enqueue_pack enqueues an outgoing icmp packet in an icmp port's write queue and then calls icmp_write() to send the packet out.
It is doubtful that the queue mentioned above will ever be more than a single icmp packet. ip_write() was rewritten and currently only returns NW_OK. If the packet is valid, ip_write() always moves the packet to the ip layer even if the packet isn't immediately sent out the ethernet or the psip interface.