[PATCH bpf-next 09/13] tools/bpf: add test for bpf_map_lookup_batch()

[Yonghong Song <yhs@fb.com>]

Test bpf_map_lookup_batch() functionality.
  $ ./test_maps
  ...
  test_map_lookup_batch:PASS
  ...

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 .../bpf/map_tests/map_lookup_batch.c          | 166 ++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/map_tests/map_lookup_batch.c

diff --git a/tools/testing/selftests/bpf/map_tests/map_lookup_batch.c b/tools/testing/selftests/bpf/map_tests/map_lookup_batch.c
new file mode 100644
index 000000000000..9c88e8adc556
--- /dev/null
+++ b/tools/testing/selftests/bpf/map_tests/map_lookup_batch.c
@@ -0,0 +1,166 @@
+// 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>
+
+static void map_batch_verify(int *visited, __u32 max_entries,
+			     int *keys, int *values)
+{
+	int i;
+
+	memset(visited, 0, max_entries * sizeof(*visited));
+	for (i = 0; i < max_entries; i++) {
+		CHECK(keys[i] + 1 != values[i], "key/value checking",
+		      "error: i %d key %d value %d\n", i, keys[i], values[i]);
+		visited[i] = 1;
+	}
+	for (i = 0; i < max_entries; i++) {
+		CHECK(visited[i] != 1, "visited checking",
+		      "error: keys array at index %d missing\n", i);
+	}
+}
+
+void test_map_lookup_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, *visited, key;
+	const __u32 max_entries = 10;
+	void *p_skey, *p_next_skey;
+	__u32 count, total;
+	int err, i, step;
+
+	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));
+	visited = malloc(max_entries * sizeof(int));
+	CHECK(!keys || !values || !visited, "malloc()", "error:%s\n", strerror(errno));
+
+	/* test 1: lookup an empty hash table, success */
+	count = max_entries;
+	p_next_skey = &key;
+	err = bpf_map_lookup_batch(map_fd, NULL, &p_next_skey, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "empty map", "error: %s\n", strerror(errno));
+	CHECK(p_next_skey || count, "empty map",
+	      "p_next_skey = %p, count = %u\n", p_next_skey, count);
+
+	/* populate elements to the map */
+	for (i = 0; i < max_entries; i++) {
+		keys[i] = i + 1;
+		values[i] = i + 2;
+	}
+
+	count = max_entries;
+	err = bpf_map_update_batch(map_fd, keys, values, &count, 0, 0);
+	CHECK(err, "bpf_map_update_batch()", "error:%s\n", strerror(errno));
+
+	/* test 2: lookup with count = 0, success */
+	count = 0;
+	err = bpf_map_lookup_batch(map_fd, NULL, NULL, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "count = 0", "error: %s\n", strerror(errno));
+
+	/* test 3: lookup with count = max_entries, skey && !nskey, failure */
+	count = max_entries;
+	key = 1;
+	err = bpf_map_lookup_batch(map_fd, &key, NULL, keys, values,
+				   &count, 0, 0);
+	CHECK(!err, "skey && !nskey", "unexpected success\n");
+
+	/* test 4: lookup with count = max_entries, success */
+	memset(keys, 0, max_entries * sizeof(*keys));
+	memset(values, 0, max_entries * sizeof(*values));
+	count = max_entries;
+	p_next_skey = &key;
+	err = bpf_map_lookup_batch(map_fd, NULL, &p_next_skey, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "count = max_entries", "error: %s\n", strerror(errno));
+	CHECK(count != max_entries || p_next_skey != NULL, "count = max_entries",
+	      "count = %u, max_entries = %u, p_next_skey = %p\n",
+	      count, max_entries, p_next_skey);
+
+
+	/* test 5: lookup with count = max_entries, it should return
+	 * success with count = max_entries.
+	 */
+	memset(keys, 0, max_entries * sizeof(*keys));
+	memset(values, 0, max_entries * sizeof(*values));
+	count = max_entries;
+	p_next_skey = &key;
+	err = bpf_map_lookup_batch(map_fd, NULL, &p_next_skey, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "count = max_entries", "error: %s\n", strerror(errno));
+	CHECK(count != max_entries || p_next_skey != NULL, "count = max_entries",
+	      "count = %u, max_entries = %u, p_next_skey = %p\n",
+	      count, max_entries, p_next_skey);
+
+	/* test 6: lookup with an invalid start key, failure */
+	count = max_entries;
+	key = max_entries + 10;
+	p_next_skey = &key;
+	err = bpf_map_lookup_batch(map_fd, &key, &p_next_skey, keys, values,
+				   &count, 0, 0);
+	CHECK(!err, "invalid start_key", "unexpected success\n");
+
+	/* test 7: lookup in a loop with various steps. */
+	for (step = 1; step < max_entries; step++) {
+		memset(keys, 0, max_entries * sizeof(*keys));
+		memset(values, 0, max_entries * sizeof(*values));
+		p_skey = NULL;
+		p_next_skey = &key;
+		total = 0;
+		i = 0;
+		/* iteratively lookup elements with 'step' elements each */
+		count = step;
+		while (true) {
+			err = bpf_map_lookup_batch(map_fd, p_skey, &p_next_skey,
+						   keys + i * step,
+						   values + i * step,
+						   &count, 0, 0);
+			CHECK(err, "lookup with steps", "error: %s\n",
+			      strerror(errno));
+
+			total += count;
+			if (!p_next_skey)
+				break;
+
+			CHECK(count != step, "lookup with steps",
+			      "i = %d, count = %u, step = %d\n",
+			      i, count, step);
+
+			if (!p_skey)
+				p_skey = p_next_skey;
+			i++;
+		}
+
+		CHECK(total != max_entries, "lookup with steps",
+		      "total = %u, max_entries = %u\n", total, max_entries);
+
+		map_batch_verify(visited, max_entries, keys, values);
+	}
+
+	/* test 8: lookup with keys in keys[]. */
+	memset(values, 0, max_entries * sizeof(*values));
+	count = max_entries;
+	err = bpf_map_lookup_batch(map_fd, NULL, NULL, keys, values,
+				   &count, 0, 0);
+	CHECK(err, "lookup key in keys[]", "error: %s\n", strerror(errno));
+	map_batch_verify(visited, max_entries, keys, values);
+
+	printf("%s:PASS\n", __func__);
+}
-- 
2.17.1