[asterisk-dev] [svn-commits] russell: branch 1.8 r353077 - /branches/1.8/main/netsock.c

[Jason Parker]

On 01/27/2012 10:25 PM, SVN commits to the Digium repositories wrote:
> Author: russell
> Log:
> Update ast_set_default_eid() to find more network interfaces.
>
>      http://domsch.com/blog/?p=455
>
> ==============================================================================
> --- branches/1.8/main/netsock.c (original)
> +++ branches/1.8/main/netsock.c Fri Jan 27 22:25:25 2012
> @@ -243,10 +243,22 @@
>   	if (s<  0)
>   		return;
>   	for (x = 0; x<  10; x++) {
> +		static const char *prefixes[] = { "eth", "em", "pci" };
> +		unsigned int i;
> +
>   		memset(&ifr, 0, sizeof(ifr));
> -		snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "eth%d", x);
> -		if (ioctl(s, SIOCGIFHWADDR,&ifr))
> +
> +		for (i = 0; i<  ARRAY_LEN(prefixes); i++) {
> +			snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", prefixes[i], x);
> +			if (!ioctl(s, SIOCGIFHWADDR,&ifr)) {
> +				break;
> +			}
> +		}
> +
> +		if (i == ARRAY_LEN(prefixes)) {
>   			continue;
> +		}
> +
>   		memcpy(eid, ((unsigned char *)&ifr.ifr_hwaddr) + 2, sizeof(*eid));
>   		ast_debug(1, "Seeding global EID '%s' from '%s' using 'siocgifhwaddr'\n", ast_eid_to_str(eid_str, sizeof(eid_str), eid), ifr.ifr_name);
>   		close(s);
>
This looks weird.

ifr is only being reset between x iterations.  ioctl may be doing weird 
things to it.

According to the link, em is [1...N], pci is pci[1...N]#[1...N], while 
eth is still [0...N].  The pci loop can't be made efficient - would it 
make sense to loop over the lists in the opposite order?  eth0, eth1, 
..., em1, em2, ..., pci1#1, pci1#2, ..., pci2#1, ...

I'm surprised the POSIX folks haven't added SIOCGIFCONF.  That would be 
a much better solution to this problem.