text: // Copyright 2018 Google LLC
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #ifndef GVISOR_TEST_SYSCALLS_SOCKET_NETLINK_UTIL_H_
  #define GVISOR_TEST_SYSCALLS_SOCKET_NETLINK_UTIL_H_
  
  #include <linux/if_arp.h>
  #include <linux/netlink.h>
  #include <linux/rtnetlink.h>
  
  #include "test/util/file_descriptor.h"
  #include "test/util/posix_error.h"
  
  namespace gvisor {
  namespace testing {
  
  // Returns a bound NETLINK_ROUTE socket.
  PosixErrorOr<FileDescriptor> NetlinkBoundSocket();
  
  // Returns the port ID of the passed socket.
  PosixErrorOr<uint32_t> NetlinkPortID(int fd);
  
  // Send the passed request and call fn will all response netlink messages.
  PosixError NetlinkRequestResponse(
      const FileDescriptor& fd, void* request, size_t len,
      const std::function<void(const struct nlmsghdr* hdr)>& fn);
  
  }  // namespace testing
  }  // namespace gvisor
  
  #endif  // GVISOR_TEST_SYSCALLS_SOCKET_NETLINK_UTIL_H_
  