Merge pull request #3630 from matrix-org/neilj/mau_sign_in_log_in_limits

Initial impl of capping MAU

7 files changed, 90 insertions, 4 deletions

diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 6074df292f..14f5540280 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -55,6 +55,7 @@ class Codes(object):
     SERVER_NOT_TRUSTED = "M_SERVER_NOT_TRUSTED"
     CONSENT_NOT_GIVEN = "M_CONSENT_NOT_GIVEN"
     CANNOT_LEAVE_SERVER_NOTICE_ROOM = "M_CANNOT_LEAVE_SERVER_NOTICE_ROOM"
+    MAU_LIMIT_EXCEEDED = "M_MAU_LIMIT_EXCEEDED"
 
 
 class CodeMessageException(RuntimeError):
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 57b815d777..fba51c26e8 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -20,6 +20,8 @@ import sys
 
 from six import iteritems
 
+from prometheus_client import Gauge
+
 from twisted.application import service
 from twisted.internet import defer, reactor
 from twisted.web.resource import EncodingResourceWrapper, NoResource
@@ -300,6 +302,11 @@ class SynapseHomeServer(HomeServer):
             quit_with_error(e.message)
 
 
+# Gauges to expose monthly active user control metrics
+current_mau_gauge = Gauge("synapse_admin_current_mau", "Current MAU")
+max_mau_value_gauge = Gauge("synapse_admin_max_mau_value", "MAU Limit")
+
+
 def setup(config_options):
     """
     Args:
@@ -512,6 +519,18 @@ def run(hs):
     # table will decrease
     clock.looping_call(generate_user_daily_visit_stats, 5 * 60 * 1000)
 
+    @defer.inlineCallbacks
+    def generate_monthly_active_users():
+        count = 0
+        if hs.config.limit_usage_by_mau:
+            count = yield hs.get_datastore().count_monthly_users()
+        current_mau_gauge.set(float(count))
+        max_mau_value_gauge.set(float(hs.config.max_mau_value))
+
+    generate_monthly_active_users()
+    if hs.config.limit_usage_by_mau:
+        clock.looping_call(generate_monthly_active_users, 5 * 60 * 1000)
+
     if hs.config.report_stats:
         logger.info("Scheduling stats reporting for 3 hour intervals")
         clock.looping_call(start_phone_stats_home, 3 * 60 * 60 * 1000)
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 18102656b0..a8014e9c50 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -67,6 +67,14 @@ class ServerConfig(Config):
             "block_non_admin_invites", False,
         )
 
+        # Options to control access by tracking MAU
+        self.limit_usage_by_mau = config.get("limit_usage_by_mau", False)
+        if self.limit_usage_by_mau:
+            self.max_mau_value = config.get(
+                "max_mau_value", 0,
+            )
+        else:
+            self.max_mau_value = 0
         # FIXME: federation_domain_whitelist needs sytests
         self.federation_domain_whitelist = None
         federation_domain_whitelist = config.get(
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 5d03bfa5f7..184eef09d0 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -520,6 +520,7 @@ class AuthHandler(BaseHandler):
         """
         logger.info("Logging in user %s on device %s", user_id, device_id)
         access_token = yield self.issue_access_token(user_id, device_id)
+        yield self._check_mau_limits()
 
         # the device *should* have been registered before we got here; however,
         # it's possible we raced against a DELETE operation. The thing we
@@ -731,15 +732,18 @@ class AuthHandler(BaseHandler):
                                                   device_id)
         defer.returnValue(access_token)
 
+    @defer.inlineCallbacks
     def validate_short_term_login_token_and_get_user_id(self, login_token):
+        yield self._check_mau_limits()
         auth_api = self.hs.get_auth()
+        user_id = None
         try:
             macaroon = pymacaroons.Macaroon.deserialize(login_token)
             user_id = auth_api.get_user_id_from_macaroon(macaroon)
             auth_api.validate_macaroon(macaroon, "login", True, user_id)
-            return user_id
         except Exception:
             raise AuthError(403, "Invalid token", errcode=Codes.FORBIDDEN)
+        defer.returnValue(user_id)
 
     @defer.inlineCallbacks
     def delete_access_token(self, access_token):
@@ -903,6 +907,19 @@ class AuthHandler(BaseHandler):
         else:
             return defer.succeed(False)
 
+    @defer.inlineCallbacks
+    def _check_mau_limits(self):
+        """
+        Ensure that if mau blocking is enabled that invalid users cannot
+        log in.
+        """
+        if self.hs.config.limit_usage_by_mau is True:
+            current_mau = yield self.store.count_monthly_users()
+            if current_mau >= self.hs.config.max_mau_value:
+                raise AuthError(
+                    403, "MAU Limit Exceeded", errcode=Codes.MAU_LIMIT_EXCEEDED
+                )
+
 
 @attr.s
 class MacaroonGenerator(object):
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 234f8e8019..289704b241 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -45,7 +45,7 @@ class RegistrationHandler(BaseHandler):
             hs (synapse.server.HomeServer):
         """
         super(RegistrationHandler, self).__init__(hs)
-
+        self.hs = hs
         self.auth = hs.get_auth()
         self._auth_handler = hs.get_auth_handler()
         self.profile_handler = hs.get_profile_handler()
@@ -144,6 +144,7 @@ class RegistrationHandler(BaseHandler):
         Raises:
             RegistrationError if there was a problem registering.
         """
+        yield self._check_mau_limits()
         password_hash = None
         if password:
             password_hash = yield self.auth_handler().hash(password)
@@ -288,6 +289,7 @@ class RegistrationHandler(BaseHandler):
                 400,
                 "User ID can only contain characters a-z, 0-9, or '=_-./'",
             )
+        yield self._check_mau_limits()
         user = UserID(localpart, self.hs.hostname)
         user_id = user.to_string()
 
@@ -437,7 +439,7 @@ class RegistrationHandler(BaseHandler):
         """
         if localpart is None:
             raise SynapseError(400, "Request must include user id")
-
+        yield self._check_mau_limits()
         need_register = True
 
         try:
@@ -531,3 +533,16 @@ class RegistrationHandler(BaseHandler):
             remote_room_hosts=remote_room_hosts,
             action="join",
         )
+
+    @defer.inlineCallbacks
+    def _check_mau_limits(self):
+        """
+        Do not accept registrations if monthly active user limits exceeded
+         and limiting is enabled
+        """
+        if self.hs.config.limit_usage_by_mau is True:
+            current_mau = yield self.store.count_monthly_users()
+            if current_mau >= self.hs.config.max_mau_value:
+                raise RegistrationError(
+                    403, "MAU Limit Exceeded", Codes.MAU_LIMIT_EXCEEDED
+                )
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 3bd63cd195..134e4a80f1 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -94,6 +94,7 @@ class DataStore(RoomMemberStore, RoomStore,
         self._clock = hs.get_clock()
         self.database_engine = hs.database_engine
 
+        self.db_conn = db_conn
         self._stream_id_gen = StreamIdGenerator(
             db_conn, "events", "stream_ordering",
             extra_tables=[("local_invites", "stream_id")]
@@ -266,6 +267,31 @@ class DataStore(RoomMemberStore, RoomStore,
 
         return self.runInteraction("count_users", _count_users)
 
+    def count_monthly_users(self):
+        """Counts the number of users who used this homeserver in the last 30 days
+
+        This method should be refactored with count_daily_users - the only
+        reason not to is waiting on definition of mau
+
+        Returns:
+            Defered[int]
+        """
+        def _count_monthly_users(txn):
+            thirty_days_ago = int(self._clock.time_msec()) - (1000 * 60 * 60 * 24 * 30)
+            sql = """
+                SELECT COALESCE(count(*), 0) FROM (
+                    SELECT user_id FROM user_ips
+                    WHERE last_seen > ?
+                    GROUP BY user_id
+                ) u
+            """
+
+            txn.execute(sql, (thirty_days_ago,))
+            count, = txn.fetchone()
+            return count
+
+        return self.runInteraction("count_monthly_users", _count_monthly_users)
+
     def count_r30_users(self):
         """
         Counts the number of 30 day retained users, defined as:-
diff --git a/synapse/storage/schema/delta/50/make_event_content_nullable.py b/synapse/storage/schema/delta/50/make_event_content_nullable.py
index 7d27342e39..6dd467b6c5 100644
--- a/synapse/storage/schema/delta/50/make_event_content_nullable.py
+++ b/synapse/storage/schema/delta/50/make_event_content_nullable.py
@@ -88,5 +88,5 @@ def run_upgrade(cur, database_engine, *args, **kwargs):
         "UPDATE sqlite_master SET sql=? WHERE tbl_name='events' AND type='table'",
         (sql, ),
     )
-    cur.execute("PRAGMA schema_version=%i" % (oldver+1,))
+    cur.execute("PRAGMA schema_version=%i" % (oldver + 1,))
     cur.execute("PRAGMA writable_schema=OFF")