| // Copyright 2013 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. |
| |
| #include "mojo/public/cpp/bindings/lib/bindings_serialization.h" |
| |
| #include "mojo/public/cpp/bindings/lib/bindings_internal.h" |
| #include "mojo/public/cpp/bindings/lib/bounds_checker.h" |
| #include "mojo/public/cpp/bindings/lib/validation_errors.h" |
| #include "mojo/public/cpp/environment/logging.h" |
| |
| namespace mojo { |
| namespace internal { |
| |
| namespace { |
| |
| const size_t kAlignment = 8; |
| |
| template <typename T> |
| T AlignImpl(T t) { |
| return t + (kAlignment - (t % kAlignment)) % kAlignment; |
| } |
| |
| } // namespace |
| |
| size_t Align(size_t size) { |
| return AlignImpl(size); |
| } |
| |
| char* AlignPointer(char* ptr) { |
| return reinterpret_cast<char*>(AlignImpl(reinterpret_cast<uintptr_t>(ptr))); |
| } |
| |
| bool IsAligned(const void* ptr) { |
| return !(reinterpret_cast<uintptr_t>(ptr) % kAlignment); |
| } |
| |
| void EncodePointer(const void* ptr, uint64_t* offset) { |
| if (!ptr) { |
| *offset = 0; |
| return; |
| } |
| |
| const char* p_obj = reinterpret_cast<const char*>(ptr); |
| const char* p_slot = reinterpret_cast<const char*>(offset); |
| MOJO_DCHECK(p_obj > p_slot); |
| |
| *offset = static_cast<uint64_t>(p_obj - p_slot); |
| } |
| |
| const void* DecodePointerRaw(const uint64_t* offset) { |
| if (!*offset) |
| return nullptr; |
| return reinterpret_cast<const char*>(offset) + *offset; |
| } |
| |
| bool ValidateEncodedPointer(const uint64_t* offset) { |
| // Cast to uintptr_t so overflow behavior is well defined. |
| return reinterpret_cast<uintptr_t>(offset) + *offset >= |
| reinterpret_cast<uintptr_t>(offset); |
| } |
| |
| void EncodeHandle(Handle* handle, std::vector<Handle>* handles) { |
| if (handle->is_valid()) { |
| handles->push_back(*handle); |
| handle->set_value(static_cast<MojoHandle>(handles->size() - 1)); |
| } else { |
| handle->set_value(kEncodedInvalidHandleValue); |
| } |
| } |
| |
| void DecodeHandle(Handle* handle, std::vector<Handle>* handles) { |
| if (handle->value() == kEncodedInvalidHandleValue) { |
| *handle = Handle(); |
| return; |
| } |
| MOJO_DCHECK(handle->value() < handles->size()); |
| // Just leave holes in the vector so we don't screw up other indices. |
| *handle = FetchAndReset(&handles->at(handle->value())); |
| } |
| |
| bool ValidateStructHeader(const void* data, |
| uint32_t min_num_bytes, |
| uint32_t min_num_fields, |
| BoundsChecker* bounds_checker) { |
| MOJO_DCHECK(min_num_bytes >= sizeof(StructHeader)); |
| |
| if (!IsAligned(data)) { |
| ReportValidationError(VALIDATION_ERROR_MISALIGNED_OBJECT); |
| return false; |
| } |
| if (!bounds_checker->IsValidRange(data, sizeof(StructHeader))) { |
| ReportValidationError(VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE); |
| return false; |
| } |
| |
| const StructHeader* header = static_cast<const StructHeader*>(data); |
| |
| // TODO(yzshen): Currently our binding code cannot handle structs of smaller |
| // size or with fewer fields than the version that it sees. That needs to be |
| // changed in order to provide backward compatibility. |
| if (header->num_bytes < min_num_bytes || |
| header->num_fields < min_num_fields) { |
| ReportValidationError(VALIDATION_ERROR_UNEXPECTED_STRUCT_HEADER); |
| return false; |
| } |
| |
| if (!bounds_checker->ClaimMemory(data, header->num_bytes)) { |
| ReportValidationError(VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| } // namespace internal |
| } // namespace mojo |