network_service_matcher/smtp/smtp.go

package smtp

import (
	"strings"

	cnsm "git.loafle.net/commons_go/network_service_matcher"
)

type SmtpMatcher struct {
	cnsm.Matchers
}

func (t *SmtpMatcher) ServiceName() string {
	return "SMTP"
}

func (t *SmtpMatcher) String() string {
	return "SMTP"
}

func (t *SmtpMatcher) IsPrePacket() bool {
	return true
}

func (t *SmtpMatcher) HasResponse(index int) bool {
	return true
}

func (t *SmtpMatcher) IsError(info cnsm.MatchInfo, index int, packet *cnsm.Packet) bool {
	return false
}

func (t *SmtpMatcher) Match(info cnsm.MatchInfo, index int, packet *cnsm.Packet) bool {
	if packet == nil {
		return false
	}
	buf := string(packet.Buffer)
	if len(buf) == 0 || len(buf) < 5 {
		return false
	}

	splits := strings.Split(buf, "\r\n")
	splits = strings.Split(buf, " ")
	if index == 0 {
		if splits[0] == "220" {
			return true
		}
	} else if index == 1 {
		if splits[0] == "250" {
			return true
		}
	} else if index == 2 {
		if splits[0] == "221" {
			return true
		}
	}
	return false
}

func NewMatcher() cnsm.Matcher {

	m := &SmtpMatcher{}

	b := []byte("helo test\r\n")
	m.AddPacket(cnsm.NewPacket(b, len(b)))

	b = []byte("quit\r\n")
	m.AddPacket(cnsm.NewPacket(b, len(b)))

	return m
}