tungstenite/protocol/mod.rs
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861
//! Generic WebSocket message stream.
pub mod frame;
mod message;
pub use self::{frame::CloseFrame, message::Message};
use self::{
frame::{
coding::{CloseCode, Control as OpCtl, Data as OpData, OpCode},
Frame, FrameCodec,
},
message::{IncompleteMessage, IncompleteMessageType},
};
use crate::error::{Error, ProtocolError, Result};
use log::*;
use std::{
io::{self, Read, Write},
mem::replace,
};
/// Indicates a Client or Server role of the websocket
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Role {
/// This socket is a server
Server,
/// This socket is a client
Client,
}
/// The configuration for WebSocket connection.
#[derive(Debug, Clone, Copy)]
pub struct WebSocketConfig {
/// Does nothing, instead use `max_write_buffer_size`.
#[deprecated]
pub max_send_queue: Option<usize>,
/// The target minimum size of the write buffer to reach before writing the data
/// to the underlying stream.
/// The default value is 128 KiB.
///
/// If set to `0` each message will be eagerly written to the underlying stream.
/// It is often more optimal to allow them to buffer a little, hence the default value.
///
/// Note: [`flush`](WebSocket::flush) will always fully write the buffer regardless.
pub write_buffer_size: usize,
/// The max size of the write buffer in bytes. Setting this can provide backpressure
/// in the case the write buffer is filling up due to write errors.
/// The default value is unlimited.
///
/// Note: The write buffer only builds up past [`write_buffer_size`](Self::write_buffer_size)
/// when writes to the underlying stream are failing. So the **write buffer can not
/// fill up if you are not observing write errors even if not flushing**.
///
/// Note: Should always be at least [`write_buffer_size + 1 message`](Self::write_buffer_size)
/// and probably a little more depending on error handling strategy.
pub max_write_buffer_size: usize,
/// The maximum size of an incoming message. `None` means no size limit. The default value is 64 MiB
/// which should be reasonably big for all normal use-cases but small enough to prevent
/// memory eating by a malicious user.
pub max_message_size: Option<usize>,
/// The maximum size of a single incoming message frame. `None` means no size limit. The limit is for
/// frame payload NOT including the frame header. The default value is 16 MiB which should
/// be reasonably big for all normal use-cases but small enough to prevent memory eating
/// by a malicious user.
pub max_frame_size: Option<usize>,
/// When set to `true`, the server will accept and handle unmasked frames
/// from the client. According to the RFC 6455, the server must close the
/// connection to the client in such cases, however it seems like there are
/// some popular libraries that are sending unmasked frames, ignoring the RFC.
/// By default this option is set to `false`, i.e. according to RFC 6455.
pub accept_unmasked_frames: bool,
}
impl Default for WebSocketConfig {
fn default() -> Self {
#[allow(deprecated)]
WebSocketConfig {
max_send_queue: None,
write_buffer_size: 128 * 1024,
max_write_buffer_size: usize::MAX,
max_message_size: Some(64 << 20),
max_frame_size: Some(16 << 20),
accept_unmasked_frames: false,
}
}
}
impl WebSocketConfig {
/// Panic if values are invalid.
pub(crate) fn assert_valid(&self) {
assert!(
self.max_write_buffer_size > self.write_buffer_size,
"WebSocketConfig::max_write_buffer_size must be greater than write_buffer_size, \
see WebSocketConfig docs`"
);
}
}
/// WebSocket input-output stream.
///
/// This is THE structure you want to create to be able to speak the WebSocket protocol.
/// It may be created by calling `connect`, `accept` or `client` functions.
///
/// Use [`WebSocket::read`], [`WebSocket::send`] to received and send messages.
#[derive(Debug)]
pub struct WebSocket<Stream> {
/// The underlying socket.
socket: Stream,
/// The context for managing a WebSocket.
context: WebSocketContext,
}
impl<Stream> WebSocket<Stream> {
/// Convert a raw socket into a WebSocket without performing a handshake.
///
/// Call this function if you're using Tungstenite as a part of a web framework
/// or together with an existing one. If you need an initial handshake, use
/// `connect()` or `accept()` functions of the crate to construct a websocket.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn from_raw_socket(stream: Stream, role: Role, config: Option<WebSocketConfig>) -> Self {
WebSocket { socket: stream, context: WebSocketContext::new(role, config) }
}
/// Convert a raw socket into a WebSocket without performing a handshake.
///
/// Call this function if you're using Tungstenite as a part of a web framework
/// or together with an existing one. If you need an initial handshake, use
/// `connect()` or `accept()` functions of the crate to construct a websocket.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn from_partially_read(
stream: Stream,
part: Vec<u8>,
role: Role,
config: Option<WebSocketConfig>,
) -> Self {
WebSocket {
socket: stream,
context: WebSocketContext::from_partially_read(part, role, config),
}
}
/// Returns a shared reference to the inner stream.
pub fn get_ref(&self) -> &Stream {
&self.socket
}
/// Returns a mutable reference to the inner stream.
pub fn get_mut(&mut self) -> &mut Stream {
&mut self.socket
}
/// Change the configuration.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn set_config(&mut self, set_func: impl FnOnce(&mut WebSocketConfig)) {
self.context.set_config(set_func)
}
/// Read the configuration.
pub fn get_config(&self) -> &WebSocketConfig {
self.context.get_config()
}
/// Check if it is possible to read messages.
///
/// Reading is impossible after receiving `Message::Close`. It is still possible after
/// sending close frame since the peer still may send some data before confirming close.
pub fn can_read(&self) -> bool {
self.context.can_read()
}
/// Check if it is possible to write messages.
///
/// Writing gets impossible immediately after sending or receiving `Message::Close`.
pub fn can_write(&self) -> bool {
self.context.can_write()
}
}
impl<Stream: Read + Write> WebSocket<Stream> {
/// Read a message from stream, if possible.
///
/// This will also queue responses to ping and close messages. These responses
/// will be written and flushed on the next call to [`read`](Self::read),
/// [`write`](Self::write) or [`flush`](Self::flush).
///
/// # Closing the connection
/// When the remote endpoint decides to close the connection this will return
/// the close message with an optional close frame.
///
/// You should continue calling [`read`](Self::read), [`write`](Self::write) or
/// [`flush`](Self::flush) to drive the reply to the close frame until [`Error::ConnectionClosed`]
/// is returned. Once that happens it is safe to drop the underlying connection.
pub fn read(&mut self) -> Result<Message> {
self.context.read(&mut self.socket)
}
/// Writes and immediately flushes a message.
/// Equivalent to calling [`write`](Self::write) then [`flush`](Self::flush).
pub fn send(&mut self, message: Message) -> Result<()> {
self.write(message)?;
self.flush()
}
/// Write a message to the provided stream, if possible.
///
/// A subsequent call should be made to [`flush`](Self::flush) to flush writes.
///
/// In the event of stream write failure the message frame will be stored
/// in the write buffer and will try again on the next call to [`write`](Self::write)
/// or [`flush`](Self::flush).
///
/// If the write buffer would exceed the configured [`WebSocketConfig::max_write_buffer_size`]
/// [`Err(WriteBufferFull(msg_frame))`](Error::WriteBufferFull) is returned.
///
/// This call will generally not flush. However, if there are queued automatic messages
/// they will be written and eagerly flushed.
///
/// For example, upon receiving ping messages tungstenite queues pong replies automatically.
/// The next call to [`read`](Self::read), [`write`](Self::write) or [`flush`](Self::flush)
/// will write & flush the pong reply. This means you should not respond to ping frames manually.
///
/// You can however send pong frames manually in order to indicate a unidirectional heartbeat
/// as described in [RFC 6455](https://tools.ietf.org/html/rfc6455#section-5.5.3). Note that
/// if [`read`](Self::read) returns a ping, you should [`flush`](Self::flush) before passing
/// a custom pong to [`write`](Self::write), otherwise the automatic queued response to the
/// ping will not be sent as it will be replaced by your custom pong message.
///
/// # Errors
/// - If the WebSocket's write buffer is full, [`Error::WriteBufferFull`] will be returned
/// along with the equivalent passed message frame.
/// - If the connection is closed and should be dropped, this will return [`Error::ConnectionClosed`].
/// - If you try again after [`Error::ConnectionClosed`] was returned either from here or from
/// [`read`](Self::read), [`Error::AlreadyClosed`] will be returned. This indicates a program
/// error on your part.
/// - [`Error::Io`] is returned if the underlying connection returns an error
/// (consider these fatal except for WouldBlock).
/// - [`Error::Capacity`] if your message size is bigger than the configured max message size.
pub fn write(&mut self, message: Message) -> Result<()> {
self.context.write(&mut self.socket, message)
}
/// Flush writes.
///
/// Ensures all messages previously passed to [`write`](Self::write) and automatic
/// queued pong responses are written & flushed into the underlying stream.
pub fn flush(&mut self) -> Result<()> {
self.context.flush(&mut self.socket)
}
/// Close the connection.
///
/// This function guarantees that the close frame will be queued.
/// There is no need to call it again. Calling this function is
/// the same as calling `write(Message::Close(..))`.
///
/// After queuing the close frame you should continue calling [`read`](Self::read) or
/// [`flush`](Self::flush) to drive the close handshake to completion.
///
/// The websocket RFC defines that the underlying connection should be closed
/// by the server. Tungstenite takes care of this asymmetry for you.
///
/// When the close handshake is finished (we have both sent and received
/// a close message), [`read`](Self::read) or [`flush`](Self::flush) will return
/// [Error::ConnectionClosed] if this endpoint is the server.
///
/// If this endpoint is a client, [Error::ConnectionClosed] will only be
/// returned after the server has closed the underlying connection.
///
/// It is thus safe to drop the underlying connection as soon as [Error::ConnectionClosed]
/// is returned from [`read`](Self::read) or [`flush`](Self::flush).
pub fn close(&mut self, code: Option<CloseFrame>) -> Result<()> {
self.context.close(&mut self.socket, code)
}
/// Old name for [`read`](Self::read).
#[deprecated(note = "Use `read`")]
pub fn read_message(&mut self) -> Result<Message> {
self.read()
}
/// Old name for [`send`](Self::send).
#[deprecated(note = "Use `send`")]
pub fn write_message(&mut self, message: Message) -> Result<()> {
self.send(message)
}
/// Old name for [`flush`](Self::flush).
#[deprecated(note = "Use `flush`")]
pub fn write_pending(&mut self) -> Result<()> {
self.flush()
}
}
/// A context for managing WebSocket stream.
#[derive(Debug)]
pub struct WebSocketContext {
/// Server or client?
role: Role,
/// encoder/decoder of frame.
frame: FrameCodec,
/// The state of processing, either "active" or "closing".
state: WebSocketState,
/// Receive: an incomplete message being processed.
incomplete: Option<IncompleteMessage>,
/// Send in addition to regular messages E.g. "pong" or "close".
additional_send: Option<Frame>,
/// True indicates there is an additional message (like a pong)
/// that failed to flush previously and we should try again.
unflushed_additional: bool,
/// The configuration for the websocket session.
config: WebSocketConfig,
}
impl WebSocketContext {
/// Create a WebSocket context that manages a post-handshake stream.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn new(role: Role, config: Option<WebSocketConfig>) -> Self {
Self::_new(role, FrameCodec::new(), config.unwrap_or_default())
}
/// Create a WebSocket context that manages an post-handshake stream.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn from_partially_read(part: Vec<u8>, role: Role, config: Option<WebSocketConfig>) -> Self {
Self::_new(role, FrameCodec::from_partially_read(part), config.unwrap_or_default())
}
fn _new(role: Role, mut frame: FrameCodec, config: WebSocketConfig) -> Self {
config.assert_valid();
frame.set_max_out_buffer_len(config.max_write_buffer_size);
frame.set_out_buffer_write_len(config.write_buffer_size);
Self {
role,
frame,
state: WebSocketState::Active,
incomplete: None,
additional_send: None,
unflushed_additional: false,
config,
}
}
/// Change the configuration.
///
/// # Panics
/// Panics if config is invalid e.g. `max_write_buffer_size <= write_buffer_size`.
pub fn set_config(&mut self, set_func: impl FnOnce(&mut WebSocketConfig)) {
set_func(&mut self.config);
self.config.assert_valid();
self.frame.set_max_out_buffer_len(self.config.max_write_buffer_size);
self.frame.set_out_buffer_write_len(self.config.write_buffer_size);
}
/// Read the configuration.
pub fn get_config(&self) -> &WebSocketConfig {
&self.config
}
/// Check if it is possible to read messages.
///
/// Reading is impossible after receiving `Message::Close`. It is still possible after
/// sending close frame since the peer still may send some data before confirming close.
pub fn can_read(&self) -> bool {
self.state.can_read()
}
/// Check if it is possible to write messages.
///
/// Writing gets impossible immediately after sending or receiving `Message::Close`.
pub fn can_write(&self) -> bool {
self.state.is_active()
}
/// Read a message from the provided stream, if possible.
///
/// This function sends pong and close responses automatically.
/// However, it never blocks on write.
pub fn read<Stream>(&mut self, stream: &mut Stream) -> Result<Message>
where
Stream: Read + Write,
{
// Do not read from already closed connections.
self.state.check_not_terminated()?;
loop {
if self.additional_send.is_some() || self.unflushed_additional {
// Since we may get ping or close, we need to reply to the messages even during read.
match self.flush(stream) {
Ok(_) => {}
Err(Error::Io(err)) if err.kind() == io::ErrorKind::WouldBlock => {
// If blocked continue reading, but try again later
self.unflushed_additional = true;
}
Err(err) => return Err(err),
}
} else if self.role == Role::Server && !self.state.can_read() {
self.state = WebSocketState::Terminated;
return Err(Error::ConnectionClosed);
}
// If we get here, either write blocks or we have nothing to write.
// Thus if read blocks, just let it return WouldBlock.
if let Some(message) = self.read_message_frame(stream)? {
trace!("Received message {}", message);
return Ok(message);
}
}
}
/// Write a message to the provided stream.
///
/// A subsequent call should be made to [`flush`](Self::flush) to flush writes.
///
/// In the event of stream write failure the message frame will be stored
/// in the write buffer and will try again on the next call to [`write`](Self::write)
/// or [`flush`](Self::flush).
///
/// If the write buffer would exceed the configured [`WebSocketConfig::max_write_buffer_size`]
/// [`Err(WriteBufferFull(msg_frame))`](Error::WriteBufferFull) is returned.
pub fn write<Stream>(&mut self, stream: &mut Stream, message: Message) -> Result<()>
where
Stream: Read + Write,
{
// When terminated, return AlreadyClosed.
self.state.check_not_terminated()?;
// Do not write after sending a close frame.
if !self.state.is_active() {
return Err(Error::Protocol(ProtocolError::SendAfterClosing));
}
let frame = match message {
Message::Text(data) => Frame::message(data.into(), OpCode::Data(OpData::Text), true),
Message::Binary(data) => Frame::message(data, OpCode::Data(OpData::Binary), true),
Message::Ping(data) => Frame::ping(data),
Message::Pong(data) => {
self.set_additional(Frame::pong(data));
// Note: user pongs can be user flushed so no need to flush here
return self._write(stream, None).map(|_| ());
}
Message::Close(code) => return self.close(stream, code),
Message::Frame(f) => f,
};
let should_flush = self._write(stream, Some(frame))?;
if should_flush {
self.flush(stream)?;
}
Ok(())
}
/// Flush writes.
///
/// Ensures all messages previously passed to [`write`](Self::write) and automatically
/// queued pong responses are written & flushed into the `stream`.
#[inline]
pub fn flush<Stream>(&mut self, stream: &mut Stream) -> Result<()>
where
Stream: Read + Write,
{
self._write(stream, None)?;
self.frame.write_out_buffer(stream)?;
stream.flush()?;
self.unflushed_additional = false;
Ok(())
}
/// Writes any data in the out_buffer, `additional_send` and given `data`.
///
/// Does **not** flush.
///
/// Returns true if the write contents indicate we should flush immediately.
fn _write<Stream>(&mut self, stream: &mut Stream, data: Option<Frame>) -> Result<bool>
where
Stream: Read + Write,
{
if let Some(data) = data {
self.buffer_frame(stream, data)?;
}
// Upon receipt of a Ping frame, an endpoint MUST send a Pong frame in
// response, unless it already received a Close frame. It SHOULD
// respond with Pong frame as soon as is practical. (RFC 6455)
let should_flush = if let Some(msg) = self.additional_send.take() {
trace!("Sending pong/close");
match self.buffer_frame(stream, msg) {
Err(Error::WriteBufferFull(Message::Frame(msg))) => {
// if an system message would exceed the buffer put it back in
// `additional_send` for retry. Otherwise returning this error
// may not make sense to the user, e.g. calling `flush`.
self.set_additional(msg);
false
}
Err(err) => return Err(err),
Ok(_) => true,
}
} else {
self.unflushed_additional
};
// If we're closing and there is nothing to send anymore, we should close the connection.
if self.role == Role::Server && !self.state.can_read() {
// The underlying TCP connection, in most normal cases, SHOULD be closed
// first by the server, so that it holds the TIME_WAIT state and not the
// client (as this would prevent it from re-opening the connection for 2
// maximum segment lifetimes (2MSL), while there is no corresponding
// server impact as a TIME_WAIT connection is immediately reopened upon
// a new SYN with a higher seq number). (RFC 6455)
self.frame.write_out_buffer(stream)?;
self.state = WebSocketState::Terminated;
Err(Error::ConnectionClosed)
} else {
Ok(should_flush)
}
}
/// Close the connection.
///
/// This function guarantees that the close frame will be queued.
/// There is no need to call it again. Calling this function is
/// the same as calling `send(Message::Close(..))`.
pub fn close<Stream>(&mut self, stream: &mut Stream, code: Option<CloseFrame>) -> Result<()>
where
Stream: Read + Write,
{
if let WebSocketState::Active = self.state {
self.state = WebSocketState::ClosedByUs;
let frame = Frame::close(code);
self._write(stream, Some(frame))?;
}
self.flush(stream)
}
/// Try to decode one message frame. May return None.
fn read_message_frame<Stream>(&mut self, stream: &mut Stream) -> Result<Option<Message>>
where
Stream: Read + Write,
{
if let Some(mut frame) = self
.frame
.read_frame(stream, self.config.max_frame_size)
.check_connection_reset(self.state)?
{
if !self.state.can_read() {
return Err(Error::Protocol(ProtocolError::ReceivedAfterClosing));
}
// MUST be 0 unless an extension is negotiated that defines meanings
// for non-zero values. If a nonzero value is received and none of
// the negotiated extensions defines the meaning of such a nonzero
// value, the receiving endpoint MUST _Fail the WebSocket
// Connection_.
{
let hdr = frame.header();
if hdr.rsv1 || hdr.rsv2 || hdr.rsv3 {
return Err(Error::Protocol(ProtocolError::NonZeroReservedBits));
}
}
match self.role {
Role::Server => {
if frame.is_masked() {
// A server MUST remove masking for data frames received from a client
// as described in Section 5.3. (RFC 6455)
frame.apply_mask()
} else if !self.config.accept_unmasked_frames {
// The server MUST close the connection upon receiving a
// frame that is not masked. (RFC 6455)
// The only exception here is if the user explicitly accepts given
// stream by setting WebSocketConfig.accept_unmasked_frames to true
return Err(Error::Protocol(ProtocolError::UnmaskedFrameFromClient));
}
}
Role::Client => {
if frame.is_masked() {
// A client MUST close a connection if it detects a masked frame. (RFC 6455)
return Err(Error::Protocol(ProtocolError::MaskedFrameFromServer));
}
}
}
match frame.header().opcode {
OpCode::Control(ctl) => {
match ctl {
// All control frames MUST have a payload length of 125 bytes or less
// and MUST NOT be fragmented. (RFC 6455)
_ if !frame.header().is_final => {
Err(Error::Protocol(ProtocolError::FragmentedControlFrame))
}
_ if frame.payload().len() > 125 => {
Err(Error::Protocol(ProtocolError::ControlFrameTooBig))
}
OpCtl::Close => Ok(self.do_close(frame.into_close()?).map(Message::Close)),
OpCtl::Reserved(i) => {
Err(Error::Protocol(ProtocolError::UnknownControlFrameType(i)))
}
OpCtl::Ping => {
let data = frame.into_data();
// No ping processing after we sent a close frame.
if self.state.is_active() {
self.set_additional(Frame::pong(data.clone()));
}
Ok(Some(Message::Ping(data)))
}
OpCtl::Pong => Ok(Some(Message::Pong(frame.into_data()))),
}
}
OpCode::Data(data) => {
let fin = frame.header().is_final;
match data {
OpData::Continue => {
if let Some(ref mut msg) = self.incomplete {
msg.extend(frame.into_data(), self.config.max_message_size)?;
} else {
return Err(Error::Protocol(
ProtocolError::UnexpectedContinueFrame,
));
}
if fin {
Ok(Some(self.incomplete.take().unwrap().complete()?))
} else {
Ok(None)
}
}
c if self.incomplete.is_some() => {
Err(Error::Protocol(ProtocolError::ExpectedFragment(c)))
}
OpData::Text | OpData::Binary => {
let msg = {
let message_type = match data {
OpData::Text => IncompleteMessageType::Text,
OpData::Binary => IncompleteMessageType::Binary,
_ => panic!("Bug: message is not text nor binary"),
};
let mut m = IncompleteMessage::new(message_type);
m.extend(frame.into_data(), self.config.max_message_size)?;
m
};
if fin {
Ok(Some(msg.complete()?))
} else {
self.incomplete = Some(msg);
Ok(None)
}
}
OpData::Reserved(i) => {
Err(Error::Protocol(ProtocolError::UnknownDataFrameType(i)))
}
}
}
} // match opcode
} else {
// Connection closed by peer
match replace(&mut self.state, WebSocketState::Terminated) {
WebSocketState::ClosedByPeer | WebSocketState::CloseAcknowledged => {
Err(Error::ConnectionClosed)
}
_ => Err(Error::Protocol(ProtocolError::ResetWithoutClosingHandshake)),
}
}
}
/// Received a close frame. Tells if we need to return a close frame to the user.
#[allow(clippy::option_option)]
fn do_close<'t>(&mut self, close: Option<CloseFrame<'t>>) -> Option<Option<CloseFrame<'t>>> {
debug!("Received close frame: {:?}", close);
match self.state {
WebSocketState::Active => {
self.state = WebSocketState::ClosedByPeer;
let close = close.map(|frame| {
if !frame.code.is_allowed() {
CloseFrame {
code: CloseCode::Protocol,
reason: "Protocol violation".into(),
}
} else {
frame
}
});
let reply = Frame::close(close.clone());
debug!("Replying to close with {:?}", reply);
self.set_additional(reply);
Some(close)
}
WebSocketState::ClosedByPeer | WebSocketState::CloseAcknowledged => {
// It is already closed, just ignore.
None
}
WebSocketState::ClosedByUs => {
// We received a reply.
self.state = WebSocketState::CloseAcknowledged;
Some(close)
}
WebSocketState::Terminated => unreachable!(),
}
}
/// Write a single frame into the write-buffer.
fn buffer_frame<Stream>(&mut self, stream: &mut Stream, mut frame: Frame) -> Result<()>
where
Stream: Read + Write,
{
match self.role {
Role::Server => {}
Role::Client => {
// 5. If the data is being sent by the client, the frame(s) MUST be
// masked as defined in Section 5.3. (RFC 6455)
frame.set_random_mask();
}
}
trace!("Sending frame: {:?}", frame);
self.frame.buffer_frame(stream, frame).check_connection_reset(self.state)
}
/// Replace `additional_send` if it is currently a `Pong` message.
fn set_additional(&mut self, add: Frame) {
let empty_or_pong = self
.additional_send
.as_ref()
.map_or(true, |f| f.header().opcode == OpCode::Control(OpCtl::Pong));
if empty_or_pong {
self.additional_send.replace(add);
}
}
}
/// The current connection state.
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
enum WebSocketState {
/// The connection is active.
Active,
/// We initiated a close handshake.
ClosedByUs,
/// The peer initiated a close handshake.
ClosedByPeer,
/// The peer replied to our close handshake.
CloseAcknowledged,
/// The connection does not exist anymore.
Terminated,
}
impl WebSocketState {
/// Tell if we're allowed to process normal messages.
fn is_active(self) -> bool {
matches!(self, WebSocketState::Active)
}
/// Tell if we should process incoming data. Note that if we send a close frame
/// but the remote hasn't confirmed, they might have sent data before they receive our
/// close frame, so we should still pass those to client code, hence ClosedByUs is valid.
fn can_read(self) -> bool {
matches!(self, WebSocketState::Active | WebSocketState::ClosedByUs)
}
/// Check if the state is active, return error if not.
fn check_not_terminated(self) -> Result<()> {
match self {
WebSocketState::Terminated => Err(Error::AlreadyClosed),
_ => Ok(()),
}
}
}
/// Translate "Connection reset by peer" into `ConnectionClosed` if appropriate.
trait CheckConnectionReset {
fn check_connection_reset(self, state: WebSocketState) -> Self;
}
impl<T> CheckConnectionReset for Result<T> {
fn check_connection_reset(self, state: WebSocketState) -> Self {
match self {
Err(Error::Io(io_error)) => Err({
if !state.can_read() && io_error.kind() == io::ErrorKind::ConnectionReset {
Error::ConnectionClosed
} else {
Error::Io(io_error)
}
}),
x => x,
}
}
}
#[cfg(test)]
mod tests {
use super::{Message, Role, WebSocket, WebSocketConfig};
use crate::error::{CapacityError, Error};
use std::{io, io::Cursor};
struct WriteMoc<Stream>(Stream);
impl<Stream> io::Write for WriteMoc<Stream> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
impl<Stream: io::Read> io::Read for WriteMoc<Stream> {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
}
#[test]
fn receive_messages() {
let incoming = Cursor::new(vec![
0x89, 0x02, 0x01, 0x02, 0x8a, 0x01, 0x03, 0x01, 0x07, 0x48, 0x65, 0x6c, 0x6c, 0x6f,
0x2c, 0x20, 0x80, 0x06, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x21, 0x82, 0x03, 0x01, 0x02,
0x03,
]);
let mut socket = WebSocket::from_raw_socket(WriteMoc(incoming), Role::Client, None);
assert_eq!(socket.read().unwrap(), Message::Ping(vec![1, 2]));
assert_eq!(socket.read().unwrap(), Message::Pong(vec![3]));
assert_eq!(socket.read().unwrap(), Message::Text("Hello, World!".into()));
assert_eq!(socket.read().unwrap(), Message::Binary(vec![0x01, 0x02, 0x03]));
}
#[test]
fn size_limiting_text_fragmented() {
let incoming = Cursor::new(vec![
0x01, 0x07, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20, 0x80, 0x06, 0x57, 0x6f, 0x72,
0x6c, 0x64, 0x21,
]);
let limit = WebSocketConfig { max_message_size: Some(10), ..WebSocketConfig::default() };
let mut socket = WebSocket::from_raw_socket(WriteMoc(incoming), Role::Client, Some(limit));
assert!(matches!(
socket.read(),
Err(Error::Capacity(CapacityError::MessageTooLong { size: 13, max_size: 10 }))
));
}
#[test]
fn size_limiting_binary() {
let incoming = Cursor::new(vec![0x82, 0x03, 0x01, 0x02, 0x03]);
let limit = WebSocketConfig { max_message_size: Some(2), ..WebSocketConfig::default() };
let mut socket = WebSocket::from_raw_socket(WriteMoc(incoming), Role::Client, Some(limit));
assert!(matches!(
socket.read(),
Err(Error::Capacity(CapacityError::MessageTooLong { size: 3, max_size: 2 }))
));
}
}