Source code of Windows XP (NT5)
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/*++
Copyright (c) 1997, Microsoft Corporation
Module Name:
nbt.h
Abstract:
This module contains declarations for the NAT's NetBT support.
NetBT's datagram service embeds source IP address/port in the datagrams
that it sends out, hence the need for additional translation.
Author:
Abolade Gbadegesin (t-abolag) 25-Aug-1997
Revision History:
--*/
#ifndef _NAT_NBT_H_
#define _NAT_NBT_H_
//
// Structure: NAT_NBT_MAPPING
//
// This structure describes a mapping defined to allow translation of
// NetBT datagram-service sessions across the NAT.
//
// The NetBT datagram-service operates over UDP using port 138 for sending
// and receiving messages. This means that regardless of what value the NAT
// places in the NetBT datagram header, replies will be directed to port 138.
// Therefore, in order to translate NetBT datagrams, the NAT must incorporate
// additional information.
//
// The NAT registers a handler for outbound traffic destined for the NetBT
// datagram-service port, as well as implementing an IP-layer translator
// for inbound traffic destined for the NetBT datagram-service port.
// Each outgoing message is then examined, and a mapping is created using
// (a) the source (private) IP address in the datagram header
// (b) the public IP address chosen by the NAT
// (c) the source name in the datagram header
// The source IP address is then replaced with the public IP address,
// and the source port is replaced with the NetBT datagram-service port.
//
// Each incoming message is in turn examined by the IP-layer translator,
// and a lookup is done using
// (a) the receiving (public) IP address
// (b) the destination name in the datagram header.
// after which the packet's destination IP address is translated.
//
// A list of mappings is maintained on each interface, ordered by
// by public IP address and source name for outbound searching.
//
typedef struct _NAT_NBT_MAPPING {
LIST_ENTRY Link;
ULONG PrivateAddress;
ULONG PublicAddress;
UCHAR SourceName[NBT_NAME_LENGTH];
LONG64 LastAccessTime;
} NAT_NBT_MAPPING, *PNAT_NBT_MAPPING;
//
// NBT mapping allocation macros
//
#define ALLOCATE_NBT_BLOCK() \
ExAllocateFromNPagedLookasideList(&NbtLookasideList)
#define FREE_NBT_BLOCK(Block) \
ExFreeToNPagedLookasideList(&NbtLookasideList,(Block))
//
// FUNCTION DECLARATIONS
//
NTSTATUS
NatCreateNbtMapping(
PNAT_INTERFACE Interfacep,
ULONG PrivateAddress,
ULONG PublicAddress,
UCHAR SourceName[],
PLIST_ENTRY InboundInsertionPoint,
PNAT_NBT_MAPPING* MappingCreated
);
PNAT_NBT_MAPPING
NatLookupInboundNbtMapping(
PNAT_INTERFACE Interfacep,
ULONG PublicAddress,
UCHAR SourceName[],
PLIST_ENTRY* InboundInsertionPoint
);
NTSTATUS
NatInitializeEditorNbt(
VOID
);
NTSTATUS
NatOutboundDataHandlerNbt(
IN PVOID InterfaceHandle,
IN PVOID SessionHandle,
IN PVOID DataHandle,
IN PVOID EditorContext,
IN PVOID EditorSessionContext,
IN PVOID RecvBuffer,
IN ULONG DataOffset
);
XLATE_IP_ROUTINE(NatTranslateNbt)
extern IP_NAT_REGISTER_EDITOR NbtRegisterEditor;
#endif // _NAT_NBT_H_