Add a selftest that exercises the sysctl added in the previous patches.
Test that set/get works as expected; that across seeds we eventually hit
all NHs (test_mpath_seed_*); and that a given seed keeps hitting the same
NHs even across seed changes (test_mpath_seed_stability_*).
Signed-off-by: Petr Machata <petrm@xxxxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
---
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
.../testing/selftests/net/forwarding/Makefile | 1 +
.../net/forwarding/router_mpath_seed.sh | 322 ++++++++++++++++++
2 files changed, 323 insertions(+)
create mode 100755 tools/testing/selftests/net/forwarding/router_mpath_seed.sh
diff --git a/tools/testing/selftests/net/forwarding/Makefile b/tools/testing/selftests/net/forwarding/Makefile
index fa7b59ff4029..99576d7ecbf6 100644
--- a/tools/testing/selftests/net/forwarding/Makefile
+++ b/tools/testing/selftests/net/forwarding/Makefile
@@ -70,6 +70,7 @@ TEST_PROGS = bridge_fdb_learning_limit.sh \
router_broadcast.sh \
router_mpath_nh_res.sh \
router_mpath_nh.sh \
+ router_mpath_seed.sh \
router_multicast.sh \
router_multipath.sh \
router_nh.sh \
diff --git a/tools/testing/selftests/net/forwarding/router_mpath_seed.sh b/tools/testing/selftests/net/forwarding/router_mpath_seed.sh
new file mode 100755
index 000000000000..0ef3687da8b2
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/router_mpath_seed.sh
@@ -0,0 +1,322 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# +-------------------------+ +-------------------------+
+# | H1 | | H2 |
+# | $h1 + | | + $h2 |
+# | 192.0.2.1/28 | | | | 192.0.2.34/28 |
+# | 2001:db8:1::1/64 | | | | 2001:db8:3::2/64 |
+# +-------------------|-----+ +-|-----------------------+
+# | |
+# +-------------------|-----+ +-|-----------------------+
+# | R1 | | | | R2 |
+# | $rp11 + | | + $rp21 |
+# | 192.0.2.2/28 | | 192.0.2.33/28 |
+# | 2001:db8:1::2/64 | | 2001:db8:3::1/64 |
+# | | | |
+# | $rp12 + | | + $rp22 |
+# | 192.0.2.17/28 | | | | 192.0.2.18..27/28 |
+# | 2001:db8:2::17/64 | | | | 2001:db8:2::18..27/64 |
+# +-------------------|-----+ +-|-----------------------+
+# | |
+# `----------'
+
+ALL_TESTS="
+ ping_ipv4
+ ping_ipv6
+ test_mpath_seed_get
+ test_mpath_seed_ipv4
+ test_mpath_seed_ipv6
+ test_mpath_seed_stability_ipv4
+ test_mpath_seed_stability_ipv6
+"
+NUM_NETIFS=6
+source lib.sh
+
+h1_create()
+{
+ simple_if_init $h1 192.0.2.1/28 2001:db8:1::1/64
+ ip -4 route add 192.0.2.32/28 vrf v$h1 nexthop via 192.0.2.2
+ ip -6 route add 2001:db8:3::/64 vrf v$h1 nexthop via 2001:db8:1::2
+}
+
+h1_destroy()
+{
+ ip -6 route del 2001:db8:3::/64 vrf v$h1 nexthop via 2001:db8:1::2
+ ip -4 route del 192.0.2.32/28 vrf v$h1 nexthop via 192.0.2.2
+ simple_if_fini $h1 192.0.2.1/28 2001:db8:1::1/64
+}
+
+h2_create()
+{
+ simple_if_init $h2 192.0.2.34/28 2001:db8:3::2/64
+ ip -4 route add 192.0.2.0/28 vrf v$h2 nexthop via 192.0.2.33
+ ip -6 route add 2001:db8:1::/64 vrf v$h2 nexthop via 2001:db8:3::1
+}
+
+h2_destroy()
+{
+ ip -6 route del 2001:db8:1::/64 vrf v$h2 nexthop via 2001:db8:3::1
+ ip -4 route del 192.0.2.0/28 vrf v$h2 nexthop via 192.0.2.33
+ simple_if_fini $h2 192.0.2.34/28 2001:db8:3::2/64
+}
+
+router1_create()
+{
+ simple_if_init $rp11 192.0.2.2/28 2001:db8:1::2/64
+ __simple_if_init $rp12 v$rp11 192.0.2.17/28 2001:db8:2::17/64
+}
+
+router1_destroy()
+{
+ __simple_if_fini $rp12 192.0.2.17/28 2001:db8:2::17/64
+ simple_if_fini $rp11 192.0.2.2/28 2001:db8:1::2/64
+}
+
+router2_create()
+{
+ simple_if_init $rp21 192.0.2.33/28 2001:db8:3::1/64
+ __simple_if_init $rp22 v$rp21 192.0.2.18/28 2001:db8:2::18/64
+ ip -4 route add 192.0.2.0/28 vrf v$rp21 nexthop via 192.0.2.17
+ ip -6 route add 2001:db8:1::/64 vrf v$rp21 nexthop via 2001:db8:2::17
+}
+
+router2_destroy()
+{
+ ip -6 route del 2001:db8:1::/64 vrf v$rp21 nexthop via 2001:db8:2::17
+ ip -4 route del 192.0.2.0/28 vrf v$rp21 nexthop via 192.0.2.17
+ __simple_if_fini $rp22 192.0.2.18/28 2001:db8:2::18/64
+ simple_if_fini $rp21 192.0.2.33/28 2001:db8:3::1/64
+}
+
+nexthops_create()
+{
+ local i
+ for i in $(seq 10); do
+ ip nexthop add id $((1000 + i)) via 192.0.2.18 dev $rp12
+ ip nexthop add id $((2000 + i)) via 2001:db8:2::18 dev $rp12
+ done
+
+ ip nexthop add id 1000 group $(seq -s / 1001 1010) hw_stats on
+ ip nexthop add id 2000 group $(seq -s / 2001 2010) hw_stats on
+ ip -4 route add 192.0.2.32/28 vrf v$rp11 nhid 1000
+ ip -6 route add 2001:db8:3::/64 vrf v$rp11 nhid 2000
+}
+
+nexthops_destroy()
+{
+ local i
+
+ ip -6 route del 2001:db8:3::/64 vrf v$rp11 nhid 2000
+ ip -4 route del 192.0.2.32/28 vrf v$rp11 nhid 1000
+ ip nexthop del id 2000
+ ip nexthop del id 1000
+
+ for i in $(seq 10 -1 1); do
+ ip nexthop del id $((2000 + i))
+ ip nexthop del id $((1000 + i))
+ done
+}
+
+setup_prepare()
+{
+ h1=${NETIFS[p1]}
+ rp11=${NETIFS[p2]}
+
+ rp12=${NETIFS[p3]}
+ rp22=${NETIFS[p4]}
+
+ rp21=${NETIFS[p5]}
+ h2=${NETIFS[p6]}
+
+ sysctl_set net.ipv4.fib_multipath_hash_seed 0
+
+ vrf_prepare
+
+ h1_create
+ h2_create
+ router1_create
+ router2_create
+
+ forwarding_enable
+}
+
+cleanup()
+{
+ pre_cleanup
+
+ forwarding_restore
+
+ nexthops_destroy
+ router2_destroy
+ router1_destroy
+ h2_destroy
+ h1_destroy
+
+ vrf_cleanup
+
+ sysctl_restore net.ipv4.fib_multipath_hash_seed
+}
+
+ping_ipv4()
+{
+ ping_test $h1 192.0.2.34
+}
+
+ping_ipv6()
+{
+ ping6_test $h1 2001:db8:3::2
+}
+
+test_mpath_seed_get()
+{
+ RET=0
+
+ local i
+ for ((i = 0; i < 100; i++)); do
+ local seed_w=$((999331 * i))
+ sysctl -qw net.ipv4.fib_multipath_hash_seed=$seed_w
+ local seed_r=$(sysctl -n net.ipv4.fib_multipath_hash_seed)
+ ((seed_r == seed_w))
+ check_err $? "mpath seed written as $seed_w, but read as $seed_r"
+ done
+
+ log_test "mpath seed set/get"
+}
+
+nh_stats_snapshot()
+{
+ local group_id=$1; shift
+
+ ip -j -s -s nexthop show id $group_id |
+ jq -c '[.[].group_stats | sort_by(.id) | .[].packets]'
+}
+
+get_active_nh()
+{
+ local s0=$1; shift
+ local s1=$1; shift
+
+ jq -n --argjson s0 "$s0" --argjson s1 "$s1" -f /dev/stdin <<-"EOF"
+ [range($s0 | length)] |
+ map($s1[.] - $s0[.]) |
+ map(if . > 8 then 1 else 0 end) |
+ index(1)
+ EOF
+}
+
+probe_seed()
+{
+ local group_id=$1; shift
+ local seed=$1; shift
+ local -a mz=("$@")
+
+ sysctl -qw net.ipv4.fib_multipath_hash_seed=$seed
+
+ local s0=$(nh_stats_snapshot $group_id)
+ "${mz[@]}"
+ local s1=$(nh_stats_snapshot $group_id)
+
+ get_active_nh "$s0" "$s1"
+}
+
+test_mpath_seed()
+{
+ local group_id=$1; shift
+ local what=$1; shift
+ local -a mz=("$@")
+ local ii
+
+ RET=0
+
+ local -a tally=(0 0 0 0 0 0 0 0 0 0)
+ for ((ii = 0; ii < 100; ii++)); do
+ local act=$(probe_seed $group_id $((999331 * ii)) "${mz[@]}")
+ ((tally[act]++))
+ done
+
+ local tally_str="${tally[@]}"
+ for ((ii = 0; ii < ${#tally[@]}; ii++)); do
+ ((tally[ii] > 0))
+ check_err $? "NH #$ii not hit, tally='$tally_str'"
+ done
+
+ log_test "mpath seed $what"
+ sysctl -qw net.ipv4.fib_multipath_hash_seed=0
+}
+
+test_mpath_seed_ipv4()
+{
+ test_mpath_seed 1000 IPv4 \
+ $MZ $h1 -A 192.0.2.1 -B 192.0.2.34 -q \
+ -p 64 -d 0 -c 10 -t udp
+}
+
+test_mpath_seed_ipv6()
+{
+ test_mpath_seed 2000 IPv6 \
+ $MZ -6 $h1 -A 2001:db8:1::1 -B 2001:db8:3::2 -q \
+ -p 64 -d 0 -c 10 -t udp
+}
+
+check_mpath_seed_stability()
+{
+ local seed=$1; shift
+ local act_0=$1; shift
+ local act_1=$1; shift
+
+ ((act_0 == act_1))
+ check_err $? "seed $seed: active NH moved from $act_0 to $act_1 after seed change"
+}
+
+test_mpath_seed_stability()
+{
+ local group_id=$1; shift
+ local what=$1; shift
+ local -a mz=("$@")
+
+ RET=0
+
+ local seed_0=0
+ local seed_1=3221338814
+ local seed_2=3735928559
+
+ local act_0_0=$(probe_seed $group_id $seed_0 "${mz[@]}")
+ local act_1_0=$(probe_seed $group_id $seed_1 "${mz[@]}")
+ local act_2_0=$(probe_seed $group_id $seed_2 "${mz[@]}")
+
+ local act_0_1=$(probe_seed $group_id $seed_0 "${mz[@]}")
+ local act_1_1=$(probe_seed $group_id $seed_1 "${mz[@]}")
+ local act_2_1=$(probe_seed $group_id $seed_2 "${mz[@]}")
+
+ check_mpath_seed_stability $seed_0 $act_0_0 $act_0_1
+ check_mpath_seed_stability $seed_1 $act_1_0 $act_1_1
+ check_mpath_seed_stability $seed_2 $act_2_0 $act_2_1
+
+ log_test "mpath seed stability $what"
+ sysctl -qw net.ipv4.fib_multipath_hash_seed=0
+}
+
+test_mpath_seed_stability_ipv4()
+{
+ test_mpath_seed_stability 1000 IPv4 \
+ $MZ $h1 -A 192.0.2.1 -B 192.0.2.34 -q \
+ -p 64 -d 0 -c 10 -t udp
+}
+
+test_mpath_seed_stability_ipv6()
+{
+ test_mpath_seed_stability 2000 IPv6 \
+ $MZ -6 $h1 -A 2001:db8:1::1 -B 2001:db8:3::2 -q \
+ -p 64 -d 0 -c 10 -t udp
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+nexthops_create
+
+tests_run
+
+exit $EXIT_STATUS
--
2.45.0
