bpf: add initial suite for selftests

Add a start of a test suite for kernel selftests. This moves test_verifier
and test_maps over to tools/testing/selftests/bpf/ along with various
code improvements and also adds a script for invoking test_bpf module.
The test suite can simply be run via selftest framework, f.e.:

  # cd tools/testing/selftests/bpf/
  # make
  # make run_tests

Both test_verifier and test_maps were kind of misplaced in samples/bpf/
directory and we were looking into adding them to selftests for a while
now, so it can be picked up by kbuild bot et al and hopefully also get
more exposure and thus new test case additions.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 525 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
new file mode 100644
index 000000000000..ee384f02cb6e
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -0,0 +1,525 @@
+/*
+ * Testsuite for eBPF maps
+ *
+ * Copyright (c) 2014 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#include <sys/wait.h>
+#include <sys/resource.h>
+
+#include <linux/bpf.h>
+
+#include "bpf_sys.h"
+
+static int map_flags;
+
+static void test_hashmap(int task, void *data)
+{
+	long long key, next_key, value;
+	int fd;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
+			    2, map_flags);
+	if (fd < 0) {
+		printf("Failed to create hashmap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	key = 1;
+	value = 1234;
+	/* Insert key=1 element. */
+	assert(bpf_map_update(fd, &key, &value, BPF_ANY) == 0);
+
+	value = 0;
+	/* BPF_NOEXIST means add new element if it doesn't exist. */
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == -1 &&
+	       /* key=1 already exists. */
+	       errno == EEXIST);
+
+	/* -1 is an invalid flag. */
+	assert(bpf_map_update(fd, &key, &value, -1) == -1 && errno == EINVAL);
+
+	/* Check that key=1 can be found. */
+	assert(bpf_map_lookup(fd, &key, &value) == 0 && value == 1234);
+
+	key = 2;
+	/* Check that key=2 is not found. */
+	assert(bpf_map_lookup(fd, &key, &value) == -1 && errno == ENOENT);
+
+	/* BPF_EXIST means update existing element. */
+	assert(bpf_map_update(fd, &key, &value, BPF_EXIST) == -1 &&
+	       /* key=2 is not there. */
+	       errno == ENOENT);
+
+	/* Insert key=2 element. */
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == 0);
+
+	/* key=1 and key=2 were inserted, check that key=0 cannot be
+	 * inserted due to max_entries limit.
+	 */
+	key = 0;
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == -1 &&
+	       errno == E2BIG);
+
+	/* Update existing element, though the map is full. */
+	key = 1;
+	assert(bpf_map_update(fd, &key, &value, BPF_EXIST) == 0);
+	key = 2;
+	assert(bpf_map_update(fd, &key, &value, BPF_ANY) == 0);
+	key = 1;
+	assert(bpf_map_update(fd, &key, &value, BPF_ANY) == 0);
+
+	/* Check that key = 0 doesn't exist. */
+	key = 0;
+	assert(bpf_map_delete(fd, &key) == -1 && errno == ENOENT);
+
+	/* Iterate over two elements. */
+	assert(bpf_map_next_key(fd, &key, &next_key) == 0 &&
+	       (next_key == 1 || next_key == 2));
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == 0 &&
+	       (next_key == 1 || next_key == 2));
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == -1 &&
+	       errno == ENOENT);
+
+	/* Delete both elements. */
+	key = 1;
+	assert(bpf_map_delete(fd, &key) == 0);
+	key = 2;
+	assert(bpf_map_delete(fd, &key) == 0);
+	assert(bpf_map_delete(fd, &key) == -1 && errno == ENOENT);
+
+	key = 0;
+	/* Check that map is empty. */
+	assert(bpf_map_next_key(fd, &key, &next_key) == -1 &&
+	       errno == ENOENT);
+
+	close(fd);
+}
+
+static void test_hashmap_percpu(int task, void *data)
+{
+	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	long long value[nr_cpus];
+	long long key, next_key;
+	int expected_key_mask = 0;
+	int fd, i;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_PERCPU_HASH, sizeof(key),
+			    sizeof(value[0]), 2, map_flags);
+	if (fd < 0) {
+		printf("Failed to create hashmap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	for (i = 0; i < nr_cpus; i++)
+		value[i] = i + 100;
+
+	key = 1;
+	/* Insert key=1 element. */
+	assert(!(expected_key_mask & key));
+	assert(bpf_map_update(fd, &key, value, BPF_ANY) == 0);
+	expected_key_mask |= key;
+
+	/* BPF_NOEXIST means add new element if it doesn't exist. */
+	assert(bpf_map_update(fd, &key, value, BPF_NOEXIST) == -1 &&
+	       /* key=1 already exists. */
+	       errno == EEXIST);
+
+	/* -1 is an invalid flag. */
+	assert(bpf_map_update(fd, &key, value, -1) == -1 && errno == EINVAL);
+
+	/* Check that key=1 can be found. Value could be 0 if the lookup
+	 * was run from a different CPU.
+	 */
+	value[0] = 1;
+	assert(bpf_map_lookup(fd, &key, value) == 0 && value[0] == 100);
+
+	key = 2;
+	/* Check that key=2 is not found. */
+	assert(bpf_map_lookup(fd, &key, value) == -1 && errno == ENOENT);
+
+	/* BPF_EXIST means update existing element. */
+	assert(bpf_map_update(fd, &key, value, BPF_EXIST) == -1 &&
+	       /* key=2 is not there. */
+	       errno == ENOENT);
+
+	/* Insert key=2 element. */
+	assert(!(expected_key_mask & key));
+	assert(bpf_map_update(fd, &key, value, BPF_NOEXIST) == 0);
+	expected_key_mask |= key;
+
+	/* key=1 and key=2 were inserted, check that key=0 cannot be
+	 * inserted due to max_entries limit.
+	 */
+	key = 0;
+	assert(bpf_map_update(fd, &key, value, BPF_NOEXIST) == -1 &&
+	       errno == E2BIG);
+
+	/* Check that key = 0 doesn't exist. */
+	assert(bpf_map_delete(fd, &key) == -1 && errno == ENOENT);
+
+	/* Iterate over two elements. */
+	while (!bpf_map_next_key(fd, &key, &next_key)) {
+		assert((expected_key_mask & next_key) == next_key);
+		expected_key_mask &= ~next_key;
+
+		assert(bpf_map_lookup(fd, &next_key, value) == 0);
+
+		for (i = 0; i < nr_cpus; i++)
+			assert(value[i] == i + 100);
+
+		key = next_key;
+	}
+	assert(errno == ENOENT);
+
+	/* Update with BPF_EXIST. */
+	key = 1;
+	assert(bpf_map_update(fd, &key, value, BPF_EXIST) == 0);
+
+	/* Delete both elements. */
+	key = 1;
+	assert(bpf_map_delete(fd, &key) == 0);
+	key = 2;
+	assert(bpf_map_delete(fd, &key) == 0);
+	assert(bpf_map_delete(fd, &key) == -1 && errno == ENOENT);
+
+	key = 0;
+	/* Check that map is empty. */
+	assert(bpf_map_next_key(fd, &key, &next_key) == -1 &&
+	       errno == ENOENT);
+
+	close(fd);
+}
+
+static void test_arraymap(int task, void *data)
+{
+	int key, next_key, fd;
+	long long value;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, sizeof(key), sizeof(value),
+			    2, 0);
+	if (fd < 0) {
+		printf("Failed to create arraymap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	key = 1;
+	value = 1234;
+	/* Insert key=1 element. */
+	assert(bpf_map_update(fd, &key, &value, BPF_ANY) == 0);
+
+	value = 0;
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == -1 &&
+	       errno == EEXIST);
+
+	/* Check that key=1 can be found. */
+	assert(bpf_map_lookup(fd, &key, &value) == 0 && value == 1234);
+
+	key = 0;
+	/* Check that key=0 is also found and zero initialized. */
+	assert(bpf_map_lookup(fd, &key, &value) == 0 && value == 0);
+
+	/* key=0 and key=1 were inserted, check that key=2 cannot be inserted
+	 * due to max_entries limit.
+	 */
+	key = 2;
+	assert(bpf_map_update(fd, &key, &value, BPF_EXIST) == -1 &&
+	       errno == E2BIG);
+
+	/* Check that key = 2 doesn't exist. */
+	assert(bpf_map_lookup(fd, &key, &value) == -1 && errno == ENOENT);
+
+	/* Iterate over two elements. */
+	assert(bpf_map_next_key(fd, &key, &next_key) == 0 &&
+	       next_key == 0);
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == 0 &&
+	       next_key == 1);
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == -1 &&
+	       errno == ENOENT);
+
+	/* Delete shouldn't succeed. */
+	key = 1;
+	assert(bpf_map_delete(fd, &key) == -1 && errno == EINVAL);
+
+	close(fd);
+}
+
+static void test_arraymap_percpu(int task, void *data)
+{
+	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	int key, next_key, fd, i;
+	long values[nr_cpus];
+
+	fd = bpf_map_create(BPF_MAP_TYPE_PERCPU_ARRAY, sizeof(key),
+			    sizeof(values[0]), 2, 0);
+	if (fd < 0) {
+		printf("Failed to create arraymap '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	for (i = 0; i < nr_cpus; i++)
+		values[i] = i + 100;
+
+	key = 1;
+	/* Insert key=1 element. */
+	assert(bpf_map_update(fd, &key, values, BPF_ANY) == 0);
+
+	values[0] = 0;
+	assert(bpf_map_update(fd, &key, values, BPF_NOEXIST) == -1 &&
+	       errno == EEXIST);
+
+	/* Check that key=1 can be found. */
+	assert(bpf_map_lookup(fd, &key, values) == 0 && values[0] == 100);
+
+	key = 0;
+	/* Check that key=0 is also found and zero initialized. */
+	assert(bpf_map_lookup(fd, &key, values) == 0 &&
+	       values[0] == 0 && values[nr_cpus - 1] == 0);
+
+	/* Check that key=2 cannot be inserted due to max_entries limit. */
+	key = 2;
+	assert(bpf_map_update(fd, &key, values, BPF_EXIST) == -1 &&
+	       errno == E2BIG);
+
+	/* Check that key = 2 doesn't exist. */
+	assert(bpf_map_lookup(fd, &key, values) == -1 && errno == ENOENT);
+
+	/* Iterate over two elements. */
+	assert(bpf_map_next_key(fd, &key, &next_key) == 0 &&
+	       next_key == 0);
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == 0 &&
+	       next_key == 1);
+	assert(bpf_map_next_key(fd, &next_key, &next_key) == -1 &&
+	       errno == ENOENT);
+
+	/* Delete shouldn't succeed. */
+	key = 1;
+	assert(bpf_map_delete(fd, &key) == -1 && errno == EINVAL);
+
+	close(fd);
+}
+
+static void test_arraymap_percpu_many_keys(void)
+{
+	unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	unsigned int nr_keys = 20000;
+	long values[nr_cpus];
+	int key, fd, i;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_PERCPU_ARRAY, sizeof(key),
+			    sizeof(values[0]), nr_keys, 0);
+	if (fd < 0) {
+		printf("Failed to create per-cpu arraymap '%s'!\n",
+		       strerror(errno));
+		exit(1);
+	}
+
+	for (i = 0; i < nr_cpus; i++)
+		values[i] = i + 10;
+
+	for (key = 0; key < nr_keys; key++)
+		assert(bpf_map_update(fd, &key, values, BPF_ANY) == 0);
+
+	for (key = 0; key < nr_keys; key++) {
+		for (i = 0; i < nr_cpus; i++)
+			values[i] = 0;
+
+		assert(bpf_map_lookup(fd, &key, values) == 0);
+
+		for (i = 0; i < nr_cpus; i++)
+			assert(values[i] == i + 10);
+	}
+
+	close(fd);
+}
+
+#define MAP_SIZE (32 * 1024)
+
+static void test_map_large(void)
+{
+	struct bigkey {
+		int a;
+		char b[116];
+		long long c;
+	} key;
+	int fd, i, value;
+
+	fd = bpf_map_create(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
+			    MAP_SIZE, map_flags);
+	if (fd < 0) {
+		printf("Failed to create large map '%s'!\n", strerror(errno));
+		exit(1);
+	}
+
+	for (i = 0; i < MAP_SIZE; i++) {
+		key = (struct bigkey) { .c = i };
+		value = i;
+
+		assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == 0);
+	}
+
+	key.c = -1;
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == -1 &&
+	       errno == E2BIG);
+
+	/* Iterate through all elements. */
+	for (i = 0; i < MAP_SIZE; i++)
+		assert(bpf_map_next_key(fd, &key, &key) == 0);
+	assert(bpf_map_next_key(fd, &key, &key) == -1 && errno == ENOENT);
+
+	key.c = 0;
+	assert(bpf_map_lookup(fd, &key, &value) == 0 && value == 0);
+	key.a = 1;
+	assert(bpf_map_lookup(fd, &key, &value) == -1 && errno == ENOENT);
+
+	close(fd);
+}
+
+static void run_parallel(int tasks, void (*fn)(int task, void *data),
+			 void *data)
+{
+	pid_t pid[tasks];
+	int i;
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			fn(i, data);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("Couldn't spawn #%d process!\n", i);
+			exit(1);
+		}
+	}
+
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void test_map_stress(void)
+{
+	run_parallel(100, test_hashmap, NULL);
+	run_parallel(100, test_hashmap_percpu, NULL);
+
+	run_parallel(100, test_arraymap, NULL);
+	run_parallel(100, test_arraymap_percpu, NULL);
+}
+
+#define TASKS 1024
+
+#define DO_UPDATE 1
+#define DO_DELETE 0
+
+static void do_work(int fn, void *data)
+{
+	int do_update = ((int *)data)[1];
+	int fd = ((int *)data)[0];
+	int i, key, value;
+
+	for (i = fn; i < MAP_SIZE; i += TASKS) {
+		key = value = i;
+
+		if (do_update) {
+			assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == 0);
+			assert(bpf_map_update(fd, &key, &value, BPF_EXIST) == 0);
+		} else {
+			assert(bpf_map_delete(fd, &key) == 0);
+		}
+	}
+}
+
+static void test_map_parallel(void)
+{
+	int i, fd, key = 0, value = 0;
+	int data[2];
+
+	fd = bpf_map_create(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
+			    MAP_SIZE, map_flags);
+	if (fd < 0) {
+		printf("Failed to create map for parallel test '%s'!\n",
+		       strerror(errno));
+		exit(1);
+	}
+
+	/* Use the same fd in children to add elements to this map:
+	 * child_0 adds key=0, key=1024, key=2048, ...
+	 * child_1 adds key=1, key=1025, key=2049, ...
+	 * child_1023 adds key=1023, ...
+	 */
+	data[0] = fd;
+	data[1] = DO_UPDATE;
+	run_parallel(TASKS, do_work, data);
+
+	/* Check that key=0 is already there. */
+	assert(bpf_map_update(fd, &key, &value, BPF_NOEXIST) == -1 &&
+	       errno == EEXIST);
+
+	/* Check that all elements were inserted. */
+	key = -1;
+	for (i = 0; i < MAP_SIZE; i++)
+		assert(bpf_map_next_key(fd, &key, &key) == 0);
+	assert(bpf_map_next_key(fd, &key, &key) == -1 && errno == ENOENT);
+
+	/* Another check for all elements */
+	for (i = 0; i < MAP_SIZE; i++) {
+		key = MAP_SIZE - i - 1;
+
+		assert(bpf_map_lookup(fd, &key, &value) == 0 &&
+		       value == key);
+	}
+
+	/* Now let's delete all elemenets in parallel. */
+	data[1] = DO_DELETE;
+	run_parallel(TASKS, do_work, data);
+
+	/* Nothing should be left. */
+	key = -1;
+	assert(bpf_map_next_key(fd, &key, &key) == -1 && errno == ENOENT);
+}
+
+static void run_all_tests(void)
+{
+	test_hashmap(0, NULL);
+	test_hashmap_percpu(0, NULL);
+
+	test_arraymap(0, NULL);
+	test_arraymap_percpu(0, NULL);
+
+	test_arraymap_percpu_many_keys();
+
+	test_map_large();
+	test_map_parallel();
+	test_map_stress();
+}
+
+int main(void)
+{
+	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
+
+	setrlimit(RLIMIT_MEMLOCK, &rinf);
+
+	map_flags = 0;
+	run_all_tests();
+
+	map_flags = BPF_F_NO_PREALLOC;
+	run_all_tests();
+
+	printf("test_maps: OK\n");
+	return 0;
+}