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