IOCTL_NDISRD_GET_ADAPTER_MODE

This IOCTL returns the redirection flags for the selected adapter. See details in _ADAPTER_MODE structure description.

Remarks:

For this call the following field of ADAPTER_MODE must be initialized:

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

As a result of this call driver fills the field of ADAPTER_MODE below:

• ADAPTER_MODE.dwFlags is a combination of the XXX_LISTEN or XXX_TUNNEL flags:
  • MSTCP_FLAG_SENT_TUNNEL - queue all packets sent from MSTCP to network interface. Original packet dropped.
  • MSTCP_FLAG_RECV_TUNNEL - queue all packets indicated by network interface to MSTCP. Original packet dropped.
  • MSTCP_FLAG_SENT_LISTEN - queue all packets sent from MSTCP to network interface. Original packet goes ahead.
  • MSTCP_FLAG_RECV_LISTEN - queue all packets indicated by network interface to MSTCP. Original packet goes ahead.

  Version 2.0 of WinpkFilter has added three new flags:

  • 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 MSTCP.

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

  • MSTCP_FLAG_LOOPBACK_FILTER - Pass loopback packet for processing by helper driver routines (redirected to user-mode if requested).
  • MSTCP_FLAG_LOOPBACK_BLOCK - Silently drop loopback packets, this flag is recommended for usage in combination with promiscuous mode to avoid multiply processing of one packet.