1 // Copyright 2011 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 // PacFileFetcher is an async interface for fetching a proxy auto config 6 // script. It is specific to fetching a PAC script; enforces timeout, max-size, 7 // status code. 8 9 #ifndef NET_PROXY_RESOLUTION_PAC_FILE_FETCHER_H_ 10 #define NET_PROXY_RESOLUTION_PAC_FILE_FETCHER_H_ 11 12 #include <string> 13 14 #include "net/base/completion_once_callback.h" 15 #include "net/base/isolation_info.h" 16 #include "net/base/net_export.h" 17 #include "net/traffic_annotation/network_traffic_annotation.h" 18 19 class GURL; 20 21 namespace net { 22 23 class URLRequestContext; 24 25 // Interface for downloading a PAC script. Implementations can enforce 26 // timeouts, maximum size constraints, content encoding, etc.. 27 class NET_EXPORT_PRIVATE PacFileFetcher { 28 public: 29 PacFileFetcher(); 30 PacFileFetcher(const PacFileFetcher&) = delete; 31 PacFileFetcher& operator=(const PacFileFetcher&) = delete; 32 33 // Destruction should cancel any outstanding requests. 34 virtual ~PacFileFetcher(); 35 36 // Downloads the given PAC URL, and invokes |callback| on completion. 37 // Returns OK on success, otherwise the error code. If the return code is 38 // ERR_IO_PENDING, then the request completes asynchronously, and |callback| 39 // will be invoked later with the final error code. 40 // After synchronous or asynchronous completion with a result code of OK, 41 // |*utf16_text| is filled with the response. On failure, the result text is 42 // an empty string, and the result code is a network error. Some special 43 // network errors that may occur are: 44 // 45 // ERR_TIMED_OUT -- the fetch took too long to complete. 46 // ERR_FILE_TOO_BIG -- the response's body was too large. 47 // ERR_HTTP_RESPONSE_CODE_FAILURE -- non-200 HTTP status code. 48 // ERR_NOT_IMPLEMENTED -- the response required authentication. 49 // 50 // If the request is cancelled (either using the "Cancel()" method or by 51 // deleting |this|), then no callback is invoked. 52 // 53 // Only one fetch is allowed to be outstanding at a time. 54 virtual int Fetch(const GURL& url, 55 std::u16string* utf16_text, 56 CompletionOnceCallback callback, 57 const NetworkTrafficAnnotationTag traffic_annotation) = 0; 58 59 // Aborts the in-progress fetch (if any). 60 virtual void Cancel() = 0; 61 62 // Returns the request context that this fetcher uses to issue downloads, 63 // or NULL. 64 virtual URLRequestContext* GetRequestContext() const = 0; 65 66 // Fails the in-progress fetch (if any) and future requests will fail 67 // immediately. GetRequestContext() will always return nullptr after this is 68 // called. Must be called before the URLRequestContext the fetcher was 69 // created with is torn down. 70 virtual void OnShutdown() = 0; 71 isolation_info()72 const IsolationInfo& isolation_info() const { return isolation_info_; } 73 74 private: 75 // Transient IsolationInfo used to fetch PAC scripts and resolve hostnames. 76 // Safe to reuse because delays for WPAD fetches don't provide information 77 // to the web platform useful to attackers, and WPAD fetches uniformly 78 // block all network requests. 79 const IsolationInfo isolation_info_ = IsolationInfo::CreateTransient(); 80 }; 81 82 } // namespace net 83 84 #endif // NET_PROXY_RESOLUTION_PAC_FILE_FETCHER_H_ 85