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 #include <stdlib.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <ctype.h>
  31
  32 #include "libsysfs/sysfs/libsysfs.h"
  33 #include "udev_libc_wrapper.h"
  34 #include "udev.h"
  35 #include "udev_utils.h"
  36 #include "udev_version.h"
  37 #include "logging.h"
  38 #include "udev_rules.h"
  39
  40 /* global variables */
  41 char sysfs_path[PATH_SIZE];
  42 char udev_root[PATH_SIZE];
  43 char udev_db_path[PATH_SIZE];
  44 char udev_rules_filename[PATH_SIZE];
  45 char udev_config_filename[PATH_SIZE];
  46 int udev_log;
  47 int udev_dev_d;
  48 int udev_hotplug_d;
  49
  50
  51 static int string_is_true(const char *str)
  52 {
  53         if (strcasecmp(str, "true") == 0)
  54                 return 1;
  55         if (strcasecmp(str, "yes") == 0)
  56                 return 1;
  57         if (strcasecmp(str, "1") == 0)
  58                 return 1;
  59         return 0;
  60 }
  61
  62 static int get_key(char **line, char **key, char **value)
  63 {
  64         char *linepos;
  65         char *temp;
  66
  67         linepos = *line;
  68         if (!linepos)
  69                 return -1;
  70
  71         /* skip whitespace */
  72         while (isspace(linepos[0]))
  73                 linepos++;
  74
  75         /* get the key */
  76         *key = linepos;
  77         while (1) {
  78                 linepos++;
  79                 if (linepos[0] == '\0')
  80                         return -1;
  81                 if (isspace(linepos[0]))
  82                         break;
  83                 if (linepos[0] == '=')
  84                         break;
  85         }
  86
  87         /* terminate key */
  88         linepos[0] = '\0';
  89         linepos++;
  90
  91         /* skip whitespace */
  92         while (isspace(linepos[0]))
  93                 linepos++;
  94
  95         /* get the value*/
  96         if (linepos[0] == '"')
  97                 linepos++;
  98         else
  99                 return -1;
 100         *value = linepos;
 101
 102         temp = strchr(linepos, '"');
 103         if (!temp)
 104                 return -1;
 105         temp[0] = '\0';
 106
 107         return 0;
 108 }
 109
 110 static void init_variables(void)
 111 {
 112         const char *env;
 113
 114         /* If any config values are specified, they will override these values. */
 115         strcpy(udev_root, UDEV_ROOT);
 116         strcpy(udev_db_path, UDEV_DB);
 117         strcpy(udev_config_filename, UDEV_CONFIG_FILE);
 118         strcpy(udev_rules_filename, UDEV_RULES_FILE);
 119
 120         udev_log = string_is_true(UDEV_LOG_DEFAULT);
 121
 122         udev_dev_d = 1;
 123         env = getenv("UDEV_NO_DEVD");
 124         if (env && string_is_true(env))
 125                 udev_dev_d = 0;
 126
 127         udev_hotplug_d = 1;
 128         env = getenv("UDEV_NO_HOTPLUGD");
 129         if (env && string_is_true(env))
 130                 udev_hotplug_d = 0;
 131 }
 132
 133 static int parse_config_file(void)
 134 {
 135         char line[LINE_SIZE];
 136         char *bufline;
 137         char *linepos;
 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("can't open '%s' as config file", udev_config_filename);
 149                 return -ENODEV;
 150         }
 151         dbg("reading '%s' as config file", udev_config_filename);
 152
 153         /* loop through the whole file */
 154         lineno = 0;
 155         cur = 0;
 156         while (cur < bufsize) {
 157                 count = buf_get_line(buf, bufsize, cur);
 158                 bufline = &buf[cur];
 159                 cur += count+1;
 160                 lineno++;
 161
 162                 if (count >= sizeof(line)) {
 163                         info("line too long, conf line skipped %s, line %d",
 164                                         udev_config_filename, lineno);
 165                         continue;
 166                 }
 167
 168                 /* eat the whitespace */
 169                 while ((count > 0) && isspace(bufline[0])) {
 170                         bufline++;
 171                         count--;
 172                 }
 173                 if (count == 0)
 174                         continue;
 175
 176                 /* see if this is a comment */
 177                 if (bufline[0] == COMMENT_CHARACTER)
 178                         continue;
 179
 180                 strlcpy(line, bufline, count);
 181                 dbg("read '%s'", line);
 182
 183                 linepos = line;
 184                 retval = get_key(&linepos, &variable, &value);
 185                 if (retval != 0) {
 186                         info("error parsing %s, line %d:%d", udev_config_filename, lineno, (int) (linepos-line));
 187                         continue;
 188                 }
 189
 190                 dbg("variable='%s', value='%s'", variable, value);
 191
 192                 if (strcasecmp(variable, "udev_root") == 0) {
 193                         strlcpy(udev_root, value, sizeof(udev_root));
 194                         no_trailing_slash(udev_root);
 195                         continue;
 196                 }
 197
 198                 if (strcasecmp(variable, "udev_db") == 0) {
 199                         strlcpy(udev_db_path, value, sizeof(udev_db_path));
 200                         no_trailing_slash(udev_db_path);
 201                         continue;
 202                 }
 203
 204                 if (strcasecmp(variable, "udev_rules") == 0) {
 205                         strlcpy(udev_rules_filename, value, sizeof(udev_rules_filename));
 206                         no_trailing_slash(udev_rules_filename);
 207                         continue;
 208                 }
 209
 210                 if (strcasecmp(variable, "udev_log") == 0) {
 211                         udev_log = string_is_true(value);
 212                         continue;
 213                 }
 214         }
 215
 216         file_unmap(buf, bufsize);
 217         return retval;
 218 }
 219
 220 void udev_init_config(void)
 221 {
 222
 223         init_variables();
 224         sysfs_get_mnt_path(sysfs_path, sizeof(sysfs_path));
 225
 226         /* see if we should try to override any of the default values */
 227         if (getenv("UDEV_TEST") != NULL) {
 228                 char *temp;
 229
 230                 temp = getenv("SYSFS_PATH");
 231                 if (temp != NULL) {
 232                         strlcpy(sysfs_path, temp, sizeof(sysfs_path));
 233                         no_trailing_slash(sysfs_path);
 234                 }
 235
 236                 temp = getenv("UDEV_CONFIG_FILE");
 237                 if (temp != NULL)
 238                         strlcpy(udev_config_filename, temp, sizeof(udev_config_filename));
 239         }
 240
 241         parse_config_file();
 242         dbg("sysfs_path='%s'", sysfs_path);
 243         dbg("udev_root='%s'", udev_root);
 244         dbg("udev_config_filename='%s'", udev_config_filename);
 245         dbg("udev_db_path='%s'", udev_db_path);
 246         dbg("udev_rules_filename='%s'", udev_rules_filename);
 247         dbg("udev_log=%d", udev_log);
 248 }