net/dns/dns_config_service_win.h

   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 #ifndef NET_DNS_DNS_CONFIG_SERVICE_WIN_H_
   6 #define NET_DNS_DNS_CONFIG_SERVICE_WIN_H_
   7
   8 // The sole purpose of dns_config_service_win.h is for unittests so we just
   9 // include these headers here.
  10 #include <winsock2.h>
  11 #include <iphlpapi.h>
  12
  13 #include <string>
  14 #include <vector>
  15
  16 #include "base/memory/ref_counted.h"
  17 #include "base/memory/scoped_ptr.h"
  18 #include "base/string16.h"
  19 #include "net/base/net_export.h"
  20 #include "net/dns/dns_config_service.h"
  21
  22 // The general effort of DnsConfigServiceWin is to configure |nameservers| and
  23 // |search| in DnsConfig. The settings are stored in the Windows registry, but
  24 // to simplify the task we use the IP Helper API wherever possible. That API
  25 // yields the complete and ordered |nameservers|, but to determine |search| we
  26 // need to use the registry. On Windows 7, WMI does return the correct |search|
  27 // but on earlier versions it is insufficient.
  28 //
  29 // Experimental evaluation of Windows behavior suggests that domain parsing is
  30 // naive. Domain suffixes in |search| are not validated until they are appended
  31 // to the resolved name. We attempt to replicate this behavior.
  32
  33 namespace net {
  34
  35 namespace internal {
  36
  37 // Registry key paths.
  38 const wchar_t* const kTcpipPath =
  39     L"SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters";
  40 const wchar_t* const kTcpip6Path =
  41     L"SYSTEM\\CurrentControlSet\\Services\\Tcpip6\\Parameters";
  42 const wchar_t* const kDnscachePath =
  43     L"SYSTEM\\CurrentControlSet\\Services\\Dnscache\\Parameters";
  44 const wchar_t* const kPolicyPath =
  45     L"SOFTWARE\\Policies\\Microsoft\\Windows NT\\DNSClient";
  46
  47 // Returns the path to the HOSTS file.
  48 base::FilePath GetHostsPath();
  49
  50 // Parses |value| as search list (comma-delimited list of domain names) from
  51 // a registry key and stores it in |out|. Returns true on success. Empty
  52 // entries (e.g., "chromium.org,,org") terminate the list. Non-ascii hostnames
  53 // are converted to punycode.
  54 bool NET_EXPORT_PRIVATE ParseSearchList(const base::string16& value,
  55                                         std::vector<std::string>* out);
  56
  57 // All relevant settings read from registry and IP Helper. This isolates our
  58 // logic from system calls and is exposed for unit tests. Keep it an aggregate
  59 // struct for easy initialization.
  60 struct NET_EXPORT_PRIVATE DnsSystemSettings {
  61   // The |set| flag distinguishes between empty and unset values.
  62   struct RegString {
  63     bool set;
  64     base::string16 value;
  65   };
  66
  67   struct RegDword {
  68     bool set;
  69     DWORD value;
  70   };
  71
  72   struct DevolutionSetting {
  73     // UseDomainNameDevolution
  74     RegDword enabled;
  75     // DomainNameDevolutionLevel
  76     RegDword level;
  77   };
  78
  79   // Filled in by GetAdapterAddresses. Note that the alternative
  80   // GetNetworkParams does not include IPv6 addresses.
  81   scoped_ptr_malloc<IP_ADAPTER_ADDRESSES> addresses;
  82
  83   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\SearchList
  84   RegString policy_search_list;
  85   // SYSTEM\CurrentControlSet\Tcpip\Parameters\SearchList
  86   RegString tcpip_search_list;
  87   // SYSTEM\CurrentControlSet\Tcpip\Parameters\Domain
  88   RegString tcpip_domain;
  89   // SOFTWARE\Policies\Microsoft\System\DNSClient\PrimaryDnsSuffix
  90   RegString primary_dns_suffix;
  91
  92   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient
  93   DevolutionSetting policy_devolution;
  94   // SYSTEM\CurrentControlSet\Dnscache\Parameters
  95   DevolutionSetting dnscache_devolution;
  96   // SYSTEM\CurrentControlSet\Tcpip\Parameters
  97   DevolutionSetting tcpip_devolution;
  98
  99   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\AppendToMultiLabelName
 100   RegDword append_to_multi_label_name;
 101 };
 102
 103 enum ConfigParseWinResult {
 104   CONFIG_PARSE_WIN_OK = 0,
 105   CONFIG_PARSE_WIN_READ_IPHELPER,
 106   CONFIG_PARSE_WIN_READ_POLICY_SEARCHLIST,
 107   CONFIG_PARSE_WIN_READ_TCPIP_SEARCHLIST,
 108   CONFIG_PARSE_WIN_READ_DOMAIN,
 109   CONFIG_PARSE_WIN_READ_POLICY_DEVOLUTION,
 110   CONFIG_PARSE_WIN_READ_DNSCACHE_DEVOLUTION,
 111   CONFIG_PARSE_WIN_READ_TCPIP_DEVOLUTION,
 112   CONFIG_PARSE_WIN_READ_APPEND_MULTILABEL,
 113   CONFIG_PARSE_WIN_READ_PRIMARY_SUFFIX,
 114   CONFIG_PARSE_WIN_BAD_ADDRESS,
 115   CONFIG_PARSE_WIN_NO_NAMESERVERS,
 116   CONFIG_PARSE_WIN_MAX  // Bounding values for enumeration.
 117 };
 118
 119 // Fills in |dns_config| from |settings|. Exposed for tests.
 120 ConfigParseWinResult NET_EXPORT_PRIVATE ConvertSettingsToDnsConfig(
 121     const DnsSystemSettings& settings,
 122     DnsConfig* dns_config);
 123
 124 // Use DnsConfigService::CreateSystemService to use it outside of tests.
 125 class NET_EXPORT_PRIVATE DnsConfigServiceWin : public DnsConfigService {
 126  public:
 127   DnsConfigServiceWin();
 128   virtual ~DnsConfigServiceWin();
 129
 130  private:
 131   class Watcher;
 132   class ConfigReader;
 133   class HostsReader;
 134
 135   // DnsConfigService:
 136   virtual void ReadNow() OVERRIDE;
 137   virtual bool StartWatching() OVERRIDE;
 138
 139   void OnConfigChanged(bool succeeded);
 140   void OnHostsChanged(bool succeeded);
 141
 142   scoped_ptr<Watcher> watcher_;
 143   scoped_refptr<ConfigReader> config_reader_;
 144   scoped_refptr<HostsReader> hosts_reader_;
 145
 146   DISALLOW_COPY_AND_ASSIGN(DnsConfigServiceWin);
 147 };
 148
 149 }  // namespace internal
 150
 151 }  // namespace net
 152
 153 #endif  // NET_DNS_DNS_CONFIG_SERVICE_WIN_H_
 154