udev.c

   1 /*
   2  * udev.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 #include <stdlib.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30
  31 #include "udev.h"
  32 #include "udev_version.h"
  33 #include "namedev.h"
  34 #include "udevdb.h"
  35 #include "libsysfs/libsysfs.h"
  36
  37 /* global variables */
  38 char **main_argv;
  39 char **main_envp;
  40
  41 char sysfs_path[SYSFS_PATH_MAX];
  42 char *udev_config_dir = UDEV_CONFIG_DIR;
  43 char *udev_root = UDEV_ROOT;
  44 char udev_db_filename[PATH_MAX+NAME_MAX];
  45 char udev_config_permission_filename[PATH_MAX+NAME_MAX];
  46 char udev_config_filename[PATH_MAX+NAME_MAX];
  47
  48
  49 static inline char *get_action(void)
  50 {
  51         char *action;
  52
  53         action = getenv("ACTION");
  54         return action;
  55 }
  56
  57 static inline char *get_devpath(void)
  58 {
  59         char *devpath;
  60
  61         devpath = getenv("DEVPATH");
  62         return devpath;
  63 }
  64
  65 static inline char *get_seqnum(void)
  66 {
  67         char *seqnum;
  68
  69         seqnum = getenv("SEQNUM");
  70         return seqnum;
  71 }
  72
  73 static void get_dirs(void)
  74 {
  75         char *temp;
  76         char *udev_db = UDEV_DB;
  77         char *udev_config = UDEV_CONFIG_FILE;
  78         char *udev_permission = UDEV_CONFIG_PERMISSION_FILE;
  79         int retval;
  80
  81         retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
  82         if (retval)
  83                 dbg("sysfs_get_mnt_path failed");
  84
  85         /* see if we should try to override any of the default values */
  86         temp = getenv("UDEV_TEST");
  87         if (temp != NULL) {
  88                 /* hm testing is happening, use the specified values, if they are present */
  89                 temp = getenv("SYSFS_PATH");
  90                 if (temp)
  91                         strncpy(sysfs_path, temp, sizeof(sysfs_path));
  92                 temp = getenv("UDEV_CONFIG_DIR");
  93                 if (temp)
  94                         udev_config_dir = temp;
  95                 temp = getenv("UDEV_ROOT");
  96                 if (temp)
  97                         udev_root = temp;
  98                 temp = getenv("UDEV_DB");
  99                 if (temp)
 100                         udev_db = temp;
 101                 temp = getenv("UDEV_CONFIG_FILE");
 102                 if (temp)
 103                         udev_config = temp;
 104                 temp = getenv("UDEV_PERMISSION_FILE");
 105                 if (temp)
 106                         udev_permission = temp;
 107         }
 108         dbg("sysfs_path = %s", sysfs_path);
 109
 110         strncpy(udev_db_filename, udev_config_dir, sizeof(udev_db_filename));
 111         strncat(udev_db_filename, udev_db, sizeof(udev_db_filename));
 112
 113         strncpy(udev_config_filename, udev_config_dir, sizeof(udev_config_filename));
 114         strncat(udev_config_filename, udev_config, sizeof(udev_config_filename));
 115
 116         strncpy(udev_config_permission_filename, udev_config_dir, sizeof(udev_config_permission_filename));
 117         strncat(udev_config_permission_filename, udev_permission, sizeof(udev_config_permission_filename));
 118 }
 119
 120 int main(int argc, char **argv, char **envp)
 121 {
 122         char *action;
 123         char *devpath;
 124         char *subsystem;
 125         int retval = -EINVAL;
 126
 127         main_argv = argv;
 128         main_envp = envp;
 129
 130         dbg("version %s", UDEV_VERSION);
 131
 132         if (argc != 2) {
 133                 dbg ("unknown number of arguments");
 134                 goto exit;
 135         }
 136
 137         subsystem = argv[1];
 138
 139         devpath = get_devpath();
 140         if (!devpath) {
 141                 dbg ("no devpath?");
 142                 goto exit;
 143         }
 144         dbg("looking at %s", devpath);
 145
 146         /* we only care about class devices and block stuff */
 147         if (!strstr(devpath, "class") &&
 148             !strstr(devpath, "block")) {
 149                 dbg("not block or class");
 150                 goto exit;
 151         }
 152
 153         /* but we don't care about net class devices */
 154         if (strcmp(subsystem, "net") == 0) {
 155                 dbg("don't care about net devices");
 156                 goto exit;
 157         }
 158
 159         action = get_action();
 160         if (!action) {
 161                 dbg ("no action?");
 162                 goto exit;
 163         }
 164
 165         /* initialize udev database */
 166         get_dirs();
 167         retval = udevdb_init(UDEVDB_DEFAULT);
 168         if (retval != 0) {
 169                 dbg("Unable to initialize database.");
 170                 goto exit;
 171         }
 172
 173         /* initialize the naming deamon */
 174         namedev_init();
 175
 176         if (strcmp(action, "add") == 0)
 177                 retval = udev_add_device(devpath, subsystem);
 178
 179         else if (strcmp(action, "remove") == 0)
 180                 retval = udev_remove_device(devpath, subsystem);
 181
 182         else {
 183                 dbg("Unknown action: %s", action);
 184                 retval = -EINVAL;
 185         }
 186         udevdb_exit();
 187
 188 exit:
 189         return retval;
 190 }
 191