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         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  74         return 0;
  75 }
  76
  77 /* list of devices that we should run last due to any one of a number of reasons */
  78 static char *last_list[] = {
  79         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  80         NULL,
  81 };
  82
  83 /* list of devices that we should run first due to any one of a number of reasons */
  84 static char *first_list[] = {
  85         "/class/mem",   /* people tend to like their memory devices around first... */
  86         NULL,
  87 };
  88
  89 static void exec_list(struct list_head *device_list)
  90 {
  91         struct device *loop_device;
  92         struct device *tmp_device;
  93         int i;
  94
  95         /* handle the "first" type devices first */
  96         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
  97                 for (i=0; first_list[i] != NULL; i++) {
  98                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
  99                                 udev_add_device(loop_device->path, loop_device->subsys, NOFAKE);
 100                                 list_del(&loop_device->list);
 101                                 free(loop_device);
 102                                 break;
 103                         }
 104                 }
 105         }
 106
 107         /* handle the devices we are allowed to, excluding the "last" type devices */
 108         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 109                 int found = 0;
 110                 for (i=0; last_list[i] != NULL; i++) {
 111                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 112                                 found = 1;
 113                                 break;
 114                         }
 115                 }
 116                 if (found)
 117                         continue;
 118
 119                 udev_add_device(loop_device->path, loop_device->subsys, NOFAKE);
 120                 list_del(&loop_device->list);
 121                 free(loop_device);
 122         }
 123
 124         /* handle the rest of the devices left over, if any */
 125         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 126                 udev_add_device(loop_device->path, loop_device->subsys, NOFAKE);
 127                 list_del(&loop_device->list);
 128                 free(loop_device);
 129         }
 130 }
 131
 132 static void udev_scan_block(void)
 133 {
 134         DIR *dir;
 135         struct dirent *dent;
 136         LIST_HEAD(device_list);
 137
 138         dir = opendir(SYSBLOCK);
 139         if (dir != NULL) {
 140                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 141                         char dirname[MAX_PATHLEN];
 142                         DIR *dir2;
 143                         struct dirent *dent2;
 144
 145                         if ((strcmp(dent->d_name, ".") == 0) ||
 146                             (strcmp(dent->d_name, "..") == 0))
 147                                 continue;
 148
 149                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 150                         dirname[MAX_PATHLEN-1] = '\0';
 151                         device_list_insert(dirname, "block", &device_list);
 152
 153                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 154                         dir2 = opendir(dirname);
 155                         if (dir2 != NULL) {
 156                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 157                                         char dirname2[MAX_PATHLEN];
 158                                         DIR *dir3;
 159                                         struct dirent *dent3;
 160
 161                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 162                                             (strcmp(dent2->d_name, "..") == 0))
 163                                                 continue;
 164
 165                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 166                                         dirname2[MAX_PATHLEN-1] = '\0';
 167
 168                                         dir3 = opendir(dirname2);
 169                                         if (dir3 != NULL) {
 170                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 171                                                         char filename[MAX_PATHLEN];
 172
 173                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 174                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 175                                                                          dent->d_name, dent2->d_name);
 176                                                                 filename[MAX_PATHLEN-1] = '\0';
 177                                                                 device_list_insert(filename, "block", &device_list);
 178                                                         }
 179                                                 }
 180                                                 closedir(dir3);
 181                                         }
 182                                 }
 183                                 closedir(dir2);
 184                         }
 185                 }
 186                 closedir(dir);
 187         }
 188
 189         exec_list(&device_list);
 190 }
 191
 192 static void udev_scan_class(void)
 193 {
 194         DIR *dir;
 195         struct dirent *dent;
 196         LIST_HEAD(device_list);
 197
 198         dir = opendir(SYSCLASS);
 199         if (dir != NULL) {
 200                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 201                         char dirname[MAX_PATHLEN];
 202                         DIR *dir2;
 203                         struct dirent *dent2;
 204
 205                         if ((strcmp(dent->d_name, ".") == 0) ||
 206                             (strcmp(dent->d_name, "..") == 0))
 207                                 continue;
 208
 209                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 210                         dirname[MAX_PATHLEN-1] = '\0';
 211                         dir2 = opendir(dirname);
 212                         if (dir2 != NULL) {
 213                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 214                                         char dirname2[MAX_PATHLEN-1];
 215                                         DIR *dir3;
 216                                         struct dirent *dent3;
 217
 218                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 219                                             (strcmp(dent2->d_name, "..") == 0))
 220                                                 continue;
 221
 222                                         /* pass the net class as it is */
 223                                         if (strcmp(dent->d_name, "net") == 0) {
 224                                                 snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
 225                                                 device_list_insert(dirname2, "net", &device_list);
 226                                                 continue;
 227                                         }
 228
 229                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 230                                         dirname2[MAX_PATHLEN-1] = '\0';
 231                                         dir3 = opendir(dirname2);
 232                                         if (dir3 != NULL) {
 233                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 234                                                         char filename[MAX_PATHLEN];
 235
 236                                                         /* pass devices with a "dev" file */
 237                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 238                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 239                                                                          dent->d_name, dent2->d_name);
 240                                                                 filename[MAX_PATHLEN-1] = '\0';
 241                                                                 device_list_insert(filename, dent->d_name, &device_list);
 242                                                                 break;
 243                                                         }
 244                                                 }
 245                                                 closedir(dir3);
 246                                         }
 247                                 }
 248                                 closedir(dir2);
 249                         }
 250                 }
 251                 closedir(dir);
 252         }
 253
 254         exec_list(&device_list);
 255 }
 256
 257 int udev_start(void)
 258 {
 259         udev_scan_class();
 260         udev_scan_block();
 261         return 0;
 262 }