCP
];
1135 struct nlattr
*tb
[CTA_PROTOINFO_TCP_MAX
+1];
1138 /* updates could not contain anything about the private
1139 * protocol info, in that case skip the parsing */
1143 err
= nla_parse_nested(tb
, CTA_PROTOINFO_TCP_MAX
, pattr
, tcp_nla_policy
);
1147 if (tb
[CTA_PROTOINFO_TCP_STATE
] &&
1148 nla_get_u8(tb
[CTA_PROTOINFO_TCP_STATE
]) >= TCP_CONNTRACK_MAX
)
1151 write_lock_bh(&tcp_lock
);
1152 if (tb
[CTA_PROTOINFO_TCP_STATE
])
1153 ct
->proto
.tcp
.state
= nla_get_u8(tb
[CTA_PROTOINFO_TCP_STATE
]);
1155 if (tb
[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
]) {
1156 struct nf_ct_tcp_flags
*attr
=
1157 nla_data(tb
[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL
]);
1158 ct
->proto
.tcp
.seen
[0].flags
&= ~attr
->mask
;
1159 ct
->proto
.tcp
.seen
[0].flags
|= attr
->flags
& attr
->mask
;
1162 if (tb
[CTA_PROTOINFO_TCP_FLAGS_REPLY
]) {
1163 struct nf_ct_tcp_flags
*attr
=
1164 nla_data(tb
[CTA_PROTOINFO_TCP_FLAGS_REPLY
]);
1165 ct
->proto
.tcp
.seen
[1].flags
&= ~attr
->mask
;
1166 ct
->proto
.tcp
.seen
[1].flags
|= attr
->flags
& attr
->mask
;
1169 if (tb
[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
] &&
1170 tb
[CTA_PROTOINFO_TCP_WSCALE_REPLY
] &&
1171 ct
->proto
.tcp
.seen
[0].flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
&&
1172 ct
->proto
.tcp
.seen
[1].flags
& IP_CT_TCP_FLAG_WINDOW_SCALE
) {
1173 ct
->proto
.tcp
.seen
[0].td_scale
=
1174 nla_get_u8(tb
[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL
]);
1175 ct
->proto
.tcp
.seen
[1].td_scale
=
1176 nla_get_u8(tb
[CTA_PROTOINFO_TCP_WSCALE_REPLY
]);
1178 write_unlock_bh(&tcp_lock
);
1184 #ifdef CONFIG_SYSCTL
1185 static unsigned int tcp_sysctl_table_users
;
1186 static struct ctl_table_header
*tcp_sysctl_header
;
1187 static struct ctl_table tcp_sysctl_table
[] = {
1189 .procname
= "nf_conntrack_tcp_timeout_syn_sent",
1190 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_SENT
],
1191 .maxlen
= sizeof(unsigned int),
1193 .proc_handler
= &proc_dointvec_jiffies
,
1196 .procname
= "nf_conntrack_tcp_timeout_syn_recv",
1197 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_RECV
],
1198 .maxlen
= sizeof(unsigned int),
1200 .proc_handler
= &proc_dointvec_jiffies
,
1203 .procname
= "nf_conntrack_tcp_timeout_established",
1204 .data
= &tcp_timeouts
[TCP_CONNTRACK_ESTABLISHED
],
1205 .maxlen
= sizeof(unsigned int),
1207 .proc_handler
= &proc_dointvec_jiffies
,
1210 .procname
= "nf_conntrack_tcp_timeout_fin_wait",
1211 .data
= &tcp_timeouts
[TCP_CONNTRACK_FIN_WAIT
],
1212 .maxlen
= sizeof(unsigned int),
1214 .proc_handler
= &proc_dointvec_jiffies
,
1217 .procname
= "nf_conntrack_tcp_timeout_close_wait",
1218 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE_WAIT
],
1219 .maxlen
= sizeof(unsigned int),
1221 .proc_handler
= &proc_dointvec_jiffies
,
1224 .procname
= "nf_conntrack_tcp_timeout_last_ack",
1225 .data
= &tcp_timeouts
[TCP_CONNTRACK_LAST_ACK
],
1226 .maxlen
= sizeof(unsigned int),
1228 .proc_handler
= &proc_dointvec_jiffies
,
1231 .procname
= "nf_conntrack_tcp_timeout_time_wait",
1232 .data
= &tcp_timeouts
[TCP_CONNTRACK_TIME_WAIT
],
1233 .maxlen
= sizeof(unsigned int),
1235 .proc_handler
= &proc_dointvec_jiffies
,
1238 .procname
= "nf_conntrack_tcp_timeout_close",
1239 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE
],
1240 .maxlen
= sizeof(unsigned int),
1242 .proc_handler
= &proc_dointvec_jiffies
,
1245 .procname
= "nf_conntrack_tcp_timeout_max_retrans",
1246 .data
= &nf_ct_tcp_timeout_max_retrans
,
1247 .maxlen
= sizeof(unsigned int),
1249 .proc_handler
= &proc_dointvec_jiffies
,
1252 .procname
= "nf_conntrack_tcp_timeout_unacknowledged",
1253 .data
= &nf_ct_tcp_timeout_unacknowledged
,
1254 .maxlen
= sizeof(unsigned int),
1256 .proc_handler
= &proc_dointvec_jiffies
,
1259 .ctl_name
= NET_NF_CONNTRACK_TCP_LOOSE
,
1260 .procname
= "nf_conntrack_tcp_loose",
1261 .data
= &nf_ct_tcp_loose
,
1262 .maxlen
= sizeof(unsigned int),
1264 .proc_handler
= &proc_dointvec
,
1267 .ctl_name
= NET_NF_CONNTRACK_TCP_BE_LIBERAL
,
1268 .procname
= "nf_conntrack_tcp_be_liberal",
1269 .data
= &nf_ct_tcp_be_liberal
,
1270 .maxlen
= sizeof(unsigned int),
1272 .proc_handler
= &proc_dointvec
,
1275 .ctl_name
= NET_NF_CONNTRACK_TCP_MAX_RETRANS
,
1276 .procname
= "nf_conntrack_tcp_max_retrans",
1277 .data
= &nf_ct_tcp_max_retrans
,
1278 .maxlen
= sizeof(unsigned int),
1280 .proc_handler
= &proc_dointvec
,
1287 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1288 static struct ctl_table tcp_compat_sysctl_table
[] = {
1290 .procname
= "ip_conntrack_tcp_timeout_syn_sent",
1291 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_SENT
],
1292 .maxlen
= sizeof(unsigned int),
1294 .proc_handler
= &proc_dointvec_jiffies
,
1297 .procname
= "ip_conntrack_tcp_timeout_syn_recv",
1298 .data
= &tcp_timeouts
[TCP_CONNTRACK_SYN_RECV
],
1299 .maxlen
= sizeof(unsigned int),
1301 .proc_handler
= &proc_dointvec_jiffies
,
1304 .procname
= "ip_conntrack_tcp_timeout_established",
1305 .data
= &tcp_timeouts
[TCP_CONNTRACK_ESTABLISHED
],
1306 .maxlen
= sizeof(unsigned int),
1308 .proc_handler
= &proc_dointvec_jiffies
,
1311 .procname
= "ip_conntrack_tcp_timeout_fin_wait",
1312 .data
= &tcp_timeouts
[TCP_CONNTRACK_FIN_WAIT
],
1313 .maxlen
= sizeof(unsigned int),
1315 .proc_handler
= &proc_dointvec_jiffies
,
1318 .procname
= "ip_conntrack_tcp_timeout_close_wait",
1319 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE_WAIT
],
1320 .maxlen
= sizeof(unsigned int),
1322 .proc_handler
= &proc_dointvec_jiffies
,
1325 .procname
= "ip_conntrack_tcp_timeout_last_ack",
1326 .data
= &tcp_timeouts
[TCP_CONNTRACK_LAST_ACK
],
1327 .maxlen
= sizeof(unsigned int),
1329 .proc_handler
= &proc_dointvec_jiffies
,
1332 .procname
= "ip_conntrack_tcp_timeout_time_wait",
1333 .data
= &tcp_timeouts
[TCP_CONNTRACK_TIME_WAIT
],
1334 .maxlen
= sizeof(unsigned int),
1336 .proc_handler
= &proc_dointvec_jiffies
,
1339 .procname
= "ip_conntrack_tcp_timeout_close",
1340 .data
= &tcp_timeouts
[TCP_CONNTRACK_CLOSE
],
1341 .maxlen
= sizeof(unsigned int),
1343 .proc_handler
= &proc_dointvec_jiffies
,
1346 .procname
= "ip_conntrack_tcp_timeout_max_retrans",
1347 .data
= &nf_ct_tcp_timeout_max_retrans
,
1348 .maxlen
= sizeof(unsigned int),
1350 .proc_handler
= &proc_dointvec_jiffies
,
1353 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_LOOSE
,
1354 .procname
= "ip_conntrack_tcp_loose",
1355 .data
= &nf_ct_tcp_loose
,
1356 .maxlen
= sizeof(unsigned int),
1358 .proc_handler
= &proc_dointvec
,
1361 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL
,
1362 .procname
= "ip_conntrack_tcp_be_liberal",
1363 .data
= &nf_ct_tcp_be_liberal
,
1364 .maxlen
= sizeof(unsigned int),
1366 .proc_handler
= &proc_dointvec
,
1369 .ctl_name
= NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS
,
1370 .procname
= "ip_conntrack_tcp_max_retrans",
1371 .data
= &nf_ct_tcp_max_retrans
,
1372 .maxlen
= sizeof(unsigned int),
1374 .proc_handler
= &proc_dointvec
,
1380 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
1381 #endif /* CONFIG_SYSCTL */
1383 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly
=
1386 .l4proto
= IPPROTO_TCP
,
1388 .pkt_to_tuple
= tcp_pkt_to_tuple
,
1389 .invert_tuple
= tcp_invert_tuple
,
1390 .print_tuple
= tcp_print_tuple
,
1391 .print_conntrack
= tcp_print_conntrack
,
1392 .packet
= tcp_packet
,
1395 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1396 .to_nlattr
= tcp_to_nlattr
,
1397 .from_nlattr
= nlattr_to_tcp
,
1398 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
1399 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
1400 .nla_policy
= nf_ct_port_nla_policy
,
1402 #ifdef CONFIG_SYSCTL
1403 .ctl_table_users
= &tcp_sysctl_table_users
,
1404 .ctl_table_header
= &tcp_sysctl_header
,
1405 .ctl_table
= tcp_sysctl_table
,
1406 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
1407 .ctl_compat_table
= tcp_compat_sysctl_table
,
1411 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4
);
1413 struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly
=
1415 .l3proto
= PF_INET6
,
1416 .l4proto
= IPPROTO_TCP
,
1418 .pkt_to_tuple
= tcp_pkt_to_tuple
,
1419 .invert_tuple
= tcp_invert_tuple
,
1420 .print_tuple
= tcp_print_tuple
,
1421 .print_conntrack
= tcp_print_conntrack
,
1422 .packet
= tcp_packet
,
1425 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
1426 .to_nlattr
= tcp_to_nlattr
,
1427 .from_nlattr
= nlattr_to_tcp
,
1428 .tuple_to_nlattr
= nf_ct_port_tuple_to_nlattr
,
1429 .nlattr_to_tuple
= nf_ct_port_nlattr_to_tuple
,
1430 .nla_policy
= nf_ct_port_nla_policy
,
1432 #ifdef CONFIG_SYSCTL
1433 .ctl_table_users
= &tcp_sysctl_table_users
,
1434 .ctl_table_header
= &tcp_sysctl_header
,
1435 .ctl_table
= tcp_sysctl_table
,
1438 EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6
);