string link_ntop(int hardware_type, void *addr)

The link_ntop function translates a hardware address into a string. The hardware_type can be ARPHRD_ETHER or ARPHRD_INFINIBAND. The returned string is allocated out of scratch memory, and is therefore valid only during the clause. If insufficient scratch space is available, link_ntop doesn't run and an error is generated. The function is the link-level equivalent of inet_ntop.