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Sourcecode: udev version File versions

udevstart.c

/*
 * udevstart.c
 *
 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
 * 
 * Quick and dirty way to populate a /dev with udev if your system
 * does not have access to a shell.  Based originally on a patch to udev 
 * from Harald Hoyer <harald@redhat.com>
 *
 *    This program is free software; you can redistribute it and/or modify it
 *    under the terms of the GNU General Public License as published by the
 *    Free Software Foundation version 2 of the License.
 * 
 *    This program is distributed in the hope that it will be useful, but
 *    WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    General Public License for more details.
 * 
 *    You should have received a copy of the GNU General Public License along
 *    with this program; if not, write to the Free Software Foundation, Inc.,
 *    675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <dirent.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "libsysfs/sysfs/libsysfs.h"
#include "udev_libc_wrapper.h"
#include "udev.h"
#include "logging.h"
#include "udev_rules.h"
#include "udev_utils.h"
#include "list.h"

#ifdef USE_LOG
void log_message(int level, const char *format, ...)
{
}
#endif

struct device {
      struct list_head node;
      char path[PATH_SIZE];
      char subsys[NAME_SIZE];
};

/* sort files in lexical order */
static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
{
      struct device *loop_device;
      struct device *new_device;

      dbg("insert: '%s'\n", path);

      list_for_each_entry(loop_device, device_list, node) {
            if (strcmp(loop_device->path, path) > 0) {
                  break;
            }
      }

      new_device = malloc(sizeof(struct device));
      if (new_device == NULL) {
            dbg("error malloc");
            return -ENOMEM;
      }

      strlcpy(new_device->path, path, sizeof(new_device->path));
      strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
      list_add_tail(&new_device->node, &loop_device->node);
      dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
      return 0;
}

/* list of devices that we should run last due to any one of a number of reasons */
static char *last_list[] = {
      "/block/dm",      /* on here because dm wants to have the block devices around before it */
      NULL,
};

/* list of devices that we should run first due to any one of a number of reasons */
static char *first_list[] = {
      "/class/mem",     /* people tend to like their memory devices around first... */
      NULL,
};

static int add_device(const char *path, const char *subsystem)
{
      struct udevice udev;
      struct sysfs_class_device *class_dev;
      const char *devpath;

      devpath = &path[strlen(sysfs_path)];

      /* set environment for callouts and dev.d/ */
      setenv("DEVPATH", devpath, 1);
      setenv("SUBSYSTEM", subsystem, 1);

      dbg("exec: '%s' (%s)\n", devpath, path);

      class_dev = sysfs_open_class_device_path(path);
      if (class_dev == NULL) {
            dbg ("sysfs_open_class_device_path failed");
            return -ENODEV;
      }

      udev_init_device(&udev, devpath, subsystem);
      udev_add_device(&udev, class_dev);

      /* run dev.d/ scripts if we created a node or changed a netif name */
      if (udev_dev_d && udev.devname[0] != '\0') {
            setenv("DEVNAME", udev.devname, 1);
            udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
      }

      sysfs_close_class_device(class_dev);
      udev_cleanup_device(&udev);

      return 0;
}

static void exec_list(struct list_head *device_list)
{
      struct device *loop_device;
      struct device *tmp_device;
      int i;

      /* handle the "first" type devices first */
      list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
            for (i = 0; first_list[i] != NULL; i++) {
                  if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
                        add_device(loop_device->path, loop_device->subsys);
                        list_del(&loop_device->node);
                        free(loop_device);
                        break;
                  }
            }
      }

      /* handle the devices we are allowed to, excluding the "last" type devices */
      list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
            int found = 0;
            for (i = 0; last_list[i] != NULL; i++) {
                  if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
                        found = 1;
                        break;
                  }
            }
            if (found)
                  continue;

            add_device(loop_device->path, loop_device->subsys);
            list_del(&loop_device->node);
            free(loop_device);
      }

      /* handle the rest of the devices left over, if any */
      list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
            add_device(loop_device->path, loop_device->subsys);
            list_del(&loop_device->node);
            free(loop_device);
      }
}

static int has_devt(const char *directory)
{
      char filename[PATH_SIZE];
      struct stat statbuf;

      snprintf(filename, sizeof(filename), "%s/dev", directory);
      filename[sizeof(filename)-1] = '\0';

      if (stat(filename, &statbuf) == 0)
            return 1;

      return 0;
}

static void udev_scan_block(void)
{
      char base[PATH_SIZE];
      DIR *dir;
      struct dirent *dent;
      LIST_HEAD(device_list);

      snprintf(base, sizeof(base), "%s/block", sysfs_path);
      base[sizeof(base)-1] = '\0';

      dir = opendir(base);
      if (dir != NULL) {
            for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
                  char dirname[PATH_SIZE];
                  DIR *dir2;
                  struct dirent *dent2;

                  if (dent->d_name[0] == '.')
                        continue;

                  snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
                  dirname[sizeof(dirname)-1] = '\0';
                  if (has_devt(dirname))
                        device_list_insert(dirname, "block", &device_list);
                  else
                        continue;

                  /* look for partitions */
                  dir2 = opendir(dirname);
                  if (dir2 != NULL) {
                        for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
                              char dirname2[PATH_SIZE];

                              if (dent2->d_name[0] == '.')
                                    continue;

                              snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
                              dirname2[sizeof(dirname2)-1] = '\0';

                              if (has_devt(dirname2))
                                    device_list_insert(dirname2, "block", &device_list);
                        }
                        closedir(dir2);
                  }
            }
            closedir(dir);
      }
      exec_list(&device_list);
}

static void udev_scan_class(void)
{
      char base[PATH_SIZE];
      DIR *dir;
      struct dirent *dent;
      LIST_HEAD(device_list);

      snprintf(base, sizeof(base), "%s/class", sysfs_path);
      base[sizeof(base)-1] = '\0';

      dir = opendir(base);
      if (dir != NULL) {
            for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
                  char dirname[PATH_SIZE];
                  DIR *dir2;
                  struct dirent *dent2;

                  if (dent->d_name[0] == '.')
                        continue;

                  snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
                  dirname[sizeof(dirname)-1] = '\0';

                  dir2 = opendir(dirname);
                  if (dir2 != NULL) {
                        for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
                              char dirname2[PATH_SIZE];

                              if (dent2->d_name[0] == '.')
                                    continue;

                              snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
                              dirname2[sizeof(dirname2)-1] = '\0';

                              /* pass the net class as it is */
                              if (strcmp(dent->d_name, "net") == 0)
                                    device_list_insert(dirname2, "net", &device_list);
                              else if (has_devt(dirname2))
                                    device_list_insert(dirname2, dent->d_name, &device_list);
                        }
                        closedir(dir2);
                  }
            }
            closedir(dir);
      }
      exec_list(&device_list);
}

static void asmlinkage sig_handler(int signum)
{
      switch (signum) {
            case SIGALRM:
                  exit(1);
            case SIGINT:
            case SIGTERM:
                  exit(20 + signum);
      }
}

int main(int argc, char *argv[], char *envp[])
{
      struct sigaction act;

      udev_init_config();

      /* set signal handlers */
      memset(&act, 0x00, sizeof(act));
      act.sa_handler = (void (*) (int))sig_handler;
      sigemptyset (&act.sa_mask);
      act.sa_flags = 0;
      sigaction(SIGALRM, &act, NULL);
      sigaction(SIGINT, &act, NULL);
      sigaction(SIGTERM, &act, NULL);

      /* trigger timeout to prevent hanging processes */
      alarm(ALARM_TIMEOUT);

      /* set environment for executed programs */
      setenv("ACTION", "add", 1);
      setenv("UDEV_START", "1", 1);

      udev_rules_init();

      udev_scan_block();
      udev_scan_class();

      return 0;
}

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