release/src/router/udevtrigger/udevtrigger.c

   1 /*
   2  * Copyright (C) 2004-2006 Kay Sievers <kay@vrfy.org>
   3  * Copyright (C) 2006 Hannes Reinecke <hare@suse.de>
   4  *
   5  *      This program is free software; you can redistribute it and/or modify it
   6  *      under the terms of the GNU General Public License as published by the
   7  *      Free Software Foundation version 2 of the License.
   8  *
   9  *      This program is distributed in the hope that it will be useful, but
  10  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *      General Public License for more details.
  13  *
  14  *      You should have received a copy of the GNU General Public License along
  15  *      with this program; if not, write to the Free Software Foundation, Inc.,
  16  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  *
  18  */
  19
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <stdio.h>
  25 #include <unistd.h>
  26 #include <getopt.h>
  27 #include <errno.h>
  28 #include <dirent.h>
  29 #include <fcntl.h>
  30 #include <syslog.h>
  31 #include <sys/stat.h>
  32 #include <sys/types.h>
  33
  34 #define PATH_SIZE 512
  35
  36 static int verbose;
  37 static int dry_run;
  38
  39 void log_message(int priority, const char *format, ...)
  40 {
  41         va_list args;
  42
  43         va_start(args, format);
  44         vsyslog(priority, format, args);
  45         va_end(args);
  46 }
  47
  48 #undef err
  49 #define err(format, arg...)                         \
  50     do {                                    \
  51         log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg);  \
  52     } while (0)
  53
  54 #undef info
  55 #define info(format, arg...)                            \
  56     do {                                    \
  57         log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \
  58     } while (0)
  59
  60 #ifdef DEBUG
  61 #undef dbg
  62 #define dbg(format, arg...)                         \
  63     do {                                    \
  64         log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg);    \
  65     } while (0)
  66 #else
  67 #define dbg(...) do {} while(0)
  68 #endif
  69
  70
  71 static void trigger_uevent(const char *devpath)
  72 {
  73         char filename[PATH_SIZE];
  74         int fd;
  75
  76         strlcpy(filename, "/sys", sizeof(filename));
  77         strlcat(filename, devpath, sizeof(filename));
  78         strlcat(filename, "/uevent", sizeof(filename));
  79
  80         if (verbose)
  81                 printf("%s\n", devpath);
  82
  83         if (dry_run)
  84                 return;
  85
  86         fd = open(filename, O_WRONLY);
  87         if (fd < 0) {
  88                 dbg("error on opening %s: %s\n", filename, strerror(errno));
  89                 return;
  90         }
  91
  92         if (write(fd, "add", 3) < 0)
  93                 info("error on triggering %s: %s\n", filename, strerror(errno));
  94
  95         close(fd);
  96 }
  97
  98 static int sysfs_resolve_link(char *devpath, size_t size)
  99 {
 100         char link_path[PATH_SIZE];
 101         char link_target[PATH_SIZE];
 102         int len;
 103         int i;
 104         int back;
 105
 106         strlcpy(link_path, "/sys", sizeof(link_path));
 107         strlcat(link_path, devpath, sizeof(link_path));
 108         len = readlink(link_path, link_target, sizeof(link_target));
 109         if (len <= 0)
 110                 return -1;
 111         link_target[len] = '\0';
 112         dbg("path link '%s' points to '%s'", devpath, link_target);
 113
 114         for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
 115                 ;
 116         dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
 117         for (i = 0; i <= back; i++) {
 118                 char *pos = strrchr(devpath, '/');
 119
 120                 if (pos == NULL)
 121                         return -1;
 122                 pos[0] = '\0';
 123         }
 124         dbg("after moving back '%s'", devpath);
 125         strlcat(devpath, "/", size);
 126         strlcat(devpath, &link_target[back * 3], size);
 127         return 0;
 128 }
 129
 130
 131 static int device_list_insert(const char *path)
 132 {
 133         char filename[PATH_SIZE];
 134         char devpath[PATH_SIZE];
 135         struct stat statbuf;
 136
 137         dbg("add '%s'" , path);
 138
 139         /* we only have a device, if we have an uevent file */
 140         strlcpy(filename, path, sizeof(filename));
 141         strlcat(filename, "/uevent", sizeof(filename));
 142         if (stat(filename, &statbuf) < 0)
 143                 return -1;
 144         if (!(statbuf.st_mode & S_IWUSR))
 145                 return -1;
 146
 147         strlcpy(devpath, &path[4], sizeof(devpath));
 148
 149         /* resolve possible link to real target */
 150         if (lstat(path, &statbuf) < 0)
 151                 return -1;
 152         if (S_ISLNK(statbuf.st_mode))
 153                 if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
 154                         return -1;
 155
 156         trigger_uevent(devpath);
 157         return 0;
 158 }
 159
 160
 161 static void scan_subsystem(const char *subsys)
 162 {
 163         char base[PATH_SIZE];
 164         DIR *dir;
 165         struct dirent *dent;
 166
 167         strlcpy(base, "/sys/", sizeof(base));
 168         strlcat(base, subsys, sizeof(base));
 169
 170         dir = opendir(base);
 171         if (dir != NULL) {
 172                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 173                         char dirname[PATH_SIZE];
 174                         DIR *dir2;
 175                         struct dirent *dent2;
 176
 177                         if (dent->d_name[0] == '.')
 178                                 continue;
 179
 180                         strlcpy(dirname, base, sizeof(dirname));
 181                         strlcat(dirname, "/", sizeof(dirname));
 182                         strlcat(dirname, dent->d_name, sizeof(dirname));
 183                         strlcat(dirname, "/devices", sizeof(dirname));
 184
 185                         /* look for devices */
 186                         dir2 = opendir(dirname);
 187                         if (dir2 != NULL) {
 188                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 189                                         char dirname2[PATH_SIZE];
 190
 191                                         if (dent2->d_name[0] == '.')
 192                                                 continue;
 193
 194                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 195                                         strlcat(dirname2, "/", sizeof(dirname2));
 196                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 197                                         device_list_insert(dirname2);
 198                                 }
 199                                 closedir(dir2);
 200                         }
 201                 }
 202                 closedir(dir);
 203         }
 204 }
 205
 206 static void scan_block(void)
 207 {
 208         char base[PATH_SIZE];
 209         DIR *dir;
 210         struct dirent *dent;
 211
 212         strlcpy(base, "/sys/block", sizeof(base));
 213
 214         dir = opendir(base);
 215         if (dir != NULL) {
 216                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 217                         char dirname[PATH_SIZE];
 218                         DIR *dir2;
 219                         struct dirent *dent2;
 220
 221                         if (dent->d_name[0] == '.')
 222                                 continue;
 223
 224                         strlcpy(dirname, base, sizeof(dirname));
 225                         strlcat(dirname, "/", sizeof(dirname));
 226                         strlcat(dirname, dent->d_name, sizeof(dirname));
 227                         if (device_list_insert(dirname) != 0)
 228                                 continue;
 229
 230                         /* look for partitions */
 231                         dir2 = opendir(dirname);
 232                         if (dir2 != NULL) {
 233                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 234                                         char dirname2[PATH_SIZE];
 235
 236                                         if (dent2->d_name[0] == '.')
 237                                                 continue;
 238
 239                                         if (!strcmp(dent2->d_name,"device"))
 240                                                 continue;
 241
 242                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 243                                         strlcat(dirname2, "/", sizeof(dirname2));
 244                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 245                                         device_list_insert(dirname2);
 246                                 }
 247                                 closedir(dir2);
 248                         }
 249                 }
 250                 closedir(dir);
 251         }
 252 }
 253
 254 static void scan_class(void)
 255 {
 256         char base[PATH_SIZE];
 257         DIR *dir;
 258         struct dirent *dent;
 259
 260         strlcpy(base, "/sys/class", sizeof(base));
 261
 262         dir = opendir(base);
 263         if (dir != NULL) {
 264                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 265                         char dirname[PATH_SIZE];
 266                         DIR *dir2;
 267                         struct dirent *dent2;
 268
 269                         if (dent->d_name[0] == '.')
 270                                 continue;
 271
 272                         strlcpy(dirname, base, sizeof(dirname));
 273                         strlcat(dirname, "/", sizeof(dirname));
 274                         strlcat(dirname, dent->d_name, sizeof(dirname));
 275                         dir2 = opendir(dirname);
 276                         if (dir2 != NULL) {
 277                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 278                                         char dirname2[PATH_SIZE];
 279
 280                                         if (dent2->d_name[0] == '.')
 281                                                 continue;
 282
 283                                         if (!strcmp(dent2->d_name, "device"))
 284                                                 continue;
 285
 286                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 287                                         strlcat(dirname2, "/", sizeof(dirname2));
 288                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 289                                         device_list_insert(dirname2);
 290                                 }
 291                                 closedir(dir2);
 292                         }
 293                 }
 294                 closedir(dir);
 295         }
 296 }
 297
 298 int main(int argc, char *argv[], char *envp[])
 299 {
 300         char base[PATH_SIZE];
 301         struct stat statbuf;
 302         int option;
 303
 304         openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON);
 305
 306         while (1) {
 307                 option = getopt(argc, argv, "vnh");
 308                 if (option == -1)
 309                         break;
 310
 311                 switch (option) {
 312                 case 'v':
 313                         verbose = 1;
 314                         break;
 315                 case 'n':
 316                         dry_run = 1;
 317                         break;
 318                 case 'h':
 319                         printf("Usage: udevtrigger OPTIONS\n"
 320                                "  -v                     print the list of devices while running\n"
 321                                "  -n                     do not actually trigger the events\n"
 322                                "  -h                     print this text\n"
 323                                "\n");
 324                         goto exit;
 325                 default:
 326                         goto exit;
 327                 }
 328         }
 329
 330
 331         /* if we have /sys/subsystem, forget all the old stuff */
 332         scan_subsystem("bus");
 333         scan_class();
 334
 335         /* scan "block" if it isn't a "class" */
 336         strlcpy(base, "/sys/class/block", sizeof(base));
 337         if (stat(base, &statbuf) != 0)
 338                 scan_block();
 339
 340 exit:
 341
 342         closelog();
 343         return 0;
 344 }