4 files changed, 100 insertions, 2 deletions
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index 2932fe2123..42cc2b062a 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -29,7 +29,7 @@ from synapse.rest.admin._base import (
 from synapse.rest.admin.groups import DeleteGroupAdminRestServlet
 from synapse.rest.admin.media import ListMediaInRoom, register_servlets_for_media_repo
 from synapse.rest.admin.purge_room_servlet import PurgeRoomServlet
-from synapse.rest.admin.rooms import ShutdownRoomRestServlet
+from synapse.rest.admin.rooms import ListRoomRestServlet, ShutdownRoomRestServlet
 from synapse.rest.admin.server_notice_servlet import SendServerNoticeServlet
 from synapse.rest.admin.users import (
     AccountValidityRenewServlet,
@@ -188,6 +188,7 @@ def register_servlets(hs, http_server):
     Register all the admin servlets.
     """
     register_servlets_for_client_rest_resource(hs, http_server)
+    ListRoomRestServlet(hs).register(http_server)
     PurgeRoomServlet(hs).register(http_server)
     SendServerNoticeServlet(hs).register(http_server)
     VersionServlet(hs).register(http_server)
diff --git a/synapse/rest/admin/_base.py b/synapse/rest/admin/_base.py
index afd0647205..459482eb6d 100644
--- a/synapse/rest/admin/_base.py
+++ b/synapse/rest/admin/_base.py
@@ -40,6 +40,21 @@ def historical_admin_path_patterns(path_regex):
     )
 
 
+def admin_patterns(path_regex: str):
+    """Returns the list of patterns for an admin endpoint
+
+    Args:
+        path_regex: The regex string to match. This should NOT have a ^
+            as this will be prefixed.
+
+    Returns:
+        A list of regex patterns.
+    """
+    admin_prefix = "^/_synapse/admin/v1"
+    patterns = [re.compile(admin_prefix + path_regex)]
+    return patterns
+
+
 async def assert_requester_is_admin(auth, request):
     """Verify that the requester is an admin user
 
diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py
index f7cc5e9be9..f9b8c0a4f0 100644
--- a/synapse/rest/admin/rooms.py
+++ b/synapse/rest/admin/rooms.py
@@ -15,15 +15,20 @@
 import logging
 
 from synapse.api.constants import Membership
+from synapse.api.errors import Codes, SynapseError
 from synapse.http.servlet import (
     RestServlet,
     assert_params_in_dict,
+    parse_integer,
     parse_json_object_from_request,
+    parse_string,
 )
 from synapse.rest.admin._base import (
+    admin_patterns,
     assert_user_is_admin,
     historical_admin_path_patterns,
 )
+from synapse.storage.data_stores.main.room import RoomSortOrder
 from synapse.types import create_requester
 from synapse.util.async_helpers import maybe_awaitable
 
@@ -155,3 +160,80 @@ class ShutdownRoomRestServlet(RestServlet):
                 "new_room_id": new_room_id,
             },
         )
+
+
+class ListRoomRestServlet(RestServlet):
+    """
+    List all rooms that are known to the homeserver. Results are returned
+    in a dictionary containing room information. Supports pagination.
+    """
+
+    PATTERNS = admin_patterns("/rooms")
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+        self.auth = hs.get_auth()
+        self.admin_handler = hs.get_handlers().admin_handler
+
+    async def on_GET(self, request):
+        requester = await self.auth.get_user_by_req(request)
+        await assert_user_is_admin(self.auth, requester.user)
+
+        # Extract query parameters
+        start = parse_integer(request, "from", default=0)
+        limit = parse_integer(request, "limit", default=100)
+        order_by = parse_string(request, "order_by", default="alphabetical")
+        if order_by not in (
+            RoomSortOrder.ALPHABETICAL.value,
+            RoomSortOrder.SIZE.value,
+        ):
+            raise SynapseError(
+                400,
+                "Unknown value for order_by: %s" % (order_by,),
+                errcode=Codes.INVALID_PARAM,
+            )
+
+        search_term = parse_string(request, "search_term")
+        if search_term == "":
+            raise SynapseError(
+                400,
+                "search_term cannot be an empty string",
+                errcode=Codes.INVALID_PARAM,
+            )
+
+        direction = parse_string(request, "dir", default="f")
+        if direction not in ("f", "b"):
+            raise SynapseError(
+                400, "Unknown direction: %s" % (direction,), errcode=Codes.INVALID_PARAM
+            )
+
+        reverse_order = True if direction == "b" else False
+
+        # Return list of rooms according to parameters
+        rooms, total_rooms = await self.store.get_rooms_paginate(
+            start, limit, order_by, reverse_order, search_term
+        )
+        response = {
+            # next_token should be opaque, so return a value the client can parse
+            "offset": start,
+            "rooms": rooms,
+            "total_rooms": total_rooms,
+        }
+
+        # Are there more rooms to paginate through after this?
+        if (start + limit) < total_rooms:
+            # There are. Calculate where the query should start from next time
+            # to get the next part of the list
+            response["next_batch"] = start + limit
+
+        # Is it possible to paginate backwards? Check if we currently have an
+        # offset
+        if start > 0:
+            if start > limit:
+                # Going back one iteration won't take us to the start.
+                # Calculate new offset
+                response["prev_batch"] = start - limit
+            else:
+                response["prev_batch"] = 0
+
+        return 200, response
diff --git a/synapse/rest/client/v2_alpha/_base.py b/synapse/rest/client/v2_alpha/_base.py
index 2a3f4dd58f..bc11b4dda4 100644
--- a/synapse/rest/client/v2_alpha/_base.py
+++ b/synapse/rest/client/v2_alpha/_base.py
@@ -32,7 +32,7 @@ def client_patterns(path_regex, releases=(0,), unstable=True, v1=False):
 
     Args:
         path_regex (str): The regex string to match. This should NOT have a ^
-        as this will be prefixed.
+            as this will be prefixed.
     Returns:
         SRE_Pattern
     """