net/dns/address_sorter_posix.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_ADDRESS_SORTER_POSIX_H_
   6 #define NET_DNS_ADDRESS_SORTER_POSIX_H_
   7
   8 #include <map>
   9 #include <vector>
  10
  11 #include "base/threading/non_thread_safe.h"
  12 #include "net/base/address_list.h"
  13 #include "net/base/ip_address_number.h"
  14 #include "net/base/net_export.h"
  15 #include "net/base/network_change_notifier.h"
  16 #include "net/dns/address_sorter.h"
  17
  18 namespace net {
  19
  20 class ClientSocketFactory;
  21
  22 // This implementation uses explicit policy to perform the sorting. It is not
  23 // thread-safe and always completes synchronously.
  24 class NET_EXPORT_PRIVATE AddressSorterPosix
  25     : public AddressSorter,
  26       public base::NonThreadSafe,
  27       public NetworkChangeNotifier::IPAddressObserver {
  28  public:
  29   // Generic policy entry.
  30   struct PolicyEntry {
  31     // IPv4 addresses must be mapped to IPv6.
  32     unsigned char prefix[kIPv6AddressSize];
  33     unsigned prefix_length;
  34     unsigned value;
  35   };
  36
  37   typedef std::vector<PolicyEntry> PolicyTable;
  38
  39   enum AddressScope {
  40     SCOPE_UNDEFINED = 0,
  41     SCOPE_NODELOCAL = 1,
  42     SCOPE_LINKLOCAL = 2,
  43     SCOPE_SITELOCAL = 5,
  44     SCOPE_ORGLOCAL = 8,
  45     SCOPE_GLOBAL = 14,
  46   };
  47
  48   struct SourceAddressInfo {
  49     // Values read from policy tables.
  50     AddressScope scope;
  51     unsigned label;
  52
  53     // Values from the OS, matter only if more than one source address is used.
  54     unsigned prefix_length;
  55     bool deprecated;  // vs. preferred RFC4862
  56     bool home;        // vs. care-of RFC6275
  57     bool native;
  58   };
  59
  60   typedef std::map<IPAddressNumber, SourceAddressInfo> SourceAddressMap;
  61
  62   explicit AddressSorterPosix(ClientSocketFactory* socket_factory);
  63   ~AddressSorterPosix() override;
  64
  65   // AddressSorter:
  66   void Sort(const AddressList& list,
  67             const CallbackType& callback) const override;
  68
  69  private:
  70   friend class AddressSorterPosixTest;
  71
  72   // NetworkChangeNotifier::IPAddressObserver:
  73   void OnIPAddressChanged() override;
  74
  75   // Fills |info| with values for |address| from policy tables.
  76   void FillPolicy(const IPAddressNumber& address,
  77                   SourceAddressInfo* info) const;
  78
  79   // Mutable to allow using default values for source addresses which were not
  80   // found in most recent OnIPAddressChanged.
  81   mutable SourceAddressMap source_map_;
  82
  83   ClientSocketFactory* socket_factory_;
  84   PolicyTable precedence_table_;
  85   PolicyTable label_table_;
  86   PolicyTable ipv4_scope_table_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(AddressSorterPosix);
  89 };
  90
  91 }  // namespace net
  92
  93 #endif  // NET_DNS_ADDRESS_SORTER_POSIX_H_