testcases/kernel/syscalls/bpf/bpf_map01.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2019 Richard Palethorpe <rpalethorpe@suse.com>
 *
 * Trivial Extended Berkeley Packet Filter (eBPF) test.
 *
 * Sanity check creating and updating maps.
 */
/*
 * If test is executed in a loop and limit for locked memory (ulimit -l) is
 * too low bpf() call can fail with EPERM due to deffered freeing.
 */

#include <limits.h>
#include <string.h>

#include "config.h"
#include "tst_test.h"
#include "bpf_common.h"

#define VAL_SZ 1024

static void *key4;
static void *key8;
static char *val_set;
static char *val_get;
static union bpf_attr *attr;

struct map_type {
	uint32_t id;
	char *name;
	int key_size;
	void **key;
};

static const struct map_type map_types[] = {
	{BPF_MAP_TYPE_HASH, "hash", 8, &key8},
	{BPF_MAP_TYPE_ARRAY, "array", 4, &key4}
};

void run(unsigned int n)
{
	int fd, i;
	void *key = *map_types[n].key;

	memset(attr, 0, sizeof(*attr));
	attr->map_type = map_types[n].id;
	attr->key_size = map_types[n].key_size;
	attr->value_size = VAL_SZ;
	attr->max_entries = 1;

	fd = bpf_map_create(attr);
	tst_res(TPASS, "Created %s map", map_types[n].name);

	memset(attr, 0, sizeof(*attr));
	attr->map_fd = fd;
	attr->key = ptr_to_u64(key);
	attr->value = ptr_to_u64(val_get);

	memset(val_get, 'x', VAL_SZ);

	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));

	switch (map_types[n].id) {
	case BPF_MAP_TYPE_HASH:
		if (TST_RET != -1 || TST_ERR != ENOENT) {
			tst_res(TFAIL | TTERRNO,
				"Empty hash map lookup should fail with ENOENT");
		} else {
			tst_res(TPASS | TTERRNO, "Empty hash map lookup");
		}
	break;
	case BPF_MAP_TYPE_ARRAY:
		if (TST_RET != -1) {
			for (i = 0; i < VAL_SZ; i++) {
				if (val_get[i] != 0) {
					tst_res(TFAIL,
						"Preallocated array map val not zero");
					break;
				}
			}
			if (i < VAL_SZ)
				tst_res(TPASS, "Preallocated array map lookup");
		} else {
			tst_res(TFAIL | TTERRNO, "Prellocated array map lookup");
		}
	break;
	}

	memset(attr, 0, sizeof(*attr));
	attr->map_fd = fd;
	attr->key = ptr_to_u64(key);
	attr->value = ptr_to_u64(val_set);
	attr->flags = BPF_ANY;

	TEST(bpf(BPF_MAP_UPDATE_ELEM, attr, sizeof(*attr)));
	if (TST_RET == -1) {
		tst_brk(TFAIL | TTERRNO,
			"Update %s map element",
			map_types[n].name);
	} else {
		tst_res(TPASS,
			"Update %s map element",
			map_types[n].name);
	}

	memset(attr, 0, sizeof(*attr));
	attr->map_fd = fd;
	attr->key = ptr_to_u64(key);
	attr->value = ptr_to_u64(val_get);

	TEST(bpf(BPF_MAP_LOOKUP_ELEM, attr, sizeof(*attr)));
	if (TST_RET == -1) {
		tst_res(TFAIL | TTERRNO,
			"%s map lookup missing",
			map_types[n].name);
	} else if (memcmp(val_set, val_get, (size_t) VAL_SZ)) {
		tst_res(TFAIL,
			"%s map lookup returned different value",
			map_types[n].name);
	} else {
		tst_res(TPASS, "%s map lookup", map_types[n].name);
	}

	SAFE_CLOSE(fd);
}

static void setup(void)
{
	unsigned int i;

	rlimit_bump_memlock();

	memcpy(key8, "12345678", 8);
	memset(key4, 0, 4);

	for (i = 0; i < VAL_SZ; i++)
		val_set[i] = i % 256;
}

static struct tst_test test = {
	.tcnt = ARRAY_SIZE(map_types),
	.test = run,
	.setup = setup,
	.min_kver = "3.19",
	.bufs = (struct tst_buffers []) {
		{&key4, .size = 4},
		{&key8, .size = 8},
		{&val_set, .size = VAL_SZ},
		{&val_get, .size = VAL_SZ},
		{&attr, .size = sizeof(*attr)},
		{},
	},
};