rc.mtrngd

#!/bin/bash
# start/stop/restart of the mtrngd
#

export PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin:.

# root privileges required
ID=`id -u`
if (( $? != 0 )); then ID=999; fi
if (( $ID != 0 )); then
  echo "root privileges are required for starting or stopping mtrngd."
  exit 1
fi

modprobe=/sbin/modprobe
rmmod=/sbin/rmmod
MODOPTS="rngsrc=0 rdelay=10 rawbit=0 strflt=1 fltlen=32"

# It is suggested that the kernel hwrandom source be used as it performs
# better under load and also while longhaul frequency scaling is in use.
USE_XSTORE=false
USE_MSR=false
USE_RAWBITS=false
USE_STRFILT=false
USE_BIAS=false

# NOTE: do not set EASY_FIPS unless you know exactly what you are doing!
EASY_FIPS=false


DEF_MODE="--background"
DEF_LOGDIR="/var/log/mtrngd"
DEF_STATFILE="${DEF_LOGDIR}/mtrngd.status"
DEF_LOGDIRARG="--logdir ${DEF_LOGDIR}"
DEF_RDEV="--random-device /dev/random"
DEF_ESRC="--entropy-source /dev/hwrandom"
DEF_XSTORE="--xstore"
DEF_DENSITY="--rng-density 80"
DEF_TIMEOUT="--timeout 60"
DEF_POOLSZ="--poolsize 512"
DEF_WRITEMK="--writemark 128"
DEF_STATS="--stats 600"
DEF_STATMAX="--statmax 128"
DEF_MSR="--msr"
DEF_MSRDEV="/dev/cpu/0/msr"
DEF_MSRDEVARG="--msr-device ${DEF_MSRDEV}"
DEF_FILTERSZ="--filtersz 32"
DEF_DCBIAS="--dcbias 0"
DEF_RAWBITS="--rawbits"
DEF_NSRC="--noisesrc 0"
DEF_DISABLE="--disable"
DEF_EASYFIPS="--forgiving"

OPTS="${OPTS} ${DEF_MODE}"
OPTS="${OPTS} ${DEF_LOGDIRARG}"
OPTS="${OPTS} ${DEF_RDEV}"
if [[ "$USE_XSTORE" == "true" ]]; then
  OPTS="${OPTS} ${DEF_XSTORE}"
else
  OPTS="${OPTS} ${DEF_ESRC}"
fi
OPTS="${OPTS} ${DEF_DENSITY}"
OPTS="${OPTS} ${DEF_TIMEOUT}"
OPTS="${OPTS} ${DEF_POOLSZ}"
OPTS="${OPTS} ${DEF_WRITEMK}"
OPTS="${OPTS} ${DEF_STATS}"
OPTS="${OPTS} ${DEF_STATMAX}"
if [[ "$USE_MSR" == "true" ]]; then
  OPTS="${OPTS} ${DEF_MSR}"
  OPTS="${OPTS} ${DEF_MSRDEVARG}"
fi
if [[ "$USE_RAWBITS" == "true" ]]; then
  OPTS="${OPTS} ${DEF_RAWBITS}"
fi
if [[ "$USE_BIAS" == "true" ]]; then
  OPTS="${OPTS} ${DEF_DCBIAS}"
fi
if [[ "$USE_STRFILT" == "true" ]]; then
  OPTS="${OPTS} ${DEF_FILTERSZ}"
fi
OPTS="${OPTS} ${DEF_NSRC}"
OPTS="${OPTS} ${DEF_DISABLE}"
if [[ "$EASY_FIPS" == "true" ]]; then
  OPTS="${OPTS} ${DEF_EASYFIPS}"
fi


check_paths () {
  if [ ! -d $DEF_LOGDIR ]; then
    # log directory does not exist, attempt to create it.
    mkdir -p $DEF_LOGDIR 1>/dev/null 2>&1
    if [ ! -d $DEF_LOGDIR ]; then
      echo "Error: the log directory: $DEF_LOGDIR does not exist.  Exiting."
      exit 1
    fi
  fi
  if [[ "$USE_MSR" == "true" ]]; then
    if [ ! -c $DEF_MSRDEV ]; then
      echo "Error: the MSR character device file: $DEF_MSRDEV does not exist.  Exiting."
      exit 1
    fi
  fi
}

check_modules () {
  if [[ "$USE_XSTORE" != "true" ]]; then
    grep hw_random /proc/modules 1>/dev/null 2>&1
    if (( $? != 0 )); then
      echo "Loading hw_random kernel module..."
      $modprobe hw_random $MODOPTS 1>/dev/null 2>&1
      if (( $? != 0 )); then
        echo "Unable to load the hw_random kernel module.  Exiting."
        exit 1
      fi
    fi
  fi
}

get_pid () {
  export pid=`ps -fea | grep ' mtrngd' | sed 's/ *[^ ]* *//' | sort | head -1 | sed 's/ .*//'`
  kill -0 $pid 1>/dev/null 2>&1
  if (( $? != 0 )); then
    export pid=0
  fi
}

mtrngd_start() {
  check_paths
  check_modules
  get_pid
  if (( $pid != 0 )); then
    echo "mtrngd is already running with pid: $pid"
    exit 1
  fi
  rm -f $DEF_LOGDIR/mtrngd-stats* 1>/dev/null 2>&1
  echo "starting mtrngd $OPTS"
  mtrngd $OPTS
}

mtrngd_stop() {
  get_pid
  if (( $pid != 0 )); then
    kill -TERM $pid
    get_pid
    if (( $pid != 0 )); then
      kill -9 $pid
    fi
  else
    echo "mtrngd is not running"
  fi
}

mtrngd_status() {
  get_pid
  if (( $pid == 0 )); then
    echo "mtrngd does not appear to be running."
    exit 1;
  fi
  if [ -f $DEF_STATFILE ]; then
    rm -f $DEF_STATFILE 1>/dev/null 2>/dev/null
  fi
  kill -USR1 $pid
  max=10
  for ((i=1; i <= $max ; i++)); do
    if [ -f $DEF_STATFILE ]; then
      cat $DEF_STATFILE
      exit 0;
    fi
    usleep 20000
  done
  echo "Unable to get current status.  Is mtrngd hung?"
  exit 2;
}

case "$1" in
'start')
  mtrngd_start
  ;;
'stop')
  mtrngd_stop
  ;;
'restart')
  mtrngd_stop
  mtrngd_start
  ;;
'status')
  mtrngd_status
  ;;
*)
  echo "usage $0 start|stop|restart"
esac