#!/bin/ksh
#
# set_fin_time:
#
# Script to modify the keepalive values:
#    tcp_fin_wait_timer  - time period before connection in fin_wait2 
#			   is silently dropped.
#
# Hewlett Packard Corporation
# This script is UNSUPPORTED.  Use at own risk.
# Written:  11 October 95 	Scott Millward
#
# @(#)$Revision: 1.3 $   $Author: scotty $   $Date: 95/12/06 14:35:59 $
#
PATH=/bin:/usr/bin:/etc:.
#
# Range of accepted values
#
max_maxidle=32767		# maximum for a short.
min_maxidle=1200		# 10 minutes

#
# Default Values
#
bsdmaxidle=1200                 # 8 * 75 seconds (10 minutes)
defmaxidle=0			# default is infinite
#
#
# Temporary Dumping Ground
#
TMPFILE=/tmp/keep$$

# initialize variables
#

max=$defmaxidle

#flags

setmax=0

#misc  New for version 1.3 .. Allow for 9.X and 10.X
OS_VERSION=$(uname -r | awk -F. '{print $2}')
kernel_file="/hp-ux"
#
# Usage Subroutine
#
#
usage()
{

echo "usage: set_fin_time [-d] [-i] [-b] [-t <value>] [-help] [-p]"
exit

}

#
# Help Information Subroutine - called when -help option given
#
printhelp()
{
  echo "set_fin_time:"
  echo "  Will set the kernel's TCP FIN_WAIT_2 timer"
  echo ""
  echo "- The \"- i\" option sets the timer to infinite(0)"
  echo ""
  echo "- The \"-t\" option will set the FIN_WAIT_2 timer to the"
  echo "  specified value.  This value is in half-seconds."
  echo ""
  echo "- The \"-d\" option sets these values to their defaults."
  echo ""
  echo "- The \"-b\" option sets these values to the BSD 4.4 value (10 minutes)"
  echo ""
  echo "- The \"-help\" option prints this message."
  echo ""
  echo "- The \"- p\" option prints out the current values."
  
}

#
# Kernel value reading subroutine
#

read_values()
{

adb $kernel_file /dev/kmem << EOF > $TMPFILE
tcp_fin_wait_timer/d
EOF

vals=`cat $TMPFILE | grep tcp | awk '{if ($2 != "") printf "%d ", $2}'`

once=0
for i in $vals
do
    case $once in
	0) max_image=$i
           once=`expr $once + 1`;;
        *) echo "internal error"
    esac
done

rm $TMPFILE
}




# Begin of Program
#
# check for options

if [ $(id -u) -ne 0 ]
then
        print
        print "Sorry, you are not a super-user."
        print
        print "You must be a super-user to run this script."
        print
        exit 1
fi

if [ $OS_VERSION -lt 10 ]
then
	kernel_file="/hp-ux"
else
	kernel_file="/stand/vmunix"
fi
 

for i in $*
do
    case $i in
        -t ) shift
             setmax=1
             max=$1
             if [ $max -le $max_maxidle ]  && [ $max -ge $min_maxidle ]
             then 
                shift
             else
                echo "FIN_WAIT_2 timer, $max, is out of recommended range ( $min_maxidle to $max_maxidle ), "
		shift
		if [ $max -ge $max_maxidle+1 ]
		then
			echo "Setting FIN_WAIT_2 timer to 0 (infinite)"
			echo ""
			max=0
		else
			echo "but change will be made" 
			echo ""
		fi
             fi;;
        -d ) max=$defmaxidle
	     echo "Setting FIN_WAIT_2 timer to 0 (infinite)"
             setmax=1;;
        -b ) max=$bsdmaxidle
             setmax=1;;
        -i ) max=0
	     echo "Setting FIN_WAIT_2 timer to 0 (infinite)"
             setmax=1;;
        -p)  ;;                         #default case
        -help ) printhelp 
                exit ;;
        -* ) echo $1 is an unknown parameter
             usage;;
    esac
done
           

read_values


#
# if we are not setting values, then print out the current ones
#
if [ $setmax -eq 0 ]
then
   echo "The FIN_WAIT_2 timer is set to $max_image half seconds"
   exit
fi

#
# Set the value
#
if [ $setmax -eq 1 ]
then

# write value to kernel 

adb -w $kernel_file /dev/kmem << EOF  > /dev/null
tcp_fin_wait_timer/w 0d$max
EOF

    read_values

    if [ $max_image -eq $max ]
    then
        echo "FIN_WAIT_2 timer changed to $max half seconds."
    else
	echo "ERROR: FIN_WAIT_2 timer change failed. Timer left at $max_image"
    fi
fi