// Copyright 2018 The gVisor Authors. // // 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. #ifndef GVISOR_TEST_UTIL_FS_UTIL_H_ #define GVISOR_TEST_UTIL_FS_UTIL_H_ #include <dirent.h> #include <sys/stat.h> #include <sys/statfs.h> #include <sys/types.h> #include <unistd.h> #include "absl/strings/string_view.h" #include "test/util/file_descriptor.h" #include "test/util/posix_error.h" namespace gvisor { namespace testing { // O_LARGEFILE as defined by Linux. glibc tries to be clever by setting it to 0 // because "it isn't needed", even though Linux can return it via F_GETFL. #if defined(__x86_64__) constexpr int kOLargeFile = 00100000; #elif defined(__aarch64__) constexpr int kOLargeFile = 00400000; #else #error "Unknown architecture" #endif // From linux/magic.h. For some reason, not defined in the headers for some // build environments. #define OVERLAYFS_SUPER_MAGIC 0x794c7630 // Returns a status or the current working directory. PosixErrorOr<std::string> GetCWD(); // Returns true/false depending on whether or not path exists, or an error if it // can't be determined. PosixErrorOr<bool> Exists(absl::string_view path); // Returns a stat structure for the given path or an error. If the path // represents a symlink, it will be traversed. PosixErrorOr<struct stat> Stat(absl::string_view path); // Returns a stat structure for the given path or an error. If the path // represents a symlink, it will not be traversed. PosixErrorOr<struct stat> Lstat(absl::string_view path); // Returns a stat struct for the given fd. PosixErrorOr<struct stat> Fstat(int fd); // Deletes the file or directory at path or returns an error. PosixError Delete(absl::string_view path); // Changes the mode of a file or returns an error. PosixError Chmod(absl::string_view path, int mode); // Create a special or ordinary file. PosixError MknodAt(const FileDescriptor& dfd, absl::string_view path, int mode, dev_t dev); // Unlink the file. PosixError UnlinkAt(const FileDescriptor& dfd, absl::string_view path, int flags); // Truncates a file to the given length or returns an error. PosixError Truncate(absl::string_view path, int length); // Returns true/false depending on whether or not the path is a directory or // returns an error. PosixErrorOr<bool> IsDirectory(absl::string_view path); // Makes a directory or returns an error. PosixError Mkdir(absl::string_view path, int mode = 0755); // Removes a directory or returns an error. PosixError Rmdir(absl::string_view path); // Attempts to set the contents of a file or returns an error. PosixError SetContents(absl::string_view path, absl::string_view contents); // Creates a file with the given contents and mode or returns an error. PosixError CreateWithContents(absl::string_view path, absl::string_view contents, int mode = 0666); // Attempts to read the entire contents of the file into the provided string // buffer or returns an error. PosixError GetContents(absl::string_view path, std::string* output); // Attempts to read the entire contents of the file or returns an error. PosixErrorOr<std::string> GetContents(absl::string_view path); // Attempts to read the entire contents of the provided fd into the provided // string or returns an error. PosixError GetContentsFD(int fd, std::string* output); // Attempts to read the entire contents of the provided fd or returns an error. PosixErrorOr<std::string> GetContentsFD(int fd); // Executes the readlink(2) system call or returns an error. PosixErrorOr<std::string> ReadLink(absl::string_view path); // WalkTree will walk a directory tree in a depth first search manner (if // recursive). It will invoke a provided callback for each file and directory, // the parent will always be invoked last making this appropriate for things // such as deleting an entire directory tree. // // This method will return an error when it's unable to access the provided // path, or when the path is not a directory. PosixError WalkTree( absl::string_view path, bool recursive, const std::function<void(absl::string_view, const struct stat&)>& cb); // Returns the base filenames for all files under a given absolute path. If // skipdots is true the returned vector will not contain "." or "..". This // method does not walk the tree recursively it only returns the elements // in that directory. PosixErrorOr<std::vector<std::string>> ListDir(absl::string_view abspath, bool skipdots); // Check that a directory contains children nodes named in expect, and does not // contain any children nodes named in exclude. PosixError DirContains(absl::string_view path, const std::vector<std::string>& expect, const std::vector<std::string>& exclude); // Same as DirContains, but adds a retry. Suitable for checking a directory // being modified asynchronously. PosixError EventuallyDirContains(absl::string_view path, const std::vector<std::string>& expect, const std::vector<std::string>& exclude); // Attempt to recursively delete a directory or file. Returns an error and // the number of undeleted directories and files. If either // undeleted_dirs or undeleted_files is nullptr then it will not be used. PosixError RecursivelyDelete(absl::string_view path, int* undeleted_dirs, int* undeleted_files); // Recursively create the directory provided or return an error. PosixError RecursivelyCreateDir(absl::string_view path); // Makes a path absolute with respect to an optional base. If no base is // provided it will use the current working directory. PosixErrorOr<std::string> MakeAbsolute(absl::string_view filename, absl::string_view base); // Generates a relative path from the source directory to the destination // (dest) file or directory. This uses ../ when necessary for destinations // which are not nested within the source. Both source and dest are required // to be absolute paths, and an empty string will be returned if they are not. PosixErrorOr<std::string> GetRelativePath(absl::string_view source, absl::string_view dest); // Returns the part of the path before the final "/", EXCEPT: // * If there is a single leading "/" in the path, the result will be the // leading "/". // * If there is no "/" in the path, the result is the empty prefix of the // input string. absl::string_view Dirname(absl::string_view path); // Return the parts of the path, split on the final "/". If there is no // "/" in the path, the first part of the output is empty and the second // is the input. If the only "/" in the path is the first character, it is // the first part of the output. std::pair<absl::string_view, absl::string_view> SplitPath( absl::string_view path); // Returns the part of the path after the final "/". If there is no // "/" in the path, the result is the same as the input. // Note that this function's behavior differs from the Unix basename // command if path ends with "/". For such paths, this function returns the // empty string. absl::string_view Basename(absl::string_view path); // Collapse duplicate "/"s, resolve ".." and "." path elements, remove // trailing "/". // // NOTE: This respects relative vs. absolute paths, but does not // invoke any system calls (getcwd(2)) in order to resolve relative // paths wrt actual working directory. That is, this is purely a // string manipulation, completely independent of process state. std::string CleanPath(absl::string_view path); // Returns the full path to the executable of the given pid or a PosixError. PosixErrorOr<std::string> ProcessExePath(int pid); #ifdef __linux__ // IsTmpfs returns true if the file at path is backed by tmpfs. PosixErrorOr<bool> IsTmpfs(const std::string& path); #endif // __linux__ // IsOverlayfs returns true if the file at path is backed by overlayfs. PosixErrorOr<bool> IsOverlayfs(const std::string& path); PosixError CheckSameFile(const FileDescriptor& fd1, const FileDescriptor& fd2); namespace internal { // Not part of the public API. std::string JoinPathImpl(std::initializer_list<absl::string_view> paths); } // namespace internal // Join multiple paths together. // All paths will be treated as relative paths, regardless of whether or not // they start with a leading '/'. That is, all paths will be concatenated // together, with the appropriate path separator inserted in between. // Arguments must be convertible to absl::string_view. // // Usage: // std::string path = JoinPath("/foo", dirname, filename); // std::string path = JoinPath(FLAGS_test_srcdir, filename); // // 0, 1, 2-path specializations exist to optimize common cases. inline std::string JoinPath() { return std::string(); } inline std::string JoinPath(absl::string_view path) { return std::string(path.data(), path.size()); } std::string JoinPath(absl::string_view path1, absl::string_view path2); template <typename... T> inline std::string JoinPath(absl::string_view path1, absl::string_view path2, absl::string_view path3, const T&... args) { return internal::JoinPathImpl({path1, path2, path3, args...}); } } // namespace testing } // namespace gvisor #endif // GVISOR_TEST_UTIL_FS_UTIL_H_