From a0470760a9f46666b60e4459dba04e0489ff49e3 Mon Sep 17 00:00:00 2001
From: Rene <rene@manqueros.com>
Date: Tue, 27 Sep 2022 18:06:32 -0600
Subject: [PATCH] Feature/multithreaded_arpscan :: Made ARP Scan run in
 multiple threads to speed up detection

---
 src/arpscan.go | 87 ++++++++++++++++++++++++++++----------------------
 1 file changed, 48 insertions(+), 39 deletions(-)

diff --git a/src/arpscan.go b/src/arpscan.go
index f3c4fb7..98960de 100644
--- a/src/arpscan.go
+++ b/src/arpscan.go
@@ -1,55 +1,64 @@
 package main
 
 import (
-    "log"
-    "os/exec"
-    "strings"
+	"log"
+	"os/exec"
+	"strings"
+	"sync"
 	"time"
 )
 
-func scan_iface(iface string) (string) {
-    cmd, err := exec.Command("arp-scan", "-glNx", "-I", iface).Output()
-    if err != nil {
-        return string("")
-    } else {
-        return string(cmd)
-    }
+func scan_iface(iface string) string {
+	cmd, err := exec.Command("arp-scan", "-glNx", "-I", iface).Output()
+	if err != nil {
+		return string("")
+	} else {
+		return string(cmd)
+	}
 }
 
-func parse_output(text string) ([]Host) {    
-    var foundHosts = []Host{}
+func parse_output(text string) []Host {
+	var foundHosts = []Host{}
 
-    perString := strings.Split(text, "\n")
+	perString := strings.Split(text, "\n")
 	currentTime := time.Now()
 
-    for _, host := range perString {
-        if host != "" {
-            var oneHost Host
-            p := strings.Split(host, "	")
-            oneHost.Ip = p[0]
-            oneHost.Mac = p[1]
-            oneHost.Hw = p[2]
+	for _, host := range perString {
+		if host != "" {
+			var oneHost Host
+			p := strings.Split(host, "	")
+			oneHost.Ip = p[0]
+			oneHost.Mac = p[1]
+			oneHost.Hw = p[2]
 			oneHost.Date = currentTime.Format("2006-01-02 15:04:05")
-            oneHost.Now = 1
-            foundHosts = append(foundHosts, oneHost)
-        }
-    }
+			oneHost.Now = 1
+			foundHosts = append(foundHosts, oneHost)
+		}
+	}
 
-    return foundHosts
+	return foundHosts
 }
 
-func arp_scan() ([]Host) {
-    var text string
-    var foundHosts = []Host{}
+func arp_scan() []Host {
+	var foundHosts = []Host{}
+	perString := strings.Split(AppConfig.Iface, " ")
+	wg := sync.WaitGroup{}
+	wg.Add(len(perString))
+	arpScanMutex := &sync.Mutex{}
 
-    perString := strings.Split(AppConfig.Iface, " ")
-
-    for _, iface := range perString {
-        log.Println("INFO: scanning interface", iface)
-        text = scan_iface(iface)
-        log.Println("INFO: found IPs:", text)
-        foundHosts = append(foundHosts, parse_output(text)...)
-    }
-
-    return foundHosts
-}
\ No newline at end of file
+	for _, iface := range perString {
+		// Multi thread arp-scan
+		go func(thisInterface string) {
+			log.Println("INFO: scanning interface", thisInterface)
+			text := scan_iface(thisInterface)
+			log.Println("INFO: found IPs:", text)
+			parsedHosts := parse_output(text)
+			arpScanMutex.Lock()
+			foundHosts = append(foundHosts, parsedHosts...)
+			arpScanMutex.Unlock()
+			wg.Done()
+		}(iface)
+	}
+	wg.Wait()
+	return foundHosts
+}