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
  51 #ifdef USE_LOG
  52 void log_message(int priority, const char *format, ...)
  53 {
  54         va_list args;
  55
  56         if (priority > udev_log_priority)
  57                 return;
  58
  59         va_start(args, format);
  60         vsyslog(priority, format, args);
  61         va_end(args);
  62 }
  63 #endif
  64
  65 struct device {
  66         struct list_head node;
  67         char path[PATH_SIZE];
  68         char subsys[NAME_SIZE];
  69 };
  70
  71 /* sort files in lexical order */
  72 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  73 {
  74         struct device *loop_device;
  75         struct device *new_device;
  76
  77         dbg("insert: '%s'\n", path);
  78
  79         list_for_each_entry(loop_device, device_list, node) {
  80                 if (strcmp(loop_device->path, path) > 0) {
  81                         break;
  82                 }
  83         }
  84
  85         new_device = malloc(sizeof(struct device));
  86         if (new_device == NULL) {
  87                 dbg("error malloc");
  88                 return -ENOMEM;
  89         }
  90
  91         strlcpy(new_device->path, path, sizeof(new_device->path));
  92         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  93         list_add_tail(&new_device->node, &loop_device->node);
  94         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  95         return 0;
  96 }
  97
  98 /* list of devices that we should run last due to any one of a number of reasons */
  99 static char *last_list[] = {
 100         "/block/dm",    /* on here because dm wants to have the block devices around before it */
 101         NULL,
 102 };
 103
 104 /* list of devices that we should run first due to any one of a number of reasons */
 105 static char *first_list[] = {
 106         "/class/mem",   /* people tend to like their memory devices around first... */
 107         NULL,
 108 };
 109
 110 static int add_device(const char *path, const char *subsystem)
 111 {
 112         struct udevice udev;
 113         struct sysfs_class_device *class_dev;
 114         const char *devpath;
 115
 116         devpath = &path[strlen(sysfs_path)];
 117
 118         /* clear and set environment for next event */
 119         clearenv();
 120         setenv("ACTION", "add", 1);
 121         setenv("DEVPATH", devpath, 1);
 122         setenv("SUBSYSTEM", subsystem, 1);
 123         setenv("UDEV_START", "1", 1);
 124         if (udev_log_str)
 125                 setenv("UDEV_LOG", udev_log_str, 1);
 126         if (udev_run_str)
 127                 setenv("UDEV_RUN", udev_run_str, 1);
 128         dbg("exec: '%s' (%s)\n", devpath, path);
 129
 130         class_dev = sysfs_open_class_device_path(path);
 131         if (class_dev == NULL) {
 132                 dbg("sysfs_open_class_device_path failed");
 133                 return -1;
 134         }
 135
 136         udev_init_device(&udev, devpath, subsystem, "add");
 137         udev.devt = get_devt(class_dev);
 138         if (!udev.devt && udev.type != DEV_NET) {
 139                 dbg("sysfs_open_class_device_path failed");
 140                 return -1;
 141         }
 142         udev_rules_get_name(&udev, class_dev);
 143         if (udev.ignore_device) {
 144                 dbg("device event will be ignored");
 145                 goto exit;
 146         }
 147         if (udev.name[0] == '\0') {
 148                 dbg("device node creation supressed");
 149                 goto run;
 150         }
 151
 152         udev_add_device(&udev, class_dev);
 153         if (udev.devname[0] != '\0')
 154                 setenv("DEVNAME", udev.devname, 1);
 155 run:
 156         if (udev_run && !list_empty(&udev.run_list)) {
 157                 struct name_entry *name_loop;
 158
 159                 dbg("executing run list");
 160                 list_for_each_entry(name_loop, &udev.run_list, node)
 161                         execute_program(name_loop->name, udev.subsystem, NULL, 0, NULL);
 162         }
 163 exit:
 164         sysfs_close_class_device(class_dev);
 165         udev_cleanup_device(&udev);
 166
 167         return 0;
 168 }
 169
 170 static void exec_list(struct list_head *device_list)
 171 {
 172         struct device *loop_device;
 173         struct device *tmp_device;
 174         int i;
 175
 176         /* handle the "first" type devices first */
 177         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 178                 for (i = 0; first_list[i] != NULL; i++) {
 179                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 180                                 add_device(loop_device->path, loop_device->subsys);
 181                                 list_del(&loop_device->node);
 182                                 free(loop_device);
 183                                 break;
 184                         }
 185                 }
 186         }
 187
 188         /* handle the devices we are allowed to, excluding the "last" type devices */
 189         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 190                 int found = 0;
 191                 for (i = 0; last_list[i] != NULL; i++) {
 192                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 193                                 found = 1;
 194                                 break;
 195                         }
 196                 }
 197                 if (found)
 198                         continue;
 199
 200                 add_device(loop_device->path, loop_device->subsys);
 201                 list_del(&loop_device->node);
 202                 free(loop_device);
 203         }
 204
 205         /* handle the rest of the devices left over, if any */
 206         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 207                 add_device(loop_device->path, loop_device->subsys);
 208                 list_del(&loop_device->node);
 209                 free(loop_device);
 210         }
 211 }
 212
 213 static int has_devt(const char *directory)
 214 {
 215         char filename[PATH_SIZE];
 216         struct stat statbuf;
 217
 218         snprintf(filename, sizeof(filename), "%s/dev", directory);
 219         filename[sizeof(filename)-1] = '\0';
 220
 221         if (stat(filename, &statbuf) == 0)
 222                 return 1;
 223
 224         return 0;
 225 }
 226
 227 static void udev_scan_block(void)
 228 {
 229         char base[PATH_SIZE];
 230         DIR *dir;
 231         struct dirent *dent;
 232         LIST_HEAD(device_list);
 233
 234         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 235         base[sizeof(base)-1] = '\0';
 236
 237         dir = opendir(base);
 238         if (dir != NULL) {
 239                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 240                         char dirname[PATH_SIZE];
 241                         DIR *dir2;
 242                         struct dirent *dent2;
 243
 244                         if (dent->d_name[0] == '.')
 245                                 continue;
 246
 247                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 248                         dirname[sizeof(dirname)-1] = '\0';
 249                         if (has_devt(dirname))
 250                                 device_list_insert(dirname, "block", &device_list);
 251                         else
 252                                 continue;
 253
 254                         /* look for partitions */
 255                         dir2 = opendir(dirname);
 256                         if (dir2 != NULL) {
 257                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 258                                         char dirname2[PATH_SIZE];
 259
 260                                         if (dent2->d_name[0] == '.')
 261                                                 continue;
 262
 263                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 264                                         dirname2[sizeof(dirname2)-1] = '\0';
 265
 266                                         if (has_devt(dirname2))
 267                                                 device_list_insert(dirname2, "block", &device_list);
 268                                 }
 269                                 closedir(dir2);
 270                         }
 271                 }
 272                 closedir(dir);
 273         }
 274         exec_list(&device_list);
 275 }
 276
 277 static void udev_scan_class(void)
 278 {
 279         char base[PATH_SIZE];
 280         DIR *dir;
 281         struct dirent *dent;
 282         LIST_HEAD(device_list);
 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                                         /* pass the net class as it is */
 312                                         if (strcmp(dent->d_name, "net") == 0)
 313                                                 device_list_insert(dirname2, "net", &device_list);
 314                                         else if (has_devt(dirname2))
 315                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 316                                 }
 317                                 closedir(dir2);
 318                         }
 319                 }
 320                 closedir(dir);
 321         }
 322         exec_list(&device_list);
 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         struct sigaction act;
 339
 340         logging_init("udevstart");
 341         udev_init_config();
 342         dbg("version %s", UDEV_VERSION);
 343
 344         udev_run_str = getenv("UDEV_RUN");
 345         udev_log_str = getenv("UDEV_LOG");
 346
 347         /* disable all logging if not explicitely requested */
 348         if (udev_log_str == NULL)
 349                 udev_log_priority = 0;
 350
 351         /* set signal handlers */
 352         memset(&act, 0x00, sizeof(act));
 353         act.sa_handler = (void (*) (int))sig_handler;
 354         sigemptyset (&act.sa_mask);
 355         act.sa_flags = 0;
 356         sigaction(SIGALRM, &act, NULL);
 357         sigaction(SIGINT, &act, NULL);
 358         sigaction(SIGTERM, &act, NULL);
 359
 360         /* trigger timeout to prevent hanging processes */
 361         alarm(ALARM_TIMEOUT);
 362
 363         udev_rules_init();
 364
 365         udev_scan_block();
 366         udev_scan_class();
 367
 368         logging_close();
 369         return 0;
 370 }