tests/test-socket-activation.c

   1 /* nbdkit
   2  * Copyright (C) 2017-2019 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 /* Test socket activation.
  34  *
  35  * We cannot use the test framework for this since the framework
  36  * always uses the -U flag which is incompatible with socket
  37  * activation.  Unfortunately this does mean we duplicate some code
  38  * from the test framework.
  39  *
  40  * It's *almost* possible to test this from a shell script
  41  * (cf. test-ip.sh) but as far as I can tell setting LISTEN_PID
  42  * correctly is impossible from shell.
  43  */
  44
  45 #include <config.h>
  46
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <stdint.h>
  50 #include <inttypes.h>
  51 #include <string.h>
  52 #include <fcntl.h>
  53 #include <unistd.h>
  54 #include <signal.h>
  55 #include <errno.h>
  56 #include <sys/types.h>
  57 #include <sys/socket.h>
  58 #include <sys/un.h>
  59 #include <sys/wait.h>
  60
  61 #ifndef SOCK_CLOEXEC
  62 /* For this file, we don't care if fds are marked cloexec; leaking is okay.  */
  63 #define SOCK_CLOEXEC 0
  64 #endif
  65
  66 #define FIRST_SOCKET_ACTIVATION_FD 3
  67
  68 #define NBDKIT_START_TIMEOUT 30 /* seconds */
  69
  70 /* Declare program_name. */
  71 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
  72 #include <errno.h>
  73 #define program_name program_invocation_short_name
  74 #else
  75 #define program_name "nbdkit"
  76 #endif
  77
  78 static char tmpdir[] =   "/tmp/nbdkitXXXXXX";
  79 static char sockpath[] = "/tmp/nbdkitXXXXXX/sock";
  80 static char pidpath[] =  "/tmp/nbdkitXXXXXX/pid";
  81
  82 static pid_t pid = 0;
  83
  84 static void
  85 cleanup (void)
  86 {
  87   int status;
  88
  89   if (pid > 0) {
  90     kill (pid, SIGTERM);
  91
  92     /* Check the status of nbdkit is normal on exit. */
  93     if (waitpid (pid, &status, 0) == -1) {
  94       perror ("waitpid");
  95       _exit (EXIT_FAILURE);
  96     }
  97     if (WIFEXITED (status) && WEXITSTATUS (status) != 0) {
  98       _exit (WEXITSTATUS (status));
  99     }
 100     if (WIFSIGNALED (status)) {
 101       /* Note that nbdkit is supposed to catch the signal we send and
 102        * exit cleanly, so the following shouldn't happen.
 103        */
 104       fprintf (stderr, "nbdkit terminated by signal %d\n", WTERMSIG (status));
 105       _exit (EXIT_FAILURE);
 106     }
 107     if (WIFSTOPPED (status)) {
 108       fprintf (stderr, "nbdkit stopped by signal %d\n", WSTOPSIG (status));
 109       _exit (EXIT_FAILURE);
 110     }
 111   }
 112
 113   unlink (pidpath);
 114   unlink (sockpath);
 115   rmdir (tmpdir);
 116 }
 117
 118 int
 119 main (int argc, char *argv[])
 120 {
 121   int sock;
 122   struct sockaddr_un addr;
 123   char pid_str[16];
 124   size_t i, len;
 125   char magic[8];
 126
 127   if (mkdtemp (tmpdir) == NULL) {
 128     perror ("mkdtemp");
 129     exit (EXIT_FAILURE);
 130   }
 131   len = strlen (tmpdir);
 132   memcpy (sockpath, tmpdir, len);
 133   memcpy (pidpath, tmpdir, len);
 134
 135   atexit (cleanup);
 136
 137   /* Open the listening socket which will be passed into nbdkit. */
 138   sock = socket (AF_UNIX, SOCK_STREAM /* NB do not use SOCK_CLOEXEC */, 0);
 139   if (sock == -1) {
 140     perror ("socket");
 141     exit (EXIT_FAILURE);
 142   }
 143
 144   addr.sun_family = AF_UNIX;
 145   len = strlen (sockpath);
 146   memcpy (addr.sun_path, sockpath, len+1 /* trailing \0 */);
 147
 148   if (bind (sock, (struct sockaddr *) &addr, sizeof addr) == -1) {
 149     perror (sockpath);
 150     exit (EXIT_FAILURE);
 151   }
 152
 153   if (listen (sock, 1) == -1) {
 154     perror ("listen");
 155     exit (EXIT_FAILURE);
 156   }
 157
 158   if (sock != FIRST_SOCKET_ACTIVATION_FD) {
 159     if (dup2 (sock, FIRST_SOCKET_ACTIVATION_FD) == -1) {
 160       perror ("dup2");
 161       exit (EXIT_FAILURE);
 162     }
 163     close (sock);
 164   }
 165
 166   /* Run nbdkit. */
 167   pid = fork ();
 168   if (pid == -1) {
 169     perror ("fork");
 170     exit (EXIT_FAILURE);
 171   }
 172   if (pid == 0) {
 173     /* Run nbdkit in the child. */
 174     setenv ("LISTEN_FDS", "1", 1);
 175     snprintf (pid_str, sizeof pid_str, "%d", (int) getpid ());
 176     setenv ("LISTEN_PID", pid_str, 1);
 177
 178     execlp ("nbdkit",
 179             "nbdkit",
 180             "-P", pidpath,
 181             "-o",
 182             "-v",
 183             "example1", NULL);
 184     perror ("exec: nbdkit");
 185     _exit (EXIT_FAILURE);
 186   }
 187
 188   /* We don't need the listening socket now. */
 189   close (sock);
 190
 191   /* Wait for the pidfile to turn up, which indicates that nbdkit has
 192    * started up successfully and is ready to serve requests.  However
 193    * if 'pid' exits in this time it indicates a failure to start up.
 194    * Also there is a timeout in case nbdkit hangs.
 195    */
 196   for (i = 0; i < NBDKIT_START_TIMEOUT; ++i) {
 197     if (waitpid (pid, NULL, WNOHANG) == pid)
 198       goto early_exit;
 199
 200     if (kill (pid, 0) == -1) {
 201       if (errno == ESRCH) {
 202       early_exit:
 203         fprintf (stderr,
 204                  "%s FAILED: nbdkit exited before starting to serve files\n",
 205                  program_name);
 206         pid = 0;
 207         exit (EXIT_FAILURE);
 208       }
 209       perror ("kill");
 210     }
 211
 212     if (access (pidpath, F_OK) == 0)
 213       break;
 214
 215     sleep (1);
 216   }
 217
 218   /* Now nbdkit is supposed to be listening on the Unix domain socket
 219    * (which it got via the listening socket that we passed down to it,
 220    * not from the path), so we should be able to connect to the Unix
 221    * domain socket by its path and receive an NBD magic string.
 222    */
 223   sock = socket (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 224   if (sock == -1) {
 225     perror ("socket");
 226     exit (EXIT_FAILURE);
 227   }
 228
 229   /* Reuse addr which was set up above. */
 230   if (connect (sock, (struct sockaddr *) &addr, sizeof addr) == -1) {
 231     perror (sockpath);
 232     exit (EXIT_FAILURE);
 233   }
 234
 235   if (read (sock, magic, 8) != 8) {
 236     perror ("read");
 237     exit (EXIT_FAILURE);
 238   }
 239
 240   if (memcmp (magic, "NBDMAGIC", 8) != 0) {
 241     fprintf (stderr, "%s FAILED: did not read magic string from server\n",
 242              program_name);
 243     exit (EXIT_FAILURE);
 244   }
 245
 246   close (sock);
 247
 248   /* Test succeeded. */
 249   exit (EXIT_SUCCESS);
 250 }