1. Pass options to SIP003 plug-in through the Agruments property; 2. …

[ylhyh]

…The Port of SIP003's "LocalEndPoint" should be Remote Server's port when a plug-in enabled.

[celeron533]

To whom also reviewing this PR:
as mentioned in shadowsocks/shadowsocks-org#28

3. Passing arguments to a plugin
   A plugin accepts arguments through environment variables.

Standard SIP003 implementation not only take care on Windows, Linux or Mac, but also need to provide maximum compatibility to embedded system such as routers, or cellphones. That's why it chooses environment variables.

[celeron533]

SS_LOCAL_HOST SS_LOCAL_PORT: the plugin listens SS native connection.
SS_REMOTE_HOST SS_REMOTE_PORT: the plugin then connect to the remote server.

SS ===> to plugin's LOCAL HOST/PORT ===> plug-in data processing ===> send to REMOTE HOST/PORT

[ylhyh]

@celeron533 , I agree with you that Plugin should following the standard.
I am using kcptun (https://github.com/xtaci/kcptun) in Shadowsocks, it seems kcptun never use the environment variable %SS_LOCAL_PORT%, so it always listened on the default port 12948, I have to create a bat file to bypass this issue:
%~dp0client_windows_amd64.exe -l 127.0.0.1:%SS_LOCAL_PORT% -r xxx.xxx.xxx.xxx:xxxx -crypt none -mtu 1400 -sndwnd 2048 -rcvwnd 2048 -mode fast2

The only issue is that I can not specify the listen port of kcptun, because it's generated by Shadowsocks.

[celeron533]

@ylhyh ,
Both designs has their pros and cons.
GetNextFreeTcpPort() makes sure that the port has no conflict and free to use.
SS_REMOTE_PORT (or "SS_LOCAL_PORT") lock the port as pre-defined.

BTW, in your code change it is SS_REMOTE_PORT but in your comment it is variable %SS_LOCAL_PORT%. Which one do you want?

SIP003 is a standard. You 'should' always uses the plugin programs which follow the standard.
#1672 is talking about mapping the environment variables to parameter to give maximum compatibility to normal plugin programs.

[ylhyh]

1. It seems %SS_REMOTE_PORT% is useless when a plugin being launched, so I use it to specify the plugin's listening port.
2. Yes, I did same thing as Add an option to let user wrap SIP003 environment variables as normal in-line arguments #1672 mentioned.

[ylhyh]

anyway, cancel the request now.