Re: SIOCGIFHWADDR support for pfinet

[Marco Gerards]

Marcus Brinkmann <marcus.brinkmann@ruhr-uni-bochum.de> writes:

> At Tue, 03 Aug 2004 16:03:11 +0200,
> Marco Gerards wrote:
>> On debian-hurd someone noticed SIOCGIFHWADDR does not exist for
>> GNU/Hurd.  I have included the required patches for the Hurd and glibc
>> with this email.  Or can someone suggest a better way to read the
>> hardware address?
>
> It seems basically ok to me.  However, I think that two small changes
> could/should be made.
>
> 1. Only copy dev->addr_len bytes into the user buffer.  It's best to
>    give out less information than more.

Right.

> 2. Independent of that, do we need to check if there even is a
>    hardware address?  For example, what is the dev_addr of the
>    loopback interface?  How does Linux ifconfig detect that the
>    loopback interface doesn't have a valid MAC?  Do we initialize it
>    correctly in loopback.c and does your code deal with it in a
>    compatible way?

My guess is that it will be -1 or so.  But I can check that to be
sure.

> I didn't do much to try to answer the second question, although the
> answer should be readily available by looking at Linux and net-tools
> source code.  Once we have determined that unconditionally copying the
> dev_addr field is ok, or did an appropriate check, it can go in (with
> the addr_len change mentioned above).

Ok.

Thanks,
Marco