wrapper.c

   1 /* nbdkit
   2  * Copyright (C) 2017-2018 Red Hat Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *
  12  * * Redistributions in binary form must reproduce the above copyright
  13  * notice, this list of conditions and the following disclaimer in the
  14  * documentation and/or other materials provided with the distribution.
  15  *
  16  * * Neither the name of Red Hat nor the names of its contributors may be
  17  * used to endorse or promote products derived from this software without
  18  * specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*------------------------------------------------------------
  35  * This wrapper lets you run nbdkit from the source directory.
  36  *
  37  * You can use either:
  38  * ./nbdkit file [arg=value] [arg=value] ...
  39  * or:
  40  *   /path/to/nbdkit file [arg=value] [arg=value] ...
  41  *
  42  * Or you can set $PATH to include the nbdkit source directory and run
  43  * the bare "nbdkit" command without supplying the full path.
  44  *
  45  * The wrapper modifies the bare plugin name (eg. "file") to be the
  46  * full path to the locally compiled plugin.  If you don't use this
  47  * program and run src/nbdkit directly then it will pick up the
  48  * installed plugins which is not usually what you want.
  49  *
  50  * This program is also used to run the tests (make check).
  51  *
  52  * You can enable valgrind by setting NBDKIT_VALGRIND=1 (this
  53  * is mainly used by the internal tests).
  54  *
  55  * You can enable debugging by setting NBDKIT_GDB=1
  56  *------------------------------------------------------------
  57  */
  58
  59 #include <config.h>
  60
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <stdbool.h>
  64 #include <stdarg.h>
  65 #include <string.h>
  66 #include <unistd.h>
  67 #include <getopt.h>
  68 #include <limits.h>
  69
  70 #include "options.h"
  71
  72 /* Construct an array of parameters passed through to real nbdkit. */
  73 static const char **cmd;
  74 static size_t len;
  75
  76 static void
  77 passthru (const char *s)
  78 {
  79   cmd = realloc (cmd, (len+1) * sizeof (const char *));
  80   if (cmd == NULL)
  81     abort ();
  82   cmd[len] = s;
  83   ++len;
  84 }
  85
  86 static void __attribute__((format (printf, 1, 2)))
  87 passthru_format (const char *fs, ...)
  88 {
  89   va_list args;
  90   char *str;
  91
  92   va_start (args, fs);
  93   if (vasprintf (&str, fs, args) == -1)
  94     abort ();
  95   va_end (args);
  96   passthru (str);
  97 }
  98
  99 static void
 100 end_passthru (void)
 101 {
 102   passthru (NULL);
 103 }
 104
 105 static void
 106 print_command (void)
 107 {
 108   size_t i;
 109
 110   if (len > 0)
 111     fprintf (stderr, "%s", cmd[0]);
 112   for (i = 1; i < len && cmd[i] != NULL; ++i)
 113     fprintf (stderr, " %s", cmd[i]);
 114   fprintf (stderr, "\n");
 115 }
 116
 117 int
 118 main (int argc, char *argv[])
 119 {
 120   bool verbose = false;
 121   char *s;
 122
 123   /* If NBDKIT_VALGRIND=1 is set in the environment, then we run the
 124    * program under valgrind.  This is used by the tests.  Similarly if
 125    * NBDKIT_GDB=1 is set, we run the program under GDB, useful during
 126    * development.
 127    */
 128   s = getenv ("NBDKIT_VALGRIND");
 129   if (s && strcmp (s, "1") == 0) {
 130     passthru (VALGRIND);
 131     passthru ("--vgdb=no");
 132     passthru ("--leak-check=full");
 133     passthru ("--error-exitcode=119");
 134     passthru_format ("--suppressions=%s/valgrind-suppressions", srcdir);
 135     passthru ("--trace-children=no");
 136     passthru ("--child-silent-after-fork=yes");
 137     passthru ("--run-libc-freeres=no");
 138     passthru ("--num-callers=20");
 139   }
 140   else {
 141     s = getenv ("NBDKIT_GDB");
 142     if (s && strcmp (s, "1") == 0) {
 143       passthru ("gdb");
 144       passthru ("--args");
 145     }
 146   }
 147
 148   /* Absolute path of the real nbdkit command. */
 149   passthru_format ("%s/src/nbdkit", builddir);
 150
 151   /* Option parsing.  We don't really parse options here.  We are only
 152    * interested in which options have arguments and which need
 153    * rewriting.
 154    */
 155   for (;;) {
 156     int c;
 157     int long_index = -1;
 158     bool is_long_option;
 159
 160     c = getopt_long (argc, argv, short_options, long_options, &long_index);
 161     if (c == -1)
 162       break;
 163
 164     if (c == '?')               /* getopt prints an error */
 165       exit (EXIT_FAILURE);
 166
 167     /* long_index is only set if it's an actual long option. */
 168     is_long_option = long_index >= 0;
 169
 170     /* Verbose is special because we will print the final command. */
 171     if (c == 'v') {
 172       verbose = true;
 173       if (is_long_option)
 174         passthru ("--verbose");
 175       else
 176         passthru ("-v");
 177     }
 178     /* Filters can be rewritten if they are a short name. */
 179     else if (c == FILTER_OPTION) {
 180       if (is_short_name (optarg))
 181         passthru_format ("--filter=%s/filters/%s/.libs/nbdkit-%s-filter.so",
 182                          builddir, optarg, optarg);
 183       else
 184         passthru_format ("--filter=%s", optarg);
 185     }
 186     /* Any long option. */
 187     else if (is_long_option) {
 188       if (optarg)           /* Long option which takes an argument. */
 189         passthru_format ("--%s=%s", long_options[long_index].name, optarg);
 190       else                  /* Long option which takes no argument. */
 191         passthru_format ("--%s", long_options[long_index].name);
 192     }
 193     /* Any short option. */
 194     else {
 195       passthru_format ("-%c", c);
 196       if (optarg)
 197         passthru (optarg);
 198     }
 199   }
 200
 201   /* Are there any non-option arguments? */
 202   if (optind < argc) {
 203     /* Ensure any further parameters can never be parsed as options by
 204      * real nbdkit.
 205      */
 206     passthru ("--");
 207
 208     /* The first non-option argument is the plugin name.  If it is a
 209      * short name then rewrite it.
 210      */
 211     if (is_short_name (argv[optind])) {
 212       /* Special plugins written in Perl. */
 213       if (strcmp (argv[optind], "example4") == 0 ||
 214           strcmp (argv[optind], "tar") == 0) {
 215         passthru_format ("%s/plugins/perl/.libs/nbdkit-perl-plugin.so",
 216                          builddir);
 217         passthru_format ("%s/plugins/%s/nbdkit-%s-plugin",
 218                          builddir, argv[optind], argv[optind]);
 219       }
 220       else {
 221         passthru_format ("%s/plugins/%s/.libs/nbdkit-%s-plugin.so",
 222                          builddir, argv[optind], argv[optind]);
 223       }
 224       ++optind;
 225     }
 226
 227     /* Everything else is passed through without rewriting. */
 228     while (optind < argc) {
 229       passthru (argv[optind]);
 230       ++optind;
 231     }
 232   }
 233
 234   end_passthru ();
 235   if (verbose)
 236     print_command ();
 237
 238   /* Run the final command. */
 239   execvp (cmd[0], (char **) cmd);
 240   perror (cmd[0]);
 241   exit (EXIT_FAILURE);
 242 }