// Copyright 2015 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 "chromeos/network/firewall_hole.h"

#include <fcntl.h>
#include <stdint.h>
#include <unistd.h>

#include <utility>

#include "base/bind.h"
#include "base/location.h"
#include "base/memory/ptr_util.h"
#include "base/threading/thread_task_runner_handle.h"
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/permission_broker_client.h"

namespace chromeos {

namespace {

const char* PortTypeToString(FirewallHole::PortType type) {
  switch (type) {
    case FirewallHole::PortType::TCP:
      return "TCP";
    case FirewallHole::PortType::UDP:
      return "UDP";
  }
  NOTREACHED();
  return nullptr;
}

void PortReleased(FirewallHole::PortType type,
                  uint16_t port,
                  const std::string& interface,
                  base::ScopedFD lifeline_fd,
                  bool success) {
  if (!success) {
    LOG(WARNING) << "Failed to release firewall hole for "
                 << PortTypeToString(type) << " port " << port << " on "
                 << interface << ".";
  }
}

}  // namespace

// static
void FirewallHole::Open(PortType type,
                        uint16_t port,
                        const std::string& interface,
                        const OpenCallback& callback) {
  int lifeline[2] = {-1, -1};
  if (pipe2(lifeline, O_CLOEXEC) < 0) {
    PLOG(ERROR) << "Failed to create a lifeline pipe";
    base::ThreadTaskRunnerHandle::Get()->PostTask(
        FROM_HERE, base::BindOnce(callback, nullptr));
    return;
  }
  base::ScopedFD lifeline_local(lifeline[0]);
  base::ScopedFD lifeline_remote(lifeline[1]);

  base::Callback<void(bool)> access_granted_closure =
      base::Bind(&FirewallHole::PortAccessGranted, type, port, interface,
                 base::Passed(&lifeline_local), callback);

  PermissionBrokerClient* client =
      DBusThreadManager::Get()->GetPermissionBrokerClient();
  DCHECK(client) << "Could not get permission broker client.";

  switch (type) {
    case PortType::TCP:
      client->RequestTcpPortAccess(port, interface, lifeline_remote.get(),
                                   access_granted_closure);
      return;
    case PortType::UDP:
      client->RequestUdpPortAccess(port, interface, lifeline_remote.get(),
                                   access_granted_closure);
      return;
  }
}

FirewallHole::~FirewallHole() {
  base::Callback<void(bool)> port_released_closure = base::Bind(
      &PortReleased, type_, port_, interface_, base::Passed(&lifeline_fd_));

  PermissionBrokerClient* client =
      DBusThreadManager::Get()->GetPermissionBrokerClient();
  DCHECK(client) << "Could not get permission broker client.";
  switch (type_) {
    case PortType::TCP:
      client->ReleaseTcpPort(port_, interface_, port_released_closure);
      return;
    case PortType::UDP:
      client->ReleaseUdpPort(port_, interface_, port_released_closure);
      return;
  }
}

void FirewallHole::PortAccessGranted(PortType type,
                                     uint16_t port,
                                     const std::string& interface,
                                     base::ScopedFD lifeline_fd,
                                     const FirewallHole::OpenCallback& callback,
                                     bool success) {
  if (success) {
    callback.Run(base::WrapUnique(
        new FirewallHole(type, port, interface, std::move(lifeline_fd))));
  } else {
    callback.Run(nullptr);
  }
}

FirewallHole::FirewallHole(PortType type,
                           uint16_t port,
                           const std::string& interface,
                           base::ScopedFD lifeline_fd)
    : type_(type),
      port_(port),
      interface_(interface),
      lifeline_fd_(std::move(lifeline_fd)) {}

}  // namespace chromeos