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 "logging.h"
  37 #include "udev_lib.h"
  38 #include "list.h"
  39 #include "udev.h"
  40
  41
  42 #define MAX_PATHLEN             1024
  43 #define SYSBLOCK                "/sys/block"
  44 #define SYSCLASS                "/sys/class"
  45
  46 struct device {
  47         struct list_head list;
  48         char path[MAX_PATHLEN];
  49         char subsys[MAX_PATHLEN];
  50 };
  51
  52 /* sort files in lexical order */
  53 static int device_list_insert(char *path, char *subsystem, struct list_head *device_list)
  54 {
  55         struct device *loop_device;
  56         struct device *new_device;
  57
  58         list_for_each_entry(loop_device, device_list, list) {
  59                 if (strcmp(loop_device->path, path) > 0) {
  60                         break;
  61                 }
  62         }
  63
  64         new_device = malloc(sizeof(struct device));
  65         if (new_device == NULL) {
  66                 dbg("error malloc");
  67                 return -ENOMEM;
  68         }
  69
  70         strfieldcpy(new_device->path, path);
  71         strfieldcpy(new_device->subsys, subsystem);
  72         list_add_tail(&new_device->list, &loop_device->list);
  73         return 0;
  74 }
  75
  76 static void udev_exec(const char *path, const char* subsystem)
  77 {
  78         /* Setup env variables. */
  79         setenv("UDEV_NO_SLEEP", "1", 1);
  80
  81         /* Now call __udev_hotplug(). */
  82         if (__udev_hotplug("add", path, subsystem)) {
  83                 dbg("Calling of udev_hotplug failed");
  84                 exit(1);
  85         }
  86 }
  87
  88 /* list of devices that we should run last due to any one of a number of reasons */
  89 static char *last_list[] = {
  90         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  91         NULL,
  92 };
  93
  94 static void exec_list(struct list_head *device_list)
  95 {
  96         struct device *loop_device;
  97         struct device *tmp_device;
  98
  99         /* handle the devices we are allowed to, excluding the "last" type devices */
 100         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 101                 int found = 0;
 102                 int i;
 103                 for (i=0; last_list[i] != NULL; i++) {
 104                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 105                                 found = 1;
 106                                 break;
 107                         }
 108                 }
 109                 if (found)
 110                         continue;
 111
 112                 udev_exec(loop_device->path, loop_device->subsys);
 113                 list_del(&loop_device->list);
 114                 free(loop_device);
 115         }
 116
 117         /* handle the rest of the devices left over, if any */
 118         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 119                 udev_exec(loop_device->path, loop_device->subsys);
 120                 list_del(&loop_device->list);
 121                 free(loop_device);
 122         }
 123 }
 124
 125 static void udev_scan_block(void)
 126 {
 127         DIR *dir;
 128         struct dirent *dent;
 129         LIST_HEAD(device_list);
 130
 131         dir = opendir(SYSBLOCK);
 132         if (dir != NULL) {
 133                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 134                         char dirname[MAX_PATHLEN];
 135                         DIR *dir2;
 136                         struct dirent *dent2;
 137
 138                         if ((strcmp(dent->d_name, ".") == 0) ||
 139                             (strcmp(dent->d_name, "..") == 0))
 140                                 continue;
 141
 142                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 143                         dirname[MAX_PATHLEN-1] = '\0';
 144                         device_list_insert(dirname, "block", &device_list);
 145
 146                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 147                         dir2 = opendir(dirname);
 148                         if (dir2 != NULL) {
 149                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 150                                         char dirname2[MAX_PATHLEN];
 151                                         DIR *dir3;
 152                                         struct dirent *dent3;
 153
 154                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 155                                             (strcmp(dent2->d_name, "..") == 0))
 156                                                 continue;
 157
 158                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 159                                         dirname2[MAX_PATHLEN-1] = '\0';
 160
 161                                         dir3 = opendir(dirname2);
 162                                         if (dir3 != NULL) {
 163                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 164                                                         char filename[MAX_PATHLEN];
 165
 166                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 167                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 168                                                                          dent->d_name, dent2->d_name);
 169                                                                 filename[MAX_PATHLEN-1] = '\0';
 170                                                                 device_list_insert(filename, "block", &device_list);
 171                                                         }
 172                                                 }
 173                                                 closedir(dir3);
 174                                         }
 175                                 }
 176                                 closedir(dir2);
 177                         }
 178                 }
 179                 closedir(dir);
 180         }
 181
 182         exec_list(&device_list);
 183 }
 184
 185 static void udev_scan_class(void)
 186 {
 187         DIR *dir;
 188         struct dirent *dent;
 189         LIST_HEAD(device_list);
 190
 191         dir = opendir(SYSCLASS);
 192         if (dir != NULL) {
 193                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 194                         char dirname[MAX_PATHLEN];
 195                         DIR *dir2;
 196                         struct dirent *dent2;
 197
 198                         if ((strcmp(dent->d_name, ".") == 0) ||
 199                             (strcmp(dent->d_name, "..") == 0))
 200                                 continue;
 201
 202                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 203                         dirname[MAX_PATHLEN-1] = '\0';
 204                         dir2 = opendir(dirname);
 205                         if (dir2 != NULL) {
 206                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 207                                         char dirname2[MAX_PATHLEN-1];
 208                                         DIR *dir3;
 209                                         struct dirent *dent3;
 210
 211                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 212                                             (strcmp(dent2->d_name, "..") == 0))
 213                                                 continue;
 214
 215                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 216                                         dirname2[MAX_PATHLEN-1] = '\0';
 217
 218                                         dir3 = opendir(dirname2);
 219                                         if (dir3 != NULL) {
 220                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 221                                                         char filename[MAX_PATHLEN];
 222
 223                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 224                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 225                                                                          dent->d_name, dent2->d_name);
 226                                                                 filename[MAX_PATHLEN-1] = '\0';
 227                                                                 device_list_insert(filename, dent->d_name, &device_list);
 228                                                         }
 229                                                 }
 230                                                 closedir(dir3);
 231                                         }
 232                                 }
 233                                 closedir(dir2);
 234                         }
 235                 }
 236                 closedir(dir);
 237         }
 238
 239         exec_list(&device_list);
 240 }
 241
 242 int udev_start(void)
 243 {
 244         udev_scan_class();
 245         udev_scan_block();
 246         return 0;
 247 }