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_sysfs.h"
  44 #include "udev.h"
  45 #include "udev_version.h"
  46 #include "logging.h"
  47 #include "udev_utils.h"
  48 #include "udev_rules.h"
  49 #include "list.h"
  50
  51 static const char *udev_run_str;
  52 static const char *udev_log_str;
  53 static struct udev_rules rules;
  54
  55 #ifdef USE_LOG
  56 void log_message(int priority, const char *format, ...)
  57 {
  58         va_list args;
  59
  60         if (priority > udev_log_priority)
  61                 return;
  62
  63         va_start(args, format);
  64         vsyslog(priority, format, args);
  65         va_end(args);
  66 }
  67 #endif
  68
  69 struct device {
  70         struct list_head node;
  71         char path[PATH_SIZE];
  72         char subsys[NAME_SIZE];
  73 };
  74
  75 /* sort files in lexical order */
  76 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  77 {
  78         struct device *loop_device;
  79         struct device *new_device;
  80
  81         dbg("insert: '%s'\n", path);
  82
  83         list_for_each_entry(loop_device, device_list, node) {
  84                 if (strcmp(loop_device->path, path) > 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, path, 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",   /* people tend to like their memory devices around first... */
 111         NULL,
 112 };
 113
 114 static int add_device(const char *path, const char *subsystem)
 115 {
 116         struct udevice udev;
 117         struct sysfs_class_device *class_dev;
 118         const char *devpath;
 119
 120         devpath = &path[strlen(sysfs_path)];
 121
 122         /* clear and set environment for next event */
 123         clearenv();
 124         setenv("ACTION", "add", 1);
 125         setenv("DEVPATH", devpath, 1);
 126         setenv("SUBSYSTEM", subsystem, 1);
 127         setenv("UDEV_START", "1", 1);
 128         if (udev_log_str)
 129                 setenv("UDEV_LOG", udev_log_str, 1);
 130         if (udev_run_str)
 131                 setenv("UDEV_RUN", udev_run_str, 1);
 132         dbg("exec: '%s' (%s)\n", devpath, path);
 133
 134         class_dev = sysfs_open_class_device_path(path);
 135         if (class_dev == NULL) {
 136                 dbg("sysfs_open_class_device_path failed");
 137                 return -1;
 138         }
 139
 140         udev_init_device(&udev, devpath, subsystem, "add");
 141         udev.devt = get_devt(class_dev);
 142         if (!udev.devt && udev.type != DEV_NET) {
 143                 dbg("sysfs_open_class_device_path failed");
 144                 return -1;
 145         }
 146         udev_rules_get_name(&rules, &udev, class_dev);
 147         if (udev.ignore_device) {
 148                 dbg("device event will be ignored");
 149                 goto exit;
 150         }
 151         if (udev.name[0] == '\0') {
 152                 dbg("device node creation supressed");
 153                 goto run;
 154         }
 155
 156         udev_add_device(&udev, class_dev);
 157         if (udev.devname[0] != '\0')
 158                 setenv("DEVNAME", udev.devname, 1);
 159 run:
 160         if (udev_run && !list_empty(&udev.run_list)) {
 161                 struct name_entry *name_loop;
 162
 163                 dbg("executing run list");
 164                 list_for_each_entry(name_loop, &udev.run_list, node) {
 165                         if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
 166                                 pass_env_to_socket(&name_loop->name[strlen("socket:")], devpath, "add");
 167                         else
 168                                 run_program(name_loop->name, udev.subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_DEBUG));
 169                 }
 170         }
 171 exit:
 172         sysfs_close_class_device(class_dev);
 173         udev_cleanup_device(&udev);
 174
 175         return 0;
 176 }
 177
 178 static void exec_list(struct list_head *device_list)
 179 {
 180         struct device *loop_device;
 181         struct device *tmp_device;
 182         int i;
 183
 184         /* handle the "first" type devices first */
 185         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 186                 for (i = 0; first_list[i] != NULL; i++) {
 187                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 188                                 add_device(loop_device->path, loop_device->subsys);
 189                                 list_del(&loop_device->node);
 190                                 free(loop_device);
 191                                 break;
 192                         }
 193                 }
 194         }
 195
 196         /* handle the devices we are allowed to, excluding the "last" type devices */
 197         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 198                 int found = 0;
 199                 for (i = 0; last_list[i] != NULL; i++) {
 200                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 201                                 found = 1;
 202                                 break;
 203                         }
 204                 }
 205                 if (found)
 206                         continue;
 207
 208                 add_device(loop_device->path, loop_device->subsys);
 209                 list_del(&loop_device->node);
 210                 free(loop_device);
 211         }
 212
 213         /* handle the rest of the devices left over, if any */
 214         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 215                 add_device(loop_device->path, loop_device->subsys);
 216                 list_del(&loop_device->node);
 217                 free(loop_device);
 218         }
 219 }
 220
 221 static int has_devt(const char *directory)
 222 {
 223         char filename[PATH_SIZE];
 224         struct stat statbuf;
 225
 226         snprintf(filename, sizeof(filename), "%s/dev", directory);
 227         filename[sizeof(filename)-1] = '\0';
 228
 229         if (stat(filename, &statbuf) == 0)
 230                 return 1;
 231
 232         return 0;
 233 }
 234
 235 static void udev_scan_block(void)
 236 {
 237         char base[PATH_SIZE];
 238         DIR *dir;
 239         struct dirent *dent;
 240         LIST_HEAD(device_list);
 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         exec_list(&device_list);
 283 }
 284
 285 static void udev_scan_class(void)
 286 {
 287         char base[PATH_SIZE];
 288         DIR *dir;
 289         struct dirent *dent;
 290         LIST_HEAD(device_list);
 291
 292         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 293         base[sizeof(base)-1] = '\0';
 294
 295         dir = opendir(base);
 296         if (dir != NULL) {
 297                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 298                         char dirname[PATH_SIZE];
 299                         DIR *dir2;
 300                         struct dirent *dent2;
 301
 302                         if (dent->d_name[0] == '.')
 303                                 continue;
 304
 305                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 306                         dirname[sizeof(dirname)-1] = '\0';
 307
 308                         dir2 = opendir(dirname);
 309                         if (dir2 != NULL) {
 310                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 311                                         char dirname2[PATH_SIZE];
 312
 313                                         if (dent2->d_name[0] == '.')
 314                                                 continue;
 315
 316                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 317                                         dirname2[sizeof(dirname2)-1] = '\0';
 318
 319                                         if (has_devt(dirname2) || strcmp(dent->d_name, "net") == 0)
 320                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 321                                 }
 322                                 closedir(dir2);
 323                         }
 324                 }
 325                 closedir(dir);
 326         }
 327         exec_list(&device_list);
 328 }
 329
 330 static void asmlinkage sig_handler(int signum)
 331 {
 332         switch (signum) {
 333                 case SIGALRM:
 334                         exit(1);
 335                 case SIGINT:
 336                 case SIGTERM:
 337                         exit(20 + signum);
 338         }
 339 }
 340
 341 int main(int argc, char *argv[], char *envp[])
 342 {
 343         struct sigaction act;
 344
 345         logging_init("udevstart");
 346         udev_init_config();
 347         dbg("version %s", UDEV_VERSION);
 348
 349         udev_run_str = getenv("UDEV_RUN");
 350         udev_log_str = getenv("UDEV_LOG");
 351
 352         /* disable all logging if not explicitely requested */
 353         if (udev_log_str == NULL)
 354                 udev_log_priority = 0;
 355
 356         /* set signal handlers */
 357         memset(&act, 0x00, sizeof(act));
 358         act.sa_handler = (void (*) (int))sig_handler;
 359         sigemptyset (&act.sa_mask);
 360         act.sa_flags = 0;
 361         sigaction(SIGALRM, &act, NULL);
 362         sigaction(SIGINT, &act, NULL);
 363         sigaction(SIGTERM, &act, NULL);
 364
 365         /* trigger timeout to prevent hanging processes */
 366         alarm(UDEV_ALARM_TIMEOUT);
 367
 368         udev_rules_init(&rules, 0, 1);
 369
 370         udev_scan_block();
 371         udev_scan_class();
 372
 373         udev_rules_close(&rules);
 374         logging_close();
 375         return 0;
 376 }