GetAdapterMode

BOOL __stdcall GetAdapterMode ( HANDLE hOpen, PADAPTER_MODE pMode );

Return Value:
TRUE if call was successful, FALSE otherwise

Parameters:
hOpen
Specifies driver object open handle.

pMode
Pointer to the user allocated and initialized ADAPTER_MODE structure.

Remarks:
The following fields of ADAPTER_MODE must be initialized:

ADAPTER_MODE::hAdapterHandle – must be set to the interface handle (obtained via call to GetTcpipBoundAdaptersInfo).

As a result of the call, the driver fills the ADAPTER_MODE::dwFlags with a combination of the XXX_LISTEN or XXX_TUNNEL flags:

  • MSTCP_FLAG_SENT_TUNNEL – queue all packets sent from TCP/IP to network interface. Original packet is dropped.
  • MSTCP_FLAG_RECV_TUNNEL – queue all packets indicated by network interface to TCP/IP. Original packet is dropped.
  • MSTCP_FLAG_SENT_LISTEN – queue all packets sent from TCP/IP to network interface. Original packet goes ahead.
  • MSTCP_FLAG_RECV_LISTEN – queue all packets indicated by network interface to TCP/IP. Original packet goes ahead.
  • MSTCP_FLAG_FILTER_DIRECT – In promiscuous mode TCP/IP stack receives all packets in the Ethernet segment and replies with various ICMP packets, to prevent this set this flag. All packets with destination MAC different from FF-FF-FF-FF-FF-FF and network interface current MAC will never reach TCP/IP.

By default, loopback packets are passed to original TCP/IP handlers without processing, to change this behavior use the flags below:

  • MSTCP_FLAG_LOOPBACK_FILTER – if not set, then loopback packets are silently passed over, otherwise these packets are passed for further processing (queued for redirecting to the application if not dropped by the MSTCP_FLAG_LOOPBACK_BLOCK below).
  • MSTCP_FLAG_LOOPBACK_BLOCK – if set, then loopback packets (with exception to broadcast/multicast) are silently dropped.
  • MSTCP_FLAG_LOOPBACK_BLOCK | MSTCP_FLAG_LOOPBACK_FILTER – does not allow loopback packet to pass silently and results blocking them (with exception to broadcast/multicast).

This function is a C-style wrapper for CNdisApi::GetAdapterMode.