#!/bin/ash
# -----------------------------------------------------------------------------
#
# Copyright (c) 2007..2018 bwLehrpool-Projektteam
#
# This program/file is free software distributed under the GPL version 2.
# See https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
#
# If you have any feedback please consult https://bwlehrpool.de and
# send your feedback to support@bwlehrpool.de.
#
# General information about bwLehrpool can be found at https://bwlehrpool.de
#
# -----------------------------------------------------------------------------
# systemd-vmchooser_env
#    - This is the preparation script for the configuration of the virtuali-
#      zation tools used later on.
#    - This creates '$VMCHOOSER_CONF_DIR/virtualization.conf' that is later
#      evaluated by the runvirt script.
################################################################################

################################################################################
### Define default dirs / get configs
################################################################################

# source config file with vars (e.g. ipaddr, macaddr, HOSTNAME)
. /opt/openslx/config

# from plugins/vmchooser/XX_vmchooser.sh
VMCHOOSER_DIR="/opt/openslx/vmchooser"
VMCHOOSER_CONF_DIR="${VMCHOOSER_DIR}/config"
VMCHOOSER_VIRT_CONF="${VMCHOOSER_CONF_DIR}/virtualization.conf"

echo "# Generated $(date)" > "$VMCHOOSER_VIRT_CONF"

# setup more scratch space for virtual machines, if configured
for DIR in /tmp/virt /var/log/samba /run/samba; do
	if ! mkdir -p "$DIR"; then
		echo "Could not create '$DIR'!"
		exit 1
	fi
done

################################################################################
echo "Determine host's hardware configuration"
################################################################################

# general machine architecture (32/64bit)
echo "HOST_ARCH=$(uname -m)" >> "${VMCHOOSER_VIRT_CONF}"

# generated mac address parts from the host's mac address
if [ -n "$SLX_PXE_MAC" ]; then
	HOSTMACADDR="${SLX_PXE_MAC}"
else ## Fallback:
	HOSTMACADDR="$(ip a | grep ether | grep -o -E -i '([0-9a-f]{2}:){5}[0-9a-f]{2}' | head -n 1)"
fi
echo "HOSTMACADDR='$HOSTMACADDR'" >> "${VMCHOOSER_VIRT_CONF}"
# NG: we define 10 fixed prefixes (00:FF:00 -> 00:FF:09) to use for VMs
# First, check if the first 3 bytes of the host's mac address is
# contained in our list. If it is, use the next one in the list.
# If not, or the host's prefix is the last one in the list, use the first one.
# This lays the groundwork to avoid mac addresses collisions in nested operations.
MACADDRPREFIX=
for i in 0 1 2 3 4 5 6 7 8; do
	if [ "x${HOSTMACADDR#00:FF:0$i}" != "x${HOSTMACADDR}" ]; then
		# current prefix is indeed part of the host's mac address
		# use the next prefix if != 9
		MACADDRPREFIX="00:FF:0$(( i + 1 ))"
		break
	fi
done
# if it is still unset, then either the host's prefix did not match any in the list
# or it matched the 9th. Either way, use the first prefix for this level of VMs.
[ -n "${MACADDRPREFIX}" ] || MACADDRPREFIX='00:FF:00'
# grab the last 2 bytes of the host's mac and prepend our VMID
# placeholder (later replaced used by run-virt).
MACADDRSUFFIX="$( printf "%s" "$HOSTMACADDR" | awk -F ":" '{print "%VMID%:" $(NF-1) ":" $NF}' | tr 'a-z' 'A-Z' )"
{ # ### stdout redirect start

	echo "MACADDRPREFIX='$MACADDRPREFIX'"
	echo "MACADDRSUFFIX='$MACADDRSUFFIX'"

	# read in ip address
	echo "HOSTIP=${SLX_PXE_CLIENT_IP}"
	# hostname
	echo "HOSTNAME='$( hostname -s )'"

	# get further hw information and check for traces of available optical and floppy drives
	j=0
	for CDROM in $(dmesg|grep -i "Attached scsi CD-ROM sr" | sed "s,.*Attached scsi CD-ROM ,,"); do
		echo "CDROM_${j}=/dev/${CDROM}"
		j="$(( j + 1 ))"
	done

	j=0
	for FLOPPY in $(dmesg|grep -i "Floppy drive"|sed "s,.*(s): ,,;s, is .*,,"); do
		echo "FLOPPY_${j}=/dev/${FLOPPY}"
		j="$(( j + 1 ))"
	done

	# Serial ports
	echo "SERIAL_PORTS='$(dmesg | grep -Eo 'ttyS[0-9]+' | sed 's,^,/dev/,' | tr '\n' ' ')'"

} >> "${VMCHOOSER_VIRT_CONF}" # ### redirect end

# Parallel ports
modprobe parport_pc

################################################################################
echo "Setup VM networking"
################################################################################

# there will be three types of network interfaces for virtual machines available
# all will be configured for every type of virtualization tool
# a) br0 is the direct host bridge into the local LAN (br0 already exists)
#    vmnet0 for VMware
#    vboxnet0 for VirtualBox
#    kvmnet0* for Qemu/KVM
# b) nat1 is an internal bridge which "NATes" into the local LAN (with DHCP)
#    vmnet1 for VMware
#    vboxnet1 for VirtualBox
#    kvmnet1* for Qemu/KVM
# c) vsw2 is an internal host bridge to connect software defined LANs to
#    vmnet2 for VMware
#    vboxnet2 for VirtualBox
#    kvmnet2* for Qemu/KVM

# creating and configuring nat0
# 192.168.101.0/24 is vm nat. If you ever change this there are a couple of other files
# where you'd need to make changes, so think twice before doing so. ;)
brctl addbr nat1
ip link set dev nat1 up
ip addr add 192.168.101.1/24 dev nat1
echo "1" >/proc/sys/net/ipv4/conf/nat1/forwarding
echo "1" >/proc/sys/net/ipv4/conf/br0/forwarding 2>/dev/null
# iptables masquerade rule is now inserted by /opt/openslx/iptables/rules.d/50-virt-nat1-masquerading

# Whitelist all additionally bridged nics for forwarding
extra=
echo "#!/bin/ash" > "/tmp/nic-forward.tmp"
for nic in /sys/class/net/br-nic-*; do
	[ -d "$nic" ] || continue
	extra=1
	echo "iptables -A FORWARD -i ${nic##*/} -j ACCEPT"
	echo "iptables -A FORWARD -o ${nic##*/} -j ACCEPT"
done >> "/tmp/nic-forward.tmp"
if [ -n "$extra" ]; then
	chmod +x "/tmp/nic-forward.tmp"
	mv "/tmp/nic-forward.tmp" "/opt/openslx/iptables/rules.d/10-forward-additional-nics"
else
	unlink "/tmp/nic-forward.tmp"
fi

# creating and configuring vsw2
brctl addbr vsw2
ip link set dev vsw2 up
echo "1" >/proc/sys/net/ipv4/conf/vsw2/forwarding

# Write proper DHCPd config for VM network
/opt/openslx/scripts/runvirt-start_dhcpd

# estimate free mem during clean boot
# TODO: Does that even make sense? We determine available memory during bootup and then blindly use
# this value to configure the VM's memory size later on. Shouldn't we query this right before starting the VM?
MEM_TOTAL="$( awk '{if ($1 == "MemAvailable:") { print $2; exit; }}' /proc/meminfo )"
[ -z "$MEM_TOTAL" ] && MEM_TOTAL=2048000
echo "HOST_MEM_TOTAL=$(( MEM_TOTAL / 1024 ))" >> "${VMCHOOSER_VIRT_CONF}"

exit 0