TCP

[cgm999]

Hi,
TYVM for fping project !

I modified fping to work with TCP probing (only v4 for now), tested on Linux OS only .
I think it can be extended to create UDP probing,for example DNS Q.
Is more of a POC because some of the options uses env vars and program name (easier to confirm this works).
Also we need to have ip the source of packet for TCP csum ,so I had to "fix" a source . Also we can figure a src for each destination.

It sends Syn and expect back RST packet or Syn+Ack . Uses BPF to filter what packets we allow.

Also option to modify TCP payload to add send time , current packet (all this for unidirectional latency and PL)

Pls let me know if there is interest to create a PR.

[gsnw-sebast]

That would probably mean a significant expansion of the “wait_for_reply()” function and/or a major intervention in the event loop?
In general, you can create a pull request at any time, as with the traceroute suggestion, but a negative decision may be made until a better solution is available.
However, the idea is not lost and you can keep the patch up to date, allowing anyone to use it independently.