ff-offline-ssid

#!/bin/sh
# ff-offline-ssid by RubenKelevra 2013-2017 - ruben@vfn-nrw.de
# Lizenz: AGPL 3.0

#Warning: If SSID was changed in uci, which belongs to freifunk, you need to run "wifi" before you rerun this script.

#This script expect that an temporary SSID is set on boot. The script will read an online-ssid from uci and set it when node sees batman-gateways.

RUNTIME=60 #recommended runtime, to avoid memory-leaks.
END=0 #var

#Parameter Checking
if ! [ $# -eq 1 -o "$1" -eq "$1" ] 2>/dev/null; then
	echo "Error: Please define a runtime in seconds, 60 is recommended" && exit 2
else
	RUNTIME=$1
	echo "Debug: Runtime will be $RUNTIME seconds, please restart me after this time"
	echo ""
fi

START=`cat /proc/uptime | cut -d"." -f1`
END=$(( $START + $RUNTIME ))
END=$(( $END - 1 ))

#running-pid
OWNPID=$$
PIDFILE='/tmp/ff-offline-ssid.pid'
echo "Debug: Own PID is $OWNPID"

if [ ! -f "$PIDFILE" -a -f "$PIDFILE"_"STOP" ]; then
	echo "Debug: No PID-File; but a stop file, wait one second..."
	sleep 1 #sleep to fix possible race-conditions
fi

if [ ! -f "$PIDFILE" ]; then
	echo -n "Debug: No PID-File found, writing own one..."
	echo $OWNPID > $PIDFILE
	echo " done."
	[ -f "$PIDFILE"_"STOP" ] && rm "$PIDFILE"_"STOP" #cleanup
else
	echo -n "Debug: PID-File found..."
	#check if pid from pid-file is running
	if ! kill -0 $(cat "$PIDFILE") > /dev/null 2>&1; then #it's not running
		echo " but foreign process is no longer running."
		echo -n "Writing own PID to file..."
		echo $OWNPID > $PIDFILE
		echo " done."
		[ -f "$PIDFILE"_"STOP" ] && rm "$PIDFILE"_"STOP" #cleanup
	else #pid is running
		echo -n " foreign process is still running..."
		if [ -f "$PIDFILE"_"STOP" ]; then # we're exiting now - one waiting process is enouth.
			echo ""; echo "Warning: Offline-ssid exiting because pid-file (pid running!) and stopfile already exist."
			exit 15
		fi
		echo "... request 'em to stop."
		touch "$PIDFILE"_"STOP"
		while [ `cat /proc/uptime | cut -d"." -f1` -lt $END ]; do # wait until the pid-process has ended gracefully
			echo "waiting ..."
			if [ ! -f $PIDFILE ]; then
				echo "Debug: pid-file is now gone."
				echo -n "Writing own PID-File..."
				echo $OWNPID > $PIDFILE
				echo " done."
				[ -f "$PIDFILE"_"STOP" ] && rm "$PIDFILE"_"STOP" #cleanup
				break
			fi
			sleep 1
		done
	fi
	echo "";echo "starting up now...";echo ""
fi

# options
SLEEP=2        # sleep time in seconds between checks
ACTIVE_CHECK=1 # enable L2-ping checks to the selected gateways, if last-seen is too high. Needs batctl.
PING_CNT=10    # ping-packets for ACTIVE_CHECK: 3 is recommended, 5-10 for lossy connections
OGM_INT_MULT=2 # tolerable missing OGMs, before pinging (if ACTIVE_CHECK=1): 1 for fast responses, 2 for slower reactions, 3-4 for lossy connections
LED_STATUS=1   # change system-led, when offline: pulsing flashes with long pauses
SUB_CONF_ONLINE_SSID='ssid_online'
SUB_CONF_BOOT_SSID='ssid'
MINIMAL_ACCEPTABLE_GWQ=40
MIN_PING_PERCENT=80 #to be considered online while active checking

# vars
MODE=1
GWQ=0
GWM=""
GWLS=0
GWL=0

# checking batctl
if [ $ACTIVE_CHECK -eq 1 ]; then
	batctl -v >/dev/null 2>&1 || { echo >&2 "batctl is required for Active-Checking, but it's not installed.  Aborting."; exit 1; }
fi

# checking files and options
if [ "$(ls -l /var/run/hostapd-phy*.conf | wc -l)" -eq 0 ]; then
	echo "Error: No Hostapd-Config-File was found" && exit 2

elif ! [ -f /etc/diag.sh ]; then
	if [ $LED_STATUS -eq 1 ]; then
		echo "Error: /etc/diag.sh not found." && exit 2
	fi
fi

# init led-change-functions
if [ $LED_STATUS -eq 1 ]; then
	. /etc/diag.sh
	get_status_led
fi

HN=`cat /proc/sys/kernel/hostname`
if [ ${#HN} -gt 16 ]; then #cut hostname
	HN="${HN:0:13}..."
fi

while [ `cat /proc/uptime | cut -d"." -f1` -lt $END ]; do
	if [ -f "$PIDFILE"_"STOP" ]; then
		echo "we're exiting now, because we're requested to."
		rm $PIDFILE
		exit 42
	fi

	case $MODE in
	1) # check: does batman know any gateway?
		GWQ=`cat /sys/kernel/debug/batman_adv/bat0/gateways | egrep ' \([\ 0-9]+\) ' | cut -d\( -f2 | cut -d\) -f1 | sort -n | tail -n1`
		if ! [ "$GWQ" -eq "$GWQ" ] 2>/dev/null; then
			GWQ=0
		fi
		echo -n "Debug: Gateway-quality is $GWQ"
		if [ "$GWQ" -lt "$MINIMAL_ACCEPTABLE_GWQ" ]; then
			echo " - this is not okay, we're offline"
			OFFLINE=1
			MODE=4
		else
			echo " - this seem fine"
			OFFLINE=0
			MODE=2
			continue
		fi
		;;
	2) #check: Selected gateway's last-seen
		GWM=`cat /sys/kernel/debug/batman_adv/bat0/gateways | grep "^=>" | cut -d" " -f2`
		if [ "$GWM" == "" ]; then
			GWM="00:00:00:00:00"
		fi
		GWLS=`cat /sys/kernel/debug/batman_adv/bat0/originators | grep "^$GWM" | cut -d" " -f3-5 | cut -d"s" -f1 | cut -d"." -f1`
		if ! [ "$GWLS" -eq "$GWLS" ] 2>/dev/null; then # there's no gateway found, skipping active ACTIVE_CHECK
			MODE=4
			OFFLINE=1
			echo "Debug: No gateway in originators found - we're offline."
		else
			echo -n "Debug: Selected gateway last-seen $GWLS second(s) ago"
			if [ $GWLS -gt $(( `cat /sys/devices/virtual/net/bat0/mesh/orig_interval` / 1000 * $OGM_INT_MULT)) ]; then
				echo " - this is not okay, we seem to be offline"
				OFFLINE=1
				MODE=3
				continue
			else
				echo " - this is fine, we're online"
				OFFLINE=0
				MODE=4
			fi
		fi
		;;
	3) #check: gateway is reachable
		if [ $ACTIVE_CHECK -eq 1 ]; then
			echo -n "Debug: Active-checking enabled, pinging selected gateway..."
			GWL=`batctl ping -c$PING_CNT $GWM | grep "packet loss" | cut -d" " -f6 | cut -d"%" -f1`
			if ! [ "$GWL" -eq "$GWL" ] 2>/dev/null; then
				echo " ERROR: Ping-command failed"
				OFFLINE=1
			else
				echo " done."
				echo -n "Debug: Packetloss ($GWL %) "
				if [ "$GWL" -gt "$MIN_PING_PERCENT" ]; then
					OFFLINE=0
					echo "fine."
				else
					OFFLINE=1
					echo "to high."
				fi
			fi
			MODE=4
		else
			echo "Debug: Active-checking disabled. Skipping"
			MODE=4
		fi
		;;
	4) #sleep
		echo "Debug: Sleeping now for $SLEEP seconds"
		sleep $SLEEP
		echo ""
		MODE=1
		continue
		;;
	*)
		echo "Error: Fatal error." && exit 2
		;;
	esac

	LED_STATUS_SET=0 #Only change LED once if there are multiply phy's

	for CLIENT_RADIO in $(uci show wireless | grep 'wireless.client_radio' | grep 'ifname' | grep '='\''client' | cut -d '=' -f1 | cut -d '.' -f2); do

		FORCE_CHANGE=0
		ISOFFLINE=0
		SSID_BOOT=""
		SSID_ONLINE=""
		SSID_OFFLINE=""
		NEED_CHANGE=0
		HPID=""
		PHY_DEV=""
		IFNAME=""

		SSID_ONLINE="$(uci get wireless.$CLIENT_RADIO.$SUB_CONF_ONLINE_SSID)"
		SSID_BOOT="$(uci get wireless.$CLIENT_RADIO.$SUB_CONF_BOOT_SSID)"

		IFNAME="$(uci get wireless.$CLIENT_RADIO.ifname)"
		tmp="$(readlink -f /sys/devices/platform/*/net/$IFNAME/phy80211)"
		[ -z "$tmp" ] && tmp=`echo "/$(cat /sys/devices/pci*/*/net/$IFNAME/phy80211/name)"`
		PHY_DEV="${tmp##*/}"
		unset tmp
		if [ -z "$PHY_DEV" ]; then
			echo "ERROR: Could not detect phy-dev for ifname '$IFNAME'. Skipping any SSID change."
			continue
		fi
		HOSTAPD_CONF="/var/run/hostapd-$PHY_DEV.conf"


		if ! [ -f $HOSTAPD_CONF ]; then
			echo "ERROR: Hostapd conf missing (PHY_DEV=$PHY_DEV;IFNAME=$IFNAME). Skipping any SSID change."
			continue
		elif [ "$SSID_BOOT" == "" ]; then
			echo "Error: UCI can't find Boot-SSID for interface '$IFNAME'. Append them with:"
			echo "uci set wireless.$CLIENT_RADIO.$SUB_CONF_BOOT_SSID=x"
			echo "uci commit wireless"
			exit 2
		elif [ "$SSID_ONLINE" == "" ]; then
			echo "Error: UCI can't find SSID for interface '$IFNAME'. Append them with:"
			echo "uci set wireless.$CLIENT_RADIO.$SUB_CONF_ONLINE_SSID=x"
			echo "uci commit wireless"
			exit 2
		fi

		# generate offline-SSID
		if [ ${#SSID_ONLINE} -gt $(( 23 - ${#HN} )) ]; then  #cut ssid to the maximum
			SSID_OFFLINE="${SSID_0_ONLINE:0:$(( 20 - ${#HN} ))}..."
		else
			SSID_OFFLINE=$SSID_ONLINE
		fi
		SSID_OFFLINE="Offline-$SSID_OFFLINE-$HN"

		if [ "$SSID_OFFLINE" == "" ]; then
			echo "ERROR: generating of Offline-SSID failed for $IFNAME"
			continue
		fi

		# get hostap-status
		CURRENT_SSID=`cat $HOSTAPD_CONF | grep "^ssid=$SSID_ONLINE"`
		[ -z "$CURRENT_SSID" ] && CURRENT_SSID=`cat $HOSTAPD_CONF | grep "^ssid=$SSID_OFFLINE"`
		[ -z "$CURRENT_SSID" ] && CURRENT_SSID=`cat $HOSTAPD_CONF | grep "^ssid=$SSID_BOOT"`
		CURRENT_SSID=${CURRENT_SSID:5} #rm ssid=

#		echo "Debug: $IFNAME:"
#		echo "      SSID for boot   : '$SSID_BOOT'"
#		echo "      SSID for online : '$SSID_ONLINE'"
#		echo "      SSID for offline: '$SSID_OFFLINE'"
#		echo "      Current SSID is : '$CURRENT_SSID'"

		echo -n "Debug: Hostapd for $IFNAME is configured to SSID '$CURRENT_SSID', "

		if [ "$CURRENT_SSID" == "$SSID_ONLINE" ]; then
			ISOFFLINE=0
			echo "our online-SSID"
		elif [ "$CURRENT_SSID" == "$SSID_OFFLINE" ]; then
			ISOFFLINE=1
			echo "our offline-SSID"
		elif [ "$CURRENT_SSID" == "$SSID_BOOT" ]; then
			FORCE_CHANGE=1
			echo "our boot-SSID"
		else
			FORCE_CHANGE=1
			echo "WARNING: this seems wrong, we're changing it now."
		fi

		### Checking if update is needed ###

		echo "Debug: OFFLINE=$OFFLINE ISOFFLINE=$ISOFFLINE FORCE_CHANGE=$FORCE_CHANGE"

		if ! [ $FORCE_CHANGE -eq 1 ]; then
			if [ $OFFLINE -eq 1 -a $ISOFFLINE -eq 0 ]; then
				echo "Debug: Our check says, we're offline, need to change SSIDs"
				NEED_CHANGE=1
			elif [ $OFFLINE -eq 0 -a $ISOFFLINE -eq 1 ]; then
				echo "Debug: Our check says, we're back online, need to change SSIDs"
				NEED_CHANGE=1
			fi
		else
			echo "Debug: Need to change SSIDs."
		fi

		### setting SSIDs and LED-Status (on the first interface only) ###

		if [ $NEED_CHANGE -eq 1 -o $FORCE_CHANGE -eq 1 ]; then
			if [ $OFFLINE -eq 1 ]; then
				SSID="$SSID_OFFLINE"
				if [ $LED_STATUS -eq 1 -a $LED_STATUS_SET -eq 0 ]; then
					status_led_set_timer 50 1200
					LED_STATUS_SET=1
				fi
			else
				SSID="$SSID_ONLINE"
				if [ $LED_STATUS -eq 1 -a $LED_STATUS_SET -eq 0 ]; then
					status_led_on
					LED_STATUS_SET=1
				fi
			fi

			SSID="ssid=$SSID"

			if ! [ -f $HOSTAPD_CONF ]; then
				echo "ERROR: $HOSTAPD_CONF gone. Skipping the SSID-change."
				continue
			fi

			sed -i -e "s/^ssid=$SSID_ONLINE/$SSID/" "$HOSTAPD_CONF"
			sed -i -e "s/^ssid=$SSID_OFFLINE/$SSID/" "$HOSTAPD_CONF"
			sed -i -e "s/^ssid=$SSID_BOOT/$SSID/" "$HOSTAPD_CONF"

			HPID="$(ps | grep "$HOSTAPD_CONF" | grep -v "grep" | awk '{ print $1; }')"
			if [ -z "$HPID" ]; then
				echo "ERROR: Hostapd pid for $PHY_DEV could not be found. Skipping the SSID-change."
				continue
			fi
			echo -n "Debug: HUPing hostapd PID $HPID now..."
			kill -HUP $HPID
			echo "done."
		fi
	done
done
[ -f "$PIDFILE" ] && rm "$PIDFILE" #cleanup