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 static void print_record(char *path, struct udevice *dev)
  86 {
  87         printf("P: %s\n", path);
  88         printf("N: %s\n", dev->name);
  89         printf("S: %s\n", dev->symlink);
  90         printf("O: %s\n", dev->owner);
  91         printf("G: %s\n", dev->group);
  92         printf("\n");
  93 }
  94
  95 enum query_type {
  96         NONE,
  97         NAME,
  98         SYMLINK,
  99         OWNER,
 100         GROUP
 101 };
 102
 103 static inline int udev_user(int argc, char **argv)
 104 {
 105         static const char short_options[] = "dp:q:rVh";
 106         int option;
 107         int retval = -EINVAL;
 108         struct udevice dev;
 109         int root = 0;
 110         enum query_type query = NONE;
 111         char result[NAME_SIZE] = "";
 112         char path[NAME_SIZE] = "";
 113
 114         /* get command line options */
 115         while (1) {
 116                 option = getopt(argc, argv, short_options);
 117                 if (option == -1)
 118                         break;
 119
 120                 dbg("option '%c'", option);
 121                 switch (option) {
 122                 case 'p':
 123                         dbg("udev path: %s\n", optarg);
 124                         strfieldcpy(path, optarg);
 125                         break;
 126
 127                 case 'q':
 128                         dbg("udev query: %s\n", optarg);
 129
 130                         if (strcmp(optarg, "name") == 0) {
 131                                 query = NAME;
 132                                 break;
 133                         }
 134
 135                         if (strcmp(optarg, "symlink") == 0) {
 136                                 query = SYMLINK;
 137                                 break;
 138                         }
 139
 140                         if (strcmp(optarg, "owner") == 0) {
 141                                 query = OWNER;
 142                                 break;
 143                         }
 144
 145                         if (strcmp(optarg, "group") == 0) {
 146                                 query = GROUP;
 147                                 break;
 148                         }
 149
 150                         printf("unknown query type\n");
 151                         return -EINVAL;
 152
 153                 case 'r':
 154                         root = 1;
 155                         break;
 156
 157                 case 'd':
 158                         retval = udevdb_open_ro();
 159                         if (retval != 0) {
 160                                 printf("unable to open udev database\n");
 161                                 return -EACCES;
 162                         }
 163                         retval = udevdb_dump(print_record);
 164                         udevdb_exit();
 165                         return retval;
 166
 167                 case 'V':
 168                         printf("udev, version %s\n", UDEV_VERSION);
 169                         return 0;
 170
 171                 case 'h':
 172                         retval = 0;
 173                 case '?':
 174                 default:
 175                         goto help;
 176                 }
 177         }
 178
 179         /* process options */
 180         if (query != NONE) {
 181                 if (path[0] == '\0') {
 182                         printf("query needs device path specified\n");
 183                         return -EINVAL;
 184                 }
 185
 186                 retval = udevdb_open_ro();
 187                 if (retval != 0) {
 188                         printf("unable to open udev database\n");
 189                         return -EACCES;
 190                 }
 191                 retval = udevdb_get_dev(path, &dev);
 192                 if (retval == 0) {
 193                         switch(query) {
 194                         case NAME:
 195                                 if (root)
 196                                 strfieldcpy(result, udev_root);
 197                                 strncat(result, dev.name, sizeof(result));
 198                                 break;
 199
 200                         case SYMLINK:
 201                                 strfieldcpy(result, dev.symlink);
 202                                 break;
 203
 204                         case GROUP:
 205                                 strfieldcpy(result, dev.group);
 206                                 break;
 207
 208                         case OWNER:
 209                                 strfieldcpy(result, dev.owner);
 210                                 break;
 211
 212                         default:
 213                                 break;
 214                         }
 215                         printf("%s\n", result);
 216                 } else {
 217                         printf("device not found in udev database\n");
 218                 }
 219                 udevdb_exit();
 220                 return retval;
 221         }
 222
 223         if (root) {
 224                 printf("%s\n", udev_root);
 225                 return 0;
 226         }
 227
 228 help:
 229         printf("Usage: [-pqrdVh]\n"
 230                "  -q TYPE  query database for the specified value:\n"
 231                "             'name'    name of device node\n"
 232                "             'symlink' pointing to node\n"
 233                "             'owner'   of node\n"
 234                "             'group'   of node\n"
 235                "  -p PATH  sysfs device path used for query\n"
 236                "  -r       print udev root\n"
 237                "  -d       dump whole database\n"
 238                "  -V       print udev version\n"
 239                "  -h       print this help text\n"
 240                "\n");
 241         return retval;
 242 }
 243
 244 static char *subsystem_blacklist[] = {
 245         "net",
 246         "scsi_host",
 247         "scsi_device",
 248         "",
 249 };
 250
 251 static inline int udev_hotplug(int argc, char **argv)
 252 {
 253         char *action;
 254         char *devpath;
 255         char *subsystem;
 256         int retval = -EINVAL;
 257         int i;
 258
 259         subsystem = argv[1];
 260
 261         devpath = get_devpath();
 262         if (!devpath) {
 263                 dbg ("no devpath?");
 264                 goto exit;
 265         }
 266         dbg("looking at '%s'", devpath);
 267
 268         /* we only care about class devices and block stuff */
 269         if (!strstr(devpath, "class") &&
 270             !strstr(devpath, "block")) {
 271                 dbg("not a block or class device");
 272                 goto exit;
 273         }
 274
 275         /* skip blacklisted subsystems */
 276         i = 0;
 277         while (subsystem_blacklist[i][0] != '\0') {
 278                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 279                         dbg("don't care about '%s' devices", subsystem);
 280                         goto exit;
 281                 }
 282                 i++;
 283         }
 284
 285         action = get_action();
 286         if (!action) {
 287                 dbg ("no action?");
 288                 goto exit;
 289         }
 290
 291         /* connect to the system message bus */
 292         sysbus_connect();
 293
 294         /* initialize udev database */
 295         retval = udevdb_init(UDEVDB_DEFAULT);
 296         if (retval != 0) {
 297                 dbg("unable to initialize database");
 298                 goto exit_sysbus;
 299         }
 300
 301         /* set up a default signal handler for now */
 302         signal(SIGINT, sig_handler);
 303         signal(SIGTERM, sig_handler);
 304         signal(SIGKILL, sig_handler);
 305
 306         /* initialize the naming deamon */
 307         namedev_init();
 308
 309         if (strcmp(action, "add") == 0)
 310                 retval = udev_add_device(devpath, subsystem);
 311
 312         else if (strcmp(action, "remove") == 0)
 313                 retval = udev_remove_device(devpath, subsystem);
 314
 315         else {
 316                 dbg("unknown action '%s'", action);
 317                 retval = -EINVAL;
 318         }
 319         udevdb_exit();
 320
 321 exit_sysbus:
 322         /* disconnect from the system message bus */
 323         sysbus_disconnect();
 324
 325 exit:
 326         if (retval > 0)
 327                 retval = 0;
 328
 329         return -retval;
 330 }
 331
 332 int main(int argc, char **argv, char **envp)
 333 {
 334         int retval;
 335         main_argv = argv;
 336         main_envp = envp;
 337
 338         dbg("version %s", UDEV_VERSION);
 339
 340         /* initialize our configuration */
 341         udev_init_config();
 342
 343         if (argc == 2 && argv[1][0] != '-') {
 344                 dbg("called by hotplug");
 345                 retval = udev_hotplug(argc, argv);
 346         } else {
 347                 dbg("called by user");
 348                 retval = udev_user(argc, argv);
 349         }
 350
 351         return retval;
 352 }
 353
 354