(re-) Implement ethernet face

[pulsejet]

There's an implementation in the repo history at https://github.com/named-data/YaNFD/tree/b7be124b6d578ae83b17db1a3e4b75e8402b1e90

gopacket should be replaced with the newer one.

[yoursunny]

gopacket should be replaced with the newer one.

What newer one?
It's already using github.com/gopacket/gopacket the maintained fork.

[pulsejet]

gopacket should be replaced with the newer one.

What newer one? It's already using github.com/gopacket/gopacket the maintained fork.

Okay, good. I thought it wasn't.

[yoursunny]

With github.com/gopacket/gopacket, libpcap and C compiler are no longer necessary if CGO_ENABLED=0 environment is set.
The README should be updated as such.

[zjkmxy]

With github.com/gopacket/gopacket, libpcap and C compiler are no longer necessary if CGO_ENABLED=0 environment is set. The README should be updated as such.

#71