SOP_GETPEERNAME
if (SOP_GETPEERNAME(so, name, &vlen, B_FALSE, cred) == 0 && vlen > 0)
return (SOP_GETPEERNAME(so, addr, addrlen, accept, cr));
SO_BLOCK_FALLBACK(so, SOP_GETPEERNAME(so, addr, addrlen, accept, cr));