nss.qos

################################################################################
# nss.qos (HW Accelerated Simple Traffic Shaper)
################################################################################
# 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) 2021
################################################################################

. ${SQM_LIB_DIR}/defaults.sh

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

ipt_setup() {

    ipt -t mangle -N QOS_MARK_${IFACE}
    
    case $QDISC in
        cake*)
            sqm_debug "cake does all the diffserv work - no need for iptables rules"
            ;;
        *)
            ipt -t mangle -A QOS_MARK_${IFACE} -j MARK --set-mark 0x2/${IPT_MASK}
            ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class CS1 -j MARK --set-mark 0x3/${IPT_MASK}
            ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class CS6 -j MARK --set-mark 0x1/${IPT_MASK}
            ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class EF -j MARK --set-mark 0x1/${IPT_MASK}
            ipt -t mangle -A QOS_MARK_${IFACE} -m dscp --dscp-class AF42 -j MARK --set-mark 0x1/${IPT_MASK}
            ipt -t mangle -A QOS_MARK_${IFACE} -m tos  --tos Minimize-Delay -j MARK --set-mark 0x1/${IPT_MASK}
    esac
    
    # Turn it on. Preserve classification if already performed
    #
    #sm: is it correct to do this in $IFACE? Should ingress not be on $DEV? since HTB acts on $DEV?
    #
    # ZERO also does not work on $DEV (that is the IFB will still see the
    # incoming ToS bits whether we squash or not)
    #
    # ZERO is still useful to protect internal machines...
    if [ "$ZERO_DSCP_INGRESS" = "1" ]; then
        sqm_debug "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_debug "Keeping differentiated services code points (DSCP) from ingress."
        ipt -t mangle -A PREROUTING -i $IFACE -m mark --mark 0x00/${IPT_MASK} -g QOS_MARK_${IFACE}
    fi

    ipt -t mangle -A POSTROUTING -o $IFACE -m mark --mark 0x00/${IPT_MASK} -g QOS_MARK_${IFACE}
    ipt -t mangle -A OUTPUT -p udp -m multiport --ports 123,53 -j DSCP --set-dscp-class AF42
}

cake_egress() {
    sqm_debug "(EGRESS) Nothing here."
}

egress() {
    $TC qdisc add dev $IFACE root handle 1: nsstbl rate ${UPLINK}kbit burst 1Mb
    $TC qdisc add dev $IFACE parent 1: handle 10: nssfq_codel limit 4096 flows 1024 quantum 1514 target 5ms interval 100ms set_default
    $TC filter add dev $IFACE parent 1:0 protocol ip prio 0 u32 match ip protocol 1 0xff flowid 1:13
    $TC filter add dev $IFACE parent 1:0 protocol ipv6 prio 1 u32 match ip protocol 1 0xff flowid 1:13
}

cake_ingress() {
    sqm_debug "(INGRESS) Nothing here."
}

ingress() {
    #cut off ifb4
    DEV=`echo $DEV | cut -c 5-`
    printf $DEV > /sys/module/nss_ifb/parameters/nss_dev_name
    DEV=nssifb
    
    $TC qdisc add dev $DEV root handle 1: nsstbl rate ${DOWNLINK}kbit burst 1Mb
    $TC qdisc add dev $DEV parent 1: handle 10: nssfq_codel limit 4096 flows 1024 quantum 1514 target 5ms interval 100ms set_default
    
    $IP link set up nssifb
}

sqm_prepare_script() {
    do_modules
    #quick workaround to fill dropdown, will fix this later
    touch /var/run/sqm/available_qdiscs/nssfq_codel
    verify_qdisc "nssfq_codel" || 1
    ipt_setup
}