Ping without root — Linux capabilities

On Linux, sending a real ICMP echo (a ping) traditionally needs elevated privileges, because it uses a raw socket. SubnetSlinger is built to avoid making you run the whole app as root.

The basics: in most cases ping just works. If raw sockets aren't available, the app quietly falls back to using the system's own ping program, so you still get results — you generally don't have to think about this.

How to tell: the "local interfaces" readout prints a line — Raw sockets (cap_net_raw): yes / no. "yes" means the app can open raw ICMP sockets directly. "no" means it's using the fallback, and it prints the exact command to fix it.

Going deeper — granting it properly: the clean Linux way is a file capability, not sudo. Grant just the raw-socket capability to the binary:

sudo setcap cap_net_raw+ep /path/to/SubnetSlinger.App

That lets unprivileged ICMP work without running anything as root. The .deb package does this for you in its post-install step. Under Flatpak the sandbox won't grant it at all (the fallback handles that); under Snap it comes from the network-control interface.

Good to know: capabilities are a real security control — cap_net_raw lets a program craft raw packets, so only grant it to binaries you trust (this one). If setcap isn't available or your filesystem doesn't support file capabilities, nothing breaks; you're just on the system-ping fallback. When in doubt, `man capabilities` and `man 8 setcap` are the authoritative reference.