MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Route.h

   1 /** @file
   2   EFI IP4 route table and route cache table defintions.
   3
   4 Copyright (c) 2005 - 2006, Intel Corporation.<BR>
   5 All rights reserved. This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #ifndef __EFI_IP4_ROUTE_H__
  16 #define __EFI_IP4_ROUTE_H__
  17
  18 #include "Ip4Common.h"
  19
  20 typedef enum {
  21   IP4_DIRECT_ROUTE      = 0x00000001,
  22
  23   IP4_ROUTE_CACHE_HASH  = 31,
  24   IP4_ROUTE_CACHE_MAX   = 64  // Max NO. of cache entry per hash bucket
  25 } IP4_ROUTE_ENUM_TYPES;
  26
  27 #define IP4_ROUTE_CACHE_HASH(Dst, Src)  (((Dst) ^ (Src)) % IP4_ROUTE_CACHE_HASH)
  28
  29 ///
  30 /// The route entry in the route table. Dest/Netmask is the destion
  31 /// network. The nexthop is the gateway to send the packet to in
  32 /// order to reach the Dest/Netmask. If the Flag has IP4_DIRECT_ROUTE
  33 /// on, the gateway is the destination of the IP packet itself. Route
  34 /// enties of the connected network have the flag on.
  35 ///
  36 typedef struct {
  37   LIST_ENTRY                Link;
  38   INTN                      RefCnt;
  39   IP4_ADDR                  Dest;
  40   IP4_ADDR                  Netmask;
  41   IP4_ADDR                  NextHop;
  42   UINT32                    Flag;
  43 } IP4_ROUTE_ENTRY;
  44
  45 ///
  46 /// The route cache entry. The route cache entry is optional.
  47 /// But it is necessary to support the ICMP redirect message.
  48 /// Check Ip4ProcessIcmpRedirect for information.
  49 ///
  50 /// The cache entry field Tag is used to tag all the route
  51 /// cache entry spawned from a route table entry. This makes
  52 /// it simple to delete all the route cache entries from a
  53 /// to-be-deleted route entry.
  54 ///
  55 typedef struct {
  56   LIST_ENTRY                Link;
  57   INTN                      RefCnt;
  58   IP4_ADDR                  Dest;
  59   IP4_ADDR                  Src;
  60   IP4_ADDR                  NextHop;
  61   UINTN                     Tag;
  62 } IP4_ROUTE_CACHE_ENTRY;
  63
  64 ///
  65 /// The route cache table is organized as a hash table. Each
  66 /// IP4 route table has a embedded route cache. For now the
  67 /// route cache and route table are binded togehter. But keep
  68 /// the route cache a seperated structure in case we want to
  69 /// detach them later.
  70 ///
  71 typedef struct {
  72   LIST_ENTRY                CacheBucket[IP4_ROUTE_CACHE_HASH];
  73 } IP4_ROUTE_CACHE;
  74
  75 ///
  76 /// Each IP4 instance has its own route table. Each ServiceBinding
  77 /// instance has a default route table and default address.
  78 ///
  79 /// All the route table entries with the same mask are linked
  80 /// together in one route area. For example, RouteArea[0] contains
  81 /// the default routes. A route table also contains a route cache.
  82 ///
  83 typedef struct _IP4_ROUTE_TABLE IP4_ROUTE_TABLE;
  84
  85 struct _IP4_ROUTE_TABLE {
  86   INTN                      RefCnt;
  87   UINT32                    TotalNum;
  88   LIST_ENTRY                RouteArea[IP4_MASK_NUM];
  89   IP4_ROUTE_TABLE           *Next;
  90   IP4_ROUTE_CACHE           Cache;
  91 };
  92
  93 /**
  94   Create an empty route table, includes its internal route cache
  95
  96   @return NULL if failed to allocate memory for the route table, otherwise
  97           the point to newly created route table.
  98
  99 **/
 100 IP4_ROUTE_TABLE *
 101 Ip4CreateRouteTable (
 102   VOID
 103   );
 104
 105 /**
 106   Free the route table and its associated route cache. Route
 107   table is reference counted.
 108
 109   @param[in]  RtTable               The route table to free.
 110
 111 **/
 112 VOID
 113 Ip4FreeRouteTable (
 114   IN IP4_ROUTE_TABLE        *RtTable
 115   );
 116
 117 /**
 118   Add a route entry to the route table. All the IP4_ADDRs are in
 119   host byte order.
 120
 121   @param[in, out]  RtTable      Route table to add route to
 122   @param[in]       Dest         The destination of the network
 123   @param[in]       Netmask      The netmask of the destination
 124   @param[in]       Gateway      The next hop address
 125
 126   @retval EFI_ACCESS_DENIED     The same route already exists
 127   @retval EFI_OUT_OF_RESOURCES  Failed to allocate memory for the entry
 128   @retval EFI_SUCCESS           The route is added successfully.
 129
 130 **/
 131 EFI_STATUS
 132 Ip4AddRoute (
 133   IN OUT IP4_ROUTE_TABLE        *RtTable,
 134   IN     IP4_ADDR               Dest,
 135   IN     IP4_ADDR               Netmask,
 136   IN     IP4_ADDR               Gateway
 137   );
 138
 139 /**
 140   Remove a route entry and all the route caches spawn from it.
 141
 142   @param  RtTable           The route table to remove the route from
 143   @param  Dest              The destination network
 144   @param  Netmask           The netmask of the Dest
 145   @param  Gateway           The next hop address
 146
 147   @retval EFI_SUCCESS           The route entry is successfully removed
 148   @retval EFI_NOT_FOUND         There is no route entry in the table with that
 149                                 properity.
 150
 151 **/
 152 EFI_STATUS
 153 Ip4DelRoute (
 154   IN OUT IP4_ROUTE_TABLE      *RtTable,
 155   IN     IP4_ADDR             Dest,
 156   IN     IP4_ADDR             Netmask,
 157   IN     IP4_ADDR             Gateway
 158   );
 159
 160 /**
 161   Find a route cache with the dst and src. This is used by ICMP
 162   redirect messasge process. All kinds of redirect is treated as
 163   host redirect according to RFC1122. So, only route cache entries
 164   are modified according to the ICMP redirect message.
 165
 166   @param[in]  RtTable               The route table to search the cache for
 167   @param[in]  Dest                  The destination address
 168   @param[in]  Src                   The source address
 169
 170   @return NULL if no route entry to the (Dest, Src). Otherwise the point
 171           to the correct route cache entry.
 172
 173 **/
 174 IP4_ROUTE_CACHE_ENTRY *
 175 Ip4FindRouteCache (
 176   IN IP4_ROUTE_TABLE        *RtTable,
 177   IN IP4_ADDR               Dest,
 178   IN IP4_ADDR               Src
 179   );
 180
 181 /**
 182   Free the route cache entry. It is reference counted.
 183
 184   @param  RtCacheEntry          The route cache entry to free.
 185
 186 **/
 187 VOID
 188 Ip4FreeRouteCacheEntry (
 189   IN IP4_ROUTE_CACHE_ENTRY  *RtCacheEntry
 190   );
 191
 192 /**
 193   Search the route table to route the packet. Return/create a route
 194   cache if there is a route to the destination.
 195
 196   @param[in]  RtTable               The route table to search from
 197   @param[in]  Dest                  The destination address to search for
 198   @param[in]  Src                   The source address to search for
 199
 200   @return NULL if failed to route packet, otherwise a route cache
 201           entry that can be used to route packet.
 202
 203 **/
 204 IP4_ROUTE_CACHE_ENTRY *
 205 Ip4Route (
 206   IN IP4_ROUTE_TABLE        *RtTable,
 207   IN IP4_ADDR               Dest,
 208   IN IP4_ADDR               Src
 209   );
 210
 211 /**
 212   Build a EFI_IP4_ROUTE_TABLE to be returned to the caller of
 213   GetModeData. The EFI_IP4_ROUTE_TABLE is clumsy to use in the
 214   internal operation of the IP4 driver.
 215
 216   @param[in]  IpInstance        The IP4 child that requests the route table.
 217
 218   @retval EFI_SUCCESS           The route table is successfully build
 219   @retval EFI_OUT_OF_RESOURCES  Failed to allocate the memory for the rotue table.
 220
 221 **/
 222 EFI_STATUS
 223 Ip4BuildEfiRouteTable (
 224   IN IP4_PROTOCOL           *IpInstance
 225   );
 226 #endif