OSX/libsecurity_utilities/lib/FileLockTransaction.cpp

   1 /*
   2  * Copyright (c) 2015 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include <TargetConditionals.h>
  24 #if TARGET_OS_OSX
  25
  26 #include "FileLockTransaction.h"
  27 #include <Security/SecBasePriv.h>
  28 #include <syslog.h>
  29
  30 FileLockTransaction::FileLockTransaction(Security::CssmClient::Db& db)
  31     : mDb(db), mSuccess(false), mFinalized(false), mDeleteOnFailure(false) {
  32     initialize();
  33 }
  34
  35 void FileLockTransaction::initialize() {
  36     mDb->takeFileLock();
  37 }
  38
  39 FileLockTransaction::~FileLockTransaction() {
  40     finalize();
  41 }
  42
  43 void FileLockTransaction::success() {
  44     mSuccess = true;
  45 }
  46
  47 void FileLockTransaction::setDeleteOnFailure() {
  48     mDeleteOnFailure = true;
  49 }
  50
  51 void FileLockTransaction::finalize() {
  52     if(mFinalized) {
  53         return;
  54     }
  55
  56     // if this transaction was a success, commit. Otherwise, roll back.
  57     if(mSuccess) {
  58         mDb->releaseFileLock(true);
  59     } else {
  60         // This is a failure.
  61
  62         // Note that we're likely (but not necessarily) unwinding the stack for an exception right now.
  63         // (If this transaction succeeded, we wouldn't be here. So, it failed, and this code likes to fail with exceptions.)
  64         // If this throws an exception, we might crash the whole process.
  65         // Swallow exceptions whole, but log them aggressively.
  66         try {
  67             if(mDeleteOnFailure) {
  68                 mDb->deleteFile();
  69             }
  70             mDb->releaseFileLock(false);
  71         } catch(CssmError cssme) {
  72             const char* errStr = cssmErrorString(cssme.error);
  73             secnotice("integrity", "caught CssmError during transaction rollback: %d %s", (int) cssme.error, errStr);
  74             syslog(LOG_ERR, "ERROR: failed to rollback keychain transaction: %d %s", (int) cssme.error, errStr);
  75         }
  76     }
  77     mFinalized = true;
  78 }
  79
  80 #endif //TARGET_OS_OSX