Fix errors on error paths found by oomer.

* Use-after-free because we free network before dht in one case.
* Various unchecked allocs in tests (not so important).
* We used to not check whether ping arrays were actually allocated in DHT.
* `ping_kill` and `ping_array_kill` used to crash when passing NULL.

Also:
* Added an assert in all public API functions to ensure tox isn't NULL.
  The error message you get from that is a bit nicer than "Segmentation
  fault" when clients (or our tests) do things wrong.
* Decreased the sleep time in iterate_all_wait from 20ms to 5ms.
  Everything seems to still work with 5ms, and this greatly decreases
  the amount of time spent per test run, making oomer run much faster.

1 files changed, 5 insertions, 0 deletions

diff --git a/toxcore/DHT.c b/toxcore/DHT.c
index 7525e695..b3017259 100644
--- a/toxcore/DHT.c
+++ b/toxcore/DHT.c
@@ -2721,6 +2721,11 @@ DHT *new_dht(const Logger *log, Mono_Time *mono_time, Networking_Core *net, bool
     dht->dht_ping_array = ping_array_new(DHT_PING_ARRAY_SIZE, PING_TIMEOUT);
     dht->dht_harden_ping_array = ping_array_new(DHT_PING_ARRAY_SIZE, PING_TIMEOUT);
 
+    if (dht->dht_ping_array == nullptr || dht->dht_harden_ping_array == nullptr) {
+        kill_dht(dht);
+        return nullptr;
+    }
+
     for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER; ++i) {
         uint8_t random_public_key_bytes[CRYPTO_PUBLIC_KEY_SIZE];
         uint8_t random_secret_key_bytes[CRYPTO_SECRET_KEY_SIZE];