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 #include <ctype.h>
  31 #include <signal.h>
  32 #include <stdarg.h>
  33
  34 #include "udev.h"
  35 #include "udev_version.h"
  36 #include "udev_dbus.h"
  37 #include "namedev.h"
  38 #include "udevdb.h"
  39 #include "libsysfs/libsysfs.h"
  40
  41 /* global variables */
  42 char **main_argv;
  43 char **main_envp;
  44
  45 static void sig_handler(int signum)
  46 {
  47         dbg("caught signal %d", signum);
  48         switch (signum) {
  49                 case SIGINT:
  50                 case SIGTERM:
  51                 case SIGKILL:
  52                         sysbus_disconnect();
  53                         udevdb_exit();
  54                         exit(20 + signum);
  55                         break;
  56                 default:
  57                         dbg("unhandled signal");
  58         }
  59 }
  60
  61 static inline char *get_action(void)
  62 {
  63         char *action;
  64
  65         action = getenv("ACTION");
  66         return action;
  67 }
  68
  69 static inline char *get_devpath(void)
  70 {
  71         char *devpath;
  72
  73         devpath = getenv("DEVPATH");
  74         return devpath;
  75 }
  76
  77 static inline char *get_seqnum(void)
  78 {
  79         char *seqnum;
  80
  81         seqnum = getenv("SEQNUM");
  82         return seqnum;
  83 }
  84
  85 enum query_type {
  86         NONE,
  87         NAME,
  88         SYMLINK,
  89         OWNER,
  90         GROUP
  91 };
  92
  93 static inline int udev_user(int argc, char **argv)
  94 {
  95         static const char short_options[] = "p:q:rVh";
  96         int option;
  97         int retval = -EINVAL;
  98         struct udevice dev;
  99         int root = 0;
 100         enum query_type query = NONE;
 101         char result[NAME_SIZE] = "";
 102         char path[NAME_SIZE] = "";
 103
 104         /* get command line options */
 105         while (1) {
 106                 option = getopt(argc, argv, short_options);
 107                 if (option == -1)
 108                         break;
 109
 110                 dbg("option '%c'", option);
 111                 switch (option) {
 112                 case 'p':
 113                         dbg("udev path: %s\n", optarg);
 114                         strfieldcpy(path, optarg);
 115                         break;
 116
 117                 case 'q':
 118                         dbg("udev query: %s\n", optarg);
 119
 120                         if (strcmp(optarg, "name") == 0) {
 121                                 query = NAME;
 122                                 break;
 123                         }
 124
 125                         if (strcmp(optarg, "symlink") == 0) {
 126                                 query = SYMLINK;
 127                                 break;
 128                         }
 129
 130                         if (strcmp(optarg, "owner") == 0) {
 131                                 query = OWNER;
 132                                 break;
 133                         }
 134
 135                         if (strcmp(optarg, "group") == 0) {
 136                                 query = GROUP;
 137                                 break;
 138                         }
 139
 140                         printf("unknown query type\n");
 141                         return -EINVAL;
 142
 143                 case 'r':
 144                         root = 1;
 145                         break;
 146
 147                 case 'V':
 148                         printf("udev, version %s\n", UDEV_VERSION);
 149                         return 0;
 150
 151                 case 'h':
 152                         retval = 0;
 153                 case '?':
 154                 default:
 155                         goto help;
 156                 }
 157         }
 158
 159         /* process options */
 160         if (query != NONE) {
 161                 if (path[0] == '\0') {
 162                         printf("query needs device path specified\n");
 163                         return -EINVAL;
 164                 }
 165
 166                 retval = udevdb_open_ro();
 167                 if (retval != 0) {
 168                         printf("unable to open udev database\n");
 169                         return -EACCES;
 170                 }
 171                 retval = udevdb_get_dev(path, &dev);
 172                 if (retval == 0) {
 173                         switch(query) {
 174                         case NAME:
 175                                 if (root)
 176                                 strfieldcpy(result, udev_root);
 177                                 strncat(result, dev.name, sizeof(result));
 178                                 break;
 179
 180                         case SYMLINK:
 181                                 strfieldcpy(result, dev.symlink);
 182                                 break;
 183
 184                         case GROUP:
 185                                 strfieldcpy(result, dev.group);
 186                                 break;
 187
 188                         case OWNER:
 189                                 strfieldcpy(result, dev.owner);
 190                                 break;
 191
 192                         default:
 193                                 break;
 194                         }
 195                         printf("%s\n", result);
 196                 } else {
 197                         printf("device not found in udev database\n");
 198                 }
 199                 udevdb_exit();
 200                 return retval;
 201         }
 202
 203         if (root) {
 204                 printf("%s\n", udev_root);
 205                 return 0;
 206         }
 207
 208 help:
 209         printf("Usage: [-qrVh]\n"
 210                "  -q <name>  query database for the specified value\n"
 211                "  -p <path>  device path used for query\n"
 212                "  -r         print udev root\n"
 213                "  -V         print udev version\n"
 214                "  -h         print this help text\n"
 215                "\n");
 216         return retval;
 217 }
 218
 219 static char *subsystem_blacklist[] = {
 220         "net",
 221         "scsi_host",
 222         "scsi_device",
 223         "",
 224 };
 225
 226 static inline int udev_hotplug(int argc, char **argv)
 227 {
 228         char *action;
 229         char *devpath;
 230         char *subsystem;
 231         int retval = -EINVAL;
 232         int i;
 233
 234         subsystem = argv[1];
 235
 236         devpath = get_devpath();
 237         if (!devpath) {
 238                 dbg ("no devpath?");
 239                 goto exit;
 240         }
 241         dbg("looking at '%s'", devpath);
 242
 243         /* we only care about class devices and block stuff */
 244         if (!strstr(devpath, "class") &&
 245             !strstr(devpath, "block")) {
 246                 dbg("not a block or class device");
 247                 goto exit;
 248         }
 249
 250         /* skip blacklisted subsystems */
 251         i = 0;
 252         while (subsystem_blacklist[i][0] != '\0') {
 253                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 254                         dbg("don't care about '%s' devices", subsystem);
 255                         goto exit;
 256                 }
 257                 i++;
 258         }
 259
 260         action = get_action();
 261         if (!action) {
 262                 dbg ("no action?");
 263                 goto exit;
 264         }
 265
 266         /* connect to the system message bus */
 267         sysbus_connect();
 268
 269         /* initialize udev database */
 270         retval = udevdb_init(UDEVDB_DEFAULT);
 271         if (retval != 0) {
 272                 dbg("unable to initialize database");
 273                 goto exit_sysbus;
 274         }
 275
 276         /* set up a default signal handler for now */
 277         signal(SIGINT, sig_handler);
 278         signal(SIGTERM, sig_handler);
 279         signal(SIGKILL, sig_handler);
 280
 281         /* initialize the naming deamon */
 282         namedev_init();
 283
 284         if (strcmp(action, "add") == 0)
 285                 retval = udev_add_device(devpath, subsystem);
 286
 287         else if (strcmp(action, "remove") == 0)
 288                 retval = udev_remove_device(devpath, subsystem);
 289
 290         else {
 291                 dbg("unknown action '%s'", action);
 292                 retval = -EINVAL;
 293         }
 294         udevdb_exit();
 295
 296 exit_sysbus:
 297         /* disconnect from the system message bus */
 298         sysbus_disconnect();
 299
 300 exit:
 301         if (retval > 0)
 302                 retval = 0;
 303
 304         return -retval;
 305 }
 306
 307 int main(int argc, char **argv, char **envp)
 308 {
 309         int retval;
 310         main_argv = argv;
 311         main_envp = envp;
 312
 313         dbg("version %s", UDEV_VERSION);
 314
 315         /* initialize our configuration */
 316         udev_init_config();
 317
 318         if (argc == 2 && argv[1][0] != '-') {
 319                 dbg("called by hotplug");
 320                 retval = udev_hotplug(argc, argv);
 321         } else {
 322                 dbg("called by user");
 323                 retval = udev_user(argc, argv);
 324         }
 325
 326         return retval;
 327 }
 328
 329