[PATCH] [NETFILTER]: Allow SYN+PSH as valid flag combination

[Harald Welte]

On Fri, Nov 11, 2005 at 11:48:01AM -0800, David S. Miller wrote:
> From: Patrick McHardy <kaber at trash.net>
> Date: Fri, 11 Nov 2005 14:58:01 +0100
> 
> > Unfortunately this is unlikely to happen, and if Linux itself
> > accepts SYN|PSH, I don't see a reason why ip_conntrack shouldn't
> > as well.
> 
> I totally agree.

Me, too.  However, we also need to update nf_conntrack now:


[NETFILTER] {ip,nf}_conntrack TCP: Accept SYN+PUSH like SYN

Some devices (e.g. Qlogic iSCSI HBA hardware like QLA4010 up to firmware
3.0.0.4) initiates TCP with SYN and PUSH flags set.

The Linux TCP/IP stack deals fine with that, but the connection tracking
code doesn't.

This patch alters TCP connection tracking to accept SYN+PUSH as a valid
flag combination.

Signed-off-by: Vlad Drukker <vlad at storewiz.com>
Signed-off-by: Harald Welte <laforge at netfilter.org>

---
commit 933c4adfa34fbc151dd9908b2ce59335b22e6fe4
tree 041e7fc4116cd3b2774429cf8da9caee6e77a74b
parent 106c77b9b51b61bcd926ab5100761b2832791b74
author Harald Welte <laforge at netfilter.org> Sat, 12 Nov 2005 11:36:56 +0100
committer Harald Welte <laforge at netfilter.org> Sat, 12 Nov 2005 11:36:56 +0100

 net/ipv4/netfilter/ip_conntrack_proto_tcp.c |    1 +
 net/netfilter/nf_conntrack_proto_tcp.c      |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -814,6 +814,7 @@ static u8 tcp_valid_flags[(TH_FIN|TH_SYN
 {
 	[TH_SYN]			= 1,
 	[TH_SYN|TH_ACK]			= 1,
+	[TH_SYN|TH_PUSH]		= 1,
 	[TH_SYN|TH_ACK|TH_PUSH]		= 1,
 	[TH_RST]			= 1,
 	[TH_RST|TH_ACK]			= 1,
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -779,6 +779,7 @@ static u8 tcp_valid_flags[(TH_FIN|TH_SYN
 {
 	[TH_SYN]			= 1,
 	[TH_SYN|TH_ACK]			= 1,
+	[TH_SYN|TH_PUSH]		= 1,
 	[TH_SYN|TH_ACK|TH_PUSH]		= 1,
 	[TH_RST]			= 1,
 	[TH_RST|TH_ACK]			= 1,

-- 
- Harald Welte <laforge at netfilter.org>                 http://netfilter.org/
============================================================================
  "Fragmentation is like classful addressing -- an interesting early
   architectural error that shows how much experimentation was going
   on while IP was being designed."                    -- Paul Vixie
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