script/lua/grub_main.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2009  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "lua.h"
  20 #include "lauxlib.h"
  21 #include "lualib.h"
  22 #include "grub_lib.h"
  23
  24 #include <grub/dl.h>
  25 #include <grub/parser.h>
  26
  27 static lua_State *state;
  28
  29 static grub_err_t
  30 grub_lua_parse_line (char *line, grub_reader_getline_t getline)
  31 {
  32   int r;
  33   char *old_line = 0;
  34
  35   lua_settop(state, 0);
  36   while (1)
  37     {
  38       r = luaL_loadbuffer (state, line, grub_strlen (line), "grub");
  39       if (! r)
  40         {
  41           r = lua_pcall (state, 0, 0, 0);
  42           if (r)
  43             grub_error (GRUB_ERR_BAD_ARGUMENT, "lua command fails");
  44           else
  45             {
  46               grub_free (old_line);
  47               return grub_errno;
  48             }
  49           break;
  50         }
  51
  52       if (r == LUA_ERRSYNTAX)
  53         {
  54           size_t lmsg;
  55           const char *msg = lua_tolstring(state, -1, &lmsg);
  56           const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
  57           if (grub_strstr(msg, LUA_QL("<eof>")) == tp)
  58             {
  59               char *n, *t;
  60               int len;
  61
  62               lua_pop(state, 1);
  63               if ((getline (&n, 1)) || (! n))
  64                 {
  65                   grub_error (GRUB_ERR_BAD_ARGUMENT, "incomplete command");
  66                   break;
  67                 }
  68
  69               len = grub_strlen (line);
  70               t = grub_malloc (len + grub_strlen (n) + 2);
  71               if (! t)
  72                 break;
  73
  74               grub_strcpy (t, line);
  75               t[len] = '\n';
  76               grub_strcpy (t + len + 1, n);
  77               grub_free (old_line);
  78               line = old_line = t;
  79               continue;
  80             }
  81         }
  82
  83       break;
  84     }
  85
  86   grub_free (old_line);
  87   lua_gc (state, LUA_GCCOLLECT, 0);
  88
  89   return grub_errno;
  90 }
  91
  92 static struct grub_parser grub_lua_parser =
  93   {
  94     .name = "lua",
  95     .parse_line = grub_lua_parse_line
  96   };
  97
  98 GRUB_MOD_INIT(lua)
  99 {
 100   (void) mod;
 101
 102   state = lua_open ();
 103   if (state)
 104     {
 105       lua_gc(state, LUA_GCSTOP, 0);
 106       luaL_openlibs(state);
 107       luaL_register(state, "grub", grub_lua_lib);
 108       lua_gc(state, LUA_GCRESTART, 0);
 109       grub_parser_register ("lua", &grub_lua_parser);
 110     }
 111 }
 112
 113 GRUB_MOD_FINI(lua)
 114 {
 115   if (state)
 116     {
 117       grub_parser_unregister (&grub_lua_parser);
 118       lua_close(state);
 119     }
 120 }