wrapper.c

   1 /* nbdkit
   2  * Copyright (C) 2017-2018 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 /*------------------------------------------------------------
  34  * This is not nbdkit.  This is a wrapper which lets you run nbdkit
  35  * from the source directory without installing nbdkit.
  36  *
  37  * You can use either:
  38  *
  39  *   ./nbdkit file [arg=value] [arg=value] ...
  40  *
  41  * or:
  42  *
  43  *   /path/to/nbdkit file [arg=value] [arg=value] ...
  44  *
  45  * or you can set $PATH to include the nbdkit source directory and run
  46  * the bare "nbdkit" command without supplying the full path.
  47  *
  48  * The wrapper modifies the bare plugin name (eg. "file") to be the
  49  * full path to the locally compiled plugin.  If you don't use this
  50  * program and run server/nbdkit directly then it will pick up the
  51  * globally installed plugins which is usually not what you want.
  52  *
  53  * This program is also used to run the tests (make check).
  54  *
  55  * You can enable valgrind by setting NBDKIT_VALGRIND=1 (this
  56  * is mainly used by the internal tests).
  57  *
  58  * You can enable debugging by setting NBDKIT_GDB=1
  59  *------------------------------------------------------------
  60  */
  61
  62 #include <config.h>
  63
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <stdbool.h>
  67 #include <stdarg.h>
  68 #include <string.h>
  69 #include <unistd.h>
  70 #include <getopt.h>
  71 #include <limits.h>
  72 #include <time.h>
  73
  74 #include "options.h"
  75
  76 /* Construct an array of parameters passed through to real nbdkit. */
  77 static const char **cmd;
  78 static size_t len;
  79
  80 /* Plugins written in scripting languages (only Perl right now) need
  81  * to be rewritten on the command line in a different way from plugins
  82  * written in C.  So we have to list those here.
  83  */
  84 static bool
  85 is_perl_plugin (const char *name)
  86 {
  87   return strcmp (name, "example4") == 0 || strcmp (name, "tar") == 0;
  88 }
  89
  90 static void
  91 passthru (const char *s)
  92 {
  93   cmd = realloc (cmd, (len+1) * sizeof (const char *));
  94   if (cmd == NULL)
  95     abort ();
  96   cmd[len] = s;
  97   ++len;
  98 }
  99
 100 static void __attribute__((format (printf, 1, 2)))
 101 passthru_format (const char *fs, ...)
 102 {
 103   va_list args;
 104   char *str;
 105
 106   va_start (args, fs);
 107   if (vasprintf (&str, fs, args) == -1)
 108     abort ();
 109   va_end (args);
 110   passthru (str);
 111 }
 112
 113 static void
 114 end_passthru (void)
 115 {
 116   passthru (NULL);
 117 }
 118
 119 static void
 120 print_command (void)
 121 {
 122   size_t i;
 123
 124   if (len > 0)
 125     fprintf (stderr, "%s", cmd[0]);
 126   for (i = 1; i < len && cmd[i] != NULL; ++i)
 127     fprintf (stderr, " %s", cmd[i]);
 128   fprintf (stderr, "\n");
 129 }
 130
 131 int
 132 main (int argc, char *argv[])
 133 {
 134   bool verbose = false;
 135   char *s;
 136   time_t t;
 137   unsigned tu;
 138   char ts[32];
 139   int r;
 140
 141   /* If NBDKIT_VALGRIND=1 is set in the environment, then we run the
 142    * program under valgrind.  This is used by the tests.  Similarly if
 143    * NBDKIT_GDB=1 is set, we run the program under GDB, useful during
 144    * development.
 145    */
 146   s = getenv ("NBDKIT_VALGRIND");
 147   if (s && strcmp (s, "1") == 0) {
 148     passthru (VALGRIND);
 149     passthru ("--vgdb=no");
 150     passthru ("--leak-check=full");
 151     passthru ("--show-leak-kinds=all");
 152     passthru ("--error-exitcode=119");
 153     passthru_format ("--suppressions=%s/valgrind/suppressions", builddir);
 154     passthru ("--trace-children=no");
 155     passthru ("--run-libc-freeres=no");
 156     passthru ("--num-callers=100");
 157     /* This is a temporary workaround until RHBZ#1662656 is fixed: */
 158     passthru ("--read-inline-info=no");
 159   }
 160   else {
 161     s = getenv ("NBDKIT_GDB");
 162     if (s && strcmp (s, "1") == 0) {
 163       passthru ("gdb");
 164       passthru ("--args");
 165     }
 166   }
 167
 168   /* Needed for plugins written in OCaml. */
 169   s = getenv ("LD_LIBRARY_PATH");
 170   if (s)
 171     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 172   else
 173     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 174   if (r < 0) {
 175     perror ("asprintf");
 176     exit (EXIT_FAILURE);
 177   }
 178   setenv ("LD_LIBRARY_PATH", s, 1);
 179   free (s);
 180   s = getenv ("LIBRARY_PATH");
 181   if (s)
 182     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 183   else
 184     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 185   if (r < 0) {
 186     perror ("asprintf");
 187     exit (EXIT_FAILURE);
 188   }
 189   setenv ("LIBRARY_PATH", s, 1);
 190   free (s);
 191
 192   /* Absolute path of the real nbdkit command. */
 193   passthru_format ("%s/server/nbdkit", builddir);
 194
 195   /* Option parsing.  We don't really parse options here.  We are only
 196    * interested in which options have arguments and which need
 197    * rewriting.
 198    */
 199   for (;;) {
 200     int c;
 201     int long_index = -1;
 202     bool is_long_option;
 203
 204     c = getopt_long (argc, argv, short_options, long_options, &long_index);
 205     if (c == -1)
 206       break;
 207
 208     if (c == '?')               /* getopt prints an error */
 209       exit (EXIT_FAILURE);
 210
 211     /* long_index is only set if it's an actual long option. */
 212     is_long_option = long_index >= 0;
 213
 214     /* Verbose is special because we will print the final command. */
 215     if (c == 'v') {
 216       verbose = true;
 217       if (is_long_option)
 218         passthru ("--verbose");
 219       else
 220         passthru ("-v");
 221     }
 222     /* Filters can be rewritten if they are a short name. */
 223     else if (c == FILTER_OPTION) {
 224       if (is_short_name (optarg))
 225         passthru_format ("--filter=%s/filters/%s/.libs/nbdkit-%s-filter.so",
 226                          builddir, optarg, optarg);
 227       else
 228         passthru_format ("--filter=%s", optarg);
 229     }
 230     /* Any long option. */
 231     else if (is_long_option) {
 232       if (optarg)           /* Long option which takes an argument. */
 233         passthru_format ("--%s=%s", long_options[long_index].name, optarg);
 234       else                  /* Long option which takes no argument. */
 235         passthru_format ("--%s", long_options[long_index].name);
 236     }
 237     /* Any short option. */
 238     else {
 239       passthru_format ("-%c", c);
 240       if (optarg)
 241         passthru (optarg);
 242     }
 243   }
 244
 245   /* Are there any non-option arguments? */
 246   if (optind < argc) {
 247     /* Ensure any further parameters can never be parsed as options by
 248      * real nbdkit.
 249      */
 250     passthru ("--");
 251
 252     /* The first non-option argument is the plugin name.  If it is a
 253      * short name then rewrite it.
 254      */
 255     if (is_short_name (argv[optind])) {
 256       /* Special plugins written in Perl. */
 257       if (is_perl_plugin (argv[optind])) {
 258         passthru_format ("%s/plugins/perl/.libs/nbdkit-perl-plugin.so",
 259                          builddir);
 260         passthru_format ("%s/plugins/%s/nbdkit-%s-plugin",
 261                          builddir, argv[optind], argv[optind]);
 262       }
 263       else {
 264         passthru_format ("%s/plugins/%s/.libs/nbdkit-%s-plugin.so",
 265                          builddir, argv[optind], argv[optind]);
 266       }
 267       ++optind;
 268     }
 269
 270     /* Everything else is passed through without rewriting. */
 271     while (optind < argc) {
 272       passthru (argv[optind]);
 273       ++optind;
 274     }
 275   }
 276
 277   end_passthru ();
 278   if (verbose)
 279     print_command ();
 280
 281   /* This is a cheap way to find some use-after-free and uninitialized
 282    * read problems when using glibc, and doesn't affect normal
 283    * operation or other libc.  We don't overwrite existing values so
 284    * this can be disabled or overridden at runtime.
 285    */
 286   setenv ("MALLOC_CHECK_", "1", 0);
 287   time (&t);
 288   tu = t;
 289   tu %= 255;
 290   tu++;
 291   snprintf (ts, sizeof ts, "%u", tu);
 292   setenv ("MALLOC_PERTURB_", ts, 0);
 293
 294   /* Run the final command. */
 295   execvp (cmd[0], (char **) cmd);
 296   perror (cmd[0]);
 297   exit (EXIT_FAILURE);
 298 }