An interesting question, and a tough one. I looked up some commentaries on Luke 6:30, which refer also to Matthew 5:42 which is very similar.
Here is a link to
those commentaries (see the left column).
The verse you cite comes shortly after the Beatitudes, in which Jesus tells us that they are blessed who are poor, hungry, weeping, and mistreated by others. Do we believe that? Do you really believe that? If we accept that, and that’s a big if, then we may understand what Jesus says next, that we should not resist one who strikes us, takes our cloak or other property, or (in Matthew’s version) presses us into service (makes us work). Because if those things happen, we are blessed. Right?
This is a hard teaching, but some of the commentaries (cited above) soften it.
Here’s how I look at it. The greatest commandments are that we should love God and love one another. Therefore our ownership of property should be oriented toward love. The Catechism teaches that the ownership of property is legitimate for meeting our basic needs and those of our families and others in our charge. Beyond that, we can use our property and spend our money in ways that are compatible with love: helping those around us, promoting good will, building up our community, and providing for the material needs of the Church.
Ellicott’s Commentary, available from the link given above, suggests how we may respond with love when someone asks to have something of ours:
That which the words really teach as the ideal of the perfect life which we ought to aim at, is the loving and the giving temper that sees in every request made to us the expression of a want of some kind, which we are to consider as a call to thoughtful inquiry how best to meet the want, giving what is asked for if we honestly believe that it is really for the good of him who asks, giving something else if that would seem to be really better for him. Rightly understood, the words do not bid us idly give alms to the idle or the impostor.