-source-ip is ignored about naabu HOT 2 CLOSED

naabu verifies if there is a route to the destination from the source-ip, otherwise it fallback to system routes, otherwise it would be impossible to receive the packets from the target. This behavior was opted to make it easier to handle mixed cases where nmap would just error out:

# nmap -S 30.0.0.1 188.42.216.83 -e eth0
WARNING: If -S is being used to fake your source address, you may also have to use -e <interface> and -Pn .  If you are using it to specify your real source address, you can ignore this warning.
Starting Nmap 7.94SVN ( https://nmap.org ) at 2024-03-15 09:12 UTC
Note: Host seems down. If it is really up, but blocking our ping probes, try -Pn
Nmap done: 1 IP address (0 hosts up) scanned in 3.09 seconds

from naabu.

I hit this bug in a production configuration with real (working IPs).

• one network card with local IP (10.x.x.x) with route to 10.0.0.0/8
• second network card with internet IP and default route
• There is an alias (second internet) IP on the second network card, and it's functional (e.g. I can ping with this IP as a source and I get reply).

from naabu.