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
  40
  41 #ifdef LOG
  42 unsigned char logname[LOGNAME_SIZE];
  43 void log_message(int level, const char *format, ...)
  44 {
  45         va_list args;
  46
  47         va_start(args, format);
  48         vsyslog(level, format, args);
  49         va_end(args);
  50 }
  51 #endif
  52
  53
  54 #define MAX_PATHLEN             1024
  55 #define SYSBLOCK                "/sys/block"
  56 #define SYSCLASS                "/sys/class"
  57 #define UDEV_BIN                "/sbin/udev"
  58
  59 struct device {
  60         struct list_head list;
  61         char path[MAX_PATHLEN];
  62         char subsys[MAX_PATHLEN];
  63 };
  64
  65 /* sort files in lexical order */
  66 static int device_list_insert(char *path, char *subsystem, struct list_head *device_list)
  67 {
  68         struct device *loop_device;
  69         struct device *new_device;
  70
  71         list_for_each_entry(loop_device, device_list, list) {
  72                 if (strcmp(loop_device->path, path) > 0) {
  73                         break;
  74                 }
  75         }
  76
  77         new_device = malloc(sizeof(struct device));
  78         if (new_device == NULL) {
  79                 dbg("error malloc");
  80                 return -ENOMEM;
  81         }
  82
  83         strfieldcpy(new_device->path, path);
  84         strfieldcpy(new_device->subsys, subsystem);
  85         list_add_tail(&new_device->list, &loop_device->list);
  86         return 0;
  87 }
  88
  89 static void udev_exec(const char *path, const char* subsystem)
  90 {
  91         pid_t pid;
  92         char action[] = "ACTION=add";
  93         char devpath[MAX_PATHLEN];
  94         char nosleep[] = "UDEV_NO_SLEEP=1";
  95         char *env[] = { action, devpath, nosleep, NULL };
  96
  97         return;
  98         strcpy(devpath, "DEVPATH=");
  99         strfieldcat(devpath, path);
 100
 101         pid = fork();
 102         switch (pid) {
 103         case 0:
 104                 /* child */
 105                 execle(UDEV_BIN, "udev", subsystem, NULL, env);
 106                 dbg("exec of child failed");
 107                 exit(1);
 108                 break;
 109         case -1:
 110                 dbg("fork of child failed");
 111                 break;
 112         default:
 113                 wait(NULL);
 114         }
 115 }
 116
 117 /* list of devices that we should run last due to any one of a number of reasons */
 118 static char *last_list[] = {
 119         "/block/dm",    /* on here because dm wants to have the block devices around before it */
 120         NULL,
 121 };
 122
 123 static void exec_list(struct list_head *device_list)
 124 {
 125         struct device *loop_device;
 126         struct device *tmp_device;
 127
 128         /* handle the devices we are allowed to, excluding the "last" type devices */
 129         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 130                 int found = 0;
 131                 int i;
 132                 for (i=0; last_list[i] != NULL; i++) {
 133                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 134                                 found = 1;
 135                                 break;
 136                         }
 137                 }
 138                 if (found)
 139                         continue;
 140
 141                 udev_exec(loop_device->path, loop_device->subsys);
 142                 list_del(&loop_device->list);
 143                 free(loop_device);
 144         }
 145
 146         /* handle the rest of the devices left over, if any */
 147         list_for_each_entry_safe(loop_device, tmp_device, device_list, list) {
 148                 udev_exec(loop_device->path, loop_device->subsys);
 149                 list_del(&loop_device->list);
 150                 free(loop_device);
 151         }
 152 }
 153
 154 static void udev_scan_block(void)
 155 {
 156         DIR *dir;
 157         struct dirent *dent;
 158         LIST_HEAD(device_list);
 159
 160         dir = opendir(SYSBLOCK);
 161         if (dir != NULL) {
 162                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 163                         char dirname[MAX_PATHLEN];
 164                         DIR *dir2;
 165                         struct dirent *dent2;
 166
 167                         if ((strcmp(dent->d_name, ".") == 0) ||
 168                             (strcmp(dent->d_name, "..") == 0))
 169                                 continue;
 170
 171                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 172                         dirname[MAX_PATHLEN-1] = '\0';
 173                         device_list_insert(dirname, "block", &device_list);
 174
 175                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 176                         dir2 = opendir(dirname);
 177                         if (dir2 != NULL) {
 178                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 179                                         char dirname2[MAX_PATHLEN];
 180                                         DIR *dir3;
 181                                         struct dirent *dent3;
 182
 183                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 184                                             (strcmp(dent2->d_name, "..") == 0))
 185                                                 continue;
 186
 187                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 188                                         dirname2[MAX_PATHLEN-1] = '\0';
 189
 190                                         dir3 = opendir(dirname2);
 191                                         if (dir3 != NULL) {
 192                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 193                                                         char filename[MAX_PATHLEN];
 194
 195                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 196                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 197                                                                          dent->d_name, dent2->d_name);
 198                                                                 filename[MAX_PATHLEN-1] = '\0';
 199                                                                 device_list_insert(filename, "block", &device_list);
 200                                                         }
 201                                                 }
 202                                                 closedir(dir3);
 203                                         }
 204                                 }
 205                                 closedir(dir2);
 206                         }
 207                 }
 208                 closedir(dir);
 209         }
 210
 211         exec_list(&device_list);
 212 }
 213
 214 static void udev_scan_class(void)
 215 {
 216         DIR *dir;
 217         struct dirent *dent;
 218         LIST_HEAD(device_list);
 219
 220         dir = opendir(SYSCLASS);
 221         if (dir != NULL) {
 222                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 223                         char dirname[MAX_PATHLEN];
 224                         DIR *dir2;
 225                         struct dirent *dent2;
 226
 227                         if ((strcmp(dent->d_name, ".") == 0) ||
 228                             (strcmp(dent->d_name, "..") == 0))
 229                                 continue;
 230
 231                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 232                         dirname[MAX_PATHLEN] = '\0';
 233                         dir2 = opendir(dirname);
 234                         if (dir2 != NULL) {
 235                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 236                                         char dirname2[MAX_PATHLEN-1];
 237                                         DIR *dir3;
 238                                         struct dirent *dent3;
 239
 240                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 241                                             (strcmp(dent2->d_name, "..") == 0))
 242                                                 continue;
 243
 244                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 245                                         dirname2[MAX_PATHLEN-1] = '\0';
 246
 247                                         dir3 = opendir(dirname2);
 248                                         if (dir3 != NULL) {
 249                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 250                                                         char filename[MAX_PATHLEN];
 251
 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                                                         }
 258                                                 }
 259                                                 closedir(dir3);
 260                                         }
 261                                 }
 262                                 closedir(dir2);
 263                         }
 264                 }
 265                 closedir(dir);
 266         }
 267
 268         exec_list(&device_list);
 269 }
 270
 271 int main(int argc, char *argv[], char *envp[])
 272 {
 273         init_logging("udevstart");
 274
 275         udev_scan_class();
 276         udev_scan_block();
 277
 278         return 0;
 279 }