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 "logging.h"
  38 #include "namedev.h"
  39 #include "udevdb.h"
  40 #include "libsysfs/libsysfs.h"
  41
  42 /* global variables */
  43 char **main_argv;
  44 char **main_envp;
  45
  46 static void sig_handler(int signum)
  47 {
  48         dbg("caught signal %d", signum);
  49         switch (signum) {
  50                 case SIGINT:
  51                 case SIGTERM:
  52                 case SIGKILL:
  53                         sysbus_disconnect();
  54                         udevdb_exit();
  55                         exit(20 + signum);
  56                         break;
  57                 default:
  58                         dbg("unhandled signal");
  59         }
  60 }
  61
  62 static inline char *get_action(void)
  63 {
  64         char *action;
  65
  66         action = getenv("ACTION");
  67         return action;
  68 }
  69
  70 static inline char *get_devpath(void)
  71 {
  72         char *devpath;
  73
  74         devpath = getenv("DEVPATH");
  75         return devpath;
  76 }
  77
  78 static inline char *get_seqnum(void)
  79 {
  80         char *seqnum;
  81
  82         seqnum = getenv("SEQNUM");
  83         return seqnum;
  84 }
  85
  86 /* callback for database dump */
  87 static int print_record(char *path, struct udevice *dev)
  88 {
  89         printf("P: %s\n", path);
  90         printf("N: %s\n", dev->name);
  91         printf("S: %s\n", dev->symlink);
  92         printf("O: %s\n", dev->owner);
  93         printf("G: %s\n", dev->group);
  94         printf("\n");
  95         return 0;
  96 }
  97
  98 enum query_type {
  99         NONE,
 100         NAME,
 101         PATH,
 102         SYMLINK,
 103         OWNER,
 104         GROUP
 105 };
 106
 107 static inline int udev_user(int argc, char **argv)
 108 {
 109         static const char short_options[] = "dn:p:q:rVh";
 110         int option;
 111         int retval = -EINVAL;
 112         struct udevice dev;
 113         int root = 0;
 114         enum query_type query = NONE;
 115         char result[NAME_SIZE] = "";
 116         char path[NAME_SIZE] = "";
 117         char name[NAME_SIZE] = "";
 118
 119         /* get command line options */
 120         while (1) {
 121                 option = getopt(argc, argv, short_options);
 122                 if (option == -1)
 123                         break;
 124
 125                 dbg("option '%c'", option);
 126                 switch (option) {
 127                 case 'n':
 128                         dbg("udev name: %s\n", optarg);
 129                         strfieldcpy(name, optarg);
 130                         break;
 131
 132                 case 'p':
 133                         dbg("udev path: %s\n", optarg);
 134                         strfieldcpy(path, optarg);
 135                         break;
 136
 137                 case 'q':
 138                         dbg("udev query: %s\n", optarg);
 139
 140                         if (strcmp(optarg, "name") == 0) {
 141                                 query = NAME;
 142                                 break;
 143                         }
 144
 145                         if (strcmp(optarg, "symlink") == 0) {
 146                                 query = SYMLINK;
 147                                 break;
 148                         }
 149
 150                         if (strcmp(optarg, "owner") == 0) {
 151                                 query = OWNER;
 152                                 break;
 153                         }
 154
 155                         if (strcmp(optarg, "group") == 0) {
 156                                 query = GROUP;
 157                                 break;
 158                         }
 159
 160                         if (strcmp(optarg, "path") == 0) {
 161                                 query = PATH;
 162                                 break;
 163                         }
 164
 165                         printf("unknown query type\n");
 166                         return -EINVAL;
 167
 168                 case 'r':
 169                         root = 1;
 170                         break;
 171
 172                 case 'd':
 173                         retval = udevdb_open_ro();
 174                         if (retval != 0) {
 175                                 printf("unable to open udev database\n");
 176                                 return -EACCES;
 177                         }
 178                         retval = udevdb_call_foreach(print_record);
 179                         udevdb_exit();
 180                         return retval;
 181
 182                 case 'V':
 183                         printf("udev, version %s\n", UDEV_VERSION);
 184                         return 0;
 185
 186                 case 'h':
 187                         retval = 0;
 188                 case '?':
 189                 default:
 190                         goto help;
 191                 }
 192         }
 193
 194         /* process options */
 195         if (query != NONE) {
 196                 retval = udevdb_open_ro();
 197                 if (retval != 0) {
 198                         printf("unable to open udev database\n");
 199                         return -EACCES;
 200                 }
 201
 202                 if (path[0] != '\0') {
 203                         retval = udevdb_get_dev(path, &dev);
 204                         if (retval != 0) {
 205                                 printf("device not found in database\n");
 206                                 goto exit;
 207                         }
 208                         goto print;
 209                 }
 210
 211                 if (name[0] != '\0') {
 212                         retval = udevdb_get_dev_byname(name, path, &dev);
 213                         if (retval != 0) {
 214                                 printf("device not found in database\n");
 215                                 goto exit;
 216                         }
 217                         goto print;
 218                 }
 219
 220                 printf("query needs device path(-p) or node name(-n) specified\n");
 221                 goto exit;
 222
 223 print:
 224                 switch(query) {
 225                 case NAME:
 226                         if (root)
 227                                 strfieldcpy(result, udev_root);
 228                         strncat(result, dev.name, sizeof(result));
 229                         break;
 230
 231                 case SYMLINK:
 232                         strfieldcpy(result, dev.symlink);
 233                         break;
 234
 235                 case GROUP:
 236                         strfieldcpy(result, dev.group);
 237                         break;
 238
 239                 case OWNER:
 240                         strfieldcpy(result, dev.owner);
 241                         break;
 242
 243                 case PATH:
 244                         strfieldcpy(result, path);
 245                         break;
 246
 247                 default:
 248                         goto exit;
 249                 }
 250                 printf("%s\n", result);
 251
 252 exit:
 253                 udevdb_exit();
 254                 return retval;
 255         }
 256
 257         if (root) {
 258                 printf("%s\n", udev_root);
 259                 return 0;
 260         }
 261
 262 help:
 263         printf("Usage: [-npqrdVh]\n"
 264                "  -q TYPE  query database for the specified value:\n"
 265                "             'name'    name of device node\n"
 266                "             'symlink' pointing to node\n"
 267                "             'owner'   of node\n"
 268                "             'group'   of node\n"
 269                "             'path'    sysfs device path\n"
 270                "  -p PATH  sysfs device path used for query\n"
 271                "  -n NAME  node name used for query\n"
 272                "\n"
 273                "  -r       print udev root\n"
 274                "  -d       dump whole database\n"
 275                "  -V       print udev version\n"
 276                "  -h       print this help text\n"
 277                "\n");
 278         return retval;
 279 }
 280
 281 static char *subsystem_blacklist[] = {
 282         "net",
 283         "scsi_host",
 284         "scsi_device",
 285         "usb_host",
 286         "pci_bus",
 287         "",
 288 };
 289
 290 static inline int udev_hotplug(int argc, char **argv)
 291 {
 292         char *action;
 293         char *devpath;
 294         char *subsystem;
 295         int retval = -EINVAL;
 296         int i;
 297
 298         subsystem = argv[1];
 299
 300         devpath = get_devpath();
 301         if (!devpath) {
 302                 dbg ("no devpath?");
 303                 goto exit;
 304         }
 305         dbg("looking at '%s'", devpath);
 306
 307         /* we only care about class devices and block stuff */
 308         if (!strstr(devpath, "class") &&
 309             !strstr(devpath, "block")) {
 310                 dbg("not a block or class device");
 311                 goto exit;
 312         }
 313
 314         /* skip blacklisted subsystems */
 315         i = 0;
 316         while (subsystem_blacklist[i][0] != '\0') {
 317                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 318                         dbg("don't care about '%s' devices", subsystem);
 319                         goto exit;
 320                 }
 321                 i++;
 322         }
 323
 324         action = get_action();
 325         if (!action) {
 326                 dbg ("no action?");
 327                 goto exit;
 328         }
 329
 330         /* connect to the system message bus */
 331         sysbus_connect();
 332
 333         /* initialize udev database */
 334         retval = udevdb_init(UDEVDB_DEFAULT);
 335         if (retval != 0) {
 336                 dbg("unable to initialize database");
 337                 goto exit_sysbus;
 338         }
 339
 340         /* set up a default signal handler for now */
 341         signal(SIGINT, sig_handler);
 342         signal(SIGTERM, sig_handler);
 343         signal(SIGKILL, sig_handler);
 344
 345         /* initialize the naming deamon */
 346         namedev_init();
 347
 348         if (strcmp(action, "add") == 0)
 349                 retval = udev_add_device(devpath, subsystem);
 350
 351         else if (strcmp(action, "remove") == 0)
 352                 retval = udev_remove_device(devpath, subsystem);
 353
 354         else {
 355                 dbg("unknown action '%s'", action);
 356                 retval = -EINVAL;
 357         }
 358         udevdb_exit();
 359
 360 exit_sysbus:
 361         /* disconnect from the system message bus */
 362         sysbus_disconnect();
 363
 364 exit:
 365         if (retval > 0)
 366                 retval = 0;
 367
 368         return -retval;
 369 }
 370
 371 int main(int argc, char **argv, char **envp)
 372 {
 373         int retval;
 374         main_argv = argv;
 375         main_envp = envp;
 376
 377         dbg("version %s", UDEV_VERSION);
 378
 379         /* initialize our configuration */
 380         udev_init_config();
 381
 382         if (argc == 2 && argv[1][0] != '-') {
 383                 dbg("called by hotplug");
 384                 retval = udev_hotplug(argc, argv);
 385         } else {
 386                 dbg("called by user");
 387                 retval = udev_user(argc, argv);
 388         }
 389
 390         return retval;
 391 }
 392
 393