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
19namespace net {
20
21class ClientSocketFactory;
22
23// This implementation uses explicit policy to perform the sorting. It is not
24// thread-safe and always completes synchronously.
25class 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