selftests: net: lib: do not set ns var as readonly

It sounds good to mark the global netns variable as 'readonly', but Bash
doesn't allow the creation of local variables with the same name.

Because it looks like 'readonly' is mainly used here to check if a netns
with that name has already been set, it sounds fine to check if a
variable with this name has already been set instead. By doing that, we
avoid having to modify helpers from MPTCP selftests using the same
variable name as the one used to store the created netns name.

While at it, also avoid an unnecessary call to 'eval' to set a local
variable.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240607-upstream-net-next-20240607-selftests-mptcp-net-lib-v1-3-e36986faac94@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
index c7a8cfb477ccacdec5d62719454fa3fc3bfe0c6e..114b927fee2560556ea48566fe203ea656046543 100644 (file)
--- a/tools/testing/selftests/net/lib.sh
+++ b/tools/testing/selftests/net/lib.sh
@@ -172,11 +172,11 @@ setup_ns()
        local ns_list=()
        for ns_name in "$@"; do
                # Some test may setup/remove same netns multi times
-               if unset ${ns_name} 2> /dev/null; then
+               if [ -z "${!ns_name}" ]; then
                        ns="${ns_name,,}-$(mktemp -u XXXXXX)"
-                       eval readonly ${ns_name}="$ns"
+                       eval "${ns_name}=${ns}"
                else
-                       eval ns='$'${ns_name}
+                       ns="${!ns_name}"
                        cleanup_ns "$ns"
                fi