diff options
Diffstat (limited to 'synapse/federation/federation_base.py')
| -rw-r--r-- | synapse/federation/federation_base.py | 182 |
1 files changed, 120 insertions, 62 deletions
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py index 2339cc9034..c11798093d 100644 --- a/synapse/federation/federation_base.py +++ b/synapse/federation/federation_base.py @@ -12,28 +12,32 @@ # 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 logging +import six from twisted.internet import defer -from synapse.events.utils import prune_event - +from synapse.api.constants import MAX_DEPTH +from synapse.api.errors import Codes, SynapseError from synapse.crypto.event_signing import check_event_content_hash - -from synapse.api.errors import SynapseError - -from synapse.util import unwrapFirstError -from synapse.util.logcontext import preserve_fn, preserve_context_over_deferred - -import logging - +from synapse.events import FrozenEvent +from synapse.events.utils import prune_event +from synapse.http.servlet import assert_params_in_dict +from synapse.util import logcontext, unwrapFirstError logger = logging.getLogger(__name__) class FederationBase(object): def __init__(self, hs): - pass + self.hs = hs + + self.server_name = hs.hostname + self.keyring = hs.get_keyring() + self.spam_checker = hs.get_spam_checker() + self.store = hs.get_datastore() + self._clock = hs.get_clock() @defer.inlineCallbacks def _check_sigs_and_hash_and_fetch(self, origin, pdus, outlier=False, @@ -57,56 +61,52 @@ class FederationBase(object): """ deferreds = self._check_sigs_and_hashes(pdus) - def callback(pdu): - return pdu + @defer.inlineCallbacks + def handle_check_result(pdu, deferred): + try: + res = yield logcontext.make_deferred_yieldable(deferred) + except SynapseError: + res = None - def errback(failure, pdu): - failure.trap(SynapseError) - return None - - def try_local_db(res, pdu): if not res: # Check local db. - return self.store.get_event( + res = yield self.store.get_event( pdu.event_id, allow_rejected=True, allow_none=True, ) - return res - def try_remote(res, pdu): if not res and pdu.origin != origin: - return self.get_pdu( - destinations=[pdu.origin], - event_id=pdu.event_id, - outlier=outlier, - timeout=10000, - ).addErrback(lambda e: None) - return res - - def warn(res, pdu): + try: + res = yield self.get_pdu( + destinations=[pdu.origin], + event_id=pdu.event_id, + outlier=outlier, + timeout=10000, + ) + except SynapseError: + pass + if not res: logger.warn( "Failed to find copy of %s with valid signature", pdu.event_id, ) - return res - for pdu, deferred in zip(pdus, deferreds): - deferred.addCallbacks( - callback, errback, errbackArgs=[pdu] - ).addCallback( - try_local_db, pdu - ).addCallback( - try_remote, pdu - ).addCallback( - warn, pdu - ) + defer.returnValue(res) + + handle = logcontext.preserve_fn(handle_check_result) + deferreds2 = [ + handle(pdu, deferred) + for pdu, deferred in zip(pdus, deferreds) + ] - valid_pdus = yield preserve_context_over_deferred(defer.gatherResults( - deferreds, - consumeErrors=True - )).addErrback(unwrapFirstError) + valid_pdus = yield logcontext.make_deferred_yieldable( + defer.gatherResults( + deferreds2, + consumeErrors=True, + ) + ).addErrback(unwrapFirstError) if include_none: defer.returnValue(valid_pdus) @@ -114,15 +114,24 @@ class FederationBase(object): defer.returnValue([p for p in valid_pdus if p]) def _check_sigs_and_hash(self, pdu): - return self._check_sigs_and_hashes([pdu])[0] + return logcontext.make_deferred_yieldable( + self._check_sigs_and_hashes([pdu])[0], + ) def _check_sigs_and_hashes(self, pdus): - """Throws a SynapseError if a PDU does not have the correct - signatures. + """Checks that each of the received events is correctly signed by the + sending server. + + Args: + pdus (list[FrozenEvent]): the events to be checked Returns: - FrozenEvent: Either the given event or it redacted if it failed the - content hash check. + list[Deferred]: for each input event, a deferred which: + * returns the original event if the checks pass + * returns a redacted version of the event (if the signature + matched but the hash did not) + * throws a SynapseError if the signature check failed. + The deferreds run their callbacks in the sentinel logcontext. """ redacted_pdus = [ @@ -130,26 +139,38 @@ class FederationBase(object): for pdu in pdus ] - deferreds = preserve_fn(self.keyring.verify_json_objects_for_server)([ + deferreds = self.keyring.verify_json_objects_for_server([ (p.origin, p.get_pdu_json()) for p in redacted_pdus ]) + ctx = logcontext.LoggingContext.current_context() + def callback(_, pdu, redacted): - if not check_event_content_hash(pdu): - logger.warn( - "Event content has been tampered, redacting %s: %s", - pdu.event_id, pdu.get_pdu_json() - ) - return redacted - return pdu + with logcontext.PreserveLoggingContext(ctx): + if not check_event_content_hash(pdu): + logger.warn( + "Event content has been tampered, redacting %s: %s", + pdu.event_id, pdu.get_pdu_json() + ) + return redacted + + if self.spam_checker.check_event_for_spam(pdu): + logger.warn( + "Event contains spam, redacting %s: %s", + pdu.event_id, pdu.get_pdu_json() + ) + return redacted + + return pdu def errback(failure, pdu): failure.trap(SynapseError) - logger.warn( - "Signature check failed for %s", - pdu.event_id, - ) + with logcontext.PreserveLoggingContext(ctx): + logger.warn( + "Signature check failed for %s", + pdu.event_id, + ) return failure for deferred, pdu, redacted in zip(deferreds, pdus, redacted_pdus): @@ -160,3 +181,40 @@ class FederationBase(object): ) return deferreds + + +def event_from_pdu_json(pdu_json, outlier=False): + """Construct a FrozenEvent from an event json received over federation + + Args: + pdu_json (object): pdu as received over federation + outlier (bool): True to mark this event as an outlier + + Returns: + FrozenEvent + + Raises: + SynapseError: if the pdu is missing required fields or is otherwise + not a valid matrix event + """ + # we could probably enforce a bunch of other fields here (room_id, sender, + # origin, etc etc) + assert_params_in_dict(pdu_json, ('event_id', 'type', 'depth')) + + depth = pdu_json['depth'] + if not isinstance(depth, six.integer_types): + raise SynapseError(400, "Depth %r not an intger" % (depth, ), + Codes.BAD_JSON) + + if depth < 0: + raise SynapseError(400, "Depth too small", Codes.BAD_JSON) + elif depth > MAX_DEPTH: + raise SynapseError(400, "Depth too large", Codes.BAD_JSON) + + event = FrozenEvent( + pdu_json + ) + + event.internal_metadata.outlier = outlier + + return event |