selftests/bpf: Add some tests with new bpf_program__attach_sockmap() APIs

Add a few more tests in sockmap_basic.c and sockmap_listen.c to
test bpf_link based APIs for SK_MSG and SK_SKB programs.
Link attach/detach/update are all tested.

All tests are passed.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043547.3738448-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 133 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index 63fb2da7930a..1337153eb0ad 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -131,6 +131,65 @@ out:
 	test_skmsg_load_helpers__destroy(skel);
 }
 
+static void test_skmsg_helpers_with_link(enum bpf_map_type map_type)
+{
+	struct bpf_program *prog, *prog_clone, *prog_clone2;
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, opts);
+	struct test_skmsg_load_helpers *skel;
+	struct bpf_link *link, *link2;
+	int err, map;
+
+	skel = test_skmsg_load_helpers__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "test_skmsg_load_helpers__open_and_load"))
+		return;
+
+	prog = skel->progs.prog_msg_verdict;
+	prog_clone = skel->progs.prog_msg_verdict_clone;
+	prog_clone2 = skel->progs.prog_msg_verdict_clone2;
+	map = bpf_map__fd(skel->maps.sock_map);
+
+	link = bpf_program__attach_sockmap(prog, map);
+	if (!ASSERT_OK_PTR(link, "bpf_program__attach_sockmap"))
+		goto out;
+
+	/* Fail since bpf_link for the same prog has been created. */
+	err = bpf_prog_attach(bpf_program__fd(prog), map, BPF_SK_MSG_VERDICT, 0);
+	if (!ASSERT_ERR(err, "bpf_prog_attach"))
+		goto out;
+
+	/* Fail since bpf_link for the same prog type has been created. */
+	link2 = bpf_program__attach_sockmap(prog_clone, map);
+	if (!ASSERT_ERR_PTR(link2, "bpf_program__attach_sockmap")) {
+		bpf_link__detach(link2);
+		goto out;
+	}
+
+	err = bpf_link__update_program(link, prog_clone);
+	if (!ASSERT_OK(err, "bpf_link__update_program"))
+		goto out;
+
+	/* Fail since a prog with different type attempts to do update. */
+	err = bpf_link__update_program(link, skel->progs.prog_skb_verdict);
+	if (!ASSERT_ERR(err, "bpf_link__update_program"))
+		goto out;
+
+	/* Fail since the old prog does not match the one in the kernel. */
+	opts.old_prog_fd = bpf_program__fd(prog_clone2);
+	opts.flags = BPF_F_REPLACE;
+	err = bpf_link_update(bpf_link__fd(link), bpf_program__fd(prog), &opts);
+	if (!ASSERT_ERR(err, "bpf_link_update"))
+		goto out;
+
+	opts.old_prog_fd = bpf_program__fd(prog_clone);
+	opts.flags = BPF_F_REPLACE;
+	err = bpf_link_update(bpf_link__fd(link), bpf_program__fd(prog), &opts);
+	if (!ASSERT_OK(err, "bpf_link_update"))
+		goto out;
+out:
+	bpf_link__detach(link);
+	test_skmsg_load_helpers__destroy(skel);
+}
+
 static void test_sockmap_update(enum bpf_map_type map_type)
 {
 	int err, prog, src;
@@ -298,6 +357,40 @@ out:
 	test_sockmap_skb_verdict_attach__destroy(skel);
 }
 
+static void test_sockmap_skb_verdict_attach_with_link(void)
+{
+	struct test_sockmap_skb_verdict_attach *skel;
+	struct bpf_program *prog;
+	struct bpf_link *link;
+	int err, map;
+
+	skel = test_sockmap_skb_verdict_attach__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+	prog = skel->progs.prog_skb_verdict;
+	map = bpf_map__fd(skel->maps.sock_map);
+	link = bpf_program__attach_sockmap(prog, map);
+	if (!ASSERT_OK_PTR(link, "bpf_program__attach_sockmap"))
+		goto out;
+
+	bpf_link__detach(link);
+
+	err = bpf_prog_attach(bpf_program__fd(prog), map, BPF_SK_SKB_STREAM_VERDICT, 0);
+	if (!ASSERT_OK(err, "bpf_prog_attach"))
+		goto out;
+
+	/* Fail since attaching with the same prog/map has been done. */
+	link = bpf_program__attach_sockmap(prog, map);
+	if (!ASSERT_ERR_PTR(link, "bpf_program__attach_sockmap"))
+		bpf_link__detach(link);
+
+	err = bpf_prog_detach2(bpf_program__fd(prog), map, BPF_SK_SKB_STREAM_VERDICT);
+	if (!ASSERT_OK(err, "bpf_prog_detach2"))
+		goto out;
+out:
+	test_sockmap_skb_verdict_attach__destroy(skel);
+}
+
 static __u32 query_prog_id(int prog_fd)
 {
 	struct bpf_prog_info info = {};
@@ -532,6 +625,38 @@ out:
 	test_sockmap_pass_prog__destroy(pass);
 }
 
+static void test_sockmap_skb_verdict_peek_with_link(void)
+{
+	struct test_sockmap_pass_prog *pass;
+	struct bpf_program *prog;
+	struct bpf_link *link;
+	int err, map;
+
+	pass = test_sockmap_pass_prog__open_and_load();
+	if (!ASSERT_OK_PTR(pass, "open_and_load"))
+		return;
+	prog = pass->progs.prog_skb_verdict;
+	map = bpf_map__fd(pass->maps.sock_map_rx);
+	link = bpf_program__attach_sockmap(prog, map);
+	if (!ASSERT_OK_PTR(link, "bpf_program__attach_sockmap"))
+		goto out;
+
+	err = bpf_link__update_program(link, pass->progs.prog_skb_verdict_clone);
+	if (!ASSERT_OK(err, "bpf_link__update_program"))
+		goto out;
+
+	/* Fail since a prog with different attach type attempts to do update. */
+	err = bpf_link__update_program(link, pass->progs.prog_skb_parser);
+	if (!ASSERT_ERR(err, "bpf_link__update_program"))
+		goto out;
+
+	test_sockmap_skb_verdict_peek_helper(map);
+	ASSERT_EQ(pass->bss->clone_called, 1, "clone_called");
+out:
+	bpf_link__detach(link);
+	test_sockmap_pass_prog__destroy(pass);
+}
+
 static void test_sockmap_unconnected_unix(void)
 {
 	int err, map, stream = 0, dgram = 0, zero = 0;
@@ -796,6 +921,8 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_attach(BPF_SK_SKB_STREAM_VERDICT,
 						BPF_SK_SKB_VERDICT);
 	}
+	if (test__start_subtest("sockmap skb_verdict attach_with_link"))
+		test_sockmap_skb_verdict_attach_with_link();
 	if (test__start_subtest("sockmap msg_verdict progs query"))
 		test_sockmap_progs_query(BPF_SK_MSG_VERDICT);
 	if (test__start_subtest("sockmap stream_parser progs query"))
@@ -812,6 +939,8 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_fionread(false);
 	if (test__start_subtest("sockmap skb_verdict msg_f_peek"))
 		test_sockmap_skb_verdict_peek();
+	if (test__start_subtest("sockmap skb_verdict msg_f_peek with link"))
+		test_sockmap_skb_verdict_peek_with_link();
 	if (test__start_subtest("sockmap unconnected af_unix"))
 		test_sockmap_unconnected_unix();
 	if (test__start_subtest("sockmap one socket to many map entries"))
@@ -820,4 +949,8 @@ void test_sockmap_basic(void)
 		test_sockmap_many_maps();
 	if (test__start_subtest("sockmap same socket replace"))
 		test_sockmap_same_sock();
+	if (test__start_subtest("sockmap sk_msg attach sockmap helpers with link"))
+		test_skmsg_helpers_with_link(BPF_MAP_TYPE_SOCKMAP);
+	if (test__start_subtest("sockhash sk_msg attach sockhash helpers with link"))
+		test_skmsg_helpers_with_link(BPF_MAP_TYPE_SOCKHASH);
 }