Library net/libnet10 defines structures for contents of network packets.
Fields of the packets have fixed size according to the respective protocol
definitions, but the library uses type u_long for some of the 32bit fields.
This is a problem on amd64 architecture, where type long has 64 bits. On
amd64, libnet creates packets with bad contents.
Submitted by: Martin Beran <email@example.com>