# HG changeset patch
# User Tom Henderson <tomh@tomh.org>
# Date 1260602617 28800
# Node ID b40d352e92bc4f4b0ab0abc863658382312c266e
# Parent  74d9ac708677fd927b3893ab63e12fd50f4c0232
possible fix for bug 606

diff -r 74d9ac708677 -r b40d352e92bc src/internet-stack/arp-l3-protocol.cc
--- a/src/internet-stack/arp-l3-protocol.cc	Fri Dec 11 11:48:12 2009 -0500
+++ b/src/internet-stack/arp-l3-protocol.cc	Fri Dec 11 23:23:37 2009 -0800
@@ -23,7 +23,6 @@
 #include "ns3/net-device.h"
 #include "ns3/object-vector.h"
 #include "ns3/trace-source-accessor.h"
-#include "ns3/ipv4-route.h"
 
 #include "ipv4-l3-protocol.h"
 #include "arp-l3-protocol.h"
@@ -320,19 +319,15 @@
   NS_ASSERT (interface >= 0);
   Ipv4Header header;
   header.SetDestination (to);
-  Socket::SocketErrno errno_;
   Ptr<Packet> packet = Create<Packet> ();
-  Ptr<Ipv4Route> route = ipv4->GetRoutingProtocol ()->RouteOutput (packet, header, interface, errno_);
-  NS_ASSERT (route != 0);
+  Ipv4Address source = ipv4->SelectSourceAddress (cache->GetDevice (), to, Ipv4InterfaceAddress::GLOBAL);
   NS_LOG_LOGIC ("ARP: sending request from node "<<m_node->GetId ()<<
             " || src: " << cache->GetDevice ()->GetAddress () <<
-            " / " << route->GetSource () <<
+            " / " << source <<
             " || dst: " << cache->GetDevice ()->GetBroadcast () <<
             " / " << to);
-  arp.SetRequest (cache->GetDevice ()->GetAddress (),
-		  route->GetSource (),
-                  cache->GetDevice ()->GetBroadcast (),
-                  to);
+  arp.SetRequest (cache->GetDevice ()->GetAddress (), source,
+                  cache->GetDevice ()->GetBroadcast (), to);
   packet->AddHeader (arp);
   cache->GetDevice ()->Send (packet, cache->GetDevice ()->GetBroadcast (), PROT_NUMBER);
 }
diff -r 74d9ac708677 -r b40d352e92bc src/internet-stack/ipv4-l3-protocol.cc
--- a/src/internet-stack/ipv4-l3-protocol.cc	Fri Dec 11 11:48:12 2009 -0500
+++ b/src/internet-stack/ipv4-l3-protocol.cc	Fri Dec 11 23:23:37 2009 -0800
@@ -866,6 +866,59 @@
   return false;
 }
 
+Ipv4Address 
+Ipv4L3Protocol::SelectSourceAddress (Ptr<const NetDevice> device,
+    Ipv4Address dst, Ipv4InterfaceAddress::InterfaceAddressScope_e scope)
+{
+  NS_LOG_FUNCTION (device << dst << scope);
+  Ipv4Address addr ("0.0.0.0");
+  Ipv4InterfaceAddress iaddr; 
+  bool found = false;
+
+  if (device != 0)
+    {
+      int32_t i = GetInterfaceForDevice (device);
+      NS_ASSERT_MSG (i >= 0, "No device found on node");
+      for (uint32_t j = 0; j < GetNAddresses (i); j++)
+        {
+          iaddr = GetAddress (i, j);
+          if (iaddr.IsSecondary ()) continue;
+          if (iaddr.GetScope () > scope) continue; 
+          if (dst.CombineMask (iaddr.GetMask ())  == iaddr.GetLocal ().CombineMask (iaddr.GetMask ()) )  
+            {
+              return iaddr.GetLocal ();
+            }
+          if (!found)
+            {
+              addr = iaddr.GetLocal ();
+              found = true;
+            }
+        }
+    }
+  if (found)
+    {
+      return addr;
+    }
+
+  // Iterate among all interfaces
+  for (uint32_t i = 0; i < GetNInterfaces (); i++)
+    {
+      for (uint32_t j = 0; j < GetNAddresses (i); j++)
+        {
+          iaddr = GetAddress (i, j);
+          if (iaddr.IsSecondary ()) continue;
+          if (iaddr.GetScope () != Ipv4InterfaceAddress::LINK 
+              && iaddr.GetScope () <= scope) 
+            {
+              return iaddr.GetLocal ();
+            }
+        }
+    }
+  NS_LOG_WARN ("Could not find source address for " << dst << " and scope " 
+    << scope << ", returning 0");
+  return addr;  
+}
+
 void 
 Ipv4L3Protocol::SetMetric (uint32_t i, uint16_t metric)
 {
diff -r 74d9ac708677 -r b40d352e92bc src/internet-stack/ipv4-l3-protocol.h
--- a/src/internet-stack/ipv4-l3-protocol.h	Fri Dec 11 11:48:12 2009 -0500
+++ b/src/internet-stack/ipv4-l3-protocol.h	Fri Dec 11 23:23:37 2009 -0800
@@ -176,6 +176,9 @@
   Ipv4InterfaceAddress GetAddress (uint32_t interfaceIndex, uint32_t addressIndex) const;
   uint32_t GetNAddresses (uint32_t interface) const;
   bool RemoveAddress (uint32_t interfaceIndex, uint32_t addressIndex);
+  Ipv4Address SelectSourceAddress (Ptr<const NetDevice> device,
+    Ipv4Address dst, Ipv4InterfaceAddress::InterfaceAddressScope_e scope);
+
 
   void SetMetric (uint32_t i, uint16_t metric);
   uint16_t GetMetric (uint32_t i) const;
diff -r 74d9ac708677 -r b40d352e92bc src/node/ipv4.h
--- a/src/node/ipv4.h	Fri Dec 11 11:48:12 2009 -0500
+++ b/src/node/ipv4.h	Fri Dec 11 23:23:37 2009 -0800
@@ -216,6 +216,44 @@
   virtual bool RemoveAddress (uint32_t interface, uint32_t addressIndex) = 0;
 
   /**
+   * \brief Return the first primary source address with scope less than 
+   * or equal to the requested scope, to use in sending a packet to 
+   * destination dst out of the specified device.
+   *
+   * This method mirrors the behavior of Linux inet_select_addr() and is
+   * provided because interfaces may have multiple IP addresses configured
+   * on them with different scopes, and with a primary and secondary status.
+   * Secondary addresses are never returned.
+   * \see Ipv4InterfaceAddress
+   *
+   * If a non-zero device pointer is provided, the method first tries to
+   * return a primary address that is configured on that device, and whose
+   * subnet matches that of dst and whose scope is less than or equal to
+   * the requested scope.  If a primary address does not match the
+   * subnet of dst but otherwise matches the scope, it is returned.  
+   * If no such address on the device is found, the other devices are 
+   * searched in order of their interface index, but not considering dst
+   * as a factor in the search.  Because a loopback interface is typically 
+   * the first one configured on a node, it will be the first alternate 
+   * device to be tried.  Addresses scoped at LINK scope are not returned
+   * in this phase.
+   * 
+   * If no device pointer is provided, the same logic as above applies, only
+   * that there is no preferred device that is consulted first.  This means
+   * that if the device pointer is null, input parameter dst will be ignored.
+   * 
+   * If there are no possible addresses to return, a warning log message 
+   * is issued and the all-zeroes address is returned.
+   *
+   * \param device output NetDevice (optionally provided, only to constrain the search)
+   * \param dst Destination address to match, if device is provided 
+   * \param scope Scope of returned address must be less than or equal to this
+   * \returns the first primary Ipv4Address that meets the search criteria
+   */
+  virtual Ipv4Address SelectSourceAddress (Ptr<const NetDevice> device, 
+    Ipv4Address dst, Ipv4InterfaceAddress::InterfaceAddressScope_e scope) = 0;
+
+  /**
    * \param interface The interface number of an Ipv4 interface
    * \param metric routing metric (cost) associated to the underlying 
    *          Ipv4 interface