1 use std::collections::HashMap;
2 use std::fs::{File, OpenOptions, remove_file};
3 use std::io::{Read, Write};
5 use rustc::ty::layout::Size;
7 use crate::stacked_borrows::Tag;
10 pub struct FileHandle {
15 pub struct FileHandler {
16 handles: HashMap<i32, FileHandle>,
20 impl Default for FileHandler {
21 fn default() -> Self {
23 handles: Default::default(),
24 // 0, 1 and 2 are reserved for stdin, stdout and stderr
30 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
31 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
34 path_op: OpTy<'tcx, Tag>,
35 flag_op: OpTy<'tcx, Tag>,
36 ) -> InterpResult<'tcx, i32> {
37 let this = self.eval_context_mut();
39 if !this.machine.communicate {
40 throw_unsup_format!("`open` not available when isolation is enabled")
43 let flag = this.read_scalar(flag_op)?.to_i32()?;
45 let mut options = OpenOptions::new();
47 // The first two bits of the flag correspond to the access mode of the file in linux.
48 let access_mode = flag & 0b11;
50 if access_mode == this.eval_libc_i32("O_RDONLY")? {
52 } else if access_mode == this.eval_libc_i32("O_WRONLY")? {
54 } else if access_mode == this.eval_libc_i32("O_RDWR")? {
55 options.read(true).write(true);
57 throw_unsup_format!("Unsupported access mode {:#x}", access_mode);
60 if flag & this.eval_libc_i32("O_APPEND")? != 0 {
63 if flag & this.eval_libc_i32("O_TRUNC")? != 0 {
64 options.truncate(true);
66 if flag & this.eval_libc_i32("O_CREAT")? != 0 {
72 .read_c_str(this.read_scalar(path_op)?.not_undef()?)?;
73 let path = std::str::from_utf8(path_bytes)
74 .map_err(|_| err_unsup_format!("{:?} is not a valid utf-8 string", path_bytes))?;
76 let fd = options.open(path).map(|file| {
77 let mut fh = &mut this.machine.file_handler;
79 fh.handles.insert(fh.low, FileHandle { file, flag });
83 this.consume_result(fd)
88 fd_op: OpTy<'tcx, Tag>,
89 cmd_op: OpTy<'tcx, Tag>,
90 arg_op: Option<OpTy<'tcx, Tag>>,
91 ) -> InterpResult<'tcx, i32> {
92 let this = self.eval_context_mut();
94 if !this.machine.communicate {
95 throw_unsup_format!("`fcntl` not available when isolation is enabled")
98 let fd = this.read_scalar(fd_op)?.to_i32()?;
99 let cmd = this.read_scalar(cmd_op)?.to_i32()?;
101 if cmd == this.eval_libc_i32("F_SETFD")? {
102 // This does not affect the file itself. Certain flags might require changing the file
103 // or the way it is accessed somehow.
104 let flag = this.read_scalar(arg_op.unwrap())?.to_i32()?;
105 // The only usage of this in stdlib at the moment is to enable the `FD_CLOEXEC` flag.
106 let fd_cloexec = this.eval_libc_i32("FD_CLOEXEC")?;
107 if let Some(FileHandle { flag: old_flag, .. }) =
108 this.machine.file_handler.handles.get_mut(&fd)
110 // Check that the only difference between the old flag and the current flag is
111 // exactly the `FD_CLOEXEC` value.
112 if flag ^ *old_flag == fd_cloexec {
115 throw_unsup_format!("Unsupported arg {:#x} for `F_SETFD`", flag);
119 } else if cmd == this.eval_libc_i32("F_GETFD")? {
120 this.get_handle_and(fd, |handle| Ok(handle.flag))
122 throw_unsup_format!("Unsupported command {:#x}", cmd);
126 fn close(&mut self, fd_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
127 let this = self.eval_context_mut();
129 if !this.machine.communicate {
130 throw_unsup_format!("`close` not available when isolation is enabled")
133 let fd = this.read_scalar(fd_op)?.to_i32()?;
135 this.remove_handle_and(fd, |handle, this| {
136 this.consume_result(handle.file.sync_all().map(|_| 0i32))
142 fd_op: OpTy<'tcx, Tag>,
143 buf_op: OpTy<'tcx, Tag>,
144 count_op: OpTy<'tcx, Tag>,
145 ) -> InterpResult<'tcx, i64> {
146 let this = self.eval_context_mut();
148 if !this.machine.communicate {
149 throw_unsup_format!("`read` not available when isolation is enabled")
152 let tcx = &{ this.tcx.tcx };
154 let count = this.read_scalar(count_op)?.to_usize(&*this.tcx)?;
155 // Reading zero bytes should not change `buf`
159 let fd = this.read_scalar(fd_op)?.to_i32()?;
160 let buf_scalar = this.read_scalar(buf_op)?.not_undef()?;
162 // Remove the file handle to avoid borrowing issues
163 this.remove_handle_and(fd, |mut handle, this| {
164 // Don't use `?` to avoid returning before reinserting the handle
165 let bytes = this.force_ptr(buf_scalar).and_then(|buf| {
167 .get_mut(buf.alloc_id)?
168 .get_bytes_mut(tcx, buf, Size::from_bytes(count))
169 .map(|buffer| handle.file.read(buffer))
171 // Reinsert the file handle
172 this.machine.file_handler.handles.insert(fd, handle);
173 this.consume_result(bytes?.map(|bytes| bytes as i64))
179 fd_op: OpTy<'tcx, Tag>,
180 buf_op: OpTy<'tcx, Tag>,
181 count_op: OpTy<'tcx, Tag>,
182 ) -> InterpResult<'tcx, i64> {
183 let this = self.eval_context_mut();
185 if !this.machine.communicate {
186 throw_unsup_format!("`write` not available when isolation is enabled")
189 let tcx = &{ this.tcx.tcx };
191 let count = this.read_scalar(count_op)?.to_usize(&*this.tcx)?;
192 // Writing zero bytes should not change `buf`
196 let fd = this.read_scalar(fd_op)?.to_i32()?;
197 let buf = this.force_ptr(this.read_scalar(buf_op)?.not_undef()?)?;
199 this.remove_handle_and(fd, |mut handle, this| {
200 let bytes = this.memory().get(buf.alloc_id).and_then(|alloc| {
202 .get_bytes(tcx, buf, Size::from_bytes(count))
203 .map(|bytes| handle.file.write(bytes).map(|bytes| bytes as i64))
205 this.machine.file_handler.handles.insert(fd, handle);
206 this.consume_result(bytes?)
210 fn unlink( &mut self, path_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
211 let this = self.eval_context_mut();
213 if !this.machine.communicate {
214 throw_unsup_format!("`write` not available when isolation is enabled")
217 let path_bytes = this
219 .read_c_str(this.read_scalar(path_op)?.not_undef()?)?;
220 let path = std::str::from_utf8(path_bytes)
221 .map_err(|_| err_unsup_format!("{:?} is not a valid utf-8 string", path_bytes))?;
223 let result = remove_file(path).map(|_| 0);
225 this.consume_result(result)
228 /// Helper function that gets a `FileHandle` immutable reference and allows to manipulate it
229 /// using the `f` closure.
231 /// If the `fd` file descriptor does not correspond to a file, this functions returns `Ok(-1)`
232 /// and sets `Evaluator::last_error` to `libc::EBADF` (invalid file descriptor).
234 /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
235 /// functions return different integer types (like `read`, that returns an `i64`)
236 fn get_handle_and<F, T: From<i32>>(&mut self, fd: i32, f: F) -> InterpResult<'tcx, T>
238 F: Fn(&FileHandle) -> InterpResult<'tcx, T>,
240 let this = self.eval_context_mut();
241 if let Some(handle) = this.machine.file_handler.handles.get(&fd) {
244 let ebadf = this.eval_libc("EBADF")?;
245 this.set_last_error(ebadf)?;
250 /// Helper function that removes a `FileHandle` and allows to manipulate it using the `f`
251 /// closure. This function is quite useful when you need to modify a `FileHandle` but you need
252 /// to modify `MiriEvalContext` at the same time, so you can modify the handle and reinsert it
255 /// If the `fd` file descriptor does not correspond to a file, this functions returns `Ok(-1)`
256 /// and sets `Evaluator::last_error` to `libc::EBADF` (invalid file descriptor).
258 /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
259 /// functions return different integer types (like `read`, that returns an `i64`)
260 fn remove_handle_and<F, T: From<i32>>(&mut self, fd: i32, mut f: F) -> InterpResult<'tcx, T>
262 F: FnMut(FileHandle, &mut MiriEvalContext<'mir, 'tcx>) -> InterpResult<'tcx, T>,
264 let this = self.eval_context_mut();
265 if let Some(handle) = this.machine.file_handler.handles.remove(&fd) {
268 let ebadf = this.eval_libc("EBADF")?;
269 this.set_last_error(ebadf)?;
274 /// Helper function that consumes an `std::io::Result<T>` and returns an
275 /// `InterpResult<'tcx,T>::Ok` instead. It is expected that the result can be converted to an
276 /// OS error using `std::io::Error::raw_os_error`.
278 /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
279 /// functions return different integer types (like `read`, that returns an `i64`)
280 fn consume_result<T: From<i32>>(
282 result: std::io::Result<T>,
283 ) -> InterpResult<'tcx, T> {
287 self.eval_context_mut().consume_io_error(e)?;