platform/impl/socket_address_posix.h

// Copyright 2019 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.

#ifndef PLATFORM_IMPL_SOCKET_ADDRESS_POSIX_H_
#define PLATFORM_IMPL_SOCKET_ADDRESS_POSIX_H_

#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include <string>

#include "platform/base/ip_address.h"

namespace openscreen {

class SocketAddressPosix {
 public:
  explicit SocketAddressPosix(const struct sockaddr& address);
  explicit SocketAddressPosix(const IPEndpoint& endpoint);

  SocketAddressPosix(const SocketAddressPosix&) = default;
  SocketAddressPosix(SocketAddressPosix&&) noexcept = default;
  SocketAddressPosix& operator=(const SocketAddressPosix&) = default;
  SocketAddressPosix& operator=(SocketAddressPosix&&) noexcept = default;

  struct sockaddr* address();
  const struct sockaddr* address() const;
  socklen_t size() const;
  IPAddress::Version version() const { return endpoint_.address.version(); }
  IPEndpoint endpoint() const { return endpoint_; }

  // Recomputes |endpoint_| if |internal_address_| is written to directly, e.g.
  // by a system call.
  void RecomputeEndpoint();

 private:
  void RecomputeEndpoint(IPAddress::Version version);

  // The way the sockaddr_* family works in POSIX is pretty unintuitive. The
  // sockaddr_in and sockaddr_in6 structs can be reinterpreted as type
  // sockaddr, however they don't have a common parent--the types are unrelated.
  // Our solution for this is to wrap sockaddr_in* in a union, so that our code
  // can be simplified since most platform APIs just take a sockaddr.
  union SocketAddressIn {
    struct sockaddr_in v4;
    struct sockaddr_in6 v6;
  };

  SocketAddressIn internal_address_;
  IPEndpoint endpoint_;
};

}  // namespace openscreen

#endif  // PLATFORM_IMPL_SOCKET_ADDRESS_POSIX_H_