/*
    * Copyright (C) 2004-2006 Kay Sievers <kay@vrfy.org>
    * Copyright (C) 2006 Hannes Reinecke <hare@suse.de>
    *
    *      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.,
   *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   *
   */
  
  #include <stdlib.h>
  #include <stddef.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdbool.h>
  #include <unistd.h>
  #include <getopt.h>
  #include <errno.h>
  #include <dirent.h>
  #include <fcntl.h>
  #include <syslog.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  #include <string.h>
  
  #define PATH_SIZE 512
  
  #ifndef strlcpy
  #define strlcpy(d,s,l) (strncpy(d,s,l), (d)[(l)-1] = '\0')
  #endif
  
  #ifndef strlcat
  #define strlcat(d,s,l) strncat(d,s,(l)-strlen(d)-1)
  #endif
  
  static int verbose;
  static int dry_run;
  
  static void log_message(int priority, const char *format, ...)
  {
          va_list args;
  
          va_start(args, format);
          vsyslog(priority, format, args);
          va_end(args);
  }
  
  #undef err
  #define err(format, arg...)                         \
      do {                                    \
          log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg);  \
      } while (0)
  
  #undef info
  #define info(format, arg...)                            \
      do {                                    \
          log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \
      } while (0)
  
  #ifdef UDEV_DEBUG
  #undef dbg
  #define dbg(format, arg...)                         \
      do {                                    \
          log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg);    \
      } while (0)
  #else
  #define dbg(...) do {} while(0)
  #endif
  
  
  static void trigger_uevent(const char *devpath)
  {
          char filename[PATH_SIZE];
          int fd;
  
          strlcpy(filename, "/sys", sizeof(filename));
          strlcat(filename, devpath, sizeof(filename));
          strlcat(filename, "/uevent", sizeof(filename));
  
          if (verbose)
                  printf("%s\n", devpath);
  
          if (dry_run)
                  return;
  
          fd = open(filename, O_WRONLY);
          if (fd < 0) {
                  dbg("error on opening %s: %m\n", filename);
                  return;
          }
 
         if (write(fd, "add", 3) < 0)
                 info("error on triggering %s: %m\n", filename);
 
         close(fd);
 }
 
 static int sysfs_resolve_link(char *devpath, size_t size)
 {
         char link_path[PATH_SIZE];
         char link_target[PATH_SIZE];
         int len;
         int i;
         int back;
 
         strlcpy(link_path, "/sys", sizeof(link_path));
         strlcat(link_path, devpath, sizeof(link_path));
         len = readlink(link_path, link_target, sizeof(link_target) - 1);
         if (len <= 0)
                 return -1;
         link_target[len] = '\0';
         dbg("path link '%s' points to '%s'", devpath, link_target);
 
         for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
                 ;
         dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
         for (i = 0; i <= back; i++) {
                 char *pos = strrchr(devpath, '/');
 
                 if (pos == NULL)
                         return -1;
                 pos[0] = '\0';
         }
         dbg("after moving back '%s'", devpath);
         strlcat(devpath, "/", size);
         strlcat(devpath, &link_target[back * 3], size);
         return 0;
 }
 
 static bool device_has_attribute(const char *path, const char *attr,
                                  mode_t mode)
 {
         char filename[PATH_SIZE];
         struct stat statbuf;
 
         strlcpy(filename, path, sizeof(filename));
         strlcat(filename, attr, sizeof(filename));
 
         if (stat(filename, &statbuf) < 0)
                 return false;
 
         if (!(statbuf.st_mode & mode))
                 return false;
 
         return true;
 }
 
 static int device_list_insert(const char *path)
 {
         char devpath[PATH_SIZE];
         struct stat statbuf;
 
         dbg("add '%s'" , path);
 
         /* we only have a device, if we have a dev and an uevent file */
         if (!device_has_attribute(path, "/dev", S_IRUSR) ||
             !device_has_attribute(path, "/uevent", S_IWUSR))
                 return -1;
 
         strlcpy(devpath, &path[4], sizeof(devpath));
 
         /* resolve possible link to real target */
         if (lstat(path, &statbuf) < 0)
                 return -1;
         if (S_ISLNK(statbuf.st_mode))
                 if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
                         return -1;
 
         trigger_uevent(devpath);
         return 0;
 }
 
 static void scan_subdir(const char *base, const char *subdir,
                         bool insert, int depth)
 {
         DIR *dir;
         struct dirent *dent;
 
         dir = opendir(base);
         if (dir == NULL)
                 return;
 
         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
                 char dirname[PATH_SIZE];
 
                 if (dent->d_name[0] == '.')
                         continue;
 
                 strlcpy(dirname, base, sizeof(dirname));
                 strlcat(dirname, "/", sizeof(dirname));
                 strlcat(dirname, dent->d_name, sizeof(dirname));
 
                 if (insert) {
                         int err;
 
                         err = device_list_insert(dirname);
                         if (err)
                                 continue;
                 }
 
                 if (subdir)
                         strlcat(dirname, subdir, sizeof(base));
 
                 if (depth)
                         scan_subdir(dirname, NULL, true, depth - 1);
         }
 
         closedir(dir);
 }
 
 int main(int argc, char *argv[], char *envp[])
 {
         struct stat statbuf;
         int option;
 
         openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON);
 
         while (1) {
                 option = getopt(argc, argv, "vnh");
                 if (option == -1)
                         break;
 
                 switch (option) {
                 case 'v':
                         verbose = 1;
                         break;
                 case 'n':
                         dry_run = 1;
                         break;
                 case 'h':
                         printf("Usage: udevtrigger OPTIONS\n"
                                "  -v                     print the list of devices while running\n"
                                "  -n                     do not actually trigger the events\n"
                                "  -h                     print this text\n"
                                "\n");
                         goto exit;
                 default:
                         goto exit;
                 }
         }
 
 
         /* if we have /sys/subsystem, forget all the old stuff */
         scan_subdir("/sys/bus", "/devices", false, 1);
         scan_subdir("/sys/class", NULL, false, 1);
 
         /* scan "block" if it isn't a "class" */
         if (stat("/sys/class/block", &statbuf) != 0)
                 scan_subdir("/sys/block", NULL, true, 1);
 
 exit:
 
         closelog();
         return 0;
 }
 

• Git
• Wiki