arch/common/boot/grub2/normal/main.c

   1 /* main.c - the normal mode main routine */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2000,2001,2002,2003,2005,2006,2007,2008  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 <grub/kernel.h>
  21 #include <grub/normal.h>
  22 #include <grub/dl.h>
  23 #include <grub/rescue.h>
  24 #include <grub/misc.h>
  25 #include <grub/file.h>
  26 #include <grub/mm.h>
  27 #include <grub/term.h>
  28 #include <grub/env.h>
  29 #include <grub/parser.h>
  30 #include <grub/script.h>
  31
  32 grub_jmp_buf grub_exit_env;
  33
  34 static grub_fs_module_list_t fs_module_list = 0;
  35
  36 #define GRUB_DEFAULT_HISTORY_SIZE       50
  37
  38 /* Read a line from the file FILE.  */
  39 static char *
  40 get_line (grub_file_t file)
  41 {
  42   char c;
  43   int pos = 0;
  44   int literal = 0;
  45   int comment = 0;
  46   char *cmdline;
  47   int max_len = 64;
  48
  49   /* Initially locate some space.  */
  50   cmdline = grub_malloc (max_len);
  51   if (! cmdline)
  52     return 0;
  53
  54   while (1)
  55     {
  56       if (grub_file_read (file, &c, 1) != 1)
  57         break;
  58
  59       /* Skip all carriage returns.  */
  60       if (c == '\r')
  61         continue;
  62
  63       /* Replace tabs with spaces.  */
  64       if (c == '\t')
  65         c = ' ';
  66
  67       /* The previous is a backslash, then...  */
  68       if (literal)
  69         {
  70           /* If it is a newline, replace it with a space and continue.  */
  71           if (c == '\n')
  72             {
  73               c = ' ';
  74
  75               /* Go back to overwrite the backslash.  */
  76               if (pos > 0)
  77                 pos--;
  78             }
  79
  80           literal = 0;
  81         }
  82
  83       if (c == '\\')
  84         literal = 1;
  85
  86       if (comment)
  87         {
  88           if (c == '\n')
  89             comment = 0;
  90         }
  91       else if (pos == 0)
  92         {
  93           if (c == '#')
  94             comment = 1;
  95           else if (! grub_isspace (c))
  96             cmdline[pos++] = c;
  97         }
  98       else
  99         {
 100           if (pos >= max_len)
 101             {
 102               char *old_cmdline = cmdline;
 103               max_len = max_len * 2;
 104               cmdline = grub_realloc (cmdline, max_len);
 105               if (! cmdline)
 106                 {
 107                   grub_free (old_cmdline);
 108                   return 0;
 109                 }
 110             }
 111
 112           if (c == '\n')
 113             break;
 114
 115           cmdline[pos++] = c;
 116         }
 117     }
 118
 119   cmdline[pos] = '\0';
 120
 121   /* If the buffer is empty, don't return anything at all.  */
 122   if (pos == 0)
 123     {
 124       grub_free (cmdline);
 125       cmdline = 0;
 126     }
 127
 128   return cmdline;
 129 }
 130
 131 static void
 132 free_menu (grub_menu_t menu)
 133 {
 134   grub_menu_entry_t entry = menu->entry_list;
 135
 136   while (entry)
 137     {
 138       grub_menu_entry_t next_entry = entry->next;
 139
 140       grub_script_free (entry->commands);
 141       grub_free ((void *) entry->title);
 142       grub_free ((void *) entry->sourcecode);
 143       entry = next_entry;
 144     }
 145
 146   grub_free (menu);
 147   grub_env_unset_data_slot ("menu");
 148 }
 149
 150 grub_err_t
 151 grub_normal_menu_addentry (const char *title, struct grub_script *script,
 152                            const char *sourcecode)
 153 {
 154   const char *menutitle;
 155   const char *menusourcecode;
 156   grub_menu_t menu;
 157   grub_menu_entry_t *last;
 158
 159   menu = grub_env_get_data_slot("menu");
 160   if (! menu)
 161     return grub_error (GRUB_ERR_MENU, "no menu context");
 162
 163   last = &menu->entry_list;
 164
 165   menusourcecode = grub_strdup (sourcecode);
 166   if (! menusourcecode)
 167     return grub_errno;
 168
 169   menutitle = grub_strdup (title);
 170   if (! menutitle)
 171     {
 172       grub_free ((void *) menusourcecode);
 173       return grub_errno;
 174     }
 175
 176   /* Add the menu entry at the end of the list.  */
 177   while (*last)
 178     last = &(*last)->next;
 179
 180   *last = grub_malloc (sizeof (**last));
 181   if (! *last)
 182     {
 183       grub_free ((void *) menutitle);
 184       grub_free ((void *) menusourcecode);
 185       return grub_errno;
 186     }
 187
 188   (*last)->commands = script;
 189   (*last)->title = menutitle;
 190   (*last)->next = 0;
 191   (*last)->sourcecode = menusourcecode;
 192
 193   menu->size++;
 194
 195   return GRUB_ERR_NONE;
 196 }
 197
 198 static grub_menu_t
 199 read_config_file (const char *config, int nested)
 200 {
 201   grub_file_t file;
 202   auto grub_err_t getline (char **line);
 203   int currline = 0;
 204   int errors = 0;
 205
 206   grub_err_t getline (char **line)
 207     {
 208       currline++;
 209
 210       *line = get_line (file);
 211       if (! *line)
 212         return grub_errno;
 213
 214       return GRUB_ERR_NONE;
 215     }
 216
 217   grub_menu_t newmenu;
 218
 219   newmenu = grub_env_get_data_slot ("menu");
 220
 221   if (nested || ! newmenu)
 222     {
 223       newmenu = grub_malloc (sizeof (*newmenu));
 224       if (! newmenu)
 225         return 0;
 226       newmenu->size = 0;
 227       newmenu->entry_list = 0;
 228     }
 229
 230   /* Try to open the config file.  */
 231   file = grub_file_open (config);
 232   if (! file)
 233     return 0;
 234
 235   grub_env_set_data_slot ("menu", newmenu);
 236
 237   while (1)
 238     {
 239       struct grub_script *parsed_script;
 240       int startline;
 241       char *cmdline;
 242
 243       cmdline = get_line (file);
 244       if (!cmdline)
 245         break;
 246
 247       startline = ++currline;
 248
 249       /* Execute the script, line for line.  */
 250       parsed_script = grub_script_parse (cmdline, getline);
 251
 252       grub_free (cmdline);
 253
 254       if (! parsed_script)
 255         {
 256           grub_printf ("(line %d-%d)\n", startline, currline);
 257           errors++;
 258           continue;
 259         }
 260
 261       /* Execute the command(s).  */
 262       grub_script_execute (parsed_script);
 263
 264       /* Ignore errors.  */
 265       grub_errno = GRUB_ERR_NONE;
 266
 267       /* The parsed script was executed, throw it away.  */
 268       grub_script_free (parsed_script);
 269     }
 270
 271   grub_file_close (file);
 272
 273   if (errors > 0)
 274     grub_wait_after_message ();
 275
 276   return newmenu;
 277 }
 278
 279 /* This starts the normal mode.  */
 280 void
 281 grub_enter_normal_mode (const char *config)
 282 {
 283   if (grub_setjmp (grub_exit_env) == 0)
 284     grub_normal_execute (config, 0);
 285 }
 286
 287 /* Initialize the screen.  */
 288 void
 289 grub_normal_init_page (void)
 290 {
 291   grub_cls ();
 292   grub_printf ("\n\
 293                          GNU GRUB  version %s\n\n",
 294                PACKAGE_VERSION);
 295 }
 296
 297 /* Read the file command.lst for auto-loading.  */
 298 static void
 299 read_command_list (void)
 300 {
 301   const char *prefix;
 302
 303   prefix = grub_env_get ("prefix");
 304   if (prefix)
 305     {
 306       char *filename;
 307
 308       filename = grub_malloc (grub_strlen (prefix) + sizeof ("/command.lst"));
 309       if (filename)
 310         {
 311           grub_file_t file;
 312
 313           grub_sprintf (filename, "%s/command.lst", prefix);
 314           file = grub_file_open (filename);
 315           if (file)
 316             {
 317               while (1)
 318                 {
 319                   char *p;
 320                   grub_command_t cmd;
 321                   char *buf = get_line (file);
 322
 323                   if (! buf)
 324                     break;
 325
 326                   if (! grub_isgraph (buf[0]))
 327                     continue;
 328
 329                   p = grub_strchr (buf, ':');
 330                   if (! p)
 331                     continue;
 332
 333                   *p = '\0';
 334                   while (*++p == ' ')
 335                     ;
 336
 337                   if (! grub_isgraph (*p))
 338                     continue;
 339
 340                   cmd = grub_register_command (buf, 0,
 341                                                GRUB_COMMAND_FLAG_NOT_LOADED,
 342                                                0, 0, 0);
 343                   if (! cmd)
 344                     {
 345                       grub_free (buf);
 346                       continue;
 347                     }
 348
 349                   cmd->module_name = grub_strdup (p);
 350                   if (! cmd->module_name)
 351                     grub_unregister_command (buf);
 352                   grub_free (buf);
 353                 }
 354
 355               grub_file_close (file);
 356             }
 357
 358           grub_free (filename);
 359         }
 360     }
 361
 362   /* Ignore errors.  */
 363   grub_errno = GRUB_ERR_NONE;
 364 }
 365
 366 /* The auto-loading hook for filesystems.  */
 367 static int
 368 autoload_fs_module (void)
 369 {
 370   grub_fs_module_list_t p;
 371
 372   while ((p = fs_module_list) != 0)
 373     {
 374       if (! grub_dl_get (p->name) && grub_dl_load (p->name))
 375         return 1;
 376
 377       fs_module_list = p->next;
 378       grub_free (p->name);
 379       grub_free (p);
 380     }
 381
 382   return 0;
 383 }
 384
 385 /* Read the file fs.lst for auto-loading.  */
 386 static void
 387 read_fs_list (void)
 388 {
 389   const char *prefix;
 390
 391   prefix = grub_env_get ("prefix");
 392   if (prefix)
 393     {
 394       char *filename;
 395
 396       filename = grub_malloc (grub_strlen (prefix) + sizeof ("/fs.lst"));
 397       if (filename)
 398         {
 399           grub_file_t file;
 400
 401           grub_sprintf (filename, "%s/fs.lst", prefix);
 402           file = grub_file_open (filename);
 403           if (file)
 404             {
 405               while (1)
 406                 {
 407                   char *buf;
 408                   char *p;
 409                   char *q;
 410                   grub_fs_module_list_t fs_mod;
 411
 412                   buf = get_line (file);
 413                   if (! buf)
 414                     break;
 415
 416                   p = buf;
 417                   q = buf + grub_strlen (buf) - 1;
 418
 419                   /* Ignore space.  */
 420                   while (grub_isspace (*p))
 421                     p++;
 422
 423                   while (p < q && grub_isspace (*q))
 424                     *q-- = '\0';
 425
 426                   /* If the line is empty, skip it.  */
 427                   if (p >= q)
 428                     continue;
 429
 430                   fs_mod = grub_malloc (sizeof (*fs_mod));
 431                   if (! fs_mod)
 432                     continue;
 433
 434                   fs_mod->name = grub_strdup (p);
 435                   if (! fs_mod->name)
 436                     {
 437                       grub_free (fs_mod);
 438                       continue;
 439                     }
 440
 441                   fs_mod->next = fs_module_list;
 442                   fs_module_list = fs_mod;
 443                 }
 444
 445               grub_file_close (file);
 446             }
 447
 448           grub_free (filename);
 449         }
 450     }
 451
 452   /* Ignore errors.  */
 453   grub_errno = GRUB_ERR_NONE;
 454
 455   /* Set the hook.  */
 456   grub_fs_autoload_hook = autoload_fs_module;
 457 }
 458
 459 /* Read the config file CONFIG and execute the menu interface or
 460    the command-line interface.  */
 461 void
 462 grub_normal_execute (const char *config, int nested)
 463 {
 464   grub_menu_t menu = 0;
 465
 466   read_command_list ();
 467   read_fs_list ();
 468
 469   if (config)
 470     {
 471       menu = read_config_file (config, nested);
 472
 473       /* Ignore any error.  */
 474       grub_errno = GRUB_ERR_NONE;
 475     }
 476
 477   if (menu && menu->size)
 478     {
 479       grub_menu_run (menu, nested);
 480       if (nested)
 481         free_menu (menu);
 482     }
 483   else
 484     grub_cmdline_run (nested);
 485 }
 486
 487 /* Enter normal mode from rescue mode.  */
 488 static void
 489 grub_rescue_cmd_normal (int argc, char *argv[])
 490 {
 491   if (argc == 0)
 492     {
 493       /* Guess the config filename. It is necessary to make CONFIG static,
 494          so that it won't get broken by longjmp.  */
 495       static char *config;
 496       const char *prefix;
 497
 498       prefix = grub_env_get ("prefix");
 499       if (prefix)
 500         {
 501           config = grub_malloc (grub_strlen (prefix) + sizeof ("/grub.cfg"));
 502           if (! config)
 503             return;
 504
 505           grub_sprintf (config, "%s/grub.cfg", prefix);
 506           grub_enter_normal_mode (config);
 507           grub_free (config);
 508         }
 509       else
 510         grub_enter_normal_mode (0);
 511     }
 512   else
 513     grub_enter_normal_mode (argv[0]);
 514 }
 515
 516 GRUB_MOD_INIT(normal)
 517 {
 518   /* Normal mode shouldn't be unloaded.  */
 519   if (mod)
 520     grub_dl_ref (mod);
 521
 522   grub_set_history (GRUB_DEFAULT_HISTORY_SIZE);
 523
 524   /* Register a command "normal" for the rescue mode.  */
 525   grub_rescue_register_command ("normal", grub_rescue_cmd_normal,
 526                                 "enter normal mode");
 527
 528   /* Reload terminal colors when these variables are written to.  */
 529   grub_register_variable_hook ("color_normal", NULL, grub_env_write_color_normal);
 530   grub_register_variable_hook ("color_highlight", NULL, grub_env_write_color_highlight);
 531
 532   /* Preserve hooks after context changes.  */
 533   grub_env_export ("color_normal");
 534   grub_env_export ("color_highlight");
 535
 536   /* This registers some built-in commands.  */
 537   grub_command_init ();
 538 }
 539
 540 GRUB_MOD_FINI(normal)
 541 {
 542   grub_set_history (0);
 543   grub_rescue_unregister_command ("normal");
 544 }
 545