How to read ipi_ifindex/ip_pktinfo/in_pktinfo packet data?

[Lincoln Yeoh]

Hi,

On Linux, it seems to check which network interface a packet (e.g.
udp) is coming from one is supposed to set the necessary socket
options and then read the ip_pktinfo/in_pktinfo message and then
determine the ipi_ifindex value. A similar thing is supposed to be
done to choose which interface to send a packet out from.

But how does one do that in perl?

Why? I'm wondering whether it's possible to write a DHCP server in
perl, and one which works with multiple network interfaces. So far I
haven't seen one yet.

Cheerio!

Link.