dev_d.c

   1 /*
   2  * dev_d.c - dev.d/ multiplexer
   3  *
   4  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  */
  10
  11 /*
  12  * This essentially emulates the following shell script logic in C:
  13  *      DIR="/etc/dev.d"
  14  *      export DEVNAME="whatever_dev_name_udev_just_gave"
  15  *      for I in "${DIR}/$DEVNAME/"*.dev "${DIR}/$1/"*.dev "${DIR}/default/"*.dev ; do
  16  *              if [ -f $I ]; then $I $1 ; fi
  17  *      done
  18  *      exit 1;
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/wait.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29
  30 #include "udev.h"
  31 #include "udev_lib.h"
  32 #include "udevdb.h"
  33 #include "logging.h"
  34
  35 static int run_program(const char *filename, void *data)
  36 {
  37         pid_t pid;
  38         int fd;
  39         struct udevice *udev = data;
  40
  41         dbg("running %s", filename);
  42
  43         pid = fork();
  44         switch (pid) {
  45         case 0:
  46                 /* child */
  47                 fd = open("/dev/null", O_RDWR);
  48                 if ( fd >= 0) {
  49                         dup2(fd, STDOUT_FILENO);
  50                         dup2(fd, STDIN_FILENO);
  51                         dup2(fd, STDERR_FILENO);
  52                 }
  53                 close(fd);
  54
  55                 execl(filename, filename, udev->subsystem, NULL);
  56                 dbg("exec of child failed");
  57                 _exit(1);
  58         case -1:
  59                 dbg("fork of child failed");
  60                 break;
  61                 return -1;
  62         default:
  63                 waitpid(pid, NULL, 0);
  64         }
  65
  66         return 0;
  67 }
  68
  69 /*
  70  * runs files in these directories in order:
  71  *      <node name given by udev>/
  72  *      subsystem/
  73  *      default/
  74  */
  75 void dev_d_execute(struct udevice *udev, const char *basedir, const char *suffix)
  76 {
  77         char dirname[PATH_MAX];
  78         char devname[NAME_SIZE];
  79         char *temp;
  80
  81         /* skip if UDEV_NO_DEVD is set */
  82         if (udev_dev_d == 0)
  83                 return;
  84
  85         strfieldcpy(devname, udev->name);
  86
  87         /* chop the device name up into pieces based on '/' */
  88         temp = strchr(devname, '/');
  89         while (temp != NULL) {
  90                 temp[0] = '\0';
  91                 snprintf(dirname, PATH_MAX, "%s/%s", basedir, devname);
  92                 dirname[PATH_MAX-1] = '\0';
  93                 call_foreach_file(run_program, dirname, suffix, udev);
  94
  95                 temp[0] = '/';
  96                 ++temp;
  97                 temp = strchr(temp, '/');
  98         }
  99
 100         snprintf(dirname, PATH_MAX, "%s/%s", basedir, udev->name);
 101         dirname[PATH_MAX-1] = '\0';
 102         call_foreach_file(run_program, dirname, suffix, udev);
 103
 104         snprintf(dirname, PATH_MAX, "%s/%s", basedir, udev->subsystem);
 105         dirname[PATH_MAX-1] = '\0';
 106         call_foreach_file(run_program, dirname, suffix, udev);
 107
 108         snprintf(dirname, PATH_MAX, "%s/default", basedir);
 109         dirname[PATH_MAX-1] = '\0';
 110         call_foreach_file(run_program, dirname, suffix, udev);
 111 }