1 files changed, 128 insertions, 0 deletions
diff --git a/cmd/vrouter/main.go b/cmd/vrouter/main.go
new file mode 100644
index 0000000..f338b80
--- /dev/null
+++ b/cmd/vrouter/main.go
@@ -0,0 +1,128 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"iptcp/pkg/ipstack"
+	// "iptcp/pkg/tcpstack"
+	"net/netip"
+	"os"
+	"strings"
+	// "strconv"
+)
+
+func main() {
+	// checks that a config file is passed as an argument
+	if len(os.Args) == 1 {
+		fmt.Printf("Usage:  %s <configFile>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	// get config file name from command line argument
+	fileName := os.Args[2]
+
+	// initialize the router with its config file
+	err := ipstack.Initialize(fileName)
+	if err != nil {
+		// return if there is an error
+		return
+	}
+
+	// register the test protocol
+	ipstack.RegisterProtocolHandler(ipstack.TEST_PROTOCOL)
+	// register the rip protocol for the router
+	ipstack.RegisterProtocolHandler(ipstack.RIP_PROTOCOL)
+	// register the TCP protocol for the handler
+	ipstack.RegisterProtocolHandler(ipstack.TCP_PROTOCOL)
+
+
+	// create a scanner to read from stdin for command-line inputs
+	scanner := bufio.NewScanner(os.Stdin)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		tokens := strings.Split(line, " ")
+		switch tokens[0] {
+		// print the interfaces
+		case "li":
+			fmt.Println("Name\tAddr/Prefix\tState")
+			fmt.Println(ipstack.SprintInterfaces())
+		// print the neighbors
+		case "ln":
+			fmt.Println("Iface\tVIP\t\tUDPAddr")
+			fmt.Println(ipstack.SprintNeighbors())
+		// print the routing table
+		case "lr":
+			fmt.Println("T\tPrefix\t\tNext Hop\tCost")
+			fmt.Println(ipstack.SprintRoutingTable())
+		// exit the program
+		case "q":
+			ipstack.CleanUp()
+			os.Exit(0)
+		case "exit":
+			ipstack.CleanUp()
+			os.Exit(0)
+		default:
+			if len(line) > 4 {
+				// disable an interface
+				if line[:4] == "down" {
+					ifaceName := line[5:]
+					ipstack.InterfaceDownREPL(ifaceName)
+				}
+
+				// attempts to send message to destination
+				if line[:4] == "send" {
+					// get IP address and message that follows it
+					IPAndMessage := strings.Split(line, " ")
+					ipAddr := IPAndMessage[1]
+					message := IPAndMessage[2:]
+
+					// combine message into one string
+					messageToSend := strings.Join(message, " ")
+					messageToSendBytes := []byte(messageToSend)
+
+					// get the longest prefix match for the destination
+					address, _ := netip.ParseAddr(ipAddr)
+					hop, err := ipstack.Route(address)
+					if err != nil {
+						fmt.Println(err)
+						continue
+					}
+
+					myAddr := hop.Interface.IpPrefix.Addr()
+					// attempt to send the message to the destination
+					for _, neighbor := range ipstack.GetNeighbors()[hop.Interface.Name] {
+						if neighbor.VipAddr == address ||
+							neighbor.VipAddr == hop.VIP {
+							// send the message to the neighbor
+							bytesWritten, err := ipstack.SendIP(&myAddr, neighbor, ipstack.TEST_PROTOCOL, messageToSendBytes, ipAddr, nil)
+							fmt.Printf("Sent %d bytes to %s\n", bytesWritten, neighbor.VipAddr.String())
+							if err != nil {
+								fmt.Println(err)
+							}
+						}
+					}
+				}
+			}
+			if len(line) > 2 {
+				// enable an interface
+				if line[:2] == "up" {
+					// get interface name
+					ifaceName := line[3:]
+					ipstack.InterfaceUpREPL(ifaceName)
+				}
+			} else {
+				fmt.Println("Invalid command: ", line)
+				fmt.Println("Commands: ")
+				fmt.Println("  exit/q Terminate this program")
+				fmt.Println("    li List interfaces")
+				fmt.Println("    lr List routes")
+				fmt.Println("    ln List available neighbors")
+				fmt.Println("    up Enable an interface")
+				fmt.Println("  down Disable an interface")
+				fmt.Println("  send Send test packet")
+			}
+			continue
+		}
+	}
+}