1//
2// Copyright (C) 2010 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17#ifndef UPDATE_ENGINE_PROXY_RESOLVER_H_
18#define UPDATE_ENGINE_PROXY_RESOLVER_H_
19
20#include <deque>
21#include <string>
22
23#include <base/logging.h>
24#include <brillo/message_loops/message_loop.h>
25
26#include "update_engine/common/utils.h"
27
28namespace chromeos_update_engine {
29
30extern const char kNoProxy[];
31
32// Callback for a call to GetProxiesForUrl().
33// Resultant proxies are in |out_proxy|. Each will be in one of the
34// following forms:
35// http://<host>[:<port>] - HTTP proxy
36// socks{4,5}://<host>[:<port>] - SOCKS4/5 proxy
37// kNoProxy - no proxy
38typedef void (*ProxiesResolvedFn)(const std::deque<std::string>& proxies,
39                                  void* data);
40
41class ProxyResolver {
42 public:
43  ProxyResolver() {}
44  virtual ~ProxyResolver() {}
45
46  // Finds proxies for the given URL and returns them via the callback.
47  // |data| will be passed to the callback.
48  // Returns true on success.
49  virtual bool GetProxiesForUrl(const std::string& url,
50                                ProxiesResolvedFn callback,
51                                void* data) = 0;
52
53 private:
54  DISALLOW_COPY_AND_ASSIGN(ProxyResolver);
55};
56
57// Always says to not use a proxy
58class DirectProxyResolver : public ProxyResolver {
59 public:
60  DirectProxyResolver() = default;
61  ~DirectProxyResolver() override;
62  bool GetProxiesForUrl(const std::string& url,
63                        ProxiesResolvedFn callback,
64                        void* data) override;
65
66  // Set the number of direct (non-) proxies to be returned by resolver.
67  // The default value is 1; higher numbers are currently used in testing.
68  inline void set_num_proxies(size_t num_proxies) {
69    num_proxies_ = num_proxies;
70  }
71
72 private:
73  // The ID of the main loop callback.
74  brillo::MessageLoop::TaskId idle_callback_id_{
75      brillo::MessageLoop::kTaskIdNull};
76
77  // Number of direct proxies to return on resolved list; currently used for
78  // testing.
79  size_t num_proxies_{1};
80
81  // The MainLoop callback, from here we return to the client.
82  void ReturnCallback(ProxiesResolvedFn callback, void* data);
83  DISALLOW_COPY_AND_ASSIGN(DirectProxyResolver);
84};
85
86}  // namespace chromeos_update_engine
87
88#endif  // UPDATE_ENGINE_PROXY_RESOLVER_H_
89