added network scanning code

network_scanner/concurrent_scanning.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"sync"
+)
+
+func main() {
+	// scanning too quickly
+	//for i := 1; i <= 1024; i++ {
+	//	go func(j int) {
+	//		address := fmt.Sprintf("192.168.56.101:%d", j)
+	//		conn, err := net.Dial("tcp", address)
+	//		if err != nil {
+	//			return
+	//		}
+	//		err = conn.Close()
+	//		if err != nil {
+	//			log.Fatal(err)
+	//		}
+	//		fmt.Println("%d open\n", j)
+	//	}(i)
+	//}
+
+	host := "scanme.nmap.org"
+	var wg sync.WaitGroup
+	for i := 1; i < 1024; i++ {
+		wg.Add(1)
+		go func(j int) {
+			defer wg.Done()
+			address := fmt.Sprintf("%s:%d", host, j)
+			conn, err := net.Dial("tcp", address)
+			if err != nil {
+				return
+			}
+			err = conn.Close()
+			if err != nil {
+				fmt.Println("[-] Error closing connection!")
+				return
+			}
+			fmt.Printf("[+] %d open\n", j)
+		}(i)
+	}
+	wg.Wait()
+}

network_scanner/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"sync"
+)
+
+func scanPort(port int, wg *sync.WaitGroup) {
+	defer wg.Done()
+	IP := "192.168.56.101"
+	address := fmt.Sprintf(IP+":%d", port)
+	connection, err := net.Dial("tcp", address)
+	if err == nil {
+		fmt.Printf("[+] Connection established... PORT %v\n", port)
+	} else {
+		fmt.Printf("[-] No connection established... PORT %v\n", port)
+		return
+	}
+	connection.Close()
+}
+
+func main() {
+	var wg sync.WaitGroup
+	for i := 1; i < 100; i++ {
+		wg.Add(1)
+		go scanPort(i, &wg)
+	}
+	wg.Wait()
+	fmt.Println("[+] Execution completed.")
+}

network_scanner/nmap.go

@@ -0,0 +1,5 @@
+package main
+
+func main() {
+
+}

network_scanner/nonconcurrent_scanning.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net"
+)
+
+func main() {
+	// testing for loop
+	//for i := 1; i <= 1024; i++ {
+	//	address := fmt.Sprintf("scanme.nmap.org:%d", i)
+	//	fmt.Println(address)
+	//}
+
+	for i := 1; i <= 1024; i++ {
+		host := "192.168.56.101"
+		address := fmt.Sprintf("%s:%d", host, i)
+		// fmt.Printf("Scanning host: %s\n", address)
+		conn, err := net.Dial("tcp", address)
+		if err != nil {
+			// port is closed or filtered if err != nil
+			continue
+		}
+		err = conn.Close()
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("PORT %d: open\n", i)
+	}
+
+}

network_scanner/notes

@@ -0,0 +1,2 @@
+# bypassing firewalls with port forwarding
+

network_scanner/scanner.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"fmt"
+	"net"
+)
+
+// main contains a basic port scanner
+func main() {
+	_, err := net.Dial("tcp", "scanme.nmap.org:80")
+	if err == nil {
+		fmt.Println("[+] Connection successful.")
+	}
+}

network_scanner/time

@@ -0,0 +1,2 @@
+[+] 22 open
+[+] 80 open