#!/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 new
	eval "actual=\$$varname"

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

validate_server_section() {
	uci_load_validate sshtunnel server "$1" "$2" \
		'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(0)' \
		'StrictHostKeyChecking:or("yes", "no", "accept-new")' \
		'TCPKeepAlive:or("yes", "no")' \
		'VerifyHostKeyDNS:or("yes", "no")'
}

validate_tunnelR_section() {
	uci_load_validate sshtunnel tunnelR "$1" "$2" \
		'remoteaddress:or(host, "*"):*' \
		'remoteport:port' \
		'localaddress:host' \
		'localport:port'
}

validate_tunnelL_section() {
	uci_load_validate sshtunnel tunnelL "$1" "$2" \
		'remoteaddress:host' \
		'remoteport:port' \
		'localaddress:or(host, "*"):*' \
		'localport:port'
}

validate_tunnelD_section() {
	uci_load_validate sshtunnel tunnelD "$1" "$2" \
		'localaddress:or(host, "*"):*' \
		'localport:port'
}

validate_tunnelW_section() {
	uci_load_validate sshtunnel tunnelW "$1" "$2" \
		'vpntype:or("ethernet", "point-to-point"):point-to-point' \
		'localdev:or("any", min(0))' \
		'remotedev:or("any", min(0))'
}

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
	[ "$2" = 0 ] || { _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
	count=$((count+=1))

	_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
	[ "$2" = 0 ] || { _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
	count=$((count+=1))

	_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
	[ "$2" = 0 ] || { _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
	count=$((count+=1))

	_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
	[ "$2" = 0 ] || { _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
	count=$((count+=1))

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

load_server() {
	local server="$1"

	[ "$2" = 0 ] || { _err "server $server: validation failed"; return 1; }

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

	config_foreach validate_tunnelR_section "tunnelR" load_tunnelR
	config_foreach validate_tunnelL_section "tunnelL" load_tunnelL
	config_foreach validate_tunnelD_section "tunnelD" load_tunnelD
	config_foreach validate_tunnelW_section "tunnelW" load_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 validate_server_section "server" load_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
}