selftests/net: allow GRO coalesce test on veth

This change extends the existing GRO coalesce test to
allow running on top of a veth pair, so that no H/W dep
is required to run them.

By default gro.sh will use the veth backend, and will try
to use exiting H/W in loopback mode if a specific device
name is provided with the '-i' command line option.

No functional change is intended for the loopback-based
tests, just move all the relevant initialization/cleanup
code into the related script.

Introduces a new initialization helper script for the
veth backend, and plugs the correct helper script according
to the provided command line.

Additionally, enable veth-based tests by default.

v1 -> v2:
  - drop unused code in setup_veth_ns() - Willem
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/Makefile

@@ -26,6 +26,7 @@ TEST_PROGS += unicast_extensions.sh
 TEST_PROGS += udpgro_fwd.sh
 TEST_PROGS += veth.sh
 TEST_PROGS += ioam6.sh
+TEST_PROGS += gro.sh
 TEST_PROGS_EXTENDED := in_netns.sh
 TEST_GEN_FILES =  socket nettest
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any

tools/testing/selftests/net/gro.sh

 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
-source setup_loopback.sh
 readonly SERVER_MAC="aa:00:00:00:00:02"
 readonly CLIENT_MAC="aa:00:00:00:00:01"
 readonly TESTS=("data" "ack" "flags" "tcp" "ip" "large")
 readonly PROTOS=("ipv4" "ipv6")
-dev="eth0"
+dev=""
 test="all"
 proto="ipv4"
 
-setup_interrupt() {
-  # Use timer on  host to trigger the network stack
-  # Also disable device interrupt to not depend on NIC interrupt
-  # Reduce test flakiness caused by unexpected interrupts
-  echo 100000 >"${FLUSH_PATH}"
-  echo 50 >"${IRQ_PATH}"
-}
-
-setup_ns() {
-  # Set up server_ns namespace and client_ns namespace
-  setup_macvlan_ns "${dev}" server_ns server "${SERVER_MAC}"
-  setup_macvlan_ns "${dev}" client_ns client "${CLIENT_MAC}"
-}
-
-cleanup_ns() {
-  cleanup_macvlan_ns server_ns server client_ns client
-}
-
-setup() {
-  setup_loopback_environment "${dev}"
-  setup_interrupt
-}
-
-cleanup() {
-  cleanup_loopback "${dev}"
-
-  echo "${FLUSH_TIMEOUT}" >"${FLUSH_PATH}"
-  echo "${HARD_IRQS}" >"${IRQ_PATH}"
-}
-
 run_test() {
   local server_pid=0
   local exit_code=0
@@ -115,10 +84,12 @@ while getopts "i:t:p:" opt; do
   esac
 done
 
-readonly FLUSH_PATH="/sys/class/net/${dev}/gro_flush_timeout"
-readonly IRQ_PATH="/sys/class/net/${dev}/napi_defer_hard_irqs"
-readonly FLUSH_TIMEOUT="$(< ${FLUSH_PATH})"
-readonly HARD_IRQS="$(< ${IRQ_PATH})"
+if [ -n "$dev" ]; then
+	source setup_loopback.sh
+else
+	source setup_veth.sh
+fi
+
 setup
 trap cleanup EXIT
 if [[ "${test}" == "all" ]]; then

tools/testing/selftests/net/setup_loopback.sh

 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
+
+readonly FLUSH_PATH="/sys/class/net/${dev}/gro_flush_timeout"
+readonly IRQ_PATH="/sys/class/net/${dev}/napi_defer_hard_irqs"
+readonly FLUSH_TIMEOUT="$(< ${FLUSH_PATH})"
+readonly HARD_IRQS="$(< ${IRQ_PATH})"
+
 netdev_check_for_carrier() {
 	local -r dev="$1"
 
@@ -18,7 +24,7 @@ netdev_check_for_carrier() {
 
 # Assumes that there is no existing ipvlan device on the physical device
 setup_loopback_environment() {
-    local dev="$1"
+	local dev="$1"
 
 	# Fail hard if cannot turn on loopback mode for current NIC
 	ethtool -K "${dev}" loopback on || exit 1
@@ -80,3 +86,33 @@ cleanup_loopback(){
 		exit 1
 	fi
 }
+
+setup_interrupt() {
+	# Use timer on  host to trigger the network stack
+	# Also disable device interrupt to not depend on NIC interrupt
+	# Reduce test flakiness caused by unexpected interrupts
+	echo 100000 >"${FLUSH_PATH}"
+	echo 50 >"${IRQ_PATH}"
+}
+
+setup_ns() {
+	# Set up server_ns namespace and client_ns namespace
+	setup_macvlan_ns "${dev}" server_ns server "${SERVER_MAC}"
+	setup_macvlan_ns "${dev}" client_ns client "${CLIENT_MAC}"
+}
+
+cleanup_ns() {
+	cleanup_macvlan_ns server_ns server client_ns client
+}
+
+setup() {
+	setup_loopback_environment "${dev}"
+	setup_interrupt
+}
+
+cleanup() {
+	cleanup_loopback "${dev}"
+
+	echo "${FLUSH_TIMEOUT}" >"${FLUSH_PATH}"
+	echo "${HARD_IRQS}" >"${IRQ_PATH}"
+}

tools/testing/selftests/net/setup_veth.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+setup_veth_ns() {
+	local -r link_dev="$1"
+	local -r ns_name="$2"
+	local -r ns_dev="$3"
+	local -r ns_mac="$4"
+
+	[[ -e /var/run/netns/"${ns_name}" ]] || ip netns add "${ns_name}"
+	echo 100000 > "/sys/class/net/${ns_dev}/gro_flush_timeout"
+	ip link set dev "${ns_dev}" netns "${ns_name}" mtu 65535
+	ip -netns "${ns_name}" link set dev "${ns_dev}" up
+
+	ip netns exec "${ns_name}" ethtool -K "${ns_dev}" gro on tso off
+}
+
+setup_ns() {
+	# Set up server_ns namespace and client_ns namespace
+	ip link add name server type veth peer name client
+
+	setup_veth_ns "${dev}" server_ns server "${SERVER_MAC}"
+	setup_veth_ns "${dev}" client_ns client "${CLIENT_MAC}"
+}
+
+cleanup_ns() {
+	local ns_name
+
+	for ns_name in client_ns server_ns; do
+		[[ -e /var/run/netns/"${ns_name}" ]] && ip netns del "${ns_name}"
+	done
+}
+
+setup() {
+	# no global init setup step needed
+	:
+}
+
+cleanup() {
+	cleanup_ns
+}