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
  11 # Source function library.
  12 . /etc/rc.d/init.d/functions
  13
  14 # do nothing in vserver
  15 if is_yes "$VSERVER"; then
  16         return
  17 fi
  18
  19 random_seed=/var/run/random-seed
  20
  21 poolfile=/proc/sys/kernel/random/poolsize
  22 [ -r $poolfile ] && bytes="$(cat $poolfile)" || bytes=512
  23
  24 start() {
  25         # Check if the service is already running?
  26         if [ -f /var/lock/subsys/random ]; then
  27                 return
  28         fi
  29
  30         show "Initializing random number generator"
  31         busy
  32         # Carry a random seed from start-up to start-up
  33         if [ -f $random_seed ]; then
  34                 cat $random_seed >/dev/urandom
  35         else
  36                 touch $random_seed
  37         fi
  38         chmod 600 $random_seed
  39         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  40         touch /var/lock/subsys/random
  41         deltext
  42         ok
  43 }
  44
  45 stop() {
  46         if [ ! -f /var/lock/subsys/random ]; then
  47                 return
  48         fi
  49
  50         # Carry a random seed from shut-down to start-up
  51         show "Saving random seed"
  52         busy
  53         touch $random_seed
  54         chmod 600 $random_seed
  55         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  56
  57         rm -f /var/lock/subsys/random >/dev/null 2>&1
  58         deltext
  59         ok
  60 }
  61
  62 status() {
  63         entropy_avail="$(cat /proc/sys/kernel/random/entropy_avail)"
  64         if [ "$entropy_avail" -eq 0 -o ! -c /dev/random ] ; then
  65                 nls "The random data source is missing"
  66                 RETVAL=1
  67         else
  68                 nls "%d bytes of entropy available" $entropy_avail
  69         fi
  70 }
  71
  72 # See how we were called.
  73 case "$1" in
  74   start)
  75         start
  76         ;;
  77   stop)
  78         stop
  79         ;;
  80   status)
  81         status
  82         ;;
  83   *)
  84         msg_usage "$0 {start|stop|status}"
  85         exit 3
  86 esac
  87
  88 exit 0