|Microsoft DirectX 9.0|
Retrieves the capabilities of the Internet gateway server(s) and information about leased ports.
PPDPNHCAPS *const pdpnhcaps, const DWORD dwFlags );
- [in] Pointer to a DPNHCAPS structure to be filled with Network Address Translation (NAT) helper's capabilities. The dwSize member of the structure must be set.
- [in] May be the following value.
- Automatically extend expiring leases and detect changes in the server status.
Returns DPNH_OK if successful, or one of the following error values.
DPNHERR_GENERIC An error occurred while closing. DPNHERR_INVALIDFLAGS Invalid flags were specified. DPNHERR_INVALIDOBJECT The interface object is invalid. DPNHERR_INVALIDPARAM An invalid parameter was specified. DPNHERR_INVALIDPOINTER An invalid pointer was specified. DPNHERR_NOTINITIALIZED The object has not been initialized. DPNHERR_OUTOFMEMORY There is not enough memory to perform this operation. DPNHERR_REENTRANT The interface has been re-entered on the same thread.
This method should be called periodically with the DPNHGETCATS_UPDATESERVERSTATUS flag set to automatically extend port leases that are about to expire. The DPNHGETCATS_UPDATESERVERSTATUS flag also causes detection of changes in the status of the servers since the last call to IDirectPlayNATHelp::GetCaps. If a new server becomes available, an existing server becomes unavailable, or a server's public address changes in a way that affects an existing registered port mapping, then DPNHSUCCESS_ADDRESSESCHANGED is returned instead of DPNH_OK.
If DPNHSUCCESS_ADDRESSESCHANGED is returned, the user should call IDirectPlayNATHelp::GetRegisteredAddresses to update port binding information.
When the DPNHGETCATS_UPDATESERVERSTATUS flag is set, this method may stall while attempts are made to communicate with the server.
This method must be called with the DPNHGETCATS_UPDATESERVERSTATUS flag set at least once before calling IDirectPlayNATHelp::GetRegisteredAddresses or IDirectPlayNATHelp::QueryAddress.