348 lines
8.8 KiB
C
348 lines
8.8 KiB
C
/*++
|
|
|
|
Copyright(c) 1999-2000 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
brdgtbl.c
|
|
|
|
Abstract:
|
|
|
|
Ethernet MAC level bridge.
|
|
MAC Table section
|
|
|
|
Author:
|
|
|
|
Mark Aiken
|
|
(original bridge by Jameel Hyder)
|
|
|
|
Environment:
|
|
|
|
Kernel mode driver
|
|
|
|
Revision History:
|
|
|
|
Feb 2000 - Original version
|
|
|
|
--*/
|
|
|
|
#define NDIS_MINIPORT_DRIVER
|
|
#define NDIS50_MINIPORT 1
|
|
#define NDIS_WDM 1
|
|
|
|
#pragma warning( push, 3 )
|
|
#include <ndis.h>
|
|
#include <ntddk.h>
|
|
#pragma warning( pop )
|
|
|
|
#include <netevent.h>
|
|
|
|
#include "bridge.h"
|
|
#include "brdgtbl.h"
|
|
|
|
// ===========================================================================
|
|
//
|
|
// PRIVATE DECLARATIONS
|
|
//
|
|
// ===========================================================================
|
|
|
|
// Default age at which entries are removed from table
|
|
#define DEFAULT_MAX_TBL_AGE (300 * 1000) // 5 minutes in milliseconds
|
|
|
|
//
|
|
// Default cap on forwarding table size
|
|
//
|
|
#define DEFAULT_MAX_TBL_MEMORY (500 * 1024) // 500K in bytes
|
|
|
|
//
|
|
// Registry values that hold our config values
|
|
//
|
|
const PWCHAR gMaxTableMemoryParameterName = L"MaxTableMemory";
|
|
|
|
// Structure of a table entry
|
|
typedef struct _MAC_FWDTABLE_ENTRY
|
|
{
|
|
|
|
HASH_TABLE_ENTRY hte;
|
|
PADAPT pAdapt;
|
|
|
|
} MAC_FWDTABLE_ENTRY, *PMAC_FWDTABLE_ENTRY;
|
|
|
|
// ===========================================================================
|
|
//
|
|
// GLOBALS
|
|
//
|
|
// ===========================================================================
|
|
|
|
// The MAC forwarding table
|
|
PHASH_TABLE gMACForwardingTable;
|
|
|
|
// Number of hash buckets (needs to be N^2 for the hash function to work)
|
|
#define NUM_HASH_BUCKETS 256
|
|
|
|
// ===========================================================================
|
|
//
|
|
// PRIVATE FUNCTIONS
|
|
//
|
|
// ===========================================================================
|
|
|
|
// These would all be inlines except that we have to pass pointers to them
|
|
|
|
//
|
|
// Our hash function for Ethernet addresses. Uses the lower bits of byte #4.
|
|
//
|
|
// This hash function requires NUM_HASH_BUCKETS buckets; don't change this
|
|
// without updating the number of hash buckets available.
|
|
//
|
|
ULONG
|
|
BrdgTblHashAddress(
|
|
IN PUCHAR pAddr
|
|
)
|
|
{
|
|
return *((pAddr)+ETH_LENGTH_OF_ADDRESS-2) & (NUM_HASH_BUCKETS-1);
|
|
}
|
|
|
|
//
|
|
// Returns TRUE if the pAdapt field in two entries match
|
|
//
|
|
BOOLEAN
|
|
BrdgTblEntriesMatch(
|
|
IN PHASH_TABLE_ENTRY pEntry,
|
|
IN PVOID pAdapt
|
|
)
|
|
{
|
|
return (BOOLEAN)(((PMAC_FWDTABLE_ENTRY)pEntry)->pAdapt == (PADAPT)pAdapt);
|
|
}
|
|
|
|
//
|
|
// Copies the MAC address from a table entry to a data buffer.
|
|
//
|
|
VOID
|
|
BrdgTblCopyEntries(
|
|
PHASH_TABLE_ENTRY pEntry,
|
|
PUCHAR pDest
|
|
)
|
|
{
|
|
PMAC_FWDTABLE_ENTRY pMACEntry = (PMAC_FWDTABLE_ENTRY)pEntry;
|
|
|
|
// The MAC address is the key. Copy it to the target buffer.
|
|
ETH_COPY_NETWORK_ADDRESS( pDest, pMACEntry->hte.key );
|
|
}
|
|
|
|
// ===========================================================================
|
|
//
|
|
// PUBLIC FUNCTIONS
|
|
//
|
|
// ===========================================================================
|
|
|
|
NTSTATUS
|
|
BrdgTblDriverInit()
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Load-time initialization function
|
|
|
|
Arguments:
|
|
|
|
None
|
|
|
|
Return Value:
|
|
|
|
Status of initialization. A return code != STATUS_SUCCESS aborts driver load.
|
|
|
|
--*/
|
|
{
|
|
NTSTATUS NtStatus;
|
|
ULONG MaxMemory, MaxEntries;
|
|
|
|
NtStatus = BrdgReadRegDWord( &gRegistryPath, gMaxTableMemoryParameterName, &MaxMemory );
|
|
|
|
if( NtStatus != STATUS_SUCCESS )
|
|
{
|
|
DBGPRINT(GENERAL, ("Failed to read MaxTableMemory value: %08x\n", NtStatus));
|
|
MaxMemory = DEFAULT_MAX_TBL_MEMORY;
|
|
DBGPRINT(GENERAL, ( "Using DEFAULT maximum memory of %i\n", MaxMemory ));
|
|
}
|
|
|
|
MaxEntries = MaxMemory / sizeof(MAC_FWDTABLE_ENTRY);
|
|
DBGPRINT(GENERAL, ( "Forwarding table cap set at %i entries (%iK of memory)\n", MaxEntries, MaxMemory / 1024 ));
|
|
|
|
gMACForwardingTable = BrdgHashCreateTable( BrdgTblHashAddress, NUM_HASH_BUCKETS, sizeof(MAC_FWDTABLE_ENTRY),
|
|
MaxEntries, DEFAULT_MAX_TBL_AGE, DEFAULT_MAX_TBL_AGE,
|
|
ETH_LENGTH_OF_ADDRESS );
|
|
|
|
if( gMACForwardingTable == NULL )
|
|
{
|
|
DBGPRINT(FWD, ("FAILED TO ALLOCATE MAC TABLE!\n"));
|
|
return STATUS_INSUFFICIENT_RESOURCES;
|
|
}
|
|
else
|
|
{
|
|
return STATUS_SUCCESS;
|
|
}
|
|
}
|
|
|
|
//
|
|
// Creates a new table entry associating the given MAC address with the given
|
|
// adapter, or refreshes an existing entry.
|
|
//
|
|
VOID
|
|
BrdgTblNoteAddress(
|
|
IN PUCHAR pAddr,
|
|
IN PADAPT pAdapt
|
|
)
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Creates a new table entry associating the given MAC address with the given
|
|
adapter, or refreshes an existing entry.
|
|
|
|
Arguments:
|
|
|
|
pAddr The MAC address to look up
|
|
pAdapt The adapter to associate it with
|
|
|
|
Return Value:
|
|
|
|
None
|
|
|
|
--*/
|
|
{
|
|
PMAC_FWDTABLE_ENTRY pEntry;
|
|
BOOLEAN bIsNewEntry;
|
|
LOCK_STATE LockState;
|
|
|
|
// Refuse to record non-unicast addresses
|
|
if( ETH_IS_MULTICAST(pAddr) )
|
|
{
|
|
THROTTLED_DBGPRINT(FWD, ("## BRIDGE ## Not recording multicast address in BrdgTblNoteAddress\n"));
|
|
return;
|
|
}
|
|
|
|
pEntry = (PMAC_FWDTABLE_ENTRY)BrdgHashRefreshOrInsert( gMACForwardingTable, pAddr, &bIsNewEntry, &LockState);
|
|
|
|
if( pEntry != NULL )
|
|
{
|
|
// Regardless of whether or not this is a new table entry or an existing one,
|
|
// just cram in the adapter pointer with an interlocked instruction.
|
|
InterlockedExchangePointer( &pEntry->pAdapt, pAdapt );
|
|
|
|
// Since the function came back != NULL, we must release the table lock.
|
|
NdisReleaseReadWriteLock( &gMACForwardingTable->tableLock, &LockState );
|
|
}
|
|
}
|
|
|
|
|
|
PADAPT
|
|
BrdgTblFindTargetAdapter(
|
|
IN PUCHAR pAddr
|
|
)
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Locates the adapter corresponding to a particular MAC address.
|
|
|
|
If an adapter is found, this function returns a PADAPT pointer after
|
|
having INCREMENTED THE REFCOUNT for that adapter. This is to ensure that
|
|
the adapter is not unbound until the caller is done using it. The caller
|
|
should be sure to decrement the PADAPT's refcount when it is done using
|
|
the pointer.
|
|
|
|
Arguments:
|
|
|
|
pAddr The MAC address to look up
|
|
|
|
Return Value:
|
|
|
|
A pointer to the ADAPT structure describing the adapter associated with
|
|
the given MAC address, with its refcount INCREMENTED, or NULL if an
|
|
entry associating the given MAC address to an adapter was not found.
|
|
|
|
--*/
|
|
{
|
|
PMAC_FWDTABLE_ENTRY pEntry;
|
|
LOCK_STATE LockState;
|
|
PADAPT pAdapt = NULL;
|
|
|
|
pEntry = (PMAC_FWDTABLE_ENTRY)BrdgHashFindEntry( gMACForwardingTable, pAddr, &LockState );
|
|
|
|
if( pEntry != NULL )
|
|
{
|
|
// Read this once since it can be changed even while we hold the RW lock
|
|
pAdapt = pEntry->pAdapt;
|
|
SAFEASSERT( pAdapt != NULL );
|
|
|
|
//
|
|
// Increment this adapter's refcount while inside the RW lock for the table.
|
|
// This lets us close a race condition window for unbinding the adapter;
|
|
// the caller will hang on to the returned PADAPT after we return, leading
|
|
// to problems if the adapter is unbound before our caller is done using
|
|
// the PADAPT structure.
|
|
//
|
|
BrdgAcquireAdapterInLock( pAdapt );
|
|
|
|
// Release the table lock
|
|
NdisReleaseReadWriteLock( &gMACForwardingTable->tableLock, &LockState );
|
|
}
|
|
|
|
return pAdapt;
|
|
}
|
|
|
|
//
|
|
// This function cleans all the adapters from the tables (this is in the case of a GPO changing
|
|
// our bridging settings)
|
|
//
|
|
|
|
VOID
|
|
BrdgTblScrubAllAdapters()
|
|
{
|
|
PADAPT pAdapt = NULL;
|
|
LOCK_STATE LockStateMACTable;
|
|
LOCK_STATE LockStateAdapterList;
|
|
|
|
//
|
|
// We don't want the table to be modified while we're doing this, and we also don't want an adapter
|
|
// to go away while we're enumerating the list of adapters.
|
|
//
|
|
NdisAcquireReadWriteLock(&gMACForwardingTable->tableLock, FALSE /*Read Only*/, &LockStateMACTable);
|
|
NdisAcquireReadWriteLock(&gAdapterListLock, FALSE /*Read Only*/, &LockStateAdapterList);
|
|
|
|
for( pAdapt = gAdapterList; pAdapt != NULL; pAdapt = pAdapt->Next )
|
|
{
|
|
// Scrub adapter from the table.
|
|
BrdgTblScrubAdapter(pAdapt);
|
|
}
|
|
|
|
NdisReleaseReadWriteLock(&gAdapterListLock, &LockStateAdapterList);
|
|
NdisReleaseReadWriteLock(&gMACForwardingTable->tableLock, &LockStateMACTable);
|
|
}
|
|
|
|
VOID
|
|
BrdgTblCleanup()
|
|
/*++
|
|
|
|
Routine Description:
|
|
|
|
Unload-time orderly shutdown
|
|
|
|
This function is guaranteed to be called exactly once
|
|
|
|
Arguments:
|
|
|
|
None
|
|
|
|
Return Value:
|
|
|
|
None
|
|
|
|
--*/
|
|
{
|
|
SAFEASSERT( gMACForwardingTable != NULL );
|
|
BrdgHashFreeHashTable( gMACForwardingTable );
|
|
gMACForwardingTable = NULL;
|
|
}
|
|
|