Working of traffic flow from android device to host

[rjhigh]

This is not an issue but more of a query for understanding purpose. I did read around networking rules but still could not figure out completely due to missing pieces. Everything works perfectly but wish to understand what is the command exactly that's helping in directing the traffic from android device to host especially because I do not see any adb reverse command being used.

1. Once VpnService intercepts a request, via file descriptors the packets are being written to ANDROID_SOCK.
2. Is the ANDROID_SOCK responsible to pass the packet directly to host just because an adb forward tunnel (from host to device) is already created?
3. On doing tcpdump on host side, I actually see request originating from different ports. Is the file descriptor of ANDROID_SOCK communicating with these ports or the VpnInterface?
4. On seeing other vpn setups, I see peer (host in this case) also being mentioned if one tries to check ip addr show dev tun0 on android device. I do not see such peer being mentioned in this setup. It only shows this inet 10.0.0.2/32 scope global tun0 with no mention of peer.

P.S. Apologies as this might not be the right forum for the question. But would be grateful if anybody could help.