#!/bin/sh
#
# Generate s6 network definitions

set -ex

header_eb() {
	echo '#!/bin/execlineb -P'
}

header_if() {
	local if="${1:?missing if}"
	echo "define INTERFACE $if"
}

header_addr() {
	local addr="${1:?missing addr}"
	echo "define ADDR $addr"
}

header_fam() {
	local fam="${1:?missing family}"
	echo "define FAMILY $fam"
}

header_vlan() {
	local vlan="${1:?missing vlan}"
	local parent="${2:?missing parent}"
	echo "define VLAN $vlan"
	echo "define PARENT $parent"
}

header_vrf() {
	local vrf="${1:?missing vrf}"
	echo "define VRF $vrf"
}

header_prop() {
	local prop="${1:?missing prop}"
	echo "define PROP $prop"
}

header_path() {
	cat <<EOF
s6-envdir -i /etc/s6/env/path
emptyenv -p
EOF
}

addrfam() {
	# Use ipv6 if cannot autodetect of if no semicolons are present
	local addr="$1"
	local fam='6'
	if which grep >/dev/null 2>&1 && echo "$addr" | grep -v ':' >/dev/null 2>&1; then
		fam='4'
	fi
	echo "$fam"
}

linkdel() {
	local if="${1:?missing if}"
	header_eb
	header_path
	header_if "$if"
	echo 'ip link del $INTERFACE'
}

depends() {
	echo "$@"
	local svcname="${1:?missing sname}"

	shift 1
	local sname # God i fucking hate global contexts by default
	for sname in $@; do
		install -Dm644 /dev/null rc/"$svcname"/dependencies.d/"$sname"
	done
}

contains() {
	local svcname="${1:?missing sname}"

	shift 1
	local sname # God i fucking hate global contexts by default
	for sname in $@; do
		install -Dm644 /dev/null rc/"$svcname"/contents.d/"$sname"
	done
}

#
# Bundle management
#

bundle_deps() {
	local if="${1:?missing if}"

	local svcname="bundle.interface.$if"
	[ -r "rc/$svcname/type" ] || install -Dm644 <(echo bundle) rc/"$svcname"/type

	shift 1
	contains "$svcname" $@
}

# Currently used stages
# > configure
#   - create
#   - enslave
#   - configure (anything that must be configured before interface is up)
# > ready
#   - link
#   - configure (anything that may be configured after interface is up)
bundle_stage_create() {
	local if="${1:?missing if}"
	local stage="${2:?missing stage}"

	local svcname="bundle.interface.$if.$stage"
	[ -r "rc/$svcname/type" ] || install -Dm644 <(echo bundle) rc/"$svcname"/type

	# Add to parent bundle
	bundle_deps "$if" "$svcname"

	shift 2
	contains "$svcname" $@
}

bundle_stage_depend_on() {
	local if="${1:?missing if}"
	local stage="${2:?missing stage}"

	local svcname="bundle.interface.$if.$stage"

	shift 2
	local sname
	for sname in $@; do
		depends "$sname" "$svcname"
	done
}

bundle_stage_step_configure() {
	local if="$1"
	local stage="configure"

	shift 1
	bundle_stage_create "$if" "$stage" $@
}

bundle_stage_step_ready() {
	local if="$1"
	local stage="ready"

	shift 1
	bundle_stage_create "$if" "$stage" $@
}

#
# Interface creation
#

new_link() {
	local if="${1:?missing if}"

	local sname="interface.$if.link"
	bundle_stage_step_ready "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		echo 'ip link set dev $INTERFACE up'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		echo 'ip link set dev $INTERFACE down'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	bundle_stage_depend_on "$if" "configure" "$sname"
}

new_if_bridge() {
	local if="${1:?missing if}"

	local sname="interface.$if.create"
	bundle_stage_step_configure "$if" "$sname"
	new_link "$if"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
	shift 1
		echo 'ip link add $INTERFACE type bridge'
	) rc/"$sname"/up
	install -Dm644 <(linkdel "$if") rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" module.bridge
}

new_if_phys() {
	local if="${1:?missing if}"

	local sname="interface.$if.create"
	bundle_stage_step_configure "$if" "$sname"
	new_link "$if"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		echo 'bcnm-waitif 1 $INTERFACE'
	) rc/"$sname"/up
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" mdevd.coldplug
}

new_if_wg() {
	local if="${1:?missing if}"

	# Main service for creating interface
	local sname="interface.$if.create"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		echo 'ip link add $INTERFACE type wireguard'
	) rc/"$sname"/up
	install -Dm644 <(linkdel "$if") rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" module.wireguard

	new_link "$if"
	# Secondary service for loading config
	if_wg_conf "$if"
}

new_if_vrf() {
	local if="${1:?missing if}"
	local table="${2:?missing table}"

	local sname="interface.$if.create"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		cat <<EOF
s6-envdir -i /etc/s6/env/interface.\${INTERFACE}
importas -i TABLE TABLE
EOF
		echo 'ip link add $INTERFACE type vrf table $TABLE'
	) rc/"$sname"/up
	install -Dm644 <(linkdel "$if") rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type
	install -Dm644 <(echo "$table") env/interface."$if"/TABLE

	depends "$sname" module.vrf sysctl.net-ipv6-conf-all-keep_addr_on_down

	new_link "$if"
}

new_if_vlan() {
	local if="${1:?missing if}"
	local vlan="$(echo $if | cut -d'-' -f2)"
	local parent="$(echo $if | cut -d'-' -f1)"

	local sname="interface.$if.create"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_vlan "$vlan" "$parent"
		echo 'ip link add link $PARENT name $INTERFACE type vlan id $VLAN'
	) rc/"$sname"/up
	install -Dm644 <(linkdel "$if") rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" module.8021q interface."$parent".create

	new_link "$if"
}

#
# Interface configuration and properties
#

if_slave() {
	local master="${1:?missing master}"
	local slave="${2:?missing slave}"

	local sname="interface.$master.slave.$slave"
	bundle_stage_step_configure "$master" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		cat <<EOF
define MASTERIF $master
define SLAVEIF $slave
EOF
		echo 'ip link set dev $SLAVEIF master $MASTERIF'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		cat <<EOF
define SLAVEIF $slave
EOF
		echo 'ip link set dev $SLAVEIF nomaster'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$master".create interface."$slave".create
}

if_forward() {
	local if="${1:?missing if}"
	local fam="${2:-6}"

	if_sysctl "$if" "forwarding" '1' '0' "$fam"
}

if_accept_ra() {
	local if="${1:?missing if}"
	local fam="6"

	if_sysctl "$if" "accept_ra" '2' '0' "$fam"
}

if_sysctl() {
	local if="${1:?missing if}"
	local prop="${2:?missing property}"
	local val_e="${3:-1}"
	local val_d="${4:-0}"
	local fam="${5:-6}"

	local sname="sysctl.net-ipv$fam-conf-$if-$prop"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_fam "$fam"
		header_prop "$prop"
		cat <<EOF
export VAL $val_e
s6-envdir -I /etc/s6/env/sysctl.net-ipv\${FAMILY}-conf-\${INTERFACE}-\${PROP}
export SYSCTL net/ipv\${FAMILY}/conf/\${INTERFACE}/\${PROP}
/usr/libexec/nnd/s6/sysctl
EOF
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_fam "$fam"
		header_prop "$prop"
		cat <<EOF
export SYSCTL net/ipv\${FAMILY}/conf/\${INTERFACE}/\${PROP}
export VAL $val_d
/usr/libexec/nnd/s6/sysctl
EOF
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	[ "$fam" = '6' ] && depends "$sname" module.ipv6
	depends "$sname" mount.proc interface."$if".create
}

if_bridge_property() {
	local prop="${1:?missing prop}"
	local if="${2:?missing if}"
	local state="${3:-1}"
	local downstate="${4-0}"

	local sname="interface.$if.bridge.$prop"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		cat <<EOF
define PROP $prop
define STATE $state
EOF
		echo 'ip link set $INTERFACE type bridge $PROP $STATE'
	) rc/"$sname"/up
	[ -z "$downstate" ] || install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		cat <<EOF
define PROP $prop
define STATE $downstate
EOF
		echo 'ip link set $INTERFACE type bridge $PROP $STATE'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	# Might not be a requirement since STP is probably a hard dependency of bridges
	[ "$prop" == 'stp_state' ] && depends "$sname" module.stp
	depends "$sname" interface."$if".create
}

if_ether_address() {
	local if="${1:?missing if}"
	local addr="${2:?missing addr}"

	local sname="interface.$if.ether.addr"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_addr "$addr"
		echo 'ip link set $INTERFACE address $ADDR'
	) rc/"$sname"/up
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".create
}

if_wg_conf() {
	local if="${1:?missing if}"

	local sname="interface.$if.wg.config"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		cat <<EOF
s6-envdir -I /etc/s6/env/interface.\${INTERFACE}.wg-config
importas -D /etc/wireguard/\${INTERFACE} CONFIG CONFIG
EOF
		echo 'wg setconf $INTERFACE $CONFIG'
	) rc/"$sname"/up
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".create
}

if_dhcp() {
	local if="${1:?missing if}"

	local sname="interface.$if.dhcp"
	bundle_stage_step_ready "$if" "$sname"

	install -Dm755 <(
		header_eb
		header_path
		header_if "$if"
		cat <<EOF
fdmove -c 2 1
udhcpc -i \$INTERFACE -f -S
EOF
	) rc/"$sname"/run
	install -Dm644 <(echo longrun) rc/"$sname"/type

	depends "$sname" interface."$if".link syslogd
}

if_ip_addr() {
	local if="${1:?missing if}"
	local addr="${2:?missing addr}"
	local fam="${3:-$(addrfam "$addr")}"
	local addrn="$(echo "$addr" | sed 's/\//_/g')"

	local sname="interface.$if.ip.addr.$fam.$addrn"
	bundle_stage_step_ready "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} address add $ADDR dev $INTERFACE'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} address del $ADDR dev $INTERFACE'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".link
}

if_route_vrf_addr() {
	local vrf="${1:?missing vrf}"
	local if="${2:?missing if}"
	local addr="${3:?missing addr}"
	local fam="${4:-6}"
	local addrn="$(echo "$addr" | sed 's/\//_/g')"

	local sname="interface.$if.route.$vrf.$fam.$addrn"
	bundle_stage_step_ready "$if" "$sname" # Interface route may be added only if it's up

	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} route add to $ADDR dev $INTERFACE vrf $VRF'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} route del to $ADDR dev $INTERFACE vrf $VRF'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".link interface."$vrf".create
}

if_route_vrf_addr_gateway() {
	local vrf="${1:?missing vrf}"
	local if="${2:?missing if}"
	local gateway="${3:?missing gw}"
	local addr="${4:?missing addr}"
	local fam="${5:-6}"
	local gatewayn="$(echo "$gateway" | sed 's/\//_/g')"
	local addrn="$(echo "$addr" | sed 's/\//_/g')"

	local sname="interface.$if.gateway.$vrf.$fam.$gatewayn"
	bundle_stage_step_ready "$if" "$sname" # Interface route may be added only if it's up

	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_addr "$gateway"
		header_fam "$fam"
		echo 'ip -${FAMILY} route add default via $ADDR dev $INTERFACE vrf $VRF'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_addr "$gateway"
		header_fam "$fam"
		echo 'ip -${FAMILY} route del default via $ADDR dev $INTERFACE vrf $VRF'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" "interface.$if.route.$vrf.$fam.$addrn" interface."$if".link interface."$vrf".create
}

if_route_vrf_default_interface() {
	local vrf="${1:?missing vrf}"
	local if="${2:?missing if}"
	local fam="${3:-6}"

	local sname="interface.$vrf.route.$fam.default"
	bundle_stage_step_configure "$vrf" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_fam "$fam"
		echo 'ip -${FAMILY} route add default dev $INTERFACE vrf $VRF'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_vrf "$vrf"
		header_if "$if"
		header_fam "$fam"
		echo 'ip -${FAMILY} route del default dev $INTERFACE vrf $VRF'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".link interface."$vrf".create
}

if_route_vrf_default_unreach() {
	local if="${1:?missing if}"
	local fam="${2:-6}"

	local sname="interface.$if.route.$fam.unreach"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_fam "$fam"
		echo 'ip -${FAMILY} route add unreachable default metric 4096 vrf $INTERFACE'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_fam "$fam"
		echo 'ip -${FAMILY} route del unreachable default metric 4096 vrf $INTERFACE'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".create
}

if_route_vrf_sink_unreach() {
	local if="${1:?missing if}"
	local addr="${2:?missing addr}"
	local fam="${3:-6}"
	local addrn="$(echo "$addr" | sed 's/\//_/g')"

	local sname="interface.$if.route.$fam.sink.$addrn"
	bundle_stage_step_configure "$if" "$sname"

	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} route add unreachable $ADDR vrf $INTERFACE'
	) rc/"$sname"/up
	install -Dm644 <(
		header_eb
		header_path
		header_if "$if"
		header_addr "$addr"
		header_fam "$fam"
		echo 'ip -${FAMILY} route del unreachable $ADDR vrf $INTERFACE'
	) rc/"$sname"/down
	install -Dm644 <(echo oneshot) rc/"$sname"/type

	depends "$sname" interface."$if".create
}