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/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, "%s%s", sysfs_path, devpath);
 101         path[SYSFS_PATH_MAX-1] = '\0';
 102         class_dev = sysfs_open_class_device_path(path);
 103         if (class_dev == NULL) {
 104                 dbg ("sysfs_open_class_device_path failed");
 105                 return -ENODEV;
 106         }
 107
 108         udev_set_values(&udev, devpath, subsystem, "add");
 109         udev_add_device(&udev, class_dev);
 110
 111         /* run dev.d/ scripts if we created a node or changed a netif name */
 112         if (udev.devname[0] != '\0') {
 113                 setenv("DEVNAME", udev.devname, 1);
 114                 dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
 115         }
 116
 117         sysfs_close_class_device(class_dev);
 118
 119         return 0;
 120 }
 121
 122 static void exec_list(struct list_head *device_list)
 123 {
 124         struct device *loop_device;
 125         struct device *tmp_device;
 126         int i;
 127
 128         /* handle the "first" type devices first */
 129         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 130                 for (i=0; first_list[i] != NULL; i++) {
 131                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 132                                 add_device(loop_device->path, loop_device->subsys);
 133                                 list_del(&loop_device->list);
 134                                 free(loop_device);
 135                                 break;
 136                         }
 137                 }
 138         }
 139
 140         /* handle the devices we are allowed to, excluding the "last" type devices */
 141         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 142                 int found = 0;
 143                 for (i=0; last_list[i] != NULL; i++) {
 144                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 145                                 found = 1;
 146                                 break;
 147                         }
 148                 }
 149                 if (found)
 150                         continue;
 151
 152                 add_device(loop_device->path, loop_device->subsys);
 153                 list_del(&loop_device->list);
 154                 free(loop_device);
 155         }
 156
 157         /* handle the rest of the devices left over, if any */
 158         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 159                 add_device(loop_device->path, loop_device->subsys);
 160                 list_del(&loop_device->list);
 161                 free(loop_device);
 162         }
 163 }
 164
 165 static void udev_scan_block(void)
 166 {
 167         DIR *dir;
 168         struct dirent *dent;
 169         LIST_HEAD(device_list);
 170
 171         dir = opendir(SYSBLOCK);
 172         if (dir != NULL) {
 173                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 174                         char dirname[MAX_PATHLEN];
 175                         DIR *dir2;
 176                         struct dirent *dent2;
 177
 178                         if ((strcmp(dent->d_name, ".") == 0) ||
 179                             (strcmp(dent->d_name, "..") == 0))
 180                                 continue;
 181
 182                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 183                         dirname[MAX_PATHLEN-1] = '\0';
 184                         device_list_insert(dirname, "block", &device_list);
 185
 186                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 187                         dir2 = opendir(dirname);
 188                         if (dir2 != NULL) {
 189                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 190                                         char dirname2[MAX_PATHLEN];
 191                                         DIR *dir3;
 192                                         struct dirent *dent3;
 193
 194                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 195                                             (strcmp(dent2->d_name, "..") == 0))
 196                                                 continue;
 197
 198                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 199                                         dirname2[MAX_PATHLEN-1] = '\0';
 200
 201                                         dir3 = opendir(dirname2);
 202                                         if (dir3 != NULL) {
 203                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 204                                                         char filename[MAX_PATHLEN];
 205
 206                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 207                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 208                                                                          dent->d_name, dent2->d_name);
 209                                                                 filename[MAX_PATHLEN-1] = '\0';
 210                                                                 device_list_insert(filename, "block", &device_list);
 211                                                         }
 212                                                 }
 213                                                 closedir(dir3);
 214                                         }
 215                                 }
 216                                 closedir(dir2);
 217                         }
 218                 }
 219                 closedir(dir);
 220         }
 221
 222         exec_list(&device_list);
 223 }
 224
 225 static void udev_scan_class(void)
 226 {
 227         DIR *dir;
 228         struct dirent *dent;
 229         LIST_HEAD(device_list);
 230
 231         dir = opendir(SYSCLASS);
 232         if (dir != NULL) {
 233                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 234                         char dirname[MAX_PATHLEN];
 235                         DIR *dir2;
 236                         struct dirent *dent2;
 237
 238                         if ((strcmp(dent->d_name, ".") == 0) ||
 239                             (strcmp(dent->d_name, "..") == 0))
 240                                 continue;
 241
 242                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 243                         dirname[MAX_PATHLEN-1] = '\0';
 244                         dir2 = opendir(dirname);
 245                         if (dir2 != NULL) {
 246                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 247                                         char dirname2[MAX_PATHLEN];
 248                                         DIR *dir3;
 249                                         struct dirent *dent3;
 250
 251                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 252                                             (strcmp(dent2->d_name, "..") == 0))
 253                                                 continue;
 254
 255                                         /* pass the net class as it is */
 256                                         if (strcmp(dent->d_name, "net") == 0) {
 257                                                 snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
 258                                                 device_list_insert(dirname2, "net", &device_list);
 259                                                 continue;
 260                                         }
 261
 262                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 263                                         dirname2[MAX_PATHLEN-1] = '\0';
 264                                         dir3 = opendir(dirname2);
 265                                         if (dir3 != NULL) {
 266                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 267                                                         char filename[MAX_PATHLEN];
 268
 269                                                         /* pass devices with a "dev" file */
 270                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 271                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 272                                                                          dent->d_name, dent2->d_name);
 273                                                                 filename[MAX_PATHLEN-1] = '\0';
 274                                                                 device_list_insert(filename, dent->d_name, &device_list);
 275                                                                 break;
 276                                                         }
 277                                                 }
 278                                                 closedir(dir3);
 279                                         }
 280                                 }
 281                                 closedir(dir2);
 282                         }
 283                 }
 284                 closedir(dir);
 285         }
 286
 287         exec_list(&device_list);
 288 }
 289
 290 int udev_start(void)
 291 {
 292         /* set environment for callouts and dev.d/ */
 293         setenv("ACTION", "add", 1);
 294         setenv("UDEVSTART", "1", 1);
 295
 296         udev_scan_class();
 297         udev_scan_block();
 298
 299         return 0;
 300 }