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 #include <sys/types.h>
  33 #include <unistd.h>
  34
  35 #include "logging.h"
  36 #include "udev_lib.h"
  37
  38
  39 #ifdef LOG
  40 unsigned char logname[LOGNAME_SIZE];
  41 void log_message(int level, const char *format, ...)
  42 {
  43         va_list args;
  44
  45         va_start(args, format);
  46         vsyslog(level, format, args);
  47         va_end(args);
  48 }
  49 #endif
  50
  51
  52 #define MAX_PATHLEN             1024
  53 #define SYSBLOCK                "/sys/block"
  54 #define SYSCLASS                "/sys/class"
  55 #define UDEV_BIN                "/sbin/udev"
  56
  57 static void udev_exec(const char *path, const char* subsystem)
  58 {
  59         pid_t pid;
  60         char action[] = "ACTION=add";
  61         char devpath[MAX_PATHLEN];
  62         char nosleep[] = "UDEV_NO_SLEEP=1";
  63         char *env[] = { action, devpath, nosleep, NULL };
  64
  65         strcpy(devpath, "DEVPATH=");
  66         strfieldcat(devpath, path);
  67
  68         pid = fork();
  69         switch (pid) {
  70         case 0:
  71                 /* child */
  72                 execle(UDEV_BIN, "udev", subsystem, NULL, env);
  73                 dbg("exec of child failed");
  74                 exit(1);
  75                 break;
  76         case -1:
  77                 dbg("fork of child failed");
  78                 break;
  79         default:
  80                 wait(NULL);
  81         }
  82 }
  83
  84 static void udev_scan(void)
  85 {
  86         char *devpath;
  87         DIR *dir;
  88         struct dirent *dent;
  89
  90         /*
  91          * We want to scan the class tree first as lvm and dm needs to be able
  92          * to have access to the char control device when probing the block
  93          * devices.
  94          */
  95         devpath = "class";
  96         dir = opendir(SYSCLASS);
  97         if (dir != NULL) {
  98                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
  99                         char dirname[MAX_PATHLEN];
 100                         DIR *dir2;
 101                         struct dirent *dent2;
 102
 103                         if ((strcmp(dent->d_name, ".") == 0) ||
 104                             (strcmp(dent->d_name, "..") == 0))
 105                                 continue;
 106
 107                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSCLASS, dent->d_name);
 108                         dirname[MAX_PATHLEN] = '\0';
 109                         dir2 = opendir(dirname);
 110                         if (dir2 != NULL) {
 111                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 112                                         char dirname2[MAX_PATHLEN-1];
 113                                         DIR *dir3;
 114                                         struct dirent *dent3;
 115
 116                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 117                                             (strcmp(dent2->d_name, "..") == 0))
 118                                                 continue;
 119
 120                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 121                                         dirname2[MAX_PATHLEN-1] = '\0';
 122
 123                                         dir3 = opendir(dirname2);
 124                                         if (dir3 != NULL) {
 125                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 126                                                         char filename[MAX_PATHLEN];
 127
 128                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 129                                                                 snprintf(filename, MAX_PATHLEN, "/class/%s/%s",
 130                                                                          dent->d_name, dent2->d_name);
 131                                                                 filename[MAX_PATHLEN-1] = '\0';
 132                                                                 udev_exec(filename, dent->d_name);
 133                                                         }
 134                                                 }
 135                                                 closedir(dir3);
 136                                         }
 137                                 }
 138                                 closedir(dir2);
 139                         }
 140                 }
 141                 closedir(dir);
 142         }
 143
 144         devpath = "block";
 145         dir = opendir(SYSBLOCK);
 146         if (dir != NULL) {
 147                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 148                         char dirname[MAX_PATHLEN];
 149                         DIR *dir2;
 150                         struct dirent *dent2;
 151
 152                         if ((strcmp(dent->d_name, ".") == 0) ||
 153                             (strcmp(dent->d_name, "..") == 0))
 154                                 continue;
 155
 156                         snprintf(dirname, MAX_PATHLEN, "/block/%s", dent->d_name);
 157                         dirname[MAX_PATHLEN-1] = '\0';
 158                         udev_exec(dirname, "block");
 159
 160                         snprintf(dirname, MAX_PATHLEN, "%s/%s", SYSBLOCK, dent->d_name);
 161                         dir2 = opendir(dirname);
 162                         if (dir2 != NULL) {
 163                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 164                                         char dirname2[MAX_PATHLEN];
 165                                         DIR *dir3;
 166                                         struct dirent *dent3;
 167
 168                                         if ((strcmp(dent2->d_name, ".") == 0) ||
 169                                             (strcmp(dent2->d_name, "..") == 0))
 170                                                 continue;
 171
 172                                         snprintf(dirname2, MAX_PATHLEN, "%s/%s", dirname, dent2->d_name);
 173                                         dirname2[MAX_PATHLEN-1] = '\0';
 174
 175                                         dir3 = opendir(dirname2);
 176                                         if (dir3 != NULL) {
 177                                                 for (dent3 = readdir(dir3); dent3 != NULL; dent3 = readdir(dir3)) {
 178                                                         char filename[MAX_PATHLEN];
 179
 180                                                         if (strcmp(dent3->d_name, "dev") == 0) {
 181                                                                 snprintf(filename, MAX_PATHLEN, "/block/%s/%s",
 182                                                                          dent->d_name, dent2->d_name);
 183                                                                 filename[MAX_PATHLEN-1] = '\0';
 184                                                                 udev_exec(filename, "block");
 185                                                         }
 186                                                 }
 187                                                 closedir(dir3);
 188                                         }
 189                                 }
 190                                 closedir(dir2);
 191                         }
 192                 }
 193                 closedir(dir);
 194         }
 195 }
 196
 197 int main(int argc, char *argv[], char *envp[])
 198 {
 199         init_logging("udevstart");
 200
 201         udev_scan();
 202
 203         return 0;
 204 }