avtobiff/erlang-uuid — pull request #6 by rflynn (2013-01-31 18:01:38+00:00)
Title: filter_if: handle hwaddr not existing

couldn't handle hwaddr element not existing, patched.

```
(dev@192.168.1.254)8> inet:getifaddrs().
{ok,[{"lo0",
[{flags,[up,loopback,running,multicast]},
{addr,{65152,0,0,0,0,0,0,1}},
{netmask,{65535,65535,65535,65535,0,0,0,0}},
{addr,{127,0,0,1}},
{netmask,{255,0,0,0}},
{addr,{0,0,0,0,0,0,0,1}},
{netmask,{65535,65535,65535,65535,65535,65535,65535,
65535}}]},
{"gif0",[{flags,[pointtopoint,multicast]}]},
{"stf0",[{flags,[]}]},
{"en0",
[{flags,[up,broadcast,running,multicast]},
{hwaddr,[60,7,84,49,199,123]},
{addr,{65152,0,0,0,15879,21759,65073,51067}},
{netmask,{65535,65535,65535,65535,0,0,0,0}},
{addr,{192,168,1,254}},
{netmask,{255,255,255,0}},
{broadaddr,{192,168,1,255}}]},
{"en1",
[{flags,[up,broadcast,running,multicast]},
{hwaddr,[104,168,109,27,250,132]}]},
{"p2p0",
[{flags,[broadcast,multicast]},
{hwaddr,[10,168,109,27,250,132]}]},
{"fw0",
[{flags,[up,broadcast,running,multicast]},
{hwaddr,[164,177,151,255,254,104,48,212]}]},
{"vnic0",
[{flags,[up,broadcast,running,multicast]},
{hwaddr,[0,28,66,0,0,8]},
{addr,{10,211,55,2}},
{netmask,{255,255,255,0}},
{broadaddr,{10,211,55,255}},
{addr,{65152,0,0,0,540,17151,65024,8}},
{netmask,{65535,65535,65535,65535,0,0,0,0}},
{addr,{65216,0,0,65193,0,0,0,...}},
{netmask,{65535,65535,65535,65535,0,0,...}}]},
{"vnic1",
[{flags,[up,broadcast,running,multicast]},
{hwaddr,[0,28,66,0,0,9]},
{addr,{10,37,129,2}},
{netmask,{255,255,255,0}},
{broadaddr,{10,37,129,255}},
{addr,{65152,0,0,0,540,17151,65024,9}},
{netmask,{65535,65535,65535,65535,0,0,0,...}},
{addr,{65216,0,0,65194,0,0,...}},
{netmask,{65535,65535,65535,65535,0,...}}]},
{"jnc0",
[{flags,[up,running]},
{addr,{10,172,10,43}},
{netmask,{255,255,255,255}}]},
{"jnc1",[{flags,[up,running]}]}]}
```