From 6cf0291f95172db68d8a283854389a1966e43c65 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Sat, 27 Jun 2020 01:45:29 +0300 Subject: [PATCH] selftests: forwarding: Add a RED test for SW datapath This test is inspired by the mlxsw RED selftest. It is much simpler to set up (also because there is no point in testing PRIO / RED encapsulation). It tests bare RED, ECN and ECN+nodrop modes of operation. On top of that it tests RED early_drop and mark qevents. Signed-off-by: Petr Machata Signed-off-by: David S. Miller --- .../selftests/net/forwarding/sch_red.sh | 492 ++++++++++++++++++ 1 file changed, 492 insertions(+) create mode 100755 tools/testing/selftests/net/forwarding/sch_red.sh diff --git a/tools/testing/selftests/net/forwarding/sch_red.sh b/tools/testing/selftests/net/forwarding/sch_red.sh new file mode 100755 index 000000000000..e714bae473fb --- /dev/null +++ b/tools/testing/selftests/net/forwarding/sch_red.sh @@ -0,0 +1,492 @@ +# SPDX-License-Identifier: GPL-2.0 + +# This test sends one stream of traffic from H1 through a TBF shaper, to a RED +# within TBF shaper on $swp3. The two shapers have the same configuration, and +# thus the resulting stream should fill all available bandwidth on the latter +# shaper. A second stream is sent from H2 also via $swp3, and used to inject +# additional traffic. Since all available bandwidth is taken, this traffic has +# to go to backlog. +# +# +--------------------------+ +--------------------------+ +# | H1 | | H2 | +# | + $h1 | | + $h2 | +# | | 192.0.2.1/28 | | | 192.0.2.2/28 | +# | | TBF 10Mbps | | | | +# +-----|--------------------+ +-----|--------------------+ +# | | +# +-----|------------------------------------------------|--------------------+ +# | SW | | | +# | +--|------------------------------------------------|----------------+ | +# | | + $swp1 + $swp2 | | +# | | BR | | +# | | | | +# | | + $swp3 | | +# | | | TBF 10Mbps / RED | | +# | +--------------------------------|-----------------------------------+ | +# | | | +# +-----------------------------------|---------------------------------------+ +# | +# +-----|--------------------+ +# | H3 | | +# | + $h1 | +# | 192.0.2.3/28 | +# | | +# +--------------------------+ + +ALL_TESTS=" + ping_ipv4 + ecn_test + ecn_nodrop_test + red_test + red_qevent_test + ecn_qevent_test +" + +NUM_NETIFS=6 +CHECK_TC="yes" +source lib.sh + +BACKLOG=30000 +PKTSZ=1400 + +h1_create() +{ + simple_if_init $h1 192.0.2.1/28 + mtu_set $h1 10000 + tc qdisc replace dev $h1 root handle 1: tbf \ + rate 10Mbit burst 10K limit 1M +} + +h1_destroy() +{ + tc qdisc del dev $h1 root + mtu_restore $h1 + simple_if_fini $h1 192.0.2.1/28 +} + +h2_create() +{ + simple_if_init $h2 192.0.2.2/28 + mtu_set $h2 10000 +} + +h2_destroy() +{ + mtu_restore $h2 + simple_if_fini $h2 192.0.2.2/28 +} + +h3_create() +{ + simple_if_init $h3 192.0.2.3/28 + mtu_set $h3 10000 +} + +h3_destroy() +{ + mtu_restore $h3 + simple_if_fini $h3 192.0.2.3/28 +} + +switch_create() +{ + ip link add dev br up type bridge + ip link set dev $swp1 up master br + ip link set dev $swp2 up master br + ip link set dev $swp3 up master br + + mtu_set $swp1 10000 + mtu_set $swp2 10000 + mtu_set $swp3 10000 + + tc qdisc replace dev $swp3 root handle 1: tbf \ + rate 10Mbit burst 10K limit 1M + ip link add name _drop_test up type dummy +} + +switch_destroy() +{ + ip link del dev _drop_test + tc qdisc del dev $swp3 root + + mtu_restore $h3 + mtu_restore $h2 + mtu_restore $h1 + + ip link set dev $swp3 down nomaster + ip link set dev $swp2 down nomaster + ip link set dev $swp1 down nomaster + ip link del dev br +} + +setup_prepare() +{ + h1=${NETIFS[p1]} + swp1=${NETIFS[p2]} + + h2=${NETIFS[p3]} + swp2=${NETIFS[p4]} + + swp3=${NETIFS[p5]} + h3=${NETIFS[p6]} + + h3_mac=$(mac_get $h3) + + vrf_prepare + + h1_create + h2_create + h3_create + switch_create +} + +cleanup() +{ + pre_cleanup + + switch_destroy + h3_destroy + h2_destroy + h1_destroy + + vrf_cleanup +} + +ping_ipv4() +{ + ping_test $h1 192.0.2.3 " from host 1" + ping_test $h2 192.0.2.3 " from host 2" +} + +get_qdisc_backlog() +{ + qdisc_stats_get $swp3 11: .backlog +} + +get_nmarked() +{ + qdisc_stats_get $swp3 11: .marked +} + +get_qdisc_npackets() +{ + qdisc_stats_get $swp3 11: .packets +} + +get_nmirrored() +{ + link_stats_get _drop_test tx packets +} + +send_packets() +{ + local proto=$1; shift + local pkts=$1; shift + + $MZ $h2 -p $PKTSZ -a own -b $h3_mac -A 192.0.2.2 -B 192.0.2.3 -t $proto -q -c $pkts "$@" +} + +# This sends traffic in an attempt to build a backlog of $size. Returns 0 on +# success. After 10 failed attempts it bails out and returns 1. It dumps the +# backlog size to stdout. +build_backlog() +{ + local size=$1; shift + local proto=$1; shift + + local i=0 + + while :; do + local cur=$(get_qdisc_backlog) + local diff=$((size - cur)) + local pkts=$(((diff + PKTSZ - 1) / PKTSZ)) + + if ((cur >= size)); then + echo $cur + return 0 + elif ((i++ > 10)); then + echo $cur + return 1 + fi + + send_packets $proto $pkts "$@" + sleep 1 + done +} + +check_marking() +{ + local cond=$1; shift + + local npackets_0=$(get_qdisc_npackets) + local nmarked_0=$(get_nmarked) + sleep 5 + local npackets_1=$(get_qdisc_npackets) + local nmarked_1=$(get_nmarked) + + local nmarked_d=$((nmarked_1 - nmarked_0)) + local npackets_d=$((npackets_1 - npackets_0)) + local pct=$((100 * nmarked_d / npackets_d)) + + echo $pct + ((pct $cond)) +} + +check_mirroring() +{ + local cond=$1; shift + + local npackets_0=$(get_qdisc_npackets) + local nmirrored_0=$(get_nmirrored) + sleep 5 + local npackets_1=$(get_qdisc_npackets) + local nmirrored_1=$(get_nmirrored) + + local nmirrored_d=$((nmirrored_1 - nmirrored_0)) + local npackets_d=$((npackets_1 - npackets_0)) + local pct=$((100 * nmirrored_d / npackets_d)) + + echo $pct + ((pct $cond)) +} + +ecn_test_common() +{ + local name=$1; shift + local limit=$1; shift + local backlog + local pct + + # Build the below-the-limit backlog using UDP. We could use TCP just + # fine, but this way we get a proof that UDP is accepted when queue + # length is below the limit. The main stream is using TCP, and if the + # limit is misconfigured, we would see this traffic being ECN marked. + RET=0 + backlog=$(build_backlog $((2 * limit / 3)) udp) + check_err $? "Could not build the requested backlog" + pct=$(check_marking "== 0") + check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected == 0." + log_test "$name backlog < limit" + + # Now push TCP, because non-TCP traffic would be early-dropped after the + # backlog crosses the limit, and we want to make sure that the backlog + # is above the limit. + RET=0 + backlog=$(build_backlog $((3 * limit / 2)) tcp tos=0x01) + check_err $? "Could not build the requested backlog" + pct=$(check_marking ">= 95") + check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected >= 95." + log_test "$name backlog > limit" +} + +do_ecn_test() +{ + local limit=$1; shift + local name=ECN + + $MZ $h1 -p $PKTSZ -A 192.0.2.1 -B 192.0.2.3 -c 0 \ + -a own -b $h3_mac -t tcp -q tos=0x01 & + sleep 1 + + ecn_test_common "$name" $limit + + # Up there we saw that UDP gets accepted when backlog is below the + # limit. Now that it is above, it should all get dropped, and backlog + # building should fail. + RET=0 + build_backlog $((2 * limit)) udp >/dev/null + check_fail $? "UDP traffic went into backlog instead of being early-dropped" + log_test "$name backlog > limit: UDP early-dropped" + + stop_traffic + sleep 1 +} + +do_ecn_nodrop_test() +{ + local limit=$1; shift + local name="ECN nodrop" + + $MZ $h1 -p $PKTSZ -A 192.0.2.1 -B 192.0.2.3 -c 0 \ + -a own -b $h3_mac -t tcp -q tos=0x01 & + sleep 1 + + ecn_test_common "$name" $limit + + # Up there we saw that UDP gets accepted when backlog is below the + # limit. Now that it is above, in nodrop mode, make sure it goes to + # backlog as well. + RET=0 + build_backlog $((2 * limit)) udp >/dev/null + check_err $? "UDP traffic was early-dropped instead of getting into backlog" + log_test "$name backlog > limit: UDP not dropped" + + stop_traffic + sleep 1 +} + +do_red_test() +{ + local limit=$1; shift + local backlog + local pct + + # Use ECN-capable TCP to verify there's no marking even though the queue + # is above limit. + $MZ $h1 -p $PKTSZ -A 192.0.2.1 -B 192.0.2.3 -c 0 \ + -a own -b $h3_mac -t tcp -q tos=0x01 & + + # Pushing below the queue limit should work. + RET=0 + backlog=$(build_backlog $((2 * limit / 3)) tcp tos=0x01) + check_err $? "Could not build the requested backlog" + pct=$(check_marking "== 0") + check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected == 0." + log_test "RED backlog < limit" + + # Pushing above should not. + RET=0 + backlog=$(build_backlog $((3 * limit / 2)) tcp tos=0x01) + check_fail $? "Traffic went into backlog instead of being early-dropped" + pct=$(check_marking "== 0") + check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected == 0." + log_test "RED backlog > limit" + + stop_traffic + sleep 1 +} + +do_red_qevent_test() +{ + local limit=$1; shift + local backlog + local base + local now + local pct + + RET=0 + + $MZ $h1 -p $PKTSZ -A 192.0.2.1 -B 192.0.2.3 -c 0 \ + -a own -b $h3_mac -t udp -q & + sleep 1 + + tc filter add block 10 pref 1234 handle 102 matchall skip_hw \ + action mirred egress mirror dev _drop_test + + # Push to the queue until it's at the limit. The configured limit is + # rounded by the qdisc, so this is the best we can do to get to the real + # limit. + build_backlog $((3 * limit / 2)) udp >/dev/null + + base=$(get_nmirrored) + send_packets udp 100 + sleep 1 + now=$(get_nmirrored) + ((now >= base + 100)) + check_err $? "Dropped packets not observed: 100 expected, $((now - base)) seen" + + tc filter del block 10 pref 1234 handle 102 matchall + + base=$(get_nmirrored) + send_packets udp 100 + sleep 1 + now=$(get_nmirrored) + ((now == base)) + check_err $? "Dropped packets still observed: 0 expected, $((now - base)) seen" + + log_test "RED early_dropped packets mirrored" + + stop_traffic + sleep 1 +} + +do_ecn_qevent_test() +{ + local limit=$1; shift + local name=ECN + + RET=0 + + $MZ $h1 -p $PKTSZ -A 192.0.2.1 -B 192.0.2.3 -c 0 \ + -a own -b $h3_mac -t tcp -q tos=0x01 & + sleep 1 + + tc filter add block 10 pref 1234 handle 102 matchall skip_hw \ + action mirred egress mirror dev _drop_test + + backlog=$(build_backlog $((2 * limit / 3)) tcp tos=0x01) + check_err $? "Could not build the requested backlog" + pct=$(check_mirroring "== 0") + check_err $? "backlog $backlog / $limit Got $pct% mirrored packets, expected == 0." + + backlog=$(build_backlog $((3 * limit / 2)) tcp tos=0x01) + check_err $? "Could not build the requested backlog" + pct=$(check_mirroring ">= 95") + check_err $? "backlog $backlog / $limit Got $pct% mirrored packets, expected >= 95." + + tc filter del block 10 pref 1234 handle 102 matchall + + log_test "ECN marked packets mirrored" + + stop_traffic + sleep 1 +} + +install_qdisc() +{ + local -a args=("$@") + + tc qdisc replace dev $swp3 parent 1:1 handle 11: red \ + limit 1M avpkt $PKTSZ probability 1 \ + min $BACKLOG max $((BACKLOG + 1)) burst 38 "${args[@]}" + sleep 1 +} + +uninstall_qdisc() +{ + tc qdisc del dev $swp3 parent 1:1 +} + +ecn_test() +{ + install_qdisc ecn + do_ecn_test $BACKLOG + uninstall_qdisc +} + +ecn_nodrop_test() +{ + install_qdisc ecn nodrop + do_ecn_nodrop_test $BACKLOG + uninstall_qdisc +} + +red_test() +{ + install_qdisc + do_red_test $BACKLOG + uninstall_qdisc +} + +red_qevent_test() +{ + install_qdisc qevent early_drop block 10 + do_red_qevent_test $BACKLOG + uninstall_qdisc +} + +ecn_qevent_test() +{ + install_qdisc ecn qevent mark block 10 + do_ecn_qevent_test $BACKLOG + uninstall_qdisc +} + +trap cleanup EXIT + +setup_prepare +setup_wait + +tests_run + +exit $EXIT_STATUS -- 2.34.1