Commit initial
This commit is contained in:
+178
@@ -0,0 +1,178 @@
|
||||
// mxrouter
|
||||
// Copyright (c) 2020 yo000 <johan@nosd.in>
|
||||
//
|
||||
//
|
||||
|
||||
// checkmx : postfix tcp_table server which returns second-level domain name of the MX of a domain
|
||||
// ex :
|
||||
// "get cfnews.net"
|
||||
// returns : 200 google.com
|
||||
//
|
||||
// Use a single LDAP connection protected by a mutex
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"log"
|
||||
"log/syslog"
|
||||
"net"
|
||||
"os"
|
||||
"flag"
|
||||
"strings"
|
||||
"sync"
|
||||
|
||||
"github.com/go-ldap/ldap/v3"
|
||||
"github.com/peterbourgon/ff"
|
||||
)
|
||||
|
||||
const (
|
||||
version = "0.8"
|
||||
)
|
||||
|
||||
var (
|
||||
logstream *syslog.Writer
|
||||
mutex sync.Mutex
|
||||
debug *bool
|
||||
listen *string
|
||||
ldapURL *string
|
||||
ldapBaseDN *string
|
||||
ldapUser *string
|
||||
ldapPass *string
|
||||
)
|
||||
|
||||
func handleConnection(connClt net.Conn, conLdap *ldap.Conn) {
|
||||
buf := make([]byte, 1024)
|
||||
|
||||
defer connClt.Close()
|
||||
readlen, err := connClt.Read(buf)
|
||||
if err != nil {
|
||||
fmt.Println("Error reading:", err.Error())
|
||||
}
|
||||
|
||||
// 1) Recupere le MX du domaine de l'adresse mail recue
|
||||
if strings.HasPrefix(string(buf[:readlen-1]), "get ") && strings.Contains(string(buf[:readlen-1]), "@") {
|
||||
mail := string(buf[4:readlen-1])
|
||||
domain := strings.Split(mail, "@")[1]
|
||||
mxs, err := net.LookupMX(domain)
|
||||
if err != nil {
|
||||
logstream.Err(fmt.Sprintln("Error lookup mx: ", err))
|
||||
s := strings.Replace(fmt.Sprintf("Error lookup MX: %s", err.Error()), " ", "%20", -1)
|
||||
response := fmt.Sprintf("500 %s\n", s)
|
||||
connClt.Write([]byte(response))
|
||||
return
|
||||
}
|
||||
// 2) Requete LDAP pour voir si le domaine de second niveau du MX possede un routage particulier
|
||||
// Protection contre ca : example.org. 72 IN MX 0 .
|
||||
// Considerons qu'il n'y aura jamais de "one letter TLD"
|
||||
if len(mxs[0].Host) < 4 {
|
||||
logstream.Err(fmt.Sprintln("No usable mx found"))
|
||||
s := strings.Replace("No usable MX found", " ", "%20", -1)
|
||||
resp := fmt.Sprintf("500 %s\n", s)
|
||||
connClt.Write([]byte(resp))
|
||||
return
|
||||
}
|
||||
|
||||
mxslic := strings.Split(mxs[0].Host, ".")
|
||||
// les MXs terminent par '.', on le retire
|
||||
mxdom := strings.Join(mxslic[len(mxslic)-3:len(mxslic)-1], ".")
|
||||
|
||||
filter := fmt.Sprintf("(dc=%s)", ldap.EscapeFilter(mxdom))
|
||||
searchReq := ldap.NewSearchRequest(*ldapBaseDN, ldap.ScopeWholeSubtree, 0, 0, 0,
|
||||
false, filter, []string{"relayName"}, []ldap.Control{})
|
||||
|
||||
mutex.Lock()
|
||||
result, err := conLdap.Search(searchReq)
|
||||
mutex.Unlock()
|
||||
if err != nil {
|
||||
logstream.Err(fmt.Sprintln("Error searching into LDAP: ", err))
|
||||
s := strings.Replace(err.Error(), " ", "%20", -1)
|
||||
response := fmt.Sprintf("500 %s\n", s)
|
||||
connClt.Write([]byte(response))
|
||||
return
|
||||
}
|
||||
|
||||
if len(result.Entries) != 1 {
|
||||
if *debug {
|
||||
logstream.Debug("Got no result, returning 500")
|
||||
}
|
||||
s := strings.Replace("No route defined", " ", "%20", -1)
|
||||
response := fmt.Sprintf("500 %s\n", s)
|
||||
connClt.Write([]byte(response))
|
||||
return
|
||||
}
|
||||
if *debug {
|
||||
logstream.Debug("Got result, returning " + result.Entries[0].Attributes[0].Values[0])
|
||||
}
|
||||
s := strings.Replace(fmt.Sprintf("FILTER relay:[%s]", result.Entries[0].Attributes[0].Values[0]), " ", "%20", -1)
|
||||
connClt.Write([]byte(fmt.Sprintf("200 %s\n", s)))
|
||||
} else {
|
||||
if *debug {
|
||||
logstream.Debug("Incorrect input format : " + string(buf[:readlen-1]))
|
||||
}
|
||||
s := strings.Replace("Incorrect input format", " ", "%20", -1)
|
||||
response := fmt.Sprintf("500 %s\n", s)
|
||||
connClt.Write([]byte(response))
|
||||
return
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
func run() {
|
||||
logstream.Info("start")
|
||||
defer logstream.Info("exit")
|
||||
listener, err := net.Listen("tcp", *listen)
|
||||
if err != nil {
|
||||
log.Fatal(fmt.Sprintln("Error listening: ", err))
|
||||
}
|
||||
|
||||
conLdap, err := ldap.DialURL(*ldapURL)
|
||||
defer conLdap.Close()
|
||||
|
||||
err = conLdap.Bind(*ldapUser, *ldapPass)
|
||||
if err != nil {
|
||||
logstream.Err(fmt.Sprintln("Error binding LDAP: ", err))
|
||||
return
|
||||
}
|
||||
|
||||
for {
|
||||
connClt, err := listener.Accept()
|
||||
if err != nil {
|
||||
logstream.Err(fmt.Sprintln("Error accepting: ", err))
|
||||
}
|
||||
go handleConnection(connClt, conLdap)
|
||||
}
|
||||
}
|
||||
|
||||
func main() {
|
||||
var e error
|
||||
|
||||
fs := flag.NewFlagSet("mxrouter", flag.ExitOnError)
|
||||
listen = fs.String("listen-addr", "127.0.0.1:8080", "listen address for server (also via LISTEN env var)")
|
||||
debug = fs.Bool("debug", false, "log debug information (also via DEBUG env var)")
|
||||
ldapURL = fs.String("ldap", "", "LDAP Server URL (also via LDAP env var)")
|
||||
ldapBaseDN = fs.String("ldapDN", "", "LDAP base DN (also via LDAPDN env var)")
|
||||
ldapUser = fs.String("ldapUser", "", "LDAP user DN (also via LDAPUSER env var)")
|
||||
ldapPass = fs.String("ldapPass", "", "LDAP user password (also via LDAPPASS env var)")
|
||||
_ = fs.String("config", "", "config file (optional)")
|
||||
|
||||
// Surcharge de la fonction Usage()
|
||||
fs.Usage = func() {
|
||||
fmt.Fprintf(flag.CommandLine.Output(), "%s version %s\n", os.Args[0], version)
|
||||
fmt.Fprintf(flag.CommandLine.Output(), "Usage:\n")
|
||||
fs.PrintDefaults()
|
||||
}
|
||||
ff.Parse(fs, os.Args[1:], ff.WithEnvVarNoPrefix(), ff.WithConfigFileFlag("config"), ff.WithConfigFileParser(ff.PlainParser))
|
||||
|
||||
if len(*ldapURL) == 0 || len(*ldapBaseDN) == 0 || len (*ldapUser) == 0 || len(*ldapPass) == 0 {
|
||||
fs.Usage()
|
||||
return
|
||||
}
|
||||
|
||||
if logstream, e = syslog.New(syslog.LOG_MAIL, "mxrouter"); e != nil {
|
||||
log.Fatal(e)
|
||||
}
|
||||
defer logstream.Close()
|
||||
run()
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user