diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ae56d94f68d9fb074fcc74a54f98cc20a8a3e0a1..0bda6916ebcfbfdc2f3d60b0bd576efb53d80f91 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1046,6 +1046,19 @@ static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
struct fib_nh_common *nhc;
fib_select_path(net, &res, fl4, NULL);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (fib_info_num_path(res.fi) > 1) {
+ int nhsel;
+
+ for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) {
+ nhc = fib_info_nhc(res.fi, nhsel);
+ update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
+ jiffies + net->ipv4.ip_rt_mtu_expires);
+ }
+ rcu_read_unlock();
+ return;
+ }
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
nhc = FIB_RES_NHC(res);
update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
jiffies + net->ipv4.ip_rt_mtu_expires);
diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index dbfa56173d2916ed2d3bc642bc0ae79138058a64..33f4fb34ac9b24b8ac1b21391e603a8367f8b6a3 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -197,6 +197,12 @@
#
# - pmtu_ipv6_route_change
# Same as above but with IPv6
+#
+# - pmtu_ipv4_mp_exceptions
+# Use the same topology as in pmtu_ipv4, but add routeable addresses
+# on host A and B on lo reachable via both routers. Host A and B
+# addresses have multipath routes to each other, b_r1 mtu = 1500.
+# Check that PMTU exceptions are created for both paths.
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
@@ -266,7 +272,8 @@ tests="
list_flush_ipv4_exception ipv4: list and flush cached exceptions 1
list_flush_ipv6_exception ipv6: list and flush cached exceptions 1
pmtu_ipv4_route_change ipv4: PMTU exception w/route replace 1
- pmtu_ipv6_route_change ipv6: PMTU exception w/route replace 1"
+ pmtu_ipv6_route_change ipv6: PMTU exception w/route replace 1
+ pmtu_ipv4_mp_exceptions ipv4: PMTU multipath nh exceptions 1"
NS_A="ns-A"
NS_B="ns-B"
@@ -353,6 +360,9 @@ tunnel6_a_addr="fd00:2::a"
tunnel6_b_addr="fd00:2::b"
tunnel6_mask="64"
+host4_a_addr="192.168.99.99"
+host4_b_addr="192.168.88.88"
+
dummy6_0_prefix="fc00:1000::"
dummy6_1_prefix="fc00:1001::"
dummy6_mask="64"
@@ -907,6 +917,52 @@ setup_ovs_bridge() {
run_cmd ip route add ${prefix6}:${b_r1}::1 via ${prefix6}:${a_r1}::2
}
+setup_multipath_new() {
+ # Set up host A with multipath routes to host B host4_b_addr
+ run_cmd ${ns_a} ip addr add ${host4_a_addr} dev lo
+ run_cmd ${ns_a} ip nexthop add id 401 via ${prefix4}.${a_r1}.2 dev veth_A-R1
+ run_cmd ${ns_a} ip nexthop add id 402 via ${prefix4}.${a_r2}.2 dev veth_A-R2
+ run_cmd ${ns_a} ip nexthop add id 403 group 401/402
+ run_cmd ${ns_a} ip route add ${host4_b_addr} src ${host4_a_addr} nhid 403
+
+ # Set up host B with multipath routes to host A host4_a_addr
+ run_cmd ${ns_b} ip addr add ${host4_b_addr} dev lo
+ run_cmd ${ns_b} ip nexthop add id 401 via ${prefix4}.${b_r1}.2 dev veth_B-R1
+ run_cmd ${ns_b} ip nexthop add id 402 via ${prefix4}.${b_r2}.2 dev veth_B-R2
+ run_cmd ${ns_b} ip nexthop add id 403 group 401/402
+ run_cmd ${ns_b} ip route add ${host4_a_addr} src ${host4_b_addr} nhid 403
+}
+
+setup_multipath_old() {
+ # Set up host A with multipath routes to host B host4_b_addr
+ run_cmd ${ns_a} ip addr add ${host4_a_addr} dev lo
+ run_cmd ${ns_a} ip route add ${host4_b_addr} \
+ src ${host4_a_addr} \
+ nexthop via ${prefix4}.${a_r1}.2 weight 1 \
+ nexthop via ${prefix4}.${a_r2}.2 weight 1
+
+ # Set up host B with multipath routes to host A host4_a_addr
+ run_cmd ${ns_b} ip addr add ${host4_b_addr} dev lo
+ run_cmd ${ns_b} ip route add ${host4_a_addr} \
+ src ${host4_b_addr} \
+ nexthop via ${prefix4}.${b_r1}.2 weight 1 \
+ nexthop via ${prefix4}.${b_r2}.2 weight 1
+}
+
+setup_multipath() {
+ if [ "$USE_NH" = "yes" ]; then
+ setup_multipath_new
+ else
+ setup_multipath_old
+ fi
+
+ # Set up routers with routes to dummies
+ run_cmd ${ns_r1} ip route add ${host4_a_addr} via ${prefix4}.${a_r1}.1
+ run_cmd ${ns_r2} ip route add ${host4_a_addr} via ${prefix4}.${a_r2}.1
+ run_cmd ${ns_r1} ip route add ${host4_b_addr} via ${prefix4}.${b_r1}.1
+ run_cmd ${ns_r2} ip route add ${host4_b_addr} via ${prefix4}.${b_r2}.1
+}
+
setup() {
[ "$(id -u)" -ne 0 ] && echo " need to run as root" && return $ksft_skip
@@ -988,23 +1044,15 @@ link_get_mtu() {
}
route_get_dst_exception() {
- ns_cmd="${1}"
- dst="${2}"
- dsfield="${3}"
+ ns_cmd="${1}"; shift
- if [ -z "${dsfield}" ]; then
- dsfield=0
- fi
-
- ${ns_cmd} ip route get "${dst}" dsfield "${dsfield}"
+ ${ns_cmd} ip route get "$@"
}
route_get_dst_pmtu_from_exception() {
- ns_cmd="${1}"
- dst="${2}"
- dsfield="${3}"
+ ns_cmd="${1}"; shift
- mtu_parse "$(route_get_dst_exception "${ns_cmd}" "${dst}" "${dsfield}")"
+ mtu_parse "$(route_get_dst_exception "${ns_cmd}" "$@")"
}
check_pmtu_value() {
@@ -1147,10 +1195,10 @@ test_pmtu_ipv4_dscp_icmp_exception() {
run_cmd "${ns_a}" ping -q -M want -Q "${dsfield}" -c 1 -w 1 -s "${len}" "${dst2}"
# Check that exceptions have been created with the correct PMTU
- pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" "${policy_mark}")"
+ pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" dsfield "${policy_mark}")"
check_pmtu_value "1400" "${pmtu_1}" "exceeding MTU" || return 1
- pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" "${policy_mark}")"
+ pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" dsfield "${policy_mark}")"
check_pmtu_value "1500" "${pmtu_2}" "exceeding MTU" || return 1
}
@@ -1197,9 +1245,9 @@ test_pmtu_ipv4_dscp_udp_exception() {
UDP:"${dst2}":50000,tos="${dsfield}"
# Check that exceptions have been created with the correct PMTU
- pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" "${policy_mark}")"
+ pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst1}" dsfield "${policy_mark}")"
check_pmtu_value "1400" "${pmtu_1}" "exceeding MTU" || return 1
- pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" "${policy_mark}")"
+ pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${dst2}" dsfield "${policy_mark}")"
check_pmtu_value "1500" "${pmtu_2}" "exceeding MTU" || return 1
}
@@ -2205,6 +2253,36 @@ test_pmtu_ipv6_route_change() {
test_pmtu_ipvX_route_change 6
}
+test_pmtu_ipv4_mp_exceptions() {
+ setup namespaces routing multipath || return $ksft_skip
+
+ trace "${ns_a}" veth_A-R1 "${ns_r1}" veth_R1-A \
+ "${ns_r1}" veth_R1-B "${ns_b}" veth_B-R1 \
+ "${ns_a}" veth_A-R2 "${ns_r2}" veth_R2-A \
+ "${ns_r2}" veth_R2-B "${ns_b}" veth_B-R2
+
+ # Set up initial MTU values
+ mtu "${ns_a}" veth_A-R1 2000
+ mtu "${ns_r1}" veth_R1-A 2000
+ mtu "${ns_r1}" veth_R1-B 1500
+ mtu "${ns_b}" veth_B-R1 1500
+
+ mtu "${ns_a}" veth_A-R2 2000
+ mtu "${ns_r2}" veth_R2-A 2000
+ mtu "${ns_r2}" veth_R2-B 1500
+ mtu "${ns_b}" veth_B-R2 1500
+
+ # Ping and expect two nexthop exceptions for two routes
+ run_cmd ${ns_a} ping -q -M want -i 0.1 -c 1 -s 1800 "${host4_b_addr}"
+
+ # Check that exceptions have been created with the correct PMTU
+ pmtu_a_R1="$(route_get_dst_pmtu_from_exception "${ns_a}" "${host4_b_addr}" oif veth_A-R1)"
+ pmtu_a_R2="$(route_get_dst_pmtu_from_exception "${ns_a}" "${host4_b_addr}" oif veth_A-R2)"
+
+ check_pmtu_value "1500" "${pmtu_a_R1}" "exceeding MTU (veth_A-R1)" || return 1
+ check_pmtu_value "1500" "${pmtu_a_R2}" "exceeding MTU (veth_A-R2)" || return 1
+}
+
usage() {
echo
echo "$0 [OPTIONS] [TEST]..."