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 <errno.h>
  30 #include <ctype.h>
  31 #include <dirent.h>
  32 #include <sys/wait.h>
  33 #include <sys/types.h>
  34 #include <unistd.h>
  35
  36 #include "libsysfs/sysfs/libsysfs.h"
  37 #include "logging.h"
  38 #include "udev_lib.h"
  39 #include "list.h"
  40 #include "udev.h"
  41
  42
  43 #define MAX_PATHLEN             1024
  44 #define SYSBLOCK                "/sys/block"
  45 #define SYSCLASS                "/sys/class"
  46
  47 struct device {
  48         struct list_head list;
  49         char path[MAX_PATHLEN];
  50         char subsys[MAX_PATHLEN];
  51 };
  52
  53 /* sort files in lexical order */
  54 static int device_list_insert(char *path, char *subsystem, struct list_head *device_list)
  55 {
  56         struct device *loop_device;
  57         struct device *new_device;
  58
  59         list_for_each_entry(loop_device, device_list, list) {
  60                 if (strcmp(loop_device->path, path) > 0) {
  61                         break;
  62                 }
  63         }
  64
  65         new_device = malloc(sizeof(struct device));
  66         if (new_device == NULL) {
  67                 dbg("error malloc");
  68                 return -ENOMEM;
  69         }
  70
  71         strfieldcpy(new_device->path, path);
  72         strfieldcpy(new_device->subsys, subsystem);
  73         list_add_tail(&new_device->list, &loop_device->list);
  74         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  75         return 0;
  76 }
  77
  78 /* list of devices that we should run last due to any one of a number of reasons */
  79 static char *last_list[] = {
  80         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  81         NULL,
  82 };
  83
  84 /* list of devices that we should run first due to any one of a number of reasons */
  85 static char *first_list[] = {
  86         "/class/mem",   /* people tend to like their memory devices around first... */
  87         NULL,
  88 };
  89
  90 static int add_device(char *devpath, char *subsystem)
  91 {
  92         struct udevice udev;
  93         char path[SYSFS_PATH_MAX];
  94         struct sysfs_class_device *class_dev;
  95         char *argv[3];
  96
  97         /* fake argument vector and environment for callouts and dev.d/ */
  98         argv[0] = "udev";
  99         argv[1] = subsystem;
 100         argv[2] = NULL;
 101
 102         main_argv = argv;
 103         setenv("DEVPATH", devpath, 1);
 104         setenv("ACTION", "add", 1);
 105
 106         snprintf(path, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
 107         class_dev = sysfs_open_class_device_path(path);
 108         if (class_dev == NULL) {
 109                 dbg ("sysfs_open_class_device_path failed");
 110                 return -ENODEV;
 111         }
 112
 113         udev_set_values(&udev, devpath, subsystem);
 114         udev_add_device(&udev, class_dev);
 115
 116         /* run scripts */
 117         dev_d_execute(&udev);
 118
 119         sysfs_close_class_device(class_dev);
 120
 121         return 0;
 122 }
 123
 124 static void exec_list(struct list_head *device_list)
 125 {
 126         struct device *loop_device;
 127         struct device *tmp_device;
 128         int i;
 129
 130         /* handle the "first" type devices first */
 131         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 132                 for (i=0; first_list[i] != NULL; i++) {
 133                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 134                                 add_device(loop_device->path, loop_device->subsys);
 135                                 list_del(&loop_device->list);
 136                                 free(loop_device);
 137                                 break;
 138                         }
 139                 }
 140         }
 141
 142         /* handle the devices we are allowed to, excluding the "last" type devices */
 143         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 144                 int found = 0;
 145                 for (i=0; last_list[i] != NULL; i++) {
 146                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 147                                 found = 1;
 148                                 break;
 149                         }
 150                 }
 151                 if (found)
 152                         continue;
 153
 154                 add_device(loop_device->path, loop_device->subsys);
 155                 list_del(&loop_device->list);
 156                 free(loop_device);
 157         }
 158
 159         /* handle the rest of the devices left over, if any */
 160         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 161                 add_device(loop_device->path, loop_device->subsys);
 162                 list_del(&loop_device->list);
 163                 free(loop_device);
 164         }
 165 }
 166
 167 static void udev_scan_block(void)
 168 {
 169         DIR *dir;
 170         struct dirent *dent;
 171         LIST_HEAD(device_list);
 172
 173         dir = opendir(SYSBLOCK);
 174         if (dir != NULL) {
 175                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 176                         char dirname[MAX_PATHLEN];
 177                         DIR *dir2;
 178                         struct dirent *dent2;
 179
 180                         if ((strcmp(dent->d_name, ".") == 0) ||
 181                             (strcmp(dent->d_name, "..") == 0))
 182                                 continue;
 183
 184                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 185                         dirname[MAX_PATHLEN-1] = '\0';
 186                         device_list_insert(dirname, "block", &device_list);
 187
 188                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 189                         dir2 = opendir(dirname);
 190                         if (dir2 != NULL) {
 191                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 192                                         char dirname2[MAX_PATHLEN];
 193                                         DIR *dir3;
 194                                         struct dirent *dent3;
 195
 196                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 197                                             (strcmp(dent2->d_name, "..") == 0))
 198                                                 continue;
 199
 200                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 201                                         dirname2[MAX_PATHLEN-1] = '\0';
 202
 203                                         dir3 = opendir(dirname2);
 204                                         if (dir3 != NULL) {
 205                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 206                                                         char filename[MAX_PATHLEN];
 207
 208                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 209                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 210                                                                          dent->d_name, dent2->d_name);
 211                                                                 filename[MAX_PATHLEN-1] = '\0';
 212                                                                 device_list_insert(filename, "block", &device_list);
 213                                                         }
 214                                                 }
 215                                                 closedir(dir3);
 216                                         }
 217                                 }
 218                                 closedir(dir2);
 219                         }
 220                 }
 221                 closedir(dir);
 222         }
 223
 224         exec_list(&device_list);
 225 }
 226
 227 static void udev_scan_class(void)
 228 {
 229         DIR *dir;
 230         struct dirent *dent;
 231         LIST_HEAD(device_list);
 232
 233         dir = opendir(SYSCLASS);
 234         if (dir != NULL) {
 235                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 236                         char dirname[MAX_PATHLEN];
 237                         DIR *dir2;
 238                         struct dirent *dent2;
 239
 240                         if ((strcmp(dent->d_name, ".") == 0) ||
 241                             (strcmp(dent->d_name, "..") == 0))
 242                                 continue;
 243
 244                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 245                         dirname[MAX_PATHLEN-1] = '\0';
 246                         dir2 = opendir(dirname);
 247                         if (dir2 != NULL) {
 248                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 249                                         char dirname2[MAX_PATHLEN];
 250                                         DIR *dir3;
 251                                         struct dirent *dent3;
 252
 253                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 254                                             (strcmp(dent2->d_name, "..") == 0))
 255                                                 continue;
 256
 257                                         /* pass the net class as it is */
 258                                         if (strcmp(dent->d_name, "net") == 0) {
 259                                                 snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
 260                                                 device_list_insert(dirname2, "net", &device_list);
 261                                                 continue;
 262                                         }
 263
 264                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 265                                         dirname2[MAX_PATHLEN-1] = '\0';
 266                                         dir3 = opendir(dirname2);
 267                                         if (dir3 != NULL) {
 268                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 269                                                         char filename[MAX_PATHLEN];
 270
 271                                                         /* pass devices with a "dev" file */
 272                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 273                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 274                                                                          dent->d_name, dent2->d_name);
 275                                                                 filename[MAX_PATHLEN-1] = '\0';
 276                                                                 device_list_insert(filename, dent->d_name, &device_list);
 277                                                                 break;
 278                                                         }
 279                                                 }
 280                                                 closedir(dir3);
 281                                         }
 282                                 }
 283                                 closedir(dir2);
 284                         }
 285                 }
 286                 closedir(dir);
 287         }
 288
 289         exec_list(&device_list);
 290 }
 291
 292 int udev_start(void)
 293 {
 294         udev_scan_class();
 295         udev_scan_block();
 296         return 0;
 297 }