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      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   // Filled in by GetAdapterAddresses. Note that the alternative
     67   // GetNetworkParams does not include IPv6 addresses.
     68   scoped_ptr<IP_ADAPTER_ADDRESSES, base::FreeDeleter> addresses;
     69 
     70   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\SearchList
     71   RegString policy_search_list;
     72   // SYSTEM\CurrentControlSet\Tcpip\Parameters\SearchList
     73   RegString tcpip_search_list;
     74   // SYSTEM\CurrentControlSet\Tcpip\Parameters\Domain
     75   RegString tcpip_domain;
     76   // SOFTWARE\Policies\Microsoft\System\DNSClient\PrimaryDnsSuffix
     77   RegString primary_dns_suffix;
     78 
     79   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient
     80   DevolutionSetting policy_devolution;
     81   // SYSTEM\CurrentControlSet\Dnscache\Parameters
     82   DevolutionSetting dnscache_devolution;
     83   // SYSTEM\CurrentControlSet\Tcpip\Parameters
     84   DevolutionSetting tcpip_devolution;
     85 
     86   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\AppendToMultiLabelName
     87   RegDword append_to_multi_label_name;
     88 
     89   // True when the Name Resolution Policy Table (NRPT) has at least one rule:
     90   // SOFTWARE\Policies\Microsoft\Windows NT\DNSClient\DnsPolicyConfig\Rule*
     91   bool have_name_resolution_policy;
     92 };
     93 
     94 enum ConfigParseWinResult {
     95   CONFIG_PARSE_WIN_OK = 0,
     96   CONFIG_PARSE_WIN_READ_IPHELPER,
     97   CONFIG_PARSE_WIN_READ_POLICY_SEARCHLIST,
     98   CONFIG_PARSE_WIN_READ_TCPIP_SEARCHLIST,
     99   CONFIG_PARSE_WIN_READ_DOMAIN,
    100   CONFIG_PARSE_WIN_READ_POLICY_DEVOLUTION,
    101   CONFIG_PARSE_WIN_READ_DNSCACHE_DEVOLUTION,
    102   CONFIG_PARSE_WIN_READ_TCPIP_DEVOLUTION,
    103   CONFIG_PARSE_WIN_READ_APPEND_MULTILABEL,
    104   CONFIG_PARSE_WIN_READ_PRIMARY_SUFFIX,
    105   CONFIG_PARSE_WIN_BAD_ADDRESS,
    106   CONFIG_PARSE_WIN_NO_NAMESERVERS,
    107   CONFIG_PARSE_WIN_UNHANDLED_OPTIONS,
    108   CONFIG_PARSE_WIN_MAX  // Bounding values for enumeration.
    109 };
    110 
    111 // Fills in |dns_config| from |settings|. Exposed for tests.
    112 ConfigParseWinResult NET_EXPORT_PRIVATE ConvertSettingsToDnsConfig(
    113     const DnsSystemSettings& settings,
    114     DnsConfig* dns_config);
    115 
    116 // Use DnsConfigService::CreateSystemService to use it outside of tests.
    117 class NET_EXPORT_PRIVATE DnsConfigServiceWin : public DnsConfigService {
    118  public:
    119   DnsConfigServiceWin();
    120   virtual ~DnsConfigServiceWin();
    121 
    122  private:
    123   class Watcher;
    124   class ConfigReader;
    125   class HostsReader;
    126 
    127   // DnsConfigService:
    128   virtual void ReadNow() OVERRIDE;
    129   virtual bool StartWatching() OVERRIDE;
    130 
    131   void OnConfigChanged(bool succeeded);
    132   void OnHostsChanged(bool succeeded);
    133 
    134   scoped_ptr<Watcher> watcher_;
    135   scoped_refptr<ConfigReader> config_reader_;
    136   scoped_refptr<HostsReader> hosts_reader_;
    137 
    138   DISALLOW_COPY_AND_ASSIGN(DnsConfigServiceWin);
    139 };
    140 
    141 }  // namespace internal
    142 
    143 }  // namespace net
    144 
    145 #endif  // NET_DNS_DNS_CONFIG_SERVICE_WIN_H_
    146 
    147