#!/bin/sh /etc/rc.common
# Copyright (C) 2006-2010 OpenWrt.org
# Copyright (C) 2006 Carlos Sobrinho

START=50
STOP=50

USE_PROCD=1
PROG=/usr/sbin/dropbear
NAME=dropbear
PIDCOUNT=0
EXTRA_COMMANDS="killclients"
EXTRA_HELP="	killclients Kill ${NAME} processes except servers and yourself"

append_ports()
{
	local ipaddrs="$1"
	local port="$2"

	[ -z "$ipaddrs" ] && {
		procd_append_param command -p "$port"
		return
	}

	for addr in $ipaddrs; do
		procd_append_param command -p "$addr:$port"
	done
}

validate_section_dropbear()
{
	uci_validate_section dropbear dropbear "${1}" \
		'PasswordAuth:bool:1' \
		'enable:bool:1' \
		'Interface:string' \
		'GatewayPorts:bool:0' \
		'RootPasswordAuth:bool:1' \
		'RootLogin:bool:1' \
		'rsakeyfile:file' \
		'BannerFile:file' \
		'Port:list(port):22' \
		'SSHKeepAlive:uinteger:300' \
		'IdleTimeout:uinteger:0' \
		'MaxAuthTries:uinteger:3' \
		'mdns:bool:1'
}

dropbear_instance()
{
	local PasswordAuth enable Interface GatewayPorts \
		RootPasswordAuth RootLogin rsakeyfile \
		BannerFile Port SSHKeepAlive IdleTimeout \
		MaxAuthTries mdns ipaddrs

	validate_section_dropbear "${1}" || {
		echo "validation failed"
		return 1
	}

	[ -n "${Interface}" ] && {
		network_get_ipaddrs_all ipaddrs "${Interface}" || {
			echo "interface ${Interface} has no physdev or physdev has no suitable ip"
			return 1
		}
	}

	[ "${enable}" = "0" ] && return 1
	PIDCOUNT="$(( ${PIDCOUNT} + 1))"
	local pid_file="/var/run/${NAME}.${PIDCOUNT}.pid"

	procd_open_instance
	procd_set_param command "$PROG" -F -P "$pid_file"
	[ "${PasswordAuth}" -eq 0 ] && procd_append_param command -s
	[ "${GatewayPorts}" -eq 1 ] && procd_append_param command -a
	[ "${RootPasswordAuth}" -eq 0 ] && procd_append_param command -g
	[ "${RootLogin}" -eq 0 ] && procd_append_param command -w
	[ -n "${rsakeyfile}" ] && procd_append_param command -r "${rsakeyfile}"
	[ -n "${BannerFile}" ] && procd_append_param command -b "${BannerFile}"
	append_ports "${ipaddrs}" "${Port}"
	[ "${IdleTimeout}" -ne 0 ] && procd_append_param command -I "${IdleTimeout}"
	[ "${SSHKeepAlive}" -ne 0 ] && procd_append_param command -K "${SSHKeepAlive}"
	[ "${MaxAuthTries}" -ne 0 ] && procd_append_param command -T "${MaxAuthTries}"
	[ "${mdns}" -ne 0 ] && procd_add_mdns "ssh" "tcp" "$Port" "daemon=dropbear"
	procd_set_param respawn
	procd_close_instance
}

keygen()
{
	for keytype in rsa; do
		# check for keys
		key=dropbear/dropbear_${keytype}_host_key
		[ -f /tmp/$key -o -s /etc/$key ] || {
			# generate missing keys
			mkdir -p /tmp/dropbear
			[ -x /usr/bin/dropbearkey ] && {
				/usr/bin/dropbearkey -t $keytype -f /tmp/$key 2>&- >&- && exec /etc/rc.common "$initscript" start
			} &
		exit 0
		}
	done

	lock /tmp/.switch2jffs
	mkdir -p /etc/dropbear
	mv /tmp/dropbear/dropbear_* /etc/dropbear/
	lock -u /tmp/.switch2jffs
	chown root /etc/dropbear
	chmod 0700 /etc/dropbear
}

load_interfaces()
{
	config_get interface "$1" Interface
	config_get enable "$1" enable 1

	[ "${enable}" = "1" ] && interfaces=" ${interface} ${interfaces}"
}

start_service()
{
	[ -s /etc/dropbear/dropbear_rsa_host_key ] || keygen

	. /lib/functions.sh
	. /lib/functions/network.sh

	config_load "${NAME}"
	config_foreach dropbear_instance dropbear
}

service_triggers()
{
	local interfaces

	procd_add_config_trigger "config.change" "dropbear" /etc/init.d/dropbear reload

	config_load "${NAME}"
	config_foreach load_interfaces dropbear

	[ -n "${interfaces}" ] && {
		for n in $interfaces ; do
			procd_add_interface_trigger "interface.*" $n /etc/init.d/dropbear reload
		done
	}

	procd_add_validation validate_section_dropbear
}

killclients()
{
	local ignore=''
	local server
	local pid

	# if this script is run from inside a client session, then ignore that session
	pid="$$"
	while [ "${pid}" -ne 0 ]
	 do
		# get parent process id
		pid=`cut -d ' ' -f 4 "/proc/${pid}/stat"`
		[ "${pid}" -eq 0 ] && break

		# check if client connection
		grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" && {
			append ignore "${pid}"
			break
		}
	done

	# get all server pids that should be ignored
	for server in `cat /var/run/${NAME}.*.pid`
	 do
		append ignore "${server}"
	done

	# get all running pids and kill client connections
	local skip
	for pid in `pidof "${NAME}"`
	 do
		# check if correct program, otherwise process next pid
		grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" || {
			continue
		}

		# check if pid should be ignored (servers, ourself)
		skip=0
		for server in ${ignore}
		 do
			if [ "${pid}" = "${server}" ]
			 then
				skip=1
				break
			fi
		done
		[ "${skip}" -ne 0 ] && continue

		# kill process
		echo "${initscript}: Killing ${pid}..."
		kill -KILL ${pid}
	done
}
