client: support custom HTTP headers ✅

closes #9

Co-Authored-By: Jannis R <[email protected]>

cli/client.js

@@ -5,19 +5,23 @@ const mri = require('mri')
 const pkg = require('../package.json')
 
 const argv = mri(process.argv.slice(2), {
-	boolean: ['help', 'h', 'version', 'v']
+	boolean: ['help', 'h', 'version', 'v'],
+	alias : {H: 'header'}
 })
 
 if (argv.help || argv.h) {
 	process.stdout.write(`
 Usage:
-    tcp-over-websockets <tunnel-url> <tunnelled-target> <port-to-listen-on>
+    tcp-over-websockets [options] <tunnel-url> <tunnelled-target> <port-to-listen-on>
 Arguments:
     tunnel-url         The WebSocket address of the tunnel server.
     tunnelled-target   The hostname & port to let the tunnel server connect to.
     port-to-listen-on  The (local) port to expose the tunnel on.
+Options:
+	-H, --header <header>    Pass custom header(s) to tunnel server
 Example:
     tcp-over-websockets wss://example.org localhost:22 8022
+	tcp-over-websockets --header "Cookie:FOOL" wss://example.org localhost:22 8022
 \n`)
 	process.exit(0)
 }
@@ -40,7 +44,19 @@ if (!target) showError('missing target argument')
 const port = argv._[2]
 if (!port) showError('missing port argument')
 
-startClient(tunnel, target, port, (err) => {
+const headers = {}
+const headerArgs = Array.isArray(argv.header) ? argv.header : [argv.header]
+for (const arg of headerArgs) {
+	// we follow curl's mechanism here
+	// https://github.com/curl/curl/blob/d5b0fee39a7898dac42cb4fc64e35f5bc085e766/lib/headers.c#L200-L219
+	const match = /(?<=\w):\s+(?=.)/.exec(arg);
+	if (!match) showError(`invalid --header value: '${arg}'`)
+	const name = arg.slice(0, match.index)
+	const val = arg.slice(match.index + match[0].length)
+	headers[name] = val
+}
+
+startClient(tunnel, target, port, {headers}, (err) => {
 	if (err) showError(err)
 	else console.info(`tunneling ${target} via ${tunnel} & exposing it on port ${port}`)
 })

client.js

@@ -3,8 +3,12 @@
 const {createServer} = require('net')
 const {tunnelTo} = require('./tunnel')
 
-const startClient = (tunnel, target, port, cb) => {
-	const tcpServer = createServer(tunnelTo(tunnel, target))
+const startClient = (tunnel, target, port, opt, cb) => {
+	if (arguments.length === 4 && 'function' === typeof opt) {
+		cb = opt
+		opt = {}
+	}
+	const tcpServer = createServer(tunnelTo(tunnel, target, opt))
 
 	tcpServer.listen(port, cb)
 	return tcpServer

test.js

@@ -18,7 +18,11 @@ httpServer.listen(5000, (err) => {
 	const server = startServer(8080, (err) => {
 		if (err) return showError(err)
 
-		const client = startClient('ws://localhost:8080', 'localhost:5000', 5001, (err) => {
+		const headers = {
+			foo: 'BaR',
+			hello: 'world',
+		}
+		const client = startClient('ws://localhost:8080', 'localhost:5000', 5001, {headers}, (err) => {
 			if (err) return showError(err)
 
 			httpGet('http://localhost:5001', (res) => {

tunnel.js

@@ -4,8 +4,8 @@ const ws = require('websocket-stream')
 const pipe = require('pump')
 const debug = require('debug')('tcp-over-websockets:client')
 
-const tunnelTo = (tunnel, target) => (local) => {
-	const remote = ws(tunnel + (tunnel.slice(-1) === '/' ? '' : '/') + target)
+const tunnelTo = (tunnel, target, opt) => (local) => {
+	const remote = ws(tunnel + (tunnel.slice(-1) === '/' ? '' : '/') + target, opt)
 
 	const onError = (err) => {
 		if (err) debug(err)