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 <dlfcn.h>
8#include <sys/system_properties.h>
9
10#include "base/lazy_instance.h"
11#include "base/logging.h"
12#include "base/strings/string_number_conversions.h"
13#include "base/strings/string_piece.h"
14#include "base/strings/stringprintf.h"
15#include "base/sys_info_internal.h"
16
17// TODO(rmcilroy): Update API level when 'L' gets an official API level.
18#if (__ANDROID_API__ >= 9999 /* 'L' */)
19
20namespace {
21
22typedef int (SystemPropertyGetFunction)(const char*, char*);
23
24SystemPropertyGetFunction* DynamicallyLoadRealSystemPropertyGet() {
25  // libc.so should already be open, get a handle to it.
26  void* handle = dlopen("libc.so", RTLD_NOLOAD);
27  if (!handle) {
28    LOG(FATAL) << "Cannot dlopen libc.so: " << dlerror();
29  }
30  SystemPropertyGetFunction* real_system_property_get =
31      reinterpret_cast<SystemPropertyGetFunction*>(
32          dlsym(handle, "__system_property_get"));
33  if (!real_system_property_get) {
34    LOG(FATAL) << "Cannot resolve __system_property_get(): " << dlerror();
35  }
36  return real_system_property_get;
37}
38
39static base::LazyInstance<base::internal::LazySysInfoValue<
40    SystemPropertyGetFunction*, DynamicallyLoadRealSystemPropertyGet> >::Leaky
41    g_lazy_real_system_property_get = LAZY_INSTANCE_INITIALIZER;
42
43}  // namespace
44
45// Android 'L' removes __system_property_get from the NDK, however it is still
46// a hidden symbol in libc. Until we remove all calls of __system_property_get
47// from Chrome we work around this by defining a weak stub here, which uses
48// dlsym to but ensures that Chrome uses the real system
49// implementatation when loaded.  http://crbug.com/392191.
50int __system_property_get(const char* name, char* value) {
51  return g_lazy_real_system_property_get.Get().value()(name, value);
52}
53
54#endif
55
56namespace {
57
58// Default version of Android to fall back to when actual version numbers
59// cannot be acquired. Use the latest Android release with a higher bug fix
60// version to avoid unnecessarily comparison errors with the latest release.
61// This should be manually kept up-to-date on each Android release.
62const int kDefaultAndroidMajorVersion = 4;
63const int kDefaultAndroidMinorVersion = 4;
64const int kDefaultAndroidBugfixVersion = 99;
65
66// Parse out the OS version numbers from the system properties.
67void ParseOSVersionNumbers(const char* os_version_str,
68                           int32 *major_version,
69                           int32 *minor_version,
70                           int32 *bugfix_version) {
71  if (os_version_str[0]) {
72    // Try to parse out the version numbers from the string.
73    int num_read = sscanf(os_version_str, "%d.%d.%d", major_version,
74                          minor_version, bugfix_version);
75
76    if (num_read > 0) {
77      // If we don't have a full set of version numbers, make the extras 0.
78      if (num_read < 2) *minor_version = 0;
79      if (num_read < 3) *bugfix_version = 0;
80      return;
81    }
82  }
83
84  // For some reason, we couldn't parse the version number string.
85  *major_version = kDefaultAndroidMajorVersion;
86  *minor_version = kDefaultAndroidMinorVersion;
87  *bugfix_version = kDefaultAndroidBugfixVersion;
88}
89
90// Parses a system property (specified with unit 'k','m' or 'g').
91// Returns a value in bytes.
92// Returns -1 if the string could not be parsed.
93int64 ParseSystemPropertyBytes(const base::StringPiece& str) {
94  const int64 KB = 1024;
95  const int64 MB = 1024 * KB;
96  const int64 GB = 1024 * MB;
97  if (str.size() == 0u)
98    return -1;
99  int64 unit_multiplier = 1;
100  size_t length = str.size();
101  if (str[length - 1] == 'k') {
102    unit_multiplier = KB;
103    length--;
104  } else if (str[length - 1] == 'm') {
105    unit_multiplier = MB;
106    length--;
107  } else if (str[length - 1] == 'g') {
108    unit_multiplier = GB;
109    length--;
110  }
111  int64 result = 0;
112  bool parsed = base::StringToInt64(str.substr(0, length), &result);
113  bool negative = result <= 0;
114  bool overflow = result >= std::numeric_limits<int64>::max() / unit_multiplier;
115  if (!parsed || negative || overflow)
116    return -1;
117  return result * unit_multiplier;
118}
119
120int GetDalvikHeapSizeMB() {
121  char heap_size_str[PROP_VALUE_MAX];
122  __system_property_get("dalvik.vm.heapsize", heap_size_str);
123  // dalvik.vm.heapsize property is writable by a root user.
124  // Clamp it to reasonable range as a sanity check,
125  // a typical android device will never have less than 48MB.
126  const int64 MB = 1024 * 1024;
127  int64 result = ParseSystemPropertyBytes(heap_size_str);
128  if (result == -1) {
129     // We should consider not exposing these values if they are not reliable.
130     LOG(ERROR) << "Can't parse dalvik.vm.heapsize: " << heap_size_str;
131     result = base::SysInfo::AmountOfPhysicalMemoryMB() / 3;
132  }
133  result = std::min<int64>(std::max<int64>(32 * MB, result), 1024 * MB) / MB;
134  return static_cast<int>(result);
135}
136
137int GetDalvikHeapGrowthLimitMB() {
138  char heap_size_str[PROP_VALUE_MAX];
139  __system_property_get("dalvik.vm.heapgrowthlimit", heap_size_str);
140  // dalvik.vm.heapgrowthlimit property is writable by a root user.
141  // Clamp it to reasonable range as a sanity check,
142  // a typical android device will never have less than 24MB.
143  const int64 MB = 1024 * 1024;
144  int64 result = ParseSystemPropertyBytes(heap_size_str);
145  if (result == -1) {
146     // We should consider not exposing these values if they are not reliable.
147     LOG(ERROR) << "Can't parse dalvik.vm.heapgrowthlimit: " << heap_size_str;
148     result = base::SysInfo::AmountOfPhysicalMemoryMB() / 6;
149  }
150  result = std::min<int64>(std::max<int64>(16 * MB, result), 512 * MB) / MB;
151  return static_cast<int>(result);
152}
153
154}  // anonymous namespace
155
156namespace base {
157
158std::string SysInfo::OperatingSystemName() {
159  return "Android";
160}
161
162std::string SysInfo::GetAndroidBuildCodename() {
163  char os_version_codename_str[PROP_VALUE_MAX];
164  __system_property_get("ro.build.version.codename", os_version_codename_str);
165  return std::string(os_version_codename_str);
166}
167
168std::string SysInfo::GetAndroidBuildID() {
169  char os_build_id_str[PROP_VALUE_MAX];
170  __system_property_get("ro.build.id", os_build_id_str);
171  return std::string(os_build_id_str);
172}
173
174std::string SysInfo::GetDeviceName() {
175  char device_model_str[PROP_VALUE_MAX];
176  __system_property_get("ro.product.model", device_model_str);
177  return std::string(device_model_str);
178}
179
180std::string SysInfo::OperatingSystemVersion() {
181  int32 major, minor, bugfix;
182  OperatingSystemVersionNumbers(&major, &minor, &bugfix);
183  return StringPrintf("%d.%d.%d", major, minor, bugfix);
184}
185
186void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
187                                            int32* minor_version,
188                                            int32* bugfix_version) {
189  // Read the version number string out from the properties.
190  char os_version_str[PROP_VALUE_MAX];
191  __system_property_get("ro.build.version.release", os_version_str);
192
193  // Parse out the numbers.
194  ParseOSVersionNumbers(os_version_str, major_version, minor_version,
195                        bugfix_version);
196}
197
198int SysInfo::DalvikHeapSizeMB() {
199  static int heap_size = GetDalvikHeapSizeMB();
200  return heap_size;
201}
202
203int SysInfo::DalvikHeapGrowthLimitMB() {
204  static int heap_growth_limit = GetDalvikHeapGrowthLimitMB();
205  return heap_growth_limit;
206}
207
208
209}  // namespace base
210