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 #include <sysfs/libsysfs.h>
  35
  36 #include "udev.h"
  37 #include "udev_version.h"
  38 #include "logging.h"
  39 #include "namedev.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 int udev_sleep;
  53
  54
  55 static int string_is_true(char *str)
  56 {
  57         if (strcasecmp(str, "true") == 0)
  58                 return 1;
  59         if (strcasecmp(str, "yes") == 0)
  60                 return 1;
  61         return 0;
  62 }
  63
  64 static void init_variables(void)
  65 {
  66         /* fill up the defaults.
  67          * If any config values are specified, they will
  68          * override these values. */
  69         strfieldcpy(udev_root, UDEV_ROOT);
  70         strfieldcpy(udev_db_filename, UDEV_DB);
  71         strfieldcpy(udev_config_filename, UDEV_CONFIG_FILE);
  72         strfieldcpy(udev_rules_filename, UDEV_RULES_FILE);
  73         strfieldcpy(udev_permissions_filename, UDEV_PERMISSION_FILE);
  74         udev_log = string_is_true(UDEV_LOG_DEFAULT);
  75
  76         udev_sleep = 1;
  77         if (getenv("UDEV_NO_SLEEP") != NULL)
  78                 udev_sleep = 0;
  79 }
  80
  81 #define set_var(_name, _var)                            \
  82         if (strcasecmp(variable, _name) == 0) {         \
  83                 dbg_parse("%s = '%s'", _name, value);   \
  84                 strncpy(_var, value, sizeof(_var));     \
  85         }
  86
  87 #define set_bool(_name, _var)                           \
  88         if (strcasecmp(variable, _name) == 0) {         \
  89                 dbg_parse("%s = '%s'", _name, value);   \
  90                 _var = string_is_true(value);           \
  91         }
  92
  93 int parse_get_pair(char **orig_string, char **left, char **right)
  94 {
  95         char *temp;
  96         char *string = *orig_string;
  97
  98         if (!string)
  99                 return -ENODEV;
 100
 101         /* eat any whitespace */
 102         while (isspace(*string) || *string == ',')
 103                 ++string;
 104
 105         /* split based on '=' */
 106         temp = strsep(&string, "=");
 107         *left = temp;
 108         if (!string)
 109                 return -ENODEV;
 110
 111         /* take the right side and strip off the '"' */
 112         while (isspace(*string))
 113                 ++string;
 114         if (*string == '"')
 115                 ++string;
 116         else
 117                 return -ENODEV;
 118
 119         temp = strsep(&string, "\"");
 120         if (!string || *temp == '\0')
 121                 return -ENODEV;
 122         *right = temp;
 123         *orig_string = string;
 124
 125         return 0;
 126 }
 127
 128 static int parse_config_file(void)
 129 {
 130         char line[255];
 131         char *temp;
 132         char *variable;
 133         char *value;
 134         FILE *fd;
 135         int lineno = 0;
 136         int retval = 0;
 137
 138         fd = fopen(udev_config_filename, "r");
 139         if (fd != NULL) {
 140                 dbg("reading '%s' as config file", udev_config_filename);
 141         } else {
 142                 dbg("can't open '%s' as config file", udev_config_filename);
 143                 return -ENODEV;
 144         }
 145
 146         /* loop through the whole file */
 147         while (1) {
 148                 /* get a line */
 149                 temp = fgets(line, sizeof(line), fd);
 150                 if (temp == NULL)
 151                         goto exit;
 152                 lineno++;
 153
 154                 dbg_parse("read '%s'", temp);
 155
 156                 /* eat the whitespace at the beginning of the line */
 157                 while (isspace(*temp))
 158                         ++temp;
 159
 160                 /* empty line? */
 161                 if (*temp == 0x00)
 162                         continue;
 163
 164                 /* see if this is a comment */
 165                 if (*temp == COMMENT_CHARACTER)
 166                         continue;
 167
 168                 retval = parse_get_pair(&temp, &variable, &value);
 169                 if (retval)
 170                         break;
 171
 172                 dbg_parse("variable = '%s', value = '%s'", variable, value);
 173
 174                 set_var("udev_root", udev_root);
 175                 set_var("udev_db", udev_db_filename);
 176                 set_var("udev_rules", udev_rules_filename);
 177                 set_var("udev_permissions", udev_permissions_filename);
 178                 set_var("default_mode", default_mode_str);
 179                 set_var("default_owner", default_owner_str);
 180                 set_var("default_group", default_group_str);
 181                 set_bool("udev_log", udev_log);
 182         }
 183         dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 184                   lineno, temp - line, temp);
 185 exit:
 186         fclose(fd);
 187         return retval;
 188 }
 189
 190 static void get_dirs(void)
 191 {
 192         char *temp;
 193         int retval;
 194
 195         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
 196         if (retval)
 197                 dbg("sysfs_get_mnt_path failed");
 198
 199         /* see if we should try to override any of the default values */
 200         temp = getenv("UDEV_TEST");
 201         if (temp != NULL) {
 202                 /* hm testing is happening, use the specified values, if they are present */
 203                 temp = getenv("SYSFS_PATH");
 204                 if (temp)
 205                         strfieldcpy(sysfs_path, temp);
 206                 temp = getenv("UDEV_CONFIG_FILE");
 207                 if (temp)
 208                         strfieldcpy(udev_config_filename, temp);
 209         }
 210         dbg("sysfs_path='%s'", sysfs_path);
 211
 212         dbg_parse("udev_root = %s", udev_root);
 213         dbg_parse("udev_config_filename = %s", udev_config_filename);
 214         dbg_parse("udev_db_filename = %s", udev_db_filename);
 215         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 216         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 217         dbg_parse("udev_log = %d", udev_log);
 218         parse_config_file();
 219
 220         dbg_parse("udev_root = %s", udev_root);
 221         dbg_parse("udev_config_filename = %s", udev_config_filename);
 222         dbg_parse("udev_db_filename = %s", udev_db_filename);
 223         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 224         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 225         dbg_parse("udev_log_str = %d", udev_log);
 226 }
 227
 228 void udev_init_config(void)
 229 {
 230         init_variables();
 231         get_dirs();
 232 }
 233
 234