socat.in

#!/bin/sh
#
# Author: Emanuel Haupt <ehaupt@FreeBSD.org>

# PROVIDE: socat
# REQUIRE: LOGIN
# KEYWORD: shutdown

# Add the following lines to /etc/rc.conf to enable socat:
# socat_enable="YES"
# socat_daemonuser="root" for priviledged ports e.g.
# socat_flags="<set as needed>" or create /usr/local/etc/socat-instances.conf

. /etc/rc.subr

name="socat"
rcvar=socat_enable

load_rc_config $name

: ${socat_enable="NO"}
: ${socat_daemonuser:=nobody}
: ${socat_config:=%%PREFIX%%/etc/socat-instances.conf}

start_precmd="socat_prestart"
pidfile=/var/run/socat.pid
procname="%%PREFIX%%/bin/socat"
command=/usr/sbin/daemon
command_args=' -f -p ${pidfile} -u ${socat_daemonuser} ${procname} ${socat_flags}'

[ -n "${2}" ] && socat_instance_arg=`echo "${2}" | tr '[:lower:]' '[:upper:]'`

socat_prestart()
{
	# socat_flags gets applied too early if we don't do this.
	# I didn't want to force people to update their rc.conf files
	# and change the socat_flags to something else.
	rc_flags=""
}

socat_parse_instances()
{
  local _line _section_search

  socat_instances=`grep -Eo "^[[:blank:]]*\[[[:alnum:]_]+\]" ${socat_config} |
    tr '[:lower:]' '[:upper:]'`
				
  if [ -n "${socat_instance_arg}" ] && ! echo "${socat_instances}" |
      grep -q -E '(^|[[:blank:]])\['${socat_instance_arg}'\]([[:blank:]]|$)'
  then
    echo -n "$name: Can't find instance definition " >&2
    echo "\"[${1}]\" in config file ${socat_config}." >&2
    return 1
  fi

  [ -n "${socat_instance_arg}" ] && socat_instances="[${socat_instance_arg}]"

  for i in ${socat_instances}; do
    _section_search=1
    _instance=${i#[}
    _instance=${_instance%]}

    # Process each line of the optional config file, which
    # matches the regex, defined at the end of the loop.
    # There we filter to only process definitions and section separators.
    while read -r _line; do

      # Look for ${i} section until found
      if [ ${_section_search} ]; then
        if echo "${_line}" | grep -qi "^[[:blank:]]*\[${_instance}\]"; then
          unset _section_search
          continue # Nothing to do with section identifiers
        else
          # Continue with next line s_instance we haven't reached our section yet
          continue
        fi
      fi

      # Stop processing if the current line is another section identifier.
      echo "${_line}" | grep -q "^[[:blank:]]*\[[^]]*\]" && break

      # Only proceed with lines which contain variable declaration.
      echo "${_line}" | grep -q -E \
                        -e "^[[:blank:]]*[[:alpha:]_][[:alnum:]_]{0,30}=" ||
                            continue
      # Filter malformed lines (which could cause command execution)
      #   (shell exits with test result, wich is false as soon as
      #   there's a 2nd argument (1st is considered as 0))
      eval sh -c \'[ \$# -eq 0 ]\' "${_line}" \|\| continue

      eval socat_${_instance}_${_line%%=*}=${_line#*=}

    done << EOCFF
$(cat "${socat_config}")
EOCFF
  done
}

# Check if daemon(8) handles title and syslog parameters
if [ "${1%start}" != "${1}" ]; then
	daemon_extended_args=" -l daemon"
	${command} -t "test" ${daemon_extended_args} -f -u nobody true \
		> /dev/null 2>&1 || unset daemon_extended_args
fi


# If we can read the config file, handle multiple instances,
# else just process a single instance.
if [ -r ${socat_config} ]; then

	# T O D O :   Check rc(8) how restarts are handled and make
	#		all-instaces restart working.
	#	For now refuse restart commands without instance argument.
	#
	if [ "${1%restart}" != "${1}" ] && [ -z "${socat_instance_arg}" ]; then
		echo -n "$name: Restart command requires a instance argument,"
		echo "since config file is in use."
		exit 1
	fi

	if [ -n "${socat_flags}" ]; then
		echo -n "${name}: WARNING:"
		echo -n " Ignoring \"socat_flags\" in rc.conf because"
                echo " \"${socat_config}\" is present."
	fi

	socat_parse_instances "${2}" || exit 1

	default_pidfile="${pidfile}"
	default_socat_daemonuser="${socat_daemonuser}"
	eval default_command_args=\'${command_args}\'

	for i in ${socat_instances}; do
		_instance=${i#[}
		_instance=${_instance%]}

		eval socat_flags=\"\$\{socat_${_instance}_flags\}\"

		# We need to have socat_flags to start, else skip start commands
		if [ "${1%start}" != "${1}" ] && [ -z "${socat_flags}" ]; then
			echo -n "$name: Missing \"flags\" definition for"
			echo " instance ${i}, skipping \"${1}\" command."
			continue
		fi

		eval pidfile=\"\$\{socat_${_instance}_pidfile\}\"
		[ -n "${pidfile}" ] ||
			pidfile="${default_pidfile%.pid}_${_instance}.pid"

		eval socat_daemonuser=\"\$\{socat_${_instance}_daemonuser\}\"
		[ -n "${socat_daemonuser}" ] ||
			socat_daemonuser="${default_socat_daemonuser}"

		eval command_args=\"${default_command_args}\"
		if [ -n "${daemon_extended_args}" ]; then
			# A bit confusing, but to keep 80 chars line break:
			command_args="(${_instance})\" ${command_args}"
			command_args="-t \"${procname} ${command_args}"
			command_args="${daemon_extended_args} ${command_args}"
		fi

		run_rc_command "$1"
	done

else

	if [ -n "${socat_instance_arg}" ]; then
		echo -n "$name: Missing config file (${socat_config}), " >&2
		echo "can't handle instance \"${2}\"." >&2
		exit 1
	fi

	eval command_args=\"${daemon_extended_args} ${command_args}\"
	run_rc_command "$1"

fi