/** @file
  EFI IP6 route table and route cache table defintions.

  Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef __EFI_IP6_ROUTE_H__
#define __EFI_IP6_ROUTE_H__

#define IP6_DIRECT_ROUTE          0x00000001
#define IP6_PACKET_TOO_BIG        0x00000010

#define IP6_ROUTE_CACHE_HASH_SIZE 31
///
/// Max NO. of cache entry per hash bucket
///
#define IP6_ROUTE_CACHE_MAX       32

#define IP6_ROUTE_CACHE_HASH(Ip1, Ip2) Ip6RouteCacheHash ((Ip1), (Ip2))

typedef struct {
  LIST_ENTRY                Link;
  INTN                      RefCnt;
  UINT32                    Flag;
  UINT8                     PrefixLength;
  EFI_IPv6_ADDRESS          Destination;
  EFI_IPv6_ADDRESS          NextHop;
} IP6_ROUTE_ENTRY;

typedef struct {
  LIST_ENTRY                Link;
  INTN                      RefCnt;
  UINTN                     Tag;
  EFI_IPv6_ADDRESS          Destination;
  EFI_IPv6_ADDRESS          Source;
  EFI_IPv6_ADDRESS          NextHop;
} IP6_ROUTE_CACHE_ENTRY;

typedef struct {
  LIST_ENTRY                CacheBucket[IP6_ROUTE_CACHE_HASH_SIZE];
  UINT8                     CacheNum[IP6_ROUTE_CACHE_HASH_SIZE];
} IP6_ROUTE_CACHE;

//
// Each IP6 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 prefix length 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 _IP6_ROUTE_TABLE {
  INTN                      RefCnt;
  UINT32                    TotalNum;
  LIST_ENTRY                RouteArea[IP6_PREFIX_NUM];
  IP6_ROUTE_CACHE           Cache;
} IP6_ROUTE_TABLE;

/**
  This is the worker function for IP6_ROUTE_CACHE_HASH(). It calculates the value
  as the index of the route cache bucket according to the prefix of two IPv6 addresses.

  @param[in]  Ip1     The IPv6 address.
  @param[in]  Ip2     The IPv6 address.

  @return The hash value of the prefix of two IPv6 addresses.

**/
UINT32
Ip6RouteCacheHash (
  IN EFI_IPv6_ADDRESS       *Ip1,
  IN EFI_IPv6_ADDRESS       *Ip2
  );

/**
  Allocate and initialize an IP6 route cache entry.

  @param[in]  Dst           The destination address.
  @param[in]  Src           The source address.
  @param[in]  GateWay       The next hop address.
  @param[in]  Tag           The tag from the caller. This marks all the cache entries
                            spawned from one route table entry.

  @return NULL if it failed to allocate memory for the cache. Otherwise, point
          to the created route cache entry.

**/
IP6_ROUTE_CACHE_ENTRY *
Ip6CreateRouteCacheEntry (
  IN EFI_IPv6_ADDRESS       *Dst,
  IN EFI_IPv6_ADDRESS       *Src,
  IN EFI_IPv6_ADDRESS       *GateWay,
  IN UINTN                  Tag
  );

/**
  Free the route cache entry. It is reference counted.

  @param[in, out]  RtCacheEntry  The route cache entry to free.

**/
VOID
Ip6FreeRouteCacheEntry (
  IN OUT IP6_ROUTE_CACHE_ENTRY  *RtCacheEntry
  );

/**
  Find a route cache with the destination and source address. This is
  used by the ICMPv6 redirect messasge process.

  @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, point
          to the correct route cache entry.

**/
IP6_ROUTE_CACHE_ENTRY *
Ip6FindRouteCache (
  IN IP6_ROUTE_TABLE        *RtTable,
  IN EFI_IPv6_ADDRESS       *Dest,
  IN EFI_IPv6_ADDRESS       *Src
  );

/**
  Build a array of EFI_IP6_ROUTE_TABLE to be returned to the caller. The number
  of EFI_IP6_ROUTE_TABLE is also returned.

  @param[in]  RouteTable        The pointer of IP6_ROUTE_TABLE internal used.
  @param[out] EfiRouteCount     The number of returned route entries.
  @param[out] EfiRouteTable     The pointer to the array of EFI_IP6_ROUTE_TABLE.
                                If NULL, only the route entry count is returned.

  @retval EFI_SUCCESS           The EFI_IP6_ROUTE_TABLE successfully built.
  @retval EFI_OUT_OF_RESOURCES  Failed to allocate the memory for the route table.

**/
EFI_STATUS
Ip6BuildEfiRouteTable (
  IN IP6_ROUTE_TABLE        *RouteTable,
  OUT UINT32                *EfiRouteCount,
  OUT EFI_IP6_ROUTE_TABLE   **EfiRouteTable OPTIONAL
  );

/**
  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.

**/
IP6_ROUTE_TABLE *
Ip6CreateRouteTable (
  VOID
  );

/**
  Free the route table and its associated route cache. Route
  table is reference counted.

  @param[in, out]  RtTable      The route table to free.

**/
VOID
Ip6CleanRouteTable (
  IN OUT IP6_ROUTE_TABLE        *RtTable
  );

/**
  Allocate a route entry then initialize it with the Destination/PrefixLength
  and Gateway.

  @param[in]  Destination     The IPv6 destination address. This is an optional
                              parameter that may be NULL.
  @param[in]  PrefixLength    The destination network's prefix length.
  @param[in]  GatewayAddress  The next hop address. This is optional parameter
                              that may be NULL.

  @return NULL if it failed to allocate memeory. Otherwise, the newly created route entry.

**/
IP6_ROUTE_ENTRY *
Ip6CreateRouteEntry (
  IN EFI_IPv6_ADDRESS       *Destination    OPTIONAL,
  IN UINT8                  PrefixLength,
  IN EFI_IPv6_ADDRESS       *GatewayAddress OPTIONAL
  );

/**
  Search the route table for a most specific match to the Dst. It searches
  from the longest route area (prefix length == 128) to the shortest route area
  (default routes). In each route area, it will first search the instance's
  route table, then the default route table. This is required per the following
  requirements:
  1. IP search the route table for a most specific match.
  2. The local route entries have precedence over the default route entry.

  @param[in]  RtTable       The route table to search from.
  @param[in]  Destination   The destionation address to search. If NULL, search
                            the route table by NextHop.
  @param[in]  NextHop       The next hop address. If NULL, search the route table
                            by Destination.

  @return NULL if no route matches the Dst. Otherwise the point to the
          most specific route to the Dst.

**/
IP6_ROUTE_ENTRY *
Ip6FindRouteEntry (
  IN IP6_ROUTE_TABLE        *RtTable,
  IN EFI_IPv6_ADDRESS       *Destination OPTIONAL,
  IN EFI_IPv6_ADDRESS       *NextHop     OPTIONAL
  );

/**
  Free the route table entry. It is reference counted.

  @param[in, out]  RtEntry  The route entry to free.

**/
VOID
Ip6FreeRouteEntry (
  IN OUT IP6_ROUTE_ENTRY    *RtEntry
  );

/**
  Add a route entry to the route table. It is the help function for EfiIp6Routes.

  @param[in, out]  RtTable        Route table to add route to.
  @param[in]       Destination    The destination of the network.
  @param[in]       PrefixLength   The PrefixLength of the destination.
  @param[in]       GatewayAddress 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 was added successfully.

**/
EFI_STATUS
Ip6AddRoute (
  IN OUT IP6_ROUTE_TABLE    *RtTable,
  IN EFI_IPv6_ADDRESS       *Destination,
  IN UINT8                  PrefixLength,
  IN EFI_IPv6_ADDRESS       *GatewayAddress
  );

/**
  Remove a route entry and all the route caches spawn from it.
  It is the help function for EfiIp6Routes.

  @param[in, out] RtTable           The route table to remove the route from.
  @param[in]      Destination       The destination network.
  @param[in]      PrefixLength      The PrefixLength of the Destination.
  @param[in]      GatewayAddress    The next hop address.

  @retval EFI_SUCCESS           Successfully removed the route entry.
  @retval EFI_NOT_FOUND         There is no route entry in the table with that
                                properity.

**/
EFI_STATUS
Ip6DelRoute (
  IN OUT IP6_ROUTE_TABLE    *RtTable,
  IN EFI_IPv6_ADDRESS       *Destination,
  IN UINT8                  PrefixLength,
  IN EFI_IPv6_ADDRESS       *GatewayAddress
  );

/**
  Search the route table to route the packet. Return/create a route
  cache if there is a route to the destination.

  @param[in]  IpSb          The IP6 service data.
  @param[in]  Dest          The destination address to search for.
  @param[in]  Src           The source address to search for.

  @return NULL if failed to route packet. Otherwise, a route cache
          entry that can be used to route packet.

**/
IP6_ROUTE_CACHE_ENTRY *
Ip6Route (
  IN IP6_SERVICE            *IpSb,
  IN EFI_IPv6_ADDRESS       *Dest,
  IN EFI_IPv6_ADDRESS       *Src
  );

#endif
