// 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_ARP_PACKET_H_
#define SHILL_NET_ARP_PACKET_H_

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

namespace shill {

// ArpPacket encapsulates the task of creating and parsing
// Address Resolution Protocol (ARP) packets for IP and
// IPv6 protocols on Ethernet (or Ethernet-like) networks.
class SHILL_EXPORT ArpPacket {
 public:
  ArpPacket();
  ArpPacket(const IPAddress& local_ip,
            const IPAddress& remote_ip,
            const ByteString& local_mac,
            const ByteString& remote_mac);
  ArpPacket(const ArpPacket&) = delete;
  ArpPacket& operator=(const ArpPacket&) = delete;

  virtual ~ArpPacket();

  // Parse a payload and save to local parameters.
  bool Parse(const ByteString& packet);

  // Output a payload from local parameters.
  bool FormatRequest(ByteString* packet) const;

  // Returns true if this packet is an ARP response.
  bool IsReply() const;

  // Getters and seters.
  const IPAddress& local_ip_address() const { return local_ip_address_; }
  void set_local_ip_address(const IPAddress& address) {
    local_ip_address_ = address;
  }

  const IPAddress& remote_ip_address() const { return remote_ip_address_; }
  void set_remote_ip_address(const IPAddress& address) {
    remote_ip_address_ = address;
  }

  const ByteString& local_mac_address() const { return local_mac_address_; }
  void set_local_mac_address(const ByteString& address) {
    local_mac_address_ = address;
  }

  const ByteString& remote_mac_address() const { return remote_mac_address_; }
  void set_remote_mac_address(const ByteString& address) {
    remote_mac_address_ = address;
  }

  uint16_t operation() const { return operation_; }
  void set_operation(uint16_t operation) { operation_ = operation; }

 private:
  friend class ArpPacketTest;

  // The minimum number of bytes of ARP payload which will produce the
  // smallest valid Ethernet frame.
  static const size_t kMinPayloadSize;

  uint16_t operation_;
  IPAddress local_ip_address_;
  IPAddress remote_ip_address_;
  ByteString local_mac_address_;
  ByteString remote_mac_address_;
};

}  // namespace shill

#endif  // SHILL_NET_ARP_PACKET_H_