Merge branch 'mp-inner-L3'

Stephen Suryaputra says:

====================
net: Multipath hashing on inner L3

This series extends commit 363887a2cdfe ("ipv4: Support multipath
hashing on inner IP pkts for GRE tunnel") to include support when the
outer L3 is IPv6 and to consider the case where the inner L3 is
different version from the outer L3, such as IPv6 tunneled by IPv4 GRE
or vice versa. It also includes kselftest scripts to test the use cases.

v2: Clarify the commit messages in the commits in this series to use the
    term tunneled by IPv4 GRE or by IPv6 GRE so that it's clear which
    one is the inner and which one is the outer (per David Miller).
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 1220 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/forwarding/gre_inner_v4_multipath.sh b/tools/testing/selftests/net/forwarding/gre_inner_v4_multipath.sh
new file mode 100755
index 000000000000..e4009f658003
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/gre_inner_v4_multipath.sh
@@ -0,0 +1,305 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test traffic distribution when there are multiple routes between an IPv4
+# GRE tunnel. The tunnel carries IPv4 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 +     |
+# | 192.0.3.{2-62}/24 |     |
+# +-------------------|-----+
+#                     |
+# +-------------------|------------------------+
+# | SW1               |                        |
+# |              $ol1 +                        |
+# |      192.0.3.1/24                          |
+# |                                            |
+# |  + g1 (gre)                                |
+# |    loc=192.0.2.65                          |
+# |    rem=192.0.2.66 --.                      |
+# |    tos=inherit      |                      |
+# |                     v                      |
+# |                     + $ul1                 |
+# |                     | 192.0.2.129/28       |
+# +---------------------|----------------------+
+#                       |
+# +---------------------|----------------------+
+# | SW2                 |                      |
+# |               $ul21 +                      |
+# |      192.0.2.130/28                        |
+# |                   |                        |
+# !   ________________|_____                   |
+# |  /                      \                  |
+# |  |                      |                  |
+# |  + $ul22.111 (vlan)     + $ul22.222 (vlan) |
+# |  | 192.0.2.145/28       | 192.0.2.161/28   |
+# |  |                      |                  |
+# +--|----------------------|------------------+
+#    |                      |
+# +--|----------------------|------------------+
+# |  |                      |                  |
+# |  + $ul32.111 (vlan)     + $ul32.222 (vlan) |
+# |  | 192.0.2.146/28       | 192.0.2.162/28   |
+# |  |                      |                  |
+# |  \______________________/                  |
+# |                   |                        |
+# |                   |                        |
+# |               $ul31 +                      |
+# |      192.0.2.177/28 |                  SW3 |
+# +---------------------|----------------------+
+#                       |
+# +---------------------|----------------------+
+# |                     + $ul4                 |
+# |                     ^ 192.0.2.178/28       |
+# |                     |                      |
+# |  + g2 (gre)         |                      |
+# |    loc=192.0.2.66   |                      |
+# |    rem=192.0.2.65 --'                      |
+# |    tos=inherit                             |
+# |                                            |
+# |               $ol4 +                       |
+# |       192.0.4.1/24 |                   SW4 |
+# +--------------------|-----------------------+
+#                      |
+# +--------------------|---------+
+# |                    |         |
+# |                $h2 +         |
+# |  192.0.4.{2-62}/24        H2 |
+# +------------------------------+
+
+ALL_TESTS="
+	ping_ipv4
+	multipath_ipv4
+"
+
+NUM_NETIFS=10
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 192.0.3.2/24
+	ip route add vrf v$h1 192.0.4.0/24 via 192.0.3.1
+}
+
+h1_destroy()
+{
+	ip route del vrf v$h1 192.0.4.0/24 via 192.0.3.1
+	simple_if_fini $h1 192.0.3.2/24
+}
+
+sw1_create()
+{
+	simple_if_init $ol1 192.0.3.1/24
+	__simple_if_init $ul1 v$ol1 192.0.2.129/28
+
+	tunnel_create g1 gre 192.0.2.65 192.0.2.66 tos inherit dev v$ol1
+	__simple_if_init g1 v$ol1 192.0.2.65/32
+	ip route add vrf v$ol1 192.0.2.66/32 via 192.0.2.130
+
+	ip route add vrf v$ol1 192.0.4.0/24 nexthop dev g1
+}
+
+sw1_destroy()
+{
+	ip route del vrf v$ol1 192.0.4.0/24
+
+	ip route del vrf v$ol1 192.0.2.66/32
+	__simple_if_fini g1 192.0.2.65/32
+	tunnel_destroy g1
+
+	__simple_if_fini $ul1 192.0.2.129/28
+	simple_if_fini $ol1 192.0.3.1/24
+}
+
+sw2_create()
+{
+	simple_if_init $ul21 192.0.2.130/28
+	__simple_if_init $ul22 v$ul21
+	vlan_create $ul22 111 v$ul21 192.0.2.145/28
+	vlan_create $ul22 222 v$ul21 192.0.2.161/28
+
+	ip route add vrf v$ul21 192.0.2.65/32 via 192.0.2.129
+	ip route add vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 \
+	   nexthop via 192.0.2.162
+}
+
+sw2_destroy()
+{
+	ip route del vrf v$ul21 192.0.2.66/32
+	ip route del vrf v$ul21 192.0.2.65/32
+
+	vlan_destroy $ul22 222
+	vlan_destroy $ul22 111
+	__simple_if_fini $ul22
+	simple_if_fini $ul21 192.0.2.130/28
+}
+
+sw3_create()
+{
+	simple_if_init $ul31 192.0.2.177/28
+	__simple_if_init $ul32 v$ul31
+	vlan_create $ul32 111 v$ul31 192.0.2.146/28
+	vlan_create $ul32 222 v$ul31 192.0.2.162/28
+
+	ip route add vrf v$ul31 192.0.2.66/32 via 192.0.2.178
+	ip route add vrf v$ul31 192.0.2.65/32 \
+	   nexthop via 192.0.2.145 \
+	   nexthop via 192.0.2.161
+
+	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 $ul32 clsact
+
+	ip route del vrf v$ul31 192.0.2.65/32
+	ip route del vrf v$ul31 192.0.2.66/32
+
+	vlan_destroy $ul32 222
+	vlan_destroy $ul32 111
+	__simple_if_fini $ul32
+	simple_if_fini $ul31 192.0.2.177/28
+}
+
+sw4_create()
+{
+	simple_if_init $ol4 192.0.4.1/24
+	__simple_if_init $ul4 v$ol4 192.0.2.178/28
+
+	tunnel_create g2 gre 192.0.2.66 192.0.2.65 tos inherit dev v$ol4
+	__simple_if_init g2 v$ol4 192.0.2.66/32
+	ip route add vrf v$ol4 192.0.2.65/32 via 192.0.2.177
+
+	ip route add vrf v$ol4 192.0.3.0/24 nexthop dev g2
+}
+
+sw4_destroy()
+{
+	ip route del vrf v$ol4 192.0.3.0/24
+
+	ip route del vrf v$ol4 192.0.2.65/32
+	__simple_if_fini g2 192.0.2.66/32
+	tunnel_destroy g2
+
+	__simple_if_fini $ul4 192.0.2.178/28
+	simple_if_fini $ol4 192.0.4.1/24
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.4.2/24
+	ip route add vrf v$h2 192.0.3.0/24 via 192.0.4.1
+}
+
+h2_destroy()
+{
+	ip route del vrf v$h2 192.0.3.0/24 via 192.0.4.1
+	simple_if_fini $h2 192.0.4.2/24
+}
+
+setup_prepare()
+{
+	h1=${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
+}
+
+multipath4_test()
+{
+	local what=$1; shift
+	local weight1=$1; shift
+	local weight2=$1; shift
+
+	sysctl_set net.ipv4.fib_multipath_hash_policy 2
+	ip route replace vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 weight $weight1 \
+	   nexthop via 192.0.2.162 weight $weight2
+
+	local t0_111=$(tc_rule_stats_get $ul32 111 ingress)
+	local t0_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+	ip vrf exec v$h1 \
+	   $MZ $h1 -q -p 64 -A "192.0.3.2-192.0.3.62" -B "192.0.4.2-192.0.4.62" \
+	       -d 1msec -c 50 -t udp "sp=1024,dp=1024"
+	sleep 1
+
+	local t1_111=$(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=$((t1_222 - t0_222))
+	multipath_eval "$what" $weight1 $weight2 $d111 $d222
+
+	ip route replace vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 \
+	   nexthop via 192.0.2.162
+	sysctl_restore net.ipv4.fib_multipath_hash_policy
+}
+
+ping_ipv4()
+{
+	ping_test $h1 192.0.4.2
+}
+
+multipath_ipv4()
+{
+	log_info "Running IPv4 over GRE over IPv4 multipath tests"
+	multipath4_test "ECMP" 1 1
+	multipath4_test "Weighted MP 2:1" 2 1
+	multipath4_test "Weighted MP 11:45" 11 45
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS
diff --git a/tools/testing/selftests/net/forwarding/gre_inner_v6_multipath.sh b/tools/testing/selftests/net/forwarding/gre_inner_v6_multipath.sh
new file mode 100755
index 000000000000..e449475c4d3e
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/gre_inner_v6_multipath.sh
@@ -0,0 +1,306 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test traffic distribution when there are multiple routes between an IPv4
+# GRE tunnel. The tunnel carries 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 +     |
+# |  2001:db8:1::2/64 |     |
+# +-------------------|-----+
+#                     |
+# +-------------------|------------------------+
+# | SW1               |                        |
+# |              $ol1 +                        |
+# |  2001:db8:1::1/64                          |
+# |                                            |
+# |  + g1 (gre)                                |
+# |    loc=192.0.2.65                          |
+# |    rem=192.0.2.66 --.                      |
+# |    tos=inherit      |                      |
+# |                     v                      |
+# |                     + $ul1                 |
+# |                     | 192.0.2.129/28       |
+# +---------------------|----------------------+
+#                       |
+# +---------------------|----------------------+
+# | SW2                 |                      |
+# |               $ul21 +                      |
+# |      192.0.2.130/28                        |
+# |                   |                        |
+# !   ________________|_____                   |
+# |  /                      \                  |
+# |  |                      |                  |
+# |  + $ul22.111 (vlan)     + $ul22.222 (vlan) |
+# |  | 192.0.2.145/28       | 192.0.2.161/28   |
+# |  |                      |                  |
+# +--|----------------------|------------------+
+#    |                      |
+# +--|----------------------|------------------+
+# |  |                      |                  |
+# |  + $ul32.111 (vlan)     + $ul32.222 (vlan) |
+# |  | 192.0.2.146/28       | 192.0.2.162/28   |
+# |  |                      |                  |
+# |  \______________________/                  |
+# |                   |                        |
+# |                   |                        |
+# |               $ul31 +                      |
+# |      192.0.2.177/28 |                  SW3 |
+# +---------------------|----------------------+
+#                       |
+# +---------------------|----------------------+
+# |                     + $ul4                 |
+# |                     ^ 192.0.2.178/28       |
+# |                     |                      |
+# |  + g2 (gre)         |                      |
+# |    loc=192.0.2.66   |                      |
+# |    rem=192.0.2.65 --'                      |
+# |    tos=inherit                             |
+# |                                            |
+# |               $ol4 +                       |
+# |   2001:db8:2::1/64 |                   SW4 |
+# +--------------------|-----------------------+
+#                      |
+# +--------------------|---------+
+# |                    |         |
+# |                $h2 +         |
+# |   2001:db8:2::2/64        H2 |
+# +------------------------------+
+
+ALL_TESTS="
+	ping_ipv6
+	multipath_ipv6
+"
+
+NUM_NETIFS=10
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 2001:db8:1::2/64
+	ip -6 route add vrf v$h1 2001:db8:2::/64 via 2001:db8:1::1
+}
+
+h1_destroy()
+{
+	ip -6 route del vrf v$h1 2001:db8:2::/64 via 2001:db8:1::1
+	simple_if_fini $h1 2001:db8:1::2/64
+}
+
+sw1_create()
+{
+	simple_if_init $ol1 2001:db8:1::1/64
+	__simple_if_init $ul1 v$ol1 192.0.2.129/28
+
+	tunnel_create g1 gre 192.0.2.65 192.0.2.66 tos inherit dev v$ol1
+	__simple_if_init g1 v$ol1 192.0.2.65/32
+	ip route add vrf v$ol1 192.0.2.66/32 via 192.0.2.130
+
+	ip -6 route add vrf v$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 192.0.2.66/32
+	__simple_if_fini g1 192.0.2.65/32
+	tunnel_destroy g1
+
+	__simple_if_fini $ul1 192.0.2.129/28
+	simple_if_fini $ol1 2001:db8:1::1/64
+}
+
+sw2_create()
+{
+	simple_if_init $ul21 192.0.2.130/28
+	__simple_if_init $ul22 v$ul21
+	vlan_create $ul22 111 v$ul21 192.0.2.145/28
+	vlan_create $ul22 222 v$ul21 192.0.2.161/28
+
+	ip route add vrf v$ul21 192.0.2.65/32 via 192.0.2.129
+	ip route add vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 \
+	   nexthop via 192.0.2.162
+}
+
+sw2_destroy()
+{
+	ip route del vrf v$ul21 192.0.2.66/32
+	ip route del vrf v$ul21 192.0.2.65/32
+
+	vlan_destroy $ul22 222
+	vlan_destroy $ul22 111
+	__simple_if_fini $ul22
+	simple_if_fini $ul21 192.0.2.130/28
+}
+
+sw3_create()
+{
+	simple_if_init $ul31 192.0.2.177/28
+	__simple_if_init $ul32 v$ul31
+	vlan_create $ul32 111 v$ul31 192.0.2.146/28
+	vlan_create $ul32 222 v$ul31 192.0.2.162/28
+
+	ip route add vrf v$ul31 192.0.2.66/32 via 192.0.2.178
+	ip route add vrf v$ul31 192.0.2.65/32 \
+	   nexthop via 192.0.2.145 \
+	   nexthop via 192.0.2.161
+
+	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 $ul32 clsact
+
+	ip route del vrf v$ul31 192.0.2.65/32
+	ip route del vrf v$ul31 192.0.2.66/32
+
+	vlan_destroy $ul32 222
+	vlan_destroy $ul32 111
+	__simple_if_fini $ul32
+	simple_if_fini $ul31 192.0.2.177/28
+}
+
+sw4_create()
+{
+	simple_if_init $ol4 2001:db8:2::1/64
+	__simple_if_init $ul4 v$ol4 192.0.2.178/28
+
+	tunnel_create g2 gre 192.0.2.66 192.0.2.65 tos inherit dev v$ol4
+	__simple_if_init g2 v$ol4 192.0.2.66/32
+	ip route add vrf v$ol4 192.0.2.65/32 via 192.0.2.177
+
+	ip -6 route add vrf v$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 192.0.2.65/32
+	__simple_if_fini g2 192.0.2.66/32
+	tunnel_destroy g2
+
+	__simple_if_fini $ul4 192.0.2.178/28
+	simple_if_fini $ol4 2001:db8:2::1/64
+}
+
+h2_create()
+{
+	simple_if_init $h2 2001:db8:2::2/64
+	ip -6 route add vrf v$h2 2001:db8:1::/64 via 2001:db8:2::1
+}
+
+h2_destroy()
+{
+	ip -6 route del vrf v$h2 2001:db8:1::/64 via 2001:db8:2::1
+	simple_if_fini $h2 2001:db8:2::2/64
+}
+
+setup_prepare()
+{
+	h1=${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
+}
+
+multipath6_test()
+{
+	local what=$1; shift
+	local weight1=$1; shift
+	local weight2=$1; shift
+
+	sysctl_set net.ipv4.fib_multipath_hash_policy 2
+	ip route replace vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 weight $weight1 \
+	   nexthop via 192.0.2.162 weight $weight2
+
+	local t0_111=$(tc_rule_stats_get $ul32 111 ingress)
+	local t0_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+	ip vrf exec v$h1 \
+	   $MZ $h1 -6 -q -p 64 -A "2001:db8:1::2-2001:db8:1::1e" \
+	       -B "2001:db8:2::2-2001:db8:2::1e" \
+	       -d 1msec -c 50 -t udp "sp=1024,dp=1024"
+	sleep 1
+
+	local t1_111=$(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=$((t1_222 - t0_222))
+	multipath_eval "$what" $weight1 $weight2 $d111 $d222
+
+	ip route replace vrf v$ul21 192.0.2.66/32 \
+	   nexthop via 192.0.2.146 \
+	   nexthop via 192.0.2.162
+	sysctl_restore net.ipv4.fib_multipath_hash_policy
+}
+
+ping_ipv6()
+{
+	ping_test $h1 2001:db8:2::2
+}
+
+multipath_ipv6()
+{
+	log_info "Running IPv6 over GRE over IPv4 multipath tests"
+	multipath6_test "ECMP" 1 1
+	multipath6_test "Weighted MP 2:1" 2 1
+	multipath6_test "Weighted MP 11:45" 11 45
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS
diff --git a/tools/testing/selftests/net/forwarding/ip6gre_inner_v4_multipath.sh b/tools/testing/selftests/net/forwarding/ip6gre_inner_v4_multipath.sh
new file mode 100755
index 000000000000..a257979d3fc5
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/ip6gre_inner_v4_multipath.sh
@@ -0,0 +1,304 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test traffic distribution when there are multiple routes between an IPv6
+# GRE tunnel. The tunnel carries IPv4 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 +     |
+# | 192.0.3.{2-62}/24 |     |
+# +-------------------|-----+
+#                     |
+# +-------------------|-------------------------+
+# | SW1               |                         |
+# |              $ol1 +                         |
+# |      192.0.3.1/24                           |
+# |                                             |
+# |  + g1 (gre)                                 |
+# |    loc=2001:db8:40::1                       |
+# |    rem=2001:db8:40::2 --.                   |
+# |    tos=inherit          |                   |
+# |                         v                   |
+# |                         + $ul1              |
+# |                         | 2001:db8:80::1/64 |
+# +-------------------------|-------------------+
+#                           |
+# +-------------------------|-------------------+
+# | SW2                     |                   |
+# |                   $ul21 +                   |
+# |       2001:db8:80::2/64                     |
+# |                   |                         |
+# !   ________________|_____                    |
+# |  /                      \                   |
+# |  |                      |                   |
+# |  + $ul22.111 (vlan)     + $ul22.222 (vlan)  |
+# |  | 2001:db8:81::1/64    | 2001:db8:82::1/64 |
+# |  |                      |                   |
+# +--|----------------------|-------------------+
+#    |                      |
+# +--|----------------------|-------------------+
+# |  |                      |                   |
+# |  + $ul32.111 (vlan)     + $ul32.222 (vlan)  |
+# |  | 2001:db8:81::2/64    | 2001:db8:82::2/64 |
+# |  |                      |                   |
+# |  \______________________/                   |
+# |                   |                         |
+# |                   |                         |
+# |                   $ul31 +                   |
+# |       2001:db8:83::2/64 |               SW3 |
+# +-------------------------|-------------------+
+#                           |
+# +-------------------------|-------------------+
+# |                         + $ul4              |
+# |                         ^ 2001:db8:83::1/64 |
+# |  + g2 (gre)             |                   |
+# |    loc=2001:db8:40::2   |                   |
+# |    rem=2001:db8:40::1 --'                   |
+# |    tos=inherit                              |
+# |                                             |
+# |               $ol4 +                        |
+# |       192.0.4.1/24 |                    SW4 |
+# +--------------------|------------------------+
+#                      |
+# +--------------------|---------+
+# |                    |         |
+# |                $h2 +         |
+# |  192.0.4.{2-62}/24        H2 |
+# +------------------------------+
+
+ALL_TESTS="
+	ping_ipv4
+	multipath_ipv4
+"
+
+NUM_NETIFS=10
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 192.0.3.2/24
+	ip route add vrf v$h1 192.0.4.0/24 via 192.0.3.1
+}
+
+h1_destroy()
+{
+	ip route del vrf v$h1 192.0.4.0/24 via 192.0.3.1
+	simple_if_fini $h1 192.0.3.2/24
+}
+
+sw1_create()
+{
+	simple_if_init $ol1 192.0.3.1/24
+	__simple_if_init $ul1 v$ol1 2001:db8:80::1/64
+
+	tunnel_create g1 ip6gre 2001:db8:40::1 2001:db8:40::2 tos inherit dev v$ol1
+	__simple_if_init g1 v$ol1 2001:db8:40::1/128
+	ip -6 route add vrf v$ol1 2001:db8:40::2/128 via 2001:db8:80::2
+
+	ip route add vrf v$ol1 192.0.4.0/24 nexthop dev g1
+}
+
+sw1_destroy()
+{
+	ip route del vrf v$ol1 192.0.4.0/24
+
+	ip -6 route del vrf v$ol1 2001:db8:40::2/128
+	__simple_if_fini g1 2001:db8:40::1/128
+	tunnel_destroy g1
+
+	__simple_if_fini $ul1 2001:db8:80::1/64
+	simple_if_fini $ol1 192.0.3.1/24
+}
+
+sw2_create()
+{
+	simple_if_init $ul21 2001:db8:80::2/64
+	__simple_if_init $ul22 v$ul21
+	vlan_create $ul22 111 v$ul21 2001:db8:81::1/64
+	vlan_create $ul22 222 v$ul21 2001:db8:82::1/64
+
+	ip -6 route add vrf v$ul21 2001:db8:40::1/128 via 2001:db8:80::1
+	ip -6 route add vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 \
+	   nexthop via 2001:db8:82::2
+}
+
+sw2_destroy()
+{
+	ip -6 route del vrf v$ul21 2001:db8:40::2/128
+	ip -6 route del vrf v$ul21 2001:db8:40::1/128
+
+	vlan_destroy $ul22 222
+	vlan_destroy $ul22 111
+	__simple_if_fini $ul22
+	simple_if_fini $ul21 2001:db8:80::2/64
+}
+
+sw3_create()
+{
+	simple_if_init $ul31 2001:db8:83::2/64
+	__simple_if_init $ul32 v$ul31
+	vlan_create $ul32 111 v$ul31 2001:db8:81::2/64
+	vlan_create $ul32 222 v$ul31 2001:db8:82::2/64
+
+	ip -6 route add vrf v$ul31 2001:db8:40::2/128 via 2001:db8:83::1
+	ip -6 route add vrf v$ul31 2001:db8:40::1/128 \
+	   nexthop via 2001:db8:81::1 \
+	   nexthop via 2001:db8:82::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:db8:40::1/128
+	ip -6 route del vrf v$ul31 2001:db8:40::2/128
+
+	vlan_destroy $ul32 222
+	vlan_destroy $ul32 111
+	__simple_if_fini $ul32
+	simple_if_fini $ul31 2001:Db8:83::2/64
+}
+
+sw4_create()
+{
+	simple_if_init $ol4 192.0.4.1/24
+	__simple_if_init $ul4 v$ol4 2001:db8:83::1/64
+
+	tunnel_create g2 ip6gre 2001:db8:40::2 2001:db8:40::1 tos inherit dev v$ol4
+	__simple_if_init g2 v$ol4 2001:db8:40::2/128
+	ip -6 route add vrf v$ol4 2001:db8:40::1/128 via 2001:db8:83::2
+
+	ip route add vrf v$ol4 192.0.3.0/24 nexthop dev g2
+}
+
+sw4_destroy()
+{
+	ip route del vrf v$ol4 192.0.3.0/24
+
+	ip -6 route del vrf v$ol4 2001:db8:40::1/128
+	__simple_if_fini g2 2001:db8:40::2/128
+	tunnel_destroy g2
+
+	__simple_if_fini $ul4 2001:db8:83::1/64
+	simple_if_fini $ol4 192.0.4.1/24
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.4.2/24
+	ip route add vrf v$h2 192.0.3.0/24 via 192.0.4.1
+}
+
+h2_destroy()
+{
+	ip route del vrf v$h2 192.0.3.0/24 via 192.0.4.1
+	simple_if_fini $h2 192.0.4.2/24
+}
+
+setup_prepare()
+{
+	h1=${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
+}
+
+multipath4_test()
+{
+	local what=$1; shift
+	local weight1=$1; shift
+	local weight2=$1; shift
+
+	sysctl_set net.ipv6.fib_multipath_hash_policy 2
+	ip route replace vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 weight $weight1 \
+	   nexthop via 2001:db8:82::2 weight $weight2
+
+	local t0_111=$(tc_rule_stats_get $ul32 111 ingress)
+	local t0_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+	ip vrf exec v$h1 \
+	   $MZ $h1 -q -p 64 -A "192.0.3.2-192.0.3.62" -B "192.0.4.2-192.0.4.62" \
+	       -d 1msec -c 50 -t udp "sp=1024,dp=1024"
+	sleep 1
+
+	local t1_111=$(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=$((t1_222 - t0_222))
+	multipath_eval "$what" $weight1 $weight2 $d111 $d222
+
+	ip route replace vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 \
+	   nexthop via 2001:db8:82::2
+	sysctl_restore net.ipv6.fib_multipath_hash_policy
+}
+
+ping_ipv4()
+{
+	ping_test $h1 192.0.4.2
+}
+
+multipath_ipv4()
+{
+	log_info "Running IPv4 over GRE over IPv6 multipath tests"
+	multipath4_test "ECMP" 1 1
+	multipath4_test "Weighted MP 2:1" 2 1
+	multipath4_test "Weighted MP 11:45" 11 45
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS
diff --git a/tools/testing/selftests/net/forwarding/ip6gre_inner_v6_multipath.sh b/tools/testing/selftests/net/forwarding/ip6gre_inner_v6_multipath.sh
new file mode 100755
index 000000000000..d208f5243ade
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/ip6gre_inner_v6_multipath.sh
@@ -0,0 +1,305 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Test traffic distribution when there are multiple routes between an IPv6
+# GRE tunnel. The tunnel carries 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 +     |
+# |  2001:db8:1::2/64 |     |
+# +-------------------|-----+
+#                     |
+# +-------------------|-------------------------+
+# | SW1               |                         |
+# |              $ol1 +                         |
+# |  2001:db8:1::1/64                           |
+# |                                             |
+# |  + g1 (gre)                                 |
+# |    loc=2001:db8:40::1                       |
+# |    rem=2001:db8:40::2 --.                   |
+# |    tos=inherit          |                   |
+# |                         v                   |
+# |                         + $ul1              |
+# |                         | 2001:db8:80::1/64 |
+# +-------------------------|-------------------+
+#                           |
+# +-------------------------|-------------------+
+# | SW2                     |                   |
+# |                   $ul21 +                   |
+# |       2001:db8:80::2/64                     |
+# |                   |                         |
+# !   ________________|_____                    |
+# |  /                      \                   |
+# |  |                      |                   |
+# |  + $ul22.111 (vlan)     + $ul22.222 (vlan)  |
+# |  | 2001:db8:81::1/64    | 2001:db8:82::1/64 |
+# |  |                      |                   |
+# +--|----------------------|-------------------+
+#    |                      |
+# +--|----------------------|-------------------+
+# |  |                      |                   |
+# |  + $ul32.111 (vlan)     + $ul32.222 (vlan)  |
+# |  | 2001:db8:81::2/64    | 2001:db8:82::2/64 |
+# |  |                      |                   |
+# |  \______________________/                   |
+# |                   |                         |
+# |                   |                         |
+# |                   $ul31 +                   |
+# |       2001:db8:83::2/64 |               SW3 |
+# +-------------------------|-------------------+
+#                           |
+# +-------------------------|-------------------+
+# |                         + $ul4              |
+# |                         ^ 2001:db8:83::1/64 |
+# |  + g2 (gre)             |                   |
+# |    loc=2001:db8:40::2   |                   |
+# |    rem=2001:db8:40::1 --'                   |
+# |    tos=inherit                              |
+# |                                             |
+# |               $ol4 +                        |
+# |   2001:db8:2::1/64 |                    SW4 |
+# +--------------------|------------------------+
+#                      |
+# +--------------------|---------+
+# |                    |         |
+# |                $h2 +         |
+# |   2001:db8:2::2/64        H2 |
+# +------------------------------+
+
+ALL_TESTS="
+	ping_ipv6
+	multipath_ipv6
+"
+
+NUM_NETIFS=10
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 2001:db8:1::2/64
+	ip -6 route add vrf v$h1 2001:db8:2::/64 via 2001:db8:1::1
+}
+
+h1_destroy()
+{
+	ip -6 route del vrf v$h1 2001:db8:2::/64 via 2001:db8:1::1
+	simple_if_fini $h1 2001:db8:1::2/64
+}
+
+sw1_create()
+{
+	simple_if_init $ol1 2001:db8:1::1/64
+	__simple_if_init $ul1 v$ol1 2001:db8:80::1/64
+
+	tunnel_create g1 ip6gre 2001:db8:40::1 2001:db8:40::2 tos inherit dev v$ol1
+	__simple_if_init g1 v$ol1 2001:db8:40::1/128
+	ip -6 route add vrf v$ol1 2001:db8:40::2/128 via 2001:db8:80::2
+
+	ip -6 route add vrf v$ol1 2001:db8:2::/64 dev g1
+}
+
+sw1_destroy()
+{
+	ip -6 route del vrf v$ol1 2001:db8:2::/64
+
+	ip -6 route del vrf v$ol1 2001:db8:40::2/128
+	__simple_if_fini g1 2001:db8:40::1/128
+	tunnel_destroy g1
+
+	__simple_if_fini $ul1 2001:db8:80::1/64
+	simple_if_fini $ol1 2001:db8:1::1/64
+}
+
+sw2_create()
+{
+	simple_if_init $ul21 2001:db8:80::2/64
+	__simple_if_init $ul22 v$ul21
+	vlan_create $ul22 111 v$ul21 2001:db8:81::1/64
+	vlan_create $ul22 222 v$ul21 2001:db8:82::1/64
+
+	ip -6 route add vrf v$ul21 2001:db8:40::1/128 via 2001:db8:80::1
+	ip -6 route add vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 \
+	   nexthop via 2001:db8:82::2
+}
+
+sw2_destroy()
+{
+	ip -6 route del vrf v$ul21 2001:db8:40::2/128
+	ip -6 route del vrf v$ul21 2001:db8:40::1/128
+
+	vlan_destroy $ul22 222
+	vlan_destroy $ul22 111
+	__simple_if_fini $ul22
+	simple_if_fini $ul21 2001:db8:80::2/64
+}
+
+sw3_create()
+{
+	simple_if_init $ul31 2001:db8:83::2/64
+	__simple_if_init $ul32 v$ul31
+	vlan_create $ul32 111 v$ul31 2001:db8:81::2/64
+	vlan_create $ul32 222 v$ul31 2001:db8:82::2/64
+
+	ip -6 route add vrf v$ul31 2001:db8:40::2/128 via 2001:db8:83::1
+	ip -6 route add vrf v$ul31 2001:db8:40::1/128 \
+	   nexthop via 2001:db8:81::1 \
+	   nexthop via 2001:db8:82::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:db8:40::1/128
+	ip -6 route del vrf v$ul31 2001:db8:40::2/128
+
+	vlan_destroy $ul32 222
+	vlan_destroy $ul32 111
+	__simple_if_fini $ul32
+	simple_if_fini $ul31 2001:Db8:83::2/64
+}
+
+sw4_create()
+{
+	simple_if_init $ol4 2001:db8:2::1/64
+	__simple_if_init $ul4 v$ol4 2001:db8:83::1/64
+
+	tunnel_create g2 ip6gre 2001:db8:40::2 2001:db8:40::1 tos inherit dev v$ol4
+	__simple_if_init g2 v$ol4 2001:db8:40::2/128
+	ip -6 route add vrf v$ol4 2001:db8:40::1/128 via 2001:db8:83::2
+
+	ip -6 route add vrf v$ol4 2001:db8:1::/64 dev g2
+}
+
+sw4_destroy()
+{
+	ip -6 route del vrf v$ol4 2001:db8:1::/64
+
+	ip -6 route del vrf v$ol4 2001:db8:40::1/128
+	__simple_if_fini g2 2001:db8:40::2/128
+	tunnel_destroy g2
+
+	__simple_if_fini $ul4 2001:db8:83::1/64
+	simple_if_fini $ol4 2001:db8:2::1/64
+}
+
+h2_create()
+{
+	simple_if_init $h2 2001:db8:2::2/64
+	ip -6 route add vrf v$h2 2001:db8:1::/64 via 2001:db8:2::1
+}
+
+h2_destroy()
+{
+	ip -6 route del vrf v$h2 2001:db8:1::/64 via 2001:db8:2::1
+	simple_if_fini $h2 2001:db8:2::2/64
+}
+
+setup_prepare()
+{
+	h1=${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
+}
+
+multipath6_test()
+{
+	local what=$1; shift
+	local weight1=$1; shift
+	local weight2=$1; shift
+
+	sysctl_set net.ipv6.fib_multipath_hash_policy 2
+	ip route replace vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 weight $weight1 \
+	   nexthop via 2001:db8:82::2 weight $weight2
+
+	local t0_111=$(tc_rule_stats_get $ul32 111 ingress)
+	local t0_222=$(tc_rule_stats_get $ul32 222 ingress)
+
+	ip vrf exec v$h1 \
+	   $MZ $h1 -6 -q -p 64 -A "2001:db8:1::2-2001:db8:1::1e" \
+	       -B "2001:db8:2::2-2001:db8:2::1e" \
+	       -d 1msec -c 50 -t udp "sp=1024,dp=1024"
+	sleep 1
+
+	local t1_111=$(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=$((t1_222 - t0_222))
+	multipath_eval "$what" $weight1 $weight2 $d111 $d222
+
+	ip route replace vrf v$ul21 2001:db8:40::2/128 \
+	   nexthop via 2001:db8:81::2 \
+	   nexthop via 2001:db8:82::2
+	sysctl_restore net.ipv6.fib_multipath_hash_policy
+}
+
+ping_ipv6()
+{
+	ping_test $h1 2001:db8:2::2
+}
+
+multipath_ipv6()
+{
+	log_info "Running IPv6 over GRE over IPv6 multipath tests"
+	multipath6_test "ECMP" 1 1
+	multipath6_test "Weighted MP 2:1" 2 1
+	multipath6_test "Weighted MP 11:45" 11 45
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+tests_run
+
+exit $EXIT_STATUS