// Copyright 2018 The Chromium OS 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 SHILL_NET_NETLINK_SOCK_DIAG_H_
#define SHILL_NET_NETLINK_SOCK_DIAG_H_

#include <stdint.h>

#include <memory>
#include <vector>

#include <base/macros.h>

#include "shill/net/ip_address.h"
#include "shill/net/netlink_fd.h"
#include "shill/net/shill_export.h"

struct inet_diag_sockid;

namespace shill {

class Sockets;

// NetlinkSockDiag allows for the destruction of sockets on the system.
// Destruction of both UDP and TCP sockets is supported. Note, however, that TCP
// sockets will not be immediately destroyed, but will first perform the TCP
// termination handshake.
//
// Also note that the proper functioning of this class is contingent on kernel
// support for SOCK_DESTROY.
class SHILL_EXPORT NetlinkSockDiag {
 public:
  static std::unique_ptr<NetlinkSockDiag> Create(
      std::unique_ptr<Sockets> sockets);
  virtual ~NetlinkSockDiag();

  // Send SOCK_DESTROY for each socket matching the |protocol| and |saddr|
  // given. This interrupts all blocking socket operations on those sockets
  // with ECONNABORTED so that the application can discard the socket and
  // make another connection.
  bool DestroySockets(uint8_t protocol, const IPAddress& saddr);

 private:
  // Hidden; use the static Create function above.
  NetlinkSockDiag(std::unique_ptr<Sockets> sockets, int file_descriptor);
  NetlinkSockDiag(const NetlinkSockDiag&) = delete;
  NetlinkSockDiag& operator=(const NetlinkSockDiag&) = delete;

  // Get a list of sockets matching the family and protocol.
  bool GetSockets(uint8_t family,
                  uint8_t protocol,
                  std::vector<struct inet_diag_sockid>* out_socks);

  // Read the socket dump from the netlink socket.
  bool ReadDumpContents(std::vector<struct inet_diag_sockid>* out_socks);

  std::unique_ptr<Sockets> sockets_;
  int file_descriptor_;
  int sequence_number_;
};

}  // namespace shill

#endif  // SHILL_NET_NETLINK_SOCK_DIAG_H_