Validate incoming JS Message Headers: test message parser

mojo/public/js/bindings/tests/validation_test_input_parser.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Support for parsing binary sequences encoded as readable strings
+// or ".data" files. The input format is described here:
+// mojo/public/cpp/bindings/tests/validation_test_input_parser.h
+
+define([
+    "mojo/public/js/bindings/buffer"
+  ], function(buffer) {
+
+  // Files and Lines represent the raw text from an input string
+  // or ".data" file.
+
+  function InputError(message, line) {
+    this.message = message;
+    this.line = line;
+  }
+
+  InputError.prototype.toString = function() {
+    var s = 'Error: ' + this.message;
+    if (this.line)
+      s += ', at line ' +
+           (this.line.number + 1) + ': "' + this.line.contents + '"';
+    return s;
+  }
+
+  function File(contents) {
+    this.contents = contents;
+    this.index = 0;
+    this.lineNumber = 0;
+  }
+
+  File.prototype.isEmpty = function() {

[yzshen1, 2014/07/23 20:31:10]

nit: maybe "reachEnd" is more clear. (and similar comment for Line)

[hansmuller, 2014/07/24 00:36:37]

OK, I used "endReached()".

+    return this.index >= this.contents.length;
+  }
+
+  File.prototype.nextLine = function() {
+    if (this.isEmpty())
+      return null;
+    var start = this.index;
+    var end = this.contents.indexOf('\n', start);

[yzshen1, 2014/07/23 20:31:10]

Does \r matter here?

[hansmuller, 2014/07/24 00:36:37]

Not really, since breaking the input up into "lines" is just to make it possible
to report input error line numbers.

[yzshen1, 2014/07/24 01:15:10]

It also matters where to end a comment, right?

On 2014/07/24 00:36:37, hansmuller wrote:

+    if (end == -1)
+      end = this.contents.length;
+    this.index = end + 1;
+    return new Line(this.contents.substring(start, end), this.lineNumber++);
+  }
+
+  function Line(contents, number) {
+    var i = contents.indexOf('//');
+    var s = (i == -1) ? contents.trim() : contents.substring(0, i).trim();
+    this.contents = contents;
+    this.items = (s.length > 0) ? s.split(/\s+/) : [];
+    this.index = 0;
+    this.number = number;
+  }
+
+  Line.prototype.isEmpty = function() {
+    return this.index >= this.items.length;
+  }
+
+  var itemTypeSizes = {

[yzshen1, 2014/07/23 20:31:10]

Shall we name it kItemTypeSizes because it is constant? (But I am not familiar
with JS style guide.)

[hansmuller, 2014/07/24 00:36:37]

According to the style guide I should write:
var ITEM_TYPE_SIZES = {...};

The mojo JS code doesn't appear to consistently follow the style guide on this
point, but I can do so.

+    u1: 1, u2: 2, u4: 4, u8: 8, s1: 1, s2: 2, s4: 4, s8: 8, b: 1, f: 4, d: 8,
+    dist4: 4, dist8: 8, anchr: 0, handles: 0
+  };
+
+  function isValidItemType(type) {
+    return itemTypeSizes[type] !== undefined;
+  }
+
+  Line.prototype.nextItem = function() {
+    if (this.isEmpty())
+      return null;
+
+    var itemString = this.items[this.index++];
+    var type = 'u1';
+    var value = itemString;
+
+    if (itemString.charAt(0) == '[') {
+      var i = itemString.indexOf(']');
+      if (i != -1 && i + 1 < itemString.length) {
+        type = itemString.substring(1, i);
+        value = itemString.substring(i + 1);
+      } else {
+        throw new InputError('invalid item', this);
+      }
+    }
+    if (!isValidItemType(type))
+      throw new InputError('invalid item type', this);
+
+    return new Item(this, type, value);
+  }
+
+  // The text for Each whitespace delimited binary data "item"
+  // file is represented by an Item.

[yzshen1, 2014/07/23 20:31:10]

Is this line correct?

[hansmuller, 2014/07/24 00:36:37]

That "...file is" was a typo, thanks for pointing it out.

+
+  function Item(line, type, value) {
+    this.line = line;
+    this.type = type;
+    this.value = value;
+    this.size = itemTypeSizes[type];
+  }
+
+  Item.prototype.isFloat = function() {
+    return this.type == 'f' || this.type == 'd';
+  }
+
+  Item.prototype.isInteger = function() {
+    return ['u1', 'u2', 'u4', 'u8',
+            's1', 's2', 's4', 's8'].indexOf(this.type) != -1;
+  }
+
+  Item.prototype.isNumber = function() {
+    return this.isFloat() || this.isInteger();
+  }
+
+  Item.prototype.isByte = function() {
+    return this.type == 'b';
+  }
+
+  Item.prototype.isDistance = function() {
+    return this.type == 'dist4' || this.type == 'dist8';
+  }
+
+  Item.prototype.isAnchor = function() {
+    return this.type == 'anchr';
+  }
+
+  Item.prototype.isHandles = function() {
+    return this.type == 'handles';
+  }
+
+  // A TestMessage represents the complete binary message loaded from
+  // an input string or ".data" file. The parseTestMessage() function
+  // below constructs a TestMessage from a File.
+
+  function TestMessage(byteLength) {
+    this.index = 0;
+    this.buffer = new buffer.Buffer(byteLength);
+    this.distances = {};
+    this.handleCount = 0;
+  }
+
+  function checkItemNumberValue(item, n, min, max) {
+    if (n < min || n > max)
+      throw new InputError('invalid item value', item.line);
+  }
+
+  TestMessage.prototype.addNumber = function(item) {
+    var n = item.isInteger() ? parseInt(item.value) : parseFloat(item.value);
+    if (Number.isNaN(n))
+      throw new InputError("can't parse item value", item.line);
+
+    switch(item.type) {
+    case 'u1':

[yzshen1, 2014/07/23 20:31:10]

2 more spaces of indent, please.

[hansmuller, 2014/07/24 00:36:37]

Done.

+      checkItemNumberValue(item, n, 0, 0xFF);
+      this.buffer.setUint8(this.index, n);
+      this.index += 1;

[yzshen1, 2014/07/23 20:31:10]

We could consider advancing this.index with item.size and moving this line out
of the switch (or even out of addX() methods).

[hansmuller, 2014/07/24 00:36:37]

Good point. I moved it to addItem().

+      break;
+    case 'u2':
+      checkItemNumberValue(item, n, 0, 0xFFFF);
+      this.buffer.setUint16(this.index, n);
+      this.index += 2;
+      break;
+    case 'u4':
+      checkItemNumberValue(item, n, 0, 0xFFFFFFFF);
+      this.buffer.setUint32(this.index, n);
+      this.index += 4;
+      break;
+    case 'u8':
+      checkItemNumberValue(item, n, 0, Number.MAX_SAFE_INTEGER);
+      this.buffer.setUint64(this.index, n);
+      this.index += 8;
+      break;
+    case 's1':
+      checkItemNumberValue(item, n, -128, 127);
+      this.buffer.setInt8(this.index, n);
+      this.index += 1;
+      break;
+    case 's2':
+      checkItemNumberValue(item, n, -32768, 32767);
+      this.buffer.setInt16(this.index, n);
+      this.index += 2;
+      break;
+    case 's4':
+      checkItemNumberValue(item, n, -2147483648, 2147483647);
+      this.buffer.setInt32(this.index, n);
+      this.index += 4;
+      break;
+    case 's8':
+      checkItemNumberValue(item, n,
+                           Number.MIN_SAFE_INTEGER,
+                           Number.MAX_SAFE_INTEGER);
+      this.buffer.setInt64(this.index, n);
+      this.index += 8;
+      break;
+    case 'f':
+      this.buffer.setFloat32(this.index, n);
+      this.index += 4;
+      break;
+    case 'd':
+      this.buffer.setFloat64(this.index, n);
+      this.index += 8;
+      break;
+
+    default:
+      throw new InputError('unrecognized item type', item.line);
+    }
+  }
+
+  TestMessage.prototype.addByte = function(item) {
+    if (!/^[01]{8}$/.test(item.value))
+      throw new InputError('invalid byte item value', item.line);
+    function b(i) {
+      return (item.value.charAt(7 - i) == '1') ? 1 << i : 0;
+    }
+    var n = b(0) | b(1) | b(2) | b(3) | b(4) | b(5) | b(6) | b(7);
+    this.buffer.setUint8(this.index, n);
+    this.index += 1;
+  }
+
+  TestMessage.prototype.addDistance = function(item) {
+    if (this.distances[item.value])
+      throw new InputError('duplicate distance item', item.line);
+    this.distances[item.value] = {index: this.index, item: item};
+    this.index += item.type == 'dist4' ? 4 : 8;
+  }
+
+  TestMessage.prototype.addAnchor = function(item) {
+    var dist = this.distances[item.value];
+    if (!dist)
+      throw new InputError('unmatched anchor item', item.line);
+    delete this.distances[item.value];
+
+    var n = this.index - dist.index;
+    // TODO(hansmuller): validate n
+
+    if (dist.item.type == 'dist4')
+      this.buffer.setUint32(dist.index, n);
+    else if (dist.item.type == 'dist8')
+      this.buffer.setUint64(dist.index, n);
+    else
+      throw new InputError('unrecognzed distance item type', dist.item.line);
+  }
+
+  TestMessage.prototype.addHandles = function(item) {
+    this.handleCount = parseInt(item.value);
+    if (Number.isNaN(this.handleCount))
+      throw new InputError("can't parse handleCount", item.line);
+  }
+
+  TestMessage.prototype.addItem = function(item) {
+    if (item.isNumber())
+      this.addNumber(item);
+    else if (item.isByte())
+      this.addByte(item);
+    else if (item.isDistance())
+      this.addDistance(item);
+    else if (item.isAnchor())
+      this.addAnchor(item);
+    else if (item.isHandles())
+      this.addHandles(item);
+    else
+      throw new InputError('unrecognized item type', item.line);
+  }
+
+  TestMessage.prototype.unanchoredDistances = function() {
+    var names = null;
+    for (var name in this.distances) {
+      if (this.distances.hasOwnProperty(name))
+        names = (names === null) ? name : names + ' ' + name;
+    }
+    return names;
+  }
+
+  function parseTestMessage(file) {
+    var items = [];
+    var messageLength = 0;
+    while(!file.isEmpty()) {
+      var line = file.nextLine();
+      while (!line.isEmpty()) {
+        var item = line.nextItem();
+        if (item.isHandles() && items.length > 0)
+          throw new InputError('handles item is not first');
+        messageLength += item.size;
+        items.push(item);
+      }
+    }
+
+    var msg = new TestMessage(messageLength);
+    for (var i = 0; i < items.length; i++)
+      msg.addItem(items[i]);
+
+    if (messageLength != msg.index)
+      throw new InputError('failed to compute message length');
+    var names = msg.unanchoredDistances();
+    if (names)
+      throw new InputError('no anchors for ' + names, 0);
+
+    return msg;
+  }
+
+  // Verify that the TestMessage (et al) data file loading code is OK.
+
+  function checkMessageFileParser() {
+    function ParserTestFailure(message, file) {
+      this.message = message;
+      this.file = file;
+    }
+
+    ParserTestFailure.prototype.toString = function() {
+      return 'Error: ' + this.message + ' for "' + this.file.contents + '"';
+    }
+
+    function checkData(data, expectedData, file) {
+      if (data.byteLength != expectedData.byteLength) {
+        var s = "message length (" + data.byteLength + ") doesn't match " +
+          "expected length: " + expectedData.byteLength;

[yzshen1, 2014/07/23 20:31:10]

wrong indent.

[hansmuller, 2014/07/24 00:36:37]

Done.

+        throw new ParserTestFailure(s, file);
+      }
+
+      for (var i = 0; i < data.byteLength; i++) {
+        if (data.getUint8(i) != expectedData.getUint8(i)) {
+          var s = 'message data mismatch at byte offset ' + i;
+          throw new ParserTestFailure(s, file);
+        }
+      }
+    }
+
+    function testFloatItems() {
+      var file = new File('[f]+.3e9 [d]-10.03');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(12);
+      expectedData.setFloat32(0, +.3e9);
+      expectedData.setFloat64(4, -10.03);
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testUnsignedIntegerItems() {
+      var file = new File('[u1]0x10// hello world !! \n\r  \t [u2]65535 \n' +
+                          '[u4]65536 [u8]0xFFFFFFFFFFFFF 0 0Xff');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(17);
+      expectedData.setUint8(0, 0x10);
+      expectedData.setUint16(1, 65535);
+      expectedData.setUint32(3, 65536);
+      expectedData.setUint64(7, 0xFFFFFFFFFFFFF);
+      expectedData.setUint8(15, 0);
+      expectedData.setUint8(16, 0xff);
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testSignedIntegerItems() {
+      var file = new File('[s8]-0x800 [s1]-128\t[s2]+0 [s4]-40');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(15);
+      expectedData.setInt64(0, -0x800);
+      expectedData.setInt8(8, -128);
+      expectedData.setInt16(9, 0);
+      expectedData.setInt32(11, -40);
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testByteItems() {
+      var file =
+          new File('[b]00001011 [b]10000000  // hello world\n [b]00000000');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(3);
+      expectedData.setUint8(0, 11);
+      expectedData.setUint8(1, 128);
+      expectedData.setUint8(2, 0);
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testAnchors() {
+      var file = new File('[dist4]foo 0 [dist8]bar 0 [anchr]foo [anchr]bar');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(14);
+      expectedData.setUint32(0, 14);
+      expectedData.setUint8(4, 0);
+      expectedData.setUint64(5, 9);
+      expectedData.setUint8(13, 0);
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testHandles() {
+      var file = new File('// This message has handles! \n[handles]50 [u8]2');
+      var msg = parseTestMessage(file);
+      var expectedData = new buffer.Buffer(8);
+      expectedData.setUint64(0, 2);
+
+      if (msg.handleCount != 50) {
+        var s = 'wrong handle count (' + msg.handleCount + ')';
+        throw new ParserTestFailure(s, file);
+      }
+      checkData(msg.buffer, expectedData, file);
+    }
+
+    function testEmptyInput() {
+      var file = new File('');
+      var msg = parseTestMessage(file);
+      if (msg.buffer.byteLength != 0)
+        throw new ParserTestFailure('expected empty message', file);
+    }
+
+    function testBlankInput() {
+      var file =
+          new File('    \t  // hello world \n\r \t// the answer is 42   ');
+      var msg = parseTestMessage(file);
+      if (msg.buffer.byteLength != 0)
+        throw new ParserTestFailure('expected empty message', file);
+    }
+
+    function testInvalidInput() {
+      function parserShouldFail(fileContents) {
+        var file = new File(fileContents);
+        try {
+          parseTestMessage(file);
+        } catch (e) {
+          if (e instanceof InputError)
+            return;
+          throw new ParserTestFailure(
+            'unexpected exception ' + e.toString(), file);
+        }
+        throw new ParserTestFailure("didn't detect invalid input", file);
+      }
+
+      ['/ hello world',
+       '[u1]x',
+       '[u2]-1000',
+       '[u1]0x100',
+       '[s2]-0x8001',
+       '[b]1',
+       '[b]1111111k',
+       '[dist4]unmatched',
+       '[anchr]hello [dist8]hello',
+       '[dist4]a [dist4]a [anchr]a',
+       // '[dist4]a [anchr]a [dist4]a [anchr]a',
+       '0 [handles]50'
+      ].forEach(parserShouldFail);
+    }
+
+    try {
+      testFloatItems();
+      testUnsignedIntegerItems();
+      testSignedIntegerItems();
+      testByteItems();
+      testInvalidInput();
+      testEmptyInput();
+      testBlankInput();
+      testHandles();
+      testAnchors();
+    } catch (e) {
+      return e;
+    }
+    return null;
+  }
+
+  var exports = {};
+  exports.checkMessageFileParser = checkMessageFileParser;
+  return exports;
+});