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                 dbg("device event will be ignored");
 133                 goto exit;
 134         }
 135         if (udev.name[0] == '\0') {
 136                 dbg("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 run:
 144         if (udev_run && !list_empty(&udev.run_list)) {
 145                 struct name_entry *name_loop;
 146
 147                 dbg("executing run list");
 148                 list_for_each_entry(name_loop, &udev.run_list, node)
 149                         execute_command(name_loop->name, udev.subsystem);
 150         }
 151 exit:
 152         sysfs_close_class_device(class_dev);
 153         udev_cleanup_device(&udev);
 154
 155         return 0;
 156 }
 157
 158 static void exec_list(struct list_head *device_list)
 159 {
 160         struct device *loop_device;
 161         struct device *tmp_device;
 162         int i;
 163
 164         /* handle the "first" type devices first */
 165         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 166                 for (i = 0; first_list[i] != NULL; i++) {
 167                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 168                                 add_device(loop_device->path, loop_device->subsys);
 169                                 list_del(&loop_device->node);
 170                                 free(loop_device);
 171                                 break;
 172                         }
 173                 }
 174         }
 175
 176         /* handle the devices we are allowed to, excluding the "last" type devices */
 177         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 178                 int found = 0;
 179                 for (i = 0; last_list[i] != NULL; i++) {
 180                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 181                                 found = 1;
 182                                 break;
 183                         }
 184                 }
 185                 if (found)
 186                         continue;
 187
 188                 add_device(loop_device->path, loop_device->subsys);
 189                 list_del(&loop_device->node);
 190                 free(loop_device);
 191         }
 192
 193         /* handle the rest of the devices left over, if any */
 194         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 195                 add_device(loop_device->path, loop_device->subsys);
 196                 list_del(&loop_device->node);
 197                 free(loop_device);
 198         }
 199 }
 200
 201 static int has_devt(const char *directory)
 202 {
 203         char filename[PATH_SIZE];
 204         struct stat statbuf;
 205
 206         snprintf(filename, sizeof(filename), "%s/dev", directory);
 207         filename[sizeof(filename)-1] = '\0';
 208
 209         if (stat(filename, &statbuf) == 0)
 210                 return 1;
 211
 212         return 0;
 213 }
 214
 215 static void udev_scan_block(void)
 216 {
 217         char base[PATH_SIZE];
 218         DIR *dir;
 219         struct dirent *dent;
 220         LIST_HEAD(device_list);
 221
 222         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 223         base[sizeof(base)-1] = '\0';
 224
 225         dir = opendir(base);
 226         if (dir != NULL) {
 227                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 228                         char dirname[PATH_SIZE];
 229                         DIR *dir2;
 230                         struct dirent *dent2;
 231
 232                         if (dent->d_name[0] == '.')
 233                                 continue;
 234
 235                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 236                         dirname[sizeof(dirname)-1] = '\0';
 237                         if (has_devt(dirname))
 238                                 device_list_insert(dirname, "block", &device_list);
 239                         else
 240                                 continue;
 241
 242                         /* look for partitions */
 243                         dir2 = opendir(dirname);
 244                         if (dir2 != NULL) {
 245                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 246                                         char dirname2[PATH_SIZE];
 247
 248                                         if (dent2->d_name[0] == '.')
 249                                                 continue;
 250
 251                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 252                                         dirname2[sizeof(dirname2)-1] = '\0';
 253
 254                                         if (has_devt(dirname2))
 255                                                 device_list_insert(dirname2, "block", &device_list);
 256                                 }
 257                                 closedir(dir2);
 258                         }
 259                 }
 260                 closedir(dir);
 261         }
 262         exec_list(&device_list);
 263 }
 264
 265 static void udev_scan_class(void)
 266 {
 267         char base[PATH_SIZE];
 268         DIR *dir;
 269         struct dirent *dent;
 270         LIST_HEAD(device_list);
 271
 272         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 273         base[sizeof(base)-1] = '\0';
 274
 275         dir = opendir(base);
 276         if (dir != NULL) {
 277                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 278                         char dirname[PATH_SIZE];
 279                         DIR *dir2;
 280                         struct dirent *dent2;
 281
 282                         if (dent->d_name[0] == '.')
 283                                 continue;
 284
 285                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 286                         dirname[sizeof(dirname)-1] = '\0';
 287
 288                         dir2 = opendir(dirname);
 289                         if (dir2 != NULL) {
 290                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 291                                         char dirname2[PATH_SIZE];
 292
 293                                         if (dent2->d_name[0] == '.')
 294                                                 continue;
 295
 296                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 297                                         dirname2[sizeof(dirname2)-1] = '\0';
 298
 299                                         /* pass the net class as it is */
 300                                         if (strcmp(dent->d_name, "net") == 0)
 301                                                 device_list_insert(dirname2, "net", &device_list);
 302                                         else if (has_devt(dirname2))
 303                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 304                                 }
 305                                 closedir(dir2);
 306                         }
 307                 }
 308                 closedir(dir);
 309         }
 310         exec_list(&device_list);
 311 }
 312
 313 static void asmlinkage sig_handler(int signum)
 314 {
 315         switch (signum) {
 316                 case SIGALRM:
 317                         exit(1);
 318                 case SIGINT:
 319                 case SIGTERM:
 320                         exit(20 + signum);
 321         }
 322 }
 323
 324 int main(int argc, char *argv[], char *envp[])
 325 {
 326         struct sigaction act;
 327
 328         logging_init("udev");
 329         udev_init_config();
 330         /* disable all logging if not explicitely requested */
 331         if (getenv("UDEV_LOG") == NULL)
 332                 udev_log_priority = 0;
 333         dbg("version %s", UDEV_VERSION);
 334
 335         /* set signal handlers */
 336         memset(&act, 0x00, sizeof(act));
 337         act.sa_handler = (void (*) (int))sig_handler;
 338         sigemptyset (&act.sa_mask);
 339         act.sa_flags = 0;
 340         sigaction(SIGALRM, &act, NULL);
 341         sigaction(SIGINT, &act, NULL);
 342         sigaction(SIGTERM, &act, NULL);
 343
 344         /* trigger timeout to prevent hanging processes */
 345         alarm(ALARM_TIMEOUT);
 346
 347         /* set environment for executed programs */
 348         setenv("ACTION", "add", 1);
 349         setenv("UDEV_START", "1", 1);
 350
 351         udev_rules_init();
 352
 353         udev_scan_block();
 354         udev_scan_class();
 355
 356         logging_close();
 357         return 0;
 358 }