1 // Copyright (c) 2012 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_PROXY_DHCP_SCRIPT_FETCHER_H_ 6 #define NET_PROXY_DHCP_SCRIPT_FETCHER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/compiler_specific.h" 10 #include "base/strings/string16.h" 11 #include "net/base/completion_callback.h" 12 #include "net/base/net_export.h" 13 #include "net/proxy/proxy_script_fetcher.h" 14 #include "url/gurl.h" 15 16 namespace net { 17 18 // Interface for classes that can fetch a proxy script as configured via DHCP. 19 // 20 // The Fetch method on this interface tries to retrieve the most appropriate 21 // PAC script configured via DHCP. 22 // 23 // Normally there are zero or one DHCP scripts configured, but in the 24 // presence of multiple adapters with DHCP enabled, the fetcher resolves 25 // which PAC script to use if one or more are available. 26 class NET_EXPORT_PRIVATE DhcpProxyScriptFetcher { 27 public: 28 // Destruction should cancel any outstanding requests. 29 virtual ~DhcpProxyScriptFetcher(); 30 31 // Attempts to retrieve the most appropriate PAC script configured via DHCP, 32 // and invokes |callback| on completion. 33 // 34 // Returns OK on success, otherwise the error code. If the return code is 35 // ERR_IO_PENDING, then the request completes asynchronously, and |callback| 36 // will be invoked later with the final error code. 37 // 38 // After synchronous or asynchronous completion with a result code of OK, 39 // |*utf16_text| is filled with the response. On failure, the result text is 40 // an empty string, and the result code is a network error. Some special 41 // network errors that may occur are: 42 // 43 // ERR_PAC_NOT_IN_DHCP -- no script configured in DHCP. 44 // 45 // The following all indicate there was one or more script configured 46 // in DHCP but all failed to download, and the error for the most 47 // preferred adapter that had a script configured was what the error 48 // code says: 49 // 50 // ERR_TIMED_OUT -- fetch took too long to complete. 51 // ERR_FILE_TOO_BIG -- response body was too large. 52 // ERR_PAC_STATUS_NOT_OK -- script failed to download. 53 // ERR_NOT_IMPLEMENTED -- script required authentication. 54 // 55 // If the request is cancelled (either using the "Cancel()" method or by 56 // deleting |this|), then no callback is invoked. 57 // 58 // Only one fetch is allowed to be outstanding at a time. 59 virtual int Fetch(base::string16* utf16_text, 60 const CompletionCallback& callback) = 0; 61 62 // Aborts the in-progress fetch (if any). 63 virtual void Cancel() = 0; 64 65 // After successful completion of |Fetch()|, this will return the URL 66 // retrieved from DHCP. It is reset if/when |Fetch()| is called again. 67 virtual const GURL& GetPacURL() const = 0; 68 69 // Intended for unit tests only, so they can test that factories return 70 // the right types under given circumstances. 71 virtual std::string GetFetcherName() const; 72 73 protected: 74 DhcpProxyScriptFetcher(); 75 76 private: 77 DISALLOW_COPY_AND_ASSIGN(DhcpProxyScriptFetcher); 78 }; 79 80 // A do-nothing retriever, always returns synchronously with 81 // ERR_NOT_IMPLEMENTED result and empty text. 82 class NET_EXPORT_PRIVATE DoNothingDhcpProxyScriptFetcher 83 : public DhcpProxyScriptFetcher { 84 public: 85 DoNothingDhcpProxyScriptFetcher(); 86 virtual ~DoNothingDhcpProxyScriptFetcher(); 87 88 virtual int Fetch(base::string16* utf16_text, 89 const CompletionCallback& callback) OVERRIDE; 90 virtual void Cancel() OVERRIDE; 91 virtual const GURL& GetPacURL() const OVERRIDE; 92 private: 93 GURL gurl_; 94 DISALLOW_COPY_AND_ASSIGN(DoNothingDhcpProxyScriptFetcher); 95 }; 96 97 } // namespace net 98 99 #endif // NET_PROXY_DHCP_SCRIPT_FETCHER_H_ 100