test/tvnd.c

   1 /* Tests for the VND driver API.  Part of testvnd.sh. */
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <sys/ioctl.h>
   5 #include <unistd.h>
   6 #include <fcntl.h>
   7 #include <errno.h>
   8 #include <string.h>
   9
  10 /*
  11  * For now, just test the most dreaded case: the driver being told to use the
  12  * file descriptor used to configure the device.  Without appropriate checks,
  13  * this would cause a deadlock in VFS, since the corresponding filp object is
  14  * locked to perform the ioctl(2) call when VFS gets the copyfd(2) back-call.
  15  */
  16 int
  17 main(int argc, char **argv)
  18 {
  19         struct vnd_ioctl vnd;
  20         int fd;
  21
  22         if (argc != 2) {
  23                 fprintf(stderr, "usage: %s /dev/vnd0\n", argv[0]);
  24                 return EXIT_FAILURE;
  25         }
  26
  27         if ((fd = open(argv[1], O_RDONLY)) < 0) {
  28                 perror("open");
  29                 return EXIT_FAILURE;
  30         }
  31
  32         memset(&vnd, 0, sizeof(vnd));
  33
  34         if (ioctl(fd, VNDIOCCLR, &vnd) < 0) {
  35                 perror("ioctl(VNDIOCCLR)");
  36                 return EXIT_FAILURE;
  37         }
  38
  39         vnd.vnd_fildes = fd;
  40
  41         if (ioctl(fd, VNDIOCSET, &vnd) >= 0) {
  42                 fprintf(stderr, "ioctl(VNDIOCSET): unexpected success\n");
  43                 return EXIT_FAILURE;
  44         }
  45
  46         if (errno != EBADF) {
  47                 perror("ioctl(VNDIOCSET)");
  48                 return EXIT_FAILURE;
  49         }
  50
  51         close(fd);
  52
  53         return EXIT_SUCCESS;
  54 }