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1 // Copyright (c) 2011 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_MOCK_HOST_RESOLVER_H_ | |
6 #define NET_DNS_MOCK_HOST_RESOLVER_H_ | |
7 | |
8 #include <list> | |
9 #include <map> | |
10 | |
11 #include "base/memory/weak_ptr.h" | |
12 #include "base/synchronization/waitable_event.h" | |
13 #include "base/threading/non_thread_safe.h" | |
14 #include "net/dns/host_resolver.h" | |
15 #include "net/dns/host_resolver_proc.h" | |
16 | |
17 namespace net { | |
18 | |
19 class HostCache; | |
20 class RuleBasedHostResolverProc; | |
21 | |
22 // Fills |*addrlist| with a socket address for |host_list| which should be a | |
23 // comma-separated list of IPv4 or IPv6 literal(s) without enclosing brackets. | |
24 // If |canonical_name| is non-empty it is used as the DNS canonical name for | |
25 // the host. Returns OK on success, ERR_UNEXPECTED otherwise. | |
26 int ParseAddressList(const std::string& host_list, | |
27 const std::string& canonical_name, | |
28 AddressList* addrlist); | |
29 | |
30 // In most cases, it is important that unit tests avoid relying on making actual | |
31 // DNS queries since the resulting tests can be flaky, especially if the network | |
32 // is unreliable for some reason. To simplify writing tests that avoid making | |
33 // actual DNS queries, pass a MockHostResolver as the HostResolver dependency. | |
34 // The socket addresses returned can be configured using the | |
35 // RuleBasedHostResolverProc: | |
36 // | |
37 // host_resolver->rules()->AddRule("foo.com", "1.2.3.4"); | |
38 // host_resolver->rules()->AddRule("bar.com", "2.3.4.5"); | |
39 // | |
40 // The above rules define a static mapping from hostnames to IP address | |
41 // literals. The first parameter to AddRule specifies a host pattern to match | |
42 // against, and the second parameter indicates what value should be used to | |
43 // replace the given hostname. So, the following is also supported: | |
44 // | |
45 // host_mapper->AddRule("*.com", "127.0.0.1"); | |
46 // | |
47 // Replacement doesn't have to be string representing an IP address. It can | |
48 // re-map one hostname to another as well. | |
49 // | |
50 // By default, MockHostResolvers include a single rule that maps all hosts to | |
51 // 127.0.0.1. | |
52 | |
53 // Base class shared by MockHostResolver and MockCachingHostResolver. | |
54 class MockHostResolverBase : public HostResolver, | |
55 public base::SupportsWeakPtr<MockHostResolverBase>, | |
56 public base::NonThreadSafe { | |
57 public: | |
58 ~MockHostResolverBase() override; | |
59 | |
60 RuleBasedHostResolverProc* rules() { return rules_.get(); } | |
61 void set_rules(RuleBasedHostResolverProc* rules) { rules_ = rules; } | |
62 | |
63 // Controls whether resolutions complete synchronously or asynchronously. | |
64 void set_synchronous_mode(bool is_synchronous) { | |
65 synchronous_mode_ = is_synchronous; | |
66 } | |
67 | |
68 // Asynchronous requests are automatically resolved by default. | |
69 // If set_ondemand_mode() is set then Resolve() returns IO_PENDING and | |
70 // ResolveAllPending() must be explicitly invoked to resolve all requests | |
71 // that are pending. | |
72 void set_ondemand_mode(bool is_ondemand) { | |
73 ondemand_mode_ = is_ondemand; | |
74 } | |
75 | |
76 // HostResolver methods: | |
77 int Resolve(const RequestInfo& info, | |
78 RequestPriority priority, | |
79 AddressList* addresses, | |
80 const CompletionCallback& callback, | |
81 RequestHandle* out_req, | |
82 const BoundNetLog& net_log) override; | |
83 int ResolveFromCache(const RequestInfo& info, | |
84 AddressList* addresses, | |
85 const BoundNetLog& net_log) override; | |
86 void CancelRequest(RequestHandle req) override; | |
87 HostCache* GetHostCache() override; | |
88 | |
89 // Resolves all pending requests. It is only valid to invoke this if | |
90 // set_ondemand_mode was set before. The requests are resolved asynchronously, | |
91 // after this call returns. | |
92 void ResolveAllPending(); | |
93 | |
94 // Returns true if there are pending requests that can be resolved by invoking | |
95 // ResolveAllPending(). | |
96 bool has_pending_requests() const { return !requests_.empty(); } | |
97 | |
98 // The number of times that Resolve() has been called. | |
99 size_t num_resolve() const { | |
100 return num_resolve_; | |
101 } | |
102 | |
103 // The number of times that ResolveFromCache() has been called. | |
104 size_t num_resolve_from_cache() const { | |
105 return num_resolve_from_cache_; | |
106 } | |
107 | |
108 // Returns the RequestPriority of the last call to Resolve() (or | |
109 // DEFAULT_PRIORITY if Resolve() hasn't been called yet). | |
110 RequestPriority last_request_priority() const { | |
111 return last_request_priority_; | |
112 } | |
113 | |
114 protected: | |
115 explicit MockHostResolverBase(bool use_caching); | |
116 | |
117 private: | |
118 struct Request; | |
119 typedef std::map<size_t, Request*> RequestMap; | |
120 | |
121 // Resolve as IP or from |cache_| return cached error or | |
122 // DNS_CACHE_MISS if failed. | |
123 int ResolveFromIPLiteralOrCache(const RequestInfo& info, | |
124 AddressList* addresses); | |
125 // Resolve via |proc_|. | |
126 int ResolveProc(size_t id, const RequestInfo& info, AddressList* addresses); | |
127 // Resolve request stored in |requests_|. Pass rv to callback. | |
128 void ResolveNow(size_t id); | |
129 | |
130 RequestPriority last_request_priority_; | |
131 bool synchronous_mode_; | |
132 bool ondemand_mode_; | |
133 scoped_refptr<RuleBasedHostResolverProc> rules_; | |
134 scoped_ptr<HostCache> cache_; | |
135 RequestMap requests_; | |
136 size_t next_request_id_; | |
137 | |
138 size_t num_resolve_; | |
139 size_t num_resolve_from_cache_; | |
140 | |
141 DISALLOW_COPY_AND_ASSIGN(MockHostResolverBase); | |
142 }; | |
143 | |
144 class MockHostResolver : public MockHostResolverBase { | |
145 public: | |
146 MockHostResolver() : MockHostResolverBase(false /*use_caching*/) {} | |
147 ~MockHostResolver() override {} | |
148 }; | |
149 | |
150 // Same as MockHostResolver, except internally it uses a host-cache. | |
151 // | |
152 // Note that tests are advised to use MockHostResolver instead, since it is | |
153 // more predictable. (MockHostResolver also can be put into synchronous | |
154 // operation mode in case that is what you needed from the caching version). | |
155 class MockCachingHostResolver : public MockHostResolverBase { | |
156 public: | |
157 MockCachingHostResolver() : MockHostResolverBase(true /*use_caching*/) {} | |
158 ~MockCachingHostResolver() override {} | |
159 }; | |
160 | |
161 // RuleBasedHostResolverProc applies a set of rules to map a host string to | |
162 // a replacement host string. It then uses the system host resolver to return | |
163 // a socket address. Generally the replacement should be an IPv4 literal so | |
164 // there is no network dependency. | |
165 class RuleBasedHostResolverProc : public HostResolverProc { | |
166 public: | |
167 explicit RuleBasedHostResolverProc(HostResolverProc* previous); | |
168 | |
169 // Any hostname matching the given pattern will be replaced with the given | |
170 // replacement value. Usually, replacement should be an IP address literal. | |
171 void AddRule(const std::string& host_pattern, | |
172 const std::string& replacement); | |
173 | |
174 // Same as AddRule(), but further restricts to |address_family|. | |
175 void AddRuleForAddressFamily(const std::string& host_pattern, | |
176 AddressFamily address_family, | |
177 const std::string& replacement); | |
178 | |
179 // Same as AddRule(), but the replacement is expected to be an IPv4 or IPv6 | |
180 // literal. This can be used in place of AddRule() to bypass the system's | |
181 // host resolver (the address list will be constructed manually). | |
182 // If |canonical_name| is non-empty, it is copied to the resulting AddressList | |
183 // but does not impact DNS resolution. | |
184 // |ip_literal| can be a single IP address like "192.168.1.1" or a comma | |
185 // separated list of IP addresses, like "::1,192:168.1.2". | |
186 void AddIPLiteralRule(const std::string& host_pattern, | |
187 const std::string& ip_literal, | |
188 const std::string& canonical_name); | |
189 | |
190 void AddRuleWithLatency(const std::string& host_pattern, | |
191 const std::string& replacement, | |
192 int latency_ms); | |
193 | |
194 // Make sure that |host| will not be re-mapped or even processed by underlying | |
195 // host resolver procedures. It can also be a pattern. | |
196 void AllowDirectLookup(const std::string& host); | |
197 | |
198 // Simulate a lookup failure for |host| (it also can be a pattern). | |
199 void AddSimulatedFailure(const std::string& host); | |
200 | |
201 // Deletes all the rules that have been added. | |
202 void ClearRules(); | |
203 | |
204 // HostResolverProc methods: | |
205 int Resolve(const std::string& host, | |
206 AddressFamily address_family, | |
207 HostResolverFlags host_resolver_flags, | |
208 AddressList* addrlist, | |
209 int* os_error) override; | |
210 | |
211 private: | |
212 struct Rule; | |
213 typedef std::list<Rule> RuleList; | |
214 | |
215 ~RuleBasedHostResolverProc() override; | |
216 | |
217 RuleList rules_; | |
218 }; | |
219 | |
220 // Create rules that map all requests to localhost. | |
221 RuleBasedHostResolverProc* CreateCatchAllHostResolverProc(); | |
222 | |
223 // HangingHostResolver never completes its |Resolve| request. | |
224 class HangingHostResolver : public HostResolver { | |
225 public: | |
226 int Resolve(const RequestInfo& info, | |
227 RequestPriority priority, | |
228 AddressList* addresses, | |
229 const CompletionCallback& callback, | |
230 RequestHandle* out_req, | |
231 const BoundNetLog& net_log) override; | |
232 int ResolveFromCache(const RequestInfo& info, | |
233 AddressList* addresses, | |
234 const BoundNetLog& net_log) override; | |
235 void CancelRequest(RequestHandle req) override {} | |
236 }; | |
237 | |
238 // This class sets the default HostResolverProc for a particular scope. The | |
239 // chain of resolver procs starting at |proc| is placed in front of any existing | |
240 // default resolver proc(s). This means that if multiple | |
241 // ScopedDefaultHostResolverProcs are declared, then resolving will start with | |
242 // the procs given to the last-allocated one, then fall back to the procs given | |
243 // to the previously-allocated one, and so forth. | |
244 // | |
245 // NOTE: Only use this as a catch-all safety net. Individual tests should use | |
246 // MockHostResolver. | |
247 class ScopedDefaultHostResolverProc { | |
248 public: | |
249 ScopedDefaultHostResolverProc(); | |
250 explicit ScopedDefaultHostResolverProc(HostResolverProc* proc); | |
251 | |
252 ~ScopedDefaultHostResolverProc(); | |
253 | |
254 void Init(HostResolverProc* proc); | |
255 | |
256 private: | |
257 scoped_refptr<HostResolverProc> current_proc_; | |
258 scoped_refptr<HostResolverProc> previous_proc_; | |
259 }; | |
260 | |
261 } // namespace net | |
262 | |
263 #endif // NET_DNS_MOCK_HOST_RESOLVER_H_ | |
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