Merge branch 'develop' of github.com:matrix-org/synapse into erikj/fix_get_missing_events_error

1 files changed, 289 insertions, 132 deletions

diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 07a5dc182d..cc08e3e027 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014-2016 OpenMarket Ltd
-# Copyright 2018 New Vector Ltd
+# Copyright 2017-2018 New Vector Ltd
+# Copyright 2019 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -33,6 +34,7 @@ from synapse.api.constants import EventTypes, Membership, RejectedReason
 from synapse.api.errors import (
     AuthError,
     CodeMessageException,
+    Codes,
     FederationDeniedError,
     FederationError,
     RequestSendFailed,
@@ -127,6 +129,8 @@ class FederationHandler(BaseHandler):
         self.room_queues = {}
         self._room_pdu_linearizer = Linearizer("fed_room_pdu")
 
+        self.third_party_event_rules = hs.get_third_party_event_rules()
+
     @defer.inlineCallbacks
     def on_receive_pdu(
             self, origin, pdu, sent_to_us_directly=False,
@@ -1268,6 +1272,15 @@ class FederationHandler(BaseHandler):
             logger.warn("Failed to create join %r because %s", event, e)
             raise e
 
+        event_allowed = yield self.third_party_event_rules.check_event_allowed(
+            event, context,
+        )
+        if not event_allowed:
+            logger.info("Creation of join %s forbidden by third-party rules", event)
+            raise SynapseError(
+                403, "This event is not allowed in this context", Codes.FORBIDDEN,
+            )
+
         # The remote hasn't signed it yet, obviously. We'll do the full checks
         # when we get the event back in `on_send_join_request`
         yield self.auth.check_from_context(
@@ -1310,6 +1323,15 @@ class FederationHandler(BaseHandler):
             origin, event
         )
 
+        event_allowed = yield self.third_party_event_rules.check_event_allowed(
+            event, context,
+        )
+        if not event_allowed:
+            logger.info("Sending of join %s forbidden by third-party rules", event)
+            raise SynapseError(
+                403, "This event is not allowed in this context", Codes.FORBIDDEN,
+            )
+
         logger.debug(
             "on_send_join_request: After _handle_new_event: %s, sigs: %s",
             event.event_id,
@@ -1468,6 +1490,15 @@ class FederationHandler(BaseHandler):
             builder=builder,
         )
 
+        event_allowed = yield self.third_party_event_rules.check_event_allowed(
+            event, context,
+        )
+        if not event_allowed:
+            logger.warning("Creation of leave %s forbidden by third-party rules", event)
+            raise SynapseError(
+                403, "This event is not allowed in this context", Codes.FORBIDDEN,
+            )
+
         try:
             # The remote hasn't signed it yet, obviously. We'll do the full checks
             # when we get the event back in `on_send_leave_request`
@@ -1494,10 +1525,19 @@ class FederationHandler(BaseHandler):
 
         event.internal_metadata.outlier = False
 
-        yield self._handle_new_event(
+        context = yield self._handle_new_event(
             origin, event
         )
 
+        event_allowed = yield self.third_party_event_rules.check_event_allowed(
+            event, context,
+        )
+        if not event_allowed:
+            logger.info("Sending of leave %s forbidden by third-party rules", event)
+            raise SynapseError(
+                403, "This event is not allowed in this context", Codes.FORBIDDEN,
+            )
+
         logger.debug(
             "on_send_leave_request: After _handle_new_event: %s, sigs: %s",
             event.event_id,
@@ -1927,6 +1967,11 @@ class FederationHandler(BaseHandler):
                     event.room_id, latest_event_ids=extrem_ids,
                 )
 
+            logger.debug(
+                "Doing soft-fail check for %s: state %s",
+                event.event_id, current_state_ids,
+            )
+
             # Now check if event pass auth against said current state
             auth_types = auth_types_for_event(event)
             current_state_ids = [
@@ -1943,7 +1988,7 @@ class FederationHandler(BaseHandler):
                 self.auth.check(room_version, event, auth_events=current_auth_events)
             except AuthError as e:
                 logger.warn(
-                    "Failed current state auth resolution for %r because %s",
+                    "Soft-failing %r because %s",
                     event, e,
                 )
                 event.internal_metadata.soft_failed = True
@@ -2019,15 +2064,65 @@ class FederationHandler(BaseHandler):
 
         Args:
             origin (str):
-            event (synapse.events.FrozenEvent):
+            event (synapse.events.EventBase):
             context (synapse.events.snapshot.EventContext):
-            auth_events (dict[(str, str)->str]):
+            auth_events (dict[(str, str)->synapse.events.EventBase]):
+                Map from (event_type, state_key) to event
+
+                What we expect the event's auth_events to be, based on the event's
+                position in the dag. I think? maybe??
+
+                Also NB that this function adds entries to it.
+        Returns:
+            defer.Deferred[None]
+        """
+        room_version = yield self.store.get_room_version(event.room_id)
+
+        try:
+            yield self._update_auth_events_and_context_for_auth(
+                origin, event, context, auth_events
+            )
+        except Exception:
+            # We don't really mind if the above fails, so lets not fail
+            # processing if it does. However, it really shouldn't fail so
+            # let's still log as an exception since we'll still want to fix
+            # any bugs.
+            logger.exception(
+                "Failed to double check auth events for %s with remote. "
+                "Ignoring failure and continuing processing of event.",
+                event.event_id,
+            )
+
+        try:
+            self.auth.check(room_version, event, auth_events=auth_events)
+        except AuthError as e:
+            logger.warn("Failed auth resolution for %r because %s", event, e)
+            raise e
+
+    @defer.inlineCallbacks
+    def _update_auth_events_and_context_for_auth(
+        self, origin, event, context, auth_events
+    ):
+        """Helper for do_auth. See there for docs.
+
+        Checks whether a given event has the expected auth events. If it
+        doesn't then we talk to the remote server to compare state to see if
+        we can come to a consensus (e.g. if one server missed some valid
+        state).
+
+        This attempts to resovle any potential divergence of state between
+        servers, but is not essential and so failures should not block further
+        processing of the event.
+
+        Args:
+            origin (str):
+            event (synapse.events.EventBase):
+            context (synapse.events.snapshot.EventContext):
+            auth_events (dict[(str, str)->synapse.events.EventBase]):
 
         Returns:
             defer.Deferred[None]
         """
-        # Check if we have all the auth events.
-        current_state = set(e.event_id for e in auth_events.values())
         event_auth_events = set(event.auth_event_ids())
 
         if event.is_state():
@@ -2035,11 +2130,21 @@ class FederationHandler(BaseHandler):
         else:
             event_key = None
 
-        if event_auth_events - current_state:
+        # if the event's auth_events refers to events which are not in our
+        # calculated auth_events, we need to fetch those events from somewhere.
+        #
+        # we start by fetching them from the store, and then try calling /event_auth/.
+        missing_auth = event_auth_events.difference(
+            e.event_id for e in auth_events.values()
+        )
+
+        if missing_auth:
             # TODO: can we use store.have_seen_events here instead?
             have_events = yield self.store.get_seen_events_with_rejections(
-                event_auth_events - current_state
+                missing_auth
             )
+            logger.debug("Got events %s from store", have_events)
+            missing_auth.difference_update(have_events.keys())
         else:
             have_events = {}
 
@@ -2048,17 +2153,22 @@ class FederationHandler(BaseHandler):
             for e in auth_events.values()
         })
 
-        seen_events = set(have_events.keys())
-
-        missing_auth = event_auth_events - seen_events - current_state
-
         if missing_auth:
-            logger.info("Missing auth: %s", missing_auth)
             # If we don't have all the auth events, we need to get them.
+            logger.info(
+                "auth_events contains unknown events: %s",
+                missing_auth,
+            )
             try:
-                remote_auth_chain = yield self.federation_client.get_event_auth(
-                    origin, event.room_id, event.event_id
-                )
+                try:
+                    remote_auth_chain = yield self.federation_client.get_event_auth(
+                        origin, event.room_id, event.event_id
+                    )
+                except RequestSendFailed as e:
+                    # The other side isn't around or doesn't implement the
+                    # endpoint, so lets just bail out.
+                    logger.info("Failed to get event auth from remote: %s", e)
+                    return
 
                 seen_remotes = yield self.store.have_seen_events(
                     [e.event_id for e in remote_auth_chain]
@@ -2095,145 +2205,174 @@ class FederationHandler(BaseHandler):
                 have_events = yield self.store.get_seen_events_with_rejections(
                     event.auth_event_ids()
                 )
-                seen_events = set(have_events.keys())
             except Exception:
                 # FIXME:
                 logger.exception("Failed to get auth chain")
 
+        if event.internal_metadata.is_outlier():
+            logger.info("Skipping auth_event fetch for outlier")
+            return
+
         # FIXME: Assumes we have and stored all the state for all the
         # prev_events
-        current_state = set(e.event_id for e in auth_events.values())
-        different_auth = event_auth_events - current_state
+        different_auth = event_auth_events.difference(
+            e.event_id for e in auth_events.values()
+        )
 
-        room_version = yield self.store.get_room_version(event.room_id)
+        if not different_auth:
+            return
 
-        if different_auth and not event.internal_metadata.is_outlier():
-            # Do auth conflict res.
-            logger.info("Different auth: %s", different_auth)
-
-            different_events = yield logcontext.make_deferred_yieldable(
-                defer.gatherResults([
-                    logcontext.run_in_background(
-                        self.store.get_event,
-                        d,
-                        allow_none=True,
-                        allow_rejected=False,
-                    )
-                    for d in different_auth
-                    if d in have_events and not have_events[d]
-                ], consumeErrors=True)
-            ).addErrback(unwrapFirstError)
-
-            if different_events:
-                local_view = dict(auth_events)
-                remote_view = dict(auth_events)
-                remote_view.update({
-                    (d.type, d.state_key): d for d in different_events if d
-                })
+        logger.info(
+            "auth_events refers to events which are not in our calculated auth "
+            "chain: %s",
+            different_auth,
+        )
+
+        room_version = yield self.store.get_room_version(event.room_id)
 
-                new_state = yield self.state_handler.resolve_events(
-                    room_version,
-                    [list(local_view.values()), list(remote_view.values())],
-                    event
+        different_events = yield logcontext.make_deferred_yieldable(
+            defer.gatherResults([
+                logcontext.run_in_background(
+                    self.store.get_event,
+                    d,
+                    allow_none=True,
+                    allow_rejected=False,
                 )
+                for d in different_auth
+                if d in have_events and not have_events[d]
+            ], consumeErrors=True)
+        ).addErrback(unwrapFirstError)
+
+        if different_events:
+            local_view = dict(auth_events)
+            remote_view = dict(auth_events)
+            remote_view.update({
+                (d.type, d.state_key): d for d in different_events if d
+            })
 
-                auth_events.update(new_state)
+            new_state = yield self.state_handler.resolve_events(
+                room_version,
+                [list(local_view.values()), list(remote_view.values())],
+                event
+            )
 
-                current_state = set(e.event_id for e in auth_events.values())
-                different_auth = event_auth_events - current_state
+            logger.info(
+                "After state res: updating auth_events with new state %s",
+                {
+                    (d.type, d.state_key): d.event_id for d in new_state.values()
+                    if auth_events.get((d.type, d.state_key)) != d
+                },
+            )
 
-                yield self._update_context_for_auth_events(
-                    event, context, auth_events, event_key,
-                )
+            auth_events.update(new_state)
 
-        if different_auth and not event.internal_metadata.is_outlier():
-            logger.info("Different auth after resolution: %s", different_auth)
+            different_auth = event_auth_events.difference(
+                e.event_id for e in auth_events.values()
+            )
 
-            # Only do auth resolution if we have something new to say.
-            # We can't rove an auth failure.
-            do_resolution = False
+            yield self._update_context_for_auth_events(
+                event, context, auth_events, event_key,
+            )
 
-            provable = [
-                RejectedReason.NOT_ANCESTOR, RejectedReason.NOT_ANCESTOR,
-            ]
+        if not different_auth:
+            # we're done
+            return
 
-            for e_id in different_auth:
-                if e_id in have_events:
-                    if have_events[e_id] in provable:
-                        do_resolution = True
-                        break
+        logger.info(
+            "auth_events still refers to events which are not in the calculated auth "
+            "chain after state resolution: %s",
+            different_auth,
+        )
 
-            if do_resolution:
-                prev_state_ids = yield context.get_prev_state_ids(self.store)
-                # 1. Get what we think is the auth chain.
-                auth_ids = yield self.auth.compute_auth_events(
-                    event, prev_state_ids
-                )
-                local_auth_chain = yield self.store.get_auth_chain(
-                    auth_ids, include_given=True
-                )
+        # Only do auth resolution if we have something new to say.
+        # We can't prove an auth failure.
+        do_resolution = False
 
-                try:
-                    # 2. Get remote difference.
-                    result = yield self.federation_client.query_auth(
-                        origin,
-                        event.room_id,
-                        event.event_id,
-                        local_auth_chain,
-                    )
+        for e_id in different_auth:
+            if e_id in have_events:
+                if have_events[e_id] == RejectedReason.NOT_ANCESTOR:
+                    do_resolution = True
+                    break
 
-                    seen_remotes = yield self.store.have_seen_events(
-                        [e.event_id for e in result["auth_chain"]]
-                    )
+        if not do_resolution:
+            logger.info(
+                "Skipping auth resolution due to lack of provable rejection reasons"
+            )
+            return
 
-                    # 3. Process any remote auth chain events we haven't seen.
-                    for ev in result["auth_chain"]:
-                        if ev.event_id in seen_remotes:
-                            continue
+        logger.info("Doing auth resolution")
 
-                        if ev.event_id == event.event_id:
-                            continue
+        prev_state_ids = yield context.get_prev_state_ids(self.store)
 
-                        try:
-                            auth_ids = ev.auth_event_ids()
-                            auth = {
-                                (e.type, e.state_key): e
-                                for e in result["auth_chain"]
-                                if e.event_id in auth_ids
-                                or event.type == EventTypes.Create
-                            }
-                            ev.internal_metadata.outlier = True
+        # 1. Get what we think is the auth chain.
+        auth_ids = yield self.auth.compute_auth_events(
+            event, prev_state_ids
+        )
+        local_auth_chain = yield self.store.get_auth_chain(
+            auth_ids, include_given=True
+        )
 
-                            logger.debug(
-                                "do_auth %s different_auth: %s",
-                                event.event_id, e.event_id
-                            )
+        try:
+            # 2. Get remote difference.
+            try:
+                result = yield self.federation_client.query_auth(
+                    origin,
+                    event.room_id,
+                    event.event_id,
+                    local_auth_chain,
+                )
+            except RequestSendFailed as e:
+                # The other side isn't around or doesn't implement the
+                # endpoint, so lets just bail out.
+                logger.info("Failed to query auth from remote: %s", e)
+                return
+
+            seen_remotes = yield self.store.have_seen_events(
+                [e.event_id for e in result["auth_chain"]]
+            )
 
-                            yield self._handle_new_event(
-                                origin, ev, auth_events=auth
-                            )
+            # 3. Process any remote auth chain events we haven't seen.
+            for ev in result["auth_chain"]:
+                if ev.event_id in seen_remotes:
+                    continue
 
-                            if ev.event_id in event_auth_events:
-                                auth_events[(ev.type, ev.state_key)] = ev
-                        except AuthError:
-                            pass
+                if ev.event_id == event.event_id:
+                    continue
 
-                except Exception:
-                    # FIXME:
-                    logger.exception("Failed to query auth chain")
+                try:
+                    auth_ids = ev.auth_event_ids()
+                    auth = {
+                        (e.type, e.state_key): e
+                        for e in result["auth_chain"]
+                        if e.event_id in auth_ids
+                        or event.type == EventTypes.Create
+                    }
+                    ev.internal_metadata.outlier = True
+
+                    logger.debug(
+                        "do_auth %s different_auth: %s",
+                        event.event_id, e.event_id
+                    )
 
-                # 4. Look at rejects and their proofs.
-                # TODO.
+                    yield self._handle_new_event(
+                        origin, ev, auth_events=auth
+                    )
 
-                yield self._update_context_for_auth_events(
-                    event, context, auth_events, event_key,
-                )
+                    if ev.event_id in event_auth_events:
+                        auth_events[(ev.type, ev.state_key)] = ev
+                except AuthError:
+                    pass
 
-        try:
-            self.auth.check(room_version, event, auth_events=auth_events)
-        except AuthError as e:
-            logger.warn("Failed auth resolution for %r because %s", event, e)
-            raise e
+        except Exception:
+            # FIXME:
+            logger.exception("Failed to query auth chain")
+
+        # 4. Look at rejects and their proofs.
+        # TODO.
+
+        yield self._update_context_for_auth_events(
+            event, context, auth_events, event_key,
+        )
 
     @defer.inlineCallbacks
     def _update_context_for_auth_events(self, event, context, auth_events,
@@ -2461,6 +2600,18 @@ class FederationHandler(BaseHandler):
                 builder=builder
             )
 
+            event_allowed = yield self.third_party_event_rules.check_event_allowed(
+                event, context,
+            )
+            if not event_allowed:
+                logger.info(
+                    "Creation of threepid invite %s forbidden by third-party rules",
+                    event,
+                )
+                raise SynapseError(
+                    403, "This event is not allowed in this context", Codes.FORBIDDEN,
+                )
+
             event, context = yield self.add_display_name_to_third_party_invite(
                 room_version, event_dict, event, context
             )
@@ -2509,6 +2660,18 @@ class FederationHandler(BaseHandler):
             builder=builder,
         )
 
+        event_allowed = yield self.third_party_event_rules.check_event_allowed(
+            event, context,
+        )
+        if not event_allowed:
+            logger.warning(
+                "Exchange of threepid invite %s forbidden by third-party rules",
+                event,
+            )
+            raise SynapseError(
+                403, "This event is not allowed in this context", Codes.FORBIDDEN,
+            )
+
         event, context = yield self.add_display_name_to_third_party_invite(
             room_version, event_dict, event, context
         )
@@ -2524,12 +2687,6 @@ class FederationHandler(BaseHandler):
         # though the sender isn't a local user.
         event.internal_metadata.send_on_behalf_of = get_domain_from_id(event.sender)
 
-        # XXX we send the invite here, but send_membership_event also sends it,
-        # so we end up making two requests. I think this is redundant.
-        returned_invite = yield self.send_invite(origin, event)
-        # TODO: Make sure the signatures actually are correct.
-        event.signatures.update(returned_invite.signatures)
-
         member_handler = self.hs.get_room_member_handler()
         yield member_handler.send_membership_event(None, event, context)