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