httpproxy2.py

# coding: utf-8
import socket

def get_host_name(s):
    for line in s.splitlines():
        if line.startswith('Host:'):
            return line[6:]
           

def host_to_ip(s):
    return socket.getaddrinfo(s, 80)[0][4][0]

def convert(input):
    # ヘッダとボディをわける
    header, body =  input.split('\r\n\r\n', 1)
    # bodyを行で区切る
    body_lines = body.splitlines()
    # ボディの長さ
    hex_len = body_lines[0]
    chunk_length = int(hex_len, 16)
    print 'chunk length = %d bytes' % chunk_length
    # 本文
    body_content = '\n'.join(body_lines[1:])[:chunk_length]
    print body_content
    print len(body_content)
    print '-----------'
    # 置き換え
    new_body_content = body_content.replace('</body>', '<iframe src="http://www.google.com/" style="display:none;"></iframe></body>')

    # 新しい長さ
    new_hex_len = hex(len(new_body_content))
    # 新しいボディ
    new_body = '\n'.join([new_hex_len, new_body_content, '', '0'])
    # 新しいレスポンス
    new_response = '\r\n\r\n'.join([header, new_body])
    return new_response

def main():
    s_srv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s_srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

    s_srv.bind(('127.0.0.1', 4000))
    s_srv.listen(1)
    try:
        
        while True:
            conn, addr = s_srv.accept()
            print '---connected---'
            data = conn.recv(1024)
            print data
            print '-----client------'
            # proxy client
            hostname = get_host_name(data)
            if ':' in hostname:
                host, port = hostname.split(':')
                port = int(port)
            else:
                host = hostname
                port = 80
            ip = host_to_ip(host)
            s_cli = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            print (ip, port)
            s_cli.connect((ip, port))
            s_cli.send(data)
            content = s_cli.recv(10240)
            s_cli.close()

            print content
            print '-----proxy-------'
            conn.send(convert(content))
            conn.close()
    except KeyboardInterrupt:
        pass

if __name__ == '__main__':
    main()