WIP: Implement a PAC script parser and resolver for dojo#335

bryanforbes · May 21, 2017 · 30b490f · 30b490f
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diff --git a/package.json b/package.json
@@ -29,17 +29,23 @@
     "@dojo/loader": "beta1",
     "@types/benchmark": "~1.0.0",
     "@types/chai": "~3.4.0",
+    "@types/fibers": "0.0.29",
     "@types/formidable": "~1.0.0",
     "@types/glob": "~5.0.0",
     "@types/grunt": "~0.4.0",
+    "@types/ip": "0.0.29",
+    "@types/netmask": "^1.0.29",
     "@types/sinon": "~1.16.0",
     "benchmark": "^1.0.0",
+    "fibers": "^1.0.15",
     "formidable": "1.0.17",
     "grunt": "^1.0.1",
     "grunt-dojo2": "beta1",
     "http-proxy": "0.10.3",
     "intern": "^3.4.1",
+    "ip": "^1.1.5",
     "istanbul": "0.4.3",
+    "netmask": "^1.0.6",
     "sinon": "~1.17.6",
     "typescript": "~2.3.2"
   }

diff --git a/src/request/providers/node/pac.ts b/src/request/providers/node/pac.ts
@@ -0,0 +1,245 @@
+import { runInNewContext } from 'vm';
+import { lookup as lookupAsync } from 'dns';
+import Promise from '@dojo/shim/Promise';
+import DateObject, { DateProperties } from '../../../DateObject';
+import Fiber = require('fibers');
+import { Netmask } from 'netmask';
+import { address } from 'ip';
+
+/**
+ * Wraps `dns.lookup` for use in a Fiber so it works synchronously
+ * inside a PAC script.
+ */
+function lookup(hostname: string, family: number = 4): void {
+	const fiber = Fiber.current;
+	lookupAsync(hostname, family, (err, address) => {
+		if (err) {
+			// Notify of the error
+			(fiber as any).throwInto(err);
+		} else {
+			// Resume execution
+			fiber.run(address as any);
+		}
+	});
+
+	// Tell the Fiber to pause execution
+	(Fiber as any).yield();
+}
+
+const dotRegExp = /\./g;
+
+function isPlainHostName(host: string): boolean {
+	return !(dotRegExp.test(host));
+}
+
+function dnsDomainIs(host: string, domain: string): boolean {
+	domain = String(domain);
+	return String(host).substr(domain.length * -1) === domain;
+}
+
+function localHostOrDomainIs(host: string, hostdom: string): boolean {
+	if (!isPlainHostName(host)) {
+		return host === hostdom;
+	}
+	return host === String(hostdom).split('.')[0];
+}
+
+function isResolvable(host: string): boolean {
+	try {
+		lookup(host);
+	}
+	catch (_) {
+		return false;
+	}
+	return true;
+}
+
+function isInNet(host: string, pattern: string, mask: string): boolean {
+	const ip = lookup(host) || '127.0.0.1';
+	const netmask = new Netmask(pattern, mask);
+	return Boolean(netmask.contains(ip));
+}
+
+function dnsResolve(host: string): string {
+	return lookup(host) || '127.0.0.1';
+}
+
+function myIpAddress(): string {
+	return address();
+}
+
+function dnsDomainLevels(host: string): number {
+	const match = String(host).match(dotRegExp);
+	if (!match) {
+		return 0;
+	}
+	return match.length;
+}
+
+function shExpMatch(str: string, shexp: string): boolean {
+	shexp = String(shexp)
+		.replace(/\?/g, '.')
+		.replace(/\*/g, '(:?.*)');
+	return new RegExp(`^${shexp}$`).test(str);
+}
+
+type Weekday = 'SUN' | 'MON' | 'TUE' | 'WED' | 'THU' | 'FRI' | 'SAT';
+
+const dayMap: { [key: string]: number } = {
+	SUN: 0,
+	MON: 1,
+	TUE: 2,
+	WED: 3,
+	THU: 4,
+	FRI: 5,
+	SAT: 6
+};
+
+function weekdayRange(weekDay1: Weekday, gmt?: 'GMT'): boolean;
+function weekdayRange(weekDay1: Weekday, weekDay2: Weekday, gmt?: 'GMT'): boolean;
+function weekdayRange(weekDay1: Weekday, weekDay2: string = '', gmt?: 'GMT'): boolean {
+	let wd1 = dayMap[weekDay1] || -1;
+	let wd2 = dayMap[weekDay2] || -1;
+	let useUTC = weekDay2 === 'GMT' || gmt === 'GMT';
+	let now = DateObject.now();
+	let today: number = (useUTC ? now.utc : now).dayOfWeek;
+
+	if (wd2 === -1) {
+		return wd1 === today;
+	}
+	else {
+		if (wd1 <= wd2) {
+			return weekdayInRange(today, wd1, wd2);
+		}
+		else {
+			return weekdayInRange(today, wd1, 6) || weekdayInRange(today, 0, wd2);
+		}
+	}
+}
+
+function weekdayInRange(today: number, start: number, end: number): boolean {
+	return today >= start && today <= end;
+}
+
+type Month = 'JAN' | 'FEB' | 'MAR' | 'APR' | 'MAY' | 'JUN' | 'JUL' | 'AUG' | 'SEP' | 'OCT' | 'NOV' | 'DEC';
+
+/*const monthMap: { [key: string]: number; } = {
+	JAN: 1,
+	FEB: 2,
+	MAR: 3,
+	APR: 4,
+	MAY: 5,
+	JUN: 6,
+	JUL: 7,
+	AUG: 8,
+	SEP: 9,
+	OCT: 10,
+	NOV: 11,
+	DEC: 12
+};*/
+
+function dateRange(dayOrYear: number, gmt?: 'GMT'): boolean;
+function dateRange(dayOrYear1: number, dayOrYear2: number, gmt?: 'GMT'): boolean;
+function dateRange(mon: Month, gmt?: 'GMT'): boolean;
+function dateRange(mon1: Month, mon2: Month, gmt?: 'GMT'): boolean;
+function dateRange(day1: number, mon1: Month, day2: number, mon2: Month, gmt?: 'GMT'): boolean;
+function dateRange(mon1: Month, year1: number, mon2: Month, year2: number, gmt?: 'GMT'): boolean;
+function dateRange(day1: number, mon1: Month, year1: number, day2: number, mon2: Month, year2: number, gmt?: 'GMT'): boolean;
+function dateRange(...args: any[]): boolean {
+	let useUTC = false;
+	if (args[args.length - 1] === 'GMT') {
+		args.pop();
+		useUTC = true;
+	}
+
+	return false;
+}
+
+function timeRange(hour: number, gmt?: 'GMT'): boolean;
+function timeRange(hour1: number, hour2: number, gmt?: 'GMT'): boolean;
+function timeRange(hour1: number, min1: number, hour2: number, min2: number, gmt?: 'GMT'): boolean;
+function timeRange(hour1: number, min1: number, sec1: number, hour2: number, min2: number, sec2: number, gmt?: 'GMT'): boolean;
+function timeRange(...args: any[]): boolean {
+	let useUTC = false;
+	if (args[args.length - 1] === 'GMT') {
+		args.pop();
+		useUTC = true;
+	}
+
+	let now: DateProperties = useUTC ? DateObject.now() : DateObject.now().utc;
+	let integers = args.map(arg => parseInt(arg, 10));
+
+	if (args.length === 1) {
+		return now.hours === integers[0];
+	}
+	else if (args.length === 2) {
+		return integers[0] <= now.hours && now.hours < integers[1];
+	}
+	else if (args.length === 4) {
+		let seconds = getSeconds(now.hours, now.minutes, 0);
+
+		return getSeconds(integers[0], integers[1], 0) <= seconds &&
+			seconds <= getSeconds(integers[2], integers[3], 59);
+	}
+	else if (args.length === 6) {
+		let seconds = getSeconds(now.hours, now.minutes, now.seconds);
+
+		return getSeconds(integers[0], integers[1], integers[2]) <= seconds &&
+			seconds <= getSeconds(integers[3], integers[4], integers[5]);
+	}
+
+	return false;
+}
+
+function getSeconds(hours: number, minutes: number, seconds: number): number {
+	return (hours * 3600) + (minutes * 60) + seconds;
+}
+
+export interface FindProxyForURL {
+	(url: string, host: string): Promise<string>;
+}
+
+export default function pac(content: string, fileName?: string): FindProxyForURL {
+	const pacFind = new Promise<FindProxyForURL>((resolve, reject) => {
+		Fiber(() => {
+			try {
+				const pacFind = runInNewContext(`${content};FindProxyForURL`, {
+					isPlainHostName,
+					dnsDomainIs,
+					localHostOrDomainIs,
+					isResolvable,
+					isInNet,
+					dnsResolve,
+					myIpAddress,
+					dnsDomainLevels,
+					shExpMatch,
+					weekdayRange,
+					dateRange,
+					timeRange
+				}, fileName);
+
+				if (typeof pacFind !== 'function') {
+					throw new TypeError('A PAC file must declare a function named "FindProxyForURL"');
+				}
+			}
+			catch (error) {
+				reject(error);
+			}
+		}).run();
+	});
+
+	return function FindProxyForURL(url: string, host: string): Promise<string> {
+		return pacFind.then(pacFind => {
+			return new Promise<string>((resolve, reject) => {
+				Fiber(() => {
+					try {
+						resolve(pacFind(url, host));
+					}
+					catch (error) {
+						reject(error);
+					}
+				}).run();
+			});
+		});
+	};
+}