linux-kernel - Re: poll problem with PF_PACKET when using PACKET_RX

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 16 Oct 2006 11:56:41 +0100
From:	Pádraig Brady <P@...igBrady.com>
To:	Joan Raventos <jraventos@...oo.com>
CC:	linux-kernel@...r.kernel.org
Subject: Re: poll problem with PF_PACKET when using PACKET_RX_RING

Joan Raventos wrote:
> Hello,
>
> In order to use PF_PACKET/SOCK_RAW with PACKET_RX_RING
> one would possibly do (as described in
> Documentation/networking/packet_mmap.txt):
> 1. setup PF_PACKET socket via socket call.
> 2. use setsockopt to change the PF_PACKET socket into
> PACKET_RX_RING mode and alloc the ring.
> 3. mmap the ring.
> 4. use poll with the socket descriptor and then
> directly access the pkts from the mmaped ring.

A few years back I developed a network sniffer
on 2.4.20 using PACKET_MMAP supporting very high packet rates.
When testing with high packet rates, invariably if traffic
was present while the buffers were being setup, the buffer data
would be corrupted. I worked around it by ensuring no packets went
into the stack before the userspace process sniffing the packets was started.

Pádraig.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/