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 "udev.h"
  42 #include "udev_rules.h"
  43
  44 static const char *udev_run_str;
  45 static const char *udev_log_str;
  46 static struct udev_rules rules;
  47
  48 #ifdef USE_LOG
  49 void log_message(int priority, const char *format, ...)
  50 {
  51         va_list args;
  52
  53         if (priority > udev_log_priority)
  54                 return;
  55
  56         va_start(args, format);
  57         vsyslog(priority, format, args);
  58         va_end(args);
  59 }
  60 #endif
  61
  62 struct device {
  63         struct list_head node;
  64         char path[PATH_SIZE];
  65 };
  66
  67 /* sort files in lexical order */
  68 static int device_list_insert(const char *path, struct list_head *device_list)
  69 {
  70         struct device *loop_device;
  71         struct device *new_device;
  72         const char *devpath = &path[strlen(sysfs_path)];
  73
  74         dbg("insert: '%s'\n", devpath);
  75
  76         list_for_each_entry(loop_device, device_list, node) {
  77                 if (strcmp(loop_device->path, devpath) > 0) {
  78                         break;
  79                 }
  80         }
  81
  82         new_device = malloc(sizeof(struct device));
  83         if (new_device == NULL) {
  84                 dbg("error malloc");
  85                 return -ENOMEM;
  86         }
  87
  88         strlcpy(new_device->path, devpath, sizeof(new_device->path));
  89         list_add_tail(&new_device->node, &loop_device->node);
  90         dbg("add '%s'" , new_device->path);
  91         return 0;
  92 }
  93
  94 /* list of devices that we should run last due to any one of a number of reasons */
  95 static char *last_list[] = {
  96         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  97         NULL,
  98 };
  99
 100 /* list of devices that we should run first due to any one of a number of reasons */
 101 static char *first_list[] = {
 102         "/class/mem",
 103         "/class/tty",
 104         NULL,
 105 };
 106
 107 static int add_device(const char *devpath)
 108 {
 109         struct sysfs_device *dev;
 110         struct udevice *udev;
 111         int retval = 0;
 112
 113         /* clear and set environment for next event */
 114         clearenv();
 115         setenv("ACTION", "add", 1);
 116         setenv("UDEV_START", "1", 1);
 117         if (udev_log_str)
 118                 setenv("UDEV_LOG", udev_log_str, 1);
 119         if (udev_run_str)
 120                 setenv("UDEV_RUN", udev_run_str, 1);
 121
 122         dev = sysfs_device_get(devpath);
 123         if (dev == NULL)
 124                 return -1;
 125
 126         udev = udev_device_init();
 127         if (udev == NULL)
 128                 return -1;
 129
 130         /* override built-in sysfs device */
 131         udev->dev = dev;
 132         strcpy(udev->action, "add");
 133         udev->devt = udev_device_get_devt(udev);
 134
 135         if (strcmp(udev->dev->subsystem, "net") != 0) {
 136                 udev->devt = udev_device_get_devt(udev);
 137                 if (major(udev->devt) == 0)
 138                         return -1;
 139         }
 140
 141         dbg("add '%s'", udev->dev->devpath);
 142         setenv("DEVPATH", udev->dev->devpath, 1);
 143         setenv("SUBSYSTEM", udev->dev->subsystem, 1);
 144
 145         udev_rules_get_name(&rules, udev);
 146         if (udev->ignore_device) {
 147                 dbg("device event will be ignored");
 148                 goto exit;
 149         }
 150         if (udev->name[0] != '\0')
 151                 retval = udev_add_device(udev);
 152         else
 153                 info("device node creation supressed");
 154
 155         if (retval == 0 && udev_run) {
 156                 struct name_entry *name_loop;
 157
 158                 dbg("executing run list");
 159                 list_for_each_entry(name_loop, &udev->run_list, node) {
 160                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 161                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, "add");
 162                         else {
 163                                 char program[PATH_SIZE];
 164
 165                                 strlcpy(program, name_loop->name, sizeof(program));
 166                                 udev_rules_apply_format(udev, program, sizeof(program));
 167                                 run_program(program, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
 168                         }
 169                 }
 170         }
 171
 172 exit:
 173         udev_device_cleanup(udev);
 174         return 0;
 175 }
 176
 177 static void exec_list(struct list_head *device_list)
 178 {
 179         struct device *loop_device;
 180         struct device *tmp_device;
 181         int i;
 182
 183         /* handle the "first" type devices first */
 184         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 185                 for (i = 0; first_list[i] != NULL; i++) {
 186                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 187                                 add_device(loop_device->path);
 188                                 list_del(&loop_device->node);
 189                                 free(loop_device);
 190                                 break;
 191                         }
 192                 }
 193         }
 194
 195         /* handle the devices we are allowed to, excluding the "last" type devices */
 196         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 197                 int found = 0;
 198                 for (i = 0; last_list[i] != NULL; i++) {
 199                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 200                                 found = 1;
 201                                 break;
 202                         }
 203                 }
 204                 if (found)
 205                         continue;
 206
 207                 add_device(loop_device->path);
 208                 list_del(&loop_device->node);
 209                 free(loop_device);
 210         }
 211
 212         /* handle the rest of the devices left over, if any */
 213         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 214                 add_device(loop_device->path);
 215                 list_del(&loop_device->node);
 216                 free(loop_device);
 217         }
 218 }
 219
 220 static int has_devt(const char *path)
 221 {
 222         char filename[PATH_SIZE];
 223         struct stat statbuf;
 224
 225         snprintf(filename, sizeof(filename), "%s/dev", path);
 226         filename[sizeof(filename)-1] = '\0';
 227
 228         if (stat(filename, &statbuf) == 0)
 229                 return 1;
 230
 231         return 0;
 232 }
 233
 234 static void udev_scan_block(struct list_head *device_list)
 235 {
 236         char base[PATH_SIZE];
 237         DIR *dir;
 238         struct dirent *dent;
 239
 240         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 241         base[sizeof(base)-1] = '\0';
 242
 243         dir = opendir(base);
 244         if (dir != NULL) {
 245                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 246                         char dirname[PATH_SIZE];
 247                         DIR *dir2;
 248                         struct dirent *dent2;
 249
 250                         if (dent->d_name[0] == '.')
 251                                 continue;
 252
 253                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 254                         dirname[sizeof(dirname)-1] = '\0';
 255                         if (has_devt(dirname))
 256                                 device_list_insert(dirname, device_list);
 257                         else
 258                                 continue;
 259
 260                         /* look for partitions */
 261                         dir2 = opendir(dirname);
 262                         if (dir2 != NULL) {
 263                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 264                                         char dirname2[PATH_SIZE];
 265
 266                                         if (dent2->d_name[0] == '.')
 267                                                 continue;
 268
 269                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 270                                         dirname2[sizeof(dirname2)-1] = '\0';
 271
 272                                         if (has_devt(dirname2))
 273                                                 device_list_insert(dirname2, device_list);
 274                                 }
 275                                 closedir(dir2);
 276                         }
 277                 }
 278                 closedir(dir);
 279         }
 280 }
 281
 282 static void udev_scan_class(struct list_head *device_list)
 283 {
 284         char base[PATH_SIZE];
 285         DIR *dir;
 286         struct dirent *dent;
 287
 288         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 289         base[sizeof(base)-1] = '\0';
 290
 291         dir = opendir(base);
 292         if (dir != NULL) {
 293                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 294                         char dirname[PATH_SIZE];
 295                         DIR *dir2;
 296                         struct dirent *dent2;
 297
 298                         if (dent->d_name[0] == '.')
 299                                 continue;
 300
 301                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 302                         dirname[sizeof(dirname)-1] = '\0';
 303
 304                         dir2 = opendir(dirname);
 305                         if (dir2 != NULL) {
 306                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 307                                         char dirname2[PATH_SIZE];
 308
 309                                         if (dent2->d_name[0] == '.')
 310                                                 continue;
 311
 312                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 313                                         dirname2[sizeof(dirname2)-1] = '\0';
 314
 315                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 316                                                 device_list_insert(dirname2, device_list);
 317                                 }
 318                                 closedir(dir2);
 319                         }
 320                 }
 321                 closedir(dir);
 322         }
 323 }
 324
 325 static void asmlinkage sig_handler(int signum)
 326 {
 327         switch (signum) {
 328                 case SIGALRM:
 329                         exit(1);
 330                 case SIGINT:
 331                 case SIGTERM:
 332                         exit(20 + signum);
 333         }
 334 }
 335
 336 int main(int argc, char *argv[], char *envp[])
 337 {
 338         LIST_HEAD(device_list);
 339         struct sigaction act;
 340
 341         logging_init("udevstart");
 342         udev_config_init();
 343         dbg("version %s", UDEV_VERSION);
 344
 345         udev_run_str = getenv("UDEV_RUN");
 346         udev_log_str = getenv("UDEV_LOG");
 347
 348         /* disable all logging if not explicitely requested */
 349         if (udev_log_str == NULL)
 350                 udev_log_priority = 0;
 351
 352         /* set signal handlers */
 353         memset(&act, 0x00, sizeof(act));
 354         act.sa_handler = (void (*) (int))sig_handler;
 355         sigemptyset (&act.sa_mask);
 356         act.sa_flags = 0;
 357         sigaction(SIGALRM, &act, NULL);
 358         sigaction(SIGINT, &act, NULL);
 359         sigaction(SIGTERM, &act, NULL);
 360
 361         /* trigger timeout to prevent hanging processes */
 362         alarm(UDEV_ALARM_TIMEOUT);
 363
 364         sysfs_init();
 365         udev_rules_init(&rules, 1);
 366
 367         udev_scan_class(&device_list);
 368         udev_scan_block(&device_list);
 369         exec_list(&device_list);
 370
 371         udev_rules_cleanup(&rules);
 372         sysfs_cleanup();
 373         logging_close();
 374         return 0;
 375 }