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 #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         char subsys[NAME_SIZE];
  66 };
  67
  68 /* sort files in lexical order */
  69 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  70 {
  71         struct device *loop_device;
  72         struct device *new_device;
  73
  74         dbg("insert: '%s'\n", path);
  75
  76         list_for_each_entry(loop_device, device_list, node) {
  77                 if (strcmp(loop_device->path, path) > 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, path, sizeof(new_device->path));
  89         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  90         list_add_tail(&new_device->node, &loop_device->node);
  91         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  92         return 0;
  93 }
  94
  95 /* list of devices that we should run last due to any one of a number of reasons */
  96 static char *last_list[] = {
  97         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  98         NULL,
  99 };
 100
 101 /* list of devices that we should run first due to any one of a number of reasons */
 102 static char *first_list[] = {
 103         "/class/mem",   /* people tend to like their memory devices around first... */
 104         NULL,
 105 };
 106
 107 static int add_device(const char *path, const char *subsystem)
 108 {
 109         struct udevice udev;
 110         struct sysfs_class_device *class_dev;
 111         const char *devpath;
 112
 113         devpath = &path[strlen(sysfs_path)];
 114         setenv("DEVPATH", devpath, 1);
 115         setenv("SUBSYSTEM", subsystem, 1);
 116         dbg("exec: '%s' (%s)\n", devpath, path);
 117
 118         class_dev = sysfs_open_class_device_path(path);
 119         if (class_dev == NULL) {
 120                 dbg ("sysfs_open_class_device_path failed");
 121                 return -1;
 122         }
 123
 124         udev_init_device(&udev, devpath, subsystem, "add");
 125         udev.devt = get_devt(class_dev);
 126         if (!udev.devt) {
 127                 dbg ("sysfs_open_class_device_path failed");
 128                 return -1;
 129         }
 130         udev_rules_get_name(&udev, class_dev);
 131         if (udev.ignore_device) {
 132                 info("device event will be ignored");
 133                 goto exit;
 134         }
 135         if (udev.name[0] == '\0') {
 136                 info("device node creation supressed");
 137                 goto run;
 138         }
 139
 140         udev_add_device(&udev, class_dev);
 141         if (udev.devname[0] != '\0')
 142                 setenv("DEVNAME", udev.devname, 1);
 143
 144 run:
 145         if (udev_run && !list_empty(&udev.run_list)) {
 146                 struct name_entry *name_loop;
 147
 148                 dbg("executing run list");
 149                 list_for_each_entry(name_loop, &udev.run_list, node)
 150                         execute_command(name_loop->name, udev.subsystem);
 151         }
 152
 153 exit:
 154         sysfs_close_class_device(class_dev);
 155         udev_cleanup_device(&udev);
 156
 157         return 0;
 158 }
 159
 160 static void exec_list(struct list_head *device_list)
 161 {
 162         struct device *loop_device;
 163         struct device *tmp_device;
 164         int i;
 165
 166         /* handle the "first" type devices first */
 167         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 168                 for (i = 0; first_list[i] != NULL; i++) {
 169                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 170                                 add_device(loop_device->path, loop_device->subsys);
 171                                 list_del(&loop_device->node);
 172                                 free(loop_device);
 173                                 break;
 174                         }
 175                 }
 176         }
 177
 178         /* handle the devices we are allowed to, excluding the "last" type devices */
 179         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 180                 int found = 0;
 181                 for (i = 0; last_list[i] != NULL; i++) {
 182                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 183                                 found = 1;
 184                                 break;
 185                         }
 186                 }
 187                 if (found)
 188                         continue;
 189
 190                 add_device(loop_device->path, loop_device->subsys);
 191                 list_del(&loop_device->node);
 192                 free(loop_device);
 193         }
 194
 195         /* handle the rest of the devices left over, if any */
 196         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 197                 add_device(loop_device->path, loop_device->subsys);
 198                 list_del(&loop_device->node);
 199                 free(loop_device);
 200         }
 201 }
 202
 203 static int has_devt(const char *directory)
 204 {
 205         char filename[PATH_SIZE];
 206         struct stat statbuf;
 207
 208         snprintf(filename, sizeof(filename), "%s/dev", directory);
 209         filename[sizeof(filename)-1] = '\0';
 210
 211         if (stat(filename, &statbuf) == 0)
 212                 return 1;
 213
 214         return 0;
 215 }
 216
 217 static void udev_scan_block(void)
 218 {
 219         char base[PATH_SIZE];
 220         DIR *dir;
 221         struct dirent *dent;
 222         LIST_HEAD(device_list);
 223
 224         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 225         base[sizeof(base)-1] = '\0';
 226
 227         dir = opendir(base);
 228         if (dir != NULL) {
 229                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 230                         char dirname[PATH_SIZE];
 231                         DIR *dir2;
 232                         struct dirent *dent2;
 233
 234                         if (dent->d_name[0] == '.')
 235                                 continue;
 236
 237                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 238                         dirname[sizeof(dirname)-1] = '\0';
 239                         if (has_devt(dirname))
 240                                 device_list_insert(dirname, "block", &device_list);
 241                         else
 242                                 continue;
 243
 244                         /* look for partitions */
 245                         dir2 = opendir(dirname);
 246                         if (dir2 != NULL) {
 247                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 248                                         char dirname2[PATH_SIZE];
 249
 250                                         if (dent2->d_name[0] == '.')
 251                                                 continue;
 252
 253                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 254                                         dirname2[sizeof(dirname2)-1] = '\0';
 255
 256                                         if (has_devt(dirname2))
 257                                                 device_list_insert(dirname2, "block", &device_list);
 258                                 }
 259                                 closedir(dir2);
 260                         }
 261                 }
 262                 closedir(dir);
 263         }
 264         exec_list(&device_list);
 265 }
 266
 267 static void udev_scan_class(void)
 268 {
 269         char base[PATH_SIZE];
 270         DIR *dir;
 271         struct dirent *dent;
 272         LIST_HEAD(device_list);
 273
 274         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 275         base[sizeof(base)-1] = '\0';
 276
 277         dir = opendir(base);
 278         if (dir != NULL) {
 279                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 280                         char dirname[PATH_SIZE];
 281                         DIR *dir2;
 282                         struct dirent *dent2;
 283
 284                         if (dent->d_name[0] == '.')
 285                                 continue;
 286
 287                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 288                         dirname[sizeof(dirname)-1] = '\0';
 289
 290                         dir2 = opendir(dirname);
 291                         if (dir2 != NULL) {
 292                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 293                                         char dirname2[PATH_SIZE];
 294
 295                                         if (dent2->d_name[0] == '.')
 296                                                 continue;
 297
 298                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 299                                         dirname2[sizeof(dirname2)-1] = '\0';
 300
 301                                         /* pass the net class as it is */
 302                                         if (strcmp(dent->d_name, "net") == 0)
 303                                                 device_list_insert(dirname2, "net", &device_list);
 304                                         else if (has_devt(dirname2))
 305                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 306                                 }
 307                                 closedir(dir2);
 308                         }
 309                 }
 310                 closedir(dir);
 311         }
 312         exec_list(&device_list);
 313 }
 314
 315 static void asmlinkage sig_handler(int signum)
 316 {
 317         switch (signum) {
 318                 case SIGALRM:
 319                         exit(1);
 320                 case SIGINT:
 321                 case SIGTERM:
 322                         exit(20 + signum);
 323         }
 324 }
 325
 326 int main(int argc, char *argv[], char *envp[])
 327 {
 328         struct sigaction act;
 329
 330         logging_init("udev");
 331         udev_init_config();
 332         /* disable all logging if not explicitely requested */
 333         if (getenv("UDEV_LOG") == NULL)
 334                 udev_log_priority = 0;
 335         dbg("version %s", UDEV_VERSION);
 336
 337         /* set signal handlers */
 338         memset(&act, 0x00, sizeof(act));
 339         act.sa_handler = (void (*) (int))sig_handler;
 340         sigemptyset (&act.sa_mask);
 341         act.sa_flags = 0;
 342         sigaction(SIGALRM, &act, NULL);
 343         sigaction(SIGINT, &act, NULL);
 344         sigaction(SIGTERM, &act, NULL);
 345
 346         /* trigger timeout to prevent hanging processes */
 347         alarm(ALARM_TIMEOUT);
 348
 349         /* set environment for executed programs */
 350         setenv("ACTION", "add", 1);
 351         setenv("UDEV_START", "1", 1);
 352
 353         udev_rules_init();
 354
 355         udev_scan_block();
 356         udev_scan_class();
 357
 358         logging_close();
 359         return 0;
 360 }