udev_config.c

   1 /*
   2  * udev_config.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 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[NAME_MAX];
  49
  50
  51 static void init_variables(void)
  52 {
  53         /* fill up the defaults.
  54          * If any config values are specified, they will
  55          * override these values. */
  56         strfieldcpy(udev_root, UDEV_ROOT);
  57         strfieldcpy(udev_db_filename, UDEV_DB);
  58         strfieldcpy(udev_config_filename, UDEV_CONFIG_FILE);
  59         strfieldcpy(udev_rules_filename, UDEV_RULES_FILE);
  60         strfieldcpy(udev_permissions_filename, UDEV_PERMISSION_FILE);
  61 }
  62
  63 #define set_var(_name, _var)                            \
  64         if (strcasecmp(variable, _name) == 0) {         \
  65                 dbg_parse("%s = '%s'", _name, value);   \
  66                 strncpy(_var, value, sizeof(_var));     \
  67         }
  68
  69 static int parse_config_file(void)
  70 {
  71         char line[255];
  72         char *temp;
  73         char *variable;
  74         char *value;
  75         FILE *fd;
  76         int lineno = 0;
  77         int retval = 0;
  78
  79         fd = fopen(udev_config_filename, "r");
  80         if (fd != NULL) {
  81                 dbg("reading '%s' as config file", udev_config_filename);
  82         } else {
  83                 dbg("can't open '%s' as config file", udev_config_filename);
  84                 return -ENODEV;
  85         }
  86
  87         /* loop through the whole file */
  88         while (1) {
  89                 /* get a line */
  90                 temp = fgets(line, sizeof(line), fd);
  91                 if (temp == NULL)
  92                         goto exit;
  93                 lineno++;
  94
  95                 dbg_parse("read '%s'", temp);
  96
  97                 /* eat the whitespace at the beginning of the line */
  98                 while (isspace(*temp))
  99                         ++temp;
 100
 101                 /* empty line? */
 102                 if (*temp == 0x00)
 103                         continue;
 104
 105                 /* see if this is a comment */
 106                 if (*temp == COMMENT_CHARACTER)
 107                         continue;
 108
 109                 retval = get_pair(&temp, &variable, &value);
 110                 if (retval)
 111                         break;
 112
 113                 dbg_parse("variable = '%s', value = '%s'", variable, value);
 114
 115                 set_var("udev_root", udev_root);
 116                 set_var("udev_db", udev_db_filename);
 117                 set_var("udev_rules", udev_rules_filename);
 118                 set_var("udev_permissions", udev_permissions_filename);
 119                 set_var("default_mode", default_mode_str);
 120         }
 121         dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 122                   lineno, temp - line, temp);
 123 exit:
 124         fclose(fd);
 125         return retval;
 126 }
 127
 128 static void get_dirs(void)
 129 {
 130         char *temp;
 131         int retval;
 132
 133         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
 134         if (retval)
 135                 dbg("sysfs_get_mnt_path failed");
 136
 137         /* see if we should try to override any of the default values */
 138         temp = getenv("UDEV_TEST");
 139         if (temp != NULL) {
 140                 /* hm testing is happening, use the specified values, if they are present */
 141                 temp = getenv("SYSFS_PATH");
 142                 if (temp)
 143                         strfieldcpy(sysfs_path, temp);
 144                 temp = getenv("UDEV_CONFIG_FILE");
 145                 if (temp)
 146                         strfieldcpy(udev_config_filename, temp);
 147         }
 148         dbg("sysfs_path='%s'", sysfs_path);
 149
 150         dbg_parse("udev_root = %s", udev_root);
 151         dbg_parse("udev_config_filename = %s", udev_config_filename);
 152         dbg_parse("udev_db_filename = %s", udev_db_filename);
 153         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 154         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 155         parse_config_file();
 156
 157         dbg_parse("udev_root = %s", udev_root);
 158         dbg_parse("udev_config_filename = %s", udev_config_filename);
 159         dbg_parse("udev_db_filename = %s", udev_db_filename);
 160         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 161         dbg_parse("udev_permissions_filename = %s", udev_permissions_filename);
 162 }
 163
 164 void udev_init_config(void)
 165 {
 166         init_variables();
 167         get_dirs();
 168 }
 169
 170