Adds upnp port forwarder skeleton

src/util/UpnpPunch.py

@@ -0,0 +1,151 @@
+import socket
+import re
+import urllib2
+import httplib
+from urlparse import urlparse
+from xml.dom.minidom import parseString
+
+# Relevant UPnP spec: http://www.upnp.org/specs/gw/UPnP-gw-WANIPConnection-v1-Service.pdf
+
+# General TODOs:
+# Handle 0 or >1 IGDs
+# Format the SOAP AddPortEntry message correctly (remove spaces/whitespace)
+# Find robust way to find own ip
+
+
+def _m_search_ssdp():
+    """
+    Broadcast a UDP SSDP M-SEARCH packet and return response.
+    """
+    search_target = "urn:schemas-upnp-org:device:InternetGatewayDevice:1"
+
+    ssdp_request = ''.join(
+        ['M-SEARCH * HTTP/1.1\r\n',
+         'HOST: 239.255.255.250:1900\r\n',
+         'MAN: "ssdp:discover"\r\n',
+         'MX: 2\r\n',
+         'ST: {0}\r\n'.format(search_target),
+         '\r\n']
+    )
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.sendto(ssdp_request, ('239.255.255.250', 1900))
+
+    # TODO: add timeout
+    return sock.recv(1024)
+
+
+def _retrieve_location_from_ssdp(response):
+    """
+    Parse raw HTTP response to retrieve the UPnP location header
+    and return a ParseResult object.
+    """
+    parsed = re.findall(r'(?P<name>.*?): (?P<value>.*?)\r\n', response)
+    location_header = filter(lambda x: x[0].lower() == 'location', parsed)
+
+    if not len(location_header):
+        # no location header returned :(
+        return False
+
+    return urlparse(location_header[0][1])
+
+
+def _retrieve_igd_profile(url):
+    """
+    Retrieve the device's UPnP profile.
+    """
+    # TODO: add exception handling
+    return urllib2.urlopen(url.geturl()).read()
+
+
+def __get_node_value(node):
+    """ 
+    Get the text value of the first child text node of a node.
+    """
+    return node.childeNodes[0].data
+
+
+def _parse_igd_profile(profile_xml):
+    """
+    Traverse the profile xml DOM looking for either
+    WANIPConnection or WANPPPConnection and return
+    the value found as well as the 'controlURL'.
+    """
+    # TODO: return upnp schema as well
+    dom = parseString(profile_xml)
+
+    service_types = dom.getElementsByTagName('serviceType')
+    for service in service_types:
+        if __get_node_value(service).find('WANIPConnection') > 0 or \
+           __get_node_value(service).find('WANPPPConnection') > 0:
+            control_url = service.parentNode.getElementsByTagName(
+                'controlURL'
+            )[0].childNodes[0].data
+
+    return control_url, upnp_schema
+
+
+def _create_soap_message(port, description="UPnPPunch", protocol="TCP",
+                         upnp_schema='WANIPConnection'):
+    """
+    Build a SOAP AddPortMapping message.
+    """
+    # TODO: get current ip
+    current_ip = '192.168.0.2'
+
+    soap_message = """<?xml version="1.0"?>
+<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
+    <s:Body>
+        <u:AddPortMapping xmlns:u="urn:schemas-upnp-org:service:{upnp_schema}:1">
+            <NewRemoteHost></NewRemoteHost>
+            <NewExternalPort>{port}</NewExternalPort>
+            <NewProtocol>{protocol}</NewProtocol>
+            <NewInternalPort>{port}</NewInternalPort>
+            <NewInternalClient>{host_ip}</NewInternalClient>
+            <NewEnabled>1</NewEnabled>
+            <NewPortMappingDescription>{description}</NewPortMappingDescription>
+            <NewLeaseDuration>0</NewLeaseDuration>
+        </u:AddPortMapping>
+    </s:Body>
+</s:Envelope>""".format(port=port,
+                        protocol=protocol,
+                        host_ip=current_ip,
+                        description=description,
+                        upnp_schema=upnp_schema)
+
+    return soap_message
+
+
+def _send_soap_request(location, upnp_schema, control_url, soap_message):
+    """
+    Send out SOAP request to UPnP device and return a response.
+    """
+    headers = {
+        'SOAPAction': (
+            '"urn:schemas-upnp-org:service:{schema}:'
+            '1#AddPortMapping"'.format(schema=upnp_schema)
+        ),
+        'Content-Type': 'text/xml'
+    }
+    conn = httplib.HTTPConnection(location.hostname, location.port)
+    conn.request('POST', control_url, soap_message, headers)
+
+    response_body = conn.getresponse().read()
+
+    return response_body
+
+
+def open_port(port=15441):
+    """
+    Attempt to forward a port using UPnP.
+    """
+    location = _retrieve_location_from_ssdp(_m_search_ssdp())
+    control_url, upnp_schema = _parse_igd_profile(
+        _retrieve_igd_profile(location)
+    )
+
+    for protocol in ["TCP", "UDP"]:
+        message = _create_soap_message(port, protocol, upnp_schema)
+        # TODO: gevent this
+        _send_soap_request(location, upnp_schema, control_url, message)
+        # TODO: handle error code in response