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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "base/sys_info.h"
      6 
      7 #include <sys/system_properties.h>
      8 
      9 #include "base/logging.h"
     10 #include "base/strings/string_number_conversions.h"
     11 #include "base/strings/string_piece.h"
     12 #include "base/strings/stringprintf.h"
     13 
     14 namespace {
     15 
     16 // Default version of Android to fall back to when actual version numbers
     17 // cannot be acquired.
     18 // TODO(dfalcantara): Keep this reasonably up to date with the latest publicly
     19 //                    available version of Android.
     20 const int kDefaultAndroidMajorVersion = 4;
     21 const int kDefaultAndroidMinorVersion = 3;
     22 const int kDefaultAndroidBugfixVersion = 0;
     23 
     24 // Parse out the OS version numbers from the system properties.
     25 void ParseOSVersionNumbers(const char* os_version_str,
     26                            int32 *major_version,
     27                            int32 *minor_version,
     28                            int32 *bugfix_version) {
     29   if (os_version_str[0]) {
     30     // Try to parse out the version numbers from the string.
     31     int num_read = sscanf(os_version_str, "%d.%d.%d", major_version,
     32                           minor_version, bugfix_version);
     33 
     34     if (num_read > 0) {
     35       // If we don't have a full set of version numbers, make the extras 0.
     36       if (num_read < 2) *minor_version = 0;
     37       if (num_read < 3) *bugfix_version = 0;
     38       return;
     39     }
     40   }
     41 
     42   // For some reason, we couldn't parse the version number string.
     43   *major_version = kDefaultAndroidMajorVersion;
     44   *minor_version = kDefaultAndroidMinorVersion;
     45   *bugfix_version = kDefaultAndroidBugfixVersion;
     46 }
     47 
     48 // Parses a system property (specified with unit 'k','m' or 'g').
     49 // Returns a value in bytes.
     50 // Returns -1 if the string could not be parsed.
     51 int64 ParseSystemPropertyBytes(const base::StringPiece& str) {
     52   const int64 KB = 1024;
     53   const int64 MB = 1024 * KB;
     54   const int64 GB = 1024 * MB;
     55   if (str.size() == 0u)
     56     return -1;
     57   int64 unit_multiplier = 1;
     58   size_t length = str.size();
     59   if (str[length - 1] == 'k') {
     60     unit_multiplier = KB;
     61     length--;
     62   } else if (str[length - 1] == 'm') {
     63     unit_multiplier = MB;
     64     length--;
     65   } else if (str[length - 1] == 'g') {
     66     unit_multiplier = GB;
     67     length--;
     68   }
     69   int64 result = 0;
     70   bool parsed = base::StringToInt64(str.substr(0, length), &result);
     71   bool negative = result <= 0;
     72   bool overflow = result >= std::numeric_limits<int64>::max() / unit_multiplier;
     73   if (!parsed || negative || overflow)
     74     return -1;
     75   return result * unit_multiplier;
     76 }
     77 
     78 int GetDalvikHeapSizeMB() {
     79   char heap_size_str[PROP_VALUE_MAX];
     80   __system_property_get("dalvik.vm.heapsize", heap_size_str);
     81   // dalvik.vm.heapsize property is writable by a root user.
     82   // Clamp it to reasonable range as a sanity check,
     83   // a typical android device will never have less than 48MB.
     84   const int64 MB = 1024 * 1024;
     85   int64 result = ParseSystemPropertyBytes(heap_size_str);
     86   if (result == -1) {
     87      // We should consider not exposing these values if they are not reliable.
     88      LOG(ERROR) << "Can't parse dalvik.vm.heapsize: " << heap_size_str;
     89      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 3;
     90   }
     91   result = std::min<int64>(std::max<int64>(32 * MB, result), 1024 * MB) / MB;
     92   return static_cast<int>(result);
     93 }
     94 
     95 int GetDalvikHeapGrowthLimitMB() {
     96   char heap_size_str[PROP_VALUE_MAX];
     97   __system_property_get("dalvik.vm.heapgrowthlimit", heap_size_str);
     98   // dalvik.vm.heapgrowthlimit property is writable by a root user.
     99   // Clamp it to reasonable range as a sanity check,
    100   // a typical android device will never have less than 24MB.
    101   const int64 MB = 1024 * 1024;
    102   int64 result = ParseSystemPropertyBytes(heap_size_str);
    103   if (result == -1) {
    104      // We should consider not exposing these values if they are not reliable.
    105      LOG(ERROR) << "Can't parse dalvik.vm.heapgrowthlimit: " << heap_size_str;
    106      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 6;
    107   }
    108   result = std::min<int64>(std::max<int64>(16 * MB, result), 512 * MB) / MB;
    109   return static_cast<int>(result);
    110 }
    111 
    112 }  // anonymous namespace
    113 
    114 namespace base {
    115 
    116 std::string SysInfo::OperatingSystemName() {
    117   return "Android";
    118 }
    119 
    120 std::string SysInfo::GetAndroidBuildCodename() {
    121   char os_version_codename_str[PROP_VALUE_MAX];
    122   __system_property_get("ro.build.version.codename", os_version_codename_str);
    123   return std::string(os_version_codename_str);
    124 }
    125 
    126 std::string SysInfo::GetAndroidBuildID() {
    127   char os_build_id_str[PROP_VALUE_MAX];
    128   __system_property_get("ro.build.id", os_build_id_str);
    129   return std::string(os_build_id_str);
    130 }
    131 
    132 std::string SysInfo::GetDeviceName() {
    133   char device_model_str[PROP_VALUE_MAX];
    134   __system_property_get("ro.product.model", device_model_str);
    135   return std::string(device_model_str);
    136 }
    137 
    138 std::string SysInfo::OperatingSystemVersion() {
    139   int32 major, minor, bugfix;
    140   OperatingSystemVersionNumbers(&major, &minor, &bugfix);
    141   return StringPrintf("%d.%d.%d", major, minor, bugfix);
    142 }
    143 
    144 void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
    145                                             int32* minor_version,
    146                                             int32* bugfix_version) {
    147   // Read the version number string out from the properties.
    148   char os_version_str[PROP_VALUE_MAX];
    149   __system_property_get("ro.build.version.release", os_version_str);
    150 
    151   // Parse out the numbers.
    152   ParseOSVersionNumbers(os_version_str, major_version, minor_version,
    153                         bugfix_version);
    154 }
    155 
    156 int SysInfo::DalvikHeapSizeMB() {
    157   static int heap_size = GetDalvikHeapSizeMB();
    158   return heap_size;
    159 }
    160 
    161 int SysInfo::DalvikHeapGrowthLimitMB() {
    162   static int heap_growth_limit = GetDalvikHeapGrowthLimitMB();
    163   return heap_growth_limit;
    164 }
    165 
    166 
    167 }  // namespace base
    168