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/strings/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 // Parses |value| as search list (comma-delimited list of domain names) from
  38 // a registry key and stores it in |out|. Returns true on success. Empty
  39 // entries (e.g., "chromium.org,,org") terminate the list. Non-ascii hostnames
  40 // are converted to punycode.
  41 bool NET_EXPORT_PRIVATE ParseSearchList(const base::string16& value,
  42                                         std::vector<std::string>* out);
  43
  44 // All relevant settings read from registry and IP Helper. This isolates our
  45 // logic from system calls and is exposed for unit tests. Keep it an aggregate
  46 // struct for easy initialization.
  47 struct NET_EXPORT_PRIVATE DnsSystemSettings {
  48   // The |set| flag distinguishes between empty and unset values.
  49   struct RegString {
  50     bool set;
  51     base::string16 value;
  52   };
  53
  54   struct RegDword {
  55     bool set;
  56     DWORD value;
  57   };
  58
  59   struct DevolutionSetting {
  60     // UseDomainNameDevolution
  61     RegDword enabled;
  62     // DomainNameDevolutionLevel
  63     RegDword level;
  64   };
  65
  66   DnsSystemSettings();
  67   ~DnsSystemSettings();
  68
  69   // Filled in by GetAdapterAddresses. Note that the alternative
  70   // GetNetworkParams does not include IPv6 addresses.
  71   scoped_ptr<IP_ADAPTER_ADDRESSES, base::FreeDeleter> addresses;
  72
  73   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\SearchList
  74   RegString policy_search_list;
  75   // SYSTEM\CurrentControlSet\Tcpip\Parameters\SearchList
  76   RegString tcpip_search_list;
  77   // SYSTEM\CurrentControlSet\Tcpip\Parameters\Domain
  78   RegString tcpip_domain;
  79   // SOFTWARE\Policies\Microsoft\System\DNSClient\PrimaryDnsSuffix
  80   RegString primary_dns_suffix;
  81
  82   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient
  83   DevolutionSetting policy_devolution;
  84   // SYSTEM\CurrentControlSet\Dnscache\Parameters
  85   DevolutionSetting dnscache_devolution;
  86   // SYSTEM\CurrentControlSet\Tcpip\Parameters
  87   DevolutionSetting tcpip_devolution;
  88
  89   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\AppendToMultiLabelName
  90   RegDword append_to_multi_label_name;
  91
  92   // True when the Name Resolution Policy Table (NRPT) has at least one rule:
  93   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\DnsPolicyConfig\Rule*
  94   bool have_name_resolution_policy;
  95 };
  96
  97 enum ConfigParseWinResult {
  98   CONFIG_PARSE_WIN_OK = 0,
  99   CONFIG_PARSE_WIN_READ_IPHELPER,
 100   CONFIG_PARSE_WIN_READ_POLICY_SEARCHLIST,
 101   CONFIG_PARSE_WIN_READ_TCPIP_SEARCHLIST,
 102   CONFIG_PARSE_WIN_READ_DOMAIN,
 103   CONFIG_PARSE_WIN_READ_POLICY_DEVOLUTION,
 104   CONFIG_PARSE_WIN_READ_DNSCACHE_DEVOLUTION,
 105   CONFIG_PARSE_WIN_READ_TCPIP_DEVOLUTION,
 106   CONFIG_PARSE_WIN_READ_APPEND_MULTILABEL,
 107   CONFIG_PARSE_WIN_READ_PRIMARY_SUFFIX,
 108   CONFIG_PARSE_WIN_BAD_ADDRESS,
 109   CONFIG_PARSE_WIN_NO_NAMESERVERS,
 110   CONFIG_PARSE_WIN_UNHANDLED_OPTIONS,
 111   CONFIG_PARSE_WIN_MAX  // Bounding values for enumeration.
 112 };
 113
 114 // Fills in |dns_config| from |settings|. Exposed for tests.
 115 ConfigParseWinResult NET_EXPORT_PRIVATE ConvertSettingsToDnsConfig(
 116     const DnsSystemSettings& settings,
 117     DnsConfig* dns_config);
 118
 119 // Use DnsConfigService::CreateSystemService to use it outside of tests.
 120 class NET_EXPORT_PRIVATE DnsConfigServiceWin : public DnsConfigService {
 121  public:
 122   DnsConfigServiceWin();
 123   ~DnsConfigServiceWin() override;
 124
 125  private:
 126   class Watcher;
 127   class ConfigReader;
 128   class HostsReader;
 129
 130   // DnsConfigService:
 131   void ReadNow() override;
 132   bool StartWatching() override;
 133
 134   void OnConfigChanged(bool succeeded);
 135   void OnHostsChanged(bool succeeded);
 136
 137   scoped_ptr<Watcher> watcher_;
 138   scoped_refptr<ConfigReader> config_reader_;
 139   scoped_refptr<HostsReader> hosts_reader_;
 140
 141   DISALLOW_COPY_AND_ASSIGN(DnsConfigServiceWin);
 142 };
 143
 144 }  // namespace internal
 145
 146 }  // namespace net
 147
 148 #endif  // NET_DNS_DNS_CONFIG_SERVICE_WIN_H_
 149