| // Copyright (c) 2012 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 NET_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_ |
| #define NET_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_ |
| |
| #include <set> |
| #include <string> |
| |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/scoped_vector.h" |
| #include "base/message_loop/message_loop_proxy.h" |
| #include "base/threading/non_thread_safe.h" |
| #include "base/time/time.h" |
| #include "base/timer/timer.h" |
| #include "net/proxy/dhcp_proxy_script_fetcher.h" |
| |
| namespace base { |
| class SequencedWorkerPool; |
| } |
| |
| namespace net { |
| |
| class DhcpProxyScriptAdapterFetcher; |
| class URLRequestContext; |
| |
| // Windows-specific implementation. |
| class NET_EXPORT_PRIVATE DhcpProxyScriptFetcherWin |
| : public DhcpProxyScriptFetcher, |
| public base::SupportsWeakPtr<DhcpProxyScriptFetcherWin>, |
| NON_EXPORTED_BASE(public base::NonThreadSafe) { |
| public: |
| // Creates a DhcpProxyScriptFetcherWin that issues requests through |
| // |url_request_context|. |url_request_context| must remain valid for |
| // the lifetime of DhcpProxyScriptFetcherWin. |
| explicit DhcpProxyScriptFetcherWin(URLRequestContext* url_request_context); |
| virtual ~DhcpProxyScriptFetcherWin(); |
| |
| // DhcpProxyScriptFetcher implementation. |
| int Fetch(base::string16* utf16_text, |
| const net::CompletionCallback& callback) OVERRIDE; |
| void Cancel() OVERRIDE; |
| const GURL& GetPacURL() const OVERRIDE; |
| std::string GetFetcherName() const OVERRIDE; |
| |
| // Sets |adapter_names| to contain the name of each network adapter on |
| // this machine that has DHCP enabled and is not a loop-back adapter. Returns |
| // false on error. |
| static bool GetCandidateAdapterNames(std::set<std::string>* adapter_names); |
| |
| protected: |
| int num_pending_fetchers() const; |
| |
| URLRequestContext* url_request_context() const; |
| |
| scoped_refptr<base::TaskRunner> GetTaskRunner(); |
| |
| // This inner class encapsulate work done on a worker pool thread. |
| // The class calls GetCandidateAdapterNames, which can take a couple of |
| // hundred milliseconds. |
| class NET_EXPORT_PRIVATE AdapterQuery |
| : public base::RefCountedThreadSafe<AdapterQuery> { |
| public: |
| AdapterQuery(); |
| virtual ~AdapterQuery(); |
| |
| // This is the method that runs on the worker pool thread. |
| void GetCandidateAdapterNames(); |
| |
| // This set is valid after GetCandidateAdapterNames has |
| // been run. Its lifetime is scoped by this object. |
| const std::set<std::string>& adapter_names() const; |
| |
| protected: |
| // Virtual method introduced to allow unit testing. |
| virtual bool ImplGetCandidateAdapterNames( |
| std::set<std::string>* adapter_names); |
| |
| private: |
| // This is constructed on the originating thread, then used on the |
| // worker thread, then used again on the originating thread only when |
| // the task has completed on the worker thread. No locking required. |
| std::set<std::string> adapter_names_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AdapterQuery); |
| }; |
| |
| // Virtual methods introduced to allow unit testing. |
| virtual DhcpProxyScriptAdapterFetcher* ImplCreateAdapterFetcher(); |
| virtual AdapterQuery* ImplCreateAdapterQuery(); |
| virtual base::TimeDelta ImplGetMaxWait(); |
| virtual void ImplOnGetCandidateAdapterNamesDone() {} |
| |
| private: |
| // Event/state transition handlers |
| void CancelImpl(); |
| void OnGetCandidateAdapterNamesDone(scoped_refptr<AdapterQuery> query); |
| void OnFetcherDone(int result); |
| void OnWaitTimer(); |
| void TransitionToDone(); |
| |
| // This is the outer state machine for fetching PAC configuration from |
| // DHCP. It relies for sub-states on the state machine of the |
| // DhcpProxyScriptAdapterFetcher class. |
| // |
| // The goal of the implementation is to the following work in parallel |
| // for all network adapters that are using DHCP: |
| // a) Try to get the PAC URL configured in DHCP; |
| // b) If one is configured, try to fetch the PAC URL. |
| // c) Once this is done for all adapters, or a timeout has passed after |
| // it has completed for the fastest adapter, return the PAC file |
| // available for the most preferred network adapter, if any. |
| // |
| // The state machine goes from START->WAIT_ADAPTERS when it starts a |
| // worker thread to get the list of adapters with DHCP enabled. |
| // It then goes from WAIT_ADAPTERS->NO_RESULTS when it creates |
| // and starts an DhcpProxyScriptAdapterFetcher for each adapter. It goes |
| // from NO_RESULTS->SOME_RESULTS when it gets the first result; at this |
| // point a wait timer is started. It goes from SOME_RESULTS->DONE in |
| // two cases: All results are known, or the wait timer expired. A call |
| // to Cancel() will also go straight to DONE from any state. Any |
| // way the DONE state is entered, we will at that point cancel any |
| // outstanding work and return the best known PAC script or the empty |
| // string. |
| // |
| // The state machine is reset for each Fetch(), a call to which is |
| // only valid in states START and DONE, as only one Fetch() is |
| // allowed to be outstanding at any given time. |
| enum State { |
| STATE_START, |
| STATE_WAIT_ADAPTERS, |
| STATE_NO_RESULTS, |
| STATE_SOME_RESULTS, |
| STATE_DONE, |
| }; |
| |
| // Current state of this state machine. |
| State state_; |
| |
| // Vector, in Windows' network adapter preference order, of |
| // DhcpProxyScriptAdapterFetcher objects that are or were attempting |
| // to fetch a PAC file based on DHCP configuration. |
| typedef ScopedVector<DhcpProxyScriptAdapterFetcher> FetcherVector; |
| FetcherVector fetchers_; |
| |
| // Number of fetchers we are waiting for. |
| int num_pending_fetchers_; |
| |
| // Lets our client know we're done. Not valid in states START or DONE. |
| net::CompletionCallback callback_; |
| |
| // Pointer to string we will write results to. Not valid in states |
| // START and DONE. |
| base::string16* destination_string_; |
| |
| // PAC URL retrieved from DHCP, if any. Valid only in state STATE_DONE. |
| GURL pac_url_; |
| |
| base::OneShotTimer<DhcpProxyScriptFetcherWin> wait_timer_; |
| |
| URLRequestContext* const url_request_context_; |
| |
| // NULL or the AdapterQuery currently in flight. |
| scoped_refptr<AdapterQuery> last_query_; |
| |
| // Time |Fetch()| was last called, 0 if never. |
| base::TimeTicks fetch_start_time_; |
| |
| // Worker pool we use for all DHCP lookup tasks. |
| scoped_refptr<base::SequencedWorkerPool> worker_pool_; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(DhcpProxyScriptFetcherWin); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_PROXY_DHCP_PROXY_SCRIPT_FETCHER_WIN_H_ |