netdev - Re: [PATCH] ipv6: sr: update the struct ipv6_sr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20171115.095427.136250865702817393.davem@davemloft.net>
Date:   Wed, 15 Nov 2017 09:54:27 +0900 (KST)
From:   David Miller <davem@...emloft.net>
To:     ecree@...arflare.com
Cc:     amsalam20@...il.com, david.lebrun@...ouvain.be,
        netdev@...r.kernel.org
Subject: Re: [PATCH] ipv6: sr: update the struct ipv6_sr_hdr

From: Edward Cree <ecree@...arflare.com>
Date: Tue, 14 Nov 2017 14:14:01 +0000

> On 14/11/17 12:37, David Miller wrote:
>> From: Ahmed Abdelsalam <amsalam20@...il.com>
>> Date: Sun, 12 Nov 2017 21:37:01 +0100
>> 
>>> diff --git a/include/uapi/linux/seg6.h b/include/uapi/linux/seg6.h
>>> index 2f6fb0d..3f4b3ab 100644
>>> --- a/include/uapi/linux/seg6.h
>>> +++ b/include/uapi/linux/seg6.h
>>> @@ -26,9 +26,9 @@ struct ipv6_sr_hdr {
>>>  	__u8	hdrlen;
>>>  	__u8	type;
>>>  	__u8	segments_left;
>>> -	__u8	first_segment;
>>> +	__u8	last_entry;
>> 
>> This is user ABI and cannot be changed.
>> 
>> Sorry, folks should have considered these issues when the SR
>> changes were submitted.  This field must keep the name 'first_segment'
>> forever.
> 
> Surely renaming struct fields only changes the API, not the ABI?
> Binaries compiled against the old struct definition will still behave the
>  same (AFAICT the patch doesn't change how these fields are used), while
>  sources being recompiled (so they care about the name change) can be
>  changed.

Yes, it will stop existing applications from compiling and we can't
do that.