#
# /etc/rc.diskless - general BOOTP startup
#
#	BOOTP has mounted / for us.  Assume a read-only mount.  We must then
#	- figure out where the NFS mount is coming from
#	- figure out our IP by querying the interface
#	- retarget /conf/ME softlink to proper configuration script directory
#
#	It is expected that /etc/fstab and /etc/rc.conf.local will be
#	set by the system operator on the server to be softlinks to
#	/conf/ME/fstab and /conf/ME/rc.conf.local.  The system operator may
#	choose to retarget other files as well.  The server itself boots
#	properly with its default /conf/ME softlink pointing to 
#	/conf/server.host.name.  
#
#	During a diskless boot, we retarget the /conf/ME softlink to point
#	to /conf/DISKLESS.CLIENT.IP.ADDRESS.  Thus, various system config
#	files that are softlinks through /conf/ME also get retargeted.
#
# SEE SAMPLE FILES IN /usr/share/examples/diskless. 

# chkerr:
#
# Routine to check for error
#
#	checks error code and drops into shell on failure.
#	if shell exits, terminates script as well as /etc/rc.

chkerr() {
	if [ $1 != 0 ]; then
		echo "$2 failed: dropping into /bin/sh"
		/bin/sh
		# RESUME
	fi
}

# DEBUGGING
#
# XXX
# set -v

#  Figure out where the root mount is coming from, synthesize a mount
#  for /usr and mount it.
#
#  e.g. nfs_root might wind up as "A.B.C.D:/"
#
#  NOTE! the /usr mount is only temporary so we can access commands necessary
#  to retarget /conf/ME.  The actual /usr mount should be part of the
#  retargeted /etc/fstab.  See instructions in /usr/share/examples/diskless.
#
set `/bin/df /`
nfs_root=$8

# XXX we should extract the host part from nfs_root, but we don't have
# any good tool for string parsing yet. The ../ is a dirty hack. We
# can add more than one. But this whole section to determine the boot
# ifc etc. needs some cleanup
mount_nfs -o ro ${nfs_root}/../usr /usr

chkerr $? "mount of /usr"

#  Figure out our interface and IP.
#

bootp_ifc=`route -n get default | fgrep interface | awk '{ print $2; }'`
bootp_ipa=`ifconfig $bootp_ifc | fgrep inet | head -1 | awk '{ print $2; }'`
bootp_ipbca=`ifconfig $bootp_ifc | fgrep inet | head -1 | awk '{ print $6; }'`

echo "Interface $bootp_ifc IP-Address $bootp_ipa Broadcast $bootp_ipbca"

umount /usr

# Files in /etc are copied to /conf/etc which is writable. Then
# per-machine configs from /conf/ip.address/etc are copied onto this
# directory. First choice is using the client's IP, then the client's
# broadcast address, then a default configuration.
# This way we have some flexibility to handle clusters of machines
# on separate subnets.
#
# WARNING! null mounts cannot handle mmap, and since many programs
# use mmap (such as 'cp'), we have to copy.

mount_mfs -s 2048 -T qp120at dummy /conf/etc
cp -Rp /etc/* /conf/etc
chkerr $? "MFS mount on /conf/etc"

if [ -d /conf/$bootp_ipa ]
then
	cp -Rp /conf/$bootp_ipa/etc/* /conf/etc
elif [ -d /conf/$bootp_ipbca ]
then
	cp -Rp /conf/$bootp_ipbca/etc/* /conf/etc
else
	cp -Rp /conf/default/etc/* /conf/etc
fi

#
# Make the new directory available as /etc
#
mount_null /conf/etc /etc

# Tell /etc/rc to run the specified script after
# it does its mounts but before it does anything
# else.
#
# This script is responsible for setting up the
# diskless mount environment.  This can be 
# overriden by /conf/ME/rc.conf.local if, for
# example, you do not want to run the standard
# system /etc/rc.diskless2

diskless_mount="/etc/rc.diskless2"