Revert 151586 - [net/dns] Resolve AF_UNSPEC on dual-stacked systems. Sort addresses according to RF…

net/dns/address_sorter_posix.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef NET_DNS_ADDRESS_SORTER_POSIX_H_
-#define NET_DNS_ADDRESS_SORTER_POSIX_H_
-
-#include <map>
-#include <vector>
-
-#include "base/threading/non_thread_safe.h"
-#include "net/base/address_list.h"
-#include "net/base/net_errors.h"
-#include "net/base/net_export.h"
-#include "net/base/net_util.h"
-#include "net/base/network_change_notifier.h"
-#include "net/dns/address_sorter.h"
-
-namespace net {
-
-class ClientSocketFactory;
-
-// This implementation uses explicit policy to perform the sorting. It is not
-// thread-safe and always completes synchronously.
-class NET_EXPORT_PRIVATE AddressSorterPosix
-    : public AddressSorter,
-      public base::NonThreadSafe,
-      public NetworkChangeNotifier::IPAddressObserver {
- public:
-  // Generic policy entry.
-  struct PolicyEntry {
-    // IPv4 addresses must be mapped to IPv6.
-    unsigned char prefix[kIPv6AddressSize];
-    unsigned prefix_length;
-    unsigned value;
-  };
-
-  typedef std::vector<PolicyEntry> PolicyTable;
-
-  enum AddressScope {
-    SCOPE_UNDEFINED = 0,
-    SCOPE_NODELOCAL = 1,
-    SCOPE_LINKLOCAL = 2,
-    SCOPE_SITELOCAL = 5,
-    SCOPE_ORGLOCAL = 8,
-    SCOPE_GLOBAL = 14,
-  };
-
-  struct SourceAddressInfo {
-    // Values read from policy tables.
-    AddressScope scope;
-    unsigned label;
-
-    // Values from the OS, matter only if more than one source address is used.
-    unsigned prefix_length;
-    bool deprecated;  // vs. preferred RFC4862
-    bool home;        // vs. care-of RFC6275
-    bool native;
-  };
-
-  typedef std::map<IPAddressNumber, SourceAddressInfo> SourceAddressMap;
-
-  explicit AddressSorterPosix(ClientSocketFactory* socket_factory);
-  virtual ~AddressSorterPosix();
-
-  // AddressSorter:
-  virtual void Sort(const AddressList& list,
-                    const CallbackType& callback) const OVERRIDE;
-
- private:
-  friend class AddressSorterPosixTest;
-
-  // NetworkChangeNotifier::IPAddressObserver:
-  virtual void OnIPAddressChanged() OVERRIDE;
-
-  // Fills |info| with values for |address| from policy tables.
-  void FillPolicy(const IPAddressNumber& address,
-                  SourceAddressInfo* info) const;
-
-  // Mutable to allow using default values for source addresses which were not
-  // found in most recent OnIPAddressChanged.
-  mutable SourceAddressMap source_map_;
-
-  ClientSocketFactory* socket_factory_;
-  PolicyTable precedence_table_;
-  PolicyTable label_table_;
-  PolicyTable ipv4_scope_table_;
-
-  DISALLOW_COPY_AND_ASSIGN(AddressSorterPosix);
-};
-
-}  // namespace net
-
-#endif  // NET_DNS_ADDRESS_SORTER_POSIX_H_