diff options
Diffstat (limited to 'mojo/edk/system/transport_data.cc')
-rw-r--r-- | mojo/edk/system/transport_data.cc | 337 |
1 files changed, 0 insertions, 337 deletions
diff --git a/mojo/edk/system/transport_data.cc b/mojo/edk/system/transport_data.cc deleted file mode 100644 index d388151..0000000 --- a/mojo/edk/system/transport_data.cc +++ /dev/null @@ -1,337 +0,0 @@ -// Copyright 2014 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/edk/system/transport_data.h" - -#include <string.h> - -#include "base/compiler_specific.h" -#include "base/logging.h" -#include "mojo/edk/system/channel.h" -#include "mojo/edk/system/configuration.h" -#include "mojo/edk/system/message_in_transit.h" - -namespace mojo { -namespace system { - -// The maximum amount of space needed per platform handle. -// (|{Channel,RawChannel}::GetSerializedPlatformHandleSize()| should always -// return a value which is at most this. This is only used to calculate -// |TransportData::kMaxBufferSize|. This value should be a multiple of the -// alignment in order to simplify calculations, even though the actual amount of -// space needed need not be a multiple of the alignment. -const size_t kMaxSizePerPlatformHandle = 8; -static_assert(kMaxSizePerPlatformHandle % MessageInTransit::kMessageAlignment == - 0, - "kMaxSizePerPlatformHandle not a multiple of alignment"); - -STATIC_CONST_MEMBER_DEFINITION const size_t - TransportData::kMaxSerializedDispatcherSize; -STATIC_CONST_MEMBER_DEFINITION const size_t - TransportData::kMaxSerializedDispatcherPlatformHandles; - -// static -size_t TransportData::GetMaxBufferSize() { - // In additional to the header, for each attached (Mojo) handle there'll be a - // handle table entry and serialized dispatcher data. - return sizeof(Header) + - GetConfiguration().max_message_num_handles * - (sizeof(HandleTableEntry) + kMaxSerializedDispatcherSize) + - GetMaxPlatformHandles() * kMaxSizePerPlatformHandle; -} - -// static -size_t TransportData::GetMaxPlatformHandles() { - return GetConfiguration().max_message_num_handles * - kMaxSerializedDispatcherPlatformHandles; -} - -struct TransportData::PrivateStructForCompileAsserts { - static_assert(sizeof(Header) % MessageInTransit::kMessageAlignment == 0, - "sizeof(MessageInTransit::Header) not a multiple of alignment"); - static_assert(kMaxSerializedDispatcherSize % - MessageInTransit::kMessageAlignment == - 0, - "kMaxSerializedDispatcherSize not a multiple of alignment"); - static_assert(sizeof(HandleTableEntry) % - MessageInTransit::kMessageAlignment == - 0, - "sizeof(MessageInTransit::HandleTableEntry) not a multiple of " - "alignment"); -}; - -TransportData::TransportData(scoped_ptr<DispatcherVector> dispatchers, - Channel* channel) { - DCHECK(dispatchers); - DCHECK(channel); - - const size_t num_handles = dispatchers->size(); - DCHECK_GT(num_handles, 0u); - - // The offset to the start of the (Mojo) handle table. - const size_t handle_table_start_offset = sizeof(Header); - // The offset to the start of the serialized dispatcher data. - const size_t serialized_dispatcher_start_offset = - handle_table_start_offset + num_handles * sizeof(HandleTableEntry); - // The estimated size of the secondary buffer. We compute this estimate below. - // It must be at least as big as the (eventual) actual size. - size_t estimated_size = serialized_dispatcher_start_offset; - size_t estimated_num_platform_handles = 0; -#if DCHECK_IS_ON() - std::vector<size_t> all_max_sizes(num_handles); - std::vector<size_t> all_max_platform_handles(num_handles); -#endif - for (size_t i = 0; i < num_handles; i++) { - if (Dispatcher* dispatcher = (*dispatchers)[i].get()) { - size_t max_size = 0; - size_t max_platform_handles = 0; - Dispatcher::TransportDataAccess::StartSerialize( - dispatcher, channel, &max_size, &max_platform_handles); - - DCHECK_LE(max_size, kMaxSerializedDispatcherSize); - estimated_size += MessageInTransit::RoundUpMessageAlignment(max_size); - DCHECK_LE(estimated_size, GetMaxBufferSize()); - - DCHECK_LE(max_platform_handles, kMaxSerializedDispatcherPlatformHandles); - estimated_num_platform_handles += max_platform_handles; - DCHECK_LE(estimated_num_platform_handles, GetMaxPlatformHandles()); - -#if DCHECK_IS_ON() - all_max_sizes[i] = max_size; - all_max_platform_handles[i] = max_platform_handles; -#endif - } - } - - size_t size_per_platform_handle = 0; - if (estimated_num_platform_handles > 0) { - size_per_platform_handle = channel->GetSerializedPlatformHandleSize(); - DCHECK_LE(size_per_platform_handle, kMaxSizePerPlatformHandle); - estimated_size += estimated_num_platform_handles * size_per_platform_handle; - estimated_size = MessageInTransit::RoundUpMessageAlignment(estimated_size); - DCHECK_LE(estimated_size, GetMaxBufferSize()); - } - - buffer_.reset(static_cast<char*>( - base::AlignedAlloc(estimated_size, MessageInTransit::kMessageAlignment))); - // Entirely clear out the secondary buffer, since then we won't have to worry - // about clearing padding or unused space (e.g., if a dispatcher fails to - // serialize). - memset(buffer_.get(), 0, estimated_size); - - if (estimated_num_platform_handles > 0) { - DCHECK(!platform_handles_); - platform_handles_.reset(new embedder::PlatformHandleVector()); - } - - Header* header = reinterpret_cast<Header*>(buffer_.get()); - header->num_handles = static_cast<uint32_t>(num_handles); - // (Okay to leave |platform_handle_table_offset|, |num_platform_handles|, and - // |unused| be zero; we'll set the former two later if necessary.) - - HandleTableEntry* handle_table = reinterpret_cast<HandleTableEntry*>( - buffer_.get() + handle_table_start_offset); - size_t current_offset = serialized_dispatcher_start_offset; - for (size_t i = 0; i < num_handles; i++) { - Dispatcher* dispatcher = (*dispatchers)[i].get(); - if (!dispatcher) { - static_assert(Dispatcher::kTypeUnknown == 0, - "Value of Dispatcher::kTypeUnknown must be 0"); - continue; - } - -#if DCHECK_IS_ON() - size_t old_platform_handles_size = - platform_handles_ ? platform_handles_->size() : 0; -#endif - - void* destination = buffer_.get() + current_offset; - size_t actual_size = 0; - if (Dispatcher::TransportDataAccess::EndSerializeAndClose( - dispatcher, channel, destination, &actual_size, - platform_handles_.get())) { - handle_table[i].type = static_cast<int32_t>(dispatcher->GetType()); - handle_table[i].offset = static_cast<uint32_t>(current_offset); - handle_table[i].size = static_cast<uint32_t>(actual_size); -// (Okay to not set |unused| since we cleared the entire buffer.) - -#if DCHECK_IS_ON() - DCHECK_LE(actual_size, all_max_sizes[i]); - DCHECK_LE(platform_handles_ - ? (platform_handles_->size() - old_platform_handles_size) - : 0, - all_max_platform_handles[i]); -#endif - } else { - // Nothing to do on failure, since |buffer_| was cleared, and - // |kTypeUnknown| is zero. The handle was simply closed. - LOG(ERROR) << "Failed to serialize handle to remote message pipe"; - } - - current_offset += MessageInTransit::RoundUpMessageAlignment(actual_size); - DCHECK_LE(current_offset, estimated_size); - DCHECK_LE(platform_handles_ ? platform_handles_->size() : 0, - estimated_num_platform_handles); - } - - if (platform_handles_ && platform_handles_->size() > 0) { - header->platform_handle_table_offset = - static_cast<uint32_t>(current_offset); - header->num_platform_handles = - static_cast<uint32_t>(platform_handles_->size()); - current_offset += platform_handles_->size() * size_per_platform_handle; - current_offset = MessageInTransit::RoundUpMessageAlignment(current_offset); - } - - // There's no aligned realloc, so it's no good way to release unused space (if - // we overshot our estimated space requirements). - buffer_size_ = current_offset; - - // |dispatchers_| will be destroyed as it goes out of scope. -} - -TransportData::TransportData( - embedder::ScopedPlatformHandleVectorPtr platform_handles) - : buffer_size_(sizeof(Header)), platform_handles_(platform_handles.Pass()) { - buffer_.reset(static_cast<char*>( - base::AlignedAlloc(buffer_size_, MessageInTransit::kMessageAlignment))); - memset(buffer_.get(), 0, buffer_size_); - - Header* header = reinterpret_cast<Header*>(buffer_.get()); - header->num_platform_handles = - static_cast<uint32_t>(platform_handles_->size()); -} - -TransportData::~TransportData() { -} - -// static -const char* TransportData::ValidateBuffer( - size_t serialized_platform_handle_size, - const void* buffer, - size_t buffer_size) { - DCHECK(buffer); - DCHECK_GT(buffer_size, 0u); - - // Always make sure that the buffer size is sane; if it's not, someone's - // messing with us. - if (buffer_size < sizeof(Header) || buffer_size > GetMaxBufferSize() || - buffer_size % MessageInTransit::kMessageAlignment != 0) - return "Invalid message secondary buffer size"; - - const Header* header = static_cast<const Header*>(buffer); - const size_t num_handles = header->num_handles; - - // Sanity-check |num_handles| (before multiplying it against anything). - if (num_handles > GetConfiguration().max_message_num_handles) - return "Message handle payload too large"; - - if (buffer_size < sizeof(Header) + num_handles * sizeof(HandleTableEntry)) - return "Message secondary buffer too small"; - - if (header->num_platform_handles == 0) { - // Then |platform_handle_table_offset| should also be zero. - if (header->platform_handle_table_offset != 0) { - return "Message has no handles attached, but platform handle table " - "present"; - } - } else { - if (header->num_platform_handles > - GetConfiguration().max_message_num_handles * - kMaxSerializedDispatcherPlatformHandles) - return "Message has too many platform handles attached"; - - static const char kInvalidPlatformHandleTableOffset[] = - "Message has invalid platform handle table offset"; - // This doesn't check that the platform handle table doesn't alias other - // stuff, but it doesn't matter, since it's all read-only. - if (header->platform_handle_table_offset % - MessageInTransit::kMessageAlignment != - 0) - return kInvalidPlatformHandleTableOffset; - - // ">" instead of ">=" since the size per handle may be zero. - if (header->platform_handle_table_offset > buffer_size) - return kInvalidPlatformHandleTableOffset; - - // We already checked |platform_handle_table_offset| and - // |num_platform_handles|, so the addition and multiplication are okay. - if (header->platform_handle_table_offset + - header->num_platform_handles * serialized_platform_handle_size > - buffer_size) - return kInvalidPlatformHandleTableOffset; - } - - const HandleTableEntry* handle_table = - reinterpret_cast<const HandleTableEntry*>( - static_cast<const char*>(buffer) + sizeof(Header)); - static const char kInvalidSerializedDispatcher[] = - "Message contains invalid serialized dispatcher"; - for (size_t i = 0; i < num_handles; i++) { - size_t offset = handle_table[i].offset; - if (offset % MessageInTransit::kMessageAlignment != 0) - return kInvalidSerializedDispatcher; - - size_t size = handle_table[i].size; - if (size > kMaxSerializedDispatcherSize || size > buffer_size) - return kInvalidSerializedDispatcher; - - // Note: This is an overflow-safe check for |offset + size > buffer_size| - // (we know that |size <= buffer_size| from the previous check). - if (offset > buffer_size - size) - return kInvalidSerializedDispatcher; - } - - return nullptr; -} - -// static -void TransportData::GetPlatformHandleTable(const void* transport_data_buffer, - size_t* num_platform_handles, - const void** platform_handle_table) { - DCHECK(transport_data_buffer); - DCHECK(num_platform_handles); - DCHECK(platform_handle_table); - - const Header* header = static_cast<const Header*>(transport_data_buffer); - *num_platform_handles = header->num_platform_handles; - *platform_handle_table = static_cast<const char*>(transport_data_buffer) + - header->platform_handle_table_offset; -} - -// static -scoped_ptr<DispatcherVector> TransportData::DeserializeDispatchers( - const void* buffer, - size_t buffer_size, - embedder::ScopedPlatformHandleVectorPtr platform_handles, - Channel* channel) { - DCHECK(buffer); - DCHECK_GT(buffer_size, 0u); - DCHECK(channel); - - const Header* header = static_cast<const Header*>(buffer); - const size_t num_handles = header->num_handles; - scoped_ptr<DispatcherVector> dispatchers(new DispatcherVector(num_handles)); - - const HandleTableEntry* handle_table = - reinterpret_cast<const HandleTableEntry*>( - static_cast<const char*>(buffer) + sizeof(Header)); - for (size_t i = 0; i < num_handles; i++) { - size_t offset = handle_table[i].offset; - size_t size = handle_table[i].size; - // Should already have been checked by |ValidateBuffer()|: - DCHECK_EQ(offset % MessageInTransit::kMessageAlignment, 0u); - DCHECK_LE(offset, buffer_size); - DCHECK_LE(offset + size, buffer_size); - - const void* source = static_cast<const char*>(buffer) + offset; - (*dispatchers)[i] = Dispatcher::TransportDataAccess::Deserialize( - channel, handle_table[i].type, source, size, platform_handles.get()); - } - - return dispatchers.Pass(); -} - -} // namespace system -} // namespace mojo |