Don't trigger ARP/NDP if already resolved

server/device.cpp

@@ -186,10 +186,10 @@ void Device::transmitPacket(PacketBuffer *pktBuf)
 
 void Device::resolveGateway()
 {
-    if (hasIp4_)
+    if (hasIp4_ && !isResolved(ip4Gateway_))
         sendArpRequest(ip4Gateway_);
 
-    if (hasIp6_)
+    if (hasIp6_ && !isResolved(ip6Gateway_))
         sendNeighborSolicit(ip6Gateway_);
 }
 
@@ -368,7 +368,8 @@ void Device::sendArpRequest(PacketBuffer *pktBuf)
 
     tgtIp = ((dstIp & ip4Mask_) == ip4Subnet_) ? dstIp : ip4Gateway_;
 
-    sendArpRequest(tgtIp);
+    if (!isResolved(tgtIp))
+        sendArpRequest(tgtIp);
 
 }
 
@@ -390,7 +391,18 @@ void Device::sendNeighborSolicit(PacketBuffer *pktBuf)
 
     tgtIp = ((dstIp & ip6Mask_) == ip6Subnet_) ? dstIp : ip6Gateway_;
 
-    sendNeighborSolicit(tgtIp);
+    if (!isResolved(tgtIp))
+        sendNeighborSolicit(tgtIp);
+}
+
+bool Device::isResolved(quint32 ip)
+{
+    return arpLookup(ip) > 0;
+}
+
+bool Device::isResolved(UInt128 ip)
+{
+    return ndpLookup(ip) > 0;
 }
 
 //

server/device.h

@@ -106,6 +106,8 @@ protected: // data
 private: // methods
     void sendArpRequest(PacketBuffer *pktBuf);
     void sendNeighborSolicit(PacketBuffer *pktBuf);
+    bool isResolved(quint32 ip);
+    bool isResolved(UInt128 ip);
 
 };
 

server/emuldevice.cpp

@@ -303,14 +303,14 @@ void EmulDevice::sendArpRequest(quint32 tgtIp)
     if (!tgtIp)
         return;
 
+    // FIXME: Now that the caller does a isResolved check, re-evaluate
+    // the below behaviour
     // This function will be called once per unique stream - which
     // may all have the same dst IP; even if dst IP are different the
     // gateway for the different dst IP may all be same. However,
     // we don't want to send duplicate ARP requests, so we check
     // if the tgtIP is already in the cache (resolved or unresolved)
     // and if so, we don't resend it
-    // FIXME: this check needs to happen at caller so that HostDevices
-    // can also benefit from this check
     if (arpTable_.contains(tgtIp))
         return;