1 /*
2  * Copyright (C) 2011 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 ART_LIBARTBASE_BASE_FILE_UTILS_H_
18 #define ART_LIBARTBASE_BASE_FILE_UTILS_H_
19 
20 #include <stdlib.h>
21 
22 #include <string>
23 #include <string_view>
24 
25 #include <android-base/logging.h>
26 
27 #include "arch/instruction_set.h"
28 
29 namespace art {
30 
31 static constexpr const char kAndroidArtApexDefaultPath[] = "/apex/com.android.art";
32 static constexpr const char kArtApexDataDefaultPath[] = "/data/misc/apexdata/com.android.art";
33 static constexpr const char kAndroidConscryptApexDefaultPath[] = "/apex/com.android.conscrypt";
34 static constexpr const char kAndroidI18nApexDefaultPath[] = "/apex/com.android.i18n";
35 
36 static constexpr const char kArtImageExtension[] = "art";
37 
38 // These methods return the Android Root, which is the historical location of
39 // the Android "system" directory, containing the built Android artifacts. On
40 // target, this is normally "/system". On host this is usually a directory under
41 // the build tree, e.g. "$ANDROID_BUILD_TOP/out/host/linux-x86". The location of
42 // the Android Root can be overriden using the ANDROID_ROOT environment
43 // variable.
44 //
45 // Find $ANDROID_ROOT, /system, or abort.
46 std::string GetAndroidRoot();
47 // Find $ANDROID_ROOT, /system, or return an empty string.
48 std::string GetAndroidRootSafe(/*out*/ std::string* error_msg);
49 
50 // Find $SYSTEM_EXT_ROOT, /system_ext, or abort.
51 std::string GetSystemExtRoot();
52 // Find $SYSTEM_EXT_ROOT, /system_ext, or return an empty string.
53 std::string GetSystemExtRootSafe(/*out*/ std::string* error_msg);
54 
55 // These methods return the ART Root, which is the location of the (activated)
56 // ART APEX module. On target, this is normally "/apex/com.android.art". On
57 // host, this is usually a subdirectory of the Android Root, e.g.
58 // "$ANDROID_BUILD_TOP/out/host/linux-x86/com.android.art". The location of the
59 // ART root can be overridden using the ANDROID_ART_ROOT environment variable.
60 //
61 // Find $ANDROID_ART_ROOT, /apex/com.android.art, or abort.
62 std::string GetArtRoot();
63 // Find $ANDROID_ART_ROOT, /apex/com.android.art, or return an empty string.
64 std::string GetArtRootSafe(/*out*/ std::string* error_msg);
65 
66 // Return the path to the directory containing the ART binaries.
67 std::string GetArtBinDir();
68 
69 // Find $ANDROID_DATA, /data, or abort.
70 std::string GetAndroidData();
71 // Find $ANDROID_DATA, /data, or return an empty string.
72 std::string GetAndroidDataSafe(/*out*/ std::string* error_msg);
73 
74 // Find $ANDROID_EXPAND, /mnt/expand, or abort.
75 std::string GetAndroidExpand();
76 // Find $ANDROID_EXPAND, /mnt/expand, or return an empty string.
77 std::string GetAndroidExpandSafe(/*out*/ std::string* error_msg);
78 
79 // Find $ART_APEX_DATA, /data/misc/apexdata/com.android.art, or abort.
80 std::string GetArtApexData();
81 
82 // Returns the directory that contains the prebuilt version of the primary boot image (i.e., the one
83 // generated at build time).
84 std::string GetPrebuiltPrimaryBootImageDir();
85 
86 // Returns the filename of the first mainline framework library.
87 std::string GetFirstMainlineFrameworkLibraryFilename(std::string* error_msg);
88 
89 // Returns the default boot image location, based on the passed `android_root`.
90 // Returns an empty string if an error occurs.
91 // The default boot image location can only be used with the default bootclasspath (the value of the
92 // BOOTCLASSPATH environment variable).
93 std::string GetDefaultBootImageLocationSafe(const std::string& android_root,
94                                             bool deny_art_apex_data_files,
95                                             std::string* error_msg);
96 
97 // Same as above, but fails if an error occurs.
98 std::string GetDefaultBootImageLocation(const std::string& android_root,
99                                         bool deny_art_apex_data_files);
100 
101 // Returns the boot image location that forces the runtime to run in JIT Zygote mode.
102 std::string GetJitZygoteBootImageLocation();
103 
104 // A helper function to pick the most appropriate boot image based on the given options.
105 // The boot image location can only be used with the default bootclasspath (the value of the
106 // BOOTCLASSPATH environment variable).
107 std::string GetBootImageLocationForDefaultBcp(bool no_boot_image,
108                                               std::string user_defined_boot_image,
109                                               bool deny_art_apex_data_files,
110                                               std::string* error_msg);
111 
112 // A helper function to pick the most appropriate boot image based on system properties.
113 // The boot image location can only be used with the default bootclasspath (the value of the
114 // BOOTCLASSPATH environment variable).
115 std::string GetBootImageLocationForDefaultBcpRespectingSysProps(std::string* error_msg);
116 
117 // Allows the name to be used for the dalvik cache directory (normally "dalvik-cache") to be
118 // overridden with a new value.
119 void OverrideDalvikCacheSubDirectory(std::string sub_dir);
120 
121 // Return true if we found the dalvik cache and stored it in the dalvik_cache argument.
122 // `have_android_data` will be set to true if we have an ANDROID_DATA that exists,
123 // `dalvik_cache_exists` will be true if there is a dalvik-cache directory that is present.
124 // The flag `is_global_cache` tells whether this cache is /data/dalvik-cache.
125 void GetDalvikCache(const char* subdir, bool create_if_absent, std::string* dalvik_cache,
126                     bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache);
127 
128 // Returns the absolute dalvik-cache path for a DexFile or OatFile. The path returned will be
129 // rooted at `cache_location`.
130 bool GetDalvikCacheFilename(std::string_view location,
131                             std::string_view cache_location,
132                             std::string* filename,
133                             std::string* error_msg);
134 
135 // Returns the absolute dalvik-cache path. The path may include the instruction set sub-directory
136 // if specified.
137 std::string GetApexDataDalvikCacheDirectory(InstructionSet isa);
138 
139 // Gets the oat location in the ART APEX data directory for a DEX file installed anywhere other
140 // than in an APEX. Returns the oat filename if `location` is valid, empty string otherwise.
141 std::string GetApexDataOatFilename(std::string_view location, InstructionSet isa);
142 
143 // Gets the odex location in the ART APEX data directory for a DEX file. Returns the odex filename
144 // if `location` is valid, empty string otherwise.
145 std::string GetApexDataOdexFilename(std::string_view location, InstructionSet isa);
146 
147 // Gets the boot image in the ART APEX data directory for a DEX file installed anywhere other
148 // than in an APEX. Returns the image location if `dex_location` is valid, empty string otherwise.
149 std::string GetApexDataBootImage(std::string_view dex_location);
150 
151 // Gets the image in the ART APEX data directory for a DEX file. Returns the image location if
152 // `dex_location` is valid, empty string otherwise.
153 std::string GetApexDataImage(std::string_view dex_location);
154 
155 // Gets the name of a file in the ART APEX directory dalvik-cache. This method assumes the
156 // `dex_location` is for an application.
157 // Returns the location of the file in the dalvik-cache
158 std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
159                                            InstructionSet isa,
160                                            std::string_view file_extension);
161 
162 // Returns the system location for an image. This method inserts the `isa` between the
163 // dirname and basename of `location`.
164 std::string GetSystemImageFilename(const char* location, InstructionSet isa);
165 
166 // Returns the vdex filename for the given oat filename.
167 std::string GetVdexFilename(const std::string& oat_filename);
168 
169 // Returns the dm filename for the given dex location.
170 std::string GetDmFilename(const std::string& dex_location);
171 
172 // Returns the odex location on /system for a DEX file on /apex. The caller must make sure that
173 // `location` is on /apex.
174 std::string GetSystemOdexFilenameForApex(std::string_view location, InstructionSet isa);
175 
176 // Returns `filename` with the text after the last occurrence of '.' replaced with
177 // `extension`. If `filename` does not contain a period, returns a string containing `filename`,
178 // a period, and `new_extension`.
179 // Example: ReplaceFileExtension("foo.bar", "abc") == "foo.abc"
180 //          ReplaceFileExtension("foo", "abc") == "foo.abc"
181 std::string ReplaceFileExtension(std::string_view filename, std::string_view new_extension);
182 
183 // Return whether the location is on /apex/com.android.art
184 bool LocationIsOnArtModule(std::string_view location);
185 
186 // Return whether the location is on /data/misc/apexdata/com.android.art/.
187 bool LocationIsOnArtApexData(std::string_view location);
188 
189 // Return whether the location is on /apex/com.android.conscrypt
190 bool LocationIsOnConscryptModule(std::string_view location);
191 
192 // Return whether the location is on /apex/com.android.i18n
193 bool LocationIsOnI18nModule(std::string_view location);
194 
195 // Return whether the location is on system (i.e. android root).
196 bool LocationIsOnSystem(const std::string& location);
197 
198 // Return whether the location is on system_ext
199 bool LocationIsOnSystemExt(const std::string& location);
200 
201 // Return whether the location is on system/framework (i.e. $ANDROID_ROOT/framework).
202 bool LocationIsOnSystemFramework(std::string_view location);
203 
204 // Return whether the location is on system_ext/framework
205 bool LocationIsOnSystemExtFramework(std::string_view location);
206 
207 // Return whether the location is on /apex/.
208 bool LocationIsOnApex(std::string_view location);
209 
210 // If the given location is /apex/<apexname>/..., return <apexname>, otherwise return an empty
211 // string. Note that the result is a view into full_path and is valid only as long as it is.
212 std::string_view ApexNameFromLocation(std::string_view full_path);
213 
214 // Returns whether the location is trusted for loading oat files. Trusted locations are protected
215 // by dm-verity or fs-verity. The recognized locations are on /system or
216 // /data/misc/apexdata/com.android.art.
217 bool LocationIsTrusted(const std::string& location, bool trust_art_apex_data_files);
218 
219 // Compare the ART module root against android root. Returns true if they are
220 // both known and distinct. This is meant to be a proxy for 'running with apex'.
221 bool ArtModuleRootDistinctFromAndroidRoot();
222 
223 // dup(2), except setting the O_CLOEXEC flag atomically, when possible.
224 int DupCloexec(int fd);
225 
226 // Returns true if `path` begins with a slash.
IsAbsoluteLocation(const std::string & path)227 inline bool IsAbsoluteLocation(const std::string& path) { return !path.empty() && path[0] == '/'; }
228 
229 }  // namespace art
230 
231 #endif  // ART_LIBARTBASE_BASE_FILE_UTILS_H_
232