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 #include <syslog.h>
  32
  33 #include "libsysfs/sysfs/libsysfs.h"
  34 #include "udev_libc_wrapper.h"
  35 #include "udev.h"
  36 #include "udev_utils.h"
  37 #include "udev_version.h"
  38 #include "logging.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_config_filename[PATH_SIZE];
  45 char udev_rules_filename[PATH_SIZE];
  46 int udev_log_priority;
  47 int udev_run;
  48
  49 static int get_key(char **line, char **key, char **value)
  50 {
  51         char *linepos;
  52         char *temp;
  53
  54         linepos = *line;
  55         if (!linepos)
  56                 return -1;
  57
  58         /* skip whitespace */
  59         while (isspace(linepos[0]))
  60                 linepos++;
  61
  62         /* get the key */
  63         *key = linepos;
  64         while (1) {
  65                 linepos++;
  66                 if (linepos[0] == '\0')
  67                         return -1;
  68                 if (isspace(linepos[0]))
  69                         break;
  70                 if (linepos[0] == '=')
  71                         break;
  72         }
  73
  74         /* terminate key */
  75         linepos[0] = '\0';
  76         linepos++;
  77
  78         /* skip whitespace */
  79         while (isspace(linepos[0]))
  80                 linepos++;
  81
  82         /* get the value*/
  83         if (linepos[0] == '"')
  84                 linepos++;
  85         else
  86                 return -1;
  87         *value = linepos;
  88
  89         temp = strchr(linepos, '"');
  90         if (!temp)
  91                 return -1;
  92         temp[0] = '\0';
  93
  94         return 0;
  95 }
  96
  97 static int parse_config_file(void)
  98 {
  99         char line[LINE_SIZE];
 100         char *bufline;
 101         char *linepos;
 102         char *variable;
 103         char *value;
 104         char *buf;
 105         size_t bufsize;
 106         size_t cur;
 107         size_t count;
 108         int lineno;
 109         int retval = 0;
 110
 111         if (file_map(udev_config_filename, &buf, &bufsize) != 0) {
 112                 err("can't open '%s' as config file", udev_config_filename);
 113                 return -ENODEV;
 114         }
 115
 116         /* loop through the whole file */
 117         lineno = 0;
 118         cur = 0;
 119         while (cur < bufsize) {
 120                 count = buf_get_line(buf, bufsize, cur);
 121                 bufline = &buf[cur];
 122                 cur += count+1;
 123                 lineno++;
 124
 125                 if (count >= sizeof(line)) {
 126                         err("line too long, conf line skipped %s, line %d", udev_config_filename, lineno);
 127                         continue;
 128                 }
 129
 130                 /* eat the whitespace */
 131                 while ((count > 0) && isspace(bufline[0])) {
 132                         bufline++;
 133                         count--;
 134                 }
 135                 if (count == 0)
 136                         continue;
 137
 138                 /* see if this is a comment */
 139                 if (bufline[0] == COMMENT_CHARACTER)
 140                         continue;
 141
 142                 strlcpy(line, bufline, count+1);
 143
 144                 linepos = line;
 145                 retval = get_key(&linepos, &variable, &value);
 146                 if (retval != 0) {
 147                         err("error parsing %s, line %d:%d", udev_config_filename, lineno, (int) (linepos-line));
 148                         continue;
 149                 }
 150
 151                 if (strcasecmp(variable, "udev_root") == 0) {
 152                         strlcpy(udev_root, value, sizeof(udev_root));
 153                         remove_trailing_char(udev_root, '/');
 154                         continue;
 155                 }
 156
 157                 if (strcasecmp(variable, "udev_db") == 0) {
 158                         strlcpy(udev_db_path, value, sizeof(udev_db_path));
 159                         remove_trailing_char(udev_db_path, '/');
 160                         continue;
 161                 }
 162
 163                 if (strcasecmp(variable, "udev_rules") == 0) {
 164                         strlcpy(udev_rules_filename, value, sizeof(udev_rules_filename));
 165                         remove_trailing_char(udev_rules_filename, '/');
 166                         continue;
 167                 }
 168
 169                 if (strcasecmp(variable, "udev_log") == 0) {
 170                         udev_log_priority = log_priority(value);
 171                         continue;
 172                 }
 173         }
 174
 175         file_unmap(buf, bufsize);
 176         return retval;
 177 }
 178
 179 void udev_init_config(void)
 180 {
 181         const char *env;
 182
 183         strcpy(udev_root, UDEV_ROOT);
 184         strcpy(udev_db_path, UDEV_DB);
 185         strcpy(udev_config_filename, UDEV_CONFIG_FILE);
 186         strcpy(udev_rules_filename, UDEV_RULES_FILE);
 187         udev_log_priority = LOG_ERR;
 188         udev_run = 1;
 189         sysfs_get_mnt_path(sysfs_path, sizeof(sysfs_path));
 190
 191         /* disable RUN key execution */
 192         env = getenv("UDEV_RUN");
 193         if (env && !string_is_true(env))
 194                 udev_run = 0;
 195
 196         env = getenv("UDEV_CONFIG_FILE");
 197         if (env) {
 198                 strlcpy(udev_config_filename, env, sizeof(udev_config_filename));
 199                 remove_trailing_char(udev_config_filename, '/');
 200         }
 201
 202         parse_config_file();
 203
 204         env = getenv("UDEV_LOG");
 205         if (env)
 206                 udev_log_priority = log_priority(env);
 207
 208         dbg("sysfs_path='%s'", sysfs_path);
 209         dbg("UDEV_CONFIG_FILE='%s'", udev_config_filename);
 210         dbg("udev_root='%s'", udev_root);
 211         dbg("udev_db='%s'", udev_db_path);
 212         dbg("udev_rules='%s'", udev_rules_filename);
 213         dbg("udev_log=%d", udev_log_priority);
 214 }