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Commit 753ae03f authored by Harald Welte's avatar Harald Welte Committed by David S. Miller
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[NETFILTER]: Add tcp window tracking 

This is the tcp window tracking patch, incremental to all previous
changes.  It is now by default enabled (i.e. in 'conservative' mode).
If you think it's better to leave it disabled ('liberal' mode), you can
change ip_conntrack_tcp_be_liberal to a different default value.

Cheers,
Signed-off-by: default avatarJozsef Kadlecski <kadlec@blackhole.kfki.hu>
Signed-off-by: default avatarHarald Welte <laforge@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@redhat.com>
parent 51b03285
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Showing with 973 additions and 113 deletions
include/linux/netfilter_ipv4/ip_conntrack.h
View file @ 753ae03f
......@@ -262,6 +262,11 @@ extern void ip_ct_refresh_acct(struct ip_conntrack *ct,
unsigned long extra_jiffies);
/* These are for NAT. Icky. */
/* Update TCP window tracking data when NAT mangles the packet */
extern int ip_conntrack_tcp_update(struct sk_buff *skb,
struct ip_conntrack *conntrack,
int dir);
/* Call me when a conntrack is destroyed. */
extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
......
include/linux/netfilter_ipv4/ip_conntrack_tcp.h
View file @ 753ae03f
......@@ -4,25 +4,44 @@
enum tcp_conntrack {
TCP_CONNTRACK_NONE,
TCP_CONNTRACK_ESTABLISHED,
TCP_CONNTRACK_SYN_SENT,
TCP_CONNTRACK_SYN_RECV,
TCP_CONNTRACK_ESTABLISHED,
TCP_CONNTRACK_FIN_WAIT,
TCP_CONNTRACK_TIME_WAIT,
TCP_CONNTRACK_CLOSE,
TCP_CONNTRACK_CLOSE_WAIT,
TCP_CONNTRACK_LAST_ACK,
TCP_CONNTRACK_TIME_WAIT,
TCP_CONNTRACK_CLOSE,
TCP_CONNTRACK_LISTEN,
TCP_CONNTRACK_MAX
TCP_CONNTRACK_MAX,
TCP_CONNTRACK_IGNORE
};
/* Window scaling is advertised by the sender */
#define IP_CT_TCP_STATE_FLAG_WINDOW_SCALE 0x01
/* SACK is permitted by the sender */
#define IP_CT_TCP_FLAG_SACK_PERM 0x02
struct ip_ct_tcp_state {
u_int32_t td_end; /* max of seq + len */
u_int32_t td_maxend; /* max of ack + max(win, 1) */
u_int32_t td_maxwin; /* max(win) */
u_int8_t td_scale; /* window scale factor */
u_int8_t loose; /* used when connection picked up from the middle */
u_int8_t flags; /* per direction state flags */
};
struct ip_ct_tcp
{
enum tcp_conntrack state;
/* Poor man's window tracking: sequence number of valid ACK
handshake completion packet */
u_int32_t handshake_ack;
struct ip_ct_tcp_state seen[2]; /* connection parameters per direction */
u_int8_t state; /* state of the connection (enum tcp_conntrack) */
/* For detecting stale connections */
u_int8_t last_dir; /* Direction of the last packet (enum ip_conntrack_dir) */
u_int8_t retrans; /* Number of retransmitted packets */
u_int8_t last_index; /* Index of the last packet */
u_int32_t last_seq; /* Last sequence number seen in dir */
u_int32_t last_end; /* Last seq + len */
};
#endif /* _IP_CONNTRACK_TCP_H */
net/ipv4/netfilter/ip_conntrack_core.c
View file @ 753ae03f
......@@ -807,12 +807,13 @@ unsigned int ip_conntrack_in(unsigned int hooknum,
IP_NF_ASSERT((*pskb)->nfct);
ret = proto->packet(ct, *pskb, ctinfo);
if (ret == -1) {
/* Invalid */
if (ret < 0) {
/* Invalid: inverse of the return code tells
* the netfilter core what to do*/
nf_conntrack_put((*pskb)->nfct);
(*pskb)->nfct = NULL;
__get_cpu_var(ip_conntrack_stat).invalid++;
return NF_ACCEPT;
return -ret;
}
if (ret != NF_DROP && ct->helper) {
......
net/ipv4/netfilter/ip_conntrack_proto_tcp.c
View file @ 753ae03f
......@@ -4,8 +4,22 @@
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>:
* - Real stateful connection tracking
* - Modified state transitions table
* - Window scaling support added
* - SACK support added
*
* Willy Tarreau:
* - State table bugfixes
* - More robust state changes
* - Tuning timer parameters
*
* version 2.2
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/timer.h>
......@@ -14,16 +28,18 @@
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <net/tcp.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4/ip_conntrack.h>
#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
#include <linux/netfilter_ipv4/lockhelp.h>
#if 0
#define DEBUGP printk
#define DEBUGP_VARS
#else
#define DEBUGP(format, args...)
#endif
......@@ -31,28 +47,40 @@
/* Protects conntrack->proto.tcp */
static DECLARE_RWLOCK(tcp_lock);
/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
closely. They're more complex. --RR */
/* "Be conservative in what you do,
be liberal in what you accept from others."
If it's non-zero, we mark only out of window RST segments as INVALID. */
int ip_ct_tcp_be_liberal = 0;
/* Actually, I believe that neither ipmasq (where this code is stolen
from) nor ipfilter do it exactly right. A new conntrack machine taking
into account packet loss (which creates uncertainty as to exactly
the conntrack of the connection) is required. RSN. --RR */
/* When connection is picked up from the middle, how many packets are required
to pass in each direction when we assume we are in sync - if any side uses
window scaling, we lost the game.
If it is set to zero, we disable picking up already established
connections. */
int ip_ct_tcp_loose = 3;
/* Max number of the retransmitted packets without receiving an (acceptable)
ACK from the destination. If this number is reached, a shorter timer
will be started. */
int ip_ct_tcp_max_retrans = 3;
/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
closely. They're more complex. --RR */
static const char *tcp_conntrack_names[] = {
"NONE",
"ESTABLISHED",
"SYN_SENT",
"SYN_RECV",
"ESTABLISHED",
"FIN_WAIT",
"TIME_WAIT",
"CLOSE",
"CLOSE_WAIT",
"LAST_ACK",
"TIME_WAIT",
"CLOSE",
"LISTEN"
};
#define SECS *HZ
#define SECS * HZ
#define MINS * 60 SECS
#define HOURS * 60 MINS
#define DAYS * 24 HOURS
......@@ -66,55 +94,204 @@ unsigned long ip_ct_tcp_timeout_last_ack = 30 SECS;
unsigned long ip_ct_tcp_timeout_time_wait = 2 MINS;
unsigned long ip_ct_tcp_timeout_close = 10 SECS;
/* RFC1122 says the R2 limit should be at least 100 seconds.
Linux uses 15 packets as limit, which corresponds
to ~13-30min depending on RTO. */
unsigned long ip_ct_tcp_timeout_max_retrans = 5 MINS;
static unsigned long * tcp_timeouts[]
= { NULL, /* TCP_CONNTRACK_NONE */
&ip_ct_tcp_timeout_established, /* TCP_CONNTRACK_ESTABLISHED, */
&ip_ct_tcp_timeout_syn_sent, /* TCP_CONNTRACK_SYN_SENT, */
&ip_ct_tcp_timeout_syn_recv, /* TCP_CONNTRACK_SYN_RECV, */
&ip_ct_tcp_timeout_established, /* TCP_CONNTRACK_ESTABLISHED, */
&ip_ct_tcp_timeout_fin_wait, /* TCP_CONNTRACK_FIN_WAIT, */
&ip_ct_tcp_timeout_time_wait, /* TCP_CONNTRACK_TIME_WAIT, */
&ip_ct_tcp_timeout_close, /* TCP_CONNTRACK_CLOSE, */
&ip_ct_tcp_timeout_close_wait, /* TCP_CONNTRACK_CLOSE_WAIT, */
&ip_ct_tcp_timeout_last_ack, /* TCP_CONNTRACK_LAST_ACK, */
&ip_ct_tcp_timeout_time_wait, /* TCP_CONNTRACK_TIME_WAIT, */
&ip_ct_tcp_timeout_close, /* TCP_CONNTRACK_CLOSE, */
NULL, /* TCP_CONNTRACK_LISTEN */
};
#define sNO TCP_CONNTRACK_NONE
#define sES TCP_CONNTRACK_ESTABLISHED
#define sSS TCP_CONNTRACK_SYN_SENT
#define sSR TCP_CONNTRACK_SYN_RECV
#define sES TCP_CONNTRACK_ESTABLISHED
#define sFW TCP_CONNTRACK_FIN_WAIT
#define sTW TCP_CONNTRACK_TIME_WAIT
#define sCL TCP_CONNTRACK_CLOSE
#define sCW TCP_CONNTRACK_CLOSE_WAIT
#define sLA TCP_CONNTRACK_LAST_ACK
#define sTW TCP_CONNTRACK_TIME_WAIT
#define sCL TCP_CONNTRACK_CLOSE
#define sLI TCP_CONNTRACK_LISTEN
#define sIV TCP_CONNTRACK_MAX
#define sIG TCP_CONNTRACK_IGNORE
static enum tcp_conntrack tcp_conntracks[2][5][TCP_CONNTRACK_MAX] = {
/* What TCP flags are set from RST/SYN/FIN/ACK. */
enum tcp_bit_set {
TCP_SYN_SET,
TCP_SYNACK_SET,
TCP_FIN_SET,
TCP_ACK_SET,
TCP_RST_SET,
TCP_NONE_SET,
};
/*
* The TCP state transition table needs a few words...
*
* We are the man in the middle. All the packets go through us
* but might get lost in transit to the destination.
* It is assumed that the destinations can't receive segments
* we haven't seen.
*
* The checked segment is in window, but our windows are *not*
* equivalent with the ones of the sender/receiver. We always
* try to guess the state of the current sender.
*
* The meaning of the states are:
*
* NONE: initial state
* SYN_SENT: SYN-only packet seen
* SYN_RECV: SYN-ACK packet seen
* ESTABLISHED: ACK packet seen
* FIN_WAIT: FIN packet seen
* CLOSE_WAIT: ACK seen (after FIN)
* LAST_ACK: FIN seen (after FIN)
* TIME_WAIT: last ACK seen
* CLOSE: closed connection
*
* LISTEN state is not used.
*
* Packets marked as IGNORED (sIG):
* if they may be either invalid or valid
* and the receiver may send back a connection
* closing RST or a SYN/ACK.
*
* Packets marked as INVALID (sIV):
* if they are invalid
* or we do not support the request (simultaneous open)
*/
static enum tcp_conntrack tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
{
/* ORIGINAL */
/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI */
/*syn*/ {sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI },
/*fin*/ {sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI },
/*ack*/ {sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES },
/*rst*/ {sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL },
/*none*/{sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
/* ORIGINAL */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
/*
* sNO -> sSS Initialize a new connection
* sSS -> sSS Retransmitted SYN
* sSR -> sIG Late retransmitted SYN?
* sES -> sIG Error: SYNs in window outside the SYN_SENT state
* are errors. Receiver will reply with RST
* and close the connection.
* Or we are not in sync and hold a dead connection.
* sFW -> sIG
* sCW -> sIG
* sLA -> sIG
* sTW -> sSS Reopened connection (RFC 1122).
* sCL -> sSS
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*synack*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
/*
* A SYN/ACK from the client is always invalid:
* - either it tries to set up a simultaneous open, which is
* not supported;
* - or the firewall has just been inserted between the two hosts
* during the session set-up. The SYN will be retransmitted
* by the true client (or it'll time out).
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
/*
* sNO -> sIV Too late and no reason to do anything...
* sSS -> sIV Client migth not send FIN in this state:
* we enforce waiting for a SYN/ACK reply first.
* sSR -> sFW Close started.
* sES -> sFW
* sFW -> sLA FIN seen in both directions, waiting for
* the last ACK.
* Migth be a retransmitted FIN as well...
* sCW -> sLA
* sLA -> sLA Retransmitted FIN. Remain in the same state.
* sTW -> sTW
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV },
/*
* sNO -> sES Assumed.
* sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
* sSR -> sES Established state is reached.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
* sCW -> sCW
* sLA -> sTW Last ACK detected.
* sTW -> sTW Retransmitted last ACK. Remain in the same state.
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
},
{
/* REPLY */
/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI */
/*syn*/ {sSR, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR },
/*fin*/ {sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI },
/*ack*/ {sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI },
/*rst*/ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sLA, sLI },
/*none*/{sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
}
/* REPLY */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*syn*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV },
/*
* sNO -> sIV Never reached.
* sSS -> sIV Simultaneous open, not supported
* sSR -> sIV Simultaneous open, not supported.
* sES -> sIV Server may not initiate a connection.
* sFW -> sIV
* sCW -> sIV
* sLA -> sIV
* sTW -> sIV Reopened connection, but server may not do it.
* sCL -> sIV
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIV },
/*
* sSS -> sSR Standard open.
* sSR -> sSR Retransmitted SYN/ACK.
* sES -> sIG Late retransmitted SYN/ACK?
* sFW -> sIG
* sCW -> sIG
* sLA -> sIG
* sTW -> sIG
* sCL -> sIG
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
/*
* sSS -> sIV Server might not send FIN in this state.
* sSR -> sFW Close started.
* sES -> sFW
* sFW -> sLA FIN seen in both directions.
* sCW -> sLA
* sLA -> sLA Retransmitted FIN.
* sTW -> sTW
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*ack*/ { sIV, sIV, sIV, sES, sCW, sCW, sTW, sTW, sCL, sIV },
/*
* sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet.
* sSR -> sIV Simultaneous open.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
* sCW -> sCW
* sLA -> sTW Last ACK detected.
* sTW -> sTW Retransmitted last ACK.
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV },
/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
}
};
static int tcp_pkt_to_tuple(const struct sk_buff *skb,
unsigned int dataoff,
struct ip_conntrack_tuple *tuple)
unsigned int dataoff,
struct ip_conntrack_tuple *tuple)
{
struct tcphdr hdr;
......@@ -160,11 +337,488 @@ static unsigned int tcp_print_conntrack(char *buffer,
static unsigned int get_conntrack_index(const struct tcphdr *tcph)
{
if (tcph->rst) return 3;
else if (tcph->syn) return 0;
else if (tcph->fin) return 1;
else if (tcph->ack) return 2;
else return 4;
if (tcph->rst) return TCP_RST_SET;
else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET);
else if (tcph->fin) return TCP_FIN_SET;
else if (tcph->ack) return TCP_ACK_SET;
else return TCP_NONE_SET;
}
/* TCP connection tracking based on 'Real Stateful TCP Packet Filtering
in IP Filter' by Guido van Rooij.
http://www.nluug.nl/events/sane2000/papers.html
http://www.iae.nl/users/guido/papers/tcp_filtering.ps.gz
The boundaries and the conditions are slightly changed:
td_maxend = max(sack + max(win,1)) seen in reply packets
td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets
td_end = max(seq + len) seen in sent packets
I. Upper bound for valid data: seq + len <= sender.td_maxend
II. Lower bound for valid data: seq >= sender.td_end - receiver.td_maxwin
III. Upper bound for valid ack: sack <= receiver.td_end
IV. Lower bound for valid ack: ack >= receiver.td_end - MAXACKWINDOW
where sack is the highest right edge of sack block found in the packet.
The upper bound limit for a valid ack is not ignored -
we doesn't have to deal with fragments.
*/
static inline __u32 segment_seq_plus_len(__u32 seq,
size_t len,
struct iphdr *iph,
struct tcphdr *tcph)
{
return (seq + len - (iph->ihl + tcph->doff)*4
+ (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0));
}
/* Fixme: what about big packets? */
#define MAXACKWINCONST 66000
#define MAXACKWINDOW(sender) \
((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \
: MAXACKWINCONST)
/*
* Simplified tcp_parse_options routine from tcp_input.c
*/
static void tcp_options(struct tcphdr *tcph,
struct ip_ct_tcp_state *state)
{
unsigned char *ptr = (unsigned char *)(tcph + 1);
int length = (tcph->doff*4) - sizeof(struct tcphdr);
state->td_scale =
state->flags = 0;
while (length > 0) {
int opcode=*ptr++;
int opsize;
switch (opcode) {
case TCPOPT_EOL:
return;
case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
length--;
continue;
default:
opsize=*ptr++;
if (opsize < 2) /* "silly options" */
return;
if (opsize > length)
break; /* don't parse partial options */
if (opcode == TCPOPT_SACK_PERM
&& opsize == TCPOLEN_SACK_PERM)
state->flags |= IP_CT_TCP_FLAG_SACK_PERM;
else if (opcode == TCPOPT_WINDOW
&& opsize == TCPOLEN_WINDOW) {
state->td_scale = *(u_int8_t *)ptr;
if (state->td_scale > 14) {
/* See RFC1323 */
state->td_scale = 14;
}
state->flags |=
IP_CT_TCP_STATE_FLAG_WINDOW_SCALE;
}
ptr += opsize - 2;
length -= opsize;
}
}
}
static void tcp_sack(struct tcphdr *tcph, __u32 *sack)
{
__u32 tmp;
unsigned char *ptr;
int length = (tcph->doff*4) - sizeof(struct tcphdr);
/* Fast path for timestamp-only option */
if (length == TCPOLEN_TSTAMP_ALIGNED*4
&& *(__u32 *)(tcph + 1) ==
__constant_ntohl((TCPOPT_NOP << 24)
| (TCPOPT_NOP << 16)
| (TCPOPT_TIMESTAMP << 8)
| TCPOLEN_TIMESTAMP))
return;
ptr = (unsigned char *)(tcph + 1);
while (length > 0) {
int opcode=*ptr++;
int opsize, i;
switch (opcode) {
case TCPOPT_EOL:
return;
case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
length--;
continue;
default:
opsize=*ptr++;
if (opsize < 2) /* "silly options" */
return;
if (opsize > length)
break; /* don't parse partial options */
if (opcode == TCPOPT_SACK
&& opsize >= (TCPOLEN_SACK_BASE
+ TCPOLEN_SACK_PERBLOCK)
&& !((opsize - TCPOLEN_SACK_BASE)
% TCPOLEN_SACK_PERBLOCK)) {
for (i = 0;
i < (opsize - TCPOLEN_SACK_BASE);
i += TCPOLEN_SACK_PERBLOCK) {
tmp = ntohl(*((u_int32_t *)(ptr+i)+1));
if (after(tmp, *sack))
*sack = tmp;
}
return;
}
ptr += opsize - 2;
length -= opsize;
}
}
}
static int tcp_in_window(struct ip_ct_tcp *state,
enum ip_conntrack_dir dir,
unsigned int *index,
const struct sk_buff *skb,
struct iphdr *iph,
struct tcphdr *tcph)
{
struct ip_ct_tcp_state *sender = &state->seen[dir];
struct ip_ct_tcp_state *receiver = &state->seen[!dir];
__u32 seq, ack, sack, end, win, swin;
int res;
/*
* Get the required data from the packet.
*/
seq = ntohl(tcph->seq);
ack = sack = ntohl(tcph->ack_seq);
win = ntohs(tcph->window);
end = segment_seq_plus_len(seq, skb->len, iph, tcph);
if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM)
tcp_sack(tcph, &sack);
DEBUGP("tcp_in_window: START\n");
DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
"seq=%u ack=%u sack=%u win=%u end=%u\n",
NIPQUAD(iph->saddr), ntohs(tcph->source),
NIPQUAD(iph->daddr), ntohs(tcph->dest),
seq, ack, sack, win, end);
DEBUGP("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
"receiver end=%u maxend=%u maxwin=%u scale=%i\n",
sender->td_end, sender->td_maxend, sender->td_maxwin,
sender->td_scale,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
receiver->td_scale);
if (sender->td_end == 0) {
/*
* Initialize sender data.
*/
if (tcph->syn && tcph->ack) {
/*
* Outgoing SYN-ACK in reply to a SYN.
*/
sender->td_end =
sender->td_maxend = end;
sender->td_maxwin = (win == 0 ? 1 : win);
tcp_options(tcph, sender);
/*
* RFC 1323:
* Both sides must send the Window Scale option
* to enable window scaling in either direction.
*/
if (!(sender->flags & IP_CT_TCP_STATE_FLAG_WINDOW_SCALE
&& receiver->flags & IP_CT_TCP_STATE_FLAG_WINDOW_SCALE))
sender->td_scale =
receiver->td_scale = 0;
} else {
/*
* We are in the middle of a connection,
* its history is lost for us.
* Let's try to use the data from the packet.
*/
sender->td_end = end;
sender->td_maxwin = (win == 0 ? 1 : win);
sender->td_maxend = end + sender->td_maxwin;
}
} else if (state->state == TCP_CONNTRACK_SYN_SENT
&& dir == IP_CT_DIR_ORIGINAL
&& after(end, sender->td_end)) {
/*
* RFC 793: "if a TCP is reinitialized ... then it need
* not wait at all; it must only be sure to use sequence
* numbers larger than those recently used."
*/
sender->td_end =
sender->td_maxend = end;
sender->td_maxwin = (win == 0 ? 1 : win);
tcp_options(tcph, sender);
}
if (!(tcph->ack)) {
/*
* If there is no ACK, just pretend it was set and OK.
*/
ack = sack = receiver->td_end;
} else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) ==
(TCP_FLAG_ACK|TCP_FLAG_RST))
&& (ack == 0)) {
/*
* Broken TCP stacks, that set ACK in RST packets as well
* with zero ack value.
*/
ack = sack = receiver->td_end;
}
if (seq == end)
/*
* Packets contains no data: we assume it is valid
* and check the ack value only.
*/
seq = end = sender->td_end;
DEBUGP("tcp_in_window: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
"seq=%u ack=%u sack =%u win=%u end=%u trim=%u\n",
NIPQUAD(iph->saddr), ntohs(tcph->source),
NIPQUAD(iph->daddr), ntohs(tcph->dest),
seq, ack, sack, win, end,
after(end, sender->td_maxend) && before(seq, sender->td_maxend)
? sender->td_maxend : end);
DEBUGP("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i "
"receiver end=%u maxend=%u maxwin=%u scale=%i\n",
sender->td_end, sender->td_maxend, sender->td_maxwin,
sender->td_scale,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
receiver->td_scale);
/* Ignore data over the right edge of the receiver's window. */
if (after(end, sender->td_maxend) &&
before(seq, sender->td_maxend)) {
end = sender->td_maxend;
if (*index == TCP_FIN_SET)
*index = TCP_ACK_SET;
}
DEBUGP("tcp_in_window: I=%i II=%i III=%i IV=%i\n",
before(end, sender->td_maxend + 1)
|| before(seq, sender->td_maxend + 1),
after(seq, sender->td_end - receiver->td_maxwin - 1)
|| after(end, sender->td_end - receiver->td_maxwin - 1),
before(sack, receiver->td_end + 1),
after(ack, receiver->td_end - MAXACKWINDOW(sender)));
if (sender->loose || receiver->loose ||
(before(end, sender->td_maxend + 1) &&
after(seq, sender->td_end - receiver->td_maxwin - 1) &&
before(sack, receiver->td_end + 1) &&
after(ack, receiver->td_end - MAXACKWINDOW(sender)))) {
/*
* Take into account window scaling (RFC 1323).
*/
if (!tcph->syn)
win <<= sender->td_scale;
/*
* Update sender data.
*/
swin = win + (sack - ack);
if (sender->td_maxwin < swin)
sender->td_maxwin = swin;
if (after(end, sender->td_end))
sender->td_end = end;
if (after(sack + win, receiver->td_maxend - 1)) {
receiver->td_maxend = sack + win;
if (win == 0)
receiver->td_maxend++;
}
/*
* Check retransmissions.
*/
if (*index == TCP_ACK_SET) {
if (state->last_dir == dir
&& state->last_seq == seq
&& state->last_end == end)
state->retrans++;
else {
state->last_dir = dir;
state->last_seq = seq;
state->last_end = end;
state->retrans = 0;
}
}
/*
* Close the window of disabled window tracking :-)
*/
if (sender->loose)
sender->loose--;
res = 1;
} else {
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: %s ",
before(end, sender->td_maxend + 1) ?
after(seq, sender->td_end - receiver->td_maxwin - 1) ?
before(ack, receiver->td_end + 1) ?
after(ack, receiver->td_end - MAXACKWINDOW(sender)) ? "BUG"
: "ACK is under the lower bound (possibly overly delayed ACK)"
: "ACK is over the upper bound (ACKed data has never seen yet)"
: "SEQ is under the lower bound (retransmitted already ACKed data)"
: "SEQ is over the upper bound (over the window of the receiver)");
res = ip_ct_tcp_be_liberal && !tcph->rst;
}
DEBUGP("tcp_in_window: res=%i sender end=%u maxend=%u maxwin=%u "
"receiver end=%u maxend=%u maxwin=%u\n",
res, sender->td_end, sender->td_maxend, sender->td_maxwin,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin);
return res;
}
#ifdef CONFIG_IP_NF_NAT_NEEDED
/* Update sender->td_end after NAT successfully mangled the packet */
int ip_conntrack_tcp_update(struct sk_buff *skb,
struct ip_conntrack *conntrack,
int dir)
{
struct iphdr *iph = skb->nh.iph;
struct tcphdr *tcph = (void *)skb->nh.iph + skb->nh.iph->ihl*4;
__u32 end;
#ifdef DEBUGP_VARS
struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[dir];
struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[!dir];
#endif
end = segment_seq_plus_len(ntohl(tcph->seq), skb->len, iph, tcph);
WRITE_LOCK(&tcp_lock);
/*
* We have to worry for the ack in the reply packet only...
*/
if (after(end, conntrack->proto.tcp.seen[dir].td_end))
conntrack->proto.tcp.seen[dir].td_end = end;
conntrack->proto.tcp.last_end = end;
WRITE_UNLOCK(&tcp_lock);
DEBUGP("tcp_update: sender end=%u maxend=%u maxwin=%u scale=%i "
"receiver end=%u maxend=%u maxwin=%u scale=%i\n",
sender->td_end, sender->td_maxend, sender->td_maxwin,
sender->td_scale,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
receiver->td_scale);
return 1;
}
EXPORT_SYMBOL(ip_conntrack_tcp_update);
#endif
#define TH_FIN 0x01
#define TH_SYN 0x02
#define TH_RST 0x04
#define TH_PUSH 0x08
#define TH_ACK 0x10
#define TH_URG 0x20
#define TH_ECE 0x40
#define TH_CWR 0x80
/* table of valid flag combinations - ECE and CWR are always valid */
static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] =
{
[TH_SYN] = 1,
[TH_SYN|TH_ACK] = 1,
[TH_RST] = 1,
[TH_RST|TH_ACK] = 1,
[TH_RST|TH_ACK|TH_PUSH] = 1,
[TH_FIN|TH_ACK] = 1,
[TH_ACK] = 1,
[TH_ACK|TH_PUSH] = 1,
[TH_ACK|TH_URG] = 1,
[TH_ACK|TH_URG|TH_PUSH] = 1,
[TH_FIN|TH_ACK|TH_PUSH] = 1,
[TH_FIN|TH_ACK|TH_URG] = 1,
[TH_FIN|TH_ACK|TH_URG|TH_PUSH] = 1,
};
/* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */
static int tcp_error(struct sk_buff *skb,
enum ip_conntrack_info *ctinfo,
unsigned int hooknum)
{
struct iphdr *iph = skb->nh.iph;
struct tcphdr tcph;
unsigned int tcplen = skb->len - iph->ihl * 4;
u_int8_t tcpflags;
/* Smaller that minimal TCP header? */
if (skb_copy_bits(skb, iph->ihl * 4, &tcph, sizeof(tcph)) != 0) {
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: short packet ");
return -NF_ACCEPT;
}
/* Not whole TCP header or malformed packet */
if (tcph.doff*4 < sizeof(struct tcphdr) || tcplen < tcph.doff*4) {
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: truncated/malformed packet ");
return -NF_ACCEPT;
}
/* Checksum invalid? Ignore.
* We skip checking packets on the outgoing path
* because the semantic of CHECKSUM_HW is different there
* and moreover root might send raw packets.
*/
/* FIXME: Source route IP option packets --RR */
if (hooknum == NF_IP_PRE_ROUTING
&& csum_tcpudp_magic(iph->saddr, iph->daddr, tcplen, IPPROTO_TCP,
skb->ip_summed == CHECKSUM_HW ? skb->csum
: skb_checksum(skb, iph->ihl*4, tcplen, 0))) {
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: bad TCP checksum ");
return -NF_ACCEPT;
}
/* Check TCP flags. */
tcpflags = (((u_int8_t *)&tcph)[13] & ~(TH_ECE|TH_CWR));
if (!tcp_valid_flags[tcpflags]) {
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: invalid TCP flag combination ");
return -NF_ACCEPT;
}
return NF_ACCEPT;
}
static inline void copy_whole_tcp_header(const struct sk_buff *skb,
unsigned char *buff)
{
struct iphdr *iph = skb->nh.iph;
struct tcphdr *tcph = (struct tcphdr *)buff;
/* tcp_error guarantees for us that the packet is not malformed */
skb_copy_bits(skb, iph->ihl * 4, buff, sizeof(*tcph));
skb_copy_bits(skb, iph->ihl * 4 + sizeof(*tcph),
buff + sizeof(*tcph),
tcph->doff * 4 - sizeof(*tcph));
}
/* Returns verdict for packet, or -1 for invalid. */
......@@ -172,88 +826,232 @@ static int tcp_packet(struct ip_conntrack *conntrack,
const struct sk_buff *skb,
enum ip_conntrack_info ctinfo)
{
enum tcp_conntrack newconntrack, oldtcpstate;
struct tcphdr tcph;
enum tcp_conntrack new_state, old_state;
enum ip_conntrack_dir dir;
struct iphdr *iph = skb->nh.iph;
unsigned char buff[15 * 4];
struct tcphdr *tcph = (struct tcphdr *)buff;
unsigned long timeout;
unsigned int index;
copy_whole_tcp_header(skb, buff);
WRITE_LOCK(&tcp_lock);
old_state = conntrack->proto.tcp.state;
dir = CTINFO2DIR(ctinfo);
index = get_conntrack_index(tcph);
new_state = tcp_conntracks[dir][index][old_state];
if (skb_copy_bits(skb, skb->nh.iph->ihl * 4, &tcph, sizeof(tcph)) != 0)
return -1;
if (skb->len < skb->nh.iph->ihl * 4 + tcph.doff * 4)
return -1;
/* If only reply is a RST, we can consider ourselves not to
have an established connection: this is a fairly common
problem case, so we can delete the conntrack
immediately. --RR */
if (!test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status) && tcph.rst) {
if (del_timer(&conntrack->timeout))
conntrack->timeout.function((unsigned long)conntrack);
switch (new_state) {
case TCP_CONNTRACK_IGNORE:
/* Either SYN in ORIGINAL, or SYN/ACK in REPLY direction. */
if (index == TCP_SYNACK_SET
&& conntrack->proto.tcp.last_index == TCP_SYN_SET
&& conntrack->proto.tcp.last_dir != dir
&& after(ntohl(tcph->ack_seq),
conntrack->proto.tcp.last_seq)) {
/* This SYN/ACK acknowledges a SYN that we earlier
* ignored as invalid. This means that the client and
* the server are both in sync, while the firewall is
* not. We kill this session and block the SYN/ACK so
* that the client cannot but retransmit its SYN and
* thus initiate a clean new session.
*/
WRITE_UNLOCK(&tcp_lock);
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: killing out of sync session ");
if (del_timer(&conntrack->timeout))
conntrack->timeout.function((unsigned long)
conntrack);
return -NF_DROP;
}
conntrack->proto.tcp.last_index = index;
conntrack->proto.tcp.last_dir = dir;
conntrack->proto.tcp.last_seq = ntohl(tcph->seq);
WRITE_UNLOCK(&tcp_lock);
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: invalid SYN (ignored) ");
return NF_ACCEPT;
case TCP_CONNTRACK_MAX:
/* Invalid packet */
DEBUGP("ip_ct_tcp: Invalid dir=%i index=%u ostate=%u\n",
dir, get_conntrack_index(tcph),
old_state);
WRITE_UNLOCK(&tcp_lock);
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: invalid state ");
return -NF_ACCEPT;
case TCP_CONNTRACK_SYN_SENT:
if (old_state >= TCP_CONNTRACK_TIME_WAIT) {
/* Attempt to reopen a closed connection.
* Delete this connection and look up again. */
WRITE_UNLOCK(&tcp_lock);
if (del_timer(&conntrack->timeout))
conntrack->timeout.function((unsigned long)
conntrack);
return -NF_REPEAT;
}
break;
case TCP_CONNTRACK_CLOSE:
if (index == TCP_RST_SET
&& test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
&& conntrack->proto.tcp.last_index <= TCP_SYNACK_SET
&& after(ntohl(tcph->ack_seq),
conntrack->proto.tcp.last_seq)) {
/* Ignore RST closing down invalid SYN
we had let trough. */
WRITE_UNLOCK(&tcp_lock);
if (LOG_INVALID(IPPROTO_TCP))
nf_log_packet(PF_INET, 0, skb, NULL, NULL,
"ip_ct_tcp: invalid RST (ignored) ");
return NF_ACCEPT;
}
/* Just fall trough */
default:
/* Keep compilers happy. */
break;
}
WRITE_LOCK(&tcp_lock);
oldtcpstate = conntrack->proto.tcp.state;
newconntrack
= tcp_conntracks
[CTINFO2DIR(ctinfo)]
[get_conntrack_index(&tcph)][oldtcpstate];
/* Invalid */
if (newconntrack == TCP_CONNTRACK_MAX) {
DEBUGP("ip_conntrack_tcp: Invalid dir=%i index=%u conntrack=%u\n",
CTINFO2DIR(ctinfo), get_conntrack_index(&tcph),
conntrack->proto.tcp.state);
if (!tcp_in_window(&conntrack->proto.tcp, dir, &index,
skb, iph, tcph)) {
WRITE_UNLOCK(&tcp_lock);
return -1;
return -NF_ACCEPT;
}
/* From now on we have got in-window packets */
/* If FIN was trimmed off, we don't change state. */
conntrack->proto.tcp.last_index = index;
new_state = tcp_conntracks[dir][index][old_state];
conntrack->proto.tcp.state = newconntrack;
DEBUGP("tcp_conntracks: src=%u.%u.%u.%u:%hu dst=%u.%u.%u.%u:%hu "
"syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n",
NIPQUAD(iph->saddr), ntohs(tcph->source),
NIPQUAD(iph->daddr), ntohs(tcph->dest),
(tcph->syn ? 1 : 0), (tcph->ack ? 1 : 0),
(tcph->fin ? 1 : 0), (tcph->rst ? 1 : 0),
old_state, new_state);
/* Poor man's window tracking: record SYN/ACK for handshake check */
if (oldtcpstate == TCP_CONNTRACK_SYN_SENT
&& CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY
&& tcph.syn && tcph.ack) {
conntrack->proto.tcp.handshake_ack
= htonl(ntohl(tcph.seq) + 1);
goto out;
}
/* Set ASSURED if we see valid ack in ESTABLISHED after SYN_RECV */
if (oldtcpstate == TCP_CONNTRACK_SYN_RECV
&& CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL
&& tcph.ack && !tcph.syn
&& tcph.ack_seq == conntrack->proto.tcp.handshake_ack)
set_bit(IPS_ASSURED_BIT, &conntrack->status);
conntrack->proto.tcp.state = new_state;
timeout = conntrack->proto.tcp.retrans >= ip_ct_tcp_max_retrans
&& *tcp_timeouts[new_state] > ip_ct_tcp_timeout_max_retrans
? ip_ct_tcp_timeout_max_retrans : *tcp_timeouts[new_state];
WRITE_UNLOCK(&tcp_lock);
out: WRITE_UNLOCK(&tcp_lock);
ip_ct_refresh_acct(conntrack, ctinfo, skb, *tcp_timeouts[newconntrack]);
if (!test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
/* If only reply is a RST, we can consider ourselves not to
have an established connection: this is a fairly common
problem case, so we can delete the conntrack
immediately. --RR */
if (tcph->rst) {
if (del_timer(&conntrack->timeout))
conntrack->timeout.function((unsigned long)
conntrack);
return NF_ACCEPT;
}
} else if (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
&& (old_state == TCP_CONNTRACK_SYN_RECV
|| old_state == TCP_CONNTRACK_ESTABLISHED)
&& new_state == TCP_CONNTRACK_ESTABLISHED) {
/* Set ASSURED if we see see valid ack in ESTABLISHED
after SYN_RECV or a valid answer for a picked up
connection. */
set_bit(IPS_ASSURED_BIT, &conntrack->status);
}
ip_ct_refresh_acct(conntrack, ctinfo, skb, timeout);
return NF_ACCEPT;
}
/* Called when a new connection for this protocol found. */
static int tcp_new(struct ip_conntrack *conntrack, const struct sk_buff *skb)
/* Called when a new connection for this protocol found. */
static int tcp_new(struct ip_conntrack *conntrack,
const struct sk_buff *skb)
{
enum tcp_conntrack newconntrack;
struct tcphdr tcph;
if (skb_copy_bits(skb, skb->nh.iph->ihl * 4, &tcph, sizeof(tcph)) != 0)
return -1;
enum tcp_conntrack new_state;
struct iphdr *iph = skb->nh.iph;
unsigned char buff[15 * 4];
struct tcphdr *tcph = (struct tcphdr *)buff;
#ifdef DEBUGP_VARS
struct ip_ct_tcp_state *sender = &conntrack->proto.tcp.seen[0];
struct ip_ct_tcp_state *receiver = &conntrack->proto.tcp.seen[1];
#endif
copy_whole_tcp_header(skb, buff);
/* Don't need lock here: this conntrack not in circulation yet */
newconntrack
= tcp_conntracks[0][get_conntrack_index(&tcph)]
new_state
= tcp_conntracks[0][get_conntrack_index(tcph)]
[TCP_CONNTRACK_NONE];
/* Invalid: delete conntrack */
if (newconntrack == TCP_CONNTRACK_MAX) {
DEBUGP("ip_conntrack_tcp: invalid new deleting.\n");
if (new_state >= TCP_CONNTRACK_MAX) {
DEBUGP("ip_ct_tcp: invalid new deleting.\n");
return 0;
}
conntrack->proto.tcp.state = newconntrack;
if (new_state == TCP_CONNTRACK_SYN_SENT) {
/* SYN packet */
conntrack->proto.tcp.seen[0].td_end =
segment_seq_plus_len(ntohl(tcph->seq), skb->len,
iph, tcph);
conntrack->proto.tcp.seen[0].td_maxwin = ntohs(tcph->window);
if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
conntrack->proto.tcp.seen[0].td_maxwin = 1;
conntrack->proto.tcp.seen[0].td_maxend =
conntrack->proto.tcp.seen[0].td_end;
tcp_options(tcph, &conntrack->proto.tcp.seen[0]);
conntrack->proto.tcp.seen[1].flags = 0;
conntrack->proto.tcp.seen[0].loose =
conntrack->proto.tcp.seen[1].loose = 0;
} else if (ip_ct_tcp_loose == 0) {
/* Don't try to pick up connections. */
return 0;
} else {
/*
* We are in the middle of a connection,
* its history is lost for us.
* Let's try to use the data from the packet.
*/
conntrack->proto.tcp.seen[0].td_end =
segment_seq_plus_len(ntohl(tcph->seq), skb->len,
iph, tcph);
conntrack->proto.tcp.seen[0].td_maxwin = ntohs(tcph->window);
if (conntrack->proto.tcp.seen[0].td_maxwin == 0)
conntrack->proto.tcp.seen[0].td_maxwin = 1;
conntrack->proto.tcp.seen[0].td_maxend =
conntrack->proto.tcp.seen[0].td_end +
conntrack->proto.tcp.seen[0].td_maxwin;
conntrack->proto.tcp.seen[0].td_scale = 0;
/* We assume SACK. Should we assume window scaling too? */
conntrack->proto.tcp.seen[0].flags =
conntrack->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM;
conntrack->proto.tcp.seen[0].loose =
conntrack->proto.tcp.seen[1].loose = ip_ct_tcp_loose;
}
conntrack->proto.tcp.seen[1].td_end = 0;
conntrack->proto.tcp.seen[1].td_maxend = 0;
conntrack->proto.tcp.seen[1].td_maxwin = 1;
conntrack->proto.tcp.seen[1].td_scale = 0;
/* tcp_packet will set them */
conntrack->proto.tcp.state = TCP_CONNTRACK_NONE;
conntrack->proto.tcp.last_index = TCP_NONE_SET;
DEBUGP("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "
"receiver end=%u maxend=%u maxwin=%u scale=%i\n",
sender->td_end, sender->td_maxend, sender->td_maxwin,
sender->td_scale,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
receiver->td_scale);
return 1;
}
static int tcp_exp_matches_pkt(struct ip_conntrack_expect *exp,
const struct sk_buff *skb)
{
......@@ -261,7 +1059,7 @@ static int tcp_exp_matches_pkt(struct ip_conntrack_expect *exp,
struct tcphdr tcph;
unsigned int datalen;
if (skb_copy_bits(skb, skb->nh.iph->ihl * 4, &tcph, sizeof(tcph)) != 0)
if (skb_copy_bits(skb, iph->ihl * 4, &tcph, sizeof(tcph)) != 0)
return 0;
datalen = skb->len - iph->ihl*4 - tcph.doff*4;
......@@ -279,4 +1077,5 @@ struct ip_conntrack_protocol ip_conntrack_protocol_tcp =
.packet = tcp_packet,
.new = tcp_new,
.exp_matches_pkt = tcp_exp_matches_pkt,
.error = tcp_error,
};
net/ipv4/netfilter/ip_conntrack_standalone.c
View file @ 753ae03f
......@@ -505,6 +505,10 @@ extern unsigned long ip_ct_tcp_timeout_close_wait;
extern unsigned long ip_ct_tcp_timeout_last_ack;
extern unsigned long ip_ct_tcp_timeout_time_wait;
extern unsigned long ip_ct_tcp_timeout_close;
extern unsigned long ip_ct_tcp_timeout_max_retrans;
extern int ip_ct_tcp_loose;
extern int ip_ct_tcp_be_liberal;
extern int ip_ct_tcp_max_retrans;
/* From ip_conntrack_proto_udp.c */
extern unsigned long ip_ct_udp_timeout;
......@@ -647,6 +651,38 @@ static ctl_table ip_ct_sysctl_table[] = {
.extra1 = &log_invalid_proto_min,
.extra2 = &log_invalid_proto_max,
},
{
.ctl_name = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS,
.procname = "ip_conntrack_tcp_timeout_max_retrans",
.data = &ip_ct_tcp_timeout_max_retrans,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec_jiffies,
},
{
.ctl_name = NET_IPV4_NF_CONNTRACK_TCP_LOOSE,
.procname = "ip_conntrack_tcp_loose",
.data = &ip_ct_tcp_loose,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,
.procname = "ip_conntrack_tcp_be_liberal",
.data = &ip_ct_tcp_be_liberal,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,
.procname = "ip_conntrack_tcp_max_retrans",
.data = &ip_ct_tcp_max_retrans,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = &proc_dointvec,
},
{ .ctl_name = 0 }
};
......
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