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 "libsysfs/sysfs/libsysfs.h"
  36 #include "udev.h"
  37 #include "udev_lib.h"
  38 #include "udev_version.h"
  39 #include "logging.h"
  40 #include "namedev.h"
  41
  42 /* global variables */
  43 char sysfs_path[SYSFS_PATH_MAX];
  44 char udev_root[PATH_MAX];
  45 char udev_db_filename[PATH_MAX+NAME_MAX];
  46 char udev_permissions_filename[PATH_MAX+NAME_MAX];
  47 char udev_rules_filename[PATH_MAX+NAME_MAX];
  48 char udev_config_filename[PATH_MAX+NAME_MAX];
  49 char default_mode_str[MODE_SIZE];
  50 char default_owner_str[OWNER_SIZE];
  51 char default_group_str[GROUP_SIZE];
  52 int udev_log;
  53 int udev_sleep;
  54 int udev_dev_d;
  55
  56
  57 static int string_is_true(char *str)
  58 {
  59         if (strcasecmp(str, "true") == 0)
  60                 return 1;
  61         if (strcasecmp(str, "yes") == 0)
  62                 return 1;
  63         return 0;
  64 }
  65
  66 static void init_variables(void)
  67 {
  68         /* fill up the defaults.
  69          * If any config values are specified, they will
  70          * override these values. */
  71         strfieldcpy(udev_root, UDEV_ROOT);
  72         strfieldcpy(udev_db_filename, UDEV_DB);
  73         strfieldcpy(udev_config_filename, UDEV_CONFIG_FILE);
  74         strfieldcpy(udev_rules_filename, UDEV_RULES_FILE);
  75         strfieldcpy(udev_permissions_filename, UDEV_PERMISSION_FILE);
  76         udev_log = string_is_true(UDEV_LOG_DEFAULT);
  77
  78         udev_sleep = 1;
  79         if (getenv("UDEV_NO_SLEEP") != NULL)
  80                 udev_sleep = 0;
  81
  82         udev_dev_d = 1;
  83         if (getenv("UDEV_NO_DEVD") != NULL)
  84                 udev_dev_d = 0;
  85 }
  86
  87 #define set_var(_name, _var)                            \
  88         if (strcasecmp(variable, _name) == 0) {         \
  89                 dbg_parse("%s='%s'", _name, value);     \
  90                 strfieldcpy(_var, value);\
  91         }
  92
  93 #define set_bool(_name, _var)                           \
  94         if (strcasecmp(variable, _name) == 0) {         \
  95                 dbg_parse("%s='%s'", _name, value);     \
  96                 _var = string_is_true(value);           \
  97         }
  98
  99 int parse_get_pair(char **orig_string, char **left, char **right)
 100 {
 101         char *temp;
 102         char *string = *orig_string;
 103
 104         if (!string)
 105                 return -ENODEV;
 106
 107         /* eat any whitespace */
 108         while (isspace(*string) || *string == ',')
 109                 ++string;
 110
 111         /* split based on '=' */
 112         temp = strsep(&string, "=");
 113         *left = temp;
 114         if (!string)
 115                 return -ENODEV;
 116
 117         /* take the right side and strip off the '"' */
 118         while (isspace(*string))
 119                 ++string;
 120         if (*string == '"')
 121                 ++string;
 122         else
 123                 return -ENODEV;
 124
 125         temp = strsep(&string, "\"");
 126         if (!string || *temp == '\0')
 127                 return -ENODEV;
 128         *right = temp;
 129         *orig_string = string;
 130
 131         return 0;
 132 }
 133
 134 static int parse_config_file(void)
 135 {
 136         char line[255];
 137         char *temp;
 138         char *variable;
 139         char *value;
 140         char *buf;
 141         size_t bufsize;
 142         size_t cur;
 143         size_t count;
 144         int lineno;
 145         int retval = 0;
 146
 147         if (file_map(udev_config_filename, &buf, &bufsize) == 0) {
 148                 dbg("reading '%s' as config file", udev_config_filename);
 149         } else {
 150                 dbg("can't open '%s' as config file", udev_config_filename);
 151                 return -ENODEV;
 152         }
 153
 154         /* loop through the whole file */
 155         lineno = 0;
 156         cur = 0;
 157         while (1) {
 158                 count = buf_get_line(buf, bufsize, cur);
 159
 160                 strncpy(line, buf + cur, count);
 161                 line[count] = '\0';
 162                 temp = line;
 163                 lineno++;
 164
 165                 cur += count+1;
 166                 if (cur > bufsize)
 167                         break;
 168
 169                 dbg_parse("read '%s'", temp);
 170
 171                 /* eat the whitespace at the beginning of the line */
 172                 while (isspace(*temp))
 173                         ++temp;
 174
 175                 /* empty line? */
 176                 if (*temp == 0x00)
 177                         continue;
 178
 179                 /* see if this is a comment */
 180                 if (*temp == COMMENT_CHARACTER)
 181                         continue;
 182
 183                 retval = parse_get_pair(&temp, &variable, &value);
 184                 if (retval)
 185                         break;
 186
 187                 dbg_parse("variable = '%s', value = '%s'", variable, value);
 188
 189                 set_var("udev_root", udev_root);
 190                 set_var("udev_db", udev_db_filename);
 191                 set_var("udev_rules", udev_rules_filename);
 192                 set_var("udev_permissions", udev_permissions_filename);
 193                 set_var("default_mode", default_mode_str);
 194                 set_var("default_owner", default_owner_str);
 195                 set_var("default_group", default_group_str);
 196                 set_bool("udev_log", udev_log);
 197         }
 198         dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 199                   lineno, temp - line, temp);
 200
 201         file_unmap(buf, bufsize);
 202         return retval;
 203 }
 204
 205 static void get_dirs(void)
 206 {
 207         char *temp;
 208         int retval;
 209
 210         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
 211         if (retval)
 212                 dbg("sysfs_get_mnt_path failed");
 213
 214         /* see if we should try to override any of the default values */
 215         temp = getenv("UDEV_TEST");
 216         if (temp != NULL) {
 217                 /* hm testing is happening, use the specified values, if they are present */
 218                 temp = getenv("SYSFS_PATH");
 219                 if (temp)
 220                         strfieldcpy(sysfs_path, temp);
 221                 temp = getenv("UDEV_CONFIG_FILE");
 222                 if (temp)
 223                         strfieldcpy(udev_config_filename, temp);
 224         }
 225         dbg("sysfs_path='%s'", sysfs_path);
 226
 227         dbg_parse("udev_root = %s", udev_root);
 228         dbg_parse("udev_config_filename = %s", udev_config_filename);
 229         dbg_parse("udev_db_filename = %s", udev_db_filename);
 230         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 231         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 232         dbg_parse("udev_log = %d", udev_log);
 233         parse_config_file();
 234
 235         dbg_parse("udev_root = %s", udev_root);
 236         dbg_parse("udev_config_filename = %s", udev_config_filename);
 237         dbg_parse("udev_db_filename = %s", udev_db_filename);
 238         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 239         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 240         dbg_parse("udev_log_str = %d", udev_log);
 241 }
 242
 243 void udev_init_config(void)
 244 {
 245         init_variables();
 246         get_dirs();
 247 }
 248
 249