commit 10e4dfeb23cddbb6d367d85f536b0d473a163b45 Author: David Fifield david@bamsoftware.com Date: Sat Mar 15 20:27:38 2014 -0700

Handle connections, do JSON, make requests. --- firefox/components/main.js | 302 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 263 insertions(+), 39 deletions(-)

diff --git a/firefox/components/main.js b/firefox/components/main.js index c38eeda..8bda493 100644 --- a/firefox/components/main.js +++ b/firefox/components/main.js @@ -2,31 +2,20 @@ // https://developer.mozilla.org/en-US/docs/Mozilla/JavaScript_code_modules/XPC... Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

+// Everything resides within the MeekHTTPHelper namespace. MeekHTTPHelper is +// also the type from which NSGetFactory is constructed, and it is the top-level +// nsIServerSocketListener. function MeekHTTPHelper() { this.wrappedJSObject = this;

const LOCAL_PORT = 7000;

- // Create a "direct" nsIProxyInfo that bypasses the default proxy. - // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIProtoc... - var pps = Components.classes["@mozilla.org/network/protocol-proxy-service;1"] - .getService(Components.interfaces.nsIProtocolProxyService); - // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIProxyI... - this.directProxyInfo = pps.newProxyInfo("direct", "", 0, 0, 0xffffffff, null); - - // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIIOServ... - this.ioService = Components.classes["@mozilla.org/network/io-service;1"] - .getService(Components.interfaces.nsIIOService); - this.httpProtocolHandler = this.ioService.getProtocolHandler("http") - .QueryInterface(Components.interfaces.nsIHttpProtocolHandler); - // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIServer... var serverSocket = Components.classes["@mozilla.org/network/server-socket;1"] .createInstance(Components.interfaces.nsIServerSocket); serverSocket.init(LOCAL_PORT, true, -1); serverSocket.asyncListen(this); } - MeekHTTPHelper.prototype = { classDescription: "meek HTTP helper component", classID: Components.ID("{e7bc2b9c-f454-49f3-a19f-14848a4d871d}"), @@ -39,51 +28,286 @@ MeekHTTPHelper.prototype = { ]),

// nsIServerSocketListener implementation. - onSocketAccepted: function(aServ, aTransport) { - dump("onSocketAccepted host " + aTransport.host + "\n"); + onSocketAccepted: function(server, transport) { + dump("onSocketAccepted " + transport.host + ":" + transport.port + "\n"); + new MeekHTTPHelper.LocalConnectionHandler(transport); + }, + onStopListening: function(server, status) { + dump("onStopListening status " + status + "\n"); + }, +};

- const FRONT_URL = "https://www.google.com/"; - const HOST = "meek-reflect.appspot.com"; +// Global variables and functions.

- var uri = this.ioService.newURI(FRONT_URL, null, null); +MeekHTTPHelper.LOCAL_READ_TIMEOUT = 2.0; +MeekHTTPHelper.LOCAL_WRITE_TIMEOUT = 2.0; + +// A "direct" nsIProxyInfo that bypasses the default proxy. +// https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIProtoc... +// https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIProxyI... +MeekHTTPHelper.directProxyInfo = Components.classes["@mozilla.org/network/protocol-proxy-service;1"] + .getService(Components.interfaces.nsIProtocolProxyService) + .newProxyInfo("direct", "", 0, 0, 0xffffffff, null); + +// https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIIOServ... +MeekHTTPHelper.ioService = Components.classes["@mozilla.org/network/io-service;1"] + .getService(Components.interfaces.nsIIOService); +MeekHTTPHelper.httpProtocolHandler = MeekHTTPHelper.ioService.getProtocolHandler("http") + .QueryInterface(Components.interfaces.nsIHttpProtocolHandler); + +// Set the transport to time out at the given absolute deadline. +MeekHTTPHelper.refreshDeadline = function(transport, deadline) { + var timeout; + if (deadline === null) + timeout = 0xffffffff; + else + timeout = Math.max(0.0, Math.ceil((deadline - Date.now()) / 1000.0)); + transport.setTimeout(Components.interfaces.nsISocketTransport.TIMEOUT_READ_WRITE, timeout); +}; + +// Reverse-index the Components.results table. +MeekHTTPHelper.lookupStatus = function(status) { + for (var name in Components.results) { + if (Components.results[name] === status) + return name; + } + return null; +}; + +// LocalConnectionHandler handles each new client connection received on the +// socket opened by MeekHTTPHelper. It reads a JSON request, makes the request +// on the Internet, and writes the result back to the socket. Error handling +// happens within callbacks. +MeekHTTPHelper.LocalConnectionHandler = function(transport) { + dump("LocalConnectionHandler\n"); + this.transport = transport; + this.readRequest(this.makeRequest.bind(this)); +}; +MeekHTTPHelper.LocalConnectionHandler.prototype = { + readRequest: function(callback) { + dump("readRequest\n"); + new MeekHTTPHelper.RequestReader(this.transport, this.makeRequest.bind(this)); + }, + + makeRequest: function(req) { + dump("makeRequest " + JSON.stringify(req) + "\n"); + if (!this.requestOk(req)) { + this.transport.close(0); + return; + } + var uri = MeekHTTPHelper.ioService.newURI(req.url, null, null); // Construct an HTTP channel with the proxy bypass. // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIHttpCh... - var channel = this.httpProtocolHandler.newProxiedChannel(uri, this.directProxyInfo, 0, null) + var channel = MeekHTTPHelper.httpProtocolHandler.newProxiedChannel(uri, MeekHTTPHelper.directProxyInfo, 0, null) .QueryInterface(Components.interfaces.nsIHttpChannel); - // Set the host we really want. - channel.setRequestHeader("Host", HOST, false); - channel.redirectionLimit = 0; + if (req.header !== undefined) { + for (var key in req.header) { + dump("setting header " + key + ": " + req.header[key] + "\n"); + channel.setRequestHeader(key, req.header[key], false); + } + } + if (req.body !== undefined) { + let body = atob(req.body); + let inputStream = Components.classes["@mozilla.org/io/string-input-stream;1"] + .createInstance(Components.interfaces.nsIStringInputStream); + inputStream.setData(body, body.length); + let uploadChannel = channel.QueryInterface(Components.interfaces.nsIUploadChannel); + uploadChannel.setUploadStream(inputStream, "application/octet-stream", body.length); + } // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIUpload... - // channel.requestMethod = "POST"; + // says we must set requestMethod after calling setUploadStream. + channel.requestMethod = req.method; + channel.redirectionLimit = 0;

- channel.asyncOpen(new this.httpResponseStreamListener(), null); + channel.asyncOpen(new MeekHTTPHelper.HttpStreamListener(this.returnResponse.bind(this)), channel); }, - onStopListening: function(aServ, aStatus) { - dump("onStopListening status " + aStatus + "\n"); + + returnResponse: function(resp) { + dump("returnResponse " + JSON.stringify(resp) + "\n"); + outputStream = this.transport.openOutputStream( + Components.interfaces.nsITransport.OPEN_BLOCKING | Components.interfaces.nsITransport.OPEN_UNBUFFERED, 0, 0); + var output = Components.classes["@mozilla.org/binaryoutputstream;1"] + .createInstance(Components.interfaces.nsIBinaryOutputStream); + output.setOutputStream(outputStream); + + var converter = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"] + .createInstance(Components.interfaces.nsIScriptableUnicodeConverter); + converter.charset = "UTF-8"; + var s = JSON.stringify(resp); + var data = converter.convertToByteArray(s); + + var deadline = Date.now() + MeekHTTPHelper.LOCAL_WRITE_TIMEOUT * 1000; + try { + MeekHTTPHelper.refreshDeadline(this.transport, deadline); + output.write32(data.length); + MeekHTTPHelper.refreshDeadline(this.transport, deadline); + output.writeByteArray(data, data.length); + } finally { + output.close(); + } + }, + + // Enforce restrictions on what requests we are willing to make. These can + // probably be loosened up. Try and rule out anything unexpected until we + // know we need otherwise. + requestOk: function(req) { + if (req.method === undefined) { + dump("req missing "method".\n"); + return false; + } + if (req.url === undefined) { + dump("req missing "url".\n"); + return false; + } + + if (req.method !== "POST") { + dump("req.method is " + JSON.stringify(req.method) + ", not "POST".\n"); + return false; + } + if (!req.url.startsWith("https://")) { + dump("req.url doesn't start with "https://%5C%22.%5Cn"); + return false; + } + + return true; }, };

+// RequestReader reads a JSON-encoded request from the given transport, and +// calls the given callback with the request as an argument. In case of error, +// the transport is closed and the callback is not called. +MeekHTTPHelper.RequestReader = function(transport, callback) { + dump("RequestReader\n"); + this.transport = transport; + this.callback = callback;

-// https://developer.mozilla.org/en-US/docs/Creating_Sandboxed_HTTP_Connections -MeekHTTPHelper.prototype.httpResponseStreamListener = function() { + this.curThread = Components.classes["@mozilla.org/thread-manager;1"].getService().currentThread; + this.inputStream = this.transport.openInputStream( + Components.interfaces.nsITransport.OPEN_BLOCKING | Components.interfaces.nsITransport.OPEN_UNBUFFERED, 0, 0); + + this.state = this.STATE_READING_LENGTH; + this.buf = new Uint8Array(4); + this.bytesToRead = this.buf.length; + this.deadline = Date.now() + MeekHTTPHelper.LOCAL_READ_TIMEOUT * 1000; + this.asyncWait(); }; -MeekHTTPHelper.prototype.httpResponseStreamListener.prototype = { +MeekHTTPHelper.RequestReader.prototype = { + STATE_READING_LENGTH: 1, + STATE_READING_OBJECT: 2, + STATE_DONE: 3, + + // Do an asyncWait and handle the result. + asyncWait: function() { + MeekHTTPHelper.refreshDeadline(this.transport, this.deadline); + this.inputStream.asyncWait(this, 0, 0, this.curThread); + }, + + // nsIInputStreamCallback implementation. + onInputStreamReady: function(inputStream) { + var input = Components.classes["@mozilla.org/binaryinputstream;1"] + .createInstance(Components.interfaces.nsIBinaryInputStream); + input.setInputStream(inputStream); + try { + switch (this.state) { + case this.STATE_READING_LENGTH: + this.doStateReadingLength(input); + this.asyncWait(inputStream); + break; + case this.STATE_READING_OBJECT: + this.doStateReadingObject(input); + if (this.bytesToRead > 0) + this.asyncWait(inputStream); + break; + } + } catch (e) { + dump("got exception " + e + "\n"); + this.transport.close(0); + return; + } + }, + + // Read into this.buf (up to its capacity) and decrement this.bytesToRead. + readIntoBuf: function(input) { + var n = Math.min(input.available(), this.bytesToRead); + var data = input.readByteArray(n); + this.buf.subarray(this.buf.length - this.bytesToRead, n).set(data) + this.bytesToRead -= n; + }, + + doStateReadingLength: function(input) { + this.readIntoBuf(input); + if (this.bytesToRead > 0) + return; + + this.state = this.STATE_READING_OBJECT; + var b = this.buf; + this.bytesToRead = (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3]; + if (this.bytesToRead > 1000000) { + dump("Object length is too long (" + this.bytesToRead + "), ignoring.\n"); + throw Components.results.NS_ERROR_FAILURE; + } + this.buf = new Uint8Array(this.bytesToRead); + }, + + doStateReadingObject: function(input) { + this.readIntoBuf(input); + if (this.bytesToRead > 0) + return; + + this.state = this.STATE_DONE; + var converter = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"] + .createInstance(Components.interfaces.nsIScriptableUnicodeConverter); + converter.charset = "UTF-8"; + var s = converter.convertFromByteArray(this.buf, this.buf.length); + var req = JSON.parse(s); + this.callback(req); + }, +}; + +// HttpStreamListener makes the requested HTTP request and calls the given +// callback with a representation of the response. The "error" key of the return +// value is defined if and only if there was an error. +MeekHTTPHelper.HttpStreamListener = function(callback) { + this.callback = callback; + // This is a list of binary strings that is concatenated in onStopRequest. + this.body = []; + this.length = 0; +}; +// https://developer.mozilla.org/en-US/docs/Creating_Sandboxed_HTTP_Connections +MeekHTTPHelper.HttpStreamListener.prototype = { // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIReques... - onStartRequest: function(aRequest, aContext) { + onStartRequest: function(req, context) { dump("onStartRequest\n"); }, - onStopRequest: function(aRequest, aContext, aStatus) { - dump("onStopRequest\n"); + onStopRequest: function(req, context, status) { + dump("onStopRequest " + status + "\n"); + var resp = { + status: context.responseStatus, + }; + if (Components.isSuccessCode(status)) { + resp.body = btoa(this.body.join("")); + } else { + let err = MeekHTTPHelper.lookupStatus(status); + if (err !== null) + resp.error = err; + else + resp.error = "error " + String(status); + } + this.callback(resp); }, + // https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIStream... - onDataAvailable: function(aRequest, aContext, aStream, aSourceOffset, aLength) { - dump("onDataAvailable\n"); - var a = new Uint8Array(aLength); + onDataAvailable: function(request, context, stream, sourceOffset, length) { + dump("onDataAvailable " + length + " bytes\n"); + if (this.length + length > 1000000) { + request.cancel(Components.results.NS_ERROR_ILLEGAL_VALUE); + return; + } + this.length += length; var input = Components.classes["@mozilla.org/binaryinputstream;1"] .createInstance(Components.interfaces.nsIBinaryInputStream); - input.setInputStream(aStream); - input.readByteArray(aLength, a); - dump(aLength + ":" + a + "\n"); + input.setInputStream(stream); + this.body.push(String.fromCharCode.apply(null, input.readByteArray(length))); }, };