RetroactiveAllowBind Method of the IFWXSession Interface

The RetroactiveAllowBind method allows a Firewall client to receive a secondary inbound connection on a socket that was previously bound by the Firewall client, but was not necessarily approved by the Microsoft Firewall service.

Syntax

HRESULT RetroactiveAllowBind(
  [in]  INT Protocol,
  [in]  LPSOCKADDR Address,
  [in]  DWORD AddressLength,
  [in]  REFGUID ProtocolGuid,
  [in]  DWORD dwFlags,
  [in]  IFWXIpFilter* pIpFilter
);

Parameters

Protocol

Protocol flags. This parameter can have the following flag values:

Value	Meaning
FWX_PROTOCOL_TCP	The bind uses the TCP protocol.
FWX_PROTOCOL_UDP	The bind uses the UDP protocol.

Address

Pointer to a sockaddr structure that contains the external IP address of the Forefront TMG computer for which this request is made. The address can be INADDR_ANY. The port number must be nonzero.

AddressLength

Length, in bytes, of the structure pointed to by the Address parameter.

ProtocolGuid

GUID that identifies the protocol of which the connection is part.

dwFlags

Connection flags. This parameter can be any combination of the following flag values:

Value	Meaning
FWX_FLAG_BIDIRECTIONAL	Permission is also granted to send packets back to destinations that recently sent packets to the socket. This flag is only valid for UDP.
FWX_INCREASE_RECEIVE_BUFFER	The receive buffer will be increased to 64 kilobytes. This flag should be set to prevent packet loss if high-bandwidth packet bursts occur in a secondary UDP connection.

pIpFilter

Pointer to an IFWXIpFilter interface. All connections that are created by RetroactiveAllowBind will be restricted by the IFWXIpFilter interface pointed to by this parameter. If you specify NULL for this parameter, the connection will not be restricted by an IFWXIpFilter interface.

Return Value

S_OK: The method succeeded.
S_FALSE: The connection exists and was already allowed.
E_INVALIDARG: Invalid parameter.
HRESULT_FROM_WIN32(ERROR_NOT_FOUND): No connection with the specified address was found.
FWX_E_TERMINATING: The (bind) connection exists, but is already terminating.
FWX_E_PROTOCOL_RULES_DENIED: The access rules do not allow the user to use the protocol specified by the ProtocolGuid parameter.

Remarks

Usually a filter will know that a bind call made by a Firewall client is valid only after the bind call succeeds and the Firewall client sends the address to its peer. For this reason, the Firewall service will not fail a bind call even when the service does not allow the client inbound access. Instead, the Firewall service marks the connection, and discards datagrams sent or connection attempts to that address, unless the bind becomes valid later.

Requirements

Server	Requires Windows Server 2008.
Version	Requires Forefront Threat Management Gateway (TMG).
Header	Declared in Wspfwext.idl.
DLL	Requires Wspsrv.exe.