1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#include "chrome/installer/util/delete_reg_value_work_item.h" 6 7#include "base/logging.h" 8#include "base/strings/string_util.h" 9#include "base/win/registry.h" 10#include "chrome/installer/util/logging_installer.h" 11 12using base::win::RegKey; 13 14DeleteRegValueWorkItem::DeleteRegValueWorkItem(HKEY predefined_root, 15 const std::wstring& key_path, 16 REGSAM wow64_access, 17 const std::wstring& value_name) 18 : predefined_root_(predefined_root), 19 key_path_(key_path), 20 value_name_(value_name), 21 wow64_access_(wow64_access), 22 previous_type_(0), 23 status_(DELETE_VALUE) { 24 DCHECK(wow64_access == 0 || 25 wow64_access == KEY_WOW64_32KEY || 26 wow64_access == KEY_WOW64_64KEY); 27} 28 29DeleteRegValueWorkItem::~DeleteRegValueWorkItem() { 30} 31 32bool DeleteRegValueWorkItem::Do() { 33 if (status_ != DELETE_VALUE) { 34 // we already did something. 35 LOG(ERROR) << "multiple calls to Do()"; 36 return false; 37 } 38 39 status_ = VALUE_UNCHANGED; 40 41 RegKey key; 42 DWORD type = 0; 43 DWORD size = 0; 44 LONG result = key.Open(predefined_root_, 45 key_path_.c_str(), 46 KEY_READ | KEY_WRITE | wow64_access_); 47 if (result == ERROR_SUCCESS) 48 result = key.ReadValue(value_name_.c_str(), NULL, &size, &type); 49 50 if (result == ERROR_FILE_NOT_FOUND) { 51 LOG(INFO) << "(delete value) Key: " << key_path_ << " or Value: " 52 << value_name_ << " does not exist."; 53 status_ = VALUE_NOT_FOUND; 54 return true; 55 } 56 57 if (result == ERROR_SUCCESS) { 58 if (!size) { 59 previous_type_ = type; 60 } else { 61 previous_value_.resize(size); 62 result = key.ReadValue(value_name_.c_str(), &previous_value_[0], &size, 63 &previous_type_); 64 if (result != ERROR_SUCCESS) { 65 previous_value_.erase(); 66 VLOG(1) << "Failed to save original value. Error: " << result; 67 } 68 } 69 } 70 71 result = key.DeleteValue(value_name_.c_str()); 72 if (result != ERROR_SUCCESS) { 73 VLOG(1) << "Failed to delete value " << value_name_ << " error: " << result; 74 return false; 75 } 76 77 status_ = VALUE_DELETED; 78 return true; 79} 80 81void DeleteRegValueWorkItem::Rollback() { 82 if (status_ == DELETE_VALUE || status_ == VALUE_ROLLED_BACK) 83 return; 84 if (status_ == VALUE_UNCHANGED || status_ == VALUE_NOT_FOUND) { 85 status_ = VALUE_ROLLED_BACK; 86 VLOG(1) << "rollback: setting unchanged, nothing to do"; 87 return; 88 } 89 90 // At this point only possible state is VALUE_DELETED. 91 RegKey key; 92 LONG result = key.Open(predefined_root_, 93 key_path_.c_str(), 94 KEY_READ | KEY_WRITE | wow64_access_); 95 if (result == ERROR_SUCCESS) { 96 // try to restore the previous value 97 DWORD previous_size = static_cast<DWORD>(previous_value_.size()); 98 const char* previous_value = 99 previous_size ? &previous_value_[0] : NULL; 100 result = key.WriteValue(value_name_.c_str(), previous_value, 101 previous_size, previous_type_); 102 VLOG_IF(1, result != ERROR_SUCCESS) << "rollback: restoring " 103 << value_name_ << " error: " << result; 104 } else { 105 VLOG(1) << "can not open " << key_path_ << " error: " << result; 106 } 107} 108