#! /bin/bash
# pbuilder user-mode-linux hack.
# 
#   pbuilder -- personal Debian package builder
#   Copyright (C) 2001-2007 Junichi Uekawa
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
#

set -e

function cleanup_function () {
    rm -f ${INSIDE_PBUILDER}
    ${EXTRACLEANUP}
}

. /usr/lib/pbuilder/pbuilder-loadconfig

OPERATION="$1"
shift;
. /usr/lib/pbuilder/pbuilder-uml-checkparams

function usecow () {
    PBUILDER_COWFILENAME="${BUILDPLACE}/$$.cow"
    PBUILDER_COW="${PBUILDER_COWFILENAME},"
    if ! touch "${PBUILDER_COWFILENAME}"; then
	echo "E: Cannot write-access to the COW file, check buildplace" >&2 
	exit 1;
    fi
    rm -f "${PBUILDER_COWFILENAME}"
}

function cleancow () {
    # clean the cow file
    rm -f "${PBUILDER_COWFILENAME}"
}

function operate_uml () {
    # opeartes on UML, and runs pbuilder $1
    # use this script file to bootstrap the pbuilder inside the UML
    INSIDE_PBUILDER=$(tempfile)
    trap cleanup_function exit
    UML_CHROOT_MOUNTPOINT=/var/cache/pbuilder/pbuilder-mnt
    UML_CHROOT_BUILDRESULTMOUNTDIR=/var/cache/pbuilder/pbuilder-umlresult
#The following script is ran inside UML as soon as it is started.

    cat <<EOF > ${INSIDE_PBUILDER}
#! /bin/bash

###
### BEGIN CODE EXECUTED INSIDE User-mode-linux
###
### note that ${VARIABLE}s are evaluated outside of user-mode-linux.
### while \${VARIABLE}s are evaluated inside of user-mode-linux. 

${UML_DEBUGMODE}

mount -t proc /proc /proc
mount -t tmpfs /tmp /tmp

# create devices
mount -t tmpfs tmpfs /dev
mknod /dev/ubdb b 98 16
#if ! fsck -p /dev/ubdb; then
#  echo "W: Failed to fsck /dev/ubdb"
#fi
if ! mount -t ext2 /dev/ubdb ${UML_CHROOT_MOUNTPOINT}; then
  echo "E: Cannot mount /dev/ubdb, is UML root image accessible as current user?" >&2 
  exit 1
fi
mount --bind ${UML_CHROOT_MOUNTPOINT}/dev /dev

# mount /lib/modules on the hostfs
kernel_modules=\$(sed -ne 's\$.*/lib/modules.*hostfs.*defaults,ro,\([^[:space:]]*\).*\$\1\$p' ${UML_CHROOT_MOUNTPOINT}/etc/fstab)
if [ -n "\${kernel_modules}" ] ; then
	echo " -> Mount /lib/modules on the host \${kernel_modules}"
	mount -t hostfs -o ro,\${kernel_modules} hostfs /lib/modules
fi

export LOGNAME="${LOGNAME}"
export HOME="${HOME}"
hostname "${UML_HOSTNAME}"
if [ "${UML_MOUNT_TMPFS}" = "yes" ]; then
  mount -t tmpfs ${UML_CHROOT_MOUNTPOINT}/tmp ${UML_CHROOT_MOUNTPOINT}/tmp
else
  # clean up tmp before playing with it.
  rm -rf ${UML_CHROOT_MOUNTPOINT}/tmp
  mkdir ${UML_CHROOT_MOUNTPOINT}/tmp
  chmod 1777 ${UML_CHROOT_MOUNTPOINT}/tmp
fi

if [ -n "${PBUILDER_COW}" -a "${UML_IP}" != 'dhcp']; then
  cat <<IP > ${UML_CHROOT_MOUNTPOINT}/etc/network/interfaces
auto lo
iface lo inet loopback

# The first network card - this entry was created during the Debian installation
auto eth0
iface eth0 inet static
    address $UML_IP
    netmask $UML_NETMASK
    network $UML_NETWORK
    broadcast $UML_BROADCAST
    gateway $UML_GATEWAY

IP
fi

cat <<SHELL > ${UML_CHROOT_MOUNTPOINT}/tmp/chrootshell
#! /bin/bash
${UML_DEBUGMODE}
# the shell executed inside chroot inside UML
    echo Starting network inside the chroot
    mount -t proc /proc /proc
    /etc/init.d/networking stop
    /etc/init.d/networking start
    umount /proc
SHELL
chmod a+x ${UML_CHROOT_MOUNTPOINT}/tmp/chrootshell
chroot ${UML_CHROOT_MOUNTPOINT} /tmp/chrootshell

#some variables need to be set from outside values, possibly
export PATH="$PATH"
export TMPDIR=/tmp
unset EXTRAOPT || true
declare -a EXTRAOPT
if [ -n "${UML_DISTRIBUTION}" ]; then
  EXTRAOPT[0]="--distribution"
  EXTRAOPT[1]="${UML_DISTRIBUTION}"
fi
if [ -z "${UML_BUILDRESULT}" ]; then
  BUILDRESULT=
else
  echo " -> Mount build result dir outside UML [${UML_BUILDRESULT}] as [${UML_CHROOT_BUILDRESULTMOUNTDIR}]"
  BUILDRESULT=${UML_CHROOT_BUILDRESULTMOUNTDIR}
  mkdir -p ${UML_CHROOT_BUILDRESULTMOUNTDIR} || true
  mount -t hostfs none "${UML_CHROOT_BUILDRESULTMOUNTDIR}" -o "${UML_BUILDRESULT}"
fi
pbuilder "$1" ${UML_EXTRAOPT} \${EXTRAOPT[@]} --buildresult "\${BUILDRESULT}" --buildplace "${UML_CHROOT_MOUNTPOINT}" --internal-build-uml ${UML_DEBUGMODE:+--debug} ${BUILDING_DSC_FILE}  ${UML_EXECUTE_EXTRAOPT} 
echo \$? > /proc/exitcode

if [ -n "\${kernel_modules}" ] ; then
	umount /lib/modules
fi
umount /dev
umount ${UML_CHROOT_MOUNTPOINT}
/sbin/halt -d -f 

###
### END CODE EXECUTED INSIDE User-mode-linux
###
EOF

    chmod a+x ${INSIDE_PBUILDER}

    if [ $( id -u ) = 0 ]; then
	echo "W: You are uid=0. Don't run UML as uid=0, it's not supported." >&2 
    fi

    echo Invoking: "linux mem=${UML_MEM} eth0=${MY_ETH0} con0=fd:0,fd:1 con=pty root=/dev/root rootflags=/ rootfstype=hostfs ubd1=${PBUILDER_COW}${PBUILDER_UML_IMAGE} init=${INSIDE_PBUILDER} rw"
    if linux mem=${UML_MEM} eth0=${MY_ETH0} con0=fd:0,fd:1 con=pty root=/dev/root rootflags=/ rootfstype=hostfs ubd1="${PBUILDER_COW}${PBUILDER_UML_IMAGE}" devfs=mount init=${INSIDE_PBUILDER} rw ; then
	UML_EXITCODE=$?
	echo " -> Successful exit from user-mode linux"
    else
	UML_EXITCODE=$?
	echo " -> Exit code ${UML_EXITCODE}"
    fi
}




BUILDING_DSC_FILE=$(readlink -f "$1") || true # ignore failure here
EXTRACLEANUP=
UML_EXITCODE=1
case "${OPERATION}" in
    build)
	usecow
	EXTRACLEANUP=cleancow
	operate_uml build 
	;;
    update)
	operate_uml update
	;;
    login)
	if [ "${UML_LOGIN_NOCOW}" = "yes" ]; then
	    echo " -> Not using COW filesystem for login session, modifications to this session will persist"
	else
	    usecow
	    EXTRACLEANUP=cleancow
	fi
	operate_uml login
	;;
    execute)
	if [ "${UML_LOGIN_NOCOW}" = "yes" ]; then
	    echo " -> Not using COW filesystem for login session, modifications to this session will persist"
	else
	    usecow
	    EXTRACLEANUP=cleancow
	fi
	shift;
	UML_EXECUTE_EXTRAOPT="${UML_EXECUTE_EXTRAOPT} $@"
	operate_uml execute 
	;;
    dumpconfig)
	echo " -> start dump outside of UML"
	echo "  -> set"
	set;
	echo "  -> env"
	env;
	echo " -> end dump outside of UML"
	usecow
	EXTRACLEANUP=cleancow
	operate_uml dumpconfig
	;;
    create)
	if [ -n "${UML_DISTRIBUTION}" ]; then
	    if [ ! -d ~/.pbuilder-user-mode-linux ]; then
		mkdir ~/.pbuilder-user-mode-linux
	    fi
	    sed "s/dist=.*/dist=${UML_DISTRIBUTION}/" /etc/rootstrap/rootstrap.conf >  ~/.pbuilder-user-mode-linux/rootstrap.conf
	    if [ -f rootstrap.conf ]; then
		sed "s/dist=.*/dist=${UML_DISTRIBUTION}/" rootstrap.conf >  ~/.pbuilder-user-mode-linux/rootstrap.conf
	    fi
	    cd ~/.pbuilder-user-mode-linux
	fi
	rootstrap -s ${ROOTSTRAP_IMAGESIZE:=1000} ${PBUILDER_UML_IMAGE}
	operate_uml update
	;;
    *)
	echo "Error: Unknown option [${OPERATION}] was specified " >&2 
	;;
esac

exit ${UML_EXITCODE}