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Date:      Wed, 21 Feb 2007 22:03:40 +0100
From:      nocturnal <nocturnal@swehack.se>
To:        Pietro Cerutti <pietro.cerutti@gmail.com>
Cc:        freebsd-hackers@freebsd.org, freebsd-questions@freebsd.org
Subject:   Re: Which file to request SIOCGIFMAC on?
Message-ID:  <45DCB3AC.8090609@swehack.se>
In-Reply-To: <e572718c0702201518i67ab5289pc24592625a9ec6d4@mail.gmail.com>
References:  <45DB63B1.7050004@swehack.se>	 <AEC2C499-DC40-495A-9672-24BC2AA2CD0F@mac.com>	 <45DB7751.3010401@swehack.se> <e572718c0702201518i67ab5289pc24592625a9ec6d4@mail.gmail.com>

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Hi

Well that's weird, is MAC defined by default at all? I tried searching 
for the definition but couldn't find it.

I never thought it would be this hard just to get the ethernet address 
from an ethernet interface in FreeBSD. I think i'll take a look at the 
netlib source next, something tells me it will be easier to just 
plagiarize their method than going through the kernel source any more.



Med vänliga hälsningar

Stefan Midjich aka nocturnal
[Swehack] http://swehack.se


Pietro Cerutti wrote:
> On 2/20/07, nocturnal <nocturnal@swehack.se> wrote:
>> Hi
>>
>> The original plan is to only run it on FreeBSD 5 and higher, actually
>> only 6 by now. It's a program i'm writing for work and at work the most
>> active servers run FreeBSD 6 and are updated frequently. The ones with
>> older versions don't run anything of interest.
>>
>> I am buying a MacBook for personal use though so it would be nice to run
>> it on osx. I wouldn't like to start using another library just to get
>> the hardware address of an interface though, that seems kinda overkill
>> for what should be a simple task. The program is already using libpcap
>> but that is included in FreeBSD by default so you don't have to 
>> install it.
>>
>> Do you have any idea of why i'm getting this error from ioctl when i'm
>> doing what the manual says i should do? I am of course running it as
>> root to because the libpcap operations require it.
>>
>> What might help me is to take a look at the source of that
>> libnet_get_hwaddr function in libnet. I'll try that, thank you very much
>> for the tip.
>>
>> So far i've been trying to look at the source for ifconfig to figure out
>> how it gets the hardware address. Of course it uses SIOCGIFMAC but i
>> can't find the socket it opens because i can't find where it uses the
>> maclabel_status function.
> 
> The problem isn't with the socket type or options.
> If you debug ifconfig, you'll find out that the ioctl call always
> returns -1, and the program goes on to the "goto mac_free" line.
> 
> Take a look at /usr/src/sys/net/if.c, line 1258
> 
> Should we deduce that the particular ioctl isn't supported?
> 
> P.S. I'm forwarding this to freebsd-hackers@ too, so sorry for cross 
> posting
> 
>> Med vänliga hälsningar
>>
>> Stefan Midjich aka nocturnal
>> [Swehack] http://swehack.se
>>
>>
>> Chuck Swiger wrote:
>> > On Feb 20, 2007, at 1:10 PM, nocturnal wrote:
>> >> I'm trying to get the ethernet address and from the manuals i
>> >> understand that i need the ifreq structure for this. So i'm trying to
>> >> request SIOCGIFMAC with ioctl on a socket of type SOCK_DGRAM.
>> >
>> > If you're just targetting FreeBSD >= 5.x platforms, your current
>> > approach is reasonable (assuming you can fix whatever the problem is);
>> > if you're targetting other platforms such FreeBSD 4, Dfly, OS X, or 
>> SysV
>> > things like Solaris, try installing the libnet port and invoke
>> > libnet_get_hwaddr().
>> >
>> > ---Chuck
>> >
>> >
>> >
>> _______________________________________________
> 
> 



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