wrapper.c

   1 /* nbdkit
   2  * Copyright (C) 2017-2020 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 "const-string-vector.h"
  75 #include "options.h"
  76 #include "windows-compat.h"
  77 #include "utils.h"
  78
  79 /* Plugins written in scripting languages need to be rewritten on the
  80  * command line in a different way from plugins written in C.  So we
  81  * have to list those here, and return the language plugin needed to
  82  * run them.
  83  */
  84 static bool
  85 is_script_plugin (const char *name, const char **language)
  86 {
  87   if (strcmp (name, "example4") == 0) {
  88     *language = "perl";
  89     return true;
  90   }
  91   if (strcmp (name, "S3") == 0) {
  92     *language = "python";
  93     return true;
  94   }
  95   return false;
  96 }
  97
  98 /* Construct an array of parameters passed through to real nbdkit. */
  99 static const_string_vector cmd;
 100
 101 static void
 102 passthru (const char *s)
 103 {
 104   if (const_string_vector_append (&cmd, s) == -1)
 105     abort ();
 106 }
 107
 108 static void __attribute__((format (printf, 1, 2)))
 109 passthru_format (const char *fs, ...)
 110 {
 111   va_list args;
 112   char *str;
 113
 114   va_start (args, fs);
 115   if (vasprintf (&str, fs, args) == -1)
 116     abort ();
 117   va_end (args);
 118   passthru (str);
 119 }
 120
 121 static void
 122 end_passthru (void)
 123 {
 124   passthru (NULL);
 125 }
 126
 127 static void
 128 print_command (void)
 129 {
 130   size_t i;
 131
 132   if (cmd.len > 0)
 133     shell_quote (cmd.ptr[0], stderr);
 134   for (i = 1; i < cmd.len && cmd.ptr[i] != NULL; ++i) {
 135     fputc (' ', stderr);
 136     shell_quote (cmd.ptr[i], stderr);
 137   }
 138   fputc ('\n', stderr);
 139 }
 140
 141 #ifdef WIN32
 142 /* Windows behaviour of _spawnvp is completely insane:
 143  * https://stackoverflow.com/questions/4146980/how-to-avoid-space-splitting-and-quote-removal-with-spawnvp
 144  * See also glib sources where it's described as "really weird".
 145  */
 146 static const char *
 147 quote_string_for_spawn (const char *str)
 148 {
 149   size_t i, len, pb;
 150   char *p, *ret = (char *) str;
 151
 152   if (*str == 0 || strchr (str, ' ') || strchr (str, '\t')) {
 153     len = strlen (str);
 154
 155     p = ret = malloc (2 + len*2 + 1);
 156     if (ret == NULL) {
 157       perror ("malloc");
 158       exit (EXIT_FAILURE);
 159     }
 160
 161     *p++ = '"';
 162     pb = 0;
 163     for (i = 0; i < len; ++i) {
 164       switch (str[i]) {
 165       case '"':
 166         *p++ = '\\';
 167         for (; pb > 0; --pb)
 168           *p++ = '\\';
 169         *p++ = '"';
 170         break;
 171       case '\\':
 172         pb++;
 173         *p++ = str[i];
 174         break;
 175       default:
 176         pb = 0;
 177         *p++ = str[i];
 178       }
 179     }
 180     for (; pb > 0; --pb)
 181       *p++ = '\\';
 182     *p++ = '"';
 183     *p++ = '\0';
 184   }
 185
 186   /* We never free these strings. */
 187   return ret;
 188 }
 189 #endif /* WIN32 */
 190
 191 int
 192 main (int argc, char *argv[])
 193 {
 194   bool verbose = false;
 195   char *s;
 196   int r;
 197
 198 #ifndef WIN32
 199   /* If NBDKIT_VALGRIND=1 is set in the environment, then we run the
 200    * program under valgrind.  This is used by the tests.  Similarly if
 201    * NBDKIT_GDB=1 is set, we run the program under GDB, useful during
 202    * development.
 203    */
 204   s = getenv ("NBDKIT_VALGRIND");
 205   if (s && strcmp (s, "1") == 0) {
 206     passthru (VALGRIND);
 207     passthru ("--vgdb=no");
 208     passthru ("--leak-check=full");
 209     passthru ("--show-leak-kinds=all");
 210     passthru ("--error-exitcode=119");
 211     passthru_format ("--suppressions=%s/valgrind/suppressions", builddir);
 212     passthru ("--trace-children=no");
 213     passthru ("--run-libc-freeres=no");
 214     passthru ("--num-callers=100");
 215     /* This is a temporary workaround until RHBZ#1662656 is fixed: */
 216     passthru ("--read-inline-info=no");
 217
 218     /* Don't invoke malloc debugging when we are valgrinding because
 219      * it duplicates work done by valgrind and might even hide issues.
 220      *
 221      * Originally this was a workaround for:
 222      * https://sourceware.org/bugzilla/show_bug.cgi?id=28256
 223      */
 224     unsetenv ("GLIBC_TUNABLES");
 225   }
 226   else {
 227     s = getenv ("NBDKIT_GDB");
 228     if (s && strcmp (s, "1") == 0) {
 229       passthru ("gdb");
 230       passthru ("--args");
 231     }
 232   }
 233 #endif
 234
 235   /* Needed for plugins written in OCaml. */
 236 #ifndef WIN32
 237 #define LD_LIBRARY_PATH "LD_LIBRARY_PATH"
 238 #else
 239 #define LD_LIBRARY_PATH "PATH"
 240 #endif
 241   s = getenv (LD_LIBRARY_PATH);
 242   if (s)
 243     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 244   else
 245     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 246   if (r < 0) {
 247     perror ("asprintf");
 248     exit (EXIT_FAILURE);
 249   }
 250   setenv (LD_LIBRARY_PATH, s, 1);
 251   free (s);
 252   s = getenv ("LIBRARY_PATH");
 253   if (s)
 254     r = asprintf (&s, "%s/plugins/ocaml/.libs:%s", builddir, s);
 255   else
 256     r = asprintf (&s, "%s/plugins/ocaml/.libs", builddir);
 257   if (r < 0) {
 258     perror ("asprintf");
 259     exit (EXIT_FAILURE);
 260   }
 261   setenv ("LIBRARY_PATH", s, 1);
 262   free (s);
 263
 264   /* Absolute path of the real nbdkit command. */
 265   passthru_format ("%s/server/nbdkit" EXEEXT, builddir);
 266
 267   /* Option parsing.  We don't really parse options here.  We are only
 268    * interested in which options have arguments and which need
 269    * rewriting.
 270    */
 271   for (;;) {
 272     int c;
 273     int long_index = -1;
 274     bool is_long_option;
 275
 276     c = getopt_long (argc, argv, short_options, long_options, &long_index);
 277     if (c == -1)
 278       break;
 279
 280     if (c == '?')               /* getopt prints an error */
 281       exit (EXIT_FAILURE);
 282
 283     /* long_index is only set if it's an actual long option. */
 284     is_long_option = long_index >= 0;
 285
 286     /* Verbose is special because we will print the final command. */
 287     if (c == 'v') {
 288       verbose = true;
 289       if (is_long_option)
 290         passthru ("--verbose");
 291       else
 292         passthru ("-v");
 293     }
 294     /* Filters can be rewritten if they are a short name. */
 295     else if (c == FILTER_OPTION) {
 296       if (is_short_name (optarg))
 297         passthru_format ("--filter="
 298                          "%s/filters/%s/.libs/nbdkit-%s-filter." SOEXT,
 299                          builddir, optarg, optarg);
 300       else
 301         passthru_format ("--filter=%s", optarg);
 302     }
 303     /* Any long option. */
 304     else if (is_long_option) {
 305       if (optarg)           /* Long option which takes an argument. */
 306         passthru_format ("--%s=%s", long_options[long_index].name, optarg);
 307       else                  /* Long option which takes no argument. */
 308         passthru_format ("--%s", long_options[long_index].name);
 309     }
 310     /* Any short option. */
 311     else {
 312       passthru_format ("-%c", c);
 313       if (optarg)
 314         passthru (optarg);
 315     }
 316   }
 317
 318   /* Are there any non-option arguments? */
 319   if (optind < argc) {
 320     /* Ensure any further parameters can never be parsed as options by
 321      * real nbdkit.
 322      */
 323     passthru ("--");
 324
 325     /* The first non-option argument is the plugin name.  If it is a
 326      * short name then rewrite it.
 327      */
 328     if (is_short_name (argv[optind])) {
 329       const char *language;
 330
 331       /* Plugins written in scripting languages. */
 332       if (is_script_plugin (argv[optind], &language)) {
 333         passthru_format ("%s/plugins/%s/.libs/nbdkit-%s-plugin." SOEXT,
 334                          builddir, language, language);
 335         passthru_format ("%s/plugins/%s/nbdkit-%s-plugin",
 336                          builddir, argv[optind], argv[optind]);
 337       }
 338       /* Otherwise normal plugins written in C or other languages that
 339        * compile to .so files.
 340        */
 341       else {
 342         passthru_format ("%s/plugins/%s/.libs/nbdkit-%s-plugin." SOEXT,
 343                          builddir, argv[optind], argv[optind]);
 344       }
 345       ++optind;
 346     }
 347
 348     /* Everything else is passed through without rewriting. */
 349     while (optind < argc) {
 350       passthru (argv[optind]);
 351       ++optind;
 352     }
 353   }
 354
 355   end_passthru ();
 356   if (verbose)
 357     print_command ();
 358
 359   /* Run the final command. */
 360 #ifndef WIN32
 361   execvp (cmd.ptr[0], (char **) cmd.ptr);
 362   perror (cmd.ptr[0]);
 363   exit (EXIT_FAILURE);
 364 #else /* WIN32 */
 365   size_t i;
 366   for (i = 1; cmd.ptr[i] != NULL; ++i)
 367     cmd.ptr[i] = quote_string_for_spawn (cmd.ptr[i]);
 368   r = _spawnvp (_P_WAIT, cmd.ptr[0], cmd.ptr);
 369   if (r == -1) {
 370     perror (cmd.ptr[0]);
 371     exit (EXIT_FAILURE);
 372   }
 373   exit (r == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 374 #endif /* WIN32 */
 375 }