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      1 //
      2 // Copyright (C) 2012 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_TEST_UTILS_H_
     18 #define UPDATE_ENGINE_COMMON_TEST_UTILS_H_
     19 
     20 #include <sys/stat.h>
     21 #include <sys/types.h>
     22 #include <unistd.h>
     23 
     24 // Streams used for gtest's PrintTo() functions.
     25 #include <iostream>  // NOLINT(readability/streams)
     26 #include <memory>
     27 #include <set>
     28 #include <string>
     29 #include <vector>
     30 
     31 #include <base/callback.h>
     32 #include <base/files/file_path.h>
     33 #include <gtest/gtest.h>
     34 
     35 #include "update_engine/common/action.h"
     36 #include "update_engine/common/subprocess.h"
     37 #include "update_engine/common/utils.h"
     38 #include "update_engine/update_metadata.pb.h"
     39 
     40 // These are some handy functions for unittests.
     41 
     42 namespace chromeos_update_engine {
     43 
     44 // PrintTo() functions are used by gtest to log these objects. These PrintTo()
     45 // functions must be defined in the same namespace as the first argument.
     46 void PrintTo(const Extent& extent, ::std::ostream* os);
     47 void PrintTo(const ErrorCode& error_code, ::std::ostream* os);
     48 
     49 namespace test_utils {
     50 
     51 // 300 byte pseudo-random string. Not null terminated.
     52 // This does not gzip compress well.
     53 extern const uint8_t kRandomString[300];
     54 
     55 // Writes the data passed to path. The file at path will be overwritten if it
     56 // exists. Returns true on success, false otherwise.
     57 bool WriteFileVector(const std::string& path, const brillo::Blob& data);
     58 bool WriteFileString(const std::string& path, const std::string& data);
     59 
     60 // Binds provided |filename| to an unused loopback device, whose name is written
     61 // to the string pointed to by |out_lo_dev_name|. The new loop device will be
     62 // read-only unless |writable| is set to true. Returns true on success, false
     63 // otherwise (along with corresponding test failures), in which case the content
     64 // of |out_lo_dev_name| is unknown.
     65 bool BindToUnusedLoopDevice(const std::string& filename,
     66                             bool writable,
     67                             std::string* out_lo_dev_name);
     68 bool UnbindLoopDevice(const std::string& lo_dev_name);
     69 
     70 // Returns true iff a == b
     71 bool ExpectVectorsEq(const brillo::Blob& a, const brillo::Blob& b);
     72 
     73 inline int System(const std::string& cmd) {
     74   return system(cmd.c_str());
     75 }
     76 
     77 inline int Symlink(const std::string& oldpath, const std::string& newpath) {
     78   return symlink(oldpath.c_str(), newpath.c_str());
     79 }
     80 
     81 inline int Chmod(const std::string& path, mode_t mode) {
     82   return chmod(path.c_str(), mode);
     83 }
     84 
     85 inline int Mkdir(const std::string& path, mode_t mode) {
     86   return mkdir(path.c_str(), mode);
     87 }
     88 
     89 inline int Chdir(const std::string& path) {
     90   return chdir(path.c_str());
     91 }
     92 
     93 // Reads a symlink from disk. Returns empty string on failure.
     94 std::string Readlink(const std::string& path);
     95 
     96 // Checks if xattr is supported in the directory specified by
     97 // |dir_path| which must be writable. Returns true if the feature is
     98 // supported, false if not or if an error occurred.
     99 bool IsXAttrSupported(const base::FilePath& dir_path);
    100 
    101 void FillWithData(brillo::Blob* buffer);
    102 
    103 // Creates an empty ext image.
    104 void CreateEmptyExtImageAtPath(const std::string& path,
    105                                size_t size,
    106                                int block_size);
    107 
    108 // Creates an ext image with some files in it. The paths creates are
    109 // returned in out_paths.
    110 void CreateExtImageAtPath(const std::string& path,
    111                           std::vector<std::string>* out_paths);
    112 
    113 // Class to unmount FS when object goes out of scope
    114 class ScopedFilesystemUnmounter {
    115  public:
    116   explicit ScopedFilesystemUnmounter(const std::string& mountpoint)
    117       : mountpoint_(mountpoint),
    118         should_unmount_(true) {}
    119   ~ScopedFilesystemUnmounter() {
    120     if (should_unmount_) {
    121       utils::UnmountFilesystem(mountpoint_);
    122     }
    123   }
    124   void set_should_unmount(bool unmount) { should_unmount_ = unmount; }
    125  private:
    126   const std::string mountpoint_;
    127   bool should_unmount_;
    128   DISALLOW_COPY_AND_ASSIGN(ScopedFilesystemUnmounter);
    129 };
    130 
    131 class ScopedLoopbackDeviceBinder {
    132  public:
    133   ScopedLoopbackDeviceBinder(const std::string& file,
    134                              bool writable,
    135                              std::string* dev) {
    136     is_bound_ = BindToUnusedLoopDevice(file, writable, &dev_);
    137     EXPECT_TRUE(is_bound_);
    138 
    139     if (is_bound_ && dev)
    140       *dev = dev_;
    141   }
    142 
    143   ~ScopedLoopbackDeviceBinder() {
    144     if (!is_bound_)
    145       return;
    146 
    147     for (int retry = 0; retry < 5; retry++) {
    148       if (UnbindLoopDevice(dev_))
    149         return;
    150       sleep(1);
    151     }
    152     ADD_FAILURE();
    153   }
    154 
    155   const std::string &dev() {
    156     EXPECT_TRUE(is_bound_);
    157     return dev_;
    158   }
    159 
    160   bool is_bound() const { return is_bound_; }
    161 
    162  private:
    163   std::string dev_;
    164   bool is_bound_;
    165   DISALLOW_COPY_AND_ASSIGN(ScopedLoopbackDeviceBinder);
    166 };
    167 
    168 class ScopedTempFile {
    169  public:
    170   ScopedTempFile() : ScopedTempFile("update_engine_test_temp_file.XXXXXX") {}
    171 
    172   explicit ScopedTempFile(const std::string& pattern) {
    173     EXPECT_TRUE(utils::MakeTempFile(pattern, &path_, nullptr));
    174     unlinker_.reset(new ScopedPathUnlinker(path_));
    175   }
    176 
    177   const std::string& path() const { return path_; }
    178 
    179  private:
    180   std::string path_;
    181   std::unique_ptr<ScopedPathUnlinker> unlinker_;
    182 };
    183 
    184 class ScopedLoopMounter {
    185  public:
    186   explicit ScopedLoopMounter(const std::string& file_path,
    187                              std::string* mnt_path,
    188                              unsigned long flags);  // NOLINT(runtime/int)
    189 
    190  private:
    191   // These objects must be destructed in the following order:
    192   //   ScopedFilesystemUnmounter (the file system must be unmounted first)
    193   //   ScopedLoopbackDeviceBinder (then the loop device can be deleted)
    194   //   ScopedDirRemover (then the mount point can be deleted)
    195   std::unique_ptr<ScopedDirRemover> dir_remover_;
    196   std::unique_ptr<ScopedLoopbackDeviceBinder> loop_binder_;
    197   std::unique_ptr<ScopedFilesystemUnmounter> unmounter_;
    198 };
    199 
    200 // Returns the path where the build artifacts are stored. This is the directory
    201 // where the unittest executable is being run from.
    202 base::FilePath GetBuildArtifactsPath();
    203 
    204 }  // namespace test_utils
    205 
    206 // Useful actions for test. These need to be defined in the
    207 // chromeos_update_engine namespace.
    208 
    209 class NoneType;
    210 
    211 template<typename T>
    212 class ObjectFeederAction;
    213 
    214 template<typename T>
    215 class ActionTraits<ObjectFeederAction<T>> {
    216  public:
    217   typedef T OutputObjectType;
    218   typedef NoneType InputObjectType;
    219 };
    220 
    221 // This is a simple Action class for testing. It feeds an object into
    222 // another action.
    223 template<typename T>
    224 class ObjectFeederAction : public Action<ObjectFeederAction<T>> {
    225  public:
    226   typedef NoneType InputObjectType;
    227   typedef T OutputObjectType;
    228   void PerformAction() {
    229     LOG(INFO) << "feeder running!";
    230     CHECK(this->processor_);
    231     if (this->HasOutputPipe()) {
    232       this->SetOutputObject(out_obj_);
    233     }
    234     this->processor_->ActionComplete(this, ErrorCode::kSuccess);
    235   }
    236   static std::string StaticType() { return "ObjectFeederAction"; }
    237   std::string Type() const { return StaticType(); }
    238   void set_obj(const T& out_obj) {
    239     out_obj_ = out_obj;
    240   }
    241  private:
    242   T out_obj_;
    243 };
    244 
    245 template<typename T>
    246 class ObjectCollectorAction;
    247 
    248 template<typename T>
    249 class ActionTraits<ObjectCollectorAction<T>> {
    250  public:
    251   typedef NoneType OutputObjectType;
    252   typedef T InputObjectType;
    253 };
    254 
    255 // This is a simple Action class for testing. It receives an object from
    256 // another action.
    257 template<typename T>
    258 class ObjectCollectorAction : public Action<ObjectCollectorAction<T>> {
    259  public:
    260   typedef T InputObjectType;
    261   typedef NoneType OutputObjectType;
    262   void PerformAction() {
    263     LOG(INFO) << "collector running!";
    264     ASSERT_TRUE(this->processor_);
    265     if (this->HasInputObject()) {
    266       object_ = this->GetInputObject();
    267     }
    268     this->processor_->ActionComplete(this, ErrorCode::kSuccess);
    269   }
    270   static std::string StaticType() { return "ObjectCollectorAction"; }
    271   std::string Type() const { return StaticType(); }
    272   const T& object() const { return object_; }
    273  private:
    274   T object_;
    275 };
    276 
    277 }  // namespace chromeos_update_engine
    278 
    279 #endif  // UPDATE_ENGINE_COMMON_TEST_UTILS_H_
    280