--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_misc_ip.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,330 @@
+#!/usr/bin/env python3
+
+
+# SAT plugin for IP address discovery
+# Copyright (C) 2009-2021 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/>.
+
+import urllib.parse
+from libervia.backend.core.i18n import _, D_
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.log import getLogger
+from libervia.backend.tools import xml_tools
+from wokkel import disco, iwokkel
+from twisted.web import client as webclient
+from twisted.web import error as web_error
+from twisted.internet import defer
+from twisted.internet import reactor
+from twisted.internet import protocol
+from twisted.internet import endpoints
+from twisted.internet import error as internet_error
+from zope.interface import implementer
+from twisted.words.protocols.jabber.xmlstream import XMPPHandler
+from twisted.words.protocols.jabber.error import StanzaError
+
+log = getLogger(__name__)
+
+try:
+    import netifaces
+except ImportError:
+    log.warning(
+        "netifaces is not available, it help discovering IPs, you can install it on https://pypi.python.org/pypi/netifaces"
+    )
+    netifaces = None
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: "IP discovery",
+    C.PI_IMPORT_NAME: "IP",
+    C.PI_TYPE: C.PLUG_TYPE_MISC,
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: ["XEP-0279"],
+    C.PI_RECOMMENDATIONS: ["NAT-PORT"],
+    C.PI_MAIN: "IPPlugin",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("""This plugin help to discover our external IP address."""),
+}
+
+# TODO: GET_IP_PAGE should be configurable in sat.conf
+GET_IP_PAGE = (
+    "http://salut-a-toi.org/whereami/"
+)  # This page must only return external IP of the requester
+GET_IP_LABEL = D_("Allow external get IP")
+GET_IP_CATEGORY = "General"
+GET_IP_NAME = "allow_get_ip"
+GET_IP_CONFIRM_TITLE = D_("Confirm external site request")
+GET_IP_CONFIRM = D_(
+    """To facilitate data transfer, we need to contact a website.
+A request will be done on {page}
+That means that administrators of {domain} can know that you use "{app_name}" and your IP Address.
+
+IP address is an identifier to locate you on Internet (similar to a phone number).
+
+Do you agree to do this request ?
+"""
+).format(
+    page=GET_IP_PAGE, domain=urllib.parse.urlparse(GET_IP_PAGE).netloc, app_name=C.APP_NAME
+)
+NS_IP_CHECK = "urn:xmpp:sic:1"
+
+PARAMS = """
+    <params>
+    <general>
+    <category name="{category}">
+        <param name="{name}" label="{label}" type="bool" />
+    </category>
+    </general>
+    </params>
+    """.format(
+    category=GET_IP_CATEGORY, name=GET_IP_NAME, label=GET_IP_LABEL
+)
+
+
+class IPPlugin(object):
+    # TODO: refresh IP if a new connection is detected
+    # TODO: manage IPv6 when implemented in SàT
+
+    def __init__(self, host):
+        log.info(_("plugin IP discovery initialization"))
+        self.host = host
+        host.memory.update_params(PARAMS)
+
+        # NAT-Port
+        try:
+            self._nat = host.plugins["NAT-PORT"]
+        except KeyError:
+            log.debug("NAT port plugin not available")
+            self._nat = None
+
+        # XXX: cache is kept until SàT is restarted
+        #      if IP may have changed, use self.refresh_ip
+        self._external_ip_cache = None
+        self._local_ip_cache = None
+
+    def get_handler(self, client):
+        return IPPlugin_handler()
+
+    def refresh_ip(self):
+        # FIXME: use a trigger instead ?
+        self._external_ip_cache = None
+        self._local_ip_cache = None
+
+    def _external_allowed(self, client):
+        """Return value of parameter with autorisation of user to do external requests
+
+        if parameter is not set, a dialog is shown to use to get its confirmation, and parameted is set according to answer
+        @return (defer.Deferred[bool]): True if external request is autorised
+        """
+        allow_get_ip = self.host.memory.params.param_get_a(
+            GET_IP_NAME, GET_IP_CATEGORY, use_default=False
+        )
+
+        if allow_get_ip is None:
+            # we don't have autorisation from user yet to use get_ip, we ask him
+            def param_set(allowed):
+                # FIXME: we need to use bool_const as param_set only manage str/unicode
+                #        need to be fixed when params will be refactored
+                self.host.memory.param_set(
+                    GET_IP_NAME, C.bool_const(allowed), GET_IP_CATEGORY
+                )
+                return allowed
+
+            d = xml_tools.defer_confirm(
+                self.host,
+                _(GET_IP_CONFIRM),
+                _(GET_IP_CONFIRM_TITLE),
+                profile=client.profile,
+            )
+            d.addCallback(param_set)
+            return d
+
+        return defer.succeed(allow_get_ip)
+
+    def _filter_addresse(self, ip_addr):
+        """Filter acceptable addresses
+
+        For now, just remove IPv4 local addresses
+        @param ip_addr(str): IP addresse
+        @return (bool): True if addresse is acceptable
+        """
+        return not ip_addr.startswith("127.")
+
+    def _insert_first(self, addresses, ip_addr):
+        """Insert ip_addr as first item in addresses
+
+        @param addresses(list): list of IP addresses
+        @param ip_addr(str): IP addresse
+        """
+        if ip_addr in addresses:
+            if addresses[0] != ip_addr:
+                addresses.remove(ip_addr)
+                addresses.insert(0, ip_addr)
+        else:
+            addresses.insert(0, ip_addr)
+
+    async def _get_ip_from_external(self, ext_url):
+        """Get local IP by doing a connection on an external url
+
+        @param ext_utl(str): url to connect to
+        @return (str, None): return local IP, or None if it's not possible
+        """
+        url = urllib.parse.urlparse(ext_url)
+        port = url.port
+        if port is None:
+            if url.scheme == "http":
+                port = 80
+            elif url.scheme == "https":
+                port = 443
+            else:
+                log.error("Unknown url scheme: {}".format(url.scheme))
+                return None
+        if url.hostname is None:
+            log.error("Can't find url hostname for {}".format(GET_IP_PAGE))
+
+        point = endpoints.TCP4ClientEndpoint(reactor, url.hostname, port)
+
+        p = await endpoints.connectProtocol(point, protocol.Protocol())
+        local_ip = p.transport.getHost().host
+        p.transport.loseConnection()
+        return local_ip
+
+    @defer.inlineCallbacks
+    def get_local_i_ps(self, client):
+        """Try do discover local area network IPs
+
+        @return (deferred): list of lan IP addresses
+            if there are several addresses, the one used with the server is put first
+            if no address is found, localhost IP will be in the list
+        """
+        # TODO: manage permission requesting (e.g. for UMTS link)
+        if self._local_ip_cache is not None:
+            defer.returnValue(self._local_ip_cache)
+        addresses = []
+        localhost = ["127.0.0.1"]
+
+        # we first try our luck with netifaces
+        if netifaces is not None:
+            addresses = []
+            for interface in netifaces.interfaces():
+                if_addresses = netifaces.ifaddresses(interface)
+                try:
+                    inet_list = if_addresses[netifaces.AF_INET]
+                except KeyError:
+                    continue
+                for data in inet_list:
+                    addresse = data["addr"]
+                    if self._filter_addresse(addresse):
+                        addresses.append(addresse)
+
+        # then we use our connection to server
+        ip = client.xmlstream.transport.getHost().host
+        if self._filter_addresse(ip):
+            self._insert_first(addresses, ip)
+            defer.returnValue(addresses)
+
+        # if server is local, we try with NAT-Port
+        if self._nat is not None:
+            nat_ip = yield self._nat.get_ip(local=True)
+            if nat_ip is not None:
+                self._insert_first(addresses, nat_ip)
+                defer.returnValue(addresses)
+
+            if addresses:
+                defer.returnValue(addresses)
+
+        # still not luck, we need to contact external website
+        allow_get_ip = yield self._external_allowed(client)
+
+        if not allow_get_ip:
+            defer.returnValue(addresses or localhost)
+
+        try:
+            local_ip = yield defer.ensureDeferred(self._get_ip_from_external(GET_IP_PAGE))
+        except (internet_error.DNSLookupError, internet_error.TimeoutError):
+            log.warning("Can't access Domain Name System")
+        else:
+            if local_ip is not None:
+                self._insert_first(addresses, local_ip)
+
+        defer.returnValue(addresses or localhost)
+
+    @defer.inlineCallbacks
+    def get_external_ip(self, client):
+        """Try to discover external IP
+
+        @return (deferred): external IP address or None if it can't be discovered
+        """
+        if self._external_ip_cache is not None:
+            defer.returnValue(self._external_ip_cache)
+
+        # we first try with XEP-0279
+        ip_check = yield self.host.hasFeature(client, NS_IP_CHECK)
+        if ip_check:
+            log.debug("Server IP Check available, we use it to retrieve our IP")
+            iq_elt = client.IQ("get")
+            iq_elt.addElement((NS_IP_CHECK, "address"))
+            try:
+                result_elt = yield iq_elt.send()
+                address_elt = next(result_elt.elements(NS_IP_CHECK, "address"))
+                ip_elt = next(address_elt.elements(NS_IP_CHECK, "ip"))
+            except StopIteration:
+                log.warning(
+                    "Server returned invalid result on XEP-0279 request, we ignore it"
+                )
+            except StanzaError as e:
+                log.warning("error while requesting ip to server: {}".format(e))
+            else:
+                # FIXME: server IP may not be the same as external IP (server can be on local machine or network)
+                #        IP should be checked to see if we have a local one, and rejected in this case
+                external_ip = str(ip_elt)
+                log.debug("External IP found: {}".format(external_ip))
+                self._external_ip_cache = external_ip
+                defer.returnValue(self._external_ip_cache)
+
+        # then with NAT-Port
+        if self._nat is not None:
+            nat_ip = yield self._nat.get_ip()
+            if nat_ip is not None:
+                self._external_ip_cache = nat_ip
+                defer.returnValue(nat_ip)
+
+        # and finally by requesting external website
+        allow_get_ip = yield self._external_allowed(client)
+        try:
+            ip = ((yield webclient.getPage(GET_IP_PAGE.encode('utf-8')))
+                  if allow_get_ip else None)
+        except (internet_error.DNSLookupError, internet_error.TimeoutError):
+            log.warning("Can't access Domain Name System")
+            ip = None
+        except web_error.Error as e:
+            log.warning(
+                "Error while retrieving IP on {url}: {message}".format(
+                    url=GET_IP_PAGE, message=e
+                )
+            )
+            ip = None
+        else:
+            self._external_ip_cache = ip
+        defer.returnValue(ip)
+
+
+@implementer(iwokkel.IDisco)
+class IPPlugin_handler(XMPPHandler):
+
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
+        return [disco.DiscoFeature(NS_IP_CHECK)]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
+        return []