From: Jesper Dangaard Brouer <jdb@comx.dk>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: BUG: NIU driver: strange issues with multicast "UDP: short packet"
Date: Thu, 05 Feb 2009 13:44:00 +0100 [thread overview]
Message-ID: <1233837840.20497.129.camel@localhost.localdomain> (raw)
In-Reply-To: <20090204.010029.12969718.davem@davemloft.net>
On Wed, 2009-02-04 at 01:00 -0800, David Miller wrote:
> > Yes, but this only happens on the NIU/netpune NIC. I works with the
> igb
> > driver, I have both a 82575 and a 82576 NIC.
>
> Right, and what's unique about NIU is that NIU won't prepull
> the protocol headers into the linear area on receive.
>
> At the point when IPMR is dealing with potentially forwarding
> the frame, the UDP headers aren't yet pulled into the linear
> area. UDP input will do that with it's pskb_may_pull() call.
I think I have found the problem. And its actually due to the
pskb_may_pull() call in net/ipv4/udp.c:__udp4_lib_rcv().
pskb_may_pull() may alter the SKB and a pointer to the UDP header was
stored before the pskb_may_pull() call.
I'll send a patch...
--
Med venlig hilsen / Best regards
Jesper Brouer
ComX Networks A/S
Linux Network developer
Cand. Scient Datalog / MSc.
Author of http://adsl-optimizer.dk
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2009-02-05 12:44 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-03 13:38 BUG: NIU driver: strange issues with multicast "UDP: short packet" Jesper Dangaard Brouer
2009-02-03 23:38 ` David Miller
2009-02-04 8:55 ` Jesper Dangaard Brouer
2009-02-04 9:00 ` David Miller
2009-02-04 9:32 ` Jesper Dangaard Brouer
2009-02-04 9:34 ` David Miller
2009-02-05 12:44 ` Jesper Dangaard Brouer [this message]
2009-02-05 12:47 ` [PATCH] Fix UDP short packet false positive Jesper Dangaard Brouer
2009-02-05 23:06 ` David Miller
2009-02-06 9:00 ` [RFC] " Jesper Dangaard Brouer
2009-02-06 9:08 ` David Miller
2009-02-06 9:55 ` [PATCH] udp: Fix potential wrong ip_hdr(skb) pointers Jesper Dangaard Brouer
2009-02-06 9:59 ` David Miller
2009-02-06 10:04 ` Eric Dumazet
2009-02-06 10:49 ` Jesper Dangaard Brouer
2009-02-06 11:11 ` David Miller
2009-02-04 11:52 ` BUG: NIU driver: strange issues with multicast "UDP: short packet" Herbert Xu
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