vde-2/tunctl/vde_tunctl.c

   1 /* Copyright 2002 Jeff Dike
   2  * Licensed under the GPL
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <errno.h>
   9 #include <fcntl.h>
  10 #include <unistd.h>
  11 #include <pwd.h>
  12 #include <net/if.h>
  13 #include <sys/ioctl.h>
  14 #include <linux/if_tun.h>
  15
  16 static void Usage(char *name)
  17 {
  18   fprintf(stderr, "Create: %s [-b] [-u owner] [-t device-name] "
  19           "[-f tun-clone-device]\n", name);
  20   fprintf(stderr, "Delete: %s -d device-name [-f tun-clone-device]\n\n",
  21           name);
  22   fprintf(stderr, "The default tun clone device is /dev/net/tun - some systems"
  23           " use\n/dev/misc/net/tun instead\n\n");
  24   fprintf(stderr, "-b will result in brief output (just the device name)\n");
  25   exit(1);
  26 }
  27
  28 int main(int argc, char **argv)
  29 {
  30   struct ifreq ifr;
  31   struct passwd *pw;
  32   long owner = geteuid();
  33   int tap_fd, opt, delete = 0, brief = 0;
  34   char *tun = "", *file = "/dev/net/tun", *name = argv[0], *end;
  35
  36   while((opt = getopt(argc, argv, "bd:f:t:u:")) > 0){
  37     switch(opt) {
  38       case 'b':
  39         brief = 1;
  40         break;
  41       case 'd':
  42         delete = 1;
  43         tun = optarg;
  44         break;
  45       case 'f':
  46         file = optarg;
  47         break;
  48       case 'u':
  49         pw = getpwnam(optarg);
  50         if(pw != NULL){
  51           owner = pw->pw_uid;
  52           break;
  53         }
  54         owner = strtol(optarg, &end, 0);
  55         if(*end != '\0'){
  56           fprintf(stderr, "'%s' is neither a username nor a numeric uid.\n",
  57                   optarg);
  58           Usage(name);
  59         }
  60         break;
  61       case 't':
  62         tun = optarg;
  63         break;
  64       case 'h':
  65       default:
  66         Usage(name);
  67     }
  68   }
  69
  70   argv += optind;
  71   argc -= optind;
  72
  73   if(argc > 0)
  74     Usage(name);
  75
  76   if((tap_fd = open(file, O_RDWR)) < 0){
  77     fprintf(stderr, "Failed to open '%s' : ", file);
  78     perror("");
  79     exit(1);
  80   }
  81
  82   memset(&ifr, 0, sizeof(ifr));
  83
  84   ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  85   strncpy(ifr.ifr_name, tun, sizeof(ifr.ifr_name) - 1);
  86   if(ioctl(tap_fd, TUNSETIFF, (void *) &ifr) < 0){
  87     perror("TUNSETIFF");
  88     exit(1);
  89   }
  90
  91   if(delete){
  92     if(ioctl(tap_fd, TUNSETPERSIST, 0) < 0){
  93       perror("TUNSETPERSIST");
  94       exit(1);
  95     }
  96     printf("Set '%s' nonpersistent\n", ifr.ifr_name);
  97   }
  98   else {
  99     if(ioctl(tap_fd, TUNSETPERSIST, 1) < 0){
 100       perror("TUNSETPERSIST");
 101       exit(1);
 102     }
 103     if(ioctl(tap_fd, TUNSETOWNER, owner) < 0){
 104       perror("TUNSETPERSIST");
 105       exit(1);
 106     }
 107     if(brief)
 108       printf("%s\n", ifr.ifr_name);
 109     else printf("Set '%s' persistent and owned by uid %ld\n", ifr.ifr_name,
 110                 owner);
 111   }
 112   return(0);
 113 }