Merge "fastboot: Introduce network-connected devices storage"

fastboot/Android.bp

@@ -283,15 +283,17 @@ cc_library_host_static {
 
     srcs: [
         "bootimg_utils.cpp",
+        "fastboot_driver.cpp",
         "fastboot.cpp",
+        "filesystem.cpp",
         "fs.cpp",
         "socket.cpp",
+        "storage.cpp",
         "super_flash_helper.cpp",
         "tcp.cpp",
         "udp.cpp",
         "util.cpp",
         "vendor_boot_img_utils.cpp",
-        "fastboot_driver.cpp",
     ],
 
     // Only version the final binaries

fastboot/filesystem.cpp

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifdef _WIN32
+#include <android-base/utf8.h>
+#include <direct.h>
+#include <shlobj.h>
+#else
+#include <pwd.h>
+#endif
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include "filesystem.h"
+
+namespace {
+
+int LockFile(int fd) {
+#ifdef _WIN32
+    HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
+    OVERLAPPED overlapped = {};
+    const BOOL locked = LockFileEx(handle, LOCKFILE_EXCLUSIVE_LOCK, 0,
+                                   MAXDWORD, MAXDWORD, &overlapped);
+    return locked ? 0 : -1;
+#else
+    return flock(fd, LOCK_EX);
+#endif
+}
+
+}
+
+// inspired by adb implementation:
+// cs.android.com/android/platform/superproject/+/master:packages/modules/adb/adb_utils.cpp;l=275
+std::string GetHomeDirPath() {
+#ifdef _WIN32
+    WCHAR path[MAX_PATH];
+    const HRESULT hr = SHGetFolderPathW(NULL, CSIDL_PROFILE, NULL, 0, path);
+    if (FAILED(hr)) {
+        return {};
+    }
+    std::string home_str;
+    if (!android::base::WideToUTF8(path, &home_str)) {
+        return {};
+    }
+    return home_str;
+#else
+    if (const char* const home = getenv("HOME")) {
+        return home;
+    }
+
+    struct passwd pwent;
+    struct passwd* result;
+    int pwent_max = sysconf(_SC_GETPW_R_SIZE_MAX);
+    if (pwent_max == -1) {
+        pwent_max = 16384;
+    }
+    std::vector<char> buf(pwent_max);
+    int rc = getpwuid_r(getuid(), &pwent, buf.data(), buf.size(), &result);
+    if (rc == 0 && result) {
+        return result->pw_dir;
+    }
+#endif
+
+    return {};
+}
+
+bool FileExists(const std::string& path) {
+    return access(path.c_str(), F_OK) == 0;
+}
+
+bool EnsureDirectoryExists(const std::string& directory_path) {
+    const int result =
+#ifdef _WIN32
+                       _mkdir(directory_path.c_str());
+#else
+                       mkdir(directory_path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
+#endif
+
+    return result == 0 || errno == EEXIST;
+}
+
+FileLock::FileLock(const std::string& path) : fd_(open(path.c_str(), O_CREAT | O_WRONLY, 0644)) {
+    if (LockFile(fd_.get()) != 0) {
+        LOG(FATAL) << "Failed to acquire a lock on " << path;
+    }
+}

fastboot/filesystem.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <android-base/unique_fd.h>
+
+#include <string>
+
+using android::base::unique_fd;
+
+// TODO(b/175635923): remove after enabling libc++fs for windows
+const char kPathSeparator =
+#ifdef _WIN32
+                            '\\';
+#else
+                            '/';
+#endif
+
+std::string GetHomeDirPath();
+bool EnsureDirectoryExists(const std::string& directory_path);
+
+class FileLock {
+  public:
+    FileLock() = delete;
+    FileLock(const std::string& path);
+
+  private:
+    unique_fd fd_;
+};

fastboot/storage.cpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+
+#include <fstream>
+
+#include "storage.h"
+#include "util.h"
+
+ConnectedDevicesStorage::ConnectedDevicesStorage() {
+    const std::string home_path = GetHomeDirPath();
+    if (home_path.empty()) {
+        return;
+    }
+
+    const std::string home_fastboot_path = home_path + kPathSeparator + ".fastboot";
+
+    if (!EnsureDirectoryExists(home_fastboot_path)) {
+        LOG(FATAL) << "Cannot create directory: " << home_fastboot_path;
+    }
+
+    // We're using a separate file for locking because the Windows LockFileEx does not
+    // permit opening a file stream for the locked file, even within the same process. So,
+    // we have to use fd or handle API to manipulate the storage files, which makes it
+    // nearly impossible to fully rewrite a file content without having to recreate it.
+    // Unfortunately, this is not an option during holding a lock.
+    devices_path_ = home_fastboot_path + kPathSeparator + "devices";
+    devices_lock_path_ = home_fastboot_path + kPathSeparator + "devices.lock";
+}
+
+void ConnectedDevicesStorage::WriteDevices(const std::set<std::string>& devices) {
+    std::ofstream devices_stream(devices_path_);
+    std::copy(devices.begin(), devices.end(),
+              std::ostream_iterator<std::string>(devices_stream, "\n"));
+}
+
+std::set<std::string> ConnectedDevicesStorage::ReadDevices() {
+    std::ifstream devices_stream(devices_path_);
+    std::istream_iterator<std::string> start(devices_stream), end;
+    std::set<std::string> devices(start, end);
+    return devices;
+}
+
+void ConnectedDevicesStorage::Clear() {
+    if (!android::base::RemoveFileIfExists(devices_path_)) {
+        LOG(FATAL) << "Failed to clear connected device list: " << devices_path_;
+    }
+}
+
+FileLock ConnectedDevicesStorage::Lock() const {
+    return FileLock(devices_lock_path_);
+}

fastboot/storage.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <set>
+#include <string>
+
+#include "filesystem.h"
+
+class ConnectedDevicesStorage {
+  public:
+    ConnectedDevicesStorage();
+    void WriteDevices(const std::set<std::string>& devices);
+    std::set<std::string> ReadDevices();
+    void Clear();
+
+    FileLock Lock() const;
+  private:
+    std::string devices_path_;
+    std::string devices_lock_path_;
+};