Better user input validation, always clear filter slice

config.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bufio"
 	"fmt"
-	"log"
 	"os"
 	"pndpd/modules"
 	"pndpd/pndp"
@@ -13,7 +12,8 @@ import (
 func readConfig(dest string) {
 	file, err := os.Open(dest)
 	if err != nil {
-		log.Fatal(err)
+		fmt.Println("Error:", err.Error())
+		os.Exit(1)
 	}
 	defer func(file *os.File) {
 		_ = file.Close()

main.go

@@ -16,7 +16,7 @@ import (
 var Version = "Development"
 
 func main() {
-	fmt.Println("PNDPD Version", Version, "- Kioubit 2021")
+	fmt.Println("PNDPD Version", Version, "- Kioubit 2022")
 
 	if len(os.Args) <= 2 {
 		printUsage()
@@ -53,7 +53,7 @@ func printUsage() {
 	for i := range modules.ModuleList {
 		for d := range (*modules.ModuleList[i]).Commands {
 			if (*modules.ModuleList[i]).Commands[d].CommandLineEnabled {
-				fmt.Println("pndpd", (*modules.ModuleList[i]).Commands[d].Description)
+				fmt.Println((*modules.ModuleList[i]).Commands[d].Description)
 			}
 		}
 	}

modules/example/example.go

@@ -11,13 +11,13 @@ import (
 // This is an example module
 func init() {
 	commands := []modules.Command{{
-		CommandText:        "command1",
+		CommandText:        "pndpd command1",
 		Description:        "This is the usage description for command1",
 		BlockTerminate:     true,
 		CommandLineEnabled: true,
 		ConfigEnabled:      true,
 	}, {
-		CommandText:        "command2",
+		CommandText:        "pndpd command2",
 		Description:        "This is the usage description for command2",
 		BlockTerminate:     false,
 		CommandLineEnabled: false,

modules/userInterface/userInterface.go

@@ -5,6 +5,7 @@ package userInterface
 
 import (
 	"fmt"
+	"os"
 	"pndpd/modules"
 	"pndpd/pndp"
 	"strings"
@@ -13,19 +14,19 @@ import (
 func init() {
 	commands := []modules.Command{{
 		CommandText:        "proxy",
-		Description:        "proxy <interface1> <interface2> <optional whitelist of CIDRs separated by a semicolon applied to interface2>",
+		Description:        "pndpd proxy <interface1> <interface2> <optional whitelist of CIDRs separated by a semicolon applied to interface2>",
 		BlockTerminate:     true,
 		ConfigEnabled:      true,
 		CommandLineEnabled: true,
 	}, {
 		CommandText:        "responder",
-		Description:        "responder <interface> <optional whitelist of CIDRs separated by a semicolon>",
+		Description:        "pndpd responder <interface> <optional whitelist of CIDRs separated by a semicolon>",
 		BlockTerminate:     true,
 		ConfigEnabled:      true,
 		CommandLineEnabled: true,
 	}, {
 		CommandText:        "modules",
-		Description:        "modules available - list available modules",
+		Description:        "pndpd modules available - list available modules",
 		BlockTerminate:     false,
 		ConfigEnabled:      false,
 		CommandLineEnabled: true,
@@ -114,14 +115,23 @@ func initCallback(callback modules.CallbackInfo) {
 				if strings.HasPrefix(n, "filter") {
 					filter += strings.TrimSpace(strings.TrimPrefix(n, "filter")) + ";"
 					if strings.Contains(n, ";") {
-						panic("Invalid config file syntax")
+						showError("config: the use of semicolons is not allowed in the filter arguments")
 					}
 				}
 				if strings.HasPrefix(n, "autosense") {
 					obj.autosense = strings.TrimSpace(strings.TrimPrefix(n, "autosense"))
 				}
+				if strings.Contains(n, "//") {
+					showError("config: comments are not allowed after arguments")
+				}
 			}
 			obj.Filter = strings.TrimSuffix(filter, ";")
+			if obj.autosense != "" && obj.Filter != "" {
+				showError("config: cannot have both a filter and autosense enabled on a proxy object")
+			}
+			if obj.Iface2 == "" || obj.Iface1 == "" {
+				showError("config: two interfaces need to be specified in the config file for a proxy object. (iface1 and iface2 parameters)")
+			}
 			allProxies = append(allProxies, &obj)
 		case "responder":
 			obj := configResponder{}
@@ -133,13 +143,21 @@ func initCallback(callback modules.CallbackInfo) {
 				if strings.HasPrefix(n, "filter") {
 					filter += strings.TrimSpace(strings.TrimPrefix(n, "filter")) + ";"
 					if strings.Contains(n, ";") {
-						panic("Invalid config file syntax")
+						showError("config: the use of semicolons is not allowed in the filter arguments")
 					}
 				}
 				if strings.HasPrefix(n, "autosense") {
 					obj.autosense = strings.TrimSpace(strings.TrimPrefix(n, "autosense"))
 				}
-
+				if obj.autosense != "" && obj.Filter != "" {
+					showError("config: cannot have both a filter and autosense enabled on a responder object")
+				}
+				if obj.Iface == "" {
+					showError("config: interface not specified in the responder object. (iface parameter)")
+				}
+				if strings.Contains(n, "//") {
+					showError("config: comments are not allowed after arguments")
+				}
 			}
 			obj.Filter = strings.TrimSuffix(filter, ";")
 			allResponders = append(allResponders, &obj)
@@ -169,3 +187,9 @@ func shutdownCallback() {
 		n.instance.Stop()
 	}
 }
+
+func showError(error string) {
+	fmt.Println(error)
+	fmt.Println("Exiting due to error")
+	os.Exit(1)
+}

pndp/flow.go

@@ -35,7 +35,7 @@ type ProxyObj struct {
 // With the optional autosenseInterface argument, the whitelist is configured based on the addresses assigned to the interface specified. This works even if the IP addresses change frequently.
 // Start() must be called on the object to actually start responding
 func NewResponder(iface string, filter []*net.IPNet, autosenseInterface string) *ResponderObj {
-	if filter == nil {
+	if filter == nil && autosenseInterface == "" {
 		fmt.Println("WARNING: You should use a whitelist for the responder unless you really know what you are doing")
 	}
 	var s sync.WaitGroup
@@ -59,7 +59,8 @@ func (obj *ResponderObj) start() {
 	}()
 	go respond(obj.iface, requests, ndp_ADV, nil, obj.filter, obj.autosense, obj.stopWG, obj.stopChan)
 	go listen(obj.iface, requests, ndp_SOL, obj.stopWG, obj.stopChan)
-	fmt.Println("Started responder instance on interface", obj.iface)
+	fmt.Printf("Started responder instance on interface %s", obj.iface)
+	fmt.Println()
 	<-obj.stopChan
 }
 
@@ -130,7 +131,8 @@ func (obj *ProxyObj) start() {
 	go listen(obj.iface2, req_iface2_adv_iface1, ndp_ADV, obj.stopWG, obj.stopChan)
 	go respond(obj.iface1, req_iface2_adv_iface1, ndp_ADV, out_iface2_sol_questions_iface1_adv, nil, "", obj.stopWG, obj.stopChan)
 
-	fmt.Println("Started Proxy instance for interfaces:", obj.iface1, "and", obj.iface2)
+	fmt.Printf("Started Proxy instance on interfaces %s and %s (if enabled, the whitelist is applied on %s)", obj.iface1, obj.iface2, obj.iface2)
+	fmt.Println()
 	<-obj.stopChan
 }
 

pndp/responder.go

@@ -73,6 +73,7 @@ func respond(iface string, requests chan *ndpRequest, respondType ndpType, ndpQu
 		// Auto-sense
 		if autoSense != "" {
 			//TODO Future work: Use another sub goroutine to monitor the interface instead of checking here
+			filter = make([]*net.IPNet, 0)
 			result = selectSourceIP(respondIface)
 			autoiface, err := net.InterfaceByName(autoSense)
 			if err != nil {