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Diffstat (limited to '')
| -rw-r--r-- | private/ntos/tdi/isn/fwd/filterif.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/private/ntos/tdi/isn/fwd/filterif.c b/private/ntos/tdi/isn/fwd/filterif.c new file mode 100644 index 000000000..f1fa584a3 --- /dev/null +++ b/private/ntos/tdi/isn/fwd/filterif.c @@ -0,0 +1,211 @@ +/*++ + +Copyright (c) 1995 Microsoft Corporation + +Module Name: + + ntos\tdi\isn\fwd\filterif.c + +Abstract: + IPX Forwarder driver interface with filter driver + + +Author: + + Vadim Eydelman + +Revision History: + +--*/ + +#include "precomp.h" + + // Filter driver entry points +IPX_FLT_BIND_INPUT FltBindInput = {NULL, NULL}; + // Protects access to filter driver contexts +RW_LOCK FltLock; + + +/*++ + D o F i l t e r + +Routine Description: + + Calls filter driver entry point while holding reader access + to interface contexts + +Arguments: + ipxHdr - pointer to packet header + ipxHdrLength - size of the header buffer (must be at least 30) + ifInContext - context associated with interface on which packet + was received + ifOutContext - context associated with interface on which packet + will be sent +Return Value: + FILTER_PERMIT - packet should be passed on by the forwarder + FILTER_DENY - packet should be dropped + +--*/ +FILTER_ACTION +DoFilter ( + IN PUCHAR ipxHdr, + IN ULONG ipxHdrLength, + IN PVOID ifInContext, + IN PVOID ifOutContex + ) { + RWCOOKIE cookie; + FILTER_ACTION result; + AcquireReaderAccess (&FltLock, cookie); + result = FltBindInput.FilterHandler (ipxHdr, + ipxHdrLength, + ifInContext, + ifOutContex); + ReleaseReaderAccess (&FltLock, cookie); + return result; +} + +/*++ + D o I n t e r f a c e D e l e t e d + +Routine Description: + Resets interface contexts and calls filter dirver entry point + making sure that all no one holds reader access to filter driver + interface contexts +Arguments: + ifCB - interface to be deleted +Return Value: + None + +--*/ +VOID +DoInterfaceDeleted ( + PINTERFACE_CB ifCB + ) { + PVOID inContext = ifCB->ICB_FilterInContext, + outContext = ifCB->ICB_FilterOutContext; + ifCB->ICB_FilterInContext = NO_FILTER_CONTEXT; + ifCB->ICB_FilterOutContext = NO_FILTER_CONTEXT; + WaitForAllReaders (&FltLock); + FltBindInput.InterfaceDeletedHandler(inContext, + outContext); +} + +/*++ + S e t I f I n C o n t e x t + +Routine Description: + Associates filter driver context with + the packets received on the interface +Arguments: + InterfaceIndex - index of the interface + ifInContext - filter driver context +Return Value: + STATUS_SUCCESS - context associated ok + STATUS_UNSUCCESSFUL - interface does not exist +--*/ +NTSTATUS +SetIfInContext ( + IN ULONG InterfaceIndex, + IN PVOID ifInContext + ) { + PINTERFACE_CB ifCB; + NTSTATUS status = STATUS_SUCCESS; + + if (EnterForwarder ()) { + ifCB = GetInterfaceReference (InterfaceIndex); + if (ifCB!=NULL) { + ifCB->ICB_FilterInContext = ifInContext; + WaitForAllReaders (&FltLock); + } + else + status = STATUS_UNSUCCESSFUL; + LeaveForwarder (); + } + return status; +} + +/*++ + S e t I f O u t C o n t e x t + +Routine Description: + Associates filter driver context with + the packets sent on the interface +Arguments: + InterfaceIndex - index of the interface + ifOutContext - filter driver context +Return Value: + STATUS_SUCCESS - context associated ok + STATUS_UNSUCCESSFUL - interface does not exist +--*/ +NTSTATUS +SetIfOutContext ( + IN ULONG InterfaceIndex, + IN PVOID ifOutContext + ) { + PINTERFACE_CB ifCB; + NTSTATUS status = STATUS_SUCCESS; + + if (EnterForwarder ()) { + ifCB = GetInterfaceReference (InterfaceIndex); + if (ifCB!=NULL) { + ifCB->ICB_FilterOutContext = ifOutContext; + WaitForAllReaders (&FltLock); + } + else + status = STATUS_UNSUCCESSFUL; + LeaveForwarder (); + } + return status; +} + +/*++ + B i n d F i l t e r D r i v e r + +Routine Description: + Exchanges entry points with filter driver +Arguments: + bindInput - filter driver entry points + bindOutput - forwarder driver entry points +Return Value: + None +--*/ +VOID +BindFilterDriver ( + IN PIPX_FLT_BIND_INPUT bindInput, + OUT PIPX_FLT_BIND_OUTPUT bindOutput + ) { + memcpy (&FltBindInput, bindInput, sizeof (IPX_FLT_BIND_INPUT)); + bindOutput->Size = sizeof (IPX_FLT_BIND_OUTPUT); + bindOutput->SetIfInContextHandler = SetIfInContext; + bindOutput->SetIfOutContextHandler = SetIfOutContext; + InitializeRWLock (&FltLock); +} + +/*++ + U n b i n d F i l t e r D r i v e r + +Routine Description: + Resets locally stored filter driver entry points + and resets filter driver contexts on all interfaces +Arguments: + None +Return Value: + None +--*/ +VOID +UnbindFilterDriver ( + VOID + ) { + PINTERFACE_CB ifCB = NULL; + FltBindInput.FilterHandler = NULL; + FltBindInput.InterfaceDeletedHandler = NULL; + + while ((ifCB=GetNextInterfaceReference (ifCB))!=NULL) { + ifCB->ICB_FilterInContext = NO_FILTER_CONTEXT; + ifCB->ICB_FilterOutContext = NO_FILTER_CONTEXT; + } + InternalInterface->ICB_FilterInContext = NO_FILTER_CONTEXT; + InternalInterface->ICB_FilterOutContext = NO_FILTER_CONTEXT; + WaitForAllReaders (&FltLock); +} + |