1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3#
  4# This test installs a TC bpf program that throttles a TCP flow
  5# with dst port = 9000 down to 5MBps. Then it measures actual
  6# throughput of the flow.
  7
  8BPF_FILE="test_tc_edt.bpf.o"
  9if [[ $EUID -ne 0 ]]; then
 10	echo "This script must be run as root"
 11	echo "FAIL"
 12	exit 1
 13fi
 14
 15# check that nc, dd, and timeout are present
 16command -v nc >/dev/null 2>&1 || \
 17	{ echo >&2 "nc is not available"; exit 1; }
 18command -v dd >/dev/null 2>&1 || \
 19	{ echo >&2 "nc is not available"; exit 1; }
 20command -v timeout >/dev/null 2>&1 || \
 21	{ echo >&2 "timeout is not available"; exit 1; }
 22
 23readonly NS_SRC="ns-src-$(mktemp -u XXXXXX)"
 24readonly NS_DST="ns-dst-$(mktemp -u XXXXXX)"
 25
 26readonly IP_SRC="172.16.1.100"
 27readonly IP_DST="172.16.2.100"
 28
 29cleanup()
 30{
 31	ip netns del ${NS_SRC}
 32	ip netns del ${NS_DST}
 33}
 34
 35trap cleanup EXIT
 36
 37set -e  # exit on error
 38
 39ip netns add "${NS_SRC}"
 40ip netns add "${NS_DST}"
 41ip link add veth_src type veth peer name veth_dst
 42ip link set veth_src netns ${NS_SRC}
 43ip link set veth_dst netns ${NS_DST}
 44
 45ip -netns ${NS_SRC} addr add ${IP_SRC}/24  dev veth_src
 46ip -netns ${NS_DST} addr add ${IP_DST}/24  dev veth_dst
 47
 48ip -netns ${NS_SRC} link set dev veth_src up
 49ip -netns ${NS_DST} link set dev veth_dst up
 50
 51ip -netns ${NS_SRC} route add ${IP_DST}/32  dev veth_src
 52ip -netns ${NS_DST} route add ${IP_SRC}/32  dev veth_dst
 53
 54# set up TC on TX
 55ip netns exec ${NS_SRC} tc qdisc add dev veth_src root fq
 56ip netns exec ${NS_SRC} tc qdisc add dev veth_src clsact
 57ip netns exec ${NS_SRC} tc filter add dev veth_src egress \
 58	bpf da obj ${BPF_FILE} sec cls_test
 59
 60
 61# start the listener
 62ip netns exec ${NS_DST} bash -c \
 63	"nc -4 -l -p 9000 >/dev/null &"
 64declare -i NC_PID=$!
 65sleep 1
 66
 67declare -ir TIMEOUT=20
 68declare -ir EXPECTED_BPS=5000000
 69
 70# run the load, capture RX bytes on DST
 71declare -ir RX_BYTES_START=$( ip netns exec ${NS_DST} \
 72	cat /sys/class/net/veth_dst/statistics/rx_bytes )
 73
 74set +e
 75ip netns exec ${NS_SRC} bash -c "timeout ${TIMEOUT} dd if=/dev/zero \
 76	bs=1000 count=1000000 > /dev/tcp/${IP_DST}/9000 2>/dev/null"
 77set -e
 78
 79declare -ir RX_BYTES_END=$( ip netns exec ${NS_DST} \
 80	cat /sys/class/net/veth_dst/statistics/rx_bytes )
 81
 82declare -ir ACTUAL_BPS=$(( ($RX_BYTES_END - $RX_BYTES_START) / $TIMEOUT ))
 83
 84echo $TIMEOUT $ACTUAL_BPS $EXPECTED_BPS | \
 85	awk '{printf "elapsed: %d sec; bps difference: %.2f%%\n",
 86		$1, ($2-$3)*100.0/$3}'
 87
 88# Pass the test if the actual bps is within 1% of the expected bps.
 89# The difference is usually about 0.1% on a 20-sec test, and ==> zero
 90# the longer the test runs.
 91declare -ir RES=$( echo $ACTUAL_BPS $EXPECTED_BPS | \
 92	 awk 'function abs(x){return ((x < 0.0) ? -x : x)}
 93	      {if (abs(($1-$2)*100.0/$2) > 1.0) { print "1" }
 94		else { print "0"} }' )
 95if [ "${RES}" == "0" ] ; then
 96	echo "PASS"
 97else
 98	echo "FAIL"
 99	exit 1
100fi