1 /*
2 * Copyright (C) 2023 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 #ifdef _WIN32
18 #include <android-base/utf8.h>
19 #include <direct.h>
20 #include <shlobj.h>
21 #else
22 #include <pwd.h>
23 #endif
24
25 #include <android-base/logging.h>
26 #include <android-base/parseint.h>
27 #include <sys/file.h>
28 #include <sys/stat.h>
29 #include <unistd.h>
30
31 #include <vector>
32
33 #include "filesystem.h"
34
35 namespace {
36
LockFile(int fd)37 int LockFile(int fd) {
38 #ifdef _WIN32
39 HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
40 OVERLAPPED overlapped = {};
41 const BOOL locked =
42 LockFileEx(handle, LOCKFILE_EXCLUSIVE_LOCK, 0, MAXDWORD, MAXDWORD, &overlapped);
43 return locked ? 0 : -1;
44 #else
45 return flock(fd, LOCK_EX);
46 #endif
47 }
48
49 } // namespace
50
51 // inspired by adb implementation:
52 // cs.android.com/android/platform/superproject/+/master:packages/modules/adb/adb_utils.cpp;l=275
GetHomeDirPath()53 std::string GetHomeDirPath() {
54 #ifdef _WIN32
55 WCHAR path[MAX_PATH];
56 const HRESULT hr = SHGetFolderPathW(NULL, CSIDL_PROFILE, NULL, 0, path);
57 if (FAILED(hr)) {
58 return {};
59 }
60 std::string home_str;
61 if (!android::base::WideToUTF8(path, &home_str)) {
62 return {};
63 }
64 return home_str;
65 #else
66 if (const char* const home = getenv("HOME")) {
67 return home;
68 }
69
70 struct passwd pwent;
71 struct passwd* result;
72 int pwent_max = sysconf(_SC_GETPW_R_SIZE_MAX);
73 if (pwent_max == -1) {
74 pwent_max = 16384;
75 }
76 std::vector<char> buf(pwent_max);
77 int rc = getpwuid_r(getuid(), &pwent, buf.data(), buf.size(), &result);
78 if (rc == 0 && result) {
79 return result->pw_dir;
80 }
81 #endif
82
83 return {};
84 }
85
FileExists(const std::string & path)86 bool FileExists(const std::string& path) {
87 return access(path.c_str(), F_OK) == 0;
88 }
89
EnsureDirectoryExists(const std::string & directory_path)90 bool EnsureDirectoryExists(const std::string& directory_path) {
91 const int result =
92 #ifdef _WIN32
93 _mkdir(directory_path.c_str());
94 #else
95 mkdir(directory_path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
96 #endif
97
98 return result == 0 || errno == EEXIST;
99 }
100
FileLock(const std::string & path)101 FileLock::FileLock(const std::string& path) : fd_(open(path.c_str(), O_CREAT | O_WRONLY, 0644)) {
102 if (LockFile(fd_.get()) != 0) {
103 LOG(FATAL) << "Failed to acquire a lock on " << path;
104 }
105 }