I managed to get Firefly working on my CH3WNAS which is hardware identical to the DSM G600 using the following steps: http://dsmg600.info/howto:firefly
However, my Roku Soundbrigde complains that it sees a DAAP server, but that it can't connect (and that I should use Firefly... d'oh!). However, the iTunes running on my PC can see the Firefly server.
Maybe RSP is required? The precompiled version of mt-daapd I have now (version 0.2.4) doesn't have it. Can someone help me get it for my NAS?