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
  96         /* set environment for callouts and dev.d/ */
  97         setenv("DEVPATH", devpath, 1);
  98         setenv("SUBSYSTEM", subsystem, 1);
  99
 100         snprintf(path, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
 101         class_dev = sysfs_open_class_device_path(path);
 102         if (class_dev == NULL) {
 103                 dbg ("sysfs_open_class_device_path failed");
 104                 return -ENODEV;
 105         }
 106
 107         udev_set_values(&udev, devpath, subsystem, "add");
 108         udev_add_device(&udev, class_dev);
 109
 110         /* run scripts */
 111         dev_d_execute(&udev);
 112
 113         sysfs_close_class_device(class_dev);
 114
 115         return 0;
 116 }
 117
 118 static void exec_list(struct list_head *device_list)
 119 {
 120         struct device *loop_device;
 121         struct device *tmp_device;
 122         int i;
 123
 124         /* handle the "first" type devices first */
 125         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 126                 for (i=0; first_list[i] != NULL; i++) {
 127                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 128                                 add_device(loop_device->path, loop_device->subsys);
 129                                 list_del(&loop_device->list);
 130                                 free(loop_device);
 131                                 break;
 132                         }
 133                 }
 134         }
 135
 136         /* handle the devices we are allowed to, excluding the "last" type devices */
 137         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 138                 int found = 0;
 139                 for (i=0; last_list[i] != NULL; i++) {
 140                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 141                                 found = 1;
 142                                 break;
 143                         }
 144                 }
 145                 if (found)
 146                         continue;
 147
 148                 add_device(loop_device->path, loop_device->subsys);
 149                 list_del(&loop_device->list);
 150                 free(loop_device);
 151         }
 152
 153         /* handle the rest of the devices left over, if any */
 154         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 155                 add_device(loop_device->path, loop_device->subsys);
 156                 list_del(&loop_device->list);
 157                 free(loop_device);
 158         }
 159 }
 160
 161 static void udev_scan_block(void)
 162 {
 163         DIR *dir;
 164         struct dirent *dent;
 165         LIST_HEAD(device_list);
 166
 167         dir = opendir(SYSBLOCK);
 168         if (dir != NULL) {
 169                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 170                         char dirname[MAX_PATHLEN];
 171                         DIR *dir2;
 172                         struct dirent *dent2;
 173
 174                         if ((strcmp(dent->d_name, ".") == 0) ||
 175                             (strcmp(dent->d_name, "..") == 0))
 176                                 continue;
 177
 178                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 179                         dirname[MAX_PATHLEN-1] = '\0';
 180                         device_list_insert(dirname, "block", &device_list);
 181
 182                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 183                         dir2 = opendir(dirname);
 184                         if (dir2 != NULL) {
 185                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 186                                         char dirname2[MAX_PATHLEN];
 187                                         DIR *dir3;
 188                                         struct dirent *dent3;
 189
 190                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 191                                             (strcmp(dent2->d_name, "..") == 0))
 192                                                 continue;
 193
 194                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 195                                         dirname2[MAX_PATHLEN-1] = '\0';
 196
 197                                         dir3 = opendir(dirname2);
 198                                         if (dir3 != NULL) {
 199                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 200                                                         char filename[MAX_PATHLEN];
 201
 202                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 203                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 204                                                                          dent->d_name, dent2->d_name);
 205                                                                 filename[MAX_PATHLEN-1] = '\0';
 206                                                                 device_list_insert(filename, "block", &device_list);
 207                                                         }
 208                                                 }
 209                                                 closedir(dir3);
 210                                         }
 211                                 }
 212                                 closedir(dir2);
 213                         }
 214                 }
 215                 closedir(dir);
 216         }
 217
 218         exec_list(&device_list);
 219 }
 220
 221 static void udev_scan_class(void)
 222 {
 223         DIR *dir;
 224         struct dirent *dent;
 225         LIST_HEAD(device_list);
 226
 227         dir = opendir(SYSCLASS);
 228         if (dir != NULL) {
 229                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 230                         char dirname[MAX_PATHLEN];
 231                         DIR *dir2;
 232                         struct dirent *dent2;
 233
 234                         if ((strcmp(dent->d_name, ".") == 0) ||
 235                             (strcmp(dent->d_name, "..") == 0))
 236                                 continue;
 237
 238                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 239                         dirname[MAX_PATHLEN-1] = '\0';
 240                         dir2 = opendir(dirname);
 241                         if (dir2 != NULL) {
 242                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 243                                         char dirname2[MAX_PATHLEN];
 244                                         DIR *dir3;
 245                                         struct dirent *dent3;
 246
 247                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 248                                             (strcmp(dent2->d_name, "..") == 0))
 249                                                 continue;
 250
 251                                         /* pass the net class as it is */
 252                                         if (strcmp(dent->d_name, "net") == 0) {
 253                                                 snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
 254                                                 device_list_insert(dirname2, "net", &device_list);
 255                                                 continue;
 256                                         }
 257
 258                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 259                                         dirname2[MAX_PATHLEN-1] = '\0';
 260                                         dir3 = opendir(dirname2);
 261                                         if (dir3 != NULL) {
 262                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 263                                                         char filename[MAX_PATHLEN];
 264
 265                                                         /* pass devices with a "dev" file */
 266                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 267                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 268                                                                          dent->d_name, dent2->d_name);
 269                                                                 filename[MAX_PATHLEN-1] = '\0';
 270                                                                 device_list_insert(filename, dent->d_name, &device_list);
 271                                                                 break;
 272                                                         }
 273                                                 }
 274                                                 closedir(dir3);
 275                                         }
 276                                 }
 277                                 closedir(dir2);
 278                         }
 279                 }
 280                 closedir(dir);
 281         }
 282
 283         exec_list(&device_list);
 284 }
 285
 286 int udev_start(void)
 287 {
 288         /* set environment for callouts and dev.d/ */
 289         setenv("ACTION", "add", 1);
 290         setenv("UDEVSTART", "1", 1);
 291
 292         udev_scan_class();
 293         udev_scan_block();
 294
 295         return 0;
 296 }