# -*- 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 synapse.api.errors import (
CodeMessageException, HttpResponseException, SynapseError,
)
from synapse.util import unwrapFirstError, logcontext
from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.logutils import log_function
from synapse.util.logcontext import preserve_fn, preserve_context_over_deferred
from synapse.events import FrozenEvent, builder
import synapse.metrics
from synapse.util.retryutils import 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_queries_counter = metrics.register_counter("sent_queries", labels=["type"])
PDU_RETRY_TIME_MS = 1 * 60 * 1000
class FederationClient(FederationBase):
def __init__(self, hs):
super(FederationClient, self).__init__(hs)
self.pdu_destination_tried = {}
self._clock.looping_call(
self._clear_tried_cache, 60 * 1000,
)
self.state = hs.get_state_handler()
def _clear_tried_cache(self):
"""Clear pdu_destination_tried cache"""
now = self._clock.time_msec()
old_dict = self.pdu_destination_tried
self.pdu_destination_tried = {}
for event_id, destination_dict in old_dict.items():
destination_dict = {
dest: time
for dest, time in destination_dict.items()
if time + PDU_RETRY_TIME_MS > now
}
if destination_dict:
self.pdu_destination_tried[event_id] = destination_dict
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 make_query(self, destination, query_type, args,
retry_on_dns_fail=False, ignore_backoff=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.
ignore_backoff (bool): true to ignore the historical backoff data
and try the request anyway.
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,
ignore_backoff=ignore_backoff,
)
@log_function
def query_client_keys(self, destination, content, timeout):
"""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, timeout
)
@log_function
def query_user_devices(self, destination, user_id, timeout=30000):
"""Query the device keys for a list of user ids hosted on a remote
server.
"""
sent_queries_counter.inc("user_devices")
return self.transport_layer.query_user_devices(
destination, user_id, timeout
)
@log_function
def claim_client_keys(self, destination, content, timeout):
"""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, timeout
)
@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 logcontext.make_deferred_yieldable(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
event_id (str): event to fetch
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:
ev = self._get_pdu_cache.get(event_id)
if ev:
defer.returnValue(ev)
pdu_attempts = self.pdu_destination_tried.setdefault(event_id, {})
signed_pdu = None
for destination in destinations:
now = self._clock.time_msec()
last_attempt = pdu_attempts.get(destination, 0)
if last_attempt + PDU_RETRY_TIME_MS > now:
continue
try:
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.
signed_pdu = yield self._check_sigs_and_hash(pdu)
break
pdu_attempts[destination] = now
except SynapseError as e:
logger.info(
"Failed to get PDU %s from %s because %s",
event_id, destination, e,
)
except NotRetryingDestination as e:
logger.info(e.message)
continue
except Exception as e:
pdu_attempts[destination] = now
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 signed_pdu:
self._get_pdu_cache[event_id] = signed_pdu
defer.returnValue(signed_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.
"""
try:
# First we try and ask for just the IDs, as thats far quicker if
# we have most of the state and auth_chain already.
# However, this may 404 if the other side has an old synapse.
result = yield self.transport_layer.get_room_state_ids(
destination, room_id, event_id=event_id,
)
state_event_ids = result["pdu_ids"]
auth_event_ids = result.get("auth_chain_ids", [])
fetched_events, failed_to_fetch = yield self.get_events(
[destination], room_id, set(state_event_ids + auth_event_ids)
)
if failed_to_fetch:
logger.warn("Failed to get %r", failed_to_fetch)
event_map = {
ev.event_id: ev for ev in fetched_events
}
pdus = [event_map[e_id] for e_id in state_event_ids if e_id in event_map]
auth_chain = [
event_map[e_id] for e_id in auth_event_ids if e_id in event_map
]
auth_chain.sort(key=lambda e: e.depth)
defer.returnValue((pdus, auth_chain))
except HttpResponseException as e:
if e.code == 400 or e.code == 404:
logger.info("Failed to use get_room_state_ids API, falling back")
else:
raise e
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", [])
]
seen_events = yield self.store.get_events([
ev.event_id for ev in itertools.chain(pdus, auth_chain)
])
signed_pdus = yield self._check_sigs_and_hash_and_fetch(
destination,
[p for p in pdus if p.event_id not in seen_events],
outlier=True
)
signed_pdus.extend(
seen_events[p.event_id] for p in pdus if p.event_id in seen_events
)
signed_auth = yield self._check_sigs_and_hash_and_fetch(
destination,
[p for p in auth_chain if p.event_id not in seen_events],
outlier=True
)
signed_auth.extend(
seen_events[p.event_id] for p in auth_chain if p.event_id in seen_events
)
signed_auth.sort(key=lambda e: e.depth)
defer.returnValue((signed_pdus, signed_auth))
@defer.inlineCallbacks
def get_events(self, destinations, room_id, event_ids, return_local=True):
"""Fetch events from some remote destinations, checking if we already
have them.
Args:
destinations (list)
room_id (str)
event_ids (list)
return_local (bool): Whether to include events we already have in
the DB in the returned list of events
Returns:
Deferred: A deferred resolving to a 2-tuple where the first is a list of
events and the second is a list of event ids that we failed to fetch.
"""
if return_local:
seen_events = yield self.store.get_events(event_ids, allow_rejected=True)
signed_events = seen_events.values()
else:
seen_events = yield self.store.have_events(event_ids)
signed_events = []
failed_to_fetch = set()
missing_events = set(event_ids)
for k in seen_events:
missing_events.discard(k)
if not missing_events:
defer.returnValue((signed_events, failed_to_fetch))
def random_server_list():
srvs = list(destinations)
random.shuffle(srvs)
return srvs
batch_size = 20
missing_events = list(missing_events)
for i in xrange(0, len(missing_events), batch_size):
batch = set(missing_events[i:i + batch_size])
deferreds = [
preserve_fn(self.get_pdu)(
destinations=random_server_list(),
event_id=e_id,
)
for e_id in batch
]
res = yield preserve_context_over_deferred(
defer.DeferredList(deferreds, consumeErrors=True)
)
for success, result in res:
if success and result:
signed_events.append(result)
batch.discard(result.event_id)
# We removed all events we successfully fetched from `batch`
failed_to_fetch.update(batch)
defer.returnValue((signed_events, failed_to_fetch))
@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:
Deferred: resolves to a tuple of (origin (str), event (object))
where origin is the remote homeserver which generated the event.
Fails with a ``CodeMessageException`` if the chosen remote server
returns a 300/400 code.
Fails with a ``RuntimeError`` if no servers were reachable.
"""
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"] = []
ev = builder.EventBuilder(pdu_dict)
defer.returnValue(
(destination, ev)
)
break
except CodeMessageException as e:
if not 500 <= e.code < 600:
raise
else:
logger.warn(
"Failed to make_%s via %s: %s",
membership, destination, e.message
)
except Exception as e:
logger.warn(
"Failed to make_%s via %s: %s",
membership, destination, e.message
)
raise RuntimeError("Failed to send to any server.")
@defer.inlineCallbacks
def send_join(self, destinations, pdu):
"""Sends a join event to one of a list of homeservers.
Doing so will cause the remote server to add the event to the graph,
and send the event out to the rest of the federation.
Args:
destinations (str): Candidate homeservers which are probably
participating in the room.
pdu (BaseEvent): event to be sent
Return:
Deferred: resolves to a dict with members ``origin`` (a string
giving the serer the event was sent to, ``state`` (?) and
``auth_chain``.
Fails with a ``CodeMessageException`` if the chosen remote server
returns a 300/400 code.
Fails with a ``RuntimeError`` if no servers were reachable.
"""
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 as e:
if not 500 <= e.code < 600:
raise
else:
logger.exception(
"Failed to send_join via %s: %s",
destination, e.message
)
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):
"""Sends a leave event to one of a list of homeservers.
Doing so will cause the remote server to add the event to the graph,
and send the event out to the rest of the federation.
This is mostly useful to reject received invites.
Args:
destinations (str): Candidate homeservers which are probably
participating in the room.
pdu (BaseEvent): event to be sent
Return:
Deferred: resolves to None.
Fails with a ``CodeMessageException`` if the chosen remote server
returns a non-200 code.
Fails with a ``RuntimeError`` if no servers were reachable.
"""
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.")
def get_public_rooms(self, destination, limit=None, since_token=None,
search_filter=None, include_all_networks=False,
third_party_instance_id=None):
if destination == self.server_name:
return
return self.transport_layer.get_public_rooms(
destination, limit, since_token, search_filter,
include_all_networks=include_all_networks,
third_party_instance_id=third_party_instance_id,
)
@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, timeout):
"""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.
timeout (int): Max time to wait in ms
"""
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,
timeout=timeout,
)
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
)
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 = []
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.")