vde-2/src/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 #include <config.h>
  17 #include <vde.h>
  18 #include <vdecommon.h>
  19
  20 static void Usage(char *name)
  21 {
  22   fprintf(stderr, "Create: %s [-b] [-u owner] [-t device-name] "
  23           "[-f tun-clone-device]\n", name);
  24   fprintf(stderr, "Delete: %s -d device-name [-f tun-clone-device]\n\n",
  25           name);
  26   fprintf(stderr, "The default tun clone device is /dev/net/tun - some systems"
  27           " use\n/dev/misc/net/tun instead\n\n");
  28   fprintf(stderr, "-b will result in brief output (just the device name)\n");
  29   exit(1);
  30 }
  31
  32 int main(int argc, char **argv)
  33 {
  34   struct ifreq ifr;
  35   struct passwd *pw;
  36   long owner = geteuid();
  37   int tap_fd, opt, delete = 0, brief = 0;
  38   char *tun = "", *file = "/dev/net/tun", *name = argv[0], *end;
  39
  40   while((opt = getopt(argc, argv, "bd:f:t:u:")) > 0){
  41     switch(opt) {
  42       case 'b':
  43         brief = 1;
  44         break;
  45       case 'd':
  46         delete = 1;
  47         tun = optarg;
  48         break;
  49       case 'f':
  50         file = optarg;
  51         break;
  52       case 'u':
  53         pw = getpwnam(optarg);
  54         if(pw != NULL){
  55           owner = pw->pw_uid;
  56           break;
  57         }
  58         owner = strtol(optarg, &end, 0);
  59         if(*end != '\0'){
  60           fprintf(stderr, "'%s' is neither a username nor a numeric uid.\n",
  61                   optarg);
  62           Usage(name);
  63         }
  64         break;
  65       case 't':
  66         tun = optarg;
  67         break;
  68       case 'h':
  69       default:
  70         Usage(name);
  71     }
  72   }
  73
  74   argv += optind;
  75   argc -= optind;
  76
  77   if(argc > 0)
  78     Usage(name);
  79
  80   if((tap_fd = open(file, O_RDWR)) < 0){
  81     fprintf(stderr, "Failed to open '%s' : ", file);
  82     perror("");
  83     exit(1);
  84   }
  85
  86   memset(&ifr, 0, sizeof(ifr));
  87
  88   ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  89   strncpy(ifr.ifr_name, tun, sizeof(ifr.ifr_name) - 1);
  90   if(ioctl(tap_fd, TUNSETIFF, (void *) &ifr) < 0){
  91     perror("TUNSETIFF");
  92     exit(1);
  93   }
  94
  95   if(delete){
  96     if(ioctl(tap_fd, TUNSETPERSIST, 0) < 0){
  97       perror("TUNSETPERSIST");
  98       exit(1);
  99     }
 100     printf("Set '%s' nonpersistent\n", ifr.ifr_name);
 101   }
 102   else {
 103     if(ioctl(tap_fd, TUNSETPERSIST, 1) < 0){
 104       perror("TUNSETPERSIST");
 105       exit(1);
 106     }
 107     if(ioctl(tap_fd, TUNSETOWNER, owner) < 0){
 108       perror("TUNSETPERSIST");
 109       exit(1);
 110     }
 111     if(brief)
 112       printf("%s\n", ifr.ifr_name);
 113     else printf("Set '%s' persistent and owned by uid %ld\n", ifr.ifr_name,
 114                 owner);
 115   }
 116   return(0);
 117 }