m4_dnl hm_arg_timeval_in_rel_null(<t>) struct timeval*, pass in, relative, may be null
m4_dnl hm_arg_must(<type>,<arg>,<val>) must have correct value, or abort test
m4_dnl hm_arg_socktype(<arg>) SOCK_STREAM or SOCK_DGRAM (an int)
m4_dnl hm_arg_timeval_in_rel_null(<t>) struct timeval*, pass in, relative, may be null
m4_dnl hm_arg_must(<type>,<arg>,<val>) must have correct value, or abort test
m4_dnl hm_arg_socktype(<arg>) SOCK_STREAM or SOCK_DGRAM (an int)