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 upstart_controlled start stop
  20
  21 random_seed=/var/run/random-seed
  22
  23 poolfile=/proc/sys/kernel/random/poolsize
  24 [ -r $poolfile ] && bytes="$(cat $poolfile)" || bytes=512
  25
  26 start() {
  27         # Check if the service is already running?
  28         if [ -f /var/lock/subsys/random ]; then
  29                 return
  30         fi
  31
  32         emit starting JOB=random
  33         show "Initializing random number generator"
  34         busy
  35         # Carry a random seed from start-up to start-up
  36         if [ -f $random_seed ]; then
  37                 cat $random_seed >/dev/urandom
  38         else
  39                 touch $random_seed
  40         fi
  41         chmod 600 $random_seed
  42         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  43         touch /var/lock/subsys/random
  44         deltext
  45         ok
  46         emit --nowait started JOB=random
  47 }
  48
  49 stop() {
  50         if [ ! -f /var/lock/subsys/random ]; then
  51                 return
  52         fi
  53
  54         # Carry a random seed from shut-down to start-up
  55         emit stopping JOB=random
  56         show "Saving random seed"
  57         busy
  58         touch $random_seed
  59         chmod 600 $random_seed
  60         dd if=/dev/urandom of=$random_seed count=1 bs=$bytes 2>/dev/null
  61
  62         rm -f /var/lock/subsys/random >/dev/null 2>&1
  63         deltext
  64         ok
  65         emit --no-wait stopped JOB=random
  66 }
  67
  68 status() {
  69         entropy_avail="$(cat /proc/sys/kernel/random/entropy_avail)"
  70         if [ "$entropy_avail" -eq 0 -o ! -c /dev/random ] ; then
  71                 nls "The random data source is missing"
  72                 RETVAL=1
  73         else
  74                 nls "%d bytes of entropy available" $entropy_avail
  75         fi
  76 }
  77
  78 # See how we were called.
  79 case "$1" in
  80   start)
  81         start
  82         ;;
  83   stop)
  84         stop
  85         ;;
  86   status)
  87         status
  88         ;;
  89   *)
  90         msg_usage "$0 {start|stop|status}"
  91         exit 3
  92 esac
  93
  94 exit 0