Ausgabe der neuen DB Einträge

venv/lib/python3.9/site-packages/twisted/names/client.py

@@ -0,0 +1,776 @@
+# -*- test-case-name: twisted.names.test.test_names -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Asynchronous client DNS
+
+The functions exposed in this module can be used for asynchronous name
+resolution and dns queries.
+
+If you need to create a resolver with specific requirements, such as needing to
+do queries against a particular host, the L{createResolver} function will
+return an C{IResolver}.
+
+Future plans: Proper nameserver acquisition on Windows/MacOS,
+better caching, respect timeouts
+"""
+
+import os
+import errno
+import warnings
+
+from zope.interface import moduleProvides
+
+# Twisted imports
+from twisted.python.compat import nativeString
+from twisted.python.runtime import platform
+from twisted.python.filepath import FilePath
+from twisted.internet import error, defer, interfaces, protocol
+from twisted.python import log, failure
+from twisted.names import (
+    dns, common, resolve, cache, root, hosts as hostsModule)
+from twisted.internet.abstract import isIPv6Address
+
+
+
+moduleProvides(interfaces.IResolver)
+
+
+
+class Resolver(common.ResolverBase):
+    """
+    @ivar _waiting: A C{dict} mapping tuple keys of query name/type/class to
+        Deferreds which will be called back with the result of those queries.
+        This is used to avoid issuing the same query more than once in
+        parallel.  This is more efficient on the network and helps avoid a
+        "birthday paradox" attack by keeping the number of outstanding requests
+        for a particular query fixed at one instead of allowing the attacker to
+        raise it to an arbitrary number.
+
+    @ivar _reactor: A provider of L{IReactorTCP}, L{IReactorUDP}, and
+        L{IReactorTime} which will be used to set up network resources and
+        track timeouts.
+    """
+    index = 0
+    timeout = None
+
+    factory = None
+    servers = None
+    dynServers = ()
+    pending = None
+    connections = None
+
+    resolv = None
+    _lastResolvTime = None
+    _resolvReadInterval = 60
+
+    def __init__(self, resolv=None, servers=None, timeout=(1, 3, 11, 45), reactor=None):
+        """
+        Construct a resolver which will query domain name servers listed in
+        the C{resolv.conf(5)}-format file given by C{resolv} as well as
+        those in the given C{servers} list.  Servers are queried in a
+        round-robin fashion.  If given, C{resolv} is periodically checked
+        for modification and re-parsed if it is noticed to have changed.
+
+        @type servers: C{list} of C{(str, int)} or L{None}
+        @param servers: If not None, interpreted as a list of (host, port)
+            pairs specifying addresses of domain name servers to attempt to use
+            for this lookup.  Host addresses should be in IPv4 dotted-quad
+            form.  If specified, overrides C{resolv}.
+
+        @type resolv: C{str}
+        @param resolv: Filename to read and parse as a resolver(5)
+            configuration file.
+
+        @type timeout: Sequence of C{int}
+        @param timeout: Default number of seconds after which to reissue the
+            query.  When the last timeout expires, the query is considered
+            failed.
+
+        @param reactor: A provider of L{IReactorTime}, L{IReactorUDP}, and
+            L{IReactorTCP} which will be used to establish connections, listen
+            for DNS datagrams, and enforce timeouts.  If not provided, the
+            global reactor will be used.
+
+        @raise ValueError: Raised if no nameserver addresses can be found.
+        """
+        common.ResolverBase.__init__(self)
+
+        if reactor is None:
+            from twisted.internet import reactor
+        self._reactor = reactor
+
+        self.timeout = timeout
+
+        if servers is None:
+            self.servers = []
+        else:
+            self.servers = servers
+
+        self.resolv = resolv
+
+        if not len(self.servers) and not resolv:
+            raise ValueError("No nameservers specified")
+
+        self.factory = DNSClientFactory(self, timeout)
+        self.factory.noisy = 0   # Be quiet by default
+
+        self.connections = []
+        self.pending = []
+
+        self._waiting = {}
+
+        self.maybeParseConfig()
+
+
+    def __getstate__(self):
+        d = self.__dict__.copy()
+        d['connections'] = []
+        d['_parseCall'] = None
+        return d
+
+
+    def __setstate__(self, state):
+        self.__dict__.update(state)
+        self.maybeParseConfig()
+
+
+    def _openFile(self, path):
+        """
+        Wrapper used for opening files in the class, exists primarily for unit
+        testing purposes.
+        """
+        return FilePath(path).open()
+
+
+    def maybeParseConfig(self):
+        if self.resolv is None:
+            # Don't try to parse it, don't set up a call loop
+            return
+
+        try:
+            resolvConf = self._openFile(self.resolv)
+        except IOError as e:
+            if e.errno == errno.ENOENT:
+                # Missing resolv.conf is treated the same as an empty resolv.conf
+                self.parseConfig(())
+            else:
+                raise
+        else:
+            with resolvConf:
+                mtime = os.fstat(resolvConf.fileno()).st_mtime
+                if mtime != self._lastResolvTime:
+                    log.msg('%s changed, reparsing' % (self.resolv,))
+                    self._lastResolvTime = mtime
+                    self.parseConfig(resolvConf)
+
+        # Check again in a little while
+        self._parseCall = self._reactor.callLater(
+            self._resolvReadInterval, self.maybeParseConfig)
+
+
+    def parseConfig(self, resolvConf):
+        servers = []
+        for L in resolvConf:
+            L = L.strip()
+            if L.startswith(b'nameserver'):
+                resolver = (nativeString(L.split()[1]), dns.PORT)
+                servers.append(resolver)
+                log.msg("Resolver added %r to server list" % (resolver,))
+            elif L.startswith(b'domain'):
+                try:
+                    self.domain = L.split()[1]
+                except IndexError:
+                    self.domain = b''
+                self.search = None
+            elif L.startswith(b'search'):
+                self.search = L.split()[1:]
+                self.domain = None
+        if not servers:
+            servers.append(('127.0.0.1', dns.PORT))
+        self.dynServers = servers
+
+
+    def pickServer(self):
+        """
+        Return the address of a nameserver.
+
+        TODO: Weight servers for response time so faster ones can be
+        preferred.
+        """
+        if not self.servers and not self.dynServers:
+            return None
+        serverL = len(self.servers)
+        dynL = len(self.dynServers)
+
+        self.index += 1
+        self.index %= (serverL + dynL)
+        if self.index < serverL:
+            return self.servers[self.index]
+        else:
+            return self.dynServers[self.index - serverL]
+
+
+    def _connectedProtocol(self, interface=''):
+        """
+        Return a new L{DNSDatagramProtocol} bound to a randomly selected port
+        number.
+        """
+        failures = 0
+        proto = dns.DNSDatagramProtocol(self, reactor=self._reactor)
+
+        while True:
+            try:
+                self._reactor.listenUDP(dns.randomSource(), proto,
+                                        interface=interface)
+            except error.CannotListenError as e:
+                failures += 1
+
+                if (hasattr(e.socketError, "errno") and
+                   e.socketError.errno == errno.EMFILE):
+                    # We've run out of file descriptors. Stop trying.
+                    raise
+
+                if failures >= 1000:
+                    # We've tried a thousand times and haven't found a port.
+                    # This is almost impossible, and likely means something
+                    # else weird is going on. Raise, as to not infinite loop.
+                    raise
+            else:
+                return proto
+
+
+    def connectionMade(self, protocol):
+        """
+        Called by associated L{dns.DNSProtocol} instances when they connect.
+        """
+        self.connections.append(protocol)
+        for (d, q, t) in self.pending:
+            self.queryTCP(q, t).chainDeferred(d)
+        del self.pending[:]
+
+
+    def connectionLost(self, protocol):
+        """
+        Called by associated L{dns.DNSProtocol} instances when they disconnect.
+        """
+        if protocol in self.connections:
+            self.connections.remove(protocol)
+
+
+    def messageReceived(self, message, protocol, address = None):
+        log.msg("Unexpected message (%d) received from %r" % (message.id, address))
+
+
+    def _query(self, *args):
+        """
+        Get a new L{DNSDatagramProtocol} instance from L{_connectedProtocol},
+        issue a query to it using C{*args}, and arrange for it to be
+        disconnected from its transport after the query completes.
+
+        @param *args: Positional arguments to be passed to
+            L{DNSDatagramProtocol.query}.
+
+        @return: A L{Deferred} which will be called back with the result of the
+            query.
+        """
+        if isIPv6Address(args[0][0]):
+            protocol = self._connectedProtocol(interface='::')
+        else:
+            protocol = self._connectedProtocol()
+        d = protocol.query(*args)
+        def cbQueried(result):
+            protocol.transport.stopListening()
+            return result
+        d.addBoth(cbQueried)
+        return d
+
+
+    def queryUDP(self, queries, timeout = None):
+        """
+        Make a number of DNS queries via UDP.
+
+        @type queries: A C{list} of C{dns.Query} instances
+        @param queries: The queries to make.
+
+        @type timeout: Sequence of C{int}
+        @param timeout: Number of seconds after which to reissue the query.
+        When the last timeout expires, the query is considered failed.
+
+        @rtype: C{Deferred}
+        @raise C{twisted.internet.defer.TimeoutError}: When the query times
+        out.
+        """
+        if timeout is None:
+            timeout = self.timeout
+
+        addresses = self.servers + list(self.dynServers)
+        if not addresses:
+            return defer.fail(IOError("No domain name servers available"))
+
+        # Make sure we go through servers in the list in the order they were
+        # specified.
+        addresses.reverse()
+
+        used = addresses.pop()
+        d = self._query(used, queries, timeout[0])
+        d.addErrback(self._reissue, addresses, [used], queries, timeout)
+        return d
+
+
+    def _reissue(self, reason, addressesLeft, addressesUsed, query, timeout):
+        reason.trap(dns.DNSQueryTimeoutError)
+
+        # If there are no servers left to be tried, adjust the timeout
+        # to the next longest timeout period and move all the
+        # "used" addresses back to the list of addresses to try.
+        if not addressesLeft:
+            addressesLeft = addressesUsed
+            addressesLeft.reverse()
+            addressesUsed = []
+            timeout = timeout[1:]
+
+        # If all timeout values have been used this query has failed.  Tell the
+        # protocol we're giving up on it and return a terminal timeout failure
+        # to our caller.
+        if not timeout:
+            return failure.Failure(defer.TimeoutError(query))
+
+        # Get an address to try.  Take it out of the list of addresses
+        # to try and put it ino the list of already tried addresses.
+        address = addressesLeft.pop()
+        addressesUsed.append(address)
+
+        # Issue a query to a server.  Use the current timeout.  Add this
+        # function as a timeout errback in case another retry is required.
+        d = self._query(address, query, timeout[0], reason.value.id)
+        d.addErrback(self._reissue, addressesLeft, addressesUsed, query, timeout)
+        return d
+
+
+    def queryTCP(self, queries, timeout = 10):
+        """
+        Make a number of DNS queries via TCP.
+
+        @type queries: Any non-zero number of C{dns.Query} instances
+        @param queries: The queries to make.
+
+        @type timeout: C{int}
+        @param timeout: The number of seconds after which to fail.
+
+        @rtype: C{Deferred}
+        """
+        if not len(self.connections):
+            address = self.pickServer()
+            if address is None:
+                return defer.fail(IOError("No domain name servers available"))
+            host, port = address
+            self._reactor.connectTCP(host, port, self.factory)
+            self.pending.append((defer.Deferred(), queries, timeout))
+            return self.pending[-1][0]
+        else:
+            return self.connections[0].query(queries, timeout)
+
+
+    def filterAnswers(self, message):
+        """
+        Extract results from the given message.
+
+        If the message was truncated, re-attempt the query over TCP and return
+        a Deferred which will fire with the results of that query.
+
+        If the message's result code is not C{twisted.names.dns.OK}, return a
+        Failure indicating the type of error which occurred.
+
+        Otherwise, return a three-tuple of lists containing the results from
+        the answers section, the authority section, and the additional section.
+        """
+        if message.trunc:
+            return self.queryTCP(message.queries).addCallback(self.filterAnswers)
+        if message.rCode != dns.OK:
+            return failure.Failure(self.exceptionForCode(message.rCode)(message))
+        return (message.answers, message.authority, message.additional)
+
+
+    def _lookup(self, name, cls, type, timeout):
+        """
+        Build a L{dns.Query} for the given parameters and dispatch it via UDP.
+
+        If this query is already outstanding, it will not be re-issued.
+        Instead, when the outstanding query receives a response, that response
+        will be re-used for this query as well.
+
+        @type name: C{str}
+        @type type: C{int}
+        @type cls: C{int}
+
+        @return: A L{Deferred} which fires with a three-tuple giving the
+            answer, authority, and additional sections of the response or with
+            a L{Failure} if the response code is anything other than C{dns.OK}.
+        """
+        key = (name, type, cls)
+        waiting = self._waiting.get(key)
+        if waiting is None:
+            self._waiting[key] = []
+            d = self.queryUDP([dns.Query(name, type, cls)], timeout)
+            def cbResult(result):
+                for d in self._waiting.pop(key):
+                    d.callback(result)
+                return result
+            d.addCallback(self.filterAnswers)
+            d.addBoth(cbResult)
+        else:
+            d = defer.Deferred()
+            waiting.append(d)
+        return d
+
+
+    # This one doesn't ever belong on UDP
+    def lookupZone(self, name, timeout=10):
+        address = self.pickServer()
+        if address is None:
+            return defer.fail(IOError('No domain name servers available'))
+        host, port = address
+        d = defer.Deferred()
+        controller = AXFRController(name, d)
+        factory = DNSClientFactory(controller, timeout)
+        factory.noisy = False #stfu
+
+        connector = self._reactor.connectTCP(host, port, factory)
+        controller.timeoutCall = self._reactor.callLater(
+            timeout or 10, self._timeoutZone, d, controller,
+            connector, timeout or 10)
+
+        def eliminateTimeout(failure):
+            controller.timeoutCall.cancel()
+            controller.timeoutCall = None
+            return failure
+
+        return d.addCallbacks(self._cbLookupZone, eliminateTimeout,
+                              callbackArgs=(connector,))
+
+
+    def _timeoutZone(self, d, controller, connector, seconds):
+        connector.disconnect()
+        controller.timeoutCall = None
+        controller.deferred = None
+        d.errback(error.TimeoutError("Zone lookup timed out after %d seconds" % (seconds,)))
+
+
+    def _cbLookupZone(self, result, connector):
+        connector.disconnect()
+        return (result, [], [])
+
+
+
+class AXFRController:
+    timeoutCall = None
+
+    def __init__(self, name, deferred):
+        self.name = name
+        self.deferred = deferred
+        self.soa = None
+        self.records = []
+        self.pending = [(deferred,)]
+
+
+    def connectionMade(self, protocol):
+        # dig saids recursion-desired to 0, so I will too
+        message = dns.Message(protocol.pickID(), recDes=0)
+        message.queries = [dns.Query(self.name, dns.AXFR, dns.IN)]
+        protocol.writeMessage(message)
+
+
+    def connectionLost(self, protocol):
+        # XXX Do something here - see #3428
+        pass
+
+
+    def messageReceived(self, message, protocol):
+        # Caveat: We have to handle two cases: All records are in 1
+        # message, or all records are in N messages.
+
+        # According to http://cr.yp.to/djbdns/axfr-notes.html,
+        # 'authority' and 'additional' are always empty, and only
+        # 'answers' is present.
+        self.records.extend(message.answers)
+        if not self.records:
+            return
+        if not self.soa:
+            if self.records[0].type == dns.SOA:
+                #print "first SOA!"
+                self.soa = self.records[0]
+        if len(self.records) > 1 and self.records[-1].type == dns.SOA:
+            #print "It's the second SOA! We're done."
+            if self.timeoutCall is not None:
+                self.timeoutCall.cancel()
+                self.timeoutCall = None
+            if self.deferred is not None:
+                self.deferred.callback(self.records)
+                self.deferred = None
+
+
+
+from twisted.internet.base import ThreadedResolver as _ThreadedResolverImpl
+
+class ThreadedResolver(_ThreadedResolverImpl):
+    def __init__(self, reactor=None):
+        if reactor is None:
+            from twisted.internet import reactor
+        _ThreadedResolverImpl.__init__(self, reactor)
+        warnings.warn(
+            "twisted.names.client.ThreadedResolver is deprecated since "
+            "Twisted 9.0, use twisted.internet.base.ThreadedResolver "
+            "instead.",
+            category=DeprecationWarning, stacklevel=2)
+
+
+
+class DNSClientFactory(protocol.ClientFactory):
+    def __init__(self, controller, timeout = 10):
+        self.controller = controller
+        self.timeout = timeout
+
+
+    def clientConnectionLost(self, connector, reason):
+        pass
+
+
+    def clientConnectionFailed(self, connector, reason):
+        """
+        Fail all pending TCP DNS queries if the TCP connection attempt
+        fails.
+
+        @see: L{twisted.internet.protocol.ClientFactory}
+
+        @param connector: Not used.
+        @type connector: L{twisted.internet.interfaces.IConnector}
+
+        @param reason: A C{Failure} containing information about the
+            cause of the connection failure. This will be passed as the
+            argument to C{errback} on every pending TCP query
+            C{deferred}.
+        @type reason: L{twisted.python.failure.Failure}
+        """
+        # Copy the current pending deferreds then reset the master
+        # pending list. This prevents triggering new deferreds which
+        # may be added by callback or errback functions on the current
+        # deferreds.
+        pending = self.controller.pending[:]
+        del self.controller.pending[:]
+        for pendingState in pending:
+            d = pendingState[0]
+            d.errback(reason)
+
+
+    def buildProtocol(self, addr):
+        p = dns.DNSProtocol(self.controller)
+        p.factory = self
+        return p
+
+
+
+def createResolver(servers=None, resolvconf=None, hosts=None):
+    """
+    Create and return a Resolver.
+
+    @type servers: C{list} of C{(str, int)} or L{None}
+
+    @param servers: If not L{None}, interpreted as a list of domain name servers
+    to attempt to use. Each server is a tuple of address in C{str} dotted-quad
+    form and C{int} port number.
+
+    @type resolvconf: C{str} or L{None}
+    @param resolvconf: If not L{None}, on posix systems will be interpreted as
+    an alternate resolv.conf to use. Will do nothing on windows systems. If
+    L{None}, /etc/resolv.conf will be used.
+
+    @type hosts: C{str} or L{None}
+    @param hosts: If not L{None}, an alternate hosts file to use. If L{None}
+    on posix systems, /etc/hosts will be used. On windows, C:\windows\hosts
+    will be used.
+
+    @rtype: C{IResolver}
+    """
+    if platform.getType() == 'posix':
+        if resolvconf is None:
+            resolvconf = b'/etc/resolv.conf'
+        if hosts is None:
+            hosts = b'/etc/hosts'
+        theResolver = Resolver(resolvconf, servers)
+        hostResolver = hostsModule.Resolver(hosts)
+    else:
+        if hosts is None:
+            hosts = r'c:\windows\hosts'
+        from twisted.internet import reactor
+        bootstrap = _ThreadedResolverImpl(reactor)
+        hostResolver = hostsModule.Resolver(hosts)
+        theResolver = root.bootstrap(bootstrap, resolverFactory=Resolver)
+
+    L = [hostResolver, cache.CacheResolver(), theResolver]
+    return resolve.ResolverChain(L)
+
+
+
+theResolver = None
+def getResolver():
+    """
+    Get a Resolver instance.
+
+    Create twisted.names.client.theResolver if it is L{None}, and then return
+    that value.
+
+    @rtype: C{IResolver}
+    """
+    global theResolver
+    if theResolver is None:
+        try:
+            theResolver = createResolver()
+        except ValueError:
+            theResolver = createResolver(servers=[('127.0.0.1', 53)])
+    return theResolver
+
+
+
+def getHostByName(name, timeout=None, effort=10):
+    """
+    Resolve a name to a valid ipv4 or ipv6 address.
+
+    Will errback with C{DNSQueryTimeoutError} on a timeout, C{DomainError} or
+    C{AuthoritativeDomainError} (or subclasses) on other errors.
+
+    @type name: C{str}
+    @param name: DNS name to resolve.
+
+    @type timeout: Sequence of C{int}
+    @param timeout: Number of seconds after which to reissue the query.
+    When the last timeout expires, the query is considered failed.
+
+    @type effort: C{int}
+    @param effort: How many times CNAME and NS records to follow while
+    resolving this name.
+
+    @rtype: C{Deferred}
+    """
+    return getResolver().getHostByName(name, timeout, effort)
+
+
+
+def query(query, timeout=None):
+    return getResolver().query(query, timeout)
+
+
+
+def lookupAddress(name, timeout=None):
+    return getResolver().lookupAddress(name, timeout)
+
+
+
+def lookupIPV6Address(name, timeout=None):
+    return getResolver().lookupIPV6Address(name, timeout)
+
+
+
+def lookupAddress6(name, timeout=None):
+    return getResolver().lookupAddress6(name, timeout)
+
+
+
+def lookupMailExchange(name, timeout=None):
+    return getResolver().lookupMailExchange(name, timeout)
+
+
+
+def lookupNameservers(name, timeout=None):
+    return getResolver().lookupNameservers(name, timeout)
+
+
+
+def lookupCanonicalName(name, timeout=None):
+    return getResolver().lookupCanonicalName(name, timeout)
+
+
+
+def lookupMailBox(name, timeout=None):
+    return getResolver().lookupMailBox(name, timeout)
+
+
+
+def lookupMailGroup(name, timeout=None):
+    return getResolver().lookupMailGroup(name, timeout)
+
+
+
+def lookupMailRename(name, timeout=None):
+    return getResolver().lookupMailRename(name, timeout)
+
+
+
+def lookupPointer(name, timeout=None):
+    return getResolver().lookupPointer(name, timeout)
+
+
+
+def lookupAuthority(name, timeout=None):
+    return getResolver().lookupAuthority(name, timeout)
+
+
+
+def lookupNull(name, timeout=None):
+    return getResolver().lookupNull(name, timeout)
+
+
+
+def lookupWellKnownServices(name, timeout=None):
+    return getResolver().lookupWellKnownServices(name, timeout)
+
+
+
+def lookupService(name, timeout=None):
+    return getResolver().lookupService(name, timeout)
+
+
+
+def lookupHostInfo(name, timeout=None):
+    return getResolver().lookupHostInfo(name, timeout)
+
+
+
+def lookupMailboxInfo(name, timeout=None):
+    return getResolver().lookupMailboxInfo(name, timeout)
+
+
+
+def lookupText(name, timeout=None):
+    return getResolver().lookupText(name, timeout)
+
+
+
+def lookupSenderPolicy(name, timeout=None):
+    return getResolver().lookupSenderPolicy(name, timeout)
+
+
+
+def lookupResponsibility(name, timeout=None):
+    return getResolver().lookupResponsibility(name, timeout)
+
+
+
+def lookupAFSDatabase(name, timeout=None):
+    return getResolver().lookupAFSDatabase(name, timeout)
+
+
+
+def lookupZone(name, timeout=None):
+    return getResolver().lookupZone(name, timeout)
+
+
+
+def lookupAllRecords(name, timeout=None):
+    return getResolver().lookupAllRecords(name, timeout)
+
+
+
+def lookupNamingAuthorityPointer(name, timeout=None):
+    return getResolver().lookupNamingAuthorityPointer(name, timeout)