kernel/tools/testing/selftests/bpf/prog_tests/lookup_and_delete.c

// SPDX-License-Identifier: GPL-2.0-only

#include <test_progs.h>
#include "test_lookup_and_delete.skel.h"

#define START_VALUE 1234
#define NEW_VALUE 4321
#define MAX_ENTRIES 2

static int duration;
static int nr_cpus;

static int fill_values(int map_fd)
{
	__u64 key, value = START_VALUE;
	int err;

	for (key = 1; key < MAX_ENTRIES + 1; key++) {
		err = bpf_map_update_elem(map_fd, &key, &value, BPF_NOEXIST);
		if (!ASSERT_OK(err, "bpf_map_update_elem"))
			return -1;
	}

	return 0;
}

static int fill_values_percpu(int map_fd)
{
	__u64 key, value[nr_cpus];
	int i, err;

	for (i = 0; i < nr_cpus; i++)
		value[i] = START_VALUE;

	for (key = 1; key < MAX_ENTRIES + 1; key++) {
		err = bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST);
		if (!ASSERT_OK(err, "bpf_map_update_elem"))
			return -1;
	}

	return 0;
}

static struct test_lookup_and_delete *setup_prog(enum bpf_map_type map_type,
						 int *map_fd)
{
	struct test_lookup_and_delete *skel;
	int err;

	skel = test_lookup_and_delete__open();
	if (!ASSERT_OK_PTR(skel, "test_lookup_and_delete__open"))
		return NULL;

	err = bpf_map__set_type(skel->maps.hash_map, map_type);
	if (!ASSERT_OK(err, "bpf_map__set_type"))
		goto cleanup;

	err = bpf_map__set_max_entries(skel->maps.hash_map, MAX_ENTRIES);
	if (!ASSERT_OK(err, "bpf_map__set_max_entries"))
		goto cleanup;

	err = test_lookup_and_delete__load(skel);
	if (!ASSERT_OK(err, "test_lookup_and_delete__load"))
		goto cleanup;

	*map_fd = bpf_map__fd(skel->maps.hash_map);
	if (!ASSERT_GE(*map_fd, 0, "bpf_map__fd"))
		goto cleanup;

	return skel;

cleanup:
	test_lookup_and_delete__destroy(skel);
	return NULL;
}

/* Triggers BPF program that updates map with given key and value */
static int trigger_tp(struct test_lookup_and_delete *skel, __u64 key,
		      __u64 value)
{
	int err;

	skel->bss->set_pid = getpid();
	skel->bss->set_key = key;
	skel->bss->set_value = value;

	err = test_lookup_and_delete__attach(skel);
	if (!ASSERT_OK(err, "test_lookup_and_delete__attach"))
		return -1;

	syscall(__NR_getpgid);

	test_lookup_and_delete__detach(skel);

	return 0;
}

static void test_lookup_and_delete_hash(void)
{
	struct test_lookup_and_delete *skel;
	__u64 key, value;
	int map_fd, err;

	/* Setup program and fill the map. */
	skel = setup_prog(BPF_MAP_TYPE_HASH, &map_fd);
	if (!ASSERT_OK_PTR(skel, "setup_prog"))
		return;

	err = fill_values(map_fd);
	if (!ASSERT_OK(err, "fill_values"))
		goto cleanup;

	/* Lookup and delete element. */
	key = 1;
	err = bpf_map_lookup_and_delete_elem(map_fd, &key, &value);
	if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
		goto cleanup;

	/* Fetched value should match the initially set value. */
	if (CHECK(value != START_VALUE, "bpf_map_lookup_and_delete_elem",
		  "unexpected value=%lld\n", value))
		goto cleanup;

	/* Check that the entry is non existent. */
	err = bpf_map_lookup_elem(map_fd, &key, &value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

cleanup:
	test_lookup_and_delete__destroy(skel);
}

static void test_lookup_and_delete_percpu_hash(void)
{
	struct test_lookup_and_delete *skel;
	__u64 key, val, value[nr_cpus];
	int map_fd, err, i;

	/* Setup program and fill the map. */
	skel = setup_prog(BPF_MAP_TYPE_PERCPU_HASH, &map_fd);
	if (!ASSERT_OK_PTR(skel, "setup_prog"))
		return;

	err = fill_values_percpu(map_fd);
	if (!ASSERT_OK(err, "fill_values_percpu"))
		goto cleanup;

	/* Lookup and delete element. */
	key = 1;
	err = bpf_map_lookup_and_delete_elem(map_fd, &key, value);
	if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
		goto cleanup;

	for (i = 0; i < nr_cpus; i++) {
		val = value[i];

		/* Fetched value should match the initially set value. */
		if (CHECK(val != START_VALUE, "map value",
			  "unexpected for cpu %d: %lld\n", i, val))
			goto cleanup;
	}

	/* Check that the entry is non existent. */
	err = bpf_map_lookup_elem(map_fd, &key, value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

cleanup:
	test_lookup_and_delete__destroy(skel);
}

static void test_lookup_and_delete_lru_hash(void)
{
	struct test_lookup_and_delete *skel;
	__u64 key, value;
	int map_fd, err;

	/* Setup program and fill the LRU map. */
	skel = setup_prog(BPF_MAP_TYPE_LRU_HASH, &map_fd);
	if (!ASSERT_OK_PTR(skel, "setup_prog"))
		return;

	err = fill_values(map_fd);
	if (!ASSERT_OK(err, "fill_values"))
		goto cleanup;

	/* Insert new element at key=3, should reuse LRU element. */
	key = 3;
	err = trigger_tp(skel, key, NEW_VALUE);
	if (!ASSERT_OK(err, "trigger_tp"))
		goto cleanup;

	/* Lookup and delete element 3. */
	err = bpf_map_lookup_and_delete_elem(map_fd, &key, &value);
	if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem"))
		goto cleanup;

	/* Value should match the new value. */
	if (CHECK(value != NEW_VALUE, "bpf_map_lookup_and_delete_elem",
		  "unexpected value=%lld\n", value))
		goto cleanup;

	/* Check that entries 3 and 1 are non existent. */
	err = bpf_map_lookup_elem(map_fd, &key, &value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

	key = 1;
	err = bpf_map_lookup_elem(map_fd, &key, &value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

cleanup:
	test_lookup_and_delete__destroy(skel);
}

static void test_lookup_and_delete_lru_percpu_hash(void)
{
	struct test_lookup_and_delete *skel;
	__u64 key, val, value[nr_cpus];
	int map_fd, err, i, cpucnt = 0;

	/* Setup program and fill the LRU map. */
	skel = setup_prog(BPF_MAP_TYPE_LRU_PERCPU_HASH, &map_fd);
	if (!ASSERT_OK_PTR(skel, "setup_prog"))
		return;

	err = fill_values_percpu(map_fd);
	if (!ASSERT_OK(err, "fill_values_percpu"))
		goto cleanup;

	/* Insert new element at key=3, should reuse LRU element 1. */
	key = 3;
	err = trigger_tp(skel, key, NEW_VALUE);
	if (!ASSERT_OK(err, "trigger_tp"))
		goto cleanup;

	/* Clean value. */
	for (i = 0; i < nr_cpus; i++)
		value[i] = 0;

	/* Lookup and delete element 3. */
	err = bpf_map_lookup_and_delete_elem(map_fd, &key, value);
	if (!ASSERT_OK(err, "bpf_map_lookup_and_delete_elem")) {
		goto cleanup;
	}

	/* Check if only one CPU has set the value. */
	for (i = 0; i < nr_cpus; i++) {
		val = value[i];
		if (val) {
			if (CHECK(val != NEW_VALUE, "map value",
				  "unexpected for cpu %d: %lld\n", i, val))
				goto cleanup;
			cpucnt++;
		}
	}
	if (CHECK(cpucnt != 1, "map value", "set for %d CPUs instead of 1!\n",
		  cpucnt))
		goto cleanup;

	/* Check that entries 3 and 1 are non existent. */
	err = bpf_map_lookup_elem(map_fd, &key, &value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

	key = 1;
	err = bpf_map_lookup_elem(map_fd, &key, &value);
	if (!ASSERT_ERR(err, "bpf_map_lookup_elem"))
		goto cleanup;

cleanup:
	test_lookup_and_delete__destroy(skel);
}

void test_lookup_and_delete(void)
{
	nr_cpus = bpf_num_possible_cpus();

	if (test__start_subtest("lookup_and_delete"))
		test_lookup_and_delete_hash();
	if (test__start_subtest("lookup_and_delete_percpu"))
		test_lookup_and_delete_percpu_hash();
	if (test__start_subtest("lookup_and_delete_lru"))
		test_lookup_and_delete_lru_hash();
	if (test__start_subtest("lookup_and_delete_lru_percpu"))
		test_lookup_and_delete_lru_percpu_hash();
}