====== Limitation de bande passante ======

Ces 3 scripts sont basé sur l'outil tc, fourni dans le paquet iproute2. Ils utilisent le scheduler réseau HTB. Cet exemple traite d'une limitation de bande passante sur le port 80 de la machine hôte.

<code bash>
#!/bin/sh
# script /etc/init.d/limit-bandwidth
# run the htb-* scripts to limit (or not) the bandwith
# Author: Loïs
#
SCRDIR="/root/nyx/scripts"
BINSTART="htb-start.sh"
BINSTOP="htb-stop.sh"
MODULE="sch_htb"
ETH_DEV="eth0"

# if scripts not present, stop & exit.
test -x $SCRDIR/$BINSTART || exit 0
test -x $SCRDIR/$BINSTOP || exit 0

case "$1" in
        start)
                echo "starting HTB on eth0, port 80: "
                modprobe $MODULE
                sleep 2
                $SCRDIR/$BINSTART
                echo ""
                ;;
        stop)
                echo "stopping HTB on eth0, port 80: "
                $SCRDIR/$BINSTOP
                modprobe -r $MODULE
                echo ""
                ;;
        restart)
                echo "restarting HTB on eth0, port 80: "
                $SCRDIR/$BINSTOP
                modprobe -r $MODULE
                sleep 2
                modprobe $MODULE
                sleep 2
                $SCRDIR/$BINSTART
                echo ""
                ;;
        status)
                echo "bandwith limits status: "
                tc -s qdisc show dev $ETH_DEV
                tc -s class show dev $ETH_DEV
                echo ""
                ;;
        *)
                echo "Limit the bandwidth apache2 use"
                echo "Usage: $0 {start|stop|restart|status}"
                echo ""
                exit 1
                ;;
esac

exit 0
</code>

<code bash>
#!/bin/sh
# htb-start.sh
# Author: gentoo-wiki
# change these values to suit your needs
ETH_DEV="eth0"
LINK_SPEED="2048Kbit"
UPLOAD_SPEED="1024Kbit"
PORT="80"

# delete previous root node
tc qdisc del dev $ETH_DEV root

# create root node
tc qdisc add dev $ETH_DEV root handle 1: htb default 11

# create LINK class
tc class add dev $ETH_DEV parent 1: classid 1:1 htb rate $LINK_SPEED

# create our HTTP shaping class
tc class add dev $ETH_DEV parent 1:1 classid 1:10 htb rate $UPLOAD_SPEED

# create our REST class for unutilized bandwidth
tc class add dev $ETH_DEV parent 1:1 classid 1:11 htb rate $LINK_SPEED

# create the filter for the HTTP class, we filter on source port 80 (http)
tc filter add dev $ETH_DEV protocol ip parent 1:0 prio 1 u32 match ip sport $PORT 0xffff flowid 1:10
</code>

<code bash>
#!/bin/sh
# htb-stop.sh
# Author: gentoo-wiki
ETH_DEV="eth0"

tc qdisc del dev $ETH_DEV root
</code>