rc.d/init.d/random

   1 #!/bin/sh
   2 #
   3 # random        Script to snapshot random state and reload it at boot time.
   4 #
   5 # chkconfig:    12345 20 80
   6 #
   7 # description:  Saves and restores system entropy pool for higher quality \
   8 #               random number generation.
   9 #
  10 # $Id$
  11
  12 # Source function library.
  13 . /etc/rc.d/init.d/functions
  14
  15 # do nothing in vserver
  16 if is_yes "$VSERVER"; then
  17         return
  18 fi
  19
  20 upstart_controlled start stop
  21
  22 random_seed=/var/run/random-seed
  23
  24 poolfile=/proc/sys/kernel/random/poolsize
  25 [ -r $poolfile ] && bytes="$(cat $poolfile)" || bytes=512
  26
  27 start() {
  28         # Check if the service is already running?
  29         if [ -f /var/lock/subsys/random ]; then
  30                 return
  31         fi
  32
  33         emit starting JOB=random
  34         show "Initializing random number generator"
  35         busy
  36         # Carry a random seed from start-up to start-up
  37         if [ -f $random_seed ]; then
  38                 cat $random_seed >/dev/urandom
  39         else
  40                 touch $random_seed
  41         fi
  42         chmod 600 $random_seed
  43         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  44         touch /var/lock/subsys/random
  45         deltext
  46         ok
  47         emit --nowait started JOB=random
  48 }
  49
  50 stop() {
  51         if [ ! -f /var/lock/subsys/random ]; then
  52                 return
  53         fi
  54
  55         # Carry a random seed from shut-down to start-up
  56         emit stopping JOB=random
  57         show "Saving random seed"
  58         busy
  59         touch $random_seed
  60         chmod 600 $random_seed
  61         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  62
  63         rm -f /var/lock/subsys/random >/dev/null 2>&1
  64         deltext
  65         ok
  66         emit --no-wait stopped JOB=random
  67 }
  68
  69 status() {
  70         entropy_avail="$(cat /proc/sys/kernel/random/entropy_avail)"
  71         if [ "$entropy_avail" -eq 0 -o ! -c /dev/random ] ; then
  72                 nls "The random data source is missing"
  73                 RETVAL=1
  74         else
  75                 nls "%d bytes of entropy available" $entropy_avail
  76         fi
  77 }
  78
  79 # See how we were called.
  80 case "$1" in
  81   start)
  82         start
  83         ;;
  84   stop)
  85         stop
  86         ;;
  87   status)
  88         status
  89         ;;
  90   *)
  91         msg_usage "$0 {start|stop|status}"
  92         exit 3
  93 esac
  94
  95 exit 0