/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
auctxt.c
Abstract:
Logon process context management services.
Author:
Jim Kelly (JimK) 7-May-1993
Revision History:
--*/
#include "ausrvp.h"
#include <windows.h>
///////////////////////////////////////////////////////////////////////////////
// //
// Global variables //
// //
///////////////////////////////////////////////////////////////////////////////
//
// This resource is used to gain exclusive access to the linked list
// of client context blocks.
//
static
RTL_RESOURCE
LsapAuClientContextLock;
static
LIST_ENTRY
LsapAuClientContextListHead;
///////////////////////////////////////////////////////////////////////////////
// //
// Exported Services //
// //
///////////////////////////////////////////////////////////////////////////////
NTSTATUS
LsapAuInitializeContextMgr(
VOID
)
/*++
Routine Description:
This routine initializes the global components of the client
context management services. This includes a initializing a
database lock and a list of client contexts.
Arguments:
None.
Return Value:
Only STATUS_SUCCESS is expected. But, if we encounter an error
initializing then the error we hit will be returned.
--*/
{
//
// Initialize the database lock
//
RtlInitializeResource(&LsapAuClientContextLock);
//
// Initialize the context list to be empty.
//
InitializeListHead( &LsapAuClientContextListHead );
return(STATUS_SUCCESS);
}
VOID
LsapAuAddClientContext(
PLSAP_LOGON_PROCESS Context
)
/*++
Routine Description:
This routine adds a new client context to the list of
valid logon process contexts.
After adding a new context, that context has been referenced
to allow the caller to continue using it. Therefore, the
caller is expected to dereference the context before completing
the LPC call.
This routine will initialize the Links and References fields
of the client context.
Details:
1) Locks the context database.
2) Set's the context's reference count to 2,
one for being on the context list, one because
the caller is using it. This means the caller
must call LsapAuDereferenceClientContext() after
adding the context.
3) Adds the context to the context list.
4) Unlocks the context database.
Arguments:
Context - Points to the client's request whose context
is to be added.
Return Value:
None.
--*/
{
BOOLEAN
Success;
//
// Acquire exclusive access to the context list
//
Success = RtlAcquireResourceExclusive( &LsapAuClientContextLock, TRUE );
ASSERT(Success);
//
// The reference count is set to 2. 1 to indicate it is on the
// valid context list, and one for the caller.
//
Context->References = 2;
//
// Add it to the list of contexts.
//
InsertHeadList( &LsapAuClientContextListHead, &Context->Links );
#ifdef LSAP_AU_TRACK_CONTEXT
DbgPrint("lsa (au): Adding client context 0x%lx\n", Context);
#endif //LSAP_AU_TRACK_CONTEXT
//
// Free the lock
//
RtlReleaseResource(&LsapAuClientContextLock);
return;
}
BOOLEAN
LsapAuReferenceClientContext(
PLSAP_CLIENT_REQUEST ClientRequest,
BOOLEAN RemoveContext,
PBOOLEAN TrustedClient
)
/*++
Routine Description:
This routine checks to see if the client request is from a currently
active client, and references the context if it is valid.
The caller may optionally request that the client's context be
removed from the list of valid contexts - preventing future
requests from finding this context.
For a client's context to be valid, the request's context value
must be on our list of active logon processes.
NOTE: We can't require the caller's ClientId to match that of the
caller that registered. This is because the LM Redirector
calls from random processes, but attaches to the process it
did the register from before calling. LPC considers the call
to have come from the random process, not the attatched
process, and so the client IDs don't match.
Datails:
1) Lock the context database and verifies that the
specified context is valid.
2) Increment the context's reference count.
3) If requested, remove the context from the
context list and decrement the reference count
(to indicate it is no longer on the list). This
prevents future lookups from finding the context.
4) Unlock the context database.
Arguments:
ClientRequest - Points to the client's request whose context
is to be referenced. This is not necessarily a complete
client request. However, the context pointer and the client
IDs are expected to be valid.
RemoveContext - This boolean value indicates whether the caller
wants the logon process's context to be removed from the list
of contexts. TRUE indicates the context is to be removed.
FALSE indicates the context is not to be removed.
Return Value:
TRUE - the context was found and was referenced.
FALSE - the context was not found.
--*/
{
BOOLEAN
Success;
PLIST_ENTRY
Next;
PLSAP_LOGON_PROCESS
Context;
//
// Acquire exclusive access to the context list
//
Success = RtlAcquireResourceExclusive( &LsapAuClientContextLock, TRUE );
ASSERT(Success);
//
// Now walk the list of contexts looking for a match.
//
Next = LsapAuClientContextListHead.Flink;
while (Next != &LsapAuClientContextListHead) {
if ((PVOID)Next ==(PVOID)(ClientRequest->LogonProcessContext)) {
Context = (PLSAP_LOGON_PROCESS)Next;
//
// Found a match ... reference this context
// (if the context is being removed, we would increment
// and then decrement the reference, so don't bother doing
// either - since they cancel each other out).
//
if (!RemoveContext) {
Context->References += 1;
} else {
RemoveEntryList( Next );
#ifdef LSAP_AU_TRACK_CONTEXT
DbgPrint("lsa (au): Removing client context 0x%lx\n", Context);
#endif //LSAP_AU_TRACK_CONTEXT
}
RtlReleaseResource(&LsapAuClientContextLock);
*TrustedClient = Context->TrustedClient;
return(TRUE);
}
//
// Wasn't this one, move on to the next one.
//
Next = Next->Flink;
}
//
// No match found
//
#ifdef LSAP_AU_TRACK_CONTEXT
DbgPrint("lsa\\server: (au) Call from unknown client.\n");
Next = (PLIST_ENTRY)ClientRequest->LogonProcessContext;
DbgPrint(" Context (0x%lx)\n", Next);
DbgPrint(" Context Entry (0x%lx)\n", Next);
DbgPrint(" Flink: 0x%lx\n", Next->Flink );
DbgPrint(" Blink: 0x%lx\n", Next->Blink );
DbgPrint(" Ref: %d\n", ((PLSAP_LOGON_PROCESS)Next)->References);
DbgPrint(" Proc: 0x%lx\n", ((PLSAP_LOGON_PROCESS)Next)->ClientProcess);
DbgPrint(" Comm: 0x%lx\n", ((PLSAP_LOGON_PROCESS)Next)->CommPort);
Next = LsapAuClientContextListHead.Flink;
DbgPrint(" Active context list head: (%lx, %lx)\n",
LsapAuClientContextListHead.Flink,
LsapAuClientContextListHead.Blink);
while (Next != &LsapAuClientContextListHead) {
DbgPrint(" Context Entry (0x%lx)\n", Next);
DbgPrint(" Flink: 0x%lx\n", Next->Flink );
DbgPrint(" Blink: 0x%lx\n", Next->Blink );
DbgPrint(" Ref: %d\n", ((PLSAP_LOGON_PROCESS)Next)->References);
DbgPrint(" Proc: 0x%lx\n", ((PLSAP_LOGON_PROCESS)Next)->ClientProcess);
DbgPrint(" Comm: 0x%lx\n", ((PLSAP_LOGON_PROCESS)Next)->CommPort);
Next = Next->Flink;
}
#endif //LSAP_AU_TRACK_CONTEXT
ClientRequest->Request->ReturnedStatus = STATUS_INVALID_PARAMETER;
RtlReleaseResource(&LsapAuClientContextLock);
return(FALSE);
}
VOID
LsapAuDereferenceClientContext(
PLSAP_LOGON_PROCESS Context
)
/*++
Routine Description:
This routine decrements the specified context's reference count.
If the reference count drops to zero, then the context is run-down.
Details:
1) Locks the context database.
2) Decrements the context's reference count.
3) If the reference count drops to zero, then
rundown the logon process (close open handles
and free the context block memory).
4) Unlocks the context database.
Arguments:
Context - Points to the context to be dereferenced.
Return Value:
None.
--*/
{
BOOLEAN
Success;
NTSTATUS
IgnoreStatus;
//
// Acquire exclusive access to the context list
//
Success = RtlAcquireResourceExclusive( &LsapAuClientContextLock, TRUE );
ASSERT(Success);
//
// Decrement the reference count
//
ASSERT( Context->References >= 1 );
Context->References -= 1;
//
// If the count dropped to zero, then run-down the context
//
if (Context->References == 0) {
#ifdef LSAP_AU_TRACK_CONTEXT
DbgPrint("lsa (au): Deleting client context 0x%lx\n", Context);
#endif //LSAP_AU_TRACK_CONTEXT
#if DBG
//
// For debug systems, walk the list of contexts looking for a match.
// If we find this context on the list, then ASSERT.
//
{
PLIST_ENTRY
Next;
Next = LsapAuClientContextListHead.Flink;
while (Next != &LsapAuClientContextListHead) {
ASSERT((PVOID)Next != (PVOID)Context);
Next = Next->Flink;
}
}
#endif //DBG
IgnoreStatus = LsapAuRundownLogonProcess( Context );
}
RtlReleaseResource(&LsapAuClientContextLock);
return;
}