diff options
Diffstat (limited to 'synapse/http/endpoint.py')
| -rw-r--r-- | synapse/http/endpoint.py | 315 |
1 files changed, 0 insertions, 315 deletions
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py index 91025037a3..cd79ebab62 100644 --- a/synapse/http/endpoint.py +++ b/synapse/http/endpoint.py @@ -12,30 +12,11 @@ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. -import collections import logging -import random import re -import time - -from twisted.internet import defer -from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS -from twisted.internet.error import ConnectError -from twisted.names import client, dns -from twisted.names.error import DNSNameError, DomainError logger = logging.getLogger(__name__) -SERVER_CACHE = {} - -# our record of an individual server which can be tried to reach a destination. -# -# "host" is the hostname acquired from the SRV record. Except when there's -# no SRV record, in which case it is the original hostname. -_Server = collections.namedtuple( - "_Server", "priority weight host port expires" -) - def parse_server_name(server_name): """Split a server name into host/port parts. @@ -100,299 +81,3 @@ def parse_and_validate_server_name(server_name): )) return host, port - - -def matrix_federation_endpoint(reactor, destination, tls_client_options_factory=None, - timeout=None): - """Construct an endpoint for the given matrix destination. - - Args: - reactor: Twisted reactor. - destination (unicode): The name of the server to connect to. - tls_client_options_factory - (synapse.crypto.context_factory.ClientTLSOptionsFactory): - Factory which generates TLS options for client connections. - timeout (int): connection timeout in seconds - """ - - domain, port = parse_server_name(destination) - - endpoint_kw_args = {} - - if timeout is not None: - endpoint_kw_args.update(timeout=timeout) - - if tls_client_options_factory is None: - transport_endpoint = HostnameEndpoint - default_port = 8008 - else: - # the SNI string should be the same as the Host header, minus the port. - # as per https://github.com/matrix-org/synapse/issues/2525#issuecomment-336896777, - # the Host header and SNI should therefore be the server_name of the remote - # server. - tls_options = tls_client_options_factory.get_options(domain) - - def transport_endpoint(reactor, host, port, timeout): - return wrapClientTLS( - tls_options, - HostnameEndpoint(reactor, host, port, timeout=timeout), - ) - default_port = 8448 - - if port is None: - return _WrappingEndpointFac(SRVClientEndpoint( - reactor, "matrix", domain, protocol="tcp", - default_port=default_port, endpoint=transport_endpoint, - endpoint_kw_args=endpoint_kw_args - ), reactor) - else: - return _WrappingEndpointFac(transport_endpoint( - reactor, domain, port, **endpoint_kw_args - ), reactor) - - -class _WrappingEndpointFac(object): - def __init__(self, endpoint_fac, reactor): - self.endpoint_fac = endpoint_fac - self.reactor = reactor - - @defer.inlineCallbacks - def connect(self, protocolFactory): - conn = yield self.endpoint_fac.connect(protocolFactory) - conn = _WrappedConnection(conn, self.reactor) - defer.returnValue(conn) - - -class _WrappedConnection(object): - """Wraps a connection and calls abort on it if it hasn't seen any action - for 2.5-3 minutes. - """ - __slots__ = ["conn", "last_request"] - - def __init__(self, conn, reactor): - object.__setattr__(self, "conn", conn) - object.__setattr__(self, "last_request", time.time()) - self._reactor = reactor - - def __getattr__(self, name): - return getattr(self.conn, name) - - def __setattr__(self, name, value): - setattr(self.conn, name, value) - - def _time_things_out_maybe(self): - # We use a slightly shorter timeout here just in case the callLater is - # triggered early. Paranoia ftw. - # TODO: Cancel the previous callLater rather than comparing time.time()? - if time.time() - self.last_request >= 2.5 * 60: - self.abort() - # Abort the underlying TLS connection. The abort() method calls - # loseConnection() on the TLS connection which tries to - # shutdown the connection cleanly. We call abortConnection() - # since that will promptly close the TLS connection. - # - # In Twisted >18.4; the TLS connection will be None if it has closed - # which will make abortConnection() throw. Check that the TLS connection - # is not None before trying to close it. - if self.transport.getHandle() is not None: - self.transport.abortConnection() - - def request(self, request): - self.last_request = time.time() - - # Time this connection out if we haven't send a request in the last - # N minutes - # TODO: Cancel the previous callLater? - self._reactor.callLater(3 * 60, self._time_things_out_maybe) - - d = self.conn.request(request) - - def update_request_time(res): - self.last_request = time.time() - # TODO: Cancel the previous callLater? - self._reactor.callLater(3 * 60, self._time_things_out_maybe) - return res - - d.addCallback(update_request_time) - - return d - - -class SpiderEndpoint(object): - """An endpoint which refuses to connect to blacklisted IP addresses - Implements twisted.internet.interfaces.IStreamClientEndpoint. - """ - def __init__(self, reactor, host, port, blacklist, whitelist, - endpoint=HostnameEndpoint, endpoint_kw_args={}): - self.reactor = reactor - self.host = host - self.port = port - self.blacklist = blacklist - self.whitelist = whitelist - self.endpoint = endpoint - self.endpoint_kw_args = endpoint_kw_args - - @defer.inlineCallbacks - def connect(self, protocolFactory): - address = yield self.reactor.resolve(self.host) - - from netaddr import IPAddress - ip_address = IPAddress(address) - - if ip_address in self.blacklist: - if self.whitelist is None or ip_address not in self.whitelist: - raise ConnectError( - "Refusing to spider blacklisted IP address %s" % address - ) - - logger.info("Connecting to %s:%s", address, self.port) - endpoint = self.endpoint( - self.reactor, address, self.port, **self.endpoint_kw_args - ) - connection = yield endpoint.connect(protocolFactory) - defer.returnValue(connection) - - -class SRVClientEndpoint(object): - """An endpoint which looks up SRV records for a service. - Cycles through the list of servers starting with each call to connect - picking the next server. - Implements twisted.internet.interfaces.IStreamClientEndpoint. - """ - - def __init__(self, reactor, service, domain, protocol="tcp", - default_port=None, endpoint=HostnameEndpoint, - endpoint_kw_args={}): - self.reactor = reactor - self.service_name = "_%s._%s.%s" % (service, protocol, domain) - - if default_port is not None: - self.default_server = _Server( - host=domain, - port=default_port, - priority=0, - weight=0, - expires=0, - ) - else: - self.default_server = None - - self.endpoint = endpoint - self.endpoint_kw_args = endpoint_kw_args - - self.servers = None - self.used_servers = None - - @defer.inlineCallbacks - def fetch_servers(self): - self.used_servers = [] - self.servers = yield resolve_service(self.service_name) - - def pick_server(self): - if not self.servers: - if self.used_servers: - self.servers = self.used_servers - self.used_servers = [] - self.servers.sort() - elif self.default_server: - return self.default_server - else: - raise ConnectError( - "No server available for %s" % self.service_name - ) - - # look for all servers with the same priority - min_priority = self.servers[0].priority - weight_indexes = list( - (index, server.weight + 1) - for index, server in enumerate(self.servers) - if server.priority == min_priority - ) - - total_weight = sum(weight for index, weight in weight_indexes) - target_weight = random.randint(0, total_weight) - for index, weight in weight_indexes: - target_weight -= weight - if target_weight <= 0: - server = self.servers[index] - # XXX: this looks totally dubious: - # - # (a) we never reuse a server until we have been through - # all of the servers at the same priority, so if the - # weights are A: 100, B:1, we always do ABABAB instead of - # AAAA...AAAB (approximately). - # - # (b) After using all the servers at the lowest priority, - # we move onto the next priority. We should only use the - # second priority if servers at the top priority are - # unreachable. - # - del self.servers[index] - self.used_servers.append(server) - return server - - @defer.inlineCallbacks - def connect(self, protocolFactory): - if self.servers is None: - yield self.fetch_servers() - server = self.pick_server() - logger.info("Connecting to %s:%s", server.host, server.port) - endpoint = self.endpoint( - self.reactor, server.host, server.port, **self.endpoint_kw_args - ) - connection = yield endpoint.connect(protocolFactory) - defer.returnValue(connection) - - -@defer.inlineCallbacks -def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=time): - cache_entry = cache.get(service_name, None) - if cache_entry: - if all(s.expires > int(clock.time()) for s in cache_entry): - servers = list(cache_entry) - defer.returnValue(servers) - - servers = [] - - try: - try: - answers, _, _ = yield dns_client.lookupService(service_name) - except DNSNameError: - defer.returnValue([]) - - if (len(answers) == 1 - and answers[0].type == dns.SRV - and answers[0].payload - and answers[0].payload.target == dns.Name(b'.')): - raise ConnectError("Service %s unavailable" % service_name) - - for answer in answers: - if answer.type != dns.SRV or not answer.payload: - continue - - payload = answer.payload - - servers.append(_Server( - host=str(payload.target), - port=int(payload.port), - priority=int(payload.priority), - weight=int(payload.weight), - expires=int(clock.time()) + answer.ttl, - )) - - servers.sort() - cache[service_name] = list(servers) - except DomainError as e: - # We failed to resolve the name (other than a NameError) - # Try something in the cache, else rereaise - cache_entry = cache.get(service_name, None) - if cache_entry: - logger.warn( - "Failed to resolve %r, falling back to cache. %r", - service_name, e - ) - servers = list(cache_entry) - else: - raise e - - defer.returnValue(servers) |