bin/guest/runner/runner_impl.cc

// Copyright 2018 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 "garnet/bin/guest/runner/runner_impl.h"

#include <fuchsia/guest/vmm/cpp/fidl.h>
#include <memory>

#include "lib/fxl/logging.h"
#include "lib/svc/cpp/service_provider_bridge.h"

namespace guest_runner {

RunnerImpl::RunnerImpl()
    : context_(component::StartupContext::CreateFromStartupInfo()) {
  context_->environment()->GetLauncher(launcher_.NewRequest());
  context_->outgoing().AddPublicService(bindings_.GetHandler(this));
}

void RunnerImpl::StartComponent(
    fuchsia::sys::Package application, fuchsia::sys::StartupInfo startup_info,
    ::fidl::InterfaceRequest<fuchsia::sys::ComponentController> controller) {
  fuchsia::sys::LaunchInfo launch_info;

  // Pass-through our arguments directly to the vmm package.
  launch_info.url = "fuchsia-pkg://fuchsia.com/vmm#meta/vmm.cmx";
  launch_info.arguments = std::move(startup_info.launch_info.arguments);
  launch_info.directory_request =
      std::move(startup_info.launch_info.directory_request);
  launch_info.flat_namespace = fuchsia::sys::FlatNamespace::New();
  for (size_t i = 0; i < startup_info.flat_namespace.paths->size(); ++i) {
    const auto& path = (*startup_info.flat_namespace.paths)[i];
    if (path == "/pkg") {
      // Expose the specific guest package under the /guest namespace.
      launch_info.flat_namespace->paths.push_back("/guest");
      launch_info.flat_namespace->directories.push_back(
          std::move((*startup_info.flat_namespace.directories)[i]));
    } else if (path == "/svc") {
      // Hack: We've provided some 'additional_services' to the vmm, but those
      // are loaded in the /svc in the provided flat_namespace here. Appmgr
      // doesn't allow overriding the /svc namespace of the vmm, instead it
      // initialized it to the set of services requested in the vmm.cmx.
      //
      // The solution here is to invert the dependency between guestmgr and the
      // guest_runner. Apps that call the guestmgr directly can just embed the
      // artifacts they need into their own package and don't need to use a
      // companion guest package. Then the runner can be used for the
      // standalone guest packages (ex: linux_guest/zircon_guest).
      //
      // Note: the leaking of the |ServiceProviderBridge| is intentional. We
      // could wrap the ComponentController in one that we retain here so we can
      // intercept the error event and cleanup, but since this is temporary we
      // can live with this.
      //
      // See: MAC-181
      auto bridge = new component::ServiceProviderBridge;
      auto service_list = fuchsia::sys::ServiceList::New();
      // This must list every service the vmm depends on. We don't provide
      // any implementations here since the ServiceProviderBridge takes care
      // of that for us via the backing_dir, which is the above /svc directory.
      service_list->names.push_back(
          fuchsia::guest::vmm::LaunchInfoProvider::Name_);
      bridge->set_backing_dir(
          std::move((*startup_info.flat_namespace.directories)[i]));
      service_list->provider = bridge->AddBinding();
      launch_info.additional_services = std::move(service_list);
    }
  }

  launcher_->CreateComponent(std::move(launch_info), std::move(controller));
}

}  // namespace guest_runner