udevstart.c

   1 /*
   2  * udevstart.c
   3  *
   4  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   5  * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
   6  *
   7  * Quick and dirty way to populate a /dev with udev if your system
   8  * does not have access to a shell.  Based originally on a patch
   9  * from:
  10  *      Harald Hoyer <harald@redhat.com>
  11  *
  12  *      This program is free software; you can redistribute it and/or modify it
  13  *      under the terms of the GNU General Public License as published by the
  14  *      Free Software Foundation version 2 of the License.
  15  *
  16  *      This program is distributed in the hope that it will be useful, but
  17  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *      General Public License for more details.
  20  *
  21  *      You should have received a copy of the GNU General Public License along
  22  *      with this program; if not, write to the Free Software Foundation, Inc.,
  23  *      675 Mass Ave, Cambridge, MA 02139, USA.
  24  *
  25  */
  26
  27 #include <stdlib.h>
  28 #include <stddef.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <ctype.h>
  34 #include <dirent.h>
  35 #include <signal.h>
  36 #include <sys/wait.h>
  37 #include <sys/stat.h>
  38 #include <sys/types.h>
  39
  40 #include "libsysfs/sysfs/libsysfs.h"
  41 #include "udev_libc_wrapper.h"
  42 #include "udev_sysfs.h"
  43 #include "udev.h"
  44 #include "udev_version.h"
  45 #include "logging.h"
  46 #include "udev_utils.h"
  47 #include "udev_rules.h"
  48 #include "list.h"
  49
  50 static const char *udev_run_str;
  51 static const char *udev_log_str;
  52 static struct udev_rules rules;
  53
  54 #ifdef USE_LOG
  55 void log_message(int priority, const char *format, ...)
  56 {
  57         va_list args;
  58
  59         if (priority > udev_log_priority)
  60                 return;
  61
  62         va_start(args, format);
  63         vsyslog(priority, format, args);
  64         va_end(args);
  65 }
  66 #endif
  67
  68 struct device {
  69         struct list_head node;
  70         char path[PATH_SIZE];
  71         char subsys[NAME_SIZE];
  72 };
  73
  74 /* sort files in lexical order */
  75 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  76 {
  77         struct device *loop_device;
  78         struct device *new_device;
  79
  80         dbg("insert: '%s'\n", path);
  81
  82         list_for_each_entry(loop_device, device_list, node) {
  83                 if (strcmp(loop_device->path, path) > 0) {
  84                         break;
  85                 }
  86         }
  87
  88         new_device = malloc(sizeof(struct device));
  89         if (new_device == NULL) {
  90                 dbg("error malloc");
  91                 return -ENOMEM;
  92         }
  93
  94         strlcpy(new_device->path, path, sizeof(new_device->path));
  95         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  96         list_add_tail(&new_device->node, &loop_device->node);
  97         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  98         return 0;
  99 }
 100
 101 /* list of devices that we should run last due to any one of a number of reasons */
 102 static char *last_list[] = {
 103         "/block/dm",    /* on here because dm wants to have the block devices around before it */
 104         NULL,
 105 };
 106
 107 /* list of devices that we should run first due to any one of a number of reasons */
 108 static char *first_list[] = {
 109         "/class/mem",   /* people tend to like their memory devices around first... */
 110         NULL,
 111 };
 112
 113 static int add_device(const char *path, const char *subsystem)
 114 {
 115         struct udevice udev;
 116         struct sysfs_class_device *class_dev;
 117         const char *devpath;
 118
 119         devpath = &path[strlen(sysfs_path)];
 120
 121         /* clear and set environment for next event */
 122         clearenv();
 123         setenv("ACTION", "add", 1);
 124         setenv("DEVPATH", devpath, 1);
 125         setenv("SUBSYSTEM", subsystem, 1);
 126         setenv("UDEV_START", "1", 1);
 127         if (udev_log_str)
 128                 setenv("UDEV_LOG", udev_log_str, 1);
 129         if (udev_run_str)
 130                 setenv("UDEV_RUN", udev_run_str, 1);
 131         dbg("exec: '%s' (%s)\n", devpath, path);
 132
 133         class_dev = sysfs_open_class_device_path(path);
 134         if (class_dev == NULL) {
 135                 dbg("sysfs_open_class_device_path failed");
 136                 return -1;
 137         }
 138
 139         udev_init_device(&udev, devpath, subsystem, "add");
 140         udev.devt = get_devt(class_dev);
 141         if (!udev.devt && udev.type != DEV_NET) {
 142                 dbg("sysfs_open_class_device_path failed");
 143                 return -1;
 144         }
 145         udev_rules_get_name(&rules, &udev, class_dev);
 146         if (udev.ignore_device) {
 147                 dbg("device event will be ignored");
 148                 goto exit;
 149         }
 150         if (udev.name[0] == '\0') {
 151                 dbg("device node creation supressed");
 152                 goto run;
 153         }
 154
 155         udev_add_device(&udev, class_dev);
 156         if (udev.devname[0] != '\0')
 157                 setenv("DEVNAME", udev.devname, 1);
 158 run:
 159         if (udev_run && !list_empty(&udev.run_list)) {
 160                 struct name_entry *name_loop;
 161
 162                 dbg("executing run list");
 163                 list_for_each_entry(name_loop, &udev.run_list, node)
 164                         execute_program(name_loop->name, udev.subsystem, NULL, 0, NULL);
 165         }
 166 exit:
 167         sysfs_close_class_device(class_dev);
 168         udev_cleanup_device(&udev);
 169
 170         return 0;
 171 }
 172
 173 static void exec_list(struct list_head *device_list)
 174 {
 175         struct device *loop_device;
 176         struct device *tmp_device;
 177         int i;
 178
 179         /* handle the "first" type devices first */
 180         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 181                 for (i = 0; first_list[i] != NULL; i++) {
 182                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 183                                 add_device(loop_device->path, loop_device->subsys);
 184                                 list_del(&loop_device->node);
 185                                 free(loop_device);
 186                                 break;
 187                         }
 188                 }
 189         }
 190
 191         /* handle the devices we are allowed to, excluding the "last" type devices */
 192         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 193                 int found = 0;
 194                 for (i = 0; last_list[i] != NULL; i++) {
 195                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 196                                 found = 1;
 197                                 break;
 198                         }
 199                 }
 200                 if (found)
 201                         continue;
 202
 203                 add_device(loop_device->path, loop_device->subsys);
 204                 list_del(&loop_device->node);
 205                 free(loop_device);
 206         }
 207
 208         /* handle the rest of the devices left over, if any */
 209         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 210                 add_device(loop_device->path, loop_device->subsys);
 211                 list_del(&loop_device->node);
 212                 free(loop_device);
 213         }
 214 }
 215
 216 static int has_devt(const char *directory)
 217 {
 218         char filename[PATH_SIZE];
 219         struct stat statbuf;
 220
 221         snprintf(filename, sizeof(filename), "%s/dev", directory);
 222         filename[sizeof(filename)-1] = '\0';
 223
 224         if (stat(filename, &statbuf) == 0)
 225                 return 1;
 226
 227         return 0;
 228 }
 229
 230 static void udev_scan_block(void)
 231 {
 232         char base[PATH_SIZE];
 233         DIR *dir;
 234         struct dirent *dent;
 235         LIST_HEAD(device_list);
 236
 237         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 238         base[sizeof(base)-1] = '\0';
 239
 240         dir = opendir(base);
 241         if (dir != NULL) {
 242                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 243                         char dirname[PATH_SIZE];
 244                         DIR *dir2;
 245                         struct dirent *dent2;
 246
 247                         if (dent->d_name[0] == '.')
 248                                 continue;
 249
 250                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 251                         dirname[sizeof(dirname)-1] = '\0';
 252                         if (has_devt(dirname))
 253                                 device_list_insert(dirname, "block", &device_list);
 254                         else
 255                                 continue;
 256
 257                         /* look for partitions */
 258                         dir2 = opendir(dirname);
 259                         if (dir2 != NULL) {
 260                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 261                                         char dirname2[PATH_SIZE];
 262
 263                                         if (dent2->d_name[0] == '.')
 264                                                 continue;
 265
 266                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 267                                         dirname2[sizeof(dirname2)-1] = '\0';
 268
 269                                         if (has_devt(dirname2))
 270                                                 device_list_insert(dirname2, "block", &device_list);
 271                                 }
 272                                 closedir(dir2);
 273                         }
 274                 }
 275                 closedir(dir);
 276         }
 277         exec_list(&device_list);
 278 }
 279
 280 static void udev_scan_class(void)
 281 {
 282         char base[PATH_SIZE];
 283         DIR *dir;
 284         struct dirent *dent;
 285         LIST_HEAD(device_list);
 286
 287         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 288         base[sizeof(base)-1] = '\0';
 289
 290         dir = opendir(base);
 291         if (dir != NULL) {
 292                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 293                         char dirname[PATH_SIZE];
 294                         DIR *dir2;
 295                         struct dirent *dent2;
 296
 297                         if (dent->d_name[0] == '.')
 298                                 continue;
 299
 300                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 301                         dirname[sizeof(dirname)-1] = '\0';
 302
 303                         dir2 = opendir(dirname);
 304                         if (dir2 != NULL) {
 305                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 306                                         char dirname2[PATH_SIZE];
 307
 308                                         if (dent2->d_name[0] == '.')
 309                                                 continue;
 310
 311                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 312                                         dirname2[sizeof(dirname2)-1] = '\0';
 313
 314                                         /* pass the net class as it is */
 315                                         if (strcmp(dent->d_name, "net") == 0)
 316                                                 device_list_insert(dirname2, "net", &device_list);
 317                                         else if (has_devt(dirname2))
 318                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 319                                 }
 320                                 closedir(dir2);
 321                         }
 322                 }
 323                 closedir(dir);
 324         }
 325         exec_list(&device_list);
 326 }
 327
 328 static void asmlinkage sig_handler(int signum)
 329 {
 330         switch (signum) {
 331                 case SIGALRM:
 332                         exit(1);
 333                 case SIGINT:
 334                 case SIGTERM:
 335                         exit(20 + signum);
 336         }
 337 }
 338
 339 int main(int argc, char *argv[], char *envp[])
 340 {
 341         struct sigaction act;
 342
 343         logging_init("udevstart");
 344         udev_init_config();
 345         dbg("version %s", UDEV_VERSION);
 346
 347         udev_run_str = getenv("UDEV_RUN");
 348         udev_log_str = getenv("UDEV_LOG");
 349
 350         /* disable all logging if not explicitely requested */
 351         if (udev_log_str == NULL)
 352                 udev_log_priority = 0;
 353
 354         /* set signal handlers */
 355         memset(&act, 0x00, sizeof(act));
 356         act.sa_handler = (void (*) (int))sig_handler;
 357         sigemptyset (&act.sa_mask);
 358         act.sa_flags = 0;
 359         sigaction(SIGALRM, &act, NULL);
 360         sigaction(SIGINT, &act, NULL);
 361         sigaction(SIGTERM, &act, NULL);
 362
 363         /* trigger timeout to prevent hanging processes */
 364         alarm(UDEV_ALARM_TIMEOUT);
 365
 366         udev_rules_init(&rules, 1);
 367
 368         udev_scan_block();
 369         udev_scan_class();
 370
 371         udev_rules_close(&rules);
 372         logging_close();
 373         return 0;
 374 }