Add option to filter telegram chats from being bridged. Fixes #41

example-config.yaml

@@ -109,13 +109,21 @@ bridge:
     public_portals: true
     # Whether to send stickers as the new native m.sticker type or normal m.images.
     # Old versions of Riot don't support the new type at all.
-    #
     # Remember that proper sticker support always requires Pillow to convert webp into png.
     native_stickers: true
     # Whether or not to fetch and handle Telegram updates at startup from the time the bridge was down.
     # WARNING: Probably buggy, might get stuck in infinite loop.
     catch_up: false
 
+    filter:
+        # Filter mode to use. Either "blacklist" or "whitelist".
+        # If the mode is "blacklist", the listed chats will never be bridged. An empty blacklist disables the filter.
+        # If the mode is "whitelist", only the listed chats can be bridged.
+        # Direct chats are not affected.
+        mode: blacklist
+        # The list of group/channel IDs to filter.
+        list: []
+
     # The prefix for commands. Only required in non-management rooms.
     command_prefix: "!tg"
 

mautrix_telegram/bot.py

@@ -145,6 +145,9 @@ class Bot(AbstractUser):
         if not config["bridge.relaybot.authless_portals"]:
             return await reply("This bridge doesn't allow portal creation from Telegram.")
 
+        if not portal.allow_bridging():
+            return await reply("This bridge doesn't allow bridging this chat.")
+
         await portal.create_matrix_room(self)
         if portal.mxid:
             if portal.username:

mautrix_telegram/commands/meta.py

@@ -80,5 +80,9 @@ def help(evt):
 **group-name** <_name_|`-`> - Change the username of a supergroup/channel. To disable, use a dash
                              (`-`) as the name.  
 **clean-rooms**             - Clean up unused portal/management rooms.
+
+**filter** <`whitelist`|`blacklist`> <_chat ID_> - Allow or disallow bridging  
+**filter-mode** <`whitelist`|`blacklist`>      - Change whether the bridge will allow or disallow
+                                                 bridging rooms by default.
 """
     return evt.reply(management_status + help)

mautrix_telegram/commands/portal.py

@@ -161,6 +161,10 @@ async def bridge(evt: CommandEvent):
                                "Bridging private chats to existing rooms is not allowed.")
 
     portal = po.Portal.get_by_tgid(tgid, peer_type=peer_type)
+    if not portal.allow_bridging():
+        return await evt.reply("This bridge doesn't allow bridging that Telegram chat.\n"
+                               "If you're the bridge admin, try"
+                               "`$cmdprefix+sp whitelist <Telegram chat ID>` first.")
     if portal.mxid:
         has_portal_message = (
             "That Telegram chat already has a portal at "
@@ -353,3 +357,70 @@ async def group_name(evt: CommandEvent):
         return await evt.reply("That username is already in use.")
     except UsernameInvalidError:
         return await evt.reply("Invalid username")
+
+
+@command_handler(needs_admin=True)
+async def filter_mode(evt: CommandEvent):
+    try:
+        mode = evt.args[0]
+        if mode not in ("whitelist", "blacklist"):
+            raise ValueError()
+    except (IndexError, ValueError):
+        return await evt.reply("**Usage:** `$cmdprefix+sp filter-mode <whitelist/blacklist>`")
+
+    evt.config["bridge.filter.mode"] = mode
+    evt.config.save()
+    po.Portal.filter_mode = mode
+    if mode == "whitelist":
+        return await evt.reply("The bridge will now disallow bridging chats by default.\n"
+                               "To allow bridging a specific chat, use"
+                               "`!filter whitelist <chat ID>`.")
+    else:
+        return await evt.reply("The bridge will now allow bridging chats by default.\n"
+                               "To disallow bridging a specific chat, use"
+                               "`!filter blacklist <chat ID>`.")
+
+
+@command_handler(needs_admin=True)
+async def filter(evt: CommandEvent):
+    try:
+        action = evt.args[0]
+        if action not in ("whitelist", "blacklist", "add", "remove"):
+            raise ValueError()
+
+        id = evt.args[1]
+        if id.startswith("-100"):
+            id = int(id[4:])
+        elif id.startswith("-"):
+            id = int(id[1:])
+        else:
+            id = int(id)
+    except (IndexError, ValueError):
+        return await evt.reply("**Usage:** `$cmdprefix+sp filter <whitelist/blacklist> <chat ID>`")
+
+    mode = evt.config["bridge.filter.mode"]
+    if mode not in ("blacklist", "whitelist"):
+        return await evt.reply(f"Unknown filter mode \"{mode}\". Please fix the bridge config.")
+
+    list = evt.config["bridge.filter.list"]
+
+    if action in ("blacklist", "whitelist"):
+        action = "add" if mode == action else "remove"
+
+    def save():
+        evt.config["bridge.filter.list"] = list
+        evt.config.save()
+        po.Portal.filter_list = list
+
+    if action == "add":
+        if id in list:
+            return await evt.reply(f"That chat is already {mode}ed.")
+        list.append(id)
+        save()
+        return await evt.reply(f"Chat ID added to {mode}.")
+    elif action == "remove":
+        if id not in list:
+            return await evt.reply(f"That chat is not {mode}ed.")
+        list.remove(id)
+        save()
+        return await evt.reply(f"Chat ID removed from {mode}.")

mautrix_telegram/config.py

@@ -181,6 +181,9 @@ class Config(DictWithRecursion):
         copy("bridge.native_stickers")
         copy("bridge.catch_up")
 
+        copy("bridge.filter.mode")
+        copy("bridge.filter.list")
+
         copy("bridge.command_prefix")
 
         migrate_permissions = ("bridge.permissions" not in self

mautrix_telegram/portal.py

@@ -48,6 +48,8 @@ class Portal:
     az = None
     bot = None
     loop = None
+    filter_mode = None
+    filter_list = None
     bridge_notices = False
     alias_template = None
     mx_alias_regex = None
@@ -117,6 +119,26 @@ class Portal:
             self._main_intent = puppet.intent if direct else self.az.intent
         return self._main_intent
 
+    # endregion
+    # region Filtering
+
+    def allow_bridging(self, tgid=None):
+        tgid = tgid or self.tgid
+        if self.peer_type == "user":
+            self.log.debug(f"!!!!!!!!!!!!!!!!!!!!!!!!!!!! allow_bridging(User {tgid}) -> True")
+            return True
+        elif self.filter_mode == "whitelist":
+            self.log.debug(
+                f"!!!!!!!!!!!!!!!!!!!!!!!!!!!! allow_bridging(Chat {tgid}) -> {tgid in self.filter_list} (whitelist={self.filter_list})")
+            return tgid in self.filter_list
+        elif self.filter_mode == "blacklist":
+            self.log.debug(
+                f"!!!!!!!!!!!!!!!!!!!!!!!!!!!! allow_bridging(Chat {tgid}) -> {tgid not in self.filter_list} (blacklist={self.filter_list})")
+            return tgid not in self.filter_list
+        else:
+            self.log.debug("!!!!!!!!!!!!!!??????????????? Unknown filter mode", self.filter_mode)
+        return True
+
     # endregion
     # region Deduplication
 
@@ -233,6 +255,9 @@ class Portal:
         if self.mxid:
             return self.mxid
 
+        if not self.allow_bridging():
+            return None
+
         if not entity:
             entity = await user.client.get_entity(self.peer)
             self.log.debug("Fetched data: %s", entity)
@@ -336,6 +361,10 @@ class Portal:
             await puppet.intent.ensure_joined(self.mxid)
             await puppet.update_info(source, entity)
 
+            user = u.User.get_by_tgid(entity.id)
+            if user:
+                await self.invite_to_matrix(user.mxid)
+
         # We can't trust the member list if any of the following cases is true:
         #  * There are close to 10 000 users, because Telegram might not be sending all members.
         #  * The member sync count is limited, because then we might ignore some members.
@@ -371,7 +400,7 @@ class Portal:
         user = u.User.get_by_tgid(user_id)
         if user:
             user.register_portal(self)
-            await self.main_intent.invite(self.mxid, user.mxid)
+            await self.invite_to_matrix(user.mxid)
 
     async def delete_telegram_user(self, user_id, sender):
         puppet = p.Puppet.get(user_id)
@@ -1592,7 +1621,9 @@ def init(context):
     global config
     Portal.az, Portal.db, config, Portal.loop, Portal.bot = context
     Portal.bridge_notices = config["bridge.bridge_notices"]
+    Portal.filter_mode = config["bridge.filter.mode"]
+    Portal.filter_list = config["bridge.filter.list"]
     Portal.alias_template = config.get("bridge.alias_template", "telegram_{groupname}")
-    Portal.hs_domain = config["homeserver"]["domain"]
+    Portal.hs_domain = config["homeserver.domain"]
     localpart = Portal.alias_template.format(groupname="(.+)")
     Portal.mx_alias_regex = re.compile(f"#{localpart}:{Portal.hs_domain}")