Teamspeak 3 TSDNS/SRV Resolver

from __future__ import print_function
import sys
import socket
from contextlib import contextmanager

@contextmanager
def socketcontext(*args, **kwargs):
    s = socket.socket(*args, **kwargs)
    try:
        yield s
    finally:
        s.close()

def get_srv(host):
    try:
        response = dns.resolver.query('_ts3._udp.' + host, 'SRV')
    except:
        return None
    for entry in response:
        return socket.gethostbyname(entry.target.to_text().rstrip('.')) + ':' + str(entry.port)

def get_tsdns(host):
    with socketcontext(socket.AF_INET, socket.SOCK_STREAM) as sock:
        try:
            sock.connect((host, 41144))
        except:
            return None
        sock.send('{}'.format(host))
        ret = sock.recv(100)
    return ret

def get_ts3port(host):
    ret_tsdns = get_tsdns(host)
    ret_srv = get_srv(host)
    return ret_tsdns or ret_srv or host

def main():
    if len(sys.argv) != 2:
        sys.stderr.write('First argument must be a host\n'.encode())
        return -1
    print(get_ts3port(sys.argv[1]))
    return 0

if __name__ == '__main__':
    sys.exit(main())