1/* 2 * Copyright (C) 2010 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef ArgumentDecoder_h 27#define ArgumentDecoder_h 28 29#include "ArgumentCoder.h" 30#include "Attachment.h" 31#include <wtf/Vector.h> 32 33namespace IPC { 34 35class DataReference; 36 37class ArgumentDecoder { 38 WTF_MAKE_FAST_ALLOCATED; 39public: 40 ArgumentDecoder(const uint8_t* buffer, size_t bufferSize); 41 virtual ~ArgumentDecoder(); 42 43 size_t length() const { return m_bufferEnd - m_buffer; } 44 45 bool isInvalid() const { return m_bufferPos > m_bufferEnd; } 46 void markInvalid() { m_bufferPos = m_bufferEnd + 1; } 47 48 bool decodeFixedLengthData(uint8_t*, size_t, unsigned alignment); 49 50 // The data in the data reference here will only be valid for the lifetime of the ArgumentDecoder object. 51 bool decodeVariableLengthByteArray(DataReference&); 52 53 bool decode(bool&); 54 bool decode(uint8_t&); 55 bool decode(uint16_t&); 56 bool decode(uint32_t&); 57 bool decode(uint64_t&); 58 bool decode(int32_t&); 59 bool decode(int64_t&); 60 bool decode(float&); 61 bool decode(double&); 62 63 template<typename T> bool decodeEnum(T& result) 64 { 65 static_assert(sizeof(T) <= 8, "Enum type T must not be larger than 64 bits!"); 66 67 uint64_t value; 68 if (!decode(value)) 69 return false; 70 71 result = static_cast<T>(value); 72 return true; 73 } 74 75 template<typename T> 76 bool bufferIsLargeEnoughToContain(size_t numElements) const 77 { 78 static_assert(std::is_arithmetic<T>::value, "Type T must have a fixed, known encoded size!"); 79 80 if (numElements > std::numeric_limits<size_t>::max() / sizeof(T)) 81 return false; 82 83 return bufferIsLargeEnoughToContain(alignof(T), numElements * sizeof(T)); 84 } 85 86 // Generic type decode function. 87 template<typename T> bool decode(T& t) 88 { 89 return ArgumentCoder<T>::decode(*this, t); 90 } 91 92 bool removeAttachment(Attachment&); 93 94protected: 95 ArgumentDecoder(const uint8_t* buffer, size_t bufferSize, Vector<Attachment>); 96 97 void initialize(const uint8_t* buffer, size_t bufferSize); 98 99 bool alignBufferPosition(unsigned alignment, size_t size); 100 bool bufferIsLargeEnoughToContain(unsigned alignment, size_t size) const; 101 102private: 103 uint8_t* m_buffer; 104 uint8_t* m_bufferPos; 105 uint8_t* m_bufferEnd; 106 107 Vector<Attachment> m_attachments; 108}; 109 110} // namespace IPC 111 112#endif // ArgumentDecoder_h 113