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 add_device(char *path, char *subsys, int fake)
  90 {
  91         char *argv[3];
  92
  93         /* fake argument vector and environment for callouts and dev.d/ */
  94         argv[0] = "udev";
  95         argv[1] = subsys;
  96         argv[2] = NULL;
  97
  98         main_argv = argv;
  99         setenv("DEVPATH", path, 1);
 100         setenv("ACTION", "add", 1);
 101         udev_add_device(path, subsys, fake);
 102 }
 103
 104 static void exec_list(struct list_head *device_list)
 105 {
 106         struct device *loop_device;
 107         struct device *tmp_device;
 108         int i;
 109
 110         /* handle the "first" type devices first */
 111         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 112                 for (i=0; first_list[i] != NULL; i++) {
 113                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 114                                 add_device(loop_device->path, loop_device->subsys, NOFAKE);
 115                                 list_del(&loop_device->list);
 116                                 free(loop_device);
 117                                 break;
 118                         }
 119                 }
 120         }
 121
 122         /* handle the devices we are allowed to, excluding the "last" type devices */
 123         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 124                 int found = 0;
 125                 for (i=0; last_list[i] != NULL; i++) {
 126                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 127                                 found = 1;
 128                                 break;
 129                         }
 130                 }
 131                 if (found)
 132                         continue;
 133
 134                 add_device(loop_device->path, loop_device->subsys, NOFAKE);
 135                 list_del(&loop_device->list);
 136                 free(loop_device);
 137         }
 138
 139         /* handle the rest of the devices left over, if any */
 140         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 141                 add_device(loop_device->path, loop_device->subsys, NOFAKE);
 142                 list_del(&loop_device->list);
 143                 free(loop_device);
 144         }
 145 }
 146
 147 static void udev_scan_block(void)
 148 {
 149         DIR *dir;
 150         struct dirent *dent;
 151         LIST_HEAD(device_list);
 152
 153         dir = opendir(SYSBLOCK);
 154         if (dir != NULL) {
 155                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 156                         char dirname[MAX_PATHLEN];
 157                         DIR *dir2;
 158                         struct dirent *dent2;
 159
 160                         if ((strcmp(dent->d_name, ".") == 0) ||
 161                             (strcmp(dent->d_name, "..") == 0))
 162                                 continue;
 163
 164                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 165                         dirname[MAX_PATHLEN-1] = '\0';
 166                         device_list_insert(dirname, "block", &device_list);
 167
 168                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 169                         dir2 = opendir(dirname);
 170                         if (dir2 != NULL) {
 171                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 172                                         char dirname2[MAX_PATHLEN];
 173                                         DIR *dir3;
 174                                         struct dirent *dent3;
 175
 176                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 177                                             (strcmp(dent2->d_name, "..") == 0))
 178                                                 continue;
 179
 180                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 181                                         dirname2[MAX_PATHLEN-1] = '\0';
 182
 183                                         dir3 = opendir(dirname2);
 184                                         if (dir3 != NULL) {
 185                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 186                                                         char filename[MAX_PATHLEN];
 187
 188                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 189                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 190                                                                          dent->d_name, dent2->d_name);
 191                                                                 filename[MAX_PATHLEN-1] = '\0';
 192                                                                 device_list_insert(filename, "block", &device_list);
 193                                                         }
 194                                                 }
 195                                                 closedir(dir3);
 196                                         }
 197                                 }
 198                                 closedir(dir2);
 199                         }
 200                 }
 201                 closedir(dir);
 202         }
 203
 204         exec_list(&device_list);
 205 }
 206
 207 static void udev_scan_class(void)
 208 {
 209         DIR *dir;
 210         struct dirent *dent;
 211         LIST_HEAD(device_list);
 212
 213         dir = opendir(SYSCLASS);
 214         if (dir != NULL) {
 215                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 216                         char dirname[MAX_PATHLEN];
 217                         DIR *dir2;
 218                         struct dirent *dent2;
 219
 220                         if ((strcmp(dent->d_name, ".") == 0) ||
 221                             (strcmp(dent->d_name, "..") == 0))
 222                                 continue;
 223
 224                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 225                         dirname[MAX_PATHLEN-1] = '\0';
 226                         dir2 = opendir(dirname);
 227                         if (dir2 != NULL) {
 228                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 229                                         char dirname2[MAX_PATHLEN];
 230                                         DIR *dir3;
 231                                         struct dirent *dent3;
 232
 233                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 234                                             (strcmp(dent2->d_name, "..") == 0))
 235                                                 continue;
 236
 237                                         /* pass the net class as it is */
 238                                         if (strcmp(dent->d_name, "net") == 0) {
 239                                                 snprintf(dirname2, MAX_PATHLEN, "/class/net/%s", dent2->d_name);
 240                                                 device_list_insert(dirname2, "net", &device_list);
 241                                                 continue;
 242                                         }
 243
 244                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 245                                         dirname2[MAX_PATHLEN-1] = '\0';
 246                                         dir3 = opendir(dirname2);
 247                                         if (dir3 != NULL) {
 248                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 249                                                         char filename[MAX_PATHLEN];
 250
 251                                                         /* pass devices with a "dev" file */
 252                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 253                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 254                                                                          dent->d_name, dent2->d_name);
 255                                                                 filename[MAX_PATHLEN-1] = '\0';
 256                                                                 device_list_insert(filename, dent->d_name, &device_list);
 257                                                                 break;
 258                                                         }
 259                                                 }
 260                                                 closedir(dir3);
 261                                         }
 262                                 }
 263                                 closedir(dir2);
 264                         }
 265                 }
 266                 closedir(dir);
 267         }
 268
 269         exec_list(&device_list);
 270 }
 271
 272 int udev_start(void)
 273 {
 274         udev_scan_class();
 275         udev_scan_block();
 276         return 0;
 277 }