udev_config.c

   1 /*
   2  * udev_config.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
   7  *
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 /* define this to enable parsing debugging */
  25 /* #define DEBUG_PARSER */
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <stdio.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <ctype.h>
  34
  35 #include "udev.h"
  36 #include "udev_version.h"
  37 #include "logging.h"
  38 #include "namedev.h"
  39 #include "libsysfs/libsysfs.h"
  40
  41 /* global variables */
  42 char sysfs_path[SYSFS_PATH_MAX];
  43 char udev_root[PATH_MAX];
  44 char udev_db_filename[PATH_MAX+NAME_MAX];
  45 char udev_permissions_filename[PATH_MAX+NAME_MAX];
  46 char udev_rules_filename[PATH_MAX+NAME_MAX];
  47 char udev_config_filename[PATH_MAX+NAME_MAX];
  48 char default_mode_str[MODE_SIZE];
  49 char default_owner_str[OWNER_SIZE];
  50 char default_group_str[GROUP_SIZE];
  51 int udev_log;
  52
  53
  54 static int string_is_true(char *str)
  55 {
  56         if (strcasecmp(str, "true") == 0)
  57                 return 1;
  58         if (strcasecmp(str, "yes") == 0)
  59                 return 1;
  60         return 0;
  61 }
  62
  63 static void init_variables(void)
  64 {
  65         /* fill up the defaults.
  66          * If any config values are specified, they will
  67          * override these values. */
  68         strfieldcpy(udev_root, UDEV_ROOT);
  69         strfieldcpy(udev_db_filename, UDEV_DB);
  70         strfieldcpy(udev_config_filename, UDEV_CONFIG_FILE);
  71         strfieldcpy(udev_rules_filename, UDEV_RULES_FILE);
  72         strfieldcpy(udev_permissions_filename, UDEV_PERMISSION_FILE);
  73         udev_log = string_is_true(UDEV_LOG_DEFAULT);
  74 }
  75
  76 #define set_var(_name, _var)                            \
  77         if (strcasecmp(variable, _name) == 0) {         \
  78                 dbg_parse("%s = '%s'", _name, value);   \
  79                 strncpy(_var, value, sizeof(_var));     \
  80         }
  81
  82 #define set_bool(_name, _var)                           \
  83         if (strcasecmp(variable, _name) == 0) {         \
  84                 dbg_parse("%s = '%s'", _name, value);   \
  85                 _var = string_is_true(value);           \
  86         }
  87
  88 int parse_get_pair(char **orig_string, char **left, char **right)
  89 {
  90         char *temp;
  91         char *string = *orig_string;
  92
  93         if (!string)
  94                 return -ENODEV;
  95
  96         /* eat any whitespace */
  97         while (isspace(*string) || *string == ',')
  98                 ++string;
  99
 100         /* split based on '=' */
 101         temp = strsep(&string, "=");
 102         *left = temp;
 103         if (!string)
 104                 return -ENODEV;
 105
 106         /* take the right side and strip off the '"' */
 107         while (isspace(*string))
 108                 ++string;
 109         if (*string == '"')
 110                 ++string;
 111         else
 112                 return -ENODEV;
 113
 114         temp = strsep(&string, "\"");
 115         if (!string || *temp == '\0')
 116                 return -ENODEV;
 117         *right = temp;
 118         *orig_string = string;
 119
 120         return 0;
 121 }
 122
 123 static int parse_config_file(void)
 124 {
 125         char line[255];
 126         char *temp;
 127         char *variable;
 128         char *value;
 129         FILE *fd;
 130         int lineno = 0;
 131         int retval = 0;
 132
 133         fd = fopen(udev_config_filename, "r");
 134         if (fd != NULL) {
 135                 dbg("reading '%s' as config file", udev_config_filename);
 136         } else {
 137                 dbg("can't open '%s' as config file", udev_config_filename);
 138                 return -ENODEV;
 139         }
 140
 141         /* loop through the whole file */
 142         while (1) {
 143                 /* get a line */
 144                 temp = fgets(line, sizeof(line), fd);
 145                 if (temp == NULL)
 146                         goto exit;
 147                 lineno++;
 148
 149                 dbg_parse("read '%s'", temp);
 150
 151                 /* eat the whitespace at the beginning of the line */
 152                 while (isspace(*temp))
 153                         ++temp;
 154
 155                 /* empty line? */
 156                 if (*temp == 0x00)
 157                         continue;
 158
 159                 /* see if this is a comment */
 160                 if (*temp == COMMENT_CHARACTER)
 161                         continue;
 162
 163                 retval = parse_get_pair(&temp, &variable, &value);
 164                 if (retval)
 165                         break;
 166
 167                 dbg_parse("variable = '%s', value = '%s'", variable, value);
 168
 169                 set_var("udev_root", udev_root);
 170                 set_var("udev_db", udev_db_filename);
 171                 set_var("udev_rules", udev_rules_filename);
 172                 set_var("udev_permissions", udev_permissions_filename);
 173                 set_var("default_mode", default_mode_str);
 174                 set_var("default_owner", default_owner_str);
 175                 set_var("default_group", default_group_str);
 176                 set_bool("udev_log", udev_log);
 177         }
 178         dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 179                   lineno, temp - line, temp);
 180 exit:
 181         fclose(fd);
 182         return retval;
 183 }
 184
 185 static void get_dirs(void)
 186 {
 187         char *temp;
 188         int retval;
 189
 190         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
 191         if (retval)
 192                 dbg("sysfs_get_mnt_path failed");
 193
 194         /* see if we should try to override any of the default values */
 195         temp = getenv("UDEV_TEST");
 196         if (temp != NULL) {
 197                 /* hm testing is happening, use the specified values, if they are present */
 198                 temp = getenv("SYSFS_PATH");
 199                 if (temp)
 200                         strfieldcpy(sysfs_path, temp);
 201                 temp = getenv("UDEV_CONFIG_FILE");
 202                 if (temp)
 203                         strfieldcpy(udev_config_filename, temp);
 204         }
 205         dbg("sysfs_path='%s'", sysfs_path);
 206
 207         dbg_parse("udev_root = %s", udev_root);
 208         dbg_parse("udev_config_filename = %s", udev_config_filename);
 209         dbg_parse("udev_db_filename = %s", udev_db_filename);
 210         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 211         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 212         dbg_parse("udev_log = %d", udev_log);
 213         parse_config_file();
 214
 215         dbg_parse("udev_root = %s", udev_root);
 216         dbg_parse("udev_config_filename = %s", udev_config_filename);
 217         dbg_parse("udev_db_filename = %s", udev_db_filename);
 218         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 219         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 220         dbg_parse("udev_log_str = %d", udev_log);
 221 }
 222
 223 void udev_init_config(void)
 224 {
 225         init_variables();
 226         get_dirs();
 227 }
 228
 229