+/** @brief Received packets
+ * Protected by @ref receive_lock
+ *
+ * Received packets are added to this list, and queue_thread() picks them off
+ * it and adds them to @ref packets. Whenever a packet is added to it, @ref
+ * receive_cond is signalled.
+ */
+static struct packet *received_packets;
+
+/** @brief Tail of @ref received_packets
+ * Protected by @ref receive_lock
+ */
+static struct packet **received_tail = &received_packets;
+
+/** @brief Lock protecting @ref received_packets
+ *
+ * Only listen_thread() and queue_thread() ever hold this lock. It is vital
+ * that queue_thread() not hold it any longer than it strictly has to. */
+static pthread_mutex_t receive_lock = PTHREAD_MUTEX_INITIALIZER;
+
+/** @brief Condition variable signalled when @ref received_packets is updated
+ *
+ * Used by listen_thread() to notify queue_thread() that it has added another
+ * packet to @ref received_packets. */
+static pthread_cond_t receive_cond = PTHREAD_COND_INITIALIZER;
+
+/** @brief Length of @ref received_packets */
+static uint32_t nreceived;
+