grub/normal/main.c
bean e93e4679ce 2008-07-29 Bean <bean123ch@gmail.com>
* normal/main.c (get_line): Fix buffer overflow bug.
2008-07-29 15:07:47 +00:00

545 lines
11 KiB
C

/* main.c - the normal mode main routine */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2000,2001,2002,2003,2005,2006,2007,2008 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/kernel.h>
#include <grub/normal.h>
#include <grub/dl.h>
#include <grub/rescue.h>
#include <grub/misc.h>
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/term.h>
#include <grub/env.h>
#include <grub/parser.h>
#include <grub/script.h>
grub_jmp_buf grub_exit_env;
static grub_fs_module_list_t fs_module_list = 0;
#define GRUB_DEFAULT_HISTORY_SIZE 50
/* Read a line from the file FILE. */
static char *
get_line (grub_file_t file)
{
char c;
int pos = 0;
int literal = 0;
int comment = 0;
char *cmdline;
int max_len = 64;
/* Initially locate some space. */
cmdline = grub_malloc (max_len);
if (! cmdline)
return 0;
while (1)
{
if (grub_file_read (file, &c, 1) != 1)
break;
/* Skip all carriage returns. */
if (c == '\r')
continue;
/* Replace tabs with spaces. */
if (c == '\t')
c = ' ';
/* The previous is a backslash, then... */
if (literal)
{
/* If it is a newline, replace it with a space and continue. */
if (c == '\n')
{
c = ' ';
/* Go back to overwrite the backslash. */
if (pos > 0)
pos--;
}
literal = 0;
}
if (c == '\\')
literal = 1;
if (comment)
{
if (c == '\n')
comment = 0;
}
else if (pos == 0)
{
if (c == '#')
comment = 1;
else if (! grub_isspace (c))
cmdline[pos++] = c;
}
else
{
if (pos >= max_len)
{
char *old_cmdline = cmdline;
max_len = max_len * 2;
cmdline = grub_realloc (cmdline, max_len);
if (! cmdline)
{
grub_free (old_cmdline);
return 0;
}
}
if (c == '\n')
break;
cmdline[pos++] = c;
}
}
cmdline[pos] = '\0';
/* If the buffer is empty, don't return anything at all. */
if (pos == 0)
{
grub_free (cmdline);
cmdline = 0;
}
return cmdline;
}
static void
free_menu (grub_menu_t menu)
{
grub_menu_entry_t entry = menu->entry_list;
while (entry)
{
grub_menu_entry_t next_entry = entry->next;
grub_script_free (entry->commands);
grub_free ((void *) entry->title);
grub_free ((void *) entry->sourcecode);
entry = next_entry;
}
grub_free (menu);
grub_env_unset_data_slot ("menu");
}
grub_err_t
grub_normal_menu_addentry (const char *title, struct grub_script *script,
const char *sourcecode)
{
const char *menutitle;
const char *menusourcecode;
grub_menu_t menu;
grub_menu_entry_t *last;
menu = grub_env_get_data_slot("menu");
if (! menu)
return grub_error (GRUB_ERR_MENU, "no menu context");
last = &menu->entry_list;
menusourcecode = grub_strdup (sourcecode);
if (! menusourcecode)
return grub_errno;
menutitle = grub_strdup (title);
if (! menutitle)
{
grub_free ((void *) menusourcecode);
return grub_errno;
}
/* Add the menu entry at the end of the list. */
while (*last)
last = &(*last)->next;
*last = grub_malloc (sizeof (**last));
if (! *last)
{
grub_free ((void *) menutitle);
grub_free ((void *) menusourcecode);
return grub_errno;
}
(*last)->commands = script;
(*last)->title = menutitle;
(*last)->next = 0;
(*last)->sourcecode = menusourcecode;
menu->size++;
return GRUB_ERR_NONE;
}
static grub_menu_t
read_config_file (const char *config, int nested)
{
grub_file_t file;
auto grub_err_t getline (char **line);
int currline = 0;
int errors = 0;
grub_err_t getline (char **line)
{
currline++;
*line = get_line (file);
if (! *line)
return grub_errno;
return GRUB_ERR_NONE;
}
grub_menu_t newmenu;
newmenu = grub_env_get_data_slot ("menu");
if (nested || ! newmenu)
{
newmenu = grub_malloc (sizeof (*newmenu));
if (! newmenu)
return 0;
newmenu->size = 0;
newmenu->entry_list = 0;
}
/* Try to open the config file. */
file = grub_file_open (config);
if (! file)
return 0;
grub_env_set_data_slot ("menu", newmenu);
while (1)
{
struct grub_script *parsed_script;
int startline;
char *cmdline;
cmdline = get_line (file);
if (!cmdline)
break;
startline = ++currline;
/* Execute the script, line for line. */
parsed_script = grub_script_parse (cmdline, getline);
grub_free (cmdline);
if (! parsed_script)
{
grub_printf ("(line %d-%d)\n", startline, currline);
errors++;
continue;
}
/* Execute the command(s). */
grub_script_execute (parsed_script);
/* Ignore errors. */
grub_errno = GRUB_ERR_NONE;
/* The parsed script was executed, throw it away. */
grub_script_free (parsed_script);
}
grub_file_close (file);
if (errors > 0)
grub_wait_after_message ();
return newmenu;
}
/* This starts the normal mode. */
void
grub_enter_normal_mode (const char *config)
{
if (grub_setjmp (grub_exit_env) == 0)
grub_normal_execute (config, 0);
}
/* Initialize the screen. */
void
grub_normal_init_page (void)
{
grub_cls ();
grub_printf ("\n\
GNU GRUB version %s\n\n",
PACKAGE_VERSION);
}
/* Read the file command.lst for auto-loading. */
static void
read_command_list (void)
{
const char *prefix;
prefix = grub_env_get ("prefix");
if (prefix)
{
char *filename;
filename = grub_malloc (grub_strlen (prefix) + sizeof ("/command.lst"));
if (filename)
{
grub_file_t file;
grub_sprintf (filename, "%s/command.lst", prefix);
file = grub_file_open (filename);
if (file)
{
while (1)
{
char *p;
grub_command_t cmd;
char *buf = get_line (file);
if (! buf)
break;
if (! grub_isgraph (buf[0]))
continue;
p = grub_strchr (buf, ':');
if (! p)
continue;
*p = '\0';
while (*++p == ' ')
;
if (! grub_isgraph (*p))
continue;
cmd = grub_register_command (buf, 0,
GRUB_COMMAND_FLAG_NOT_LOADED,
0, 0, 0);
if (! cmd)
{
grub_free (buf);
continue;
}
cmd->module_name = grub_strdup (p);
if (! cmd->module_name)
grub_unregister_command (buf);
grub_free (buf);
}
grub_file_close (file);
}
grub_free (filename);
}
}
/* Ignore errors. */
grub_errno = GRUB_ERR_NONE;
}
/* The auto-loading hook for filesystems. */
static int
autoload_fs_module (void)
{
grub_fs_module_list_t p;
while ((p = fs_module_list) != 0)
{
if (! grub_dl_get (p->name) && grub_dl_load (p->name))
return 1;
fs_module_list = p->next;
grub_free (p->name);
grub_free (p);
}
return 0;
}
/* Read the file fs.lst for auto-loading. */
static void
read_fs_list (void)
{
const char *prefix;
prefix = grub_env_get ("prefix");
if (prefix)
{
char *filename;
filename = grub_malloc (grub_strlen (prefix) + sizeof ("/fs.lst"));
if (filename)
{
grub_file_t file;
grub_sprintf (filename, "%s/fs.lst", prefix);
file = grub_file_open (filename);
if (file)
{
while (1)
{
char *buf;
char *p;
char *q;
grub_fs_module_list_t fs_mod;
buf = get_line (file);
if (! buf)
break;
p = buf;
q = buf + grub_strlen (buf) - 1;
/* Ignore space. */
while (grub_isspace (*p))
p++;
while (p < q && grub_isspace (*q))
*q-- = '\0';
/* If the line is empty, skip it. */
if (p >= q)
continue;
fs_mod = grub_malloc (sizeof (*fs_mod));
if (! fs_mod)
continue;
fs_mod->name = grub_strdup (p);
if (! fs_mod->name)
{
grub_free (fs_mod);
continue;
}
fs_mod->next = fs_module_list;
fs_module_list = fs_mod;
}
grub_file_close (file);
}
grub_free (filename);
}
}
/* Ignore errors. */
grub_errno = GRUB_ERR_NONE;
/* Set the hook. */
grub_fs_autoload_hook = autoload_fs_module;
}
/* Read the config file CONFIG and execute the menu interface or
the command-line interface. */
void
grub_normal_execute (const char *config, int nested)
{
grub_menu_t menu = 0;
read_command_list ();
read_fs_list ();
if (config)
{
menu = read_config_file (config, nested);
/* Ignore any error. */
grub_errno = GRUB_ERR_NONE;
}
if (menu && menu->size)
{
grub_menu_run (menu, nested);
if (nested)
free_menu (menu);
}
else
grub_cmdline_run (nested);
}
/* Enter normal mode from rescue mode. */
static void
grub_rescue_cmd_normal (int argc, char *argv[])
{
if (argc == 0)
{
/* Guess the config filename. It is necessary to make CONFIG static,
so that it won't get broken by longjmp. */
static char *config;
const char *prefix;
prefix = grub_env_get ("prefix");
if (prefix)
{
config = grub_malloc (grub_strlen (prefix) + sizeof ("/grub.cfg"));
if (! config)
return;
grub_sprintf (config, "%s/grub.cfg", prefix);
grub_enter_normal_mode (config);
grub_free (config);
}
else
grub_enter_normal_mode (0);
}
else
grub_enter_normal_mode (argv[0]);
}
GRUB_MOD_INIT(normal)
{
/* Normal mode shouldn't be unloaded. */
if (mod)
grub_dl_ref (mod);
grub_set_history (GRUB_DEFAULT_HISTORY_SIZE);
/* Register a command "normal" for the rescue mode. */
grub_rescue_register_command ("normal", grub_rescue_cmd_normal,
"enter normal mode");
/* Reload terminal colors when these variables are written to. */
grub_register_variable_hook ("color_normal", NULL, grub_env_write_color_normal);
grub_register_variable_hook ("color_highlight", NULL, grub_env_write_color_highlight);
/* Preserve hooks after context changes. */
grub_env_export ("color_normal");
grub_env_export ("color_highlight");
/* This registers some built-in commands. */
grub_command_init ();
}
GRUB_MOD_FINI(normal)
{
grub_set_history (0);
grub_rescue_unregister_command ("normal");
}