// Copyright (c) 2012 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 "base/pickle.h" #include // for max() #include #include #include "base/bits.h" #include "base/numerics/safe_conversions.h" #include "base/numerics/safe_math.h" #include "build/build_config.h" namespace base { // static const size_t Pickle::kPayloadUnit = 64; static const size_t kCapacityReadOnly = static_cast(-1); PickleIterator::PickleIterator(const Pickle& pickle) : payload_(pickle.payload()), read_index_(0), end_index_(pickle.payload_size()) {} template inline bool PickleIterator::ReadBuiltinType(Type* result) { const char* read_from = GetReadPointerAndAdvance(); if (!read_from) return false; if (sizeof(Type) > sizeof(uint32_t)) memcpy(result, read_from, sizeof(*result)); else *result = *reinterpret_cast(read_from); return true; } inline void PickleIterator::Advance(size_t size) { size_t aligned_size = bits::AlignUp(size, sizeof(uint32_t)); if (end_index_ - read_index_ < aligned_size) { read_index_ = end_index_; } else { read_index_ += aligned_size; } } template inline const char* PickleIterator::GetReadPointerAndAdvance() { if (sizeof(Type) > end_index_ - read_index_) { read_index_ = end_index_; return nullptr; } const char* current_read_ptr = payload_ + read_index_; Advance(sizeof(Type)); return current_read_ptr; } const char* PickleIterator::GetReadPointerAndAdvance(size_t num_bytes) { if (num_bytes > end_index_ - read_index_) { read_index_ = end_index_; return nullptr; } const char* current_read_ptr = payload_ + read_index_; Advance(num_bytes); return current_read_ptr; } inline const char* PickleIterator::GetReadPointerAndAdvance( size_t num_elements, size_t size_element) { // Check for size_t overflow. size_t num_bytes; if (!CheckMul(num_elements, size_element).AssignIfValid(&num_bytes)) return nullptr; return GetReadPointerAndAdvance(num_bytes); } bool PickleIterator::ReadBool(bool* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadInt(int* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadLong(long* result) { // Always read long as a 64-bit value to ensure compatibility between 32-bit // and 64-bit processes. int64_t result_int64 = 0; if (!ReadBuiltinType(&result_int64)) return false; // CHECK if the cast truncates the value so that we know to change this IPC // parameter to use int64_t. *result = base::checked_cast(result_int64); return true; } bool PickleIterator::ReadUInt16(uint16_t* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadUInt32(uint32_t* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadInt64(int64_t* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadUInt64(uint64_t* result) { return ReadBuiltinType(result); } bool PickleIterator::ReadFloat(float* result) { // crbug.com/315213 // The source data may not be properly aligned, and unaligned float reads // cause SIGBUS on some ARM platforms, so force using memcpy to copy the data // into the result. const char* read_from = GetReadPointerAndAdvance(); if (!read_from) return false; memcpy(result, read_from, sizeof(*result)); return true; } bool PickleIterator::ReadDouble(double* result) { // crbug.com/315213 // The source data may not be properly aligned, and unaligned double reads // cause SIGBUS on some ARM platforms, so force using memcpy to copy the data // into the result. const char* read_from = GetReadPointerAndAdvance(); if (!read_from) return false; memcpy(result, read_from, sizeof(*result)); return true; } bool PickleIterator::ReadString(std::string* result) { size_t len; if (!ReadLength(&len)) return false; const char* read_from = GetReadPointerAndAdvance(len); if (!read_from) return false; result->assign(read_from, len); return true; } bool PickleIterator::ReadStringPiece(StringPiece* result) { size_t len; if (!ReadLength(&len)) return false; const char* read_from = GetReadPointerAndAdvance(len); if (!read_from) return false; *result = StringPiece(read_from, len); return true; } bool PickleIterator::ReadString16(std::u16string* result) { size_t len; if (!ReadLength(&len)) return false; const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16_t)); if (!read_from) return false; result->assign(reinterpret_cast(read_from), len); return true; } bool PickleIterator::ReadStringPiece16(StringPiece16* result) { size_t len; if (!ReadLength(&len)) return false; const char* read_from = GetReadPointerAndAdvance(len, sizeof(char16_t)); if (!read_from) return false; *result = StringPiece16(reinterpret_cast(read_from), len); return true; } bool PickleIterator::ReadData(const char** data, size_t* length) { *length = 0; *data = nullptr; if (!ReadLength(length)) return false; return ReadBytes(data, *length); } bool PickleIterator::ReadData(base::span* data) { const char* ptr; size_t length; if (!ReadData(&ptr, &length)) return false; *data = base::as_bytes(base::make_span(ptr, length)); return true; } bool PickleIterator::ReadBytes(const char** data, size_t length) { const char* read_from = GetReadPointerAndAdvance(length); if (!read_from) return false; *data = read_from; return true; } Pickle::Attachment::Attachment() = default; Pickle::Attachment::~Attachment() = default; // Payload is uint32_t aligned. Pickle::Pickle() : header_(nullptr), header_size_(sizeof(Header)), capacity_after_header_(0), write_offset_(0) { static_assert(base::bits::IsPowerOfTwo(Pickle::kPayloadUnit), "Pickle::kPayloadUnit must be a power of two"); Resize(kPayloadUnit); header_->payload_size = 0; } Pickle::Pickle(size_t header_size) : header_(nullptr), header_size_(bits::AlignUp(header_size, sizeof(uint32_t))), capacity_after_header_(0), write_offset_(0) { DCHECK_GE(header_size, sizeof(Header)); DCHECK_LE(header_size, kPayloadUnit); Resize(kPayloadUnit); header_->payload_size = 0; } Pickle::Pickle(const char* data, size_t data_len) : header_(reinterpret_cast(const_cast(data))), header_size_(0), capacity_after_header_(kCapacityReadOnly), write_offset_(0) { if (data_len >= sizeof(Header)) header_size_ = data_len - header_->payload_size; if (header_size_ > data_len) header_size_ = 0; if (header_size_ != bits::AlignUp(header_size_, sizeof(uint32_t))) header_size_ = 0; // If there is anything wrong with the data, we're not going to use it. if (!header_size_) header_ = nullptr; } Pickle::Pickle(const Pickle& other) : header_(nullptr), header_size_(other.header_size_), capacity_after_header_(0), write_offset_(other.write_offset_) { if (other.header_) { Resize(other.header_->payload_size); memcpy(header_, other.header_, header_size_ + other.header_->payload_size); } } Pickle::~Pickle() { if (capacity_after_header_ != kCapacityReadOnly) free(header_); } Pickle& Pickle::operator=(const Pickle& other) { if (this == &other) { return *this; } if (capacity_after_header_ == kCapacityReadOnly) { header_ = nullptr; capacity_after_header_ = 0; } if (header_size_ != other.header_size_) { free(header_); header_ = nullptr; header_size_ = other.header_size_; } if (other.header_) { Resize(other.header_->payload_size); memcpy(header_, other.header_, other.header_size_ + other.header_->payload_size); write_offset_ = other.write_offset_; } return *this; } void Pickle::WriteString(const StringPiece& value) { WriteData(value.data(), value.size()); } void Pickle::WriteString16(const StringPiece16& value) { WriteInt(checked_cast(value.size())); WriteBytes(value.data(), value.size() * sizeof(char16_t)); } void Pickle::WriteData(const char* data, size_t length) { WriteInt(checked_cast(length)); WriteBytes(data, length); } void Pickle::WriteBytes(const void* data, size_t length) { WriteBytesCommon(data, length); } void Pickle::Reserve(size_t length) { size_t data_len = bits::AlignUp(length, sizeof(uint32_t)); DCHECK_GE(data_len, length); #ifdef ARCH_CPU_64_BITS DCHECK_LE(data_len, std::numeric_limits::max()); #endif DCHECK_LE(write_offset_, std::numeric_limits::max() - data_len); size_t new_size = write_offset_ + data_len; if (new_size > capacity_after_header_) Resize(capacity_after_header_ * 2 + new_size); } bool Pickle::WriteAttachment(scoped_refptr attachment) { return false; } bool Pickle::ReadAttachment(base::PickleIterator* iter, scoped_refptr* attachment) const { return false; } bool Pickle::HasAttachments() const { return false; } void Pickle::Resize(size_t new_capacity) { CHECK_NE(capacity_after_header_, kCapacityReadOnly); capacity_after_header_ = bits::AlignUp(new_capacity, kPayloadUnit); void* p = realloc(header_, GetTotalAllocatedSize()); CHECK(p); header_ = reinterpret_cast(p); } void* Pickle::ClaimBytes(size_t num_bytes) { void* p = ClaimUninitializedBytesInternal(num_bytes); CHECK(p); memset(p, 0, num_bytes); return p; } size_t Pickle::GetTotalAllocatedSize() const { if (capacity_after_header_ == kCapacityReadOnly) return 0; return header_size_ + capacity_after_header_; } // static const char* Pickle::FindNext(size_t header_size, const char* start, const char* end) { size_t pickle_size = 0; if (!PeekNext(header_size, start, end, &pickle_size)) return nullptr; if (pickle_size > static_cast(end - start)) return nullptr; return start + pickle_size; } // static bool Pickle::PeekNext(size_t header_size, const char* start, const char* end, size_t* pickle_size) { DCHECK_EQ(header_size, bits::AlignUp(header_size, sizeof(uint32_t))); DCHECK_GE(header_size, sizeof(Header)); DCHECK_LE(header_size, static_cast(kPayloadUnit)); size_t length = static_cast(end - start); if (length < sizeof(Header)) return false; const Header* hdr = reinterpret_cast(start); if (length < header_size) return false; // If payload_size causes an overflow, we return maximum possible // pickle size to indicate that. *pickle_size = ClampAdd(header_size, hdr->payload_size); return true; } template void Pickle::WriteBytesStatic(const void* data) { WriteBytesCommon(data, length); } template void Pickle::WriteBytesStatic<2>(const void* data); template void Pickle::WriteBytesStatic<4>(const void* data); template void Pickle::WriteBytesStatic<8>(const void* data); inline void* Pickle::ClaimUninitializedBytesInternal(size_t length) { DCHECK_NE(kCapacityReadOnly, capacity_after_header_) << "oops: pickle is readonly"; size_t data_len = bits::AlignUp(length, sizeof(uint32_t)); DCHECK_GE(data_len, length); #ifdef ARCH_CPU_64_BITS DCHECK_LE(data_len, std::numeric_limits::max()); #endif DCHECK_LE(write_offset_, std::numeric_limits::max() - data_len); size_t new_size = write_offset_ + data_len; if (new_size > capacity_after_header_) { size_t new_capacity = capacity_after_header_ * 2; const size_t kPickleHeapAlign = 4096; if (new_capacity > kPickleHeapAlign) { new_capacity = bits::AlignUp(new_capacity, kPickleHeapAlign) - kPayloadUnit; } Resize(std::max(new_capacity, new_size)); } char* write = mutable_payload() + write_offset_; memset(write + length, 0, data_len - length); // Always initialize padding header_->payload_size = static_cast(new_size); write_offset_ = new_size; return write; } inline void Pickle::WriteBytesCommon(const void* data, size_t length) { DCHECK_NE(kCapacityReadOnly, capacity_after_header_) << "oops: pickle is readonly"; MSAN_CHECK_MEM_IS_INITIALIZED(data, length); void* write = ClaimUninitializedBytesInternal(length); memcpy(write, data, length); } } // namespace base