net/socket/datagram_socket.h

// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_SOCKET_DATAGRAM_SOCKET_H_
#define NET_SOCKET_DATAGRAM_SOCKET_H_

#include "net/base/net_export.h"
#include "net/socket/diff_serv_code_point.h"

namespace net {

class IPEndPoint;
class NetLogWithSource;

// A datagram socket is an interface to a protocol which exchanges
// datagrams, like UDP.
class NET_EXPORT_PRIVATE DatagramSocket {
 public:
  // Type of source port binding to use.
  enum BindType {
    RANDOM_BIND,
    DEFAULT_BIND,
  };

  virtual ~DatagramSocket() = default;

  // Close the socket.
  virtual void Close() = 0;

  // Copy the remote udp address into |address| and return a network error code.
  virtual int GetPeerAddress(IPEndPoint* address) const = 0;

  // Copy the local udp address into |address| and return a network error code.
  // (similar to getsockname)
  virtual int GetLocalAddress(IPEndPoint* address) const = 0;

  // Switch to use non-blocking IO. Must be called right after construction and
  // before other calls.
  virtual void UseNonBlockingIO() = 0;

  // Requests that packets sent by this socket not be fragment, either locally
  // by the host, or by routers (via the DF bit in the IPv4 packet header).
  // May not be supported by all platforms. Returns a network error code if
  // there was a problem, but the socket will still be usable. Can not
  // return ERR_IO_PENDING.
  virtual int SetDoNotFragment() = 0;

  // Requests that packets received by this socket have the ECN bit set. Returns
  // a network error code if there was a problem.
  virtual int SetRecvTos() = 0;

  // Sets both parts of the TOS byte in the IP header. DSCP_NO_CHANGE or
  // ECN_NO_CHANGE can allow the socket to preserver part of the existing
  // setting.
  virtual int SetTos(DiffServCodePoint dscp, EcnCodePoint ecn) = 0;

  // If |confirm| is true, then the MSG_CONFIRM flag will be passed to
  // subsequent writes if it's supported by the platform.
  virtual void SetMsgConfirm(bool confirm) = 0;

  // Gets the NetLog for this socket.
  virtual const NetLogWithSource& NetLog() const = 0;

  // Returns the TOS byte of the last received datagram, or 0 for sockets which
  // do not have the capability.
  virtual DscpAndEcn GetLastTos() const = 0;
};

}  // namespace net

#endif  // NET_SOCKET_DATAGRAM_SOCKET_H_