use std::collections::BTreeMap; use std::convert::{TryFrom, TryInto}; use std::fs::{read_dir, remove_dir, remove_file, rename, DirBuilder, File, FileType, OpenOptions, ReadDir}; use std::io::{Read, Seek, SeekFrom, Write}; use std::path::Path; use std::time::SystemTime; use rustc_data_structures::fx::FxHashMap; use rustc_target::abi::{Align, LayoutOf, Size}; use crate::stacked_borrows::Tag; use crate::*; use helpers::{immty_from_int_checked, immty_from_uint_checked}; use shims::time::system_time_to_duration; #[derive(Debug)] pub struct FileHandle { file: File, writable: bool, } #[derive(Debug, Default)] pub struct FileHandler { handles: BTreeMap, } // fd numbers 0, 1, and 2 are reserved for stdin, stdout, and stderr const MIN_NORMAL_FILE_FD: i32 = 3; impl FileHandler { fn insert_fd(&mut self, file_handle: FileHandle) -> i32 { self.insert_fd_with_min_fd(file_handle, 0) } fn insert_fd_with_min_fd(&mut self, file_handle: FileHandle, min_fd: i32) -> i32 { let min_fd = std::cmp::max(min_fd, MIN_NORMAL_FILE_FD); // Find the lowest unused FD, starting from min_fd. If the first such unused FD is in // between used FDs, the find_map combinator will return it. If the first such unused FD // is after all other used FDs, the find_map combinator will return None, and we will use // the FD following the greatest FD thus far. let candidate_new_fd = self .handles .range(min_fd..) .zip(min_fd..) .find_map(|((fd, _fh), counter)| { if *fd != counter { // There was a gap in the fds stored, return the first unused one // (note that this relies on BTreeMap iterating in key order) Some(counter) } else { // This fd is used, keep going None } }); let new_fd = candidate_new_fd.unwrap_or_else(|| { // find_map ran out of BTreeMap entries before finding a free fd, use one plus the // maximum fd in the map self.handles.last_entry().map(|entry| entry.key().checked_add(1).unwrap()).unwrap_or(min_fd) }); self.handles.insert(new_fd, file_handle).unwrap_none(); new_fd } } impl<'mir, 'tcx> EvalContextExtPrivate<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {} trait EvalContextExtPrivate<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> { /// Emulate `stat` or `lstat` on `macos`. This function is not intended to be /// called directly from `emulate_foreign_item_by_name`, so it does not check if isolation is /// disabled or if the target OS is the correct one. Please use `macos_stat` or /// `macos_lstat` instead. fn macos_stat_or_lstat( &mut self, follow_symlink: bool, path_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); let path_scalar = this.read_scalar(path_op)?.not_undef()?; let path = this.read_path_from_c_str(path_scalar)?.into_owned(); let metadata = match FileMetadata::from_path(this, &path, follow_symlink)? { Some(metadata) => metadata, None => return Ok(-1), }; this.macos_stat_write_buf(metadata, buf_op) } fn macos_stat_write_buf( &mut self, metadata: FileMetadata, buf_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); let mode: u16 = metadata.mode.to_u16()?; let (access_sec, access_nsec) = metadata.accessed.unwrap_or((0, 0)); let (created_sec, created_nsec) = metadata.created.unwrap_or((0, 0)); let (modified_sec, modified_nsec) = metadata.modified.unwrap_or((0, 0)); let dev_t_layout = this.libc_ty_layout("dev_t")?; let mode_t_layout = this.libc_ty_layout("mode_t")?; let nlink_t_layout = this.libc_ty_layout("nlink_t")?; let ino_t_layout = this.libc_ty_layout("ino_t")?; let uid_t_layout = this.libc_ty_layout("uid_t")?; let gid_t_layout = this.libc_ty_layout("gid_t")?; let time_t_layout = this.libc_ty_layout("time_t")?; let long_layout = this.libc_ty_layout("c_long")?; let off_t_layout = this.libc_ty_layout("off_t")?; let blkcnt_t_layout = this.libc_ty_layout("blkcnt_t")?; let blksize_t_layout = this.libc_ty_layout("blksize_t")?; let uint32_t_layout = this.libc_ty_layout("uint32_t")?; let imms = [ immty_from_uint_checked(0u128, dev_t_layout)?, // st_dev immty_from_uint_checked(mode, mode_t_layout)?, // st_mode immty_from_uint_checked(0u128, nlink_t_layout)?, // st_nlink immty_from_uint_checked(0u128, ino_t_layout)?, // st_ino immty_from_uint_checked(0u128, uid_t_layout)?, // st_uid immty_from_uint_checked(0u128, gid_t_layout)?, // st_gid immty_from_uint_checked(0u128, dev_t_layout)?, // st_rdev immty_from_uint_checked(0u128, uint32_t_layout)?, // padding immty_from_uint_checked(access_sec, time_t_layout)?, // st_atime immty_from_uint_checked(access_nsec, long_layout)?, // st_atime_nsec immty_from_uint_checked(modified_sec, time_t_layout)?, // st_mtime immty_from_uint_checked(modified_nsec, long_layout)?, // st_mtime_nsec immty_from_uint_checked(0u128, time_t_layout)?, // st_ctime immty_from_uint_checked(0u128, long_layout)?, // st_ctime_nsec immty_from_uint_checked(created_sec, time_t_layout)?, // st_birthtime immty_from_uint_checked(created_nsec, long_layout)?, // st_birthtime_nsec immty_from_uint_checked(metadata.size, off_t_layout)?, // st_size immty_from_uint_checked(0u128, blkcnt_t_layout)?, // st_blocks immty_from_uint_checked(0u128, blksize_t_layout)?, // st_blksize immty_from_uint_checked(0u128, uint32_t_layout)?, // st_flags immty_from_uint_checked(0u128, uint32_t_layout)?, // st_gen ]; let buf = this.deref_operand(buf_op)?; this.write_packed_immediates(buf, &imms)?; Ok(0) } /// Function used when a handle is not found inside `FileHandler`. It returns `Ok(-1)`and sets /// the last OS error to `libc::EBADF` (invalid file descriptor). This function uses /// `T: From` instead of `i32` directly because some fs functions return different integer /// types (like `read`, that returns an `i64`). fn handle_not_found>(&mut self) -> InterpResult<'tcx, T> { let this = self.eval_context_mut(); let ebadf = this.eval_libc("EBADF")?; this.set_last_error(ebadf)?; Ok((-1).into()) } fn file_type_to_d_type(&mut self, file_type: std::io::Result) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); match file_type { Ok(file_type) => { if file_type.is_dir() { Ok(this.eval_libc("DT_DIR")?.to_u8()?.into()) } else if file_type.is_file() { Ok(this.eval_libc("DT_REG")?.to_u8()?.into()) } else if file_type.is_symlink() { Ok(this.eval_libc("DT_LNK")?.to_u8()?.into()) } else { // Certain file types are only supported when the host is a Unix system. // (i.e. devices and sockets) If it is, check those cases, if not, fall back to // DT_UNKNOWN sooner. #[cfg(unix)] { use std::os::unix::fs::FileTypeExt; if file_type.is_block_device() { Ok(this.eval_libc("DT_BLK")?.to_u8()?.into()) } else if file_type.is_char_device() { Ok(this.eval_libc("DT_CHR")?.to_u8()?.into()) } else if file_type.is_fifo() { Ok(this.eval_libc("DT_FIFO")?.to_u8()?.into()) } else if file_type.is_socket() { Ok(this.eval_libc("DT_SOCK")?.to_u8()?.into()) } else { Ok(this.eval_libc("DT_UNKNOWN")?.to_u8()?.into()) } } #[cfg(not(unix))] Ok(this.eval_libc("DT_UNKNOWN")?.to_u8()?.into()) } } Err(e) => return match e.raw_os_error() { Some(error) => Ok(error), None => throw_unsup_format!("the error {} couldn't be converted to a return value", e), } } } } #[derive(Debug)] pub struct DirHandler { /// Directory iterators used to emulate libc "directory streams", as used in opendir, readdir, /// and closedir. /// /// When opendir is called, a directory iterator is created on the host for the target /// directory, and an entry is stored in this hash map, indexed by an ID which represents /// the directory stream. When readdir is called, the directory stream ID is used to look up /// the corresponding ReadDir iterator from this map, and information from the next /// directory entry is returned. When closedir is called, the ReadDir iterator is removed from /// the map. streams: FxHashMap, /// ID number to be used by the next call to opendir next_id: u64, } impl DirHandler { fn insert_new(&mut self, read_dir: ReadDir) -> u64 { let id = self.next_id; self.next_id += 1; self.streams.insert(id, read_dir).unwrap_none(); id } } impl Default for DirHandler { fn default() -> DirHandler { DirHandler { streams: FxHashMap::default(), // Skip 0 as an ID, because it looks like a null pointer to libc next_id: 1, } } } impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {} pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> { fn open( &mut self, path_op: OpTy<'tcx, Tag>, flag_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("open")?; let flag = this.read_scalar(flag_op)?.to_i32()?; let mut options = OpenOptions::new(); let o_rdonly = this.eval_libc_i32("O_RDONLY")?; let o_wronly = this.eval_libc_i32("O_WRONLY")?; let o_rdwr = this.eval_libc_i32("O_RDWR")?; // The first two bits of the flag correspond to the access mode in linux, macOS and // windows. We need to check that in fact the access mode flags for the current target // only use these two bits, otherwise we are in an unsupported target and should error. if (o_rdonly | o_wronly | o_rdwr) & !0b11 != 0 { throw_unsup_format!("access mode flags on this target are unsupported"); } let mut writable = true; // Now we check the access mode let access_mode = flag & 0b11; if access_mode == o_rdonly { writable = false; options.read(true); } else if access_mode == o_wronly { options.write(true); } else if access_mode == o_rdwr { options.read(true).write(true); } else { throw_unsup_format!("unsupported access mode {:#x}", access_mode); } // We need to check that there aren't unsupported options in `flag`. For this we try to // reproduce the content of `flag` in the `mirror` variable using only the supported // options. let mut mirror = access_mode; let o_append = this.eval_libc_i32("O_APPEND")?; if flag & o_append != 0 { options.append(true); mirror |= o_append; } let o_trunc = this.eval_libc_i32("O_TRUNC")?; if flag & o_trunc != 0 { options.truncate(true); mirror |= o_trunc; } let o_creat = this.eval_libc_i32("O_CREAT")?; if flag & o_creat != 0 { mirror |= o_creat; let o_excl = this.eval_libc_i32("O_EXCL")?; if flag & o_excl != 0 { mirror |= o_excl; options.create_new(true); } else { options.create(true); } } let o_cloexec = this.eval_libc_i32("O_CLOEXEC")?; if flag & o_cloexec != 0 { // We do not need to do anything for this flag because `std` already sets it. // (Technically we do not support *not* setting this flag, but we ignore that.) mirror |= o_cloexec; } // If `flag` is not equal to `mirror`, there is an unsupported option enabled in `flag`, // then we throw an error. if flag != mirror { throw_unsup_format!("unsupported flags {:#x}", flag & !mirror); } let path = this.read_path_from_c_str(this.read_scalar(path_op)?.not_undef()?)?; let fd = options.open(&path).map(|file| { let fh = &mut this.machine.file_handler; fh.insert_fd(FileHandle { file, writable }) }); this.try_unwrap_io_result(fd) } fn fcntl( &mut self, fd_op: OpTy<'tcx, Tag>, cmd_op: OpTy<'tcx, Tag>, start_op: Option>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("fcntl")?; let fd = this.read_scalar(fd_op)?.to_i32()?; let cmd = this.read_scalar(cmd_op)?.to_i32()?; // We only support getting the flags for a descriptor. if cmd == this.eval_libc_i32("F_GETFD")? { // Currently this is the only flag that `F_GETFD` returns. It is OK to just return the // `FD_CLOEXEC` value without checking if the flag is set for the file because `std` // always sets this flag when opening a file. However we still need to check that the // file itself is open. if this.machine.file_handler.handles.contains_key(&fd) { Ok(this.eval_libc_i32("FD_CLOEXEC")?) } else { this.handle_not_found() } } else if cmd == this.eval_libc_i32("F_DUPFD")? || cmd == this.eval_libc_i32("F_DUPFD_CLOEXEC")? { // Note that we always assume the FD_CLOEXEC flag is set for every open file, in part // because exec() isn't supported. The F_DUPFD and F_DUPFD_CLOEXEC commands only // differ in whether the FD_CLOEXEC flag is pre-set on the new file descriptor, // thus they can share the same implementation here. if fd < MIN_NORMAL_FILE_FD { throw_unsup_format!("duplicating file descriptors for stdin, stdout, or stderr is not supported") } let start_op = start_op.ok_or_else(|| { err_unsup_format!( "fcntl with command F_DUPFD or F_DUPFD_CLOEXEC requires a third argument" ) })?; let start = this.read_scalar(start_op)?.to_i32()?; let fh = &mut this.machine.file_handler; let (file_result, writable) = match fh.handles.get(&fd) { Some(FileHandle { file, writable }) => (file.try_clone(), *writable), None => return this.handle_not_found(), }; let fd_result = file_result.map(|duplicated| { fh.insert_fd_with_min_fd(FileHandle { file: duplicated, writable }, start) }); this.try_unwrap_io_result(fd_result) } else { throw_unsup_format!("the {:#x} command is not supported for `fcntl`)", cmd); } } fn close(&mut self, fd_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("close")?; let fd = this.read_scalar(fd_op)?.to_i32()?; if let Some(FileHandle { file, writable }) = this.machine.file_handler.handles.remove(&fd) { // We sync the file if it was opened in a mode different than read-only. if writable { // `File::sync_all` does the checks that are done when closing a file. We do this to // to handle possible errors correctly. let result = this.try_unwrap_io_result(file.sync_all().map(|_| 0i32)); // Now we actually close the file. drop(file); // And return the result. result } else { // We drop the file, this closes it but ignores any errors produced when closing // it. This is done because `File::sync_all` cannot be done over files like // `/dev/urandom` which are read-only. Check // https://github.com/rust-lang/miri/issues/999#issuecomment-568920439 for a deeper // discussion. drop(file); Ok(0) } } else { this.handle_not_found() } } fn read( &mut self, fd_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, count_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i64> { let this = self.eval_context_mut(); this.check_no_isolation("read")?; let fd = this.read_scalar(fd_op)?.to_i32()?; let buf = this.read_scalar(buf_op)?.not_undef()?; let count = this.read_scalar(count_op)?.to_machine_usize(&*this.tcx)?; // Check that the *entire* buffer is actually valid memory. this.memory.check_ptr_access( buf, Size::from_bytes(count), Align::from_bytes(1).unwrap(), )?; // We cap the number of read bytes to the largest value that we are able to fit in both the // host's and target's `isize`. This saves us from having to handle overflows later. let count = count.min(this.machine_isize_max() as u64).min(isize::MAX as u64); if let Some(FileHandle { file, writable: _ }) = this.machine.file_handler.handles.get_mut(&fd) { // This can never fail because `count` was capped to be smaller than // `isize::MAX`. let count = isize::try_from(count).unwrap(); // We want to read at most `count` bytes. We are sure that `count` is not negative // because it was a target's `usize`. Also we are sure that its smaller than // `usize::MAX` because it is a host's `isize`. let mut bytes = vec![0; count as usize]; let result = file .read(&mut bytes) // `File::read` never returns a value larger than `count`, so this cannot fail. .map(|c| i64::try_from(c).unwrap()); match result { Ok(read_bytes) => { // If reading to `bytes` did not fail, we write those bytes to the buffer. this.memory.write_bytes(buf, bytes)?; Ok(read_bytes) } Err(e) => { this.set_last_error_from_io_error(e)?; Ok(-1) } } } else { this.handle_not_found() } } fn write( &mut self, fd_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, count_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i64> { let this = self.eval_context_mut(); this.check_no_isolation("write")?; let fd = this.read_scalar(fd_op)?.to_i32()?; let buf = this.read_scalar(buf_op)?.not_undef()?; let count = this.read_scalar(count_op)?.to_machine_usize(&*this.tcx)?; // Check that the *entire* buffer is actually valid memory. this.memory.check_ptr_access( buf, Size::from_bytes(count), Align::from_bytes(1).unwrap(), )?; // We cap the number of written bytes to the largest value that we are able to fit in both the // host's and target's `isize`. This saves us from having to handle overflows later. let count = count.min(this.machine_isize_max() as u64).min(isize::MAX as u64); if let Some(FileHandle { file, writable: _ }) = this.machine.file_handler.handles.get_mut(&fd) { let bytes = this.memory.read_bytes(buf, Size::from_bytes(count))?; let result = file.write(&bytes).map(|c| i64::try_from(c).unwrap()); this.try_unwrap_io_result(result) } else { this.handle_not_found() } } fn lseek64( &mut self, fd_op: OpTy<'tcx, Tag>, offset_op: OpTy<'tcx, Tag>, whence_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i64> { let this = self.eval_context_mut(); this.check_no_isolation("lseek64")?; let fd = this.read_scalar(fd_op)?.to_i32()?; let offset = this.read_scalar(offset_op)?.to_i64()?; let whence = this.read_scalar(whence_op)?.to_i32()?; let seek_from = if whence == this.eval_libc_i32("SEEK_SET")? { SeekFrom::Start(u64::try_from(offset).unwrap()) } else if whence == this.eval_libc_i32("SEEK_CUR")? { SeekFrom::Current(offset) } else if whence == this.eval_libc_i32("SEEK_END")? { SeekFrom::End(offset) } else { let einval = this.eval_libc("EINVAL")?; this.set_last_error(einval)?; return Ok(-1); }; if let Some(FileHandle { file, writable: _ }) = this.machine.file_handler.handles.get_mut(&fd) { let result = file.seek(seek_from).map(|offset| i64::try_from(offset).unwrap()); this.try_unwrap_io_result(result) } else { this.handle_not_found() } } fn unlink(&mut self, path_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("unlink")?; let path = this.read_path_from_c_str(this.read_scalar(path_op)?.not_undef()?)?; let result = remove_file(path).map(|_| 0); this.try_unwrap_io_result(result) } fn symlink( &mut self, target_op: OpTy<'tcx, Tag>, linkpath_op: OpTy<'tcx, Tag> ) -> InterpResult<'tcx, i32> { #[cfg(target_family = "unix")] fn create_link(src: &Path, dst: &Path) -> std::io::Result<()> { std::os::unix::fs::symlink(src, dst) } #[cfg(target_family = "windows")] fn create_link(src: &Path, dst: &Path) -> std::io::Result<()> { use std::os::windows::fs; if src.is_dir() { fs::symlink_dir(src, dst) } else { fs::symlink_file(src, dst) } } let this = self.eval_context_mut(); this.check_no_isolation("symlink")?; let target = this.read_path_from_c_str(this.read_scalar(target_op)?.not_undef()?)?; let linkpath = this.read_path_from_c_str(this.read_scalar(linkpath_op)?.not_undef()?)?; let result = create_link(&target, &linkpath).map(|_| 0); this.try_unwrap_io_result(result) } fn macos_stat( &mut self, path_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("macos", "stat"); this.check_no_isolation("stat")?; // `stat` always follows symlinks. this.macos_stat_or_lstat(true, path_op, buf_op) } // `lstat` is used to get symlink metadata. fn macos_lstat( &mut self, path_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("macos", "lstat"); this.check_no_isolation("lstat")?; this.macos_stat_or_lstat(false, path_op, buf_op) } fn macos_fstat( &mut self, fd_op: OpTy<'tcx, Tag>, buf_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("macos", "fstat"); this.check_no_isolation("fstat")?; let fd = this.read_scalar(fd_op)?.to_i32()?; let metadata = match FileMetadata::from_fd(this, fd)? { Some(metadata) => metadata, None => return Ok(-1), }; this.macos_stat_write_buf(metadata, buf_op) } fn linux_statx( &mut self, dirfd_op: OpTy<'tcx, Tag>, // Should be an `int` pathname_op: OpTy<'tcx, Tag>, // Should be a `const char *` flags_op: OpTy<'tcx, Tag>, // Should be an `int` _mask_op: OpTy<'tcx, Tag>, // Should be an `unsigned int` statxbuf_op: OpTy<'tcx, Tag>, // Should be a `struct statx *` ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("linux", "statx"); this.check_no_isolation("statx")?; let statxbuf_scalar = this.read_scalar(statxbuf_op)?.not_undef()?; let pathname_scalar = this.read_scalar(pathname_op)?.not_undef()?; // If the statxbuf or pathname pointers are null, the function fails with `EFAULT`. if this.is_null(statxbuf_scalar)? || this.is_null(pathname_scalar)? { let efault = this.eval_libc("EFAULT")?; this.set_last_error(efault)?; return Ok(-1); } // Under normal circumstances, we would use `deref_operand(statxbuf_op)` to produce a // proper `MemPlace` and then write the results of this function to it. However, the // `syscall` function is untyped. This means that all the `statx` parameters are provided // as `isize`s instead of having the proper types. Thus, we have to recover the layout of // `statxbuf_op` by using the `libc::statx` struct type. let statxbuf_place = { // FIXME: This long path is required because `libc::statx` is an struct and also a // function and `resolve_path` is returning the latter. let statx_ty = this .resolve_path(&["libc", "unix", "linux_like", "linux", "gnu", "statx"]) .monomorphic_ty(*this.tcx); let statxbuf_ty = this.tcx.mk_mut_ptr(statx_ty); let statxbuf_layout = this.layout_of(statxbuf_ty)?; let statxbuf_imm = ImmTy::from_scalar(statxbuf_scalar, statxbuf_layout); this.ref_to_mplace(statxbuf_imm)? }; let path = this.read_path_from_c_str(pathname_scalar)?.into_owned(); // `flags` should be a `c_int` but the `syscall` function provides an `isize`. let flags: i32 = this.read_scalar(flags_op)?.to_machine_isize(&*this.tcx)?.try_into().map_err(|e| { err_unsup_format!("failed to convert pointer sized operand to integer: {}", e) })?; let empty_path_flag = flags & this.eval_libc("AT_EMPTY_PATH")?.to_i32()? != 0; // `dirfd` should be a `c_int` but the `syscall` function provides an `isize`. let dirfd: i32 = this.read_scalar(dirfd_op)?.to_machine_isize(&*this.tcx)?.try_into().map_err(|e| { err_unsup_format!("failed to convert pointer sized operand to integer: {}", e) })?; // We only support: // * interpreting `path` as an absolute directory, // * interpreting `path` as a path relative to `dirfd` when the latter is `AT_FDCWD`, or // * interpreting `dirfd` as any file descriptor when `path` is empty and AT_EMPTY_PATH is // set. // Other behaviors cannot be tested from `libstd` and thus are not implemented. If you // found this error, please open an issue reporting it. if !( path.is_absolute() || dirfd == this.eval_libc_i32("AT_FDCWD")? || (path.as_os_str().is_empty() && empty_path_flag) ) { throw_unsup_format!( "using statx is only supported with absolute paths, relative paths with the file \ descriptor `AT_FDCWD`, and empty paths with the `AT_EMPTY_PATH` flag set and any \ file descriptor" ) } // the `_mask_op` paramter specifies the file information that the caller requested. // However `statx` is allowed to return information that was not requested or to not // return information that was requested. This `mask` represents the information we can // actually provide for any target. let mut mask = this.eval_libc("STATX_TYPE")?.to_u32()? | this.eval_libc("STATX_SIZE")?.to_u32()?; // If the `AT_SYMLINK_NOFOLLOW` flag is set, we query the file's metadata without following // symbolic links. let follow_symlink = flags & this.eval_libc("AT_SYMLINK_NOFOLLOW")?.to_i32()? == 0; // If the path is empty, and the AT_EMPTY_PATH flag is set, we query the open file // represented by dirfd, whether it's a directory or otherwise. let metadata = if path.as_os_str().is_empty() && empty_path_flag { FileMetadata::from_fd(this, dirfd)? } else { FileMetadata::from_path(this, &path, follow_symlink)? }; let metadata = match metadata { Some(metadata) => metadata, None => return Ok(-1), }; // The `mode` field specifies the type of the file and the permissions over the file for // the owner, its group and other users. Given that we can only provide the file type // without using platform specific methods, we only set the bits corresponding to the file // type. This should be an `__u16` but `libc` provides its values as `u32`. let mode: u16 = metadata .mode .to_u32()? .try_into() .unwrap_or_else(|_| bug!("libc contains bad value for constant")); // We need to set the corresponding bits of `mask` if the access, creation and modification // times were available. Otherwise we let them be zero. let (access_sec, access_nsec) = metadata.accessed.map(|tup| { mask |= this.eval_libc("STATX_ATIME")?.to_u32()?; InterpResult::Ok(tup) }).unwrap_or(Ok((0, 0)))?; let (created_sec, created_nsec) = metadata.created.map(|tup| { mask |= this.eval_libc("STATX_BTIME")?.to_u32()?; InterpResult::Ok(tup) }).unwrap_or(Ok((0, 0)))?; let (modified_sec, modified_nsec) = metadata.modified.map(|tup| { mask |= this.eval_libc("STATX_MTIME")?.to_u32()?; InterpResult::Ok(tup) }).unwrap_or(Ok((0, 0)))?; let __u32_layout = this.libc_ty_layout("__u32")?; let __u64_layout = this.libc_ty_layout("__u64")?; let __u16_layout = this.libc_ty_layout("__u16")?; // Now we transform all this fields into `ImmTy`s and write them to `statxbuf`. We write a // zero for the unavailable fields. let imms = [ immty_from_uint_checked(mask, __u32_layout)?, // stx_mask immty_from_uint_checked(0u128, __u32_layout)?, // stx_blksize immty_from_uint_checked(0u128, __u64_layout)?, // stx_attributes immty_from_uint_checked(0u128, __u32_layout)?, // stx_nlink immty_from_uint_checked(0u128, __u32_layout)?, // stx_uid immty_from_uint_checked(0u128, __u32_layout)?, // stx_gid immty_from_uint_checked(mode, __u16_layout)?, // stx_mode immty_from_uint_checked(0u128, __u16_layout)?, // statx padding immty_from_uint_checked(0u128, __u64_layout)?, // stx_ino immty_from_uint_checked(metadata.size, __u64_layout)?, // stx_size immty_from_uint_checked(0u128, __u64_layout)?, // stx_blocks immty_from_uint_checked(0u128, __u64_layout)?, // stx_attributes immty_from_uint_checked(access_sec, __u64_layout)?, // stx_atime.tv_sec immty_from_uint_checked(access_nsec, __u32_layout)?, // stx_atime.tv_nsec immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding immty_from_uint_checked(created_sec, __u64_layout)?, // stx_btime.tv_sec immty_from_uint_checked(created_nsec, __u32_layout)?, // stx_btime.tv_nsec immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding immty_from_uint_checked(0u128, __u64_layout)?, // stx_ctime.tv_sec immty_from_uint_checked(0u128, __u32_layout)?, // stx_ctime.tv_nsec immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding immty_from_uint_checked(modified_sec, __u64_layout)?, // stx_mtime.tv_sec immty_from_uint_checked(modified_nsec, __u32_layout)?, // stx_mtime.tv_nsec immty_from_uint_checked(0u128, __u32_layout)?, // statx_timestamp padding immty_from_uint_checked(0u128, __u64_layout)?, // stx_rdev_major immty_from_uint_checked(0u128, __u64_layout)?, // stx_rdev_minor immty_from_uint_checked(0u128, __u64_layout)?, // stx_dev_major immty_from_uint_checked(0u128, __u64_layout)?, // stx_dev_minor ]; this.write_packed_immediates(statxbuf_place, &imms)?; Ok(0) } fn rename( &mut self, oldpath_op: OpTy<'tcx, Tag>, newpath_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("rename")?; let oldpath_scalar = this.read_scalar(oldpath_op)?.not_undef()?; let newpath_scalar = this.read_scalar(newpath_op)?.not_undef()?; if this.is_null(oldpath_scalar)? || this.is_null(newpath_scalar)? { let efault = this.eval_libc("EFAULT")?; this.set_last_error(efault)?; return Ok(-1); } let oldpath = this.read_path_from_c_str(oldpath_scalar)?; let newpath = this.read_path_from_c_str(newpath_scalar)?; let result = rename(oldpath, newpath).map(|_| 0); this.try_unwrap_io_result(result) } fn mkdir( &mut self, path_op: OpTy<'tcx, Tag>, mode_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("mkdir")?; let _mode = if this.tcx.sess.target.target.target_os == "macos" { u32::from(this.read_scalar(mode_op)?.not_undef()?.to_u16()?) } else { this.read_scalar(mode_op)?.to_u32()? }; let path = this.read_path_from_c_str(this.read_scalar(path_op)?.not_undef()?)?; let mut builder = DirBuilder::new(); // If the host supports it, forward on the mode of the directory // (i.e. permission bits and the sticky bit) #[cfg(target_family = "unix")] { use std::os::unix::fs::DirBuilderExt; builder.mode(_mode.into()); } let result = builder.create(path).map(|_| 0i32); this.try_unwrap_io_result(result) } fn rmdir( &mut self, path_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("rmdir")?; let path = this.read_path_from_c_str(this.read_scalar(path_op)?.not_undef()?)?; let result = remove_dir(path).map(|_| 0i32); this.try_unwrap_io_result(result) } fn opendir(&mut self, name_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, Scalar> { let this = self.eval_context_mut(); this.check_no_isolation("opendir")?; let name = this.read_path_from_c_str(this.read_scalar(name_op)?.not_undef()?)?; let result = read_dir(name); match result { Ok(dir_iter) => { let id = this.machine.dir_handler.insert_new(dir_iter); // The libc API for opendir says that this method returns a pointer to an opaque // structure, but we are returning an ID number. Thus, pass it as a scalar of // pointer width. Ok(Scalar::from_machine_usize(id, this)) } Err(e) => { this.set_last_error_from_io_error(e)?; Ok(Scalar::null_ptr(this)) } } } fn linux_readdir64_r( &mut self, dirp_op: OpTy<'tcx, Tag>, entry_op: OpTy<'tcx, Tag>, result_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("linux", "readdir64_r"); this.check_no_isolation("readdir64_r")?; let dirp = this.read_scalar(dirp_op)?.to_machine_usize(this)?; let dir_iter = this.machine.dir_handler.streams.get_mut(&dirp).ok_or_else(|| { err_unsup_format!("the DIR pointer passed to readdir64_r did not come from opendir") })?; match dir_iter.next() { Some(Ok(dir_entry)) => { // Write into entry, write pointer to result, return 0 on success. // The name is written with write_os_str_to_c_str, while the rest of the // dirent64 struct is written using write_packed_immediates. // For reference: // pub struct dirent64 { // pub d_ino: ino64_t, // pub d_off: off64_t, // pub d_reclen: c_ushort, // pub d_type: c_uchar, // pub d_name: [c_char; 256], // } let entry_place = this.deref_operand(entry_op)?; let name_place = this.mplace_field(entry_place, 4)?; let file_name = dir_entry.file_name(); // not a Path as there are no separators! let (name_fits, _) = this.write_os_str_to_c_str( &file_name, name_place.ptr, name_place.layout.size.bytes(), )?; if !name_fits { throw_unsup_format!("a directory entry had a name too large to fit in libc::dirent64"); } let entry_place = this.deref_operand(entry_op)?; let ino64_t_layout = this.libc_ty_layout("ino64_t")?; let off64_t_layout = this.libc_ty_layout("off64_t")?; let c_ushort_layout = this.libc_ty_layout("c_ushort")?; let c_uchar_layout = this.libc_ty_layout("c_uchar")?; // If the host is a Unix system, fill in the inode number with its real value. // If not, use 0 as a fallback value. #[cfg(unix)] let ino = std::os::unix::fs::DirEntryExt::ino(&dir_entry); #[cfg(not(unix))] let ino = 0u64; let file_type = this.file_type_to_d_type(dir_entry.file_type())?; let imms = [ immty_from_uint_checked(ino, ino64_t_layout)?, // d_ino immty_from_uint_checked(0u128, off64_t_layout)?, // d_off immty_from_uint_checked(0u128, c_ushort_layout)?, // d_reclen immty_from_int_checked(file_type, c_uchar_layout)?, // d_type ]; this.write_packed_immediates(entry_place, &imms)?; let result_place = this.deref_operand(result_op)?; this.write_scalar(this.read_scalar(entry_op)?, result_place.into())?; Ok(0) } None => { // end of stream: return 0, assign *result=NULL this.write_null(this.deref_operand(result_op)?.into())?; Ok(0) } Some(Err(e)) => match e.raw_os_error() { // return positive error number on error Some(error) => Ok(error), None => { throw_unsup_format!("the error {} couldn't be converted to a return value", e) } }, } } fn macos_readdir_r( &mut self, dirp_op: OpTy<'tcx, Tag>, entry_op: OpTy<'tcx, Tag>, result_op: OpTy<'tcx, Tag>, ) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.assert_target_os("macos", "readdir_r"); this.check_no_isolation("readdir_r")?; let dirp = this.read_scalar(dirp_op)?.to_machine_usize(this)?; let dir_iter = this.machine.dir_handler.streams.get_mut(&dirp).ok_or_else(|| { err_unsup_format!("the DIR pointer passed to readdir_r did not come from opendir") })?; match dir_iter.next() { Some(Ok(dir_entry)) => { // Write into entry, write pointer to result, return 0 on success. // The name is written with write_os_str_to_c_str, while the rest of the // dirent struct is written using write_packed_Immediates. // For reference: // pub struct dirent { // pub d_ino: u64, // pub d_seekoff: u64, // pub d_reclen: u16, // pub d_namlen: u16, // pub d_type: u8, // pub d_name: [c_char; 1024], // } let entry_place = this.deref_operand(entry_op)?; let name_place = this.mplace_field(entry_place, 5)?; let file_name = dir_entry.file_name(); // not a Path as there are no separators! let (name_fits, file_name_len) = this.write_os_str_to_c_str( &file_name, name_place.ptr, name_place.layout.size.bytes(), )?; if !name_fits { throw_unsup_format!("a directory entry had a name too large to fit in libc::dirent"); } let entry_place = this.deref_operand(entry_op)?; let ino_t_layout = this.libc_ty_layout("ino_t")?; let off_t_layout = this.libc_ty_layout("off_t")?; let c_ushort_layout = this.libc_ty_layout("c_ushort")?; let c_uchar_layout = this.libc_ty_layout("c_uchar")?; // If the host is a Unix system, fill in the inode number with its real value. // If not, use 0 as a fallback value. #[cfg(unix)] let ino = std::os::unix::fs::DirEntryExt::ino(&dir_entry); #[cfg(not(unix))] let ino = 0u64; let file_type = this.file_type_to_d_type(dir_entry.file_type())?; let imms = [ immty_from_uint_checked(ino, ino_t_layout)?, // d_ino immty_from_uint_checked(0u128, off_t_layout)?, // d_seekoff immty_from_uint_checked(0u128, c_ushort_layout)?, // d_reclen immty_from_uint_checked(file_name_len, c_ushort_layout)?, // d_namlen immty_from_int_checked(file_type, c_uchar_layout)?, // d_type ]; this.write_packed_immediates(entry_place, &imms)?; let result_place = this.deref_operand(result_op)?; this.write_scalar(this.read_scalar(entry_op)?, result_place.into())?; Ok(0) } None => { // end of stream: return 0, assign *result=NULL this.write_null(this.deref_operand(result_op)?.into())?; Ok(0) } Some(Err(e)) => match e.raw_os_error() { // return positive error number on error Some(error) => Ok(error), None => { throw_unsup_format!("the error {} couldn't be converted to a return value", e) } }, } } fn closedir(&mut self, dirp_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> { let this = self.eval_context_mut(); this.check_no_isolation("closedir")?; let dirp = this.read_scalar(dirp_op)?.to_machine_usize(this)?; if let Some(dir_iter) = this.machine.dir_handler.streams.remove(&dirp) { drop(dir_iter); Ok(0) } else { this.handle_not_found() } } } /// Extracts the number of seconds and nanoseconds elapsed between `time` and the unix epoch when /// `time` is Ok. Returns `None` if `time` is an error. Fails if `time` happens before the unix /// epoch. fn extract_sec_and_nsec<'tcx>( time: std::io::Result ) -> InterpResult<'tcx, Option<(u64, u32)>> { time.ok().map(|time| { let duration = system_time_to_duration(&time)?; Ok((duration.as_secs(), duration.subsec_nanos())) }).transpose() } /// Stores a file's metadata in order to avoid code duplication in the different metadata related /// shims. struct FileMetadata { mode: Scalar, size: u64, created: Option<(u64, u32)>, accessed: Option<(u64, u32)>, modified: Option<(u64, u32)>, } impl FileMetadata { fn from_path<'tcx, 'mir>( ecx: &mut MiriEvalContext<'mir, 'tcx>, path: &Path, follow_symlink: bool ) -> InterpResult<'tcx, Option> { let metadata = if follow_symlink { std::fs::metadata(path) } else { std::fs::symlink_metadata(path) }; FileMetadata::from_meta(ecx, metadata) } fn from_fd<'tcx, 'mir>( ecx: &mut MiriEvalContext<'mir, 'tcx>, fd: i32, ) -> InterpResult<'tcx, Option> { let option = ecx.machine.file_handler.handles.get(&fd); let file = match option { Some(FileHandle { file, writable: _ }) => file, None => return ecx.handle_not_found().map(|_: i32| None), }; let metadata = file.metadata(); FileMetadata::from_meta(ecx, metadata) } fn from_meta<'tcx, 'mir>( ecx: &mut MiriEvalContext<'mir, 'tcx>, metadata: Result, ) -> InterpResult<'tcx, Option> { let metadata = match metadata { Ok(metadata) => metadata, Err(e) => { ecx.set_last_error_from_io_error(e)?; return Ok(None); } }; let file_type = metadata.file_type(); let mode_name = if file_type.is_file() { "S_IFREG" } else if file_type.is_dir() { "S_IFDIR" } else { "S_IFLNK" }; let mode = ecx.eval_libc(mode_name)?; let size = metadata.len(); let created = extract_sec_and_nsec(metadata.created())?; let accessed = extract_sec_and_nsec(metadata.accessed())?; let modified = extract_sec_and_nsec(metadata.modified())?; // FIXME: Provide more fields using platform specific methods. Ok(Some(FileMetadata { mode, size, created, accessed, modified })) } }