tests/test-null.c

   1 /* nbdkit
   2  * Copyright (C) 2017-2020 Red Hat Inc.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <config.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include <libnbd.h>
  40
  41 int
  42 main (int argc, char *argv[])
  43 {
  44   struct nbd_handle *nbd;
  45   char wdata[256];
  46   char rdata[2048];
  47   size_t i;
  48
  49   nbd = nbd_create ();
  50   if (nbd == NULL) {
  51     fprintf (stderr, "%s\n", nbd_get_error ());
  52     exit (EXIT_FAILURE);
  53   }
  54
  55   if (nbd_connect_command (nbd,
  56                            (char *[]) {
  57                              "nbdkit", "-s", "--exit-with-parent",
  58                              "null", "100M",
  59                              NULL }) == -1) {
  60     fprintf (stderr, "%s\n", nbd_get_error ());
  61     exit (EXIT_FAILURE);
  62   }
  63
  64   /* The device is writable ... */
  65   memset (wdata, 'x', sizeof wdata);
  66
  67   if (nbd_pwrite (nbd, wdata, sizeof wdata, 1024, 0) == -1) {
  68     fprintf (stderr, "%s\n", nbd_get_error ());
  69     exit (EXIT_FAILURE);
  70   }
  71
  72   /* ... but everything should read back as zeroes. */
  73   if (nbd_pread (nbd, rdata, sizeof rdata, 0, 0) == -1) {
  74     fprintf (stderr, "%s\n", nbd_get_error ());
  75     exit (EXIT_FAILURE);
  76   }
  77
  78   for (i = 0; i < 2048; ++i) {
  79     if (rdata[i] != 0) {
  80       fprintf (stderr, "%s: unexpected non-zero data read\n", argv[0]);
  81       exit (EXIT_FAILURE);
  82     }
  83   }
  84
  85   nbd_close (nbd);
  86   exit (EXIT_SUCCESS);
  87 }