udevstart.c

   1 /*
   2  * udevstart.c
   3  *
   4  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   5  * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
   6  *
   7  * Quick and dirty way to populate a /dev with udev if your system
   8  * does not have access to a shell.  Based originally on a patch
   9  * from:
  10  *      Harald Hoyer <harald@redhat.com>
  11  *
  12  *      This program is free software; you can redistribute it and/or modify it
  13  *      under the terms of the GNU General Public License as published by the
  14  *      Free Software Foundation version 2 of the License.
  15  *
  16  *      This program is distributed in the hope that it will be useful, but
  17  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *      General Public License for more details.
  20  *
  21  *      You should have received a copy of the GNU General Public License along
  22  *      with this program; if not, write to the Free Software Foundation, Inc.,
  23  *      675 Mass Ave, Cambridge, MA 02139, USA.
  24  *
  25  */
  26
  27 #include <stdlib.h>
  28 #include <stddef.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <ctype.h>
  34 #include <dirent.h>
  35 #include <signal.h>
  36 #include <syslog.h>
  37 #include <sys/wait.h>
  38 #include <sys/stat.h>
  39 #include <sys/types.h>
  40
  41 #include "libsysfs/sysfs/libsysfs.h"
  42 #include "udev_libc_wrapper.h"
  43 #include "udev.h"
  44 #include "udev_version.h"
  45 #include "logging.h"
  46 #include "udev_utils.h"
  47 #include "udev_rules.h"
  48 #include "list.h"
  49
  50 static const char *udev_run_str;
  51 static const char *udev_log_str;
  52 static struct udev_rules rules;
  53
  54 #ifdef USE_LOG
  55 void log_message(int priority, const char *format, ...)
  56 {
  57         va_list args;
  58
  59         if (priority > udev_log_priority)
  60                 return;
  61
  62         va_start(args, format);
  63         vsyslog(priority, format, args);
  64         va_end(args);
  65 }
  66 #endif
  67
  68 struct device {
  69         struct list_head node;
  70         char path[PATH_SIZE];
  71         char subsys[NAME_SIZE];
  72 };
  73
  74 /* sort files in lexical order */
  75 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  76 {
  77         struct device *loop_device;
  78         struct device *new_device;
  79         const char *devpath = &path[strlen(sysfs_path)];
  80
  81         dbg("insert: '%s'\n", devpath);
  82
  83         list_for_each_entry(loop_device, device_list, node) {
  84                 if (strcmp(loop_device->path, devpath) > 0) {
  85                         break;
  86                 }
  87         }
  88
  89         new_device = malloc(sizeof(struct device));
  90         if (new_device == NULL) {
  91                 dbg("error malloc");
  92                 return -ENOMEM;
  93         }
  94
  95         strlcpy(new_device->path, devpath, sizeof(new_device->path));
  96         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  97         list_add_tail(&new_device->node, &loop_device->node);
  98         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  99         return 0;
 100 }
 101
 102 /* list of devices that we should run last due to any one of a number of reasons */
 103 static char *last_list[] = {
 104         "/block/dm",    /* on here because dm wants to have the block devices around before it */
 105         NULL,
 106 };
 107
 108 /* list of devices that we should run first due to any one of a number of reasons */
 109 static char *first_list[] = {
 110         "/class/mem",
 111         "/class/tty",
 112         NULL,
 113 };
 114
 115 static int add_device(const char *devpath, const char *subsystem)
 116 {
 117         struct udevice udev;
 118         struct sysfs_class_device *class_dev;
 119         char path[PATH_SIZE];
 120
 121         /* clear and set environment for next event */
 122         clearenv();
 123         setenv("ACTION", "add", 1);
 124         setenv("DEVPATH", devpath, 1);
 125         setenv("SUBSYSTEM", subsystem, 1);
 126         setenv("UDEV_START", "1", 1);
 127         if (udev_log_str)
 128                 setenv("UDEV_LOG", udev_log_str, 1);
 129         if (udev_run_str)
 130                 setenv("UDEV_RUN", udev_run_str, 1);
 131         dbg("add '%s'", devpath);
 132
 133         snprintf(path, sizeof(path), "%s%s", sysfs_path, devpath);
 134         path[sizeof(path)-1] = '\0';
 135         class_dev = sysfs_open_class_device_path(path);
 136         if (class_dev == NULL) {
 137                 dbg("sysfs_open_class_device_path failed");
 138                 return -1;
 139         }
 140
 141         udev_init_device(&udev, &class_dev->path[strlen(sysfs_path)], subsystem, "add");
 142         udev.devt = get_devt(class_dev);
 143         if (!udev.devt && udev.type != DEV_NET) {
 144                 dbg("sysfs_open_class_device_path failed");
 145                 return -1;
 146         }
 147         udev_rules_get_name(&rules, &udev, class_dev);
 148         if (udev.ignore_device) {
 149                 dbg("device event will be ignored");
 150                 goto exit;
 151         }
 152         if (udev.name[0] == '\0') {
 153                 dbg("device node creation supressed");
 154                 goto run;
 155         }
 156
 157         udev_add_device(&udev, class_dev);
 158         if (udev.devname[0] != '\0')
 159                 setenv("DEVNAME", udev.devname, 1);
 160 run:
 161         if (udev_run && !list_empty(&udev.run_list)) {
 162                 struct name_entry *name_loop;
 163
 164                 dbg("executing run list");
 165                 list_for_each_entry(name_loop, &udev.run_list, node) {
 166                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 167                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], devpath, "add");
 168                         else
 169                                 run_program(name_loop->name, udev.subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 170                 }
 171         }
 172 exit:
 173         sysfs_close_class_device(class_dev);
 174         udev_cleanup_device(&udev);
 175
 176         return 0;
 177 }
 178
 179 static void exec_list(struct list_head *device_list)
 180 {
 181         struct device *loop_device;
 182         struct device *tmp_device;
 183         int i;
 184
 185         /* handle the "first" type devices first */
 186         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 187                 for (i = 0; first_list[i] != NULL; i++) {
 188                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 189                                 add_device(loop_device->path, loop_device->subsys);
 190                                 list_del(&loop_device->node);
 191                                 free(loop_device);
 192                                 break;
 193                         }
 194                 }
 195         }
 196
 197         /* handle the devices we are allowed to, excluding the "last" type devices */
 198         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 199                 int found = 0;
 200                 for (i = 0; last_list[i] != NULL; i++) {
 201                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 202                                 found = 1;
 203                                 break;
 204                         }
 205                 }
 206                 if (found)
 207                         continue;
 208
 209                 add_device(loop_device->path, loop_device->subsys);
 210                 list_del(&loop_device->node);
 211                 free(loop_device);
 212         }
 213
 214         /* handle the rest of the devices left over, if any */
 215         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 216                 add_device(loop_device->path, loop_device->subsys);
 217                 list_del(&loop_device->node);
 218                 free(loop_device);
 219         }
 220 }
 221
 222 static int has_devt(const char *path)
 223 {
 224         char filename[PATH_SIZE];
 225         struct stat statbuf;
 226
 227         snprintf(filename, sizeof(filename), "%s/dev", path);
 228         filename[sizeof(filename)-1] = '\0';
 229
 230         if (stat(filename, &statbuf) == 0)
 231                 return 1;
 232
 233         return 0;
 234 }
 235
 236 static void udev_scan_block(struct list_head *device_list)
 237 {
 238         char base[PATH_SIZE];
 239         DIR *dir;
 240         struct dirent *dent;
 241
 242         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 243         base[sizeof(base)-1] = '\0';
 244
 245         dir = opendir(base);
 246         if (dir != NULL) {
 247                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 248                         char dirname[PATH_SIZE];
 249                         DIR *dir2;
 250                         struct dirent *dent2;
 251
 252                         if (dent->d_name[0] == '.')
 253                                 continue;
 254
 255                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 256                         dirname[sizeof(dirname)-1] = '\0';
 257                         if (has_devt(dirname))
 258                                 device_list_insert(dirname, "block", device_list);
 259                         else
 260                                 continue;
 261
 262                         /* look for partitions */
 263                         dir2 = opendir(dirname);
 264                         if (dir2 != NULL) {
 265                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 266                                         char dirname2[PATH_SIZE];
 267
 268                                         if (dent2->d_name[0] == '.')
 269                                                 continue;
 270
 271                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 272                                         dirname2[sizeof(dirname2)-1] = '\0';
 273
 274                                         if (has_devt(dirname2))
 275                                                 device_list_insert(dirname2, "block", device_list);
 276                                 }
 277                                 closedir(dir2);
 278                         }
 279                 }
 280                 closedir(dir);
 281         }
 282 }
 283
 284 static void udev_scan_class(struct list_head *device_list)
 285 {
 286         char base[PATH_SIZE];
 287         DIR *dir;
 288         struct dirent *dent;
 289
 290         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 291         base[sizeof(base)-1] = '\0';
 292
 293         dir = opendir(base);
 294         if (dir != NULL) {
 295                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 296                         char dirname[PATH_SIZE];
 297                         DIR *dir2;
 298                         struct dirent *dent2;
 299
 300                         if (dent->d_name[0] == '.')
 301                                 continue;
 302
 303                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 304                         dirname[sizeof(dirname)-1] = '\0';
 305
 306                         dir2 = opendir(dirname);
 307                         if (dir2 != NULL) {
 308                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 309                                         char dirname2[PATH_SIZE];
 310
 311                                         if (dent2->d_name[0] == '.')
 312                                                 continue;
 313
 314                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 315                                         dirname2[sizeof(dirname2)-1] = '\0';
 316
 317                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 318                                                 device_list_insert(dirname2, dent->d_name, device_list);
 319                                 }
 320                                 closedir(dir2);
 321                         }
 322                 }
 323                 closedir(dir);
 324         }
 325 }
 326
 327 static void asmlinkage sig_handler(int signum)
 328 {
 329         switch (signum) {
 330                 case SIGALRM:
 331                         exit(1);
 332                 case SIGINT:
 333                 case SIGTERM:
 334                         exit(20 + signum);
 335         }
 336 }
 337
 338 int main(int argc, char *argv[], char *envp[])
 339 {
 340         LIST_HEAD(device_list);
 341         struct sigaction act;
 342
 343         logging_init("udevstart");
 344         udev_init_config();
 345         dbg("version %s", UDEV_VERSION);
 346
 347         udev_run_str = getenv("UDEV_RUN");
 348         udev_log_str = getenv("UDEV_LOG");
 349
 350         /* disable all logging if not explicitely requested */
 351         if (udev_log_str == NULL)
 352                 udev_log_priority = 0;
 353
 354         /* set signal handlers */
 355         memset(&act, 0x00, sizeof(act));
 356         act.sa_handler = (void (*) (int))sig_handler;
 357         sigemptyset (&act.sa_mask);
 358         act.sa_flags = 0;
 359         sigaction(SIGALRM, &act, NULL);
 360         sigaction(SIGINT, &act, NULL);
 361         sigaction(SIGTERM, &act, NULL);
 362
 363         /* trigger timeout to prevent hanging processes */
 364         alarm(UDEV_ALARM_TIMEOUT);
 365
 366         udev_rules_init(&rules, 1);
 367
 368         udev_scan_class(&device_list);
 369         udev_scan_block(&device_list);
 370         exec_list(&device_list);
 371
 372         udev_rules_close(&rules);
 373         logging_close();
 374         return 0;
 375 }