437 lines
9.0 KiB
JavaScript
437 lines
9.0 KiB
JavaScript
|
'use strict';
|
||
|
|
const {
|
||
|
|
V4MAPPED,
|
||
|
|
ADDRCONFIG,
|
||
|
|
ALL,
|
||
|
|
promises: {
|
||
|
|
Resolver: AsyncResolver
|
||
|
|
},
|
||
|
|
lookup: dnsLookup
|
||
|
|
} = require('dns');
|
||
|
|
const {promisify} = require('util');
|
||
|
|
const os = require('os');
|
||
|
|
|
||
|
|
const kCacheableLookupCreateConnection = Symbol('cacheableLookupCreateConnection');
|
||
|
|
const kCacheableLookupInstance = Symbol('cacheableLookupInstance');
|
||
|
|
const kExpires = Symbol('expires');
|
||
|
|
|
||
|
|
const supportsALL = typeof ALL === 'number';
|
||
|
|
|
||
|
|
const verifyAgent = agent => {
|
||
|
|
if (!(agent && typeof agent.createConnection === 'function')) {
|
||
|
|
throw new Error('Expected an Agent instance as the first argument');
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const map4to6 = entries => {
|
||
|
|
for (const entry of entries) {
|
||
|
|
if (entry.family === 6) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
entry.address = `::ffff:${entry.address}`;
|
||
|
|
entry.family = 6;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const getIfaceInfo = () => {
|
||
|
|
let has4 = false;
|
||
|
|
let has6 = false;
|
||
|
|
|
||
|
|
for (const device of Object.values(os.networkInterfaces())) {
|
||
|
|
for (const iface of device) {
|
||
|
|
if (iface.internal) {
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (iface.family === 'IPv6') {
|
||
|
|
has6 = true;
|
||
|
|
} else {
|
||
|
|
has4 = true;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (has4 && has6) {
|
||
|
|
return {has4, has6};
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return {has4, has6};
|
||
|
|
};
|
||
|
|
|
||
|
|
const isIterable = map => {
|
||
|
|
return Symbol.iterator in map;
|
||
|
|
};
|
||
|
|
|
||
|
|
const ttl = {ttl: true};
|
||
|
|
const all = {all: true};
|
||
|
|
|
||
|
|
class CacheableLookup {
|
||
|
|
constructor({
|
||
|
|
cache = new Map(),
|
||
|
|
maxTtl = Infinity,
|
||
|
|
fallbackDuration = 3600,
|
||
|
|
errorTtl = 0.15,
|
||
|
|
resolver = new AsyncResolver(),
|
||
|
|
lookup = dnsLookup
|
||
|
|
} = {}) {
|
||
|
|
this.maxTtl = maxTtl;
|
||
|
|
this.errorTtl = errorTtl;
|
||
|
|
|
||
|
|
this._cache = cache;
|
||
|
|
this._resolver = resolver;
|
||
|
|
this._dnsLookup = promisify(lookup);
|
||
|
|
|
||
|
|
if (this._resolver instanceof AsyncResolver) {
|
||
|
|
this._resolve4 = this._resolver.resolve4.bind(this._resolver);
|
||
|
|
this._resolve6 = this._resolver.resolve6.bind(this._resolver);
|
||
|
|
} else {
|
||
|
|
this._resolve4 = promisify(this._resolver.resolve4.bind(this._resolver));
|
||
|
|
this._resolve6 = promisify(this._resolver.resolve6.bind(this._resolver));
|
||
|
|
}
|
||
|
|
|
||
|
|
this._iface = getIfaceInfo();
|
||
|
|
|
||
|
|
this._pending = {};
|
||
|
|
this._nextRemovalTime = false;
|
||
|
|
this._hostnamesToFallback = new Set();
|
||
|
|
|
||
|
|
if (fallbackDuration < 1) {
|
||
|
|
this._fallback = false;
|
||
|
|
} else {
|
||
|
|
this._fallback = true;
|
||
|
|
|
||
|
|
const interval = setInterval(() => {
|
||
|
|
this._hostnamesToFallback.clear();
|
||
|
|
}, fallbackDuration * 1000);
|
||
|
|
|
||
|
|
/* istanbul ignore next: There is no `interval.unref()` when running inside an Electron renderer */
|
||
|
|
if (interval.unref) {
|
||
|
|
interval.unref();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
this.lookup = this.lookup.bind(this);
|
||
|
|
this.lookupAsync = this.lookupAsync.bind(this);
|
||
|
|
}
|
||
|
|
|
||
|
|
set servers(servers) {
|
||
|
|
this.clear();
|
||
|
|
|
||
|
|
this._resolver.setServers(servers);
|
||
|
|
}
|
||
|
|
|
||
|
|
get servers() {
|
||
|
|
return this._resolver.getServers();
|
||
|
|
}
|
||
|
|
|
||
|
|
lookup(hostname, options, callback) {
|
||
|
|
if (typeof options === 'function') {
|
||
|
|
callback = options;
|
||
|
|
options = {};
|
||
|
|
} else if (typeof options === 'number') {
|
||
|
|
options = {
|
||
|
|
family: options
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!callback) {
|
||
|
|
throw new Error('Callback must be a function.');
|
||
|
|
}
|
||
|
|
|
||
|
|
// eslint-disable-next-line promise/prefer-await-to-then
|
||
|
|
this.lookupAsync(hostname, options).then(result => {
|
||
|
|
if (options.all) {
|
||
|
|
callback(null, result);
|
||
|
|
} else {
|
||
|
|
callback(null, result.address, result.family, result.expires, result.ttl);
|
||
|
|
}
|
||
|
|
}, callback);
|
||
|
|
}
|
||
|
|
|
||
|
|
async lookupAsync(hostname, options = {}) {
|
||
|
|
if (typeof options === 'number') {
|
||
|
|
options = {
|
||
|
|
family: options
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
let cached = await this.query(hostname);
|
||
|
|
|
||
|
|
if (options.family === 6) {
|
||
|
|
const filtered = cached.filter(entry => entry.family === 6);
|
||
|
|
|
||
|
|
if (options.hints & V4MAPPED) {
|
||
|
|
if ((supportsALL && options.hints & ALL) || filtered.length === 0) {
|
||
|
|
map4to6(cached);
|
||
|
|
} else {
|
||
|
|
cached = filtered;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
cached = filtered;
|
||
|
|
}
|
||
|
|
} else if (options.family === 4) {
|
||
|
|
cached = cached.filter(entry => entry.family === 4);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (options.hints & ADDRCONFIG) {
|
||
|
|
const {_iface} = this;
|
||
|
|
cached = cached.filter(entry => entry.family === 6 ? _iface.has6 : _iface.has4);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (cached.length === 0) {
|
||
|
|
const error = new Error(`cacheableLookup ENOTFOUND ${hostname}`);
|
||
|
|
error.code = 'ENOTFOUND';
|
||
|
|
error.hostname = hostname;
|
||
|
|
|
||
|
|
throw error;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (options.all) {
|
||
|
|
return cached;
|
||
|
|
}
|
||
|
|
|
||
|
|
return cached[0];
|
||
|
|
}
|
||
|
|
|
||
|
|
async query(hostname) {
|
||
|
|
let cached = await this._cache.get(hostname);
|
||
|
|
|
||
|
|
if (!cached) {
|
||
|
|
const pending = this._pending[hostname];
|
||
|
|
|
||
|
|
if (pending) {
|
||
|
|
cached = await pending;
|
||
|
|
} else {
|
||
|
|
const newPromise = this.queryAndCache(hostname);
|
||
|
|
this._pending[hostname] = newPromise;
|
||
|
|
|
||
|
|
try {
|
||
|
|
cached = await newPromise;
|
||
|
|
} finally {
|
||
|
|
delete this._pending[hostname];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
cached = cached.map(entry => {
|
||
|
|
return {...entry};
|
||
|
|
});
|
||
|
|
|
||
|
|
return cached;
|
||
|
|
}
|
||
|
|
|
||
|
|
async _resolve(hostname) {
|
||
|
|
const wrap = async promise => {
|
||
|
|
try {
|
||
|
|
return await promise;
|
||
|
|
} catch (error) {
|
||
|
|
if (error.code === 'ENODATA' || error.code === 'ENOTFOUND') {
|
||
|
|
return [];
|
||
|
|
}
|
||
|
|
|
||
|
|
throw error;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
// ANY is unsafe as it doesn't trigger new queries in the underlying server.
|
||
|
|
const [A, AAAA] = await Promise.all([
|
||
|
|
this._resolve4(hostname, ttl),
|
||
|
|
this._resolve6(hostname, ttl)
|
||
|
|
].map(promise => wrap(promise)));
|
||
|
|
|
||
|
|
let aTtl = 0;
|
||
|
|
let aaaaTtl = 0;
|
||
|
|
let cacheTtl = 0;
|
||
|
|
|
||
|
|
const now = Date.now();
|
||
|
|
|
||
|
|
for (const entry of A) {
|
||
|
|
entry.family = 4;
|
||
|
|
entry.expires = now + (entry.ttl * 1000);
|
||
|
|
|
||
|
|
aTtl = Math.max(aTtl, entry.ttl);
|
||
|
|
}
|
||
|
|
|
||
|
|
for (const entry of AAAA) {
|
||
|
|
entry.family = 6;
|
||
|
|
entry.expires = now + (entry.ttl * 1000);
|
||
|
|
|
||
|
|
aaaaTtl = Math.max(aaaaTtl, entry.ttl);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (A.length > 0) {
|
||
|
|
if (AAAA.length > 0) {
|
||
|
|
cacheTtl = Math.min(aTtl, aaaaTtl);
|
||
|
|
} else {
|
||
|
|
cacheTtl = aTtl;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
cacheTtl = aaaaTtl;
|
||
|
|
}
|
||
|
|
|
||
|
|
return {
|
||
|
|
entries: [
|
||
|
|
...A,
|
||
|
|
...AAAA
|
||
|
|
],
|
||
|
|
cacheTtl
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
async _lookup(hostname) {
|
||
|
|
try {
|
||
|
|
const entries = await this._dnsLookup(hostname, {
|
||
|
|
all: true
|
||
|
|
});
|
||
|
|
|
||
|
|
return {
|
||
|
|
entries,
|
||
|
|
cacheTtl: 0
|
||
|
|
};
|
||
|
|
} catch (_) {
|
||
|
|
return {
|
||
|
|
entries: [],
|
||
|
|
cacheTtl: 0
|
||
|
|
};
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
async _set(hostname, data, cacheTtl) {
|
||
|
|
if (this.maxTtl > 0 && cacheTtl > 0) {
|
||
|
|
cacheTtl = Math.min(cacheTtl, this.maxTtl) * 1000;
|
||
|
|
data[kExpires] = Date.now() + cacheTtl;
|
||
|
|
|
||
|
|
try {
|
||
|
|
await this._cache.set(hostname, data, cacheTtl);
|
||
|
|
} catch (error) {
|
||
|
|
this.lookupAsync = async () => {
|
||
|
|
const cacheError = new Error('Cache Error. Please recreate the CacheableLookup instance.');
|
||
|
|
cacheError.cause = error;
|
||
|
|
|
||
|
|
throw cacheError;
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
if (isIterable(this._cache)) {
|
||
|
|
this._tick(cacheTtl);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
async queryAndCache(hostname) {
|
||
|
|
if (this._hostnamesToFallback.has(hostname)) {
|
||
|
|
return this._dnsLookup(hostname, all);
|
||
|
|
}
|
||
|
|
|
||
|
|
let query = await this._resolve(hostname);
|
||
|
|
|
||
|
|
if (query.entries.length === 0 && this._fallback) {
|
||
|
|
query = await this._lookup(hostname);
|
||
|
|
|
||
|
|
if (query.entries.length !== 0) {
|
||
|
|
// Use `dns.lookup(...)` for that particular hostname
|
||
|
|
this._hostnamesToFallback.add(hostname);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
const cacheTtl = query.entries.length === 0 ? this.errorTtl : query.cacheTtl;
|
||
|
|
await this._set(hostname, query.entries, cacheTtl);
|
||
|
|
|
||
|
|
return query.entries;
|
||
|
|
}
|
||
|
|
|
||
|
|
_tick(ms) {
|
||
|
|
const nextRemovalTime = this._nextRemovalTime;
|
||
|
|
|
||
|
|
if (!nextRemovalTime || ms < nextRemovalTime) {
|
||
|
|
clearTimeout(this._removalTimeout);
|
||
|
|
|
||
|
|
this._nextRemovalTime = ms;
|
||
|
|
|
||
|
|
this._removalTimeout = setTimeout(() => {
|
||
|
|
this._nextRemovalTime = false;
|
||
|
|
|
||
|
|
let nextExpiry = Infinity;
|
||
|
|
|
||
|
|
const now = Date.now();
|
||
|
|
|
||
|
|
for (const [hostname, entries] of this._cache) {
|
||
|
|
const expires = entries[kExpires];
|
||
|
|
|
||
|
|
if (now >= expires) {
|
||
|
|
this._cache.delete(hostname);
|
||
|
|
} else if (expires < nextExpiry) {
|
||
|
|
nextExpiry = expires;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (nextExpiry !== Infinity) {
|
||
|
|
this._tick(nextExpiry - now);
|
||
|
|
}
|
||
|
|
}, ms);
|
||
|
|
|
||
|
|
/* istanbul ignore next: There is no `timeout.unref()` when running inside an Electron renderer */
|
||
|
|
if (this._removalTimeout.unref) {
|
||
|
|
this._removalTimeout.unref();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
install(agent) {
|
||
|
|
verifyAgent(agent);
|
||
|
|
|
||
|
|
if (kCacheableLookupCreateConnection in agent) {
|
||
|
|
throw new Error('CacheableLookup has been already installed');
|
||
|
|
}
|
||
|
|
|
||
|
|
agent[kCacheableLookupCreateConnection] = agent.createConnection;
|
||
|
|
agent[kCacheableLookupInstance] = this;
|
||
|
|
|
||
|
|
agent.createConnection = (options, callback) => {
|
||
|
|
if (!('lookup' in options)) {
|
||
|
|
options.lookup = this.lookup;
|
||
|
|
}
|
||
|
|
|
||
|
|
return agent[kCacheableLookupCreateConnection](options, callback);
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
uninstall(agent) {
|
||
|
|
verifyAgent(agent);
|
||
|
|
|
||
|
|
if (agent[kCacheableLookupCreateConnection]) {
|
||
|
|
if (agent[kCacheableLookupInstance] !== this) {
|
||
|
|
throw new Error('The agent is not owned by this CacheableLookup instance');
|
||
|
|
}
|
||
|
|
|
||
|
|
agent.createConnection = agent[kCacheableLookupCreateConnection];
|
||
|
|
|
||
|
|
delete agent[kCacheableLookupCreateConnection];
|
||
|
|
delete agent[kCacheableLookupInstance];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
updateInterfaceInfo() {
|
||
|
|
const {_iface} = this;
|
||
|
|
|
||
|
|
this._iface = getIfaceInfo();
|
||
|
|
|
||
|
|
if ((_iface.has4 && !this._iface.has4) || (_iface.has6 && !this._iface.has6)) {
|
||
|
|
this._cache.clear();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
clear(hostname) {
|
||
|
|
if (hostname) {
|
||
|
|
this._cache.delete(hostname);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
this._cache.clear();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = CacheableLookup;
|
||
|
|
module.exports.default = CacheableLookup;
|