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 "udev.h"
  42 #include "udev_rules.h"
  43
  44 static const char *udev_run_str;
  45 static const char *udev_log_str;
  46 static struct udev_rules rules;
  47
  48 #ifdef USE_LOG
  49 void log_message(int priority, const char *format, ...)
  50 {
  51         va_list args;
  52
  53         if (priority > udev_log_priority)
  54                 return;
  55
  56         va_start(args, format);
  57         vsyslog(priority, format, args);
  58         va_end(args);
  59 }
  60 #endif
  61
  62 struct device {
  63         struct list_head node;
  64         char path[PATH_SIZE];
  65 };
  66
  67 /* sort files in lexical order */
  68 static int device_list_insert(const char *path, struct list_head *device_list)
  69 {
  70         struct device *loop_device;
  71         struct device *new_device;
  72         const char *devpath = &path[strlen(sysfs_path)];
  73
  74         dbg("insert: '%s'\n", devpath);
  75
  76         list_for_each_entry(loop_device, device_list, node) {
  77                 if (strcmp(loop_device->path, devpath) > 0) {
  78                         break;
  79                 }
  80         }
  81
  82         new_device = malloc(sizeof(struct device));
  83         if (new_device == NULL) {
  84                 dbg("error malloc");
  85                 return -ENOMEM;
  86         }
  87
  88         strlcpy(new_device->path, devpath, sizeof(new_device->path));
  89         list_add_tail(&new_device->node, &loop_device->node);
  90         dbg("add '%s'" , new_device->path);
  91         return 0;
  92 }
  93
  94 /* list of devices that we should run last due to any one of a number of reasons */
  95 static char *last_list[] = {
  96         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  97         NULL,
  98 };
  99
 100 /* list of devices that we should run first due to any one of a number of reasons */
 101 static char *first_list[] = {
 102         "/class/mem",
 103         "/class/tty",
 104         NULL,
 105 };
 106
 107 static int add_device(const char *devpath)
 108 {
 109         struct sysfs_device *dev;
 110         struct udevice *udev;
 111
 112         /* clear and set environment for next event */
 113         clearenv();
 114         setenv("ACTION", "add", 1);
 115         setenv("UDEV_START", "1", 1);
 116         if (udev_log_str)
 117                 setenv("UDEV_LOG", udev_log_str, 1);
 118         if (udev_run_str)
 119                 setenv("UDEV_RUN", udev_run_str, 1);
 120
 121         dev = sysfs_device_get(devpath);
 122         if (dev == NULL)
 123                 return -1;
 124
 125         udev = udev_device_init();
 126         if (udev == NULL)
 127                 return -1;
 128
 129         /* override built-in sysfs device */
 130         udev->dev = dev;
 131         strcpy(udev->action, "add");
 132         udev->devt = udev_device_get_devt(udev);
 133
 134         if (strcmp(udev->dev->subsystem, "net") != 0) {
 135                 udev->devt = udev_device_get_devt(udev);
 136                 if (major(udev->devt) == 0)
 137                         return -1;
 138         }
 139
 140         dbg("add '%s'", udev->dev->devpath);
 141         setenv("DEVPATH", udev->dev->devpath, 1);
 142         setenv("SUBSYSTEM", udev->dev->subsystem, 1);
 143
 144         udev_rules_get_name(&rules, udev);
 145         if (udev->ignore_device) {
 146                 dbg("device event will be ignored");
 147                 goto exit;
 148         }
 149         if (udev->name[0] == '\0') {
 150                 dbg("device node creation supressed");
 151                 goto run;
 152         }
 153
 154         udev_add_device(udev);
 155 run:
 156         if (udev_run && !list_empty(&udev->run_list)) {
 157                 struct name_entry *name_loop;
 158
 159                 dbg("executing run list");
 160                 list_for_each_entry(name_loop, &udev->run_list, node) {
 161                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 162                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, "add");
 163                         else
 164                                 run_program(name_loop->name, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 165                 }
 166         }
 167 exit:
 168         udev_device_cleanup(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);
 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);
 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);
 211                 list_del(&loop_device->node);
 212                 free(loop_device);
 213         }
 214 }
 215
 216 static int has_devt(const char *path)
 217 {
 218         char filename[PATH_SIZE];
 219         struct stat statbuf;
 220
 221         snprintf(filename, sizeof(filename), "%s/dev", path);
 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(struct list_head *device_list)
 231 {
 232         char base[PATH_SIZE];
 233         DIR *dir;
 234         struct dirent *dent;
 235
 236         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 237         base[sizeof(base)-1] = '\0';
 238
 239         dir = opendir(base);
 240         if (dir != NULL) {
 241                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 242                         char dirname[PATH_SIZE];
 243                         DIR *dir2;
 244                         struct dirent *dent2;
 245
 246                         if (dent->d_name[0] == '.')
 247                                 continue;
 248
 249                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 250                         dirname[sizeof(dirname)-1] = '\0';
 251                         if (has_devt(dirname))
 252                                 device_list_insert(dirname, device_list);
 253                         else
 254                                 continue;
 255
 256                         /* look for partitions */
 257                         dir2 = opendir(dirname);
 258                         if (dir2 != NULL) {
 259                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 260                                         char dirname2[PATH_SIZE];
 261
 262                                         if (dent2->d_name[0] == '.')
 263                                                 continue;
 264
 265                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 266                                         dirname2[sizeof(dirname2)-1] = '\0';
 267
 268                                         if (has_devt(dirname2))
 269                                                 device_list_insert(dirname2, device_list);
 270                                 }
 271                                 closedir(dir2);
 272                         }
 273                 }
 274                 closedir(dir);
 275         }
 276 }
 277
 278 static void udev_scan_class(struct list_head *device_list)
 279 {
 280         char base[PATH_SIZE];
 281         DIR *dir;
 282         struct dirent *dent;
 283
 284         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 285         base[sizeof(base)-1] = '\0';
 286
 287         dir = opendir(base);
 288         if (dir != NULL) {
 289                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 290                         char dirname[PATH_SIZE];
 291                         DIR *dir2;
 292                         struct dirent *dent2;
 293
 294                         if (dent->d_name[0] == '.')
 295                                 continue;
 296
 297                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 298                         dirname[sizeof(dirname)-1] = '\0';
 299
 300                         dir2 = opendir(dirname);
 301                         if (dir2 != NULL) {
 302                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 303                                         char dirname2[PATH_SIZE];
 304
 305                                         if (dent2->d_name[0] == '.')
 306                                                 continue;
 307
 308                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 309                                         dirname2[sizeof(dirname2)-1] = '\0';
 310
 311                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 312                                                 device_list_insert(dirname2, device_list);
 313                                 }
 314                                 closedir(dir2);
 315                         }
 316                 }
 317                 closedir(dir);
 318         }
 319 }
 320
 321 static void asmlinkage sig_handler(int signum)
 322 {
 323         switch (signum) {
 324                 case SIGALRM:
 325                         exit(1);
 326                 case SIGINT:
 327                 case SIGTERM:
 328                         exit(20 + signum);
 329         }
 330 }
 331
 332 int main(int argc, char *argv[], char *envp[])
 333 {
 334         LIST_HEAD(device_list);
 335         struct sigaction act;
 336
 337         logging_init("udevstart");
 338         udev_config_init();
 339         dbg("version %s", UDEV_VERSION);
 340
 341         udev_run_str = getenv("UDEV_RUN");
 342         udev_log_str = getenv("UDEV_LOG");
 343
 344         /* disable all logging if not explicitely requested */
 345         if (udev_log_str == NULL)
 346                 udev_log_priority = 0;
 347
 348         /* set signal handlers */
 349         memset(&act, 0x00, sizeof(act));
 350         act.sa_handler = (void (*) (int))sig_handler;
 351         sigemptyset (&act.sa_mask);
 352         act.sa_flags = 0;
 353         sigaction(SIGALRM, &act, NULL);
 354         sigaction(SIGINT, &act, NULL);
 355         sigaction(SIGTERM, &act, NULL);
 356
 357         /* trigger timeout to prevent hanging processes */
 358         alarm(UDEV_ALARM_TIMEOUT);
 359
 360         sysfs_init();
 361         udev_rules_init(&rules, 1);
 362
 363         udev_scan_class(&device_list);
 364         udev_scan_block(&device_list);
 365         exec_list(&device_list);
 366
 367         udev_rules_cleanup(&rules);
 368         sysfs_cleanup();
 369         logging_close();
 370         return 0;
 371 }