Subject: Re: [PATCH 2/2] ipv4: make do_ip_setsockopt for IP_MULTICAST_IF support ip_mreq struct

From: Danny Feng <[email-masked]>
Date: Thu, 17 Sep 2009 17:19:16 +0800

On 09/17/2009 05:16 PM, Shan Wei wrote:
> Xiaotian Feng wrote, at 09/17/2009 01:20 PM:
>> ip_mreq and ip_mreqn is almost the same, and do_ip_setsockopt for IP_MULTICAST_IF
>> part supported ip_mreqn struct. This patch adds support for ip_mreq struct.
>>
>
> It's not meaning to support the ip_mreq struct, the imr_multiaddr member
> never be used by the IP_MULTICAST_IF.
>
> In addition, using the option normally like this:
>    struct in_addr interface_addr;
>    setsockopt (socket, IPPROTO_IP, IP_MULTICAST_IF,&interface_addr, sizeof(interface_addr));
>
> Do your patch suggest using the option like this?
>    struct ip_mreq  mreq;
>    setsockopt (socket, IPPROTO_IP, IP_MULTICAST_IF,&mreq, sizeof(mreq));
>
In fact, current implemetation supports:

struct ip_mreqn mreqn;
setsockopt(socket, IPPROTO_IP, IP_MULTICAST_IF, &mreqn, sizeof(mreqn));

Then why not support mreq?
> Best Regards
> -----
> Shan Wei