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 <syslog.h>
  37 #include <sys/wait.h>
  38 #include <sys/stat.h>
  39 #include <sys/types.h>
  40
  41 #include "libsysfs/sysfs/libsysfs.h"
  42 #include "udev_libc_wrapper.h"
  43 #include "udev_sysfs.h"
  44 #include "udev.h"
  45 #include "udev_version.h"
  46 #include "logging.h"
  47 #include "udev_utils.h"
  48 #include "udev_rules.h"
  49 #include "list.h"
  50
  51 static const char *udev_run_str;
  52 static const char *udev_log_str;
  53 static struct udev_rules rules;
  54
  55 #ifdef USE_LOG
  56 void log_message(int priority, const char *format, ...)
  57 {
  58         va_list args;
  59
  60         if (priority > udev_log_priority)
  61                 return;
  62
  63         va_start(args, format);
  64         vsyslog(priority, format, args);
  65         va_end(args);
  66 }
  67 #endif
  68
  69 struct device {
  70         struct list_head node;
  71         char path[PATH_SIZE];
  72         char subsys[NAME_SIZE];
  73 };
  74
  75 /* sort files in lexical order */
  76 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  77 {
  78         struct device *loop_device;
  79         struct device *new_device;
  80         const char *devpath = &path[strlen(sysfs_path)];
  81
  82         dbg("insert: '%s'\n", devpath);
  83
  84         list_for_each_entry(loop_device, device_list, node) {
  85                 if (strcmp(loop_device->path, devpath) > 0) {
  86                         break;
  87                 }
  88         }
  89
  90         new_device = malloc(sizeof(struct device));
  91         if (new_device == NULL) {
  92                 dbg("error malloc");
  93                 return -ENOMEM;
  94         }
  95
  96         strlcpy(new_device->path, devpath, sizeof(new_device->path));
  97         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  98         list_add_tail(&new_device->node, &loop_device->node);
  99         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
 100         return 0;
 101 }
 102
 103 /* list of devices that we should run last due to any one of a number of reasons */
 104 static char *last_list[] = {
 105         "/block/dm",    /* on here because dm wants to have the block devices around before it */
 106         NULL,
 107 };
 108
 109 /* list of devices that we should run first due to any one of a number of reasons */
 110 static char *first_list[] = {
 111         "/class/mem",
 112         "/class/tty",
 113         NULL,
 114 };
 115
 116 static int add_device(const char *devpath, const char *subsystem)
 117 {
 118         struct udevice udev;
 119         struct sysfs_class_device *class_dev;
 120         char path[PATH_SIZE];
 121
 122         /* clear and set environment for next event */
 123         clearenv();
 124         setenv("ACTION", "add", 1);
 125         setenv("DEVPATH", devpath, 1);
 126         setenv("SUBSYSTEM", subsystem, 1);
 127         setenv("UDEV_START", "1", 1);
 128         if (udev_log_str)
 129                 setenv("UDEV_LOG", udev_log_str, 1);
 130         if (udev_run_str)
 131                 setenv("UDEV_RUN", udev_run_str, 1);
 132         dbg("add '%s'", devpath);
 133
 134         snprintf(path, sizeof(path), "%s%s", sysfs_path, devpath);
 135         path[sizeof(path)-1] = '\0';
 136         class_dev = sysfs_open_class_device_path(path);
 137         if (class_dev == NULL) {
 138                 dbg("sysfs_open_class_device_path failed");
 139                 return -1;
 140         }
 141
 142         udev_init_device(&udev, devpath, subsystem, "add");
 143         udev.devt = get_devt(class_dev);
 144         if (!udev.devt && udev.type != DEV_NET) {
 145                 dbg("sysfs_open_class_device_path failed");
 146                 return -1;
 147         }
 148         udev_rules_get_name(&rules, &udev, class_dev);
 149         if (udev.ignore_device) {
 150                 dbg("device event will be ignored");
 151                 goto exit;
 152         }
 153         if (udev.name[0] == '\0') {
 154                 dbg("device node creation supressed");
 155                 goto run;
 156         }
 157
 158         udev_add_device(&udev, class_dev);
 159         if (udev.devname[0] != '\0')
 160                 setenv("DEVNAME", udev.devname, 1);
 161 run:
 162         if (udev_run && !list_empty(&udev.run_list)) {
 163                 struct name_entry *name_loop;
 164
 165                 dbg("executing run list");
 166                 list_for_each_entry(name_loop, &udev.run_list, node) {
 167                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 168                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], devpath, "add");
 169                         else
 170                                 run_program(name_loop->name, udev.subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 171                 }
 172         }
 173 exit:
 174         sysfs_close_class_device(class_dev);
 175         udev_cleanup_device(&udev);
 176
 177         return 0;
 178 }
 179
 180 static void exec_list(struct list_head *device_list)
 181 {
 182         struct device *loop_device;
 183         struct device *tmp_device;
 184         int i;
 185
 186         /* handle the "first" type devices first */
 187         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 188                 for (i = 0; first_list[i] != NULL; i++) {
 189                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 190                                 add_device(loop_device->path, loop_device->subsys);
 191                                 list_del(&loop_device->node);
 192                                 free(loop_device);
 193                                 break;
 194                         }
 195                 }
 196         }
 197
 198         /* handle the devices we are allowed to, excluding the "last" type devices */
 199         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 200                 int found = 0;
 201                 for (i = 0; last_list[i] != NULL; i++) {
 202                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 203                                 found = 1;
 204                                 break;
 205                         }
 206                 }
 207                 if (found)
 208                         continue;
 209
 210                 add_device(loop_device->path, loop_device->subsys);
 211                 list_del(&loop_device->node);
 212                 free(loop_device);
 213         }
 214
 215         /* handle the rest of the devices left over, if any */
 216         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 217                 add_device(loop_device->path, loop_device->subsys);
 218                 list_del(&loop_device->node);
 219                 free(loop_device);
 220         }
 221 }
 222
 223 static int has_devt(const char *path)
 224 {
 225         char filename[PATH_SIZE];
 226         struct stat statbuf;
 227
 228         snprintf(filename, sizeof(filename), "%s/dev", path);
 229         filename[sizeof(filename)-1] = '\0';
 230
 231         if (stat(filename, &statbuf) == 0)
 232                 return 1;
 233
 234         return 0;
 235 }
 236
 237 static void udev_scan_block(struct list_head *device_list)
 238 {
 239         char base[PATH_SIZE];
 240         DIR *dir;
 241         struct dirent *dent;
 242
 243         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 244         base[sizeof(base)-1] = '\0';
 245
 246         dir = opendir(base);
 247         if (dir != NULL) {
 248                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 249                         char dirname[PATH_SIZE];
 250                         DIR *dir2;
 251                         struct dirent *dent2;
 252
 253                         if (dent->d_name[0] == '.')
 254                                 continue;
 255
 256                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 257                         dirname[sizeof(dirname)-1] = '\0';
 258                         if (has_devt(dirname))
 259                                 device_list_insert(dirname, "block", device_list);
 260                         else
 261                                 continue;
 262
 263                         /* look for partitions */
 264                         dir2 = opendir(dirname);
 265                         if (dir2 != NULL) {
 266                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 267                                         char dirname2[PATH_SIZE];
 268
 269                                         if (dent2->d_name[0] == '.')
 270                                                 continue;
 271
 272                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 273                                         dirname2[sizeof(dirname2)-1] = '\0';
 274
 275                                         if (has_devt(dirname2))
 276                                                 device_list_insert(dirname2, "block", device_list);
 277                                 }
 278                                 closedir(dir2);
 279                         }
 280                 }
 281                 closedir(dir);
 282         }
 283 }
 284
 285 static void udev_scan_class(struct list_head *device_list)
 286 {
 287         char base[PATH_SIZE];
 288         DIR *dir;
 289         struct dirent *dent;
 290
 291         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 292         base[sizeof(base)-1] = '\0';
 293
 294         dir = opendir(base);
 295         if (dir != NULL) {
 296                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 297                         char dirname[PATH_SIZE];
 298                         DIR *dir2;
 299                         struct dirent *dent2;
 300
 301                         if (dent->d_name[0] == '.')
 302                                 continue;
 303
 304                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 305                         dirname[sizeof(dirname)-1] = '\0';
 306
 307                         dir2 = opendir(dirname);
 308                         if (dir2 != NULL) {
 309                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 310                                         char dirname2[PATH_SIZE];
 311
 312                                         if (dent2->d_name[0] == '.')
 313                                                 continue;
 314
 315                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 316                                         dirname2[sizeof(dirname2)-1] = '\0';
 317
 318                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 319                                                 device_list_insert(dirname2, dent->d_name, device_list);
 320                                 }
 321                                 closedir(dir2);
 322                         }
 323                 }
 324                 closedir(dir);
 325         }
 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         LIST_HEAD(device_list);
 342         struct sigaction act;
 343
 344         logging_init("udevstart");
 345         udev_init_config();
 346         dbg("version %s", UDEV_VERSION);
 347
 348         udev_run_str = getenv("UDEV_RUN");
 349         udev_log_str = getenv("UDEV_LOG");
 350
 351         /* disable all logging if not explicitely requested */
 352         if (udev_log_str == NULL)
 353                 udev_log_priority = 0;
 354
 355         /* set signal handlers */
 356         memset(&act, 0x00, sizeof(act));
 357         act.sa_handler = (void (*) (int))sig_handler;
 358         sigemptyset (&act.sa_mask);
 359         act.sa_flags = 0;
 360         sigaction(SIGALRM, &act, NULL);
 361         sigaction(SIGINT, &act, NULL);
 362         sigaction(SIGTERM, &act, NULL);
 363
 364         /* trigger timeout to prevent hanging processes */
 365         alarm(UDEV_ALARM_TIMEOUT);
 366
 367         udev_rules_init(&rules, 0, 1);
 368
 369         udev_scan_class(&device_list);
 370         udev_scan_block(&device_list);
 371         exec_list(&device_list);
 372
 373         udev_rules_close(&rules);
 374         logging_close();
 375         return 0;
 376 }