tests/test-streaming.c

   1 /* nbdkit
   2  * Copyright (C) 2014-2019 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 #include <fcntl.h>
  39 #include <unistd.h>
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42 #include <sys/wait.h>
  43
  44 #include <libnbd.h>
  45
  46 static char data[65536];
  47
  48 int
  49 main (int argc, char *argv[])
  50 {
  51   pid_t md5pid;
  52   struct nbd_handle *nbd;
  53   size_t i;
  54   int pipefd[2];
  55   char md5[33];
  56   int status;
  57
  58   unlink ("streaming.fifo");
  59   if (mknod ("streaming.fifo", S_IFIFO | 0600, 0) == -1) {
  60     perror ("streaming.fifo");
  61     exit (EXIT_FAILURE);
  62   }
  63
  64   nbd = nbd_create ();
  65   if (nbd == NULL) {
  66     fprintf (stderr, "%s\n", nbd_get_error ());
  67     exit (EXIT_FAILURE);
  68   }
  69
  70   char *args[] = {
  71     "nbdkit", "-s", "--exit-with-parent",
  72     "streaming", "pipe=streaming.fifo", "size=640k", NULL
  73   };
  74   if (nbd_connect_command (nbd, args) == -1) {
  75     fprintf (stderr, "%s\n", nbd_get_error ());
  76     exit (EXIT_FAILURE);
  77   }
  78
  79   /* Fork to run a second process which reads from streaming.fifo and
  80    * checks that the content is correct.  The test doesn't care about
  81    * fd leaks, so we don't bother with CLOEXEC.
  82    */
  83   if (pipe (pipefd) == -1) {
  84     perror ("pipe");
  85     exit (EXIT_FAILURE);
  86   }
  87
  88   md5pid = fork ();
  89   if (md5pid == -1) {
  90     perror ("fork");
  91     exit (EXIT_FAILURE);
  92   }
  93
  94   if (md5pid == 0) {
  95     /* Child: run md5sum on the pipe. */
  96     char *exec_argv[] = { "md5sum", NULL };
  97
  98     close (0);
  99     open ("streaming.fifo", O_RDONLY);
 100     close (1);
 101     dup2 (pipefd[1], 1);
 102     close (pipefd[0]);
 103
 104     execvp ("md5sum", exec_argv);
 105     perror ("md5sum");
 106     _exit (EXIT_FAILURE);
 107   }
 108
 109   close (pipefd[1]);
 110
 111   /* Write linearly to the virtual disk. */
 112   memset (data, 1, sizeof data);
 113   for (i = 0; i < 10; ++i) {
 114     if (nbd_pwrite (nbd, data, sizeof data, i * sizeof data, 0) == -1) {
 115       fprintf (stderr, "%s\n", nbd_get_error ());
 116       exit (EXIT_FAILURE);
 117     }
 118   }
 119
 120   /* This kills the nbdkit subprocess, which implicitly closes the
 121    * pipe.
 122    */
 123   nbd_close (nbd);
 124
 125   /* Check the hash computed by the child process. */
 126   if (read (pipefd[0], md5, 32) != 32) {
 127     perror ("read");
 128     exit (EXIT_FAILURE);
 129   }
 130   md5[32] = '\0';
 131
 132   printf ("md5 = %s\n", md5);
 133   if (strcmp (md5, "2c7f81c580f7f9eb52c1bd2f6f493b6f") != 0) {
 134     fprintf (stderr, "unexpected hash: %s\n", md5);
 135     exit (EXIT_FAILURE);
 136   }
 137
 138   if (waitpid (md5pid, &status, 0) == -1) {
 139     perror ("waitpid");
 140     exit (EXIT_FAILURE);
 141   }
 142   if (status != 0) {
 143     fprintf (stderr, "md5sum subprocess failed\n");
 144     exit (EXIT_FAILURE);
 145   }
 146
 147   exit (EXIT_SUCCESS);
 148 }