#!/bin/sh
#
# $Header: /usr/local/src/dhcp_probe-latest/extras/RCS/site-application-dhcp_probe,v 1.1 2011/12/14 20:32:03 root Exp root $
#
# This is a Solaris SMF method script (a startup script) for the dhcp_probe daemon.
#
# Usage:
#   site-application-dhcp_probe [-v] -i interface [-Q vlan_id|none] [-r] [-d debuglevel] start
#   site-application-dhcp_probe [-v] -i interface stop contract_id
#
# -d debuglevel   call dhcp_probe with '-d debuglevel' overridding default DEBUG_OPT constant below.
# -i interface    name of network interface on which to run
# -Q vlan_id      call dhcp_probe with '-Q vlan_id'
# -r              rotate capture files before starting daemon
# -v              enable verbosity
#
#
# When starting, if the daemon is already executing (based on $PIDFILE), don't re-execute it.
#
# To try to minimize the likelihood that the processid stored in the PID file corresponds
# to an unrelated process (common with startup scripts), we'll clear the contents of the
# PID file when we kill the daemon using this script.   When starting or stopping, when we find a pid in that file,
# we'll both check that a process with that pid exists, and that the commandname for the process
# looks like the one we're interested in before we treat the pid value as valid.
#
# When stopping, we kill the pid specified in $PIDFILE, if $PIDFILE exists and
# contains a value that is for a running process whose commandname looks like
# the one we're interested in.  Regardless of how that goes, we'll also
# kill the service contract (assuming a contract_id is given); that will help
# us kill the daemon in those cases where the pidfile and the daemon have
# gotten out-of-sync, as well as ensure all children of the daemon are killed.


. /lib/svc/share/smf_include.sh

PATH=/usr/bin:/bin

SERVERROOT=/usr/local/sbin

PROGNAME=dhcp_probe

# If PIDFILE exists and refers to a running process,
# and that process's command string contains PS_SEARCH,
# we'll assume this program instance is already running.
PS_SEARCH=$PROGNAME

EXECUTABLE=$SERVERROOT/$PROGNAME

# Working directory before starting daemon.
CWD=/tmp

# Directory in which to write the pidfile
PIDFILEDIR=/var/run

# Directory in which to find the config file
CONFIGFILEDIR=/etc

# Signal to kill daemon gracefully.
SIGNAL=TERM

# This will be set via cmdline option '-i interface'
INTERFACE=

# This may be overridden via cmdline option '-Q vlan_id'
VLAN_OPT=

# Directory in which to write the capture files
CAPTUREDIR=/var/local/logs

# Number of capture files to retain (when rotating these files)
CAPTUREFILES_MAX=20

# Absolute path of the rotate_logs executable.
# Used when starting service iff '-r' option specified.
ROTATE_LOGS_EXEC=/usr/local/etc/rotate_logs

# Debug option to pass to dhcp_probe.
# Set to empty string to disable.
# May be overridden via '-d debuglevel'.
DEBUG_OPT="-d 1"

cd $CWD

while [ $# -gt 0 ]
do
	case "$1" in 

		'-d')
			# The debuglevel is supposed to be the token after '-d'.
			# Overrride default DEBUG constant.
			shift
			DEBUG_OPT="-d $1"
			;;

		'-i')
			# The interface name is supposed to be the token after '-i'.
			shift
			INTERFACE="$1"
			;;

		'-Q')
			# The vlan_id is supposed to be the token after '-Q'.
			shift
			if [ "$1" = "none" ]; then
				# The token "none" is special, indicating that no -Q option should be passed.
				# It's a kludge to allow our caller to always pass a '-Q value' option,
				# for those callers (like SMF) which make it hard to pass *optional* options which take values.
				:
			else
				VLAN_OPT="-Q $1"
			fi
			;;

		'-r')
			rotate_capturefile=1
			;;

		'-v')
			verbose=1
			;;

		'start')
			# The interface must have been specified before the 'start' argument.
			if [ -z "$INTERFACE" ]; then
				echo "$0: interface not specified, cannot start $PROGNAME" 2>&1 | smf_console
				exit $SMF_EXIT_ERR_FATAL
			fi

			# Some values we could not determine until the INTERFACE was set.

			PIDFILE=$PIDFILEDIR/$PROGNAME.$INTERFACE.pid

			CONFIGFILE=$CONFIGFILEDIR/$PROGNAME.$INTERFACE.cf

			# Capture file name (without the directory name)
			CAPTUREFILENAME=$PROGNAME.$INTERFACE.capture

			# Absolute capture file name
			CAPTUREFILE=$CAPTUREDIR/$CAPTUREFILENAME

			STARTCOMMAND="$EXECUTABLE $DEBUG_OPT -c $CONFIGFILE -o $CAPTUREFILE -p $PIDFILE $VLAN_OPT $INTERFACE"

			echo "$0: starting $PROGNAME instance on interface $INTERFACE ..." 2>&1 | smf_console

			if [ !  -f $EXECUTABLE ]; then
				echo "$0: executable $EXECUTABLE does not exist, cannot start $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
				exit $SMF_EXIT_ERR_FATAL
			fi

			if [ !  -f $CONFIGFILE ]; then
				echo "$0: configuration file $CONFIGFILE does not exist, cannot start $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
				exit $SMF_EXIT_ERR_CONFIG
			fi

			# If we find the daemon already running, exit.  Else fall through to the $STARTCOMMAND
			if [ -f $PIDFILE ]; then
				pid=`/usr/bin/cat $PIDFILE`
				if [ -n "$pid" ]; then
					if kill -0 "$pid" > /dev/null 2>&1 ; then
						# there is a process with that pid, but is it the right one?
						/usr/bin/ps -f -p $pid | /usr/bin/tail -1 | /usr/bin/grep $PS_SEARCH > /dev/null 2>&1
						if [ $? -eq 0 ] ; then
							echo "$0: $PIDFILE=$pid processid exists with reasonable name, assuming $PROGNAME instance on interface $INTERFACE is already running" 2>&1 | smf_console
							exit $SMF_EXIT_OK
						else
							# that process is something else, so we can assume ours isn't already running
							# Clearing our pidfile is just good housekeeping, not required
							/usr/bin/cp /dev/null $PIDFILE
						fi
					fi	# else no process running with that pid, so we assume it's not already running
				fi	# else pidfile doesn't contain a number, so we assume it's not already running
			fi	# else no pidfile, so we assume it's not already running

			# Success!  It really looks like the daemon isn't already running, so start it

			###
			# This is specific to dhcp_probe
			#
			# As each time dhcp_probe starts, it overwrites the capture file.
			# If you want to preserve the previous capture file(s), rotate those file(s) before starting dhcp_probe.
			if [ -n "$rotate_capturefile" ] ; then
				# Note that we could not determine some of these args until after $INTERFACE was set.
  				$ROTATE_LOGS_EXEC -logdir="$CAPTUREDIR" -logname="$CAPTUREFILENAME" -max="-$CAPTUREFILES_MAX"
			fi
			#
			####

			$STARTCOMMAND
			echo "done starting $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
			exit $SMF_EXIT_OK


			;;



		'stop')

			if [ -z "$INTERFACE" ]; then
				echo "$0: interface not specified, cannot stop $PROGNAME" 2>&1 | smf_console
				exit $SMF_EXIT_ERR_FATAL

				# XXX Does Solaris ever call the stop method with just the contract_id (lacking the interface name)?
				# If so, then we should allow the method to run even without an interface name.
				# (We really want the interface name as it allows us to find the PIDFILE.)
			fi

			# We could not determine the PIDFILE until the INTERFACE was set.
			PIDFILE=$PIDFILEDIR/$PROGNAME.$INTERFACE.pid

			echo "$0: stopping $PROGNAME instance on interface $INTERFACE ..." 2>&1 | smf_console

			# The service contract_id is supposed to be the token after 'stop'.
			shift
			contract_id="$1"

			if [ -f $PIDFILE ] ; then

				pid=`/usr/bin/cat $PIDFILE`
				if [ -n "$pid" ]; then

					if kill -0 "$pid" > /dev/null 2>&1 ; then
						# there is a process with that pid, but is it the right one?
						/usr/bin/ps -f -p $pid | /usr/bin/tail -1 | /usr/bin/grep $PS_SEARCH > /dev/null 2>&1
						if [ $? -eq 0 ] ; then
							# Success! The process has reasonable name, go ahead and kill it
							kill -$SIGNAL $pid

							/usr/bin/cp /dev/null $PIDFILE

							# Kill any processes left in service contract
							if [ -n "$contract_id" ] ; then
								smf_kill_contract $contract_id $SIGNAL 1
								[ $? -ne 0 ] && exit 1
							fi

							echo "done stopping $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
							exit $SMF_EXIT_OK

						else
							# The process with that pid does NOT have a reasonable name.
							if [ -n "$verbose" ]; then
								echo "$0: $PIDFILE=$pid processid is for different daemon, will NOT kill that pid" 2>&1 | smf_console
							fi
							# Clearing our pidfile is just good housekeeping, not required
							/usr/bin/cp /dev/null $PIDFILE

							# It's not clear why the $PIDFILE doesn't correspond to the correct daemon, but perhaps the service is still running with a different pid.
							# Kill any processes left in service contract
							if [ -n "$contract_id" ] ; then
								smf_kill_contract $contract_id $SIGNAL 1
								[ $? -ne 0 ] && exit 1
							fi

							echo "done stopping $PROGNAME" 2>&1 | smf_console
							exit $SMF_EXIT_OK
						fi

					else
						# there is no process with that pid
						if [ -n "$verbose" ]; then
							echo "$0: $PIDFILE=$pid processid does not exist" 2>&1 | smf_console
						fi
						# Clearing our pidfile is just good housekeeping, not required
						/usr/bin/cp /dev/null $PIDFILE

						# Perhaps the $PIDFILE was overwritten as a result of some problem, but the service is still running.
						# Kill any processes left in service contract
						if [ -n "$contract_id" ] ; then
							smf_kill_contract $contract_id $SIGNAL 1
							[ $? -ne 0 ] && exit 1
						fi

						echo "done stopping $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
						exit $SMF_EXIT_OK
					fi
				else 
					if [ -n "$verbose" ]; then
						echo "$0: pidfile $PIDFILE is empty" 2>&1 | smf_console
					fi

					# Perhaps the $PIDFILE was emptied as a result of some problem, but the service is still running.
					# Kill any processes left in service contract
					if [ -n "$contract_id" ] ; then
						smf_kill_contract $contract_id $SIGNAL 1
						[ $? -ne 0 ] && exit 1
					fi

					echo "done stopping $PROGNAME instance on interface $INTERFACE" 2>&1 | smf_console
					exit $SMF_EXIT_OK
				fi

			else
				if [ -n "$verbose" ]; then
					echo "$0: pidfile $PIDFILE not found" 2>&1 | smf_console
				fi

				# Perhaps the $PIDFILE was removed as a result of some problem, but the service is still running.
				# Kill any processes left in service contract
				if [ -n "$contract_id" ] ; then
					smf_kill_contract $contract_id $SIGNAL 1
					[ $? -ne 0 ] && exit 1
				fi

				echo "done stopping $PROGNAME instance on interface $INTERFACE"  2>&1 | smf_console
				exit $SMF_EXIT_OK
			fi

			# NOTREACHED
			;;

		*)
			echo "$0: Unrecognized argument: $1"
			echo "Usage:"
			echo "  $0 [-v] -i interface [-Q vlan_id|none] [-r] [-d debuglevel] start"
			echo "  $0 [-v] -i interface stop contract_id"

			exit $SMF_EXIT_ERR_CONFIG
			;;
	esac

	shift

done