backport of some file readable/writable fixes from HEAD

4 files changed, 249 insertions, 14 deletions

diff --git a/ChangeLog b/ChangeLog
index 173123a..96987e8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2006-03-10  Vince Darley  <vincentdarley@sourceforge.net>
+
+	* win/tclWin32Dll.c: 
+	* win/tclWinInt.h: 
+	* win/tclWinFile.c: backported some fixes from HEAD relating
+	to 'file readable' and 'file writable', but main 'file writable' 
+	bug still outstanding.
+
 2006-03-07  Don Porter  <dgp@users.sourceforge.net>
 
 	*** 8.4.13 TAGGED FOR RELEASE ***
diff --git a/win/tclWin32Dll.c b/win/tclWin32Dll.c
index 1e4a0b3..c107396 100644
--- a/win/tclWin32Dll.c
+++ b/win/tclWin32Dll.c
@@ -9,7 +9,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclWin32Dll.c,v 1.24.2.8 2005/11/03 11:53:59 patthoyts Exp $
+ * RCS: @(#) $Id: tclWin32Dll.c,v 1.24.2.9 2006/03/10 10:35:24 vincentdarley Exp $
  */
 
 #include "tclWinInt.h"
@@ -118,6 +118,11 @@ static TclWinProcs asciiProcs = {
     (int (__cdecl*)(CONST TCHAR *, struct _utimbuf *)) _utime,
     NULL,
     NULL,
+    /* getLongPathNameProc */
+    NULL,
+    /* Security SDK - not available on 95,98,ME */
+    NULL, NULL, NULL, NULL, NULL, NULL,
+    /* ReadConsole and WriteConsole */
     (BOOL (WINAPI *)(HANDLE, LPVOID, DWORD, LPDWORD, LPVOID)) ReadConsoleA,
     (BOOL (WINAPI *)(HANDLE, const VOID*, DWORD, LPDWORD, LPVOID)) WriteConsoleA    
 };
@@ -169,6 +174,11 @@ static TclWinProcs unicodeProcs = {
     (int (__cdecl*)(CONST TCHAR *, struct _utimbuf *)) _wutime,
     NULL,
     NULL,
+    /* getLongPathNameProc */
+    NULL,
+    /* Security SDK - will be filled in on NT,XP,2000,2003 */
+    NULL, NULL, NULL, NULL, NULL, NULL,
+    /* ReadConsole and WriteConsole */
     (BOOL (WINAPI *)(HANDLE, LPVOID, DWORD, LPDWORD, LPVOID)) ReadConsoleW,
     (BOOL (WINAPI *)(HANDLE, const VOID*, DWORD, LPDWORD, LPVOID)) WriteConsoleW
 };
@@ -692,6 +702,36 @@ TclWinSetInterfaces(
 		  "GetVolumeNameForVolumeMountPointW");
 		FreeLibrary(hInstance);
 	    }
+	    hInstance = LoadLibraryA("advapi32");
+	    if (hInstance != NULL) {
+		tclWinProcs->getFileSecurityProc = (BOOL (WINAPI *)(
+			LPCTSTR lpFileName,
+			SECURITY_INFORMATION RequestedInformation,
+			PSECURITY_DESCRIPTOR pSecurityDescriptor,
+			DWORD nLength, LPDWORD lpnLengthNeeded))
+			GetProcAddress(hInstance, "GetFileSecurityW");
+		tclWinProcs->impersonateSelfProc = (BOOL (WINAPI *) (
+			SECURITY_IMPERSONATION_LEVEL ImpersonationLevel))
+			GetProcAddress(hInstance, "ImpersonateSelf");
+		tclWinProcs->openThreadTokenProc = (BOOL (WINAPI *) (
+			HANDLE ThreadHandle, DWORD DesiredAccess,
+			BOOL OpenAsSelf, PHANDLE TokenHandle))
+			GetProcAddress(hInstance, "OpenThreadToken");
+		tclWinProcs->revertToSelfProc = (BOOL (WINAPI *) (void))
+			GetProcAddress(hInstance, "RevertToSelf");
+		tclWinProcs->mapGenericMaskProc = (VOID (WINAPI *) (
+			PDWORD AccessMask, PGENERIC_MAPPING GenericMapping))
+			GetProcAddress(hInstance, "MapGenericMask");
+		tclWinProcs->accessCheckProc = (BOOL (WINAPI *)(
+			PSECURITY_DESCRIPTOR pSecurityDescriptor,
+			HANDLE ClientToken, DWORD DesiredAccess,
+			PGENERIC_MAPPING GenericMapping,
+			PPRIVILEGE_SET PrivilegeSet,
+			LPDWORD PrivilegeSetLength, LPDWORD GrantedAccess,
+			LPBOOL AccessStatus)) GetProcAddress(hInstance,
+			"AccessCheck");
+		FreeLibrary(hInstance);
+	    }
 	}
     } else {
 	tclWinProcs = &asciiProcs;
@@ -710,6 +750,7 @@ TclWinSetInterfaces(
 		  (HANDLE (WINAPI *)(CONST TCHAR*, UINT,
 		  LPVOID, UINT, LPVOID, DWORD)) GetProcAddress(hInstance, 
 		  "FindFirstFileExA");
+		tclWinProcs->getLongPathNameProc = NULL;
 		tclWinProcs->getVolumeNameForVMPProc = 
 		  (BOOL (WINAPI *)(CONST TCHAR*, TCHAR*, 
 		  DWORD)) GetProcAddress(hInstance, 
diff --git a/win/tclWinFile.c b/win/tclWinFile.c
index 4171e67..f4d882b 100644
--- a/win/tclWinFile.c
+++ b/win/tclWinFile.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclWinFile.c,v 1.44.2.13 2005/11/15 16:41:41 kennykb Exp $
+ * RCS: @(#) $Id: tclWinFile.c,v 1.44.2.14 2006/03/10 10:35:25 vincentdarley Exp $
  */
 
 //#define _WIN32_WINNT  0x0500
@@ -1334,16 +1334,22 @@ NativeAccess(
 
     if (attr == 0xffffffff) {
 	/*
-	 * File doesn't exist. 
+	 * File doesn't exist.
 	 */
 
 	TclWinConvertError(GetLastError());
 	return -1;
     }
 
-    if ((mode & W_OK) && (attr & FILE_ATTRIBUTE_READONLY)) {
+    if ((mode & W_OK) 
+      && !(attr & FILE_ATTRIBUTE_DIRECTORY)
+	/* && (tclWinProcs->getFileSecurityProc == NULL) */
+      && (attr & FILE_ATTRIBUTE_READONLY)) {
 	/*
-	 * File is not writable.
+	 * We don't have the advanced 'getFileSecurityProc', and
+	 * our attributes say the file is not writable.  If we
+	 * do have 'getFileSecurityProc', we'll do a more
+	 * robust XP-related check below.
 	 */
 
 	Tcl_SetErrno(EACCES);
@@ -1351,20 +1357,174 @@ NativeAccess(
     }
 
     if (mode & X_OK) {
-	if (attr & FILE_ATTRIBUTE_DIRECTORY) {
+	if (!(attr & FILE_ATTRIBUTE_DIRECTORY) && !NativeIsExec(nativePath)) {
 	    /*
-	     * Directories are always executable. 
+	     * It's not a directory and doesn't have the correct extension.
+	     * Therefore it can't be executable
+	     */
+
+	    Tcl_SetErrno(EACCES);
+	    return -1;
+	}
+    }
+
+    /*
+     * It looks as if the permissions are ok, but if we are on NT, 2000 or XP,
+     * we have a more complex permissions structure so we try to check that.
+     * The code below is remarkably complex for such a simple thing as finding
+     * what permissions the OS has set for a file.
+     *
+     * If we are simply checking for file existence, then we don't need all
+     * these complications (which are really quite slow: with this code 'file
+     * readable' is 5-6 times slower than 'file exists').
+     */
+
+    if ((mode != F_OK) && (tclWinProcs->getFileSecurityProc != NULL)) {
+	SECURITY_DESCRIPTOR *sdPtr = NULL;
+	unsigned long size;
+	GENERIC_MAPPING genMap;
+	HANDLE hToken = NULL;
+	DWORD desiredAccess = 0;
+	DWORD grantedAccess = 0;
+	BOOL accessYesNo = FALSE;
+	PRIVILEGE_SET privSet;
+	DWORD privSetSize = sizeof(PRIVILEGE_SET);
+	int error;
+
+	/*
+	 * First find out how big the buffer needs to be
+	 */
+
+	size = 0;
+	(*tclWinProcs->getFileSecurityProc)(nativePath,
+		OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
+		| DACL_SECURITY_INFORMATION, 0, 0, &size);
+
+	/*
+	 * Should have failed with ERROR_INSUFFICIENT_BUFFER
+	 */
+
+	error = GetLastError();
+	if (error != ERROR_INSUFFICIENT_BUFFER) {
+	    /*
+	     * Most likely case is ERROR_ACCESS_DENIED, which we will convert
+	     * to EACCES - just what we want!
+	     */
+
+	    TclWinConvertError((DWORD)error);
+	    return -1;
+	}
+
+	/*
+	 * Now size contains the size of buffer needed
+	 */
+
+	sdPtr = (SECURITY_DESCRIPTOR *) HeapAlloc(GetProcessHeap(), 0, size);
+
+	if (sdPtr == NULL) {
+	    goto accessError;
+	}
+
+	/*
+	 * Call GetFileSecurity() for real
+	 */
+
+	if (!(*tclWinProcs->getFileSecurityProc)(nativePath,
+		OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
+		| DACL_SECURITY_INFORMATION, sdPtr, size, &size)) {
+	    /*
+	     * Error getting owner SD
+	     */
+
+	    goto accessError;
+	}
+
+	/*
+	 * Perform security impersonation of the user and open the
+	 * resulting thread token.
+	 */
+
+	if (!(*tclWinProcs->impersonateSelfProc)(SecurityImpersonation)) {
+	    /*
+	     * Unable to perform security impersonation.
 	     */
 	    
-	    return 0;
+	    goto accessError;
 	}
-	if (NativeIsExec(nativePath)) {
-	    return 0;
+	if (!(*tclWinProcs->openThreadTokenProc)(GetCurrentThread (),
+		TOKEN_DUPLICATE | TOKEN_QUERY, FALSE, &hToken)) {
+	    /*
+	     * Unable to get current thread's token.
+	     */
+	    
+	    goto accessError;
+	}
+	
+	(*tclWinProcs->revertToSelfProc)();
+	
+	/*
+	 * Setup desiredAccess according to the access priveleges we are
+	 * checking.
+	 */
+
+	if (mode & R_OK) {
+	    desiredAccess |= FILE_GENERIC_READ;
+	}
+	if (mode & W_OK) {
+	    desiredAccess |= FILE_GENERIC_WRITE;
+	}
+	if (mode & X_OK) {
+	    desiredAccess |= FILE_GENERIC_EXECUTE;
+	}
+
+	memset (&genMap, 0x0, sizeof (GENERIC_MAPPING));
+	genMap.GenericRead = FILE_GENERIC_READ;
+	genMap.GenericWrite = FILE_GENERIC_WRITE;
+	genMap.GenericExecute = FILE_GENERIC_EXECUTE;
+	genMap.GenericAll = FILE_ALL_ACCESS;
+	
+	/*
+	 * Perform access check using the token.
+	 */
+
+	if (!(*tclWinProcs->accessCheckProc)(sdPtr, hToken, desiredAccess,
+		&genMap, &privSet, &privSetSize, &grantedAccess,
+		&accessYesNo)) {
+	    /*
+	     * Unable to perform access check.
+	     */
+
+	accessError:
+	    TclWinConvertError(GetLastError());
+	    if (sdPtr != NULL) {
+		HeapFree(GetProcessHeap(), 0, sdPtr);
+	    }
+	    if (hToken != NULL) {
+		CloseHandle(hToken);
+	    }
+	    return -1;
 	}
-	Tcl_SetErrno(EACCES);
-	return -1;
-    }
 
+	/*
+	 * Clean up.
+	 */
+
+	HeapFree(GetProcessHeap (), 0, sdPtr);
+	CloseHandle(hToken);
+	if (!accessYesNo) {
+	    Tcl_SetErrno(EACCES);
+	    return -1;
+	}
+	/*
+	 * For directories the above checks are ok.  For files, though,
+	 * we must still check the 'attr' value.
+	 */
+	if ((mode & W_OK)
+	  && (attr & FILE_ATTRIBUTE_READONLY)) {
+	    Tcl_SetErrno(EACCES);
+	    return -1;
+	}
+    }
     return 0;
 }
 
diff --git a/win/tclWinInt.h b/win/tclWinInt.h
index 5cefc9d..3b06f50 100644
--- a/win/tclWinInt.h
+++ b/win/tclWinInt.h
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclWinInt.h,v 1.20.2.4 2005/11/03 11:53:59 patthoyts Exp $
+ * RCS: @(#) $Id: tclWinInt.h,v 1.20.2.5 2006/03/10 10:35:25 vincentdarley Exp $
  */
 
 #ifndef _TCLWININT
@@ -112,6 +112,32 @@ typedef struct TclWinProcs {
 					 LPVOID, DWORD);
     BOOL (WINAPI *getVolumeNameForVMPProc)(CONST TCHAR*, TCHAR*, DWORD);
 
+    DWORD (WINAPI *getLongPathNameProc)(CONST TCHAR*, TCHAR*, DWORD);
+    /* 
+     * These six are for the security sdk to get correct file
+     * permissions on NT, 2000, XP, etc.  On 95,98,ME they are
+     * always null.
+     */
+    BOOL (WINAPI *getFileSecurityProc)(LPCTSTR lpFileName,
+		     SECURITY_INFORMATION RequestedInformation,
+		     PSECURITY_DESCRIPTOR pSecurityDescriptor,
+		     DWORD nLength, 
+		     LPDWORD lpnLengthNeeded);
+    BOOL (WINAPI *impersonateSelfProc) (SECURITY_IMPERSONATION_LEVEL 
+		      ImpersonationLevel);
+    BOOL (WINAPI *openThreadTokenProc) (HANDLE ThreadHandle,
+		      DWORD DesiredAccess, BOOL OpenAsSelf,
+		      PHANDLE TokenHandle);
+    BOOL (WINAPI *revertToSelfProc) (void);
+    VOID (WINAPI *mapGenericMaskProc) (PDWORD AccessMask,
+		      PGENERIC_MAPPING GenericMapping);
+    BOOL (WINAPI *accessCheckProc)(PSECURITY_DESCRIPTOR pSecurityDescriptor,
+		    HANDLE ClientToken, DWORD DesiredAccess,
+		    PGENERIC_MAPPING GenericMapping,
+		    PPRIVILEGE_SET PrivilegeSet,
+		    LPDWORD PrivilegeSetLength,
+		    LPDWORD GrantedAccess,
+		    LPBOOL AccessStatus);
    /*
     * Unicode console support. WriteConsole and ReadConsole
     */