localqos



#!/bin/bash
#
# Shaper to share two connection more or less equally among a number of users.
# By Rune Kock, rune.kock@gmail.com
#
# Inspired by Jim diGriz's QoS Scheduler (http://www.digriz.org.uk/jdg-qos-script/)
# and by the WRR example.
#
# Dependencies
# ------------
# 1) HTB3, RED (has been in the kernel for years)
# 3) iptables utility (www.netfilter.org)
# 4) tc utility (developer.osdl.org/dev/iproute2)
# 6) WRR patch (www.zz9.dk/wrr) and tc patch 
# 7) IMQ patch (www.linuximq.net) and iptables patch NOTE: in AA-configuration!!!
# 8) atm and nohyst patches (http://ace-host.stuart.id.au/russell/files/tc/tc-atm/)

# This script can be edited to support more than one ADSL line.
# Each WAN-line is shaped independently -- not quite fair, but the easiest
# (probably the only) way to do it.

# Script parameters:
#   stop        removes QOS setup
#   ...any other... removes QOS setup if any, then sets new QOS.

# debug on....comment out if you want BASH script debugging off
# set -x

# load configuration from external file
. /etc/qos/config


############# Functions for each ADSL line ######################
function REMOVE-QOS
{
    local IFACE=$1      # e.g. eth0
    local DWIMQ=$2      # e.g. 0
    
    $TC qdisc del dev imq$DWIMQ root &> /dev/null
    $TC qdisc del dev $IFACE root &> /dev/null

    $IPTABLES -t mangle -D PREROUTING -i $IFACE -j IMQ --todev $DWIMQ &> /dev/null
    $IP link set imq$DWIMQ down &> /dev/null
}
#-----------------------------------------------------------------
function QOS-UPLINK
{
    local IFACE=$1
    local UPLIMIT=$2
    local WRR_CLIENTS=$3
    local OVERHEAD=$4
    local PUBIP=$5

    # more description below at QOS-DOWNLINK

    # The effect of these settings:
    # - the maximum priority is 10x minimum.
    # - it takes 25 hours without activity to gain maximum priority
    # - it takes 90 Mbyte transferred data to be bumped to mimimum priority

    local WRR_WEIGHT1_MODE=1
    local WRR_WEIGHT1_INCR=0.00001
    local WRR_WEIGHT1_DECR=0.00000001
    local WRR_WEIGHT1_MIN=0.1
    local WRR_WEIGHT1_MAX=1.0
    local WRR_WEIGHT1_VAL=1.0

    # Use HTB to limit the total speed
    $TC qdisc add dev $IFACE root handle 8000: htb default 12
    $TC class add dev $IFACE parent 8000: classid 8000:1 htb \
        rate ${UPLIMIT}kbit ceil ${UPLIMIT}kbit overhead $OVERHEAD atm nohyst

    # Create 3 HTB classes for high priority local, normal priority local,
    # and normal priority client traffic.
    $TC class add dev $IFACE parent 8000:1 classid 8000:10 htb\
        rate $[$UPLIMIT/3]kbit ceil ${UPLIMIT}kbit overhead $OVERHEAD atm nohyst prio 2
    $TC class add dev $IFACE parent 8000:1 classid 8000:11 htb \
        rate $[$UPLIMIT/3]kbit ceil ${UPLIMIT}kbit overhead $OVERHEAD atm nohyst prio 1
    $TC class add dev $IFACE parent 8000:1 classid 8000:12 htb \
        rate $[$UPLIMIT/3]kbit ceil ${UPLIMIT}kbit overhead $OVERHEAD atm nohyst prio 1

    # To distinguish between local packet and packets originating from the lan, we have
    # told Shorewall to give the latter mark 1.  (IP source cannot be used, because we are now
    # operating after NAT, so everything has our public IP as source).
    # Put local packets < 512 bytes in 8000:10
    $TC filter add dev $IFACE protocol ip parent 8000:0 prio 1 u32 \
        match mark 0 0xffff match u16 0x0000 0xfe00 at 2 flowid 8000:10
    # Put other local packets in 8000:11
    $TC filter add dev $IFACE protocol ip parent 8000:0 prio 1 u32 \
        match mark 0 0xffff flowid 8000:11
    # Non-local packets defaults to 8000:12

    # Client traffic is shared according to ip-address by WRR (the masqueraded source address)
    $TC qdisc add dev $IFACE parent 8000:12 handle 1000: wrr sour masq $WRR_CLIENTS 0
    $TC qdisc change handle 1000: dev $IFACE wrr qdisc wmode1=$WRR_WEIGHT1_MODE wmode2=0

    # Each WRR class gets a RED queue.
    # RED drops or ECN-marks packets according to queue-length.
    # At <=2kbyte the chance of a RED action is 0%.  At 100kbyte it is 100%.
    # Hopefully, the sender will get the picture at around 15kbytes.
    local RED_MIN=2000  # Start shaping if average queue exceeds 2 kbyte
    local RED_MAX=100000    # Full shaping at 100kbytes
    local RED_LIMIT=100000  # Absolut maximum queue size
    local RED_PROB=1.0  # The probability of dropping/marking a packet when
                # queue >= max. Man-page suggests 0.01 or 0.02
    local RED_AVPKT=500 # man-page suggests 1000
    local RED_BURST=8   # man-page suggests (min+min+max)/(3*avpkt)
                # (but they use min and max a lot differently than we do).

    for LOOP in `seq 1 $WRR_CLIENTS`
    do
        local LOOP_HEX=$(printf %X $LOOP)
        $TC qdisc add dev $IFACE parent 1000:$LOOP_HEX handle $[1000+$LOOP]: \
            red probability $RED_PROB \
            limit ${RED_LIMIT} min ${RED_MIN} max ${RED_MAX} \
            avpkt ${RED_AVPKT} burst $RED_BURST ecn

        $TC class change classid 1000:$LOOP_HEX dev $IFACE \
            wrr min1=$WRR_WEIGHT1_MIN max1=$WRR_WEIGHT1_MAX \
            decr1=$WRR_WEIGHT1_DECR incr1=$WRR_WEIGHT1_INCR \
            weight1=$WRR_WEIGHT1_VAL
    done
}

#----------------------------------------------------------------
function QOS-DOWNLINK
{
    local IFACE=$1
    local DWLIMIT=$2
    local WRR_CLIENTS=$3
    local OVERHEAD=$4
    local PUBIP=$5

    # The following parameters defines the way heavy downloaders are gradually
    # given a lesser share than new downloaders (a burst effect).
    # Each class has a weight that is dynamically modified as follows:
    # (Actually, there are two identical sets of parameters, but I can see absolutely
    #  no reason to use the second, so it's always inactive).

    # The effect of these settings:
    # - the maximum priority is 10x minimum.
    # - it takes 25 hours without activity to gain maximum priority
    # - it takes 900 Mbyte transferred data to be bumped to mimimum priority

    local WRR_WEIGHT1_MODE=1
    # 0: The weight parameter is not modified
    # 1: The weight parameter is decremented by decr*<packet size>
    # 2: As if wmode is 1, but also multiply with number of machines waiting
    #    to transfer data
    # 3: As if wmode is 1, but multiplied with the sum of the priorities of the
    #    machines waiting divided by the priority of this machine.

    local WRR_WEIGHT1_INCR=0.00001
    # Every second the weight parameter is incremented by this value. If
        # weight1 reaches 1.0 it is not incremented further.
    # The default value is 0.0.

    local WRR_WEIGHT1_DECR=0.000000001
    # Every time a packet is sent the weight parameter is modified depending
        # on the value of wmode for the qdisc

    local WRR_WEIGHT1_MIN=0.1
    # min: (0<min)
    # This is a lower bound for weight. 
    # The default value for this parameter is 1.0.

    local WRR_WEIGHT1_MAX=1.0
    # max: (0<max)
    # This is a upper bound for weight. 
    # The default value for this parameter is 1.0.

    local WRR_WEIGHT1_VAL=1.0
    # weight: (min<=weight<=1.0)
    # As mentioned above the used weight of the class is proportional to
    # this value. The default value is 1.0.

    # Use HTB to limit the speed
    $TC qdisc add dev $IFACE root handle 8000: htb default 12
    $TC class add dev $IFACE parent 8000: classid 8000:1 htb \
        rate ${DWLIMIT}kbit ceil ${DWLIMIT}kbit overhead $OVERHEAD atm nohyst

    # Create 3 HTB classes for high priority local, normal priority local,
    # and normal priority client traffic.
    $TC class add dev $IFACE parent 8000:1 classid 8000:10 htb\
        rate $[$DWLIMIT/3]kbit ceil ${DWLIMIT}kbit overhead $OVERHEAD atm nohyst prio 2
    $TC class add dev $IFACE parent 8000:1 classid 8000:11 htb \
        rate $[$DWLIMIT/3]kbit ceil ${DWLIMIT}kbit overhead $OVERHEAD atm nohyst prio 1
    $TC class add dev $IFACE parent 8000:1 classid 8000:12 htb \
        rate $[$DWLIMIT/3]kbit ceil ${DWLIMIT}kbit overhead $OVERHEAD atm nohyst prio 1

    # Put local packets < 512 bytes in 8000:10
    # (IMQ in AA configuration grabs the packets after NAT, so we can test on destination).
    $TC filter add dev $IFACE protocol ip parent 8000:0 prio 1 u32 \
        match ip dst $PUBIP match u16 0x0000 0xfe00 at 2 flowid 8000:10

    # Put other local packets in 8000:11
    $TC filter add dev $IFACE protocol ip parent 8000:0 prio 1 u32 \
        match ip dst $PUBIP flowid 8000:11
    # Non-local packets defaults to 8000:12

    # Share according to ip-address by WRR
    $TC qdisc add dev $IFACE parent 8000:12 handle 1000: wrr dest ip $WRR_CLIENTS 0
    $TC qdisc change handle 1000: dev $IFACE wrr qdisc wmode1=$WRR_WEIGHT1_MODE wmode2=0

    # Each WRR class gets a RED queue.
    # RED drops or ECN-marks packets according to queue-length.
    # At 2kbyte the chance of a RED action is 0%.  At 1Mbyte it is 100%.
    # Hopefully, the sender will get the picture at around 10-20kbytes.
    local RED_MIN=2000  # Start shaping if average queue exceeds 1 kbyte
    local RED_MAX=1000000   # Full shaping at 1Mbytes
    local RED_LIMIT=1000000 # Absolut maximum queue size
    local RED_PROB=1.0  # The probability of dropping/marking a packet when
                # queue >= max. Man-page suggests 0.01 or 0.02
    local RED_AVPKT=1000    # man-page suggests 1000
    local RED_BURST=2   # man-page suggests (min+min+max)/(3*avpkt)
                # (but they use min and max a lot differently than we do).

    for LOOP in `seq 1 $WRR_CLIENTS`
    do
        local LOOP_HEX=$(printf %X $LOOP)
        $TC qdisc add dev $IFACE parent 1000:$LOOP_HEX handle $[1000+$LOOP]: \
            red probability $RED_PROB \
            limit ${RED_LIMIT} min ${RED_MIN} max ${RED_MAX} \
            avpkt ${RED_AVPKT} burst $RED_BURST ecn

        $TC class change classid 1000:$LOOP_HEX dev $IFACE \
            wrr min1=$WRR_WEIGHT1_MIN max1=$WRR_WEIGHT1_MAX \
            decr1=$WRR_WEIGHT1_DECR incr1=$WRR_WEIGHT1_INCR \
            weight1=$WRR_WEIGHT1_VAL
    done
}
#-----------------------------------------------------------------------
function IFACE-SETUP
{
    local IFACE=$1
    local DWIMQ=$2

    $IPTABLES -t mangle -I PREROUTING -i $IFACE -j IMQ --todev $DWIMQ
    $IP link set imq$DWIMQ up 
}

##############################################################################

############## Remove QOS configuration ##########################

REMOVE-QOS $IF1 0       # Once for each ADSL-line
# REMOVE-QOS $IF2 1

# removing imq (version 2.6.14-imq1) causes kernel panic
#$MODPROBE -r imq &> /dev/null

if ( [ "$1" = "stop" ] )
then
    exit
fi

############## Set up QOS configuration ###########################

$MODPROBE imq numdevs=$LINES

QOS-UPLINK $IF1 $UPLIMIT1 $CLIENTS $UPOVERHEAD1 $PUBLICIP1 # Once for each ADSL-line
# QOS-UPLINK $IF2 $UPLIMIT2 $CLIENTS $UPOVERHEAD2 $PUBLICIP2

QOS-DOWNLINK imq0 $DWLIMIT1 $CLIENTS $DWOVERHEAD1 $PUBLICIP1  # Once for each ADSL-line
# QOS-DOWNLINK imq1 $DWLIMIT2 $CLIENTS $DWOVERHEAD2 $PUBLICIP2

IFACE-SETUP $IF1 0      # Once for each ADSL-line
# IFACE-SETUP $IF2 1