signal-desktop/ts/services/networkObserver.ts
2024-03-18 14:48:00 -07:00

124 lines
3.2 KiB
TypeScript

// Copyright 2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import type {
SetNetworkStatusPayloadType,
NetworkActionType,
} from '../state/ducks/network';
import { getSocketStatus } from '../shims/socketStatus';
import * as log from '../logging/log';
import { SECOND } from '../util/durations';
import { electronLookup } from '../util/dns';
import { drop } from '../util/drop';
import { SocketStatus } from '../types/SocketStatus';
// DNS TTL
const OUTAGE_CHECK_INTERVAL = 60 * SECOND;
const OUTAGE_HEALTY_ADDR = '127.0.0.1';
const OUTAGE_NO_SERVICE_ADDR = '127.0.0.2';
enum OnlineStatus {
Online = 'Online',
MaybeOffline = 'MaybeOffline',
Offline = 'Offline',
}
const OFFLINE_DELAY = 5 * SECOND;
type NetworkActions = {
setNetworkStatus: (x: SetNetworkStatusPayloadType) => NetworkActionType;
setOutage: (isOutage: boolean) => NetworkActionType;
};
export function initializeNetworkObserver(
networkActions: NetworkActions
): void {
log.info('Initializing network observer');
let onlineStatus = OnlineStatus.Online;
const refresh = () => {
const socketStatus = getSocketStatus();
networkActions.setNetworkStatus({
isOnline: onlineStatus !== OnlineStatus.Offline,
socketStatus,
});
if (socketStatus === SocketStatus.OPEN) {
onOutageEnd();
}
};
let outageTimer: NodeJS.Timeout | undefined;
const checkOutage = async (): Promise<void> => {
electronLookup('uptime.signal.org', { all: false }, (error, address) => {
if (error) {
log.error('networkObserver: outage check failure', error);
return;
}
if (address === OUTAGE_HEALTY_ADDR) {
log.info(
'networkObserver: got healthy response from uptime.signal.org'
);
onOutageEnd();
} else if (address === OUTAGE_NO_SERVICE_ADDR) {
log.warn('networkObserver: service is down');
networkActions.setOutage(true);
} else {
log.error(
'networkObserver: unexpected DNS response for uptime.signal.org'
);
}
});
};
const onPotentialOutage = (): void => {
if (outageTimer != null) {
return;
}
log.warn('networkObserver: initiating outage check');
outageTimer = setInterval(() => drop(checkOutage()), OUTAGE_CHECK_INTERVAL);
drop(checkOutage());
};
const onOutageEnd = (): void => {
if (outageTimer == null) {
return;
}
log.warn('networkObserver: clearing outage check');
clearInterval(outageTimer);
outageTimer = undefined;
networkActions.setOutage(false);
};
let offlineTimer: NodeJS.Timeout | undefined;
window.Whisper.events.on('socketStatusChange', refresh);
window.Whisper.events.on('online', () => {
onlineStatus = OnlineStatus.Online;
if (offlineTimer) {
clearTimeout(offlineTimer);
offlineTimer = undefined;
}
refresh();
});
window.Whisper.events.on('offline', () => {
if (onlineStatus !== OnlineStatus.Online) {
return;
}
onlineStatus = OnlineStatus.MaybeOffline;
offlineTimer = setTimeout(() => {
onlineStatus = OnlineStatus.Offline;
refresh();
onPotentialOutage();
}, OFFLINE_DELAY);
});
}