n2n relies on deprecated ifconfig on Linux

[pojntfx]

First of all, thanks for developing this software! It has helped me tremendously with some Kubernetes-related things.

On modern Linux distros however, ifconfig has been replaced with iproute2 for the most part; usage of n2n on these distros fails due to this. It would be great if the ifconfig calls could be replaced with their ip counterparts.

[fengdaolong]

We want to use the system API calls instead of the command line.

[pojntfx]

@fengdaolong Sure, but isn't it already using the system function here for example? I'm sorry, I'm not a C developer by any means so I might be wrong here ...

[emanuele-f]

I agree that using a system API (C api / linux api) to configure the interface is better, the system() call as it is now is a dirty way to invoke a system cli tool to do the job.