test/net: Add script for VXLAN underlay in a VRF

This script tests the support of a VXLAN underlay in a non-default VRF.

It does so by simulating two hypervisors and two VMs, an extended L2
between the VMs with the hypervisors as VTEPs with the underlay in a
VRF, and finally by pinging the two VMs.

It also tests that moving the underlay from a VRF to another works when
down/up the VXLAN interface.
Signed-off-by: Alexis Bauvin <abauvin@scaleway.com>
Reviewed-by: Amine Kherbouche <akherbouche@scaleway.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: Amine Kherbouche <akherbouche@scaleway.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/Makefile

@@ -7,7 +7,7 @@ CFLAGS += -I../../../../usr/include/
 TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh rtnetlink.sh
 TEST_PROGS += fib_tests.sh fib-onlink-tests.sh pmtu.sh udpgso.sh ip_defrag.sh
 TEST_PROGS += udpgso_bench.sh fib_rule_tests.sh msg_zerocopy.sh psock_snd.sh
-TEST_PROGS += udpgro_bench.sh udpgro.sh
+TEST_PROGS += udpgro_bench.sh udpgro.sh test_vxlan_under_vrf.sh
 TEST_PROGS_EXTENDED := in_netns.sh
 TEST_GEN_FILES =  socket
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy

tools/testing/selftests/net/test_vxlan_under_vrf.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This test is for checking VXLAN underlay in a non-default VRF.
+#
+# It simulates two hypervisors running a VM each using four network namespaces:
+# two for the HVs, two for the VMs.
+# A small VXLAN tunnel is made between the two hypervisors to have the two vms
+# in the same virtual L2:
+#
+# +-------------------+                                    +-------------------+
+# |                   |                                    |                   |
+# |    vm-1 netns     |                                    |    vm-2 netns     |
+# |                   |                                    |                   |
+# |  +-------------+  |                                    |  +-------------+  |
+# |  |   veth-hv   |  |                                    |  |   veth-hv   |  |
+# |  | 10.0.0.1/24 |  |                                    |  | 10.0.0.2/24 |  |
+# |  +-------------+  |                                    |  +-------------+  |
+# |        .          |                                    |         .         |
+# +-------------------+                                    +-------------------+
+#          .                                                         .
+#          .                                                         .
+#          .                                                         .
+# +-----------------------------------+   +------------------------------------+
+# |        .                          |   |                          .         |
+# |  +----------+                     |   |                     +----------+   |
+# |  | veth-tap |                     |   |                     | veth-tap |   |
+# |  +----+-----+                     |   |                     +----+-----+   |
+# |       |                           |   |                          |         |
+# |    +--+--+      +--------------+  |   |  +--------------+     +--+--+      |
+# |    | br0 |      | vrf-underlay |  |   |  | vrf-underlay |     | br0 |      |
+# |    +--+--+      +-------+------+  |   |  +------+-------+     +--+--+      |
+# |       |                 |         |   |         |                |         |
+# |   +---+----+    +-------+-------+ |   | +-------+-------+    +---+----+    |
+# |   | vxlan0 |....|     veth0     |.|...|.|     veth0     |....| vxlan0 |    |
+# |   +--------+    | 172.16.0.1/24 | |   | | 172.16.0.2/24 |    +--------+    |
+# |                 +---------------+ |   | +---------------+                  |
+# |                                   |   |                                    |
+# |             hv-1 netns            |   |           hv-2 netns               |
+# |                                   |   |                                    |
+# +-----------------------------------+   +------------------------------------+
+#
+# This tests both the connectivity between vm-1 and vm-2, and that the underlay
+# can be moved in and out of the vrf by unsetting and setting veth0's master.
+
+set -e
+
+cleanup() {
+    ip link del veth-hv-1 2>/dev/null || true
+    ip link del veth-tap 2>/dev/null || true
+
+    for ns in hv-1 hv-2 vm-1 vm-2; do
+        ip netns del $ns || true
+    done
+}
+
+# Clean start
+cleanup &> /dev/null
+
+[[ $1 == "clean" ]] && exit 0
+
+trap cleanup EXIT
+
+# Setup "Hypervisors" simulated with netns
+ip link add veth-hv-1 type veth peer name veth-hv-2
+setup-hv-networking() {
+    hv=$1
+
+    ip netns add hv-$hv
+    ip link set veth-hv-$hv netns hv-$hv
+    ip -netns hv-$hv link set veth-hv-$hv name veth0
+
+    ip -netns hv-$hv link add vrf-underlay type vrf table 1
+    ip -netns hv-$hv link set vrf-underlay up
+    ip -netns hv-$hv addr add 172.16.0.$hv/24 dev veth0
+    ip -netns hv-$hv link set veth0 up
+
+    ip -netns hv-$hv link add br0 type bridge
+    ip -netns hv-$hv link set br0 up
+
+    ip -netns hv-$hv link add vxlan0 type vxlan id 10 local 172.16.0.$hv dev veth0 dstport 4789
+    ip -netns hv-$hv link set vxlan0 master br0
+    ip -netns hv-$hv link set vxlan0 up
+}
+setup-hv-networking 1
+setup-hv-networking 2
+
+# Check connectivity between HVs by pinging hv-2 from hv-1
+echo -n "Checking HV connectivity                                           "
+ip netns exec hv-1 ping -c 1 -W 1 172.16.0.2 &> /dev/null || (echo "[FAIL]"; false)
+echo "[ OK ]"
+
+# Setups a "VM" simulated by a netns an a veth pair
+setup-vm() {
+    id=$1
+
+    ip netns add vm-$id
+    ip link add veth-tap type veth peer name veth-hv
+
+    ip link set veth-tap netns hv-$id
+    ip -netns hv-$id link set veth-tap master br0
+    ip -netns hv-$id link set veth-tap up
+
+    ip link set veth-hv netns vm-$id
+    ip -netns vm-$id addr add 10.0.0.$id/24 dev veth-hv
+    ip -netns vm-$id link set veth-hv up
+}
+setup-vm 1
+setup-vm 2
+
+# Setup VTEP routes to make ARP work
+bridge -netns hv-1 fdb add 00:00:00:00:00:00 dev vxlan0 dst 172.16.0.2 self permanent
+bridge -netns hv-2 fdb add 00:00:00:00:00:00 dev vxlan0 dst 172.16.0.1 self permanent
+
+echo -n "Check VM connectivity through VXLAN (underlay in the default VRF)  "
+ip netns exec vm-1 ping -c 1 -W 1 10.0.0.2 &> /dev/null || (echo "[FAIL]"; false)
+echo "[ OK ]"
+
+# Move the underlay to a non-default VRF
+ip -netns hv-1 link set veth0 vrf vrf-underlay
+ip -netns hv-1 link set veth0 down
+ip -netns hv-1 link set veth0 up
+ip -netns hv-2 link set veth0 vrf vrf-underlay
+ip -netns hv-2 link set veth0 down
+ip -netns hv-2 link set veth0 up
+
+echo -n "Check VM connectivity through VXLAN (underlay in a VRF)            "
+ip netns exec vm-1 ping -c 1 -W 1 10.0.0.2 &> /dev/null || (echo "[FAIL]"; false)
+echo "[ OK ]"