[mnordell] 29533: Beginnings of enabling THREAD_SET_THREAD_TOKEN, to allow ROS to actually be shut down. Mostly skeleton and junk, but the basic infrastructure is at least in place.

Author: mnordell
Date: Fri Oct 12 16:04:50 2007
New Revision: 29533
URL: http://svn.reactos.org/svn/reactos?rev=29533&view=rev
Log:
Beginnings of enabling THREAD_SET_THREAD_TOKEN, to allow ROS to actually be shut down.
Mostly skeleton and junk, but the basic infrastructure is at least in place.
Modified:
    trunk/reactos/base/system/winlogon/sas.c
Modified: trunk/reactos/base/system/winlogon/sas.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/system/winlogon/sas.c…
==============================================================================
--- trunk/reactos/base/system/winlogon/sas.c (original)
+++ trunk/reactos/base/system/winlogon/sas.c Fri Oct 12 16:04:50 2007
@@ -312,14 +312,94 @@
        return 1;
 }
+
+static NTSTATUS
+CreateLogoffSecurityAttributes(
+       OUT PSECURITY_ATTRIBUTES* ppsa)
+{
+#if 1
+       DPRINT1("CreateSecurityAttributes needs implementation!\n");
+       *ppsa = 0;
+       return STATUS_UNSUCCESSFUL;
+#else
+       /* The following code is no only incomplete, it's a mess and uncompilable */
+       /* Still, it gives some ideas about data types and functions involved and */
+       /* required to set up a SECURITY_DESCRIPTOR for a SECURITY_ATTRIBUTES
+       /* instance for a thread, to allow that  thread to ImpersonateLoggedOnUser(). */
+       /* Specifically THREAD_SET_THREAD_TOKEN is required. */
+       PSECURITY_DESCRIPTOR psd = 0;
+       PSECURITY_ATTRIBUTES psa = 0;
+       ACL rgAcls[2];
+       EXPLICIT_ACCESS ea[2];
+
+       /* set up the required security attributes to be able to shut down */
+       psd = HeapAlloc(GetProcessHeap(), 0, SECURITY_DESCRIPTOR_MIN_LENGTH);
+       psa = HeapAlloc(GetProcessHeap(), 0, sizeof(SECURITY_ATTRIBUTES));
+       if (!psd || !psa)
+       {
+               DPRINT("Failed to allocate memory for a security
descriptor!\n");
+               return STATUS_NO_MEMORY;
+       }
+
+       if (!InitializeSecurityDescriptor(psd, SECURITY_DESCRIPTOR_REVISION))
+       {
+               HeapFree(GetProcessHeap(), 0, psd);
+               DPRINT("Failed to initialize security descriptor for logoff
thread!\n");
+               return STATUS_UNSUCCESSFUL;
+       }
+
+       // Initialize an EXPLICIT_ACCESS structure for an ACE.
+       // The ACE will allow this thread to log off (and shut down the system,
currently).
+       ZeroMemory(ea, sizeof(ea));
+       ea[0].grfAccessPermissions = KEY_READ;
+       ea[0].grfAccessMode = SET_ACCESS;
+       ea[0].grfInheritance= NO_INHERITANCE;
+       ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
+       ea[0].Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
+       ea[0].Trustee.ptstrName  = (LPTSTR) pEveryoneSID;
+
+       if (!SetSecurityDescriptorDacl(pSD,
+               TRUE,     // bDaclPresent flag
+               pACL,
+               FALSE))   // not a default DACL
+       {
+               DPRINT("SetSecurityDescriptorDacl Error %u\n", GetLastError());
+               HeapFree(GetProcessHeap(), 0, psd);
+               return STATUS_UNSUCCESSFUL;
+       }
+
+       psa->nLength = sizeof(sa);
+       psa->lpSecurityDescriptor = psd;
+       psa->bInheritHandle = FALSE;
+
+       *ppsa = psa;
+
+       return STATUS_SUCCESS;
+#endif
+}
+
+static void
+DestroyLogoffSecurityAttributes(
+       IN PSECURITY_ATTRIBUTES psa)
+{
+       if (psa)
+       {
+               HeapFree(GetProcessHeap(), 0, psa->lpSecurityDescriptor);
+               HeapFree(GetProcessHeap(), 0, psa);
+       }
+}
+
+
 static NTSTATUS
 HandleLogoff(
        IN OUT PWLSESSION Session,
        IN UINT Flags)
 {
        PLOGOFF_SHUTDOWN_DATA LSData;
+       PSECURITY_ATTRIBUTES psa;
        HANDLE hThread;
        DWORD exitCode;
+       NTSTATUS Status;
        DisplayStatusMessage(Session, Session->WinlogonDesktop, IDS_SAVEYOURSETTINGS);
@@ -333,8 +413,26 @@
        LSData->Flags = Flags;
        LSData->Session = Session;
+       Status = CreateLogoffSecurityAttributes(&psa);
+       if (!NT_SUCCESS(Status))
+       {
+               DPRINT("Failed to create a required security descriptor. Error
0x%08x\n", Status);
+#if 1
+               DPRINT("Attempting to continue without it.\n");
+#else
+               DPRINT("Aborting logoff\n");
+               HeapFree(GetProcessHeap(), 0, LSData);
+               return Status;
+#endif
+       }
+
        /* Run logoff thread */
-       hThread = CreateThread(NULL, 0, LogoffShutdownThread, (LPVOID)LSData, 0, NULL);
+       hThread = CreateThread(psa, 0, LogoffShutdownThread, (LPVOID)LSData, 0, NULL);
+
+       /* we're done with the SECURITY_DESCRIPTOR */
+       DestroyLogoffSecurityAttributes(psa);
+       psa = NULL;
+
        if (!hThread)
        {
                ERR("Unable to create logoff thread, error %lu\n",
GetLastError());