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/** @file
EFI IP4 route table and route cache table definitions.
Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef __EFI_IP4_ROUTE_H__
#define __EFI_IP4_ROUTE_H__
#include "Ip4Common.h"
#define IP4_DIRECT_ROUTE 0x00000001
#define IP4_ROUTE_CACHE_HASH_VALUE 31
#define IP4_ROUTE_CACHE_MAX 64 // Max NO. of cache entry per hash bucket
#define IP4_ROUTE_CACHE_HASH(Dst, Src) (((Dst) ^ (Src)) % IP4_ROUTE_CACHE_HASH_VALUE)
///
/// The route entry in the route table. Dest/Netmask is the destion
/// network. The nexthop is the gateway to send the packet to in
/// order to reach the Dest/Netmask. If the Flag has IP4_DIRECT_ROUTE
/// on, the gateway is the destination of the IP packet itself. Route
/// enties of the connected network have the flag on.
///
typedef struct {
LIST_ENTRY Link;
INTN RefCnt;
IP4_ADDR Dest;
IP4_ADDR Netmask;
IP4_ADDR NextHop;
UINT32 Flag;
} IP4_ROUTE_ENTRY;
///
/// The route cache entry. The route cache entry is optional.
/// But it is necessary to support the ICMP redirect message.
/// Check Ip4ProcessIcmpRedirect for information.
///
/// The cache entry field Tag is used to tag all the route
/// cache entry spawned from a route table entry. This makes
/// it simple to delete all the route cache entries from a
/// to-be-deleted route entry.
///
typedef struct {
LIST_ENTRY Link;
INTN RefCnt;
IP4_ADDR Dest;
IP4_ADDR Src;
IP4_ADDR NextHop;
UINTN Tag;
} IP4_ROUTE_CACHE_ENTRY;
///
/// The route cache table is organized as a hash table. Each
/// IP4 route table has a embedded route cache. For now the
/// route cache and route table are binded together. But keep
/// the route cache a separated structure in case we want to
/// detach them later.
///
typedef struct {
LIST_ENTRY CacheBucket[IP4_ROUTE_CACHE_HASH_VALUE];
} IP4_ROUTE_CACHE;
///
/// Each IP4 instance has its own route table. Each ServiceBinding
/// instance has a default route table and default address.
///
/// All the route table entries with the same mask are linked
/// together in one route area. For example, RouteArea[0] contains
/// the default routes. A route table also contains a route cache.
///
typedef struct _IP4_ROUTE_TABLE IP4_ROUTE_TABLE;
struct _IP4_ROUTE_TABLE {
INTN RefCnt;
UINT32 TotalNum;
LIST_ENTRY RouteArea[IP4_MASK_NUM];
IP4_ROUTE_TABLE *Next;
IP4_ROUTE_CACHE Cache;
};
/**
Create an empty route table, includes its internal route cache
@return NULL if failed to allocate memory for the route table, otherwise
the point to newly created route table.
**/
IP4_ROUTE_TABLE *
Ip4CreateRouteTable (
VOID
);
/**
Free the route table and its associated route cache. Route
table is reference counted.
@param[in] RtTable The route table to free.
**/
VOID
Ip4FreeRouteTable (
IN IP4_ROUTE_TABLE *RtTable
);
/**
Add a route entry to the route table. All the IP4_ADDRs are in
host byte order.
@param[in, out] RtTable Route table to add route to
@param[in] Dest The destination of the network
@param[in] Netmask The netmask of the destination
@param[in] Gateway The next hop address
@retval EFI_ACCESS_DENIED The same route already exists
@retval EFI_OUT_OF_RESOURCES Failed to allocate memory for the entry
@retval EFI_SUCCESS The route is added successfully.
**/
EFI_STATUS
Ip4AddRoute (
IN OUT IP4_ROUTE_TABLE *RtTable,
IN IP4_ADDR Dest,
IN IP4_ADDR Netmask,
IN IP4_ADDR Gateway
);
/**
Remove a route entry and all the route caches spawn from it.
@param RtTable The route table to remove the route from
@param Dest The destination network
@param Netmask The netmask of the Dest
@param Gateway The next hop address
@retval EFI_SUCCESS The route entry is successfully removed
@retval EFI_NOT_FOUND There is no route entry in the table with that
property.
**/
EFI_STATUS
Ip4DelRoute (
IN OUT IP4_ROUTE_TABLE *RtTable,
IN IP4_ADDR Dest,
IN IP4_ADDR Netmask,
IN IP4_ADDR Gateway
);
/**
Find a route cache with the dst and src. This is used by ICMP
redirect message process. All kinds of redirect is treated as
host redirect according to RFC1122. So, only route cache entries
are modified according to the ICMP redirect message.
@param[in] RtTable The route table to search the cache for
@param[in] Dest The destination address
@param[in] Src The source address
@return NULL if no route entry to the (Dest, Src). Otherwise the point
to the correct route cache entry.
**/
IP4_ROUTE_CACHE_ENTRY *
Ip4FindRouteCache (
IN IP4_ROUTE_TABLE *RtTable,
IN IP4_ADDR Dest,
IN IP4_ADDR Src
);
/**
Free the route cache entry. It is reference counted.
@param RtCacheEntry The route cache entry to free.
**/
VOID
Ip4FreeRouteCacheEntry (
IN IP4_ROUTE_CACHE_ENTRY *RtCacheEntry
);
/**
Search the route table to route the packet. Return/create a route
cache if there is a route to the destination.
@param[in] RtTable The route table to search from
@param[in] Dest The destination address to search for
@param[in] Src The source address to search for
@param[in] SubnetMask The subnet mask of the Src address, this field is
used to check if the station is using /32 subnet.
@param[in] AlwaysTryDestAddr Always try to use the dest address as next hop even
though we can't find a matching route entry. This
field is only valid when using /32 subnet.
@return NULL if failed to route packet, otherwise a route cache
entry that can be used to route packet.
**/
IP4_ROUTE_CACHE_ENTRY *
Ip4Route (
IN IP4_ROUTE_TABLE *RtTable,
IN IP4_ADDR Dest,
IN IP4_ADDR Src,
IN IP4_ADDR SubnetMask,
IN BOOLEAN AlwaysTryDestAddr
);
/**
Build a EFI_IP4_ROUTE_TABLE to be returned to the caller of
GetModeData. The EFI_IP4_ROUTE_TABLE is clumsy to use in the
internal operation of the IP4 driver.
@param[in] IpInstance The IP4 child that requests the route table.
@retval EFI_SUCCESS The route table is successfully build
@retval EFI_OUT_OF_RESOURCES Failed to allocate the memory for the route table.
**/
EFI_STATUS
Ip4BuildEfiRouteTable (
IN IP4_PROTOCOL *IpInstance
);
#endif