#! /bin/sh
#
# wonderping.sh - find the highest upstream with acceptable latency
# Copyright (C) 2006 Tommi Saviranta <wnd@iki.fi>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
# Version: wonderping.sh v0.1.1  22-Jan-2006  wnd@iki.fi


WANT=50			# desired latency
UP=600			# initial upstream (kb/s)
DOWN=7000		# downstream (kb/s)
STEP=100		# initial increment for upstream

PING="83.145.228.190"	# host to ping
COUNT=128		# ping N times
IFACE="eth1"		# interface to tweak

FILE="/tmp/bob"		# scp $FILE $TARGET
TARGET="user@host.com:"	# scp $FILE $TARGET
RESULT="log"		# result file



TMP=$(tempfile)
trap "test -e "$TMP" && rm \"$TMP\"; exit" 0 1 2 15
test -e "$RESULT" && rm "$RESULT"


do_ping() {
	IP="$1"
	ping -c $COUNT $PING 2>&1 | tee "$TMP"
	LOSS=$(tail -n 2 "$TMP" | head -n 1 | sed 's/.* \([0-9]*\)%.*/\1/')
	LINE=$(tail -n 1 "$TMP" | sed 's/.*= \(.*\) m.*/\1/')
	MIN=$(echo "$LINE" | cut -d '/' -f 1 | cut -d '.' -f 1)
	AVG=$(echo "$LINE" | cut -d '/' -f 2 | cut -d '.' -f 1)
	MAX=$(echo "$LINE" | cut -d '/' -f 3 | cut -d '.' -f 1)
	MDEV=$(echo "$LINE" | cut -d '/' -f 4 | cut -d '.' -f 1)
}


transfer() {
	scp -q "$FILE" "$TARGET" &
	PID=$!
}


while true; do
	echo "Upstream: $UP kb/s"
	wondershaper clear "$IFACE"
	wondershaper "$IFACE" $DOWN $UP

	transfer "$FILE" "$WANT"
	sleep 5
	do_ping
	kill $PID
	echo "$UP\t$MIN\t$AVG\t$MAX\t$MDEV\t$LOSS" >>"$RESULT"

	if test $AVG -lt $WANT; then
		UP=$(expr $UP + $STEP)
		GOTUP=1
	elif test $AVG -gt $WANT; then
		if test $GOTUP -eq 1; then
			STEP=$(expr $STEP / 2)
			test $STEP -eq 0 && break
		fi
		UP=$(expr $UP - $STEP)
	fi
done

sort -n "$RESULT" >"$TMP"
mv "$TMP" "$RESULT"

echo "All done. See \"$RESULT\" for results (use GnuPlot)."