code/modules/tamper.js

   1 /* coded by Ketmar // Invisible Vector (psyc://ketmar.no-ip.org/~Ketmar)
   2  * Understanding is not required. Only obedience.
   3  *
   4  * This program is free software. It comes without any warranty, to
   5  * the extent permitted by applicable law. You can redistribute it
   6  * and/or modify it under the terms of the Do What The Fuck You Want
   7  * To Public License, Version 2, as published by Sam Hocevar. See
   8  * http://www.wtfpl.net/txt/copying/ for more details.
   9  */
  10 // traffic tamper
  11 let EXPORTED_SYMBOLS = [
  12   "ImgDetectListener"
  13 ];
  14
  15 const {utils:Cu, classes:Cc, interfaces:Ci, results:Cr} = Components;
  16
  17
  18 //////////////////////////////////////////////////////////////////////////////
  19 Cu.import("resource://gre/modules/Services.jsm");
  20
  21 Cu.import("chrome://k8-imago-code/content/modules/utils.js");
  22 Cu.import(MODULE_PATH+"debuglog.js");
  23 Cu.import(MODULE_PATH+"prefs.js");
  24 Cu.import(MODULE_PATH+"detector.js");
  25 Cu.import(MODULE_PATH+"hazard.js");
  26 Cu.import(MODULE_PATH+"stoplist.js");
  27
  28
  29 //////////////////////////////////////////////////////////////////////////////
  30 // this listener will collect first several kb of image, detect it's type and
  31 // size, and then will decide what to do with it (image, not size)
  32 let tmpid = 0;
  33
  34
  35 function ImgDetectListener (isoctet, blacklisted) {
  36   this.olst = null;
  37   this.receivedData = ""; // string, incoming data; will become 0
  38   this.cancelled = false;
  39   this.piping = false;
  40   this.stopSent = false;
  41   this.octets = !!isoctet;
  42   this.blacklisted = !!blacklisted;
  43   this.maxLength = PREFS.maxLength;
  44   this.checker = new FormatChecker();
  45   this.id = tmpid++;
  46   this.imageInfo = null;
  47 }
  48
  49
  50 ImgDetectListener.prototype = {
  51   log: function () {
  52     if (!PREFS.debugLog) return;
  53     if (arguments.length) {
  54       let s = ""+this.id+":: ";
  55       for (let idx = 0; idx < arguments.length; ++idx) s += arguments[idx];
  56       Services.console.logStringMessage(s);
  57     }
  58   },
  59
  60   logError: function () {
  61     if (!PREFS.debugLog) return;
  62     if (arguments.length) {
  63       let s = ""+this.id+":: ";
  64       for (let idx = 0; idx < arguments.length; ++idx) s += arguments[idx];
  65       Cu.reportError(s);
  66     }
  67   },
  68
  69   _markImage: function (request) {
  70     let srcchan = request.QueryInterface(Ci.nsIChannel);
  71     let url = srcchan.URI.spec;
  72     let dw = getDomWindowForChannel(srcchan);
  73     if (dw) {
  74       let title;
  75       if (this.imageInfo) {
  76         title = this.imageInfo.name+" "+(this.imageInfo.valid ? ""+this.imageInfo.width+"x"+this.imageInfo.height : "<INVALID>");
  77       } else {
  78         title = (this.blacklisted ? "<BLACKLISTED>" : "<INVALID>");
  79       }
  80       for (let img of dw.document.querySelectorAll("img:not([k8imago-mark])[src=\""+cssEscape(url)+"\"]")) {
  81         img.setAttribute("title", title);
  82         img.setAttribute("k8imago-mark", "tan");
  83       }
  84     }
  85   },
  86
  87   // cancel request
  88   _cancel: function (request, context, total, data) {
  89     if (typeof(total) !== "number") total = "???";
  90     // abort this request
  91     this.cancelled = true;
  92     this.receivedData = null; // just in case
  93     this.checker = null;
  94     this._markImage(request);
  95     if (PREFS.debugLog) {
  96       let srcchan = request.QueryInterface(Ci.nsIChannel);
  97       let url = srcchan.URI.spec;
  98       this.log("[", url, "] total: ", total, ": CANCELLING!");
  99     }
 100     if (typeof(data) === "string") {
 101       if (PREFS.showPlaceholder) {
 102         this.log(" sending HAZARD");
 103         this.olst.onDataAvailable(request, context, createInputStreamFromString(data), 0, data.length);
 104       } else {
 105         this.log(" sending HAZARD is blocked");
 106       }
 107       this.stopSent = true;
 108       this.olst.onStopRequest(request, context, 0);
 109     }
 110     // just in case that double cancel will throw
 111     try {
 112       request.cancel(Cr.NS_BINDING_ABORTED);
 113     } catch (e) {}
 114   },
 115
 116   _pipe: function (request, context) {
 117     this.piping = true;
 118     this.receivedData = null;
 119     this.checker = null;
 120   },
 121
 122   url: function (request) {
 123     if (!request) return "<no-url>";
 124     let srcchan = request.QueryInterface(Ci.nsIChannel);
 125     if (!srcchan) return "<no-url>";
 126     return srcchan.URI.spec;
 127   },
 128
 129   // object initialization finished
 130   inited: function () {
 131   },
 132
 133   QueryInterface: function (aIID) {
 134     if (aIID.equals(Ci.nsIStreamListener) || aIID.equals(Ci.nsISupports)) return this;
 135     throw Components.results.NS_NOINTERFACE;
 136   },
 137
 138   onDataAvailable: function (request, context, inputStream, offset, count) {
 139     if (this.cancelled) return;
 140
 141     if (!this.piping && PREFS.debugLog) this.log("[", this.url(request), "] offset=", offset, "; count=", count);
 142
 143     // if we aren't piping...
 144     if (!this.piping) {
 145       // ...and there's no more formats...
 146       if (this.checker.done) {
 147         // abort or pipe
 148         if (!PREFS.allowUnknownFormats) {
 149           this._cancel(request, context, offset+count, hazardPNG);
 150           return;
 151         }
 152         // send collected data
 153         if (this.receivedData) {
 154           if (this.receivedData.length) {
 155             if (offset == 0) this.logError("WTF000?! offset is zero, but we have receivedData!");
 156             this.olst.onDataAvailable(request, context, createInputStreamFromString(this.receivedData), 0, this.receivedData.length);
 157             if (offset != this.receivedData.length) this.logError("WTF001?! offset is not equal to receivedData length! offset=", offset, "; length=", this.receivedData.length);
 158           }
 159         } else if (offset > 0) {
 160           this.logError("WTF002?! offset is not zero, but we have no receivedData!");
 161         }
 162         this._pipe(request, context);
 163         // go on, do piping
 164       }
 165     }
 166
 167     // pipe data if we are piping
 168     if (this.piping) {
 169       // piping data
 170       if (this.maxLength > 0 && !this.octets) {
 171         if (offset+count > this.maxLength) {
 172           this._cancel(request, context, offset+count);
 173           return;
 174         }
 175       }
 176       this.olst.onDataAvailable(request, context, inputStream, offset, count);
 177       return;
 178     }
 179
 180     // collecting header data and analyzing image formats
 181     let ist = Cc["@mozilla.org/binaryinputstream;1"].createInstance(Ci.nsIBinaryInputStream);
 182     ist.setInputStream(inputStream);
 183
 184     // read up to `this.checker.maxHeaderBytes` kb
 185     let maxb = this.checker.maxHeaderBytes;
 186     if (this.receivedData.length+count < maxb) {
 187       this.log(" reading ", count, " bytes (maxb=", maxb, ")");
 188       this.receivedData += ist.readBytes(count);
 189       count = 0;
 190     } else {
 191       let left = maxb-this.receivedData.length;
 192       if (left > count) {
 193         Cu.reportError("internal error (something is heavily fucked, #000)");
 194         throw new Error("internal error (something is heavily fucked, #000)");
 195       }
 196       if (left > 0) {
 197         this.receivedData += ist.readBytes(left);
 198         count -= left;
 199       }
 200       this.log(" read ", left, " bytes, ", count, " bytes left");
 201     }
 202
 203     let res = this.checker.process(this.receivedData);
 204     this.log(" checker returned `", res, "`, done is: ", this.checker.done);
 205     if (res === true) {
 206       // no successfull detection yet, need more spice
 207       if (this.receivedData.length >= maxb) this._cancel(request, context, offset+count, hazardPNG);
 208       return;
 209     }
 210     if (res !== null) {
 211       // detected something
 212       this.imageInfo = res;
 213       if (!res.valid) {
 214         this._cancel(request, context, offset+count, hazardPNG);
 215         return;
 216       }
 217       this.log(" image: ", res.name, ": ", res.width, "x", res.height);
 218       // valid image, check dimensions
 219       if (res.width < PREFS.minWidth || res.height < PREFS.minHeight ||
 220           res.width > PREFS.maxWidth || res.height > PREFS.maxHeight)
 221       {
 222         this.log(" allowed size: min=", PREFS.minWidth, "x", PREFS.minHeight, "; max=", PREFS.maxWidth, "x", PREFS.maxHeight);
 223         this._cancel(request, context, offset+count, hazardPNG);
 224         return;
 225       }
 226     } else {
 227       // no more formats
 228       if (!PREFS.allowUnknownFormats) {
 229         this.log(" unknown format");
 230         this._cancel(request, context, offset+count, hazardPNG);
 231         return;
 232       }
 233     }
 234
 235     // here we got something good, transfer collected header and start piping
 236     this.olst.onDataAvailable(request, context, createInputStreamFromString(this.receivedData), 0, this.receivedData.length);
 237     // pass what is left
 238     if (count > 0) {
 239       offset += this.receivedData.length;
 240       this.olst.onDataAvailable(request, context, inputStream, offset, count);
 241     }
 242     this._pipe(request, context);
 243   },
 244
 245   onStartRequest: function (request, context) {
 246     if (PREFS.debugLog) this.log("onStartRequest() [", this.url(request), "]");
 247     this.olst.onStartRequest(request, context);
 248     if (this.blacklisted) {
 249       this.log("image is blacklisted");
 250       this._cancel(request, context, 0, hazardPNG);
 251       return;
 252     }
 253   },
 254
 255   onStopRequest: function (request, context, statusCode) {
 256     if (PREFS.debugLog) this.log("onStopRequest() [", this.url(request), "]: status code=", statusCode);
 257     //this.log("[", this.url(request), "]: status code=", statusCode);
 258     if (!this.stopSent && this.receivedData !== null) {
 259       // wow, we have some buffered data, check and send it!
 260       let res = this.checker.process(this.receivedData);
 261       if (typeof(res) === "object") {
 262         if (!res.valid) {
 263           this._cancel(request, context, 0, hazardPNG);
 264           return;
 265         }
 266         if (res.width < PREFS.minWidth || res.height < PREFS.minHeight ||
 267             res.width > PREFS.maxWidth || res.height > PREFS.maxHeight) {
 268           this._cancel(request, context, 0, hazardPNG);
 269           return;
 270         }
 271         // ok
 272       } else {
 273         if (!PREFS.allowUnknownFormats) {
 274           this._cancel(request, context, 0, hazardPNG);
 275           return;
 276         }
 277       }
 278       this.olst.onDataAvailable(request, context, createInputStreamFromString(this.receivedData), 0, this.receivedData.length);
 279     }
 280     this.receivedData = null; // just in case
 281     this.checker = null;
 282     if (!this.stopSent) {
 283       this.olst.onStopRequest(request, context, statusCode);
 284     }
 285   },
 286 };