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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_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_
     95