--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test traffic distribution when there are multiple paths between an IPv6 GRE
+# tunnel. The tunnel carries IPv4 and IPv6 traffic between multiple hosts.
+# Multiple routes are in the underlay network. With the default multipath
+# policy, SW2 will only look at the outer IP addresses, hence only a single
+# route would be used.
+#
+# +--------------------------------+
+# | H1 |
+# | $h1 + |
+# | 198.51.100.{2-253}/24 | |
+# | 2001:db8:1::{2-fd}/64 | |
+# +-------------------------|------+
+# |
+# +-------------------------|-------------------+
+# | SW1 | |
+# | $ol1 + |
+# | 198.51.100.1/24 |
+# | 2001:db8:1::1/64 |
+# | |
+# |+ g1 (ip6gre) |
+# | loc=2001:db8:3::1 |
+# | rem=2001:db8:3::2 -. |
+# | tos=inherit | |
+# | v |
+# | + $ul1 |
+# | | 2001:db8:10::1/64 |
+# +---------------------|-----------------------+
+# |
+# +---------------------|-----------------------+
+# | SW2 | |
+# | $ul21 + |
+# | 2001:db8:10::2/64 | |
+# | | |
+# ! __________________+___ |
+# | / \ |
+# | | | |
+# | + $ul22.111 (vlan) + $ul22.222 (vlan) |
+# | | 2001:db8:11::1/64 | 2001:db8:12::1/64 |
+# | | | |
+# +--|----------------------|-------------------+
+# | |
+# +--|----------------------|-------------------+
+# | | | |
+# | + $ul32.111 (vlan) + $ul32.222 (vlan) |
+# | | 2001:db8:11::2/64 | 2001:db8:12::2/64 |
+# | | | |
+# | \__________________+___/ |
+# | | |
+# | | |
+# | $ul31 + |
+# | 2001:db8:13::1/64 | SW3 |
+# +---------------------|-----------------------+
+# |
+# +---------------------|-----------------------+
+# | + $ul4 |
+# | ^ 2001:db8:13::2/64 |
+# | | |
+# |+ g2 (ip6gre) | |
+# | loc=2001:db8:3::2 | |
+# | rem=2001:db8:3::1 -' |
+# | tos=inherit |
+# | |
+# | $ol4 + |
+# | 203.0.113.1/24 | |
+# | 2001:db8:2::1/64 | SW4 |
+# +-------------------------|-------------------+
+# |
+# +-------------------------|------+
+# | | |
+# | $h2 + |
+# | 203.0.113.{2-253}/24 |
+# | 2001:db8:2::{2-fd}/64 H2 |
+# +--------------------------------+
+
+ALL_TESTS="
+ ping_ipv4
+ ping_ipv6
+ custom_hash
+"
+
+NUM_NETIFS=10
+source lib.sh
+
+h1_create()
+{
+ simple_if_init $h1 198.51.100.2/24 2001:db8:1::2/64
+ ip route add vrf v$h1 default via 198.51.100.1 dev $h1
+ ip -6 route add vrf v$h1 default via 2001:db8:1::1 dev $h1
+}
+
+h1_destroy()
+{
+ ip -6 route del vrf v$h1 default
+ ip route del vrf v$h1 default
+ simple_if_fini $h1 198.51.100.2/24 2001:db8:1::2/64
+}
+
+sw1_create()
+{
+ simple_if_init $ol1 198.51.100.1/24 2001:db8:1::1/64
+ __simple_if_init $ul1 v$ol1 2001:db8:10::1/64
+
+ tunnel_create g1 ip6gre 2001:db8:3::1 2001:db8:3::2 tos inherit \
+ dev v$ol1
+ __simple_if_init g1 v$ol1 2001:db8:3::1/128
+ ip route add vrf v$ol1 2001:db8:3::2/128 via 2001:db8:10::2
+
+ ip route add vrf v$ol1 203.0.113.0/24 dev g1
+ ip -6 route add vrf v$ol1 2001:db8:2::/64 dev g1
+}
+
+sw1_destroy()
+{
+ ip -6 route del vrf v$ol1 2001:db8:2::/64
+ ip route del vrf v$ol1 203.0.113.0/24
+
+ ip route del vrf v$ol1 2001:db8:3::2/128
+ __simple_if_fini g1 2001:db8:3::1/128
+ tunnel_destroy g1
+
+ __simple_if_fini $ul1 2001:db8:10::1/64
+ simple_if_fini $ol1 198.51.100.1/24 2001:db8:1::1/64
+}
+
+sw2_create()
+{
+ simple_if_init $ul21 2001:db8:10::2/64
+ __simple_if_init $ul22 v$ul21
+ vlan_create $ul22 111 v$ul21 2001:db8:11::1/64
+ vlan_create $ul22 222 v$ul21 2001:db8:12::1/64
+
+ ip -6 route add vrf v$ul21 2001:db8:3::1/128 via 2001:db8:10::1
+ ip -6 route add vrf v$ul21 2001:db8:3::2/128 \
+ nexthop via 2001:db8:11::2 \
+ nexthop via 2001:db8:12::2
+}
+
+sw2_destroy()
+{
+ ip -6 route del vrf v$ul21 2001:db8:3::2/128
+ ip -6 route del vrf v$ul21 2001:db8:3::1/128
+
+ vlan_destroy $ul22 222
+ vlan_destroy $ul22 111
+ __simple_if_fini $ul22
+ simple_if_fini $ul21 2001:db8:10::2/64
+}
+
+sw3_create()
+{
+ simple_if_init $ul31 2001:db8:13::1/64
+ __simple_if_init $ul32 v$ul31
+ vlan_create $ul32 111 v$ul31 2001:db8:11::2/64
+ vlan_create $ul32 222 v$ul31 2001:db8:12::2/64
+
+ ip -6 route add vrf v$ul31 2001:db8:3::2/128 via 2001:db8:13::2
+ ip -6 route add vrf v$ul31 2001:db8:3::1/128 \
+ nexthop via 2001:db8:11::1 \
+ nexthop via 2001:db8:12::1
+
+ tc qdisc add dev $ul32 clsact
+ tc filter add dev $ul32 ingress pref 111 prot 802.1Q \
+ flower vlan_id 111 action pass
+ tc filter add dev $ul32 ingress pref 222 prot 802.1Q \
+ flower vlan_id 222 action pass
+}
+
+sw3_destroy()
+{
+ tc qdisc del dev $ul32 clsact
+
+ ip -6 route del vrf v$ul31 2001:db8:3::1/128
+ ip -6 route del vrf v$ul31 2001:db8:3::2/128
+
+ vlan_destroy $ul32 222
+ vlan_destroy $ul32 111
+ __simple_if_fini $ul32
+ simple_if_fini $ul31 2001:db8:13::1/64
+}
+
+sw4_create()
+{
+ simple_if_init $ol4 203.0.113.1/24 2001:db8:2::1/64
+ __simple_if_init $ul4 v$ol4 2001:db8:13::2/64
+
+ tunnel_create g2 ip6gre 2001:db8:3::2 2001:db8:3::1 tos inherit \
+ dev v$ol4
+ __simple_if_init g2 v$ol4 2001:db8:3::2/128
+ ip -6 route add vrf v$ol4 2001:db8:3::1/128 via 2001:db8:13::1
+
+ ip route add vrf v$ol4 198.51.100.0/24 dev g2
+ ip -6 route add vrf v$ol4 2001:db8:1::/64 dev g2
+}
+
+sw4_destroy()
+{
+ ip -6 route del vrf v$ol4 2001:db8:1::/64
+ ip route del vrf v$ol4 198.51.100.0/24
+
+ ip -6 route del vrf v$ol4 2001:db8:3::1/128
+ __simple_if_fini g2 2001:db8:3::2/128
+ tunnel_destroy g2
+
+ __simple_if_fini $ul4 2001:db8:13::2/64
+ simple_if_fini $ol4 203.0.113.1/24 2001:db8:2::1/64
+}
+
+h2_create()
+{
+ simple_if_init $h2 203.0.113.2/24 2001:db8:2::2/64
+ ip route add vrf v$h2 default via 203.0.113.1 dev $h2
+ ip -6 route add vrf v$h2 default via 2001:db8:2::1 dev $h2
+}
+
+h2_destroy()
+{
+ ip -6 route del vrf v$h2 default
+ ip route del vrf v$h2 default
+ simple_if_fini $h2 203.0.113.2/24 2001:db8:2::2/64
+}
+
+setup_prepare()
+{
+ h1=${NETIFS[p1]}
+
+ ol1=${NETIFS[p2]}
+ ul1=${NETIFS[p3]}
+
+ ul21=${NETIFS[p4]}
+ ul22=${NETIFS[p5]}
+
+ ul32=${NETIFS[p6]}
+ ul31=${NETIFS[p7]}
+
+ ul4=${NETIFS[p8]}
+ ol4=${NETIFS[p9]}
+
+ h2=${NETIFS[p10]}
+
+ vrf_prepare
+ h1_create
+ sw1_create
+ sw2_create
+ sw3_create
+ sw4_create
+ h2_create
+
+ forwarding_enable
+}
+
+cleanup()
+{
+ pre_cleanup
+
+ forwarding_restore
+
+ h2_destroy
+ sw4_destroy
+ sw3_destroy
+ sw2_destroy
+ sw1_destroy
+ h1_destroy
+ vrf_cleanup
+}
+
+ping_ipv4()
+{
+ ping_test $h1 203.0.113.2
+}
+
+ping_ipv6()
+{
+ ping6_test $h1 2001:db8:2::2
+}
+
+send_src_ipv4()
+{
+ $MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
+ -d 1msec -c 50 -t udp "sp=20000,dp=30000"
+}
+
+send_dst_ipv4()
+{
+ $MZ $h1 -q -p 64 -A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
+ -d 1msec -c 50 -t udp "sp=20000,dp=30000"
+}
+
+send_src_udp4()
+{
+ $MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+ -d 1msec -t udp "sp=0-32768,dp=30000"
+}
+
+send_dst_udp4()
+{
+ $MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+ -d 1msec -t udp "sp=20000,dp=0-32768"
+}
+
+send_src_ipv6()
+{
+ $MZ -6 $h1 -q -p 64 -A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:2::2 \
+ -d 1msec -c 50 -t udp "sp=20000,dp=30000"
+}
+
+send_dst_ipv6()
+{
+ $MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B "2001:db8:2::2-2001:db8:2::fd" \
+ -d 1msec -c 50 -t udp "sp=20000,dp=30000"
+}
+
+send_flowlabel()
+{
+ # Generate 16384 echo requests, each with a random flow label.
+ for _ in $(seq 1 16384); do
+ ip vrf exec v$h1 \
+ $PING6 2001:db8:2::2 -F 0 -c 1 -q >/dev/null 2>&1
+ done
+}
+
+send_src_udp6()
+{
+ $MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+ -d 1msec -t udp "sp=0-32768,dp=30000"
+}
+
+send_dst_udp6()
+{
+ $MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+ -d 1msec -t udp "sp=20000,dp=0-32768"
+}
+
+custom_hash_test()
+{
+ local field="$1"; shift
+ local balanced="$1"; shift
+ local send_flows="$@"
+
+ RET=0
+
+ local t0_111=$(tc_rule_stats_get $ul32 111 ingress)
+ local t0_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+ $send_flows
+
+ local t1_111=$(tc_rule_stats_get $ul32 111 ingress)
+ local t1_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+ local d111=$((t1_111 - t0_111))
+ local d222=$((t1_222 - t0_222))
+
+ local diff=$((d222 - d111))
+ local sum=$((d111 + d222))
+
+ local pct=$(echo "$diff / $sum * 100" | bc -l)
+ local is_balanced=$(echo "-20 <= $pct && $pct <= 20" | bc)
+
+ [[ ( $is_balanced -eq 1 && $balanced == "balanced" ) ||
+ ( $is_balanced -eq 0 && $balanced == "unbalanced" ) ]]
+ check_err $? "Expected traffic to be $balanced, but it is not"
+
+ log_test "Multipath hash field: $field ($balanced)"
+ log_info "Packets sent on path1 / path2: $d111 / $d222"
+}
+
+custom_hash_v4()
+{
+ log_info "Running IPv4 overlay custom multipath hash tests"
+
+ # Prevent the neighbour table from overflowing, as different neighbour
+ # entries will be created on $ol4 when using different destination IPs.
+ sysctl_set net.ipv4.neigh.default.gc_thresh1 1024
+ sysctl_set net.ipv4.neigh.default.gc_thresh2 1024
+ sysctl_set net.ipv4.neigh.default.gc_thresh3 1024
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0040
+ custom_hash_test "Inner source IP" "balanced" send_src_ipv4
+ custom_hash_test "Inner source IP" "unbalanced" send_dst_ipv4
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0080
+ custom_hash_test "Inner destination IP" "balanced" send_dst_ipv4
+ custom_hash_test "Inner destination IP" "unbalanced" send_src_ipv4
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0400
+ custom_hash_test "Inner source port" "balanced" send_src_udp4
+ custom_hash_test "Inner source port" "unbalanced" send_dst_udp4
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0800
+ custom_hash_test "Inner destination port" "balanced" send_dst_udp4
+ custom_hash_test "Inner destination port" "unbalanced" send_src_udp4
+
+ sysctl_restore net.ipv4.neigh.default.gc_thresh3
+ sysctl_restore net.ipv4.neigh.default.gc_thresh2
+ sysctl_restore net.ipv4.neigh.default.gc_thresh1
+}
+
+custom_hash_v6()
+{
+ log_info "Running IPv6 overlay custom multipath hash tests"
+
+ # Prevent the neighbour table from overflowing, as different neighbour
+ # entries will be created on $ol4 when using different destination IPs.
+ sysctl_set net.ipv6.neigh.default.gc_thresh1 1024
+ sysctl_set net.ipv6.neigh.default.gc_thresh2 1024
+ sysctl_set net.ipv6.neigh.default.gc_thresh3 1024
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0040
+ custom_hash_test "Inner source IP" "balanced" send_src_ipv6
+ custom_hash_test "Inner source IP" "unbalanced" send_dst_ipv6
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0080
+ custom_hash_test "Inner destination IP" "balanced" send_dst_ipv6
+ custom_hash_test "Inner destination IP" "unbalanced" send_src_ipv6
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0200
+ custom_hash_test "Inner flowlabel" "balanced" send_flowlabel
+ custom_hash_test "Inner flowlabel" "unbalanced" send_src_ipv6
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0400
+ custom_hash_test "Inner source port" "balanced" send_src_udp6
+ custom_hash_test "Inner source port" "unbalanced" send_dst_udp6
+
+ sysctl_set net.ipv6.fib_multipath_hash_fields 0x0800
+ custom_hash_test "Inner destination port" "balanced" send_dst_udp6
+ custom_hash_test "Inner destination port" "unbalanced" send_src_udp6
+
+ sysctl_restore net.ipv6.neigh.default.gc_thresh3
+ sysctl_restore net.ipv6.neigh.default.gc_thresh2
+ sysctl_restore net.ipv6.neigh.default.gc_thresh1
+}
+
+custom_hash()
+{
+ # Test that when the hash policy is set to custom, traffic is
+ # distributed only according to the fields set in the
+ # fib_multipath_hash_fields sysctl.
+ #
+ # Each time set a different field and make sure traffic is only
+ # distributed when the field is changed in the packet stream.
+
+ sysctl_set net.ipv6.fib_multipath_hash_policy 3
+
+ custom_hash_v4
+ custom_hash_v6
+
+ sysctl_restore net.ipv6.fib_multipath_hash_policy
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS