OLD | NEW |
(Empty) | |
| 1 // Copyright 2014 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 define("mojo/public/js/bindings/validator", [ |
| 6 "mojo/public/js/bindings/codec", |
| 7 ], function(codec) { |
| 8 |
| 9 var validationError = { |
| 10 NONE: 'VALIDATION_ERROR_NONE', |
| 11 MISALIGNED_OBJECT: 'VALIDATION_ERROR_MISALIGNED_OBJECT', |
| 12 ILLEGAL_MEMORY_RANGE: 'VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE', |
| 13 UNEXPECTED_STRUCT_HEADER: 'VALIDATION_ERROR_UNEXPECTED_STRUCT_HEADER', |
| 14 UNEXPECTED_ARRAY_HEADER: 'VALIDATION_ERROR_UNEXPECTED_ARRAY_HEADER', |
| 15 ILLEGAL_HANDLE: 'VALIDATION_ERROR_ILLEGAL_HANDLE', |
| 16 ILLEGAL_POINTER: 'VALIDATION_ERROR_ILLEGAL_POINTER', |
| 17 MESSAGE_HEADER_INVALID_FLAG_COMBINATION: |
| 18 'VALIDATION_ERROR_MESSAGE_HEADER_INVALID_FLAG_COMBINATION', |
| 19 MESSAGE_HEADER_MISSING_REQUEST_ID: |
| 20 'VALIDATION_ERROR_MESSAGE_HEADER_MISSING_REQUEST_ID' |
| 21 }; |
| 22 |
| 23 function Validator(message) { |
| 24 this.message = message; |
| 25 this.offset = 0; |
| 26 } |
| 27 |
| 28 Object.defineProperty(Validator.prototype, "offsetLimit", { |
| 29 get: function() { return this.message.buffer.byteLength; } |
| 30 }); |
| 31 |
| 32 // True if we can safely allocate a block of bytes from start to |
| 33 // to start + numBytes. |
| 34 Validator.prototype.isValidRange = function(start, numBytes) { |
| 35 // Only positive JavaScript integers that are less than 2^53 |
| 36 // (Number.MAX_SAFE_INTEGER) can be represented exactly. |
| 37 if (start < this.offset || numBytes <= 0 || |
| 38 !Number.isSafeInteger(start) || |
| 39 !Number.isSafeInteger(numBytes)) |
| 40 return false; |
| 41 |
| 42 var newOffset = start + numBytes; |
| 43 if (!Number.isSafeInteger(newOffset) || newOffset > this.offsetLimit) |
| 44 return false; |
| 45 |
| 46 return true; |
| 47 } |
| 48 |
| 49 Validator.prototype.claimRange = function(start, numBytes) { |
| 50 if (this.isValidRange(start, numBytes)) { |
| 51 this.offset = start + numBytes; |
| 52 return true; |
| 53 } |
| 54 return false; |
| 55 } |
| 56 |
| 57 Validator.prototype.validateStructHeader = |
| 58 function(offset, minNumBytes, minNumFields) { |
| 59 if (!codec.isAligned(offset)) |
| 60 return validationError.MISALIGNED_OBJECT; |
| 61 |
| 62 if (!this.isValidRange(offset, codec.kStructHeaderSize)) |
| 63 return validationError.ILLEGAL_MEMORY_RANGE; |
| 64 |
| 65 var numBytes = this.message.buffer.getUint32(offset); |
| 66 var numFields = this.message.buffer.getUint32(offset + 4); |
| 67 |
| 68 if (numBytes < minNumBytes || numFields < minNumFields) |
| 69 return validationError.UNEXPECTED_STRUCT_HEADER; |
| 70 |
| 71 if (!this.claimRange(offset, numBytes)) |
| 72 return validationError.ILLEGAL_MEMORY_RANGE; |
| 73 |
| 74 return validationError.NONE; |
| 75 } |
| 76 |
| 77 Validator.prototype.validateMessageHeader = function() { |
| 78 var numBytes = this.message.getHeaderNumBytes(); |
| 79 var numFields = this.message.getHeaderNumFields(); |
| 80 |
| 81 var validNumFieldsAndNumBytes = |
| 82 (numFields == 2 && numBytes == codec.kMessageHeaderSize) || |
| 83 (numFields == 3 && |
| 84 numBytes == codec.kMessageWithRequestIDHeaderSize) || |
| 85 (numFields > 3 && |
| 86 numBytes >= codec.kMessageWithRequestIDHeaderSize); |
| 87 if (!validNumFieldsAndNumBytes) |
| 88 return validationError.UNEXPECTED_STRUCT_HEADER; |
| 89 |
| 90 var expectsResponse = this.message.expectsResponse(); |
| 91 var isResponse = this.message.isResponse(); |
| 92 |
| 93 if (numFields == 2 && (expectsResponse || isResponse)) |
| 94 return validationError.MESSAGE_HEADER_MISSING_REQUEST_ID; |
| 95 |
| 96 if (isResponse && expectsResponse) |
| 97 return validationError.MESSAGE_HEADER_INVALID_FLAG_COMBINATION; |
| 98 |
| 99 return validationError.NONE; |
| 100 } |
| 101 |
| 102 Validator.prototype.validateMessage = function() { |
| 103 var err = this.validateStructHeader(0, codec.kStructHeaderSize, 2); |
| 104 if (err != validationError.NONE) |
| 105 return err; |
| 106 |
| 107 return this.validateMessageHeader(); |
| 108 } |
| 109 |
| 110 var exports = {}; |
| 111 exports.validationError = validationError; |
| 112 exports.Validator = Validator; |
| 113 return exports; |
| 114 }); |
OLD | NEW |