[PATCH net-next v7 21/26] selftests/vsock: add tests for proc sys vsock ns_mode

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add tests for the /proc/sys/net/vsock/ns_mode interface.  Namely,
that it accepts "global" and "local" strings and enforces a write-once
policy.

Start a convention of commenting the test name over the test
description. Add test name comments over test descriptions that existed
before this convention.

Add a check_netns() function that checks if the test requires namespaces
and if the current kernel supports namespaces. Skip tests that require
namespaces if the system does not have namespace support.

This patch is the first to add tests that do *not* re-use the same
shared VM. For that reason, it adds a run_tests() function to run these
tests and filter out the shared VM tests.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 99 ++++++++++++++++++++++++++++++++-
 1 file changed, 98 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index b129976e27fc..4defadad5701 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -38,11 +38,28 @@ readonly KERNEL_CMDLINE="\
 	virtme.ssh virtme_ssh_channel=tcp virtme_ssh_user=$USER \
 "
 readonly LOG=$(mktemp /tmp/vsock_vmtest_XXXX.log)
-readonly TEST_NAMES=(vm_server_host_client vm_client_host_server vm_loopback)
+readonly TEST_NAMES=(
+	vm_server_host_client
+	vm_client_host_server
+	vm_loopback
+	ns_host_vsock_ns_mode_ok
+	ns_host_vsock_ns_mode_write_once_ok
+)
 readonly TEST_DESCS=(
+	# vm_server_host_client
 	"Run vsock_test in server mode on the VM and in client mode on the host."
+
+	# vm_client_host_server
 	"Run vsock_test in client mode on the VM and in server mode on the host."
+
+	# vm_loopback
 	"Run vsock_test using the loopback transport in the VM."
+
+	# ns_host_vsock_ns_mode_ok
+	"Check /proc/sys/net/vsock/ns_mode strings on the host."
+
+	# ns_host_vsock_ns_mode_write_once_ok
+	"Check /proc/sys/net/vsock/ns_mode is write-once on the host."
 )
 
 readonly USE_SHARED_VM=(vm_server_host_client vm_client_host_server vm_loopback)
@@ -201,6 +218,20 @@ check_deps() {
 	fi
 }
 
+check_netns() {
+	local tname=$1
+
+	# If the test requires NS support, check if NS support exists
+	# using /proc/self/ns
+	if [[ "${tname}" =~ ^ns_ ]] &&
+	   [[ ! -e /proc/self/ns ]]; then
+		log_host "No NS support detected for test ${tname}"
+		return 1
+	fi
+
+	return 0
+}
+
 check_vng() {
 	local tested_versions
 	local version
@@ -500,6 +531,43 @@ log_guest() {
 	LOG_PREFIX=guest log $@
 }
 
+test_ns_host_vsock_ns_mode_ok() {
+	add_namespaces
+
+	for mode in "${NS_MODES[@]}"; do
+		if ! ns_set_mode "${mode}0" "${mode}"; then
+			del_namespaces
+			return "${KSFT_FAIL}"
+		fi
+	done
+
+	del_namespaces
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_host_vsock_ns_mode_write_once_ok() {
+	add_namespaces
+
+	for mode in "${NS_MODES[@]}"; do
+		local ns="${mode}0"
+		if ! ns_set_mode "${ns}" "${mode}"; then
+			del_namespaces
+			return "${KSFT_FAIL}"
+		fi
+
+		# try writing again and expect failure
+		if ns_set_mode "${ns}" "${mode}"; then
+			del_namespaces
+			return "${KSFT_FAIL}"
+		fi
+	done
+
+	del_namespaces
+
+	return "${KSFT_PASS}"
+}
+
 test_vm_server_host_client() {
 	if ! vm_vsock_test "init_ns" "server" 2 "${TEST_GUEST_PORT}"; then
 		return "${KSFT_FAIL}"
@@ -573,6 +641,11 @@ run_shared_vm_tests() {
 			continue
 		fi
 
+		if ! check_netns "${arg}"; then
+			check_result "${KSFT_SKIP}"
+			continue
+		fi
+
 		run_shared_vm_test "${arg}"
 		check_result $?
 	done
@@ -626,6 +699,28 @@ run_shared_vm_test() {
 	return "${rc}"
 }
 
+run_tests() {
+	for arg in "${ARGS[@]}"; do
+		if shared_vm_test "${arg}"; then
+			continue
+		fi
+
+		if ! check_netns "${arg}"; then
+			check_result "${KSFT_SKIP}"
+			continue
+		fi
+
+		add_namespaces
+
+		name=$(echo "${arg}" | awk '{ print $1 }')
+		log_host "Executing test_${name}"
+		eval test_"${name}"
+		check_result $?
+
+		del_namespaces
+	done
+}
+
 BUILD=0
 QEMU="qemu-system-$(uname -m)"
 
@@ -671,6 +766,8 @@ if shared_vm_tests_requested "${ARGS[@]}"; then
 	terminate_pidfiles "${pidfile}"
 fi
 
+run_tests "${ARGS[@]}"
+
 echo "SUMMARY: PASS=${cnt_pass} SKIP=${cnt_skip} FAIL=${cnt_fail}"
 echo "Log: ${LOG}"
 

-- 
2.47.3