probe/ping/ping.go

package ping

import (
	"crypto/tls"
	"fmt"
	"net"
	"strings"
	"time"

	csm "git.loafle.net/overflow/service_matcher-go"
	opm "git.loafle.net/overflow_scanner/probe/matcher"
)

type Res struct {
	Matcher csm.Matcher
	Error   error
}

func Ping(ch chan *Res, ip string, port int, tls bool, portType, key string) {
	go func() {
		conn, err := getConnection(ip, port, portType, tls)
		if err != nil {
			ch <- &Res{nil, err}
			close(ch)
		}
		defer conn.Close()

		m := opm.GetMatcherByKey(key)
		if m.IsPrePacket() {
			processPrepacket(ch, conn, m)
		}
		processPostpacket(ch, conn, m)
	}()
}

func processPrepacket(ch chan *Res, conn net.Conn, m csm.Matcher) {
	for i := 0; i < m.PacketCount(); i++ {
		bytes := make([]byte, 1024)
		n, _ := conn.Read(bytes)
		p := csm.NewPacket(bytes, n)

		_, err := conn.Write(m.Packet(i).Buffer)
		if err != nil {
			ch <- &Res{nil, err}
			close(ch)
		}

		if err := m.Match(nil, i, p); err != nil {
			ch <- &Res{nil, err}
			close(ch)
		}
	}

	ch <- &Res{m, nil}
	close(ch)
}

func processPostpacket(ch chan *Res, conn net.Conn, m csm.Matcher) {
	for i := 0; i < m.PacketCount(); i++ {
		_, err := conn.Write(m.Packet(i).Buffer)
		if err != nil {
			ch <- &Res{nil, err}
			close(ch)
		}

		bytes := make([]byte, 1024)
		n, _ := conn.Read(bytes)
		p := csm.NewPacket(bytes, n)

		if err := m.Match(nil, i, p); err != nil {
			ch <- &Res{nil, err}
			close(ch)
		}
	}
	ch <- &Res{m, nil}
	close(ch)
}

func getConnection(ip string, port int, portType string, isTLS bool) (net.Conn, error) {
	addr := fmt.Sprintf("%s:%d", ip, port)
	portType = strings.ToLower(portType)

	if isTLS {
		dialer := &net.Dialer{
			Timeout: 5 * time.Second,
		}

		return tls.DialWithDialer(
			dialer,
			portType,
			addr,
			&tls.Config{
				InsecureSkipVerify: true,
				ServerName:         ip,
			},
		)
	}
	return net.Dial(portType, addr)
}