From 18de00adb4471a55b504f4afb9f29facf0a51785 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Fri, 31 Jul 2020 14:34:42 +0100 Subject: [PATCH] Add ratelimiting on joins --- docs/sample_config.yaml | 12 +++++++++++ synapse/config/ratelimiting.py | 21 +++++++++++++++++++ synapse/handlers/room_member.py | 37 +++++++++++++++++++++++++++++++-- tests/utils.py | 4 ++++ 4 files changed, 72 insertions(+), 2 deletions(-) diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index b21e36bb6d..fef503479e 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -731,6 +731,10 @@ log_config: "CONFDIR/SERVERNAME.log.config" # - one for ratelimiting redactions by room admins. If this is not explicitly # set then it uses the same ratelimiting as per rc_message. This is useful # to allow room admins to deal with abuse quickly. +# - two for ratelimiting number of rooms a user can join, "local" for when +# users are joining rooms the server is already in (this is cheap) vs +# "remote" for when users are trying to join rooms not on the server (which +# can be more expensive) # # The defaults are as shown below. # @@ -756,6 +760,14 @@ log_config: "CONFDIR/SERVERNAME.log.config" #rc_admin_redaction: # per_second: 1 # burst_count: 50 +# +#rc_joins: +# local: +# per_second: 0.1 +# burst_count: 3 +# remote: +# per_second: 0.01 +# burst_count: 3 # Ratelimiting settings for incoming federation diff --git a/synapse/config/ratelimiting.py b/synapse/config/ratelimiting.py index 2dd94bae2b..b2c78ac40c 100644 --- a/synapse/config/ratelimiting.py +++ b/synapse/config/ratelimiting.py @@ -93,6 +93,15 @@ class RatelimitConfig(Config): if rc_admin_redaction: self.rc_admin_redaction = RateLimitConfig(rc_admin_redaction) + self.rc_joins_local = RateLimitConfig( + config.get("rc_joins", {}).get("local", {}), + defaults={"per_second": 0.1, "burst_count": 3}, + ) + self.rc_joins_remote = RateLimitConfig( + config.get("rc_joins", {}).get("remote", {}), + defaults={"per_second": 0.01, "burst_count": 3}, + ) + def generate_config_section(self, **kwargs): return """\ ## Ratelimiting ## @@ -118,6 +127,10 @@ class RatelimitConfig(Config): # - one for ratelimiting redactions by room admins. If this is not explicitly # set then it uses the same ratelimiting as per rc_message. This is useful # to allow room admins to deal with abuse quickly. + # - two for ratelimiting number of rooms a user can join, "local" for when + # users are joining rooms the server is already in (this is cheap) vs + # "remote" for when users are trying to join rooms not on the server (which + # can be more expensive) # # The defaults are as shown below. # @@ -143,6 +156,14 @@ class RatelimitConfig(Config): #rc_admin_redaction: # per_second: 1 # burst_count: 50 + # + #rc_joins: + # local: + # per_second: 0.1 + # burst_count: 3 + # remote: + # per_second: 0.01 + # burst_count: 3 # Ratelimiting settings for incoming federation diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index a1a8fa1d3b..822ca9da6a 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -22,7 +22,8 @@ from unpaddedbase64 import encode_base64 from synapse import types from synapse.api.constants import MAX_DEPTH, EventTypes, Membership -from synapse.api.errors import AuthError, Codes, SynapseError +from synapse.api.errors import AuthError, Codes, LimitExceededError, SynapseError +from synapse.api.ratelimiting import Ratelimiter from synapse.api.room_versions import EventFormatVersions from synapse.crypto.event_signing import compute_event_reference_hash from synapse.events import EventBase @@ -77,6 +78,17 @@ class RoomMemberHandler(object): if self._is_on_event_persistence_instance: self.persist_event_storage = hs.get_storage().persistence + self._join_rate_limiter_local = Ratelimiter( + clock=self.clock, + rate_hz=hs.config.ratelimiting.rc_joins_local.per_second, + burst_count=hs.config.ratelimiting.rc_joins_local.burst_count, + ) + self._join_rate_limiter_remote = Ratelimiter( + clock=self.clock, + rate_hz=hs.config.ratelimiting.rc_joins_remote.per_second, + burst_count=hs.config.ratelimiting.rc_joins_remote.burst_count, + ) + # This is only used to get at ratelimit function, and # maybe_kick_guest_users. It's fine there are multiple of these as # it doesn't store state. @@ -441,7 +453,28 @@ class RoomMemberHandler(object): # so don't really fit into the general auth process. raise AuthError(403, "Guest access not allowed") - if not is_host_in_room: + if is_host_in_room: + time_now_s = self.clock.time() + allowed, time_allowed = self._join_rate_limiter_local.can_do_action( + requester.user.to_string(), + ) + + if not allowed: + raise LimitExceededError( + retry_after_ms=int(1000 * (time_allowed - time_now_s)) + ) + + else: + time_now_s = self.clock.time() + allowed, time_allowed = self._join_rate_limiter_remote.can_do_action( + requester.user.to_string(), + ) + + if not allowed: + raise LimitExceededError( + retry_after_ms=int(1000 * (time_allowed - time_now_s)) + ) + inviter = await self._get_inviter(target.to_string(), room_id) if inviter and not self.hs.is_mine(inviter): remote_room_hosts.append(inviter.domain) diff --git a/tests/utils.py b/tests/utils.py index ac643679aa..a8e85436f9 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -154,6 +154,10 @@ def default_config(name, parse=False): "account": {"per_second": 10000, "burst_count": 10000}, "failed_attempts": {"per_second": 10000, "burst_count": 10000}, }, + "rc_joins": { + "local": {"per_second": 10000, "burst_count": 10000}, + "remote": {"per_second": 10000, "burst_count": 10000}, + }, "saml2_enabled": False, "public_baseurl": None, "default_identity_server": None,