selftests: net: add very basic test for netdev names and namespaces

Add selftest for fixes around naming netdevs and namespaces.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/net/Makefile

@@ -34,6 +34,7 @@ TEST_PROGS += gro.sh
 TEST_PROGS += gre_gso.sh
 TEST_PROGS += cmsg_so_mark.sh
 TEST_PROGS += cmsg_time.sh cmsg_ipv6.sh
+TEST_PROGS += netns-name.sh
 TEST_PROGS += srv6_end_dt46_l3vpn_test.sh
 TEST_PROGS += srv6_end_dt4_l3vpn_test.sh
 TEST_PROGS += srv6_end_dt6_l3vpn_test.sh

tools/testing/selftests/net/netns-name.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -o pipefail
+
+NS=netns-name-test
+DEV=dummy-dev0
+DEV2=dummy-dev1
+ALT_NAME=some-alt-name
+
+RET_CODE=0
+
+cleanup() {
+    ip netns del $NS
+}
+
+trap cleanup EXIT
+
+fail() {
+    echo "ERROR: ${1:-unexpected return code} (ret: $_)" >&2
+    RET_CODE=1
+}
+
+ip netns add $NS
+
+#
+# Test basic move without a rename
+#
+ip -netns $NS link add name $DEV type dummy || fail
+ip -netns $NS link set dev $DEV netns 1 ||
+    fail "Can't perform a netns move"
+ip link show dev $DEV >> /dev/null || fail "Device not found after move"
+ip link del $DEV || fail
+
+#
+# Test move with a conflict
+#
+ip link add name $DEV type dummy
+ip -netns $NS link add name $DEV type dummy || fail
+ip -netns $NS link set dev $DEV netns 1 2> /dev/null &&
+    fail "Performed a netns move with a name conflict"
+ip link show dev $DEV >> /dev/null || fail "Device not found after move"
+ip -netns $NS link del $DEV || fail
+ip link del $DEV || fail
+
+#
+# Test move with a conflict and rename
+#
+ip link add name $DEV type dummy
+ip -netns $NS link add name $DEV type dummy || fail
+ip -netns $NS link set dev $DEV netns 1 name $DEV2 ||
+    fail "Can't perform a netns move with rename"
+ip link del $DEV2 || fail
+ip link del $DEV || fail
+
+#
+# Test dup alt-name with netns move
+#
+ip link add name $DEV type dummy || fail
+ip link property add dev $DEV altname $ALT_NAME || fail
+ip -netns $NS link add name $DEV2 type dummy || fail
+ip -netns $NS link property add dev $DEV2 altname $ALT_NAME || fail
+
+ip -netns $NS link set dev $DEV2 netns 1 2> /dev/null &&
+    fail "Moved with alt-name dup"
+
+ip link del $DEV || fail
+ip -netns $NS link del $DEV2 || fail
+
+#
+# Test creating alt-name in one net-ns and using in another
+#
+ip -netns $NS link add name $DEV type dummy || fail
+ip -netns $NS link property add dev $DEV altname $ALT_NAME || fail
+ip -netns $NS link set dev $DEV netns 1 || fail
+ip link show dev $ALT_NAME >> /dev/null || fail "Can't find alt-name after move"
+ip  -netns $NS link show dev $ALT_NAME 2> /dev/null &&
+    fail "Can still find alt-name after move"
+ip link del $DEV || fail
+
+echo -ne "$(basename $0) \t\t\t\t"
+if [ $RET_CODE -eq 0 ]; then
+    echo "[  OK  ]"
+else
+    echo "[ FAIL ]"
+fi
+exit $RET_CODE