What is the purpose of the following packet filter rule?

allow tcp $10\mathrm{.}12\mathrm{.}1\mathrm{.}1$:$*->8\mathrm{.}8\mathrm{.}8\mathrm{.}8$:$21$

allowing $8\mathrm{.}8\mathrm{.}8\mathrm{.}8$ to establish TCP connections to any port on $10\mathrm{.}12\mathrm{.}1\mathrm{.}1$

allowing $8\mathrm{.}8\mathrm{.}8\mathrm{.}8$ to establish TCP connections to port $21$ on $10\mathrm{.}12\mathrm{.}1\mathrm{.}1$

allowing $10\mathrm{.}12\mathrm{.}1\mathrm{.}1$ to establish TCP connections to port $21$ on $8\mathrm{.}8\mathrm{.}8\mathrm{.}8$

allowing $10\mathrm{.}12\mathrm{.}1\mathrm{.}1$ to establish TCP connections to any port on $8\mathrm{.}8\mathrm{.}8\mathrm{.}8$