LookupRouteInformation function

Do not write a firewall-hook driver to process incoming and outgoing packets. For more information, see Firewall-Hook Drivers.

The LookupRouteInformation function retrieves packet-routing information.

Syntax

NTSTATUS LookupRouteInformation(
  _In_      VOID             *RouteLookupData,
  _Out_opt_ VOID             *RouteEntry,
  _In_opt_  IPROUTEINFOCLASS RouteInfoClass,
  _Out_opt_ VOID             *RouteInformation,
  _Out_opt_ UINT             *RouteInfoLength
);

Parameters

• RouteLookupData [in]
  Pointer to a buffer that contains data from a route lookup table.

• RouteEntry [out, optional]
  Pointer to a buffer that optionally receives route-entry information; NULL if no information is available.

• RouteInfoClass [in, optional]
  Optionally specifies one of the following values from the IPROUTEINFOCLASS enumerated type to indicate the type of routing information to retrieve:

  Value	Meaning
  IPRouteNoInformation	No routing information
  IPRouteOutgoingFirewallContext	Route outgoing using the firewall context
  IPRouteOutgoingFilterContext	Route outgoing using the filter context

   

  Specifies zero if no information is required.

• RouteInformation [out, optional]
  Pointer to a buffer that optionally receives routing information; NULL if no information is available.

• RouteInfoLength [out, optional]
  Pointer to a buffer that optionally receives the size, in bytes, of the routing information received; NULL if no information is available.

Return value

Returns STATUS_SUCCESS on success; otherwise, it returns one of the error status values defined in ntstatus.h.

Requirements

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