[PATCH bpf-next 08/13] tools/bpf: add test for bpf_map_update_batch()

[Yonghong Song <yhs@fb.com>]

Add tests for bpf_map_update_batch().
  $ ./test_maps
  ...
  test_map_update_batch:PASS
  ...
---
 .../bpf/map_tests/map_update_batch.c          | 115 ++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/map_tests/map_update_batch.c

diff --git a/tools/testing/selftests/bpf/map_tests/map_update_batch.c b/tools/testing/selftests/bpf/map_tests/map_update_batch.c
new file mode 100644
index 000000000000..67c1e11fc911
--- /dev/null
+++ b/tools/testing/selftests/bpf/map_tests/map_update_batch.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook  */
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include <test_maps.h>
+
+void test_map_update_batch(void)
+{
+	struct bpf_create_map_attr xattr = {
+		.name = "hash_map",
+		.map_type = BPF_MAP_TYPE_HASH,
+		.key_size = sizeof(int),
+		.value_size = sizeof(int),
+	};
+	int map_fd, *keys, *values, key, value;
+	const int max_entries = 10;
+	__u32 count, max_count;
+	int err, i;
+
+	xattr.max_entries = max_entries;
+	map_fd = bpf_create_map_xattr(&xattr);
+	CHECK(map_fd == -1,
+	      "bpf_create_map_xattr()", "error:%s\n", strerror(errno));
+
+	keys = malloc(max_entries * sizeof(int));
+	values = malloc(max_entries * sizeof(int));
+	CHECK(!keys || !values, "malloc()", "error:%s\n", strerror(errno));
+
+	/* do not fill in the whole hash table, so we could test
+	 * update with new elements.
+	 */
+	max_count = max_entries - 2;
+
+	for (i = 0; i < max_count; i++) {
+		keys[i] = i + 1;
+		values[i] = i + 2;
+	}
+
+	/* test 1: count == 0, expect success. */
+	count = 0;
+	err = bpf_map_update_batch(map_fd, keys, values, &count, 0, 0);
+	CHECK(err, "count = 0", "error:%s\n", strerror(errno));
+
+	/* test 2: update initial map with BPF_NOEXIST, expect success. */
+	count = max_count;
+	err = bpf_map_update_batch(map_fd, keys, values,
+				   &count, BPF_NOEXIST, 0);
+	CHECK(err, "elem_flags = BPF_NOEXIST",
+	      "error:%s\n", strerror(errno));
+
+	/* use bpf_map_get_next_key to ensure all keys/values are indeed
+	 * covered.
+	 */
+	err = bpf_map_get_next_key(map_fd, NULL, &key);
+	CHECK(err, "bpf_map_get_next_key()", "error: %s\n", strerror(errno));
+	err = bpf_map_lookup_elem(map_fd, &key, &value);
+	CHECK(err, "bpf_map_lookup_elem()", "error: %s\n", strerror(errno));
+	CHECK(key + 1 != value, "key/value checking",
+	      "error: key %d value %d\n", key, value);
+	i = 1;
+	while (!bpf_map_get_next_key(map_fd, &key, &key)) {
+		err = bpf_map_lookup_elem(map_fd, &key, &value);
+		CHECK(err, "bpf_map_lookup_elem()", "error: %s\n",
+		      strerror(errno));
+		CHECK(key + 1 != value,
+		      "key/value checking", "error: key %d value %d\n",
+		      key, value);
+		i++;
+	}
+	CHECK(i != max_count, "checking number of entries",
+	      "err: i %u max_count %u\n", i, max_count);
+
+	/* test 3: elem_flags = BPF_NOEXIST, already exists, expect failure */
+	err = bpf_map_update_batch(map_fd, keys, values,
+				   &count, BPF_NOEXIST, 0);
+	/* failure to due to flag BPF_NOEXIST, count is set to 0 */
+	CHECK(!err || count, "elem_flags = BPF_NOEXIST again",
+	      "unexpected success\n");
+
+	/* test 4: elem_flags = 0, expect success */
+	count = max_count;
+	err = bpf_map_update_batch(map_fd, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "elem_flags = 0", "error %s\n", strerror(errno));
+
+	/* test 5: keys = NULL, expect failure */
+	count = max_count;
+	err = bpf_map_update_batch(map_fd, NULL, values,
+				   &count, 0, 0);
+	CHECK(!err, "keys = NULL", "unexpected success\n");
+
+	/* test 6: values = NULL, expect failure */
+	count = max_count;
+	err = bpf_map_update_batch(map_fd, keys, NULL, &count, 0, 0);
+	CHECK(!err, "values = NULL", "unexpected success\n");
+
+	/* test 7: modify the first key to be max_count + 10,
+	 * elem_flags = BPF_NOEXIST,
+	 * expect failure, the return count = 1.
+	 */
+	count = max_count;
+	keys[0] = max_count + 10;
+	err = bpf_map_update_batch(map_fd, keys, values,
+				   &count, BPF_NOEXIST, 0);
+	CHECK(!err, "keys[0] = max_count + 10", "unexpected success\n");
+	CHECK(count != 1, "keys[0] = max_count + 10",
+	      "error: %s, incorrect count %u\n", strerror(errno), count);
+
+	printf("%s:PASS\n", __func__);
+}
-- 
2.17.1