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 #define DEVD_DIR                        "/etc/dev.d/"
  36 #define DEVD_SUFFIX                     ".dev"
  37
  38 static int run_program(const char *filename, void *data)
  39 {
  40         pid_t pid;
  41         int fd;
  42         struct udevice *udev = data;
  43
  44         dbg("running %s", filename);
  45
  46         pid = fork();
  47         switch (pid) {
  48         case 0:
  49                 /* child */
  50                 fd = open("/dev/null", O_RDWR);
  51                 if ( fd >= 0) {
  52                         dup2(fd, STDOUT_FILENO);
  53                         dup2(fd, STDIN_FILENO);
  54                         dup2(fd, STDERR_FILENO);
  55                 }
  56                 close(fd);
  57
  58                 execl(filename, filename, udev->subsystem, NULL);
  59                 dbg("exec of child failed");
  60                 _exit(1);
  61         case -1:
  62                 dbg("fork of child failed");
  63                 break;
  64                 return -1;
  65         default:
  66                 waitpid(pid, NULL, 0);
  67         }
  68
  69         return 0;
  70 }
  71
  72 /*
  73  * runs files in these directories in order:
  74  *      <node name given by udev>/
  75  *      subsystem/
  76  *      default/
  77  */
  78 void dev_d_execute(struct udevice *udev)
  79 {
  80         char dirname[PATH_MAX];
  81         char devname[NAME_SIZE];
  82         char *temp;
  83
  84         /* skip if UDEV_NO_DEVD is set */
  85         if (udev_dev_d == 0)
  86                 return;
  87
  88         /* skip if udev did nothing, like unchanged netif or no "dev" file */
  89         if (udev->devname[0] == '\0')
  90                 return;
  91
  92         /* add the node name or the netif name to the environment */
  93         setenv("DEVNAME", udev->devname, 1);
  94         dbg("DEVNAME='%s'", udev->devname);
  95
  96         strfieldcpy(devname, udev->name);
  97
  98         /* Chop the device name up into pieces based on '/' */
  99         temp = strchr(devname, '/');
 100         while (temp != NULL) {
 101                 temp[0] = '\0';
 102                 strcpy(dirname, DEVD_DIR);
 103                 strfieldcat(dirname, devname);
 104                 call_foreach_file(run_program, dirname, DEVD_SUFFIX, udev);
 105
 106                 temp[0] = '/';
 107                 ++temp;
 108                 temp = strchr(temp, '/');
 109         }
 110
 111         strcpy(dirname, DEVD_DIR);
 112         strfieldcat(dirname, udev->name);
 113         call_foreach_file(run_program, dirname, DEVD_SUFFIX, udev);
 114
 115         strcpy(dirname, DEVD_DIR);
 116         strfieldcat(dirname, udev->subsystem);
 117         call_foreach_file(run_program, dirname, DEVD_SUFFIX, udev);
 118
 119         strcpy(dirname, DEVD_DIR "default");
 120         call_foreach_file(run_program, dirname, DEVD_SUFFIX, udev);
 121 }