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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 std::string& 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, off_t offset,
     92               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 // Converts seconds into human readable notation including days, hours, minutes
    260 // and seconds. For example, 185 will yield 3m5s, 4300 will yield 1h11m40s, and
    261 // 360000 will yield 4d4h0m0s.  Zero padding not applied. Seconds are always
    262 // shown in the result.
    263 std::string FormatSecs(unsigned secs);
    264 
    265 // Converts a TimeDelta into human readable notation including days, hours,
    266 // minutes, seconds and fractions of a second down to microsecond granularity,
    267 // as necessary; for example, an output of 5d2h0m15.053s means that the input
    268 // time was precise to the milliseconds only. Zero padding not applied, except
    269 // for fractions. Seconds are always shown, but fractions thereof are only shown
    270 // when applicable. If |delta| is negative, the output will have a leading '-'
    271 // followed by the absolute duration.
    272 std::string FormatTimeDelta(base::TimeDelta delta);
    273 
    274 // This method transforms the given error code to be suitable for UMA and
    275 // for error classification purposes by removing the higher order bits and
    276 // aggregating error codes beyond the enum range, etc. This method is
    277 // idempotent, i.e. if called with a value previously returned by this method,
    278 // it'll return the same value again.
    279 ErrorCode GetBaseErrorCode(ErrorCode code);
    280 
    281 // Decodes the data in |base64_encoded| and stores it in a temporary
    282 // file. Returns false if the given data is empty, not well-formed
    283 // base64 or if an error occurred. If true is returned, the decoded
    284 // data is stored in the file returned in |out_path|. The file should
    285 // be deleted when no longer needed.
    286 bool DecodeAndStoreBase64String(const std::string& base64_encoded,
    287                                 base::FilePath *out_path);
    288 
    289 // Converts |time| to an Omaha InstallDate which is defined as "the
    290 // number of PST8PDT calendar weeks since Jan 1st 2007 0:00 PST, times
    291 // seven" with PST8PDT defined as "Pacific Time" (e.g. UTC-07:00 if
    292 // daylight savings is observed and UTC-08:00 otherwise.)
    293 //
    294 // If the passed in |time| variable is before Monday January 1st 2007
    295 // 0:00 PST, False is returned and the value returned in
    296 // |out_num_days| is undefined. Otherwise the number of PST8PDT
    297 // calendar weeks since that date times seven is returned in
    298 // |out_num_days| and the function returns True.
    299 //
    300 // (NOTE: This function does not currently take daylight savings time
    301 // into account so the result may up to one hour off. This is because
    302 // the glibc date and timezone routines depend on the TZ environment
    303 // variable and changing environment variables is not thread-safe.
    304 bool ConvertToOmahaInstallDate(base::Time time, int *out_num_days);
    305 
    306 // Look for the minor version value in the passed |store| and set
    307 // |minor_version| to that value. Return whether the value was found and valid.
    308 bool GetMinorVersion(const brillo::KeyValueStore& store,
    309                      uint32_t* minor_version);
    310 
    311 // Returns whether zlib |fingerprint| is compatible with zlib we are using.
    312 bool IsZlibCompatible(const std::string& fingerprint);
    313 
    314 // This function reads the specified data in |extents| into |out_data|. The
    315 // extents are read from the file at |path|. |out_data_size| is the size of
    316 // |out_data|. Returns false if the number of bytes to read given in
    317 // |extents| does not equal |out_data_size|.
    318 bool ReadExtents(const std::string& path, const std::vector<Extent>& extents,
    319                  brillo::Blob* out_data, ssize_t out_data_size,
    320                  size_t block_size);
    321 
    322 // Read the current boot identifier and store it in |boot_id|. This identifier
    323 // is constants during the same boot of the kernel and is regenerated after
    324 // reboot. Returns whether it succeeded getting the boot_id.
    325 bool GetBootId(std::string* boot_id);
    326 
    327 }  // namespace utils
    328 
    329 
    330 // Utility class to close a file descriptor
    331 class ScopedFdCloser {
    332  public:
    333   explicit ScopedFdCloser(int* fd) : fd_(fd) {}
    334   ~ScopedFdCloser() {
    335     if (should_close_ && fd_ && (*fd_ >= 0) && !IGNORE_EINTR(close(*fd_)))
    336       *fd_ = -1;
    337   }
    338   void set_should_close(bool should_close) { should_close_ = should_close; }
    339  private:
    340   int* fd_;
    341   bool should_close_ = true;
    342   DISALLOW_COPY_AND_ASSIGN(ScopedFdCloser);
    343 };
    344 
    345 // Utility class to delete a file when it goes out of scope.
    346 class ScopedPathUnlinker {
    347  public:
    348   explicit ScopedPathUnlinker(const std::string& path)
    349       : path_(path),
    350         should_remove_(true) {}
    351   ~ScopedPathUnlinker() {
    352     if (should_remove_ && unlink(path_.c_str()) < 0) {
    353       PLOG(ERROR) << "Unable to unlink path " << path_;
    354     }
    355   }
    356   void set_should_remove(bool should_remove) { should_remove_ = should_remove; }
    357 
    358  private:
    359   const std::string path_;
    360   bool should_remove_;
    361   DISALLOW_COPY_AND_ASSIGN(ScopedPathUnlinker);
    362 };
    363 
    364 // A little object to call ActionComplete on the ActionProcessor when
    365 // it's destructed.
    366 class ScopedActionCompleter {
    367  public:
    368   explicit ScopedActionCompleter(ActionProcessor* processor,
    369                                  AbstractAction* action)
    370       : processor_(processor),
    371         action_(action),
    372         code_(ErrorCode::kError),
    373         should_complete_(true) {}
    374   ~ScopedActionCompleter() {
    375     if (should_complete_)
    376       processor_->ActionComplete(action_, code_);
    377   }
    378   void set_code(ErrorCode code) { code_ = code; }
    379   void set_should_complete(bool should_complete) {
    380     should_complete_ = should_complete;
    381   }
    382   ErrorCode get_code() const { return code_; }
    383 
    384  private:
    385   ActionProcessor* processor_;
    386   AbstractAction* action_;
    387   ErrorCode code_;
    388   bool should_complete_;
    389   DISALLOW_COPY_AND_ASSIGN(ScopedActionCompleter);
    390 };
    391 
    392 }  // namespace chromeos_update_engine
    393 
    394 #define TEST_AND_RETURN_FALSE_ERRNO(_x)                                        \
    395   do {                                                                         \
    396     bool _success = static_cast<bool>(_x);                                     \
    397     if (!_success) {                                                           \
    398       std::string _msg =                                                       \
    399           chromeos_update_engine::utils::ErrnoNumberAsString(errno);           \
    400       LOG(ERROR) << #_x " failed: " << _msg;                                   \
    401       return false;                                                            \
    402     }                                                                          \
    403   } while (0)
    404 
    405 #define TEST_AND_RETURN_FALSE(_x)                                              \
    406   do {                                                                         \
    407     bool _success = static_cast<bool>(_x);                                     \
    408     if (!_success) {                                                           \
    409       LOG(ERROR) << #_x " failed.";                                            \
    410       return false;                                                            \
    411     }                                                                          \
    412   } while (0)
    413 
    414 #define TEST_AND_RETURN_ERRNO(_x)                                              \
    415   do {                                                                         \
    416     bool _success = static_cast<bool>(_x);                                     \
    417     if (!_success) {                                                           \
    418       std::string _msg =                                                       \
    419           chromeos_update_engine::utils::ErrnoNumberAsString(errno);           \
    420       LOG(ERROR) << #_x " failed: " << _msg;                                   \
    421       return;                                                                  \
    422     }                                                                          \
    423   } while (0)
    424 
    425 #define TEST_AND_RETURN(_x)                                                    \
    426   do {                                                                         \
    427     bool _success = static_cast<bool>(_x);                                     \
    428     if (!_success) {                                                           \
    429       LOG(ERROR) << #_x " failed.";                                            \
    430       return;                                                                  \
    431     }                                                                          \
    432   } while (0)
    433 
    434 #define TEST_AND_RETURN_FALSE_ERRCODE(_x)                                      \
    435   do {                                                                         \
    436     errcode_t _error = (_x);                                                   \
    437     if (_error) {                                                              \
    438       errno = _error;                                                          \
    439       LOG(ERROR) << #_x " failed: " << _error;                                 \
    440       return false;                                                            \
    441     }                                                                          \
    442   } while (0)
    443 
    444 #endif  // UPDATE_ENGINE_COMMON_UTILS_H_
    445