code-server/src/node/socket.ts

100 lines
3.1 KiB
TypeScript

import { promises as fs } from "fs"
import * as net from "net"
import * as path from "path"
import * as tls from "tls"
import { Emitter } from "../common/emitter"
import { generateUuid } from "../common/util"
import { canConnect, tmpdir } from "./util"
/**
* Provides a way to proxy a TLS socket. Can be used when you need to pass a
* socket to a child process since you can't pass the TLS socket.
*/
export class SocketProxyProvider {
private readonly onProxyConnect = new Emitter<net.Socket>()
private proxyPipe = path.join(tmpdir, "tls-proxy")
private _proxyServer?: Promise<net.Server>
private readonly proxyTimeout = 5000
/**
* Stop the proxy server.
*/
public stop(): void {
if (this._proxyServer) {
this._proxyServer.then((server) => server.close())
this._proxyServer = undefined
}
}
/**
* Create a socket proxy for TLS sockets. If it's not a TLS socket the
* original socket is returned. This will spawn a proxy server on demand.
*/
public async createProxy(socket: net.Socket): Promise<net.Socket> {
if (!(socket instanceof tls.TLSSocket)) {
return socket
}
await this.startProxyServer()
return new Promise((resolve, reject) => {
const id = generateUuid()
const proxy = net.connect(this.proxyPipe)
proxy.once("connect", () => proxy.write(id))
const timeout = setTimeout(() => {
listener.dispose() // eslint-disable-line @typescript-eslint/no-use-before-define
socket.destroy()
proxy.destroy()
reject(new Error("TLS socket proxy timed out"))
}, this.proxyTimeout)
const listener = this.onProxyConnect.event((connection) => {
connection.once("data", (data) => {
if (!socket.destroyed && !proxy.destroyed && data.toString() === id) {
clearTimeout(timeout)
listener.dispose()
;[
[proxy, socket],
[socket, proxy],
].forEach(([a, b]) => {
a.pipe(b)
a.on("error", () => b.destroy())
a.on("close", () => b.destroy())
a.on("end", () => b.end())
})
resolve(connection)
}
})
})
})
}
private async startProxyServer(): Promise<net.Server> {
if (!this._proxyServer) {
this._proxyServer = this.findFreeSocketPath(this.proxyPipe)
.then((pipe) => {
this.proxyPipe = pipe
return Promise.all([fs.mkdir(tmpdir, { recursive: true }), fs.rmdir(this.proxyPipe, { recursive: true })])
})
.then(() => {
return new Promise((resolve) => {
const proxyServer = net.createServer((p) => this.onProxyConnect.emit(p))
proxyServer.once("listening", () => resolve(proxyServer))
proxyServer.listen(this.proxyPipe)
})
})
}
return this._proxyServer
}
public async findFreeSocketPath(basePath: string, maxTries = 100): Promise<string> {
let i = 0
let path = basePath
while ((await canConnect(path)) && i < maxTries) {
path = `${basePath}-${++i}`
}
return path
}
}