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- // Copyright 2019 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/core/channel.h"
- #include <mach/mach.h>
- #include <string.h>
- #include <unistd.h>
- #include <algorithm>
- #include <memory>
- #include <tuple>
- #include <utility>
- #include <vector>
- #include "base/bind.h"
- #include "base/containers/buffer_iterator.h"
- #include "base/containers/circular_deque.h"
- #include "base/containers/span.h"
- #include "base/logging.h"
- #include "base/mac/mach_logging.h"
- #include "base/mac/scoped_mach_msg_destroy.h"
- #include "base/mac/scoped_mach_port.h"
- #include "base/mac/scoped_mach_vm.h"
- #include "base/message_loop/message_pump_for_io.h"
- #include "base/task/current_thread.h"
- #include "base/trace_event/typed_macros.h"
- extern "C" {
- kern_return_t fileport_makeport(int fd, mach_port_t*);
- int fileport_makefd(mach_port_t);
- } // extern "C"
- namespace mojo {
- namespace core {
- namespace {
- constexpr mach_msg_id_t kChannelMacHandshakeMsgId = 'mjhs';
- constexpr mach_msg_id_t kChannelMacInlineMsgId = 'MOJO';
- constexpr mach_msg_id_t kChannelMacOOLMsgId = 'MOJ+';
- class ChannelMac : public Channel,
- public base::CurrentThread::DestructionObserver,
- public base::MessagePumpKqueue::MachPortWatcher {
- public:
- ChannelMac(Delegate* delegate,
- ConnectionParams connection_params,
- HandlePolicy handle_policy,
- scoped_refptr<base::SingleThreadTaskRunner> io_task_runner)
- : Channel(delegate, handle_policy, DispatchBufferPolicy::kUnmanaged),
- self_(this),
- io_task_runner_(io_task_runner),
- watch_controller_(FROM_HERE) {
- PlatformHandle channel_handle;
- if (connection_params.server_endpoint().is_valid()) {
- channel_handle =
- connection_params.TakeServerEndpoint().TakePlatformHandle();
- } else {
- channel_handle = connection_params.TakeEndpoint().TakePlatformHandle();
- }
- if (channel_handle.is_mach_send()) {
- send_port_ = channel_handle.TakeMachSendRight();
- } else if (channel_handle.is_mach_receive()) {
- receive_port_ = channel_handle.TakeMachReceiveRight();
- } else {
- NOTREACHED();
- }
- }
- ChannelMac(const ChannelMac&) = delete;
- ChannelMac& operator=(const ChannelMac&) = delete;
- void Start() override {
- io_task_runner_->PostTask(
- FROM_HERE, base::BindOnce(&ChannelMac::StartOnIOThread, this));
- }
- void ShutDownImpl() override {
- io_task_runner_->PostTask(
- FROM_HERE, base::BindOnce(&ChannelMac::ShutDownOnIOThread, this));
- }
- void Write(MessagePtr message) override {
- base::AutoLock lock(write_lock_);
- if (reject_writes_) {
- return;
- }
- // If the channel is not fully established, queue pending messages.
- if (!handshake_done_) {
- pending_messages_.push_back(std::move(message));
- return;
- }
- // If messages are being queued, enqueue |message| and try to flush
- // the queue.
- if (send_buffer_contains_message_ || !pending_messages_.empty()) {
- pending_messages_.push_back(std::move(message));
- SendPendingMessagesLocked();
- return;
- }
- SendMessageLocked(std::move(message));
- }
- void LeakHandle() override {
- DCHECK(io_task_runner_->RunsTasksInCurrentSequence());
- leak_handles_ = true;
- }
- bool GetReadPlatformHandles(const void* payload,
- size_t payload_size,
- size_t num_handles,
- const void* extra_header,
- size_t extra_header_size,
- std::vector<PlatformHandle>* handles,
- bool* deferred) override {
- // Validate the incoming handles. If validation fails, ensure they are
- // destroyed.
- std::vector<PlatformHandle> incoming_handles;
- std::swap(incoming_handles, incoming_handles_);
- if (extra_header_size <
- sizeof(Message::MachPortsExtraHeader) +
- (incoming_handles.size() * sizeof(Message::MachPortsEntry))) {
- return false;
- }
- const auto* mach_ports_header =
- reinterpret_cast<const Message::MachPortsExtraHeader*>(extra_header);
- if (mach_ports_header->num_ports != incoming_handles.size()) {
- return false;
- }
- for (uint16_t i = 0; i < mach_ports_header->num_ports; ++i) {
- auto type =
- static_cast<PlatformHandle::Type>(mach_ports_header->entries[i].type);
- if (type == PlatformHandle::Type::kNone) {
- return false;
- } else if (type == PlatformHandle::Type::kFd &&
- incoming_handles[i].is_mach_send()) {
- int fd = fileport_makefd(incoming_handles[i].GetMachSendRight().get());
- if (fd < 0) {
- return false;
- }
- incoming_handles[i] = PlatformHandle(base::ScopedFD(fd));
- } else if (type != incoming_handles[i].type()) {
- return false;
- }
- }
- *handles = std::move(incoming_handles);
- return true;
- }
- bool GetReadPlatformHandlesForIpcz(
- size_t num_handles,
- std::vector<PlatformHandle>& handles) override {
- if (incoming_handles_.size() != num_handles) {
- // ChannelMac messages are transmitted all at once or not at all, so this
- // method should always be invoked with the exact, correct number of
- // handles already in `incoming_handles_`.
- return false;
- }
- DCHECK(handles.empty());
- incoming_handles_.swap(handles);
- return true;
- }
- private:
- ~ChannelMac() override = default;
- void StartOnIOThread() {
- vm_address_t address = 0;
- const vm_size_t size = getpagesize();
- kern_return_t kr =
- vm_allocate(mach_task_self(), &address, size,
- VM_MAKE_TAG(VM_MEMORY_MACH_MSG) | VM_FLAGS_ANYWHERE);
- MACH_CHECK(kr == KERN_SUCCESS, kr) << "vm_allocate";
- send_buffer_.reset(address, size);
- kr = vm_allocate(mach_task_self(), &address, size,
- VM_MAKE_TAG(VM_MEMORY_MACH_MSG) | VM_FLAGS_ANYWHERE);
- MACH_CHECK(kr == KERN_SUCCESS, kr) << "vm_allocate";
- receive_buffer_.reset(address, size);
- // When a channel is created, it only has one end of communication (either
- // send or receive). If it was created with a receive port, the first thing
- // a channel does is receive a special channel-internal message containing
- // its peer's send right. If the channel was created with a send right, it
- // creates a new receive right and sends to its peer (using the send right
- // it was created with) a new send right to the receive right. This
- // establishes the bidirectional communication channel.
- if (send_port_ != MACH_PORT_NULL) {
- DCHECK(receive_port_ == MACH_PORT_NULL);
- CHECK(base::mac::CreateMachPort(&receive_port_, nullptr,
- MACH_PORT_QLIMIT_LARGE));
- if (!RequestSendDeadNameNotification()) {
- OnError(Error::kConnectionFailed);
- return;
- }
- SendHandshake();
- } else if (receive_port_ != MACH_PORT_NULL) {
- DCHECK(send_port_ == MACH_PORT_NULL);
- // Wait for the received message via the MessageLoop.
- } else {
- NOTREACHED();
- }
- base::CurrentThread::Get()->AddDestructionObserver(this);
- base::CurrentIOThread::Get()->WatchMachReceivePort(
- receive_port_.get(), &watch_controller_, this);
- }
- void ShutDownOnIOThread() {
- base::CurrentThread::Get()->RemoveDestructionObserver(this);
- watch_controller_.StopWatchingMachPort();
- send_buffer_.reset();
- receive_buffer_.reset();
- incoming_handles_.clear();
- if (leak_handles_) {
- std::ignore = receive_port_.release();
- std::ignore = send_port_.release();
- } else {
- receive_port_.reset();
- send_port_.reset();
- }
- // May destroy the |this| if it was the last reference.
- self_ = nullptr;
- }
- // Requests that the kernel notify the |receive_port_| when the receive right
- // connected to |send_port_| becomes a dead name. This should be called as
- // soon as the Channel establishes both the send and receive ports.
- bool RequestSendDeadNameNotification() {
- base::mac::ScopedMachSendRight previous;
- kern_return_t kr = mach_port_request_notification(
- mach_task_self(), send_port_.get(), MACH_NOTIFY_DEAD_NAME, 0,
- receive_port_.get(), MACH_MSG_TYPE_MAKE_SEND_ONCE,
- base::mac::ScopedMachSendRight::Receiver(previous).get());
- if (kr != KERN_SUCCESS) {
- // If port is already a dead name (i.e. the receiver is already gone),
- // then the channel should be shut down by the caller.
- MACH_LOG_IF(ERROR, kr != KERN_INVALID_ARGUMENT, kr)
- << "mach_port_request_notification";
- return false;
- }
- return true;
- }
- // SendHandshake() sends to the |receive_port_| a right to |send_port_|,
- // establishing bi-directional communication with the peer. After the
- // handshake message has been sent, this Channel can queue any pending
- // messages for its peer.
- void SendHandshake() {
- mach_msg_header_t message{};
- message.msgh_bits =
- MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, MACH_MSG_TYPE_MAKE_SEND);
- message.msgh_size = sizeof(message);
- message.msgh_remote_port = send_port_.get();
- message.msgh_local_port = receive_port_.get();
- message.msgh_id = kChannelMacHandshakeMsgId;
- kern_return_t kr =
- mach_msg(&message, MACH_SEND_MSG, sizeof(message), 0, MACH_PORT_NULL,
- MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
- if (kr != KERN_SUCCESS) {
- MACH_LOG(ERROR, kr) << "mach_msg send handshake";
- base::AutoLock lock(write_lock_);
- OnWriteErrorLocked(Error::kConnectionFailed);
- return;
- }
- base::AutoLock lock(write_lock_);
- handshake_done_ = true;
- SendPendingMessagesLocked();
- }
- // Acquires the peer's send right from the handshake message sent via
- // SendHandshake(). After this, bi-directional communication is established
- // and this Channel can send to its peer any pending messages.
- bool ReceiveHandshake(base::BufferIterator<const char> buffer) {
- if (handshake_done_) {
- OnError(Error::kReceivedMalformedData);
- return false;
- }
- DCHECK(send_port_ == MACH_PORT_NULL);
- auto* message = buffer.Object<mach_msg_header_t>();
- if (message->msgh_id != kChannelMacHandshakeMsgId ||
- message->msgh_local_port == MACH_PORT_NULL) {
- OnError(Error::kConnectionFailed);
- return false;
- }
- send_port_ = base::mac::ScopedMachSendRight(message->msgh_remote_port);
- if (!RequestSendDeadNameNotification()) {
- send_port_.reset();
- OnError(Error::kConnectionFailed);
- return false;
- }
- // Record the audit token of the sender. All messages received by the
- // channel must be from this same sender.
- auto* trailer = buffer.Object<mach_msg_audit_trailer_t>();
- peer_audit_token_ = std::make_unique<audit_token_t>();
- memcpy(peer_audit_token_.get(), &trailer->msgh_audit,
- sizeof(audit_token_t));
- base::AutoLock lock(write_lock_);
- handshake_done_ = true;
- SendPendingMessagesLocked();
- return true;
- }
- void SendPendingMessages() {
- base::AutoLock lock(write_lock_);
- SendPendingMessagesLocked();
- }
- void SendPendingMessagesLocked() {
- // If a previous send failed due to the receiver's kernel message queue
- // being full, attempt to send that failed message first.
- if (send_buffer_contains_message_ && !reject_writes_) {
- auto* header =
- reinterpret_cast<mach_msg_header_t*>(send_buffer_.address());
- if (!MachMessageSendLocked(header)) {
- // The send failed again. If the peer is still unable to receive,
- // MachMessageSendLocked() will have arranged another attempt. If an
- // error occurred, the channel will be shut down.
- return;
- }
- }
- // Try and send any other pending messages that were queued.
- while (!pending_messages_.empty() && !reject_writes_) {
- bool did_send = SendMessageLocked(std::move(pending_messages_.front()));
- // If the message failed to send because the kernel message queue is
- // full, the message will have been fully serialized and
- // |send_buffer_contains_message_| will be set to true. The Mojo message
- // object can be destroyed at this point.
- pending_messages_.pop_front();
- if (!did_send)
- break;
- }
- }
- bool SendMessageLocked(MessagePtr message) {
- DCHECK(!send_buffer_contains_message_);
- base::BufferIterator<char> buffer(
- reinterpret_cast<char*>(send_buffer_.address()), send_buffer_.size());
- auto* header = buffer.MutableObject<mach_msg_header_t>();
- *header = mach_msg_header_t{};
- std::vector<PlatformHandleInTransit> handles = message->TakeHandles();
- // Compute the total size of the message. If the message data are larger
- // than the allocated receive buffer, the data will be transferred out-of-
- // line. The receive buffer is the same size as the send buffer, but there
- // also needs to be room to receive the trailer.
- const size_t mach_header_size =
- sizeof(mach_msg_header_t) + sizeof(mach_msg_body_t) +
- (handles.size() * sizeof(mach_msg_port_descriptor_t));
- const size_t expected_message_size =
- round_msg(mach_header_size + sizeof(uint64_t) +
- message->data_num_bytes() + sizeof(mach_msg_audit_trailer_t));
- const bool transfer_message_ool =
- expected_message_size >= send_buffer_.size();
- const bool is_complex = !handles.empty() || transfer_message_ool;
- header->msgh_bits = MACH_MSGH_BITS_REMOTE(MACH_MSG_TYPE_COPY_SEND) |
- (is_complex ? MACH_MSGH_BITS_COMPLEX : 0);
- header->msgh_remote_port = send_port_.get();
- header->msgh_id =
- transfer_message_ool ? kChannelMacOOLMsgId : kChannelMacInlineMsgId;
- auto* body = buffer.MutableObject<mach_msg_body_t>();
- body->msgh_descriptor_count = handles.size();
- auto descriptors =
- buffer.MutableSpan<mach_msg_port_descriptor_t>(handles.size());
- for (size_t i = 0; i < handles.size(); ++i) {
- auto* descriptor = &descriptors[i];
- descriptor->pad1 = 0;
- descriptor->pad2 = 0;
- descriptor->type = MACH_MSG_PORT_DESCRIPTOR;
- PlatformHandle handle = handles[i].TakeHandle();
- switch (handle.type()) {
- case PlatformHandle::Type::kMachSend:
- descriptor->name = handle.ReleaseMachSendRight();
- descriptor->disposition = MACH_MSG_TYPE_MOVE_SEND;
- break;
- case PlatformHandle::Type::kMachReceive:
- descriptor->name = handle.ReleaseMachReceiveRight();
- descriptor->disposition = MACH_MSG_TYPE_MOVE_RECEIVE;
- break;
- case PlatformHandle::Type::kFd: {
- // After putting the FD in a fileport, the kernel will keep a
- // reference to the opened file, and the local descriptor can be
- // closed.
- kern_return_t kr =
- fileport_makeport(handle.GetFD().get(), &descriptor->name);
- if (kr != KERN_SUCCESS) {
- MACH_LOG(ERROR, kr) << "fileport_makeport";
- OnWriteErrorLocked(Error::kDisconnected);
- return false;
- }
- descriptor->disposition = MACH_MSG_TYPE_MOVE_SEND;
- break;
- }
- default:
- NOTREACHED() << "Unsupported handle type "
- << static_cast<int>(handle.type());
- OnWriteErrorLocked(Error::kDisconnected);
- }
- }
- if (transfer_message_ool) {
- auto* descriptor = buffer.MutableObject<mach_msg_ool_descriptor_t>();
- descriptor->address = const_cast<void*>(message->data());
- descriptor->size = message->data_num_bytes();
- descriptor->copy = MACH_MSG_VIRTUAL_COPY;
- descriptor->deallocate = false;
- descriptor->pad1 = 0;
- descriptor->type = MACH_MSG_OOL_DESCRIPTOR;
- ++body->msgh_descriptor_count;
- } else {
- auto* data_size = buffer.MutableObject<uint64_t>();
- *data_size = message->data_num_bytes();
- auto data = buffer.MutableSpan<char>(message->data_num_bytes());
- memcpy(data.data(), message->data(), message->data_num_bytes());
- }
- header->msgh_size = round_msg(buffer.position());
- return MachMessageSendLocked(header);
- }
- bool MachMessageSendLocked(mach_msg_header_t* header) {
- kern_return_t kr = mach_msg(header, MACH_SEND_MSG | MACH_SEND_TIMEOUT,
- header->msgh_size, 0, MACH_PORT_NULL,
- /*timeout=*/0, MACH_PORT_NULL);
- if (kr != KERN_SUCCESS) {
- if (kr == MACH_SEND_TIMED_OUT) {
- // The kernel message queue for the peer's receive port is full, so the
- // send timed out. Since the send buffer contains a fully serialized
- // message, set a flag to indicate this condition and arrange to try
- // sending it again.
- send_buffer_contains_message_ = true;
- io_task_runner_->PostTask(
- FROM_HERE, base::BindOnce(&ChannelMac::SendPendingMessages, this));
- } else {
- // If the message failed to send for other reasons, destroy it.
- send_buffer_contains_message_ = false;
- mach_msg_destroy(header);
- if (kr != MACH_SEND_INVALID_DEST) {
- // If the message failed to send because the receiver is a dead-name,
- // wait for the Channel to process the dead-name notification.
- // Otherwise, the notification message will never be received and the
- // dead-name right contained within it will be leaked
- // (https://crbug.com/1041682). If the message failed to send for any
- // other reason, report an error and shut down.
- MACH_LOG(ERROR, kr) << "mach_msg send";
- OnWriteErrorLocked(Error::kDisconnected);
- }
- }
- return false;
- }
- send_buffer_contains_message_ = false;
- return true;
- }
- // base::CurrentThread::DestructionObserver:
- void WillDestroyCurrentMessageLoop() override {
- DCHECK(io_task_runner_->RunsTasksInCurrentSequence());
- if (self_)
- ShutDownOnIOThread();
- }
- // base::MessagePumpKqueue::MachPortWatcher:
- void OnMachMessageReceived(mach_port_t port) override {
- TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("toplevel.ipc"), "Mojo read message");
- DCHECK(io_task_runner_->RunsTasksInCurrentSequence());
- base::BufferIterator<const char> buffer(
- reinterpret_cast<const char*>(receive_buffer_.address()),
- receive_buffer_.size());
- auto* header = buffer.MutableObject<mach_msg_header_t>();
- *header = mach_msg_header_t{};
- header->msgh_size = buffer.total_size();
- header->msgh_local_port = receive_port_.get();
- const mach_msg_option_t rcv_options =
- MACH_RCV_MSG | MACH_RCV_TIMEOUT |
- MACH_RCV_TRAILER_TYPE(MACH_MSG_TRAILER_FORMAT_0) |
- MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT);
- kern_return_t kr =
- mach_msg(header, rcv_options, 0, header->msgh_size, receive_port_.get(),
- /*timeout=*/0, MACH_PORT_NULL);
- if (kr != KERN_SUCCESS) {
- if (kr == MACH_RCV_TIMED_OUT)
- return;
- MACH_LOG(ERROR, kr) << "mach_msg receive";
- OnError(Error::kDisconnected);
- return;
- }
- base::ScopedMachMsgDestroy scoped_message(header);
- if (header->msgh_id == kChannelMacHandshakeMsgId) {
- buffer.Seek(0);
- if (ReceiveHandshake(buffer))
- scoped_message.Disarm();
- return;
- }
- if (header->msgh_id == MACH_NOTIFY_DEAD_NAME) {
- // The DEAD_NAME notification contains a port right that must be
- // explicitly destroyed, as it is not carried in a descriptor.
- buffer.Seek(0);
- auto* notification = buffer.Object<mach_dead_name_notification_t>();
- // Verify that the kernel sent the notification.
- buffer.Seek(notification->not_header.msgh_size);
- auto* trailer = buffer.Object<mach_msg_audit_trailer_t>();
- static const audit_token_t kernel_audit_token = KERNEL_AUDIT_TOKEN_VALUE;
- if (memcmp(&trailer->msgh_audit, &kernel_audit_token,
- sizeof(audit_token_t)) == 0) {
- DCHECK(notification->not_port == send_port_);
- // Release the notification's send right using this scoper.
- base::mac::ScopedMachSendRight notify_port(notification->not_port);
- }
- OnError(Error::kDisconnected);
- return;
- } else if (header->msgh_id == MACH_NOTIFY_SEND_ONCE) {
- // Notification of an extant send-once right being destroyed. This is
- // sent for the right allocated in RequestSendDeadNameNotification(),
- // and no action needs to be taken. Since it is ignored, the kernel
- // audit token need not be checked.
- return;
- }
- if (header->msgh_size < sizeof(mach_msg_base_t)) {
- OnError(Error::kReceivedMalformedData);
- return;
- }
- if (peer_audit_token_) {
- buffer.Seek(header->msgh_size);
- auto* trailer = buffer.Object<mach_msg_audit_trailer_t>();
- if (memcmp(&trailer->msgh_audit, peer_audit_token_.get(),
- sizeof(audit_token_t)) != 0) {
- // Do not shut down the channel because this endpoint could be
- // accessible via the bootstrap server, which means anyone could send
- // messages to it.
- LOG(ERROR) << "Rejecting message from unauthorized peer";
- return;
- }
- buffer.Seek(sizeof(*header));
- }
- auto* body = buffer.Object<mach_msg_body_t>();
- if (((header->msgh_bits & MACH_MSGH_BITS_COMPLEX) != 0) !=
- (body->msgh_descriptor_count > 0)) {
- LOG(ERROR) << "Message complex bit does not match descriptor count";
- OnError(Error::kReceivedMalformedData);
- return;
- }
- bool transfer_message_ool = false;
- mach_msg_size_t mojo_handle_count = body->msgh_descriptor_count;
- if (header->msgh_id == kChannelMacOOLMsgId) {
- transfer_message_ool = true;
- // The number of Mojo handles to process will be one fewer, since the
- // message itself was transferred using OOL memory.
- if (body->msgh_descriptor_count < 1) {
- LOG(ERROR) << "OOL message does not have descriptor";
- OnError(Error::kReceivedMalformedData);
- return;
- }
- --mojo_handle_count;
- } else if (header->msgh_id != kChannelMacInlineMsgId) {
- OnError(Error::kReceivedMalformedData);
- return;
- }
- incoming_handles_.clear();
- incoming_handles_.reserve(mojo_handle_count);
- // Accept the descriptors into |incoming_handles_|. They will be validated
- // in GetReadPlatformHandles(). If the handle is accepted, the name in the
- // descriptor is cleared, so that it is not double-unrefed if the
- // |scoped_message| destroys the message on error.
- auto descriptors =
- buffer.MutableSpan<mach_msg_port_descriptor_t>(mojo_handle_count);
- for (auto& descriptor : descriptors) {
- if (descriptor.type != MACH_MSG_PORT_DESCRIPTOR) {
- LOG(ERROR) << "Incorrect descriptor type " << descriptor.type;
- OnError(Error::kReceivedMalformedData);
- return;
- }
- switch (descriptor.disposition) {
- case MACH_MSG_TYPE_MOVE_SEND:
- incoming_handles_.emplace_back(
- base::mac::ScopedMachSendRight(descriptor.name));
- descriptor.name = MACH_PORT_NULL;
- break;
- case MACH_MSG_TYPE_MOVE_RECEIVE:
- incoming_handles_.emplace_back(
- base::mac::ScopedMachReceiveRight(descriptor.name));
- descriptor.name = MACH_PORT_NULL;
- break;
- default:
- DLOG(ERROR) << "Unhandled descriptor disposition "
- << descriptor.disposition;
- OnError(Error::kReceivedMalformedData);
- return;
- }
- }
- base::span<const char> payload;
- base::mac::ScopedMachVM ool_memory;
- if (transfer_message_ool) {
- auto* descriptor = buffer.Object<mach_msg_ool_descriptor_t>();
- if (descriptor->type != MACH_MSG_OOL_DESCRIPTOR) {
- LOG(ERROR) << "Incorrect descriptor type " << descriptor->type;
- OnError(Error::kReceivedMalformedData);
- return;
- }
- payload = base::span<const char>(
- reinterpret_cast<const char*>(descriptor->address), descriptor->size);
- // The kernel page-aligns the OOL memory when performing the mach_msg on
- // the send side, but it preserves the original size in the descriptor.
- ool_memory.reset_unaligned(
- reinterpret_cast<vm_address_t>(descriptor->address),
- descriptor->size);
- } else {
- auto* data_size_ptr = buffer.Object<uint64_t>();
- payload = buffer.Span<const char>(*data_size_ptr);
- }
- if (payload.empty()) {
- OnError(Error::kReceivedMalformedData);
- return;
- }
- scoped_message.Disarm();
- size_t ignored;
- DispatchResult result = TryDispatchMessage(payload, &ignored);
- if (result != DispatchResult::kOK) {
- OnError(Error::kReceivedMalformedData);
- return;
- }
- }
- // Marks the channel as unaccepting of new messages and shuts it down.
- void OnWriteErrorLocked(Error error) {
- reject_writes_ = true;
- io_task_runner_->PostTask(
- FROM_HERE, base::BindOnce(&ChannelMac::OnError, this, error));
- }
- // Keeps the Channel alive at least until explicit shutdown on the IO thread.
- scoped_refptr<ChannelMac> self_;
- scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
- base::mac::ScopedMachReceiveRight receive_port_;
- base::mac::ScopedMachSendRight send_port_;
- // Whether to leak the above Mach ports when the channel is shut down.
- bool leak_handles_ = false;
- // Whether or not the channel-internal handshake, which establishes bi-
- // directional communication, is complete. If false, calls to Write() will
- // enqueue messages on |pending_messages_|.
- bool handshake_done_ = false;
- // If the channel was created with a receive right, the first message it
- // receives is the internal handshake. The audit token of the sender of the
- // handshake is recorded here, and all future messages are required to be
- // from that sender.
- std::unique_ptr<audit_token_t> peer_audit_token_;
- // IO buffer for receiving Mach messages. Only accessed on |io_task_runner_|.
- base::mac::ScopedMachVM receive_buffer_;
- // Handles that were received with a message that are validated and returned
- // in GetReadPlatformHandles(). Only accessed on |io_task_runner_|.
- std::vector<PlatformHandle> incoming_handles_;
- // Watch controller for |receive_port_|, calls OnMachMessageReceived() when
- // new messages are available.
- base::MessagePumpForIO::MachPortWatchController watch_controller_;
- // Lock that protects the following members.
- base::Lock write_lock_;
- // Whether writes should be rejected due to an internal error.
- bool reject_writes_ = false;
- // IO buffer for sending Mach messages.
- base::mac::ScopedMachVM send_buffer_;
- // If a message timed out during send in MachMessageSendLocked(), this will
- // be true to indicate that |send_buffer_| contains a message that must
- // be sent. If this is true, then other calls to Write() queue messages onto
- // |pending_messages_|.
- bool send_buffer_contains_message_ = false;
- // When |handshake_done_| is false or |send_buffer_contains_message_| is true,
- // calls to Write() will enqueue messages here.
- base::circular_deque<MessagePtr> pending_messages_;
- };
- } // namespace
- MOJO_SYSTEM_IMPL_EXPORT
- scoped_refptr<Channel> Channel::Create(
- Channel::Delegate* delegate,
- ConnectionParams connection_params,
- Channel::HandlePolicy handle_policy,
- scoped_refptr<base::SingleThreadTaskRunner> io_task_runner) {
- return new ChannelMac(delegate, std::move(connection_params), handle_policy,
- io_task_runner);
- }
- } // namespace core
- } // namespace mojo
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