diff options
Diffstat (limited to 'toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js')
| -rw-r--r-- | toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js b/toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js new file mode 100644 index 000000000..ba4bf225a --- /dev/null +++ b/toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js @@ -0,0 +1,589 @@ +/* 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/. */ + +const Cc = Components.classes; +const Ci = Components.interfaces; +const Cr = Components.results; +const Cu = Components.utils; + +// COMPLETE_LENGTH and PARTIAL_LENGTH copied from nsUrlClassifierDBService.h, +// they correspond to the length, in bytes, of a hash prefix and the total +// hash. +const COMPLETE_LENGTH = 32; +const PARTIAL_LENGTH = 4; + +Cu.import("resource://gre/modules/XPCOMUtils.jsm"); +Cu.import("resource://gre/modules/Services.jsm"); +Cu.import("resource://gre/modules/NetUtil.jsm"); + + +// Log only if browser.safebrowsing.debug is true +function log(...stuff) { + let logging = null; + try { + logging = Services.prefs.getBoolPref("browser.safebrowsing.debug"); + } catch(e) { + return; + } + if (!logging) { + return; + } + + var d = new Date(); + let msg = "hashcompleter: " + d.toTimeString() + ": " + stuff.join(" "); + dump(Services.urlFormatter.trimSensitiveURLs(msg) + "\n"); +} + +// Map the HTTP response code to a Telemetry bucket +// https://developers.google.com/safe-browsing/developers_guide_v2?hl=en +function httpStatusToBucket(httpStatus) { + var statusBucket; + switch (httpStatus) { + case 100: + case 101: + // Unexpected 1xx return code + statusBucket = 0; + break; + case 200: + // OK - Data is available in the HTTP response body. + statusBucket = 1; + break; + case 201: + case 202: + case 203: + case 205: + case 206: + // Unexpected 2xx return code + statusBucket = 2; + break; + case 204: + // No Content - There are no full-length hashes with the requested prefix. + statusBucket = 3; + break; + case 300: + case 301: + case 302: + case 303: + case 304: + case 305: + case 307: + case 308: + // Unexpected 3xx return code + statusBucket = 4; + break; + case 400: + // Bad Request - The HTTP request was not correctly formed. + // The client did not provide all required CGI parameters. + statusBucket = 5; + break; + case 401: + case 402: + case 405: + case 406: + case 407: + case 409: + case 410: + case 411: + case 412: + case 414: + case 415: + case 416: + case 417: + case 421: + case 426: + case 428: + case 429: + case 431: + case 451: + // Unexpected 4xx return code + statusBucket = 6; + break; + case 403: + // Forbidden - The client id is invalid. + statusBucket = 7; + break; + case 404: + // Not Found + statusBucket = 8; + break; + case 408: + // Request Timeout + statusBucket = 9; + break; + case 413: + // Request Entity Too Large - Bug 1150334 + statusBucket = 10; + break; + case 500: + case 501: + case 510: + // Unexpected 5xx return code + statusBucket = 11; + break; + case 502: + case 504: + case 511: + // Local network errors, we'll ignore these. + statusBucket = 12; + break; + case 503: + // Service Unavailable - The server cannot handle the request. + // Clients MUST follow the backoff behavior specified in the + // Request Frequency section. + statusBucket = 13; + break; + case 505: + // HTTP Version Not Supported - The server CANNOT handle the requested + // protocol major version. + statusBucket = 14; + break; + default: + statusBucket = 15; + }; + return statusBucket; +} + +function HashCompleter() { + // The current HashCompleterRequest in flight. Once it is started, it is set + // to null. It may be used by multiple calls to |complete| in succession to + // avoid creating multiple requests to the same gethash URL. + this._currentRequest = null; + // A map of gethashUrls to HashCompleterRequests that haven't yet begun. + this._pendingRequests = {}; + + // A map of gethash URLs to RequestBackoff objects. + this._backoffs = {}; + + // Whether we have been informed of a shutdown by the shutdown event. + this._shuttingDown = false; + + Services.obs.addObserver(this, "quit-application", false); + +} + +HashCompleter.prototype = { + classID: Components.ID("{9111de73-9322-4bfc-8b65-2b727f3e6ec8}"), + QueryInterface: XPCOMUtils.generateQI([Ci.nsIUrlClassifierHashCompleter, + Ci.nsIRunnable, + Ci.nsIObserver, + Ci.nsISupportsWeakReference, + Ci.nsITimerCallback, + Ci.nsISupports]), + + // This is mainly how the HashCompleter interacts with other components. + // Even though it only takes one partial hash and callback, subsequent + // calls are made into the same HTTP request by using a thread dispatch. + complete: function HC_complete(aPartialHash, aGethashUrl, aCallback) { + if (!aGethashUrl) { + throw Cr.NS_ERROR_NOT_INITIALIZED; + } + + if (!this._currentRequest) { + this._currentRequest = new HashCompleterRequest(this, aGethashUrl); + } + if (this._currentRequest.gethashUrl == aGethashUrl) { + this._currentRequest.add(aPartialHash, aCallback); + } else { + if (!this._pendingRequests[aGethashUrl]) { + this._pendingRequests[aGethashUrl] = + new HashCompleterRequest(this, aGethashUrl); + } + this._pendingRequests[aGethashUrl].add(aPartialHash, aCallback); + } + + if (!this._backoffs[aGethashUrl]) { + // Initialize request backoffs separately, since requests are deleted + // after they are dispatched. + var jslib = Cc["@mozilla.org/url-classifier/jslib;1"] + .getService().wrappedJSObject; + + // Using the V4 backoff algorithm for both V2 and V4. See bug 1273398. + this._backoffs[aGethashUrl] = new jslib.RequestBackoffV4( + 10 /* keep track of max requests */, + 0 /* don't throttle on successful requests per time period */); + } + // Start off this request. Without dispatching to a thread, every call to + // complete makes an individual HTTP request. + Services.tm.currentThread.dispatch(this, Ci.nsIThread.DISPATCH_NORMAL); + }, + + // This is called after several calls to |complete|, or after the + // currentRequest has finished. It starts off the HTTP request by making a + // |begin| call to the HashCompleterRequest. + run: function() { + // Clear everything on shutdown + if (this._shuttingDown) { + this._currentRequest = null; + this._pendingRequests = null; + for (var url in this._backoffs) { + this._backoffs[url] = null; + } + throw Cr.NS_ERROR_NOT_INITIALIZED; + } + + // If we don't have an in-flight request, make one + let pendingUrls = Object.keys(this._pendingRequests); + if (!this._currentRequest && (pendingUrls.length > 0)) { + let nextUrl = pendingUrls[0]; + this._currentRequest = this._pendingRequests[nextUrl]; + delete this._pendingRequests[nextUrl]; + } + + if (this._currentRequest) { + try { + this._currentRequest.begin(); + } finally { + // If |begin| fails, we should get rid of our request. + this._currentRequest = null; + } + } + }, + + // Pass the server response status to the RequestBackoff for the given + // gethashUrl and fetch the next pending request, if there is one. + finishRequest: function(url, aStatus) { + this._backoffs[url].noteServerResponse(aStatus); + Services.tm.currentThread.dispatch(this, Ci.nsIThread.DISPATCH_NORMAL); + }, + + // Returns true if we can make a request from the given url, false otherwise. + canMakeRequest: function(aGethashUrl) { + return this._backoffs[aGethashUrl].canMakeRequest(); + }, + + // Notifies the RequestBackoff of a new request so we can throttle based on + // max requests/time period. This must be called before a channel is opened, + // and finishRequest must be called once the response is received. + noteRequest: function(aGethashUrl) { + return this._backoffs[aGethashUrl].noteRequest(); + }, + + observe: function HC_observe(aSubject, aTopic, aData) { + if (aTopic == "quit-application") { + this._shuttingDown = true; + Services.obs.removeObserver(this, "quit-application"); + } + }, +}; + +function HashCompleterRequest(aCompleter, aGethashUrl) { + // HashCompleter object that created this HashCompleterRequest. + this._completer = aCompleter; + // The internal set of hashes and callbacks that this request corresponds to. + this._requests = []; + // nsIChannel that the hash completion query is transmitted over. + this._channel = null; + // Response body of hash completion. Created in onDataAvailable. + this._response = ""; + // Whether we have been informed of a shutdown by the quit-application event. + this._shuttingDown = false; + this.gethashUrl = aGethashUrl; +} +HashCompleterRequest.prototype = { + QueryInterface: XPCOMUtils.generateQI([Ci.nsIRequestObserver, + Ci.nsIStreamListener, + Ci.nsIObserver, + Ci.nsISupports]), + + // This is called by the HashCompleter to add a hash and callback to the + // HashCompleterRequest. It must be called before calling |begin|. + add: function HCR_add(aPartialHash, aCallback) { + this._requests.push({ + partialHash: aPartialHash, + callback: aCallback, + responses: [] + }); + }, + + // This initiates the HTTP request. It can fail due to backoff timings and + // will notify all callbacks as necessary. We notify the backoff object on + // begin. + begin: function HCR_begin() { + if (!this._completer.canMakeRequest(this.gethashUrl)) { + log("Can't make request to " + this.gethashUrl + "\n"); + this.notifyFailure(Cr.NS_ERROR_ABORT); + return; + } + + Services.obs.addObserver(this, "quit-application", false); + + try { + this.openChannel(); + // Notify the RequestBackoff if opening the channel succeeded. At this + // point, finishRequest must be called. + this._completer.noteRequest(this.gethashUrl); + } + catch (err) { + this.notifyFailure(err); + throw err; + } + }, + + notify: function HCR_notify() { + // If we haven't gotten onStopRequest, just cancel. This will call us + // with onStopRequest since we implement nsIStreamListener on the + // channel. + if (this._channel && this._channel.isPending()) { + log("cancelling request to " + this.gethashUrl + "\n"); + Services.telemetry.getHistogramById("URLCLASSIFIER_COMPLETE_TIMEOUT").add(1); + this._channel.cancel(Cr.NS_BINDING_ABORTED); + } + }, + + // Creates an nsIChannel for the request and fills the body. + openChannel: function HCR_openChannel() { + let loadFlags = Ci.nsIChannel.INHIBIT_CACHING | + Ci.nsIChannel.LOAD_BYPASS_CACHE; + + let channel = NetUtil.newChannel({ + uri: this.gethashUrl, + loadUsingSystemPrincipal: true + }); + channel.loadFlags = loadFlags; + + // Disable keepalive. + let httpChannel = channel.QueryInterface(Ci.nsIHttpChannel); + httpChannel.setRequestHeader("Connection", "close", false); + + this._channel = channel; + + let body = this.buildRequest(); + this.addRequestBody(body); + + // Set a timer that cancels the channel after timeout_ms in case we + // don't get a gethash response. + this.timer_ = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); + // Ask the timer to use nsITimerCallback (.notify()) when ready + let timeout = Services.prefs.getIntPref( + "urlclassifier.gethash.timeout_ms"); + this.timer_.initWithCallback(this, timeout, this.timer_.TYPE_ONE_SHOT); + channel.asyncOpen2(this); + }, + + // Returns a string for the request body based on the contents of + // this._requests. + buildRequest: function HCR_buildRequest() { + // Sometimes duplicate entries are sent to HashCompleter but we do not need + // to propagate these to the server. (bug 633644) + let prefixes = []; + + for (let i = 0; i < this._requests.length; i++) { + let request = this._requests[i]; + if (prefixes.indexOf(request.partialHash) == -1) { + prefixes.push(request.partialHash); + } + } + + // Randomize the order to obscure the original request from noise + // unbiased Fisher-Yates shuffle + let i = prefixes.length; + while (i--) { + let j = Math.floor(Math.random() * (i + 1)); + let temp = prefixes[i]; + prefixes[i] = prefixes[j]; + prefixes[j] = temp; + } + + let body; + body = PARTIAL_LENGTH + ":" + (PARTIAL_LENGTH * prefixes.length) + + "\n" + prefixes.join(""); + + log('Requesting completions for ' + prefixes.length + ' ' + PARTIAL_LENGTH + '-byte prefixes: ' + body); + return body; + }, + + // Sets the request body of this._channel. + addRequestBody: function HCR_addRequestBody(aBody) { + let inputStream = Cc["@mozilla.org/io/string-input-stream;1"]. + createInstance(Ci.nsIStringInputStream); + + inputStream.setData(aBody, aBody.length); + + let uploadChannel = this._channel.QueryInterface(Ci.nsIUploadChannel); + uploadChannel.setUploadStream(inputStream, "text/plain", -1); + + let httpChannel = this._channel.QueryInterface(Ci.nsIHttpChannel); + httpChannel.requestMethod = "POST"; + }, + + // Parses the response body and eventually adds items to the |responses| array + // for elements of |this._requests|. + handleResponse: function HCR_handleResponse() { + if (this._response == "") { + return; + } + + log('Response: ' + this._response); + let start = 0; + + let length = this._response.length; + while (start != length) { + start = this.handleTable(start); + } + }, + + // This parses a table entry in the response body and calls |handleItem| + // for complete hash in the table entry. + handleTable: function HCR_handleTable(aStart) { + let body = this._response.substring(aStart); + + // deal with new line indexes as there could be + // new line characters in the data parts. + let newlineIndex = body.indexOf("\n"); + if (newlineIndex == -1) { + throw errorWithStack(); + } + let header = body.substring(0, newlineIndex); + let entries = header.split(":"); + if (entries.length != 3) { + throw errorWithStack(); + } + + let list = entries[0]; + let addChunk = parseInt(entries[1]); + let dataLength = parseInt(entries[2]); + + log('Response includes add chunks for ' + list + ': ' + addChunk); + if (dataLength % COMPLETE_LENGTH != 0 || + dataLength == 0 || + dataLength > body.length - (newlineIndex + 1)) { + throw errorWithStack(); + } + + let data = body.substr(newlineIndex + 1, dataLength); + for (let i = 0; i < (dataLength / COMPLETE_LENGTH); i++) { + this.handleItem(data.substr(i * COMPLETE_LENGTH, COMPLETE_LENGTH), list, + addChunk); + } + + return aStart + newlineIndex + 1 + dataLength; + }, + + // This adds a complete hash to any entry in |this._requests| that matches + // the hash. + handleItem: function HCR_handleItem(aData, aTableName, aChunkId) { + for (let i = 0; i < this._requests.length; i++) { + let request = this._requests[i]; + if (aData.substring(0,4) == request.partialHash) { + request.responses.push({ + completeHash: aData, + tableName: aTableName, + chunkId: aChunkId, + }); + } + } + }, + + // notifySuccess and notifyFailure are used to alert the callbacks with + // results. notifySuccess makes |completion| and |completionFinished| calls + // while notifyFailure only makes a |completionFinished| call with the error + // code. + notifySuccess: function HCR_notifySuccess() { + for (let i = 0; i < this._requests.length; i++) { + let request = this._requests[i]; + for (let j = 0; j < request.responses.length; j++) { + let response = request.responses[j]; + request.callback.completion(response.completeHash, response.tableName, + response.chunkId); + } + + request.callback.completionFinished(Cr.NS_OK); + } + }, + + notifyFailure: function HCR_notifyFailure(aStatus) { + log("notifying failure\n"); + for (let i = 0; i < this._requests.length; i++) { + let request = this._requests[i]; + request.callback.completionFinished(aStatus); + } + }, + + onDataAvailable: function HCR_onDataAvailable(aRequest, aContext, + aInputStream, aOffset, aCount) { + let sis = Cc["@mozilla.org/scriptableinputstream;1"]. + createInstance(Ci.nsIScriptableInputStream); + sis.init(aInputStream); + this._response += sis.readBytes(aCount); + }, + + onStartRequest: function HCR_onStartRequest(aRequest, aContext) { + // At this point no data is available for us and we have no reason to + // terminate the connection, so we do nothing until |onStopRequest|. + }, + + onStopRequest: function HCR_onStopRequest(aRequest, aContext, aStatusCode) { + Services.obs.removeObserver(this, "quit-application"); + + if (this._shuttingDown) { + throw Cr.NS_ERROR_ABORT; + } + + // Default HTTP status to service unavailable, in case we can't retrieve + // the true status from the channel. + let httpStatus = 503; + if (Components.isSuccessCode(aStatusCode)) { + let channel = aRequest.QueryInterface(Ci.nsIHttpChannel); + let success = channel.requestSucceeded; + httpStatus = channel.responseStatus; + if (!success) { + aStatusCode = Cr.NS_ERROR_ABORT; + } + } + let success = Components.isSuccessCode(aStatusCode); + log('Received a ' + httpStatus + ' status code from the gethash server (success=' + success + ').'); + + let histogram = + Services.telemetry.getHistogramById("URLCLASSIFIER_COMPLETE_REMOTE_STATUS"); + histogram.add(httpStatusToBucket(httpStatus)); + Services.telemetry.getHistogramById("URLCLASSIFIER_COMPLETE_TIMEOUT").add(0); + + // Notify the RequestBackoff once a response is received. + this._completer.finishRequest(this.gethashUrl, httpStatus); + + if (success) { + try { + this.handleResponse(); + } + catch (err) { + log(err.stack); + aStatusCode = err.value; + success = false; + } + } + + if (success) { + this.notifySuccess(); + } else { + this.notifyFailure(aStatusCode); + } + }, + + observe: function HCR_observe(aSubject, aTopic, aData) { + if (aTopic == "quit-application") { + this._shuttingDown = true; + if (this._channel) { + this._channel.cancel(Cr.NS_ERROR_ABORT); + } + + Services.obs.removeObserver(this, "quit-application"); + } + }, +}; + +// Converts a URL safe base64 string to a normal base64 string. Will not change +// normal base64 strings. This is modelled after the same function in +// nsUrlClassifierUtils.h. +function unUrlsafeBase64(aStr) { + return !aStr ? "" : aStr.replace(/-/g, "+") + .replace(/_/g, "/"); +} + +function errorWithStack() { + let err = new Error(); + err.value = Cr.NS_ERROR_FAILURE; + return err; +} + +this.NSGetFactory = XPCOMUtils.generateNSGetFactory([HashCompleter]); |