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