linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Ahern <dsa@cumulusnetworks.com>
To: David Miller <davem@davemloft.net>, asuka.com@163.com
Cc: kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org,
	kaber@trash.net, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: fix incorrect original ingress device index in PKTINFO
Date: Wed, 28 Dec 2016 21:42:34 -0700	[thread overview]
Message-ID: <c60a95e6-b02b-2108-c0fd-9dd6f128316f@cumulusnetworks.com> (raw)
In-Reply-To: <20161227.140313.1837464529059496066.davem@davemloft.net>

On 12/27/16 12:03 PM, David Miller wrote:
> From: Wei Zhang <asuka.com@163.com>
> Date: Tue, 27 Dec 2016 17:52:24 +0800
> 
>> When we send a packet for our own local address on a non-loopback
>> interface (e.g. eth0), due to the change had been introduced from
>> commit 0b922b7a829c ("net: original ingress device index in PKTINFO"), the
>> original ingress device index would be set as the loopback interface.
>> However, the packet should be considered as if it is being arrived via the
>> sending interface (eth0), otherwise it would break the expectation of the
>> userspace application (e.g. the DHCPRELEASE message from dhcp_release
>> binary would be ignored by the dnsmasq daemon, since it come from lo which
>> is not the interface dnsmasq bind to)
>>

Add a Fixes line before the sign-off:

Fixes: 0b922b7a829c ("net: original ingress device index in PKTINFO")
>> Signed-off-by: Wei Zhang <asuka.com@163.com>
> 
> When you are fixing a problem introduced by another change, always CC:
> the author of that change as I have done so here.
> 
> David, please take a look at this, thanks.
> 
>> ---
>>  net/ipv4/ip_sockglue.c | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
>> index b8a2d63..76d78a7 100644
>> --- a/net/ipv4/ip_sockglue.c
>> +++ b/net/ipv4/ip_sockglue.c
>> @@ -1202,8 +1202,14 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
>>  		 * which has interface index (iif) as the first member of the
>>  		 * underlying inet{6}_skb_parm struct. This code then overlays
>>  		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
>> -		 * element so the iif is picked up from the prior IPCB
>> +		 * element so the iif is picked up from the prior IPCB except
>> +		 * iif is loopback interface which the packet should be
>> +		 * considered as if it is being arrived via the sending
>> +		 * interface

That comment change could use an adjustment (adjust to fit with in the 80 columns):

element so the iif is picked up from the prior IPCB. If iif
is the loopback interface, then return the sending interface
(e.g., process binds socket to eth0 for Tx which is redirected
to loopback in the rtable/dst).


>>  		 */
>> +		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
>> +			pktinfo->ipi_ifindex = inet_iif(skb);
>> +
>>  		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
>>  	} else {
>>  		pktinfo->ipi_ifindex = 0;


The actual change looks ok to me.

Acked-by: David Ahern <dsa@cumulusnetworks.com>

  reply	other threads:[~2016-12-29  4:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-27  9:52 [PATCH] net: fix incorrect original ingress device index in PKTINFO Wei Zhang
2016-12-27 19:03 ` David Miller
2016-12-29  4:42   ` David Ahern [this message]
  -- strict thread matches above, loose matches on Subject: below --
2016-12-27  7:52 Wei Zhang
2016-12-27 10:01 ` Sergei Shtylyov

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=c60a95e6-b02b-2108-c0fd-9dd6f128316f@cumulusnetworks.com \
    --to=dsa@cumulusnetworks.com \
    --cc=asuka.com@163.com \
    --cc=davem@davemloft.net \
    --cc=jmorris@namei.org \
    --cc=kaber@trash.net \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=yoshfuji@linux-ipv6.org \
    /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).