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(char *name)
  39 {
  40         pid_t pid;
  41         int fd;
  42         char *argv[3];
  43
  44         dbg("running %s", name);
  45
  46         pid = fork();
  47         switch (pid) {
  48         case 0:
  49                 /* child */
  50                 udevdb_exit();  /* close udevdb */
  51                 fd = open("/dev/null", O_RDWR);
  52                 if ( fd >= 0) {
  53                         dup2(fd, STDOUT_FILENO);
  54                         dup2(fd, STDIN_FILENO);
  55                         dup2(fd, STDERR_FILENO);
  56                 }
  57                 close(fd);
  58
  59                 argv[0] = name;
  60                 argv[1] = main_argv[1];
  61                 argv[2] = NULL;
  62
  63                 execv(name, argv);
  64                 dbg("exec of child failed");
  65                 _exit(1);
  66         case -1:
  67                 dbg("fork of child failed");
  68                 break;
  69                 return -1;
  70         default:
  71                 wait(NULL);
  72         }
  73
  74         return 0;
  75 }
  76
  77 /*
  78  * runs files in these directories in order:
  79  *      <node name given by udev>/
  80  *      subsystem/
  81  *      default/
  82  */
  83 void dev_d_execute(struct udevice *udev)
  84 {
  85         char dirname[PATH_MAX];
  86         char devname[NAME_SIZE];
  87         char *temp;
  88
  89         /* skip if UDEV_NO_DEVD is set */
  90         if (udev_dev_d == 0)
  91                 return;
  92
  93         /* skip if udev did nothing, like unchanged netif or no "dev" file */
  94         if (udev->devname[0] == '\0')
  95                 return;
  96
  97         /* add the node name or the netif name to the environment */
  98         setenv("DEVNAME", udev->devname, 1);
  99         dbg("DEVNAME='%s'", udev->devname);
 100
 101         strfieldcpy(devname, udev->name);
 102
 103         /* Chop the device name up into pieces based on '/' */
 104         temp = strchr(devname, '/');
 105         while (temp != NULL) {
 106                 temp[0] = '\0';
 107                 strcpy(dirname, DEVD_DIR);
 108                 strfieldcat(dirname, devname);
 109                 call_foreach_file(run_program, dirname, DEVD_SUFFIX);
 110
 111                 temp[0] = '/';
 112                 ++temp;
 113                 temp = strchr(temp, '/');
 114         }
 115
 116         strcpy(dirname, DEVD_DIR);
 117         strfieldcat(dirname, udev->name);
 118         call_foreach_file(run_program, dirname, DEVD_SUFFIX);
 119
 120         strcpy(dirname, DEVD_DIR);
 121         strfieldcat(dirname, udev->subsystem);
 122         call_foreach_file(run_program, dirname, DEVD_SUFFIX);
 123
 124         strcpy(dirname, DEVD_DIR "default");
 125         call_foreach_file(run_program, dirname, DEVD_SUFFIX);
 126 }