udevstart.c

   1 /*
   2  * quick and dirty way to populate a /dev directory
   3  *
   4  * Copyright (C) 2004 Harald Hoyer <harald@redhat.com>
   5  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   6  * Copyright (C) 2004-2006 Kay Sievers <kay@vrfy.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or modify it
   9  *      under the terms of the GNU General Public License as published by the
  10  *      Free Software Foundation version 2 of the License.
  11  *
  12  *      This program is distributed in the hope that it will be useful, but
  13  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *      General Public License for more details.
  16  *
  17  *      You should have received a copy of the GNU General Public License along
  18  *      with this program; if not, write to the Free Software Foundation, Inc.,
  19  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  *
  21  */
  22
  23 #include <stdlib.h>
  24 #include <stddef.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <ctype.h>
  30 #include <dirent.h>
  31 #include <signal.h>
  32 #include <syslog.h>
  33 #include <sys/wait.h>
  34 #include <sys/stat.h>
  35 #include <sys/types.h>
  36
  37 #include "udev.h"
  38 #include "udev_rules.h"
  39 #include "udev_selinux.h"
  40
  41 static const char *udev_run_str;
  42 static const char *udev_log_str;
  43 static struct udev_rules rules;
  44
  45 #ifdef USE_LOG
  46 void log_message(int priority, const char *format, ...)
  47 {
  48         va_list args;
  49
  50         if (priority > udev_log_priority)
  51                 return;
  52
  53         va_start(args, format);
  54         vsyslog(priority, format, args);
  55         va_end(args);
  56 }
  57 #endif
  58
  59 struct device {
  60         struct list_head node;
  61         char path[PATH_SIZE];
  62 };
  63
  64 /* sort files in lexical order */
  65 static int device_list_insert(const char *path, struct list_head *device_list)
  66 {
  67         struct device *loop_device;
  68         struct device *new_device;
  69         const char *devpath = &path[strlen(sysfs_path)];
  70
  71         dbg("insert: '%s'\n", devpath);
  72
  73         list_for_each_entry(loop_device, device_list, node) {
  74                 if (strcmp(loop_device->path, devpath) > 0) {
  75                         break;
  76                 }
  77         }
  78
  79         new_device = malloc(sizeof(struct device));
  80         if (new_device == NULL) {
  81                 dbg("error malloc");
  82                 return -ENOMEM;
  83         }
  84
  85         strlcpy(new_device->path, devpath, sizeof(new_device->path));
  86         list_add_tail(&new_device->node, &loop_device->node);
  87         dbg("add '%s'" , new_device->path);
  88         return 0;
  89 }
  90
  91 /* list of devices that we should run last due to any one of a number of reasons */
  92 static char *last_list[] = {
  93         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  94         NULL,
  95 };
  96
  97 /* list of devices that we should run first due to any one of a number of reasons */
  98 static char *first_list[] = {
  99         "/class/mem",
 100         "/class/tty",
 101         NULL,
 102 };
 103
 104 static int add_device(const char *devpath)
 105 {
 106         struct sysfs_device *dev;
 107         struct udevice *udev;
 108         int retval = 0;
 109
 110         /* clear and set environment for next event */
 111         clearenv();
 112         setenv("ACTION", "add", 1);
 113         setenv("UDEV_START", "1", 1);
 114         if (udev_log_str)
 115                 setenv("UDEV_LOG", udev_log_str, 1);
 116         if (udev_run_str)
 117                 setenv("UDEV_RUN", udev_run_str, 1);
 118
 119         dev = sysfs_device_get(devpath);
 120         if (dev == NULL)
 121                 return -1;
 122
 123         udev = udev_device_init();
 124         if (udev == NULL)
 125                 return -1;
 126
 127         /* override built-in sysfs device */
 128         udev->dev = dev;
 129         strcpy(udev->action, "add");
 130
 131         if (strcmp(udev->dev->subsystem, "net") != 0) {
 132                 udev->devt = udev_device_get_devt(udev);
 133                 if (major(udev->devt) == 0)
 134                         return -1;
 135         }
 136
 137         dbg("add '%s'", udev->dev->devpath);
 138         setenv("DEVPATH", udev->dev->devpath, 1);
 139         setenv("SUBSYSTEM", udev->dev->subsystem, 1);
 140
 141         udev_rules_get_name(&rules, udev);
 142         if (udev->ignore_device) {
 143                 dbg("device event will be ignored");
 144                 goto exit;
 145         }
 146         if (udev->name[0] != '\0')
 147                 retval = udev_device_event(&rules, udev);
 148         else
 149                 info("device node creation supressed");
 150
 151         if (retval == 0 && udev_run) {
 152                 struct name_entry *name_loop;
 153
 154                 dbg("executing run list");
 155                 list_for_each_entry(name_loop, &udev->run_list, node) {
 156                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 157                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, "add");
 158                         else {
 159                                 char program[PATH_SIZE];
 160
 161                                 strlcpy(program, name_loop->name, sizeof(program));
 162                                 udev_rules_apply_format(udev, program, sizeof(program));
 163                                 run_program(program, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 164                         }
 165                 }
 166         }
 167
 168 exit:
 169         udev_device_cleanup(udev);
 170         return 0;
 171 }
 172
 173 static void exec_list(struct list_head *device_list)
 174 {
 175         struct device *loop_device;
 176         struct device *tmp_device;
 177         int i;
 178
 179         /* handle the "first" type devices first */
 180         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 181                 for (i = 0; first_list[i] != NULL; i++) {
 182                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 183                                 add_device(loop_device->path);
 184                                 list_del(&loop_device->node);
 185                                 free(loop_device);
 186                                 break;
 187                         }
 188                 }
 189         }
 190
 191         /* handle the devices we are allowed to, excluding the "last" type devices */
 192         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 193                 int found = 0;
 194                 for (i = 0; last_list[i] != NULL; i++) {
 195                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 196                                 found = 1;
 197                                 break;
 198                         }
 199                 }
 200                 if (found)
 201                         continue;
 202
 203                 add_device(loop_device->path);
 204                 list_del(&loop_device->node);
 205                 free(loop_device);
 206         }
 207
 208         /* handle the rest of the devices left over, if any */
 209         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 210                 add_device(loop_device->path);
 211                 list_del(&loop_device->node);
 212                 free(loop_device);
 213         }
 214 }
 215
 216 static int has_devt(const char *path)
 217 {
 218         char filename[PATH_SIZE];
 219         struct stat statbuf;
 220
 221         snprintf(filename, sizeof(filename), "%s/dev", path);
 222         filename[sizeof(filename)-1] = '\0';
 223
 224         if (stat(filename, &statbuf) == 0)
 225                 return 1;
 226
 227         return 0;
 228 }
 229
 230 static void udev_scan_block(struct list_head *device_list)
 231 {
 232         char base[PATH_SIZE];
 233         DIR *dir;
 234         struct dirent *dent;
 235
 236         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 237         base[sizeof(base)-1] = '\0';
 238
 239         dir = opendir(base);
 240         if (dir != NULL) {
 241                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 242                         char dirname[PATH_SIZE];
 243                         DIR *dir2;
 244                         struct dirent *dent2;
 245
 246                         if (dent->d_name[0] == '.')
 247                                 continue;
 248
 249                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 250                         dirname[sizeof(dirname)-1] = '\0';
 251                         if (has_devt(dirname))
 252                                 device_list_insert(dirname, device_list);
 253                         else
 254                                 continue;
 255
 256                         /* look for partitions */
 257                         dir2 = opendir(dirname);
 258                         if (dir2 != NULL) {
 259                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 260                                         char dirname2[PATH_SIZE];
 261
 262                                         if (dent2->d_name[0] == '.')
 263                                                 continue;
 264
 265                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 266                                         dirname2[sizeof(dirname2)-1] = '\0';
 267
 268                                         if (has_devt(dirname2))
 269                                                 device_list_insert(dirname2, device_list);
 270                                 }
 271                                 closedir(dir2);
 272                         }
 273                 }
 274                 closedir(dir);
 275         }
 276 }
 277
 278 static void udev_scan_class(struct list_head *device_list)
 279 {
 280         char base[PATH_SIZE];
 281         DIR *dir;
 282         struct dirent *dent;
 283
 284         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 285         base[sizeof(base)-1] = '\0';
 286
 287         dir = opendir(base);
 288         if (dir != NULL) {
 289                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 290                         char dirname[PATH_SIZE];
 291                         DIR *dir2;
 292                         struct dirent *dent2;
 293
 294                         if (dent->d_name[0] == '.')
 295                                 continue;
 296
 297                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 298                         dirname[sizeof(dirname)-1] = '\0';
 299
 300                         dir2 = opendir(dirname);
 301                         if (dir2 != NULL) {
 302                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 303                                         char dirname2[PATH_SIZE];
 304
 305                                         if (dent2->d_name[0] == '.')
 306                                                 continue;
 307
 308                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 309                                         dirname2[sizeof(dirname2)-1] = '\0';
 310
 311                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 312                                                 device_list_insert(dirname2, device_list);
 313                                 }
 314                                 closedir(dir2);
 315                         }
 316                 }
 317                 closedir(dir);
 318         }
 319 }
 320
 321 static void asmlinkage sig_handler(int signum)
 322 {
 323         switch (signum) {
 324                 case SIGALRM:
 325                         exit(1);
 326                 case SIGINT:
 327                 case SIGTERM:
 328                         exit(20 + signum);
 329         }
 330 }
 331
 332 int main(int argc, char *argv[], char *envp[])
 333 {
 334         LIST_HEAD(device_list);
 335         struct sigaction act;
 336
 337         logging_init("udevstart");
 338         udev_config_init();
 339         selinux_init();
 340         dbg("version %s", UDEV_VERSION);
 341
 342         udev_run_str = getenv("UDEV_RUN");
 343         udev_log_str = getenv("UDEV_LOG");
 344
 345         /* disable all logging if not explicitely requested */
 346         if (udev_log_str == NULL)
 347                 udev_log_priority = 0;
 348
 349         /* set signal handlers */
 350         memset(&act, 0x00, sizeof(act));
 351         act.sa_handler = (void (*) (int))sig_handler;
 352         sigemptyset (&act.sa_mask);
 353         act.sa_flags = 0;
 354         sigaction(SIGALRM, &act, NULL);
 355         sigaction(SIGINT, &act, NULL);
 356         sigaction(SIGTERM, &act, NULL);
 357
 358         /* trigger timeout to prevent hanging processes */
 359         alarm(UDEV_ALARM_TIMEOUT);
 360
 361         sysfs_init();
 362         udev_rules_init(&rules, 1);
 363
 364         udev_scan_class(&device_list);
 365         udev_scan_block(&device_list);
 366         exec_list(&device_list);
 367
 368         udev_rules_cleanup(&rules);
 369         sysfs_cleanup();
 370         logging_close();
 371         return 0;
 372 }