1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
use super::{sockaddr_un, SocketAddr, UnixStream};
use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
use crate::path::Path;
use crate::sys::cvt;
use crate::sys::net::Socket;
use crate::sys_common::{AsInner, FromInner, IntoInner};
use crate::{fmt, io, mem};

/// A structure representing a Unix domain socket server.
///
/// # Examples
///
/// ```no_run
/// use std::thread;
/// use std::os::unix::net::{UnixStream, UnixListener};
///
/// fn handle_client(stream: UnixStream) {
///     // ...
/// }
///
/// fn main() -> std::io::Result<()> {
///     let listener = UnixListener::bind("/path/to/the/socket")?;
///
///     // accept connections and process them, spawning a new thread for each one
///     for stream in listener.incoming() {
///         match stream {
///             Ok(stream) => {
///                 /* connection succeeded */
///                 thread::spawn(|| handle_client(stream));
///             }
///             Err(err) => {
///                 /* connection failed */
///                 break;
///             }
///         }
///     }
///     Ok(())
/// }
/// ```
#[stable(feature = "unix_socket", since = "1.10.0")]
pub struct UnixListener(Socket);

#[stable(feature = "unix_socket", since = "1.10.0")]
impl fmt::Debug for UnixListener {
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut builder = fmt.debug_struct("UnixListener");
        builder.field("fd", self.0.as_inner());
        if let Ok(addr) = self.local_addr() {
            builder.field("local", &addr);
        }
        builder.finish()
    }
}

impl UnixListener {
    /// Creates a new `UnixListener` bound to the specified socket.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// let listener = match UnixListener::bind("/path/to/the/socket") {
    ///     Ok(sock) => sock,
    ///     Err(e) => {
    ///         println!("Couldn't connect: {e:?}");
    ///         return
    ///     }
    /// };
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn bind<P: AsRef<Path>>(path: P) -> io::Result<UnixListener> {
        unsafe {
            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
            let (addr, len) = sockaddr_un(path.as_ref())?;
            #[cfg(any(
                target_os = "windows",
                target_os = "redox",
                target_os = "espidf",
                target_os = "horizon"
            ))]
            const backlog: libc::c_int = 128;
            #[cfg(any(
                target_os = "linux",
                target_os = "freebsd",
                target_os = "openbsd",
                target_os = "macos"
            ))]
            const backlog: libc::c_int = -1;
            #[cfg(not(any(
                target_os = "windows",
                target_os = "redox",
                target_os = "linux",
                target_os = "freebsd",
                target_os = "openbsd",
                target_os = "macos",
                target_os = "espidf",
                target_os = "horizon"
            )))]
            const backlog: libc::c_int = libc::SOMAXCONN;

            cvt(libc::bind(inner.as_inner().as_raw_fd(), &addr as *const _ as *const _, len as _))?;
            cvt(libc::listen(inner.as_inner().as_raw_fd(), backlog))?;

            Ok(UnixListener(inner))
        }
    }

    /// Creates a new `UnixListener` bound to the specified [`socket address`].
    ///
    /// [`socket address`]: crate::os::unix::net::SocketAddr
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::{UnixListener};
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener1 = UnixListener::bind("path/to/socket")?;
    ///     let addr = listener1.local_addr()?;
    ///
    ///     let listener2 = match UnixListener::bind_addr(&addr) {
    ///         Ok(sock) => sock,
    ///         Err(err) => {
    ///             println!("Couldn't bind: {err:?}");
    ///             return Err(err);
    ///         }
    ///     };
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket_abstract", since = "1.70.0")]
    pub fn bind_addr(socket_addr: &SocketAddr) -> io::Result<UnixListener> {
        unsafe {
            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
            #[cfg(target_os = "linux")]
            const backlog: libc::c_int = -1;
            #[cfg(not(target_os = "linux"))]
            const backlog: libc::c_int = 128;
            cvt(libc::bind(
                inner.as_raw_fd(),
                &socket_addr.addr as *const _ as *const _,
                socket_addr.len as _,
            ))?;
            cvt(libc::listen(inner.as_raw_fd(), backlog))?;
            Ok(UnixListener(inner))
        }
    }

    /// Accepts a new incoming connection to this listener.
    ///
    /// This function will block the calling thread until a new Unix connection
    /// is established. When established, the corresponding [`UnixStream`] and
    /// the remote peer's address will be returned.
    ///
    /// [`UnixStream`]: crate::os::unix::net::UnixStream
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
    ///
    ///     match listener.accept() {
    ///         Ok((socket, addr)) => println!("Got a client: {addr:?}"),
    ///         Err(e) => println!("accept function failed: {e:?}"),
    ///     }
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn accept(&self) -> io::Result<(UnixStream, SocketAddr)> {
        let mut storage: libc::sockaddr_un = unsafe { mem::zeroed() };
        let mut len = mem::size_of_val(&storage) as libc::socklen_t;
        let sock = self.0.accept(&mut storage as *mut _ as *mut _, &mut len)?;
        let addr = SocketAddr::from_parts(storage, len)?;
        Ok((UnixStream(sock), addr))
    }

    /// Creates a new independently owned handle to the underlying socket.
    ///
    /// The returned `UnixListener` is a reference to the same socket that this
    /// object references. Both handles can be used to accept incoming
    /// connections and options set on one listener will affect the other.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
    ///     let listener_copy = listener.try_clone().expect("try_clone failed");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn try_clone(&self) -> io::Result<UnixListener> {
        self.0.duplicate().map(UnixListener)
    }

    /// Returns the local socket address of this listener.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
    ///     let addr = listener.local_addr().expect("Couldn't get local address");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn local_addr(&self) -> io::Result<SocketAddr> {
        SocketAddr::new(|addr, len| unsafe { libc::getsockname(self.as_raw_fd(), addr, len) })
    }

    /// Moves the socket into or out of nonblocking mode.
    ///
    /// This will result in the `accept` operation becoming nonblocking,
    /// i.e., immediately returning from their calls. If the IO operation is
    /// successful, `Ok` is returned and no further action is required. If the
    /// IO operation could not be completed and needs to be retried, an error
    /// with kind [`io::ErrorKind::WouldBlock`] is returned.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
    ///     listener.set_nonblocking(true).expect("Couldn't set non blocking");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
        self.0.set_nonblocking(nonblocking)
    }

    /// Returns the value of the `SO_ERROR` option.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixListener;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/tmp/sock")?;
    ///
    ///     if let Ok(Some(err)) = listener.take_error() {
    ///         println!("Got error: {err:?}");
    ///     }
    ///     Ok(())
    /// }
    /// ```
    ///
    /// # Platform specific
    /// On Redox this always returns `None`.
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
        self.0.take_error()
    }

    /// Returns an iterator over incoming connections.
    ///
    /// The iterator will never return [`None`] and will also not yield the
    /// peer's [`SocketAddr`] structure.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::thread;
    /// use std::os::unix::net::{UnixStream, UnixListener};
    ///
    /// fn handle_client(stream: UnixStream) {
    ///     // ...
    /// }
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
    ///
    ///     for stream in listener.incoming() {
    ///         match stream {
    ///             Ok(stream) => {
    ///                 thread::spawn(|| handle_client(stream));
    ///             }
    ///             Err(err) => {
    ///                 break;
    ///             }
    ///         }
    ///     }
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn incoming(&self) -> Incoming<'_> {
        Incoming { listener: self }
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl AsRawFd for UnixListener {
    #[inline]
    fn as_raw_fd(&self) -> RawFd {
        self.0.as_inner().as_raw_fd()
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl FromRawFd for UnixListener {
    #[inline]
    unsafe fn from_raw_fd(fd: RawFd) -> UnixListener {
        UnixListener(Socket::from_inner(FromInner::from_inner(OwnedFd::from_raw_fd(fd))))
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl IntoRawFd for UnixListener {
    #[inline]
    fn into_raw_fd(self) -> RawFd {
        self.0.into_inner().into_inner().into_raw_fd()
    }
}

#[stable(feature = "io_safety", since = "1.63.0")]
impl AsFd for UnixListener {
    #[inline]
    fn as_fd(&self) -> BorrowedFd<'_> {
        self.0.as_inner().as_fd()
    }
}

#[stable(feature = "io_safety", since = "1.63.0")]
impl From<OwnedFd> for UnixListener {
    #[inline]
    fn from(fd: OwnedFd) -> UnixListener {
        UnixListener(Socket::from_inner(FromInner::from_inner(fd)))
    }
}

#[stable(feature = "io_safety", since = "1.63.0")]
impl From<UnixListener> for OwnedFd {
    #[inline]
    fn from(listener: UnixListener) -> OwnedFd {
        listener.0.into_inner().into_inner()
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl<'a> IntoIterator for &'a UnixListener {
    type Item = io::Result<UnixStream>;
    type IntoIter = Incoming<'a>;

    fn into_iter(self) -> Incoming<'a> {
        self.incoming()
    }
}

/// An iterator over incoming connections to a [`UnixListener`].
///
/// It will never return [`None`].
///
/// # Examples
///
/// ```no_run
/// use std::thread;
/// use std::os::unix::net::{UnixStream, UnixListener};
///
/// fn handle_client(stream: UnixStream) {
///     // ...
/// }
///
/// fn main() -> std::io::Result<()> {
///     let listener = UnixListener::bind("/path/to/the/socket")?;
///
///     for stream in listener.incoming() {
///         match stream {
///             Ok(stream) => {
///                 thread::spawn(|| handle_client(stream));
///             }
///             Err(err) => {
///                 break;
///             }
///         }
///     }
///     Ok(())
/// }
/// ```
#[derive(Debug)]
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[stable(feature = "unix_socket", since = "1.10.0")]
pub struct Incoming<'a> {
    listener: &'a UnixListener,
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl<'a> Iterator for Incoming<'a> {
    type Item = io::Result<UnixStream>;

    fn next(&mut self) -> Option<io::Result<UnixStream>> {
        Some(self.listener.accept().map(|s| s.0))
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        (usize::MAX, None)
    }
}