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 "namedev.h"
  38 #include "libsysfs/libsysfs.h"
  39
  40 /* global variables */
  41 char sysfs_path[SYSFS_PATH_MAX];
  42 char udev_config_dir[PATH_MAX];
  43 char udev_root[PATH_MAX];
  44 char udev_db_filename[PATH_MAX+NAME_MAX];
  45 char udev_permission_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         strfieldcpy(udev_root, UDEV_ROOT);
  54         strfieldcpy(udev_config_dir, UDEV_CONFIG_DIR);
  55 }
  56
  57 #define set_var(_name, _var)                            \
  58         if (strcasecmp(variable, _name) == 0) {         \
  59                 dbg_parse("%s = '%s'", _name, value);   \
  60                 strncpy(_var, value, sizeof(_var));     \
  61         }
  62
  63 static int parse_config_file(void)
  64 {
  65         char line[255];
  66         char *temp;
  67         char *variable;
  68         char *value;
  69         FILE *fd;
  70         int lineno = 0;
  71         int retval = 0;
  72
  73         fd = fopen(udev_config_filename, "r");
  74         if (fd != NULL) {
  75                 dbg("reading '%s' as config file", udev_config_filename);
  76         } else {
  77                 dbg("can't open '%s' as config file", udev_config_filename);
  78                 return -ENODEV;
  79         }
  80
  81         /* loop through the whole file */
  82         while (1) {
  83                 /* get a line */
  84                 temp = fgets(line, sizeof(line), fd);
  85                 if (temp == NULL)
  86                         goto exit;
  87                 lineno++;
  88
  89                 dbg_parse("read '%s'", temp);
  90
  91                 /* eat the whitespace at the beginning of the line */
  92                 while (isspace(*temp))
  93                         ++temp;
  94
  95                 /* empty line? */
  96                 if (*temp == 0x00)
  97                         continue;
  98
  99                 /* see if this is a comment */
 100                 if (*temp == COMMENT_CHARACTER)
 101                         continue;
 102
 103                 retval = get_pair(&temp, &variable, &value);
 104                 if (retval)
 105                         break;
 106
 107                 dbg_parse("variable = '%s', value = '%s'", variable, value);
 108
 109                 set_var("udev_root", udev_root);
 110                 set_var("udev_db", udev_db_filename);
 111                 set_var("udev_rules", udev_rules_filename);
 112                 set_var("udev_permissions", udev_permission_filename);
 113                 set_var("default_mode", default_mode_str);
 114         }
 115         dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 116                   lineno, temp - line, temp);
 117 exit:
 118         fclose(fd);
 119         return retval;
 120 }
 121
 122 static void get_dirs(void)
 123 {
 124         char *temp;
 125         char *udev_db = UDEV_DB;
 126         char *udev_config = UDEV_CONFIG_FILE;
 127         char *udev_rules = UDEV_RULES_FILE;
 128         char *udev_permission = UDEV_PERMISSION_FILE;
 129         int retval;
 130
 131         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
 132         if (retval)
 133                 dbg("sysfs_get_mnt_path failed");
 134
 135         /* see if we should try to override any of the default values */
 136         temp = getenv("UDEV_TEST");
 137         if (temp != NULL) {
 138                 /* hm testing is happening, use the specified values, if they are present */
 139                 temp = getenv("SYSFS_PATH");
 140                 if (temp)
 141                         strfieldcpy(sysfs_path, temp);
 142                 temp = getenv("UDEV_CONFIG_DIR");
 143                 if (temp)
 144                         strfieldcpy(udev_config_dir, temp);
 145                 temp = getenv("UDEV_ROOT");
 146                 if (temp)
 147                         strfieldcpy(udev_root, temp);
 148                 temp = getenv("UDEV_DB");
 149                 if (temp)
 150                         udev_db = temp;
 151                 temp = getenv("UDEV_CONFIG_FILE");
 152                 if (temp)
 153                         udev_config = temp;
 154                 temp = getenv("UDEV_RULES_FILE");
 155                 if (temp)
 156                         udev_rules = temp;
 157                 temp = getenv("UDEV_PERMISSION_FILE");
 158                 if (temp)
 159                         udev_permission = temp;
 160         }
 161         dbg("sysfs_path='%s'", sysfs_path);
 162
 163         strncpy(udev_db_filename, udev_root, sizeof(udev_db_filename));
 164         strncat(udev_db_filename, udev_db, sizeof(udev_db_filename));
 165
 166         strncpy(udev_config_filename, udev_config_dir, sizeof(udev_config_filename));
 167         strncat(udev_config_filename, udev_config, sizeof(udev_config_filename));
 168
 169         strncpy(udev_rules_filename, udev_config_dir, sizeof(udev_permission_filename));
 170         strncat(udev_rules_filename, udev_rules, sizeof(udev_permission_filename));
 171
 172         strncpy(udev_permission_filename, udev_config_dir, sizeof(udev_permission_filename));
 173         strncat(udev_permission_filename, udev_permission, sizeof(udev_permission_filename));
 174
 175         dbg_parse("udev_root = %s", udev_root);
 176         dbg_parse("udev_config_filename = %s", udev_config_filename);
 177         dbg_parse("udev_db_filename = %s", udev_db_filename);
 178         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 179         dbg_parse("udev_permission_filename = %s", udev_permission_filename);
 180         parse_config_file();
 181
 182         dbg_parse("udev_root = %s", udev_root);
 183         dbg_parse("udev_config_filename = %s", udev_config_filename);
 184         dbg_parse("udev_db_filename = %s", udev_db_filename);
 185         dbg_parse("udev_rules_filename = %s", udev_rules_filename);
 186         dbg_parse("udev_permission_filename = %s", udev_permission_filename);
 187 }
 188
 189 void udev_init_config(void)
 190 {
 191         init_variables();
 192         get_dirs();
 193 }
 194
 195