[PATCH net-next v7 16/26] selftests/vsock: add namespace initialization function

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add functions for initializing namespaces with the different vsock NS
modes. Callers can use add_namespaces() and del_namespaces() to create
namespaces global0, global1, local0, and local1.

The init_namespaces() function initializes global0, local0, etc...  with
their respective vsock NS mode. This function is separate so that tests
that depend on this initialization can use it, while other tests that
want to test the initialization interface itself can start with a clean
slate by omitting this call.

This patch is in preparation for later namespace tests.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 40 +++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 4ee77e6570e8..914d7c873ad9 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -46,6 +46,7 @@ readonly TEST_DESCS=(
 )
 
 readonly USE_SHARED_VM=(vm_server_host_client vm_client_host_server vm_loopback)
+readonly NS_MODES=("local" "global")
 
 VERBOSE=0
 
@@ -100,6 +101,45 @@ check_result() {
 	cnt_total=$(( cnt_total + 1 ))
 }
 
+add_namespaces() {
+	# add namespaces local0, local1, global0, and global1
+	for mode in "${NS_MODES[@]}"; do
+		ip netns add "${mode}0" 2>/dev/null
+		ip netns add "${mode}1" 2>/dev/null
+	done
+}
+
+init_namespaces() {
+	for mode in "${NS_MODES[@]}"; do
+		ns_set_mode "${mode}0" "${mode}"
+		ns_set_mode "${mode}1" "${mode}"
+
+		log_host "set ns ${mode}0 to mode ${mode}"
+		log_host "set ns ${mode}1 to mode ${mode}"
+
+		# we need lo for qemu port forwarding
+		ip netns exec "${mode}0" ip link set dev lo up
+		ip netns exec "${mode}1" ip link set dev lo up
+	done
+}
+
+del_namespaces() {
+	for mode in "${NS_MODES[@]}"; do
+		ip netns del "${mode}0" &>/dev/null
+		ip netns del "${mode}1" &>/dev/null
+		log_host "removed ns ${mode}0"
+		log_host "removed ns ${mode}1"
+	done
+}
+
+ns_set_mode() {
+	local ns=$1
+	local mode=$2
+
+	echo "${mode}" | ip netns exec "${ns}" \
+		tee /proc/sys/net/vsock/ns_mode &>/dev/null
+}
+
 vm_ssh() {
 	ssh -q -o UserKnownHostsFile=/dev/null -p ${SSH_HOST_PORT} localhost "$@"
 	return $?

-- 
2.47.3