Fast-fail WPAD detection.

net/proxy/proxy_script_decider.h

 // 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_PROXY_SCRIPT_DECIDER_H_
 #define NET_PROXY_PROXY_SCRIPT_DECIDER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
+#include "net/base/address_list.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 #include "net/base/net_log.h"
+#include "net/dns/host_resolver.h"
+#include "net/dns/single_request_host_resolver.h"
 #include "net/proxy/proxy_config.h"
 #include "net/proxy/proxy_resolver.h"
 #include "url/gurl.h"
 
 namespace net {
 
 class DhcpProxyScriptFetcher;
 class NetLogParameter;
 class ProxyResolver;
 class ProxyScriptFetcher;
@@ skipping 41 matching lines @@
   int Start(const ProxyConfig& config,
             const base::TimeDelta wait_delay,
             bool fetch_pac_bytes,
             const net::CompletionCallback& callback);
 
   const ProxyConfig& effective_config() const;
 
   // TODO(eroman): Return a const-pointer.
   ProxyResolverScriptData* script_data() const;
 
+  void SetHostResolverForTesting(HostResolver* resolver);

[szym, 2013/09/16 21:50:32]

Needs comment. Is this going to be used for quickcheck or for everything? Why
isn't the HostResolver from the fetcher enough?

[Elly Fong-Jones, 2013/09/16 22:10:11]

Deleted.

+
  private:
   // Represents the sources from which we can get PAC files; two types of
   // auto-detect or a custom URL.
   struct PacSource {
     enum Type {
       WPAD_DHCP,
       WPAD_DNS,
       CUSTOM
     };
 
     PacSource(Type type, const GURL& url)
         : type(type), url(url) {}
 
     // Returns a Value representing the PacSource.  |effective_pac_url| must
     // be non-NULL and point to the URL derived from information contained in
     // |this|, if Type is not WPAD_DHCP.
     base::Value* NetLogCallback(const GURL* effective_pac_url,
                                 NetLog::LogLevel log_level) const;
 
     Type type;
     GURL url;  // Empty unless |type == PAC_SOURCE_CUSTOM|.
   };
 
   typedef std::vector<PacSource> PacSourceList;
 
   enum State {
     STATE_NONE,
     STATE_WAIT,
     STATE_WAIT_COMPLETE,
+    STATE_QUICK_CHECK,
+    STATE_QUICK_CHECK_COMPLETE,
     STATE_FETCH_PAC_SCRIPT,
     STATE_FETCH_PAC_SCRIPT_COMPLETE,
     STATE_VERIFY_PAC_SCRIPT,
     STATE_VERIFY_PAC_SCRIPT_COMPLETE,
   };
 
   // Returns ordered list of PAC urls to try for |config|.
   PacSourceList BuildPacSourcesFallbackList(const ProxyConfig& config) const;
 
   void OnIOCompletion(int result);
   int DoLoop(int result);
   void DoCallback(int result);
 
   int DoWait();
   int DoWaitComplete(int result);
 
+  int DoQuickCheck();
+  int DoQuickCheckComplete(int result);
+
   int DoFetchPacScript();
   int DoFetchPacScriptComplete(int result);
 
   int DoVerifyPacScript();
   int DoVerifyPacScriptComplete(int result);
 
   // Tries restarting using the next fallback PAC URL:
   // |pac_sources_[++current_pac_source_index]|.
   // Returns OK and rewinds the state machine when there
   // is something to try, otherwise returns |error|.
@@ skipping 34 matching lines @@
 
   bool fetch_pac_bytes_;
 
   base::TimeDelta wait_delay_;
   base::OneShotTimer<ProxyScriptDecider> wait_timer_;
 
   // Results.
   ProxyConfig effective_config_;
   scoped_refptr<ProxyResolverScriptData> script_data_;
 
+  AddressList wpad_addresses_;
+  base::OneShotTimer<ProxyScriptDecider> quick_check_timer_;
+  scoped_ptr<SingleRequestHostResolver> host_resolver_;
+  base::Time quick_check_start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyScriptDecider);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SCRIPT_DECIDER_H_