--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/node/arp.cc	Mon Feb 12 15:55:49 2007 +0100
@@ -0,0 +1,196 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006 INRIA
+ * All rights reserved.
+ *
+ * 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 "arp.h"
+#include "arp-header.h"
+#include "arp-cache.h"
+#include "net-device.h"
+#include "ipv4-interface.h"
+#include "node.h"
+#include "ipv4.h"
+
+#define TRACE(x)
+
+namespace ns3 {
+
+Arp::Arp (Node *node)
+  : m_node (node)
+{}
+
+Arp *
+Arp::Copy (Node *node)
+{
+  return new Arp (node);
+}
+
+ArpCache *
+Arp::FindCache (NetDevice *device)
+{
+  for (CacheList::const_iterator i = m_cacheList.begin (); i != m_cacheList.end (); i++)
+    {
+      if ((*i)->GetDevice () == device)
+	{
+	  return *i;
+	}
+    }
+  Ipv4Interface *interface = m_node->GetIpv4 ()->FindInterfaceForDevice (device);
+  ArpCache * cache = new ArpCache (device, interface);
+  assert (device->IsBroadcast ());
+  device->SetLinkChangeCallback (MakeCallback (&ArpCache::Flush, cache));
+  m_cacheList.push_back (cache);
+  return cache;
+}
+
+void 
+Arp::Receive(Packet& packet, NetDevice *device)
+{
+  ArpCache *cache = FindCache (device);
+  ArpHeader arp;
+  packet.Peek (arp);
+  packet.Remove (arp);
+  if (arp.IsRequest () && 
+      arp.GetDestinationIpv4Address () == cache->GetInterface ()->GetAddress ()) 
+    {
+      TRACE ("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 ().IsEqual (device->GetAddress ())) 
+    {
+      Ipv4Address from = arp.GetSourceIpv4Address ();
+      ArpCache::Entry *entry = cache->Lookup (from);
+      if (entry != 0)
+        {
+          if (entry->IsWaitReply ()) 
+            {
+              TRACE ("got reply from " << arp.GetSourceIpv4Address ()
+                     << " for waiting entry -- flush");
+              MacAddress from_mac = arp.GetSourceHardwareAddress ();
+              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.
+              TRACE ("got reply from " << arp.GetSourceIpv4Address () << 
+                     " for non-waiting entry -- drop");
+	      // XXX report packet as dropped.
+            }
+        } 
+      else 
+        {
+          TRACE ("got reply for unknown entry -- drop");
+	  // XXX report packet as dropped.
+        }
+    }
+}
+bool 
+Arp::Lookup (Packet &packet, Ipv4Address destination, 
+	     NetDevice *device,
+	     MacAddress *hardwareDestination)
+{
+  ArpCache *cache = FindCache (device);
+  ArpCache::Entry *entry = cache->Lookup (destination);
+  if (entry != 0)
+    {
+      if (entry->IsExpired ()) 
+        {
+          if (entry->IsDead ()) 
+            {
+              TRACE ("dead entry for " << destination << " expired -- send arp request");
+              entry->MarkWaitReply (packet);
+              SendArpRequest (cache, destination);
+            } 
+          else if (entry->IsAlive ()) 
+            {
+              TRACE ("alive entry for " << destination << " expired -- send arp request");
+              entry->MarkWaitReply (packet);
+              SendArpRequest (cache, destination);
+            } 
+          else if (entry->IsWaitReply ()) 
+            {
+              TRACE ("wait reply for " << destination << " expired -- drop");
+              entry->MarkDead ();
+	      // XXX report packet as 'dropped'
+            }
+        } 
+      else 
+        {
+          if (entry->IsDead ()) 
+            {
+              TRACE ("dead entry for " << destination << " valid -- drop");
+	      // XXX report packet as 'dropped'
+            } 
+          else if (entry->IsAlive ()) 
+            {
+              TRACE ("alive entry for " << destination << " valid -- send");
+	      *hardwareDestination = entry->GetMacAddress ();
+              return true;
+            } 
+          else if (entry->IsWaitReply ()) 
+            {
+              TRACE ("wait reply for " << destination << " valid -- drop previous");
+              Packet old = entry->UpdateWaitReply (packet);
+	      // XXX report 'old' packet as 'dropped'
+            }
+        }
+
+    }
+  else
+    {
+      // This is our first attempt to transmit data to this destination.
+      TRACE ("no entry for " << to << " -- send arp request");
+      entry = cache->Add (destination);
+      entry->MarkWaitReply (packet);
+      SendArpRequest (cache, destination);
+    }
+  return false;
+}
+
+void
+Arp::SendArpRequest (ArpCache const *cache, Ipv4Address to)
+{
+  ArpHeader arp;
+  arp.SetRequest (cache->GetDevice ()->GetAddress (),
+		  cache->GetInterface ()->GetAddress (), 
+                  cache->GetDevice ()->GetBroadcast (),
+                  to);
+  Packet packet;
+  packet.Add (arp);
+  cache->GetDevice ()->Send (packet, cache->GetDevice ()->GetBroadcast (), 0x0806);
+}
+
+void
+Arp::SendArpReply (ArpCache const *cache, Ipv4Address toIp, MacAddress toMac)
+{
+  ArpHeader arp;
+  arp.SetReply (cache->GetDevice ()->GetAddress (),
+                cache->GetInterface ()->GetAddress (),
+                toMac, toIp);
+  Packet packet;
+  packet.Add (arp);
+  cache->GetDevice ()->Send (packet, toMac, 0x0806);
+}
+
+}//namespace ns3