TCPScan

TCPScan is a simple utility for discovering open (or closed) TCP ports on servers. It uses gopacket(https://github.com/google/gopacket) to craft SYN packets, listening asynchronously for (SYN-)ACK or RST responses without completing the full TCP handshake. TCPScan uses goroutines for asynchronous scans and it searches for the most likely listening ports first, using NMap's "port frequency" ordering. Anecdotal results show that TCPScan is really fast!

TCPScan is not a replacement for the awesome NMap tool, but it promises to be a useful library for go applications that need a fast and simple TCP port scanning capability.

Using TCPScan as a library

In order to start, go get this repository:

go get github.com/adedayo/tcpscan

Example

In your code simply import as usual and enjoy:

package main

import 
(
    "fmt"
    "github.com/adedayo/tcpscan"
)

func main() {
	result := portscan.ScanCIDR(ipRange)
	for ack := range result {
         fmt.Printf("%s:\tPort %s(%s) is %s\n", ack.Host, ack.Port, ack.GetServiceName(), status(ack))
    }
}

func status(ack portscan.PortACK) string {
	if ack.IsClosed() {
		return "Closed"
	}
	if ack.IsOpen() {
		return "Open"
	}
	return "of Unknown Status"
}

This should produce an output similar to the following:

8.8.8.8:        Port 80(http) is Open
8.8.8.8:        Port 21(ftp) is Open
8.8.8.8:        Port 143(imap) is Open
8.8.8.8:        Port 110(pop3) is Open
8.8.8.8:        Port 113(ident) is Closed
8.8.8.8:        Port 443(https) is Open
8.8.8.8:        Port 8008(http-alt) is Open
8.8.8.8:        Port 119(nntp) is Open
8.8.8.8:        Port 8010 is Open

Using it as a command-line tool

TCPScan is also available as a command-line tool.

Installation

Prebuilt binaries may be found for your operating system here: https://github.com/adedayo/tcpscan/releases

For macOS X, you could install via brew as follows:

brew tap adedayo/tap
brew install tcpscan

Scanning CIDR ranges

tcpscan 192.168.2.5/30 10.11.12.13/31

For JSON-formatted output simply add the --json or -j flag:

tcpscan --json 192.168.2.5/30 10.11.12.13/31

License

BSD 3-Clause License

dean2021 / tcpscan