plugin nat-port: NAT port first draft:

- this plugin use UPnP-IGD (and maybe later NAT-PMP) to open a port or get local/external IP
    - for now, only IP retrieval is implemented

src/plugins/plugin_misc_nat-port.py

@@ -0,0 +1,84 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# SAT plugin for NAT port mapping
+# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from sat.core.i18n import _
+from sat.core.constants import Const as C
+from sat.core.log import getLogger
+log = getLogger(__name__)
+from sat.core import exceptions
+from twisted.internet import threads
+from twisted.internet import defer
+
+try:
+    import miniupnpc
+except ImportError:
+    raise exceptions.MissingModule(u"Missing module MiniUPnPc, please download/install it (and its Python binding) at http://miniupnp.free.fr/")
+
+
+PLUGIN_INFO = {
+    "name": "NAT port mapping",
+    "import_name": "NAT-PORT",
+    "type": C.PLUG_TYPE_MISC,
+    "main": "NatPort",
+    "handler": "no",
+    "description": _("""Automatic NAT port mapping using UPnP"""),
+}
+
+
+class NatPort(object):
+    # TODO: refresh data if a new connection is detected (see plugin_misc_ip)
+
+    def __init__(self, host):
+        log.info(_("plugin NAT Port initialization"))
+        self.host = host
+        self._external_ip = None
+        self._initialised = defer.Deferred()
+        self._upnp = miniupnpc.UPnP() # will be None if no device is available
+        self._upnp.discoverdelay=200
+        discover_d = threads.deferToThread(self._discover)
+        discover_d.chainDeferred(self._initialised)
+        self._initialised.addErrback(self._init_failed)
+
+    def _init_failed(self, failure):
+        log.info(u"UPnP-GID not available")
+        self._upnp = None
+
+    def _discover(self):
+        devices = self._upnp.discover()
+        if devices:
+            log.info(u"{nb} UPnP-IGD device(s) found".format(nb=devices))
+        else:
+            log.info(u"Can't find UPnP-IGD device on the local network")
+            raise exceptions.NotFound
+        self._upnp.selectigd()
+        self._external_ip = self._upnp.externalipaddress()
+
+    def getIP(self, local=False):
+        """Return IP address found with UPnP-IGD
+
+        @param local(bool): True to get external IP address, False to get local network one
+        @return (None, str): found IP address, or None of something got wrong
+        """
+        def getIP(dummy):
+            if self._upnp is None:
+                return None
+            # lanaddr can be the empty string if not found,
+            # we need to return None in this case
+            return (self._upnp.lanaddr or None) if local else self._external_ip
+        return self._initialised.addCallback(getIP)