GetIpForwardEntry2 (NETIOAPI) (Compact 2013)

  • Article

3/26/2014

This function retrieves information for an IP route entry on a local device.

Syntax

NETIOAPI_API
  GetIpForwardEntry2(
    IN OUT PMIB_IPFORWARD_ROW2  Row
    );

Parameters

  • Row
    A pointer to a MIB_IPFORWARD_ROW2 structure entry for an IP route entry. On successful return, this structure is updated with the properties for the IP route entry.

Return Value

GetIpForwardEntry2 returns STATUS_SUCCESS if the function succeeds.

If the function fails, GetIpForwardEntry2 returns one of the following error codes:

Error Code

Meaning

STATUS_INVALID_PARAMETER

An invalid parameter was passed to the function. This error is returned if one of the following situations occurs:

  • A NULL pointer is passed in the Row parameter.
  • The DestinationPrefix member of the MIB_IPFORWARD_ROW2 structure that the Row parameter points to was not specified.
  • The NextHop member of the MIB_IPFORWARD_ROW2 structure was not specified.
  • Both InterfaceLuid and InterfaceIndex members of the MIB_IPFORWARD_ROW2 structure were unspecified.
  • The PreferredLifetime member of the MIB_IPFORWARD_ROW2 structure is greater than the ValidLifetime member.
  • The SitePrefixLength member of the MIB_IPFORWARD_ROW2 structure is greater than the prefix length that is specified by the DestinationPrefix member.

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_IPFORWARD_ROW2 structure that the Row parameter points to.

STATUS_NOT_SUPPORTED

The request is not supported. This error is returned if no IPv4 stack is located on the local device and AF_INET was specified in the address family in the DestinationPrefix member of the MIB_IPFORWARD_ROW2 structure that the Row parameter points to, or if no IPv6 stack is located on the local device and AF_INET6 was specified for the address family in the DestinationPrefix member.

Other

Use the FormatMessage function to obtain the message string for the returned error.

Remarks

The GetIpForwardEntry2 function is used to retrieve a MIB_IPFORWARD_ROW2 structure entry.

On input, your driver must initialize the following members of the MIB_IPFORWARD_ROW2 structure that the Row parameter points to.

  • DestinationPrefix
    Set to a valid IPv4 or IPv6 address prefix and family.
  • NextHop
    Set to a valid IPv4 or IPv6 address and family.
  • 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, when the call is successful, GetIpForwardEntry2 retrieves the other properties for the IP route entry and fills out the MIB_IPFORWARD_ROW2 structure that the Row parameter points to.

The route metric offset that is specified in the Metric member of the MIB_IPFORWARD_ROW2 structure that the Row parameter points to represents only part of the complete route metric. The complete metric is a combination of this route metric added to the interface metric that is specified in the Metric member of the MIB_IPINTERFACE_ROW structure of the associated interface. A driver can retrieve the interface metric by calling the GetIpInterfaceEntry (NETIOAPI) function.

Your driver can call the GetIpForwardTable2 (NETIOAPI) function to enumerate the IP route entries on a local device.

See Also

Reference

IP Helper Kernel-Mode Functions
CreateIpForwardEntry2 (NETIOAPI)
DeleteIpForwardEntry2 (NETIOAPI)
GetBestRoute2 (NETIOAPI)
GetIpForwardTable2 (NETIOAPI)
GetIpInterfaceEntry (NETIOAPI)
InitializeIpForwardEntry (NETIOAPI)
MIB_IPFORWARD_ROW2
MIB_IPFORWARD_TABLE2
MIB_IPINTERFACE_ROW
NotifyRouteChange2 (NETIOAPI)
SetIpForwardEntry2 (NETIOAPI)