courgette/ensemble_apply.cc

   1 // Copyright (c) 2011 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 // This file contains the code to apply a Courgette patch.
   6
   7 #include "courgette/ensemble.h"
   8
   9 #include "base/basictypes.h"
  10 #include "base/file_util.h"
  11 #include "base/files/memory_mapped_file.h"
  12 #include "base/logging.h"
  13 #include "courgette/crc.h"
  14 #include "courgette/region.h"
  15 #include "courgette/streams.h"
  16 #include "courgette/simple_delta.h"
  17 #include "courgette/patcher_x86_32.h"
  18
  19 namespace courgette {
  20
  21 // EnsemblePatchApplication is all the logic and data required to apply the
  22 // multi-stage patch.
  23 class EnsemblePatchApplication {
  24  public:
  25   EnsemblePatchApplication();
  26   ~EnsemblePatchApplication();
  27
  28   Status ReadHeader(SourceStream* header_stream);
  29
  30   Status InitBase(const Region& region);
  31
  32   Status ValidateBase();
  33
  34   Status ReadInitialParameters(SourceStream* initial_parameters);
  35
  36   Status PredictTransformParameters(SinkStreamSet* predicted_parameters);
  37
  38   Status SubpatchTransformParameters(SinkStreamSet* prediction,
  39                                      SourceStream* correction,
  40                                      SourceStreamSet* corrected_parameters);
  41
  42   Status TransformUp(SourceStreamSet* parameters,
  43                      SinkStreamSet* transformed_elements);
  44
  45   Status SubpatchTransformedElements(SinkStreamSet* elements,
  46                                      SourceStream* correction,
  47                                      SourceStreamSet* corrected_elements);
  48
  49   Status TransformDown(SourceStreamSet* transformed_elements,
  50                        SinkStream* basic_elements);
  51
  52   Status SubpatchFinalOutput(SourceStream* original,
  53                              SourceStream* correction,
  54                              SinkStream* corrected_ensemble);
  55
  56  private:
  57   Status SubpatchStreamSets(SinkStreamSet* predicted_items,
  58                             SourceStream* correction,
  59                             SourceStreamSet* corrected_items,
  60                             SinkStream* corrected_items_storage);
  61
  62   Region base_region_;       // Location of in-memory copy of 'old' version.
  63
  64   uint32 source_checksum_;
  65   uint32 target_checksum_;
  66   uint32 final_patch_input_size_prediction_;
  67
  68   std::vector<TransformationPatcher*> patchers_;
  69
  70   SinkStream corrected_parameters_storage_;
  71   SinkStream corrected_elements_storage_;
  72
  73   DISALLOW_COPY_AND_ASSIGN(EnsemblePatchApplication);
  74 };
  75
  76 EnsemblePatchApplication::EnsemblePatchApplication()
  77     : source_checksum_(0), target_checksum_(0),
  78       final_patch_input_size_prediction_(0) {
  79 }
  80
  81 EnsemblePatchApplication::~EnsemblePatchApplication() {
  82   for (size_t i = 0;  i < patchers_.size();  ++i) {
  83     delete patchers_[i];
  84   }
  85 }
  86
  87 Status EnsemblePatchApplication::ReadHeader(SourceStream* header_stream) {
  88   uint32 magic;
  89   if (!header_stream->ReadVarint32(&magic))
  90     return C_BAD_ENSEMBLE_MAGIC;
  91
  92   if (magic != CourgettePatchFile::kMagic)
  93     return C_BAD_ENSEMBLE_MAGIC;
  94
  95   uint32 version;
  96   if (!header_stream->ReadVarint32(&version))
  97     return C_BAD_ENSEMBLE_VERSION;
  98
  99   if (version != CourgettePatchFile::kVersion)
 100     return C_BAD_ENSEMBLE_VERSION;
 101
 102   if (!header_stream->ReadVarint32(&source_checksum_))
 103     return C_BAD_ENSEMBLE_HEADER;
 104
 105   if (!header_stream->ReadVarint32(&target_checksum_))
 106     return C_BAD_ENSEMBLE_HEADER;
 107
 108   if (!header_stream->ReadVarint32(&final_patch_input_size_prediction_))
 109     return C_BAD_ENSEMBLE_HEADER;
 110
 111   return C_OK;
 112 }
 113
 114 Status EnsemblePatchApplication::InitBase(const Region& region) {
 115   base_region_.assign(region);
 116   return C_OK;
 117 }
 118
 119 Status EnsemblePatchApplication::ValidateBase() {
 120   uint32 checksum = CalculateCrc(base_region_.start(), base_region_.length());
 121   if (source_checksum_ != checksum)
 122     return C_BAD_ENSEMBLE_CRC;
 123
 124   return C_OK;
 125 }
 126
 127 Status EnsemblePatchApplication::ReadInitialParameters(
 128     SourceStream* transformation_parameters) {
 129   uint32 number_of_transformations = 0;
 130   if (!transformation_parameters->ReadVarint32(&number_of_transformations))
 131     return C_BAD_ENSEMBLE_HEADER;
 132
 133   for (size_t i = 0;  i < number_of_transformations;  ++i) {
 134     uint32 kind;
 135     if (!transformation_parameters->ReadVarint32(&kind))
 136       return C_BAD_ENSEMBLE_HEADER;
 137
 138     TransformationPatcher* patcher = NULL;
 139
 140     switch (kind)
 141     {
 142       case EXE_WIN_32_X86:
 143         patcher = new PatcherX86_32(base_region_);
 144         break;
 145       case EXE_ELF_32_X86:
 146         patcher = new PatcherX86_32(base_region_);
 147         break;
 148     }
 149
 150     if (patcher)
 151       patchers_.push_back(patcher);
 152     else
 153       return C_BAD_ENSEMBLE_HEADER;
 154   }
 155
 156   for (size_t i = 0;  i < patchers_.size();  ++i) {
 157     Status status = patchers_[i]->Init(transformation_parameters);
 158     if (status != C_OK)
 159       return status;
 160   }
 161
 162   // All transformation_parameters should have been consumed by the above loop.
 163   if (!transformation_parameters->Empty())
 164     return C_BAD_ENSEMBLE_HEADER;
 165
 166   return C_OK;
 167 }
 168
 169 Status EnsemblePatchApplication::PredictTransformParameters(
 170     SinkStreamSet* all_predicted_parameters) {
 171   for (size_t i = 0;  i < patchers_.size();  ++i) {
 172     SinkStreamSet single_predicted_parameters;
 173     Status status =
 174         patchers_[i]->PredictTransformParameters(&single_predicted_parameters);
 175     if (status != C_OK)
 176       return status;
 177     if (!all_predicted_parameters->WriteSet(&single_predicted_parameters))
 178       return C_STREAM_ERROR;
 179   }
 180   return C_OK;
 181 }
 182
 183 Status EnsemblePatchApplication::SubpatchTransformParameters(
 184     SinkStreamSet* predicted_parameters,
 185     SourceStream* correction,
 186     SourceStreamSet* corrected_parameters) {
 187   return SubpatchStreamSets(predicted_parameters,
 188                             correction,
 189                             corrected_parameters,
 190                             &corrected_parameters_storage_);
 191 }
 192
 193 Status EnsemblePatchApplication::TransformUp(
 194     SourceStreamSet* parameters,
 195     SinkStreamSet* transformed_elements) {
 196   for (size_t i = 0;  i < patchers_.size();  ++i) {
 197     SourceStreamSet single_parameters;
 198     if (!parameters->ReadSet(&single_parameters))
 199       return C_STREAM_ERROR;
 200     SinkStreamSet single_transformed_element;
 201     Status status = patchers_[i]->Transform(&single_parameters,
 202                                             &single_transformed_element);
 203     if (status != C_OK)
 204       return status;
 205     if (!single_parameters.Empty())
 206       return C_STREAM_NOT_CONSUMED;
 207     if (!transformed_elements->WriteSet(&single_transformed_element))
 208       return C_STREAM_ERROR;
 209   }
 210
 211   if (!parameters->Empty())
 212     return C_STREAM_NOT_CONSUMED;
 213   return C_OK;
 214 }
 215
 216 Status EnsemblePatchApplication::SubpatchTransformedElements(
 217     SinkStreamSet* predicted_elements,
 218     SourceStream* correction,
 219     SourceStreamSet* corrected_elements) {
 220   return SubpatchStreamSets(predicted_elements,
 221                             correction,
 222                             corrected_elements,
 223                             &corrected_elements_storage_);
 224 }
 225
 226 Status EnsemblePatchApplication::TransformDown(
 227     SourceStreamSet* transformed_elements,
 228     SinkStream* basic_elements) {
 229   // Construct blob of original input followed by reformed elements.
 230
 231   if (!basic_elements->Reserve(final_patch_input_size_prediction_)) {
 232     return C_STREAM_ERROR;
 233   }
 234
 235   // The original input:
 236   if (!basic_elements->Write(base_region_.start(), base_region_.length()))
 237     return C_STREAM_ERROR;
 238
 239   for (size_t i = 0;  i < patchers_.size();  ++i) {
 240     SourceStreamSet single_corrected_element;
 241     if (!transformed_elements->ReadSet(&single_corrected_element))
 242       return C_STREAM_ERROR;
 243     Status status = patchers_[i]->Reform(&single_corrected_element,
 244                                          basic_elements);
 245     if (status != C_OK)
 246       return status;
 247     if (!single_corrected_element.Empty())
 248       return C_STREAM_NOT_CONSUMED;
 249   }
 250
 251   if (!transformed_elements->Empty())
 252     return C_STREAM_NOT_CONSUMED;
 253   // We have totally consumed transformed_elements, so can free the
 254   // storage to which it referred.
 255   corrected_elements_storage_.Retire();
 256
 257   return C_OK;
 258 }
 259
 260 Status EnsemblePatchApplication::SubpatchFinalOutput(
 261     SourceStream* original,
 262     SourceStream* correction,
 263     SinkStream* corrected_ensemble) {
 264   Status delta_status = ApplySimpleDelta(original, correction,
 265                                          corrected_ensemble);
 266   if (delta_status != C_OK)
 267     return delta_status;
 268
 269   if (CalculateCrc(corrected_ensemble->Buffer(),
 270                    corrected_ensemble->Length()) != target_checksum_)
 271     return C_BAD_ENSEMBLE_CRC;
 272
 273   return C_OK;
 274 }
 275
 276 Status EnsemblePatchApplication::SubpatchStreamSets(
 277     SinkStreamSet* predicted_items,
 278     SourceStream* correction,
 279     SourceStreamSet* corrected_items,
 280     SinkStream* corrected_items_storage) {
 281   SinkStream linearized_predicted_items;
 282   if (!predicted_items->CopyTo(&linearized_predicted_items))
 283     return C_STREAM_ERROR;
 284
 285   SourceStream prediction;
 286   prediction.Init(linearized_predicted_items);
 287
 288   Status status = ApplySimpleDelta(&prediction,
 289                                    correction,
 290                                    corrected_items_storage);
 291   if (status != C_OK)
 292     return status;
 293
 294   if (!corrected_items->Init(corrected_items_storage->Buffer(),
 295                              corrected_items_storage->Length()))
 296     return C_STREAM_ERROR;
 297
 298   return C_OK;
 299 }
 300
 301 Status ApplyEnsemblePatch(SourceStream* base,
 302                           SourceStream* patch,
 303                           SinkStream* output) {
 304   Status status;
 305   EnsemblePatchApplication patch_process;
 306
 307   status = patch_process.ReadHeader(patch);
 308   if (status != C_OK)
 309     return status;
 310
 311   status = patch_process.InitBase(Region(base->Buffer(), base->Remaining()));
 312   if (status != C_OK)
 313     return status;
 314
 315   status = patch_process.ValidateBase();
 316   if (status != C_OK)
 317     return status;
 318
 319   // The rest of the patch stream is a StreamSet.
 320   SourceStreamSet patch_streams;
 321   patch_streams.Init(patch);
 322
 323   SourceStream* transformation_descriptions     = patch_streams.stream(0);
 324   SourceStream* parameter_correction            = patch_streams.stream(1);
 325   SourceStream* transformed_elements_correction = patch_streams.stream(2);
 326   SourceStream* ensemble_correction             = patch_streams.stream(3);
 327
 328   status = patch_process.ReadInitialParameters(transformation_descriptions);
 329   if (status != C_OK)
 330     return status;
 331
 332   SinkStreamSet predicted_parameters;
 333   status = patch_process.PredictTransformParameters(&predicted_parameters);
 334   if (status != C_OK)
 335     return status;
 336
 337   SourceStreamSet corrected_parameters;
 338   status = patch_process.SubpatchTransformParameters(&predicted_parameters,
 339                                                      parameter_correction,
 340                                                      &corrected_parameters);
 341   if (status != C_OK)
 342     return status;
 343
 344   SinkStreamSet transformed_elements;
 345   status = patch_process.TransformUp(&corrected_parameters,
 346                                      &transformed_elements);
 347   if (status != C_OK)
 348     return status;
 349
 350   SourceStreamSet corrected_transformed_elements;
 351   status = patch_process.SubpatchTransformedElements(
 352           &transformed_elements,
 353           transformed_elements_correction,
 354           &corrected_transformed_elements);
 355   if (status != C_OK)
 356     return status;
 357
 358   SinkStream original_ensemble_and_corrected_base_elements;
 359   status = patch_process.TransformDown(
 360       &corrected_transformed_elements,
 361       &original_ensemble_and_corrected_base_elements);
 362   if (status != C_OK)
 363     return status;
 364
 365   SourceStream final_patch_prediction;
 366   final_patch_prediction.Init(original_ensemble_and_corrected_base_elements);
 367   status = patch_process.SubpatchFinalOutput(&final_patch_prediction,
 368                                              ensemble_correction, output);
 369   if (status != C_OK)
 370     return status;
 371
 372   return C_OK;
 373 }
 374
 375 Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name,
 376                           const base::FilePath::CharType* patch_file_name,
 377                           const base::FilePath::CharType* new_file_name) {
 378   // First read enough of the patch file to validate the header is well-formed.
 379   // A few varint32 numbers should fit in 100.
 380   base::FilePath patch_file_path(patch_file_name);
 381   base::MemoryMappedFile patch_file;
 382   if (!patch_file.Initialize(patch_file_path))
 383     return C_READ_OPEN_ERROR;
 384
 385   // 'Dry-run' the first step of the patch process to validate format of header.
 386   SourceStream patch_header_stream;
 387   patch_header_stream.Init(patch_file.data(), patch_file.length());
 388   EnsemblePatchApplication patch_process;
 389   Status status = patch_process.ReadHeader(&patch_header_stream);
 390   if (status != C_OK)
 391     return status;
 392
 393   // Read the old_file.
 394   base::FilePath old_file_path(old_file_name);
 395   base::MemoryMappedFile old_file;
 396   if (!old_file.Initialize(old_file_path))
 397     return C_READ_ERROR;
 398
 399   // Apply patch on streams.
 400   SourceStream old_source_stream;
 401   SourceStream patch_source_stream;
 402   old_source_stream.Init(old_file.data(), old_file.length());
 403   patch_source_stream.Init(patch_file.data(), patch_file.length());
 404   SinkStream new_sink_stream;
 405   status = ApplyEnsemblePatch(&old_source_stream, &patch_source_stream,
 406                               &new_sink_stream);
 407   if (status != C_OK)
 408     return status;
 409
 410   // Write the patched data to |new_file_name|.
 411   base::FilePath new_file_path(new_file_name);
 412   int written =
 413       file_util::WriteFile(
 414           new_file_path,
 415           reinterpret_cast<const char*>(new_sink_stream.Buffer()),
 416           static_cast<int>(new_sink_stream.Length()));
 417   if (written == -1)
 418     return C_WRITE_OPEN_ERROR;
 419   if (static_cast<size_t>(written) != new_sink_stream.Length())
 420     return C_WRITE_ERROR;
 421
 422   return C_OK;
 423 }
 424
 425 }  // namespace