/* parser.c - the part of the parser that can return partial tokens */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2005,2007,2009 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/parser.h>
#include <grub/env.h>
#include <grub/misc.h>
#include <grub/mm.h>
/* All the possible state transitions on the command line. If a
transition can not be found, it is assumed that there is no
transition and keep_value is assumed to be 1. */
static struct grub_parser_state_transition state_transitions[] = {
{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_QUOTE, '\'', 0},
{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_DQUOTE, '\"', 0},
{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_VAR, '$', 0},
{GRUB_PARSER_STATE_TEXT, GRUB_PARSER_STATE_ESC, '\\', 0},
{GRUB_PARSER_STATE_ESC, GRUB_PARSER_STATE_TEXT, 0, 1},
{GRUB_PARSER_STATE_QUOTE, GRUB_PARSER_STATE_TEXT, '\'', 0},
{GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_TEXT, '\"', 0},
{GRUB_PARSER_STATE_DQUOTE, GRUB_PARSER_STATE_QVAR, '$', 0},
{GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME2, '{', 0},
{GRUB_PARSER_STATE_VAR, GRUB_PARSER_STATE_VARNAME, 0, 1},
{GRUB_PARSER_STATE_VARNAME, GRUB_PARSER_STATE_TEXT, ' ', 1},
{GRUB_PARSER_STATE_VARNAME2, GRUB_PARSER_STATE_TEXT, '}', 0},
{GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME2, '{', 0},
{GRUB_PARSER_STATE_QVAR, GRUB_PARSER_STATE_QVARNAME, 0, 1},
{GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_TEXT, '\"', 0},
{GRUB_PARSER_STATE_QVARNAME, GRUB_PARSER_STATE_DQUOTE, ' ', 1},
{GRUB_PARSER_STATE_QVARNAME2, GRUB_PARSER_STATE_DQUOTE, '}', 0},
{0, 0, 0, 0}
};
/* Determines the state following STATE, determined by C. */
grub_parser_state_t
grub_parser_cmdline_state (grub_parser_state_t state, char c, char *result)
{
struct grub_parser_state_transition *transition;
struct grub_parser_state_transition default_transition;
default_transition.to_state = state;
default_transition.keep_value = 1;
/* Look for a good translation. */
for (transition = state_transitions; transition->from_state; transition++)
{
if (transition->from_state != state)
continue;
/* An exact match was found, use it. */
if (transition->input == c)
break;
if (transition->input == ' ' && !grub_isalpha (c)
&& !grub_isdigit (c) && c != '_')
break;
/* A less perfect match was found, use this one if no exact
match can be found. */
if (transition->input == 0)
break;
}
if (!transition->from_state)
transition = &default_transition;
if (transition->keep_value)
*result = c;
else
*result = 0;
return transition->to_state;
}
grub_err_t
grub_parser_split_cmdline (const char *cmdline, grub_reader_getline_t getline,
int *argc, char ***argv)
{
grub_parser_state_t state = GRUB_PARSER_STATE_TEXT;
/* XXX: Fixed size buffer, perhaps this buffer should be dynamically
allocated. */
char buffer[1024];
char *bp = buffer;
char *rd = (char *) cmdline;
char varname[200];
char *vp = varname;
char *args;
int i;
auto int check_varstate (grub_parser_state_t s);
int check_varstate (grub_parser_state_t s)
{
return (s == GRUB_PARSER_STATE_VARNAME
|| s == GRUB_PARSER_STATE_VARNAME2
|| s == GRUB_PARSER_STATE_QVARNAME
|| s == GRUB_PARSER_STATE_QVARNAME2);
}
auto void add_var (grub_parser_state_t newstate);
void add_var (grub_parser_state_t newstate)
{
const char *val;
/* Check if a variable was being read in and the end of the name
was reached. */
if (!(check_varstate (state) && !check_varstate (newstate)))
return;
*(vp++) = '\0';
val = grub_env_get (varname);
vp = varname;
if (!val)
return;
/* Insert the contents of the variable in the buffer. */
for (; *val; val++)
*(bp++) = *val;
}
*argc = 0;
do
{
if (!rd || !*rd)
{
if (getline)
getline (&rd, 1);
else
break;
}
if (!rd)
break;
for (; *rd; rd++)
{
grub_parser_state_t newstate;
char use;
newstate = grub_parser_cmdline_state (state, *rd, &use);
/* If a variable was being processed and this character does
not describe the variable anymore, write the variable to
the buffer. */
add_var (newstate);
if (check_varstate (newstate))
{
if (use)
*(vp++) = use;
}
else
{
if (newstate == GRUB_PARSER_STATE_TEXT
&& state != GRUB_PARSER_STATE_ESC && use == ' ')
{
/* Don't add more than one argument if multiple
spaces are used. */
if (bp != buffer && *(bp - 1))
{
*(bp++) = '\0';
(*argc)++;
}
}
else if (use)
*(bp++) = use;
}
state = newstate;
}
}
while (state != GRUB_PARSER_STATE_TEXT && !check_varstate (state));
/* A special case for when the last character was part of a
variable. */
add_var (GRUB_PARSER_STATE_TEXT);
if (bp != buffer && *(bp - 1))
{
*(bp++) = '\0';
(*argc)++;
}
/* Reserve memory for the return values. */
args = grub_malloc (bp - buffer);
if (!args)
return grub_errno;
grub_memcpy (args, buffer, bp - buffer);
*argv = grub_malloc (sizeof (char *) * (*argc + 1));
if (!*argv)
{
grub_free (args);
return grub_errno;
}
/* The arguments are separated with 0's, setup argv so it points to
the right values. */
bp = args;
for (i = 0; i < *argc; i++)
{
(*argv)[i] = bp;
while (*bp)
bp++;
bp++;
}
return 0;
}
grub_err_t
grub_parser_execute (char *source)
{
auto grub_err_t getline (char **line, int cont);
grub_err_t getline (char **line, int cont __attribute__ ((unused)))
{
char *p;
if (!source)
{
*line = 0;
return 0;
}
p = grub_strchr (source, '\n');
if (p)
*line = grub_strndup (source, p - source);
else
*line = grub_strdup (source);
source = p ? p + 1 : 0;
return 0;
}
while (source)
{
char *line;
getline (&line, 0);
grub_rescue_parse_line (line, getline);
grub_free (line);
}
return grub_errno;
}