Security-57740.1.18.tar.gz

[apple/security.git] / OSX / libsecurity_utilities / lib / FileLockTransaction.cpp

diff --git a/OSX/libsecurity_utilities/lib/FileLockTransaction.cpp b/OSX/libsecurity_utilities/lib/FileLockTransaction.cpp
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+++ b/OSX/libsecurity_utilities/lib/FileLockTransaction.cpp
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+/*
+ * Copyright (c) 2015 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include "FileLockTransaction.h"
+#include <Security/SecBasePriv.h>
+#include <syslog.h>
+
+FileLockTransaction::FileLockTransaction(Security::CssmClient::Db& db)
+    : mDb(db), mSuccess(false), mFinalized(false), mDeleteOnFailure(false) {
+    initialize();
+}
+
+void FileLockTransaction::initialize() {
+    mDb->takeFileLock();
+}
+
+FileLockTransaction::~FileLockTransaction() {
+    finalize();
+}
+
+void FileLockTransaction::success() {
+    mSuccess = true;
+}
+
+void FileLockTransaction::setDeleteOnFailure() {
+    mDeleteOnFailure = true;
+}
+
+void FileLockTransaction::finalize() {
+    if(mFinalized) {
+        return;
+    }
+
+    // if this transaction was a success, commit. Otherwise, roll back.
+    if(mSuccess) {
+        mDb->releaseFileLock(true);
+    } else {
+        // This is a failure.
+
+        // Note that we're likely (but not necessarily) unwinding the stack for an exception right now.
+        // (If this transaction succeeded, we wouldn't be here. So, it failed, and this code likes to fail with exceptions.)
+        // If this throws an exception, we might crash the whole process.
+        // Swallow exceptions whole, but log them aggressively.
+        try {
+            if(mDeleteOnFailure) {
+                mDb->deleteFile();
+            }
+            mDb->releaseFileLock(false);
+        } catch(CssmError cssme) {
+            const char* errStr = cssmErrorString(cssme.error);
+            secnotice("integrity", "caught CssmError during transaction rollback: %d %s", (int) cssme.error, errStr);
+            syslog(LOG_ERR, "ERROR: failed to rollback keychain transaction: %d %s", (int) cssme.error, errStr);
+        }
+    }
+    mFinalized = true;
+}