# Derrived from Anthony Baxter's code in Shtoom. Modified by Eric Ries
# and Malcolm Handley to remove the use of twisted. Anthony Baxter
# released this code under the LGPL, reproduced at the end of this
# file.
#
#
# Copyright (C) 2004 Anthony Baxter
# $Id: upnp.py,v 1.6 2005/07/29 02:44:54 eries Exp $
#
# UPnP support.

# UPnP_IGD_WANIPConnection 1.0.doc defines the ExternalPort configuration
# magic.

# Theory of operation:
#
# Multicast address for SSDP is 239.255.255.250 port 1900 (multicast)
#    Listen for SSDP NOTIFYs on mcast
#    Send an M_SEARCH request to query for any IGDs that are out there -
#       send 3 packets, listen for a response.
#    Walk through existing port mappings to see if we've left one behind
#    Expose UI to add/delete/query port mappings


# To be done:
#    Higher level APIs - check if we've left an entry behind, for instance


import random
import sys
import socket
import SocketServer
import struct
import time
import urlparse
import threading

from urllib2 import urlopen
from kenosis import soap
from kenosis.soap import BeautifulSoap, SOAPRequestFactory, soapenurl


from ds import dsthread
from ds import dsunittest

UPNP_PORT = 1900
UPNP_MCAST = '239.255.255.250'

class UPnPError(Exception): pass
class NoUPnPFound(UPnPError): pass


class Log:
    def msg(self, text, system):
        dsunittest.trace("msg: %s" % text)
    def err(self, text, system):
        dsunittest.traceException("err: %s" % text)
log = Log()


def getLocalIPAddress():
    return socket.gethostbyname(socket.gethostname())

def isBogusAddress(addr):
    """ Returns true if the given address is bogus, i.e. 0.0.0.0 or
        127.0.0.1. Additional forms of bogus might be added later.
    """
    # ===
    if not addr:
        return True # this may cause problems for platforms like linux
    if addr.startswith('0.') or addr.startswith('127.'):
        return True
    return False

def cannedUPnPSearch():
    return """M-SEARCH * HTTP/1.1\r
Host:%s:%s\r
ST:urn:schemas-upnp-org:device:InternetGatewayDevice:1\r
Man:"ssdp:discover"\r
MX:3\r
\r
"""%(UPNP_MCAST, UPNP_PORT)

def hostFromPort(port):
    return port[0]

def portFromPort(port):
    return port[1]

def typeFromPort(port):
    return port[2]

def descFromPort(port):
    return port[3]
    

class UPnPClientServer(SocketServer.UDPServer):
    def __init__(self, *args, **kwargs):
        SocketServer.UDPServer.__init__(self, *args, **kwargs)

        self.timeoutEvent_ = threading.Event()
        self.controlURL = None
        self.upnpInfo = {}
        self.urlbase = None
        self.gotSearchResponse = False

    def discoverUPnP(self):
        "Discover UPnP devices. Returns a Deferred"

        self.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)

        search = cannedUPnPSearch()
        try:
            self.socket.sendto(search, (UPNP_MCAST, UPNP_PORT))
            self.socket.sendto(search, (UPNP_MCAST, UPNP_PORT))
            self.socket.sendto(search, (UPNP_MCAST, UPNP_PORT))
        except socket.error:
            self.timeoutEvent_.set()
            raise NoUPnPFound('no network available')

        startTime = time.time()
        while not self.timeoutEvent_.isSet():
            self.socket.settimeout(6)
            self.handle_request()
            if time.time() > startTime + 6:
                break
        #self.timeoutEvent_.wait(6)
        self.timeoutEvent_.set()

        if self.urlbase is None:
            raise NoUPnPFound()

        return self

    def handle(self, handler):
        dgram = handler.rfile.read()
        address = handler.client_address

        #log.msg("got a response from %s, dgram is %s "%(address, dgram), system='UPnP')

        if not "\r\n" in dgram:
            return
        response, message = dgram.split('\r\n', 1)
        version, status, textstatus = response.split(None, 2)
        if not version.startswith('HTTP'):
            return
        if self.controlURL:
            return
        #slog.msg("got a response from %s, status %s "%(address, status),
        #                               system='UPnP')
        if status == "200":
            self.gotSearchResponse = True
            self.handleSearchResponse(message)
            self.timeoutEvent_.set()

    def handleSearchResponse(self, message):
        import urlparse
        headers, body = self.parseSearchResponse(message)
        loc = headers.get('location')
        if not loc:
            log.msg("No location header in response to M-SEARCH!", 
                                                            system='UPnP')
            return
        loc = loc[0]
        # === Should catch some errors from urlopen
        f = urlopen(loc)
        log.msg("found a UPnP device at %s"%loc, system="UPnP")
        return self.handleIGDeviceResponse(f, loc)

    def parseSearchResponse(self, message):
        hdict = {}
        body = ''
        remaining = message
        while remaining:
            line, remaining = remaining.split('\r\n', 1)
            line = line.strip()
            if not line:
                body = remaining
                break
            key, val = line.split(':', 1)
            key = key.lower()
            hdict.setdefault(key, []).append(val.strip())
        return hdict, body

    def completedDiscovery(self):
        log.msg("discovery completed", system="UPnP")
        self.timeoutEvent_.set()
        if self.controlURL is not None:
            return self

    def handleIGDeviceResponse(self, body, loc):
        log.msg("got an IGDevice from %s"%(loc,), system='UPnP')
        if self.controlURL is not None:
            log.msg("already found UPnP, discarding duplicate response", 
                                                                system="UPnP")
            # We already got a working one - ignore this one
            return
        data = body.read()
        bs = BeautifulSoap(data)
        manufacturer = bs.first('manufacturer')
        if manufacturer and manufacturer.contents:
            log.msg("you're behind a %s"%(manufacturer.contents[0]), 
                                                                system='UPnP')
            self.upnpInfo['manufacturer'] = manufacturer.contents[0]
        friendly = bs.first('friendlyName')
        if friendly:
            self.upnpInfo['friendlyName'] = str(friendly.contents[0])
        urlbase = bs.first('URLBase')
        if urlbase and urlbase.contents:
            self.urlbase = str(urlbase.contents[0])
            log.msg("upnp urlbase is %s"%(self.urlbase), system='UPnP')
        else:
            log.msg("upnp response has no urlbase, falling back to %s"%(loc,), system='UPnP')
            self.urlbase = loc

        wanservices = bs.fetch('service', 
            dict(serviceType='urn:schemas-upnp-org:service:WANIPConnection:%'))
        for service in wanservices:
            scpdurl = service.get('SCPDURL')
            controlurl = service.get('controlURL')
            if scpdurl and controlurl:
                break
        else:
            log.msg("upnp response showed no WANIPConnections", system='UPnP')
            return

        self.controlURL = urlparse.urljoin(self.urlbase, controlurl)
        log.msg("upnp %r controlURL is %s"%(self, self.controlURL), system='UPnP')
        # === catch exceptions from urlopen
        f = urlopen(urlparse.urljoin(self.urlbase, scpdurl))
        return self.handleWanServiceDesc(f)

    def handleWanServiceDesc(self, body):
        log.msg("got WANServiceDesc from %s"%(self.urlbase,), system='UPnP')
        data = body.read()
        self.soap = SOAPRequestFactory(self.controlURL, 
                            "urn:schemas-upnp-org:service:WANIPConnection:1")
        self.soap.setSCPD(data)
        return self.completedDiscovery()

    def getExternalIPAddress(self):
        req = self.soap.GetExternalIPAddress()
        try:
            f = soapenurl(req)
            return self.cb_gotExternalIPAddress(f)
        except soap.SOAPError, e:
            raise self.cb_failedExternalIPAddress(e)

    def cb_gotExternalIPAddress(self, res):
        return res['NewExternalIPAddress']

    def cb_failedExternalIPAddress(self, failure):
        err = failure.args[0]
        return UPnPError("GetGenericPortMappingEntry got %s"%(err))

    def getPortMappings(self):
        return self.getGenericPortMappingEntry(0)

    def getGenericPortMappingEntry(self, nextPMI=0, saved=None):
        if saved is None: 
            saved = {}
        request = self.soap.GetGenericPortMappingEntry(
                                                NewPortMappingIndex=nextPMI)
        try:
            x = soapenurl(request)
            return self.cb_gotGenericPortMappingEntry(x, nextPMI+1, saved)
        except soap.SOAPError, e:
            return self.cb_failedGenericPortMappingEntry(e, saved)

    def cb_gotGenericPortMappingEntry(self, response, nextPMI, saved):
        saved[response['NewProtocol'], response['NewExternalPort']] = response
        return self.getGenericPortMappingEntry(nextPMI, saved)

    def cb_failedGenericPortMappingEntry(self, failure, saved):
        err = failure.args[0]
        if err in ("SpecifiedArrayIndexInvalid", "NoSuchEntryInArray", "Invalid Args"):
            return saved
        else:
            raise UPnPError("GetGenericPortMappingEntry got %s"%(err))

    def addPortMapping(self, intport, extport, desc, proto='UDP', lease=0, locIP=None):
        "add a port mapping. returns a deferred"
        if locIP is None:
            locIP = getLocalIPAddress()
        return self._cbAddPortMapping(intport, extport,
                               desc, proto, lease, 
                               locIP)

    def _cbAddPortMapping(self, iport, eport, desc, proto, lease, locip):
        request = self.soap.AddPortMapping(NewRemoteHost=None, 
                                           NewExternalPort=eport,
                                           NewProtocol=proto,
                                           NewInternalPort=iport,
                                           NewInternalClient=locip,
                                           NewEnabled=1,
                                           NewPortMappingDescription=desc,
                                           NewLeaseDuration=lease)
        try:
            f = soapenurl(request)
            return self.cb_gotAddPortMapping(f)
        except soap.SOAPError, e:
            raise self.cb_failedAddPortMapping(e)
        
    def cb_gotAddPortMapping(self, response):
        log.msg('AddPortMapping ok', system='UPnP')
        return None

    def cb_failedAddPortMapping(self, failure):
        err = failure.args[0]
        log.err('AddPortMapping failed with: %s'%(err), system='UPnP')
        return UPnPError(err)

    def deletePortMapping(self, extport, proto='UDP'):
        "remove a port mapping"
        request = self.soap.DeletePortMapping(NewRemoteHost=None, 
                                              NewExternalPort=extport,
                                              NewProtocol=proto)
        try:
            f = soapenurl(request)
            self.cb_gotDeletePortMapping(f)
        except soap.SOAPError, e:
            raise self.cb_failedDeletePortMapping(e)
        
    def cb_gotDeletePortMapping(self, response):
        log.msg('DeletePortMapping ok', system='UPnP')
        return None

    def cb_failedDeletePortMapping(self, failure):
        err = failure.args[0]
        log.err('DeletePortMapping failed with: %s'%(err), system='UPnP')
        return UPnPError(err)

class UPnPProtocol(SocketServer.DatagramRequestHandler):
    def handle(self):
        #dsunittest.trace("in handle()")
        self.server.handle(handler=self)

class UPnPMapper:
    def __init__(self):
        self._mapped = {}
        self.upnp = None

    def map(self, port):
        "See shtoom.interfaces.NATMapper.map"

        if port in self._mapped:
            return self._mapped[port]

        if self.upnp is None:
            self.upnp =  getUPnP()
        result = self._cb_map_gotUPnP(self.upnp, port)
        self._mapped[port] = result
        return result

    def _cb_map_gotUPnP(self, upnp, port):
        # Extract local address from the port
        locAddr = hostFromPort(port=port)
        if isBogusAddress(locAddr):
            # lookup local IP.
            locAddr = getLocalIPAddress()
        return self._cb_map_gotLocalIP(locAddr, port)

    def _cb_map_gotLocalIP(self, locIP, port):
        # Ok, we have the local IP, and the upnp object is setup. Let's rock.
        mappings = self.upnp.getPortMappings()
        return self._cb_map_gotPortMappings(mappings, locIP, port)

    def _cb_map_gotPortMappings(self, mappings, locIP, port):
        log.msg("existing mappings %r"%(mappings.keys(),), system="UPnP")
        ptype = typeFromPort(port=port)
        intport = extport = portFromPort(port=port)
        while True:
            existing = mappings.get((ptype,extport))
            # XXX when the SOAP code fixes up types, remove the 'str()' version
            if existing is None:
                existing = mappings.get((ptype,str(extport)))
            if existing is None: 
                break
            exhost = existing['NewInternalClient'] 
            exint = existing['NewInternalPort'] 
            exproto = existing['NewProtocol']
            # More string nasties when I fix SOAP typing
            if exproto == ptype and exhost == locIP and exint in (intport, str(intport)):
                # Existing binding for this host/port/proto - replace it
                log.msg("replacing existing mapping for %s:%s"%(ptype,extport),
                                            system="UPnP")
                break
            # skip the obvious race condition as everyone wants 5060 :-(
            extport += random.randint(1,20)
        mapping = self.upnp.addPortMapping(intport=intport, extport=extport, locIP=locIP,
                                           desc=descFromPort(port=port), proto=ptype, lease=0)
        extaddr = self.upnp.getExternalIPAddress()
        return self.cb_map_addedPortMapping(extaddr, extport, port)

    def cb_map_addedPortMapping(self, extaddr, extport, port):
        return  (extaddr, extport)

    def info(self, port):
        "See shtoom.interfaces.NATMapper.info"
        if port in self._mapped:
            return self._mapped[port]
        else:
            raise ValueError('Port %s is not currently mapped' % (repr(port)))

    def unmap(self, port):
        "See shtoom.interfaces.NATMapper.unmap"
        existing = self._mapped.get(port)
        if not existing:
            raise ValueError('Port %s is not currently mapped'%repr(port))
        del self._mapped[port]
        return self.upnp.deletePortMapping(existing[1], typeFromPort(port=port))

def getUPnP():
    "Returns a deferred, which returns a UPnP object"

    attempt = 0
    while True:
        try:
            server = UPnPClientServer(("", 1900+attempt), UPnPProtocol)

            i = socket.inet_aton(getLocalIPAddress())
            server.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, i)
            #mcast = reactor.listenMulticast(1900+attempt, self)
            break
        except socket.error:
            attempt = random.randint(0,500)
            log.msg("couldn't listen on UPnP port, trying %d"%(
                                attempt+1900), system='UPnP')
    if attempt != 0:
        log.msg("warning: couldn't listen on std upnp port", system='UPnP')

    #mcast.joinGroup('239.255.255.250', socket.INADDR_ANY)
    grpaddr = struct.unpack("i", socket.inet_aton(UPNP_MCAST))[0]

    mreq = struct.pack('ll', socket.htonl(grpaddr), socket.htonl(socket.INADDR_ANY))
    try:
        server.socket.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
    except socket.error:
        dsunittest.traceException("Failed doing IP_ADD_MEMBERSHIP for mreq %r" % mreq)
        # apparently on win32, even though this call fails, UPnP works just fine
        # so I'm commenting out this raise statement --eries
        # raise NoUPnPFound()

    return server.discoverUPnP()



# This collective work is Copyright (C)2004 by Anthony Baxter
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