comments and refactoring

1 files changed, 30 insertions, 37 deletions

diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index 959e5ff..c2d83ba 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -12,8 +12,6 @@ import (
 	"net/netip"
 	"sync"
 	"time"
-	// "bytes"
-	// "unicode"
 )
 
 const (
@@ -64,8 +62,8 @@ type Hop struct {
 }
 
 // GLOBAL VARIABLES (data structures) ------------------------------------------
-var myVIP Interface
 var myInterfaces []*Interface
+
 var myNeighbors = make(map[string][]*Neighbor)
 
 var myRIPNeighbors = make(map[string]*Neighbor)
@@ -78,6 +76,8 @@ var routingTable = make(map[netip.Prefix]Hop)
 
 // ************************************** INIT FUNCTIONS **********************************************************
 // reference: https://github.com/brown-csci1680/lecture-examples/blob/main/ip-demo/cmd/udp-ip-recv/main.go
+
+// createUDPListener creates a UDP listener.
 func createUDPListener(UdpAddr netip.AddrPort, conn *net.UDPConn) error {
 	listenString := UdpAddr.String()
 	listenAddr, err := net.ResolveUDPAddr("udp4", listenString)
@@ -93,6 +93,7 @@ func createUDPListener(UdpAddr netip.AddrPort, conn *net.UDPConn) error {
 	return nil
 }
 
+// initialize parse the lnxfile and initializes the data structures and listener routines
 func Initialize(lnxFilePath string) error {
 	// Parse the file
 	lnxConfig, err := lnxconfig.ParseConfig(lnxFilePath)
@@ -100,7 +101,7 @@ func Initialize(lnxFilePath string) error {
 		return errors.WithMessage(err, "Error parsing config file->\t"+lnxFilePath)
 	}
 
-	// 1) add each local if to the routing table, as dictated by its subnet
+	// 1) add each local "if" to the routing table, as dictated by its subnet
 	for _, iface := range lnxConfig.Interfaces {
 		prefix := netip.PrefixFrom(iface.AssignedIP, iface.AssignedPrefix.Bits())
 		i := &Interface{
@@ -111,16 +112,20 @@ func Initialize(lnxFilePath string) error {
 			SocketChannel: make(chan bool),
 			State:         true,
 		}
-		// Added this for printing purposes for REPL FYI, if you have a better way lmk
 
+		// create the UDP listener
 		err := createUDPListener(iface.UDPAddr, &i.RecvSocket)
 		if err != nil {
 			return errors.WithMessage(err, "Error creating UDP socket for interface->\t"+iface.Name)
 		}
 
+		// start the listener routine
 		go InterfaceListenerRoutine(i)
+
+		// add to the list of interfaces
 		myInterfaces = append(myInterfaces, i)
 
+		// add to the routing table
 		routingTable[prefix.Masked()] = Hop{LOCAL_COST, "L", i, prefix.Addr()}
 	}
 
@@ -162,10 +167,10 @@ func Initialize(lnxFilePath string) error {
 		}
 	}
 
-	// add protocol handlers
 	return nil
 }
 
+// defines the go routine that listens on the UDP socket
 func InterfaceListenerRoutine(i *Interface) {
 	// decompose the interface
 	socket := i.RecvSocket
@@ -175,8 +180,9 @@ func InterfaceListenerRoutine(i *Interface) {
 	isUp := true
 	closed := false
 
-	// go routine that hangs on the recv
 	// fmt.Println("MAKING GO ROUTINE TO LISTEN:\t", socket.LocalAddr().String())
+
+	// go routine that hangs on the recv
 	go func() {
 		defer func() {
 			fmt.Println("exiting go routine that listens on ", socket.LocalAddr().String())
@@ -186,14 +192,15 @@ func InterfaceListenerRoutine(i *Interface) {
 			if closed { // stop this go routine if channel is closed
 				return
 			}
+
 			//if !isUp { // don't call the listeners if interface is down
 			//	continue
 			//}
+
 			// TODO: remove these "training wheels"
 			time.Sleep(1 * time.Millisecond)
 			err := RecvIP(i, &isUp)
 			if err != nil {
-				// fmt.Println("Error receiving IP packet", err)
 				continue
 			}
 		}
@@ -201,6 +208,7 @@ func InterfaceListenerRoutine(i *Interface) {
 
 	for {
 		select {
+		// if the channel is closed, exit
 		case sig, ok := <-signal:
 			if !ok {
 				fmt.Println("channel closed, exiting")
@@ -209,6 +217,7 @@ func InterfaceListenerRoutine(i *Interface) {
 			}
 			// fmt.Println("received isUP SIGNAL with value", sig)
 			isUp = sig
+		// if the channel is not closed, continue
 		default:
 			continue
 		}
@@ -217,7 +226,9 @@ func InterfaceListenerRoutine(i *Interface) {
 
 // ************************************** DOWN/UP FUNCTIONS ******************************************************
 
+// sets the interface to be up and sends a triggered update
 func InterfaceUp(iface *Interface) {
+	// set the state to up and send the signal
 	iface.State = true
 	iface.SocketChannel <- true
 
@@ -235,12 +246,13 @@ func InterfaceUpREPL(ifaceName string) {
 		fmt.Println("Error getting interface by name", err)
 		return
 	}
+	// set the state to up and send the signal
 	InterfaceUp(iface)
 }
 
-// we could do either of these but the REPL results in less work done in router and host
-
+// sets the interface to be down and sends a triggered update
 func InterfaceDown(iface *Interface) {
+	// set the state to down and send the signal
 	iface.SocketChannel <- false
 	iface.State = false
 
@@ -258,6 +270,7 @@ func InterfaceDownREPL(ifaceName string) {
 		fmt.Println("Error getting interface by name", err)
 		return
 	}
+	// set the state to down and send the signal
 	InterfaceDown(iface)
 }
 
@@ -272,31 +285,6 @@ func GetInterfaceByName(ifaceName string) (*Interface, error) {
 	return nil, errors.Errorf("No interface with name %s", ifaceName)
 }
 
-func GetNeighborByIP(ipAddr string) (*Neighbor, error) {
-	// iterate through the neighbors and return the one with the same ipAddr
-	for _, neighbors := range myNeighbors {
-		for _, neighbor := range neighbors {
-			if neighbor.VipAddr.String() == ipAddr {
-				return neighbor, nil
-			}
-		}
-	}
-
-	return nil, errors.Errorf("No interface with ip %s", ipAddr)
-}
-
-func GetNeighborsToInterface(ifaceName string) ([]*Neighbor, error) {
-	if neighbors, ok := myNeighbors[ifaceName]; ok {
-		return neighbors, nil
-	}
-
-	return nil, errors.Errorf("No interface with name %s", ifaceName)
-}
-
-func GetMyVIP() Interface {
-	return myVIP
-}
-
 func GetInterfaces() []*Interface {
 	return myInterfaces
 }
@@ -311,22 +299,27 @@ func GetRoutes() map[netip.Prefix]Hop {
 
 // ************************************** PRINT FUNCTIONS **********************************************************
 
+// Sprint functions return a string representation of the myInterfaces data structure
 func SprintInterfaces() string {
 	tmp := ""
 	for _, iface := range myInterfaces {
 		if iface.State {
+			// if the state is up, print UP
 			tmp += fmt.Sprintf("%s\t%s\t%s\n", iface.Name, iface.IpPrefix.String(), "UP")
 		} else {
+			// if the state is down, print DOWN
 			tmp += fmt.Sprintf("%s\t%s\t%s\n", iface.Name, iface.IpPrefix.String(), "DOWN")
 		}
 	}
 	return tmp
 }
 
+// Sprint functions return a string representation of the myNeighbors data structure
 func SprintNeighbors() string {
 	tmp := ""
 	for _, iface := range myInterfaces {
 		if !iface.State {
+			// if the interface is down, skip it
 			continue
 		}
 		for _, n := range myNeighbors[iface.Name] {
@@ -1017,7 +1010,7 @@ func LongestPrefix(src netip.Addr) (Hop, error) {
 //			for _, ripNeighbor := range myRIPNeighbors {
 //				if neighbor.VipAddr.String() == ripNeighbor.String() {
 //					// send RIP message
-//					err := SendRIPMessage(myVIP, neighbor, message)
+					// err := SendRIPMessage(myVIP, neighbor, message)
 //					if err != nil {
 //						continue
 //					}
@@ -1107,7 +1100,7 @@ func LongestPrefix(src netip.Addr) (Hop, error) {
 //			// send RIP message
 //			for _, Interfaces := range myInterfaces {
 //				if Interfaces.Name == neighbor.Name {
-//					err := SendRIPMessage(myVIP, neighbor, message)
+					// err := SendRIPMessage(myVIP, neighbor, message)
 //					if err != nil {
 //						continue
 //					}