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 <stdio.h>
  24 #include <unistd.h>
  25 #include <getopt.h>
  26 #include <errno.h>
  27 #include <dirent.h>
  28 #include <fcntl.h>
  29 #include <syslog.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32 #include <string.h>
  33
  34 #define PATH_SIZE 512
  35
  36 #ifndef strlcpy
  37 #define strlcpy(d,s,l) (strncpy(d,s,l), (d)[(l)-1] = '\0')
  38 #endif
  39
  40 #ifndef strlcat
  41 #define strlcat(d,s,l) strncat(d,s,(l)-strlen(d)-1)
  42 #endif
  43
  44 static int verbose;
  45 static int dry_run;
  46
  47 static void log_message(int priority, const char *format, ...)
  48 {
  49         va_list args;
  50
  51         va_start(args, format);
  52         vsyslog(priority, format, args);
  53         va_end(args);
  54 }
  55
  56 #undef err
  57 #define err(format, arg...)                         \
  58     do {                                    \
  59         log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg);  \
  60     } while (0)
  61
  62 #undef info
  63 #define info(format, arg...)                            \
  64     do {                                    \
  65         log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \
  66     } while (0)
  67
  68 #ifdef DEBUG
  69 #undef dbg
  70 #define dbg(format, arg...)                         \
  71     do {                                    \
  72         log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg);    \
  73     } while (0)
  74 #else
  75 #define dbg(...) do {} while(0)
  76 #endif
  77
  78
  79 static void trigger_uevent(const char *devpath)
  80 {
  81         char filename[PATH_SIZE];
  82         int fd;
  83
  84         strlcpy(filename, "/sys", sizeof(filename));
  85         strlcat(filename, devpath, sizeof(filename));
  86         strlcat(filename, "/uevent", sizeof(filename));
  87
  88         if (verbose)
  89                 printf("%s\n", devpath);
  90
  91         if (dry_run)
  92                 return;
  93
  94         fd = open(filename, O_WRONLY);
  95         if (fd < 0) {
  96                 dbg("error on opening %s: %s\n", filename, strerror(errno));
  97                 return;
  98         }
  99
 100         if (write(fd, "add", 3) < 0)
 101                 info("error on triggering %s: %s\n", filename, strerror(errno));
 102
 103         close(fd);
 104 }
 105
 106 static int sysfs_resolve_link(char *devpath, size_t size)
 107 {
 108         char link_path[PATH_SIZE];
 109         char link_target[PATH_SIZE];
 110         int len;
 111         int i;
 112         int back;
 113
 114         strlcpy(link_path, "/sys", sizeof(link_path));
 115         strlcat(link_path, devpath, sizeof(link_path));
 116         len = readlink(link_path, link_target, sizeof(link_target));
 117         if (len <= 0)
 118                 return -1;
 119         link_target[len] = '\0';
 120         dbg("path link '%s' points to '%s'", devpath, link_target);
 121
 122         for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
 123                 ;
 124         dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
 125         for (i = 0; i <= back; i++) {
 126                 char *pos = strrchr(devpath, '/');
 127
 128                 if (pos == NULL)
 129                         return -1;
 130                 pos[0] = '\0';
 131         }
 132         dbg("after moving back '%s'", devpath);
 133         strlcat(devpath, "/", size);
 134         strlcat(devpath, &link_target[back * 3], size);
 135         return 0;
 136 }
 137
 138
 139 static int device_list_insert(const char *path)
 140 {
 141         char filename[PATH_SIZE];
 142         char devpath[PATH_SIZE];
 143         struct stat statbuf;
 144
 145         dbg("add '%s'" , path);
 146
 147         /* we only have a device, if we have an uevent file */
 148         strlcpy(filename, path, sizeof(filename));
 149         strlcat(filename, "/uevent", sizeof(filename));
 150         if (stat(filename, &statbuf) < 0)
 151                 return -1;
 152         if (!(statbuf.st_mode & S_IWUSR))
 153                 return -1;
 154
 155         strlcpy(devpath, &path[4], sizeof(devpath));
 156
 157         /* resolve possible link to real target */
 158         if (lstat(path, &statbuf) < 0)
 159                 return -1;
 160         if (S_ISLNK(statbuf.st_mode))
 161                 if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
 162                         return -1;
 163
 164         trigger_uevent(devpath);
 165         return 0;
 166 }
 167
 168
 169 static void scan_subsystem(const char *subsys)
 170 {
 171         char base[PATH_SIZE];
 172         DIR *dir;
 173         struct dirent *dent;
 174
 175         strlcpy(base, "/sys/", sizeof(base));
 176         strlcat(base, subsys, sizeof(base));
 177
 178         dir = opendir(base);
 179         if (dir != NULL) {
 180                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 181                         char dirname[PATH_SIZE];
 182                         DIR *dir2;
 183                         struct dirent *dent2;
 184
 185                         if (dent->d_name[0] == '.')
 186                                 continue;
 187
 188                         strlcpy(dirname, base, sizeof(dirname));
 189                         strlcat(dirname, "/", sizeof(dirname));
 190                         strlcat(dirname, dent->d_name, sizeof(dirname));
 191                         strlcat(dirname, "/devices", sizeof(dirname));
 192
 193                         /* look for devices */
 194                         dir2 = opendir(dirname);
 195                         if (dir2 != NULL) {
 196                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 197                                         char dirname2[PATH_SIZE];
 198
 199                                         if (dent2->d_name[0] == '.')
 200                                                 continue;
 201
 202                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 203                                         strlcat(dirname2, "/", sizeof(dirname2));
 204                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 205                                         device_list_insert(dirname2);
 206                                 }
 207                                 closedir(dir2);
 208                         }
 209                 }
 210                 closedir(dir);
 211         }
 212 }
 213
 214 static void scan_block(void)
 215 {
 216         char base[PATH_SIZE];
 217         DIR *dir;
 218         struct dirent *dent;
 219
 220         strlcpy(base, "/sys/block", sizeof(base));
 221
 222         dir = opendir(base);
 223         if (dir != NULL) {
 224                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 225                         char dirname[PATH_SIZE];
 226                         DIR *dir2;
 227                         struct dirent *dent2;
 228
 229                         if (dent->d_name[0] == '.')
 230                                 continue;
 231
 232                         strlcpy(dirname, base, sizeof(dirname));
 233                         strlcat(dirname, "/", sizeof(dirname));
 234                         strlcat(dirname, dent->d_name, sizeof(dirname));
 235                         if (device_list_insert(dirname) != 0)
 236                                 continue;
 237
 238                         /* look for partitions */
 239                         dir2 = opendir(dirname);
 240                         if (dir2 != NULL) {
 241                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 242                                         char dirname2[PATH_SIZE];
 243
 244                                         if (dent2->d_name[0] == '.')
 245                                                 continue;
 246
 247                                         if (!strcmp(dent2->d_name,"device"))
 248                                                 continue;
 249
 250                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 251                                         strlcat(dirname2, "/", sizeof(dirname2));
 252                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 253                                         device_list_insert(dirname2);
 254                                 }
 255                                 closedir(dir2);
 256                         }
 257                 }
 258                 closedir(dir);
 259         }
 260 }
 261
 262 static void scan_class(void)
 263 {
 264         char base[PATH_SIZE];
 265         DIR *dir;
 266         struct dirent *dent;
 267
 268         strlcpy(base, "/sys/class", sizeof(base));
 269
 270         dir = opendir(base);
 271         if (dir != NULL) {
 272                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 273                         char dirname[PATH_SIZE];
 274                         DIR *dir2;
 275                         struct dirent *dent2;
 276
 277                         if (dent->d_name[0] == '.')
 278                                 continue;
 279
 280                         strlcpy(dirname, base, sizeof(dirname));
 281                         strlcat(dirname, "/", sizeof(dirname));
 282                         strlcat(dirname, dent->d_name, sizeof(dirname));
 283                         dir2 = opendir(dirname);
 284                         if (dir2 != NULL) {
 285                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 286                                         char dirname2[PATH_SIZE];
 287
 288                                         if (dent2->d_name[0] == '.')
 289                                                 continue;
 290
 291                                         if (!strcmp(dent2->d_name, "device"))
 292                                                 continue;
 293
 294                                         strlcpy(dirname2, dirname, sizeof(dirname2));
 295                                         strlcat(dirname2, "/", sizeof(dirname2));
 296                                         strlcat(dirname2, dent2->d_name, sizeof(dirname2));
 297                                         device_list_insert(dirname2);
 298                                 }
 299                                 closedir(dir2);
 300                         }
 301                 }
 302                 closedir(dir);
 303         }
 304 }
 305
 306 int main(int argc, char *argv[], char *envp[])
 307 {
 308         char base[PATH_SIZE];
 309         struct stat statbuf;
 310         int option;
 311
 312         openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON);
 313
 314         while (1) {
 315                 option = getopt(argc, argv, "vnh");
 316                 if (option == -1)
 317                         break;
 318
 319                 switch (option) {
 320                 case 'v':
 321                         verbose = 1;
 322                         break;
 323                 case 'n':
 324                         dry_run = 1;
 325                         break;
 326                 case 'h':
 327                         printf("Usage: udevtrigger OPTIONS\n"
 328                                "  -v                     print the list of devices while running\n"
 329                                "  -n                     do not actually trigger the events\n"
 330                                "  -h                     print this text\n"
 331                                "\n");
 332                         goto exit;
 333                 default:
 334                         goto exit;
 335                 }
 336         }
 337
 338
 339         /* if we have /sys/subsystem, forget all the old stuff */
 340         scan_subsystem("bus");
 341         scan_class();
 342
 343         /* scan "block" if it isn't a "class" */
 344         strlcpy(base, "/sys/class/block", sizeof(base));
 345         if (stat(base, &statbuf) != 0)
 346                 scan_block();
 347
 348 exit:
 349
 350         closelog();
 351         return 0;
 352 }