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authordgp <dgp@users.sourceforge.net>2012-01-11 21:24:55 (GMT)
committerdgp <dgp@users.sourceforge.net>2012-01-11 21:24:55 (GMT)
commit9b9a88cd34149fc95d3ffdd23d657e7b3daf0c7d (patch)
tree0d53adf2ca5154f41c0b78d71e769d4541b5bb34
parent0f369563d656dc5592d01b9736568bf7421ef93d (diff)
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Contributed patch aiming to fix [file writable] problems on Windows & Samba.
-rw-r--r--win/tclWinFile.c65
1 files changed, 45 insertions, 20 deletions
diff --git a/win/tclWinFile.c b/win/tclWinFile.c
index 54cf0cf..64b2a0e 100644
--- a/win/tclWinFile.c
+++ b/win/tclWinFile.c
@@ -1550,14 +1550,25 @@ NativeAccess(
return -1;
}
+ if (mode == F_OK) {
+ /*
+ * File exists, nothing else to check.
+ */
+
+ return 0;
+ }
+
if ((mode & W_OK)
- && (tclWinProcs->getFileSecurityProc == NULL)
- && (attr & FILE_ATTRIBUTE_READONLY)) {
+ && (attr & FILE_ATTRIBUTE_READONLY)
+ && !(attr & FILE_ATTRIBUTE_DIRECTORY)) {
/*
- * 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.
+ * The attributes say the file is not writable. If the file is a
+ * regular file (i.e., not a directory), then the file is not
+ * writable, full stop. For directories, the read-only bit is
+ * (mostly) ignored by Windows, so we can't ascertain anything about
+ * directory access from the attrib data. However, if we have the
+ * advanced 'getFileSecurityProc', then more robust ACL checks
+ * will be done below.
*/
Tcl_SetErrno(EACCES);
@@ -1587,9 +1598,12 @@ NativeAccess(
* readable' is 5-6 times slower than 'file exists').
*/
- if ((mode != F_OK) && (tclWinProcs->getFileSecurityProc != NULL)) {
+ if (tclWinProcs->getFileSecurityProc != NULL) {
SECURITY_DESCRIPTOR *sdPtr = NULL;
unsigned long size;
+ SID *pSid = 0;
+ BOOL SidDefaulted;
+ SID_IDENTIFIER_AUTHORITY samba_unmapped = { 0, 0, 0, 0, 0, 22 };
GENERIC_MAPPING genMap;
HANDLE hToken = NULL;
DWORD desiredAccess = 0, grantedAccess = 0;
@@ -1605,7 +1619,8 @@ NativeAccess(
size = 0;
(*tclWinProcs->getFileSecurityProc)(nativePath,
OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
- | DACL_SECURITY_INFORMATION, 0, 0, &size);
+ | DACL_SECURITY_INFORMATION | LABEL_SECURITY_INFORMATION,
+ 0, 0, &size);
/*
* Should have failed with ERROR_INSUFFICIENT_BUFFER
@@ -1638,7 +1653,8 @@ NativeAccess(
if (!(*tclWinProcs->getFileSecurityProc)(nativePath,
OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION
- | DACL_SECURITY_INFORMATION, sdPtr, size, &size)) {
+ | DACL_SECURITY_INFORMATION | LABEL_SECURITY_INFORMATION,
+ sdPtr, size, &size)) {
/*
* Error getting owner SD
*/
@@ -1647,6 +1663,26 @@ NativeAccess(
}
/*
+ * As of Samba 3.0.23 (10-Jul-2006), unmapped users and groups are
+ * assigned to SID domains S-1-22-1 and S-1-22-2, where "22" is the
+ * top-level authority. If the file owner and group is unmapped then
+ * the ACL access check below will only test against world access,
+ * which is likely to be more restrictive than the actual access
+ * restrictions. Since the ACL tests are more likely wrong than
+ * right, skip them. Moreover, the unix owner access permissions are
+ * usually mapped to the Windows attributes, so if the user is the
+ * file owner then the attrib checks above are correct (as far as they
+ * go).
+ */
+
+ if(!GetSecurityDescriptorOwner(sdPtr,&pSid,&SidDefaulted) ||
+ memcmp(GetSidIdentifierAuthority(pSid),&samba_unmapped,
+ sizeof(SID_IDENTIFIER_AUTHORITY))==0) {
+ HeapFree(GetProcessHeap(), 0, sdPtr);
+ return 0; /* Attrib tests say access allowed. */
+ }
+
+ /*
* Perform security impersonation of the user and open the resulting
* thread token.
*/
@@ -1723,17 +1759,6 @@ NativeAccess(
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_DIRECTORY)
- && (attr & FILE_ATTRIBUTE_READONLY)) {
- Tcl_SetErrno(EACCES);
- return -1;
- }
}
return 0;
}