# SPDX-License-Identifier: GPL-2.0

# Global interface:
#  $put -- port under test (e.g. $swp2)
#  collect_stats($streams...) -- A function to get stats for individual streams
#  ets_start_traffic($band) -- Start traffic for this band
#  ets_change_qdisc($op, $dev, $nstrict, $quanta...) -- Add or change qdisc

# WS describes the Qdisc configuration. It has one value per band (so the
# number of array elements indicates the number of bands). If the value is
# 0, it is a strict band, otherwise the it's a DRR band and the value is
# that band's quantum.
declare -a WS

qdisc_describe()
{
        local nbands=${#WS[@]}
        local nstrict=0
        local i

        for ((i = 0; i < nbands; i++)); do
                if ((!${WS[$i]})); then
                        : $((nstrict++))
                fi
        done

        echo -n "ets bands $nbands"
        if ((nstrict)); then
                echo -n " strict $nstrict"
        fi
        if ((nstrict < nbands)); then
                echo -n " quanta"
                for ((i = nstrict; i < nbands; i++)); do
                        echo -n " ${WS[$i]}"
                done
        fi
}

__strict_eval()
{
        local desc=$1; shift
        local d=$1; shift
        local total=$1; shift
        local above=$1; shift

        RET=0

        if ((! total)); then
                check_err 1 "No traffic observed"
                log_test "$desc"
                return
        fi

        local ratio=$(echo "scale=2; 100 * $d / $total" | bc -l)
        if ((above)); then
                test $(echo "$ratio > 95.0" | bc -l) -eq 1
                check_err $? "Not enough traffic"
                log_test "$desc"
                log_info "Expected ratio >95% Measured ratio $ratio"
        else
                test $(echo "$ratio < 5" | bc -l) -eq 1
                check_err $? "Too much traffic"
                log_test "$desc"
                log_info "Expected ratio <5% Measured ratio $ratio"
        fi
}

strict_eval()
{
        __strict_eval "$@" 1
}

notraf_eval()
{
        __strict_eval "$@" 0
}

__ets_dwrr_test()
{
        local -a streams=("$@")

        local low_stream=${streams[0]}
        local seen_strict=0
        local -a t0 t1 d
        local stream
        local total
        local i

        echo "Testing $(qdisc_describe), streams ${streams[@]}"

        for stream in ${streams[@]}; do
                ets_start_traffic $stream
        done

        sleep 10

        t0=($(collect_stats "${streams[@]}"))

        sleep 10

        t1=($(collect_stats "${streams[@]}"))
        d=($(for ((i = 0; i < ${#streams[@]}; i++)); do
                 echo $((${t1[$i]} - ${t0[$i]}))
             done))
        total=$(echo ${d[@]} | sed 's/ /+/g' | bc)

        for ((i = 0; i < ${#streams[@]}; i++)); do
                local stream=${streams[$i]}
                if ((seen_strict)); then
                        notraf_eval "band $stream" ${d[$i]} $total
                elif ((${WS[$stream]} == 0)); then
                        strict_eval "band $stream" ${d[$i]} $total
                        seen_strict=1
                elif ((stream == low_stream)); then
                        # Low stream is used as DWRR evaluation reference.
                        continue
                else
                        multipath_eval "bands $low_stream:$stream" \
                                       ${WS[$low_stream]} ${WS[$stream]} \
                                       ${d[0]} ${d[$i]}
                fi
        done

        for stream in ${streams[@]}; do
                stop_traffic
        done
}

ets_dwrr_test_012()
{
        __ets_dwrr_test 0 1 2
}

ets_dwrr_test_01()
{
        __ets_dwrr_test 0 1
}

ets_dwrr_test_12()
{
        __ets_dwrr_test 1 2
}

ets_qdisc_setup()
{
        local dev=$1; shift
        local nstrict=$1; shift
        local -a quanta=("$@")

        local ndwrr=${#quanta[@]}
        local nbands=$((nstrict + ndwrr))
        local nstreams=$(if ((nbands > 3)); then echo 3; else echo $nbands; fi)
        local priomap=$(seq 0 $((nstreams - 1)))
        local i

        WS=($(
                for ((i = 0; i < nstrict; i++)); do
                        echo 0
                done
                for ((i = 0; i < ndwrr; i++)); do
                        echo ${quanta[$i]}
                done
        ))

        ets_change_qdisc $dev $nstrict "$priomap" ${quanta[@]}
}

ets_set_dwrr_uniform()
{
        ets_qdisc_setup $put 0 3300 3300 3300
}

ets_set_dwrr_varying()
{
        ets_qdisc_setup $put 0 5000 3500 1500
}

ets_set_strict()
{
        ets_qdisc_setup $put 3
}

ets_set_mixed()
{
        ets_qdisc_setup $put 1 5000 2500 1500
}

ets_change_quantum()
{
        tc class change dev $put classid 10:2 ets quantum 8000
        WS[1]=8000
}

ets_set_dwrr_two_bands()
{
        ets_qdisc_setup $put 0 5000 2500
}

ets_test_strict()
{
        ets_set_strict
        ets_dwrr_test_01
        ets_dwrr_test_12
}

ets_test_mixed()
{
        ets_set_mixed
        ets_dwrr_test_01
        ets_dwrr_test_12
}

ets_test_dwrr()
{
        ets_set_dwrr_uniform
        ets_dwrr_test_012
        ets_set_dwrr_varying
        ets_dwrr_test_012
        ets_change_quantum
        ets_dwrr_test_012
        ets_set_dwrr_two_bands
        ets_dwrr_test_01
}