TLA Line data Source code
1 : //
2 : // Copyright (c) 2026 Steve Gerbino
3 : // Copyright (c) 2026 Michael Vandeberg
4 : //
5 : // Distributed under the Boost Software License, Version 1.0. (See accompanying
6 : // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 : //
8 : // Official repository: https://github.com/cppalliance/corosio
9 : //
10 :
11 : #ifndef BOOST_COROSIO_UDP_SOCKET_HPP
12 : #define BOOST_COROSIO_UDP_SOCKET_HPP
13 :
14 : #include <boost/corosio/family.hpp>
15 : #include <boost/corosio/detail/config.hpp>
16 : #include <boost/corosio/detail/platform.hpp>
17 : #include <boost/corosio/detail/except.hpp>
18 : #include <boost/corosio/detail/native_handle.hpp>
19 : #include <boost/corosio/detail/op_base.hpp>
20 : #include <boost/corosio/io/io_object.hpp>
21 : #include <boost/capy/results.hpp>
22 : #include <boost/corosio/detail/buffer_param.hpp>
23 : #include <boost/corosio/error.hpp>
24 : #include <boost/corosio/endpoint.hpp>
25 : #include <boost/corosio/message_flags.hpp>
26 : #include <boost/corosio/shutdown_type.hpp>
27 : #include <boost/corosio/wait_type.hpp>
28 : #include <boost/capy/ex/executor_ref.hpp>
29 : #include <boost/capy/ex/execution_context.hpp>
30 : #include <boost/capy/ex/await_context.hpp>
31 : #include <boost/capy/concept/executor.hpp>
32 :
33 : #include <system_error>
34 :
35 : #include <concepts>
36 : #include <boost/capy/continuation.hpp>
37 :
38 : #include <coroutine>
39 : #include <cstddef>
40 : #include <stop_token>
41 : #include <type_traits>
42 :
43 : namespace boost::corosio {
44 :
45 : /** Sends and receives datagrams over UDP, from a coroutine.
46 :
47 : This class provides asynchronous UDP datagram operations that
48 : return awaitable types. Each operation participates in the affine
49 : awaitable protocol, ensuring coroutines resume on the correct
50 : executor.
51 :
52 : Supports two modes of operation:
53 :
54 : **Connectionless mode**: each `send_to` specifies a destination
55 : endpoint, and each `recv_from` captures the source endpoint.
56 : The socket must be opened (and optionally bound) before I/O.
57 :
58 : **Connected mode**: call `connect()` to set a default peer,
59 : then use `send()`/`recv()` without endpoint arguments.
60 : The kernel filters incoming datagrams to those from the
61 : connected peer.
62 :
63 : @par Thread Safety
64 : Distinct objects: Safe.@n
65 : Shared objects: Unsafe. A socket must not have concurrent
66 : operations of the same type (e.g., two simultaneous `recv_from`).
67 : One `send_to` and one `recv_from` may be in flight simultaneously.
68 :
69 : @par Example
70 : @par !example udp_socket
71 : */
72 : class BOOST_COROSIO_DECL udp_socket : public io_object
73 : {
74 : public:
75 : /// The shutdown direction type used by this socket.
76 : using shutdown_type = corosio::shutdown_type;
77 : using enum corosio::shutdown_type;
78 :
79 : /** Define backend hooks for UDP socket operations.
80 :
81 : Platform backends (epoll, kqueue, select) derive from
82 : this to implement datagram I/O and option management.
83 : */
84 : struct implementation : io_object::implementation
85 : {
86 : /** Initiate an asynchronous `send_to` operation.
87 :
88 : @param cont Continuation to resume on completion; it lives in
89 : the awaiting frame until then.
90 : @param ex Executor for dispatching the completion.
91 : @param buf The buffer data to send.
92 : @param dest The destination endpoint.
93 : @param flags Portable @ref message_flags bits (for example
94 : `message_flags::do_not_route`). The backend translates
95 : these to native `MSG_*` constants.
96 : @param token Stop token for cancellation.
97 : @param ec Output error code.
98 : @param bytes_out Output bytes transferred.
99 :
100 : @return Coroutine handle to resume immediately.
101 : */
102 : virtual std::coroutine_handle<> send_to(
103 : capy::continuation& cont,
104 : capy::executor_ref ex,
105 : buffer_param buf,
106 : endpoint dest,
107 : int flags,
108 : std::stop_token token,
109 : std::error_code* ec,
110 : std::size_t* bytes_out) = 0;
111 :
112 : /** Initiate an asynchronous `recv_from` operation.
113 :
114 : @param cont Continuation to resume on completion; it lives in
115 : the awaiting frame until then.
116 : @param ex Executor for dispatching the completion.
117 : @param buf The buffer to receive into.
118 : @param source Output endpoint for the sender's address.
119 : @param flags Portable @ref message_flags bits (for example
120 : `message_flags::peek`). The backend translates these to
121 : native `MSG_*` constants.
122 : @param token Stop token for cancellation.
123 : @param ec Output error code.
124 : @param bytes_out Output bytes transferred.
125 :
126 : @return Coroutine handle to resume immediately.
127 : */
128 : virtual std::coroutine_handle<> recv_from(
129 : capy::continuation& cont,
130 : capy::executor_ref ex,
131 : buffer_param buf,
132 : endpoint* source,
133 : int flags,
134 : std::stop_token token,
135 : std::error_code* ec,
136 : std::size_t* bytes_out) = 0;
137 :
138 : /// Return the platform socket descriptor.
139 : virtual native_handle_type native_handle() const noexcept = 0;
140 :
141 : /** Return the socket's address family.
142 :
143 : Socket options render for this family.
144 :
145 : @return The socket's address family.
146 : */
147 : virtual corosio::family family() const noexcept = 0;
148 :
149 : /** Release ownership of the native socket handle.
150 :
151 : Deregisters the socket from the backend and cancels
152 : pending operations without closing the descriptor. The
153 : caller takes ownership.
154 :
155 : @return The native handle.
156 : */
157 : virtual native_handle_type release_socket() noexcept = 0;
158 :
159 : /** Request cancellation of pending asynchronous operations.
160 :
161 : Operations still in flight complete with `operation_canceled`;
162 : an operation whose result is already decided reports that
163 : result. Check `ec == cond::canceled` for portable comparison.
164 : */
165 : virtual void cancel() noexcept = 0;
166 :
167 : /** Shut down the socket in one or both directions.
168 :
169 : @param what Which directions to disable.
170 :
171 : @return The error code, empty on success.
172 : */
173 : virtual std::error_code shutdown(shutdown_type what) noexcept = 0;
174 :
175 : /** Set a socket option.
176 :
177 : @param level The protocol level (e.g. `SOL_SOCKET`).
178 : @param optname The option name.
179 : @param data Pointer to the option value.
180 : @param size Size of the option value in bytes.
181 : @return Error code on failure, empty on success.
182 : */
183 : virtual std::error_code set_option(
184 : int level,
185 : int optname,
186 : void const* data,
187 : std::size_t size) noexcept = 0;
188 :
189 : /** Get a socket option.
190 :
191 : @param level The protocol level (e.g. `SOL_SOCKET`).
192 : @param optname The option name.
193 : @param data Pointer to receive the option value.
194 : @param size On entry, the size of the buffer. On exit,
195 : the size of the option value.
196 : @return Error code on failure, empty on success.
197 : */
198 : virtual std::error_code
199 : get_option(int level, int optname, void* data, std::size_t* size)
200 : const noexcept = 0;
201 :
202 : /// Return the cached local endpoint.
203 : virtual endpoint local_endpoint() const noexcept = 0;
204 :
205 : /// Return the cached remote endpoint (connected mode).
206 : virtual endpoint remote_endpoint() const noexcept = 0;
207 :
208 : /** Initiate an asynchronous connect to set the default peer.
209 :
210 : @param cont Continuation to resume on completion; it lives in
211 : the awaiting frame until then.
212 : @param ex Executor for dispatching the completion.
213 : @param ep The remote endpoint to connect to.
214 : @param token Stop token for cancellation.
215 : @param ec Output error code.
216 :
217 : @return Coroutine handle to resume immediately.
218 : */
219 : virtual std::coroutine_handle<> connect(
220 : capy::continuation& cont,
221 : capy::executor_ref ex,
222 : endpoint ep,
223 : std::stop_token token,
224 : std::error_code* ec) = 0;
225 :
226 : /** Initiate an asynchronous connected send operation.
227 :
228 : @param cont Continuation to resume on completion; it lives in
229 : the awaiting frame until then.
230 : @param ex Executor for dispatching the completion.
231 : @param buf The buffer data to send.
232 : @param flags Portable @ref message_flags bits (for example
233 : `message_flags::do_not_route`). The backend translates
234 : these to native `MSG_*` constants.
235 : @param token Stop token for cancellation.
236 : @param ec Output error code.
237 : @param bytes_out Output bytes transferred.
238 :
239 : @return Coroutine handle to resume immediately.
240 : */
241 : virtual std::coroutine_handle<> send(
242 : capy::continuation& cont,
243 : capy::executor_ref ex,
244 : buffer_param buf,
245 : int flags,
246 : std::stop_token token,
247 : std::error_code* ec,
248 : std::size_t* bytes_out) = 0;
249 :
250 : /** Initiate an asynchronous connected `recv` operation.
251 :
252 : @param cont Continuation to resume on completion; it lives in
253 : the awaiting frame until then.
254 : @param ex Executor for dispatching the completion.
255 : @param buf The buffer to receive into.
256 : @param flags Portable @ref message_flags bits (for example
257 : `message_flags::peek`). The backend translates these to
258 : native `MSG_*` constants.
259 : @param token Stop token for cancellation.
260 : @param ec Output error code.
261 : @param bytes_out Output bytes transferred.
262 :
263 : @return Coroutine handle to resume immediately.
264 : */
265 : virtual std::coroutine_handle<> recv(
266 : capy::continuation& cont,
267 : capy::executor_ref ex,
268 : buffer_param buf,
269 : int flags,
270 : std::stop_token token,
271 : std::error_code* ec,
272 : std::size_t* bytes_out) = 0;
273 :
274 : /** Initiate an asynchronous wait for socket readiness.
275 :
276 : Completes when the socket becomes ready for the
277 : specified direction, or an error condition is
278 : reported. No bytes are transferred.
279 :
280 : @param cont Continuation to resume on completion; it lives in
281 : the awaiting frame until then.
282 : @param ex Executor for dispatching the completion.
283 : @param w The direction to wait on.
284 : @param token Stop token for cancellation.
285 : @param ec Output error code.
286 :
287 : @return Coroutine handle to resume immediately.
288 : */
289 : virtual std::coroutine_handle<> wait(
290 : capy::continuation& cont,
291 : capy::executor_ref ex,
292 : wait_type w,
293 : std::stop_token token,
294 : std::error_code* ec) = 0;
295 : };
296 :
297 : /** Represent the awaitable returned by @ref send_to.
298 :
299 : Captures the destination endpoint and buffer, then dispatches
300 : to the backend implementation on suspension.
301 : */
302 : struct send_to_awaitable : detail::bytes_op_base<send_to_awaitable>
303 : {
304 : private:
305 : friend udp_socket;
306 :
307 HIT 79 : send_to_awaitable(
308 : udp_socket& s,
309 : buffer_param buf,
310 : endpoint dest,
311 : int flags = 0) noexcept
312 158 : : s_(s)
313 79 : , buf_(buf)
314 79 : , dest_(dest)
315 79 : , flags_(flags)
316 : {
317 79 : }
318 :
319 : friend detail::bytes_op_base<send_to_awaitable>;
320 :
321 : udp_socket& s_;
322 : buffer_param buf_;
323 : endpoint dest_;
324 : int flags_;
325 :
326 : std::coroutine_handle<>
327 75 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
328 : {
329 150 : return s_.get().send_to(
330 150 : cont, ex, buf_, dest_, flags_, token_, &ec_, &bytes_);
331 : }
332 : };
333 :
334 : /** Represent the awaitable returned by @ref recv_from.
335 :
336 : Captures the source endpoint reference and buffer, then
337 : dispatches to the backend implementation on suspension.
338 : */
339 : struct recv_from_awaitable : detail::bytes_op_base<recv_from_awaitable>
340 : {
341 : private:
342 : friend udp_socket;
343 :
344 99 : recv_from_awaitable(
345 : udp_socket& s,
346 : buffer_param buf,
347 : endpoint& source,
348 : int flags = 0) noexcept
349 198 : : s_(s)
350 99 : , buf_(buf)
351 99 : , source_(source)
352 99 : , flags_(flags)
353 : {
354 99 : }
355 :
356 : friend detail::bytes_op_base<recv_from_awaitable>;
357 :
358 : udp_socket& s_;
359 : buffer_param buf_;
360 : endpoint& source_;
361 : int flags_;
362 :
363 : std::coroutine_handle<>
364 93 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
365 : {
366 186 : return s_.get().recv_from(
367 186 : cont, ex, buf_, &source_, flags_, token_, &ec_, &bytes_);
368 : }
369 : };
370 :
371 : /// Represent the awaitable returned by @ref connect.
372 : struct connect_awaitable : detail::void_op_base<connect_awaitable>
373 : {
374 : private:
375 : friend udp_socket;
376 :
377 44 : connect_awaitable(udp_socket& s, endpoint ep) noexcept
378 88 : : s_(s)
379 44 : , endpoint_(ep)
380 : {
381 44 : }
382 :
383 : friend detail::void_op_base<connect_awaitable>;
384 :
385 : udp_socket& s_;
386 : endpoint endpoint_;
387 :
388 : std::coroutine_handle<>
389 42 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
390 : {
391 42 : return s_.get().connect(cont, ex, endpoint_, token_, &ec_);
392 : }
393 : };
394 :
395 : /// Represent the awaitable returned by @ref wait.
396 : struct wait_awaitable : detail::void_op_base<wait_awaitable>
397 : {
398 : private:
399 : friend udp_socket;
400 :
401 30 : wait_awaitable(udp_socket& s, wait_type w) noexcept : s_(s), w_(w) {}
402 :
403 : friend detail::void_op_base<wait_awaitable>;
404 :
405 : udp_socket& s_;
406 : wait_type w_;
407 :
408 : std::coroutine_handle<>
409 28 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
410 : {
411 28 : return s_.get().wait(cont, ex, w_, token_, &ec_);
412 : }
413 : };
414 :
415 : /// Represent the awaitable returned by @ref send.
416 : struct send_awaitable : detail::bytes_op_base<send_awaitable>
417 : {
418 : private:
419 : friend udp_socket;
420 :
421 28 : send_awaitable(udp_socket& s, buffer_param buf, int flags = 0) noexcept
422 56 : : s_(s)
423 28 : , buf_(buf)
424 28 : , flags_(flags)
425 : {
426 28 : }
427 :
428 : friend detail::bytes_op_base<send_awaitable>;
429 :
430 : udp_socket& s_;
431 : buffer_param buf_;
432 : int flags_;
433 :
434 : std::coroutine_handle<>
435 24 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
436 : {
437 24 : return s_.get().send(cont, ex, buf_, flags_, token_, &ec_, &bytes_);
438 : }
439 : };
440 :
441 : /// Represent the awaitable returned by @ref recv.
442 : struct recv_awaitable : detail::bytes_op_base<recv_awaitable>
443 : {
444 : private:
445 : friend udp_socket;
446 :
447 72 : recv_awaitable(udp_socket& s, buffer_param buf, int flags = 0) noexcept
448 144 : : s_(s)
449 72 : , buf_(buf)
450 72 : , flags_(flags)
451 : {
452 72 : }
453 :
454 : friend detail::bytes_op_base<recv_awaitable>;
455 :
456 : udp_socket& s_;
457 : buffer_param buf_;
458 : int flags_;
459 :
460 : std::coroutine_handle<>
461 68 : dispatch(capy::continuation& cont, capy::executor_ref ex) const
462 : {
463 68 : return s_.get().recv(cont, ex, buf_, flags_, token_, &ec_, &bytes_);
464 : }
465 : };
466 :
467 : public:
468 : /** Closes the socket if open, cancelling any pending operations.
469 : */
470 : ~udp_socket() override;
471 :
472 : /** Construct a socket from an execution context.
473 :
474 : @param ctx The execution context that owns this socket.
475 : */
476 : explicit udp_socket(capy::execution_context& ctx);
477 :
478 : /** Construct a socket from an executor.
479 :
480 : The socket is associated with the executor's context.
481 :
482 : @param ex The executor whose context owns the socket.
483 : */
484 : template<class Ex>
485 : requires(!std::same_as<std::remove_cvref_t<Ex>, udp_socket>) &&
486 : capy::Executor<Ex>
487 : explicit udp_socket(Ex const& ex) : udp_socket(ex.context())
488 : {
489 : }
490 :
491 : /** Transfers ownership of the socket resources.
492 :
493 : @param other The socket to move from.
494 : */
495 4 : udp_socket(udp_socket&& other) noexcept : io_object(std::move(other)) {}
496 :
497 : /** Closes any existing socket and transfers ownership.
498 :
499 : @param other The socket to move from.
500 : @return Reference to this socket.
501 : */
502 2 : udp_socket& operator=(udp_socket&& other) noexcept
503 : {
504 2 : if (this != &other)
505 : {
506 2 : close();
507 2 : h_ = std::move(other.h_);
508 : }
509 2 : return *this;
510 : }
511 :
512 : /// Copy construction is disabled; the handle is uniquely owned.
513 : udp_socket(udp_socket const&) = delete;
514 : /// Copy assignment is disabled; the handle is uniquely owned.
515 : udp_socket& operator=(udp_socket const&) = delete;
516 :
517 : /** Open the socket.
518 :
519 : Creates a UDP socket and associates it with the platform
520 : reactor.
521 :
522 : Failures such as descriptor exhaustion are normal runtime
523 : conditions and are reported through the returned error code.
524 : Opening an already-open socket is a no-op that reports
525 : success.
526 :
527 : @param f The address family (IPv4 or IPv6). Defaults to
528 : `family::v4`.
529 :
530 : @return The error code, empty on success.
531 : */
532 : [[nodiscard]] std::error_code open(family f = family::v4) noexcept;
533 :
534 : /** Close the socket.
535 :
536 : Releases socket resources. Any pending operations complete
537 : with `errc::operation_canceled`.
538 : */
539 : void close() noexcept;
540 :
541 : /** Check if the socket is open.
542 :
543 : @return `true` if the socket is open and ready for operations.
544 : */
545 1932 : bool is_open() const noexcept
546 : {
547 : #if BOOST_COROSIO_HAS_IOCP && !defined(BOOST_COROSIO_MRDOCS)
548 : return h_ && get().native_handle() != ~native_handle_type(0);
549 : #else
550 1932 : return h_ && get().native_handle() >= 0;
551 : #endif
552 : }
553 :
554 : /** Bind the socket to a local endpoint.
555 :
556 : Associates the socket with a local address and port.
557 : Required before calling `recv_from`.
558 :
559 : @param ep The local endpoint to bind to.
560 :
561 : @return Error code on failure, empty on success.
562 :
563 : A closed socket reports `errc::bad_file_descriptor`.
564 : */
565 : [[nodiscard]] std::error_code bind(endpoint ep) noexcept;
566 :
567 : /** Disable sends or receives on the socket.
568 :
569 : Failures such as an unconnected socket are normal runtime
570 : conditions and are reported through the returned error
571 : code. A closed socket reports `errc::bad_file_descriptor`.
572 :
573 : @param what Determines which operations are no longer
574 : allowed.
575 :
576 : @return The error code, empty on success.
577 : */
578 : [[nodiscard]] std::error_code shutdown(shutdown_type what) noexcept;
579 :
580 : /** Cancel any pending asynchronous operations.
581 :
582 : Operations still in flight complete with
583 : `errc::operation_canceled`; an operation whose result is
584 : already decided reports that result. Check
585 : `ec == cond::canceled` for portable comparison.
586 : */
587 : void cancel() noexcept;
588 :
589 : /** Get the native socket handle.
590 :
591 : @return The native socket handle, or -1 if not open.
592 : */
593 : native_handle_type native_handle() const noexcept;
594 :
595 : /** Assign an existing native socket to this object.
596 :
597 : Adopts a UDP socket created outside the library — received
598 : from another process, inherited, or made natively — and
599 : registers it with the backend. The socket must be a datagram
600 : socket in the `AF_INET` or `AF_INET6` family. Adoption never
601 : alters the descriptor's flags or options: on POSIX the fd
602 : must already be non-blocking, and on Windows the socket must
603 : be overlapped-capable.
604 :
605 : The object must be closed. To replace a held socket, `close()`
606 : or `release()` it first.
607 :
608 : @par Exception Safety
609 : Throws nothing. On failure the object is unchanged and the
610 : caller retains ownership of `fd`.
611 :
612 : @param fd The native socket to adopt. On success the object
613 : owns it and closes it.
614 :
615 : @return `error::already_open` if this object is open.
616 : Otherwise the error code, empty on success. Validation and
617 : registration failures are normal runtime conditions when
618 : adopting foreign descriptors.
619 : */
620 : [[nodiscard]] std::error_code assign(native_handle_type fd) noexcept;
621 :
622 : /** Release ownership of the native socket handle.
623 :
624 : Deregisters the socket from the backend and cancels pending
625 : operations without closing the descriptor. The caller takes
626 : ownership of the returned handle.
627 :
628 : @note With the IOCP backend, a socket released while operations
629 : on it are in flight stays bound to this context's completion
630 : port for good. Windows refuses to unbind a handle with I/O
631 : outstanding, so no context, this one included, can assign it
632 : afterwards. Its cancelled operations still complete normally.
633 :
634 : @return The native handle.
635 :
636 : @throws std::system_error `errc::bad_file_descriptor` if the
637 : socket is not open.
638 :
639 : @post is_open() == false
640 : */
641 : native_handle_type release();
642 :
643 : /** Set a socket option.
644 :
645 : @param opt The option to set.
646 :
647 : @throws std::system_error `errc::bad_file_descriptor` if the
648 : socket is not open; otherwise thrown on failure.
649 : */
650 : template<class Option>
651 97 : void set_option(Option const& opt)
652 : {
653 97 : if (!is_open())
654 2 : detail::throw_system_error(
655 4 : make_error_code(std::errc::bad_file_descriptor),
656 : "udp_socket::set_option");
657 95 : auto const fam = get().family();
658 95 : std::error_code ec = get().set_option(
659 : opt.level(fam), opt.name(fam), opt.data(fam), opt.size(fam));
660 95 : if (ec)
661 6 : detail::throw_system_error(ec, "udp_socket::set_option");
662 89 : }
663 :
664 : /** Get a socket option.
665 :
666 : @return The current option value.
667 :
668 : @throws std::system_error `errc::bad_file_descriptor` if the
669 : socket is not open; otherwise thrown on failure.
670 : */
671 : template<class Option>
672 63 : Option get_option() const
673 : {
674 63 : if (!is_open())
675 2 : detail::throw_system_error(
676 4 : make_error_code(std::errc::bad_file_descriptor),
677 : "udp_socket::get_option");
678 61 : Option opt{};
679 61 : auto const fam = get().family();
680 61 : std::size_t sz = opt.size(fam);
681 : std::error_code ec =
682 61 : get().get_option(opt.level(fam), opt.name(fam), opt.data(fam), &sz);
683 61 : if (ec)
684 2 : detail::throw_system_error(ec, "udp_socket::get_option");
685 59 : opt.resize(fam, sz);
686 59 : return opt;
687 : }
688 :
689 : /** Get the local endpoint of the socket.
690 :
691 : @return The local endpoint, or a default endpoint if not bound.
692 : */
693 : endpoint local_endpoint() const noexcept;
694 :
695 : /** Send a datagram to the specified destination.
696 :
697 : @param buf The buffer containing data to send.
698 : @param dest The destination endpoint.
699 : @param flags Message flags (e.g. message_flags::do_not_route).
700 :
701 : @return An awaitable that completes with
702 : `results<std::size_t>`.
703 :
704 : A closed socket reports `errc::bad_file_descriptor`.
705 : */
706 : template<capy::ConstBufferSequence Buffers>
707 : [[nodiscard]] auto
708 79 : send_to(Buffers const& buf, endpoint dest, corosio::message_flags flags)
709 : {
710 79 : send_to_awaitable aw(*this, buf, dest, static_cast<int>(flags));
711 79 : if (!is_open())
712 2 : aw.ec_ = make_error_code(std::errc::bad_file_descriptor);
713 79 : return aw;
714 : }
715 :
716 : /// @overload
717 : template<capy::ConstBufferSequence Buffers>
718 79 : [[nodiscard]] auto send_to(Buffers const& buf, endpoint dest)
719 : {
720 79 : return send_to(buf, dest, corosio::message_flags::none);
721 : }
722 :
723 : /** Receive a datagram and capture the sender's endpoint.
724 :
725 : @param buf The buffer to receive data into.
726 : @param source Reference to an endpoint that receives
727 : the sender's address on successful completion.
728 : @param flags Message flags (e.g. message_flags::peek).
729 :
730 : @return An awaitable that completes with
731 : `results<std::size_t>`.
732 :
733 : A closed socket reports `errc::bad_file_descriptor`.
734 : */
735 : template<capy::MutableBufferSequence Buffers>
736 99 : [[nodiscard]] auto recv_from(
737 : Buffers const& buf, endpoint& source, corosio::message_flags flags)
738 : {
739 99 : recv_from_awaitable aw(*this, buf, source, static_cast<int>(flags));
740 99 : if (!is_open())
741 2 : aw.ec_ = make_error_code(std::errc::bad_file_descriptor);
742 99 : return aw;
743 : }
744 :
745 : /// @overload
746 : template<capy::MutableBufferSequence Buffers>
747 96 : [[nodiscard]] auto recv_from(Buffers const& buf, endpoint& source)
748 : {
749 96 : return recv_from(buf, source, corosio::message_flags::none);
750 : }
751 :
752 : /** Initiate an asynchronous connect to set the default peer.
753 :
754 : If the socket is not already open, it is opened automatically
755 : using the address family of @p ep.
756 :
757 : @param ep The remote endpoint to connect to.
758 :
759 : @return An awaitable that completes with `results<>`.
760 :
761 : If the socket needs to be opened and the open fails, the
762 : awaitable completes immediately with that error.
763 : */
764 44 : [[nodiscard]] auto connect(endpoint ep)
765 : {
766 44 : connect_awaitable aw(*this, ep);
767 44 : if (!is_open())
768 10 : aw.ec_ = open(ep.address().family());
769 44 : return aw;
770 : }
771 :
772 : /** Wait for the socket to become ready in a given direction.
773 :
774 : Suspends until the socket is ready for the requested
775 : direction, or an error condition is reported. No bytes
776 : are transferred.
777 :
778 : The operation supports cancellation via `std::stop_token`.
779 :
780 : @param w The wait direction (read, write, or error).
781 :
782 : @return An awaitable that completes with `results<>`.
783 :
784 : A closed socket completes with `errc::bad_file_descriptor`.
785 :
786 : @pre This socket must outlive the returned awaitable.
787 : */
788 30 : [[nodiscard]] auto wait(wait_type w)
789 : {
790 30 : return wait_awaitable(*this, w);
791 : }
792 :
793 : /** Send a datagram to the connected peer.
794 :
795 : @param buf The buffer containing data to send.
796 : @param flags Message flags.
797 :
798 : @return An awaitable that completes with
799 : `results<std::size_t>`.
800 :
801 : A closed socket reports `errc::bad_file_descriptor`.
802 : */
803 : template<capy::ConstBufferSequence Buffers>
804 28 : [[nodiscard]] auto send(Buffers const& buf, corosio::message_flags flags)
805 : {
806 28 : send_awaitable aw(*this, buf, static_cast<int>(flags));
807 28 : if (!is_open())
808 2 : aw.ec_ = make_error_code(std::errc::bad_file_descriptor);
809 28 : return aw;
810 : }
811 :
812 : /// @overload
813 : template<capy::ConstBufferSequence Buffers>
814 28 : [[nodiscard]] auto send(Buffers const& buf)
815 : {
816 28 : return send(buf, corosio::message_flags::none);
817 : }
818 :
819 : /** Receive a datagram from the connected peer.
820 :
821 : @param buf The buffer to receive data into.
822 : @param flags Message flags (e.g. message_flags::peek).
823 :
824 : @return An awaitable that completes with
825 : `results<std::size_t>`.
826 :
827 : A closed socket reports `errc::bad_file_descriptor`.
828 : */
829 : template<capy::MutableBufferSequence Buffers>
830 72 : [[nodiscard]] auto recv(Buffers const& buf, corosio::message_flags flags)
831 : {
832 72 : recv_awaitable aw(*this, buf, static_cast<int>(flags));
833 72 : if (!is_open())
834 2 : aw.ec_ = make_error_code(std::errc::bad_file_descriptor);
835 72 : return aw;
836 : }
837 :
838 : /// @overload
839 : template<capy::MutableBufferSequence Buffers>
840 70 : [[nodiscard]] auto recv(Buffers const& buf)
841 : {
842 70 : return recv(buf, corosio::message_flags::none);
843 : }
844 :
845 : /** Get the remote endpoint of the socket.
846 :
847 : Returns the address and port of the connected peer.
848 :
849 : @return The remote endpoint, or a default endpoint if
850 : not connected.
851 : */
852 : endpoint remote_endpoint() const noexcept;
853 :
854 : protected:
855 : /// Construct from a pre-built handle (for native_udp_socket).
856 42 : explicit udp_socket(io_object::handle h) noexcept : io_object(std::move(h))
857 : {
858 42 : }
859 :
860 : private:
861 : /// Open the socket for the given protocol triple.
862 : [[nodiscard]] std::error_code
863 : open_for_family(int family, int type, int protocol) noexcept;
864 :
865 2795 : inline implementation& get() const noexcept
866 : {
867 2795 : return *static_cast<implementation*>(h_.get());
868 : }
869 : };
870 :
871 : } // namespace boost::corosio
872 :
873 : #endif // BOOST_COROSIO_UDP_SOCKET_HPP
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