# -*- coding: utf-8 -*-
# Copyright 2015, 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# 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.
from twisted.internet import defer
from .federation_base import FederationBase
from synapse.api.constants import Membership
from .units import Edu
from synapse.api.errors import (
CodeMessageException, HttpResponseException, SynapseError,
)
from synapse.util import unwrapFirstError
from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.logutils import log_function
from synapse.events import FrozenEvent
import synapse.metrics
from synapse.util.retryutils import get_retry_limiter, NotRetryingDestination
import copy
import itertools
import logging
import random
logger = logging.getLogger(__name__)
# synapse.federation.federation_client is a silly name
metrics = synapse.metrics.get_metrics_for("synapse.federation.client")
sent_pdus_destination_dist = metrics.register_distribution("sent_pdu_destinations")
sent_edus_counter = metrics.register_counter("sent_edus")
sent_queries_counter = metrics.register_counter("sent_queries", labels=["type"])
class FederationClient(FederationBase):
def start_get_pdu_cache(self):
self._get_pdu_cache = ExpiringCache(
cache_name="get_pdu_cache",
clock=self._clock,
max_len=1000,
expiry_ms=120 * 1000,
reset_expiry_on_get=False,
)
self._get_pdu_cache.start()
@log_function
def send_pdu(self, pdu, destinations):
"""Informs the replication layer about a new PDU generated within the
home server that should be transmitted to others.
TODO: Figure out when we should actually resolve the deferred.
Args:
pdu (Pdu): The new Pdu.
Returns:
Deferred: Completes when we have successfully processed the PDU
and replicated it to any interested remote home servers.
"""
order = self._order
self._order += 1
sent_pdus_destination_dist.inc_by(len(destinations))
logger.debug("[%s] transaction_layer.enqueue_pdu... ", pdu.event_id)
# TODO, add errback, etc.
self._transaction_queue.enqueue_pdu(pdu, destinations, order)
logger.debug(
"[%s] transaction_layer.enqueue_pdu... done",
pdu.event_id
)
@log_function
def send_edu(self, destination, edu_type, content):
edu = Edu(
origin=self.server_name,
destination=destination,
edu_type=edu_type,
content=content,
)
sent_edus_counter.inc()
# TODO, add errback, etc.
self._transaction_queue.enqueue_edu(edu)
return defer.succeed(None)
@log_function
def send_failure(self, failure, destination):
self._transaction_queue.enqueue_failure(failure, destination)
return defer.succeed(None)
@log_function
def make_query(self, destination, query_type, args,
retry_on_dns_fail=False):
"""Sends a federation Query to a remote homeserver of the given type
and arguments.
Args:
destination (str): Domain name of the remote homeserver
query_type (str): Category of the query type; should match the
handler name used in register_query_handler().
args (dict): Mapping of strings to strings containing the details
of the query request.
Returns:
a Deferred which will eventually yield a JSON object from the
response
"""
sent_queries_counter.inc(query_type)
return self.transport_layer.make_query(
destination, query_type, args, retry_on_dns_fail=retry_on_dns_fail
)
@log_function
def query_client_keys(self, destination, content):
"""Query device keys for a device hosted on a remote server.
Args:
destination (str): Domain name of the remote homeserver
content (dict): The query content.
Returns:
a Deferred which will eventually yield a JSON object from the
response
"""
sent_queries_counter.inc("client_device_keys")
return self.transport_layer.query_client_keys(destination, content)
@log_function
def claim_client_keys(self, destination, content):
"""Claims one-time keys for a device hosted on a remote server.
Args:
destination (str): Domain name of the remote homeserver
content (dict): The query content.
Returns:
a Deferred which will eventually yield a JSON object from the
response
"""
sent_queries_counter.inc("client_one_time_keys")
return self.transport_layer.claim_client_keys(destination, content)
@defer.inlineCallbacks
@log_function
def backfill(self, dest, context, limit, extremities):
"""Requests some more historic PDUs for the given context from the
given destination server.
Args:
dest (str): The remote home server to ask.
context (str): The context to backfill.
limit (int): The maximum number of PDUs to return.
extremities (list): List of PDU id and origins of the first pdus
we have seen from the context
Returns:
Deferred: Results in the received PDUs.
"""
logger.debug("backfill extrem=%s", extremities)
# If there are no extremeties then we've (probably) reached the start.
if not extremities:
return
transaction_data = yield self.transport_layer.backfill(
dest, context, extremities, limit)
logger.debug("backfill transaction_data=%s", repr(transaction_data))
pdus = [
self.event_from_pdu_json(p, outlier=False)
for p in transaction_data["pdus"]
]
# FIXME: We should handle signature failures more gracefully.
pdus[:] = yield defer.gatherResults(
self._check_sigs_and_hashes(pdus),
consumeErrors=True,
).addErrback(unwrapFirstError)
defer.returnValue(pdus)
@defer.inlineCallbacks
@log_function
def get_pdu(self, destinations, event_id, outlier=False, timeout=None):
"""Requests the PDU with given origin and ID from the remote home
servers.
Will attempt to get the PDU from each destination in the list until
one succeeds.
This will persist the PDU locally upon receipt.
Args:
destinations (list): Which home servers to query
pdu_origin (str): The home server that originally sent the pdu.
event_id (str)
outlier (bool): Indicates whether the PDU is an `outlier`, i.e. if
it's from an arbitary point in the context as opposed to part
of the current block of PDUs. Defaults to `False`
timeout (int): How long to try (in ms) each destination for before
moving to the next destination. None indicates no timeout.
Returns:
Deferred: Results in the requested PDU.
"""
# TODO: Rate limit the number of times we try and get the same event.
if self._get_pdu_cache:
e = self._get_pdu_cache.get(event_id)
if e:
defer.returnValue(e)
pdu = None
for destination in destinations:
try:
limiter = yield get_retry_limiter(
destination,
self._clock,
self.store,
)
with limiter:
transaction_data = yield self.transport_layer.get_event(
destination, event_id, timeout=timeout,
)
logger.debug("transaction_data %r", transaction_data)
pdu_list = [
self.event_from_pdu_json(p, outlier=outlier)
for p in transaction_data["pdus"]
]
if pdu_list and pdu_list[0]:
pdu = pdu_list[0]
# Check signatures are correct.
pdu = yield self._check_sigs_and_hashes([pdu])[0]
break
except SynapseError:
logger.info(
"Failed to get PDU %s from %s because %s",
event_id, destination, e,
)
continue
except CodeMessageException as e:
if 400 <= e.code < 500:
raise
logger.info(
"Failed to get PDU %s from %s because %s",
event_id, destination, e,
)
continue
except NotRetryingDestination as e:
logger.info(e.message)
continue
except Exception as e:
logger.info(
"Failed to get PDU %s from %s because %s",
event_id, destination, e,
)
continue
if self._get_pdu_cache is not None and pdu:
self._get_pdu_cache[event_id] = pdu
defer.returnValue(pdu)
@defer.inlineCallbacks
@log_function
def get_state_for_room(self, destination, room_id, event_id):
"""Requests all of the `current` state PDUs for a given room from
a remote home server.
Args:
destination (str): The remote homeserver to query for the state.
room_id (str): The id of the room we're interested in.
event_id (str): The id of the event we want the state at.
Returns:
Deferred: Results in a list of PDUs.
"""
result = yield self.transport_layer.get_room_state(
destination, room_id, event_id=event_id,
)
pdus = [
self.event_from_pdu_json(p, outlier=True) for p in result["pdus"]
]
auth_chain = [
self.event_from_pdu_json(p, outlier=True)
for p in result.get("auth_chain", [])
]
signed_pdus = yield self._check_sigs_and_hash_and_fetch(
destination, pdus, outlier=True
)
signed_auth = yield self._check_sigs_and_hash_and_fetch(
destination, auth_chain, outlier=True
)
signed_auth.sort(key=lambda e: e.depth)
defer.returnValue((signed_pdus, signed_auth))
@defer.inlineCallbacks
@log_function
def get_event_auth(self, destination, room_id, event_id):
res = yield self.transport_layer.get_event_auth(
destination, room_id, event_id,
)
auth_chain = [
self.event_from_pdu_json(p, outlier=True)
for p in res["auth_chain"]
]
signed_auth = yield self._check_sigs_and_hash_and_fetch(
destination, auth_chain, outlier=True
)
signed_auth.sort(key=lambda e: e.depth)
defer.returnValue(signed_auth)
@defer.inlineCallbacks
def make_membership_event(self, destinations, room_id, user_id, membership,
content={},):
"""
Creates an m.room.member event, with context, without participating in the room.
Does so by asking one of the already participating servers to create an
event with proper context.
Note that this does not append any events to any graphs.
Args:
destinations (str): Candidate homeservers which are probably
participating in the room.
room_id (str): The room in which the event will happen.
user_id (str): The user whose membership is being evented.
membership (str): The "membership" property of the event. Must be
one of "join" or "leave".
content (object): Any additional data to put into the content field
of the event.
Return:
A tuple of (origin (str), event (object)) where origin is the remote
homeserver which generated the event.
"""
valid_memberships = {Membership.JOIN, Membership.LEAVE}
if membership not in valid_memberships:
raise RuntimeError(
"make_membership_event called with membership='%s', must be one of %s" %
(membership, ",".join(valid_memberships))
)
for destination in destinations:
if destination == self.server_name:
continue
try:
ret = yield self.transport_layer.make_membership_event(
destination, room_id, user_id, membership
)
pdu_dict = ret["event"]
logger.debug("Got response to make_%s: %s", membership, pdu_dict)
pdu_dict["content"].update(content)
# The protoevent received over the JSON wire may not have all
# the required fields. Lets just gloss over that because
# there's some we never care about
if "prev_state" not in pdu_dict:
pdu_dict["prev_state"] = []
defer.returnValue(
(destination, self.event_from_pdu_json(pdu_dict))
)
break
except CodeMessageException:
raise
except Exception as e:
logger.warn(
"Failed to make_%s via %s: %s",
membership, destination, e.message
)
raise
raise RuntimeError("Failed to send to any server.")
@defer.inlineCallbacks
def send_join(self, destinations, pdu):
for destination in destinations:
if destination == self.server_name:
continue
try:
time_now = self._clock.time_msec()
_, content = yield self.transport_layer.send_join(
destination=destination,
room_id=pdu.room_id,
event_id=pdu.event_id,
content=pdu.get_pdu_json(time_now),
)
logger.debug("Got content: %s", content)
state = [
self.event_from_pdu_json(p, outlier=True)
for p in content.get("state", [])
]
auth_chain = [
self.event_from_pdu_json(p, outlier=True)
for p in content.get("auth_chain", [])
]
pdus = {
p.event_id: p
for p in itertools.chain(state, auth_chain)
}
valid_pdus = yield self._check_sigs_and_hash_and_fetch(
destination, pdus.values(),
outlier=True,
)
valid_pdus_map = {
p.event_id: p
for p in valid_pdus
}
# NB: We *need* to copy to ensure that we don't have multiple
# references being passed on, as that causes... issues.
signed_state = [
copy.copy(valid_pdus_map[p.event_id])
for p in state
if p.event_id in valid_pdus_map
]
signed_auth = [
valid_pdus_map[p.event_id]
for p in auth_chain
if p.event_id in valid_pdus_map
]
# NB: We *need* to copy to ensure that we don't have multiple
# references being passed on, as that causes... issues.
for s in signed_state:
s.internal_metadata = copy.deepcopy(s.internal_metadata)
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue({
"state": signed_state,
"auth_chain": signed_auth,
"origin": destination,
})
except CodeMessageException:
raise
except Exception as e:
logger.exception(
"Failed to send_join via %s: %s",
destination, e.message
)
raise RuntimeError("Failed to send to any server.")
@defer.inlineCallbacks
def send_invite(self, destination, room_id, event_id, pdu):
time_now = self._clock.time_msec()
code, content = yield self.transport_layer.send_invite(
destination=destination,
room_id=room_id,
event_id=event_id,
content=pdu.get_pdu_json(time_now),
)
pdu_dict = content["event"]
logger.debug("Got response to send_invite: %s", pdu_dict)
pdu = self.event_from_pdu_json(pdu_dict)
# Check signatures are correct.
pdu = yield self._check_sigs_and_hash(pdu)
# FIXME: We should handle signature failures more gracefully.
defer.returnValue(pdu)
@defer.inlineCallbacks
def send_leave(self, destinations, pdu):
for destination in destinations:
if destination == self.server_name:
continue
try:
time_now = self._clock.time_msec()
_, content = yield self.transport_layer.send_leave(
destination=destination,
room_id=pdu.room_id,
event_id=pdu.event_id,
content=pdu.get_pdu_json(time_now),
)
logger.debug("Got content: %s", content)
defer.returnValue(None)
except CodeMessageException:
raise
except Exception as e:
logger.exception(
"Failed to send_leave via %s: %s",
destination, e.message
)
raise RuntimeError("Failed to send to any server.")
@defer.inlineCallbacks
def query_auth(self, destination, room_id, event_id, local_auth):
"""
Params:
destination (str)
event_it (str)
local_auth (list)
"""
time_now = self._clock.time_msec()
send_content = {
"auth_chain": [e.get_pdu_json(time_now) for e in local_auth],
}
code, content = yield self.transport_layer.send_query_auth(
destination=destination,
room_id=room_id,
event_id=event_id,
content=send_content,
)
auth_chain = [
self.event_from_pdu_json(e)
for e in content["auth_chain"]
]
signed_auth = yield self._check_sigs_and_hash_and_fetch(
destination, auth_chain, outlier=True
)
signed_auth.sort(key=lambda e: e.depth)
ret = {
"auth_chain": signed_auth,
"rejects": content.get("rejects", []),
"missing": content.get("missing", []),
}
defer.returnValue(ret)
@defer.inlineCallbacks
def get_missing_events(self, destination, room_id, earliest_events_ids,
latest_events, limit, min_depth):
"""Tries to fetch events we are missing. This is called when we receive
an event without having received all of its ancestors.
Args:
destination (str)
room_id (str)
earliest_events_ids (list): List of event ids. Effectively the
events we expected to receive, but haven't. `get_missing_events`
should only return events that didn't happen before these.
latest_events (list): List of events we have received that we don't
have all previous events for.
limit (int): Maximum number of events to return.
min_depth (int): Minimum depth of events tor return.
"""
try:
content = yield self.transport_layer.get_missing_events(
destination=destination,
room_id=room_id,
earliest_events=earliest_events_ids,
latest_events=[e.event_id for e in latest_events],
limit=limit,
min_depth=min_depth,
)
events = [
self.event_from_pdu_json(e)
for e in content.get("events", [])
]
signed_events = yield self._check_sigs_and_hash_and_fetch(
destination, events, outlier=False
)
have_gotten_all_from_destination = True
except HttpResponseException as e:
if not e.code == 400:
raise
# We are probably hitting an old server that doesn't support
# get_missing_events
signed_events = []
have_gotten_all_from_destination = False
if len(signed_events) >= limit:
defer.returnValue(signed_events)
servers = yield self.store.get_joined_hosts_for_room(room_id)
servers = set(servers)
servers.discard(self.server_name)
failed_to_fetch = set()
while len(signed_events) < limit:
# Are we missing any?
seen_events = set(earliest_events_ids)
seen_events.update(e.event_id for e in signed_events if e)
missing_events = {}
for e in itertools.chain(latest_events, signed_events):
if e.depth > min_depth:
missing_events.update({
e_id: e.depth for e_id, _ in e.prev_events
if e_id not in seen_events
and e_id not in failed_to_fetch
})
if not missing_events:
break
have_seen = yield self.store.have_events(missing_events)
for k in have_seen:
missing_events.pop(k, None)
if not missing_events:
break
# Okay, we haven't gotten everything yet. Lets get them.
ordered_missing = sorted(missing_events.items(), key=lambda x: x[0])
if have_gotten_all_from_destination:
servers.discard(destination)
def random_server_list():
srvs = list(servers)
random.shuffle(srvs)
return srvs
deferreds = [
self.get_pdu(
destinations=random_server_list(),
event_id=e_id,
)
for e_id, depth in ordered_missing[:limit - len(signed_events)]
]
res = yield defer.DeferredList(deferreds, consumeErrors=True)
for (result, val), (e_id, _) in zip(res, ordered_missing):
if result and val:
signed_events.append(val)
else:
failed_to_fetch.add(e_id)
defer.returnValue(signed_events)
def event_from_pdu_json(self, pdu_json, outlier=False):
event = FrozenEvent(
pdu_json
)
event.internal_metadata.outlier = outlier
return event
@defer.inlineCallbacks
def forward_third_party_invite(self, destinations, room_id, event_dict):
for destination in destinations:
if destination == self.server_name:
continue
try:
yield self.transport_layer.exchange_third_party_invite(
destination=destination,
room_id=room_id,
event_dict=event_dict,
)
defer.returnValue(None)
except CodeMessageException:
raise
except Exception as e:
logger.exception(
"Failed to send_third_party_invite via %s: %s",
destination, e.message
)
raise RuntimeError("Failed to send to any server.")