GetIpInterfaceEntry function

Article
03/03/2023

The GetIpInterfaceEntry function retrieves IP information for the specified interface on a local computer.

Syntax

NETIOAPI_API GetIpInterfaceEntry(
  _Inout_ PMIB_IPINTERFACE_ROW Row
);

Parameters

Row [in, out]
A pointer to a MIB_IPINTERFACE_ROW structure that, on successful return, receives information for an interface on the local computer. On input, your driver must set the InterfaceLuid member or the InterfaceIndex member of the MIB_IPINTERFACE_ROW to the interface to retrieve information for.

Return value

GetIpInterfaceEntry returns STATUS_SUCCESS if the function succeeds.

If the function fails, GetIpInterfaceEntry returns one of the following error codes:

Return code	Description
STATUS_INVALID_PARAMETER	An invalid parameter was passed to the function. This error is returned if a NULL pointer is passed in the Row parameter, the Family member of the MIB_IPINTERFACE_ROW structure that the Row parameter points to was not specified as AF_INET or AF_INET6, or the InterfaceLuid and InterfaceIndex members of the MIB_IPINTERFACE_ROW structure were unspecified.
STATUS_NOT_FOUND	The specified interface could not be found. This error is returned if the function cannot find the network interface that is specified by the InterfaceLuid or InterfaceIndex member of the MIB_IPINTERFACE_ROW structure that the Row parameter points to.
Other	Use the FormatMessage function to obtain the message string for the returned error.

Remarks

On input, your driver must initialize the following members of the MIB_IPINTERFACE_ROW structure that the Row parameter points to.

Family
Set to either AF_INET or AF_INET6.
InterfaceLuid or InterfaceIndex
These members are used in the order that is listed earlier. So if InterfaceLuid is specified, this member is used to determine the interface. If no value was set for the InterfaceLuid member (the value of this member was set to zero), the InterfaceIndex member is next used to determine the interface.

On output, GetIpInterfaceEntry fills in the remaining members of the MIB_IPINTERFACE_ROW structure that the Row parameter points to.

Your driver must use the InitializeIpInterfaceEntry function to initialize the fields of a MIB_IPINTERFACE_ROW structure entry with default values. A driver can then change the fields in the MIB_IPINTERFACE_ROW entry that it wants to modify, and then call the SetIpInterfaceEntry function.

Unprivileged simultaneous access to multiple networks of different security requirements creates a security hole and enables an unprivileged driver to accidentally relay data between the two networks. A typical example is simultaneous access to a virtual private network (VPN) and the Internet. The Windows Server 2003 and Windows XP operating systems use a weak host model, where Remote Access Service (RAS) prevents such simultaneous access by increasing the route metric of all default routes over other interfaces. Therefore, all traffic is routed through the VPN interface, disrupting other network connectivity.

On Windows Vista and later versions of the Windows operating systems, by default, a strong host model is used. If a source IP address is specified in the route lookup by using the GetBestRoute2 function, the route lookup is restricted to the interface of the source IP address. The route metric modification by RAS has no effect because the list of potential routes does not even have the route for the VPN interface, which enables traffic to the Internet. Your driver can use the DisableDefaultRoutes member of the MIB_IPINTERFACE_ROW to disable using the default route on an interface. VPN clients can use this member as a security measure to restrict split tunneling when split tunneling is not required by the VPN client. A VPN client can call the SetIpInterfaceEntry function to set the DisableDefaultRoutes member to TRUE when it is required. A VPN client can query the current state of the DisableDefaultRoutes member by calling the GetIpInterfaceEntry function.

Requirements

Target platform	Universal
Version	Available in Windows Vista and later versions of the Windows operating systems.
Header	Netioapi.h (include Netioapi.h)
Library	Netio.lib
IRQL	< DISPATCH_LEVEL