From: David Miller <davem@davemloft.net>
To: timo.teras@iki.fi
Cc: netdev@vger.kernel.org, pshelar@nicira.com
Subject: Re: [PATCH net] ip_gre: fix msg_name parsing for recvfrom/recvmsg
Date: Sat, 14 Dec 2013 00:52:32 -0500 (EST) [thread overview]
Message-ID: <20131214.005232.1773340007123224291.davem@davemloft.net> (raw)
In-Reply-To: <20131213080844.3b48e774@vostro>
From: Timo Teras <timo.teras@iki.fi>
Date: Fri, 13 Dec 2013 08:08:44 +0200
> On Thu, 12 Dec 2013 15:34:29 -0500 (EST)
> David Miller <davem@davemloft.net> wrote:
>
>> From: Timo Teräs <timo.teras@iki.fi>
>> Date: Thu, 12 Dec 2013 10:53:52 +0200
>>
>> > ipgre_header_parse() needs to parse the tunnel's ip header for
>> > getting the link-layer addresses, and uses mac_header to get the
>> > header. This fixes setting mac_header on the receive path to
>> > original behaviour.
>> >
>> > Bug added in commit c54419321455 (GRE: Refactor GRE tunneling code.)
>> >
>> > Cc: Pravin B Shelar <pshelar@nicira.com>
>> > Signed-off-by: Timo Teräs <timo.teras@iki.fi>
>> > ---
>> > Alternate would be to do skb_reset_inner_headers() in
>> > ip_tunnel_rcv() and update ipgre_header_parse() to use
>> > skb_inner_network_header(). Though, then inner would then be
>> > referring to the "outer" headers.
>> >
>> > If applied as-is, should go to -stable too.
>>
>> Would skb_reset_mac_header() work just as equally? I'd prefer that
>> over direct modification of skb->*_header values.
>
> No. It was actually converted originally to skb_reset_mac_header() but
> that led to problems. See commit 1d0691674764098304ae4c63c715f588.
>
> When ipgre_rcv is entered, the outer iphdr has been already pulled,
> thus head points to the GRE header. So skb_reset_mac_header() would
> make it point at the GRE header instead of the desired outer IP header.
>
> But I agree that it'd be better to use helpers. That's why I suggested
> the skb_reset_inner_headers() as an alternative. But as it's slightly
> more intrusive approach, I opted to just restore the original assignment
> as first suggestion.
Just make a helper that does this mac_header = network_header thing,
call it something like "skb_pop_mac_header(skb)" and the make the ip_gre
code use it.
Thanks.
next prev parent reply other threads:[~2013-12-14 5:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-12 8:53 [PATCH net] ip_gre: fix msg_name parsing for recvfrom/recvmsg Timo Teräs
2013-12-12 20:34 ` David Miller
2013-12-13 6:08 ` Timo Teras
2013-12-14 5:52 ` David Miller [this message]
2013-12-16 9:02 ` [PATCH net,v2] " Timo Teräs
2013-12-18 22:45 ` David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20131214.005232.1773340007123224291.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=pshelar@nicira.com \
--cc=timo.teras@iki.fi \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).