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