udevstart.c

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