new: improved syn.scan module performances when scanning multiple addresses

modules/syn_scan/tcp_grabber.go

@@ -4,15 +4,25 @@ import (
 	"bufio"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 )
 
+func cleanBanner(banner string) string {
+	clean := ""
+	for _, c := range banner {
+		if strconv.IsPrint(c) {
+			clean += string(c)
+		}
+	}
+	return clean
+}
+
 func tcpGrabber(mod *SynScanner, ip string, port int) string {
 	if conn, err := net.Dial("tcp", fmt.Sprintf("%s:%d", ip, port)); err == nil {
 		defer conn.Close()
 		msg, _ := bufio.NewReader(conn).ReadString('\n')
-		return strings.Trim(msg, "\r\n\t ")
+		return cleanBanner(strings.Trim(msg, "\r\n\t "))
 	}
-
 	return ""
 }