zutils/cmd/network.go

package cmd

import (
	"fmt"
	"net"
	"os/exec"
	"runtime"
	"strings"

	"github.com/zemenawi/zutils/pkg/colors"
)

func NetworkInfoCommand(args []string) error {
	PrintBoxHeader("NETWORK INFORMATION", colors.Cyan)

	PrintSectionHeader("IP ADDRESSES")

	interfaces, err := net.Interfaces()
	if err == nil {
		for _, iface := range interfaces {
			if iface.Flags&net.FlagUp != 0 && iface.Flags&net.FlagLoopback == 0 {
				addrs, err := iface.Addrs()
				if err == nil {
					for _, addr := range addrs {
						var ip net.IP
						switch v := addr.(type) {
						case *net.IPNet:
							ip = v.IP
						case *net.IPAddr:
							ip = v.IP
						}

						if ip != nil && !ip.IsLoopback() {
							fmt.Printf("%s%s🌐%s %s%-18s%s %s\n",
								colors.Green, colors.Bold, colors.Reset,
								colors.Cyan, iface.Name, colors.Reset,
								ip.String())
						}
					}
				}
			}
		}
	} else {
		fmt.Printf("%sError getting network interfaces: %v%s\n", colors.Red, err, colors.Reset)
	}
	fmt.Println()

	PrintSectionHeader("PUBLIC IP")
	publicIP := getPublicIP()
	if publicIP != "" {
		fmt.Printf("%s%s🌍%s Public IP:      %s%s%s\n",
			colors.Green, colors.Bold, colors.Reset,
			colors.Cyan, publicIP, colors.Reset)
	} else {
		fmt.Printf("%sUnable to determine public IP%s\n", colors.Yellow, colors.Reset)
	}
	fmt.Println()

	PrintSectionHeader("DNS INFO")
	dnsServers := getDNSServers()
	for i, dns := range dnsServers {
		fmt.Printf("%s%s🔗%s DNS Server %d:  %s%s%s\n",
			colors.Green, colors.Bold, colors.Reset,
			i+1,
			colors.Cyan, dns, colors.Reset)
	}
	fmt.Println()

	PrintSectionHeader("ACTIVE CONNECTIONS")
	connections := getNetworkConnections()
	if len(connections) > 0 {
		maxShow := 10
		if len(connections) < maxShow {
			maxShow = len(connections)
		}

		headers := []string{"#", "Proto", "State", "Local Address", "Remote Address"}
		data := make([][]string, 0, maxShow)

		for i := 0; i < maxShow; i++ {
			parsed := parseConnection(connections[i])
			row := []string{
				fmt.Sprintf("%d", i+1),
				parsed.proto,
				parsed.state,
				parsed.local,
				parsed.remote,
			}
			data = append(data, row)
		}

		printSimpleTable(headers, data)

		if len(connections) > maxShow {
			fmt.Printf("%s%s...and %d more connections%s\n",
				colors.Gray, colors.Bold, len(connections)-maxShow, colors.Reset)
		}
		fmt.Println()
	} else {
		fmt.Printf("%sNo active connections detected%s\n", colors.Yellow, colors.Reset)
		fmt.Println()
	}

	return nil
}

func getPublicIP() string {
	var cmd *exec.Cmd

	if runtime.GOOS == "windows" {
		cmd = exec.Command("curl", "-s", "ifconfig.me")
	} else {
		cmd = exec.Command("curl", "-s", "ifconfig.me")
	}

	output, err := cmd.CombinedOutput()
	if err == nil {
		return strings.TrimSpace(string(output))
	}

	cmd = exec.Command("wget", "-qO-", "ifconfig.me")
	output, err = cmd.CombinedOutput()
	if err == nil {
		return strings.TrimSpace(string(output))
	}

	return ""
}

func getDNSServers() []string {
	var dnsServers []string

	if runtime.GOOS == "linux" {
		cmd := exec.Command("sh", "-c", "grep '^nameserver' /etc/resolv.conf | awk '{print $2}'")
		output, err := cmd.CombinedOutput()
		if err == nil {
			lines := strings.Split(strings.TrimSpace(string(output)), "\n")
			for _, line := range lines {
				if line != "" {
					dnsServers = append(dnsServers, line)
				}
			}
		}
	} else if runtime.GOOS == "darwin" {
		cmd := exec.Command("scutil", "--dns")
		output, err := cmd.CombinedOutput()
		if err == nil {
			lines := strings.Split(string(output), "\n")
			for _, line := range lines {
				if strings.Contains(line, "nameserver[") {
					parts := strings.Fields(line)
					if len(parts) >= 3 {
						dnsServers = append(dnsServers, parts[2])
					}
				}
			}
		}
	}

	if len(dnsServers) == 0 {
		dnsServers = append(dnsServers, "8.8.8.8 (Google DNS)")
		dnsServers = append(dnsServers, "1.1.1.1 (Cloudflare DNS)")
	}

	return dnsServers
}

func getNetworkConnections() []string {
	var connections []string

	if runtime.GOOS == "linux" {
		cmd := exec.Command("ss", "-tun")
		output, err := cmd.CombinedOutput()
		if err == nil {
			lines := strings.Split(string(output), "\n")
			for i := 1; i < len(lines) && i < 12; i++ {
				line := strings.TrimSpace(lines[i])
				if line != "" {
					connections = append(connections, line)
				}
			}
		}
	} else if runtime.GOOS == "darwin" {
		cmd := exec.Command("netstat", "-an")
		output, err := cmd.CombinedOutput()
		if err == nil {
			lines := strings.Split(string(output), "\n")
			for i := 0; i < len(lines) && i < 11; i++ {
				line := strings.TrimSpace(lines[i])
				if strings.Contains(line, "ESTABLISHED") {
					connections = append(connections, line)
				}
			}
		}
	}

	return connections
}

type connectionInfo struct {
	proto  string
	state  string
	local  string
	remote string
}

func parseConnection(conn string) connectionInfo {
	parts := strings.Fields(conn)
	result := connectionInfo{}

	if len(parts) >= 5 {
		result.proto = parts[0]
		result.state = parts[1]

		// ss output format: proto state recv-q send-q local remote
		// Try to find addresses by position
		for i := 4; i < len(parts); i++ {
			part := parts[i]
			// Look for IP:port patterns
			if strings.Contains(part, ":") && (strings.Contains(part, ".") || strings.Contains(part, ":")) {
				if result.local == "" {
					result.local = part
				} else {
					result.remote = part
				}
			}
		}
	}

	return result
}