anonymousland-synapse/synapse/federation/federation_server.py

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# -*- coding: utf-8 -*-
# Copyright 2015 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 .units import Transaction, Edu
from synapse.util.logutils import log_function
from synapse.util.logcontext import PreserveLoggingContext
from synapse.events import FrozenEvent
from synapse.api.errors import FederationError, SynapseError
from synapse.crypto.event_signing import compute_event_signature
import logging
logger = logging.getLogger(__name__)
class FederationServer(FederationBase):
def set_handler(self, handler):
"""Sets the handler that the replication layer will use to communicate
receipt of new PDUs from other home servers. The required methods are
documented on :py:class:`.ReplicationHandler`.
"""
self.handler = handler
def register_edu_handler(self, edu_type, handler):
if edu_type in self.edu_handlers:
raise KeyError("Already have an EDU handler for %s" % (edu_type,))
self.edu_handlers[edu_type] = handler
def register_query_handler(self, query_type, handler):
"""Sets the handler callable that will be used to handle an incoming
federation Query of the given type.
Args:
query_type (str): Category name of the query, which should match
the string used by make_query.
handler (callable): Invoked to handle incoming queries of this type
handler is invoked as:
result = handler(args)
where 'args' is a dict mapping strings to strings of the query
arguments. It should return a Deferred that will eventually yield an
object to encode as JSON.
"""
if query_type in self.query_handlers:
raise KeyError(
"Already have a Query handler for %s" % (query_type,)
)
self.query_handlers[query_type] = handler
@defer.inlineCallbacks
@log_function
def on_backfill_request(self, origin, room_id, versions, limit):
pdus = yield self.handler.on_backfill_request(
origin, room_id, versions, limit
)
defer.returnValue((200, self._transaction_from_pdus(pdus).get_dict()))
@defer.inlineCallbacks
@log_function
def on_incoming_transaction(self, transaction_data):
transaction = Transaction(**transaction_data)
for p in transaction.pdus:
if "unsigned" in p:
unsigned = p["unsigned"]
if "age" in unsigned:
p["age"] = unsigned["age"]
if "age" in p:
p["age_ts"] = int(self._clock.time_msec()) - int(p["age"])
del p["age"]
pdu_list = [
self.event_from_pdu_json(p) for p in transaction.pdus
]
logger.debug("[%s] Got transaction", transaction.transaction_id)
response = yield self.transaction_actions.have_responded(transaction)
if response:
logger.debug(
"[%s] We've already responed to this request",
transaction.transaction_id
)
defer.returnValue(response)
return
logger.debug("[%s] Transaction is new", transaction.transaction_id)
with PreserveLoggingContext():
dl = []
for pdu in pdu_list:
dl.append(self._handle_new_pdu(transaction.origin, pdu))
if hasattr(transaction, "edus"):
for edu in [Edu(**x) for x in transaction.edus]:
self.received_edu(
transaction.origin,
edu.edu_type,
edu.content
)
results = yield defer.DeferredList(dl, consumeErrors=True)
ret = []
for r in results:
if r[0]:
ret.append({})
else:
logger.exception(r[1])
ret.append({"error": str(r[1])})
logger.debug("Returning: %s", str(ret))
yield self.transaction_actions.set_response(
transaction,
200, response
)
defer.returnValue((200, response))
def received_edu(self, origin, edu_type, content):
if edu_type in self.edu_handlers:
self.edu_handlers[edu_type](origin, content)
else:
logger.warn("Received EDU of type %s with no handler", edu_type)
@defer.inlineCallbacks
@log_function
def on_context_state_request(self, origin, room_id, event_id):
if event_id:
pdus = yield self.handler.get_state_for_pdu(
origin, room_id, event_id,
)
auth_chain = yield self.store.get_auth_chain(
[pdu.event_id for pdu in pdus]
)
for event in auth_chain:
event.signatures.update(
compute_event_signature(
event,
self.hs.hostname,
self.hs.config.signing_key[0]
)
)
else:
raise NotImplementedError("Specify an event")
defer.returnValue((200, {
"pdus": [pdu.get_pdu_json() for pdu in pdus],
"auth_chain": [pdu.get_pdu_json() for pdu in auth_chain],
}))
@defer.inlineCallbacks
@log_function
def on_pdu_request(self, origin, event_id):
pdu = yield self._get_persisted_pdu(origin, event_id)
if pdu:
defer.returnValue(
(200, self._transaction_from_pdus([pdu]).get_dict())
)
else:
defer.returnValue((404, ""))
@defer.inlineCallbacks
@log_function
def on_pull_request(self, origin, versions):
raise NotImplementedError("Pull transactions not implemented")
@defer.inlineCallbacks
def on_query_request(self, query_type, args):
if query_type in self.query_handlers:
response = yield self.query_handlers[query_type](args)
defer.returnValue((200, response))
else:
defer.returnValue(
(404, "No handler for Query type '%s'" % (query_type,))
)
@defer.inlineCallbacks
def on_make_join_request(self, room_id, user_id):
pdu = yield self.handler.on_make_join_request(room_id, user_id)
time_now = self._clock.time_msec()
defer.returnValue({"event": pdu.get_pdu_json(time_now)})
@defer.inlineCallbacks
def on_invite_request(self, origin, content):
pdu = self.event_from_pdu_json(content)
ret_pdu = yield self.handler.on_invite_request(origin, pdu)
time_now = self._clock.time_msec()
defer.returnValue((200, {"event": ret_pdu.get_pdu_json(time_now)}))
@defer.inlineCallbacks
def on_send_join_request(self, origin, content):
logger.debug("on_send_join_request: content: %s", content)
pdu = self.event_from_pdu_json(content)
logger.debug("on_send_join_request: pdu sigs: %s", pdu.signatures)
res_pdus = yield self.handler.on_send_join_request(origin, pdu)
time_now = self._clock.time_msec()
defer.returnValue((200, {
"state": [p.get_pdu_json(time_now) for p in res_pdus["state"]],
"auth_chain": [
p.get_pdu_json(time_now) for p in res_pdus["auth_chain"]
],
}))
@defer.inlineCallbacks
def on_event_auth(self, origin, room_id, event_id):
time_now = self._clock.time_msec()
auth_pdus = yield self.handler.on_event_auth(event_id)
defer.returnValue((200, {
"auth_chain": [a.get_pdu_json(time_now) for a in auth_pdus],
}))
@defer.inlineCallbacks
def on_query_auth_request(self, origin, content, event_id):
"""
Content is a dict with keys::
auth_chain (list): A list of events that give the auth chain.
missing (list): A list of event_ids indicating what the other
side (`origin`) think we're missing.
rejects (dict): A mapping from event_id to a 2-tuple of reason
string and a proof (or None) of why the event was rejected.
The keys of this dict give the list of events the `origin` has
rejected.
Args:
origin (str)
content (dict)
event_id (str)
Returns:
Deferred: Results in `dict` with the same format as `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(
origin, auth_chain, outlier=True
)
ret = yield self.handler.on_query_auth(
origin,
event_id,
signed_auth,
content.get("rejects", []),
content.get("missing", []),
)
time_now = self._clock.time_msec()
send_content = {
"auth_chain": [
e.get_pdu_json(time_now)
for e in ret["auth_chain"]
],
"rejects": ret.get("rejects", []),
"missing": ret.get("missing", []),
}
defer.returnValue(
(200, send_content)
)
@log_function
def _get_persisted_pdu(self, origin, event_id, do_auth=True):
""" Get a PDU from the database with given origin and id.
Returns:
Deferred: Results in a `Pdu`.
"""
return self.handler.get_persisted_pdu(
origin, event_id, do_auth=do_auth
)
def _transaction_from_pdus(self, pdu_list):
"""Returns a new Transaction containing the given PDUs suitable for
transmission.
"""
time_now = self._clock.time_msec()
pdus = [p.get_pdu_json(time_now) for p in pdu_list]
return Transaction(
origin=self.server_name,
pdus=pdus,
origin_server_ts=int(time_now),
destination=None,
)
@defer.inlineCallbacks
@log_function
def _handle_new_pdu(self, origin, pdu, max_recursion=10):
# We reprocess pdus when we have seen them only as outliers
existing = yield self._get_persisted_pdu(
origin, pdu.event_id, do_auth=False
)
# FIXME: Currently we fetch an event again when we already have it
# if it has been marked as an outlier.
already_seen = (
existing and (
not existing.internal_metadata.is_outlier()
or pdu.internal_metadata.is_outlier()
)
)
if already_seen:
logger.debug("Already seen pdu %s", pdu.event_id)
defer.returnValue({})
return
# Check signature.
try:
pdu = yield self._check_sigs_and_hash(pdu)
except SynapseError as e:
raise FederationError(
"ERROR",
e.code,
e.msg,
affected=pdu.event_id,
)
state = None
auth_chain = []
have_seen = yield self.store.have_events(
[ev for ev, _ in pdu.prev_events]
)
fetch_state = False
# Get missing pdus if necessary.
if not pdu.internal_metadata.is_outlier():
# We only backfill backwards to the min depth.
min_depth = yield self.handler.get_min_depth_for_context(
pdu.room_id
)
logger.debug(
"_handle_new_pdu min_depth for %s: %d",
pdu.room_id, min_depth
)
if min_depth and pdu.depth > min_depth and max_recursion > 0:
for event_id, hashes in pdu.prev_events:
if event_id not in have_seen:
logger.debug(
"_handle_new_pdu requesting pdu %s",
event_id
)
try:
new_pdu = yield self.federation_client.get_pdu(
[origin, pdu.origin],
event_id=event_id,
)
if new_pdu:
yield self._handle_new_pdu(
origin,
new_pdu,
max_recursion=max_recursion-1
)
logger.debug("Processed pdu %s", event_id)
else:
logger.warn("Failed to get PDU %s", event_id)
fetch_state = True
except:
# TODO(erikj): Do some more intelligent retries.
logger.exception("Failed to get PDU")
fetch_state = True
else:
prevs = {e_id for e_id, _ in pdu.prev_events}
seen = set(have_seen.keys())
if prevs - seen:
fetch_state = True
else:
fetch_state = True
if fetch_state:
# We need to get the state at this event, since we haven't
# processed all the prev events.
logger.debug(
"_handle_new_pdu getting state for %s",
pdu.room_id
)
try:
state, auth_chain = yield self.get_state_for_room(
origin, pdu.room_id, pdu.event_id,
)
except:
logger.warn("Failed to get state for event: %s", pdu.event_id)
ret = yield self.handler.on_receive_pdu(
origin,
pdu,
backfilled=False,
state=state,
auth_chain=auth_chain,
)
defer.returnValue(ret)
def __str__(self):
return "<ReplicationLayer(%s)>" % self.server_name
def event_from_pdu_json(self, pdu_json, outlier=False):
event = FrozenEvent(
pdu_json
)
event.internal_metadata.outlier = outlier
return event