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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /devtools/server/websocket-server.js | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'devtools/server/websocket-server.js')
-rw-r--r-- | devtools/server/websocket-server.js | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/devtools/server/websocket-server.js b/devtools/server/websocket-server.js new file mode 100644 index 000000000..6e8a80fec --- /dev/null +++ b/devtools/server/websocket-server.js @@ -0,0 +1,221 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +const { Cc, CC } = require("chrome"); +const Promise = require("promise"); +const { Task } = require("devtools/shared/task"); +const { executeSoon } = require("devtools/shared/DevToolsUtils"); +const { delimitedRead } = require("devtools/shared/transport/stream-utils"); +const CryptoHash = CC("@mozilla.org/security/hash;1", "nsICryptoHash", "initWithString"); +const threadManager = Cc["@mozilla.org/thread-manager;1"].getService(); + +// Limit the header size to put an upper bound on allocated memory +const HEADER_MAX_LEN = 8000; + +/** + * Read a line from async input stream and return promise that resolves to the line once + * it has been read. If the line is longer than HEADER_MAX_LEN, will throw error. + */ +function readLine(input) { + return new Promise((resolve, reject) => { + let line = ""; + let wait = () => { + input.asyncWait(stream => { + try { + let amountToRead = HEADER_MAX_LEN - line.length; + line += delimitedRead(input, "\n", amountToRead); + + if (line.endsWith("\n")) { + resolve(line.trimRight()); + return; + } + + if (line.length >= HEADER_MAX_LEN) { + throw new Error( + `Failed to read HTTP header longer than ${HEADER_MAX_LEN} bytes`); + } + + wait(); + } catch (ex) { + reject(ex); + } + }, 0, 0, threadManager.currentThread); + }; + + wait(); + }); +} + +/** + * Write a string of bytes to async output stream and return promise that resolves once + * all data has been written. Doesn't do any utf-16/utf-8 conversion - the string is + * treated as an array of bytes. + */ +function writeString(output, data) { + return new Promise((resolve, reject) => { + let wait = () => { + if (data.length === 0) { + resolve(); + return; + } + + output.asyncWait(stream => { + try { + let written = output.write(data, data.length); + data = data.slice(written); + wait(); + } catch (ex) { + reject(ex); + } + }, 0, 0, threadManager.currentThread); + }; + + wait(); + }); +} + +/** + * Read HTTP request from async input stream. + * @return Request line (string) and Map of header names and values. + */ +const readHttpRequest = Task.async(function* (input) { + let requestLine = ""; + let headers = new Map(); + + while (true) { + let line = yield readLine(input); + if (line.length == 0) { + break; + } + + if (!requestLine) { + requestLine = line; + } else { + let colon = line.indexOf(":"); + if (colon == -1) { + throw new Error(`Malformed HTTP header: ${line}`); + } + + let name = line.slice(0, colon).toLowerCase(); + let value = line.slice(colon + 1).trim(); + headers.set(name, value); + } + } + + return { requestLine, headers }; +}); + +/** + * Write HTTP response (array of strings) to async output stream. + */ +function writeHttpResponse(output, response) { + let responseString = response.join("\r\n") + "\r\n\r\n"; + return writeString(output, responseString); +} + +/** + * Process the WebSocket handshake headers and return the key to be sent in + * Sec-WebSocket-Accept response header. + */ +function processRequest({ requestLine, headers }) { + let [ method, path ] = requestLine.split(" "); + if (method !== "GET") { + throw new Error("The handshake request must use GET method"); + } + + if (path !== "/") { + throw new Error("The handshake request has unknown path"); + } + + let upgrade = headers.get("upgrade"); + if (!upgrade || upgrade !== "websocket") { + throw new Error("The handshake request has incorrect Upgrade header"); + } + + let connection = headers.get("connection"); + if (!connection || !connection.split(",").map(t => t.trim()).includes("Upgrade")) { + throw new Error("The handshake request has incorrect Connection header"); + } + + let version = headers.get("sec-websocket-version"); + if (!version || version !== "13") { + throw new Error("The handshake request must have Sec-WebSocket-Version: 13"); + } + + // Compute the accept key + let key = headers.get("sec-websocket-key"); + if (!key) { + throw new Error("The handshake request must have a Sec-WebSocket-Key header"); + } + + return { acceptKey: computeKey(key) }; +} + +function computeKey(key) { + let str = key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; + + let data = Array.from(str, ch => ch.charCodeAt(0)); + let hash = new CryptoHash("sha1"); + hash.update(data, data.length); + return hash.finish(true); +} + +/** + * Perform the server part of a WebSocket opening handshake on an incoming connection. + */ +const serverHandshake = Task.async(function* (input, output) { + // Read the request + let request = yield readHttpRequest(input); + + try { + // Check and extract info from the request + let { acceptKey } = processRequest(request); + + // Send response headers + yield writeHttpResponse(output, [ + "HTTP/1.1 101 Switching Protocols", + "Upgrade: websocket", + "Connection: Upgrade", + `Sec-WebSocket-Accept: ${acceptKey}`, + ]); + } catch (error) { + // Send error response in case of error + yield writeHttpResponse(output, [ "HTTP/1.1 400 Bad Request" ]); + throw error; + } +}); + +/** + * Accept an incoming WebSocket server connection. + * Takes an established nsISocketTransport in the parameters. + * Performs the WebSocket handshake and waits for the WebSocket to open. + * Returns Promise with a WebSocket ready to send and receive messages. + */ +const accept = Task.async(function* (transport, input, output) { + yield serverHandshake(input, output); + + let transportProvider = { + setListener(upgradeListener) { + // The onTransportAvailable callback shouldn't be called synchronously. + executeSoon(() => { + upgradeListener.onTransportAvailable(transport, input, output); + }); + } + }; + + return new Promise((resolve, reject) => { + let socket = WebSocket.createServerWebSocket(null, [], transportProvider, ""); + socket.addEventListener("close", () => { + input.close(); + output.close(); + }); + + socket.onopen = () => resolve(socket); + socket.onerror = err => reject(err); + }); +}); + +exports.accept = accept; |