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 <string.h>
  27 #include <stdio.h>
  28 #include <errno.h>
  29 #include <ctype.h>
  30 #include <dirent.h>
  31 #include <sys/wait.h>
  32
  33 #include "logging.h"
  34
  35
  36 #ifdef LOG
  37 unsigned char logname[LOGNAME_SIZE];
  38 void log_message(int level, const char *format, ...)
  39 {
  40         va_list args;
  41
  42         va_start(args, format);
  43         vsyslog(level, format, args);
  44         va_end(args);
  45 }
  46 #endif
  47
  48
  49 #define MAX_PATHLEN             1024
  50 #define SYSBLOCK                "/sys/block"
  51 #define SYSCLASS                "/sys/class"
  52 #define UDEV_BIN                "/sbin/udev"
  53
  54 static void udev_exec(const char *path, const char* subsystem)
  55 {
  56         pid_t pid;
  57         char action[] = "ACTION=add";
  58         char devpath[MAX_PATHLEN];
  59         char nosleep[] = "UDEV_NO_SLEEP=1";
  60         char *env[] = { action, devpath, nosleep, NULL };
  61
  62         snprintf(devpath, MAX_PATHLEN, "DEVPATH=%s", path);
  63         devpath[MAX_PATHLEN-1] = '\0';
  64
  65         pid = fork();
  66         switch (pid) {
  67         case 0:
  68                 /* child */
  69                 execle(UDEV_BIN, "udev", subsystem, NULL, env);
  70                 dbg("exec of child failed");
  71                 exit(1);
  72                 break;
  73         case -1:
  74                 dbg("fork of child failed");
  75                 break;
  76         default:
  77                 wait(NULL);
  78         }
  79 }
  80
  81 static int udev_scan(void)
  82 {
  83         char *devpath;
  84         DIR *dir;
  85         struct dirent *dent;
  86         int retval = -EINVAL;
  87
  88         devpath = "block";
  89         dir = opendir(SYSBLOCK);
  90         if (dir != NULL) {
  91                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
  92                         char dirname[MAX_PATHLEN];
  93                         DIR *dir2;
  94                         struct dirent *dent2;
  95
  96                         if ((strcmp(dent->d_name, ".") == 0) ||
  97                             (strcmp(dent->d_name, "..") == 0))
  98                                 continue;
  99
 100                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 101                         dirname[MAX_PATHLEN-1] = '\0';
 102                         udev_exec(dirname, "block");
 103
 104                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 105                         dir2 = opendir(dirname);
 106                         if (dir2 != NULL) {
 107                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 108                                         char dirname2[MAX_PATHLEN];
 109                                         DIR *dir3;
 110                                         struct dirent *dent3;
 111
 112                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 113                                             (strcmp(dent2->d_name, "..") == 0))
 114                                                 continue;
 115
 116                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 117                                         dirname2[MAX_PATHLEN-1] = '\0';
 118
 119                                         dir3 = opendir(dirname2);
 120                                         if (dir3 != NULL) {
 121                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 122                                                         char filename[MAX_PATHLEN];
 123
 124                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 125                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 126                                                                          dent->d_name, dent2->d_name);
 127                                                                 filename[MAX_PATHLEN-1] = '\0';
 128                                                                 udev_exec(filename, "block");
 129                                                         }
 130                                                 }
 131                                         }
 132                                 }
 133                         }
 134                 }
 135         }
 136
 137         devpath = "class";
 138         dir = opendir(SYSCLASS);
 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, "%s/%s", SYSCLASS, dent->d_name);
 150                         dirname[MAX_PATHLEN] = '\0';
 151                         dir2 = opendir(dirname);
 152                         if (dir2 != NULL) {
 153                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 154                                         char dirname2[MAX_PATHLEN-1];
 155                                         DIR *dir3;
 156                                         struct dirent *dent3;
 157
 158                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 159                                             (strcmp(dent2->d_name, "..") == 0))
 160                                                 continue;
 161
 162                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 163                                         dirname2[MAX_PATHLEN-1] = '\0';
 164
 165                                         dir3 = opendir(dirname2);
 166                                         if (dir3 != NULL) {
 167                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 168                                                         char filename[MAX_PATHLEN];
 169
 170                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 171                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 172                                                                          dent->d_name, dent2->d_name);
 173                                                                 filename[MAX_PATHLEN-1] = '\0';
 174                                                                 udev_exec(filename, dent->d_name);
 175                                                         }
 176                                                 }
 177                                         }
 178                                 }
 179                         }
 180                 }
 181         }
 182
 183         if (retval > 0)
 184                 retval = 0;
 185
 186         return -retval;
 187 }
 188
 189
 190 int main(int argc, char *argv[], char *envp[])
 191 {
 192         init_logging("udevstart");
 193
 194         return udev_scan();
 195 }