linux-kernel - Re: [PATCH] ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish

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Message-ID: <6b85952d-a16d-2920-ebde-c69cec7e1494@cogentembedded.com>
Date:   Fri, 9 Dec 2016 15:03:47 +0300
From:   Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:     Zheng Li <lizheng043@...il.com>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, davem@...emloft.net,
        kuznet@....inr.ac.ru, jmorris@...ei.org, yoshfuji@...ux-ipv6.org,
        kaber@...sh.net
Cc:     james.z.li@...csson.com
Subject: Re: [PATCH] ipv4: Should use consistent conditional judgement for ip
 fragment in __ip_append_data and ip_finish_output

Hello!

On 12/9/2016 6:08 AM, Zheng Li wrote:

> From: zheng li <james.z.li@...csson.com>
>
> There is an inconsitent conditional judgement in __ip_append_data and

    Inconsistent.

> ip_finish_output functions, the variable length in __ip_append_data just
> include the length of applicatoin's payload and udp header, don't include

    Application.

> the length of ip header, but in ip_finish_output use
> (skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the
> length of ip header.
>
> That cuase some particular applicatoin's udp payload whose length is

    Causes, application.

> between (MTU - IP Header) and MTU were framented by ip_fragment even

    Fragmented.

> though the rst->dev support UFO feature.
>
> Add the length of ip header to length in __ip_append_data to keep
> consistent conditional judgement as ip_finish_output for ip fragment.
>
> Signed-off-by: Zheng Li <james.z.li@...csson.com>
[...]

MBR, Sergei