HTTP CONNECT by example

http-connect-proxy.rb

require 'socket'

listen_socket = TCPServer.new('127.0.0.1', 9292)

client_conn = listen_socket.accept
request_line = client_conn.gets

while(line = client_conn.gets) do
  break unless line.include?(':')
end

host, port = *request_line.split[1].split(':')
dest_conn = TCPSocket.new(host, port)
client_conn.write "HTTP/1.1 200 OK\r\n"

def transfer(src_conn, dest_conn)
  IO.copy_stream(src_conn, dest_conn)
rescue => e
  puts e.message
end

[
  Thread.new { transfer(client_conn, dest_conn) },
  Thread.new { transfer(dest_conn, client_conn) }
].each(&:join)