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