Added KeepAlive config in tcp listener.

Implemented delete user functionality from ACL.

src/main.go

@@ -156,13 +156,23 @@ func (server *Server) handleConnection(ctx context.Context, conn net.Conn) {
 	for {
 		message, err := utils.ReadMessage(connRW)
 
-		if err != nil && err == io.EOF {
+		if err != nil {
+			if err == io.EOF {
+				// Connection closed
 				break
 			}
-
+			if err, ok := err.(net.Error); ok && err.Timeout() {
-		if err != nil {
+				// Connection timeout
 				fmt.Println(err)
-			continue
+				break
+			}
+			if err, ok := err.(tls.RecordHeaderError); ok {
+				// TLS verification error
+				fmt.Println(err)
+				break
+			}
+			fmt.Println(err)
+			break
 		}
 
 		if cmd, err := utils.Decode(message); err != nil {
@@ -264,7 +274,21 @@ func (server *Server) handleConnection(ctx context.Context, conn net.Conn) {
 
 func (server *Server) StartTCP(ctx context.Context) {
 	conf := server.config
-	var listener net.Listener
+
+	listenConfig := net.ListenConfig{
+		KeepAlive: 200 * time.Millisecond,
+	}
+
+	listener, err := listenConfig.Listen(ctx, "tcp", fmt.Sprintf("%s:%d", conf.BindAddr, conf.Port))
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if !conf.TLS {
+		// TCP
+		fmt.Printf("Starting TCP server at Address %s, Port %d...\n", conf.BindAddr, conf.Port)
+	}
 
 	if conf.TLS {
 		// TLS
@@ -274,23 +298,9 @@ func (server *Server) StartTCP(ctx context.Context) {
 			log.Fatal(err)
 		}
 
-		if l, err := tls.Listen("tcp", fmt.Sprintf("%s:%d", conf.BindAddr, conf.Port), &tls.Config{
+		listener = tls.NewListener(listener, &tls.Config{
 			Certificates: []tls.Certificate{cer},
-		}); err != nil {
+		})
-			log.Fatal(err)
-		} else {
-			listener = l
-		}
-	}
-
-	if !conf.TLS {
-		// TCP
-		fmt.Printf("Starting TCP server at Address %s, Port %d...\n", conf.BindAddr, conf.Port)
-		if l, err := net.Listen("tcp", fmt.Sprintf("%s:%d", conf.BindAddr, conf.Port)); err != nil {
-			log.Fatal(err)
-		} else {
-			listener = l
-		}
 	}
 
 	// Listen to connection

src/modules/acl/acl.go

@@ -12,6 +12,7 @@ import (
 	"os"
 	"path"
 	"strings"
+	"time"
 )
 
 type Password struct {
@@ -133,6 +134,37 @@ func (acl *ACL) RegisterConnection(conn *net.Conn) {
 	}
 }
 
+func (acl *ACL) DeleteUser(usernames []string) error {
+	var user User
+	for _, username := range usernames {
+		if username == "default" {
+			// Skip default user
+			continue
+		}
+		// Extract the user
+		for _, u := range acl.Users {
+			if username == u.Username {
+				user = u
+			}
+		}
+		// Skip if the current username was not found in the ACL
+		if username != user.Username {
+			continue
+		}
+		// Terminate every connection attached to this user
+		for connRef, connection := range acl.Connections {
+			if connection.User.Username == user.Username {
+				(*connRef).SetReadDeadline(time.Now().Add(-1 * time.Second))
+			}
+		}
+		// Delete the user from the ACL
+		acl.Users = utils.Filter(acl.Users, func(u User) bool {
+			return u.Username != user.Username
+		})
+	}
+	return nil
+}
+
 func (acl *ACL) AuthenticateConnection(conn *net.Conn, cmd []string) error {
 	var passwords []Password
 	var user User

src/modules/acl/commands.go

@@ -237,7 +237,13 @@ func (p Plugin) handleSetUser(ctx context.Context, cmd []string, server utils.Se
 }
 
 func (p Plugin) handleDelUser(ctx context.Context, cmd []string, server utils.Server) ([]byte, error) {
-	return nil, errors.New("ACL DELUSER not implemented")
+	if len(cmd) < 3 {
+		return nil, errors.New(utils.WRONG_ARGS_RESPONSE)
+	}
+	if err := p.acl.DeleteUser(cmd[2:]); err != nil {
+		return nil, err
+	}
+	return []byte(utils.OK_RESPONSE), nil
 }
 
 func (p Plugin) handleWhoAmI(ctx context.Context, cmd []string, server utils.Server, conn *net.Conn) ([]byte, error) {
@@ -395,7 +401,7 @@ func NewModule(acl *ACL) Plugin {
 					{
 						Command:     "deluser",
 						Categories:  []string{utils.AdminCategory, utils.SlowCategory, utils.DangerousCategory},
-						Description: "(ACL DELUSER) Deletes users and terminates their connections",
+						Description: "(ACL DELUSER) Deletes users and terminates their connections. Cannot delete default user",
 						Sync:        true,
 						KeyExtractionFunc: func(cmd []string) ([]string, error) {
 							return []string{}, nil