General notes
Each handler function gets passed an internal context block (the ctp argument) that should be treated as “read-only,” except for the iov member. This context block contains a few items of interest, as described above in “resmgr_context_t internal context block.” Also, each function gets passed a pointer to the message (in the msg argument). You'll be using this message pointer extensively, as that contains the parameters that the client's C library call has placed there for your use.
Connect functions notes
Before we dive into the individual messages, however, it's worth pointing out that the connect functions all have an identical message structure (rearranged slightly, see <sys/iomsg.h> for the original):