udev_start.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 <errno.h>
  30 #include <ctype.h>
  31 #include <dirent.h>
  32 #include <sys/wait.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <unistd.h>
  36
  37 #include "libsysfs/sysfs/libsysfs.h"
  38 #include "logging.h"
  39 #include "udev_utils.h"
  40 #include "list.h"
  41 #include "udev.h"
  42
  43
  44 #define MAX_PATH_SIZE           512
  45
  46 struct device {
  47         struct list_head list;
  48         char path[MAX_PATH_SIZE];
  49         char subsys[MAX_PATH_SIZE];
  50 };
  51
  52 /* sort files in lexical order */
  53 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  54 {
  55         struct device *loop_device;
  56         struct device *new_device;
  57
  58         dbg("insert: '%s'\n", path);
  59
  60         list_for_each_entry(loop_device, device_list, list) {
  61                 if (strcmp(loop_device->path, path) > 0) {
  62                         break;
  63                 }
  64         }
  65
  66         new_device = malloc(sizeof(struct device));
  67         if (new_device == NULL) {
  68                 dbg("error malloc");
  69                 return -ENOMEM;
  70         }
  71
  72         strfieldcpy(new_device->path, path);
  73         strfieldcpy(new_device->subsys, subsystem);
  74         list_add_tail(&new_device->list, &loop_device->list);
  75         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  76         return 0;
  77 }
  78
  79 /* list of devices that we should run last due to any one of a number of reasons */
  80 static char *last_list[] = {
  81         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  82         NULL,
  83 };
  84
  85 /* list of devices that we should run first due to any one of a number of reasons */
  86 static char *first_list[] = {
  87         "/class/mem",   /* people tend to like their memory devices around first... */
  88         NULL,
  89 };
  90
  91 static int add_device(const char *path, const char *subsystem)
  92 {
  93         struct udevice udev;
  94         struct sysfs_class_device *class_dev;
  95         const char *devpath;
  96
  97         devpath = &path[strlen(sysfs_path)];
  98
  99         /* set environment for callouts and dev.d/ */
 100         setenv("DEVPATH", devpath, 1);
 101         setenv("SUBSYSTEM", subsystem, 1);
 102
 103         dbg("exec  : '%s' (%s)\n", devpath, path);
 104
 105         class_dev = sysfs_open_class_device_path(path);
 106         if (class_dev == NULL) {
 107                 dbg ("sysfs_open_class_device_path failed");
 108                 return -ENODEV;
 109         }
 110
 111         udev_init_device(&udev, devpath, subsystem);
 112         udev_add_device(&udev, class_dev);
 113
 114         /* run dev.d/ scripts if we created a node or changed a netif name */
 115         if (udev_dev_d && udev.devname[0] != '\0') {
 116                 setenv("DEVNAME", udev.devname, 1);
 117                 udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
 118         }
 119
 120         sysfs_close_class_device(class_dev);
 121
 122         return 0;
 123 }
 124
 125 static void exec_list(struct list_head *device_list)
 126 {
 127         struct device *loop_device;
 128         struct device *tmp_device;
 129         int i;
 130
 131         /* handle the "first" type devices first */
 132         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 133                 for (i = 0; first_list[i] != NULL; i++) {
 134                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 135                                 add_device(loop_device->path, loop_device->subsys);
 136                                 list_del(&loop_device->list);
 137                                 free(loop_device);
 138                                 break;
 139                         }
 140                 }
 141         }
 142
 143         /* handle the devices we are allowed to, excluding the "last" type devices */
 144         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 145                 int found = 0;
 146                 for (i = 0; last_list[i] != NULL; i++) {
 147                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 148                                 found = 1;
 149                                 break;
 150                         }
 151                 }
 152                 if (found)
 153                         continue;
 154
 155                 add_device(loop_device->path, loop_device->subsys);
 156                 list_del(&loop_device->list);
 157                 free(loop_device);
 158         }
 159
 160         /* handle the rest of the devices left over, if any */
 161         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 162                 add_device(loop_device->path, loop_device->subsys);
 163                 list_del(&loop_device->list);
 164                 free(loop_device);
 165         }
 166 }
 167
 168 static int has_devt(const char *directory)
 169 {
 170         char filename[MAX_PATH_SIZE];
 171         struct stat statbuf;
 172
 173         snprintf(filename, MAX_PATH_SIZE, "%s/dev", directory);
 174         filename[MAX_PATH_SIZE-1] = '\0';
 175
 176         if (stat(filename, &statbuf) == 0)
 177                 return 1;
 178
 179         return 0;
 180 }
 181
 182 static void udev_scan_block(void)
 183 {
 184         char base[MAX_PATH_SIZE];
 185         DIR *dir;
 186         struct dirent *dent;
 187         LIST_HEAD(device_list);
 188
 189         snprintf(base, MAX_PATH_SIZE, "%s/block", sysfs_path);
 190         base[MAX_PATH_SIZE-1] = '\0';
 191
 192         dir = opendir(base);
 193         if (dir != NULL) {
 194                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 195                         char dirname[MAX_PATH_SIZE];
 196                         DIR *dir2;
 197                         struct dirent *dent2;
 198
 199                         if (dent->d_name[0] == '.')
 200                                 continue;
 201
 202                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
 203                         dirname[MAX_PATH_SIZE-1] = '\0';
 204                         if (has_devt(dirname))
 205                                 device_list_insert(dirname, "block", &device_list);
 206                         else
 207                                 continue;
 208
 209                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
 210                         dir2 = opendir(dirname);
 211                         if (dir2 != NULL) {
 212                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 213                                         char dirname2[MAX_PATH_SIZE];
 214
 215                                         if (dent2->d_name[0] == '.')
 216                                                 continue;
 217
 218                                         snprintf(dirname2, MAX_PATH_SIZE, "%s/%s", dirname, dent2->d_name);
 219                                         dirname2[MAX_PATH_SIZE-1] = '\0';
 220
 221                                         if (has_devt(dirname2))
 222                                                 device_list_insert(dirname2, "block", &device_list);
 223                                 }
 224                                 closedir(dir2);
 225                         }
 226                 }
 227                 closedir(dir);
 228         }
 229
 230         exec_list(&device_list);
 231 }
 232
 233 static void udev_scan_class(void)
 234 {
 235         char base[MAX_PATH_SIZE];
 236         DIR *dir;
 237         struct dirent *dent;
 238         LIST_HEAD(device_list);
 239
 240         snprintf(base, MAX_PATH_SIZE, "%s/class", sysfs_path);
 241         base[MAX_PATH_SIZE-1] = '\0';
 242
 243         dir = opendir(base);
 244         if (dir != NULL) {
 245                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 246                         char dirname[MAX_PATH_SIZE];
 247                         DIR *dir2;
 248                         struct dirent *dent2;
 249
 250                         if (dent->d_name[0] == '.')
 251                                 continue;
 252
 253                         snprintf(dirname, MAX_PATH_SIZE, "%s/%s", base, dent->d_name);
 254                         dirname[MAX_PATH_SIZE-1] = '\0';
 255                         dir2 = opendir(dirname);
 256                         if (dir2 != NULL) {
 257                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 258                                         char dirname2[MAX_PATH_SIZE];
 259
 260                                         if (dent2->d_name[0] == '.')
 261                                                 continue;
 262
 263                                         snprintf(dirname2, MAX_PATH_SIZE, "%s/%s", dirname, dent2->d_name);
 264                                         dirname2[MAX_PATH_SIZE-1] = '\0';
 265
 266                                         /* pass the net class as it is */
 267                                         if (strcmp(dent->d_name, "net") == 0)
 268                                                 device_list_insert(dirname2, "net", &device_list);
 269                                         else if (has_devt(dirname2))
 270                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 271                                 }
 272                                 closedir(dir2);
 273                         }
 274                 }
 275                 closedir(dir);
 276         }
 277
 278         exec_list(&device_list);
 279 }
 280
 281 int udev_start(void)
 282 {
 283         /* set environment for callouts and dev.d/ */
 284         setenv("ACTION", "add", 1);
 285         setenv("UDEV_START", "1", 1);
 286
 287         udev_scan_class();
 288         udev_scan_block();
 289
 290         return 0;
 291 }