# Geodesic inside a body

Suppose that there is a body with a mass $m$. How could I get the geodesic inside the body (in Schwarzschild metric)? Because I have only described the metric outside a body before. We also know the radius $r$ of the body and the density is homogeneous.

$$ds^2 = -\left[\frac{3}{2}\sqrt{1-\frac{2M}{R}} - \frac{1}{2}\sqrt{1-\frac{2Mr^2}{R^3}}\right]^2dt^2 + \frac{dr^2}{\left(1-\frac{2Mr^2}{R^3}\right)} + r^2 (d\theta^2 + sin^2\theta d\phi^2)$$