diff options
Diffstat (limited to 'grub-core/kern/parser.c')
| -rw-r--r-- | grub-core/kern/parser.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/grub-core/kern/parser.c b/grub-core/kern/parser.c new file mode 100644 index 0000000..6370a7b --- /dev/null +++ b/grub-core/kern/parser.c @@ -0,0 +1,267 @@ +/* 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) + { + 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; +} |