arch/common/boot/grub2/util/grub-editenv.c

   1 /* grub-editenv.c - tool to edit environment block.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2008 Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #include <grub/types.h>
  22 #include <grub/util/misc.h>
  23 #include <grub/lib/envblk.h>
  24
  25 #include <stdio.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <getopt.h>
  30
  31 void
  32 grub_putchar (int c)
  33 {
  34   putchar (c);
  35 }
  36
  37 void
  38 grub_refresh (void)
  39 {
  40   fflush (stdout);
  41 }
  42
  43 void *
  44 grub_term_get_current_input (void)
  45 {
  46   return 0;
  47 }
  48
  49 void *
  50 grub_term_get_current_output (void)
  51 {
  52   return 0;
  53 }
  54
  55 int
  56 grub_getkey (void)
  57 {
  58   return 0;
  59 }
  60
  61 char *
  62 grub_env_get (const char *name __attribute__ ((unused)))
  63 {
  64   return NULL;
  65 }
  66
  67 static struct option options[] = {
  68   {"help", no_argument, 0, 'h'},
  69   {"version", no_argument, 0, 'V'},
  70   {"verbose", no_argument, 0, 'v'},
  71   {0, 0, 0, 0}
  72 };
  73
  74 char buffer[GRUB_ENVBLK_MAXLEN];
  75 grub_envblk_t envblk;
  76
  77 static void
  78 usage (int status)
  79 {
  80   if (status)
  81     fprintf (stderr, "Try ``grub-editenv --help'' for more information.\n");
  82   else
  83     printf ("\
  84 Usage: grub-editenv [OPTIONS] FILENAME COMMAND\n\
  85 \n\
  86 Tool to edit environment block.\n\
  87 \nCommands:\n\
  88   create                    create a blank environment block file\n\
  89   info                      show information about the environment block\n\
  90   list                      list the current variables\n\
  91   set [name=value] ...      change/delete variables\n\
  92   clear                     delete all variables\n\
  93 \nOptions:\n\
  94   -h, --help                display this message and exit\n\
  95   -V, --version             print version information and exit\n\
  96   -v, --verbose             print verbose messages\n\
  97 \n\
  98 Report bugs to <%s>.\n", PACKAGE_BUGREPORT);
  99
 100   exit (status);
 101 }
 102
 103 int
 104 create_envblk_file (char *name)
 105 {
 106   FILE *f;
 107   grub_envblk_t p;
 108
 109   f = fopen (name, "wb");
 110   if (! f)
 111     return 1;
 112
 113   /* Just in case OS don't save 0s.  */
 114   memset (buffer, -1, sizeof (buffer));
 115
 116   p = (grub_envblk_t) &buffer[0];
 117   p->signature = GRUB_ENVBLK_SIGNATURE;
 118   p->length = sizeof (buffer) - sizeof (struct grub_envblk);
 119   p->data[0] = p->data[1] = 0;
 120
 121   fwrite (buffer, sizeof (buffer), 1, f);
 122
 123   fclose (f);
 124   return 0;
 125 }
 126
 127 FILE *
 128 open_envblk_file (char *name)
 129 {
 130   FILE *f;
 131
 132   f = fopen (name, "r+b");
 133   if (! f)
 134     grub_util_error ("Can\'t open file %s", name);
 135
 136   if (fread (buffer, 1, sizeof (buffer), f) != sizeof (buffer))
 137     grub_util_error ("The envblk file is too short");
 138
 139   envblk = grub_envblk_find (buffer);
 140   if (! envblk)
 141     grub_util_error ("Can\'t find environment block");
 142
 143   return f;
 144 }
 145
 146 static void
 147 cmd_info (void)
 148 {
 149   printf ("Envblk offset: %ld\n", (long) (envblk->data - buffer));
 150   printf ("Envblk length: %d\n", envblk->length);
 151 }
 152
 153 static void
 154 cmd_list (void)
 155 {
 156   auto int hook (char *name, char *value);
 157   int hook (char *name, char *value)
 158     {
 159       printf ("%s=%s\n", name, value);
 160       return 0;
 161     }
 162
 163   grub_envblk_iterate (envblk, hook);
 164 }
 165
 166 static void
 167 cmd_set (int argc, char *argv[])
 168 {
 169   while (argc)
 170     {
 171       char *p;
 172
 173       p = strchr (argv[0], '=');
 174       if (! p)
 175         grub_util_error ("Invalid parameter");
 176
 177       *(p++) = 0;
 178
 179       if (*p)
 180         {
 181           if (grub_envblk_insert (envblk, argv[0], p))
 182             grub_util_error ("Environment block too small");
 183         }
 184       else
 185         grub_envblk_delete (envblk, argv[0]);
 186
 187       argc--;
 188       argv++;
 189     }
 190 }
 191
 192 static void
 193 cmd_clear (void)
 194 {
 195   envblk->data[0] = envblk->data[1] = 0;
 196 }
 197
 198 int
 199 main (int argc, char *argv[])
 200 {
 201   FILE *f;
 202
 203   progname = "grub-editenv";
 204
 205   /* Check for options.  */
 206   while (1)
 207     {
 208       int c = getopt_long (argc, argv, "hVv", options, 0);
 209
 210       if (c == -1)
 211         break;
 212       else
 213         switch (c)
 214           {
 215           case 'h':
 216             usage (0);
 217             break;
 218
 219           case 'V':
 220             printf ("%s (%s) %s\n", progname, PACKAGE_NAME, PACKAGE_VERSION);
 221             return 0;
 222
 223           case 'v':
 224             verbosity++;
 225             break;
 226
 227           default:
 228             usage (1);
 229             break;
 230           }
 231     }
 232
 233   /* Obtain PATH.  */
 234   if (optind >= argc)
 235     {
 236       fprintf (stderr, "Filename not specified.\n");
 237       usage (1);
 238     }
 239
 240   if (optind + 1 >= argc)
 241     {
 242       fprintf (stderr, "Command not specified.\n");
 243       usage (1);
 244     }
 245
 246   if (! strcmp (argv[optind + 1], "create"))
 247     return create_envblk_file (argv[optind]);
 248
 249   f = open_envblk_file (argv[optind]);
 250
 251   optind++;
 252   if (! strcmp (argv[optind], "info"))
 253     cmd_info ();
 254   else if (! strcmp (argv[optind], "list"))
 255     cmd_list ();
 256   else
 257     {
 258       if (! strcmp (argv[optind], "set"))
 259         cmd_set (argc - optind - 1, argv + optind + 1);
 260       else if (! strcmp (argv[optind], "clear"))
 261         cmd_clear ();
 262
 263       fseek (f, 0, SEEK_SET);
 264       fwrite (buffer, sizeof (buffer), 1, f);
 265     }
 266   fclose (f);
 267
 268   return 0;
 269 }