#!/bin/bash
#always have the right System.map (in /usr/src/linux), ipvsadm...
#no matter which kernel version you're running
#Joseph Mack (C) 2001 released under GPL, jmack@wm7d.net, 

#To use:
#for files/directories which are kernel version specific.
#
#eg you'll get error messages about System.map being the wrong version unless
#you have /usr/src/linux linked to the same version of linux as you booted from.
#eg in /sbin: ipvsadm-2.4.1, ipvsadm-2.2.18 which is called as /sbin/ipvsadm
#
#in main you send a list of directories/files like /usr/src/linux/, /sbin/ipvsadm
#for each item in this list, this program will
#a. delete /usr/src/linux if linux is a link, otherwise do nothing if linux is a file
#b. look for linux-x.x.x where x.x.x is the kernel version
#c. ln -s linux-x.x.x linux, else issue notice if there is no linux-x.x.x
#
#---------------------

ip_vs(){
#IPVS_VERSION is assigned the version number of IPVS currently loaded

if [ "$LINUX_KERNEL_SERIES" = "2.2" ]
then
	IPVS_VERSION=`grep "IP Virtual Server version" /proc/net/ip_masq/vs | awk '{print \$5}'`
	echo $IPVS_VERSION	

elif [ "$LINUX_KERNEL_SERIES" = "2.4" ]
then
	IPVS_VERSION=`grep "IP Virtual Server version" /proc/net/ip_vs | awk '{print \$5}'`
	echo $IPVS_VERSION	

elif [ "$LINUX_KERNEL_SERIES" = "2.6" ]
then
	IPVS_VERSION=`grep "IP Virtual Server version" /proc/net/ip_vs | awk '{print \$5}'`
	echo $IPVS_VERSION	

else
	echo "Error: kernel $UNAME_R not from 2.2 or 2.4 series"
	exit -1
fi
}

make_link(){
BASENAME=`/bin/basename $1`
#echo "BASENAME $BASENAME"

cd `/bin/dirname $1` 

#if $BASENAME a link or doesn't exist
if [ -L $BASENAME -o ! \( -e $BASENAME \) ]     
then
	#only do something if we have a target
        if [ -d $BASENAME-${UNAME_R}-${IPVS_VERSION} -o -f $BASENAME-${UNAME_R}-${IPVS_VERSION} ] 
        then
                if [ -L $BASENAME ] #if the filename is a link, delete it
                then
                        /bin/rm $BASENAME
                fi
		#there is no $BASENAME now.
        	/bin/ln -s $BASENAME-${UNAME_R}-${IPVS_VERSION} $BASENAME
        elif [ -d $BASENAME-${IPVS_VERSION}-${UNAME_R} -o -f $BASENAME-${IPVS_VERSION}-${UNAME_R} ] 
        then
                if [ -L $BASENAME ] #if the filename is a link, delete it
                then
                        /bin/rm $BASENAME
                fi
		#there is no $BASENAME now.
        	/bin/ln -s $BASENAME-${IPVS_VERSION}-${UNAME_R} $BASENAME
        elif [ -d $BASENAME-${IPVS_VERSION} -o -f $BASENAME-${IPVS_VERSION} ] 
        then
                if [ -L $BASENAME ] #if the filename is a link, delete it
                then
                        /bin/rm $BASENAME
                fi
		#there is no $BASENAME now.
        	/bin/ln -s $BASENAME-${IPVS_VERSION} $BASENAME
        elif [ -d $BASENAME-${UNAME_R} -o -f $BASENAME-${UNAME_R} ] 
        then
                if [ -L $BASENAME ] #if the filename is a link, delete it
                then
                        /bin/rm $BASENAME
                fi
		#there is no $BASENAME now.
        	/bin/ln -s $BASENAME-${UNAME_R} $BASENAME
	else
		echo "no $BASENAME-${UNAME_R} or $BASENAME-${IPVS_VERSION} to link to"
        fi
else
	echo "cannot delete $BASENAME, doesn't exist or is a regular file"
fi
cd -
}
#-----------------
#main:
echo -n "rc.system_map "
UNAME_R=`/bin/uname -r`
LINUX_KERNEL_SERIES=${UNAME_R%.*}

#when bootup, the modules (ip_vs.o) won't be loaded
#and hence there will be no /proc/net/ip_vs.
#Hence you can't tell that ip_vs has been compiled into the kernel.
#You could force the ip_vs.o module to load by running `ipvsadm`.
#However at this stage, 
#you don't know which version of ipvsadm to run.
#Punt by just loading the module

modprobe ip_vs

ip_vs
if [ $? != "0" ]
then
	echo "Error: unable to determine IPVS version"
	exit -1
fi

make_link /usr/src/linux
make_link /sbin/ipvsadm 
make_link /sbin/ipvsadm-save
make_link /sbin/ipvsadm-restore
make_link /usr/src/ipvs
make_link /boot/System.map
make_link /boot/bzImage
#make_link /bin/foo #a test, foo-x.x.x doesn't exist

#-----------------