#!/bin/sh
# Cero3 Shaper
# A 3 bin tc_codel and ipv6 enabled shaping script for
# ethernet gateways

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
#       Copyright (C) 2012-4 Michael D. Taht, Toke Høiland-Jørgensen, Sebastian Moeller

# Compared to the complexity that debloat had become
# this cleanly shows a means of going from diffserv marking
# to prioritization using the current tools (ip(6)tables
# and tc. I note that the complexity of debloat exists for
# a reason, and it is expected that script is run first
# to setup various other parameters such as BQL and ethtool.
# (And that the debloat script has setup the other interfaces)

# You need to jiggle these parameters. Note limits are tuned towards a <10Mbit uplink <60Mbup down

#sm: Goal to create a set of tc filters that also apply on pppoe encapsulated packets
#	but having multiple filters run in succession is slow, so look at tc filter hashing 
#	(this should help cut down the number of OPs per packet considerably)


. /usr/lib/sqm/functions.sh
#sqm_logger IPT_MASK: ${IPT_MASK_STRING}
ipt_setup() {

ipt -t mangle -N QOS_MARK_${IFACE}

ipt -t mangle -A QOS_MARK_${IFACE} -j MARK --set-mark 0x2${IPT_MASK_STRING}
# You can go further with classification but...
ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class CS1 -j MARK --set-mark 0x3${IPT_MASK_STRING}
ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class CS6 -j MARK --set-mark 0x1${IPT_MASK_STRING}
ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class EF -j MARK --set-mark 0x1${IPT_MASK_STRING}
ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class AF42 -j MARK --set-mark 0x1${IPT_MASK_STRING}
ipt -t mangle -A QOS_MARK_${IFACE} -m tos  --tos Minimize-Delay -j MARK --set-mark 0x1${IPT_MASK_STRING}

# and it might be a good idea to do it for udp tunnels too

# Turn it on. Preserve classification if already performed

if [ "$SQUASH_DSCP" = "1" ]
then
sqm_logger "Squashing differentiated services code points (DSCP) from ingress."
ipt -t mangle -I PREROUTING -i $IFACE -m dscp ! --dscp 0 -j DSCP --set-dscp-class be
else
sqm_logger "Keeping differentiad services code points (DSCP) from ingress."
ipt -t mangle -A PREROUTING -i $IFACE -m mark --mark 0x00${IPT_MASK_STRING} -g QOS_MARK_${IFACE} 
fi

ipt -t mangle -A POSTROUTING -o $IFACE -m mark --mark 0x00${IPT_MASK_STRING} -g QOS_MARK_${IFACE} 

# The Syn optimization was nice but fq_codel does it for us
# ipt -t mangle -A PREROUTING -i s+ -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -j MARK --set-mark 0x01
# Not sure if this will work. Encapsulation is a problem period

ipt -t mangle -I PREROUTING -i vtun+ -p tcp -j MARK --set-mark 0x2${IPT_MASK_STRING} # tcp tunnels need ordering

# Emanating from router, do a little more optimization
# but don't bother with it too much. 

ipt -t mangle -A OUTPUT -p udp -m multiport --ports 123,53 -j DSCP --set-dscp-class AF42

#Not clear if the second line is needed
#ipt -t mangle -A OUTPUT -o $IFACE -g QOS_MARK_${IFACE}

}


MYBURST=1600	#sm: make burst and cburst as well as quantum configurable for ingress and egress in the GUI
# TC rules

egress() {

CEIL=${UPLINK}
PRIO_RATE=`expr $CEIL / 3` # Ceiling for priority
BE_RATE=`expr $CEIL / 6`   # Min for best effort
BK_RATE=`expr $CEIL / 6`   # Min for background
BE_CEIL=`expr $CEIL - 16`  # A little slop at the top

LQ="quantum `get_mtu $IFACE $CEIL`"
HTB_BURSTS="burst ${MYBURST} cburst ${MYBURST}"

$TC qdisc del dev $IFACE root 2> /dev/null
$TC qdisc add dev $IFACE root handle 1: `get_stab_string` htb default 12
$TC class add dev $IFACE parent 1: classid 1:1 htb $LQ ${HTB_BURSTS} rate ${CEIL}kbit ceil ${CEIL}kbit `get_htb_adsll_string`
$TC class add dev $IFACE parent 1:1 classid 1:10 htb $LQ ${HTB_BURSTS} rate ${CEIL}kbit ceil ${CEIL}kbit prio 0 `get_htb_adsll_string`
$TC class add dev $IFACE parent 1:1 classid 1:11 htb $LQ ${HTB_BURSTS} rate 128kbit ceil ${PRIO_RATE}kbit prio 1 `get_htb_adsll_string`
$TC class add dev $IFACE parent 1:1 classid 1:12 htb $LQ ${HTB_BURSTS} rate ${BE_RATE}kbit ceil ${BE_CEIL}kbit prio 2 `get_htb_adsll_string`
$TC class add dev $IFACE parent 1:1 classid 1:13 htb $LQ ${HTB_BURSTS} rate ${BK_RATE}kbit ceil ${BE_CEIL}kbit prio 3 `get_htb_adsll_string`

$TC qdisc add dev $IFACE parent 1:11 handle 110: $QDISC `get_limit ${ELIMIT}` `get_target "${ETARGET}" ${UPLINK}` `get_ecn ${EECN}` `get_quantum 300` `get_flows ${PRIO_RATE}` ${EQDISC_OPTS}
$TC qdisc add dev $IFACE parent 1:12 handle 120: $QDISC `get_limit ${ELIMIT}` `get_target "${ETARGET}" ${UPLINK}` `get_ecn ${EECN}` `get_quantum 300` `get_flows ${BE_RATE}` ${EQDISC_OPTS}
$TC qdisc add dev $IFACE parent 1:13 handle 130: $QDISC `get_limit ${ELIMIT}` `get_target "${ETARGET}" ${UPLINK}` `get_ecn ${EECN}` `get_quantum 300` `get_flows ${BK_RATE}` ${EQDISC_OPTS}


#sm: for testing we need a band to collect PPPOEd packets
$TC class add dev $IFACE parent 1:1 classid 1:14 htb $LQ rate ${BE_RATE}kbit ceil ${BE_CEIL}kbit prio 2 `get_htb_adsll_string`
$TC qdisc add dev $IFACE parent 1:14 handle 140: $QDISC `get_limit ${ELIMIT}` `get_target "${ETARGET}" ${UPLINK}` `get_ecn ${EECN}` `get_quantum 300` `get_flows ${BK_RATE}` ${EQDISC_OPTS}


# Need a catchall rule (should also match VLANs and PPPoE packets)

$TC filter add dev $IFACE parent 1:0 protocol all prio 999 u32 \
        match ip protocol 0 0x00 flowid 1:12  

# FIXME should probably change the filter here to do pre-nat
        
$TC filter add dev $IFACE parent 1:0 protocol ip prio 1 handle 1 fw classid 1:11
$TC filter add dev $IFACE parent 1:0 protocol ip prio 2 handle 2 fw classid 1:12
$TC filter add dev $IFACE parent 1:0 protocol ip prio 3 handle 3 fw classid 1:13

# ipv6 support. Note that the handle indicates the fw mark bucket that is looked for

$TC filter add dev $IFACE parent 1:0 protocol ipv6 prio 4 handle 1 fw classid 1:11
$TC filter add dev $IFACE parent 1:0 protocol ipv6 prio 5 handle 2 fw classid 1:12
$TC filter add dev $IFACE parent 1:0 protocol ipv6 prio 6 handle 3 fw classid 1:13

# Arp traffic

$TC filter add dev $IFACE parent 1:0 protocol arp prio 7 handle 1 fw classid 1:11

# ICMP traffic - Don't impress your friends. Deoptimize to manage ping floods
# better instead

$TC filter add dev $IFACE parent 1:0 protocol ip prio 8 \
	 u32 match ip protocol 1 0xff flowid 1:13

$TC filter add dev $IFACE parent 1:0 protocol ipv6 prio 9 \
	 u32 match ip protocol 1 0xff flowid 1:13




# PPPoE encapsulated packets traversing the router (e.g.: the router does PPPoE termination but we shape 
# on the underlaying ethernet interface instead of the pppoe device)

PPPOE_SESSION_ETHERTYPE="0x8864"
PPPOE_DISCOVERY_ETHERTYPE="0x8863"
PPP_PROTO_IP4="0x0021"
PPP_PROTO_IP6="0x0057"
ARP_PROTO_IP4="0x0806"

# NOTE it seems prio can not be reused?
#$TC filter add dev $IFACE protocol 0x8863 parent 1:0 prio 1 u32 flowid 1:14
# PPPoE can be selected for by ether_type, the encapsulated IP version from the PPP (0x0021 IPv4, 0x0057 IPv6)
#U32_PREFIX="$TC filter add dev $IFACE" parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE}"

#BE: 1:12 is the default anyway, but this will catch all non marked packets
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 400 u32 \
#	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
#	match u8 0x00 0xfb at 9 \
#	flowid 1:12

#AF42
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 401 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0x90 0xfc at 9 \
	flowid 1:11
#EF
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 402 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0xb8 0xfc at 9 \
	flowid 1:11
#CS1
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 403 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0x20 0xf0 at 9 \
	flowid 1:13
#IMM
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 404 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0x10 0xf0 at 9 \
	flowid 1:11
#CS3
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 405 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0xc0 0xf0 at 9 \
	flowid 1:11
#CS6
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 406 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0xe0 0xf0 at 9 \
	flowid 1:11


## Arp traffic
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 409 u32 \
#	match u16 ${ARP_PROTO_IP4} 0xffff at 6 \
#	flowid 1:14

# ICMP traffic - Don't impress your friends. Deoptimize to manage ping floods
# better instead; sm: really only deprio echo requestst and echo replies instead?
# ECHO request, the rest stays in best effort
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 410 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0x01 0xff at 17 \
	match u8 0x08 0xff at 28 \
	flowid 1:13
# ECHO reply
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 410 u32 \
	match u16 ${PPP_PROTO_IP4} 0xffff at 6 \
	match u8 0x01 0xff at 17 \
	match u8 0x00 0xff at 28 \
	flowid 1:13

## ICMPv6 133-137 (NDP) is equivalent to IPv4 ARP, so only push echo request and reply into the bulk class
## 133
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u8 0x85 0xff at 48 \
#	match u8 0x3a 0xff at 14 \
#	flowid 1:14
## 134
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u8 0x86 0xff at 48 \
#	match u8 0x3a 0xff at 14 \
#	flowid 1:14
## 135
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u8 0x87 0xff at 48 \
#	match u8 0x3a 0xff at 14 \
#	flowid 1:14
## 136
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u8 0x88 0xff at 48 \
#	match u8 0x3a 0xff at 14 \
#	flowid 1:14
## 137
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u8 0x89 0xff at 48 \
#	match u8 0x3a 0xff at 14 \
#	flowid 1:14

# ICMPv6 echo request
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u8 0x3a 0xff at 14 \
	match u8 0x80 0xff at 48 \
	flowid 1:13
# ICMPv6 echo reply
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 610 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u8 0x3a 0xff at 14 \
	match u8 0x81 0xff at 48 \
	flowid 1:13




#IPV6
#BE: careful, will override ICMP
#$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 600 u32 \
#	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
#	match u16 0x0000 0x0fb0 at 8 \
#	flowid 1:12
#AF42
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 601 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0900 0x0fc0 at 8 \
	flowid 1:11
#EF
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 602 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0b80 0x0fc0 at 8 \
	flowid 1:11
#CS1
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 603 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0200 0x0fc0 at 8 \
	flowid 1:13
#IMM
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 604 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0100 0x0fc0 at 8 \
	flowid 1:11
#CS3
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 605 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0c00 0x0fc0 at 8 \
	flowid 1:11
#CS6
$TC filter add dev $IFACE parent 1:0 protocol ${PPPOE_SESSION_ETHERTYPE} prio 606 u32 \
	match u16 ${PPP_PROTO_IP6} 0xffff at 6 \
	match u16 0x0e00 0x0fc0 at 8 \
	flowid 1:11




#diffserv $IFACE

}

ingress() {

CEIL=$DOWNLINK
PRIO_RATE=`expr $CEIL / 3` # Ceiling for prioirty
BE_RATE=`expr $CEIL / 6`   # Min for best effort
BK_RATE=`expr $CEIL / 6`   # Min for background
BE_CEIL=`expr $CEIL - 16`  # A little slop at the top

LQ="quantum `get_mtu $IFACE $CEIL`"
HTB_BURSTS="burst ${MYBURST} cburst ${MYBURST}"

$TC qdisc del dev $IFACE handle ffff: ingress 2> /dev/null
$TC qdisc add dev $IFACE handle ffff: ingress

$TC qdisc del dev $DEV root  2> /dev/null

if [ "$SQUASH_INGRESS" = "1" ]
then
sqm_logger "Do not perform DSCP based filtering on ingress. (1-tier classification)"
# Revert to no dscp based filtering
$TC qdisc del dev $DEV root 2>/dev/null
$TC qdisc add dev $DEV root handle 1: `get_stab_string` htb default 10
$TC class add dev $DEV parent 1: classid 1:1 htb $LQ ${HTB_BURSTS} rate ${DOWNLINK}kbit ceil ${DOWNLINK}kbit `get_htb_adsll_string`
$TC class add dev $DEV parent 1:1 classid 1:10 htb $LQ ${HTB_BURSTS} rate ${DOWNLINK}kbit ceil ${DOWNLINK}kbit prio 0 `get_htb_adsll_string`
$TC qdisc add dev $DEV parent 1:10 handle 110: $QDISC `get_limit ${ILIMIT}` `get_target "${ITARGET}" ${DOWNLINK}` `get_ecn ${IECN}` `get_flows ${DOWNLINK}` ${IQDISC_OPTS}

else
sqm_logger "Perform DSCP based filtering on ingress. (3-tier classification)"
$TC qdisc add dev $DEV root handle 1: `get_stab_string` htb default 12
$TC class add dev $DEV parent 1: classid 1:1 htb $LQ ${HTB_BURSTS} rate ${CEIL}kbit ceil ${CEIL}kbit `get_htb_adsll_string`
$TC class add dev $DEV parent 1:1 classid 1:10 htb $LQ ${HTB_BURSTS} rate ${CEIL}kbit ceil ${CEIL}kbit prio 0 `get_htb_adsll_string`
$TC class add dev $DEV parent 1:1 classid 1:11 htb $LQ ${HTB_BURSTS} rate 32kbit ceil ${PRIO_RATE}kbit prio 1 `get_htb_adsll_string`
$TC class add dev $DEV parent 1:1 classid 1:12 htb $LQ ${HTB_BURSTS} rate ${BE_RATE}kbit ceil ${BE_CEIL}kbit prio 2 `get_htb_adsll_string`
$TC class add dev $DEV parent 1:1 classid 1:13 htb $LQ ${HTB_BURSTS} rate ${BK_RATE}kbit ceil ${BE_CEIL}kbit prio 3 `get_htb_adsll_string`

# I'd prefer to use a pre-nat filter but that causes permutation...

$TC qdisc add dev $DEV parent 1:11 handle 110: $QDISC `get_limit ${ILIMIT}` `get_target "${ITARGET}" ${DOWNLINK}` `get_ecn ${IECN}` `get_quantum 500` `get_flows ${PRIO_RATE}` ${IQDISC_OPTS}
$TC qdisc add dev $DEV parent 1:12 handle 120: $QDISC `get_limit ${ILIMIT}` `get_target "${ITARGET}" ${DOWNLINK}` `get_ecn ${IECN}` `get_quantum 1500` `get_flows ${BE_RATE}` ${IQDISC_OPTS}
$TC qdisc add dev $DEV parent 1:13 handle 130: $QDISC `get_limit ${ILIMIT}` `get_target "${ITARGET}" ${DOWNLINK}` `get_ecn ${IECN}` `get_quantum 300` `get_flows ${BK_RATE}` ${IQDISC_OPTS}

#sm: for PPPoE packet testing
$TC class add dev $DEV parent 1:1 classid 1:14 htb $LQ rate ${BK_RATE}kbit ceil ${BE_CEIL}kbit prio 3 `get_htb_adsll_string`
$TC qdisc add dev $DEV parent 1:14 handle 140: $QDISC `get_limit ${ILIMIT}` `get_target "${ITARGET}" ${DOWNLINK}` `get_ecn ${IECN}` `get_quantum 300` `get_flows ${BK_RATE}` ${IQDISC_OPTS}



#diffserv $DEV
diffserv_pppoe $DEV

fi

ifconfig $DEV up

# redirect all IP packets arriving in $IFACE to ifb0 

$TC filter add dev $IFACE parent ffff: protocol all prio 10 u32 \
  match u32 0 0 flowid 1:1 action mirred egress redirect dev $DEV

}

do_modules
ipt_setup

if [ "$UPLINK" -ne 0 ];
then
	egress
	sqm_logger "egress shaping activated"
else
	sqm_logger "egress shaping deactivated"
	tc qdisc del dev $IFACE root 2> /dev/null
fi
if [ "$DOWNLINK" -ne 0 ];
then
	ingress
	sqm_logger "ingress shaping activated"
else
	sqm_logger "ingress shaping deactivated"
	tc qdisc del dev $DEV root 2> /dev/null
	tc qdisc del dev $IFACE ingress 2> /dev/null
fi



# References:
# This alternate shaper attempts to go for 1/u performance in a clever way
# http://git.coverfire.com/?p=linux-qos-scripts.git;a=blob;f=src-3tos.sh;hb=HEAD

# Comments
# This does the right thing with ipv6 traffic.
# It also tries to leverage diffserv to some sane extent. In particular,
# the 'priority' queue is limited to 33% of the total, so EF, and IMM traffic
# cannot starve other types. The rfc suggested 30%. 30% is probably
# a lot in today's world.

# Flaws
# Many!