vde/tuntap.c

   1 /* Copyright 2002 Yon Uriarte and Jeff Dike
   2  * Licensed under the GPL
   3  * This file is part of the original uml_switch code
   4  * Modified 2003 Renzo Davoli
   5  */
   6
   7 #include <stdio.h>
   8 #include <fcntl.h>
   9 #include <errno.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <sys/ioctl.h>
  13 #include <net/if.h>
  14 #include <linux/if_tun.h>
  15 #include "port.h"
  16
  17 void send_tap(int fd, void *packet, int len, void *unused)
  18 {
  19   int n;
  20
  21   n = write(fd, packet, len);
  22   if(n != len){
  23     if(errno != EAGAIN) perror("send_tap");
  24   }
  25 }
  26
  27 int open_tap(char *dev)
  28 {
  29   struct ifreq ifr;
  30   int fd;
  31
  32   if((fd = open("/dev/net/tun", O_RDWR)) < 0){
  33     perror("Failed to open /dev/net/tun");
  34     return(-1);
  35   }
  36   memset(&ifr, 0, sizeof(ifr));
  37   ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  38   strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
  39   if(ioctl(fd, TUNSETIFF, (void *) &ifr) < 0){
  40     perror("TUNSETIFF failed");
  41     close(fd);
  42     return(-1);
  43   }
  44   return(fd);
  45 }