--- a/CHANGES.html Mon May 24 08:08:25 2010 -0700
+++ b/CHANGES.html Mon May 24 10:52:58 2010 -0700
@@ -62,6 +62,10 @@
list corresponds not to the packet UID but to the sequence of received
packets as observed by the error model. See src/common/error-model.h
</ul>
+<ul><b>Respond to interface events:"</b> New attribute for Ipv4GlobalRouting,
+"RespondToInterfaceEvents", which when enabled, will cause global routes
+to be recomputed upon any interface or address notification event from IPv4.
+</ul>
<h2>Changes to existing API:</h2>
--- a/RELEASE_NOTES Mon May 24 08:08:25 2010 -0700
+++ b/RELEASE_NOTES Mon May 24 10:52:58 2010 -0700
@@ -40,6 +40,7 @@
in IPv4 or IPv6 ascii traces
- ICMPv4 objects not properly registered; affected serialization code
- bug 875 - Set FCS included flag in Radiotap header
+ - bug 702 - Global routing doesn't respond to interface events
Known issues
------------
--- a/doc/manual/routing.texi Mon May 24 08:08:25 2010 -0700
+++ b/doc/manual/routing.texi Mon May 24 10:52:58 2010 -0700
@@ -147,6 +147,16 @@
&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
@end verbatim
+There are two attributes that govern the behavior. The first is
+Ipv4GlobalRouting::RandomEcmpRouting. If set to true, packets are randomly
+routed across equal-cost multipath routes. If set to false (default),
+only one route is consistently used. The second is
+Ipv4GlobalRouting::RespondToInterfaceEvents. If set to true, dynamically
+recompute the global routes upon Interface notification events (up/down,
+or add/remove address). If set to false (default), routing may break
+unless the user manually calls RecomputeRoutingTables() after such events.
+The default is set to false to preserve legacy ns-3 program behavior.
+
@subsection Global Routing Implementation
This section is for those readers who care about how this is implemented.
--- a/examples/routing/dynamic-global-routing.cc Mon May 24 08:08:25 2010 -0700
+++ b/examples/routing/dynamic-global-routing.cc Mon May 24 10:52:58 2010 -0700
@@ -18,7 +18,10 @@
// This script exercises global routing code in a mixed point-to-point
-// and csma/cd environment
+// and csma/cd environment. We bring up and down interfaces and observe
+// the effect on global routing. We explicitly enable the attribute
+// to respond to interface events, so that routes are recomputed
+// automatically.
//
// Network topology
//
@@ -41,33 +44,20 @@
// n1 to n6 is via the direct point-to-point link
// At time 1s, start CBR traffic flow from n1 to n6
// At time 2s, set the n1 point-to-point interface to down. Packets
-// will start to be dropped
-// At time 3s, call RecomputeRoutingTables() and traffic will
-// start flowing again on the alternate path
-// At time 4s, re-enable the n1/n6 interface to up. Will not change routing
-// At time 5s, call RecomputeRoutingTables() and traffic will start flowing
-// again on the original path
+// will be diverted to the n1-n2-n5-n6 path
+// At time 4s, re-enable the n1/n6 interface to up. n1-n6 route restored.
// At time 6s, set the n6-n1 point-to-point Ipv4 interface to down (note, this
-// keeps the point-to-point link "up" from n1's perspective). Packets
-// will traverse the link and be dropped at n6 upon receipt. These drops
-// are not visible in the pcap trace but in the ascii trace.
-// At time 7s, call RecomputeRoutingTables() and traffic will flow again
-// through the path n1-n2-n5-n6
-// At time 8s, bring the interface back up.
-// At time 9s, call RecomputeRoutingTables() and traffic will flow again
-// through the path n1-n6
+// keeps the point-to-point link "up" from n1's perspective). Traffic will
+// flow through the path n1-n2-n5-n6
+// At time 8s, bring the interface back up. Path n1-n6 is restored
// At time 10s, stop the first flow.
// At time 11s, start a new flow, but to n6's other IP address (the one
// on the n1/n6 p2p link)
// At time 12s, bring the n1 interface down between n1 and n6. Packets
-// will start to be dropped
-// At time 13s, call RecomputeRoutingTables() and traffic will
-// start flowing again on the alternate path
+// will be diverted to the alternate path
// At time 14s, re-enable the n1/n6 interface to up. This will change
// routing back to n1-n6 since the interface up notification will cause
// a new local interface route, at higher priority than global routing
-// At time 15s, call RecomputeRoutingTables(), but there is no effect
-// since global routing is lower in priority than static routing
// At time 16s, stop the second flow.
// - Tracing of queues and packet receptions to file "dynamic-global-routing.tr"
@@ -89,6 +79,10 @@
int
main (int argc, char *argv[])
{
+ // The below value configures the default behavior of global routing.
+ // By default, it is disabled. To respond to interface events, set to true
+ Config::SetDefault ("ns3::Ipv4GlobalRouting::RespondToInterfaceEvents", BooleanValue (true));
+
// Allow the user to override any of the defaults and the above
// Bind ()s at run-time, via command-line arguments
CommandLine cmd;
@@ -206,9 +200,7 @@
uint32_t ipv4ifIndex1 = 2;
Simulator::Schedule (Seconds (2),&Ipv4::SetDown,ipv41, ipv4ifIndex1);
- Simulator::Schedule (Seconds (3),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
Simulator::Schedule (Seconds (4),&Ipv4::SetUp,ipv41, ipv4ifIndex1);
- Simulator::Schedule (Seconds (5),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
Ptr<Node> n6 = c.Get (6);
Ptr<Ipv4> ipv46 = n6->GetObject<Ipv4> ();
@@ -216,14 +208,10 @@
// then the next p2p is numbered 2
uint32_t ipv4ifIndex6 = 2;
Simulator::Schedule (Seconds (6),&Ipv4::SetDown,ipv46, ipv4ifIndex6);
- Simulator::Schedule (Seconds (7),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
Simulator::Schedule (Seconds (8),&Ipv4::SetUp,ipv46, ipv4ifIndex6);
- Simulator::Schedule (Seconds (9),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
Simulator::Schedule (Seconds (12),&Ipv4::SetDown,ipv41, ipv4ifIndex1);
- Simulator::Schedule (Seconds (13),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
Simulator::Schedule (Seconds (14),&Ipv4::SetUp,ipv41, ipv4ifIndex1);
- Simulator::Schedule (Seconds (15),&Ipv4GlobalRoutingHelper::RecomputeRoutingTables);
NS_LOG_INFO ("Run Simulation.");
Simulator::Run ();
--- a/src/routing/global-routing/global-routing.h Mon May 24 08:08:25 2010 -0700
+++ b/src/routing/global-routing/global-routing.h Mon May 24 10:52:58 2010 -0700
@@ -33,22 +33,28 @@
* The model assumes that all nodes on an ns-3 channel are reachable to
* one another, regardless of whether the nodes can use the channel
* successfully (in the case of wireless). Therefore, this model
- * should typically be used only on wired topologies. API does not
- * yet exist to control the subset of a topology to which this global
- * static routing is applied.
+ * should typically be used only on wired topologies. Layer-2 bridge
+ * devices are supported. API does not yet exist to control the subset
+ * of a topology to which this global static routing is applied.
*
- * This model also does not yet deal with the possible presence of
- * layer-2 relays such as switches, bridges, and hubs, although ns-3 does
- * not have such devices yet.
+ * If the topology changes during the simulation, by default, routing
+ * will not adjust. There are two ways to make it adjust.
+ * - Set the attribute Ipv4GlobalRouting::RespondToInterfaceEvents to true
+ * - Manually call the sequence of GlobalRouteManager methods to delte global
+ * routes, build global routing database, and initialize routes.
+ * There is a helper method that encapsulates this
+ * (Ipv4GlobalRoutingHelper::RecomputeRoutingTables())
*
* \section api API and Usage
*
* Users must include ns3/global-route-manager.h header file. After the
* IPv4 topology has been built and addresses assigned, users call
* ns3::GlobalRouteManager::PopulateRoutingTables (), prior to the
- * ns3::Simulator::Run() call. There are no other attributes or
- * public methods that are typically called, or ways to parameterize
- * the behavior.
+ * ns3::Simulator::Run() call.
+ *
+ * There are two attributes of Ipv4GlobalRouting that govern behavior.
+ * - Ipv4GlobalRouting::RandomEcmpRouting
+ * - Ipv4GlobalRouting::RespondToInterfaceEvents
*
* \section impl Implementation
*
--- a/src/routing/global-routing/ipv4-global-routing.cc Mon May 24 08:08:25 2010 -0700
+++ b/src/routing/global-routing/ipv4-global-routing.cc Mon May 24 10:52:58 2010 -0700
@@ -17,6 +17,7 @@
//
#include "ns3/log.h"
+#include "ns3/simulator.h"
#include "ns3/object.h"
#include "ns3/packet.h"
#include "ns3/net-device.h"
@@ -24,6 +25,7 @@
#include "ns3/ipv4-routing-table-entry.h"
#include "ns3/boolean.h"
#include "ipv4-global-routing.h"
+#include "global-route-manager.h"
#include <vector>
NS_LOG_COMPONENT_DEFINE ("Ipv4GlobalRouting");
@@ -42,12 +44,18 @@
BooleanValue(false),
MakeBooleanAccessor (&Ipv4GlobalRouting::m_randomEcmpRouting),
MakeBooleanChecker ())
+ .AddAttribute ("RespondToInterfaceEvents",
+ "Set to true if you want to dynamically recompute the global routes upon Interface notification events (up/down, or add/remove address)",
+ BooleanValue(false),
+ MakeBooleanAccessor (&Ipv4GlobalRouting::m_respondToInterfaceEvents),
+ MakeBooleanChecker ())
;
return tid;
}
Ipv4GlobalRouting::Ipv4GlobalRouting ()
-: m_randomEcmpRouting (false)
+: m_randomEcmpRouting (false),
+ m_respondToInterfaceEvents (false)
{
NS_LOG_FUNCTION_NOARGS ();
}
@@ -485,16 +493,52 @@
}
void
Ipv4GlobalRouting::NotifyInterfaceUp (uint32_t i)
-{}
+{
+ NS_LOG_FUNCTION (this << i);
+ if (m_respondToInterfaceEvents && Simulator::Now ().GetSeconds () > 0) // avoid startup events
+ {
+ GlobalRouteManager::DeleteGlobalRoutes ();
+ GlobalRouteManager::BuildGlobalRoutingDatabase ();
+ GlobalRouteManager::InitializeRoutes ();
+ }
+}
+
void
Ipv4GlobalRouting::NotifyInterfaceDown (uint32_t i)
-{}
+{
+ NS_LOG_FUNCTION (this << i);
+ if (m_respondToInterfaceEvents && Simulator::Now ().GetSeconds () > 0) // avoid startup events
+ {
+ GlobalRouteManager::DeleteGlobalRoutes ();
+ GlobalRouteManager::BuildGlobalRoutingDatabase ();
+ GlobalRouteManager::InitializeRoutes ();
+ }
+}
+
void
Ipv4GlobalRouting::NotifyAddAddress (uint32_t interface, Ipv4InterfaceAddress address)
-{}
+{
+ NS_LOG_FUNCTION (this << interface << address);
+ if (m_respondToInterfaceEvents && Simulator::Now ().GetSeconds () > 0) // avoid startup events
+ {
+ GlobalRouteManager::DeleteGlobalRoutes ();
+ GlobalRouteManager::BuildGlobalRoutingDatabase ();
+ GlobalRouteManager::InitializeRoutes ();
+ }
+}
+
void
Ipv4GlobalRouting::NotifyRemoveAddress (uint32_t interface, Ipv4InterfaceAddress address)
-{}
+{
+ NS_LOG_FUNCTION (this << interface << address);
+ if (m_respondToInterfaceEvents && Simulator::Now ().GetSeconds () > 0) // avoid startup events
+ {
+ GlobalRouteManager::DeleteGlobalRoutes ();
+ GlobalRouteManager::BuildGlobalRoutingDatabase ();
+ GlobalRouteManager::InitializeRoutes ();
+ }
+}
+
void
Ipv4GlobalRouting::SetIpv4 (Ptr<Ipv4> ipv4)
{
--- a/src/routing/global-routing/ipv4-global-routing.h Mon May 24 08:08:25 2010 -0700
+++ b/src/routing/global-routing/ipv4-global-routing.h Mon May 24 10:52:58 2010 -0700
@@ -81,6 +81,7 @@
Ipv4GlobalRouting ();
virtual ~Ipv4GlobalRouting ();
+ // These methods inherited from base class
virtual Ptr<Ipv4Route> RouteOutput (Ptr<Packet> p, const Ipv4Header &header, Ptr<NetDevice> oif, Socket::SocketErrno &sockerr);
virtual bool RouteInput (Ptr<const Packet> p, const Ipv4Header &header, Ptr<const NetDevice> idev,
@@ -215,6 +216,8 @@
private:
/// Set to true if packets are randomly routed among ECMP; set to false for using only one route consistently
bool m_randomEcmpRouting;
+ /// Set to true if this interface should respond to interface events by globallly recomputing routes
+ bool m_respondToInterfaceEvents;
/// A uniform random number generator for randomly routing packets among ECMP
UniformVariable m_rand;