Socks5: Non-standard commands

The Socks5 protocol is defined by RFC 1928. It includes three commands:

0x01: CONNECT

0x02: BIND

0x03: UDP ASSOCIATE

Also, there are some proprietary extensions that introduce new commands:

0x05: UDP IN TCP (by HevSocks5)

0xF0: RESOLVE (by Tor)

0xF1: RESOLVE_PTR (by Tor)