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