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.h"
  41 #include "logging.h"
  42 #include "udev_rules.h"
  43 #include "udev_utils.h"
  44 #include "list.h"
  45
  46 #ifdef USE_LOG
  47 void log_message(int level, const char *format, ...)
  48 {
  49 }
  50 #endif
  51
  52 struct device {
  53         struct list_head node;
  54         char path[PATH_SIZE];
  55         char subsys[NAME_SIZE];
  56 };
  57
  58 /* sort files in lexical order */
  59 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  60 {
  61         struct device *loop_device;
  62         struct device *new_device;
  63
  64         dbg("insert: '%s'\n", path);
  65
  66         list_for_each_entry(loop_device, device_list, node) {
  67                 if (strcmp(loop_device->path, path) > 0) {
  68                         break;
  69                 }
  70         }
  71
  72         new_device = malloc(sizeof(struct device));
  73         if (new_device == NULL) {
  74                 dbg("error malloc");
  75                 return -ENOMEM;
  76         }
  77
  78         strlcpy(new_device->path, path, sizeof(new_device->path));
  79         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  80         list_add_tail(&new_device->node, &loop_device->node);
  81         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  82         return 0;
  83 }
  84
  85 /* list of devices that we should run last due to any one of a number of reasons */
  86 static char *last_list[] = {
  87         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  88         NULL,
  89 };
  90
  91 /* list of devices that we should run first due to any one of a number of reasons */
  92 static char *first_list[] = {
  93         "/class/mem",   /* people tend to like their memory devices around first... */
  94         NULL,
  95 };
  96
  97 static int add_device(const char *path, const char *subsystem)
  98 {
  99         struct udevice udev;
 100         struct sysfs_class_device *class_dev;
 101         const char *devpath;
 102
 103         devpath = &path[strlen(sysfs_path)];
 104
 105         /* set environment for callouts and dev.d/ */
 106         setenv("DEVPATH", devpath, 1);
 107         setenv("SUBSYSTEM", subsystem, 1);
 108
 109         dbg("exec: '%s' (%s)\n", devpath, path);
 110
 111         class_dev = sysfs_open_class_device_path(path);
 112         if (class_dev == NULL) {
 113                 dbg ("sysfs_open_class_device_path failed");
 114                 return -ENODEV;
 115         }
 116
 117         udev_init_device(&udev, devpath, subsystem);
 118         udev_add_device(&udev, class_dev);
 119
 120         /* run dev.d/ scripts if we created a node or changed a netif name */
 121         if (udev_dev_d && udev.devname[0] != '\0') {
 122                 setenv("DEVNAME", udev.devname, 1);
 123                 udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
 124         }
 125
 126         sysfs_close_class_device(class_dev);
 127         udev_cleanup_device(&udev);
 128
 129         return 0;
 130 }
 131
 132 static void exec_list(struct list_head *device_list)
 133 {
 134         struct device *loop_device;
 135         struct device *tmp_device;
 136         int i;
 137
 138         /* handle the "first" type devices first */
 139         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 140                 for (i = 0; first_list[i] != NULL; i++) {
 141                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 142                                 add_device(loop_device->path, loop_device->subsys);
 143                                 list_del(&loop_device->node);
 144                                 free(loop_device);
 145                                 break;
 146                         }
 147                 }
 148         }
 149
 150         /* handle the devices we are allowed to, excluding the "last" type devices */
 151         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 152                 int found = 0;
 153                 for (i = 0; last_list[i] != NULL; i++) {
 154                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 155                                 found = 1;
 156                                 break;
 157                         }
 158                 }
 159                 if (found)
 160                         continue;
 161
 162                 add_device(loop_device->path, loop_device->subsys);
 163                 list_del(&loop_device->node);
 164                 free(loop_device);
 165         }
 166
 167         /* handle the rest of the devices left over, if any */
 168         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 169                 add_device(loop_device->path, loop_device->subsys);
 170                 list_del(&loop_device->node);
 171                 free(loop_device);
 172         }
 173 }
 174
 175 static int has_devt(const char *directory)
 176 {
 177         char filename[PATH_SIZE];
 178         struct stat statbuf;
 179
 180         snprintf(filename, sizeof(filename), "%s/dev", directory);
 181         filename[sizeof(filename)-1] = '\0';
 182
 183         if (stat(filename, &statbuf) == 0)
 184                 return 1;
 185
 186         return 0;
 187 }
 188
 189 static void udev_scan_block(void)
 190 {
 191         char base[PATH_SIZE];
 192         DIR *dir;
 193         struct dirent *dent;
 194         LIST_HEAD(device_list);
 195
 196         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 197         base[sizeof(base)-1] = '\0';
 198
 199         dir = opendir(base);
 200         if (dir != NULL) {
 201                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 202                         char dirname[PATH_SIZE];
 203                         DIR *dir2;
 204                         struct dirent *dent2;
 205
 206                         if (dent->d_name[0] == '.')
 207                                 continue;
 208
 209                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 210                         dirname[sizeof(dirname)-1] = '\0';
 211                         if (has_devt(dirname))
 212                                 device_list_insert(dirname, "block", &device_list);
 213                         else
 214                                 continue;
 215
 216                         /* look for partitions */
 217                         dir2 = opendir(dirname);
 218                         if (dir2 != NULL) {
 219                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 220                                         char dirname2[PATH_SIZE];
 221
 222                                         if (dent2->d_name[0] == '.')
 223                                                 continue;
 224
 225                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 226                                         dirname2[sizeof(dirname2)-1] = '\0';
 227
 228                                         if (has_devt(dirname2))
 229                                                 device_list_insert(dirname2, "block", &device_list);
 230                                 }
 231                                 closedir(dir2);
 232                         }
 233                 }
 234                 closedir(dir);
 235         }
 236         exec_list(&device_list);
 237 }
 238
 239 static void udev_scan_class(void)
 240 {
 241         char base[PATH_SIZE];
 242         DIR *dir;
 243         struct dirent *dent;
 244         LIST_HEAD(device_list);
 245
 246         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 247         base[sizeof(base)-1] = '\0';
 248
 249         dir = opendir(base);
 250         if (dir != NULL) {
 251                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 252                         char dirname[PATH_SIZE];
 253                         DIR *dir2;
 254                         struct dirent *dent2;
 255
 256                         if (dent->d_name[0] == '.')
 257                                 continue;
 258
 259                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 260                         dirname[sizeof(dirname)-1] = '\0';
 261
 262                         dir2 = opendir(dirname);
 263                         if (dir2 != NULL) {
 264                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 265                                         char dirname2[PATH_SIZE];
 266
 267                                         if (dent2->d_name[0] == '.')
 268                                                 continue;
 269
 270                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 271                                         dirname2[sizeof(dirname2)-1] = '\0';
 272
 273                                         /* pass the net class as it is */
 274                                         if (strcmp(dent->d_name, "net") == 0)
 275                                                 device_list_insert(dirname2, "net", &device_list);
 276                                         else if (has_devt(dirname2))
 277                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 278                                 }
 279                                 closedir(dir2);
 280                         }
 281                 }
 282                 closedir(dir);
 283         }
 284         exec_list(&device_list);
 285 }
 286
 287 static void asmlinkage sig_handler(int signum)
 288 {
 289         switch (signum) {
 290                 case SIGALRM:
 291                         exit(1);
 292                 case SIGINT:
 293                 case SIGTERM:
 294                         exit(20 + signum);
 295         }
 296 }
 297
 298 int main(int argc, char *argv[], char *envp[])
 299 {
 300         struct sigaction act;
 301
 302         udev_init_config();
 303
 304         /* set signal handlers */
 305         memset(&act, 0x00, sizeof(act));
 306         act.sa_handler = (void (*) (int))sig_handler;
 307         sigemptyset (&act.sa_mask);
 308         act.sa_flags = 0;
 309         sigaction(SIGALRM, &act, NULL);
 310         sigaction(SIGINT, &act, NULL);
 311         sigaction(SIGTERM, &act, NULL);
 312
 313         /* trigger timeout to prevent hanging processes */
 314         alarm(ALARM_TIMEOUT);
 315
 316         /* set environment for executed programs */
 317         setenv("ACTION", "add", 1);
 318         setenv("UDEV_START", "1", 1);
 319
 320         udev_rules_init();
 321
 322         udev_scan_block();
 323         udev_scan_class();
 324
 325         return 0;
 326 }