Invalid Memory Address in client_greeting

[riklus]

I tried using the dispatch proxy with qBitTorrent (SOCK5 proxy) and this happened:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x10d4b00]

goroutine 402 [running]:
main.client_greeting({0x0, 0x0})
	/Users/riklus/cloned-repos/go-dispatch-proxy/socks.go:18 +0x40
main.handle_socks_connection({0x0, 0x0})
	/Users/riklus/cloned-repos/go-dispatch-proxy/socks.go:134 +0x27
main.handle_connection({0x0, 0x0}, 0x0)
	/Users/riklus/cloned-repos/go-dispatch-proxy/main.go:99 +0x3a
created by main.main
	/Users/riklus/cloned-repos/go-dispatch-proxy/main.go:254 +0x50c

When the function client_greeting is called the parameter conn appears to be (for some reason) nil.
I verified it by checking conn inside client_greeting by adding an if statement and it's really nil.

file socks.go

 15   func client_greeting(conn net.Conn) (byte, []byte, error) {
 16+         if conn == nil {
 17+                 fmt.Print("[PANIC] conn is nil")
 18+        }
 19          buf := make([]byte, 2)
 20 

As a quick fix we could check if conn is nil and then return an error, but I don't know why conn is null in the first place.

[riklus]

Now that I checked the documentation of net package it appears that the accepted connection's error is not properly handled inside main.go line 253.