/* -*- 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>
*/
#include "ns3/packet.h"
#include "ns3/log.h"
#include "ns3/node.h"
#include "ns3/net-device.h"
#include "ipv4-l3-protocol.h"
#include "arp-l3-protocol.h"
#include "arp-header.h"
#include "arp-cache.h"
#include "ipv4-interface.h"
NS_LOG_COMPONENT_DEFINE ("ArpL3Protocol");
namespace ns3 {
const uint16_t ArpL3Protocol::PROT_NUMBER = 0x0806;
NS_OBJECT_ENSURE_REGISTERED (ArpL3Protocol);
TypeId
ArpL3Protocol::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::ArpL3Protocol")
.SetParent<Object> ()
;
return tid;
}
ArpL3Protocol::ArpL3Protocol ()
{
NS_LOG_FUNCTION;
}
ArpL3Protocol::~ArpL3Protocol ()
{
NS_LOG_FUNCTION;
}
void
ArpL3Protocol::SetNode (Ptr<Node> node)
{
m_node = node;
}
void
ArpL3Protocol::DoDispose (void)
{
NS_LOG_FUNCTION;
for (CacheList::const_iterator i = m_cacheList.begin (); i != m_cacheList.end (); i++)
{
delete *i;
}
m_cacheList.clear ();
m_node = 0;
Object::DoDispose ();
}
ArpCache *
ArpL3Protocol::FindCache (Ptr<NetDevice> device)
{
NS_LOG_FUNCTION;
for (CacheList::const_iterator i = m_cacheList.begin (); i != m_cacheList.end (); i++)
{
if ((*i)->GetDevice () == device)
{
return *i;
}
}
Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();
Ptr<Ipv4Interface> interface = ipv4->FindInterfaceForDevice (device);
ArpCache * cache = new ArpCache (device, interface);
NS_ASSERT (device->IsBroadcast ());
device->SetLinkChangeCallback (MakeCallback (&ArpCache::Flush, cache));
m_cacheList.push_back (cache);
return cache;
}
void
ArpL3Protocol::Receive(Ptr<NetDevice> device, Ptr<Packet> packet, uint16_t protocol, const Address &from)
{
NS_LOG_FUNCTION;
ArpCache *cache = FindCache (device);
ArpHeader arp;
packet->RemoveHeader (arp);
NS_LOG_LOGIC ("ARP: received "<< (arp.IsRequest ()? "request" : "reply") <<
" node="<<m_node->GetId ()<<", got request from " <<
arp.GetSourceIpv4Address () << " for address " <<
arp.GetDestinationIpv4Address () << "; we have address " <<
cache->GetInterface ()->GetAddress ());
/**
* Note: we do not update the ARP cache when we receive an ARP request
* from an unknown node. See bug #107
*/
if (arp.IsRequest () &&
arp.GetDestinationIpv4Address () == cache->GetInterface ()->GetAddress ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId () <<", got request from " <<
arp.GetSourceIpv4Address () << " -- send reply");
SendArpReply (cache, arp.GetSourceIpv4Address (),
arp.GetSourceHardwareAddress ());
}
else if (arp.IsReply () &&
arp.GetDestinationIpv4Address ().IsEqual (cache->GetInterface ()->GetAddress ()) &&
arp.GetDestinationHardwareAddress () == device->GetAddress ())
{
Ipv4Address from = arp.GetSourceIpv4Address ();
ArpCache::Entry *entry = cache->Lookup (from);
if (entry != 0)
{
if (entry->IsWaitReply ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<", got reply from " <<
arp.GetSourceIpv4Address ()
<< " for waiting entry -- flush");
Address from_mac = arp.GetSourceHardwareAddress ();
Ptr<Packet> waiting = entry->MarkAlive (from_mac);
cache->GetInterface ()->Send (waiting, arp.GetSourceIpv4Address ());
}
else
{
// ignore this reply which might well be an attempt
// at poisening my arp cache.
NS_LOG_LOGIC("node="<<m_node->GetId ()<<", got reply from " <<
arp.GetSourceIpv4Address () <<
" for non-waiting entry -- drop");
// XXX report packet as dropped.
}
}
else
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<", got reply for unknown entry -- drop");
// XXX report packet as dropped.
}
}
else
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<", got request from " <<
arp.GetSourceIpv4Address () << " for unknown address " <<
arp.GetDestinationIpv4Address () << " -- drop");
}
}
bool
ArpL3Protocol::Lookup (Ptr<Packet> packet, Ipv4Address destination,
Ptr<NetDevice> device,
Address *hardwareDestination)
{
NS_LOG_FUNCTION;
ArpCache *cache = FindCache (device);
ArpCache::Entry *entry = cache->Lookup (destination);
if (entry != 0)
{
if (entry->IsExpired ())
{
if (entry->IsDead ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", dead entry for " << destination << " expired -- send arp request");
entry->MarkWaitReply (packet);
SendArpRequest (cache, destination);
}
else if (entry->IsAlive ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", alive entry for " << destination << " expired -- send arp request");
entry->MarkWaitReply (packet);
SendArpRequest (cache, destination);
}
else if (entry->IsWaitReply ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", wait reply for " << destination << " expired -- drop");
entry->MarkDead ();
// XXX report packet as 'dropped'
}
}
else
{
if (entry->IsDead ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", dead entry for " << destination << " valid -- drop");
// XXX report packet as 'dropped'
}
else if (entry->IsAlive ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", alive entry for " << destination << " valid -- send");
*hardwareDestination = entry->GetMacAddress ();
return true;
}
else if (entry->IsWaitReply ())
{
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", wait reply for " << destination << " valid -- drop previous");
Ptr<Packet> old = entry->UpdateWaitReply (packet);
// XXX report 'old' packet as 'dropped'
}
}
}
else
{
// This is our first attempt to transmit data to this destination.
NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
", no entry for " << destination << " -- send arp request");
entry = cache->Add (destination);
entry->MarkWaitReply (packet);
SendArpRequest (cache, destination);
}
return false;
}
void
ArpL3Protocol::SendArpRequest (ArpCache const *cache, Ipv4Address to)
{
NS_LOG_FUNCTION;
ArpHeader arp;
NS_LOG_LOGIC ("ARP: sending request from node "<<m_node->GetId ()<<
" || src: " << cache->GetDevice ()->GetAddress () <<
" / " << cache->GetInterface ()->GetAddress () <<
" || dst: " << cache->GetDevice ()->GetBroadcast () <<
" / " << to);
arp.SetRequest (cache->GetDevice ()->GetAddress (),
cache->GetInterface ()->GetAddress (),
cache->GetDevice ()->GetBroadcast (),
to);
Ptr<Packet> packet = Create<Packet> ();
packet->AddHeader (arp);
cache->GetDevice ()->Send (packet, cache->GetDevice ()->GetBroadcast (), PROT_NUMBER);
}
void
ArpL3Protocol::SendArpReply (ArpCache const *cache, Ipv4Address toIp, Address toMac)
{
NS_LOG_FUNCTION;
ArpHeader arp;
NS_LOG_LOGIC ("ARP: sending reply from node "<<m_node->GetId ()<<
"|| src: " << cache->GetDevice ()->GetAddress () <<
" / " << cache->GetInterface ()->GetAddress () <<
" || dst: " << toMac << " / " << toIp);
arp.SetReply (cache->GetDevice ()->GetAddress (),
cache->GetInterface ()->GetAddress (),
toMac, toIp);
Ptr<Packet> packet = Create<Packet> ();
packet->AddHeader (arp);
cache->GetDevice ()->Send (packet, toMac, PROT_NUMBER);
}
}//namespace ns3