// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "mojo/core/core_ipcz.h"

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <map>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "base/check_op.h"
#include "base/containers/span.h"
#include "base/memory/platform_shared_memory_region.h"
#include "base/memory/ptr_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/writable_shared_memory_region.h"
#include "base/no_destructor.h"
#include "base/notreached.h"
#include "base/numerics/safe_conversions.h"
#include "base/strings/strcat.h"
#include "base/synchronization/lock.h"
#include "base/time/time.h"
#include "mojo/core/ipcz_api.h"
#include "mojo/core/ipcz_driver/data_pipe.h"
#include "mojo/core/ipcz_driver/invitation.h"
#include "mojo/core/ipcz_driver/mojo_message.h"
#include "mojo/core/ipcz_driver/mojo_trap.h"
#include "mojo/core/ipcz_driver/shared_buffer.h"
#include "mojo/core/ipcz_driver/shared_buffer_mapping.h"
#include "mojo/core/ipcz_driver/wrapped_platform_handle.h"
#include "mojo/public/cpp/platform/platform_handle.h"
#include "third_party/ipcz/include/ipcz/ipcz.h"

namespace mojo::core {

namespace {

// Tracks active Mojo memory mappings by base address, since that's how the Mojo
// API identifies them for unmapping.
class MappingTable {
 public:
  MappingTable() = default;
  ~MappingTable() = default;

  void Add(scoped_refptr<ipcz_driver::SharedBufferMapping> mapping) {
    base::AutoLock lock(lock_);
    void* address = mapping->memory();
    mappings_.emplace(address, std::move(mapping));
  }

  MojoResult Remove(void* address) {
    base::AutoLock lock(lock_);
    if (!mappings_.erase(address)) {
      return MOJO_RESULT_INVALID_ARGUMENT;
    }
    return MOJO_RESULT_OK;
  }

 private:
  base::Lock lock_;
  std::map<void*, scoped_refptr<ipcz_driver::SharedBufferMapping>> mappings_
      GUARDED_BY(lock_);
};

MappingTable& GetMappingTable() {
  static base::NoDestructor<MappingTable> table;
  return *table;
}

// ipcz get and put operations differ slightly in their return code semantics as
// compared to Mojo read and write operations. These helpers perform the
// translation.
MojoResult GetMojoReadResultForIpczGet(IpczResult result) {
  if (result == IPCZ_RESULT_UNAVAILABLE) {
    // The peer is still open but there are not currently any parcels to read.
    return MOJO_RESULT_SHOULD_WAIT;
  }
  if (result == IPCZ_RESULT_NOT_FOUND) {
    // There are no more parcels to read and the peer is closed.
    return MOJO_RESULT_FAILED_PRECONDITION;
  }
  return result;
}

MojoResult GetMojoWriteResultForIpczPut(IpczResult result) {
  if (result == IPCZ_RESULT_RESOURCE_EXHAUSTED) {
    // For put operations with limits, which are used to emulate data pipe
    // producer writes, this indicates that the caller needs to try again later
    // due to the pipe being at capacity.
    return MOJO_RESULT_SHOULD_WAIT;
  }
  if (result == IPCZ_RESULT_NOT_FOUND) {
    // The peer is closed.
    return MOJO_RESULT_FAILED_PRECONDITION;
  }
  return result;
}

extern "C" {

MojoResult MojoInitializeIpcz(const struct MojoInitializeOptions* options) {
  NOTREACHED();
}

MojoTimeTicks MojoGetTimeTicksNowIpcz() {
  return base::Time::Now().ToDeltaSinceWindowsEpoch().InMicroseconds();
}

MojoResult MojoCloseIpcz(MojoHandle handle) {
  if (handle == MOJO_HANDLE_INVALID) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return GetIpczAPI().Close(handle, IPCZ_NO_FLAGS, nullptr);
}

MojoResult MojoQueryHandleSignalsStateIpcz(
    MojoHandle handle,
    MojoHandleSignalsState* signals_state) {
  if (handle == MOJO_HANDLE_INVALID || !signals_state) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  auto* data_pipe = ipcz_driver::DataPipe::FromBox(handle);
  if (data_pipe) {
    data_pipe->FlushUpdatesFromPeer();
    if (!data_pipe->GetSignals(*signals_state)) {
      return MOJO_RESULT_INVALID_ARGUMENT;
    }
    return MOJO_RESULT_OK;
  }

  if (ipcz_driver::ObjectBase::FromBox(handle)) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  IpczPortalStatus status = {sizeof(status)};
  IpczResult result =
      GetIpczAPI().QueryPortalStatus(handle, IPCZ_NO_FLAGS, nullptr, &status);
  if (result != IPCZ_RESULT_OK) {
    return result;
  }

  signals_state->satisfiable_signals =
      MOJO_HANDLE_SIGNAL_PEER_CLOSED | MOJO_HANDLE_SIGNAL_QUOTA_EXCEEDED;
  signals_state->satisfied_signals = 0;
  if (status.flags & IPCZ_PORTAL_STATUS_PEER_CLOSED) {
    signals_state->satisfied_signals |= MOJO_HANDLE_SIGNAL_PEER_CLOSED;
  } else {
    signals_state->satisfiable_signals |=
        MOJO_HANDLE_SIGNAL_WRITABLE | MOJO_HANDLE_SIGNAL_PEER_REMOTE;
    signals_state->satisfied_signals |= MOJO_HANDLE_SIGNAL_WRITABLE;
  }
  if ((status.flags & IPCZ_PORTAL_STATUS_DEAD) == 0) {
    signals_state->satisfiable_signals |= MOJO_HANDLE_SIGNAL_READABLE;
  }
  if (status.num_local_parcels > 0) {
    signals_state->satisfied_signals |= MOJO_HANDLE_SIGNAL_READABLE;
  }
  return MOJO_RESULT_OK;
}

MojoResult MojoCreateMessagePipeIpcz(
    const MojoCreateMessagePipeOptions* options,
    MojoHandle* message_pipe_handle0,
    MojoHandle* message_pipe_handle1) {
  return GetIpczAPI().OpenPortals(GetIpczNode(), IPCZ_NO_FLAGS, nullptr,
                                  message_pipe_handle0, message_pipe_handle1);
}

MojoResult MojoWriteMessageIpcz(MojoHandle message_pipe_handle,
                                MojoMessageHandle message,
                                const MojoWriteMessageOptions* options) {
  auto m = ipcz_driver::MojoMessage::TakeFromHandle(message);
  if (!m || !message_pipe_handle) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  if (m->context()) {
    // Wrap unserialized messages in boxes to be serialized lazily.
    ScopedIpczHandle box = ipcz_driver::MojoMessage::Box(std::move(m));
    const IpczResult result = GetIpczAPI().Put(
        message_pipe_handle, nullptr, 0, &box.get(), 1, IPCZ_NO_FLAGS, nullptr);
    if (result == IPCZ_RESULT_OK) {
      // On success, ownership of the box is passed into the portal.
      std::ignore = box.release();
    }
    return result;
  }

  m->AttachDataPipePortals();
  const IpczResult result = GetIpczAPI().Put(
      message_pipe_handle, m->data().data(), m->data().size(),
      m->handles().data(), m->handles().size(), IPCZ_NO_FLAGS, nullptr);
  if (result == IPCZ_RESULT_NOT_FOUND) {
    return MOJO_RESULT_FAILED_PRECONDITION;
  }

  if (result == IPCZ_RESULT_OK) {
    // Ensure the handles don't get freed on MojoMessage destruction, as their
    // ownership was relinquished in Put() above.
    m->handles().clear();
  }

  return GetMojoWriteResultForIpczPut(result);
}

MojoResult MojoReadMessageIpcz(MojoHandle message_pipe_handle,
                               const MojoReadMessageOptions* options,
                               MojoMessageHandle* message) {
  ScopedIpczHandle parcel;
  IpczResult result = GetIpczAPI().Get(
      message_pipe_handle, IPCZ_GET_PARTIAL, nullptr, nullptr, nullptr, nullptr,
      nullptr, ScopedIpczHandle::Receiver(parcel));
  if (result != IPCZ_RESULT_OK) {
    return GetMojoReadResultForIpczGet(result);
  }

  auto new_message = std::make_unique<ipcz_driver::MojoMessage>();
  new_message->SetParcel(std::move(parcel));
  if (auto wrapped = ipcz_driver::MojoMessage::UnwrapFrom(*new_message)) {
    *message = wrapped.release()->handle();
    return IPCZ_RESULT_OK;
  }

  *message = new_message.release()->handle();
  return MOJO_RESULT_OK;
}

MojoResult MojoFuseMessagePipesIpcz(
    MojoHandle handle0,
    MojoHandle handle1,
    const MojoFuseMessagePipesOptions* options) {
  if (handle0 == MOJO_HANDLE_INVALID || handle1 == MOJO_HANDLE_INVALID) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  const IpczResult result =
      GetIpczAPI().MergePortals(handle0, handle1, IPCZ_NO_FLAGS, nullptr);
  if (result != IPCZ_RESULT_OK) {
    // On failure, MojoFuseMessagePipes is expected to close the message pipe
    // endpoints it was given.
    MojoCloseIpcz(handle0);
    MojoCloseIpcz(handle1);
    return MOJO_RESULT_FAILED_PRECONDITION;
  }
  return result;
}

MojoResult MojoCreateMessageIpcz(const MojoCreateMessageOptions* options,
                                 MojoMessageHandle* message) {
  if (!message) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  auto new_message = std::make_unique<ipcz_driver::MojoMessage>();
  *message = new_message.release()->handle();
  return MOJO_RESULT_OK;
}

MojoResult MojoDestroyMessageIpcz(MojoMessageHandle message) {
  if (message == MOJO_MESSAGE_HANDLE_INVALID) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  std::unique_ptr<ipcz_driver::MojoMessage> scoped_message(
      ipcz_driver::MojoMessage::FromHandle(message));
  return scoped_message ? MOJO_RESULT_OK : MOJO_RESULT_INVALID_ARGUMENT;
}

MojoResult MojoSerializeMessageIpcz(
    MojoMessageHandle message,
    const MojoSerializeMessageOptions* options) {
  if (auto* m = ipcz_driver::MojoMessage::FromHandle(message)) {
    return m->Serialize();
  }
  return MOJO_RESULT_INVALID_ARGUMENT;
}

MojoResult MojoReserveMessageCapacityIpcz(MojoMessageHandle message,
                                          uint32_t payload_buffer_size,
                                          uint32_t* buffer_size) {
  if (auto* m = ipcz_driver::MojoMessage::FromHandle(message)) {
    return m->ReserveCapacity(payload_buffer_size, buffer_size);
  }
  return MOJO_RESULT_INVALID_ARGUMENT;
}

MojoResult MojoAppendMessageDataIpcz(
    MojoMessageHandle message,
    uint32_t additional_payload_size,
    const MojoHandle* handles,
    uint32_t num_handles,
    const MojoAppendMessageDataOptions* options,
    void** buffer,
    uint32_t* buffer_size) {
  if (auto* m = ipcz_driver::MojoMessage::FromHandle(message)) {
    const bool commit_size =
        options && (options->flags & MOJO_APPEND_MESSAGE_DATA_FLAG_COMMIT_SIZE);
    return m->AppendData(additional_payload_size, handles, num_handles, buffer,
                         buffer_size, commit_size);
  }
  return MOJO_RESULT_INVALID_ARGUMENT;
}

MojoResult MojoGetMessageDataIpcz(MojoMessageHandle message,
                                  const MojoGetMessageDataOptions* options,
                                  void** buffer,
                                  uint32_t* num_bytes,
                                  MojoHandle* handles,
                                  uint32_t* num_handles) {
  if (auto* m = ipcz_driver::MojoMessage::FromHandle(message)) {
    const bool consume_handles =
        !options ||
        ((options->flags & MOJO_GET_MESSAGE_DATA_FLAG_IGNORE_HANDLES) == 0);
    return m->GetData(buffer, num_bytes, handles, num_handles, consume_handles);
  }
  return MOJO_RESULT_INVALID_ARGUMENT;
}

MojoResult MojoSetMessageContextIpcz(
    MojoMessageHandle message_handle,
    uintptr_t context,
    MojoMessageContextSerializer serializer,
    MojoMessageContextDestructor destructor,
    const MojoSetMessageContextOptions* options) {
  auto* message = ipcz_driver::MojoMessage::FromHandle(message_handle);
  if (!message) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  return message->SetContext(context, serializer, destructor);
}

MojoResult MojoGetMessageContextIpcz(
    MojoMessageHandle message_handle,
    const MojoGetMessageContextOptions* options,
    uintptr_t* context) {
  auto* message = ipcz_driver::MojoMessage::FromHandle(message_handle);
  if (!message) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  if (!message->context()) {
    return MOJO_RESULT_NOT_FOUND;
  }
  *context = message->context();
  return MOJO_RESULT_OK;
}

MojoResult MojoNotifyBadMessageIpcz(
    MojoMessageHandle message_handle,
    const char* error,
    uint32_t error_num_bytes,
    const MojoNotifyBadMessageOptions* options) {
  auto* message = ipcz_driver::MojoMessage::FromHandle(message_handle);
  if (!message) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  const std::string error_string(error, error_num_bytes);
  if (message->parcel() != IPCZ_INVALID_HANDLE) {
    // Mojo prefixes bad message reports with this string if they're for
    // messages from a remote node. We duplicate it here since many tests expect
    // observation of prefixed error messages.
    const char kPrefix[] = "Received bad user message: ";
    auto prefixed_error_message =
        std::make_unique<std::string>(base::StrCat({kPrefix, error_string}));
    const IpczResult result = GetIpczAPI().Reject(
        message->parcel(),
        reinterpret_cast<uintptr_t>(prefixed_error_message.get()),
        IPCZ_NO_FLAGS, nullptr);
    if (result == IPCZ_RESULT_OK) {
      // Ownership taken by driver.
      std::ignore = prefixed_error_message.release();
      return IPCZ_RESULT_OK;
    }
    DCHECK_EQ(result, IPCZ_RESULT_FAILED_PRECONDITION);
  }

  // The parcel was not from a remote node in this case.
  ipcz_driver::Invitation::InvokeDefaultProcessErrorHandler(error_string);
  return MOJO_RESULT_OK;
}

MojoResult MojoCreateDataPipeIpcz(const MojoCreateDataPipeOptions* options,
                                  MojoHandle* data_pipe_producer_handle,
                                  MojoHandle* data_pipe_consumer_handle) {
  using DataPipe = ipcz_driver::DataPipe;

  // Mojo Core defaults to 64 kB capacity and 1-byte elements, and many callers
  // assume these defaults.
  constexpr uint32_t kDefaultCapacity = 64 * 1024;
  DataPipe::Config config = {.element_size = 1,
                             .byte_capacity = kDefaultCapacity,
                             .is_peer_closed = false};
  if (options) {
    config.element_size = options->element_num_bytes;
    if (options->capacity_num_bytes) {
      config.byte_capacity = options->capacity_num_bytes;
    }
  }
  if (!config.byte_capacity || !config.element_size ||
      config.byte_capacity < config.element_size) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  std::optional<DataPipe::Pair> pipe = DataPipe::CreatePair(config);
  if (!pipe) {
    // This result implies that we failed to allocate or map a new shared memory
    // region and therefore have no transfer buffer for the pipe.
    return MOJO_RESULT_RESOURCE_EXHAUSTED;
  }

  *data_pipe_producer_handle = DataPipe::Box(std::move(pipe->producer));
  *data_pipe_consumer_handle = DataPipe::Box(std::move(pipe->consumer));
  return MOJO_RESULT_OK;
}

MojoResult MojoWriteDataIpcz(MojoHandle data_pipe_producer_handle,
                             const void* elements,
                             uint32_t* num_bytes,
                             const MojoWriteDataOptions* options) {
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_producer_handle);
  if (!pipe || !num_bytes || !pipe->is_producer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return pipe->WriteData(elements, *num_bytes,
                         options ? options->flags : MOJO_WRITE_DATA_FLAG_NONE);
}

MojoResult MojoBeginWriteDataIpcz(MojoHandle data_pipe_producer_handle,
                                  const MojoBeginWriteDataOptions* options,
                                  void** buffer,
                                  uint32_t* buffer_num_bytes) {
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_producer_handle);
  if (!pipe || !buffer || !buffer_num_bytes || !pipe->is_producer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  if (options && options->struct_size < sizeof(*options)) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  const MojoBeginWriteDataFlags flags =
      options ? options->flags : MOJO_BEGIN_WRITE_DATA_FLAG_NONE;
  return pipe->BeginWriteData(*buffer, *buffer_num_bytes, flags);
}

MojoResult MojoEndWriteDataIpcz(MojoHandle data_pipe_producer_handle,
                                uint32_t num_bytes_produced,
                                const MojoEndWriteDataOptions* options) {
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_producer_handle);
  if (!pipe || !pipe->is_producer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return pipe->EndWriteData(num_bytes_produced);
}

MojoResult MojoReadDataIpcz(MojoHandle data_pipe_consumer_handle,
                            const MojoReadDataOptions* options,
                            void* elements,
                            uint32_t* num_bytes) {
  const MojoReadDataFlags flags =
      options ? options->flags : MOJO_READ_DATA_FLAG_NONE;
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_consumer_handle);
  if (!pipe || !num_bytes || !pipe->is_consumer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return pipe->ReadData(elements, *num_bytes, flags);
}

MojoResult MojoBeginReadDataIpcz(MojoHandle data_pipe_consumer_handle,
                                 const MojoBeginReadDataOptions* options,
                                 const void** buffer,
                                 uint32_t* buffer_num_bytes) {
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_consumer_handle);
  if (!pipe || !buffer || !buffer_num_bytes || !pipe->is_consumer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return pipe->BeginReadData(*buffer, *buffer_num_bytes);
}

MojoResult MojoEndReadDataIpcz(MojoHandle data_pipe_consumer_handle,
                               uint32_t num_bytes_consumed,
                               const MojoEndReadDataOptions* options) {
  auto* pipe = ipcz_driver::DataPipe::FromBox(data_pipe_consumer_handle);
  if (!pipe || !pipe->is_consumer()) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return pipe->EndReadData(num_bytes_consumed);
}

MojoResult MojoCreateSharedBufferIpcz(
    uint64_t num_bytes,
    const MojoCreateSharedBufferOptions* options,
    MojoHandle* shared_buffer_handle) {
  auto region = base::WritableSharedMemoryRegion::Create(num_bytes);
  if (!region.IsValid()) {
    return MOJO_RESULT_RESOURCE_EXHAUSTED;
  }

  *shared_buffer_handle = ipcz_driver::SharedBuffer::MakeBoxed(
      base::WritableSharedMemoryRegion::TakeHandleForSerialization(
          std::move(region)));
  return MOJO_RESULT_OK;
}

MojoResult MojoDuplicateBufferHandleIpcz(
    MojoHandle buffer_handle,
    const MojoDuplicateBufferHandleOptions* options,
    MojoHandle* new_buffer_handle) {
  auto* buffer = ipcz_driver::SharedBuffer::FromBox(buffer_handle);
  if (!buffer || !new_buffer_handle ||
      (options && options->struct_size < sizeof(*options))) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  const bool read_only =
      options &&
      (options->flags & MOJO_DUPLICATE_BUFFER_HANDLE_FLAG_READ_ONLY) != 0;
  auto [new_buffer, result] = buffer->Duplicate(read_only);
  if (result != IPCZ_RESULT_OK) {
    return result;
  }

  *new_buffer_handle = ipcz_driver::SharedBuffer::Box(std::move(new_buffer));
  return MOJO_RESULT_OK;
}

MojoResult MojoMapBufferIpcz(MojoHandle buffer_handle,
                             uint64_t offset,
                             uint64_t num_bytes,
                             const MojoMapBufferOptions* options,
                             void** address) {
  auto* buffer = ipcz_driver::SharedBuffer::FromBox(buffer_handle);
  if (!buffer) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  auto mapping = ipcz_driver::SharedBufferMapping::Create(
      buffer->region(), static_cast<size_t>(offset),
      static_cast<size_t>(num_bytes));
  if (!mapping) {
    return MOJO_RESULT_RESOURCE_EXHAUSTED;
  }
  *address = mapping->memory();
  GetMappingTable().Add(std::move(mapping));
  return MOJO_RESULT_OK;
}

MojoResult MojoUnmapBufferIpcz(void* address) {
  return GetMappingTable().Remove(address);
}

MojoResult MojoGetBufferInfoIpcz(MojoHandle buffer_handle,
                                 const MojoGetBufferInfoOptions* options,
                                 MojoSharedBufferInfo* info) {
  auto* buffer = ipcz_driver::SharedBuffer::FromBox(buffer_handle);
  if (!buffer || !info || info->struct_size < sizeof(*info)) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  info->size = buffer->region().GetSize();
  return MOJO_RESULT_OK;
}

MojoResult MojoCreateTrapIpcz(MojoTrapEventHandler handler,
                              const MojoCreateTrapOptions* options,
                              MojoHandle* trap_handle) {
  if (!handler || !trap_handle) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  *trap_handle = ipcz_driver::MojoTrap::MakeBoxed(handler);
  return MOJO_RESULT_OK;
}

MojoResult MojoAddTriggerIpcz(MojoHandle trap_handle,
                              MojoHandle handle,
                              MojoHandleSignals signals,
                              MojoTriggerCondition condition,
                              uintptr_t context,
                              const MojoAddTriggerOptions* options) {
  auto* trap = ipcz_driver::MojoTrap::FromBox(trap_handle);
  if (!trap) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return trap->AddTrigger(handle, signals, condition, context);
}

MojoResult MojoRemoveTriggerIpcz(MojoHandle trap_handle,
                                 uintptr_t context,
                                 const MojoRemoveTriggerOptions* options) {
  auto* trap = ipcz_driver::MojoTrap::FromBox(trap_handle);
  if (!trap) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return trap->RemoveTrigger(context);
}

MojoResult MojoArmTrapIpcz(MojoHandle trap_handle,
                           const MojoArmTrapOptions* options,
                           uint32_t* num_blocking_events,
                           MojoTrapEvent* blocking_events) {
  auto* trap = ipcz_driver::MojoTrap::FromBox(trap_handle);
  if (!trap) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return trap->Arm(blocking_events, num_blocking_events);
}

MojoResult MojoWrapPlatformHandleIpcz(
    const MojoPlatformHandle* platform_handle,
    const MojoWrapPlatformHandleOptions* options,
    MojoHandle* mojo_handle) {
  if (!platform_handle || !mojo_handle ||
      platform_handle->struct_size < sizeof(*platform_handle)) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  auto handle = PlatformHandle::FromMojoPlatformHandle(platform_handle);
  *mojo_handle =
      ipcz_driver::WrappedPlatformHandle::MakeBoxed(std::move(handle));
  return MOJO_RESULT_OK;
}

MojoResult MojoUnwrapPlatformHandleIpcz(
    MojoHandle mojo_handle,
    const MojoUnwrapPlatformHandleOptions* options,
    MojoPlatformHandle* platform_handle) {
  if (!mojo_handle || !platform_handle ||
      platform_handle->struct_size < sizeof(*platform_handle)) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  auto wrapper = ipcz_driver::WrappedPlatformHandle::Unbox(mojo_handle);
  if (!wrapper) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  PlatformHandle::ToMojoPlatformHandle(std::move(wrapper->handle()),
                                       platform_handle);
  return MOJO_RESULT_OK;
}

MojoResult MojoWrapPlatformSharedMemoryRegionIpcz(
    const MojoPlatformHandle* platform_handles,
    uint32_t num_platform_handles,
    uint64_t num_bytes,
    const MojoSharedBufferGuid* guid,
    MojoPlatformSharedMemoryRegionAccessMode access_mode,
    const MojoWrapPlatformSharedMemoryRegionOptions* options,
    MojoHandle* mojo_handle) {
  if (!platform_handles || !num_bytes || !guid || !mojo_handle) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  auto buffer = ipcz_driver::SharedBuffer::CreateForMojoWrapper(
      base::span(platform_handles, num_platform_handles), num_bytes, *guid,
      access_mode);
  if (!buffer) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  *mojo_handle = ipcz_driver::SharedBuffer::Box(std::move(buffer));
  return MOJO_RESULT_OK;
}

MojoResult MojoUnwrapPlatformSharedMemoryRegionIpcz(
    MojoHandle mojo_handle,
    const MojoUnwrapPlatformSharedMemoryRegionOptions* options,
    MojoPlatformHandle* platform_handles,
    uint32_t* num_platform_handles,
    uint64_t* num_bytes,
    MojoSharedBufferGuid* mojo_guid,
    MojoPlatformSharedMemoryRegionAccessMode* access_mode) {
  if (!mojo_handle || !platform_handles || !num_platform_handles ||
      !mojo_guid) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  auto* buffer = ipcz_driver::SharedBuffer::FromBox(mojo_handle);
  if (!buffer) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  using Mode = base::subtle::PlatformSharedMemoryRegion::Mode;
  const Mode mode = buffer->region().GetMode();
  const base::UnguessableToken guid = buffer->region().GetGUID();
  const uint32_t size = static_cast<uint32_t>(buffer->region().GetSize());

  uint32_t capacity = *num_platform_handles;
  uint32_t required_handles = 1;
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE) && !BUILDFLAG(IS_ANDROID)
  if (buffer->region().GetMode() ==
      base::subtle::PlatformSharedMemoryRegion::Mode::kWritable) {
    required_handles = 2;
  }
#endif
  *num_platform_handles = required_handles;
  if (capacity < required_handles) {
    return MOJO_RESULT_RESOURCE_EXHAUSTED;
  }

  PlatformHandle handles[2];
  base::subtle::ScopedPlatformSharedMemoryHandle region_handle =
      buffer->region().PassPlatformHandle();
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE) && !BUILDFLAG(IS_ANDROID)
  handles[0] = PlatformHandle(std::move(region_handle.fd));
  handles[1] = PlatformHandle(std::move(region_handle.readonly_fd));
#else
  handles[0] = PlatformHandle(std::move(region_handle));
#endif

  for (size_t i = 0; i < required_handles; ++i) {
    PlatformHandle::ToMojoPlatformHandle(std::move(handles[i]),
                                         &platform_handles[i]);
  }

  *num_bytes = size;
  mojo_guid->high = guid.GetHighForSerialization();
  mojo_guid->low = guid.GetLowForSerialization();

  switch (mode) {
    case Mode::kReadOnly:
      *access_mode = MOJO_PLATFORM_SHARED_MEMORY_REGION_ACCESS_MODE_READ_ONLY;
      break;
    case Mode::kWritable:
      *access_mode = MOJO_PLATFORM_SHARED_MEMORY_REGION_ACCESS_MODE_WRITABLE;
      break;
    case Mode::kUnsafe:
      *access_mode = MOJO_PLATFORM_SHARED_MEMORY_REGION_ACCESS_MODE_UNSAFE;
      break;
    default:
      NOTREACHED();
  }

  std::ignore = ipcz_driver::SharedBuffer::Unbox(mojo_handle);
  return MOJO_RESULT_OK;
}

MojoResult MojoCreateInvitationIpcz(const MojoCreateInvitationOptions* options,
                                    MojoHandle* invitation_handle) {
  if (!invitation_handle ||
      (options && options->struct_size < sizeof(*options))) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  *invitation_handle = ipcz_driver::Invitation::MakeBoxed();
  return MOJO_RESULT_OK;
}

MojoResult MojoAttachMessagePipeToInvitationIpcz(
    MojoHandle invitation_handle,
    const void* name,
    uint32_t name_num_bytes,
    const MojoAttachMessagePipeToInvitationOptions* options,
    MojoHandle* message_pipe_handle) {
  auto* invitation = ipcz_driver::Invitation::FromBox(invitation_handle);
  if (!invitation || !message_pipe_handle ||
      (options && options->struct_size < sizeof(*options))) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return invitation->Attach(
      base::span(static_cast<const uint8_t*>(name), name_num_bytes),
      message_pipe_handle);
}

MojoResult MojoExtractMessagePipeFromInvitationIpcz(
    MojoHandle invitation_handle,
    const void* name,
    uint32_t name_num_bytes,
    const MojoExtractMessagePipeFromInvitationOptions* options,
    MojoHandle* message_pipe_handle) {
  auto* invitation = ipcz_driver::Invitation::FromBox(invitation_handle);
  if (!invitation || !message_pipe_handle ||
      (options && options->struct_size < sizeof(*options))) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  return invitation->Extract(
      base::span(static_cast<const uint8_t*>(name), name_num_bytes),
      message_pipe_handle);
}

MojoResult MojoSendInvitationIpcz(
    MojoHandle invitation_handle,
    const MojoPlatformProcessHandle* process_handle,
    const MojoInvitationTransportEndpoint* transport_endpoint,
    MojoProcessErrorHandler error_handler,
    uintptr_t error_handler_context,
    const MojoSendInvitationOptions* options) {
  auto* invitation = ipcz_driver::Invitation::FromBox(invitation_handle);
  if (!invitation) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }

  const MojoResult result =
      invitation->Send(process_handle, transport_endpoint, error_handler,
                       error_handler_context, options);
  if (result == MOJO_RESULT_OK) {
    // On success, the invitation is consumed.
    GetIpczAPI().Close(invitation_handle, IPCZ_NO_FLAGS, nullptr);
  }
  return result;
}

MojoResult MojoAcceptInvitationIpcz(
    const MojoInvitationTransportEndpoint* transport_endpoint,
    const MojoAcceptInvitationOptions* options,
    MojoHandle* invitation_handle) {
  if (!transport_endpoint || !invitation_handle ||
      (options && options->struct_size < sizeof(*options))) {
    return MOJO_RESULT_INVALID_ARGUMENT;
  }
  *invitation_handle =
      ipcz_driver::Invitation::Accept(transport_endpoint, options);
  return MOJO_RESULT_OK;
}

MojoResult MojoSetQuotaIpcz(MojoHandle handle,
                            MojoQuotaType type,
                            uint64_t limit,
                            const MojoSetQuotaOptions* options) {
  return MOJO_RESULT_UNIMPLEMENTED;
}

MojoResult MojoQueryQuotaIpcz(MojoHandle handle,
                              MojoQuotaType type,
                              const MojoQueryQuotaOptions* options,
                              uint64_t* current_limit,
                              uint64_t* current_usage) {
  IpczPortalStatus status = {.size = sizeof(status)};
  const IpczResult result =
      GetIpczAPI().QueryPortalStatus(handle, IPCZ_NO_FLAGS, nullptr, &status);
  DCHECK_EQ(result, IPCZ_RESULT_OK);
  if (type == MOJO_QUOTA_TYPE_RECEIVE_QUEUE_LENGTH && current_usage) {
    *current_usage = status.num_local_parcels;
  } else if (type == MOJO_QUOTA_TYPE_RECEIVE_QUEUE_MEMORY_SIZE &&
             current_usage) {
    *current_usage = status.num_local_bytes;
  } else if (current_usage) {
    *current_usage = 0;
  }
  if (current_limit) {
    *current_limit = 0;
  }
  return MOJO_RESULT_OK;
}

MojoResult MojoShutdownIpcz(const MojoShutdownOptions* options) {
  NOTREACHED();
}

MojoResult MojoSetDefaultProcessErrorHandlerIpcz(
    MojoDefaultProcessErrorHandler handler,
    const MojoSetDefaultProcessErrorHandlerOptions* options) {
  ipcz_driver::Invitation::SetDefaultProcessErrorHandler(handler);
  return MOJO_RESULT_OK;
}

}  // extern "C"

MojoSystemThunks2 g_mojo_ipcz_thunks = {
    sizeof(MojoSystemThunks2),
    MojoInitializeIpcz,
    MojoGetTimeTicksNowIpcz,
    MojoCloseIpcz,
    MojoQueryHandleSignalsStateIpcz,
    MojoCreateMessagePipeIpcz,
    MojoWriteMessageIpcz,
    MojoReadMessageIpcz,
    MojoFuseMessagePipesIpcz,
    MojoCreateMessageIpcz,
    MojoDestroyMessageIpcz,
    MojoSerializeMessageIpcz,
    MojoAppendMessageDataIpcz,
    MojoGetMessageDataIpcz,
    MojoSetMessageContextIpcz,
    MojoGetMessageContextIpcz,
    MojoNotifyBadMessageIpcz,
    MojoCreateDataPipeIpcz,
    MojoWriteDataIpcz,
    MojoBeginWriteDataIpcz,
    MojoEndWriteDataIpcz,
    MojoReadDataIpcz,
    MojoBeginReadDataIpcz,
    MojoEndReadDataIpcz,
    MojoCreateSharedBufferIpcz,
    MojoDuplicateBufferHandleIpcz,
    MojoMapBufferIpcz,
    MojoUnmapBufferIpcz,
    MojoGetBufferInfoIpcz,
    MojoCreateTrapIpcz,
    MojoAddTriggerIpcz,
    MojoRemoveTriggerIpcz,
    MojoArmTrapIpcz,
    MojoWrapPlatformHandleIpcz,
    MojoUnwrapPlatformHandleIpcz,
    MojoWrapPlatformSharedMemoryRegionIpcz,
    MojoUnwrapPlatformSharedMemoryRegionIpcz,
    MojoCreateInvitationIpcz,
    MojoAttachMessagePipeToInvitationIpcz,
    MojoExtractMessagePipeFromInvitationIpcz,
    MojoSendInvitationIpcz,
    MojoAcceptInvitationIpcz,
    MojoSetQuotaIpcz,
    MojoQueryQuotaIpcz,
    MojoShutdownIpcz,
    MojoSetDefaultProcessErrorHandlerIpcz,
    MojoReserveMessageCapacityIpcz};

}  // namespace

const MojoSystemThunks2* GetMojoIpczImpl() {
  return &g_mojo_ipcz_thunks;
}

}  // namespace mojo::core