Handle excess reason codes in SUBACK (#431)

Author: sfod

source/v5/mqtt5_to_mqtt3_adapter.c

@@ -2093,12 +2093,11 @@ static void s_aws_mqtt5_to_mqtt3_adapter_subscribe_completion_helper(
             (*subscribe_op->on_multi_suback)(
                 &adapter->base, subscribe_op->base.id, NULL, error_code, subscribe_op->on_multi_suback_user_data);
         } else {
-            AWS_VARIABLE_LENGTH_ARRAY(
-                struct aws_mqtt_topic_subscription, multi_sub_subscription_buf, suback->reason_code_count);
-            AWS_VARIABLE_LENGTH_ARRAY(
-                struct aws_mqtt_topic_subscription *, multi_sub_subscription_ptr_buf, suback->reason_code_count);
-            struct aws_mqtt_topic_subscription *subscription_ptr =
-                (struct aws_mqtt_topic_subscription *)multi_sub_subscription_buf;
+            struct aws_mqtt_topic_subscription *multi_sub_subscription_buf = aws_mem_calloc(
+                adapter->allocator, suback->reason_code_count, sizeof(struct aws_mqtt_topic_subscription));
+            struct aws_mqtt_topic_subscription **multi_sub_subscription_ptr_buf = aws_mem_calloc(
+                adapter->allocator, suback->reason_code_count, sizeof(struct aws_mqtt_topic_subscription *));
+            struct aws_mqtt_topic_subscription *subscription_ptr = multi_sub_subscription_buf;
 
             struct aws_array_list multi_sub_list;
             aws_array_list_init_static(
@@ -2132,6 +2131,9 @@ static void s_aws_mqtt5_to_mqtt3_adapter_subscribe_completion_helper(
                 &multi_sub_list,
                 error_code,
                 subscribe_op->on_multi_suback_user_data);
+
+            aws_mem_release(adapter->allocator, multi_sub_subscription_buf);
+            aws_mem_release(adapter->allocator, multi_sub_subscription_ptr_buf);
         }
     }
 }

tests/CMakeLists.txt

@@ -480,6 +480,7 @@ add_test_case(mqtt5to3_adapter_resubscribe_nothing)
 add_test_case(mqtt5to3_adapter_resubscribe_something)
 add_test_case(mqtt5to3_adapter_subscribe_single_null_suback)
 add_test_case(mqtt5to3_adapter_subscribe_multi_null_suback)
+add_test_case(mqtt5to3_adapter_subscribe_multi_oversized_suback)
 add_test_case(mqtt5to3_adapter_operation_callbacks_after_shutdown)
 # Adapter Metrics Tests
 add_test_case(mqtt5to3_adapter_set_metrics_valid)

tests/v5/mqtt5_to_mqtt3_adapter_tests.c

@@ -3051,6 +3051,132 @@ static int s_mqtt5to3_adapter_subscribe_multi_null_suback_fn(struct aws_allocato
 
 AWS_TEST_CASE(mqtt5to3_adapter_subscribe_multi_null_suback, s_mqtt5to3_adapter_subscribe_multi_null_suback_fn)
 
+#define AWS_MQTT5TO3_OVERSIZED_SUBACK_REASON_CODE_COUNT 200000
+
+static int s_mqtt5_mock_server_send_packet_streaming(
+    struct aws_mqtt5_server_mock_connection_context *connection,
+    enum aws_mqtt5_packet_type packet_type,
+    void *packet) {
+
+    if (aws_mqtt5_encoder_append_packet_encoding(&connection->encoder, packet_type, packet)) {
+        return AWS_OP_ERR;
+    }
+
+    enum aws_mqtt5_encoding_result result = AWS_MQTT5_ER_OUT_OF_ROOM;
+    while (result == AWS_MQTT5_ER_OUT_OF_ROOM) {
+        struct aws_io_message *message =
+            aws_channel_acquire_message_from_pool(connection->slot->channel, AWS_IO_MESSAGE_APPLICATION_DATA, 4096);
+        if (message == NULL) {
+            return AWS_OP_ERR;
+        }
+
+        result = aws_mqtt5_encoder_encode_to_buffer(&connection->encoder, &message->message_data);
+        if (result == AWS_MQTT5_ER_ERROR) {
+            aws_mem_release(message->allocator, message);
+            return AWS_OP_ERR;
+        }
+
+        if (aws_channel_slot_send_message(connection->slot, message, AWS_CHANNEL_DIR_WRITE)) {
+            aws_mem_release(message->allocator, message);
+            return AWS_OP_ERR;
+        }
+    }
+
+    return AWS_OP_SUCCESS;
+}
+
+static int s_mqtt5_mock_server_handle_subscribe_suback_oversized(
+    void *packet,
+    struct aws_mqtt5_server_mock_connection_context *connection,
+    void *user_data) {
+
+    (void)user_data;
+
+    struct aws_mqtt5_packet_subscribe_view *subscribe_view = packet;
+
+    size_t reason_code_count = AWS_MQTT5TO3_OVERSIZED_SUBACK_REASON_CODE_COUNT;
+
+    enum aws_mqtt5_suback_reason_code *mqtt5_suback_codes =
+        aws_mem_calloc(connection->allocator, reason_code_count, sizeof(enum aws_mqtt5_suback_reason_code));
+    for (size_t i = 0; i < reason_code_count; ++i) {
+        mqtt5_suback_codes[i] = AWS_MQTT5_SARC_GRANTED_QOS_1;
+    }
+
+    struct aws_mqtt5_packet_suback_view suback_view = {
+        .packet_id = subscribe_view->packet_id,
+        .reason_code_count = reason_code_count,
+        .reason_codes = mqtt5_suback_codes,
+    };
+
+    int result = s_mqtt5_mock_server_send_packet_streaming(connection, AWS_MQTT5_PT_SUBACK, &suback_view);
+
+    aws_mem_release(connection->allocator, mqtt5_suback_codes);
+
+    return result;
+}
+
+static int s_mqtt5to3_adapter_subscribe_multi_oversized_suback_fn(struct aws_allocator *allocator, void *ctx) {
+    (void)ctx;
+
+    aws_mqtt_library_init(allocator);
+
+    struct mqtt5_client_test_options test_options;
+    aws_mqtt5_client_test_init_default_options(&test_options);
+
+    test_options.server_function_table.packet_handlers[AWS_MQTT5_PT_SUBSCRIBE] =
+        s_mqtt5_mock_server_handle_subscribe_suback_oversized;
+
+    struct aws_mqtt5_client_mqtt5_mock_test_fixture_options test_fixture_options = {
+        .client_options = &test_options.client_options,
+        .server_function_table = &test_options.server_function_table,
+    };
+
+    struct aws_mqtt5_to_mqtt3_adapter_test_fixture fixture;
+    ASSERT_SUCCESS(aws_mqtt5_to_mqtt3_adapter_test_fixture_init(&fixture, allocator, &test_fixture_options));
+
+    struct aws_mqtt_client_connection *connection = fixture.connection;
+
+    struct aws_mqtt_connection_options connection_options;
+    s_init_adapter_connection_options_from_fixture(&connection_options, &fixture);
+
+    connection_options.on_connection_complete = s_aws_mqtt5_to_mqtt3_adapter_test_fixture_record_connection_complete;
+    connection_options.user_data = &fixture;
+
+    aws_mqtt_client_connection_connect(connection, &connection_options);
+
+    s_wait_for_n_adapter_lifecycle_events(&fixture, AWS_MQTT3_LET_CONNECTION_COMPLETE, 1);
+
+    struct aws_mqtt_topic_subscription subscriptions[] = {
+        {
+            .topic = aws_byte_cursor_from_c_str("topic/1"),
+            .qos = AWS_MQTT_QOS_AT_LEAST_ONCE,
+        },
+        {
+            .topic = aws_byte_cursor_from_c_str("topic/2"),
+            .qos = AWS_MQTT_QOS_AT_MOST_ONCE,
+        },
+    };
+
+    struct aws_array_list subscription_list;
+    aws_array_list_init_static_from_initialized(
+        &subscription_list, subscriptions, 2, sizeof(struct aws_mqtt_topic_subscription));
+
+    aws_mqtt_client_connection_subscribe_multiple(
+        connection,
+        &subscription_list,
+        s_aws_mqtt5_to_mqtt3_adapter_test_fixture_record_subscribe_multi_complete,
+        &fixture);
+
+    s_wait_for_n_adapter_operation_events(&fixture, AWS_MQTT3_OET_SUBSCRIBE_COMPLETE, 1);
+
+    aws_mqtt5_to_mqtt3_adapter_test_fixture_clean_up(&fixture);
+    aws_mqtt_library_clean_up();
+
+    return AWS_OP_SUCCESS;
+}
+
+AWS_TEST_CASE(mqtt5to3_adapter_subscribe_multi_oversized_suback, s_mqtt5to3_adapter_subscribe_multi_oversized_suback_fn)
+
 static int s_mqtt5_mock_server_handle_subscribe_suback_failure(
     void *packet,
     struct aws_mqtt5_server_mock_connection_context *connection,