postfix-unix-users

Limit E-Mail access for users using group membership in Postfix
git clone git://git.server.ky/slackcoder/postfix-unix-users
Log | Files | Refs | README

main.go (1566B)

      1 package main
      2 
      3 import (
      4 	"flag"
      5 	"fmt"
      6 	"net"
      7 	"os"
      8 	"os/signal"
      9 	"syscall"
     10 )
     11 
     12 type Flags struct {
     13 	Groups   string
     14 	HostName string
     15 	Listen   string
     16 	StdErr   string
     17 }
     18 
     19 func ParseArgs() (*Flags, []string) {
     20 	var flags Flags
     21 
     22 	name, _ := os.Hostname()
     23 
     24 	flag.StringVar(&flags.Groups, "groups", "/etc/postfix/user_groups", "User group list")
     25 	flag.StringVar(&flags.HostName, "hostname", name, "E-Mail hostname")
     26 	flag.StringVar(&flags.Listen, "listen", "-", "listen socket path")
     27 	flag.StringVar(&flags.StdErr, "std-err", name, "Redirect errors to filepath")
     28 
     29 	flag.Parse()
     30 
     31 	return &flags, flag.Args()
     32 }
     33 
     34 func handleSignal(c <-chan os.Signal, listenner net.Listener) {
     35 	for v := range c {
     36 		switch v {
     37 		case syscall.SIGINT:
     38 			_ = listenner.Close()
     39 		default:
     40 		}
     41 	}
     42 }
     43 
     44 func exitOnErr(err error) {
     45 	if err != nil {
     46 		fmt.Fprintln(os.Stderr, err.Error())
     47 		os.Exit(1)
     48 	}
     49 }
     50 
     51 func main() {
     52 	flags, groups := ParseArgs()
     53 
     54 	if flags.StdErr != "" {
     55 		f, _ := os.OpenFile(flags.StdErr, os.O_APPEND|os.O_RDWR|os.O_CREATE, 0666)
     56 		os.Stderr = f
     57 		defer f.Close()
     58 	}
     59 
     60 	srv := &Server{
     61 		HostName:   flags.HostName,
     62 		GroupsFile: flags.Groups,
     63 		Groups:     groups,
     64 	}
     65 
     66 	if flags.Listen == "-" {
     67 		srv.HandleConn(os.Stdout, os.Stdin)
     68 
     69 		return
     70 	}
     71 
     72 	listenner, err := net.Listen("unix", flags.Listen)
     73 	exitOnErr(err)
     74 	defer os.Remove(flags.Listen)
     75 
     76 	err = os.Chmod(flags.Listen, os.ModePerm)
     77 	exitOnErr(err)
     78 
     79 	c := make(chan os.Signal, 1)
     80 	signal.Notify(c, syscall.SIGHUP, syscall.SIGINT)
     81 	go handleSignal(c, listenner)
     82 
     83 	err = ServeUnixSocket(listenner, srv)
     84 	exitOnErr(err)
     85 }