tools: add selftest for BPF_F_ZERO_SEED

Check that iterating two separate hash maps produces the same
order of keys if BPF_F_ZERO_SEED is used.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Lorenz Bauer 2018-11-16 11:41:11 +00:00 committed by Daniel Borkmann
parent 608114e441
commit bf5d68c730

View file

@ -258,23 +258,35 @@ static void test_hashmap_percpu(int task, void *data)
close(fd);
}
static int helper_fill_hashmap(int max_entries)
{
int i, fd, ret;
long long key, value;
fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
max_entries, map_flags);
CHECK(fd < 0,
"failed to create hashmap",
"err: %s, flags: 0x%x\n", strerror(errno), map_flags);
for (i = 0; i < max_entries; i++) {
key = i; value = key;
ret = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
CHECK(ret != 0,
"can't update hashmap",
"err: %s\n", strerror(ret));
}
return fd;
}
static void test_hashmap_walk(int task, void *data)
{
int fd, i, max_entries = 1000;
long long key, value, next_key;
bool next_key_valid = true;
fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
max_entries, map_flags);
if (fd < 0) {
printf("Failed to create hashmap '%s'!\n", strerror(errno));
exit(1);
}
for (i = 0; i < max_entries; i++) {
key = i; value = key;
assert(bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST) == 0);
}
fd = helper_fill_hashmap(max_entries);
for (i = 0; bpf_map_get_next_key(fd, !i ? NULL : &key,
&next_key) == 0; i++) {
@ -306,6 +318,39 @@ static void test_hashmap_walk(int task, void *data)
close(fd);
}
static void test_hashmap_zero_seed(void)
{
int i, first, second, old_flags;
long long key, next_first, next_second;
old_flags = map_flags;
map_flags |= BPF_F_ZERO_SEED;
first = helper_fill_hashmap(3);
second = helper_fill_hashmap(3);
for (i = 0; ; i++) {
void *key_ptr = !i ? NULL : &key;
if (bpf_map_get_next_key(first, key_ptr, &next_first) != 0)
break;
CHECK(bpf_map_get_next_key(second, key_ptr, &next_second) != 0,
"next_key for second map must succeed",
"key_ptr: %p", key_ptr);
CHECK(next_first != next_second,
"keys must match",
"i: %d first: %lld second: %lld\n", i,
next_first, next_second);
key = next_first;
}
map_flags = old_flags;
close(first);
close(second);
}
static void test_arraymap(int task, void *data)
{
int key, next_key, fd;
@ -1534,6 +1579,7 @@ static void run_all_tests(void)
test_hashmap(0, NULL);
test_hashmap_percpu(0, NULL);
test_hashmap_walk(0, NULL);
test_hashmap_zero_seed();
test_arraymap(0, NULL);
test_arraymap_percpu(0, NULL);