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 #include "byte-swapping.h"
  62 #include "nbd-protocol.h"
  63
  64 #ifndef SOCK_CLOEXEC
  65 /* For this file, we don't care if fds are marked cloexec; leaking is okay.  */
  66 #define SOCK_CLOEXEC 0
  67 #endif
  68
  69 #define FIRST_SOCKET_ACTIVATION_FD 3
  70
  71 #define NBDKIT_START_TIMEOUT 30 /* seconds */
  72
  73 /* Declare program_name. */
  74 #if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME == 1
  75 #include <errno.h>
  76 #define program_name program_invocation_short_name
  77 #else
  78 #define program_name "nbdkit"
  79 #endif
  80
  81 static char tmpdir[] =   "/tmp/nbdkitXXXXXX";
  82 static char sockpath[] = "/tmp/nbdkitXXXXXX/sock";
  83 static char pidpath[] =  "/tmp/nbdkitXXXXXX/pid";
  84
  85 static pid_t pid = 0;
  86
  87 static void
  88 cleanup (void)
  89 {
  90   if (pid > 0)
  91     kill (pid, SIGTERM);
  92
  93   unlink (pidpath);
  94   unlink (sockpath);
  95   rmdir (tmpdir);
  96 }
  97
  98 int
  99 main (int argc, char *argv[])
 100 {
 101   int sock;
 102   struct sockaddr_un addr;
 103   char pid_str[16];
 104   size_t i, len;
 105   uint64_t magic;
 106
 107   if (mkdtemp (tmpdir) == NULL) {
 108     perror ("mkdtemp");
 109     exit (EXIT_FAILURE);
 110   }
 111   len = strlen (tmpdir);
 112   memcpy (sockpath, tmpdir, len);
 113   memcpy (pidpath, tmpdir, len);
 114
 115   atexit (cleanup);
 116
 117   /* Open the listening socket which will be passed into nbdkit. */
 118   sock = socket (AF_UNIX, SOCK_STREAM /* NB do not use SOCK_CLOEXEC */, 0);
 119   if (sock == -1) {
 120     perror ("socket");
 121     exit (EXIT_FAILURE);
 122   }
 123
 124   addr.sun_family = AF_UNIX;
 125   len = strlen (sockpath);
 126   memcpy (addr.sun_path, sockpath, len+1 /* trailing \0 */);
 127
 128   if (bind (sock, (struct sockaddr *) &addr, sizeof addr) == -1) {
 129     perror (sockpath);
 130     exit (EXIT_FAILURE);
 131   }
 132
 133   if (listen (sock, 1) == -1) {
 134     perror ("listen");
 135     exit (EXIT_FAILURE);
 136   }
 137
 138   if (sock != FIRST_SOCKET_ACTIVATION_FD) {
 139     if (dup2 (sock, FIRST_SOCKET_ACTIVATION_FD) == -1) {
 140       perror ("dup2");
 141       exit (EXIT_FAILURE);
 142     }
 143     close (sock);
 144   }
 145
 146   /* Run nbdkit. */
 147   pid = fork ();
 148   if (pid == -1) {
 149     perror ("fork");
 150     exit (EXIT_FAILURE);
 151   }
 152   if (pid == 0) {
 153     /* Run nbdkit in the child. */
 154     setenv ("LISTEN_FDS", "1", 1);
 155     snprintf (pid_str, sizeof pid_str, "%d", (int) getpid ());
 156     setenv ("LISTEN_PID", pid_str, 1);
 157
 158     execlp ("nbdkit",
 159             "nbdkit",
 160             "-P", pidpath,
 161             "-o",
 162             "-v",
 163             "example1", NULL);
 164     perror ("exec: nbdkit");
 165     _exit (EXIT_FAILURE);
 166   }
 167
 168   /* We don't need the listening socket now. */
 169   close (sock);
 170
 171   /* Wait for the pidfile to turn up, which indicates that nbdkit has
 172    * started up successfully and is ready to serve requests.  However
 173    * if 'pid' exits in this time it indicates a failure to start up.
 174    * Also there is a timeout in case nbdkit hangs.
 175    */
 176   for (i = 0; i < NBDKIT_START_TIMEOUT; ++i) {
 177     if (waitpid (pid, NULL, WNOHANG) == pid)
 178       goto early_exit;
 179
 180     if (kill (pid, 0) == -1) {
 181       if (errno == ESRCH) {
 182       early_exit:
 183         fprintf (stderr,
 184                  "%s FAILED: nbdkit exited before starting to serve files\n",
 185                  program_name);
 186         pid = 0;
 187         exit (EXIT_FAILURE);
 188       }
 189       perror ("kill");
 190     }
 191
 192     if (access (pidpath, F_OK) == 0)
 193       break;
 194
 195     sleep (1);
 196   }
 197
 198   /* Now nbdkit is supposed to be listening on the Unix domain socket
 199    * (which it got via the listening socket that we passed down to it,
 200    * not from the path), so we should be able to connect to the Unix
 201    * domain socket by its path and receive an NBD magic string.
 202    */
 203   sock = socket (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 204   if (sock == -1) {
 205     perror ("socket");
 206     exit (EXIT_FAILURE);
 207   }
 208
 209   /* Reuse addr which was set up above. */
 210   if (connect (sock, (struct sockaddr *) &addr, sizeof addr) == -1) {
 211     perror (sockpath);
 212     exit (EXIT_FAILURE);
 213   }
 214
 215   if (read (sock, &magic, sizeof magic) != sizeof magic) {
 216     perror ("read");
 217     exit (EXIT_FAILURE);
 218   }
 219
 220   if (be64toh (magic) != NBD_MAGIC) {
 221     fprintf (stderr, "%s FAILED: did not read magic string from server\n",
 222              program_name);
 223     exit (EXIT_FAILURE);
 224   }
 225
 226   close (sock);
 227
 228   /* Test succeeded. */
 229   exit (EXIT_SUCCESS);
 230 }