try to fix infinite trigger update loop

3 files changed, 17 insertions, 15 deletions

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index ddb5b91..959e5ff 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -596,12 +596,14 @@ func makeRipMessage(command uint16, entries []RIPEntry) []byte {
 	binary.BigEndian.PutUint16(buf[0:2], command)
 	binary.BigEndian.PutUint16(buf[2:4], uint16(len(entries)))
 
-	mask := netip.MustParseAddr("255.255.255.0")
 	for i, entry := range entries {
 		offset := 2*2 + i*SIZE_OF_RIP_ENTRY
 		binary.BigEndian.PutUint32(buf[offset:offset+4], entry.cost) // 0-3 = 4 bytes
 		copy(buf[offset+4:offset+8], entry.prefix.Addr().AsSlice())  // 4-7 = 4 bytes
-		copy(buf[offset+8:offset+12], mask.AsSlice())                // 8-11 = 4 bytes
+
+		ipv4Netmask := uint32(0xffffffff)
+		ipv4Netmask <<= 32 - entry.prefix.Bits()
+		binary.BigEndian.PutUint32(buf[offset+8:offset+12], ipv4Netmask)
 	}
 
 	return buf
@@ -816,16 +818,13 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 			// each field is 4 bytes
 			cost := binary.BigEndian.Uint32(message[offset : offset+4])
 			address, _ := netip.AddrFromSlice(message[offset+4 : offset+8])
-			mask, _ := netip.AddrFromSlice(message[offset+8 : offset+12])
-			// TODO: fix the mask with the correct calculation
-			if mask != netip.MustParseAddr("255.255.255.0") {
-				fmt.Println("mask error")
-			}
-			// add to entries
-			prefix := netip.PrefixFrom(address, 24)
-			entries = append(entries, RIPEntry{prefix, cost})
+			mask := net.IPv4Mask(message[offset+8], message[offset+9], message[offset+10], message[offset+11])
+
+			// make the prefix
+			bits, _ := mask.Size()
+			prefix := netip.PrefixFrom(address, bits)
 
-			// fmt.Println("Received RIP update: ", prefix.String(), cost)
+			entries = append(entries, RIPEntry{prefix, cost})
 		}
 
 		// add to routing table
@@ -851,10 +850,10 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 				if hop.VIP == hdr.Src &&
 					entry.cost > hop.Cost {
 					// fmt.Println("Updating route to ", destination.String(), "with cost", entry.cost)
-					if entry.cost == INFINITY {
+					if entry.cost >= INFINITY {
 						// if we receive infinity from the same neighbor, then delete the route
 						delete(routingTable, destination)
-						triggeredEntries = append(triggeredEntries, RIPEntry{destination, INFINITY})
+						triggeredEntries = append(triggeredEntries, RIPEntry{destination, entry.cost + 1})
 					} else {
 						routingTable[destination] = Hop{entry.cost + 1, "R", src, hdr.Src}
 						triggeredEntries = append(triggeredEntries, RIPEntry{destination, entry.cost + 1})
@@ -880,8 +879,11 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 					mu.Unlock()
 				}
 			} else {
-				routingTable[destination] = Hop{entry.cost + 1, "R", src, hdr.Src}
-				triggeredEntries = append(triggeredEntries, RIPEntry{destination, entry.cost + 1})
+				if entry.cost < INFINITY {
+					// if we receive infinity from the same neighbor, then delete the route
+					routingTable[destination] = Hop{entry.cost + 1, "R", src, hdr.Src}
+					// triggeredEntries = append(triggeredEntries, RIPEntry{destination, entry.cost + 1})
+				}
 			}
 
 			// send out triggered updates
diff --git a/vhost b/vhost
index f641013..ac23975 100755
--- a/vhost
+++ b/vhost
diff --git a/vrouter b/vrouter
index 6708802..5455b09 100755
--- a/vrouter
+++ b/vrouter