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