[PATCH net-next 3/3] selftests: net: arp_ndisc_untracked_subnets: test for arp_accept and accept_untracked_na

Jaehee Park
2022-07-11T17:51:36Z

ipv4 arp_accept has a new option '2' to create new neighbor entries
only if the src ip is in the subnet of configured address on the
interface. This selftest tests all options in arp_accept.

ipv6 has a sysctl endpoint, accept_untracked_na, that defines the
behavior for accepting untracked neighbor advertisements. A new option
similar to that of arp_accept for learning only from the same subnet is
added to accept_untracked_na. This selftest tests this new feature.

Signed-off-by: Jaehee Park <jhpark1013@gmail.com>
Suggested-by: Roopa Prabhu <roopa@nvidia.com>
---
tools/testing/selftests/net/Makefile | 1 +
.../net/arp_ndisc_untracked_subnets.sh | 281 ++++++++++++++++++
2 files changed, 282 insertions(+)
create mode 100755 tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index ddad703ace34..9c2e9e303c37 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -38,6 +38,7 @@ TEST_PROGS += srv6_end_dt6_l3vpn_test.sh
TEST_PROGS += vrf_strict_mode_test.sh
TEST_PROGS += arp_ndisc_evict_nocarrier.sh
TEST_PROGS += ndisc_unsolicited_na_test.sh
+TEST_PROGS += arp_ndisc_untracked_subnets.sh
TEST_PROGS += stress_reuseport_listen.sh
TEST_PROGS_EXTENDED := in_netns.sh setup_loopback.sh setup_veth.sh
TEST_PROGS_EXTENDED += toeplitz_client.sh toeplitz.sh
diff --git a/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh b/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh
new file mode 100755
index 000000000000..57a14b4e26f2
--- /dev/null
+++ b/tools/testing/selftests/net/arp_ndisc_untracked_subnets.sh
@@ -0,0 +1,281 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# 2 namespaces: one host and one router. Use arping from the host to send a
+# garp to the router. Router accepts or ignores based on its arp_accept
+# configuration.
+
+TESTS="arp ndisc"
+
+ROUTER_NS="ns-router"
+ROUTER_NS_V6="ns-router-v6"
+ROUTER_INTF="veth-router"
+ROUTER_ADDR="10.0.10.1"
+ROUTER_ADDR_V6="2001:db8:abcd:0012::1"
+
+HOST_NS="ns-host"
+HOST_NS_V6="ns-host-v6"
+HOST_INTF="veth-host"
+HOST_ADDR="10.0.10.2"
+HOST_ADDR_V6="2001:db8:abcd:0012::2"
+
+SUBNET_WIDTH=24
+SUBNET_WIDTH_V6=64
+
+cleanup() {
+ ip netns del ${HOST_NS}
+ ip netns del ${ROUTER_NS}
+}
+
+cleanup_v6() {
+ ip netns del ${HOST_NS_V6}
+ ip netns del ${ROUTER_NS_V6}
+}
+
+setup() {
+ local arp_accept=$1
+
+ # setup two namespaces
+ ip netns add ${ROUTER_NS}
+ ip netns add ${HOST_NS}
+
+ # setup interfaces veth0 and veth1, which are pairs in separate
+ # namespaces. veth0 is veth-router, veth1 is veth-host.
+ # first, setup the inteface's link to the namespace
+ # then, set the interface "up"
+ ip netns exec ${ROUTER_NS} ip link add name ${ROUTER_INTF} \
+ type veth peer name ${HOST_INTF}
+
+ ip netns exec ${ROUTER_NS} ip link set dev ${ROUTER_INTF} up
+ ip netns exec ${ROUTER_NS} ip link set dev ${HOST_INTF} netns ${HOST_NS}
+
+ ip netns exec ${HOST_NS} ip link set dev ${HOST_INTF} up
+ ip netns exec ${ROUTER_NS} ip addr add ${ROUTER_ADDR}/${SUBNET_WIDTH} \
+ dev ${ROUTER_INTF}
+
+ ip netns exec ${HOST_NS} ip addr add ${HOST_ADDR}/${SUBNET_WIDTH} \
+ dev ${HOST_INTF}
+ ip netns exec ${HOST_NS} ip route add default via ${HOST_ADDR} \
+ dev ${HOST_INTF}
+ ip netns exec ${ROUTER_NS} ip route add default via ${ROUTER_ADDR} \
+ dev ${ROUTER_INTF}
+
+ ROUTER_CONF=net.ipv4.conf.${ROUTER_INTF}
+ ip netns exec ${ROUTER_NS} sysctl -w \
+ ${ROUTER_CONF}.arp_accept=${arp_accept} >/dev/null 2>&1
+}
+
+setup_v6() {
+ local accept_untracked_na=$1
+
+ # setup two namespaces
+ ip netns add ${ROUTER_NS_V6}
+ ip netns add ${HOST_NS_V6}
+
+ # setup interfaces veth0 and veth1, which are pairs in separate
+ # namespaces. veth0 is veth-router, veth1 is veth-host.
+ # first, setup the inteface's link to the namespace
+ # then, set the interface "up"
+ ip -6 -netns ${ROUTER_NS_V6} link add name ${ROUTER_INTF} \
+ type veth peer name ${HOST_INTF}
+
+ ip -6 -netns ${ROUTER_NS_V6} link set dev ${ROUTER_INTF} up
+ ip -6 -netns ${ROUTER_NS_V6} link set dev ${HOST_INTF} netns \
+ ${HOST_NS_V6}
+
+ ip -6 -netns ${HOST_NS_V6} link set dev ${HOST_INTF} up
+ ip -6 -netns ${ROUTER_NS_V6} addr add \
+ ${ROUTER_ADDR_V6}/${SUBNET_WIDTH_V6} dev ${ROUTER_INTF} nodad
+
+ HOST_CONF=net.ipv6.conf.${HOST_INTF}
+ ip netns exec ${HOST_NS_V6} sysctl -qw ${HOST_CONF}.ndisc_notify=1
+ ip netns exec ${HOST_NS_V6} sysctl -qw ${HOST_CONF}.disable_ipv6=0
+ ip -6 -netns ${HOST_NS_V6} addr add ${HOST_ADDR_V6}/${SUBNET_WIDTH_V6} \
+ dev ${HOST_INTF}
+
+ ROUTER_CONF=net.ipv6.conf.${ROUTER_INTF}
+
+ ip netns exec ${ROUTER_NS_V6} sysctl -w \
+ ${ROUTER_CONF}.forwarding=1 >/dev/null 2>&1
+ ip netns exec ${ROUTER_NS_V6} sysctl -w \
+ ${ROUTER_CONF}.drop_unsolicited_na=0 >/dev/null 2>&1
+ ip netns exec ${ROUTER_NS_V6} sysctl -w \
+ ${ROUTER_CONF}.accept_untracked_na=${accept_untracked_na} \
+ >/dev/null 2>&1
+}
+
+verify_arp() {
+ local arp_accept=$1
+ local same_subnet=$2
+
+ # If no entries, there's an error, so stderr would not be 0.
+ neigh_show_output=$(ip netns exec ${ROUTER_NS} ip neigh get \
+ ${HOST_ADDR} dev ${ROUTER_INTF} 2>/dev/null)
+
+ if [ ${arp_accept} -eq 1 ]; then
+ # Neighbor entries expected.
+ [[ ${neigh_show_output} ]]
+ elif [ ${arp_accept} -eq 2 ]; then
+ if [ ${same_subnet} -eq 1 ]; then
+ # Neighbor entries expected.
+ [[ ${neigh_show_output} ]]
+ else
+ [[ -z ${neigh_show_output} ]]
+ fi
+ else
+ [[ -z ${neigh_show_output} ]]
+ fi
+ }
+
+arp_test_gratuitous() {
+ local arp_accept=$1
+ local same_subnet=$2
+
+ if [ ${arp_accept} -eq 2 ]; then
+ test_msg=("test_arp: "
+ "accept_arp=$1 "
+ "same_subnet=$2")
+ if [ ${same_subnet} -eq 0 ]; then
+ HOST_ADDR=10.0.11.3
+ else
+ HOST_ADDR=10.0.10.3
+ fi
+ else
+ test_msg=("test_arp: "
+ "accept_arp=$1")
+ fi
+ # supply arp_accept option to setup which sets it in sysctl
+ setup ${arp_accept}
+ ip netns exec ${HOST_NS} arping -A -U ${HOST_ADDR} -c1 2>&1 >/dev/null
+ verify_arp $1 $2
+
+ if [ $? -eq 0 ]; then
+ printf " TEST: %-60s [ OK ]\n" "${test_msg[*]}"
+ else
+ printf " TEST: %-60s [FAIL]\n" "${test_msg[*]}"
+ fi
+ cleanup
+}
+
+arp_test_gratuitous_combinations() {
+ arp_test_gratuitous 0
+ arp_test_gratuitous 1
+ arp_test_gratuitous 2 0 # second entry indicates subnet or not
+ arp_test_gratuitous 2 1
+}
+
+cleanup_tcpdump() {
+ set -e
+ [[ ! -z ${tcpdump_stdout} ]] && rm -f ${tcpdump_stdout}
+ [[ ! -z ${tcpdump_stderr} ]] && rm -f ${tcpdump_stderr}
+ tcpdump_stdout=
+ tcpdump_stderr=
+ set +e
+}
+
+start_tcpdump() {
+ set -e
+ tcpdump_stdout=`mktemp`
+ tcpdump_stderr=`mktemp`
+ ip netns exec ${ROUTER_NS_V6} timeout 15s \
+ tcpdump --immediate-mode -tpni ${ROUTER_INTF} -c 1 \
+ "icmp6 && icmp6[0] == 136 && src ${HOST_ADDR_V6}" \
+ > ${tcpdump_stdout} 2> /dev/null
+ set +e
+}
+
+verify_ndisc() {
+ local accept_untracked_na=$1
+ local same_subnet=$2
+
+ neigh_show_output=$(ip -6 -netns ${ROUTER_NS_V6} neigh show \
+ to ${HOST_ADDR_V6} dev ${ROUTER_INTF} nud stale)
+
+ if [ ${accept_untracked_na} -eq 1 ]; then
+ # Neighbour entry expected to be present for 011 case
+ [[ ${neigh_show_output} ]]
+ elif [ ${accept_untracked_na} -eq 2 ]; then
+ if [ ${same_subnet} -eq 1 ]; then
+ [[ ${neigh_show_output} ]]
+ else
+ [[ -z ${neigh_show_output} ]]
+ fi
+ else
+ # Neighbour entry expected to be absent for all other cases
+ [[ -z ${neigh_show_output} ]]
+ fi
+}
+
+ndisc_test_untracked_advertisements() {
+ # HOST_ADDR_V6="2001:db8:91::3"
+ # ROUTER_ADDR_V6="2001:db8:91::1"
+ test_msg=("test_ndisc: "
+ "accept_untracked_na=$1")
+
+ local accept_untracked_na=$1
+ local same_subnet=$2
+ if [ ${accept_untracked_na} -eq 2 ]; then
+ test_msg=("test_ndisc: "
+ "accept_untracked_na=$1 "
+ "same_subnet=$2")
+ if [ ${same_subnet} -eq 0 ]; then
+ # not same subnet
+ HOST_ADDR_V6=2000:db8:abcd:0013::4
+ else
+ HOST_ADDR_V6=2001:db8:abcd:0012::3
+ fi
+ fi
+ setup_v6 $1 $2
+ start_tcpdump
+ verify_ndisc $1 $2
+
+ if [ $? -eq 0 ]; then
+ printf " TEST: %-60s [ OK ]\n" "${test_msg[*]}"
+ else
+ printf " TEST: %-60s [FAIL]\n" "${test_msg[*]}"
+ fi
+
+ cleanup_tcpdump
+ cleanup_v6
+}
+
+ndisc_test_untracked_combinations() {
+ ndisc_test_untracked_advertisements 0
+ ndisc_test_untracked_advertisements 1
+ ndisc_test_untracked_advertisements 2 0
+ ndisc_test_untracked_advertisements 2 1
+}
+
+################################################################################
+# usage
+
+usage()
+{
+ cat <<EOF
+usage: ${0##*/} OPTS
+
+ -t <test> Test(s) to run (default: all)
+ (options: $TESTS)
+EOF
+}
+
+################################################################################
+# main
+
+while getopts ":t:h" opt; do
+ case $opt in
+ t) TESTS=$OPTARG;;
+ h) usage; exit 0;;
+ *) usage; exit 1;;
+ esac
+done
+
+for t in $TESTS
+do
+ case $t in
+ arp_test_gratuitous_combinations|arp) arp_test_gratuitous_combinations;;
+ ndisc_test_untracked_combinations|ndisc) \
+ ndisc_test_untracked_combinations;;
+ help) echo "Test names: $TESTS"; exit 0;;
+esac
+done
--
2.30.2