gistfile1.txt

#!/bin/sh

set -x

# http://lartc.org/howto/lartc.qdisc.classful.html
# A single user has 5000kbit upload for himself. But they want prioritizing.

# Variables
TC=$(which tc)
IPT=$(which iptables)
IPTMO="$IPT -t mangle"
DEV=br-wan
RATE=5000

insmod sch_prio

# The PRIO qdisc is a non-shaping container for a configurable number of classes
# which are dequeued in order. This allows for easy prioritization of traffic,
# where lower classes are only able to send if higher ones have no packets
# available.

$TC qdisc add dev $DEV root       handle 1:    prio
#$TC class add dev $DEV parent 1:  classid 1:1  prio rate ${RATE}kbit
$TC qdisc add dev $DEV parent 1:1 handle 10: sfq
$TC qdisc add dev $DEV parent 1:1 handle 20: tbf rate ${RATE}kbit buffer 1600 limit 3000
$TC qdisc add dev $DEV parent 1:1 handle 30: sfq

# Filter
# Since PRIO honors the TOS/QoS-Field by default, we should be concerned with our
# applications setting the right QoS for every packet they create. Additionally we
# can not blindly trust the set TOS and change it:

$IPTMO -F CHKTOS
$IPTMO -X CHKTOS
$IPTMO -N CHKTOS                                         # create custom chain for this issue
$IPTMO -A POSTROUTING -o $DEV -j CHKTOS                  # every packet immediately jumps to custom-chain: CHKTOS
$IPTMO -A CHKTOS -m tos ! --tos Normal-Service -j RETURN # if TOS is set, leave it
$IPTMO -A CHKTOS -p udp -j TOS --set-tos Minimize-Delay  # UDP gets high priority
$IPTMO -A CHKTOS -p udp -m length --length :160 -j TOS --set-tos Minimize-Delay # small udp packets
$IPTMO -A CHKTOS -p tcp -m length --length :128 -j TOS --set-tos Minimize-Delay # small tcp packets get high priority
$IPTMO -A CHKTOS -p tcp --sport ssh -j TOS --set-tos Minimize-Delay             # prioritize ssh