selftests: ocelot: add some example VCAP IS1, IS2 and ES0 tc offloads

Provide an example script which can be used as a skeleton for offloading
TCAM rules in the Ocelot switches.

Not all actions are demoed, mostly because of difficulty to automate
this from a single board.

For example, policing. We can set up an iperf3 UDP server and client and
measure throughput at destination. But at least with DSA setups, network
namespacing the individual ports is not possible because all switch
ports are handled by the same DSA master. And we cannot assume that the
target platform (an embedded board) has 2 other non-switch generator
ports, we need to work with the generator ports as switch ports (this is
the reason why mausezahn is used, and not IP traffic like ping). When
somebody has an idea how to test policing, that can be added to this
test.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -12542,6 +12542,7 @@ F:	drivers/net/dsa/ocelot/*
 F:	drivers/net/ethernet/mscc/
 F:	include/soc/mscc/ocelot*
 F:	net/dsa/tag_ocelot.c
+F:	tools/testing/selftests/drivers/net/ocelot/*
 
 OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
 M:	Frederic Barrat <fbarrat@linux.ibm.com>

tools/testing/selftests/drivers/net/ocelot/tc_flower_chains.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2020 NXP Semiconductors
+
+WAIT_TIME=1
+NUM_NETIFS=4
+lib_dir=$(dirname $0)/../../../net/forwarding
+source $lib_dir/tc_common.sh
+source $lib_dir/lib.sh
+
+require_command tcpdump
+
+#
+#   +---------------------------------------------+
+#   |       DUT ports         Generator ports     |
+#   | +--------+ +--------+ +--------+ +--------+ |
+#   | |        | |        | |        | |        | |
+#   | |  eth0  | |  eth1  | |  eth2  | |  eth3  | |
+#   | |        | |        | |        | |        | |
+#   +-+--------+-+--------+-+--------+-+--------+-+
+#          |         |           |          |
+#          |         |           |          |
+#          |         +-----------+          |
+#          |                                |
+#          +--------------------------------+
+
+eth0=${NETIFS[p1]}
+eth1=${NETIFS[p2]}
+eth2=${NETIFS[p3]}
+eth3=${NETIFS[p4]}
+
+eth0_mac="de:ad:be:ef:00:00"
+eth1_mac="de:ad:be:ef:00:01"
+eth2_mac="de:ad:be:ef:00:02"
+eth3_mac="de:ad:be:ef:00:03"
+
+# Helpers to map a VCAP IS1 and VCAP IS2 lookup and policy to a chain number
+# used by the kernel driver. The numbers are:
+# VCAP IS1 lookup 0:            10000
+# VCAP IS1 lookup 1:            11000
+# VCAP IS1 lookup 2:            12000
+# VCAP IS2 lookup 0 policy 0:   20000
+# VCAP IS2 lookup 0 policy 1:   20001
+# VCAP IS2 lookup 0 policy 255: 20255
+# VCAP IS2 lookup 1 policy 0:   21000
+# VCAP IS2 lookup 1 policy 1:   21001
+# VCAP IS2 lookup 1 policy 255: 21255
+IS1()
+{
+	local lookup=$1
+
+	echo $((10000 + 1000 * lookup))
+}
+
+IS2()
+{
+	local lookup=$1
+	local pag=$2
+
+	echo $((20000 + 1000 * lookup + pag))
+}
+
+ES0()
+{
+	echo 0
+}
+
+# The Ocelot switches have a fixed ingress pipeline composed of:
+#
+# +----------------------------------------------+      +-----------------------------------------+
+# |                   VCAP IS1                   |      |                  VCAP IS2               |
+# |                                              |      |                                         |
+# | +----------+    +----------+    +----------+ |      |            +----------+    +----------+ |
+# | | Lookup 0 |    | Lookup 1 |    | Lookup 2 | | --+------> PAG 0: | Lookup 0 | -> | Lookup 1 | |
+# | +----------+ -> +----------+ -> +----------+ |   |  |            +----------+    +----------+ |
+# | |key&action|    |key&action|    |key&action| |   |  |            |key&action|    |key&action| |
+# | |key&action|    |key&action|    |key&action| |   |  |            |    ..    |    |    ..    | |
+# | |    ..    |    |    ..    |    |    ..    | |   |  |            +----------+    +----------+ |
+# | +----------+    +----------+    +----------+ |   |  |                                         |
+# |                                 selects PAG  |   |  |            +----------+    +----------+ |
+# +----------------------------------------------+   +------> PAG 1: | Lookup 0 | -> | Lookup 1 | |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    |  |            |key&action|    |key&action| |
+#                                                    |  |            |    ..    |    |    ..    | |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    |  |      ...                                |
+#                                                    |  |                                         |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    +----> PAG 254: | Lookup 0 | -> | Lookup 1 | |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    |  |            |key&action|    |key&action| |
+#                                                    |  |            |    ..    |    |    ..    | |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    |  |                                         |
+#                                                    |  |            +----------+    +----------+ |
+#                                                    +----> PAG 255: | Lookup 0 | -> | Lookup 1 | |
+#                                                       |            +----------+    +----------+ |
+#                                                       |            |key&action|    |key&action| |
+#                                                       |            |    ..    |    |    ..    | |
+#                                                       |            +----------+    +----------+ |
+#                                                       +-----------------------------------------+
+#
+# Both the VCAP IS1 (Ingress Stage 1) and IS2 (Ingress Stage 2) are indexed
+# (looked up) multiple times: IS1 3 times, and IS2 2 times. Each filter
+# (key and action pair) can be configured to only match during the first, or
+# second, etc, lookup.
+#
+# During one TCAM lookup, the filter processing stops at the first entry that
+# matches, then the pipeline jumps to the next lookup.
+# The driver maps each individual lookup of each individual ingress TCAM to a
+# separate chain number. For correct rule offloading, it is mandatory that each
+# filter installed in one TCAM is terminated by a non-optional GOTO action to
+# the next lookup from the fixed pipeline.
+#
+# A chain can only be used if there is a GOTO action correctly set up from the
+# prior lookup in the processing pipeline. Setting up all chains is not
+# mandatory.
+
+# NOTE: VCAP IS1 currently uses only S1_NORMAL half keys and VCAP IS2
+# dynamically chooses between MAC_ETYPE, ARP, IP4_TCP_UDP, IP4_OTHER, which are
+# all half keys as well.
+
+create_tcam_skeleton()
+{
+	local eth=$1
+
+	tc qdisc add dev $eth clsact
+
+	# VCAP IS1 is the Ingress Classification TCAM and can offload the
+	# following actions:
+	# - skbedit priority
+	# - vlan pop
+	# - vlan modify
+	# - goto (only in lookup 2, the last IS1 lookup)
+	tc filter add dev $eth ingress chain 0 pref 49152 flower \
+		skip_sw action goto chain $(IS1 0)
+	tc filter add dev $eth ingress chain $(IS1 0) pref 49152 \
+		flower skip_sw action goto chain $(IS1 1)
+	tc filter add dev $eth ingress chain $(IS1 1) pref 49152 \
+		flower skip_sw action goto chain $(IS1 2)
+	tc filter add dev $eth ingress chain $(IS1 2) pref 49152 \
+		flower skip_sw action goto chain $(IS2 0 0)
+
+	# VCAP IS2 is the Security Enforcement ingress TCAM and can offload the
+	# following actions:
+	# - trap
+	# - drop
+	# - police
+	# The two VCAP IS2 lookups can be segmented into up to 256 groups of
+	# rules, called Policies. A Policy is selected through the Policy
+	# Association Group (PAG) action of VCAP IS1 (which is the
+	# GOTO offload).
+	tc filter add dev $eth ingress chain $(IS2 0 0) pref 49152 \
+		flower skip_sw action goto chain $(IS2 1 0)
+}
+
+setup_prepare()
+{
+	create_tcam_skeleton $eth0
+
+	ip link add br0 type bridge
+	ip link set $eth0 master br0
+	ip link set $eth1 master br0
+	ip link set br0 up
+
+	ip link add link $eth3 name $eth3.100 type vlan id 100
+	ip link set $eth3.100 up
+
+	tc filter add dev $eth0 ingress chain $(IS1 1) pref 1 \
+		protocol 802.1Q flower skip_sw vlan_id 100 \
+		action vlan pop \
+		action goto chain $(IS1 2)
+
+	tc filter add dev $eth0 egress chain $(ES0) pref 1 \
+		flower skip_sw indev $eth1 \
+		action vlan push protocol 802.1Q id 100
+
+	tc filter add dev $eth0 ingress chain $(IS1 0) \
+		protocol ipv4 flower skip_sw src_ip 10.1.1.2 \
+		action skbedit priority 7 \
+		action goto chain $(IS1 1)
+
+	tc filter add dev $eth0 ingress chain $(IS2 0 0) \
+		protocol ipv4 flower skip_sw ip_proto udp dst_port 5201 \
+		action police rate 50mbit burst 64k \
+		action goto chain $(IS2 1 0)
+}
+
+cleanup()
+{
+	ip link del $eth3.100
+	tc qdisc del dev $eth0 clsact
+	ip link del br0
+}
+
+test_vlan_pop()
+{
+	printf "Testing VLAN pop..			"
+
+	tcpdump_start $eth2
+
+	# Work around Mausezahn VLAN builder bug
+	# (https://github.com/netsniff-ng/netsniff-ng/issues/225) by using
+	# an 8021q upper
+	$MZ $eth3.100 -q -c 1 -p 64 -a $eth3_mac -b $eth2_mac -t ip
+
+	sleep 1
+
+	tcpdump_stop
+
+	if tcpdump_show | grep -q "$eth3_mac > $eth2_mac, ethertype IPv4"; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+
+	tcpdump_cleanup
+}
+
+test_vlan_push()
+{
+	printf "Testing VLAN push..			"
+
+	tcpdump_start $eth3.100
+
+	$MZ $eth2 -q -c 1 -p 64 -a $eth2_mac -b $eth3_mac -t ip
+
+	sleep 1
+
+	tcpdump_stop
+
+	if tcpdump_show | grep -q "$eth2_mac > $eth3_mac"; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+
+	tcpdump_cleanup
+}
+
+test_skbedit_priority()
+{
+	local num_pkts=100
+
+	printf "Testing frame prioritization..		"
+
+	before=$(ethtool_stats_get $eth0 'rx_green_prio_7')
+
+	$MZ $eth3 -q -c $num_pkts -p 64 -a $eth3_mac -b $eth2_mac -t ip -A 10.1.1.2
+
+	after=$(ethtool_stats_get $eth0 'rx_green_prio_7')
+
+	if [ $((after - before)) = $num_pkts ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+}
+
+trap cleanup EXIT
+
+ALL_TESTS="
+	test_vlan_pop
+	test_vlan_push
+	test_skbedit_priority
+"
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS

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

@@ -1227,3 +1227,46 @@ stop_traffic()
 	# Suppress noise from killing mausezahn.
 	{ kill %% && wait %%; } 2>/dev/null
 }
+
+tcpdump_start()
+{
+	local if_name=$1; shift
+	local ns=$1; shift
+
+	capfile=$(mktemp)
+	capout=$(mktemp)
+
+	if [ -z $ns ]; then
+		ns_cmd=""
+	else
+		ns_cmd="ip netns exec ${ns}"
+	fi
+
+	if [ -z $SUDO_USER ] ; then
+		capuser=""
+	else
+		capuser="-Z $SUDO_USER"
+	fi
+
+	$ns_cmd tcpdump -e -n -Q in -i $if_name \
+		-s 65535 -B 32768 $capuser -w $capfile > "$capout" 2>&1 &
+	cappid=$!
+
+	sleep 1
+}
+
+tcpdump_stop()
+{
+	$ns_cmd kill $cappid
+	sleep 1
+}
+
+tcpdump_cleanup()
+{
+	rm $capfile $capout
+}
+
+tcpdump_show()
+{
+	tcpdump -e -n -r $capfile 2>&1
+}