#!/sbin/openrc-run
# Copyright 1999-2022 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

extra_commands="checkconfig"
extra_started_commands="reload"

: ${SSHD_CONFDIR:=${RC_PREFIX%/}/etc/ssh}
: ${SSHD_CONFIG:=${SSHD_CONFDIR}/sshd_config}
: ${SSHD_PIDFILE:=${RC_PREFIX%/}/run/${SVCNAME}.pid}
: ${SSHD_BINARY:=${RC_PREFIX%/}/usr/sbin/sshd}
: ${SSHD_KEYGEN_BINARY:=${RC_PREFIX%/}/usr/bin/ssh-keygen}
: ${SSHD_HOSTKEY_DSA_ENABLE="YES"}
: ${SSHD_HOSTKEY_ECDSA_ENABLE="YES"}
: ${SSHD_HOSTKEY_ED25519_ENABLE="YES"}
: ${SSHD_HOSTKEY_RSA_ENABLE="YES"}
: ${SSHD_HOSTKEY_XMSS_ENABLE="YES"}

command="${SSHD_BINARY}"
pidfile="${SSHD_PIDFILE}"
command_args="${SSHD_OPTS} -o PidFile=${pidfile} -f ${SSHD_CONFIG}"

# Wait one second (length chosen arbitrarily) to see if sshd actually
# creates a PID file, or if it crashes for some reason like not being
# able to bind to the address in ListenAddress (bug 617596).
: ${SSHD_SSD_OPTS:=--wait 1000}
start_stop_daemon_args="${SSHD_SSD_OPTS}"

depend() {
	# Entropy can be used by ssh-keygen, among other things, but
	# is not strictly required (bug 470020).
	use logger dns entropy
	if [ "${rc_need+set}" = "set" ] ; then
		: # Do nothing, the user has explicitly set rc_need
	else
		local x warn_addr
		for x in $(awk '/^ListenAddress/{ print $2 }' "$SSHD_CONFIG" 2>/dev/null) ; do
			case "${x}" in
				0.0.0.0|0.0.0.0:*) ;;
				::|\[::\]*) ;;
				*) warn_addr="${warn_addr} ${x}" ;;
			esac
		done
		if [ -n "${warn_addr}" ] ; then
			need net
			ewarn "You are binding an interface in ListenAddress statement in your sshd_config!"
			ewarn "You must add rc_need=\"net.FOO\" to your ${RC_PREFIX%/}/etc/conf.d/sshd"
			ewarn "where FOO is the interface(s) providing the following address(es):"
			ewarn "${warn_addr}"
		fi
	fi
}

gen_hostkey() {
	local hkey_type="${1}"
	[ -z ${hkey_type} ] && return 1

	local hkey_file="${SSHD_CONFDIR}/ssh_host_${hkey_type}_key"
	local hkey_type_upper="$(echo ${hkey_type} | tr "[:lower:]" "[:upper:]")"
	local hkey_type_var="SSHD_HOSTKEY_${hkey_type_upper}_ENABLE"
	local hkey_type_enable="$(eval echo "\$$hkey_type_var")"

	if yesno ${hkey_type_enable} && [ ! -f ${hkey_file} ] ; then
		${SSHD_KEYGEN_BINARY} -t ${hkey_type} -f ${hkey_file} -N '' || return 1
	fi
}

checkconfig() {
	checkpath --mode 0755 --directory "${RC_PREFIX%/}/var/empty"

	# Check for sshd_config.
	if [ ! -e "${SSHD_CONFIG}" ] ; then
		eerror "You need an ${SSHD_CONFIG} file to run sshd"
		eerror "There is a sample file in /usr/share/doc/openssh"
		return 1
	fi

	# HostKey generation.
	gen_hostkey "dsa" || return 2
	gen_hostkey "ecdsa" || return 2
	gen_hostkey "ed25519" || return 2
	gen_hostkey "rsa" || return 2
	gen_hostkey "xmss" || return 2

	# Check sshd config file syntax
	"${command}" -t ${command_args} || return 3
}

start_pre() {
	# Make sure that the user's config isn't busted before we try
	# to start the daemon (this will produce better error messages
	# than if we just try to start it blindly).
	#
	# We always need to call checkconfig because this function will
	# also generate any missing host key and you can start a
	# non-running service with "restart" argument.
	checkconfig || return $?
}

stop_pre() {
	if [ "${RC_CMD}" = "restart" ] ; then
		# If this is a restart, check to make sure the user's config
		# isn't busted before we stop the running daemon.
		checkconfig || return $?
	elif yesno "${RC_GOINGDOWN}" && [ -s "${pidfile}" ] && hash pgrep 2>/dev/null ; then
		# Disconnect any clients before killing the master process
		local pid=$(cat "${pidfile}" 2>/dev/null)
		if [ -n "${pid}" ] ; then
			local ssh_session_pattern='sshd: \S.*@pts/[0-9]+'

			IFS="${IFS}@"
			local daemon pid pty user
			pgrep -a -P ${pid} -f "$ssh_session_pattern" | while read pid daemon user pty ; do
				ewarn "Found ${daemon%:} session ${pid} on ${pty}; sending SIGTERM ..."
				kill "${pid}" || true
			done
		fi
	fi
}

reload() {
	checkconfig || return $?
	ebegin "Reloading ${SVCNAME}"
	start-stop-daemon --signal HUP --pidfile "${pidfile}"
	eend $?
}