100 lines
1.7 KiB
JavaScript
100 lines
1.7 KiB
JavaScript
/*!
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* dns.js - dns backend for bcoin
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* Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
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* https://github.com/bcoin-org/bcoin
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*/
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'use strict';
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/**
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* @module net/dns
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*/
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const dns = require('dns');
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const socks = require('./socks');
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const options = {
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family: 4,
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hints: dns.ADDRCONFIG | dns.V4MAPPED,
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all: true
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};
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/**
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* Resolve host (no getaddrinfo).
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* @param {String} host
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* @param {String?} proxy - Tor socks proxy.
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* @returns {Promise}
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*/
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exports.resolve = function resolve(host, proxy) {
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if (proxy)
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return socks.resolve(proxy, host);
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return new Promise((resolve, reject) => {
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dns.resolve(host, 'A', to((err, result) => {
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if (err) {
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reject(err);
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return;
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}
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if (result.length === 0) {
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reject(new Error('No DNS results.'));
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return;
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}
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resolve(result);
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}));
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});
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};
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/**
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* Resolve host (getaddrinfo).
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* @param {String} host
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* @param {String?} proxy - Tor socks proxy.
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* @returns {Promise}
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*/
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exports.lookup = function lookup(host, proxy) {
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if (proxy)
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return socks.resolve(proxy, host);
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return new Promise((resolve, reject) => {
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let addrs = [];
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dns.lookup(host, options, to((err, result) => {
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if (err) {
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reject(err);
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return;
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}
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if (result.length === 0) {
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reject(new Error('No DNS results.'));
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return;
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}
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for (let addr of result)
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addrs.push(addr.address);
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resolve(addrs);
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}));
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});
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};
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/*
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* Helpers
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*/
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function to(callback) {
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let timeout = setTimeout(() => {
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callback(new Error('DNS request timed out.'));
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callback = null;
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}, 5000);
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return function(err, result) {
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if (callback) {
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clearTimeout(timeout);
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callback(err, result);
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}
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};
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}
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