From 244484bf3c1a8c75186ad58296d6554f18bd400b Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 25 Jun 2018 13:42:55 +0100 Subject: Revert "Revert "Merge pull request #3431 from matrix-org/rav/erasure_visibility"" This reverts commit 1d009013b3c3e814177afc59f066e02a202b21cd. --- synapse/handlers/federation.py | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 2571758284..1ca56c2c97 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -495,7 +495,20 @@ class FederationHandler(BaseHandler): for e_id, key_to_eid in event_to_state_ids.iteritems() } + erased_senders = yield self.store.are_users_erased( + e.sender for e in events, + ) + def redact_disallowed(event, state): + # if the sender has been gdpr17ed, always return a redacted + # copy of the event. + if erased_senders[event.sender]: + logger.info( + "Sender of %s has been erased, redacting", + event.event_id, + ) + return prune_event(event) + if not state: return event -- cgit 1.4.1 From ea7a9c0483d547014404d3266446bb1b26c1076a Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 25 Jun 2018 19:49:13 +0100 Subject: Add fast path to _filter_events_for_server Most rooms have a trivial history visibility like "shared" or "world_readable", especially large rooms, so lets not bother getting the full membership of those rooms in that case. --- synapse/handlers/federation.py | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 1ca56c2c97..123cdb5fab 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -460,11 +460,44 @@ class FederationHandler(BaseHandler): @measure_func("_filter_events_for_server") @defer.inlineCallbacks def _filter_events_for_server(self, server_name, room_id, events): + # First lets check to see if all the events have a history visibility + # of "shared" or "world_readable". If thats the case then we don't + # need to check membership (as we know the server is in the room). event_to_state_ids = yield self.store.get_state_ids_for_events( frozenset(e.event_id for e in events), types=( (EventTypes.RoomHistoryVisibility, ""), - (EventTypes.Member, None), + ) + ) + + visibility_ids = set() + for sids in event_to_state_ids.itervalues(): + hist = event_to_state_ids.get((EventTypes.RoomHistoryVisibility, "")) + if hist: + visibility_ids.add(hist) + + # If we failed to find any history visibility events then the default + # is "shared" visiblity. + if not visibility_ids: + defer.returnValue(events) + + events = yield self.store.get_events(visibility_ids) + all_open = all( + e.content.get("history_visibility") in (None, "shared", "world_readable") + for e in events + ) + + if all_open: + defer.returnValue(events) + + # Ok, so we're dealing with events that have non-trivial visibility + # rules, so we need to also get the memberships of the room. + + event_to_state_ids = yield self.store.get_state_ids_for_events( + frozenset(e.event_id for e in events), + types=( + (EventTypes.RoomHistoryVisibility, ""), + (EventTypes.Member, None) ) ) -- cgit 1.4.1 From 7bdc5c8fa37de6256ec2f41a5c683c75ac52f9ff Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 25 Jun 2018 19:56:02 +0100 Subject: Fix bug with assuming wrong type --- synapse/handlers/federation.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 123cdb5fab..aab69550a0 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -481,10 +481,10 @@ class FederationHandler(BaseHandler): if not visibility_ids: defer.returnValue(events) - events = yield self.store.get_events(visibility_ids) + event_map = yield self.store.get_events(visibility_ids) all_open = all( e.content.get("history_visibility") in (None, "shared", "world_readable") - for e in events + for e in events.itervalues() ) if all_open: -- cgit 1.4.1 From a0e8a53c6d0ff65629aa8645d43df06558ff88af Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 25 Jun 2018 19:57:38 +0100 Subject: Comment --- synapse/handlers/federation.py | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index aab69550a0..c4ffdf887e 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -460,6 +460,14 @@ class FederationHandler(BaseHandler): @measure_func("_filter_events_for_server") @defer.inlineCallbacks def _filter_events_for_server(self, server_name, room_id, events): + """Filter the given events for the given server, redacting those the + server can't see. + + Assumes the server is currently in the room. + + Returns + list[FrozenEvent] + """ # First lets check to see if all the events have a history visibility # of "shared" or "world_readable". If thats the case then we don't # need to check membership (as we know the server is in the room). -- cgit 1.4.1 From df48f7ef37f9236a13293ef73d17c6192c7b0834 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 25 Jun 2018 20:03:41 +0100 Subject: Actually fix it --- synapse/handlers/federation.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index c4ffdf887e..b6f8d4cf82 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -480,7 +480,7 @@ class FederationHandler(BaseHandler): visibility_ids = set() for sids in event_to_state_ids.itervalues(): - hist = event_to_state_ids.get((EventTypes.RoomHistoryVisibility, "")) + hist = sids.get((EventTypes.RoomHistoryVisibility, "")) if hist: visibility_ids.add(hist) @@ -492,7 +492,7 @@ class FederationHandler(BaseHandler): event_map = yield self.store.get_events(visibility_ids) all_open = all( e.content.get("history_visibility") in (None, "shared", "world_readable") - for e in events.itervalues() + for e in event_map.itervalues() ) if all_open: @@ -505,7 +505,7 @@ class FederationHandler(BaseHandler): frozenset(e.event_id for e in events), types=( (EventTypes.RoomHistoryVisibility, ""), - (EventTypes.Member, None) + (EventTypes.Member, None), ) ) -- cgit 1.4.1 From 77078d6c8ef11e2401406edc1ca340e0d7779267 Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Wed, 27 Jun 2018 11:27:32 +0100 Subject: handle federation not telling us about prev_events --- synapse/federation/federation_server.py | 4 +- synapse/handlers/federation.py | 87 ++++++++---- tests/test_federation.py | 235 ++++++++++++++++++++++++++++++++ tests/unittest.py | 2 +- 4 files changed, 301 insertions(+), 27 deletions(-) create mode 100644 tests/test_federation.py (limited to 'synapse/handlers/federation.py') diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index d4dd967c60..4096093527 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -549,7 +549,9 @@ class FederationServer(FederationBase): affected=pdu.event_id, ) - yield self.handler.on_receive_pdu(origin, pdu, get_missing=True) + yield self.handler.on_receive_pdu( + origin, pdu, get_missing=True, sent_to_us_directly=True, + ) def __str__(self): return "" % self.server_name diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index b6f8d4cf82..250a5509d8 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -44,6 +44,7 @@ from synapse.util.frozenutils import unfreeze from synapse.crypto.event_signing import ( compute_event_signature, add_hashes_and_signatures, ) +from synapse.state import resolve_events_with_factory from synapse.types import UserID, get_domain_from_id from synapse.events.utils import prune_event @@ -89,7 +90,9 @@ class FederationHandler(BaseHandler): @defer.inlineCallbacks @log_function - def on_receive_pdu(self, origin, pdu, get_missing=True): + def on_receive_pdu( + self, origin, pdu, get_missing=True, sent_to_us_directly=False, + ): """ Process a PDU received via a federation /send/ transaction, or via backfill of missing prev_events @@ -163,7 +166,7 @@ class FederationHandler(BaseHandler): "Ignoring PDU %s for room %s from %s as we've left the room!", pdu.event_id, pdu.room_id, origin, ) - return + defer.returnValue(None) state = None @@ -225,26 +228,54 @@ class FederationHandler(BaseHandler): list(prevs - seen)[:5], ) - if prevs - seen: - logger.info( - "Still missing %d events for room %r: %r...", - len(prevs - seen), pdu.room_id, list(prevs - seen)[:5] + if sent_to_us_directly and prevs - seen: + # If they have sent it to us directly, and the server + # isn't telling us about the auth events that it's + # made a message referencing, we explode + raise FederationError( + "ERROR", + 403, + ("Your server isn't divulging details about prev_events " + "referenced in this event."), + affected=pdu.event_id, ) - fetch_state = True + elif prevs - seen: + # If we're walking back up the chain to fetch it, then + # try and find the states. If we can't get the states, + # discard it. + state_groups = [] + auth_chains = set() + try: + # Get the ones we know about + ours = yield self.store.get_state_groups(pdu.room_id, list(seen)) + state_groups.append(ours) - 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.replication_layer.get_state_for_room( - origin, pdu.room_id, pdu.event_id, - ) - except Exception: - logger.exception("Failed to get state for event: %s", pdu.event_id) + for p in prevs - seen: + state, auth_chain = yield self.replication_layer.get_state_for_room( + origin, pdu.room_id, p + ) + auth_chains.update(auth_chain) + state_group = { + (x.type, x.state_key): x.event_id for x in state + } + state_groups.append(state_group) + + def fetch(ev_ids): + return self.store.get_events( + ev_ids, get_prev_content=False, check_redacted=False, + ) + + state = yield resolve_events_with_factory(state_groups, {pdu.event_id: pdu}, fetch) + + state = yield self.store.get_events(state.values()) + state = state.values() + except Exception: + raise FederationError( + "ERROR", + 403, + "We can't get valid state history.", + affected=pdu.event_id, + ) yield self._process_received_pdu( origin, @@ -322,11 +353,17 @@ class FederationHandler(BaseHandler): for e in missing_events: logger.info("Handling found event %s", e.event_id) - yield self.on_receive_pdu( - origin, - e, - get_missing=False - ) + try: + yield self.on_receive_pdu( + origin, + e, + get_missing=False + ) + except FederationError as e: + if e.code == 403: + logger.warn("Event %s failed history check.") + else: + raise @log_function @defer.inlineCallbacks diff --git a/tests/test_federation.py b/tests/test_federation.py new file mode 100644 index 0000000000..12f4633cd5 --- /dev/null +++ b/tests/test_federation.py @@ -0,0 +1,235 @@ + +from twisted.internet.defer import Deferred, succeed, maybeDeferred + +from synapse.util import Clock +from synapse.events import FrozenEvent +from synapse.types import Requester, UserID +from synapse.replication.slave.storage.events import SlavedEventStore + +from tests import unittest +from tests.server import make_request, setup_test_homeserver, ThreadedMemoryReactorClock + +from mock import Mock + +from synapse.api.errors import CodeMessageException, HttpResponseException + + +class MessageAcceptTests(unittest.TestCase): + def setUp(self): + + self.http_client = Mock() + self.reactor = ThreadedMemoryReactorClock() + self.hs_clock = Clock(self.reactor) + self.homeserver = setup_test_homeserver( + http_client=self.http_client, clock=self.hs_clock, reactor=self.reactor + ) + + user_id = UserID("us", "test") + our_user = Requester(user_id, None, False, None, None) + room_creator = self.homeserver.get_room_creation_handler() + room = room_creator.create_room( + our_user, room_creator.PRESETS_DICT["public_chat"], ratelimit=False + ) + self.reactor.advance(0.1) + self.room_id = self.successResultOf(room)["room_id"] + + # Figure out what the most recent event is + most_recent = self.successResultOf( + self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + )[0] + + join_event = FrozenEvent( + { + "room_id": self.room_id, + "sender": "@baduser:test.serv", + "state_key": "@baduser:test.serv", + "event_id": "$join:test.serv", + "depth": 1000, + "origin_server_ts": 1, + "type": "m.room.member", + "origin": "test.servx", + "content": {"membership": "join"}, + "auth_events": [], + "prev_state": [(most_recent, {})], + "prev_events": [(most_recent, {})], + } + ) + + self.handler = self.homeserver.get_handlers().federation_handler + self.handler.do_auth = lambda *a, **b: succeed(True) + self.client = self.homeserver.get_federation_client() + self.client._check_sigs_and_hash_and_fetch = lambda dest, pdus, **k: succeed( + pdus + ) + + # Send the join, it should return None (which is not an error) + d = self.handler.on_receive_pdu( + "test.serv", join_event, sent_to_us_directly=True + ) + self.reactor.advance(1) + self.assertEqual(self.successResultOf(d), None) + + # Make sure we actually joined the room + self.assertEqual( + self.successResultOf( + self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + )[0], + "$join:test.serv", + ) + + def test_cant_hide_direct_ancestors(self): + """ + If you send a message, you must be able to provide the direct + prev_events that said event references. + """ + + def post_json(destination, path, data, headers=None, timeout=0): + # If it asks us for new missing events, give them NOTHING + if path.startswith("/_matrix/federation/v1/get_missing_events/"): + return {"events": []} + + self.http_client.post_json = post_json + + # Figure out what the most recent event is + most_recent = self.successResultOf( + self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + )[0] + + # Now lie about an event + lying_event = FrozenEvent( + { + "room_id": self.room_id, + "sender": "@baduser:test.serv", + "event_id": "one:test.serv", + "depth": 1000, + "origin_server_ts": 1, + "type": "m.room.message", + "origin": "test.serv", + "content": "hewwo?", + "auth_events": [], + "prev_events": [("two:test.serv", {}), (most_recent, {})], + } + ) + + d = self.handler.on_receive_pdu( + "test.serv", lying_event, sent_to_us_directly=True + ) + + # Step the reactor, so the database fetches come back + self.reactor.advance(1) + + # on_receive_pdu should throw an error + failure = self.failureResultOf(d) + self.assertEqual( + failure.value.args[0], + ( + "ERROR 403: Your server isn't divulging details about prev_events " + "referenced in this event." + ), + ) + + # Make sure the invalid event isn't there + extrem = self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + self.assertEqual(self.successResultOf(extrem)[0], "$join:test.serv") + + @unittest.DEBUG + def test_cant_hide_past_history(self): + """ + If you send a message, you must be able to provide the direct + prev_events that said event references. + """ + + def post_json(destination, path, data, headers=None, timeout=0): + if path.startswith("/_matrix/federation/v1/get_missing_events/"): + return { + "events": [ + { + "room_id": self.room_id, + "sender": "@baduser:test.serv", + "event_id": "three:test.serv", + "depth": 1000, + "origin_server_ts": 1, + "type": "m.room.message", + "origin": "test.serv", + "content": "hewwo?", + "auth_events": [], + "prev_events": [("four:test.serv", {})], + } + ] + } + + self.http_client.post_json = post_json + + def get_json(destination, path, args, headers=None): + print(destination, path, args) + if path.startswith("/_matrix/federation/v1/state_ids/"): + d = self.successResultOf( + self.homeserver.datastore.get_state_ids_for_event("one:test.serv") + ) + + return succeed( + { + "pdu_ids": [ + y + for x, y in d.items() + if x == ("m.room.member", "@us:test") + ], + "auth_chain_ids": d.values(), + } + ) + + self.http_client.get_json = get_json + + # Figure out what the most recent event is + most_recent = self.successResultOf( + self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + )[0] + + # Make a good event + good_event = FrozenEvent( + { + "room_id": self.room_id, + "sender": "@baduser:test.serv", + "event_id": "one:test.serv", + "depth": 1000, + "origin_server_ts": 1, + "type": "m.room.message", + "origin": "test.serv", + "content": "hewwo?", + "auth_events": [], + "prev_events": [(most_recent, {})], + } + ) + + d = self.handler.on_receive_pdu( + "test.serv", good_event, sent_to_us_directly=True + ) + self.reactor.advance(1) + self.assertEqual(self.successResultOf(d), None) + + bad_event = FrozenEvent( + { + "room_id": self.room_id, + "sender": "@baduser:test.serv", + "event_id": "two:test.serv", + "depth": 1000, + "origin_server_ts": 1, + "type": "m.room.message", + "origin": "test.serv", + "content": "hewwo?", + "auth_events": [], + "prev_events": [("one:test.serv", {}), ("three:test.serv", {})], + } + ) + + d = self.handler.on_receive_pdu( + "test.serv", bad_event, sent_to_us_directly=True + ) + self.reactor.advance(1) + + extrem = self.homeserver.datastore.get_latest_event_ids_in_room(self.room_id) + self.assertEqual(self.successResultOf(extrem)[0], "two:test.serv") + + state = self.homeserver.get_state_handler().get_current_state_ids(self.room_id) + self.reactor.advance(1) + self.assertIn(("m.room.member", "@us:test"), self.successResultOf(state).keys()) diff --git a/tests/unittest.py b/tests/unittest.py index 184fe880f3..de24b1d2d4 100644 --- a/tests/unittest.py +++ b/tests/unittest.py @@ -35,7 +35,7 @@ class ToTwistedHandler(logging.Handler): def emit(self, record): log_entry = self.format(record) log_level = record.levelname.lower().replace('warning', 'warn') - self.tx_log.emit(twisted.logger.LogLevel.levelWithName(log_level), log_entry) + self.tx_log.emit(twisted.logger.LogLevel.levelWithName(log_level), log_entry.replace("{", r"(").replace("}", r")")) handler = ToTwistedHandler() -- cgit 1.4.1 From a7ecf34b70b215f1402ce545e1f6a7c163f8ac28 Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Wed, 27 Jun 2018 11:36:03 +0100 Subject: cleanups --- synapse/handlers/federation.py | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 250a5509d8..e9c5d1026a 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -240,35 +240,37 @@ class FederationHandler(BaseHandler): affected=pdu.event_id, ) elif prevs - seen: - # If we're walking back up the chain to fetch it, then - # try and find the states. If we can't get the states, - # discard it. + # Calculate the state of the previous events, and + # de-conflict them to find the current state. state_groups = [] auth_chains = set() try: - # Get the ones we know about + # Get the state of the events we know about ours = yield self.store.get_state_groups(pdu.room_id, list(seen)) state_groups.append(ours) + # Ask the remote server for the states we don't + # know about for p in prevs - seen: - state, auth_chain = yield self.replication_layer.get_state_for_room( + state, got_auth_chain = yield self.replication_layer.get_state_for_room( origin, pdu.room_id, p ) - auth_chains.update(auth_chain) - state_group = { - (x.type, x.state_key): x.event_id for x in state - } + auth_chains.update(got_auth_chain) + state_group = {(x.type, x.state_key): x.event_id for x in state} state_groups.append(state_group) + # Resolve any conflicting state def fetch(ev_ids): return self.store.get_events( - ev_ids, get_prev_content=False, check_redacted=False, + ev_ids, get_prev_content=False, check_redacted=False ) - state = yield resolve_events_with_factory(state_groups, {pdu.event_id: pdu}, fetch) + state_map = yield resolve_events_with_factory( + state_groups, {pdu.event_id: pdu}, fetch + ) - state = yield self.store.get_events(state.values()) - state = state.values() + state = (yield self.store.get_events(state_map.values())).values() + auth_chain = list(auth_chains) except Exception: raise FederationError( "ERROR", -- cgit 1.4.1 From f03a5d1a1759221bd94d75604f3e4e787cd4133e Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Wed, 27 Jun 2018 11:38:14 +0100 Subject: pep8 --- synapse/handlers/federation.py | 10 ++++------ tests/test_federation.py | 7 ++----- 2 files changed, 6 insertions(+), 11 deletions(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index e9c5d1026a..c4d96749a3 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -169,11 +169,8 @@ class FederationHandler(BaseHandler): defer.returnValue(None) state = None - auth_chain = [] - fetch_state = False - # Get missing pdus if necessary. if not pdu.internal_metadata.is_outlier(): # We only backfill backwards to the min depth. @@ -252,9 +249,10 @@ class FederationHandler(BaseHandler): # Ask the remote server for the states we don't # know about for p in prevs - seen: - state, got_auth_chain = yield self.replication_layer.get_state_for_room( - origin, pdu.room_id, p - ) + state, got_auth_chain = ( + yield self.replication_layer.get_state_for_room( + origin, pdu.room_id, p + )) auth_chains.update(got_auth_chain) state_group = {(x.type, x.state_key): x.event_id for x in state} state_groups.append(state_group) diff --git a/tests/test_federation.py b/tests/test_federation.py index 95fa73723c..fc80a69369 100644 --- a/tests/test_federation.py +++ b/tests/test_federation.py @@ -1,18 +1,15 @@ -from twisted.internet.defer import Deferred, succeed, maybeDeferred +from twisted.internet.defer import succeed, maybeDeferred from synapse.util import Clock from synapse.events import FrozenEvent from synapse.types import Requester, UserID -from synapse.replication.slave.storage.events import SlavedEventStore from tests import unittest -from tests.server import make_request, setup_test_homeserver, ThreadedMemoryReactorClock +from tests.server import setup_test_homeserver, ThreadedMemoryReactorClock from mock import Mock -from synapse.api.errors import CodeMessageException, HttpResponseException - class MessageAcceptTests(unittest.TestCase): def setUp(self): -- cgit 1.4.1 From 99800de63ddec41125c6e1c779c33f96f1cad848 Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Wed, 27 Jun 2018 11:40:27 +0100 Subject: try and clean up --- synapse/handlers/federation.py | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'synapse/handlers/federation.py') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index c4d96749a3..13117d70fe 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -232,8 +232,10 @@ class FederationHandler(BaseHandler): raise FederationError( "ERROR", 403, - ("Your server isn't divulging details about prev_events " - "referenced in this event."), + ( + "Your server isn't divulging details about prev_events " + "referenced in this event." + ), affected=pdu.event_id, ) elif prevs - seen: @@ -252,7 +254,8 @@ class FederationHandler(BaseHandler): state, got_auth_chain = ( yield self.replication_layer.get_state_for_room( origin, pdu.room_id, p - )) + ) + ) auth_chains.update(got_auth_chain) state_group = {(x.type, x.state_key): x.event_id for x in state} state_groups.append(state_group) -- cgit 1.4.1