Files
unison/src/internet/model/arp-cache.h

333 lines
9.7 KiB
C++

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2006 INRIA
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
*/
#ifndef ARP_CACHE_H
#define ARP_CACHE_H
#include <stdint.h>
#include <list>
#include "ns3/simulator.h"
#include "ns3/callback.h"
#include "ns3/packet.h"
#include "ns3/nstime.h"
#include "ns3/net-device.h"
#include "ns3/ipv4-address.h"
#include "ns3/address.h"
#include "ns3/ptr.h"
#include "ns3/object.h"
#include "ns3/traced-callback.h"
#include "ns3/sgi-hashmap.h"
#include "ns3/output-stream-wrapper.h"
namespace ns3 {
class NetDevice;
class Ipv4Interface;
/**
* \ingroup arp
* \brief An ARP cache
*
* A cached lookup table for translating layer 3 addresses to layer 2.
* This implementation does lookups from IPv4 to a MAC address
*/
class ArpCache : public Object
{
private:
/**
* \brief Copy constructor
*
* Defined and unimplemented to avoid misuse
*/
ArpCache (ArpCache const &);
/**
* \brief Copy constructor
*
* Defined and unimplemented to avoid misuse
* \returns
*/
ArpCache& operator= (ArpCache const &);
public:
/**
* \brief Get the type ID.
* \return the object TypeId
*/
static TypeId GetTypeId (void);
class Entry;
ArpCache ();
~ArpCache ();
/**
* \brief Set the NetDevice and Ipv4Interface associated with the ArpCache
*
* \param device The hardware NetDevice associated with this ARP cache
* \param interface the Ipv4Interface associated with this ARP cache
*/
void SetDevice (Ptr<NetDevice> device, Ptr<Ipv4Interface> interface);
/**
* \brief Returns the NetDevice that this ARP cache is associated with
* \return The NetDevice that this ARP cache is associated with
*/
Ptr<NetDevice> GetDevice (void) const;
/**
* \brief Returns the Ipv4Interface that this ARP cache is associated with
* \return the Ipv4Interface that this ARP cache is associated with
*/
Ptr<Ipv4Interface> GetInterface (void) const;
/**
* \brief Set the time the entry will be in ALIVE state (unless refreshed)
* \param aliveTimeout the Alive state timeout
*/
void SetAliveTimeout (Time aliveTimeout);
/**
* \brief Set the time the entry will be in DEAD state before being removed
* \param deadTimeout the Dead state timeout
*/
void SetDeadTimeout (Time deadTimeout);
/**
* \brief Set the time the entry will be in WAIT_REPLY state
* \param waitReplyTimeout the WAIT_REPLY state timeout
*/
void SetWaitReplyTimeout (Time waitReplyTimeout);
/**
* \brief Get the time the entry will be in ALIVE state (unless refreshed)
* \returns the Alive state timeout
*/
Time GetAliveTimeout (void) const;
/**
* \brief Get the time the entry will be in DEAD state before being removed
* \returns the Dead state timeout
*/
Time GetDeadTimeout (void) const;
/**
* \brief Get the time the entry will be in WAIT_REPLY state
* \returns the WAIT_REPLY state timeout
*/
Time GetWaitReplyTimeout (void) const;
/**
* This callback is set when the ArpCache is set up and allows
* the cache to generate an Arp request when the WaitReply
* time expires and a retransmission must be sent
*
* \param arpRequestCallback Callback for transmitting an Arp request.
*/
void SetArpRequestCallback (Callback<void, Ptr<const ArpCache>,
Ipv4Address> arpRequestCallback);
/**
* This method will schedule a timeout at WaitReplyTimeout interval
* in the future, unless a timer is already running for the cache,
* in which case this method does nothing.
*/
void StartWaitReplyTimer (void);
/**
* \brief Do lookup in the ARP cache against an IP address
* \param destination The destination IPv4 address to lookup the MAC address
* of
* \return An ArpCache::Entry with info about layer 2
*/
ArpCache::Entry *Lookup (Ipv4Address destination);
/**
* \brief Add an Ipv4Address to this ARP cache
*/
ArpCache::Entry *Add (Ipv4Address to);
/**
* \brief Remove an entry.
* \param entry pointer to delete it from the list
*/
void Remove (ArpCache::Entry *entry);
/**
* \brief Clear the ArpCache of all entries
*/
void Flush (void);
/**
* \brief Print the ARP cache entries
*
* \param stream the ostream the ARP cache entries is printed to
*/
void PrintArpCache (Ptr<OutputStreamWrapper> stream);
/**
* \brief A record that that holds information about an ArpCache entry
*/
class Entry {
public:
/**
* \brief Constructor
* \param arp The ArpCache this entry belongs to
*/
Entry (ArpCache *arp);
/**
* \brief Changes the state of this entry to dead
*/
void MarkDead (void);
/**
* \param macAddress
*/
void MarkAlive (Address macAddress);
/**
* \param waiting
*/
void MarkWaitReply (Ptr<Packet> waiting);
/**
* \brief Changes the state of this entry to Permanent.
*
* The entry must have a valid MacAddress.
*/
void MarkPermanent (void);
/**
* \param waiting
* \return
*/
bool UpdateWaitReply (Ptr<Packet> waiting);
/**
* \return True if the state of this entry is dead; false otherwise.
*/
bool IsDead (void);
/**
* \return True if the state of this entry is alive; false otherwise.
*/
bool IsAlive (void);
/**
* \return True if the state of this entry is wait_reply; false otherwise.
*/
bool IsWaitReply (void);
/**
* \return True if the state of this entry is permanent; false otherwise.
*/
bool IsPermanent (void);
/**
* \return The MacAddress of this entry
*/
Address GetMacAddress (void) const;
/**
* \return The Ipv4Address for this entry
*/
Ipv4Address GetIpv4Address (void) const;
/**
* \param macAddress The MacAddress for this entry
*/
void SetMacAddresss (Address macAddress);
/**
* \param destination The Ipv4Address for this entry
*/
void SetIpv4Address (Ipv4Address destination);
/**
* \return True if this entry has timed out; false otherwise.
*
* This function returns true if the time elapsed strictly exceeds
* the timeout value (i.e., is not less than or equal to the timeout).
*/
bool IsExpired (void) const;
/**
* \returns 0 is no packet is pending, the next packet to send if
* packets are pending.
*/
Ptr<Packet> DequeuePending (void);
/**
* \brief Clear the pending packet list
*/
void ClearPendingPacket (void);
/**
* \returns number of retries that have been sent for an ArpRequest
* in WaitReply state.
*/
uint32_t GetRetries (void) const;
/**
* \brief Increment the counter of number of retries for an entry
*/
void IncrementRetries (void);
/**
* \brief Zero the counter of number of retries for an entry
*/
void ClearRetries (void);
private:
/**
* \brief ARP cache entry states
*/
enum ArpCacheEntryState_e {
ALIVE,
WAIT_REPLY,
DEAD,
PERMANENT
};
/**
* \brief Update the entry when seeing a packet
*/
void UpdateSeen (void);
/**
* \brief Returns the entry timeout
* \returns the entry timeout
*/
Time GetTimeout (void) const;
ArpCache *m_arp; //!< pointer to the ARP cache owning the entry
ArpCacheEntryState_e m_state; //!< state of the entry
Time m_lastSeen; //!< last moment a packet from that address has been seen
Address m_macAddress; //!< entry's MAC address
Ipv4Address m_ipv4Address; //!< entry's IP address
std::list<Ptr<Packet> > m_pending; //!< list of pending packets for the entry's IP
uint32_t m_retries; //!< rerty counter
};
private:
/**
* \brief ARP Cache container
*/
typedef sgi::hash_map<Ipv4Address, ArpCache::Entry *, Ipv4AddressHash> Cache;
/**
* \brief ARP Cache container iterator
*/
typedef sgi::hash_map<Ipv4Address, ArpCache::Entry *, Ipv4AddressHash>::iterator CacheI;
virtual void DoDispose (void);
Ptr<NetDevice> m_device; //!< NetDevice associated with the cache
Ptr<Ipv4Interface> m_interface; //!< Ipv4Interface associated with the cache
Time m_aliveTimeout; //!< cache alive state timeout
Time m_deadTimeout; //!< cache dead state timeout
Time m_waitReplyTimeout; //!< cache reply state timeout
EventId m_waitReplyTimer; //!< cache alive state timer
Callback<void, Ptr<const ArpCache>, Ipv4Address> m_arpRequestCallback; //!< reply timeout callback
uint32_t m_maxRetries; //!< max retries for a resolution
/**
* This function is an event handler for the event that the
* ArpCache wants to check whether it must retry any Arp requests.
* If there are no Arp requests pending, this event is not scheduled.
*/
void HandleWaitReplyTimeout (void);
uint32_t m_pendingQueueSize; //!< number of packets waiting for a resolution
Cache m_arpCache; //!< the ARP cache
TracedCallback<Ptr<const Packet> > m_dropTrace; //!< trace for packets dropped by the ARP cache queue
};
} // namespace ns3
#endif /* ARP_CACHE_H */