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Admit possibility that not all nodes are routers.

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This commit is contained in:
Craig Dowell
2008-11-19 18:44:20 -08:00
parent 23b216a600
commit 0f468c97e7
3 changed files with 140 additions and 89 deletions
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3
examples/csma-bridge-one-hop.cc
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@@ -176,7 +176,8 @@ main (int argc, char *argv[])
//
// Create router nodes, initialize routing database and set up the routing
// tables in the nodes.
// tables in the nodes. We excuse the bridge nodes from having to serve as
// routers, since they don't even have internet stacks on them.
//
NodeContainer routerNodes (n0, n1, n2, n3, n4);
GlobalRouteManager::PopulateRoutingTables (routerNodes);

222
src/routing/global-routing/global-router-interface.cc
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@@ -530,6 +530,7 @@ GlobalRouter::DiscoverLSAs (void)
// bridge devices also take up an "extra" net device.
//
uint32_t numDevices = node->GetNDevices();
NS_LOG_LOGIC ("*************************");
NS_LOG_LOGIC ("numDevices = " << numDevices);
//
@@ -538,18 +539,16 @@ GlobalRouter::DiscoverLSAs (void)
// the "everything else" class of devices.
//
// To do this, we wander through all of the devices on the node looking for
// bridge net devices. We then add any net devices associated to a bridge
// to a list of bridged devices. These devices will not be treated as stand-
// alone devices later.
// bridge net devices. We then add any net devices associated with each bridge
// to a list of bridged devices. These devices will be treated as a special
// case later.
//
std::vector<Ptr<NetDevice> > bridgedDevices;
NS_LOG_LOGIC ("*************************");
NS_LOG_LOGIC ("numDevices = " << numDevices);
for (uint32_t i = 0; i < numDevices; ++i)
{
Ptr<NetDevice> nd = node->GetDevice(i);
if (nd->IsBridge ())
{
NS_LOG_LOGIC ("**** Net device " << nd << "is a bridge");
@@ -597,7 +596,7 @@ GlobalRouter::DiscoverLSAs (void)
//
// Check to see if the net device we just got has a corresponding IP
// interface (could be a pure L2 NetDevice).
// interface (could be a pure L2 NetDevice that is not a bridge).
//
bool isIp = false;
for (uint32_t i = 0; i < ipv4Local->GetNInterfaces (); ++i )
@@ -615,6 +614,11 @@ GlobalRouter::DiscoverLSAs (void)
continue;
}
//
// We have a net device that we need to check out. If it suports broadcast and
// is not a point-point link, then it will be either a stub network or a transit
// network depending on the number of routers.
//
if (ndLocal->IsBroadcast () && !ndLocal->IsPointToPoint () )
{
NS_LOG_LOGIC ("**** Broadcast link");
@@ -636,21 +640,26 @@ GlobalRouter::DiscoverLSAs (void)
NS_LOG_LOGIC ("Working with local address " << addrLocal);
uint16_t metricLocal = ipv4Local->GetMetric (ifIndexLocal);
//
// Now, we're going to walk over to the remote net device on the other end of
// the point-to-point channel we now know we have. This is where our adjacent
// router (to use OSPF lingo) is running.
// Check to see if the net device is connected to a channel/network that has
// another router on it. If there is no other router on the link (but us) then
// this is a stub network. If we find another router, then what we have here
// is a transit network.
//
Ptr<Channel> ch = ndLocal->GetChannel();
uint32_t nDevices = ch->GetNDevices();
if (nDevices == 1)
if (AnotherRouterOnLink (ndLocal) == false)
{
// This is a stub broadcast interface
NS_LOG_LOGIC("**** Router-LSA stub broadcast link");
// XXX in future, need to consider if >1 includes other routers
//
// This is a net device connected to a stub network
//
NS_LOG_LOGIC("**** Router-LSA Stub Network");
plr->SetLinkType (GlobalRoutingLinkRecord::StubNetwork);
// Link ID is IP network number of attached network
//
// According to OSPF, the Link ID is the IP network number of
// the attached network.
//
plr->SetLinkId (addrLocal.CombineMask(maskLocal));
// Link Data is network mask; convert to Ipv4Address
//
// and the Link Data is the network mask; converted to Ipv4Address
//
Ipv4Address maskLocalAddr;
maskLocalAddr.Set(maskLocal.Get ());
plr->SetLinkData (maskLocalAddr);
@@ -661,20 +670,28 @@ GlobalRouter::DiscoverLSAs (void)
}
else
{
NS_LOG_LOGIC ("**** Router-LSA Broadcast link");
// multiple routers on a broadcast interface
// lowest IP address is designated router
//
// We have multiple routers on a broadcast interface, so this is
// a transit network.
//
NS_LOG_LOGIC ("**** Router-LSA Transit Network");
plr->SetLinkType (GlobalRoutingLinkRecord::TransitNetwork);
// Link ID is IP interface address of designated router
Ipv4Address desigRtr =
FindDesignatedRouterForLink (node, ndLocal);
//
// By definition, the router with the lowest IP address is the
// designated router for the network. OSPF says that the Link ID
// gets the IP interface address of the designated router in this
// case.
//
Ipv4Address desigRtr = FindDesignatedRouterForLink (ndLocal);
if (desigRtr == addrLocal)
{
listOfDRInterfaces.push_back (ndLocal);
NS_LOG_LOGIC (node->GetId () << " is a DR");
}
plr->SetLinkId (desigRtr);
// Link Data is router's own IP address
//
// OSPF says that the Link Data is this router's own IP address.
//
plr->SetLinkData (addrLocal);
plr->SetMetric (metricLocal);
pLSA->AddLinkRecord (plr);
@@ -787,6 +804,7 @@ GlobalRouter::DiscoverLSAs (void)
// kinds of advertisements (than Router LSAs).
//
m_LSAs.push_back (pLSA);
NS_LOG_LOGIC ("========== Link State Advertisement for node " << node->GetId () << " ==========");
NS_LOG_LOGIC (*pLSA);
//
@@ -795,20 +813,16 @@ GlobalRouter::DiscoverLSAs (void)
//
if (listOfDRInterfaces.size () > 0)
{
NS_LOG_LOGIC ("Build Network LSA");
for (std::list<Ptr<NetDevice> >::iterator i = listOfDRInterfaces.begin ();
i != listOfDRInterfaces.end (); i++)
{
//
// Build one NetworkLSA for each interface that is a DR
// Build one NetworkLSA for each net device talking to a netwok that we are the
// designated router for.
//
Ptr<NetDevice> ndLocal = *i;
//
// We are working with a list of net devices off of the local node
// on which we found a designated router. We assume there must be
// an associated ipv4 interface index.
//
uint32_t ifIndexLocal;
bool rc = FindIfIndexForDevice(node, ndLocal, ifIndexLocal);
NS_ABORT_MSG_IF (rc == false, "GlobalRouter::DiscoverLSAs (): No interface index associated with device");
@@ -823,11 +837,9 @@ GlobalRouter::DiscoverLSAs (void)
pLSA->SetNetworkLSANetworkMask (maskLocal);
pLSA->SetStatus (GlobalRoutingLSA::LSA_SPF_NOT_EXPLORED);
//
// XXX Doesn't deal with bridging
//
// Build a list of AttachedRouters by walking the devices in the channel
// and, if we find an IPv4 interface associated with that device, we
// call it an attached router.
// and, if we find a node with a GlobalRouter interface and an IPv4
// interface associated with that device, we call it an attached router.
//
Ptr<Channel> ch = ndLocal->GetChannel();
uint32_t nDevices = ch->GetNDevices();
@@ -837,15 +849,27 @@ GlobalRouter::DiscoverLSAs (void)
Ptr<NetDevice> tempNd = ch->GetDevice (i);
NS_ASSERT (tempNd);
Ptr<Node> tempNode = tempNd->GetNode ();
//
// Does the node in question have a GlobalRouter interface? If not it can
// hardly be considered an attached router.
//
Ptr<GlobalRouter> rtr = tempNode->GetObject<GlobalRouter> ();
if (rtr == 0)
{
continue;
}
//
// Does the attached node have an ipv4 interface for the device we're probing?
// If not, it can't play router.
//
uint32_t tempIfIndex;
if (FindIfIndexForDevice (tempNode, tempNd, tempIfIndex))
{
Ptr<Ipv4> tempIpv4 = tempNode->GetObject<Ipv4> ();
NS_ASSERT (tempIpv4);
Ipv4Address tempAddr = tempIpv4->GetAddress(tempIfIndex);
pLSA->AddAttachedRouter (tempAddr);
}
}
m_LSAs.push_back (pLSA);
@@ -857,82 +881,108 @@ GlobalRouter::DiscoverLSAs (void)
}
//
// Given a node and an attached net device, we need to walk the channel to which
// the net device is attached and look for the lowest IP address on all of the
// devices attached to that channel. This process is complicated by the fact
// there may be bridge devices associated with any of the net devices attached
// to the channel.
// Given a local net device, we need to walk the channel to which the net device is
// attached and look for nodes with GlobalRouter interfaces on them (one of them
// will be us). Of these, the router with the lowest IP address on the net device
// connecting to the channel becomes the designated router for the link.
//
Ipv4Address
GlobalRouter::FindDesignatedRouterForLink (Ptr<Node> node, Ptr<NetDevice> ndLocal) const
GlobalRouter::FindDesignatedRouterForLink (Ptr<NetDevice> ndLocal) const
{
NS_LOG_FUNCTION_NOARGS ();
NS_LOG_LOGIC("**** For node " << node->GetId () << " for net device " << ndLocal );
uint32_t ifIndexLocal;
bool rc = FindIfIndexForDevice(node, ndLocal, ifIndexLocal);
NS_ABORT_MSG_IF (rc == false, "GlobalRouter::DiscoverLSAs (): No interface index associated with device");
Ptr<Ipv4> ipv4Local = GetObject<Ipv4> ();
NS_ABORT_MSG_UNLESS (ipv4Local, "GlobalRouter::FindDesignatedRouterForLink(): GetObject for <Ipv4> interface failed"
" on node " << node->GetId ());
Ipv4Address addrLocal = ipv4Local->GetAddress(ifIndexLocal);
Ipv4Mask maskLocal = ipv4Local->GetNetworkMask(ifIndexLocal);
Ptr<Channel> ch = ndLocal->GetChannel();
uint32_t nDevices = ch->GetNDevices();
NS_ASSERT (nDevices);
NS_LOG_LOGIC("**** channel " << ch << " has " << nDevices << " net devices");
//
// We now have the channel associated with the net device in question. We
// need to iterate over all of the net devices attached to that channel.
//
Ipv4Address lowest = addrLocal;
Ipv4Address addr ("255.255.255.255");
for (uint32_t i = 0; i < nDevices; i++)
{
Ptr<NetDevice> ndTemp = ch->GetDevice (i);
NS_ASSERT_MSG (ndTemp, "GlobalRouter::FindDesignatedRouterForLink(): Null device attached to channel");
Ptr<NetDevice> currentNd = ch->GetDevice (i);
NS_ASSERT (currentNd);
if (ndTemp == ndLocal)
Ptr<Node> currentNode = currentNd->GetNode ();
NS_ASSERT (currentNode);
//
// We require a designated router to have a GlobalRouter interface and
// an internet stack that includes the Ipv4 interface.
//
Ptr<GlobalRouter> rtr = currentNode->GetObject<GlobalRouter> ();
Ptr<Ipv4> ipv4 = currentNode->GetObject<Ipv4> ();
if (rtr == 0 || ipv4 == 0 )
{
continue;
}
Ptr<Node> nodeTemp = ndTemp->GetNode ();
NS_LOG_LOGIC("**** channel connects to node " << nodeTemp->GetId () << " with net device " << ndTemp);
//
// XXX doesn't admit the possibility of a bridge
// This node could be a designated router, so we can check and see if
// it has a lower IP address than the one we have. In order to have
// an IP address, it needs to have an interface index. If it doesen't
// have an interface index directly, it's probably part of a bridge
// net device XXX which is not yet handled.
//
// If the remote device doesn't have an ipv4 interface index associated
// with it, it cannot be a designated router.
//
uint32_t ifIndexTemp;
bool rc = FindIfIndexForDevice(nodeTemp, ndTemp, ifIndexTemp);
uint32_t currentIfIndex;
bool rc = FindIfIndexForDevice(currentNode, currentNd, currentIfIndex);
if (rc == false)
{
continue;
}
Ptr<Ipv4> ipv4Temp = nodeTemp->GetObject<Ipv4> ();
NS_ASSERT_MSG (ipv4Temp, "GlobalRouter::FindDesignatedRouterForLink(): GetObject for <Ipv4> interface failed"
" on node " << node->GetId ());
//
// Okay, get the IP address corresponding to the interface we're
// examining and if it's the lowest so far, remember it.
//
Ipv4Address currentAddr = ipv4->GetAddress(currentIfIndex);
Ipv4Address addrTemp = ipv4Temp->GetAddress(ifIndexTemp);
NS_LOG_LOGIC("**** net device " << ndTemp << " has Ipv4Address " << addrTemp);
if (addrTemp < addrLocal)
if (currentAddr < addr)
{
addrLocal = addrTemp;
addr = currentAddr;
}
}
return addrLocal;
//
// Return the lowest IP address found, which will become the designated router
// for the link.
//
NS_ASSERT_MSG (addr.IsBroadcast() == false, "GlobalRouter::FindDesignatedRouterForLink(): Bogus address");
return addr;
}
//
// Given a node and an attached net device, take a look off in the channel to
// which the net device is attached and look for a node on the other side
// that has a GlobalRouter interface aggregated.
//
bool
GlobalRouter::AnotherRouterOnLink (Ptr<NetDevice> nd) const
{
NS_LOG_FUNCTION_NOARGS ();
Ptr<Channel> ch = nd->GetChannel();
uint32_t nDevices = ch->GetNDevices();
NS_ASSERT (nDevices);
for (uint32_t i = 0; i < nDevices; i++)
{
Ptr<NetDevice> ndTemp = ch->GetDevice (i);
NS_ASSERT (ndTemp);
if (ndTemp == nd)
{
continue;
}
Ptr<Node> nodeTemp = ndTemp->GetNode ();
NS_ASSERT (nodeTemp);
Ptr<GlobalRouter> rtr = nodeTemp->GetObject<GlobalRouter> ();
if (rtr)
{
return true;
}
}
return false;
}
uint32_t

4
src/routing/global-routing/global-router-interface.h
View File

@@ -640,8 +640,8 @@ private:
Ptr<NetDevice> GetAdjacent(Ptr<NetDevice> nd, Ptr<Channel> ch) const;
bool FindIfIndexForDevice(Ptr<Node> node, Ptr<NetDevice> nd, uint32_t &index) const;
Ipv4Address FindDesignatedRouterForLink (Ptr<Node> node,
Ptr<NetDevice> ndLocal) const;
Ipv4Address FindDesignatedRouterForLink (Ptr<NetDevice> ndLocal) const;
bool AnotherRouterOnLink (Ptr<NetDevice> nd) const;
typedef std::list<GlobalRoutingLSA*> ListOfLSAs_t;
ListOfLSAs_t m_LSAs;