[PATCH bpf-next v1 2/2] selftests/bpf: Add link update test for cgroup_storage

[Jiayuan Chen <jiayuan.chen@linux.dev>]

Add link update test for cgroup_storage.

'./test_progs -a cgroup_storage_update'
test_cgroup_storage_update:PASS:create cgroup 0 nsec
setup_network:PASS:ip netns add cgroup_storage_ns 0 nsec
setup_network:PASS:open netns 0 nsec
setup_network:PASS:ip link set lo up 0 nsec
test_cgroup_storage_update:PASS:setup network 0 nsec
test_cgroup_storage_update:PASS:load program 0 nsec
test_cgroup_storage_update:PASS:attach no map program 0 nsec
test_cgroup_storage_update:PASS:bpf_link_update 0 nsec
test_cgroup_storage_update:PASS:first ping 0 nsec
test_cgroup_storage_update:PASS:second ping 0 nsec
test_cgroup_storage_update:PASS:third ping 0 nsec
61      cgroup_storage_update:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
---
 .../selftests/bpf/prog_tests/cgroup_storage.c | 45 +++++++++++++++++++
 .../selftests/bpf/progs/cgroup_storage.c      |  6 +++
 2 files changed, 51 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_storage.c b/tools/testing/selftests/bpf/prog_tests/cgroup_storage.c
index cf395715ced4..8478b08aa62a 100644
--- a/tools/testing/selftests/bpf/prog_tests/cgroup_storage.c
+++ b/tools/testing/selftests/bpf/prog_tests/cgroup_storage.c
@@ -94,3 +94,48 @@ void test_cgroup_storage(void)
 	close(cgroup_fd);
 	cleanup_cgroup_environment();
 }
+
+void test_cgroup_storage_update(void)
+{
+	struct cgroup_storage *skel;
+	struct nstoken *ns = NULL;
+	int cgroup_fd;
+	int err;
+
+	cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
+	if (!ASSERT_OK_FD(cgroup_fd, "create cgroup"))
+		return;
+
+	if (!ASSERT_OK(setup_network(&ns), "setup network"))
+		goto cleanup_cgroup;
+
+	skel = cgroup_storage__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "load program"))
+		goto cleanup_network;
+
+	skel->links.bpf_prog_no_map =
+		bpf_program__attach_cgroup(skel->progs.bpf_prog_no_map,
+					   cgroup_fd);
+	if (!ASSERT_OK_PTR(skel->links.bpf_prog_no_map, "attach no map prog"))
+		goto cleanup_progs;
+
+	err = bpf_link_update(bpf_link__fd(skel->links.bpf_prog_no_map),
+			      bpf_program__fd(skel->progs.bpf_prog), NULL);
+	if (!ASSERT_OK(err, "bpf_link_update"))
+		goto cleanup_progs;
+
+	err = SYS_NOFAIL(PING_CMD);
+	ASSERT_OK(err, "first ping");
+	err = SYS_NOFAIL(PING_CMD);
+	ASSERT_NEQ(err, 0, "second ping");
+	err = SYS_NOFAIL(PING_CMD);
+	ASSERT_OK(err, "third ping");
+
+cleanup_progs:
+	cgroup_storage__destroy(skel);
+cleanup_network:
+	cleanup_network(ns);
+cleanup_cgroup:
+	close(cgroup_fd);
+	cleanup_cgroup_environment();
+}
diff --git a/tools/testing/selftests/bpf/progs/cgroup_storage.c b/tools/testing/selftests/bpf/progs/cgroup_storage.c
index db1e4d2d3281..33a6013ca806 100644
--- a/tools/testing/selftests/bpf/progs/cgroup_storage.c
+++ b/tools/testing/selftests/bpf/progs/cgroup_storage.c
@@ -21,4 +21,10 @@ int bpf_prog(struct __sk_buff *skb)
 	return (*counter & 1);
 }
 
+SEC("cgroup_skb/egress")
+int bpf_prog_no_map(struct __sk_buff *skb)
+{
+	return 1;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.47.1