src/devices/bin/driver_host/driver_host.cc

// Copyright 2017 The Fuchsia 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 "driver_host.h"

#include <dlfcn.h>
#include <fidl/fuchsia.driver.framework/cpp/wire.h>
#include <inttypes.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/async-loop/default.h>
#include <lib/async/cpp/receiver.h>
#include <lib/async/cpp/wait.h>
#include <lib/ddk/binding.h>
#include <lib/ddk/debug.h>
#include <lib/ddk/device.h>
#include <lib/ddk/driver.h>
#include <lib/fdf/cpp/env.h>
#include <lib/fdio/fdio.h>
#include <lib/fidl/coding.h>
#include <lib/fit/defer.h>
#include <lib/fit/function.h>
#include <lib/zx/debuglog.h>
#include <lib/zx/process.h>
#include <lib/zx/resource.h>
#include <lib/zx/vmo.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <zircon/assert.h>
#include <zircon/dlfcn.h>
#include <zircon/process.h>
#include <zircon/processargs.h>
#include <zircon/status.h>
#include <zircon/syscalls.h>
#include <zircon/syscalls/log.h>

#include <limits>
#include <memory>
#include <new>
#include <utility>
#include <vector>

#include <fbl/auto_lock.h>
#include <fbl/string_printf.h>

#include "src/devices/bin/driver_host/composite_device.h"
#include "src/devices/bin/driver_host/composite_node_spec_util.h"
#include "src/devices/bin/driver_host/device_controller_connection.h"
#include "src/devices/bin/driver_host/driver.h"
#include "src/devices/bin/driver_host/env.h"
#include "src/devices/bin/driver_host/fidl_proxy_device.h"
#include "src/devices/bin/driver_host/log.h"
#include "src/devices/bin/driver_host/main.h"
#include "src/devices/bin/driver_host/proxy_iostate.h"
#include "src/devices/bin/driver_host/scheduler_profile.h"
#include "src/devices/bin/driver_host/tracing.h"
#include "src/devices/lib/log/log.h"

namespace fdf {
using namespace fuchsia_driver_framework;
}

namespace {

namespace fio = fuchsia_io;
namespace fdm = fuchsia_device_manager;

bool property_value_type_valid(uint32_t value_type) {
  return value_type > ZX_DEVICE_PROPERTY_VALUE_UNDEFINED &&
         value_type <= ZX_DEVICE_PROPERTY_VALUE_ENUM;
}

fdm::wire::DeviceProperty convert_device_prop(const zx_device_prop_t& prop) {
  return fdm::wire::DeviceProperty{
      .id = prop.id,
      .reserved = prop.reserved,
      .value = prop.value,
  };
}

std::optional<fdm::wire::DeviceProperty> fidl_offer_to_device_prop(const char* fidl_offer) {
  static const std::unordered_map<std::string_view, uint32_t> kPropMap = {
#define DDK_FIDL_PROTOCOL_DEF(tag, val, name) \
  {                                           \
      name,                                   \
      val,                                    \
  },
#include <lib/ddk/fidl-protodefs.h>
  };

  auto prop = kPropMap.find(fidl_offer);
  if (prop == kPropMap.end()) {
    return std::nullopt;
  }
  auto& [key, value] = *prop;
  return fdm::wire::DeviceProperty{
      .id = BIND_FIDL_PROTOCOL,
      .reserved = 0,
      .value = value,
  };
}

fuchsia_device_manager::wire::DeviceStrProperty convert_device_str_prop(
    const zx_device_str_prop_t& prop, fidl::AnyArena& allocator) {
  ZX_ASSERT(property_value_type_valid(prop.property_value.data_type));

  auto str_property = fuchsia_device_manager::wire::DeviceStrProperty{
      .key = fidl::StringView(allocator, prop.key),
  };

  switch (prop.property_value.data_type) {
    case ZX_DEVICE_PROPERTY_VALUE_INT: {
      str_property.value = fuchsia_device_manager::wire::PropertyValue::WithIntValue(
          prop.property_value.data.int_val);
      break;
    }
    case ZX_DEVICE_PROPERTY_VALUE_STRING: {
      str_property.value = fuchsia_device_manager::wire::PropertyValue::WithStrValue(
          allocator, allocator, prop.property_value.data.str_val);
      break;
    }
    case ZX_DEVICE_PROPERTY_VALUE_BOOL: {
      str_property.value = fuchsia_device_manager::wire::PropertyValue::WithBoolValue(
          prop.property_value.data.bool_val);
      break;
    }
    case ZX_DEVICE_PROPERTY_VALUE_ENUM: {
      str_property.value = fuchsia_device_manager::wire::PropertyValue::WithEnumValue(
          fidl::ObjectView<fidl::StringView>(allocator, allocator,
                                             prop.property_value.data.enum_val));
      break;
    }
  }

  return str_property;
}

static fx_log_severity_t log_min_severity(const char* name, const char* flag) {
  if (!strcasecmp(flag, "error")) {
    return FX_LOG_ERROR;
  }
  if (!strcasecmp(flag, "warning")) {
    return FX_LOG_WARNING;
  }
  if (!strcasecmp(flag, "info")) {
    return FX_LOG_INFO;
  }
  if (!strcasecmp(flag, "debug")) {
    return FX_LOG_DEBUG;
  }
  if (!strcasecmp(flag, "trace")) {
    return FX_LOG_TRACE;
  }
  if (!strcasecmp(flag, "serial")) {
    return DDK_LOG_SERIAL;
  }
  LOGF(WARNING, "Invalid minimum log severity '%s' for driver '%s', will log all", flag, name);
  return std::numeric_limits<fx_log_severity_t>::min();
}

zx_status_t log_rpc_result(const fbl::RefPtr<zx_device_t>& dev, const char* opname,
                           zx_status_t status, zx_status_t call_status = ZX_OK) {
  if (status != ZX_OK) {
    constexpr char kLogFormat[] = "Failed %s RPC: %s";
    if (status == ZX_ERR_PEER_CLOSED) {
      // TODO(https://fxbug.dev/52627): change to an ERROR log once driver
      // manager can shut down gracefully.
      LOGD(WARNING, *dev, kLogFormat, opname, zx_status_get_string(status));
    } else {
      LOGD(ERROR, *dev, kLogFormat, opname, zx_status_get_string(status));
    }
    return status;
  }
  if (call_status != ZX_OK && call_status != ZX_ERR_NOT_FOUND) {
    LOGD(ERROR, *dev, "Failed %s: %s", opname, zx_status_get_string(call_status));
  }
  return call_status;
}

}  // namespace

const char* mkdevpath(const zx_device_t& dev, char* const path, size_t max) {
  if (max == 0) {
    return "";
  }
  char* end = path + max;
  char sep = 0;

  auto append_name = [&end, &path, &sep](const zx_device_t& dev) {
    *(--end) = sep;

    size_t len = strlen(dev.name());
    if (len > static_cast<size_t>(end - path)) {
      return;
    }
    end -= len;
    memcpy(end, dev.name(), len);
    sep = '/';
  };

  append_name(dev);

  fbl::RefPtr<zx_device> itr_dev = dev.parent();
  while (itr_dev && end > path) {
    append_name(*itr_dev);
    itr_dev = itr_dev->parent();
  }

  // If devpath is longer than |max|, add an ellipsis.
  constexpr char ellipsis[] = "...";
  constexpr size_t ellipsis_len = sizeof(ellipsis) - 1;
  if (*end == sep && max > ellipsis_len) {
    if (ellipsis_len > static_cast<size_t>(end - path)) {
      end = path;
    } else {
      end -= ellipsis_len;
    }
    memcpy(end, ellipsis, ellipsis_len);
  }

  return end;
}

zx_status_t zx_driver::Create(std::string_view libname, InspectNodeCollection& drivers,
                              fbl::RefPtr<zx_driver>* out_driver) {
  char process_name[ZX_MAX_NAME_LEN] = {};
  zx::process::self()->get_property(ZX_PROP_NAME, process_name, sizeof(process_name));
  auto logger = driver_logger::CreateLogger();
  if (logger.is_error()) {
    return logger.error_value();
  }
  logger->AddTag(process_name).AddTag("driver").SetSeverity(FX_LOG_SEVERITY_DEFAULT);

  *out_driver = fbl::AdoptRef(new zx_driver(std::move(*logger), libname, drivers));
  return ZX_OK;
}

zx_driver::zx_driver(driver_logger::Logger logger, std::string_view libname,
                     InspectNodeCollection& drivers)
    : logger_(std::move(logger)), libname_(libname), inspect_(drivers, std::string(libname)) {}

zx_driver::~zx_driver() {}

zx_status_t zx_driver::ReconfigureLogger(cpp20::span<const char* const> tags) {
  char process_name[ZX_MAX_NAME_LEN] = {};
  zx::process::self()->get_property(ZX_PROP_NAME, process_name, sizeof(process_name));
  auto logger = driver_logger::CreateLogger();
  if (logger.is_error()) {
    return logger.error_value();
  }
  logger->AddTag(name()).AddTag(process_name).AddTag("driver").SetSeverity(FUCHSIA_LOG_INFO);
  logger_ = std::move(*logger);
  return ZX_OK;
}

void DriverHostContext::SetupDriverHostController(
    fidl::ServerEnd<fuchsia_device_manager::DriverHostController> request) {
  auto conn = std::make_unique<internal::DriverHostControllerConnection>(this);

  internal::DriverHostControllerConnection::Bind(std::move(conn), std::move(request),
                                                 loop_.dispatcher());
}

// Send message to driver_manager asking to add child device to
// parent device.  Called under the api lock.
zx_status_t DriverHostContext::DriverManagerAdd(const fbl::RefPtr<zx_device_t>& parent,
                                                const fbl::RefPtr<zx_device_t>& child,
                                                device_add_args_t* add_args, zx::vmo inspect,
                                                fidl::ClientEnd<fio::Directory> outgoing_dir) {
  using fuchsia_device_manager::wire::AddDeviceConfig;
  AddDeviceConfig add_device_config;

  if (child->flags() & DEV_FLAG_ALLOW_MULTI_COMPOSITE) {
    add_device_config |= AddDeviceConfig::kAllowMultiComposite;
  }
  if (child->flags() & DEV_FLAG_UNBINDABLE) {
    add_device_config |= AddDeviceConfig::kSkipAutobind;
  }
  if (child->flags() & DEV_FLAG_MUST_ISOLATE) {
    add_device_config |= AddDeviceConfig::kMustIsolate;
  }

  auto coordinator_endpoints = fidl::CreateEndpoints<fuchsia_device_manager::Coordinator>();
  if (coordinator_endpoints.is_error()) {
    return coordinator_endpoints.status_value();
  }

  auto controller_endpoints = fidl::CreateEndpoints<fuchsia_device_manager::DeviceController>();
  if (controller_endpoints.is_error()) {
    return controller_endpoints.status_value();
  }

  auto coordinator =
      fidl::WireSharedClient(std::move(coordinator_endpoints->client), loop_.dispatcher());
  auto conn = DeviceControllerConnection::Create(this, child, std::move(coordinator));

  std::vector<fuchsia_device_manager::wire::DeviceProperty> props_list = {};
  for (size_t i = 0; i < add_args->prop_count; i++) {
    props_list.push_back(convert_device_prop(add_args->props[i]));
  }

  fidl::Arena allocator;
  std::vector<fuchsia_device_manager::wire::DeviceStrProperty> str_props_list = {};
  for (size_t i = 0; i < add_args->str_prop_count; i++) {
    if (!property_value_type_valid(add_args->str_props[i].property_value.data_type)) {
      return ZX_ERR_INVALID_ARGS;
    }
    str_props_list.push_back(convert_device_str_prop(add_args->str_props[i], allocator));
  }
  for (const auto& offer : child->fidl_service_offers()) {
    auto str_property = fuchsia_device_manager::wire::DeviceStrProperty{
        .key = fidl::StringView(allocator, offer),
        .value = fuchsia_device_manager::wire::PropertyValue::WithEnumValue(
            allocator, std::string(offer) + ".ZirconTransport"),
    };
    str_props_list.push_back(str_property);

    auto prop = fidl_offer_to_device_prop(offer);
    if (prop) {
      props_list.push_back(*prop);
    }
  }

  for (const auto& offer : child->runtime_service_offers()) {
    auto str_property = fuchsia_device_manager::wire::DeviceStrProperty{
        .key = fidl::StringView(allocator, offer),
        .value = fuchsia_device_manager::wire::PropertyValue::WithEnumValue(
            allocator, std::string(offer) + ".DriverTransport"),
    };
    str_props_list.push_back(str_property);

    auto prop = fidl_offer_to_device_prop(offer);
    if (prop) {
      props_list.push_back(*prop);
    }
  }

  const auto& coordinator_client = parent->coordinator_client;
  if (!coordinator_client) {
    return ZX_ERR_IO_REFUSED;
  }
  zx_status_t call_status = ZX_OK;
  static_assert(sizeof(zx_device_prop_t) == sizeof(uint64_t));
  uint64_t device_id = 0;

  ::fuchsia_device_manager::wire::DevicePropertyList property_list = {
      .props = ::fidl::VectorView<fuchsia_device_manager::wire::DeviceProperty>::FromExternal(
          props_list),
      .str_props =
          ::fidl::VectorView<fuchsia_device_manager::wire::DeviceStrProperty>::FromExternal(
              str_props_list),
  };

  fdm::wire::AddDeviceArgs add_device_args = {
      .name = fidl::StringView::FromExternal(child->name()),
      .protocol_id = child->protocol_id(),
      .property_list = std::move(property_list),
      .driver_path = fidl::StringView::FromExternal(child->zx_driver()->libname()),
      .device_add_config = add_device_config,
      .has_init = child->ops().init != nullptr,
      .dfv2_device_symbol = reinterpret_cast<uint64_t>(child->get_dfv2_symbol()),
  };

  api_lock_.Release();
  auto response = coordinator_client.sync()->AddDevice(
      std::move(add_device_args), std::move(coordinator_endpoints->server),
      std::move(controller_endpoints->client), std::move(inspect), std::move(outgoing_dir));
  api_lock_.Acquire();
  zx_status_t status = response.status();
  if (status == ZX_OK) {
    if (response->is_ok()) {
      device_id = response->value()->local_device_id;
      if (child->ops().init) {
        // Mark child as invisible until the init function is replied.
        child->set_flag(DEV_FLAG_INVISIBLE);
      }
    } else {
      call_status = response->error_value();
    }
  }

  status = log_rpc_result(parent, "add-device", status, call_status);
  if (status != ZX_OK) {
    return status;
  }

  // Add the metadata from add_args:
  for (size_t i = 0; i < add_args->metadata_count; i++) {
    status = AddMetadata(child, add_args->metadata_list[i].type, add_args->metadata_list[i].data,
                         add_args->metadata_list[i].length);
    if (status != ZX_OK) {
      return status;
    }
  }

  child->set_local_id(device_id);
  DeviceControllerConnection::Bind(std::move(conn), std::move(controller_endpoints->server),
                                   loop_.dispatcher());
  return ZX_OK;
}

// Send message to driver_manager informing it that this device
// is being removed.  Called under the api lock.
zx_status_t DriverHostContext::DriverManagerRemove(fbl::RefPtr<zx_device_t> dev) {
  fbl::AutoLock al(&dev->controller_lock);
  if (!dev->controller_binding) {
    LOGD(ERROR, *dev, "Invalid device controller connection");
    return ZX_ERR_INTERNAL;
  }
  VLOGD(1, *dev, "Removing device %p", dev.get());

  // Close all connections to the device vnode and drop it, since no one should be able to open
  // connections anymore. This will break the reference cycle between the device and its vnode.
  if (std::optional<devfs_fidl::DeviceServer>& vnode = dev->vnode; vnode.has_value()) {
    vnode.value().CloseAllConnections([dev]() { dev->vnode.reset(); });
  }

  // respond to the remove fidl call
  dev->removal_cb(ZX_OK);

  // Forget our local ID, to release the reference stored by the local ID map
  dev->set_local_id(0);

  // Forget about our coordinator channel since after the Unbind below it may be
  // closed.
  dev->coordinator_client = {};

  // queue an event to destroy the connection
  dev->controller_binding->Unbind();
  dev->controller_binding.reset();

  // shut down our proxy rpc channel if it exists
  ProxyIosDestroy(dev);

  return ZX_OK;
}

void DriverHostContext::ProxyIosDestroy(const fbl::RefPtr<zx_device_t>& dev) {
  fbl::AutoLock guard(&dev->proxy_ios_lock);

  if (dev->proxy_ios) {
    dev->proxy_ios->CancelLocked(loop_.dispatcher());
  }
}

zx_status_t DriverHostContext::FindDriver(std::string_view libname, zx::vmo vmo,
                                          std::string_view default_dispatcher_scheduler_role,
                                          fbl::RefPtr<zx_driver_t>* out,
                                          fbl::RefPtr<Driver>* out_driver) {
  // Create unique context for the new driver instance.
  // check for already-loaded driver first
  for (auto& drv : drivers_) {
    if (!libname.compare(drv.libname())) {
      *out = fbl::RefPtr(&drv);

      auto driver = Driver::Create(&drv, default_dispatcher_scheduler_role);
      if (driver.is_error()) {
        LOGF(ERROR, "Failed to create driver: %s", driver.status_string());
        return driver.status_value();
      }
      *out_driver = *std::move(driver);

      return drv.status();
    }
  }

  fbl::RefPtr<zx_driver> new_driver;
  zx_status_t status = zx_driver::Create(libname, inspect().drivers(), &new_driver);
  if (status != ZX_OK) {
    return status;
  }

  auto driver = Driver::Create(new_driver.get(), default_dispatcher_scheduler_role);
  if (driver.is_error()) {
    LOGF(ERROR, "Failed to create driver: %s", driver.status_string());
    return driver.status_value();
  }

  // Let the |drivers_| list and our out parameter each have a refcount.
  drivers_.push_back(new_driver);
  *out = new_driver;
  *out_driver = *std::move(driver);

  const char* c_libname = new_driver->libname().c_str();

  void* dl = dlopen_vmo(vmo.get(), RTLD_NOW);
  if (dl == nullptr) {
    LOGF(ERROR, "Cannot load '%s': %s", c_libname, dlerror());
    new_driver->set_status(ZX_ERR_IO);
    return new_driver->status();
  }

  auto dn = static_cast<const zircon_driver_note_t*>(dlsym(dl, "__zircon_driver_note__"));
  if (dn == nullptr) {
    LOGF(ERROR, "Driver '%s' missing __zircon_driver_note__ symbol", c_libname);
    new_driver->set_status(ZX_ERR_IO);
    return new_driver->status();
  }
  auto dr = static_cast<zx_driver_rec_t*>(dlsym(dl, "__zircon_driver_rec__"));
  if (dr == nullptr) {
    LOGF(ERROR, "Driver '%s' missing __zircon_driver_rec__ symbol", c_libname);
    new_driver->set_status(ZX_ERR_IO);
    return new_driver->status();
  }
  const zx_driver_ops_t* ops = dr->ops;
  if (!ops) {
    LOGF(ERROR, "Driver '%s' has nullptr ops", c_libname);
    new_driver->set_status(ZX_ERR_INVALID_ARGS);
    return new_driver->status();
  }
  if (ops->version != DRIVER_OPS_VERSION) {
    LOGF(ERROR, "Driver '%s' has bad driver ops version %#lx, expecting %#lx", c_libname,
         ops->version, DRIVER_OPS_VERSION);
    new_driver->set_status(ZX_ERR_INVALID_ARGS);
    return new_driver->status();
  }

  new_driver->set_driver_rec(dr);
  new_driver->set_name(dn->payload.name);
  new_driver->set_ops(*ops);
  dr->driver = new_driver.get();

  // Check for minimum log severity of driver.
  const auto flag_name = fbl::StringPrintf("driver.%s.log", new_driver->name());
  const char* flag_value = getenv(flag_name.data());
  if (flag_value != nullptr) {
    fx_log_severity_t min_severity = log_min_severity(new_driver->name(), flag_value);
    new_driver->set_driver_min_log_severity(min_severity);
    if (status != ZX_OK) {
      LOGF(ERROR, "Failed to set minimum log severity for driver '%s': %s", new_driver->name(),
           zx_status_get_string(status));
    } else {
      LOGF(INFO, "Driver '%s' set minimum log severity to %d", new_driver->name(), min_severity);
    }
  }

  if (new_driver->has_init_op()) {
    new_driver->set_status(new_driver->InitOp(*out_driver));
    if (new_driver->status() != ZX_OK) {
      LOGF(ERROR, "Driver '%s' failed in init: %s", c_libname,
           zx_status_get_string(new_driver->status()));
    }
  } else {
    new_driver->set_status(ZX_OK);
  }

  return new_driver->status();
}

zx_status_t DriverHostContext::ConnectFidlProtocol(const fbl::RefPtr<zx_device_t>& dev,
                                                   std::string_view fragment_name,
                                                   std::string_view service_name,
                                                   std::string_view protocol_name,
                                                   zx::channel request) {
  api_lock_.Release();
  fidl::WireResult result = dev->coordinator_client.sync()->ConnectFidlProtocol(
      fidl::StringView::FromExternal(fragment_name), fidl::StringView::FromExternal(service_name),
      fidl::StringView::FromExternal(protocol_name), std::move(request));
  api_lock_.Acquire();
  if (!result.ok()) {
    return result.status();
  }
  const fit::result response = result.value();
  if (response.is_error()) {
    return response.error_value();
  }
  return ZX_OK;
}

namespace internal {

namespace {

// We need a global pointer to a DriverHostContext so that we can implement the functions exported
// to drivers.  Some of these functions unfortunately do not take an argument that can be used to
// find a context.
DriverHostContext* kContextForApi = nullptr;

}  // namespace

void RegisterContextForApi(DriverHostContext* context) {
  ZX_ASSERT((context == nullptr) != (kContextForApi == nullptr));
  kContextForApi = context;
}
DriverHostContext* ContextForApi() { return kContextForApi; }

void DriverHostControllerConnection::CreateDevice(CreateDeviceRequestView request,
                                                  CreateDeviceCompleter::Sync& completer) {
  StatusOrConn newconn;
  if (request->type.is_stub()) {
    newconn = CreateStubDevice(request);
  } else if (request->type.is_proxy()) {
    newconn = CreateProxyDevice(request);
  } else if (request->type.is_fidl_proxy()) {
    newconn = CreateFidlProxyDevice(request);
  } else if (request->type.is_composite()) {
    newconn = CreateCompositeDevice(request);
  } else {
    LOGF(ERROR, "Unexpected device type");
    completer.Reply(ZX_ERR_NOT_SUPPORTED);
    return;
  }

  if (newconn.is_error()) {
    completer.Reply(newconn.status_value());
    return;
  }

  DeviceControllerConnection::Bind(std::move(*newconn), std::move(request->device_controller),
                                   driver_host_context_->loop().dispatcher());
  completer.Reply(ZX_OK);
}

StatusOrConn DriverHostControllerConnection::CreateFidlProxyDevice(
    CreateDeviceRequestView& request) {
  auto& proxy = request->type.fidl_proxy();

  auto driver = GetFidlProxyDriver(driver_host_context_);
  if (driver == nullptr) {
    return zx::error(ZX_ERR_INTERNAL);
  }

  auto drv = Driver::Create(driver.get());
  if (drv.is_error()) {
    LOGF(ERROR, "Failed to create driver: %s", drv.status_string());
    return drv.take_error();
  }

  fbl::RefPtr<zx_device_t> dev;
  zx_status_t status = zx_device::Create(driver_host_context_, "fidl-proxy", *std::move(drv), &dev);
  if (status != ZX_OK) {
    return zx::error(status);
  }
  dev->set_local_id(request->local_device_id);

  auto coordinator = fidl::WireSharedClient(std::move(request->coordinator),
                                            driver_host_context_->loop().dispatcher());
  auto newconn =
      DeviceControllerConnection::Create(driver_host_context_, dev, std::move(coordinator));

  InitializeFidlProxyDevice(dev, std::move(proxy.incoming_dir));

  VLOGF(1, "Created device FIDL proxy %p '%s'", dev.get(), dev->name());

  return zx::ok(std::move(newconn));
}

StatusOrConn DriverHostControllerConnection::CreateProxyDevice(CreateDeviceRequestView& request) {
  auto& proxy = request->type.proxy();
  // This does not operate under the driver_host api lock,
  // since the newly created device is not visible to
  // any API surface until a driver is bound to it.
  // (which can only happen via another message on this thread)

  // named driver -- ask it to create the device
  fbl::RefPtr<zx_driver_t> drv;
  fbl::RefPtr<Driver> driver;
  zx_status_t status =
      driver_host_context_->FindDriver(proxy.driver_path.get(), std::move(proxy.driver),
                                       "" /* default_dispatcher_scheduler_role */, &drv, &driver);
  if (status != ZX_OK) {
    LOGF(ERROR, "Failed to load driver '%.*s': %s", static_cast<int>(proxy.driver_path.size()),
         proxy.driver_path.data(), zx_status_get_string(status));
    return zx::error(status);
  }
  if (!drv->has_create_op()) {
    LOGF(ERROR, "Driver does not support create operation");
    return zx::error(ZX_ERR_INTERNAL);
  }

  auto coordinator = fidl::WireSharedClient(std::move(request->coordinator),
                                            driver_host_context_->loop().dispatcher());

  // Create a dummy parent device for use in this call to Create
  fbl::RefPtr<zx_device> parent;
  status =
      zx_device::Create(driver_host_context_, "device_create dummy", std::move(driver), &parent);
  if (status != ZX_OK) {
    LOGF(ERROR, "Failed to create device: %s", zx_status_get_string(status));
    return zx::error(status);
  }
  // magic cookie for device create handshake
  CreationContext creation_context = {
      .parent = std::move(parent),
      .child = nullptr,
      .coordinator_client = coordinator.Clone(),
  };

  status = drv->CreateOp(&creation_context, creation_context.parent->driver,
                         creation_context.parent, "proxy", "", proxy.parent_proxy.release());

  // Suppress a warning about dummy device being in a bad state.  The
  // message is spurious in this case, since the dummy parent never
  // actually begins its device lifecycle.  This flag is ordinarily
  // set by device_remove().
  creation_context.parent->set_flag(DEV_FLAG_DEAD);

  if (status != ZX_OK) {
    constexpr char kLogFormat[] = "Failed to create driver: %s";
    if (status == ZX_ERR_PEER_CLOSED) {
      // TODO(https://fxbug.dev/52627): change to an ERROR log once driver
      // manager can shut down gracefully.
      LOGF(WARNING, kLogFormat, zx_status_get_string(status));
    } else {
      LOGF(ERROR, kLogFormat, zx_status_get_string(status));
    }
    return zx::error(status);
  }

  auto new_device = std::move(creation_context.child);
  if (new_device == nullptr) {
    LOGF(ERROR, "Driver did not create a device");
    return zx::error(ZX_ERR_INTERNAL);
  }

  new_device->set_local_id(request->local_device_id);
  auto newconn = DeviceControllerConnection::Create(driver_host_context_, std::move(new_device),
                                                    std::move(coordinator));

  // TODO: inform devcoord
  VLOGF(1, "Created device %p '%.*s'", new_device.get(), static_cast<int>(proxy.driver_path.size()),
        proxy.driver_path.data());
  return zx::ok(std::move(newconn));
}

StatusOrConn DriverHostControllerConnection::CreateCompositeDevice(
    CreateDeviceRequestView& request) {
  auto& composite = request->type.composite();
  // Convert the fragment IDs into zx_device references
  CompositeFragments fragments_list(new CompositeFragment[composite.fragments.count()],
                                    composite.fragments.count());
  {
    // Acquire the API lock so that we don't have to worry about concurrent
    // device removes
    fbl::AutoLock lock(&driver_host_context_->api_lock());

    for (size_t i = 0; i < composite.fragments.count(); ++i) {
      const auto& fragment = composite.fragments.data()[i];
      uint64_t local_id = fragment.id;
      fbl::RefPtr<zx_device_t> dev = zx_device::GetDeviceFromLocalId(local_id);
      if (dev == nullptr || (dev->flags() & DEV_FLAG_DEAD)) {
        return zx::error(ZX_ERR_NOT_FOUND);
      }
      fragments_list[i].name = std::string(fragment.name.data(), fragment.name.size());
      fragments_list[i].device = std::move(dev);
    }
  }

  auto driver = GetCompositeDriver(driver_host_context_);
  if (driver == nullptr) {
    return zx::error(ZX_ERR_INTERNAL);
  }

  auto drv = Driver::Create(driver.get());
  if (drv.is_error()) {
    return drv.take_error();
  }

  fbl::RefPtr<zx_device_t> dev;
  static_assert(fuchsia_device_manager::wire::kDeviceNameMax + 1 >= sizeof(dev->name()));
  zx_status_t status = zx_device::Create(driver_host_context_, std::string(composite.name.get()),
                                         *std::move(drv), &dev);
  if (status != ZX_OK) {
    return zx::error(status);
  }
  dev->set_local_id(request->local_device_id);

  auto coordinator = fidl::WireSharedClient(std::move(request->coordinator),
                                            driver_host_context_->loop().dispatcher());
  auto newconn =
      DeviceControllerConnection::Create(driver_host_context_, dev, std::move(coordinator));

  status = InitializeCompositeDevice(dev, std::move(fragments_list));
  if (status != ZX_OK) {
    return zx::error(status);
  }

  VLOGF(1, "Created composite device %p '%s'", dev.get(), dev->name());
  return zx::ok(std::move(newconn));
}

StatusOrConn DriverHostControllerConnection::CreateStubDevice(CreateDeviceRequestView& request) {
  auto& stub = request->type.stub();
  // This method is used for creating driverless proxies in case of misc, root, test devices.
  // Since there are no proxy drivers backing the device, a dummy proxy driver will be used for
  // device creation.
  auto driver = GetFidlProxyDriver(driver_host_context_);
  if (driver == nullptr) {
    return zx::error(ZX_ERR_INTERNAL);
  }

  auto drv = Driver::Create(driver.get());
  if (drv.is_error()) {
    return drv.take_error();
  }

  fbl::RefPtr<zx_device_t> dev;
  zx_status_t status = zx_device::Create(driver_host_context_, "proxy", *std::move(drv), &dev);
  // TODO: dev->ops() and other lifecycle bits
  // no name means a dummy proxy device
  if (status != ZX_OK) {
    return zx::error(status);
  }
  dev->set_protocol_id(stub.protocol_id);
  dev->set_local_id(request->local_device_id);

  auto coordinator = fidl::WireSharedClient(std::move(request->coordinator),
                                            driver_host_context_->loop().dispatcher());
  auto newconn =
      DeviceControllerConnection::Create(driver_host_context_, dev, std::move(coordinator));
  VLOGF(1, "Created device stub %p '%s'", dev.get(), dev->name());

  return zx::ok(std::move(newconn));
}

// TODO(fxbug.dev/68309): Implement Restart.
void DriverHostControllerConnection::Restart(RestartCompleter::Sync& completer) {
  completer.Reply(ZX_OK);
}

void DriverHostControllerConnection::Bind(
    std::unique_ptr<DriverHostControllerConnection> conn,
    fidl::ServerEnd<fuchsia_device_manager::DriverHostController> request,
    async_dispatcher_t* dispatcher) {
  fidl::BindServer(dispatcher, std::move(request), std::move(conn),
                   [](DriverHostControllerConnection* self, fidl::UnbindInfo info,
                      fidl::ServerEnd<fuchsia_device_manager::DriverHostController> server_end) {
                     if (info.is_user_initiated()) {
                       return;
                     }
                     if (info.is_peer_closed()) {
                       // This is expected in test environments where driver_manager has
                       // terminated.
                       // TODO(fxbug.dev/52627): Support graceful termination.
                       LOGF(WARNING, "Disconnected %p from driver_manager", self);
                       zx_process_exit(1);
                       return;
                     }
                     LOGF(FATAL, "FIDL error on %p: %s", self, info.FormatDescription().c_str());
                   });
}

int main(int argc, char** argv) {
  char process_name[ZX_MAX_NAME_LEN] = {};
  zx::process::self()->get_property(ZX_PROP_NAME, process_name, sizeof(process_name));
  driver_logger::GetLogger()
      .SetSeverity(getenv_bool("devmgr.verbose", false)
                       ? std::numeric_limits<FuchsiaLogSeverity>::min()
                       : FUCHSIA_LOG_INFO)
      .AddTag(process_name)
      .AddTag("device");

  if (zx_status_t status = fdf_env_start(); status != ZX_OK) {
    LOGF(ERROR, "Failed to create the initial dispatcher thread");
    return status;
  }

  zx::resource root_resource(zx_take_startup_handle(PA_HND(PA_RESOURCE, 0)));
  if (!root_resource.is_valid()) {
    LOGF(WARNING, "No root resource handle");
  }

  fidl::ServerEnd<fuchsia_device_manager::DriverHostController> controller_request(
      zx::channel(zx_take_startup_handle(PA_HND(PA_USER0, 0))));
  if (!controller_request.is_valid()) {
    LOGF(ERROR, "Invalid root connection to driver_manager");
    return ZX_ERR_BAD_HANDLE;
  }

  DriverHostContext ctx(&kAsyncLoopConfigAttachToCurrentThread, std::move(root_resource));

  const char* root_driver_path = getenv("devmgr.root_driver_path");
  if (root_driver_path != nullptr) {
    ctx.set_root_driver_path(root_driver_path);
  }

  RegisterContextForApi(&ctx);

  zx_status_t status = connect_scheduler_profile_provider();
  if (status != ZX_OK) {
    LOGF(INFO, "Failed to connect to profile provider: %s", zx_status_get_string(status));
    return status;
  }

  if (getenv_bool("driver.tracing.enable", true)) {
    status = start_trace_provider();
    if (status != ZX_OK) {
      LOGF(INFO, "Failed to register trace provider: %s", zx_status_get_string(status));
      // This is not a fatal error.
    }
  }
  auto stop_tracing = fit::defer([]() { stop_trace_provider(); });

  ctx.SetupDriverHostController(std::move(controller_request));

  status = ctx.inspect().Serve(fidl::ServerEnd<fuchsia_io::Directory>{zx::channel{
                                   zx_take_startup_handle(PA_DIRECTORY_REQUEST)}},
                               ctx.loop().dispatcher());
  if (status != ZX_OK) {
    LOGF(WARNING, "driver_host: error serving diagnostics directory: %s\n",
         zx_status_get_string(status));
    // This is not a fatal error
  }

  return ctx.loop().Run(zx::time::infinite(), false /* once */);
}

}  // namespace internal

zx_status_t DriverHostContext::ScheduleRemove(const fbl::RefPtr<zx_device_t>& dev,
                                              bool unbind_self) {
  const auto& client = dev->coordinator_client;
  ZX_ASSERT(client);
  VLOGD(1, *dev, "schedule-remove");
  auto resp = client->ScheduleRemove(unbind_self);
  log_rpc_result(dev, "schedule-remove", resp.status());
  return resp.status();
}

zx::result<bool> DriverHostContext::ScheduleUnbindChildren(const fbl::RefPtr<zx_device_t>& dev) {
  const auto& client = dev->coordinator_client;
  ZX_ASSERT(client);
  VLOGD(1, *dev, "schedule-unbind-children");
  api_lock_.Release();
  auto resp = client.sync()->ScheduleUnbindChildren();
  api_lock_.Acquire();
  zx_status_t call_status = resp->is_error() ? resp->error_value() : ZX_OK;
  log_rpc_result(dev, "schedule-unbind-children", resp.status(), call_status);
  if (resp.status() != ZX_OK) {
    return zx::error(resp.status());
  }
  if (call_status != ZX_OK) {
    return zx::error(call_status);
  }
  return zx::ok(resp->value()->has_children);
}

zx_status_t DriverHostContext::GetTopoPath(const fbl::RefPtr<zx_device_t>& dev, char* path,
                                           size_t max, size_t* actual) {
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }

  VLOGD(1, *dev, "get-topo-path");
  auto result = client.sync()->GetTopologicalPath();
  zx_status_t status = result.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK) {
    if (result->is_error()) {
      call_status = result->error_value();
    } else {
      auto& r = *result->value();
      memcpy(path, r.path.data(), r.path.size());
      *actual = r.path.size();
    }
  }

  log_rpc_result(dev, "get-topo-path", status, call_status);
  if (status != ZX_OK) {
    return status;
  }
  if (call_status != ZX_OK) {
    return status;
  }

  path[*actual] = 0;
  *actual += 1;

  return ZX_OK;
}

zx_status_t DriverHostContext::DeviceBind(const fbl::RefPtr<zx_device_t>& dev,
                                          const char* drv_libname) {
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }
  VLOGD(1, *dev, "bind-device");
  auto driver_path = ::fidl::StringView::FromExternal(drv_libname);
  api_lock_.Release();
  auto response = client.sync()->BindDevice(std::move(driver_path));
  api_lock_.Acquire();
  zx_status_t status = response.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK && response->is_error()) {
    call_status = response->error_value();
  }
  log_rpc_result(dev, "bind-device", status, call_status);
  if (status != ZX_OK) {
    return status;
  }

  return call_status;
}

zx_status_t DriverHostContext::LoadFirmware(const zx_driver_t* drv,
                                            const fbl::RefPtr<zx_device_t>& dev, const char* path,
                                            zx_handle_t* vmo_handle, size_t* size) {
  if ((vmo_handle == nullptr) || (size == nullptr)) {
    return ZX_ERR_INVALID_ARGS;
  }

  zx::vmo vmo;
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }
  VLOGD(1, *dev, "load-firmware");
  auto drv_libname = ::fidl::StringView::FromExternal(drv->libname());
  auto str_path = ::fidl::StringView::FromExternal(path);
  api_lock_.Release();
  auto response = client.sync()->LoadFirmware(std::move(drv_libname), std::move(str_path));
  api_lock_.Acquire();
  zx_status_t status = response.status();
  zx_status_t call_status = ZX_OK;
  auto result = std::move(response.Unwrap());
  if (result->is_error()) {
    call_status = result->error_value();
  } else {
    auto resp = std::move(result->value());
    *size = resp->size;
    vmo = std::move(resp->vmo);
  }
  log_rpc_result(dev, "load-firmware", status, call_status);
  if (status != ZX_OK) {
    return status;
  }
  *vmo_handle = vmo.release();
  if (call_status == ZX_OK && *vmo_handle == ZX_HANDLE_INVALID) {
    return ZX_ERR_INTERNAL;
  }
  return call_status;
}

zx_status_t DriverHostContext::GetMetadata(const fbl::RefPtr<zx_device_t>& dev, uint32_t type,
                                           void* buf, size_t buflen, size_t* actual) {
  if (!buf) {
    return ZX_ERR_INVALID_ARGS;
  }

  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }
  VLOGD(1, *dev, "get-metadata");
  api_lock_.Release();
  auto result = client.sync()->GetMetadata(type);
  api_lock_.Acquire();
  zx_status_t status = result.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK) {
    if (result->is_ok()) {
      const auto& r = *result->value();
      if (r.data.count() > buflen) {
        return ZX_ERR_BUFFER_TOO_SMALL;
      }
      memcpy(buf, r.data.data(), r.data.count());
      if (actual != nullptr) {
        *actual = r.data.count();
      }
    } else {
      call_status = result->error_value();
    }
  }
  return log_rpc_result(dev, "get-metadata", status, call_status);
}

zx_status_t DriverHostContext::GetMetadataSize(const fbl::RefPtr<zx_device_t>& dev, uint32_t type,
                                               size_t* out_length) {
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }
  VLOGD(1, *dev, "get-metadata-size");
  api_lock_.Release();
  auto response = client.sync()->GetMetadataSize(type);
  api_lock_.Acquire();
  zx_status_t status = response.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK) {
    if (response->is_ok()) {
      *out_length = response->value()->size;
    } else {
      call_status = response->error_value();
    }
  }
  return log_rpc_result(dev, "get-metadata-size", status, call_status);
}

zx_status_t DriverHostContext::AddMetadata(const fbl::RefPtr<zx_device_t>& dev, uint32_t type,
                                           const void* data, size_t length) {
  if (!data && length) {
    return ZX_ERR_INVALID_ARGS;
  }
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }
  VLOGD(1, *dev, "add-metadata");
  api_lock_.Release();
  auto response = client.sync()->AddMetadata(
      type, ::fidl::VectorView<uint8_t>::FromExternal(
                reinterpret_cast<uint8_t*>(const_cast<void*>(data)), length));
  api_lock_.Acquire();
  zx_status_t status = response.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK && response->is_error()) {
    call_status = response->error_value();
  }
  return log_rpc_result(dev, "add-metadata", status, call_status);
}

zx_status_t DriverHostContext::DeviceAddComposite(const fbl::RefPtr<zx_device_t>& dev,
                                                  const char* name,
                                                  const composite_device_desc_t* comp_desc) {
  if (comp_desc == nullptr || (comp_desc->props == nullptr && comp_desc->props_count > 0) ||
      comp_desc->fragments == nullptr || name == nullptr ||
      comp_desc->primary_fragment == nullptr) {
    return ZX_ERR_INVALID_ARGS;
  }
  const auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }

  VLOGD(1, *dev, "create-composite");
  fidl::Arena allocator;
  std::vector<fuchsia_device_manager::wire::DeviceFragment> compvec = {};
  for (size_t i = 0; i < comp_desc->fragments_count; i++) {
    fuchsia_device_manager::wire::DeviceFragment dc;
    dc.name = ::fidl::StringView::FromExternal(comp_desc->fragments[i].name,
                                               strnlen(comp_desc->fragments[i].name, 32));
    dc.parts.Allocate(allocator, comp_desc->fragments[i].parts_count);

    for (uint32_t j = 0; j < comp_desc->fragments[i].parts_count; j++) {
      dc.parts[j].match_program.Allocate(allocator,
                                         comp_desc->fragments[i].parts[j].instruction_count);

      for (uint32_t k = 0; k < comp_desc->fragments[i].parts[j].instruction_count; k++) {
        dc.parts[j].match_program[k] = fuchsia_device_manager::wire::BindInstruction{
            .op = comp_desc->fragments[i].parts[j].match_program[k].op,
            .arg = comp_desc->fragments[i].parts[j].match_program[k].arg,
            .debug = comp_desc->fragments[i].parts[j].match_program[k].debug,
        };
      }
    }
    compvec.push_back(std::move(dc));
  }

  std::vector<fuchsia_device_manager::wire::DeviceMetadata> metadata = {};
  for (size_t i = 0; i < comp_desc->metadata_count; i++) {
    auto meta = fuchsia_device_manager::wire::DeviceMetadata{
        .key = comp_desc->metadata_list[i].type,
        .data = fidl::VectorView<uint8_t>::FromExternal(
            reinterpret_cast<uint8_t*>(const_cast<void*>(comp_desc->metadata_list[i].data)),
            comp_desc->metadata_list[i].length)};
    metadata.emplace_back(std::move(meta));
  }

  std::vector<fuchsia_device_manager::wire::DeviceProperty> props = {};
  for (size_t i = 0; i < comp_desc->props_count; i++) {
    props.push_back(convert_device_prop(comp_desc->props[i]));
  }

  std::vector<fuchsia_device_manager::wire::DeviceStrProperty> str_props = {};
  for (size_t i = 0; i < comp_desc->str_props_count; i++) {
    if (!property_value_type_valid(comp_desc->str_props[i].property_value.data_type)) {
      return ZX_ERR_INVALID_ARGS;
    }
    str_props.push_back(convert_device_str_prop(comp_desc->str_props[i], allocator));
  }

  uint32_t primary_fragment_index = UINT32_MAX;
  for (uint32_t i = 0; i < comp_desc->fragments_count; i++) {
    if (strcmp(comp_desc->primary_fragment, comp_desc->fragments[i].name) == 0) {
      primary_fragment_index = i;
      break;
    }
  }
  if (primary_fragment_index == UINT32_MAX) {
    return ZX_ERR_INVALID_ARGS;
  }

  fuchsia_device_manager::wire::CompositeDeviceDescriptor comp_dev = {
      .props =
          ::fidl::VectorView<fuchsia_device_manager::wire::DeviceProperty>::FromExternal(props),
      .str_props =
          ::fidl::VectorView<fuchsia_device_manager::wire::DeviceStrProperty>::FromExternal(
              str_props),
      .fragments =
          ::fidl::VectorView<fuchsia_device_manager::wire::DeviceFragment>::FromExternal(compvec),
      .primary_fragment_index = primary_fragment_index,
      .spawn_colocated = comp_desc->spawn_colocated,
      .metadata =
          ::fidl::VectorView<fuchsia_device_manager::wire::DeviceMetadata>::FromExternal(metadata)};

  static_assert(sizeof(comp_desc->props[0]) == sizeof(uint64_t));
  api_lock_.Release();
  auto response = client.sync()->AddCompositeDevice(::fidl::StringView::FromExternal(name),
                                                    std::move(comp_dev));
  api_lock_.Acquire();
  zx_status_t status = response.status();
  zx_status_t call_status = ZX_OK;
  if (status == ZX_OK && response->is_error()) {
    call_status = response->error_value();
  }
  return log_rpc_result(dev, "create-composite", status, call_status);
}

zx_status_t DriverHostContext::DeviceAddCompositeNodeSpec(const fbl::RefPtr<zx_device_t>& dev,
                                                          std::string_view name,
                                                          const composite_node_spec_t* spec) {
  if (name.empty() || !spec) {
    return ZX_ERR_INVALID_ARGS;
  }

  if (!spec->parents || spec->parent_count == 0) {
    return ZX_ERR_INVALID_ARGS;
  }

  if (!spec->metadata_list && spec->metadata_count > 0) {
    return ZX_ERR_INVALID_ARGS;
  }

  auto& client = dev->coordinator_client;
  if (!client) {
    return ZX_ERR_IO_REFUSED;
  }

  fidl::Arena allocator;
  auto parents = fidl::VectorView<fdf::wire::ParentSpec>(allocator, spec->parent_count);
  for (size_t i = 0; i < spec->parent_count; i++) {
    auto parent_result = ConvertNodeRepresentation(allocator, spec->parents[i]);
    if (!parent_result.is_ok()) {
      return parent_result.error_value();
    }
    parents[i] = std::move(parent_result.value());
  }

  auto metadata = fidl::VectorView<fdm::wire::DeviceMetadata>(allocator, spec->metadata_count);
  for (size_t i = 0; i < spec->metadata_count; i++) {
    metadata[i] = fdm::wire::DeviceMetadata{
        .key = spec->metadata_list[i].type,
        .data = fidl::VectorView<uint8_t>::FromExternal(
            reinterpret_cast<uint8_t*>(const_cast<void*>(spec->metadata_list[i].data)),
            spec->metadata_list[i].length)};
  }

  fdm::wire::CompositeNodeSpecDescriptor desc = {.parents = parents, .metadata = metadata};

  api_lock_.Release();
  auto response =
      client.sync()->AddCompositeNodeSpec(fidl::StringView(allocator, name), std::move(desc));
  api_lock_.Acquire();
  auto status = response.status();
  auto call_status = status == ZX_OK && response->is_error() ? response->error_value() : ZX_OK;

  return log_rpc_result(dev, "add-composite-node-spec", status, call_status);
}