| // Copyright 2013 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 CHROME_BROWSER_NET_DNS_PROBE_RUNNER_H_ |
| #define CHROME_BROWSER_NET_DNS_PROBE_RUNNER_H_ |
| |
| #include "base/basictypes.h" |
| #include "base/bind.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/memory/weak_ptr.h" |
| |
| namespace net { |
| class DnsClient; |
| class DnsResponse; |
| class DnsTransaction; |
| } |
| |
| namespace chrome_browser_net { |
| |
| // Runs DNS probes using a single DnsClient and evaluates the responses. |
| // (Currently requests A records for google.com and expects at least one IP |
| // address in the response.) |
| // Used by DnsProbeService to probe the system and public DNS configurations. |
| class DnsProbeRunner { |
| public: |
| static const char* kKnownGoodHostname; |
| |
| // Used in histograms; add new entries at the bottom, and don't remove any. |
| enum Result { |
| UNKNOWN, |
| CORRECT, // Response contains at least one A record. |
| INCORRECT, // Response claimed success but included no A records. |
| FAILING, // Response included an error or was malformed. |
| UNREACHABLE // No response received (timeout, network unreachable, etc.). |
| }; |
| |
| DnsProbeRunner(); |
| ~DnsProbeRunner(); |
| |
| // Sets the DnsClient that will be used for DNS probes sent by this runner. |
| // Must be called before RunProbe; can be called repeatedly, including during |
| // a probe. It will not affect an in-flight probe, if one is running. |
| void SetClient(scoped_ptr<net::DnsClient> client); |
| |
| // Starts a probe using the client specified with SetClient, which must have |
| // been called before RunProbe. |callback| will be called asynchronously |
| // when the result is ready, even if it is ready synchronously. Must not |
| // be called again until the callback is called, but may be called during the |
| // callback. |
| void RunProbe(const base::Closure& callback); |
| |
| // Returns true if a probe is running. Guaranteed to return true after |
| // RunProbe returns, and false during and after the callback. |
| bool IsRunning() const; |
| |
| // Returns the result of the last probe. |
| Result result() const { return result_; } |
| |
| private: |
| void OnTransactionComplete(net::DnsTransaction* transaction, |
| int net_error, |
| const net::DnsResponse* response); |
| void CallCallback(); |
| |
| base::WeakPtrFactory<DnsProbeRunner> weak_factory_; |
| |
| scoped_ptr<net::DnsClient> client_; |
| |
| // The callback passed to |RunProbe|. Cleared right before calling the |
| // callback. |
| base::Closure callback_; |
| |
| // The transaction started in |RunProbe| for the DNS probe. Reset once the |
| // results have been examined. |
| scoped_ptr<net::DnsTransaction> transaction_; |
| |
| Result result_; |
| |
| DISALLOW_COPY_AND_ASSIGN(DnsProbeRunner); |
| }; |
| |
| } // namespace chrome_browser_net |
| |
| #endif // CHROME_BROWSER_NET_DNS_PROBE_RUNNER_H_ |