PfTestPacket

[PfTestPacketis available for use in the operating systems listed in the Requirements section. In Windows Server "Longhorn", this function returns ERROR_CALL_NOT_SUPPORTED. The MprConfigInterfaceTransportSetInfo function and the Windows Filtering Platform API Management Functions provide similar functionality.]

The PfTestPacket function tests the specified packet and returns the action that would be performed given the specified interface.

DWORD PfTestPacket(
  INTERFACE_HANDLE pInInterface,
  INTERFACE_HANDLE pOutInterface,
  DWORD cBytes,
  PBYTE pbPacket,
  PPFFORWARD_ACTION ppAction
);

Parameters

• pInInterface
  [in, optional] Handle to an interface to use as an input interface for the packet. This parameter is optional and may be NULL.
• pOutInterface
  [in, optional] Handle to an interface to use as an output interface for the packet. This parameter is optional and may be NULL.
• cBytes
  [in] Specifies the size, in bytes, of the test packet specified by the pbPacket parameter.
• pbPacket
  [in] Pointer to a network packet to test with the specified interface (or interfaces).
• ppAction
  [out] Pointer to a variable of type PFFORWARD_ACTION. This variable receives the action that would have been taken given the specified interface(s) and packet.

Return Value

If the function succeeds, the return value is NO_ERROR.

If the function fails, use FormatMessage to obtain the message string for the returned error.

Remarks

Specifying only an input interface simulates a packet destined for the local computer. Specifying only an output interface simulates sending a packet from the local computer. Specifying both an input and an output interface simulates routing a network packet.

If the caller does not specify any interfaces, the PfTestPacket returns PF_ACTION_FORWARD in the ppAction parameter.

Requirements

See Also

PFFORWARD_ACTION