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
use super::Incoming;
use super::TcpStream;

use std::fmt;
use std::io;
use std::net::{self, SocketAddr};

use futures::{Poll, Async};
use mio;
use tokio_reactor::{Handle, PollEvented};

/// An I/O object representing a TCP socket listening for incoming connections.
///
/// This object can be converted into a stream of incoming connections for
/// various forms of processing.
///
/// # Examples
///
/// ```no_run
/// extern crate tokio;
/// extern crate futures;
///
/// use futures::stream::Stream;
/// use std::net::SocketAddr;
/// use tokio::net::{TcpListener, TcpStream};
///
/// fn process_socket(socket: TcpStream) {
///     // ...
/// }
///
/// fn main() -> Result<(), Box<std::error::Error>> {
///     let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
///     let listener = TcpListener::bind(&addr)?;
///
///     // accept connections and process them
///     tokio::run(listener.incoming()
///         .map_err(|e| eprintln!("failed to accept socket; error = {:?}", e))
///         .for_each(|socket| {
///             process_socket(socket);
///             Ok(())
///         })
///     );
///     Ok(())
/// }
/// ```
pub struct TcpListener {
    io: PollEvented<mio::net::TcpListener>,
}

impl TcpListener {
    /// Create a new TCP listener associated with this event loop.
    ///
    /// The TCP listener will bind to the provided `addr` address, if available.
    /// If the result is `Ok`, the socket has successfully bound.
    ///
    /// # Examples
    ///
    /// ```
    /// # extern crate tokio;
    /// use std::net::SocketAddr;
    /// use tokio::net::TcpListener;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let listener = TcpListener::bind(&addr)?;
    /// # Ok(())
    /// # }
    /// ```
    pub fn bind(addr: &SocketAddr) -> io::Result<TcpListener> {
        let l = mio::net::TcpListener::bind(addr)?;
        Ok(TcpListener::new(l))
    }

    #[deprecated(since = "0.1.2", note = "use poll_accept instead")]
    #[doc(hidden)]
    pub fn accept(&mut self) -> io::Result<(TcpStream, SocketAddr)> {
        match self.poll_accept()? {
            Async::Ready(ret) => Ok(ret),
            Async::NotReady => Err(io::ErrorKind::WouldBlock.into()),
        }
    }

    /// Attempt to accept a connection and create a new connected `TcpStream` if
    /// successful.
    ///
    /// Note that typically for simple usage it's easier to treat incoming
    /// connections as a `Stream` of `TcpStream`s with the `incoming` method
    /// below.
    ///
    /// # Return
    ///
    /// On success, returns `Ok(Async::Ready((socket, addr)))`.
    ///
    /// If the listener is not ready to accept, the method returns
    /// `Ok(Async::NotReady)` and arranges for the current task to receive a
    /// notification when the listener becomes ready to accept.
    ///
    /// # Panics
    ///
    /// This function will panic if called from outside of a task context.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// # extern crate tokio;
    /// # extern crate futures;
    /// use std::net::SocketAddr;
    /// use tokio::net::TcpListener;
    /// use futures::Async;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let mut listener = TcpListener::bind(&addr)?;
    /// match listener.poll_accept() {
    ///     Ok(Async::Ready((_socket, addr))) => println!("listener ready to accept: {:?}", addr),
    ///     Ok(Async::NotReady) => println!("listener not ready to accept!"),
    ///     Err(e) => eprintln!("got an error: {}", e),
    /// }
    /// # Ok(())
    /// # }
    /// ```
    pub fn poll_accept(&mut self) -> Poll<(TcpStream, SocketAddr), io::Error> {
        let (io, addr) = try_ready!(self.poll_accept_std());

        let io = mio::net::TcpStream::from_stream(io)?;
        let io = TcpStream::new(io);

        Ok((io, addr).into())
    }

    #[deprecated(since = "0.1.2", note = "use poll_accept_std instead")]
    #[doc(hidden)]
    pub fn accept_std(&mut self) -> io::Result<(net::TcpStream, SocketAddr)> {
        match self.poll_accept_std()? {
            Async::Ready(ret) => Ok(ret),
            Async::NotReady => Err(io::ErrorKind::WouldBlock.into()),
        }
    }

    /// Attempt to accept a connection and create a new connected `TcpStream` if
    /// successful.
    ///
    /// This function is the same as `accept` above except that it returns a
    /// `std::net::TcpStream` instead of a `tokio::net::TcpStream`. This in turn
    /// can then allow for the TCP stream to be associated with a different
    /// reactor than the one this `TcpListener` is associated with.
    ///
    /// # Return
    ///
    /// On success, returns `Ok(Async::Ready((socket, addr)))`.
    ///
    /// If the listener is not ready to accept, the method returns
    /// `Ok(Async::NotReady)` and arranges for the current task to receive a
    /// notification when the listener becomes ready to accept.
    ///
    /// # Panics
    ///
    /// This function will panic if called from outside of a task context.
    ///
    /// # Examples
    ///
    /// ```no_run
    /// # extern crate tokio;
    /// # extern crate futures;
    /// use std::net::SocketAddr;
    /// use tokio::net::TcpListener;
    /// use futures::Async;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let mut listener = TcpListener::bind(&addr)?;
    /// match listener.poll_accept_std() {
    ///     Ok(Async::Ready((_socket, addr))) => println!("listener ready to accept: {:?}", addr),
    ///     Ok(Async::NotReady) => println!("listener not ready to accept!"),
    ///     Err(e) => eprintln!("got an error: {}", e),
    /// }
    /// # Ok(())
    /// # }
    /// ```
    pub fn poll_accept_std(&mut self) -> Poll<(net::TcpStream, SocketAddr), io::Error> {
        try_ready!(self.io.poll_read_ready(mio::Ready::readable()));

        match self.io.get_ref().accept_std() {
            Ok(pair) => Ok(pair.into()),
            Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
                self.io.clear_read_ready(mio::Ready::readable())?;
                Ok(Async::NotReady)
            }
            Err(e) => Err(e),
        }
    }

    /// Create a new TCP listener from the standard library's TCP listener.
    ///
    /// This method can be used when the `Handle::tcp_listen` method isn't
    /// sufficient because perhaps some more configuration is needed in terms of
    /// before the calls to `bind` and `listen`.
    ///
    /// This API is typically paired with the `net2` crate and the `TcpBuilder`
    /// type to build up and customize a listener before it's shipped off to the
    /// backing event loop. This allows configuration of options like
    /// `SO_REUSEPORT`, binding to multiple addresses, etc.
    ///
    /// The `addr` argument here is one of the addresses that `listener` is
    /// bound to and the listener will only be guaranteed to accept connections
    /// of the same address type currently.
    ///
    /// Finally, the `handle` argument is the event loop that this listener will
    /// be bound to.
    /// Use [`Handle::default()`] to lazily bind to an event loop, just like `bind` does.
    ///
    /// The platform specific behavior of this function looks like:
    ///
    /// * On Unix, the socket is placed into nonblocking mode and connections
    ///   can be accepted as normal
    ///
    /// * On Windows, the address is stored internally and all future accepts
    ///   will only be for the same IP version as `addr` specified. That is, if
    ///   `addr` is an IPv4 address then all sockets accepted will be IPv4 as
    ///   well (same for IPv6).
    ///
    /// [`Handle::default()`]: ../reactor/struct.Handle.html
    /// # Examples
    ///
    /// ```no_run
    /// # extern crate tokio;
    /// # extern crate tokio_reactor;
    /// use tokio::net::TcpListener;
    /// use std::net::TcpListener as StdTcpListener;
    /// use tokio::reactor::Handle;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let std_listener = StdTcpListener::bind("127.0.0.1:8080")?;
    /// let listener = TcpListener::from_std(std_listener, &Handle::default())?;
    /// # Ok(())
    /// # }
    /// ```
    pub fn from_std(listener: net::TcpListener, handle: &Handle)
        -> io::Result<TcpListener>
    {
        let io = mio::net::TcpListener::from_std(listener)?;
        let io = PollEvented::new_with_handle(io, handle)?;
        Ok(TcpListener { io })
    }

    fn new(listener: mio::net::TcpListener) -> TcpListener {
        let io = PollEvented::new(listener);
        TcpListener { io }
    }

    /// Returns the local address that this listener is bound to.
    ///
    /// This can be useful, for example, when binding to port 0 to figure out
    /// which port was actually bound.
    ///
    /// # Examples
    ///
    /// ```
    /// # extern crate tokio;
    /// use tokio::net::TcpListener;
    /// use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let listener = TcpListener::bind(&addr)?;
    /// assert_eq!(listener.local_addr()?,
    ///            SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
    /// # Ok(())
    /// # }
    /// ```
    pub fn local_addr(&self) -> io::Result<SocketAddr> {
        self.io.get_ref().local_addr()
    }

    /// Consumes this listener, returning a stream of the sockets this listener
    /// accepts.
    ///
    /// This method returns an implementation of the `Stream` trait which
    /// resolves to the sockets the are accepted on this listener.
    ///
    /// # Errors
    ///
    /// Note that accepting a connection can lead to various errors and not all of them are
    /// necessarily fatal ‒ for example having too many open file descriptors or the other side
    /// closing the connection while it waits in an accept queue. These would terminate the stream
    /// if not handled in any way.
    ///
    /// If aiming for production, decision what to do about them must be made. The
    /// [`tk-listen`](https://crates.io/crates/tk-listen) crate might be of some help.
    ///
    /// # Examples
    ///
    /// ```
    /// # extern crate tokio;
    /// # extern crate futures;
    /// use tokio::net::TcpListener;
    /// use futures::stream::Stream;
    /// use std::net::SocketAddr;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let listener = TcpListener::bind(&addr)?;
    ///
    /// listener.incoming()
    ///     .map_err(|e| eprintln!("failed to accept stream; error = {:?}", e))
    ///     .for_each(|_socket| {
    ///         println!("new socket!");
    ///         Ok(())
    ///     });
    /// # Ok(())
    /// # }
    /// ```
    pub fn incoming(self) -> Incoming {
        Incoming::new(self)
    }

    /// Gets the value of the `IP_TTL` option for this socket.
    ///
    /// For more information about this option, see [`set_ttl`].
    ///
    /// [`set_ttl`]: #method.set_ttl
    ///
    /// # Examples
    ///
    /// ```
    /// # extern crate tokio;
    /// use tokio::net::TcpListener;
    /// use std::net::SocketAddr;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let listener = TcpListener::bind(&addr)?;
    /// listener.set_ttl(100).expect("could not set TTL");
    /// assert_eq!(listener.ttl()?, 100);
    /// # Ok(())
    /// # }
    /// ```
    pub fn ttl(&self) -> io::Result<u32> {
        self.io.get_ref().ttl()
    }

    /// Sets the value for the `IP_TTL` option on this socket.
    ///
    /// This value sets the time-to-live field that is used in every packet sent
    /// from this socket.
    ///
    /// # Examples
    ///
    /// ```
    /// # extern crate tokio;
    /// use tokio::net::TcpListener;
    /// use std::net::SocketAddr;
    ///
    /// # fn main() -> Result<(), Box<std::error::Error>> {
    /// let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
    /// let listener = TcpListener::bind(&addr)?;
    /// listener.set_ttl(100).expect("could not set TTL");
    /// # Ok(())
    /// # }
    /// ```
    pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
        self.io.get_ref().set_ttl(ttl)
    }
}

impl fmt::Debug for TcpListener {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.io.get_ref().fmt(f)
    }
}

#[cfg(unix)]
mod sys {
    use std::os::unix::prelude::*;
    use super::TcpListener;

    impl AsRawFd for TcpListener {
        fn as_raw_fd(&self) -> RawFd {
            self.io.get_ref().as_raw_fd()
        }
    }
}

#[cfg(windows)]
mod sys {
    // TODO: let's land these upstream with mio and then we can add them here.
    //
    // use std::os::windows::prelude::*;
    // use super::{TcpListener;
    //
    // impl AsRawHandle for TcpListener {
    //     fn as_raw_handle(&self) -> RawHandle {
    //         self.listener.io().as_raw_handle()
    //     }
    // }
}