According to Garratt's book, The Atmospheric Boundary Layer (1994 page 43), a drag law is a relation between the surface stress (or the surface value of the friction velocity) and external flow variables e.g. the geostrophic wind.
According to Csanady (1967, J.Atmos.Sci., 24, 467-471), a resistance law of a turbulent Ekman layer is a relation connecting geostrophic wind drag coefficient to surface Rossby number.
It seems to me that both laws try to do the same thing: to get a quantitative relation between the "forcing" of the outer layer and the "reaction" of the wall layer. The manner of obtaining the two types of law is the same: matching the velocity laws in the two layers in the overlapping region.
The matching of geostrophic wind (Ekman-like) and near-surface log-laws is known as the Geostrophic Drag Law--it actually relates the 'surface' friction velocity and geostrophic wind for a given surface roughness, and is used in e.g. wind energy models. See e.g. Arya+Wyngaard (1974), or Zilitinkevich+Esau(2005).
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