Created attachment 954799 [details]
Patch to close accepted socket when done

Description of problem:
Start the server side with:
nc6 -l -p xxx -e some_script --continuous
Every time a client connects to it and then quits, a socket in CLOSE_WAIT state will appear in the server system and the socket will stay in that state for a long time(if not forever) judging from the netstat output.

Version-Release number of selected component (if applicable):
nc6-1.0-17.fc20

How reproducible:
Always

Steps to Reproduce:
1. start nc6 as a listening socket as shown above
2. a client connects to it, and then quits
3.

Actual results:
A socket in CLOSE_WAIT state appeared in the server system and stay in that state like forever(unless the nc6 program on the server system quits)

Expected results:
A socket in TIME_WAIT state appeared in the server system and then disappear from the netstat output

Additional info:
From the netcat6 homepage, it seems the original authors do not care about this package anymore. But since we are still providing this package in Fedora, better to fix this problem. The benefit of nc6 over nmap-ncat is that it is small and do not depend on a lot of shared libraries.

The fix seems to be easy: just add a close(ns) in afindep_listener, I've attached a patch for this. Someone please kindly review it, as I do not have much network programming experience.