Introduced a protection which lets the room bans propagate to a defined banlist

src/protections/PropagateRoomBan.ts

@@ -0,0 +1,127 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Protection } from './IProtection';
+import { Mjolnir } from '../Mjolnir';
+import { StringProtectionSetting } from './ProtectionSettings';
+import { LogLevel, extractRequestError } from 'matrix-bot-sdk';
+import { recommendationToStable, RECOMMENDATION_BAN } from '../models/ListRule';
+import { RULE_USER } from '../models/BanList';
+import { DEFAULT_LIST_EVENT_TYPE } from '../commands/SetDefaultBanListCommand';
+
+export class PropagateRoomBan extends Protection {
+ settings = {
+ banListShortcode: new StringProtectionSetting(),
+ };
+
+ public get name(): string {
+ return 'PropagateRoomBan';
+ }
+
+ public get description(): string {
+ return (
+ 'If a user is banned in a protected room by a room administrator then the ban ' +
+ 'will be published to the banlist defined using the banListShortcode setting ' +
+ '(defaults to the default banlist).'
+ );
+ }
+
+ public async handleEvent(mjolnir: Mjolnir, roomId: string, event: any): Promise<void> {
+ if (!this.isBanEvent(event)) {
+ // only interested in ban events
+ return;
+ }
+
+ const content = event['content'] || {};
+ const bannedUser = event['state_key'];
+ const banReason = content['reason'] || '<no reason supplied>';
+ const sender = event['sender'];
+ const stateKey = `rule:${bannedUser}`;
+
+ const ruleContent = {
+ entity: bannedUser,
+ recommendation: recommendationToStable(RECOMMENDATION_BAN),
+ reason: banReason,
+ };
+
+ let banListShortcode: string = this.settings.banListShortcode.value;
+ if (banListShortcode === '') {
+ // try to use default banList
+ try {
+ const data: { shortcode: string } =
+ await mjolnir.client.getAccountData(
+ DEFAULT_LIST_EVENT_TYPE
+ );
+ banListShortcode = data['shortcode'];
+ } catch (e) {
+ await mjolnir.logMessage(
+ LogLevel.WARN,
+ 'PropagateRoomBan',
+ `Can not publish to banlist. User ${bannedUser} was banned in ${roomId}, but protection setting banListShortcode is missing and could not get default banlist`
+ );
+ await mjolnir.logMessage(
+ LogLevel.WARN,
+ 'PropagateRoomBan',
+ extractRequestError(e)
+ );
+ return;
+ }
+ }
+
+ const banlist = mjolnir.lists.find(
+ (bl) =>
+ bl.listShortcode.toLowerCase() ===
+ banListShortcode.toLowerCase()
+ );
+
+ if (!banlist) {
+ await mjolnir.logMessage(
+ LogLevel.WARN,
+ 'PropagateRoomBan',
+ `Can not publish to banlist. User ${bannedUser} was banned in ${roomId}, but banlist ${banListShortcode} is not found`
+ );
+ return;
+ }
+
+ await mjolnir.client.sendStateEvent(
+ banlist.roomId,
+ RULE_USER,
+ stateKey,
+ ruleContent
+ );
+ await mjolnir.logMessage(
+ LogLevel.INFO,
+ 'PropagateRoomBan',
+ `User ${bannedUser} added to banlist ${banlist.listShortcode}, because ${sender} banned him in ${roomId} for: ${banReason}`
+ );
+ }
+
+ private isBanEvent(event: any): boolean {
+ if (event['type'] !== 'm.room.member') {
+ return false;
+ }
+
+ const membership: string = event['content']['membership'];
+ let prevMembership = 'join';
+
+ if (event['unsigned'] && event['unsigned']['prev_content']) {
+ prevMembership =
+ event['unsigned']['prev_content']['membership'] || 'join';
+ }
+
+ return membership === 'ban' && prevMembership !== 'ban';
+ }
+}

src/protections/protections.ts

@@ -21,12 +21,14 @@ import { WordList } from "./WordList";
 import { MessageIsVoice } from "./MessageIsVoice";
 import { MessageIsMedia } from "./MessageIsMedia";
 import { TrustedReporters } from "./TrustedReporters";
+import { PropagateRoomBan } from './PropagateRoomBan';
 
 export const PROTECTIONS: IProtection[] = [
  new FirstMessageIsImage(),
  new BasicFlooding(),
  new WordList(),
  new MessageIsVoice(),
  new MessageIsMedia(),
- new TrustedReporters()
+ new TrustedReporters(),
+ new PropagateRoomBan()
 ];