Merge branch 'selftests-forwarding-Add-VRF-based-tests'

Ido Schimmel says:

====================
selftests: forwarding: Add VRF-based tests

One of the nice things about network namespaces is that they allow one
to easily create and test complex environments.

Unfortunately, these namespaces can not be used with actual switching
ASICs, as their ports can not be migrated to other network namespaces
(NETIF_F_NETNS_LOCAL) and most of them probably do not support the
L1-separation provided by namespaces.

However, a similar kind of flexibility can be achieved by using VRFs and
by looping the switch ports together. For example:

                             br0
                              +
               vrf-h1         |           vrf-h2
                 +        +---+----+        +
                 |        |        |        |
    192.0.2.1/24 +        +        +        + 192.0.2.2/24
               swp1     swp2     swp3     swp4
                 +        +        +        +
                 |        |        |        |
                 +--------+        +--------+

The VRFs act as lightweight namespaces representing hosts connected to
the switch.

This approach for testing switch ASICs has several advantages over the
traditional method that requires multiple physical machines, to name a
few:

1. Only the device under test (DUT) is being tested without noise from
other system.

2. Ability to easily provision complex topologies. Testing bridging
between 4-ports LAGs or 8-way ECMP requires many physical links that are
not always available. With the VRF-based approach one merely needs to
loopback more ports.

These tests are written with switch ASICs in mind, but they can be run
on any Linux box using veth pairs to emulate physical loopbacks.

v2:
* Order local variables declaration according to function arguments
  order (Petr)

v1:
* Change location to net/forwarding instead of forwarding/
* Add ability to pause on failure
* Add ability to pause on cleanup
* Make configuration file optional
* Make ping/ping6/mz configurable
* Add more tc tests
====================

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

tools/testing/selftests/net/forwarding/.gitignore

@@ -0,0 +1 @@
+forwarding.config

tools/testing/selftests/net/forwarding/README

@@ -0,0 +1,56 @@
+Motivation
+==========
+
+One of the nice things about network namespaces is that they allow one
+to easily create and test complex environments.
+
+Unfortunately, these namespaces can not be used with actual switching
+ASICs, as their ports can not be migrated to other network namespaces
+(NETIF_F_NETNS_LOCAL) and most of them probably do not support the
+L1-separation provided by namespaces.
+
+However, a similar kind of flexibility can be achieved by using VRFs and
+by looping the switch ports together. For example:
+
+                             br0
+                              +
+               vrf-h1         |           vrf-h2
+                 +        +---+----+        +
+                 |        |        |        |
+    192.0.2.1/24 +        +        +        + 192.0.2.2/24
+               swp1     swp2     swp3     swp4
+                 +        +        +        +
+                 |        |        |        |
+                 +--------+        +--------+
+
+The VRFs act as lightweight namespaces representing hosts connected to
+the switch.
+
+This approach for testing switch ASICs has several advantages over the
+traditional method that requires multiple physical machines, to name a
+few:
+
+1. Only the device under test (DUT) is being tested without noise from
+other system.
+
+2. Ability to easily provision complex topologies. Testing bridging
+between 4-ports LAGs or 8-way ECMP requires many physical links that are
+not always available. With the VRF-based approach one merely needs to
+loopback more ports.
+
+These tests are written with switch ASICs in mind, but they can be run
+on any Linux box using veth pairs to emulate physical loopbacks.
+
+Guidelines for Writing Tests
+============================
+
+o Where possible, reuse an existing topology for different tests instead
+  of recreating the same topology.
+o Where possible, IPv6 and IPv4 addresses shall conform to RFC 3849 and
+  RFC 5737, respectively.
+o Where possible, tests shall be written so that they can be reused by
+  multiple topologies and added to lib.sh.
+o Checks shall be added to lib.sh for any external dependencies.
+o Code shall be checked using ShellCheck [1] prior to submission.
+
+1. https://www.shellcheck.net/

tools/testing/selftests/net/forwarding/bridge_vlan_aware.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+NUM_NETIFS=4
+source lib.sh
+
+h1_create()
+{
+	simple_if_init $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1 192.0.2.1/24 2001:db8:1::1/64
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+h2_destroy()
+{
+	simple_if_fini $h2 192.0.2.2/24 2001:db8:1::2/64
+}
+
+switch_create()
+{
+	# 10 Seconds ageing time.
+	ip link add dev br0 type bridge vlan_filtering 1 ageing_time 1000 \
+		mcast_snooping 0
+
+	ip link set dev $swp1 master br0
+	ip link set dev $swp2 master br0
+
+	ip link set dev br0 up
+	ip link set dev $swp1 up
+	ip link set dev $swp2 up
+}
+
+switch_destroy()
+{
+	ip link set dev $swp2 down
+	ip link set dev $swp1 down
+
+	ip link del dev br0
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	swp1=${NETIFS[p2]}
+
+	swp2=${NETIFS[p3]}
+	h2=${NETIFS[p4]}
+
+	vrf_prepare
+
+	h1_create
+	h2_create
+
+	switch_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	switch_destroy
+
+	h2_destroy
+	h1_destroy
+
+	vrf_cleanup
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+ping_test $h1 192.0.2.2
+ping6_test $h1 2001:db8:1::2
+learning_test "br0" $swp1 $h1 $h2
+flood_test $swp2 $h1 $h2
+
+exit $EXIT_STATUS

tools/testing/selftests/net/forwarding/config

@@ -0,0 +1,12 @@
+CONFIG_BRIDGE=m
+CONFIG_VLAN_8021Q=m
+CONFIG_BRIDGE_VLAN_FILTERING=y
+CONFIG_NET_L3_MASTER_DEV=y
+CONFIG_IPV6_MULTIPLE_TABLES=y
+CONFIG_NET_VRF=m
+CONFIG_BPF_SYSCALL=y
+CONFIG_CGROUP_BPF=y
+CONFIG_NET_CLS_FLOWER=m
+CONFIG_NET_SCH_INGRESS=m
+CONFIG_NET_ACT_GACT=m
+CONFIG_VETH=m

tools/testing/selftests/net/forwarding/forwarding.config.sample

@@ -0,0 +1,31 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+##############################################################################
+# Topology description. p1 looped back to p2, p3 to p4 and so on.
+declare -A NETIFS
+
+NETIFS[p1]=veth0
+NETIFS[p2]=veth1
+NETIFS[p3]=veth2
+NETIFS[p4]=veth3
+NETIFS[p5]=veth4
+NETIFS[p6]=veth5
+NETIFS[p7]=veth6
+NETIFS[p8]=veth7
+
+##############################################################################
+# Defines
+
+# IPv4 ping utility name
+PING=ping
+# IPv6 ping utility name. Some distributions use 'ping' for IPv6.
+PING6=ping6
+# Packet generator. Some distributions use 'mz'.
+MZ=mausezahn
+# Time to wait after interfaces participating in the test are all UP
+WAIT_TIME=5
+# Whether to pause on failure or not.
+PAUSE_ON_FAIL=no
+# Whether to pause on cleanup or not.
+PAUSE_ON_CLEANUP=no