#!/bin/bash

#
# lxc: linux Container library

# Authors:
# Daniel Lezcano <daniel.lezcano@free.fr>

# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# This library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

install_sshd()
{
    rootfs=$1

    tree="\
$rootfs/var/run/sshd \
$rootfs/var/empty/sshd \
$rootfs/var/lib/empty/sshd \
$rootfs/etc/ssh \
$rootfs/dev/shm \
$rootfs/proc \
$rootfs/bin \
$rootfs/sbin \
$rootfs/usr \
$rootfs/tmp \
$rootfs/home \
$rootfs/root \
$rootfs/lib \
$rootfs/lib64"

    mkdir -p $tree
    if [ $? -ne 0 ]; then
	return 1
    fi

    return 0
}

configure_sshd()
{
    rootfs=$1

    cat <<EOF > $rootfs/etc/passwd
root:x:0:0:root:/root:/bin/bash
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
EOF

    cat <<EOF > $rootfs/etc/group
root:x:0:root
sshd:x:74:
EOF

ssh-keygen -t rsa -f $rootfs/etc/ssh/ssh_host_rsa_key
ssh-keygen -t dsa -f $rootfs/etc/ssh/ssh_host_dsa_key

    # by default setup root password with no password
    cat <<EOF > $rootfs/etc/ssh/sshd_config
Port 22
Protocol 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
UsePrivilegeSeparation yes
KeyRegenerationInterval 3600
ServerKeyBits 768
SyslogFacility AUTH
LogLevel INFO
LoginGraceTime 120
PermitRootLogin yes
StrictModes yes
RSAAuthentication yes
PubkeyAuthentication yes
IgnoreRhosts yes
RhostsRSAAuthentication no
HostbasedAuthentication no
PermitEmptyPasswords yes
ChallengeResponseAuthentication no
EOF
    return 0
}

copy_configuration()
{
    path=$1
    rootfs=$2
    name=$3

cat <<EOF >> $path/config
lxc.utsname = $name
lxc.pts = 1024
lxc.rootfs = $rootfs
lxc.mount.entry=/dev $rootfs/dev none ro,bind 0 0
lxc.mount.entry=/lib $rootfs/lib none ro,bind 0 0
lxc.mount.entry=/bin $rootfs/bin none ro,bind 0 0
lxc.mount.entry=/usr /$rootfs/usr none ro,bind 0 0
lxc.mount.entry=/sbin $rootfs/sbin none ro,bind 0 0
lxc.mount.entry=tmpfs $rootfs/var/run/sshd tmpfs mode=0644 0 0
lxc.mount.entry=/usr/lib/lxc/templates/lxc-sshd $rootfs/sbin/init none bind 0 0
EOF

if [ "$(uname -m)" = "x86_64" ]; then
    cat <<EOF >> $path/config
lxc.mount.entry=/lib64 $rootfs/lib64 none ro,bind 0 0
EOF
fi
}

usage()
{
    cat <<EOF
$1 -h|--help -p|--path=<path>
EOF
    return 0
}

options=$(getopt -o hp:n: -l help,path:,name: -- "$@")
if [ $? -ne 0 ]; then
        usage $(basename $0)
	exit 1
fi
eval set -- "$options"

while true
do
    case "$1" in
        -h|--help)      usage $0 && exit 0;;
        -p|--path)      path=$2; shift 2;;
	-n|--name)      name=$2; shift 2;;
        --)             shift 1; break ;;
        *)              break ;;
    esac
done

if [ "$(id -u)" != "0" ]; then
    echo "This script should be run as 'root'"
    exit 1
fi

if [ $0 == "/sbin/init" ]; then

    type /usr/lib/lxc/lxc-init
    if [ $? -ne 0 ]; then
	echo "'lxc-init is not accessible on the system"
	exit 1
    fi

    type sshd
    if [ $? -ne 0 ]; then
	echo "'sshd' is not accessible on the system "
	exit 1
    fi

    exec /usr/lib/lxc/lxc-init -- /usr/sbin/sshd
    exit 1
fi

if [ -z "$path" ]; then
    echo "'path' parameter is required"
    exit 1
fi

rootfs=$path/rootfs

install_sshd $rootfs
if [ $? -ne 0 ]; then
    echo "failed to install sshd's rootfs"
    exit 1
fi

configure_sshd $rootfs
if [ $? -ne 0 ]; then
    echo "failed to configure sshd template"
    exit 1
fi

copy_configuration $path $rootfs $name
if [ $? -ne 0 ]; then
    echo "failed to write configuration file"
    exit 1
fi
