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yaml
---
r: 150903
b: refs/heads/master
c: 874ab92
h: refs/heads/master
i:
  150901: d547851
  150899: d31f815
  150895: 3b5a25f
v: v3
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Jozsef Kadlecsik authored and Patrick McHardy committed Jun 2, 2009
1 parent 704c1bf commit 6eede0e
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Showing 3 changed files with 64 additions and 39 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8cc848fa3445b3503465dfba5d8ad47559faa05a
refs/heads/master: 874ab9233eeddb85fd2dd85131c145bde75da39a
3 changes: 2 additions & 1 deletion trunk/include/linux/netfilter/nf_conntrack_tcp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,8 @@ enum tcp_conntrack {
TCP_CONNTRACK_LAST_ACK,
TCP_CONNTRACK_TIME_WAIT,
TCP_CONNTRACK_CLOSE,
TCP_CONNTRACK_LISTEN,
TCP_CONNTRACK_LISTEN, /* obsolete */
#define TCP_CONNTRACK_SYN_SENT2 TCP_CONNTRACK_LISTEN
TCP_CONNTRACK_MAX,
TCP_CONNTRACK_IGNORE
};
Expand Down
98 changes: 61 additions & 37 deletions trunk/net/netfilter/nf_conntrack_proto_tcp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,7 @@ static const char *const tcp_conntrack_names[] = {
"LAST_ACK",
"TIME_WAIT",
"CLOSE",
"LISTEN"
"SYN_SENT2",
};

#define SECS * HZ
Expand All @@ -82,6 +82,7 @@ static unsigned int tcp_timeouts[TCP_CONNTRACK_MAX] __read_mostly = {
[TCP_CONNTRACK_LAST_ACK] = 30 SECS,
[TCP_CONNTRACK_TIME_WAIT] = 2 MINS,
[TCP_CONNTRACK_CLOSE] = 10 SECS,
[TCP_CONNTRACK_SYN_SENT2] = 2 MINS,
};

#define sNO TCP_CONNTRACK_NONE
Expand All @@ -93,7 +94,7 @@ static unsigned int tcp_timeouts[TCP_CONNTRACK_MAX] __read_mostly = {
#define sLA TCP_CONNTRACK_LAST_ACK
#define sTW TCP_CONNTRACK_TIME_WAIT
#define sCL TCP_CONNTRACK_CLOSE
#define sLI TCP_CONNTRACK_LISTEN
#define sS2 TCP_CONNTRACK_SYN_SENT2
#define sIV TCP_CONNTRACK_MAX
#define sIG TCP_CONNTRACK_IGNORE

Expand Down Expand Up @@ -123,6 +124,7 @@ enum tcp_bit_set {
*
* NONE: initial state
* SYN_SENT: SYN-only packet seen
* SYN_SENT2: SYN-only packet seen from reply dir, simultaneous open
* SYN_RECV: SYN-ACK packet seen
* ESTABLISHED: ACK packet seen
* FIN_WAIT: FIN packet seen
Expand All @@ -131,26 +133,24 @@ enum tcp_bit_set {
* TIME_WAIT: last ACK seen
* CLOSE: closed connection (RST)
*
* 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)
* if we regard them as truly invalid packets
*/
static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
{
/* ORIGINAL */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sIV },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sS2 },
/*
* sNO -> sSS Initialize a new connection
* sSS -> sSS Retransmitted SYN
* sSR -> sIG Late retransmitted SYN?
* sS2 -> sS2 Late retransmitted SYN
* sSR -> sIG
* sES -> sIG Error: SYNs in window outside the SYN_SENT state
* are errors. Receiver will reply with RST
* and close the connection.
Expand All @@ -161,22 +161,30 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* 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 },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*synack*/ { sIV, sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG, sSR },
/*
* 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 -> sIV Too late and no reason to do anything
* sSS -> sIV Client can't send SYN and then SYN/ACK
* sS2 -> sSR SYN/ACK sent to SYN2 in simultaneous open
* sSR -> sIG
* 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 -> sIG
* sCL -> sIG
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*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.
* sS2 -> sIV
* sSR -> sFW Close started.
* sES -> sFW
* sFW -> sLA FIN seen in both directions, waiting for
Expand All @@ -187,11 +195,12 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* sTW -> sTW
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*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.
* sS2 -> sIV
* sSR -> sES Established state is reached.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
Expand All @@ -200,29 +209,31 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* 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 },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
/*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, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*syn*/ { sIV, sS2, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sS2 },
/*
* sNO -> sIV Never reached.
* sSS -> sIV Simultaneous open, not supported
* sSR -> sIV Simultaneous open, not supported.
* sES -> sIV Server may not initiate a connection.
* sSS -> sS2 Simultaneous open
* sS2 -> sS2 Retransmitted simultaneous SYN
* sSR -> sIV Invalid SYN packets sent by the server
* sES -> sIV
* 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 },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*synack*/ { sIV, sSR, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sSR },
/*
* sSS -> sSR Standard open.
* sS2 -> sSR Simultaneous open
* sSR -> sSR Retransmitted SYN/ACK.
* sES -> sIG Late retransmitted SYN/ACK?
* sFW -> sIG Might be SYN/ACK answering ignored SYN
Expand All @@ -231,10 +242,11 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* sTW -> sIG
* sCL -> sIG
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV },
/*
* sSS -> sIV Server might not send FIN in this state.
* sS2 -> sIV
* sSR -> sFW Close started.
* sES -> sFW
* sFW -> sLA FIN seen in both directions.
Expand All @@ -243,10 +255,11 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* sTW -> sTW
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIG },
/*
* sSS -> sIG Might be a half-open connection.
* sS2 -> sIG
* sSR -> sSR Might answer late resent SYN.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
Expand All @@ -255,8 +268,8 @@ static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* 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 },
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */
/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL },
/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV }
}
};
Expand Down Expand Up @@ -521,13 +534,14 @@ static bool tcp_in_window(const struct nf_conn *ct,
receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
receiver->td_scale);

if (sender->td_end == 0) {
if (sender->td_maxwin == 0) {
/*
* Initialize sender data.
*/
if (tcph->syn && tcph->ack) {
if (tcph->syn) {
/*
* Outgoing SYN-ACK in reply to a SYN.
* SYN-ACK in reply to a SYN
* or SYN from reply direction in simultaneous open.
*/
sender->td_end =
sender->td_maxend = end;
Expand All @@ -543,6 +557,9 @@ static bool tcp_in_window(const struct nf_conn *ct,
&& receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE))
sender->td_scale =
receiver->td_scale = 0;
if (!tcph->ack)
/* Simultaneous open */
return true;
} else {
/*
* We are in the middle of a connection,
Expand Down Expand Up @@ -1068,7 +1085,7 @@ static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb,

ct->proto.tcp.seen[1].td_end = 0;
ct->proto.tcp.seen[1].td_maxend = 0;
ct->proto.tcp.seen[1].td_maxwin = 1;
ct->proto.tcp.seen[1].td_maxwin = 0;
ct->proto.tcp.seen[1].td_scale = 0;

/* tcp_packet will set them */
Expand Down Expand Up @@ -1309,6 +1326,13 @@ static struct ctl_table tcp_compat_sysctl_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "ip_conntrack_tcp_timeout_syn_sent2",
.data = &tcp_timeouts[TCP_CONNTRACK_SYN_SENT2],
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "ip_conntrack_tcp_timeout_syn_recv",
.data = &tcp_timeouts[TCP_CONNTRACK_SYN_RECV],
Expand Down

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