netdev - Re: [PATCH 5/5] net: Loopback ifindex is constant now

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] [day] [month] [year] [list]

Date:	Mon, 06 Aug 2012 16:13:35 +0400
From:	Pavel Emelyanov <xemul@...allels.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	David Miller <davem@...emloft.net>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Linux Netdev List <netdev@...r.kernel.org>
Subject: Re: [PATCH 5/5] net: Loopback ifindex is constant now

On 08/06/2012 03:54 PM, Eric Dumazet wrote:
> On Mon, 2012-08-06 at 14:32 +0400, Pavel Emelyanov wrote:
>> As pointed out, there are places, that access net->loopback_dev->ifindex
>> and after ifindex generation is made per-net this value becomes constant
>> equals 1. So go ahead and introduce the LOOPBACK_IFINDEX constant and use
>> it where appropriate.
>>
>> Signed-off-by: Pavel Emelyanov <xemul@...allels.com>
> 
> What guarantee do we have that loopback is the first device per net ?

In net_dev_init():

        /* The loopback device is special if any other network devices
         * is present in a network namespace the loopback device must
         * be present. Since we now dynamically allocate and free the
         * loopback device ensure this invariant is maintained by
         * keeping the loopback device as the first device on the
         * list of network devices.  Ensuring the loopback devices
         * is the first device that appears and the last network device
         * that disappears.
         */
        if (register_pernet_device(&loopback_net_ops))
                goto out;


> You should add this to the changelog because its not that obvious.

OK.

Thanks,
Pavel
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html