src/base/pickle.cc

   1 // Copyright (c) 2012 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 #include "base/pickle.h"
   6
   7 #include <stdlib.h>
   8
   9 #include <algorithm>  // for max()
  10
  11 //------------------------------------------------------------------------------
  12
  13 // static
  14 const int Pickle::kPayloadUnit = 64;
  15
  16 static const size_t kCapacityReadOnly = static_cast<size_t>(-1);
  17
  18 PickleIterator::PickleIterator(const Pickle& pickle)
  19     : read_ptr_(pickle.payload()),
  20       read_end_ptr_(pickle.end_of_payload()) {
  21 }
  22
  23 template <typename Type>
  24 inline bool PickleIterator::ReadBuiltinType(Type* result) {
  25   const char* read_from = GetReadPointerAndAdvance<Type>();
  26   if (!read_from)
  27     return false;
  28   if (sizeof(Type) > sizeof(uint32))
  29     memcpy(result, read_from, sizeof(*result));
  30   else
  31     *result = *reinterpret_cast<const Type*>(read_from);
  32   return true;
  33 }
  34
  35 template<typename Type>
  36 inline const char* PickleIterator::GetReadPointerAndAdvance() {
  37   const char* current_read_ptr = read_ptr_;
  38   if (read_ptr_ + sizeof(Type) > read_end_ptr_)
  39     return NULL;
  40   if (sizeof(Type) < sizeof(uint32))
  41     read_ptr_ += AlignInt(sizeof(Type), sizeof(uint32));
  42   else
  43     read_ptr_ += sizeof(Type);
  44   return current_read_ptr;
  45 }
  46
  47 const char* PickleIterator::GetReadPointerAndAdvance(int num_bytes) {
  48   if (num_bytes < 0 || read_end_ptr_ - read_ptr_ < num_bytes)
  49     return NULL;
  50   const char* current_read_ptr = read_ptr_;
  51   read_ptr_ += AlignInt(num_bytes, sizeof(uint32));
  52   return current_read_ptr;
  53 }
  54
  55 inline const char* PickleIterator::GetReadPointerAndAdvance(int num_elements,
  56                                                           size_t size_element) {
  57   // Check for int32 overflow.
  58   int64 num_bytes = static_cast<int64>(num_elements) * size_element;
  59   int num_bytes32 = static_cast<int>(num_bytes);
  60   if (num_bytes != static_cast<int64>(num_bytes32))
  61     return NULL;
  62   return GetReadPointerAndAdvance(num_bytes32);
  63 }
  64
  65 bool PickleIterator::ReadBool(bool* result) {
  66   return ReadBuiltinType(result);
  67 }
  68
  69 bool PickleIterator::ReadInt(int* result) {
  70   return ReadBuiltinType(result);
  71 }
  72
  73 bool PickleIterator::ReadLong(long* result) {
  74   return ReadBuiltinType(result);
  75 }
  76
  77 bool PickleIterator::ReadUInt16(uint16* result) {
  78   return ReadBuiltinType(result);
  79 }
  80
  81 bool PickleIterator::ReadUInt32(uint32* result) {
  82   return ReadBuiltinType(result);
  83 }
  84
  85 bool PickleIterator::ReadInt64(int64* result) {
  86   return ReadBuiltinType(result);
  87 }
  88
  89 bool PickleIterator::ReadUInt64(uint64* result) {
  90   return ReadBuiltinType(result);
  91 }
  92
  93 bool PickleIterator::ReadFloat(float* result) {
  94   return ReadBuiltinType(result);
  95 }
  96
  97 bool PickleIterator::ReadString(std::string* result) {
  98   int len;
  99   if (!ReadInt(&len))
 100     return false;
 101   const char* read_from = GetReadPointerAndAdvance(len);
 102   if (!read_from)
 103     return false;
 104
 105   result->assign(read_from, len);
 106   return true;
 107 }
 108
 109 bool PickleIterator::ReadWString(std::wstring* result) {
 110   int len;
 111   if (!ReadInt(&len))
 112     return false;
 113   const char* read_from = GetReadPointerAndAdvance(len, sizeof(wchar_t));
 114   if (!read_from)
 115     return false;
 116
 117   result->assign(reinterpret_cast<const wchar_t*>(read_from), len);
 118   return true;
 119 }
 120
 121 bool PickleIterator::ReadString16(string16* result) {
 122   int len;
 123   if (!ReadInt(&len))
 124     return false;
 125   const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16));
 126   if (!read_from)
 127     return false;
 128
 129   result->assign(reinterpret_cast<const char16*>(read_from), len);
 130   return true;
 131 }
 132
 133 bool PickleIterator::ReadData(const char** data, int* length) {
 134   *length = 0;
 135   *data = 0;
 136
 137   if (!ReadInt(length))
 138     return false;
 139
 140   return ReadBytes(data, *length);
 141 }
 142
 143 bool PickleIterator::ReadBytes(const char** data, int length) {
 144   const char* read_from = GetReadPointerAndAdvance(length);
 145   if (!read_from)
 146     return false;
 147   *data = read_from;
 148   return true;
 149 }
 150
 151 // Payload is uint32 aligned.
 152
 153 Pickle::Pickle()
 154     : header_(NULL),
 155       header_size_(sizeof(Header)),
 156       capacity_after_header_(0),
 157       write_offset_(0) {
 158   Resize(kPayloadUnit);
 159   header_->payload_size = 0;
 160 }
 161
 162 Pickle::Pickle(int header_size)
 163     : header_(NULL),
 164       header_size_(AlignInt(header_size, sizeof(uint32))),
 165       capacity_after_header_(0),
 166       write_offset_(0) {
 167   DCHECK_GE(static_cast<size_t>(header_size), sizeof(Header));
 168   DCHECK_LE(header_size, kPayloadUnit);
 169   Resize(kPayloadUnit);
 170   header_->payload_size = 0;
 171 }
 172
 173 Pickle::Pickle(const char* data, int data_len)
 174     : header_(reinterpret_cast<Header*>(const_cast<char*>(data))),
 175       header_size_(0),
 176       capacity_after_header_(kCapacityReadOnly),
 177       write_offset_(0) {
 178   if (data_len >= static_cast<int>(sizeof(Header)))
 179     header_size_ = data_len - header_->payload_size;
 180
 181   if (header_size_ > static_cast<unsigned int>(data_len))
 182     header_size_ = 0;
 183
 184   if (header_size_ != AlignInt(header_size_, sizeof(uint32)))
 185     header_size_ = 0;
 186
 187   // If there is anything wrong with the data, we're not going to use it.
 188   if (!header_size_)
 189     header_ = NULL;
 190 }
 191
 192 Pickle::Pickle(const Pickle& other)
 193     : header_(NULL),
 194       header_size_(other.header_size_),
 195       capacity_after_header_(0),
 196       write_offset_(other.write_offset_) {
 197   size_t payload_size = header_size_ + other.header_->payload_size;
 198   Resize(payload_size);
 199   memcpy(header_, other.header_, payload_size);
 200 }
 201
 202 Pickle::~Pickle() {
 203   if (capacity_after_header_ != kCapacityReadOnly)
 204     free(header_);
 205 }
 206
 207 Pickle& Pickle::operator=(const Pickle& other) {
 208   if (this == &other) {
 209     NOTREACHED();
 210     return *this;
 211   }
 212   if (capacity_after_header_ == kCapacityReadOnly) {
 213     header_ = NULL;
 214     capacity_after_header_ = 0;
 215   }
 216   if (header_size_ != other.header_size_) {
 217     free(header_);
 218     header_ = NULL;
 219     header_size_ = other.header_size_;
 220   }
 221   Resize(other.header_->payload_size);
 222   memcpy(header_, other.header_,
 223          other.header_size_ + other.header_->payload_size);
 224   write_offset_ = other.write_offset_;
 225   return *this;
 226 }
 227
 228 bool Pickle::WriteString(const std::string& value) {
 229   if (!WriteInt(static_cast<int>(value.size())))
 230     return false;
 231
 232   return WriteBytes(value.data(), static_cast<int>(value.size()));
 233 }
 234
 235 bool Pickle::WriteWString(const std::wstring& value) {
 236   if (!WriteInt(static_cast<int>(value.size())))
 237     return false;
 238
 239   return WriteBytes(value.data(),
 240                     static_cast<int>(value.size() * sizeof(wchar_t)));
 241 }
 242
 243 bool Pickle::WriteString16(const string16& value) {
 244   if (!WriteInt(static_cast<int>(value.size())))
 245     return false;
 246
 247   return WriteBytes(value.data(),
 248                     static_cast<int>(value.size()) * sizeof(char16));
 249 }
 250
 251 bool Pickle::WriteData(const char* data, int length) {
 252   return length >= 0 && WriteInt(length) && WriteBytes(data, length);
 253 }
 254
 255 bool Pickle::WriteBytes(const void* data, int length) {
 256   WriteBytesCommon(data, length);
 257   return true;
 258 }
 259
 260 void Pickle::Reserve(size_t length) {
 261   size_t data_len = AlignInt(length, sizeof(uint32));
 262   DCHECK_GE(data_len, length);
 263 #ifdef ARCH_CPU_64_BITS
 264   DCHECK_LE(data_len, kuint32max);
 265 #endif
 266   DCHECK_LE(write_offset_, kuint32max - data_len);
 267   size_t new_size = write_offset_ + data_len;
 268   if (new_size > capacity_after_header_)
 269     Resize(capacity_after_header_ * 2 + new_size);
 270 }
 271
 272 void Pickle::Resize(size_t new_capacity) {
 273   new_capacity = AlignInt(new_capacity, kPayloadUnit);
 274
 275   CHECK_NE(capacity_after_header_, kCapacityReadOnly);
 276   void* p = realloc(header_, header_size_ + new_capacity);
 277   CHECK(p);
 278   header_ = reinterpret_cast<Header*>(p);
 279   capacity_after_header_ = new_capacity;
 280 }
 281
 282 // static
 283 const char* Pickle::FindNext(size_t header_size,
 284                              const char* start,
 285                              const char* end) {
 286   DCHECK_EQ(header_size, AlignInt(header_size, sizeof(uint32)));
 287   DCHECK_LE(header_size, static_cast<size_t>(kPayloadUnit));
 288
 289   size_t length = static_cast<size_t>(end - start);
 290   if (length < sizeof(Header))
 291     return NULL;
 292
 293   const Header* hdr = reinterpret_cast<const Header*>(start);
 294   if (length < header_size || length - header_size < hdr->payload_size)
 295     return NULL;
 296   return start + header_size + hdr->payload_size;
 297 }
 298
 299 template <size_t length> void Pickle::WriteBytesStatic(const void* data) {
 300   WriteBytesCommon(data, length);
 301 }
 302
 303 template void Pickle::WriteBytesStatic<2>(const void* data);
 304 template void Pickle::WriteBytesStatic<4>(const void* data);
 305 template void Pickle::WriteBytesStatic<8>(const void* data);
 306
 307 inline void Pickle::WriteBytesCommon(const void* data, size_t length) {
 308   DCHECK_NE(kCapacityReadOnly, capacity_after_header_)
 309       << "oops: pickle is readonly";
 310   size_t data_len = AlignInt(length, sizeof(uint32));
 311   DCHECK_GE(data_len, length);
 312 #ifdef ARCH_CPU_64_BITS
 313   DCHECK_LE(data_len, kuint32max);
 314 #endif
 315   DCHECK_LE(write_offset_, kuint32max - data_len);
 316   size_t new_size = write_offset_ + data_len;
 317   if (new_size > capacity_after_header_) {
 318     Resize(std::max(capacity_after_header_ * 2, new_size));
 319   }
 320
 321   char* write = mutable_payload() + write_offset_;
 322   memcpy(write, data, length);
 323   memset(write + length, 0, data_len - length);
 324   header_->payload_size = static_cast<uint32>(write_offset_ + length);
 325   write_offset_ = new_size;
 326 }