audk/NetworkPkg/Ip6Dxe/Ip6Route.c

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/** @file
The functions and routines to handle the route caches and route table.
Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "Ip6Impl.h"
/**
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
)
{
UINT32 Prefix1;
UINT32 Prefix2;
Prefix1 = *((UINT32 *) ((UINTN *) (Ip1)));
Prefix2 = *((UINT32 *) ((UINTN *) (Ip2)));
return ((UINT32) (Prefix1 ^ Prefix2) % IP6_ROUTE_CACHE_HASH_SIZE);
}
/**
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 an optional parameter
that may be NULL.
@return NULL if 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
)
{
IP6_ROUTE_ENTRY *RtEntry;
RtEntry = AllocateZeroPool (sizeof (IP6_ROUTE_ENTRY));
if (RtEntry == NULL) {
return NULL;
}
RtEntry->RefCnt = 1;
RtEntry->Flag = 0;
RtEntry->PrefixLength = PrefixLength;
if (Destination != NULL) {
IP6_COPY_ADDRESS (&RtEntry->Destination, Destination);
}
if (GatewayAddress != NULL) {
IP6_COPY_ADDRESS (&RtEntry->NextHop, GatewayAddress);
}
return RtEntry;
}
/**
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
)
{
ASSERT ((RtEntry != NULL) && (RtEntry->RefCnt > 0));
if (--RtEntry->RefCnt == 0) {
FreePool (RtEntry);
}
}
/**
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
@return 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
)
{
LIST_ENTRY *Entry;
IP6_ROUTE_ENTRY *RtEntry;
INTN Index;
ASSERT (Destination != NULL || NextHop != NULL);
RtEntry = NULL;
for (Index = IP6_PREFIX_NUM - 1; Index >= 0; Index--) {
NET_LIST_FOR_EACH (Entry, &RtTable->RouteArea[Index]) {
RtEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_ENTRY, Link);
if (Destination != NULL) {
if (NetIp6IsNetEqual (Destination, &RtEntry->Destination, RtEntry->PrefixLength)) {
NET_GET_REF (RtEntry);
return RtEntry;
}
} else if (NextHop != NULL) {
if (NetIp6IsNetEqual (NextHop, &RtEntry->NextHop, RtEntry->PrefixLength)) {
NET_GET_REF (RtEntry);
return RtEntry;
}
}
}
}
return NULL;
}
/**
Allocate and initialize a 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 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
)
{
IP6_ROUTE_CACHE_ENTRY *RtCacheEntry;
RtCacheEntry = AllocatePool (sizeof (IP6_ROUTE_CACHE_ENTRY));
if (RtCacheEntry == NULL) {
return NULL;
}
RtCacheEntry->RefCnt = 1;
RtCacheEntry->Tag = Tag;
IP6_COPY_ADDRESS (&RtCacheEntry->Destination, Dst);
IP6_COPY_ADDRESS (&RtCacheEntry->Source, Src);
IP6_COPY_ADDRESS (&RtCacheEntry->NextHop, GateWay);
return RtCacheEntry;
}
/**
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
)
{
ASSERT (RtCacheEntry->RefCnt > 0);
if (--RtCacheEntry->RefCnt == 0) {
FreePool (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, the pointer
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
)
{
LIST_ENTRY *Entry;
IP6_ROUTE_CACHE_ENTRY *RtCacheEntry;
UINT32 Index;
Index = IP6_ROUTE_CACHE_HASH (Dest, Src);
NET_LIST_FOR_EACH (Entry, &RtTable->Cache.CacheBucket[Index]) {
RtCacheEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_CACHE_ENTRY, Link);
if (EFI_IP6_EQUAL (Dest, &RtCacheEntry->Destination)&& EFI_IP6_EQUAL (Src, &RtCacheEntry->Source)) {
NET_GET_REF (RtCacheEntry);
return RtCacheEntry;
}
}
return NULL;
}
/**
Build an 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
)
{
LIST_ENTRY *Entry;
IP6_ROUTE_ENTRY *RtEntry;
EFI_IP6_ROUTE_TABLE *EfiTable;
UINT32 Count;
INT32 Index;
ASSERT (EfiRouteCount != NULL);
Count = RouteTable->TotalNum;
*EfiRouteCount = Count;
if ((EfiRouteTable == NULL) || (Count == 0)) {
return EFI_SUCCESS;
}
if (*EfiRouteTable == NULL) {
*EfiRouteTable = AllocatePool (sizeof (EFI_IP6_ROUTE_TABLE) * Count);
if (*EfiRouteTable == NULL) {
return EFI_OUT_OF_RESOURCES;
}
}
EfiTable = *EfiRouteTable;
//
// Copy the route entry to EFI route table.
//
Count = 0;
for (Index = IP6_PREFIX_NUM - 1; Index >= 0; Index--) {
NET_LIST_FOR_EACH (Entry, &(RouteTable->RouteArea[Index])) {
RtEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_ENTRY, Link);
Ip6CopyAddressByPrefix (
&EfiTable[Count].Destination,
&RtEntry->Destination,
RtEntry->PrefixLength
);
IP6_COPY_ADDRESS (&EfiTable[Count].Gateway, &RtEntry->NextHop);
EfiTable[Count].PrefixLength = RtEntry->PrefixLength;
Count++;
}
}
ASSERT (Count == RouteTable->TotalNum);
return EFI_SUCCESS;
}
/**
Create an empty route table. This 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
)
{
IP6_ROUTE_TABLE *RtTable;
UINT32 Index;
RtTable = AllocatePool (sizeof (IP6_ROUTE_TABLE));
if (RtTable == NULL) {
return NULL;
}
RtTable->RefCnt = 1;
RtTable->TotalNum = 0;
for (Index = 0; Index < IP6_PREFIX_NUM; Index++) {
InitializeListHead (&RtTable->RouteArea[Index]);
}
for (Index = 0; Index < IP6_ROUTE_CACHE_HASH_SIZE; Index++) {
InitializeListHead (&RtTable->Cache.CacheBucket[Index]);
RtTable->Cache.CacheNum[Index] = 0;
}
return RtTable;
}
/**
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
)
{
LIST_ENTRY *Entry;
LIST_ENTRY *Next;
IP6_ROUTE_ENTRY *RtEntry;
IP6_ROUTE_CACHE_ENTRY *RtCacheEntry;
UINT32 Index;
ASSERT (RtTable->RefCnt > 0);
if (--RtTable->RefCnt > 0) {
return ;
}
//
// Free all the route table entry and its route cache.
//
for (Index = 0; Index < IP6_PREFIX_NUM; Index++) {
NET_LIST_FOR_EACH_SAFE (Entry, Next, &RtTable->RouteArea[Index]) {
RtEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_ENTRY, Link);
RemoveEntryList (Entry);
Ip6FreeRouteEntry (RtEntry);
}
}
for (Index = 0; Index < IP6_ROUTE_CACHE_HASH_SIZE; Index++) {
NET_LIST_FOR_EACH_SAFE (Entry, Next, &RtTable->Cache.CacheBucket[Index]) {
RtCacheEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_CACHE_ENTRY, Link);
RemoveEntryList (Entry);
Ip6FreeRouteCacheEntry (RtCacheEntry);
}
}
FreePool (RtTable);
}
/**
Remove all the cache entries bearing the Tag. When a route cache
entry is created, it is tagged with the address of route entry
from which it is spawned. When a route entry is deleted, the cache
entries spawned from it are also deleted.
@param[in] RtCache Route cache to remove the entries from.
@param[in] Tag The Tag of the entries to remove.
**/
VOID
Ip6PurgeRouteCache (
IN IP6_ROUTE_CACHE *RtCache,
IN UINTN Tag
)
{
LIST_ENTRY *Entry;
LIST_ENTRY *Next;
IP6_ROUTE_CACHE_ENTRY *RtCacheEntry;
UINT32 Index;
for (Index = 0; Index < IP6_ROUTE_CACHE_HASH_SIZE; Index++) {
NET_LIST_FOR_EACH_SAFE (Entry, Next, &RtCache->CacheBucket[Index]) {
RtCacheEntry = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_CACHE_ENTRY, Link);
if (RtCacheEntry->Tag == Tag) {
RemoveEntryList (Entry);
Ip6FreeRouteCacheEntry (RtCacheEntry);
}
}
}
}
/**
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
)
{
LIST_ENTRY *ListHead;
LIST_ENTRY *Entry;
IP6_ROUTE_ENTRY *Route;
ListHead = &RtTable->RouteArea[PrefixLength];
//
// First check whether the route exists
//
NET_LIST_FOR_EACH (Entry, ListHead) {
Route = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_ENTRY, Link);
if (NetIp6IsNetEqual (Destination, &Route->Destination, PrefixLength) &&
EFI_IP6_EQUAL (GatewayAddress, &Route->NextHop)) {
return EFI_ACCESS_DENIED;
}
}
//
// Create a route entry and insert it to the route area.
//
Route = Ip6CreateRouteEntry (Destination, PrefixLength, GatewayAddress);
if (Route == NULL) {
return EFI_OUT_OF_RESOURCES;
}
if (NetIp6IsUnspecifiedAddr (GatewayAddress)) {
Route->Flag = IP6_DIRECT_ROUTE;
}
InsertHeadList (ListHead, &Route->Link);
RtTable->TotalNum++;
return EFI_SUCCESS;
}
/**
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 The route entry was successfully removed.
@retval EFI_NOT_FOUND There is no route entry in the table with that
property.
**/
EFI_STATUS
Ip6DelRoute (
IN OUT IP6_ROUTE_TABLE *RtTable,
IN EFI_IPv6_ADDRESS *Destination,
IN UINT8 PrefixLength,
IN EFI_IPv6_ADDRESS *GatewayAddress
)
{
LIST_ENTRY *ListHead;
LIST_ENTRY *Entry;
LIST_ENTRY *Next;
IP6_ROUTE_ENTRY *Route;
UINT32 TotalNum;
ListHead = &RtTable->RouteArea[PrefixLength];
TotalNum = RtTable->TotalNum;
NET_LIST_FOR_EACH_SAFE (Entry, Next, ListHead) {
Route = NET_LIST_USER_STRUCT (Entry, IP6_ROUTE_ENTRY, Link);
if (Destination != NULL && !NetIp6IsNetEqual (Destination, &Route->Destination, PrefixLength)) {
continue;
}
if (GatewayAddress != NULL && !EFI_IP6_EQUAL (GatewayAddress, &Route->NextHop)) {
continue;
}
Ip6PurgeRouteCache (&RtTable->Cache, (UINTN) Route);
RemoveEntryList (Entry);
Ip6FreeRouteEntry (Route);
ASSERT (RtTable->TotalNum > 0);
RtTable->TotalNum--;
}
return TotalNum == RtTable->TotalNum ? EFI_NOT_FOUND : EFI_SUCCESS;
}
/**
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 it failed to route the packet. Otherwise, a route cache
entry that can be used to route packets.
**/
IP6_ROUTE_CACHE_ENTRY *
Ip6Route (
IN IP6_SERVICE *IpSb,
IN EFI_IPv6_ADDRESS *Dest,
IN EFI_IPv6_ADDRESS *Src
)
{
IP6_ROUTE_TABLE *RtTable;
LIST_ENTRY *ListHead;
IP6_ROUTE_CACHE_ENTRY *RtCacheEntry;
IP6_ROUTE_ENTRY *RtEntry;
EFI_IPv6_ADDRESS NextHop;
UINT32 Index;
RtTable = IpSb->RouteTable;
ASSERT (RtTable != NULL);
//
// Search the destination cache in IP6_ROUTE_TABLE.
//
Index = IP6_ROUTE_CACHE_HASH (Dest, Src);
ListHead = &RtTable->Cache.CacheBucket[Index];
RtCacheEntry = Ip6FindRouteCache (RtTable, Dest, Src);
//
// If found, promote the cache entry to the head of the hash bucket.
//
if (RtCacheEntry != NULL) {
RemoveEntryList (&RtCacheEntry->Link);
InsertHeadList (ListHead, &RtCacheEntry->Link);
return RtCacheEntry;
}
//
// Search the route table for the most specific route
//
RtEntry = Ip6FindRouteEntry (RtTable, Dest, NULL);
if (RtEntry == NULL) {
return NULL;
}
//
// Found a route to the Dest, if it is a direct route, the packet
// will be send directly to the destination, such as for connected
// network. Otherwise, it is an indirect route, the packet will be
// send the next hop router.
//
if ((RtEntry->Flag & IP6_DIRECT_ROUTE) == IP6_DIRECT_ROUTE) {
IP6_COPY_ADDRESS (&NextHop, Dest);
} else {
IP6_COPY_ADDRESS (&NextHop, &RtEntry->NextHop);
}
Ip6FreeRouteEntry (RtEntry);
//
// Create a route cache entry, and tag it as spawned from this route entry
//
RtCacheEntry = Ip6CreateRouteCacheEntry (Dest, Src, &NextHop, (UINTN) RtEntry);
if (RtCacheEntry == NULL) {
return NULL;
}
InsertHeadList (ListHead, &RtCacheEntry->Link);
NET_GET_REF (RtCacheEntry);
RtTable->Cache.CacheNum[Index]++;
return RtCacheEntry;
}