NatACL is an authentication daemon for NAT and transparent proxying that man in the middles outbound HTTP requests and forces the user to a login/password page requesting credentials to allow the outbound connection. After proper credentials are received, NAT rules are automatically generated.
917cab43b3cd49bdf8c7a7b5ca37bf5309e61c0cbef7739b08a7d0c2fffb8f83