potentially implement reverse poision. fix port sending numbers. fix bug secing bug from router static routes.

1 files changed, 54 insertions, 38 deletions

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index 7a5c235..9aaee28 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -337,26 +337,26 @@ func DebugNeighbors() {
 	}
 }
 
-// TODO @ MICHAEL:
-// func RemoveNeighbor(neighbor Neighbor) {
-// 	// TODO: remove from routing table
-// 	myRoutes := GetRoutes()
-// 	for prefix, hop := range myRoutes {
-// 		if hop.VipAsStr == neighbor.VipAddr.String() {
-// 			delete(myRoutes, prefix)
-// 		}
-// 	}
-
-// 	// TODO: remove from myNeighbors
-// 	myNeighbors[neighbor.VipAddr.String()] = nil
-
-// 	// TODO: close the UDP socket
-// 	err := neighbor.SendSocket.Close()
-// 	if err != nil {
-// 		fmt.Println("Error closing UDP socket", err)
-// 	}
-
-// }
+//// TODO @ MICHAEL:
+//func RemoveNeighbor(neighbor Neighbor) {
+//	// TODO: remove from routing table
+//	myRoutes := GetRoutes()
+//	for prefix, hop := range myRoutes {
+//		if hop.VipAsStr == neighbor.VipAddr.String() {
+//			delete(myRoutes, prefix)
+//		}
+//	}
+//
+//	// TODO: remove from myNeighbors
+//	myNeighbors[neighbor.VipAddr.String()] = nil
+//
+//	// TODO: close the UDP socket
+//	err := neighbor.SendSocket.Close()
+//	if err != nil {
+//		fmt.Println("Error closing UDP socket", err)
+//	}
+//
+//}
 // untested function above
 
 // ************************************** BASIC FUNCTIONS **********************************************************
@@ -441,14 +441,19 @@ func SendIP(src *netip.Addr, dest *Neighbor, protocolNum int, message []byte, de
 	bytesToSend = append(bytesToSend, []byte(message)...)
 
 	sendAddr, err := net.ResolveUDPAddr("udp4", dest.UdpAddr.String())
-	tmpConn, err := net.DialUDP("udp4", nil, sendAddr)
+	// tmpConn, err := net.DialUDP("udp4", nil, sendAddr)
+	// get the interface of this neighbor
 	if err != nil {
 		return errors.WithMessage(err, "Could not bind to UDP port->\t"+dest.UdpAddr.String())
 	}
 
-	bytesWritten, err := tmpConn.Write(bytesToSend)
+	// bytesWritten, err := tmpConn.Write(bytesToSend)
+	// TODO: make this faster by removing call
+	iface, err := GetInterfaceByName(dest.Name)
+	bytesWritten, err := iface.RecvSocket.WriteToUDP(bytesToSend, sendAddr)
 	if err != nil {
-		return err
+		fmt.Println("Error writing to UDP socket")
+		return errors.WithMessage(err, "Error writing to UDP socket")
 	}
 
 	fmt.Printf("Sent %d bytes to %s\n", bytesWritten, dest.VipAddr.String())
@@ -585,28 +590,36 @@ func RecvIP(iface *Interface, isOpen *bool) error {
 func periodicUpdateRoutine() {
 	for {
 		// for each periodic update, we want to send our nodes in the table
-		entries := make([]RIPEntry, len(routingTable))
-		for prefix, hop := range routingTable {
-			entries = append(entries,
-				RIPEntry{
-					address: ConvertIPToUint32(prefix.Addr().String()),
-					mask:    uint32(prefix.Bits()),
-					cost:    hop.Cost,
-				})
-			// fmt.Printf("Sending RIP update: %s\t%d\t%d\n", prefix.Addr().String(), uint32(prefix.Bits()), hop.Cost)
-		}
-
-		// send to each neighbor
 		for _, iface := range myInterfaces {
 			for _, n := range myNeighbors[iface.Name] {
 				_, in := myRIPNeighbors[n.VipAddr.String()]
 				if !in {
 					continue
 				}
+				// TODO: consider making this multithreaded and loops above more efficient
+
+				// if we're here, we are sending this to a rip neighbor
+				entries := make([]RIPEntry, len(routingTable))
+				for prefix, hop := range routingTable {
+					// implement split horizon + poison reverse at entry level
+					var cost uint32
+					if hop.VIP == n.VipAddr {
+						cost = INFINITY
+					} else {
+						cost = hop.Cost
+					}
+					entries = append(entries,
+						RIPEntry{
+							address: ConvertIPToUint32(prefix.Addr().String()),
+							mask:    uint32(prefix.Bits()),
+							cost:    cost,
+						})
+				}
+
 				message := NewRIPMessage(2, entries)
 				err := SendRIPMessage(*iface, n, message)
 				if err != nil {
-					// fmt.Printf("Error sending RIP message to %s\n", n.VipAddr.String())
+					fmt.Printf("Error sending RIP message to %s\n", n.VipAddr.String())
 					continue
 				}
 			}
@@ -846,11 +859,14 @@ func SendRIPMessage(src Interface, dest *Neighbor, message *RIPMessage) error {
 
 	// send RIP message
 	sendAddr, err := net.ResolveUDPAddr("udp4", dest.UdpAddr.String())
-	tmpConn, err := net.DialUDP("udp4", nil, sendAddr)
+	// tmpConn, err := net.DialUDP("udp4", nil, sendAddr)
 	if err != nil {
 		return errors.WithMessage(err, "Could not bind to UDP port->\t"+dest.UdpAddr.String())
 	}
-	_, err = tmpConn.Write(bytesToSend)
+
+	iface, err := GetInterfaceByName(dest.Name)
+	//_, err = tmpConn.Write(bytesToSend)
+	_, err = iface.RecvSocket.WriteToUDP(bytesToSend, sendAddr)
 	if err != nil {
 		return err
 	}