wrapper.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 /*------------------------------------------------------------
  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 #include "utils.h"
  76
  77 /* Construct an array of parameters passed through to real nbdkit. */
  78 static const char **cmd;
  79 static size_t len;
  80
  81 /* Plugins written in scripting languages (only Perl right now) need
  82  * to be rewritten on the command line in a different way from plugins
  83  * written in C.  So we have to list those here.
  84  */
  85 static bool
  86 is_perl_plugin (const char *name)
  87 {
  88   return strcmp (name, "example4") == 0 || strcmp (name, "tar") == 0;
  89 }
  90
  91 static void
  92 passthru (const char *s)
  93 {
  94   cmd = realloc (cmd, (len+1) * sizeof (const char *));
  95   if (cmd == NULL)
  96     abort ();
  97   cmd[len] = s;
  98   ++len;
  99 }
 100
 101 static void __attribute__((format (printf, 1, 2)))
 102 passthru_format (const char *fs, ...)
 103 {
 104   va_list args;
 105   char *str;
 106
 107   va_start (args, fs);
 108   if (vasprintf (&str, fs, args) == -1)
 109     abort ();
 110   va_end (args);
 111   passthru (str);
 112 }
 113
 114 static void
 115 end_passthru (void)
 116 {
 117   passthru (NULL);
 118 }
 119
 120 static void
 121 print_command (void)
 122 {
 123   size_t i;
 124
 125   if (len > 0)
 126     shell_quote (cmd[0], stderr);
 127   for (i = 1; i < len && cmd[i] != NULL; ++i) {
 128     fputc (' ', stderr);
 129     shell_quote (cmd[i], stderr);
 130   }
 131   fputc ('\n', stderr);
 132 }
 133
 134 int
 135 main (int argc, char *argv[])
 136 {
 137   bool verbose = false;
 138   char *s;
 139   time_t t;
 140   unsigned tu;
 141   char ts[32];
 142   int r;
 143
 144   /* If NBDKIT_VALGRIND=1 is set in the environment, then we run the
 145    * program under valgrind.  This is used by the tests.  Similarly if
 146    * NBDKIT_GDB=1 is set, we run the program under GDB, useful during
 147    * development.
 148    */
 149   s = getenv ("NBDKIT_VALGRIND");
 150   if (s && strcmp (s, "1") == 0) {
 151     passthru (VALGRIND);
 152     passthru ("--vgdb=no");
 153     passthru ("--leak-check=full");
 154     passthru ("--show-leak-kinds=all");
 155     passthru ("--error-exitcode=119");
 156     passthru_format ("--suppressions=%s/valgrind/suppressions", builddir);
 157     passthru ("--trace-children=no");
 158     passthru ("--run-libc-freeres=no");
 159     passthru ("--num-callers=100");
 160     /* This is a temporary workaround until RHBZ#1662656 is fixed: */
 161     passthru ("--read-inline-info=no");
 162   }
 163   else {
 164     s = getenv ("NBDKIT_GDB");
 165     if (s && strcmp (s, "1") == 0) {
 166       passthru ("gdb");
 167       passthru ("--args");
 168     }
 169   }
 170
 171   /* Needed for plugins written in OCaml. */
 172   s = getenv ("LD_LIBRARY_PATH");
 173   if (s)
 174     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 175   else
 176     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 177   if (r < 0) {
 178     perror ("asprintf");
 179     exit (EXIT_FAILURE);
 180   }
 181   setenv ("LD_LIBRARY_PATH", s, 1);
 182   free (s);
 183   s = getenv ("LIBRARY_PATH");
 184   if (s)
 185     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 186   else
 187     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 188   if (r < 0) {
 189     perror ("asprintf");
 190     exit (EXIT_FAILURE);
 191   }
 192   setenv ("LIBRARY_PATH", s, 1);
 193   free (s);
 194
 195   /* Absolute path of the real nbdkit command. */
 196   passthru_format ("%s/server/nbdkit", builddir);
 197
 198   /* Option parsing.  We don't really parse options here.  We are only
 199    * interested in which options have arguments and which need
 200    * rewriting.
 201    */
 202   for (;;) {
 203     int c;
 204     int long_index = -1;
 205     bool is_long_option;
 206
 207     c = getopt_long (argc, argv, short_options, long_options, &long_index);
 208     if (c == -1)
 209       break;
 210
 211     if (c == '?')               /* getopt prints an error */
 212       exit (EXIT_FAILURE);
 213
 214     /* long_index is only set if it's an actual long option. */
 215     is_long_option = long_index >= 0;
 216
 217     /* Verbose is special because we will print the final command. */
 218     if (c == 'v') {
 219       verbose = true;
 220       if (is_long_option)
 221         passthru ("--verbose");
 222       else
 223         passthru ("-v");
 224     }
 225     /* Filters can be rewritten if they are a short name. */
 226     else if (c == FILTER_OPTION) {
 227       if (is_short_name (optarg))
 228         passthru_format ("--filter=%s/filters/%s/.libs/nbdkit-%s-filter.so",
 229                          builddir, optarg, optarg);
 230       else
 231         passthru_format ("--filter=%s", optarg);
 232     }
 233     /* Any long option. */
 234     else if (is_long_option) {
 235       if (optarg)           /* Long option which takes an argument. */
 236         passthru_format ("--%s=%s", long_options[long_index].name, optarg);
 237       else                  /* Long option which takes no argument. */
 238         passthru_format ("--%s", long_options[long_index].name);
 239     }
 240     /* Any short option. */
 241     else {
 242       passthru_format ("-%c", c);
 243       if (optarg)
 244         passthru (optarg);
 245     }
 246   }
 247
 248   /* Are there any non-option arguments? */
 249   if (optind < argc) {
 250     /* Ensure any further parameters can never be parsed as options by
 251      * real nbdkit.
 252      */
 253     passthru ("--");
 254
 255     /* The first non-option argument is the plugin name.  If it is a
 256      * short name then rewrite it.
 257      */
 258     if (is_short_name (argv[optind])) {
 259       /* Special plugins written in Perl. */
 260       if (is_perl_plugin (argv[optind])) {
 261         passthru_format ("%s/plugins/perl/.libs/nbdkit-perl-plugin.so",
 262                          builddir);
 263         passthru_format ("%s/plugins/%s/nbdkit-%s-plugin",
 264                          builddir, argv[optind], argv[optind]);
 265       }
 266       else {
 267         passthru_format ("%s/plugins/%s/.libs/nbdkit-%s-plugin.so",
 268                          builddir, argv[optind], argv[optind]);
 269       }
 270       ++optind;
 271     }
 272
 273     /* Everything else is passed through without rewriting. */
 274     while (optind < argc) {
 275       passthru (argv[optind]);
 276       ++optind;
 277     }
 278   }
 279
 280   end_passthru ();
 281   if (verbose)
 282     print_command ();
 283
 284   /* This is a cheap way to find some use-after-free and uninitialized
 285    * read problems when using glibc, and doesn't affect normal
 286    * operation or other libc.  We don't overwrite existing values so
 287    * this can be disabled or overridden at runtime.
 288    */
 289   setenv ("MALLOC_CHECK_", "1", 0);
 290   time (&t);
 291   tu = t;
 292   tu %= 255;
 293   tu++;
 294   snprintf (ts, sizeof ts, "%u", tu);
 295   setenv ("MALLOC_PERTURB_", ts, 0);
 296
 297   /* Run the final command. */
 298   execvp (cmd[0], (char **) cmd);
 299   perror (cmd[0]);
 300   exit (EXIT_FAILURE);
 301 }