From: David Miller <davem@davemloft.net>
To: stephen.hemminger@vyatta.com
Cc: tomas.winkler@intel.com, shemminger@vyatta.com,
johannes@sipsolutions.net, netdev@vger.kernel.org,
linux-wireless@vger.kernel.org
Subject: Re: [PATCH net-2.6] bridge: fix br_multicast_ipv6_rcv for paged skbs
Date: Fri, 31 Dec 2010 12:45:33 -0800 (PST) [thread overview]
Message-ID: <20101231.124533.15243601.davem@davemloft.net> (raw)
In-Reply-To: <9mk4bme8o97ir27xi8a9fbsd.1293750376929@email.android.com>
From: Stephen Hemminger <stephen.hemminger@vyatta.com>
Date: Thu, 30 Dec 2010 15:06:16 -0800
> Although copy is slower for large packets, this is a non performance
> path. The code in question is for bridged multicast Ipv6 ICMP
> packets. This case is so uncritical it could be done in BASIC and no
> one could possibly care!
I still think we should be judicious and keep using skb_clone() here.
Simply combine the two pskb_may_pull() calls into one on "skb2" after
the clone and before the blind __skb_pull() call. Then add a error
path "out:" called "out_nopush:" for the error path to goto.
Also, I think the "+ 1" in the ipv6 stack code comes from the fact that
the parsing loop can "peek" into the next header's byte to see the type.
And I really don't think it's relevant here.
Also, all of these "x_header + ... + 1 - skb->data" factors are
irrelevent and shouldn't be used. Just pass "offset + sizeof(*icmp6h)"
to pskb_may_pull().
next prev parent reply other threads:[~2010-12-31 20:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-30 23:06 [PATCH net-2.6] bridge: fix br_multicast_ipv6_rcv for paged skbs Stephen Hemminger
[not found] ` <9mk4bme8o97ir27xi8a9fbsd.1293750376929-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2010-12-30 23:29 ` Winkler, Tomas
[not found] ` <6F5C1D715B2DA5498A628E6B9C124F04019BF36ABD-KS4eWWg9cz+vNW/NfzhIbrfspsVTdybXVpNB7YpNyf8@public.gmane.org>
2010-12-31 10:18 ` Johannes Berg
2010-12-31 20:45 ` David Miller [this message]
2010-12-31 21:16 ` Winkler, Tomas
-- strict thread matches above, loose matches on Subject: below --
2010-12-29 16:12 BUG: while bridging Ethernet and wireless device: Tomas Winkler
2010-12-30 11:32 ` [PATCH net-2.6] bridge: fix br_multicast_ipv6_rcv for paged skbs Tomas Winkler
2010-12-30 18:46 ` Stephen Hemminger
2010-12-30 18:52 ` Johannes Berg
[not found] ` <1293735134.21956.1.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2010-12-30 19:06 ` Stephen Hemminger
2010-12-30 21:00 ` Winkler, Tomas
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