Test session cookie for fsession. Multiple fsession BPF progs is attached
to bpf_fentry_test1() and session cookie is read and write in the
testcase.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
v3:
- restructure the testcase by combine the testcases for session cookie and
  get_func_ip into one patch
---
 .../selftests/bpf/prog_tests/fsession_test.c  | 25 +++++++
 .../selftests/bpf/progs/fsession_test.c       | 72 +++++++++++++++++++
 2 files changed, 97 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/fsession_test.c b/tools/testing/selftests/bpf/prog_tests/fsession_test.c
index 83f3953a1ff6..2459f9db1c92 100644
--- a/tools/testing/selftests/bpf/prog_tests/fsession_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fsession_test.c
@@ -77,6 +77,29 @@ static void test_fsession_reattach(void)
 	fsession_test__destroy(skel);
 }
 
+static void test_fsession_cookie(void)
+{
+	struct fsession_test *skel = NULL;
+	int err;
+
+	skel = fsession_test__open();
+	if (!ASSERT_OK_PTR(skel, "fsession_test__open"))
+		goto cleanup;
+
+	err = bpf_program__set_autoload(skel->progs.test11, true);
+	if (!ASSERT_OK(err, "bpf_program__set_autoload"))
+		goto cleanup;
+
+	err = fsession_test__load(skel);
+	if (!ASSERT_OK(err, "fsession_test__load"))
+		goto cleanup;
+
+	err = fsession_test__attach(skel);
+	ASSERT_EQ(err, -E2BIG, "fsession_cookie");
+cleanup:
+	fsession_test__destroy(skel);
+}
+
 void test_fsession_test(void)
 {
 #if !defined(__x86_64__)
@@ -87,4 +110,6 @@ void test_fsession_test(void)
 		test_fsession_basic();
 	if (test__start_subtest("fsession_reattach"))
 		test_fsession_reattach();
+	if (test__start_subtest("fsession_cookie"))
+		test_fsession_cookie();
 }
diff --git a/tools/testing/selftests/bpf/progs/fsession_test.c b/tools/testing/selftests/bpf/progs/fsession_test.c
index b180e339c17f..5630cf3bbd8b 100644
--- a/tools/testing/selftests/bpf/progs/fsession_test.c
+++ b/tools/testing/selftests/bpf/progs/fsession_test.c
@@ -108,3 +108,75 @@ int BPF_PROG(test6, int a)
 		test6_entry_result = (const void *) addr == &bpf_fentry_test1;
 	return 0;
 }
+
+__u64 test7_entry_ok = 0;
+__u64 test7_exit_ok = 0;
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test7, int a)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	if (!bpf_fsession_is_return(ctx)) {
+		*cookie = 0xAAAABBBBCCCCDDDDull;
+		test7_entry_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
+		return 0;
+	}
+
+	test7_exit_ok = *cookie == 0xAAAABBBBCCCCDDDDull;
+	return 0;
+}
+
+__u64 test8_entry_ok = 0;
+__u64 test8_exit_ok = 0;
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test8, int a)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	if (!bpf_fsession_is_return(ctx)) {
+		*cookie = 0x1111222233334444ull;
+		test8_entry_ok = *cookie == 0x1111222233334444ull;
+		return 0;
+	}
+
+	test8_exit_ok = *cookie == 0x1111222233334444ull;
+	return 0;
+}
+
+__u64 test9_entry_result = 0;
+__u64 test9_exit_result = 0;
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test9, int a, int ret)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	if (!bpf_fsession_is_return(ctx)) {
+		test9_entry_result = a == 1 && ret == 0;
+		*cookie = 0x123456ULL;
+		return 0;
+	}
+
+	test9_exit_result = a == 1 && ret == 2 && *cookie == 0x123456ULL;
+	return 0;
+}
+
+SEC("fsession/bpf_fentry_test1")
+int BPF_PROG(test10, int a, int ret)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	*cookie = 0;
+	return 0;
+}
+
+/* This is the 5th cookie, so it should fail */
+SEC("?fsession/bpf_fentry_test1")
+int BPF_PROG(test11, int a, int ret)
+{
+	__u64 *cookie = bpf_fsession_cookie(ctx);
+
+	*cookie = 0;
+	return 0;
+}
-- 
2.52.0