fixed split horizon algorithm. also, small bug fixes with RIP request and response.

3 files changed, 21 insertions, 14 deletions

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index 019d97b..c8a4fe8 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -652,7 +652,7 @@ func periodicUpdateRoutine() {
 }
 
 var mu sync.Mutex
-var timeoutTable = make(map[netip.Prefix]int)
+var timeoutTable = make(map[netip.Addr]int)
 var MAX_TIMEOUT = 12
 
 func sendTriggeredUpdates(newEntries []RIPEntry) {
@@ -698,23 +698,28 @@ func manageTimeoutsRoutine() {
 		//mu.Unlock()
 
 		mu.Lock()
-		for prefix, _ := range timeoutTable {
-			timeoutTable[prefix]++
-			if timeoutTable[prefix] == MAX_TIMEOUT {
-				delete(routingTable, prefix)
-				delete(timeoutTable, prefix)
+		for addr, _ := range timeoutTable {
+			timeoutTable[addr]++
+			if timeoutTable[addr] == MAX_TIMEOUT {
+				delete(timeoutTable, addr)
+
+				newEntries := make([]RIPEntry, 0)
+				for p, hop := range routingTable {
+					if hop.VIP == addr {
+						delete(routingTable, p)
+						newEntries = append(newEntries, RIPEntry{p, INFINITY})
+					}
+				}
 				// send triggered update on timeout
-				go func(p netip.Prefix) {
-					newEntries := make([]RIPEntry, 0)
-					newEntries = append(newEntries, RIPEntry{p, INFINITY})
+				if len(newEntries) > 0 {
 					sendTriggeredUpdates(newEntries)
-				}(prefix)
+				}
 			}
 		}
 		// fmt.Println("timeout table: ", timeoutTable)
 		mu.Unlock()
 
-		// fmt.Println("Timeout table: ", timeoutTable)
+		//fmt.Println("Timeout table: ", timeoutTable)
 	}
 }
 
@@ -793,7 +798,7 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 					cost:   cost,
 				})
 		}
-		res := makeRipMessage(2, nil)
+		res := makeRipMessage(2, entries)
 		_, err := SendIP(&hdr.Dst, neighbor, RIP_PROTOCOL, res, hdr.Src.String(), nil)
 		if err != nil {
 			return err
@@ -844,8 +849,10 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 				// then we can increase the cost by that new value
 				if hop.VIP == hdr.Src &&
 					entry.cost > hop.Cost {
+					// fmt.Println("Updating route to ", destination.String(), "with cost", entry.cost)
 					if entry.cost == INFINITY {
-						routingTable[destination] = Hop{entry.cost, "R", src, hdr.Src}
+						// if we receive infinity from the same neighbor, then delete the route
+						delete(routingTable, destination)
 					} else {
 						routingTable[destination] = Hop{entry.cost + 1, "R", src, hdr.Src}
 					}
@@ -864,7 +871,7 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 				// upon an update from this prefix, reset its timeout
 				if hop.Type == "R" {
 					mu.Lock()
-					timeoutTable[destination] = 0
+					timeoutTable[hdr.Src] = 0
 					mu.Unlock()
 				}
 				continue
diff --git a/vhost b/vhost
index e8e274b..88948dc 100755
--- a/vhost
+++ b/vhost
diff --git a/vrouter b/vrouter
index e9ade66..45624ed 100755
--- a/vrouter
+++ b/vrouter