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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_UTILS_H_
     18 #define UPDATE_ENGINE_COMMON_UTILS_H_
     19 
     20 #include <errno.h>
     21 #include <unistd.h>
     22 
     23 #include <algorithm>
     24 #include <map>
     25 #include <memory>
     26 #include <set>
     27 #include <string>
     28 #include <vector>
     29 
     30 #include <base/files/file_path.h>
     31 #include <base/posix/eintr_wrapper.h>
     32 #include <base/time/time.h>
     33 #include <brillo/key_value_store.h>
     34 #include <brillo/secure_blob.h>
     35 
     36 #include "update_engine/common/action.h"
     37 #include "update_engine/common/action_processor.h"
     38 #include "update_engine/common/constants.h"
     39 #include "update_engine/payload_consumer/file_descriptor.h"
     40 #include "update_engine/update_metadata.pb.h"
     41 
     42 namespace chromeos_update_engine {
     43 
     44 namespace utils {
     45 
     46 // Converts a struct timespec representing a number of seconds since
     47 // the Unix epoch to a base::Time. Sub-microsecond time is rounded
     48 // down.
     49 base::Time TimeFromStructTimespec(struct timespec *ts);
     50 
     51 // Formats |vec_str| as a string of the form ["<elem1>", "<elem2>"].
     52 // Does no escaping, only use this for presentation in error messages.
     53 std::string StringVectorToString(const std::vector<std::string> &vec_str);
     54 
     55 // Calculates the p2p file id from payload hash and size
     56 std::string CalculateP2PFileId(const brillo::Blob& payload_hash,
     57                                size_t payload_size);
     58 
     59 // Parse the firmware version from one line of output from the
     60 // "mosys" command.
     61 std::string ParseECVersion(std::string input_line);
     62 
     63 // Writes the data passed to path. The file at path will be overwritten if it
     64 // exists. Returns true on success, false otherwise.
     65 bool WriteFile(const char* path, const void* data, size_t data_len);
     66 
     67 // Calls write() or pwrite() repeatedly until all count bytes at buf are
     68 // written to fd or an error occurs. Returns true on success.
     69 bool WriteAll(int fd, const void* buf, size_t count);
     70 bool PWriteAll(int fd, const void* buf, size_t count, off_t offset);
     71 
     72 bool WriteAll(const FileDescriptorPtr& fd, const void* buf, size_t count);
     73 bool PWriteAll(const FileDescriptorPtr& fd,
     74                const void* buf,
     75                size_t count,
     76                off_t offset);
     77 
     78 // Calls read() repeatedly until |count| bytes are read or EOF or EWOULDBLOCK
     79 // is reached. Returns whether all read() calls succeeded (including EWOULDBLOCK
     80 // as a success case), sets |eof| to whether the eof was reached and sets
     81 // |out_bytes_read| to the actual number of bytes read regardless of the return
     82 // value.
     83 bool ReadAll(
     84     int fd, void* buf, size_t count, size_t* out_bytes_read, bool* eof);
     85 
     86 // Calls pread() repeatedly until count bytes are read, or EOF is reached.
     87 // Returns number of bytes read in *bytes_read. Returns true on success.
     88 bool PReadAll(int fd, void* buf, size_t count, off_t offset,
     89               ssize_t* out_bytes_read);
     90 
     91 bool PReadAll(const FileDescriptorPtr& fd, void* buf, size_t count,
     92               off_t offset, ssize_t* out_bytes_read);
     93 
     94 // Opens |path| for reading and appends its entire content to the container
     95 // pointed to by |out_p|. Returns true upon successfully reading all of the
     96 // file's content, false otherwise, in which case the state of the output
     97 // container is unknown. ReadFileChunk starts reading the file from |offset|; if
     98 // |size| is not -1, only up to |size| bytes are read in.
     99 bool ReadFile(const std::string& path, brillo::Blob* out_p);
    100 bool ReadFile(const std::string& path, std::string* out_p);
    101 bool ReadFileChunk(const std::string& path, off_t offset, off_t size,
    102                    brillo::Blob* out_p);
    103 
    104 // Invokes |cmd| in a pipe and appends its stdout to the container pointed to by
    105 // |out_p|. Returns true upon successfully reading all of the output, false
    106 // otherwise, in which case the state of the output container is unknown.
    107 bool ReadPipe(const std::string& cmd, std::string* out_p);
    108 
    109 // Returns the size of the block device at the file descriptor fd. If an error
    110 // occurs, -1 is returned.
    111 off_t BlockDevSize(int fd);
    112 
    113 // Returns the size of the file at path, or the file desciptor fd. If the file
    114 // is actually a block device, this function will automatically call
    115 // BlockDevSize. If the file doesn't exist or some error occurrs, -1 is
    116 // returned.
    117 off_t FileSize(const std::string& path);
    118 off_t FileSize(int fd);
    119 
    120 std::string ErrnoNumberAsString(int err);
    121 
    122 // Returns true if the file exists for sure. Returns false if it doesn't exist,
    123 // or an error occurs.
    124 bool FileExists(const char* path);
    125 
    126 // Returns true if |path| exists and is a symbolic link.
    127 bool IsSymlink(const char* path);
    128 
    129 // Try attaching UBI |volume_num|. If there is any error executing required
    130 // commands to attach the volume, this function returns false. This function
    131 // only returns true if "/dev/ubi%d_0" becomes available in |timeout| seconds.
    132 bool TryAttachingUbiVolume(int volume_num, int timeout);
    133 
    134 // Setup the directory |new_root_temp_dir| to be used as the root directory for
    135 // temporary files instead of the system's default. If the directory doesn't
    136 // exists, it will be created when first used.
    137 // NOTE: The memory pointed by |new_root_temp_dir| must be available until this
    138 // function is called again with a different value.
    139 void SetRootTempDir(const char* new_root_temp_dir);
    140 
    141 // If |base_filename_template| is neither absolute (starts with "/") nor
    142 // explicitly relative to the current working directory (starts with "./" or
    143 // "../"), then it is prepended the system's temporary directory. On success,
    144 // stores the name of the new temporary file in |filename|. If |fd| is
    145 // non-null, the file descriptor returned by mkstemp is written to it and
    146 // kept open; otherwise, it is closed. The template must end with "XXXXXX".
    147 // Returns true on success.
    148 bool MakeTempFile(const std::string& base_filename_template,
    149                   std::string* filename,
    150                   int* fd);
    151 
    152 // Splits the partition device name into the block device name and partition
    153 // number. For example, "/dev/sda3" will be split into {"/dev/sda", 3} and
    154 // "/dev/mmcblk0p2" into {"/dev/mmcblk0", 2}
    155 // Returns false when malformed device name is passed in.
    156 // If both output parameters are omitted (null), can be used
    157 // just to test the validity of the device name. Note that the function
    158 // simply checks if the device name looks like a valid device, no other
    159 // checks are performed (i.e. it doesn't check if the device actually exists).
    160 bool SplitPartitionName(const std::string& partition_name,
    161                         std::string* out_disk_name,
    162                         int* out_partition_num);
    163 
    164 // Builds a partition device name from the block device name and partition
    165 // number. For example:
    166 // {"/dev/sda", 1} => "/dev/sda1"
    167 // {"/dev/mmcblk2", 12} => "/dev/mmcblk2p12"
    168 // Returns empty string when invalid parameters are passed in
    169 std::string MakePartitionName(const std::string& disk_name,
    170                               int partition_num);
    171 
    172 // Similar to "MakePartitionName" but returns a name that is suitable for
    173 // mounting. On NAND system we can write to "/dev/ubiX_0", which is what
    174 // MakePartitionName returns, but we cannot mount that device. To mount, we
    175 // have to use "/dev/ubiblockX_0" for rootfs. Stateful and OEM partitions are
    176 // mountable with "/dev/ubiX_0". The input is a partition device such as
    177 // /dev/sda3. Return empty string on error.
    178 std::string MakePartitionNameForMount(const std::string& part_name);
    179 
    180 // Set the read-only attribute on the block device |device| to the value passed
    181 // in |read_only|. Return whether the operation succeeded.
    182 bool SetBlockDeviceReadOnly(const std::string& device, bool read_only);
    183 
    184 // Synchronously mount or unmount a filesystem. Return true on success.
    185 // When mounting, it will attempt to mount the device as the passed filesystem
    186 // type |type|, with the passed |flags| options. If |type| is empty, "ext2",
    187 // "ext3", "ext4" and "squashfs" will be tried.
    188 bool MountFilesystem(const std::string& device,
    189                      const std::string& mountpoint,
    190                      unsigned long flags,  // NOLINT(runtime/int)
    191                      const std::string& type,
    192                      const std::string& fs_mount_options);
    193 bool UnmountFilesystem(const std::string& mountpoint);
    194 
    195 // Return whether the passed |mountpoint| path is a directory where a filesystem
    196 // is mounted. Due to detection mechanism limitations, when used on directories
    197 // where another part of the tree was bind mounted returns true only if bind
    198 // mounted on top of a different filesystem (not inside the same filesystem).
    199 bool IsMountpoint(const std::string& mountpoint);
    200 
    201 // Returns a human-readable string with the file format based on magic constants
    202 // on the header of the file.
    203 std::string GetFileFormat(const std::string& path);
    204 
    205 // Returns the string representation of the given UTC time.
    206 // such as "11/14/2011 14:05:30 GMT".
    207 std::string ToString(const base::Time utc_time);
    208 
    209 // Returns true or false depending on the value of b.
    210 std::string ToString(bool b);
    211 
    212 // Returns a string representation of the given enum.
    213 std::string ToString(DownloadSource source);
    214 
    215 // Returns a string representation of the given enum.
    216 std::string ToString(PayloadType payload_type);
    217 
    218 // Fuzzes an integer |value| randomly in the range:
    219 // [value - range / 2, value + range - range / 2]
    220 int FuzzInt(int value, unsigned int range);
    221 
    222 // Log a string in hex to LOG(INFO). Useful for debugging.
    223 void HexDumpArray(const uint8_t* const arr, const size_t length);
    224 inline void HexDumpString(const std::string& str) {
    225   HexDumpArray(reinterpret_cast<const uint8_t*>(str.data()), str.size());
    226 }
    227 inline void HexDumpVector(const brillo::Blob& vect) {
    228   HexDumpArray(vect.data(), vect.size());
    229 }
    230 
    231 template<typename KeyType, typename ValueType>
    232 bool MapContainsKey(const std::map<KeyType, ValueType>& m, const KeyType& k) {
    233   return m.find(k) != m.end();
    234 }
    235 template<typename KeyType>
    236 bool SetContainsKey(const std::set<KeyType>& s, const KeyType& k) {
    237   return s.find(k) != s.end();
    238 }
    239 
    240 template<typename T>
    241 bool VectorContainsValue(const std::vector<T>& vect, const T& value) {
    242   return std::find(vect.begin(), vect.end(), value) != vect.end();
    243 }
    244 
    245 template<typename T>
    246 bool VectorIndexOf(const std::vector<T>& vect, const T& value,
    247                    typename std::vector<T>::size_type* out_index) {
    248   typename std::vector<T>::const_iterator it = std::find(vect.begin(),
    249                                                          vect.end(),
    250                                                          value);
    251   if (it == vect.end()) {
    252     return false;
    253   } else {
    254     *out_index = it - vect.begin();
    255     return true;
    256   }
    257 }
    258 
    259 // Return the total number of blocks in the passed |extents| collection.
    260 template <class T>
    261 uint64_t BlocksInExtents(const T& extents) {
    262   uint64_t sum = 0;
    263   for (const auto& ext : extents) {
    264     sum += ext.num_blocks();
    265   }
    266   return sum;
    267 }
    268 
    269 // Converts seconds into human readable notation including days, hours, minutes
    270 // and seconds. For example, 185 will yield 3m5s, 4300 will yield 1h11m40s, and
    271 // 360000 will yield 4d4h0m0s.  Zero padding not applied. Seconds are always
    272 // shown in the result.
    273 std::string FormatSecs(unsigned secs);
    274 
    275 // Converts a TimeDelta into human readable notation including days, hours,
    276 // minutes, seconds and fractions of a second down to microsecond granularity,
    277 // as necessary; for example, an output of 5d2h0m15.053s means that the input
    278 // time was precise to the milliseconds only. Zero padding not applied, except
    279 // for fractions. Seconds are always shown, but fractions thereof are only shown
    280 // when applicable. If |delta| is negative, the output will have a leading '-'
    281 // followed by the absolute duration.
    282 std::string FormatTimeDelta(base::TimeDelta delta);
    283 
    284 // This method transforms the given error code to be suitable for UMA and
    285 // for error classification purposes by removing the higher order bits and
    286 // aggregating error codes beyond the enum range, etc. This method is
    287 // idempotent, i.e. if called with a value previously returned by this method,
    288 // it'll return the same value again.
    289 ErrorCode GetBaseErrorCode(ErrorCode code);
    290 
    291 // Decodes the data in |base64_encoded| and stores it in a temporary
    292 // file. Returns false if the given data is empty, not well-formed
    293 // base64 or if an error occurred. If true is returned, the decoded
    294 // data is stored in the file returned in |out_path|. The file should
    295 // be deleted when no longer needed.
    296 bool DecodeAndStoreBase64String(const std::string& base64_encoded,
    297                                 base::FilePath *out_path);
    298 
    299 // Converts |time| to an Omaha InstallDate which is defined as "the
    300 // number of PST8PDT calendar weeks since Jan 1st 2007 0:00 PST, times
    301 // seven" with PST8PDT defined as "Pacific Time" (e.g. UTC-07:00 if
    302 // daylight savings is observed and UTC-08:00 otherwise.)
    303 //
    304 // If the passed in |time| variable is before Monday January 1st 2007
    305 // 0:00 PST, False is returned and the value returned in
    306 // |out_num_days| is undefined. Otherwise the number of PST8PDT
    307 // calendar weeks since that date times seven is returned in
    308 // |out_num_days| and the function returns True.
    309 //
    310 // (NOTE: This function does not currently take daylight savings time
    311 // into account so the result may up to one hour off. This is because
    312 // the glibc date and timezone routines depend on the TZ environment
    313 // variable and changing environment variables is not thread-safe.
    314 bool ConvertToOmahaInstallDate(base::Time time, int *out_num_days);
    315 
    316 // Look for the minor version value in the passed |store| and set
    317 // |minor_version| to that value. Return whether the value was found and valid.
    318 bool GetMinorVersion(const brillo::KeyValueStore& store,
    319                      uint32_t* minor_version);
    320 
    321 // This function reads the specified data in |extents| into |out_data|. The
    322 // extents are read from the file at |path|. |out_data_size| is the size of
    323 // |out_data|. Returns false if the number of bytes to read given in
    324 // |extents| does not equal |out_data_size|.
    325 bool ReadExtents(const std::string& path, const std::vector<Extent>& extents,
    326                  brillo::Blob* out_data, ssize_t out_data_size,
    327                  size_t block_size);
    328 
    329 // Read the current boot identifier and store it in |boot_id|. This identifier
    330 // is constants during the same boot of the kernel and is regenerated after
    331 // reboot. Returns whether it succeeded getting the boot_id.
    332 bool GetBootId(std::string* boot_id);
    333 
    334 }  // namespace utils
    335 
    336 
    337 // Utility class to close a file descriptor
    338 class ScopedFdCloser {
    339  public:
    340   explicit ScopedFdCloser(int* fd) : fd_(fd) {}
    341   ~ScopedFdCloser() {
    342     if (should_close_ && fd_ && (*fd_ >= 0) && !IGNORE_EINTR(close(*fd_)))
    343       *fd_ = -1;
    344   }
    345   void set_should_close(bool should_close) { should_close_ = should_close; }
    346  private:
    347   int* fd_;
    348   bool should_close_ = true;
    349   DISALLOW_COPY_AND_ASSIGN(ScopedFdCloser);
    350 };
    351 
    352 // Utility class to delete a file when it goes out of scope.
    353 class ScopedPathUnlinker {
    354  public:
    355   explicit ScopedPathUnlinker(const std::string& path)
    356       : path_(path),
    357         should_remove_(true) {}
    358   ~ScopedPathUnlinker() {
    359     if (should_remove_ && unlink(path_.c_str()) < 0) {
    360       PLOG(ERROR) << "Unable to unlink path " << path_;
    361     }
    362   }
    363   void set_should_remove(bool should_remove) { should_remove_ = should_remove; }
    364 
    365  private:
    366   const std::string path_;
    367   bool should_remove_;
    368   DISALLOW_COPY_AND_ASSIGN(ScopedPathUnlinker);
    369 };
    370 
    371 // A little object to call ActionComplete on the ActionProcessor when
    372 // it's destructed.
    373 class ScopedActionCompleter {
    374  public:
    375   explicit ScopedActionCompleter(ActionProcessor* processor,
    376                                  AbstractAction* action)
    377       : processor_(processor),
    378         action_(action),
    379         code_(ErrorCode::kError),
    380         should_complete_(true) {}
    381   ~ScopedActionCompleter() {
    382     if (should_complete_)
    383       processor_->ActionComplete(action_, code_);
    384   }
    385   void set_code(ErrorCode code) { code_ = code; }
    386   void set_should_complete(bool should_complete) {
    387     should_complete_ = should_complete;
    388   }
    389   ErrorCode get_code() const { return code_; }
    390 
    391  private:
    392   ActionProcessor* processor_;
    393   AbstractAction* action_;
    394   ErrorCode code_;
    395   bool should_complete_;
    396   DISALLOW_COPY_AND_ASSIGN(ScopedActionCompleter);
    397 };
    398 
    399 }  // namespace chromeos_update_engine
    400 
    401 #define TEST_AND_RETURN_FALSE_ERRNO(_x)                                        \
    402   do {                                                                         \
    403     bool _success = static_cast<bool>(_x);                                     \
    404     if (!_success) {                                                           \
    405       std::string _msg =                                                       \
    406           chromeos_update_engine::utils::ErrnoNumberAsString(errno);           \
    407       LOG(ERROR) << #_x " failed: " << _msg;                                   \
    408       return false;                                                            \
    409     }                                                                          \
    410   } while (0)
    411 
    412 #define TEST_AND_RETURN_FALSE(_x)                                              \
    413   do {                                                                         \
    414     bool _success = static_cast<bool>(_x);                                     \
    415     if (!_success) {                                                           \
    416       LOG(ERROR) << #_x " failed.";                                            \
    417       return false;                                                            \
    418     }                                                                          \
    419   } while (0)
    420 
    421 #define TEST_AND_RETURN_ERRNO(_x)                                              \
    422   do {                                                                         \
    423     bool _success = static_cast<bool>(_x);                                     \
    424     if (!_success) {                                                           \
    425       std::string _msg =                                                       \
    426           chromeos_update_engine::utils::ErrnoNumberAsString(errno);           \
    427       LOG(ERROR) << #_x " failed: " << _msg;                                   \
    428       return;                                                                  \
    429     }                                                                          \
    430   } while (0)
    431 
    432 #define TEST_AND_RETURN(_x)                                                    \
    433   do {                                                                         \
    434     bool _success = static_cast<bool>(_x);                                     \
    435     if (!_success) {                                                           \
    436       LOG(ERROR) << #_x " failed.";                                            \
    437       return;                                                                  \
    438     }                                                                          \
    439   } while (0)
    440 
    441 #define TEST_AND_RETURN_FALSE_ERRCODE(_x)                                      \
    442   do {                                                                         \
    443     errcode_t _error = (_x);                                                   \
    444     if (_error) {                                                              \
    445       errno = _error;                                                          \
    446       LOG(ERROR) << #_x " failed: " << _error;                                 \
    447       return false;                                                            \
    448     }                                                                          \
    449   } while (0)
    450 
    451 #endif  // UPDATE_ENGINE_COMMON_UTILS_H_
    452