#!/bin/sh /etc/rc.common
#
# Copyright (C) 2010-2015 OpenWrt.org
# Copyright (C) 2010 segal.di.ubi.pt
#

START=99
STOP=01
USE_PROCD=1

PROG=/usr/bin/ssh

_log() {
	logger -p daemon.info -t sshtunnel "$@"
}

_err() {
	logger -p daemon.err -t sshtunnel "$@"
}

append_params() {
	local p v args
	for p in $*; do
		eval "v=\$$p"
		[ -n "$v" ] && args="$args -o $p=$v"
	done

	ARGS_options="${args# *}"
}

append_string() {
	local varname="$1"; local add="$2"; local separator="${3:- }"; local actual
	eval "actual=\$$varname"

	new="${actual:+$actual$separator}$add"
	eval "$varname=\$new"
}

validate_server_section() {
	uci_validate_section sshtunnel server "$1" \
		'user:string(1)' \
		'hostname:host' \
		'port:port' \
		'retrydelay:min(1):60' \
		'PKCS11Provider:file' \
		'CheckHostIP:or("yes", "no")' \
		'Compression:or("yes", "no")' \
		'CompressionLevel:range(1,9)' \
		'IdentityFile:file' \
		'LogLevel:or("QUIET", "FATAL", "ERROR", "INFO", "VERBOSE", "DEBUG", "DEBUG1", "DEBUG2", "DEBUG3"):INFO' \
		'ServerAliveCountMax:min(1)' \
		'ServerAliveInterval:min(1)' \
		'StrictHostKeyChecking:or("yes", "no")' \
		'TCPKeepAlive:or("yes", "no")' \
		'VerifyHostKeyDNS:or("yes", "no")'
}

validate_tunnelR_section() {
	uci_validate_section sshtunnel tunnelR "$1" \
		'remoteaddress:or(host, "*"):*' \
		'remoteport:port' \
		'localaddress:host' \
		'localport:port'
}

validate_tunnelL_section() {
	uci_validate_section sshtunnel tunnelL "$1" \
		'remoteaddress:host' \
		'remoteport:port' \
		'localaddress:or(host, "*"):*' \
		'localport:port'
}

validate_tunnelD_section() {
	uci_validate_section sshtunnel tunnelD "$1" \
		'localaddress:or(host, "*"):*' \
		'localport:port'
}

validate_tunnelW_section() {
	uci_validate_section sshtunnel tunnelW "$1" \
		'vpntype:or("ethernet", "point-to-point"):point-to-point' \
		'localdev:or("any", min(1))' \
		'remotedev:or("any", min(1))'
}

load_tunnelR() {
	config_get section_server "$1" "server"

	# continue to read next section if this is not for the current server
	[ "$server" = "$section_server" ] || return 0

	# validate and load this remote tunnel config
	local remoteaddress remoteport localaddress localport
	validate_tunnelR_section "$1" || { _err "tunnelR ${1}: validation failed"; return 1; }

	[ -n "$remoteport" -a -n "$localport" -a -n "$remoteaddress" ] || { _err "tunnelR ${1}: missing required options"; return 1; }

	# count nr of valid sections to make sure there are at least one
	let count++

	_log "tunnelR at ${server}: -R $remoteaddress:$remoteport:$localaddress:$localport"
	append_string "ARGS_tunnels" "-R $remoteaddress:$remoteport:$localaddress:$localport"
}

load_tunnelL() {
	config_get section_server "$1" "server"

	# continue to read next section if this is not for the current server
	[ "$server" = "$section_server" ] || return 0

	# validate and load this remote tunnel config
	local remoteaddress remoteport localaddress localport
	validate_tunnelL_section "$1" || { _err "tunnelL ${1}: validation failed"; return 1; }

	[ -n "$remoteport" -a -n "$localport" -a -n "$remoteaddress" ] || { _err "tunnelL ${1}: missing required options"; return 1; }

	# count nr of valid sections to make sure there are at least one
	let count++

	_log "tunnelL at ${server}: -L $localaddress:$localport:$remoteaddress:$remoteport"
	append_string "ARGS_tunnels" "-L $localaddress:$localport:$remoteaddress:$remoteport"
}

load_tunnelD() {
	config_get section_server "$1" "server"

	# continue to read next section if this is not for the current server
	[ "$server" = "$section_server" ] || return 0

	# validate and load this remote tunnel config
	local localaddress localport
	validate_tunnelD_section "$1" || { _err "tunnelD ${1}: validation failed"; return 1; }

	[ -n "$localport" ] || { _err "tunnelD ${1}: missing localport"; return 1; }

	# count nr of valid sections to make sure there are at least one
	let count++

	_log "proxy via ${server}: -D $localaddress:$localport"
	append_string "ARGS_tunnels" "-D $localaddress:$localport"
}

load_tunnelW() {
	config_get section_server "$1" "server"

	# continue to read next section if this is not for the current server
	[ "$server" = "$section_server" ] || return 0

	# validate and load this remote tunnel config
	local localdev remotedev vpntype
	validate_tunnelW_section "$1" || { _err "tunnelW ${1}: validation failed"; return 1; }

	[ -n "$vpntype" -a -n "$localdev" -a -n "$remotedev" ] || { _err "tunnelW $1: missing or bad options"; return 1; }

	[ "$user" == "root" ] || { _err "tunnelW ${1}: root is required for tun"; return 1; }

	# count nr of valid sections to make sure there are at least one
	let count++

	_log "tunnelW to ${server}: -w $localdev:$remotedev -o Tunnel=$vpntype"
	append_string "ARGS_tunnels" "-w $localdev:$remotedev -o Tunnel=$vpntype"
}

load_server() {
	server="$1"
	local user hostname port retrydelay PKCS11Provider CheckHostIP Compression \
		CompressionLevel IdentityFile LogLevel ServerAliveCountMax \
		ServerAliveInterval StrictHostKeyChecking TCPKeepAlive VerifyHostKeyDNS

	validate_server_section "$server" || { _err "server ${server}: validation failed"; return 1; }

	ARGS=""
	ARGS_options=""
	ARGS_tunnels=""
	count=0

	config_foreach load_tunnelR "tunnelR"
	config_foreach load_tunnelL "tunnelL"
	config_foreach load_tunnelD "tunnelD"
	config_foreach load_tunnelW "tunnelW"
	[ "$count" -eq 0 ] && { _err "tunnels to ${server} not started - no tunnels defined"; return 1; }

	append_params CheckHostIP Compression CompressionLevel IdentityFile \
		LogLevel PKCS11Provider ServerAliveCountMax ServerAliveInterval \
		StrictHostKeyChecking TCPKeepAlive VerifyHostKeyDNS

	ARGS="$ARGS_options -o ExitOnForwardFailure=yes -o BatchMode=yes -nN $ARGS_tunnels -p $port $user@$hostname"

	procd_open_instance "$server"
	procd_set_param command "$PROG" $ARGS
	procd_set_param stdout 1
	procd_set_param stderr 1
	procd_set_param respawn 0 "$retrydelay" 1
	procd_close_instance
}

start_service() {
	config_load "sshtunnel"
	config_foreach load_server "server"
}

service_triggers() {
	procd_add_reload_trigger "sshtunnel"

	procd_open_validate
	validate_server_section
	validate_tunnelR_section
	validate_tunnelL_section
	validate_tunnelD_section
	validate_tunnelW_section
	procd_close_validate
}