bug fixing

1 files changed, 82 insertions, 61 deletions

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index 51ea07c..0cc1fff 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -11,8 +11,8 @@ import (
 	"net/netip"
 	"time"
 	"encoding/binary"
-	"bytes"
-	"unicode"
+	// "bytes"
+	// "unicode"
 )
 
 const (
@@ -111,7 +111,7 @@ func Initialize(lnxFilePath string) error {
 	}
 
 	// 1) initialize the interfaces on this node here and into the routing table
-	// static := false
+	static := false
 	interfaceToReturn := Interface{}
 	for _, iface := range lnxConfig.Interfaces {
 		prefix := netip.PrefixFrom(iface.AssignedIP, iface.AssignedPrefix.Bits())
@@ -135,6 +135,13 @@ func Initialize(lnxFilePath string) error {
 		}
 		go InterfaceListenerRoutine(i.RecvSocket, i.SocketChannel)
 		myInterfaces = append(myInterfaces, i)
+
+		// TODO @ MICHAEL: The hop shouldn't be the interface name
+		if !static {
+			ifacePrefix := netip.MustParsePrefix("0.0.0.0/0")
+			routingTable[ifacePrefix] = Hop{STATIC_COST, iface.Name, "S"}
+			static = true
+		}
 	}
 
 	// 2) initialize the neighbors connected to the node and into the routing table
@@ -171,7 +178,7 @@ func Initialize(lnxFilePath string) error {
 		routingTable[prefix] = Hop{STATIC_COST, addr.String(), "S"}
 	}
 
-	SendUpdates()
+	go SendUpdates()
 	// add protocol handlers
 	protocolHandlers[RIP_PROTOCOL] = handleRIP
 	protocolHandlers[TEST_PROTOCOL] = handleTestPackets
@@ -296,12 +303,20 @@ func GetRouteByIP(ipAddr string) (*Neighbor, error) {
 			neighbor, err := GetNeighborByIP(hop.VipAsStr)
 			if err != nil {
 				fmt.Println("Error getting neighbors to interface", err)
-				continue // fix with longest prefix matching?
+				neighbor, err = GetRouteByIP(hop.VipAsStr)
+				if err != nil {
+					fmt.Println("Error getting route by IP", err)
+					return nil, err
+				}
+				// continue // fix with longest prefix matching?
 			}
 			return neighbor, nil
 		}
 	}
 
+	if defaultRoute == nil {
+		return nil, errors.Errorf("No route to ip %s", ipAddr)
+	}
 	fmt.Println("returning default route", defaultRoute.VipAddr.String())
 	return defaultRoute, nil
 }
@@ -431,23 +446,41 @@ func CleanUp() {
 }
 
 // TODO: have it take TTL so we can decrement it when forwarding
-func SendIP(src *Interface, dest *Neighbor, protocolNum int, message []byte, destIP string) error {
-	hdr := ipv4header.IPv4Header{
-		Version:  4,
-		Len:      20, // Header length is always 20 when no IP options
-		TOS:      0,
-		TotalLen: ipv4header.HeaderLen + len(message),
-		ID:       0,
-		Flags:    0,
-		FragOff:  0,
-		TTL:      32,
-		Protocol: protocolNum,
-		Checksum: 0, // Should be 0 until checksum is computed
-		Src:      src.IpPrefix.Addr(),
-		Dst:      netip.MustParseAddr(destIP),
-		Options:  []byte{},
+func SendIP(src *Interface, dest *Neighbor, protocolNum int, message []byte, destIP string, hdr *ipv4header.IPv4Header) error {
+	if hdr == nil {
+		hdr = &ipv4header.IPv4Header{
+			Version:  4,
+			Len:      20, // Header length is always 20 when no IP options
+			TOS:      0,
+			TotalLen: ipv4header.HeaderLen + len(message),
+			ID:       0,
+			Flags:    0,
+			FragOff:  0,
+			TTL:      32,
+			Protocol: protocolNum,
+			Checksum: 0, // Should be 0 until checksum is computed
+			Src:      src.IpPrefix.Addr(),
+			Dst:      netip.MustParseAddr(destIP),
+			Options:  []byte{},
+		}
+	} else {
+		hdr = &ipv4header.IPv4Header{
+			Version:  4,
+			Len:      20, // Header length is always 20 when no IP options
+			TOS:      0,
+			TotalLen: ipv4header.HeaderLen + len(message),
+			ID:       0,
+			Flags:    0,
+			FragOff:  0,
+			TTL:      hdr.TTL - 1,
+			Protocol: protocolNum,
+			Checksum: 0, // Should be 0 until checksum is computed
+			Src:      src.IpPrefix.Addr(),
+			Dst:      netip.MustParseAddr(destIP),
+			Options:  []byte{},
+		}
 	}
-
+	
 	// Assemble the header into a byte array
 	headerBytes, err := hdr.Marshal()
 	if err != nil {
@@ -473,8 +506,7 @@ func SendIP(src *Interface, dest *Neighbor, protocolNum int, message []byte, des
 		return err
 	}
 	
-	// TODO @ MICHAEL UPDATE with appropriate src
-	fmt.Printf("Sent %d bytes to %s\n", bytesWritten, dest.UdpAddr.String())
+	fmt.Printf("Sent %d bytes to %s\n", bytesWritten, dest.VipAddr.String())
 
 	return nil
 }
@@ -521,7 +553,6 @@ func RecvIP(conn net.UDPConn, isOpen *bool) error {
 	// Next, get the message, which starts after the header
 	message := buffer[headerSize:]
 
-	// TODO:  handle the message
 	// 1) check if the TTL & checksum is valid
 	TTL := hdr.TTL
 	if TTL == 0 {
@@ -565,6 +596,7 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 	case 1:
 		// request
 		SendUpdates()
+		break
 	case 2:
 		numEntries := message[1]
 
@@ -595,8 +627,11 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 			if _, ok := routingTable[netip.MustParsePrefix(address+"/24")]; ok {
 				continue
 			}
-
-			routingTable[netip.MustParsePrefix(address+"/24")] = Hop{entry.cost + 1, mask, "R"}
+			if entry.cost == 17 {
+				routingTable[netip.MustParsePrefix(address+"/24")] = Hop{0, mask, "R"}
+			} else {
+				routingTable[netip.MustParsePrefix(address+"/24")] = Hop{entry.cost + 1, mask, "R"}
+			}
 		}
 	}
 
@@ -605,15 +640,16 @@ func handleRIP(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.I
 
 func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4header.IPv4Header) error {
 	// 2) check if the message is for me, if so, sendUP (aka call the correct handler)
-	// filter the message, still not the same
-	// TODO @ MICHAEL
-	message = bytes.Map(func(r rune) rune {
-		if unicode.IsPrint(r) {
-			return r
-		}
-		return -1
-	}, message)
-
+	
+	// potentially unneeded
+	// message = bytes.Map(func(r rune) rune {
+	// 	if unicode.IsPrint(r) {
+	// 		return r
+	// 	}
+	// 	return -1
+	// }, message)
+
+	fmt.Println("checking my interfaces")
 	for _, interfaces := range myInterfaces {
 		if hdr.Dst.String() == interfaces.IpPrefix.Addr().String() {
 			fmt.Printf("Received test packet:  Src: %s, Dst: %s, TTL: %d, Data: %s\n",
@@ -622,28 +658,12 @@ func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4
 		}
 	}
 
-	// TODO @ MICHAEL: check if this is correct...
 	// if not, need to forward the packer to a neighbor or check the table
 	// after decrementing TTL and updating checksum
-	hdr.TTL--
-	// update checksum
-	headerBytes, err := hdr.Marshal()
-	if err != nil {
-		log.Fatalln("Error marshalling header:  ", err)
-	}
-
-	hdr.Checksum = int(ComputeChecksum(headerBytes))
-	headerBytes, err = hdr.Marshal()
-	if err != nil {
-		log.Fatalln("Error marshalling header:  ", err)
-	}
-	bytesToSend := make([]byte, 0, len(headerBytes)+len(message))
-	bytesToSend = append(bytesToSend, headerBytes...)
-	bytesToSend = append(bytesToSend, message...)
-
+	// DONE IN SENDIP FUNCTION
 
 	// 3) check if message is for a neighbor, if so, sendIP there
-	// fmt.Println("checking neighbors")
+	fmt.Println("checking neighbors")
 	for _, neighbors := range myNeighbors {
 		for _, neighbor := range neighbors {
 			// check for matching neighbor
@@ -651,7 +671,7 @@ func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4
 				// get the source interface and set dst to it
 				for _, interfaces := range myInterfaces {
 					if interfaces.Name == neighbor.Name {
-						err = SendIP(interfaces, neighbor, hdr.Protocol, bytesToSend, hdr.Dst.String())
+						err := SendIP(interfaces, neighbor, hdr.Protocol, message, hdr.Dst.String(), hdr)
 						if err != nil {
 							fmt.Println(err)
 						}
@@ -663,7 +683,7 @@ func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4
 		}
 	}
 	// 4) check forwarding table. if so, forward to the neighbor with that VIP
-	// fmt.Println("checking routing table")
+	fmt.Println("checking routing table")
 	for prefix, hop := range routingTable {
 		netIP := net.ParseIP(prefix.Addr().String())
 		// check if the destination is in the routing table
@@ -682,7 +702,7 @@ func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4
 				}
 				for _, interfaces := range myInterfaces {
 					if interfaces.Name == neighbor.Name {
-						err = SendIP(interfaces, neighbor, hdr.Protocol, bytesToSend, hdr.Dst.String())
+						err = SendIP(interfaces, neighbor, hdr.Protocol, message, hdr.Dst.String(), hdr)
 						if err != nil {
 							fmt.Println(err)
 						}
@@ -694,7 +714,7 @@ func handleTestPackets(src *Interface, dest *Neighbor, message []byte, hdr *ipv4
 			// get the source interface and set dst to it
 			for _, interfaces := range myInterfaces {
 				if interfaces.Name == neighbor.Name {
-					err = SendIP(interfaces, neighbor, hdr.Protocol, bytesToSend, hdr.Dst.String())
+					err = SendIP(interfaces, neighbor, hdr.Protocol, message, hdr.Dst.String(), hdr)
 					if err != nil {
 						fmt.Println(err)
 					}
@@ -895,17 +915,18 @@ func SendUpdates() {
 			if iface.Name == iface2.Name {
 				continue
 			}
-			// cost should be 0 but it is one
+			// TODO @ MICHAEL: fix this
+			// hardcoded way to get cost to 0, fix if you want a better way
 			entry := &RIPEntry{
 				address: ConvertIPToUint32(iface2.IpPrefix.Addr().String()),
-				cost: LOCAL_COST,
+				cost: 17,
 				mask: ConvertIPToUint32(iface.IpPrefix.Addr().String()),
 			}
 			entries = append(entries, *entry)
 
 			entry = &RIPEntry{
 				address: ConvertIPToUint32(iface.IpPrefix.Addr().String()),
-				cost: LOCAL_COST,
+				cost: 17,
 				mask: ConvertIPToUint32(iface2.IpPrefix.Addr().String()),
 			}
 			entries = append(entries, *entry)
@@ -979,4 +1000,4 @@ func ConvertIPToUint32(ip string) uint32 {
 // 	}
 // }
 
-// TODO @ MICHAEL: Triggereed Updates
\ No newline at end of file
+// TODO @ MICHAEL: Triggered Updates and Split Horizon with Poisoned Reverse
\ No newline at end of file