GitLab

This change was okayed on jabber.

This option is used on BSD systems to
retrieve local IP address.

Perfdhcp can be used with option -l to specify the local address to be
used.

However, when this option is used on a secondary address of an
interface, this doesn't work correctly.

The packets are sent with:
- giaddr = adresse specified (correct)
- source ip address = the interface primary IP address

Here is a patch that correctly sets the source IP address before sending
the packet.
This allows to launch multiple perfdhcp processes at the same time,
sharing the same interface but each using a distinct IP address.

Both macros should be accepted, but CMSG_LEN appears not to work on
OpenBSD.

This overcomes the build failure on Solaris where it complains about
incompatible types of ? operands.