InterNestor Lite 2.2 with SOCKS5 client capability

[Konamiman]

This pull request modifies InterNestor Lite so that it can act as a SOCKS5 client. This allows using a proxy such as stunnel (particularly with the proposed extension for TLS) to provide wireless networking and/or support for TLS.

To configure InterNestor Lite to act as a SOCKS5 client these commands must be used:

inl tcp x1 <SOCKS server IP> <SOCKS server port>
inl tcp x2 <SOCKS server IP> <SOCKS server port>

Where x1 is used to configure the server for regular TCP connections, and x2 is used to configure the server for TLS connections - thus, using x2 adds indirect support for TLS connections to InterNestor . You can setup SOCKS for either type of connections or for both.

It is possible to undo this configuration (so that InterNestor will stop acting as a SOCKS client) with inl tcp x1 0 or inl tcp x2 0.

Alternatively, you can instruct InterNestor to do the configuration at install time by using a file named inl.cfg (in the same directory of inl.com) with this content:

tcp x1 <SOCKS server IP> <SOCKS server port>
tcp x2 <SOCKS server IP> <SOCKS server port>

Good-to-knows and limitations:

• InterNestor Lite will announce support for TLS in TCPIP_GET_CAPAB only if a SOCKS server has been configured with tcp x2.
• The SOCKS functionality is available for active TCP connections only.
• When SOCKS is configured (either for regular TCP connections, for TLS connections, or for both), it's not possible to open two TCP connections with the same local port, even with different remote IP or port. That's because incoming TCP segments will always have the SOCKS server IP and port as source, so there's no way to know where they really come from.