[PATCH bpf-next RFC v3 5/6] selftests/bpf: test BPF_MAP_DUMP command on a bpf hashmap

Brian Vazquez
2019-07-03T17:02:20Z

This tests exercise the new command on a bpf hashmap and make sure it
works as expected.

Signed-off-by: Brian Vazquez <brianvv@google.com>
---
tools/testing/selftests/bpf/test_maps.c | 82 ++++++++++++++++++++++++-
1 file changed, 80 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index a3fbc571280a..b19ba6aa8e36 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -309,6 +309,85 @@ static void test_hashmap_walk(unsigned int task, void *data)
close(fd);
}

+static void test_hashmap_dump(void)
+{
+ int fd, i, max_entries = 5;
+ uint64_t keys[max_entries], values[max_entries];
+ uint64_t key, value, next_key, prev_key;
+ bool next_key_valid = true;
+ void *buf, *elem;
+ u32 buf_len;
+ const int elem_size = sizeof(key) + sizeof(value);
+
+ fd = helper_fill_hashmap(max_entries);
+
+ // Get the elements in the hashmap, and store them in that order
+ assert(bpf_map_get_next_key(fd, NULL, &key) == 0);
+ i = 0;
+ keys[i] = key;
+ for (i = 1; next_key_valid; i++) {
+ next_key_valid = bpf_map_get_next_key(fd, &key, &next_key) == 0;
+ assert(bpf_map_lookup_elem(fd, &key, &values[i - 1]) == 0);
+ keys[i-1] = key;
+ key = next_key;
+ }
+
+ // Alloc memory for the whole table
+ buf = malloc(elem_size * max_entries);
+ assert(buf != NULL);
+
+ // Check that buf_len < elem_size returns EINVAL
+ buf_len = elem_size-1;
+ errno = 0;
+ assert(bpf_map_dump(fd, NULL, buf, &buf_len) == -1 && errno == EINVAL);
+
+ // Check that it returns the first two elements
+ errno = 0;
+ buf_len = elem_size * 2;
+ i = 0;
+ assert(bpf_map_dump(fd, NULL, buf, &buf_len) == 0 &&
+ buf_len == 2*elem_size);
+ elem = buf;
+ assert((*(uint64_t *)elem) == keys[i] &&
+ (*(uint64_t *)(elem + sizeof(key))) == values[i]);
+ elem = buf + elem_size;
+ i++;
+ assert((*(uint64_t *)elem) == keys[i] &&
+ (*(uint64_t *)(elem + sizeof(key))) == values[i]);
+ i++;
+
+ /* Check that prev_key contains key from last_elem retrieved in previous
+ * call
+ */
+ prev_key = *((uint64_t *)elem);
+ assert(bpf_map_dump(fd, &prev_key, buf, &buf_len) == 0 &&
+ buf_len == elem_size*2);
+ elem = buf;
+ assert((*(uint64_t *)elem) == keys[i] &&
+ (*(uint64_t *)(elem + sizeof(key))) == values[i]);
+ elem = buf + elem_size;
+ i++;
+ assert((*(uint64_t *)elem) == keys[i] &&
+ (*(uint64_t *)(elem + sizeof(key))) == values[i]);
+ i++;
+ assert(prev_key == (*(uint64_t *)elem));
+
+ /* Continue reading from map and verify buf_len only contains 1 element
+ * even though buf_len is 2 elem_size.
+ */
+ assert(bpf_map_dump(fd, &prev_key, buf, &buf_len) == 0 &&
+ buf_len == elem_size);
+ elem = buf;
+ assert((*(uint64_t *)elem) == keys[i] &&
+ (*(uint64_t *)(elem + sizeof(key))) == values[i]);
+
+ assert(bpf_map_dump(fd, &prev_key, buf, &buf_len) == -1 &&
+ errno == ENOENT);
+
+ free(buf);
+ close(fd);
+}
+
static void test_hashmap_zero_seed(void)
{
int i, first, second, old_flags;
@@ -1668,6 +1747,7 @@ static void run_all_tests(void)
test_hashmap_percpu(0, NULL);
test_hashmap_walk(0, NULL);
test_hashmap_zero_seed();
+ test_hashmap_dump();

test_arraymap(0, NULL);
test_arraymap_percpu(0, NULL);
@@ -1705,11 +1785,9 @@ int main(void)

map_flags = BPF_F_NO_PREALLOC;
run_all_tests();
-
#define CALL
#include <map_tests/tests.h>
#undef CALL
-
printf("test_maps: OK, %d SKIPPED\n", skips);
return 0;
}
--
2.22.0.410.gd8fdbe21b5-goog