Ability to set fwmark on outgoing packets

[logan2211]

Hello,

Many diagnostic tools like iputils-ping[1], traceroute[2], and mtr[3] support mark or --fwmark parameters which can be used by iproute2 to perform policy routing for outbound packets. It would be great if fping could begin supporting fwmark for outbound packets to facilitate easier policy routing decisions.

[1] https://manpages.ubuntu.com/manpages/bionic/man8/ping.8.html
[2] https://manpages.ubuntu.com/manpages/bionic/man1/traceroute.db.1.html
[3] https://manpages.ubuntu.com/manpages/bionic/man8/mtr.8.html

[auerswal]

Pull request #289 has just been merged. The new option -k, --fwmark should implement the requested functionality.
@logan2211: Can this issue be closed?