Only used for https://sorz.org/sms2email/

getportd.py

#!/usr/bin/python
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('0.0.0.0', 6000))


while True:
    data, addr = s.recvfrom(1024)
    s.sendto(str(addr[1]), addr)

openvpn-client.py

#!/usr/bin/env python
import random
import logging
import subprocess
import time
import socket

import requests


NAT_REQUEST_URL = 'https://vpn.sorz.org/ovpn/connect?port=%s'
SNAT_SERVER = ('vpn.sorz.org', 6000)


def get_default_param():
    return ['bin\openvpn.exe',
            '--client',
            '--bind',
            '--local', '0.0.0.0',
            '--proto', 'udp',
            '--dev', 'tun',
            '--resolv-retry', 'infinite',
            '--persist-key',
            '--persist-tun',
            '--ca', 'ca.crt',
            '--cert', 'testclient.crt',
            '--key', 'testclient.key',
            '--ns-cert-type', 'server',
            '--keepalive', '20', '60',
            '--comp-lzo',
            '--verb', '3',
            '--mute', '20',
            '--script-security', '2', 'system'
            ]


def main():
    logging.basicConfig(level=logging.DEBUG,
                        format='%(asctime)s %(levelname)-8s %(message)s',
                        datefmt='%Y-%m-%d %H:%M:%S', filemode='a+')

    logging.info('Version 0.2a1')
    port = random.randint(8192, 65535)
    logging.info('Use random port %s.' % port)
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind(('0.0.0.0', port))
    sock.settimeout(3)
    nat_port = None
    for i in range(5):
        try:
            sock.sendto('orz', SNAT_SERVER)
            nat_port = int(str(sock.recv(256)))
        except socket.timeout:
            logging.warn('Timeout, retry getting NAT port.')
            continue
        except ValueError:
            logging.warn('Illegal value, retry getting NAT port.')
            continue
    sock.shutdown(socket.SHUT_RDWR)
    sock.close()
    if nat_port is None:
        logging.error("Can't get NAT port. Using local bind port.")
        nat_port = port
    logging.info('NAT Port is %s.' % nat_port)

    r = requests.get(NAT_REQUEST_URL % nat_port)
    if r.status_code == 404:
        logging.error('Server is offline.')
        return
    server = r.text.strip()
    logging.info('Server address is %s.' % server)

    logging.info('Waiting 2 seconds...')
    time.sleep(2)
    openvpn = get_default_param()
    openvpn.extend(['--remote'] + server.split(':'))
    openvpn.extend(('--lport', str(port)))
    logging.info('Calling openvpn')
    subprocess.call(openvpn)


if __name__ == '__main__':
    main()

snatd.py

#!/usr/bin/env python
import socket

import sendudp


SNAT_BIND_PORT = 6001
SNAT_SERVER = ('sorz.org', 6002)
OPENVPN_BIND_PORT = 1194

def main():
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind(('', SNAT_BIND_PORT))
    sock.settimeout(20)

    while True:
        sock.sendto('\x00', SNAT_SERVER)
        try:
            sock.recv(1024)  # Ignore ping response
            data = sock.recv(1024)  # Receiving users' connection request.
        except socket.timeout:
            continue
        if data[0] != '\x03':
            continue

        print('a new connection from ' + data[1:])
        client = data[1:].split(':')
        sendudp.sendto(OPENVPN_BIND_PORT, (client[0], int(client[1])))


if __name__ == '__main__':
    main()

views.py

# (...)

SNAT_SERVER_PORT = 6002

@app.route('/ovpn/connect')
def movpn_openvpn():
    server = get_memcache().get('movpn.openvpn.server')
    if not server:
        return 'Server is not running.', 404
    addr = request.remote_addr
    if addr.startswith('::ffff:'):
        addr = addr[7:]
    port = request.args.get('port', 1194)

    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.sendto('\x02%s:%s' % (addr, port), ('localhost', SNAT_SERVER_PORT))

    return server

# (...)

vps-snatd.py

#!/usr/bin/env python
import memcache

SNAT_SERVER_PORT = 6002  # local listening
OPENVPN_BIND_PORT = 1194

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('0.0.0.0', SNAT_SERVER_PORT))

mc = memcache.Client(['127.0.0.1:11211'])
server = mc.get('movpn.openvpn.server')
if server:
    server = (server.split(':')[0], OPENVPN_BIND_PORT)

while True:
    data, addr = s.recvfrom(1024)
    if data[0] == '\x00':  # From openvpn server
        if addr != server:
            server = addr
            mc.set('movpn.openvpn.server', '%s:%s' % (server[0], OPENVPN_BIND_PORT))
        s.sendto('\x01', addr)

    elif data[0] == '\x02':  # From local web server (user's conn request)
        if addr[0] != '127.0.0.1':
            print('\x02 != localhost')
            continue
        print('new connect from ' + data[1:])
        s.sendto('\x03%s' % data[1:], server)

    else:
        print('unknown')