Re: packet socket can't steal packets

On Tue, May 07, 2002 at 09:02:31PM +0300, Dmitrii Tisnek wrote:

hey, I've been trying to change certain network packet mangling software
such that it would not need a kernel module, and it seems to me that,
unfortunately there's no way to make packet socket "steal" packets it
deliveres to the user mode.

"Divert Sockets for Linux" springs to my mind.. 

http://www.anr.mcnc.org/~divert/index.shtml

---
   Divert sockets enable both IP packet interception and injection on the
   end-hosts as well as on routers. Interception and injection happen at
   the IP layer. The intercepted packets are diverted to sockets in the
   user space, thus they will not be able to reach their destination
   unless they are reinjected by the user space sockets. This allows
   different tricks (e.g., routing and firewall) to be played, outside
   the operating system kernel, in between the packet interception and
   reinjection.
---


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Carl-Johan Bostorp wrote:

On Tue, May 07, 2002 at 09:02:31PM +0300, Dmitrii Tisnek wrote:

quoted

hey, I've been trying to change certain network packet mangling software
such that it would not need a kernel module, and it seems to me that,
unfortunately there's no way to make packet socket "steal" packets it
deliveres to the user mode.

"Divert Sockets for Linux" springs to my mind..

http://www.anr.mcnc.org/~divert/index.shtml

Except that the original poster is using the 2.4 kernel, for which divert
sockets do not work.

For 2.4 the netfilter module is cleanest, followed by netfilter QUEUE to
userspace (although this will give a performance hit).

When I had to move from 2.2 with divert sockets to 2.4, I used a netfilter
module with commandline parameters to pass in arguments.

Chris

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