From 5bd41d219816cf2f4c0e9f3aeb32e7ffd8176988 Mon Sep 17 00:00:00 2001
From: Tim Young <Tim.Young@LightSys.org>
Date: Wed, 26 Aug 2015 16:14:34 -0700
Subject: [PATCH] Allow devices to receive multiple DHCP responses and choose
 between them.

---
 EduNetworkBuilder/NetworkCard.cs   | 22 +++++++++++++++++++++-
 EduNetworkBuilder/NetworkDevice.cs | 30 ++++++++++++++++++++++++------
 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/EduNetworkBuilder/NetworkCard.cs b/EduNetworkBuilder/NetworkCard.cs
index 174218b..956cdbf 100644
--- a/EduNetworkBuilder/NetworkCard.cs
+++ b/EduNetworkBuilder/NetworkCard.cs
@@ -235,6 +235,8 @@ namespace EduNetworkBuilder
             {
                 if (iface.myIP.BroadcastAddress == dest.GetIP)
                     return true;//If they are pinging the broadcast IP
+                if (iface.myIP.GetIPString == NB.BroadcastIPString)
+                    return true;
             }
             return false;
         }
@@ -312,8 +314,26 @@ namespace EduNetworkBuilder
         {
             if (UsesDHCP && CanUseDHCP)
             {
-                if(interfaces.Count > 0)
+                bool doIt = true;
+                if (interfaces.Count > 0 && interfaces[0].myIP.GetIPString == NB.ZeroIPString)
+                {
+                    doIt = true;
+                }
+                else
+                {
+                    if(interfaces.Count > 0)
+                    {
+                        //The IP address is not zero.  This means it already has an IP.
+                        Random rnd = NB.GetRandom();
+                        int chance = rnd.Next(6);
+                        if (chance > 3)
+                            doIt = false;
+                    }
+                }
+                if (doIt && interfaces.Count > 0)
+                {
                     interfaces[0].myIP = newIP;
+                }
             }
         }
 
diff --git a/EduNetworkBuilder/NetworkDevice.cs b/EduNetworkBuilder/NetworkDevice.cs
index 489e10b..faa30e6 100644
--- a/EduNetworkBuilder/NetworkDevice.cs
+++ b/EduNetworkBuilder/NetworkDevice.cs
@@ -975,13 +975,21 @@ namespace EduNetworkBuilder
             return HasRouteMatching(dest);
         }
 
+        //public bool HasBroadcastAddress(IPAddress dest)
+        //{
+        //    foreach (NetworkCard nic in NICs)
+        //    {
+        //        if (nic.HasBroadcastAddresses(dest))
+        //            return true;
+        //    }
+        //    return false;
+        //}
         public bool HasBroadcastAddress(IPAddress dest)
         {
-            foreach (NetworkCard nic in NICs)
-            {
-                if (nic.HasBroadcastAddresses(dest))
-                    return true;
-            }
+            if (dest.BroadcastAddress == dest.GetIP)
+                return true;
+            if (dest.GetIPString == NB.BroadcastIPString)
+                return true;
             return false;
         }
 
@@ -1132,12 +1140,22 @@ namespace EduNetworkBuilder
             if (tPacket.sourceIP == null) return ResponseToPacket.reject;
             foreach(IPConnectionEntry ipc in IPConnections)
             {
+                if(ipc.What == PacketType.dhcp_request)
+                {
+                    Console.WriteLine(hostname + ": packet=" + tPacket.MyType.ToString());
+                    Console.WriteLine("  " + hostname + ": d:" + ipc.destIP.GetIPString + " s:" + tPacket.sourceIP.GetIPString);
+                    if (HasBroadcastAddress(ipc.destIP))
+                        Console.WriteLine("     Broadcast");
+                }
                 if(ipc.destIP.GetIP == tPacket.sourceIP.GetIP || HasBroadcastAddress(ipc.destIP))
                 {
                     if (ipc.What == PacketType.arp_request && tPacket.MyType == PacketType.arp_answer)
                         typesMatch = true;
                     if (ipc.What == PacketType.dhcp_request && tPacket.MyType == PacketType.dhcp_answer)
+                    {
+                        Console.WriteLine("  " + hostname + ": True");
                         typesMatch = true;
+                    }
                     if (ipc.What == PacketType.ping_request && tPacket.MyType == PacketType.ping_answer)
                         typesMatch = true;
                     if(typesMatch)
@@ -1632,7 +1650,7 @@ namespace EduNetworkBuilder
                         return;
                     }
                 }
-                else if(!tPacket.isFresh)
+                else if(!tPacket.isFresh && !ForwardsPackets())
                 {
                     tPacket.AddMessage(DebugLevel.info, "ERROR!  A packet returned to a machine that we were not expecting it from.");
                     string sIP = "?.?.?.?";