selftests/net: toeplitz test

To verify that this hash implements the Toeplitz hash function.

Additionally, provide a script toeplitz.sh to run the test in loopback mode
on a networking device of choice (see setup_loopback.sh). Since the
script modifies the NIC setup, it will not be run by selftests
automatically.

Tested:
./toeplitz.sh -i eth0 -irq_prefix <eth0_pattern> -t -6
carrier ready
rxq 0: cpu 14
rxq 1: cpu 20
rxq 2: cpu 17
rxq 3: cpu 23
cpu 14: rx_hash 0x69103ebc [saddr fda8::2 daddr fda8::1 sport 58938 dport 8000] OK rxq 0 (cpu 14)
...
cpu 20: rx_hash 0x257118b9 [saddr fda8::2 daddr fda8::1 sport 59258 dport 8000] OK rxq 1 (cpu 20)
count: pass=111 nohash=0 fail=0
Test Succeeded!

Signed-off-by: Coco Li <lixiaoyan@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/Makefile

@@ -41,6 +41,7 @@ TEST_GEN_FILES += ioam6_parser
 TEST_GEN_FILES += gro
 TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
 TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
+TEST_GEN_FILES += toeplitz
 
 TEST_FILES := settings
 

tools/testing/selftests/net/toeplitz.sh

@@ -0,0 +1,199 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# extended toeplitz test: test rxhash plus, optionally, either (1) rss mapping
+# from rxhash to rx queue ('-rss') or (2) rps mapping from rxhash to cpu
+# ('-rps <rps_map>')
+#
+# irq-pattern-prefix can be derived from /sys/kernel/irq/*/action,
+# which is a driver-specific encoding.
+#
+# invoke as ./toeplitz.sh (-i <iface>) -u|-t -4|-6 \
+# [(-rss -irq_prefix <irq-pattern-prefix>)|(-rps <rps_map>)]
+
+source setup_loopback.sh
+readonly SERVER_IP4="192.168.1.200/24"
+readonly SERVER_IP6="fda8::1/64"
+readonly SERVER_MAC="aa:00:00:00:00:02"
+
+readonly CLIENT_IP4="192.168.1.100/24"
+readonly CLIENT_IP6="fda8::2/64"
+readonly CLIENT_MAC="aa:00:00:00:00:01"
+
+PORT=8000
+KEY="$(</proc/sys/net/core/netdev_rss_key)"
+TEST_RSS=false
+RPS_MAP=""
+PROTO_FLAG=""
+IP_FLAG=""
+DEV="eth0"
+
+# Return the number of rxqs among which RSS is configured to spread packets.
+# This is determined by reading the RSS indirection table using ethtool.
+get_rss_cfg_num_rxqs() {
+	echo $(ethtool -x "${DEV}" |
+		egrep [[:space:]]+[0-9]+:[[:space:]]+ |
+		cut -d: -f2- |
+		awk '{$1=$1};1' |
+		tr ' ' '\n' |
+		sort -u |
+		wc -l)
+}
+
+# Return a list of the receive irq handler cpus.
+# The list is ordered by the irqs, so first rxq-0 cpu, then rxq-1 cpu, etc.
+# Reads /sys/kernel/irq/ in order, so algorithm depends on
+# irq_{rxq-0} < irq_{rxq-1}, etc.
+get_rx_irq_cpus() {
+	CPUS=""
+	# sort so that irq 2 is read before irq 10
+	SORTED_IRQS=$(for i in /sys/kernel/irq/*; do echo $i; done | sort -V)
+	# Consider only as many queues as RSS actually uses. We assume that
+	# if RSS_CFG_NUM_RXQS=N, then RSS uses rxqs 0-(N-1).
+	RSS_CFG_NUM_RXQS=$(get_rss_cfg_num_rxqs)
+	RXQ_COUNT=0
+
+	for i in ${SORTED_IRQS}
+	do
+		[[ "${RXQ_COUNT}" -lt "${RSS_CFG_NUM_RXQS}" ]] || break
+		# lookup relevant IRQs by action name
+		[[ -e "$i/actions" ]] || continue
+		cat "$i/actions" | grep -q "${IRQ_PATTERN}" || continue
+		irqname=$(<"$i/actions")
+
+		# does the IRQ get called
+		irqcount=$(cat "$i/per_cpu_count" | tr -d '0,')
+		[[ -n "${irqcount}" ]] || continue
+
+		# lookup CPU
+		irq=$(basename "$i")
+		cpu=$(cat "/proc/irq/$irq/smp_affinity_list")
+
+		if [[ -z "${CPUS}" ]]; then
+			CPUS="${cpu}"
+		else
+			CPUS="${CPUS},${cpu}"
+		fi
+		RXQ_COUNT=$((RXQ_COUNT+1))
+	done
+
+	echo "${CPUS}"
+}
+
+get_disable_rfs_cmd() {
+	echo "echo 0 > /proc/sys/net/core/rps_sock_flow_entries;"
+}
+
+get_set_rps_bitmaps_cmd() {
+	CMD=""
+	for i in /sys/class/net/${DEV}/queues/rx-*/rps_cpus
+	do
+		CMD="${CMD} echo $1 > ${i};"
+	done
+
+	echo "${CMD}"
+}
+
+get_disable_rps_cmd() {
+	echo "$(get_set_rps_bitmaps_cmd 0)"
+}
+
+die() {
+	echo "$1"
+	exit 1
+}
+
+check_nic_rxhash_enabled() {
+	local -r pattern="receive-hashing:\ on"
+
+	ethtool -k "${DEV}" | grep -q "${pattern}" || die "rxhash must be enabled"
+}
+
+parse_opts() {
+	local prog=$0
+	shift 1
+
+	while [[ "$1" =~ "-" ]]; do
+		if [[ "$1" = "-irq_prefix" ]]; then
+			shift
+			IRQ_PATTERN="^$1-[0-9]*$"
+		elif [[ "$1" = "-u" || "$1" = "-t" ]]; then
+			PROTO_FLAG="$1"
+		elif [[ "$1" = "-4" ]]; then
+			IP_FLAG="$1"
+			SERVER_IP="${SERVER_IP4}"
+			CLIENT_IP="${CLIENT_IP4}"
+		elif [[ "$1" = "-6" ]]; then
+			IP_FLAG="$1"
+			SERVER_IP="${SERVER_IP6}"
+			CLIENT_IP="${CLIENT_IP6}"
+		elif [[ "$1" = "-rss" ]]; then
+			TEST_RSS=true
+		elif [[ "$1" = "-rps" ]]; then
+			shift
+			RPS_MAP="$1"
+		elif [[ "$1" = "-i" ]]; then
+			shift
+			DEV="$1"
+		else
+			die "Usage: ${prog} (-i <iface>) -u|-t -4|-6 \
+			     [(-rss -irq_prefix <irq-pattern-prefix>)|(-rps <rps_map>)]"
+		fi
+		shift
+	done
+}
+
+setup() {
+	setup_loopback_environment "${DEV}"
+
+	# Set up server_ns namespace and client_ns namespace
+	setup_macvlan_ns "${DEV}" server_ns server \
+	"${SERVER_MAC}" "${SERVER_IP}"
+	setup_macvlan_ns "${DEV}" client_ns client \
+	"${CLIENT_MAC}" "${CLIENT_IP}"
+}
+
+cleanup() {
+	cleanup_macvlan_ns server_ns server client_ns client
+	cleanup_loopback "${DEV}"
+}
+
+parse_opts $0 $@
+
+setup
+trap cleanup EXIT
+
+check_nic_rxhash_enabled
+
+# Actual test starts here
+if [[ "${TEST_RSS}" = true ]]; then
+	# RPS/RFS must be disabled because they move packets between cpus,
+	# which breaks the PACKET_FANOUT_CPU identification of RSS decisions.
+	eval "$(get_disable_rfs_cmd) $(get_disable_rps_cmd)" \
+	  ip netns exec server_ns ./toeplitz "${IP_FLAG}" "${PROTO_FLAG}" \
+	  -d "${PORT}" -i "${DEV}" -k "${KEY}" -T 1000 \
+	  -C "$(get_rx_irq_cpus)" -s -v &
+elif [[ ! -z "${RPS_MAP}" ]]; then
+	eval "$(get_disable_rfs_cmd) $(get_set_rps_bitmaps_cmd ${RPS_MAP})" \
+	  ip netns exec server_ns ./toeplitz "${IP_FLAG}" "${PROTO_FLAG}" \
+	  -d "${PORT}" -i "${DEV}" -k "${KEY}" -T 1000 \
+	  -r "0x${RPS_MAP}" -s -v &
+else
+	ip netns exec server_ns ./toeplitz "${IP_FLAG}" "${PROTO_FLAG}" \
+	  -d "${PORT}" -i "${DEV}" -k "${KEY}" -T 1000 -s -v &
+fi
+
+server_pid=$!
+
+ip netns exec client_ns ./toeplitz_client.sh "${PROTO_FLAG}" \
+  "${IP_FLAG}" "${SERVER_IP%%/*}" "${PORT}" &
+
+client_pid=$!
+
+wait "${server_pid}"
+exit_code=$?
+kill -9 "${client_pid}"
+if [[ "${exit_code}" -eq 0 ]]; then
+	echo "Test Succeeded!"
+fi
+exit "${exit_code}"

tools/testing/selftests/net/toeplitz_client.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# A simple program for generating traffic for the toeplitz test.
+#
+# This program sends packets periodically for, conservatively, 20 seconds. The
+# intent is for the calling program to kill this program once it is no longer
+# needed, rather than waiting for the 20 second expiration.
+
+send_traffic() {
+	expiration=$((SECONDS+20))
+	while [[ "${SECONDS}" -lt "${expiration}" ]]
+	do
+		if [[ "${PROTO}" == "-u" ]]; then
+			echo "msg $i" | nc "${IPVER}" -u -w 0 "${ADDR}" "${PORT}"
+		else
+			echo "msg $i" | nc "${IPVER}" -w 0 "${ADDR}" "${PORT}"
+		fi
+		sleep 0.001
+	done
+}
+
+PROTO=$1
+IPVER=$2
+ADDR=$3
+PORT=$4
+
+send_traffic