chrome/installer/util/set_reg_value_work_item.cc

   1 // Copyright (c) 2011 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/set_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
  12 SetRegValueWorkItem::~SetRegValueWorkItem() {
  13 }
  14
  15 SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
  16                                          const std::wstring& key_path,
  17                                          const std::wstring& value_name,
  18                                          const std::wstring& value_data,
  19                                          bool overwrite)
  20     : predefined_root_(predefined_root),
  21       key_path_(key_path),
  22       value_name_(value_name),
  23       overwrite_(overwrite),
  24       status_(SET_VALUE),
  25       type_(REG_SZ),
  26       previous_type_(0) {
  27   const uint8* data = reinterpret_cast<const uint8*>(value_data.c_str());
  28   value_.assign(data, data + (value_data.length() + 1) * sizeof(wchar_t));
  29 }
  30
  31 SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
  32                                          const std::wstring& key_path,
  33                                          const std::wstring& value_name,
  34                                          DWORD value_data,
  35                                          bool overwrite)
  36     : predefined_root_(predefined_root),
  37       key_path_(key_path),
  38       value_name_(value_name),
  39       overwrite_(overwrite),
  40       status_(SET_VALUE),
  41       type_(REG_DWORD),
  42       previous_type_(0) {
  43   const uint8* data = reinterpret_cast<const uint8*>(&value_data);
  44   value_.assign(data, data + sizeof(value_data));
  45 }
  46
  47 SetRegValueWorkItem::SetRegValueWorkItem(HKEY predefined_root,
  48                                          const std::wstring& key_path,
  49                                          const std::wstring& value_name,
  50                                          int64 value_data,
  51                                          bool overwrite)
  52     : predefined_root_(predefined_root),
  53       key_path_(key_path),
  54       value_name_(value_name),
  55       overwrite_(overwrite),
  56       status_(SET_VALUE),
  57       type_(REG_QWORD),
  58       previous_type_(0) {
  59   const uint8* data = reinterpret_cast<const uint8*>(&value_data);
  60   value_.assign(data, data + sizeof(value_data));
  61 }
  62
  63 bool SetRegValueWorkItem::Do() {
  64   LONG result = ERROR_SUCCESS;
  65   base::win::RegKey key;
  66   if (status_ != SET_VALUE) {
  67     // we already did something.
  68     VLOG(1) << "multiple calls to Do()";
  69     result = ERROR_CANTWRITE;
  70     return ignore_failure_;
  71   }
  72
  73   status_ = VALUE_UNCHANGED;
  74   result = key.Open(predefined_root_, key_path_.c_str(),
  75                     KEY_READ | KEY_SET_VALUE);
  76   if (result != ERROR_SUCCESS) {
  77     VLOG(1) << "can not open " << key_path_ << " error: " << result;
  78     return ignore_failure_;
  79   }
  80
  81   DWORD type = 0;
  82   DWORD size = 0;
  83   result = key.ReadValue(value_name_.c_str(), NULL, &size, &type);
  84   // If the value exists but we don't want to overwrite then there's
  85   // nothing more to do.
  86   if ((result != ERROR_FILE_NOT_FOUND) && !overwrite_) {
  87     return true;
  88   }
  89
  90   // If there's something to be saved, save it.
  91   if (result == ERROR_SUCCESS) {
  92     if (!size) {
  93       previous_type_ = type;
  94     } else {
  95       previous_value_.resize(size);
  96       result = key.ReadValue(value_name_.c_str(), &previous_value_[0], &size,
  97                              &previous_type_);
  98       if (result != ERROR_SUCCESS) {
  99         previous_value_.clear();
 100         VLOG(1) << "Failed to save original value. Error: " << result;
 101       }
 102     }
 103   }
 104
 105   result = key.WriteValue(value_name_.c_str(), &value_[0],
 106                           static_cast<DWORD>(value_.size()), type_);
 107   if (result != ERROR_SUCCESS) {
 108     VLOG(1) << "Failed to write value " << key_path_ << " error: " << result;
 109     return ignore_failure_;
 110   }
 111
 112   status_ = previous_type_ ? VALUE_OVERWRITTEN : NEW_VALUE_CREATED;
 113   return true;
 114 }
 115
 116 void SetRegValueWorkItem::Rollback() {
 117   if (ignore_failure_)
 118     return;
 119
 120   if (status_ == SET_VALUE || status_ == VALUE_ROLL_BACK)
 121     return;
 122
 123   if (status_ == VALUE_UNCHANGED) {
 124     status_ = VALUE_ROLL_BACK;
 125     VLOG(1) << "rollback: setting unchanged, nothing to do";
 126     return;
 127   }
 128
 129   base::win::RegKey key;
 130   LONG result = key.Open(predefined_root_, key_path_.c_str(), KEY_SET_VALUE);
 131   if (result != ERROR_SUCCESS) {
 132     VLOG(1) << "rollback: can not open " << key_path_ << " error: " << result;
 133     return;
 134   }
 135
 136   if (status_ == NEW_VALUE_CREATED) {
 137     result = key.DeleteValue(value_name_.c_str());
 138     VLOG(1) << "rollback: deleting " << value_name_ << " error: " << result;
 139   } else if (status_ == VALUE_OVERWRITTEN) {
 140     const unsigned char* previous_value =
 141         previous_value_.empty() ? NULL : &previous_value_[0];
 142     result = key.WriteValue(value_name_.c_str(), previous_value,
 143                             static_cast<DWORD>(previous_value_.size()),
 144                             previous_type_);
 145     VLOG(1) << "rollback: restoring " << value_name_ << " error: " << result;
 146   } else {
 147     NOTREACHED();
 148   }
 149
 150   status_ = VALUE_ROLL_BACK;
 151 }