An injection descriptor corresponding to a destination node may be stored in memory. A network interface controller (NIC) may determine that one or more messages added to the injection descriptor are to be transmitted to the destination node. The NIC may then lock the injection descriptor so that no additional message can be added to the injection descriptor, and the NIC may load the one or more messages. The NIC may then generate a network packet that includes the one or more messages, and the NIC may transmit the network packet to the destination node.