[PATCH bpf-next 3/5] selftests/bpf: Add bloom filter map test cases

[Joanne Koong <joannekoong@fb.com>]

This patch adds test cases for bpf bloom filter maps. They
include tests for invalid operations by the userspace, checks
against false-negatives, and a bpf program that queries the
bloom filter map for values added by the userspace.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
---
 .../bpf/prog_tests/bloom_filter_map.c         | 123 ++++++++++++++++++
 .../selftests/bpf/progs/bloom_filter_map.c    |  49 +++++++
 2 files changed, 172 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c
 create mode 100644 tools/testing/selftests/bpf/progs/bloom_filter_map.c

diff --git a/tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c b/tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c
new file mode 100644
index 000000000000..6b41a8cfec6c
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#include <sys/syscall.h>
+#include <test_progs.h>
+#include "bloom_filter_map.skel.h"
+
+static void test_bloom_filter_map_fail(void)
+{
+	struct bpf_create_map_attr xattr = {
+		.name = "bloom_filter_map",
+		.map_type = BPF_MAP_TYPE_BLOOM_FILTER,
+		.max_entries = 100,
+		.value_size = sizeof(__u32),
+		.nr_hashes = 3,
+	};
+	__u32 value;
+	int fd, err;
+
+	/* Invalid key size */
+	xattr.key_size = 4;
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_LT(fd, 0, "bpf_create_map bloom filter invalid key size"))
+		close(fd);
+	xattr.key_size = 0;
+
+	/* Invalid value size */
+	xattr.value_size = 0;
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_LT(fd, 0, "bpf_create_map bloom filter invalid value size"))
+		close(fd);
+	xattr.value_size = sizeof(__u32);
+
+	/* Invalid max entries size */
+	xattr.max_entries = 0;
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_LT(fd, 0, "bpf_create_map bloom filter invalid max entries size"))
+		close(fd);
+	xattr.max_entries = 100;
+
+	/* Invalid number of hashes */
+	xattr.nr_hashes = 0;
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_LT(fd, 0, "bpf_create_map bloom filter invalid number of hashes"))
+		close(fd);
+	xattr.nr_hashes = 3;
+
+	/* Bloom filter maps do not support BPF_F_NO_PREALLOC */
+	xattr.map_flags = BPF_F_NO_PREALLOC;
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_LT(fd, 0, "bpf_create_map bloom filter invalid flags"))
+		close(fd);
+	xattr.map_flags = 0;
+
+	fd = bpf_create_map_xattr(&xattr);
+	if (!ASSERT_GE(fd, 0, "bpf_create_map bloom filter"))
+		return;
+
+	/* Test invalid flags */
+	err = bpf_map_update_elem(fd, NULL, &value, -1);
+	ASSERT_EQ(err, -EINVAL, "bpf_map_update_elem bloom filter invalid flags");
+
+	err = bpf_map_update_elem(fd, NULL, &value, BPF_EXIST);
+	ASSERT_EQ(err, -EINVAL, "bpf_map_update_elem bloom filter invalid flags");
+
+	err = bpf_map_update_elem(fd, NULL, &value, BPF_F_LOCK);
+	ASSERT_EQ(err, -EINVAL, "bpf_map_update_elem bloom filter invalid flags");
+
+	err = bpf_map_update_elem(fd, NULL, &value, BPF_NOEXIST);
+	ASSERT_EQ(err, -EINVAL, "bpf_map_update_elem bloom filter invalid flags");
+
+	err = bpf_map_update_elem(fd, NULL, &value, 10000);
+	ASSERT_EQ(err, -EINVAL, "bpf_map_update_elem bloom filter invalid flags");
+
+	close(fd);
+}
+
+static void bloom_filter_map(struct bloom_filter_map *skel)
+{
+	const int map_size = bpf_map__max_entries(skel->maps.map_random_data);
+	int err, map_random_data_fd, map_bloom_filter_fd, i;
+	__u64 val;
+
+	map_random_data_fd = bpf_map__fd(skel->maps.map_random_data);
+	map_bloom_filter_fd = bpf_map__fd(skel->maps.map_bloom_filter);
+
+	/* Generate random values and add them to the maps */
+	for (i = 0; i < map_size; i++) {
+		val = rand();
+		err = bpf_map_update_elem(map_random_data_fd, &i, &val, BPF_ANY);
+		if (!ASSERT_OK(err, "Add random value to map_random_data"))
+			continue;
+
+		err = bpf_map_update_elem(map_bloom_filter_fd, NULL, &val, 0);
+		if (!ASSERT_OK(err, "Add random value to map_bloom_filter"))
+			return;
+	}
+
+	skel->links.prog_bloom_filter =
+		bpf_program__attach_trace(skel->progs.prog_bloom_filter);
+	if (!ASSERT_OK_PTR(skel->links.prog_bloom_filter, "link"))
+		return;
+
+	syscall(SYS_getpgid);
+
+	ASSERT_EQ(skel->bss->error, 0, "error");
+}
+
+void test_bloom_filter_map(void)
+{
+	struct bloom_filter_map *skel;
+
+	test_bloom_filter_map_fail();
+
+	skel = bloom_filter_map__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "bloom_filter_map__open_and_load"))
+		goto cleanup;
+
+	bloom_filter_map(skel);
+
+cleanup:
+	bloom_filter_map__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/bloom_filter_map.c b/tools/testing/selftests/bpf/progs/bloom_filter_map.c
new file mode 100644
index 000000000000..2d9c43a30246
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bloom_filter_map.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-3.0
+/* Copyright (c) 2021 Facebook */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct bpf_map;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1000);
+	__type(key, __u32);
+	__type(value, __u64);
+} map_random_data SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_BLOOM_FILTER);
+	__uint(key_size, 0);
+	__uint(value_size, sizeof(__u64));
+	__uint(max_entries, 1000);
+	__uint(nr_hashes, 2);
+} map_bloom_filter SEC(".maps");
+
+int error = 0;
+
+static __u64
+check_elem(struct bpf_map *map, __u32 *key, __u64 *val,
+	   void *data)
+{
+	int err;
+
+	err = bpf_map_peek_elem(&map_bloom_filter, val);
+	if (err) {
+		error |= 1;
+		return 1; /* stop the iteration */
+	}
+
+	return 0;
+}
+
+SEC("fentry/__x64_sys_getpgid")
+int prog_bloom_filter(void *ctx)
+{
+	bpf_for_each_map_elem(&map_random_data, check_elem, NULL, 0);
+
+	return 0;
+}
-- 
2.30.2