selftests/bpf: add test for BPF flow dissector in the root namespace

# this is the case and run it with in_netns.sh if it is being run in the root

# namespace.

if [[ -z $(ip netns identify $$) ]]; then

	../net/in_netns.sh "$0" "$@"

	exit $?

	err=0

	if bpftool="$(which bpftool)"; then

		echo "Testing global flow dissector..."

		$bpftool prog loadall ./bpf_flow.o /sys/fs/bpf/flow \

			type flow_dissector

		if ! unshare --net $bpftool prog attach pinned \

			/sys/fs/bpf/flow/flow_dissector flow_dissector; then

			echo "Unexpected unsuccessful attach in namespace" >&2

			err=1

		fi

# Determine selftest success via shell exit code

exit_handler()

{

	if (( $? == 0 )); then

		$bpftool prog attach pinned /sys/fs/bpf/flow/flow_dissector \

			flow_dissector

		if unshare --net $bpftool prog attach pinned \

			/sys/fs/bpf/flow/flow_dissector flow_dissector; then

			echo "Unexpected successful attach in namespace" >&2

			err=1

		fi

		if ! $bpftool prog detach pinned \

			/sys/fs/bpf/flow/flow_dissector flow_dissector; then

			echo "Failed to detach flow dissector" >&2

			err=1

		fi

		rm -rf /sys/fs/bpf/flow

	else

		echo "Skipping root flow dissector test, bpftool not found" >&2

	fi

	# Run the rest of the tests in a net namespace.

	../net/in_netns.sh "$0" "$@"

	err=$(( $err + $? ))

	if (( $err == 0 )); then

		echo "selftests: $TESTNAME [PASS]";

	else

		echo "selftests: $TESTNAME [FAILED]";

	fi

	exit $err

fi

# Determine selftest success via shell exit code

exit_handler()

{

	set +e

	# Cleanup