rustix/
lib.rs

1//! `rustix` provides efficient memory-safe and [I/O-safe] wrappers to
2//! POSIX-like, Unix-like, Linux, and Winsock syscall-like APIs, with
3//! configurable backends.
4//!
5//! With rustix, you can write code like this:
6//!
7//! ```
8//! # #[cfg(feature = "net")]
9//! # fn read(sock: std::net::TcpStream, buf: &mut [u8]) -> std::io::Result<()> {
10//! # use rustix::net::RecvFlags;
11//! let (nread, _received) = rustix::net::recv(&sock, buf, RecvFlags::PEEK)?;
12//! # let _ = nread;
13//! # Ok(())
14//! # }
15//! ```
16//!
17//! instead of like this:
18//!
19//! ```
20//! # #[cfg(feature = "net")]
21//! # fn read(sock: std::net::TcpStream, buf: &mut [u8]) -> std::io::Result<()> {
22//! # #[cfg(unix)]
23//! # use std::os::unix::io::AsRawFd;
24//! # #[cfg(target_os = "wasi")]
25//! # use std::os::wasi::io::AsRawFd;
26//! # #[cfg(windows)]
27//! # use windows_sys::Win32::Networking::WinSock as libc;
28//! # #[cfg(windows)]
29//! # use std::os::windows::io::AsRawSocket;
30//! # const MSG_PEEK: i32 = libc::MSG_PEEK;
31//! let nread = unsafe {
32//!     #[cfg(any(unix, target_os = "wasi"))]
33//!     let raw = sock.as_raw_fd();
34//!     #[cfg(windows)]
35//!     let raw = sock.as_raw_socket();
36//!     match libc::recv(
37//!         raw as _,
38//!         buf.as_mut_ptr().cast(),
39//!         buf.len().try_into().unwrap_or(i32::MAX as _),
40//!         MSG_PEEK,
41//!     ) {
42//!         -1 => return Err(std::io::Error::last_os_error()),
43//!         nread => nread as usize,
44//!     }
45//! };
46//! # let _ = nread;
47//! # Ok(())
48//! # }
49//! ```
50//!
51//! rustix's APIs perform the following tasks:
52//!  - Error values are translated to [`Result`]s.
53//!  - Buffers are passed as Rust slices.
54//!  - Out-parameters are presented as return values.
55//!  - Path arguments use [`Arg`], so they accept any string type.
56//!  - File descriptors are passed and returned via [`AsFd`] and [`OwnedFd`]
57//!    instead of bare integers, ensuring I/O safety.
58//!  - Constants use `enum`s and [`bitflags`] types, and enable [support for
59//!    externally defined flags].
60//!  - Multiplexed functions (eg. `fcntl`, `ioctl`, etc.) are de-multiplexed.
61//!  - Variadic functions (eg. `openat`, etc.) are presented as non-variadic.
62//!  - Functions that return strings automatically allocate sufficient memory
63//!    and retry the syscall as needed to determine the needed length.
64//!  - Functions and types which need `l` prefixes or `64` suffixes to enable
65//!    large-file support (LFS) are used automatically. File sizes and offsets
66//!    are always presented as `u64` and `i64`.
67//!  - Behaviors that depend on the sizes of C types like `long` are hidden.
68//!  - In some places, more human-friendly and less historical-accident names
69//!    are used (and documentation aliases are used so that the original names
70//!    can still be searched for).
71//!  - Provide y2038 compatibility, on platforms which support this.
72//!  - Correct selected platform bugs, such as behavioral differences when
73//!    running under seccomp.
74//!  - Use `timespec` for timestamps and timeouts instead of `timeval` and
75//!    `c_int` milliseconds.
76//!
77//! Things they don't do include:
78//!  - Detecting whether functions are supported at runtime, except in specific
79//!    cases where new interfaces need to be detected to support y2038 and LFS.
80//!  - Hiding significant differences between platforms.
81//!  - Restricting ambient authorities.
82//!  - Imposing sandboxing features such as filesystem path or network address
83//!    sandboxing.
84//!
85//! See [`cap-std`], [`system-interface`], and [`io-streams`] for libraries
86//! which do hide significant differences between platforms, and [`cap-std`]
87//! which does perform sandboxing and restricts ambient authorities.
88//!
89//! [`cap-std`]: https://crates.io/crates/cap-std
90//! [`system-interface`]: https://crates.io/crates/system-interface
91//! [`io-streams`]: https://crates.io/crates/io-streams
92//! [`bitflags`]: bitflags
93//! [`AsFd`]: crate::fd::AsFd
94//! [`OwnedFd`]: crate::fd::OwnedFd
95//! [I/O-safe]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md
96//! [`Arg`]: path::Arg
97//! [support for externally defined flags]: bitflags#externally-defined-flags
98
99#![deny(missing_docs)]
100#![allow(stable_features)]
101#![cfg_attr(linux_raw, deny(unsafe_code))]
102#![cfg_attr(rustc_attrs, feature(rustc_attrs))]
103#![cfg_attr(docsrs, feature(doc_cfg))]
104#![cfg_attr(all(wasi_ext, target_os = "wasi", feature = "std"), feature(wasi_ext))]
105#![cfg_attr(core_ffi_c, feature(core_ffi_c))]
106#![cfg_attr(core_c_str, feature(core_c_str))]
107#![cfg_attr(error_in_core, feature(error_in_core))]
108#![cfg_attr(all(feature = "alloc", alloc_c_string), feature(alloc_c_string))]
109#![cfg_attr(all(feature = "alloc", alloc_ffi), feature(alloc_ffi))]
110#![cfg_attr(not(feature = "std"), no_std)]
111#![cfg_attr(feature = "rustc-dep-of-std", feature(ip))]
112#![cfg_attr(feature = "rustc-dep-of-std", allow(internal_features))]
113#![cfg_attr(
114    any(feature = "rustc-dep-of-std", core_intrinsics),
115    feature(core_intrinsics)
116)]
117#![cfg_attr(asm_experimental_arch, feature(asm_experimental_arch))]
118#![cfg_attr(not(feature = "all-apis"), allow(dead_code))]
119// It is common in Linux and libc APIs for types to vary between platforms.
120#![allow(clippy::unnecessary_cast)]
121// It is common in Linux and libc APIs for types to vary between platforms.
122#![allow(clippy::useless_conversion)]
123// This clippy lint gets too many false positives.
124#![allow(clippy::needless_lifetimes)]
125// Redox and WASI have enough differences that it isn't worth precisely
126// conditionalizing all the `use`s for them. Similar for if we don't have
127// "all-apis".
128#![cfg_attr(
129    any(target_os = "redox", target_os = "wasi", not(feature = "all-apis")),
130    allow(unused_imports)
131)]
132// wasip2 conditionally gates stdlib APIs such as `OsStrExt`.
133// <https://github.com/rust-lang/rust/issues/130323>
134#![cfg_attr(
135    all(
136        target_os = "wasi",
137        target_env = "p2",
138        any(feature = "fs", feature = "mount", feature = "net"),
139        wasip2,
140    ),
141    feature(wasip2)
142)]
143
144#[cfg(all(feature = "alloc", feature = "rustc-dep-of-std"))]
145extern crate rustc_std_workspace_alloc as alloc;
146
147#[cfg(all(feature = "alloc", not(feature = "rustc-dep-of-std")))]
148extern crate alloc;
149
150// Use `static_assertions` macros if we have them, or a polyfill otherwise.
151#[cfg(all(test, static_assertions))]
152#[macro_use]
153#[allow(unused_imports)]
154extern crate static_assertions;
155#[cfg(all(test, not(static_assertions)))]
156#[macro_use]
157#[allow(unused_imports)]
158mod static_assertions;
159
160pub mod buffer;
161#[cfg(not(windows))]
162#[macro_use]
163pub(crate) mod cstr;
164#[macro_use]
165pub(crate) mod utils;
166// Polyfill for `std` in `no_std` builds.
167#[cfg_attr(feature = "std", path = "maybe_polyfill/std/mod.rs")]
168#[cfg_attr(not(feature = "std"), path = "maybe_polyfill/no_std/mod.rs")]
169pub(crate) mod maybe_polyfill;
170#[cfg(test)]
171#[macro_use]
172pub(crate) mod check_types;
173#[macro_use]
174pub(crate) mod bitcast;
175
176// linux_raw: Weak symbols are used by the use-libc-auxv feature for
177// glibc 2.15 support.
178//
179// libc: Weak symbols are used to call various functions available in some
180// versions of libc and not others.
181#[cfg(any(
182    all(linux_raw, feature = "use-libc-auxv"),
183    all(libc, not(any(windows, target_os = "espidf", target_os = "wasi")))
184))]
185#[macro_use]
186mod weak;
187
188// Pick the backend implementation to use.
189#[cfg_attr(libc, path = "backend/libc/mod.rs")]
190#[cfg_attr(linux_raw, path = "backend/linux_raw/mod.rs")]
191#[cfg_attr(wasi, path = "backend/wasi/mod.rs")]
192mod backend;
193
194/// Export the `*Fd` types and traits that are used in rustix's public API.
195///
196/// This module exports the types and traits from [`std::os::fd`], or polyills
197/// on Rust < 1.66 or on Windows.
198///
199/// On Windows, the polyfill consists of aliases of the socket types and
200/// traits, For example, [`OwnedSocket`] is aliased to `OwnedFd`, and so on,
201/// and there are blanket impls for `AsFd` etc. that map to `AsSocket` impls.
202/// These blanket impls suffice for using the traits, however not for
203/// implementing them, so this module also exports `AsSocket` and the other
204/// traits as-is so that users can implement them if needed.
205///
206/// [`OwnedSocket`]: https://doc.rust-lang.org/stable/std/os/windows/io/struct.OwnedSocket.html
207pub mod fd {
208    pub use super::backend::fd::*;
209}
210
211// The public API modules.
212#[cfg(feature = "event")]
213#[cfg_attr(docsrs, doc(cfg(feature = "event")))]
214pub mod event;
215pub mod ffi;
216#[cfg(not(windows))]
217#[cfg(feature = "fs")]
218#[cfg_attr(docsrs, doc(cfg(feature = "fs")))]
219pub mod fs;
220pub mod io;
221#[cfg(linux_kernel)]
222#[cfg(feature = "io_uring")]
223#[cfg_attr(docsrs, doc(cfg(feature = "io_uring")))]
224pub mod io_uring;
225pub mod ioctl;
226#[cfg(not(any(
227    windows,
228    target_os = "espidf",
229    target_os = "horizon",
230    target_os = "vita",
231    target_os = "wasi"
232)))]
233#[cfg(feature = "mm")]
234#[cfg_attr(docsrs, doc(cfg(feature = "mm")))]
235pub mod mm;
236#[cfg(linux_kernel)]
237#[cfg(feature = "mount")]
238#[cfg_attr(docsrs, doc(cfg(feature = "mount")))]
239pub mod mount;
240#[cfg(not(target_os = "wasi"))]
241#[cfg(feature = "net")]
242#[cfg_attr(docsrs, doc(cfg(feature = "net")))]
243pub mod net;
244#[cfg(not(any(windows, target_os = "espidf")))]
245#[cfg(feature = "param")]
246#[cfg_attr(docsrs, doc(cfg(feature = "param")))]
247pub mod param;
248#[cfg(not(windows))]
249#[cfg(any(feature = "fs", feature = "mount", feature = "net"))]
250#[cfg_attr(
251    docsrs,
252    doc(cfg(any(feature = "fs", feature = "mount", feature = "net")))
253)]
254pub mod path;
255#[cfg(feature = "pipe")]
256#[cfg_attr(docsrs, doc(cfg(feature = "pipe")))]
257#[cfg(not(any(windows, target_os = "wasi")))]
258pub mod pipe;
259#[cfg(not(windows))]
260#[cfg(feature = "process")]
261#[cfg_attr(docsrs, doc(cfg(feature = "process")))]
262pub mod process;
263#[cfg(not(windows))]
264#[cfg(not(target_os = "wasi"))]
265#[cfg(feature = "pty")]
266#[cfg_attr(docsrs, doc(cfg(feature = "pty")))]
267pub mod pty;
268#[cfg(not(windows))]
269#[cfg(feature = "rand")]
270#[cfg_attr(docsrs, doc(cfg(feature = "rand")))]
271pub mod rand;
272#[cfg(not(any(
273    windows,
274    target_os = "android",
275    target_os = "espidf",
276    target_os = "horizon",
277    target_os = "vita",
278    target_os = "wasi"
279)))]
280#[cfg(feature = "shm")]
281#[cfg_attr(docsrs, doc(cfg(feature = "shm")))]
282pub mod shm;
283#[cfg(not(windows))]
284#[cfg(feature = "stdio")]
285#[cfg_attr(docsrs, doc(cfg(feature = "stdio")))]
286pub mod stdio;
287#[cfg(feature = "system")]
288#[cfg(not(any(windows, target_os = "wasi")))]
289#[cfg_attr(docsrs, doc(cfg(feature = "system")))]
290pub mod system;
291#[cfg(not(any(windows, target_os = "horizon", target_os = "vita")))]
292#[cfg(feature = "termios")]
293#[cfg_attr(docsrs, doc(cfg(feature = "termios")))]
294pub mod termios;
295#[cfg(not(windows))]
296#[cfg(feature = "thread")]
297#[cfg_attr(docsrs, doc(cfg(feature = "thread")))]
298pub mod thread;
299#[cfg(not(any(windows, target_os = "espidf")))]
300#[cfg(feature = "time")]
301#[cfg_attr(docsrs, doc(cfg(feature = "time")))]
302pub mod time;
303
304// "runtime" is also a public API module, but it's only for libc-like users.
305#[cfg(not(windows))]
306#[cfg(feature = "runtime")]
307#[cfg(linux_raw)]
308#[cfg_attr(not(document_experimental_runtime_api), doc(hidden))]
309#[cfg_attr(docsrs, doc(cfg(feature = "runtime")))]
310pub mod runtime;
311
312// Declare "fs" as a non-public module if "fs" isn't enabled but we need it for
313// reading procfs.
314#[cfg(not(windows))]
315#[cfg(not(feature = "fs"))]
316#[cfg(all(
317    linux_raw,
318    not(feature = "use-libc-auxv"),
319    not(feature = "use-explicitly-provided-auxv"),
320    any(
321        feature = "param",
322        feature = "runtime",
323        feature = "thread",
324        feature = "time",
325        target_arch = "x86",
326    )
327))]
328#[cfg_attr(docsrs, doc(cfg(feature = "fs")))]
329pub(crate) mod fs;
330
331// Similarly, declare `path` as a non-public module if needed.
332#[cfg(not(windows))]
333#[cfg(not(any(feature = "fs", feature = "mount", feature = "net")))]
334#[cfg(all(
335    linux_raw,
336    not(feature = "use-libc-auxv"),
337    not(feature = "use-explicitly-provided-auxv"),
338    any(
339        feature = "param",
340        feature = "runtime",
341        feature = "thread",
342        feature = "time",
343        target_arch = "x86",
344    )
345))]
346pub(crate) mod path;
347
348// Private modules used by multiple public modules.
349#[cfg(not(any(windows, target_os = "espidf")))]
350#[cfg(any(feature = "thread", feature = "time"))]
351mod clockid;
352#[cfg(linux_kernel)]
353#[cfg(any(feature = "io_uring", feature = "runtime"))]
354mod kernel_sigset;
355#[cfg(not(any(windows, target_os = "wasi")))]
356#[cfg(any(
357    feature = "process",
358    feature = "runtime",
359    feature = "termios",
360    feature = "thread",
361    all(bsd, feature = "event"),
362    all(linux_kernel, feature = "net")
363))]
364mod pid;
365#[cfg(any(feature = "process", feature = "thread"))]
366#[cfg(linux_kernel)]
367mod prctl;
368#[cfg(not(any(windows, target_os = "espidf", target_os = "wasi")))]
369#[cfg(any(
370    feature = "io_uring",
371    feature = "process",
372    feature = "runtime",
373    all(bsd, feature = "event")
374))]
375mod signal;
376#[cfg(any(
377    feature = "fs",
378    feature = "event",
379    feature = "process",
380    feature = "runtime",
381    feature = "thread",
382    feature = "time",
383    all(feature = "event", any(bsd, linux_kernel, windows, target_os = "wasi")),
384    all(
385        linux_raw,
386        not(feature = "use-libc-auxv"),
387        not(feature = "use-explicitly-provided-auxv"),
388        any(
389            feature = "param",
390            feature = "process",
391            feature = "runtime",
392            feature = "time",
393            target_arch = "x86",
394        )
395    )
396))]
397mod timespec;
398#[cfg(not(any(windows, target_os = "wasi")))]
399#[cfg(any(
400    feature = "fs",
401    feature = "process",
402    feature = "thread",
403    all(
404        linux_raw,
405        not(feature = "use-libc-auxv"),
406        not(feature = "use-explicitly-provided-auxv"),
407        any(
408            feature = "param",
409            feature = "runtime",
410            feature = "time",
411            target_arch = "x86",
412        )
413    ),
414    all(linux_kernel, feature = "net")
415))]
416mod ugid;
417
418#[cfg(doc)]
419#[cfg_attr(docsrs, doc(cfg(doc)))]
420pub mod not_implemented;
rustix/lib.rs

rustix/
lib.rs
