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/android/sys_utils.h"
11#include "base/lazy_instance.h"
12#include "base/logging.h"
13#include "base/strings/string_number_conversions.h"
14#include "base/strings/string_piece.h"
15#include "base/strings/stringprintf.h"
16#include "base/sys_info_internal.h"
17
18// TODO(rmcilroy): Update API level when 'L' gets an official API level.
19#if (__ANDROID_API__ >= 9999 /* 'L' */)
20
21namespace {
22
23typedef int (SystemPropertyGetFunction)(const char*, char*);
24
25SystemPropertyGetFunction* DynamicallyLoadRealSystemPropertyGet() {
26  // libc.so should already be open, get a handle to it.
27  void* handle = dlopen("libc.so", RTLD_NOLOAD);
28  if (!handle) {
29    LOG(FATAL) << "Cannot dlopen libc.so: " << dlerror();
30  }
31  SystemPropertyGetFunction* real_system_property_get =
32      reinterpret_cast<SystemPropertyGetFunction*>(
33          dlsym(handle, "__system_property_get"));
34  if (!real_system_property_get) {
35    LOG(FATAL) << "Cannot resolve __system_property_get(): " << dlerror();
36  }
37  return real_system_property_get;
38}
39
40static base::LazyInstance<base::internal::LazySysInfoValue<
41    SystemPropertyGetFunction*, DynamicallyLoadRealSystemPropertyGet> >::Leaky
42    g_lazy_real_system_property_get = LAZY_INSTANCE_INITIALIZER;
43
44}  // namespace
45
46// Android 'L' removes __system_property_get from the NDK, however it is still
47// a hidden symbol in libc. Until we remove all calls of __system_property_get
48// from Chrome we work around this by defining a weak stub here, which uses
49// dlsym to but ensures that Chrome uses the real system
50// implementatation when loaded.  http://crbug.com/392191.
51int __system_property_get(const char* name, char* value) {
52  return g_lazy_real_system_property_get.Get().value()(name, value);
53}
54
55#endif
56
57namespace {
58
59// Default version of Android to fall back to when actual version numbers
60// cannot be acquired. Use the latest Android release with a higher bug fix
61// version to avoid unnecessarily comparison errors with the latest release.
62// This should be manually kept up-to-date on each Android release.
63const int kDefaultAndroidMajorVersion = 4;
64const int kDefaultAndroidMinorVersion = 4;
65const int kDefaultAndroidBugfixVersion = 99;
66
67// Parse out the OS version numbers from the system properties.
68void ParseOSVersionNumbers(const char* os_version_str,
69                           int32 *major_version,
70                           int32 *minor_version,
71                           int32 *bugfix_version) {
72  if (os_version_str[0]) {
73    // Try to parse out the version numbers from the string.
74    int num_read = sscanf(os_version_str, "%d.%d.%d", major_version,
75                          minor_version, bugfix_version);
76
77    if (num_read > 0) {
78      // If we don't have a full set of version numbers, make the extras 0.
79      if (num_read < 2) *minor_version = 0;
80      if (num_read < 3) *bugfix_version = 0;
81      return;
82    }
83  }
84
85  // For some reason, we couldn't parse the version number string.
86  *major_version = kDefaultAndroidMajorVersion;
87  *minor_version = kDefaultAndroidMinorVersion;
88  *bugfix_version = kDefaultAndroidBugfixVersion;
89}
90
91// Parses a system property (specified with unit 'k','m' or 'g').
92// Returns a value in bytes.
93// Returns -1 if the string could not be parsed.
94int64 ParseSystemPropertyBytes(const base::StringPiece& str) {
95  const int64 KB = 1024;
96  const int64 MB = 1024 * KB;
97  const int64 GB = 1024 * MB;
98  if (str.size() == 0u)
99    return -1;
100  int64 unit_multiplier = 1;
101  size_t length = str.size();
102  if (str[length - 1] == 'k') {
103    unit_multiplier = KB;
104    length--;
105  } else if (str[length - 1] == 'm') {
106    unit_multiplier = MB;
107    length--;
108  } else if (str[length - 1] == 'g') {
109    unit_multiplier = GB;
110    length--;
111  }
112  int64 result = 0;
113  bool parsed = base::StringToInt64(str.substr(0, length), &result);
114  bool negative = result <= 0;
115  bool overflow = result >= std::numeric_limits<int64>::max() / unit_multiplier;
116  if (!parsed || negative || overflow)
117    return -1;
118  return result * unit_multiplier;
119}
120
121int GetDalvikHeapSizeMB() {
122  char heap_size_str[PROP_VALUE_MAX];
123  __system_property_get("dalvik.vm.heapsize", heap_size_str);
124  // dalvik.vm.heapsize property is writable by a root user.
125  // Clamp it to reasonable range as a sanity check,
126  // a typical android device will never have less than 48MB.
127  const int64 MB = 1024 * 1024;
128  int64 result = ParseSystemPropertyBytes(heap_size_str);
129  if (result == -1) {
130     // We should consider not exposing these values if they are not reliable.
131     LOG(ERROR) << "Can't parse dalvik.vm.heapsize: " << heap_size_str;
132     result = base::SysInfo::AmountOfPhysicalMemoryMB() / 3;
133  }
134  result = std::min<int64>(std::max<int64>(32 * MB, result), 1024 * MB) / MB;
135  return static_cast<int>(result);
136}
137
138int GetDalvikHeapGrowthLimitMB() {
139  char heap_size_str[PROP_VALUE_MAX];
140  __system_property_get("dalvik.vm.heapgrowthlimit", heap_size_str);
141  // dalvik.vm.heapgrowthlimit property is writable by a root user.
142  // Clamp it to reasonable range as a sanity check,
143  // a typical android device will never have less than 24MB.
144  const int64 MB = 1024 * 1024;
145  int64 result = ParseSystemPropertyBytes(heap_size_str);
146  if (result == -1) {
147     // We should consider not exposing these values if they are not reliable.
148     LOG(ERROR) << "Can't parse dalvik.vm.heapgrowthlimit: " << heap_size_str;
149     result = base::SysInfo::AmountOfPhysicalMemoryMB() / 6;
150  }
151  result = std::min<int64>(std::max<int64>(16 * MB, result), 512 * MB) / MB;
152  return static_cast<int>(result);
153}
154
155}  // anonymous namespace
156
157namespace base {
158
159std::string SysInfo::OperatingSystemName() {
160  return "Android";
161}
162
163std::string SysInfo::GetAndroidBuildCodename() {
164  char os_version_codename_str[PROP_VALUE_MAX];
165  __system_property_get("ro.build.version.codename", os_version_codename_str);
166  return std::string(os_version_codename_str);
167}
168
169std::string SysInfo::GetAndroidBuildID() {
170  char os_build_id_str[PROP_VALUE_MAX];
171  __system_property_get("ro.build.id", os_build_id_str);
172  return std::string(os_build_id_str);
173}
174
175std::string SysInfo::GetDeviceName() {
176  char device_model_str[PROP_VALUE_MAX];
177  __system_property_get("ro.product.model", device_model_str);
178  return std::string(device_model_str);
179}
180
181std::string SysInfo::OperatingSystemVersion() {
182  int32 major, minor, bugfix;
183  OperatingSystemVersionNumbers(&major, &minor, &bugfix);
184  return StringPrintf("%d.%d.%d", major, minor, bugfix);
185}
186
187void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
188                                            int32* minor_version,
189                                            int32* bugfix_version) {
190  // Read the version number string out from the properties.
191  char os_version_str[PROP_VALUE_MAX];
192  __system_property_get("ro.build.version.release", os_version_str);
193
194  // Parse out the numbers.
195  ParseOSVersionNumbers(os_version_str, major_version, minor_version,
196                        bugfix_version);
197}
198
199int SysInfo::DalvikHeapSizeMB() {
200  static int heap_size = GetDalvikHeapSizeMB();
201  return heap_size;
202}
203
204int SysInfo::DalvikHeapGrowthLimitMB() {
205  static int heap_growth_limit = GetDalvikHeapGrowthLimitMB();
206  return heap_growth_limit;
207}
208
209static base::LazyInstance<
210    base::internal::LazySysInfoValue<bool,
211        android::SysUtils::IsLowEndDeviceFromJni> >::Leaky
212    g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER;
213
214bool SysInfo::IsLowEndDevice() {
215  return g_lazy_low_end_device.Get().value();
216}
217
218
219}  // namespace base
220