internet: fixes to IPv4 subnet-directed broadcast

RELEASE_NOTES.md

@@ -19,13 +19,16 @@ Release 3-dev
 ### New user-visible features
 
 - (network) !938 - Add class `TimestampTag` for associating a timestamp with a packet.
-- (network) !1163 Initializing an Ipv[4,6]Address from an invalid string do not raise an exception anymore. Instead the address is marked as not initialized.
-- (internet) !1186 `TcpWestwood` model has been removed, and the class has been renamed `TcpWestwoodPlus`.
+- (network) !1163 - Initializing an Ipv[4,6]Address from an invalid string do not raise an exception anymore. Instead the address is marked as not initialized.
+- (internet) !1186 - `TcpWestwood` model has been removed, and the class has been renamed `TcpWestwoodPlus`.
+- (internet) !1229 - You can now ping broadcast addresses.
 
 ### Bugs fixed
 
 - (build) #808 - Handle profile setting changes in the first ns3 run
 - (build) #815 - Configure find_program to search for programs in PATH first, then AppBundles in MacOS
+- (network) !1229 - Fixed a bug in `Ipv4Address::IsSubnetDirectedBroadcast`
+- (internet) !1229 - Fixed a bug in `Icmpv4Header::HandleEcho` when replying to broadcast-type Echo requests, and two bugs in `Ipv4RawSocketImpl::SendTo` in handling sockets bound to a specific address and directed to a broadcast-type address.
 
 Release 3.37
 ------------

src/internet/model/icmpv4-l4-protocol.cc

@@ -300,9 +300,35 @@ Icmpv4L4Protocol::Receive(Ptr<Packet> p,
     p->RemoveHeader(icmp);
     switch (icmp.GetType())
     {
-    case Icmpv4Header::ICMPV4_ECHO:
-        HandleEcho(p, icmp, header.GetSource(), header.GetDestination());
+    case Icmpv4Header::ICMPV4_ECHO: {
+        Ipv4Address dst = header.GetDestination();
+        // We could have received an Echo request to a broadcast-type address.
+        if (dst.IsBroadcast())
+        {
+            Ipv4Address src = header.GetSource();
+            for (uint32_t index = 0; index < incomingInterface->GetNAddresses(); index++)
+            {
+                Ipv4InterfaceAddress addr = incomingInterface->GetAddress(index);
+                if (addr.IsInSameSubnet(src))
+                {
+                    dst = addr.GetAddress();
+                }
+            }
+        }
+        else
+        {
+            for (uint32_t index = 0; index < incomingInterface->GetNAddresses(); index++)
+            {
+                Ipv4InterfaceAddress addr = incomingInterface->GetAddress(index);
+                if (dst == addr.GetBroadcast())
+                {
+                    dst = addr.GetAddress();
+                }
+            }
+        }
+        HandleEcho(p, icmp, header.GetSource(), dst);
         break;
+    }
     case Icmpv4Header::ICMPV4_DEST_UNREACH:
         HandleDestUnreach(p, icmp, header.GetSource(), header.GetDestination());
         break;

src/internet/model/ipv4-raw-socket-impl.cc

@@ -275,10 +275,19 @@ Ipv4RawSocketImpl::SendTo(Ptr<Packet> p, uint32_t flags, const Address& toAddres
         p->AddPacketTag(tag);
     }
 
-    bool subnetDirectedBroadcast = false;
-    if (m_boundnetdevice)
+    Ptr<NetDevice> boundNetDevice = m_boundnetdevice;
+
+    if (!m_src.IsAny())
     {
-        uint32_t iif = ipv4->GetInterfaceForDevice(m_boundnetdevice);
+        int32_t index = ipv4->GetInterfaceForAddress(m_src);
+        NS_ASSERT(index >= 0);
+        boundNetDevice = ipv4->GetNetDevice(index);
+    }
+
+    bool subnetDirectedBroadcast = false;
+    if (boundNetDevice)
+    {
+        uint32_t iif = ipv4->GetInterfaceForDevice(boundNetDevice);
         for (uint32_t j = 0; j < ipv4->GetNAddresses(iif); j++)
         {
             Ipv4InterfaceAddress ifAddr = ipv4->GetAddress(iif, j);
@@ -291,7 +300,6 @@ Ipv4RawSocketImpl::SendTo(Ptr<Packet> p, uint32_t flags, const Address& toAddres
 
     if (dst.IsBroadcast() || subnetDirectedBroadcast)
     {
-        Ptr<NetDevice> boundNetDevice = m_boundnetdevice;
         if (ipv4->GetNInterfaces() == 1)
         {
             boundNetDevice = ipv4->GetNetDevice(0);
@@ -312,6 +320,7 @@ Ipv4RawSocketImpl::SendTo(Ptr<Packet> p, uint32_t flags, const Address& toAddres
             route->SetSource(src);
             route->SetDestination(dst);
             route->SetOutputDevice(boundNetDevice);
+            route->SetGateway("0.0.0.0");
             ipv4->Send(p, route->GetSource(), dst, m_protocol, route);
         }
         else
@@ -324,6 +333,7 @@ Ipv4RawSocketImpl::SendTo(Ptr<Packet> p, uint32_t flags, const Address& toAddres
             route->SetSource(src);
             route->SetDestination(dst);
             route->SetOutputDevice(boundNetDevice);
+            route->SetGateway("0.0.0.0");
             ipv4->SendWithHeader(p, header, route);
         }
         NotifyDataSent(pktSize);

src/network/utils/ipv4-address.cc

@@ -248,7 +248,7 @@ Ipv4Address::IsSubnetDirectedBroadcast(const Ipv4Mask& mask) const
         // broadcast for this address.
         return false;
     }
-    return ((Get() | mask.GetInverse()) == Get());
+    return ((Get() | mask.Get()) == Ipv4Address::GetBroadcast().Get());
 }
 
 bool