--- /dev/null
+/*
+ * COPYRIGHT: See COPYING in the top level directory
+ * PROJECT: ReactOS TCP/IP protocol driver
+ * FILE: network/router.c
+ * PURPOSE: IP routing subsystem
+ * PROGRAMMERS: Casper S. Hornstrup (chorns@users.sourceforge.net)
+ * NOTES:
+ * This file holds authoritative routing information.
+ * Information queries on the route table should be handled here.
+ * This information should always override the route cache info.
+ * REVISIONS:
+ * CSH 01/08-2000 Created
+ */
+
+#include "precomp.h"
+
+LIST_ENTRY FIBListHead;
+KSPIN_LOCK FIBLock;
+
+void RouterDumpRoutes() {
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+ PNEIGHBOR_CACHE_ENTRY NCE;
+
+ TI_DbgPrint(DEBUG_ROUTER,("Dumping Routes\n"));
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+
+ NCE = Current->Router;
+
+ TI_DbgPrint(DEBUG_ROUTER,("Examining FIBE %x\n", Current));
+ TI_DbgPrint(DEBUG_ROUTER,("... NetworkAddress %s\n", A2S(&Current->NetworkAddress)));
+ TI_DbgPrint(DEBUG_ROUTER,("... NCE->Address . %s\n", A2S(&NCE->Address)));
+
+ CurrentEntry = NextEntry;
+ }
+
+ TI_DbgPrint(DEBUG_ROUTER,("Dumping Routes ... Done\n"));
+}
+
+VOID FreeFIB(
+ PVOID Object)
+/*
+ * FUNCTION: Frees an forward information base object
+ * ARGUMENTS:
+ * Object = Pointer to an forward information base structure
+ */
+{
+ ExFreePoolWithTag(Object, FIB_TAG);
+}
+
+
+VOID DestroyFIBE(
+ PFIB_ENTRY FIBE)
+/*
+ * FUNCTION: Destroys an forward information base entry
+ * ARGUMENTS:
+ * FIBE = Pointer to FIB entry
+ * NOTES:
+ * The forward information base lock must be held when called
+ */
+{
+ TI_DbgPrint(DEBUG_ROUTER, ("Called. FIBE (0x%X).\n", FIBE));
+
+ /* Unlink the FIB entry from the list */
+ RemoveEntryList(&FIBE->ListEntry);
+
+ /* And free the FIB entry */
+ FreeFIB(FIBE);
+}
+
+
+VOID DestroyFIBEs(
+ VOID)
+/*
+ * FUNCTION: Destroys all forward information base entries
+ * NOTES:
+ * The forward information base lock must be held when called
+ */
+{
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+
+ /* Search the list and remove every FIB entry we find */
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+ /* Destroy the FIB entry */
+ DestroyFIBE(Current);
+ CurrentEntry = NextEntry;
+ }
+}
+
+
+UINT CountFIBs(PIP_INTERFACE IF) {
+ UINT FibCount = 0;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+ if (Current->Router->Interface == IF)
+ FibCount++;
+ CurrentEntry = NextEntry;
+ }
+
+ return FibCount;
+}
+
+
+UINT CopyFIBs( PIP_INTERFACE IF, PFIB_ENTRY Target ) {
+ UINT FibCount = 0;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+ if (Current->Router->Interface == IF)
+ {
+ Target[FibCount] = *Current;
+ FibCount++;
+ }
+ CurrentEntry = NextEntry;
+ }
+
+ return FibCount;
+}
+
+
+UINT CommonPrefixLength(
+ PIP_ADDRESS Address1,
+ PIP_ADDRESS Address2)
+/*
+ * FUNCTION: Computes the length of the longest prefix common to two addresses
+ * ARGUMENTS:
+ * Address1 = Pointer to first address
+ * Address2 = Pointer to second address
+ * NOTES:
+ * The two addresses must be of the same type
+ * RETURNS:
+ * Length of longest common prefix
+ */
+{
+ PUCHAR Addr1, Addr2;
+ UINT Size;
+ UINT i, j;
+ UINT Bitmask;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Called. Address1 (0x%X) Address2 (0x%X).\n", Address1, Address2));
+
+ /*TI_DbgPrint(DEBUG_ROUTER, ("Target (%s) \n", A2S(Address1)));*/
+ /*TI_DbgPrint(DEBUG_ROUTER, ("Adapter (%s).\n", A2S(Address2)));*/
+
+ if (Address1->Type == IP_ADDRESS_V4)
+ Size = sizeof(IPv4_RAW_ADDRESS);
+ else
+ Size = sizeof(IPv6_RAW_ADDRESS);
+
+ Addr1 = (PUCHAR)&Address1->Address.IPv4Address;
+ Addr2 = (PUCHAR)&Address2->Address.IPv4Address;
+
+ /* Find first non-matching byte */
+ for (i = 0; i < Size && Addr1[i] == Addr2[i]; i++);
+ if( i == Size ) return 8 * i;
+
+ /* Find first non-matching bit */
+ Bitmask = 0x80;
+ for (j = 0; (Addr1[i] & Bitmask) == (Addr2[i] & Bitmask); j++)
+ Bitmask >>= 1;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Returning %d\n", 8 * i + j));
+
+ return 8 * i + j;
+}
+
+
+PFIB_ENTRY RouterAddRoute(
+ PIP_ADDRESS NetworkAddress,
+ PIP_ADDRESS Netmask,
+ PNEIGHBOR_CACHE_ENTRY Router,
+ UINT Metric)
+/*
+ * FUNCTION: Adds a route to the Forward Information Base (FIB)
+ * ARGUMENTS:
+ * NetworkAddress = Pointer to address of network
+ * Netmask = Pointer to netmask of network
+ * Router = Pointer to NCE of router to use
+ * Metric = Cost of this route
+ * RETURNS:
+ * Pointer to FIB entry if the route was added, NULL if not
+ * NOTES:
+ * The FIB entry references the NetworkAddress, Netmask and
+ * the NCE of the router. The caller is responsible for providing
+ * these references
+ */
+{
+ PFIB_ENTRY FIBE;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Called. NetworkAddress (0x%X) Netmask (0x%X) "
+ "Router (0x%X) Metric (%d).\n", NetworkAddress, Netmask, Router, Metric));
+
+ TI_DbgPrint(DEBUG_ROUTER, ("NetworkAddress (%s) Netmask (%s) Router (%s).\n",
+ A2S(NetworkAddress),
+ A2S(Netmask),
+ A2S(&Router->Address)));
+
+ FIBE = ExAllocatePoolWithTag(NonPagedPool, sizeof(FIB_ENTRY), FIB_TAG);
+ if (!FIBE) {
+ TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
+ return NULL;
+ }
+
+ RtlCopyMemory( &FIBE->NetworkAddress, NetworkAddress,
+ sizeof(FIBE->NetworkAddress) );
+ RtlCopyMemory( &FIBE->Netmask, Netmask,
+ sizeof(FIBE->Netmask) );
+ FIBE->Router = Router;
+ FIBE->Metric = Metric;
+
+ /* Add FIB to the forward information base */
+ TcpipInterlockedInsertTailList(&FIBListHead, &FIBE->ListEntry, &FIBLock);
+
+ return FIBE;
+}
+
+
+PNEIGHBOR_CACHE_ENTRY RouterGetRoute(PIP_ADDRESS Destination)
+/*
+ * FUNCTION: Finds a router to use to get to Destination
+ * ARGUMENTS:
+ * Destination = Pointer to destination address (NULL means don't care)
+ * RETURNS:
+ * Pointer to NCE for router, NULL if none was found
+ * NOTES:
+ * If found the NCE is referenced
+ */
+{
+ KIRQL OldIrql;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+ UCHAR State;
+ UINT Length, BestLength = 0, MaskLength;
+ PNEIGHBOR_CACHE_ENTRY NCE, BestNCE = NULL;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Called. Destination (0x%X)\n", Destination));
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Destination (%s)\n", A2S(Destination)));
+
+ TcpipAcquireSpinLock(&FIBLock, &OldIrql);
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+
+ NCE = Current->Router;
+ State = NCE->State;
+
+ Length = CommonPrefixLength(Destination, &Current->NetworkAddress);
+ MaskLength = AddrCountPrefixBits(&Current->Netmask);
+
+ TI_DbgPrint(DEBUG_ROUTER,("This-Route: %s (Sharing %d bits)\n",
+ A2S(&NCE->Address), Length));
+
+ if(Length >= MaskLength && (Length > BestLength || !BestNCE) &&
+ ((!(State & NUD_STALE) && !(State & NUD_INCOMPLETE)) || !BestNCE)) {
+ /* This seems to be a better router */
+ BestNCE = NCE;
+ BestLength = Length;
+ TI_DbgPrint(DEBUG_ROUTER,("Route selected\n"));
+ }
+
+ CurrentEntry = NextEntry;
+ }
+
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+
+ if( BestNCE ) {
+ TI_DbgPrint(DEBUG_ROUTER,("Routing to %s\n", A2S(&BestNCE->Address)));
+ } else {
+ TI_DbgPrint(DEBUG_ROUTER,("Packet won't be routed\n"));
+ }
+
+ return BestNCE;
+}
+
+PNEIGHBOR_CACHE_ENTRY RouteGetRouteToDestination(PIP_ADDRESS Destination)
+/*
+ * FUNCTION: Locates an RCN describing a route to a destination address
+ * ARGUMENTS:
+ * Destination = Pointer to destination address to find route to
+ * RCN = Address of pointer to an RCN
+ * RETURNS:
+ * Status of operation
+ * NOTES:
+ * The RCN is referenced for the caller. The caller is responsible
+ * for dereferencing it after use
+ */
+{
+ PNEIGHBOR_CACHE_ENTRY NCE = NULL;
+ PIP_INTERFACE Interface;
+
+ TI_DbgPrint(DEBUG_RCACHE, ("Called. Destination (0x%X)\n", Destination));
+
+ TI_DbgPrint(DEBUG_RCACHE, ("Destination (%s)\n", A2S(Destination)));
+
+#if 0
+ TI_DbgPrint(MIN_TRACE, ("Displaying tree (before).\n"));
+ PrintTree(RouteCache);
+#endif
+
+ /* Check if the destination is on-link */
+ Interface = FindOnLinkInterface(Destination);
+ if (Interface) {
+ /* The destination address is on-link. Check our neighbor cache */
+ NCE = NBFindOrCreateNeighbor(Interface, Destination, FALSE);
+ } else {
+ /* Destination is not on any subnets we're on. Find a router to use */
+ NCE = RouterGetRoute(Destination);
+ }
+
+ if( NCE )
+ TI_DbgPrint(DEBUG_ROUTER,("Interface->MTU: %d\n", NCE->Interface->MTU));
+
+ return NCE;
+}
+
+VOID RouterRemoveRoutesForInterface(PIP_INTERFACE Interface)
+{
+ KIRQL OldIrql;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+
+ TcpipAcquireSpinLock(&FIBLock, &OldIrql);
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+
+ if (Interface == Current->Router->Interface)
+ DestroyFIBE(Current);
+
+ CurrentEntry = NextEntry;
+ }
+
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+}
+
+NTSTATUS RouterRemoveRoute(PIP_ADDRESS Target, PIP_ADDRESS Router)
+/*
+ * FUNCTION: Removes a route from the Forward Information Base (FIB)
+ * ARGUMENTS:
+ * Target: The machine or network targeted by the route
+ * Router: The router used to pass the packet to the destination
+ *
+ * Searches the FIB and removes a route matching the indicated parameters.
+ */
+{
+ KIRQL OldIrql;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+ BOOLEAN Found = FALSE;
+ PNEIGHBOR_CACHE_ENTRY NCE;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Called\n"));
+ TI_DbgPrint(DEBUG_ROUTER, ("Deleting Route From: %s\n", A2S(Router)));
+ TI_DbgPrint(DEBUG_ROUTER, (" To: %s\n", A2S(Target)));
+
+ TcpipAcquireSpinLock(&FIBLock, &OldIrql);
+
+ RouterDumpRoutes();
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+
+ NCE = Current->Router;
+
+ if( AddrIsEqual( &Current->NetworkAddress, Target ) &&
+ AddrIsEqual( &NCE->Address, Router ) ) {
+ Found = TRUE;
+ break;
+ }
+
+ Current = NULL;
+ CurrentEntry = NextEntry;
+ }
+
+ if( Found ) {
+ TI_DbgPrint(DEBUG_ROUTER, ("Deleting route\n"));
+ DestroyFIBE( Current );
+ }
+
+ RouterDumpRoutes();
+
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Leaving\n"));
+
+ return Found ? STATUS_SUCCESS : STATUS_UNSUCCESSFUL;
+}
+
+
+PFIB_ENTRY RouterCreateRoute(
+ PIP_ADDRESS NetworkAddress,
+ PIP_ADDRESS Netmask,
+ PIP_ADDRESS RouterAddress,
+ PIP_INTERFACE Interface,
+ UINT Metric)
+/*
+ * FUNCTION: Creates a route with IPv4 addresses as parameters
+ * ARGUMENTS:
+ * NetworkAddress = Address of network
+ * Netmask = Netmask of network
+ * RouterAddress = Address of router to use
+ * NTE = Pointer to NTE to use
+ * Metric = Cost of this route
+ * RETURNS:
+ * Pointer to FIB entry if the route was created, NULL if not.
+ * The FIB entry references the NTE. The caller is responsible
+ * for providing this reference
+ */
+{
+ KIRQL OldIrql;
+ PLIST_ENTRY CurrentEntry;
+ PLIST_ENTRY NextEntry;
+ PFIB_ENTRY Current;
+ PNEIGHBOR_CACHE_ENTRY NCE;
+
+ TcpipAcquireSpinLock(&FIBLock, &OldIrql);
+
+ CurrentEntry = FIBListHead.Flink;
+ while (CurrentEntry != &FIBListHead) {
+ NextEntry = CurrentEntry->Flink;
+ Current = CONTAINING_RECORD(CurrentEntry, FIB_ENTRY, ListEntry);
+
+ NCE = Current->Router;
+
+ if(AddrIsEqual(NetworkAddress, &Current->NetworkAddress) &&
+ AddrIsEqual(Netmask, &Current->Netmask) &&
+ NCE->Interface == Interface)
+ {
+ TI_DbgPrint(DEBUG_ROUTER,("Attempting to add duplicate route to %s\n", A2S(NetworkAddress)));
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+ return NULL;
+ }
+
+ CurrentEntry = NextEntry;
+ }
+
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+
+ /* The NCE references RouterAddress. The NCE is referenced for us */
+ NCE = NBFindOrCreateNeighbor(Interface, RouterAddress, TRUE);
+
+ if (!NCE) {
+ /* Not enough free resources */
+ return NULL;
+ }
+
+ return RouterAddRoute(NetworkAddress, Netmask, NCE, Metric);
+}
+
+
+NTSTATUS RouterStartup(
+ VOID)
+/*
+ * FUNCTION: Initializes the routing subsystem
+ * RETURNS:
+ * Status of operation
+ */
+{
+ TI_DbgPrint(DEBUG_ROUTER, ("Called.\n"));
+
+ /* Initialize the Forward Information Base */
+ InitializeListHead(&FIBListHead);
+ TcpipInitializeSpinLock(&FIBLock);
+
+ return STATUS_SUCCESS;
+}
+
+
+NTSTATUS RouterShutdown(
+ VOID)
+/*
+ * FUNCTION: Shuts down the routing subsystem
+ * RETURNS:
+ * Status of operation
+ */
+{
+ KIRQL OldIrql;
+
+ TI_DbgPrint(DEBUG_ROUTER, ("Called.\n"));
+
+ /* Clear Forward Information Base */
+ TcpipAcquireSpinLock(&FIBLock, &OldIrql);
+ DestroyFIBEs();
+ TcpipReleaseSpinLock(&FIBLock, OldIrql);
+
+ return STATUS_SUCCESS;
+}
+
+/* EOF */
projects / reactos.git / blobdiff