arch/all-pc/boot/grub2-aros/grub-core/kern/parser.c

   1 /* parser.c - the part of the parser that can return partial tokens */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2005,2007,2009  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/parser.h>
  21 #include <grub/env.h>
  22 #include <grub/misc.h>
  23 #include <grub/mm.h>
  24
  25
  26 /* All the possible state transitions on the command line.  If a
  27    transition can not be found, it is assumed that there is no
  28    transition and keep_value is assumed to be 1.  */
  29 static struct grub_parser_state_transition state_transitions[] = {
  30   {GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_QUOTE, '\'', 0},
  31   {GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_DQUOTE, '\"', 0},
  32   {GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_VAR, '$', 0},
  33   {GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_ESC, '\\', 0},
  34
  35   {GRUB_PARSER_STATE_ESC, GRUB_PARSER_STATE_TEXT, 0, 1},
  36
  37   {GRUB_PARSER_STATE_QUOTE, GRUB_PARSER_STATE_TEXT, '\'', 0},
  38
  39   {GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_TEXT, '\"', 0},
  40   {GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_QVAR, '$', 0},
  41
  42   {GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME2, '{', 0},
  43   {GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME, 0, 1},
  44   {GRUB_PARSER_STATE_VARNAME, GRUB_PARSER_STATE_TEXT, ' ', 1},
  45   {GRUB_PARSER_STATE_VARNAME, GRUB_PARSER_STATE_TEXT, '\t', 1},
  46   {GRUB_PARSER_STATE_VARNAME2, GRUB_PARSER_STATE_TEXT, '}', 0},
  47
  48   {GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME2, '{', 0},
  49   {GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME, 0, 1},
  50   {GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_TEXT, '\"', 0},
  51   {GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_DQUOTE, ' ', 1},
  52   {GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_DQUOTE, '\t', 1},
  53   {GRUB_PARSER_STATE_QVARNAME2, GRUB_PARSER_STATE_DQUOTE, '}', 0},
  54
  55   {0, 0, 0, 0}
  56 };
  57
  58
  59 /* Determines the state following STATE, determined by C.  */
  60 grub_parser_state_t
  61 grub_parser_cmdline_state (grub_parser_state_t state, char c, char *result)
  62 {
  63   struct grub_parser_state_transition *transition;
  64   struct grub_parser_state_transition default_transition;
  65
  66   default_transition.to_state = state;
  67   default_transition.keep_value = 1;
  68
  69   /* Look for a good translation.  */
  70   for (transition = state_transitions; transition->from_state; transition++)
  71     {
  72       if (transition->from_state != state)
  73         continue;
  74       /* An exact match was found, use it.  */
  75       if (transition->input == c)
  76         break;
  77
  78       if (grub_isspace (transition->input) && !grub_isalpha (c)
  79           && !grub_isdigit (c) && c != '_')
  80         break;
  81
  82       /* A less perfect match was found, use this one if no exact
  83          match can be found.  */
  84       if (transition->input == 0)
  85         break;
  86     }
  87
  88   if (!transition->from_state)
  89     transition = &default_transition;
  90
  91   if (transition->keep_value)
  92     *result = c;
  93   else
  94     *result = 0;
  95   return transition->to_state;
  96 }
  97
  98
  99 grub_err_t
 100 grub_parser_split_cmdline (const char *cmdline, grub_reader_getline_t getline,
 101                            int *argc, char ***argv)
 102 {
 103   grub_parser_state_t state = GRUB_PARSER_STATE_TEXT;
 104   /* XXX: Fixed size buffer, perhaps this buffer should be dynamically
 105      allocated.  */
 106   char buffer[1024];
 107   char *bp = buffer;
 108   char *rd = (char *) cmdline;
 109   char varname[200];
 110   char *vp = varname;
 111   char *args;
 112   int i;
 113
 114   auto int check_varstate (grub_parser_state_t s);
 115
 116   int check_varstate (grub_parser_state_t s)
 117   {
 118     return (s == GRUB_PARSER_STATE_VARNAME
 119             || s == GRUB_PARSER_STATE_VARNAME2
 120             || s == GRUB_PARSER_STATE_QVARNAME
 121             || s == GRUB_PARSER_STATE_QVARNAME2);
 122   }
 123
 124   auto void add_var (grub_parser_state_t newstate);
 125
 126   void add_var (grub_parser_state_t newstate)
 127   {
 128     const char *val;
 129
 130     /* Check if a variable was being read in and the end of the name
 131        was reached.  */
 132     if (!(check_varstate (state) && !check_varstate (newstate)))
 133       return;
 134
 135     *(vp++) = '\0';
 136     val = grub_env_get (varname);
 137     vp = varname;
 138     if (!val)
 139       return;
 140
 141     /* Insert the contents of the variable in the buffer.  */
 142     for (; *val; val++)
 143       *(bp++) = *val;
 144   }
 145
 146   *argc = 0;
 147   do
 148     {
 149       if (!rd || !*rd)
 150         {
 151           if (getline)
 152             getline (&rd, 1);
 153           else
 154             break;
 155         }
 156
 157       if (!rd)
 158         break;
 159
 160       for (; *rd; rd++)
 161         {
 162           grub_parser_state_t newstate;
 163           char use;
 164
 165           newstate = grub_parser_cmdline_state (state, *rd, &use);
 166
 167           /* If a variable was being processed and this character does
 168              not describe the variable anymore, write the variable to
 169              the buffer.  */
 170           add_var (newstate);
 171
 172           if (check_varstate (newstate))
 173             {
 174               if (use)
 175                 *(vp++) = use;
 176             }
 177           else
 178             {
 179               if (newstate == GRUB_PARSER_STATE_TEXT
 180                   && state != GRUB_PARSER_STATE_ESC && grub_isspace (use))
 181                 {
 182                   /* Don't add more than one argument if multiple
 183                      spaces are used.  */
 184                   if (bp != buffer && *(bp - 1))
 185                     {
 186                       *(bp++) = '\0';
 187                       (*argc)++;
 188                     }
 189                 }
 190               else if (use)
 191                 *(bp++) = use;
 192             }
 193           state = newstate;
 194         }
 195     }
 196   while (state != GRUB_PARSER_STATE_TEXT && !check_varstate (state));
 197
 198   /* A special case for when the last character was part of a
 199      variable.  */
 200   add_var (GRUB_PARSER_STATE_TEXT);
 201
 202   if (bp != buffer && *(bp - 1))
 203     {
 204       *(bp++) = '\0';
 205       (*argc)++;
 206     }
 207
 208   /* Reserve memory for the return values.  */
 209   args = grub_malloc (bp - buffer);
 210   if (!args)
 211     return grub_errno;
 212   grub_memcpy (args, buffer, bp - buffer);
 213
 214   *argv = grub_malloc (sizeof (char *) * (*argc + 1));
 215   if (!*argv)
 216     {
 217       grub_free (args);
 218       return grub_errno;
 219     }
 220
 221   /* The arguments are separated with 0's, setup argv so it points to
 222      the right values.  */
 223   bp = args;
 224   for (i = 0; i < *argc; i++)
 225     {
 226       (*argv)[i] = bp;
 227       while (*bp)
 228         bp++;
 229       bp++;
 230     }
 231
 232   return 0;
 233 }
 234
 235 grub_err_t
 236 grub_parser_execute (char *source)
 237 {
 238   auto grub_err_t getline (char **line, int cont);
 239   grub_err_t getline (char **line, int cont __attribute__ ((unused)))
 240   {
 241     char *p;
 242
 243     if (!source)
 244       {
 245         *line = 0;
 246         return 0;
 247       }
 248
 249     p = grub_strchr (source, '\n');
 250
 251     if (p)
 252       *line = grub_strndup (source, p - source);
 253     else
 254       *line = grub_strdup (source);
 255     source = p ? p + 1 : 0;
 256     return 0;
 257   }
 258
 259   while (source)
 260     {
 261       char *line;
 262
 263       getline (&line, 0);
 264       grub_rescue_parse_line (line, getline);
 265       grub_free (line);
 266     }
 267
 268   return grub_errno;
 269 }