Problem with sk_buff

Problem with sk_buff

[Damiano Bolzoni]

Hi people,
I wrote a kernel module that uses netfilter. I'm interested on incoming IP
packets that carry a TCP segment with SYN flag active. What I want to do is
to know which socket has been created in order to handle that connection and
I want to close it. sk_buff holds two pointer: struct sock* and struct
socket* but they point to NULL.
At this time I can test if the TCP segment has the SYN flag set but I can't
close the socket...
Anyone can help me?

Thanx a lot

Damiano
damiano.bolzoni@tin.it

Re: Problem with sk_buff

[Henrik Nordstrom]

Damiano Bolzoni wrote:
> Hi people,
> I wrote a kernel module that uses netfilter. I'm interested on incoming IP
> packets that carry a TCP segment with SYN flag active. What I want to do is
> to know which socket has been created in order to handle that connection
> and I want to close it. sk_buff holds two pointer: struct sock* and struct
> socket* but they point to NULL.
> At this time I can test if the TCP segment has the SYN flag set but I can't
> close the socket...
> Anyone can help me?

This is too early in the packet processing path. The socket is not yet known. 
These fields is only valid on locally generated packets (outgoing/sent 
packets).

You will need to make a call into the TCP/IP kernel to look up the local 
socket.

Regards
Henrik