1 //
2 // Copyright (C) 2011 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 //      http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16 
17 #ifndef UPDATE_ENGINE_COMMON_DOWNLOAD_ACTION_H_
18 #define UPDATE_ENGINE_COMMON_DOWNLOAD_ACTION_H_
19 
20 #include <fcntl.h>
21 #include <sys/stat.h>
22 #include <sys/types.h>
23 
24 #include <memory>
25 #include <string>
26 #include <utility>
27 
28 #include "update_engine/common/boot_control_interface.h"
29 #include "update_engine/common/http_fetcher.h"
30 #include "update_engine/common/multi_range_http_fetcher.h"
31 #include "update_engine/payload_consumer/delta_performer.h"
32 #include "update_engine/payload_consumer/install_plan.h"
33 
34 // The Download Action downloads a specified url to disk. The url should point
35 // to an update in a delta payload format. The payload will be piped into a
36 // DeltaPerformer that will apply the delta to the disk.
37 
38 namespace chromeos_update_engine {
39 
40 class DownloadActionDelegate {
41  public:
42   virtual ~DownloadActionDelegate() = default;
43 
44   // Called periodically after bytes are received. This method will be invoked
45   // only if the DownloadAction is running. |bytes_progressed| is the number of
46   // bytes downloaded since the last call of this method, |bytes_received|
47   // the number of bytes downloaded thus far and |total| is the number of bytes
48   // expected.
49   virtual void BytesReceived(uint64_t bytes_progressed,
50                              uint64_t bytes_received,
51                              uint64_t total) = 0;
52 
53   // Returns whether the download should be canceled, in which case the
54   // |cancel_reason| error should be set to the reason why the download was
55   // canceled.
56   virtual bool ShouldCancel(ErrorCode* cancel_reason) = 0;
57 
58   // Called once the complete payload has been downloaded. Note that any errors
59   // while applying or downloading the partial payload will result in this
60   // method not being called.
61   virtual void DownloadComplete() = 0;
62 };
63 
64 class PrefsInterface;
65 
66 class DownloadAction : public InstallPlanAction, public HttpFetcherDelegate {
67  public:
68   // Debugging/logging
StaticType()69   static std::string StaticType() { return "DownloadAction"; }
70 
71   // Takes ownership of the passed in HttpFetcher. Useful for testing.
72   // A good calling pattern is:
73   // DownloadAction(prefs, boot_contol, hardware,
74   //                new WhateverHttpFetcher, false);
75   DownloadAction(
76       PrefsInterface* prefs,
77       BootControlInterface* boot_control,
78       HardwareInterface* hardware,
79       HttpFetcher* http_fetcher,
80       bool interactive,
81       std::string update_certs_path = constants::kUpdateCertificatesPath);
82   ~DownloadAction() override;
83 
84   // InstallPlanAction overrides.
85   void PerformAction() override;
86   void SuspendAction() override;
87   void ResumeAction() override;
88   void TerminateProcessing() override;
Type()89   std::string Type() const override { return StaticType(); }
90 
91   // Testing
SetTestFileWriter(std::unique_ptr<DeltaPerformer> writer)92   void SetTestFileWriter(std::unique_ptr<DeltaPerformer> writer) {
93     delta_performer_ = std::move(writer);
94   }
95 
GetHTTPResponseCode()96   int GetHTTPResponseCode() { return http_fetcher_->http_response_code(); }
97 
98   // HttpFetcherDelegate methods (see http_fetcher.h)
99   bool ReceivedBytes(HttpFetcher* fetcher,
100                      const void* bytes,
101                      size_t length) override;
102   void SeekToOffset(off_t offset) override;
103   void TransferComplete(HttpFetcher* fetcher, bool successful) override;
104   void TransferTerminated(HttpFetcher* fetcher) override;
105 
delegate()106   DownloadActionDelegate* delegate() const { return delegate_; }
set_delegate(DownloadActionDelegate * delegate)107   void set_delegate(DownloadActionDelegate* delegate) { delegate_ = delegate; }
108 
set_base_offset(int64_t base_offset)109   void set_base_offset(int64_t base_offset) { base_offset_ = base_offset; }
110 
http_fetcher()111   HttpFetcher* http_fetcher() { return http_fetcher_.get(); }
112 
113  private:
114   // Attempt to load cached manifest data from prefs
115   // return true on success, false otherwise.
116   bool LoadCachedManifest(int64_t manifest_size);
117 
118   // Start downloading the current payload using delta_performer.
119   void StartDownloading();
120 
121   // Pointer to the current payload in install_plan_.payloads.
122   InstallPlan::Payload* payload_{nullptr};
123 
124   // Required pointers.
125   PrefsInterface* prefs_;
126   BootControlInterface* boot_control_;
127   HardwareInterface* hardware_;
128 
129   // Pointer to the MultiRangeHttpFetcher that does the http work.
130   std::unique_ptr<MultiRangeHttpFetcher> http_fetcher_;
131 
132   // If |true|, the update is user initiated (vs. periodic update checks). Hence
133   // the |delta_performer_| can decide not to use O_DSYNC flag for faster
134   // update.
135   bool interactive_;
136 
137   std::unique_ptr<DeltaPerformer> delta_performer_;
138 
139   // Used by TransferTerminated to figure if this action terminated itself or
140   // was terminated by the action processor.
141   ErrorCode code_;
142 
143   // For reporting status to outsiders
144   DownloadActionDelegate* delegate_;
145   uint64_t bytes_received_{0};  // per file/range
146   uint64_t bytes_received_previous_payloads_{0};
147   uint64_t bytes_total_{0};
148   bool download_active_{false};
149 
150   // Loaded from prefs before downloading any payload.
151   size_t resume_payload_index_{0};
152 
153   // Offset of the payload in the download URL, used by UpdateAttempterAndroid.
154   int64_t base_offset_{0};
155 
156   // The path to the zip file with X509 certificates.
157   const std::string update_certificates_path_;
158 
159   DISALLOW_COPY_AND_ASSIGN(DownloadAction);
160 };
161 
162 // We want to be sure that we're compiled with large file support on linux,
163 // just in case we find ourselves downloading large images.
164 static_assert(8 == sizeof(off_t), "off_t not 64 bit");
165 
166 }  // namespace chromeos_update_engine
167 
168 #endif  // UPDATE_ENGINE_COMMON_DOWNLOAD_ACTION_H_
169