xref: /aosp_15_r20/external/cronet/net/dns/mapped_host_resolver.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2012 The Chromium Authors
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_MAPPED_HOST_RESOLVER_H_
6 #define NET_DNS_MAPPED_HOST_RESOLVER_H_
7 
8 #include <memory>
9 #include <optional>
10 #include <string_view>
11 #include <vector>
12 
13 #include "base/values.h"
14 #include "net/base/completion_once_callback.h"
15 #include "net/base/host_mapping_rules.h"
16 #include "net/base/net_export.h"
17 #include "net/base/network_anonymization_key.h"
18 #include "net/dns/dns_config.h"
19 #include "net/dns/host_resolver.h"
20 #include "net/log/net_log_with_source.h"
21 #include "url/scheme_host_port.h"
22 
23 namespace net {
24 
25 // This class wraps an existing HostResolver instance, but modifies the
26 // request before passing it off to |impl|. This is different from
27 // MockHostResolver which does the remapping at the HostResolverProc
28 // layer, so it is able to preserve the effectiveness of the cache.
29 class NET_EXPORT MappedHostResolver : public HostResolver {
30  public:
31   // Creates a MappedHostResolver that forwards all of its requests through
32   // |impl|.
33   explicit MappedHostResolver(std::unique_ptr<HostResolver> impl);
34   ~MappedHostResolver() override;
35 
36   void OnShutdown() override;
37 
38   // Adds a rule to this mapper. The format of the rule can be one of:
39   //
40   //   "MAP" <hostname_pattern> <replacement_host> [":" <replacement_port>]
41   //   "EXCLUDE" <hostname_pattern>
42   //
43   // The <replacement_host> can be either a hostname, or an IP address literal,
44   // or "^NOTFOUND". If it is "^NOTFOUND" then all matched hostnames will fail
45   // to be resolved with ERR_NAME_NOT_RESOLVED.
46   //
47   // Returns true if the rule was successfully parsed and added.
AddRuleFromString(std::string_view rule_string)48   bool AddRuleFromString(std::string_view rule_string) {
49     return rules_.AddRuleFromString(rule_string);
50   }
51 
52   // Takes a comma separated list of rules, and assigns them to this resolver.
SetRulesFromString(std::string_view rules_string)53   void SetRulesFromString(std::string_view rules_string) {
54     rules_.SetRulesFromString(rules_string);
55   }
56 
57   // HostResolver methods:
58   std::unique_ptr<ResolveHostRequest> CreateRequest(
59       url::SchemeHostPort host,
60       NetworkAnonymizationKey network_anonymization_key,
61       NetLogWithSource net_log,
62       std::optional<ResolveHostParameters> optional_parameters) override;
63   std::unique_ptr<ResolveHostRequest> CreateRequest(
64       const HostPortPair& host,
65       const NetworkAnonymizationKey& network_anonymization_key,
66       const NetLogWithSource& net_log,
67       const std::optional<ResolveHostParameters>& optional_parameters) override;
68   std::unique_ptr<ServiceEndpointRequest> CreateServiceEndpointRequest(
69       Host host,
70       NetworkAnonymizationKey network_anonymization_key,
71       NetLogWithSource net_log,
72       ResolveHostParameters parameters) override;
73   std::unique_ptr<ProbeRequest> CreateDohProbeRequest() override;
74   HostCache* GetHostCache() override;
75   base::Value::Dict GetDnsConfigAsValue() const override;
76   void SetRequestContext(URLRequestContext* request_context) override;
77   HostResolverManager* GetManagerForTesting() override;
78 
79  private:
80   std::unique_ptr<HostResolver> impl_;
81 
82   HostMappingRules rules_;
83 };
84 
85 }  // namespace net
86 
87 #endif  // NET_DNS_MAPPED_HOST_RESOLVER_H_
88