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         int retval = 0;
 112
 113         /* clear and set environment for next event */
 114         clearenv();
 115         setenv("ACTION", "add", 1);
 116         setenv("UDEV_START", "1", 1);
 117         if (udev_log_str)
 118                 setenv("UDEV_LOG", udev_log_str, 1);
 119         if (udev_run_str)
 120                 setenv("UDEV_RUN", udev_run_str, 1);
 121
 122         dev = sysfs_device_get(devpath);
 123         if (dev == NULL)
 124                 return -1;
 125
 126         udev = udev_device_init();
 127         if (udev == NULL)
 128                 return -1;
 129
 130         /* override built-in sysfs device */
 131         udev->dev = dev;
 132         strcpy(udev->action, "add");
 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                 retval = udev_device_event(&rules, udev);
 151         else
 152                 info("device node creation supressed");
 153
 154         if (retval == 0 && udev_run) {
 155                 struct name_entry *name_loop;
 156
 157                 dbg("executing run list");
 158                 list_for_each_entry(name_loop, &udev->run_list, node) {
 159                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 160                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, "add");
 161                         else {
 162                                 char program[PATH_SIZE];
 163
 164                                 strlcpy(program, name_loop->name, sizeof(program));
 165                                 udev_rules_apply_format(udev, program, sizeof(program));
 166                                 run_program(program, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 167                         }
 168                 }
 169         }
 170
 171 exit:
 172         udev_device_cleanup(udev);
 173         return 0;
 174 }
 175
 176 static void exec_list(struct list_head *device_list)
 177 {
 178         struct device *loop_device;
 179         struct device *tmp_device;
 180         int i;
 181
 182         /* handle the "first" type devices first */
 183         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 184                 for (i = 0; first_list[i] != NULL; i++) {
 185                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 186                                 add_device(loop_device->path);
 187                                 list_del(&loop_device->node);
 188                                 free(loop_device);
 189                                 break;
 190                         }
 191                 }
 192         }
 193
 194         /* handle the devices we are allowed to, excluding the "last" type devices */
 195         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 196                 int found = 0;
 197                 for (i = 0; last_list[i] != NULL; i++) {
 198                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 199                                 found = 1;
 200                                 break;
 201                         }
 202                 }
 203                 if (found)
 204                         continue;
 205
 206                 add_device(loop_device->path);
 207                 list_del(&loop_device->node);
 208                 free(loop_device);
 209         }
 210
 211         /* handle the rest of the devices left over, if any */
 212         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 213                 add_device(loop_device->path);
 214                 list_del(&loop_device->node);
 215                 free(loop_device);
 216         }
 217 }
 218
 219 static int has_devt(const char *path)
 220 {
 221         char filename[PATH_SIZE];
 222         struct stat statbuf;
 223
 224         snprintf(filename, sizeof(filename), "%s/dev", path);
 225         filename[sizeof(filename)-1] = '\0';
 226
 227         if (stat(filename, &statbuf) == 0)
 228                 return 1;
 229
 230         return 0;
 231 }
 232
 233 static void udev_scan_block(struct list_head *device_list)
 234 {
 235         char base[PATH_SIZE];
 236         DIR *dir;
 237         struct dirent *dent;
 238
 239         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 240         base[sizeof(base)-1] = '\0';
 241
 242         dir = opendir(base);
 243         if (dir != NULL) {
 244                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 245                         char dirname[PATH_SIZE];
 246                         DIR *dir2;
 247                         struct dirent *dent2;
 248
 249                         if (dent->d_name[0] == '.')
 250                                 continue;
 251
 252                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 253                         dirname[sizeof(dirname)-1] = '\0';
 254                         if (has_devt(dirname))
 255                                 device_list_insert(dirname, device_list);
 256                         else
 257                                 continue;
 258
 259                         /* look for partitions */
 260                         dir2 = opendir(dirname);
 261                         if (dir2 != NULL) {
 262                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 263                                         char dirname2[PATH_SIZE];
 264
 265                                         if (dent2->d_name[0] == '.')
 266                                                 continue;
 267
 268                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 269                                         dirname2[sizeof(dirname2)-1] = '\0';
 270
 271                                         if (has_devt(dirname2))
 272                                                 device_list_insert(dirname2, device_list);
 273                                 }
 274                                 closedir(dir2);
 275                         }
 276                 }
 277                 closedir(dir);
 278         }
 279 }
 280
 281 static void udev_scan_class(struct list_head *device_list)
 282 {
 283         char base[PATH_SIZE];
 284         DIR *dir;
 285         struct dirent *dent;
 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                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 315                                                 device_list_insert(dirname2, device_list);
 316                                 }
 317                                 closedir(dir2);
 318                         }
 319                 }
 320                 closedir(dir);
 321         }
 322 }
 323
 324 static void asmlinkage sig_handler(int signum)
 325 {
 326         switch (signum) {
 327                 case SIGALRM:
 328                         exit(1);
 329                 case SIGINT:
 330                 case SIGTERM:
 331                         exit(20 + signum);
 332         }
 333 }
 334
 335 int main(int argc, char *argv[], char *envp[])
 336 {
 337         LIST_HEAD(device_list);
 338         struct sigaction act;
 339
 340         logging_init("udevstart");
 341         udev_config_init();
 342         dbg("version %s", UDEV_VERSION);
 343
 344         udev_run_str = getenv("UDEV_RUN");
 345         udev_log_str = getenv("UDEV_LOG");
 346
 347         /* disable all logging if not explicitely requested */
 348         if (udev_log_str == NULL)
 349                 udev_log_priority = 0;
 350
 351         /* set signal handlers */
 352         memset(&act, 0x00, sizeof(act));
 353         act.sa_handler = (void (*) (int))sig_handler;
 354         sigemptyset (&act.sa_mask);
 355         act.sa_flags = 0;
 356         sigaction(SIGALRM, &act, NULL);
 357         sigaction(SIGINT, &act, NULL);
 358         sigaction(SIGTERM, &act, NULL);
 359
 360         /* trigger timeout to prevent hanging processes */
 361         alarm(UDEV_ALARM_TIMEOUT);
 362
 363         sysfs_init();
 364         udev_rules_init(&rules, 1);
 365
 366         udev_scan_class(&device_list);
 367         udev_scan_block(&device_list);
 368         exec_list(&device_list);
 369
 370         udev_rules_cleanup(&rules);
 371         sysfs_cleanup();
 372         logging_close();
 373         return 0;
 374 }