add unix socket support on server side

[maskedeken]

No description provided.

[coveralls]

Coverage remained the same at ?% when pulling 5b2ee50 on maskedeken:master into 9f2ff06 on xtaci:master.

[coveralls]

Coverage remained the same at ?% when pulling 5b2ee50 on maskedeken:master into 9f2ff06 on xtaci:master.

[coveralls]

Coverage remained the same at ?% when pulling 5b2ee50 on maskedeken:master into 9f2ff06 on xtaci:master.

[xtaci]

Could you tell me under what circumstances this might be used?

[maskedeken]

Could you tell me under what circumstances this might be used?

Some services like v2ray could serve as a unix socket, which is hiding the listening port on a censored system like AliCloud

[xtaci]

why not just listen on 127.0.0.1?

[maskedeken]

why not just listen on 127.0.0.1?

besides, unix socket is faster than tcp socket.

UNIX domain sockets know that they’re executing on the same system, so they can avoid some checks and operations (like routing); which makes them faster and lighter than IP sockets. So if you plan to communicate with processes on the same host, this is a better option than IP sockets.

[xtaci]

how about re-try scheme? like:

var c conn
if c, err := net.Dial("tcp", xxx) err ==nil{
} else if c, err := net.Dial("unix", xxx);err==nil{
}

then we dont' have to specify unix://

[xtaci]

any comment?

[maskedeken]

any comment?

I don't think that's a good idea. using try/catch as if/else is a bad practice.

[xtaci]

https://github.com/xtaci/kcptun/blob/master/server/main.go#L57-L66

[xtaci]

or, we can just try parse target to IP address and Port

[maskedeken]

or, we can just try parse target to IP address and Port

if you don't like the unix:// prefix, error checking is the only way to dial the right conn

[xtaci]

	// check if target is unix domain socket
	var isUnix bool
	if _, _, err := net.SplitHostPort(config.Target); err != nil {
		isUnix = true
	}

a simple check, though not strict

[maskedeken]

	// check if target is unix domain socket
	var isUnix bool
	if _, _, err := net.SplitHostPort(config.Target); err != nil {
		isUnix = true
	}

a simple check, though not strict

Great