_ Git - rust-lightning/blob - lightning-block-sync/src/http.rs

   1 //! Simple HTTP implementation which supports both async and traditional execution environments
   2 //! with minimal dependencies. This is used as the basis for REST and RPC clients.
   3
   4 use chunked_transfer;
   5 use serde_json;
   6
   7 use std::convert::TryFrom;
   8 #[cfg(not(feature = "tokio"))]
   9 use std::io::Write;
  10 use std::net::ToSocketAddrs;
  11 use std::time::Duration;
  12
  13 #[cfg(feature = "tokio")]
  14 use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt};
  15 #[cfg(feature = "tokio")]
  16 use tokio::net::TcpStream;
  17
  18 #[cfg(not(feature = "tokio"))]
  19 use std::io::BufRead;
  20 use std::io::Read;
  21 #[cfg(not(feature = "tokio"))]
  22 use std::net::TcpStream;
  23
  24 /// Timeout for operations on TCP streams.
  25 const TCP_STREAM_TIMEOUT: Duration = Duration::from_secs(5);
  26
  27 /// Timeout for reading the first byte of a response. This is separate from the general read
  28 /// timeout as it is not uncommon for Bitcoin Core to be blocked waiting on UTXO cache flushes for
  29 /// upwards of a minute or more. Note that we always retry once when we time out, so the maximum
  30 /// time we allow Bitcoin Core to block for is twice this value.
  31 const TCP_STREAM_RESPONSE_TIMEOUT: Duration = Duration::from_secs(120);
  32
  33 /// Maximum HTTP message header size in bytes.
  34 const MAX_HTTP_MESSAGE_HEADER_SIZE: usize = 8192;
  35
  36 /// Maximum HTTP message body size in bytes. Enough for a hex-encoded block in JSON format and any
  37 /// overhead for HTTP chunked transfer encoding.
  38 const MAX_HTTP_MESSAGE_BODY_SIZE: usize = 2 * 4_000_000 + 32_000;
  39
  40 /// Endpoint for interacting with an HTTP-based API.
  41 #[derive(Debug)]
  42 pub struct HttpEndpoint {
  43         host: String,
  44         port: Option<u16>,
  45         path: String,
  46 }
  47
  48 impl HttpEndpoint {
  49         /// Creates an endpoint for the given host and default HTTP port.
  50         pub fn for_host(host: String) -> Self {
  51                 Self {
  52                         host,
  53                         port: None,
  54                         path: String::from("/"),
  55                 }
  56         }
  57
  58         /// Specifies a port to use with the endpoint.
  59         pub fn with_port(mut self, port: u16) -> Self {
  60                 self.port = Some(port);
  61                 self
  62         }
  63
  64         /// Specifies a path to use with the endpoint.
  65         pub fn with_path(mut self, path: String) -> Self {
  66                 self.path = path;
  67                 self
  68         }
  69
  70         /// Returns the endpoint host.
  71         pub fn host(&self) -> &str {
  72                 &self.host
  73         }
  74
  75         /// Returns the endpoint port.
  76         pub fn port(&self) -> u16 {
  77                 match self.port {
  78                         None => 80,
  79                         Some(port) => port,
  80                 }
  81         }
  82
  83         /// Returns the endpoint path.
  84         pub fn path(&self) -> &str {
  85                 &self.path
  86         }
  87 }
  88
  89 impl<'a> std::net::ToSocketAddrs for &'a HttpEndpoint {
  90         type Iter = <(&'a str, u16) as std::net::ToSocketAddrs>::Iter;
  91
  92         fn to_socket_addrs(&self) -> std::io::Result<Self::Iter> {
  93                 (self.host(), self.port()).to_socket_addrs()
  94         }
  95 }
  96
  97 /// Client for making HTTP requests.
  98 pub(crate) struct HttpClient {
  99         stream: TcpStream,
 100 }
 101
 102 impl HttpClient {
 103         /// Opens a connection to an HTTP endpoint.
 104         pub fn connect<E: ToSocketAddrs>(endpoint: E) -> std::io::Result<Self> {
 105                 let address = match endpoint.to_socket_addrs()?.next() {
 106                         None => {
 107                                 return Err(std::io::Error::new(std::io::ErrorKind::InvalidInput, "could not resolve to any addresses"));
 108                         },
 109                         Some(address) => address,
 110                 };
 111                 let stream = std::net::TcpStream::connect_timeout(&address, TCP_STREAM_TIMEOUT)?;
 112                 stream.set_read_timeout(Some(TCP_STREAM_TIMEOUT))?;
 113                 stream.set_write_timeout(Some(TCP_STREAM_TIMEOUT))?;
 114
 115                 #[cfg(feature = "tokio")]
 116                 let stream = {
 117                         stream.set_nonblocking(true)?;
 118                         TcpStream::from_std(stream)?
 119                 };
 120
 121                 Ok(Self { stream })
 122         }
 123
 124         /// Sends a `GET` request for a resource identified by `uri` at the `host`.
 125         ///
 126         /// Returns the response body in `F` format.
 127         #[allow(dead_code)]
 128         pub async fn get<F>(&mut self, uri: &str, host: &str) -> std::io::Result<F>
 129         where F: TryFrom<Vec<u8>, Error = std::io::Error> {
 130                 let request = format!(
 131                         "GET {} HTTP/1.1\r\n\
 132                          Host: {}\r\n\
 133                          Connection: keep-alive\r\n\
 134                          \r\n", uri, host);
 135                 let response_body = self.send_request_with_retry(&request).await?;
 136                 F::try_from(response_body)
 137         }
 138
 139         /// Sends a `POST` request for a resource identified by `uri` at the `host` using the given HTTP
 140         /// authentication credentials.
 141         ///
 142         /// The request body consists of the provided JSON `content`. Returns the response body in `F`
 143         /// format.
 144         #[allow(dead_code)]
 145         pub async fn post<F>(&mut self, uri: &str, host: &str, auth: &str, content: serde_json::Value) -> std::io::Result<F>
 146         where F: TryFrom<Vec<u8>, Error = std::io::Error> {
 147                 let content = content.to_string();
 148                 let request = format!(
 149                         "POST {} HTTP/1.1\r\n\
 150                          Host: {}\r\n\
 151                          Authorization: {}\r\n\
 152                          Connection: keep-alive\r\n\
 153                          Content-Type: application/json\r\n\
 154                          Content-Length: {}\r\n\
 155                          \r\n\
 156                          {}", uri, host, auth, content.len(), content);
 157                 let response_body = self.send_request_with_retry(&request).await?;
 158                 F::try_from(response_body)
 159         }
 160
 161         /// Sends an HTTP request message and reads the response, returning its body. Attempts to
 162         /// reconnect and retry if the connection has been closed.
 163         async fn send_request_with_retry(&mut self, request: &str) -> std::io::Result<Vec<u8>> {
 164                 let endpoint = self.stream.peer_addr().unwrap();
 165                 match self.send_request(request).await {
 166                         Ok(bytes) => Ok(bytes),
 167                         Err(_) => {
 168                                 // Reconnect and retry on fail. This can happen if the connection was closed after
 169                                 // the keep-alive limits are reached, or generally if the request timed out due to
 170                                 // Bitcoin Core being stuck on a long-running operation or its RPC queue being
 171                                 // full.
 172                                 // Block 100ms before retrying the request as in many cases the source of the error
 173                                 // may be persistent for some time.
 174                                 #[cfg(feature = "tokio")]
 175                                 tokio::time::sleep(Duration::from_millis(100)).await;
 176                                 #[cfg(not(feature = "tokio"))]
 177                                 std::thread::sleep(Duration::from_millis(100));
 178                                 *self = Self::connect(endpoint)?;
 179                                 self.send_request(request).await
 180                         },
 181                 }
 182         }
 183
 184         /// Sends an HTTP request message and reads the response, returning its body.
 185         async fn send_request(&mut self, request: &str) -> std::io::Result<Vec<u8>> {
 186                 self.write_request(request).await?;
 187                 self.read_response().await
 188         }
 189
 190         /// Writes an HTTP request message.
 191         async fn write_request(&mut self, request: &str) -> std::io::Result<()> {
 192                 #[cfg(feature = "tokio")]
 193                 {
 194                         self.stream.write_all(request.as_bytes()).await?;
 195                         self.stream.flush().await
 196                 }
 197                 #[cfg(not(feature = "tokio"))]
 198                 {
 199                         self.stream.write_all(request.as_bytes())?;
 200                         self.stream.flush()
 201                 }
 202         }
 203
 204         /// Reads an HTTP response message.
 205         async fn read_response(&mut self) -> std::io::Result<Vec<u8>> {
 206                 #[cfg(feature = "tokio")]
 207                 let stream = self.stream.split().0;
 208                 #[cfg(not(feature = "tokio"))]
 209                 let stream = std::io::Read::by_ref(&mut self.stream);
 210
 211                 let limited_stream = stream.take(MAX_HTTP_MESSAGE_HEADER_SIZE as u64);
 212
 213                 #[cfg(feature = "tokio")]
 214                 let mut reader = tokio::io::BufReader::new(limited_stream);
 215                 #[cfg(not(feature = "tokio"))]
 216                 let mut reader = std::io::BufReader::new(limited_stream);
 217
 218                 macro_rules! read_line {
 219                         () => { read_line!(0) };
 220                         ($retry_count: expr) => { {
 221                                 let mut line = String::new();
 222                                 let mut timeout_count: u64 = 0;
 223                                 let bytes_read = loop {
 224                                         #[cfg(feature = "tokio")]
 225                                         let read_res = reader.read_line(&mut line).await;
 226                                         #[cfg(not(feature = "tokio"))]
 227                                         let read_res = reader.read_line(&mut line);
 228                                         match read_res {
 229                                                 Ok(bytes_read) => break bytes_read,
 230                                                 Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
 231                                                         timeout_count += 1;
 232                                                         if timeout_count > $retry_count {
 233                                                                 return Err(e);
 234                                                         } else {
 235                                                                 continue;
 236                                                         }
 237                                                 }
 238                                                 Err(e) => return Err(e),
 239                                         }
 240                                 };
 241
 242                                 match bytes_read {
 243                                         0 => None,
 244                                         _ => {
 245                                                 // Remove trailing CRLF
 246                                                 if line.ends_with('\n') { line.pop(); if line.ends_with('\r') { line.pop(); } }
 247                                                 Some(line)
 248                                         },
 249                                 }
 250                         } }
 251                 }
 252
 253                 // Read and parse status line
 254                 // Note that we allow retrying a few times to reach TCP_STREAM_RESPONSE_TIMEOUT.
 255                 let status_line = read_line!(TCP_STREAM_RESPONSE_TIMEOUT.as_secs() / TCP_STREAM_TIMEOUT.as_secs())
 256                         .ok_or(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "no status line"))?;
 257                 let status = HttpStatus::parse(&status_line)?;
 258
 259                 // Read and parse relevant headers
 260                 let mut message_length = HttpMessageLength::Empty;
 261                 loop {
 262                         let line = read_line!()
 263                                 .ok_or(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "no headers"))?;
 264                         if line.is_empty() { break; }
 265
 266                         let header = HttpHeader::parse(&line)?;
 267                         if header.has_name("Content-Length") {
 268                                 let length = header.value.parse()
 269                                         .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
 270                                 if let HttpMessageLength::Empty = message_length {
 271                                         message_length = HttpMessageLength::ContentLength(length);
 272                                 }
 273                                 continue;
 274                         }
 275
 276                         if header.has_name("Transfer-Encoding") {
 277                                 message_length = HttpMessageLength::TransferEncoding(header.value.into());
 278                                 continue;
 279                         }
 280                 }
 281
 282                 if !status.is_ok() {
 283                         // TODO: Handle 3xx redirection responses.
 284                         return Err(std::io::Error::new(std::io::ErrorKind::NotFound, "not found"));
 285                 }
 286
 287                 // Read message body
 288                 let read_limit = MAX_HTTP_MESSAGE_BODY_SIZE - reader.buffer().len();
 289                 reader.get_mut().set_limit(read_limit as u64);
 290                 match message_length {
 291                         HttpMessageLength::Empty => { Ok(Vec::new()) },
 292                         HttpMessageLength::ContentLength(length) => {
 293                                 if length == 0 || length > MAX_HTTP_MESSAGE_BODY_SIZE {
 294                                         Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "out of range"))
 295                                 } else {
 296                                         let mut content = vec![0; length];
 297                                         #[cfg(feature = "tokio")]
 298                                         reader.read_exact(&mut content[..]).await?;
 299                                         #[cfg(not(feature = "tokio"))]
 300                                         reader.read_exact(&mut content[..])?;
 301                                         Ok(content)
 302                                 }
 303                         },
 304                         HttpMessageLength::TransferEncoding(coding) => {
 305                                 if !coding.eq_ignore_ascii_case("chunked") {
 306                                         Err(std::io::Error::new(
 307                                                         std::io::ErrorKind::InvalidInput, "unsupported transfer coding"))
 308                                 } else {
 309                                         let mut content = Vec::new();
 310                                         #[cfg(feature = "tokio")]
 311                                         {
 312                                                 // Since chunked_transfer doesn't have an async interface, only use it to
 313                                                 // determine the size of each chunk to read.
 314                                                 //
 315                                                 // TODO: Replace with an async interface when available.
 316                                                 // https://github.com/frewsxcv/rust-chunked-transfer/issues/7
 317                                                 loop {
 318                                                         // Read the chunk header which contains the chunk size.
 319                                                         let mut chunk_header = String::new();
 320                                                         reader.read_line(&mut chunk_header).await?;
 321                                                         if chunk_header == "0\r\n" {
 322                                                                 // Read the terminator chunk since the decoder consumes the CRLF
 323                                                                 // immediately when this chunk is encountered.
 324                                                                 reader.read_line(&mut chunk_header).await?;
 325                                                         }
 326
 327                                                         // Decode the chunk header to obtain the chunk size.
 328                                                         let mut buffer = Vec::new();
 329                                                         let mut decoder = chunked_transfer::Decoder::new(chunk_header.as_bytes());
 330                                                         decoder.read_to_end(&mut buffer)?;
 331
 332                                                         // Read the chunk body.
 333                                                         let chunk_size = match decoder.remaining_chunks_size() {
 334                                                                 None => break,
 335                                                                 Some(chunk_size) => chunk_size,
 336                                                         };
 337                                                         let chunk_offset = content.len();
 338                                                         content.resize(chunk_offset + chunk_size + "\r\n".len(), 0);
 339                                                         reader.read_exact(&mut content[chunk_offset..]).await?;
 340                                                         content.resize(chunk_offset + chunk_size, 0);
 341                                                 }
 342                                                 Ok(content)
 343                                         }
 344                                         #[cfg(not(feature = "tokio"))]
 345                                         {
 346                                                 let mut decoder = chunked_transfer::Decoder::new(reader);
 347                                                 decoder.read_to_end(&mut content)?;
 348                                                 Ok(content)
 349                                         }
 350                                 }
 351                         },
 352                 }
 353         }
 354 }
 355
 356 /// HTTP response status code as defined by [RFC 7231].
 357 ///
 358 /// [RFC 7231]: https://tools.ietf.org/html/rfc7231#section-6
 359 struct HttpStatus<'a> {
 360         code: &'a str,
 361 }
 362
 363 impl<'a> HttpStatus<'a> {
 364         /// Parses an HTTP status line as defined by [RFC 7230].
 365         ///
 366         /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.1.2
 367         fn parse(line: &'a String) -> std::io::Result<HttpStatus<'a>> {
 368                 let mut tokens = line.splitn(3, ' ');
 369
 370                 let http_version = tokens.next()
 371                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no HTTP-Version"))?;
 372                 if !http_version.eq_ignore_ascii_case("HTTP/1.1") &&
 373                         !http_version.eq_ignore_ascii_case("HTTP/1.0") {
 374                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid HTTP-Version"));
 375                 }
 376
 377                 let code = tokens.next()
 378                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no Status-Code"))?;
 379                 if code.len() != 3 || !code.chars().all(|c| c.is_ascii_digit()) {
 380                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid Status-Code"));
 381                 }
 382
 383                 let _reason = tokens.next()
 384                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no Reason-Phrase"))?;
 385
 386                 Ok(Self { code })
 387         }
 388
 389         /// Returns whether the status is successful (i.e., 2xx status class).
 390         fn is_ok(&self) -> bool {
 391                 self.code.starts_with('2')
 392         }
 393 }
 394
 395 /// HTTP response header as defined by [RFC 7231].
 396 ///
 397 /// [RFC 7231]: https://tools.ietf.org/html/rfc7231#section-7
 398 struct HttpHeader<'a> {
 399         name: &'a str,
 400         value: &'a str,
 401 }
 402
 403 impl<'a> HttpHeader<'a> {
 404         /// Parses an HTTP header field as defined by [RFC 7230].
 405         ///
 406         /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.2
 407         fn parse(line: &'a String) -> std::io::Result<HttpHeader<'a>> {
 408                 let mut tokens = line.splitn(2, ':');
 409                 let name = tokens.next()
 410                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no header name"))?;
 411                 let value = tokens.next()
 412                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no header value"))?
 413                         .trim_start();
 414                 Ok(Self { name, value })
 415         }
 416
 417         /// Returns whether the header field has the given name.
 418         fn has_name(&self, name: &str) -> bool {
 419                 self.name.eq_ignore_ascii_case(name)
 420         }
 421 }
 422
 423 /// HTTP message body length as defined by [RFC 7230].
 424 ///
 425 /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.3.3
 426 enum HttpMessageLength {
 427         Empty,
 428         ContentLength(usize),
 429         TransferEncoding(String),
 430 }
 431
 432 /// An HTTP response body in binary format.
 433 pub struct BinaryResponse(pub Vec<u8>);
 434
 435 /// An HTTP response body in JSON format.
 436 pub struct JsonResponse(pub serde_json::Value);
 437
 438 /// Interprets bytes from an HTTP response body as binary data.
 439 impl TryFrom<Vec<u8>> for BinaryResponse {
 440         type Error = std::io::Error;
 441
 442         fn try_from(bytes: Vec<u8>) -> std::io::Result<Self> {
 443                 Ok(BinaryResponse(bytes))
 444         }
 445 }
 446
 447 /// Interprets bytes from an HTTP response body as a JSON value.
 448 impl TryFrom<Vec<u8>> for JsonResponse {
 449         type Error = std::io::Error;
 450
 451         fn try_from(bytes: Vec<u8>) -> std::io::Result<Self> {
 452                 Ok(JsonResponse(serde_json::from_slice(&bytes)?))
 453         }
 454 }
 455
 456 #[cfg(test)]
 457 mod endpoint_tests {
 458         use super::HttpEndpoint;
 459
 460         #[test]
 461         fn with_default_port() {
 462                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 463                 assert_eq!(endpoint.host(), "foo.com");
 464                 assert_eq!(endpoint.port(), 80);
 465         }
 466
 467         #[test]
 468         fn with_custom_port() {
 469                 let endpoint = HttpEndpoint::for_host("foo.com".into()).with_port(8080);
 470                 assert_eq!(endpoint.host(), "foo.com");
 471                 assert_eq!(endpoint.port(), 8080);
 472         }
 473
 474         #[test]
 475         fn with_uri_path() {
 476                 let endpoint = HttpEndpoint::for_host("foo.com".into()).with_path("/path".into());
 477                 assert_eq!(endpoint.host(), "foo.com");
 478                 assert_eq!(endpoint.path(), "/path");
 479         }
 480
 481         #[test]
 482         fn without_uri_path() {
 483                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 484                 assert_eq!(endpoint.host(), "foo.com");
 485                 assert_eq!(endpoint.path(), "/");
 486         }
 487
 488         #[test]
 489         fn convert_to_socket_addrs() {
 490                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 491                 let host = endpoint.host();
 492                 let port = endpoint.port();
 493
 494                 use std::net::ToSocketAddrs;
 495                 match (&endpoint).to_socket_addrs() {
 496                         Err(e) => panic!("Unexpected error: {:?}", e),
 497                         Ok(mut socket_addrs) => {
 498                                 match socket_addrs.next() {
 499                                         None => panic!("Expected socket address"),
 500                                         Some(addr) => {
 501                                                 assert_eq!(addr, (host, port).to_socket_addrs().unwrap().next().unwrap());
 502                                                 assert!(socket_addrs.next().is_none());
 503                                         }
 504                                 }
 505                         }
 506                 }
 507         }
 508 }
 509
 510 #[cfg(test)]
 511 pub(crate) mod client_tests {
 512         use super::*;
 513         use std::io::BufRead;
 514         use std::io::Write;
 515
 516         /// Server for handling HTTP client requests with a stock response.
 517         pub struct HttpServer {
 518                 address: std::net::SocketAddr,
 519                 handler: std::thread::JoinHandle<()>,
 520                 shutdown: std::sync::Arc<std::sync::atomic::AtomicBool>,
 521         }
 522
 523         /// Body of HTTP response messages.
 524         pub enum MessageBody<T: ToString> {
 525                 Empty,
 526                 Content(T),
 527                 ChunkedContent(T),
 528         }
 529
 530         impl HttpServer {
 531                 pub fn responding_with_ok<T: ToString>(body: MessageBody<T>) -> Self {
 532                         let response = match body {
 533                                 MessageBody::Empty => "HTTP/1.1 200 OK\r\n\r\n".to_string(),
 534                                 MessageBody::Content(body) => {
 535                                         let body = body.to_string();
 536                                         format!(
 537                                                 "HTTP/1.1 200 OK\r\n\
 538                                                  Content-Length: {}\r\n\
 539                                                  \r\n\
 540                                                  {}", body.len(), body)
 541                                 },
 542                                 MessageBody::ChunkedContent(body) => {
 543                                         let mut chuncked_body = Vec::new();
 544                                         {
 545                                                 use chunked_transfer::Encoder;
 546                                                 let mut encoder = Encoder::with_chunks_size(&mut chuncked_body, 8);
 547                                                 encoder.write_all(body.to_string().as_bytes()).unwrap();
 548                                         }
 549                                         format!(
 550                                                 "HTTP/1.1 200 OK\r\n\
 551                                                  Transfer-Encoding: chunked\r\n\
 552                                                  \r\n\
 553                                                  {}", String::from_utf8(chuncked_body).unwrap())
 554                                 },
 555                         };
 556                         HttpServer::responding_with(response)
 557                 }
 558
 559                 pub fn responding_with_not_found() -> Self {
 560                         let response = "HTTP/1.1 404 Not Found\r\n\r\n".to_string();
 561                         HttpServer::responding_with(response)
 562                 }
 563
 564                 fn responding_with(response: String) -> Self {
 565                         let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
 566                         let address = listener.local_addr().unwrap();
 567
 568                         let shutdown = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
 569                         let shutdown_signaled = std::sync::Arc::clone(&shutdown);
 570                         let handler = std::thread::spawn(move || {
 571                                 for stream in listener.incoming() {
 572                                         let mut stream = stream.unwrap();
 573                                         stream.set_write_timeout(Some(TCP_STREAM_TIMEOUT)).unwrap();
 574
 575                                         let lines_read = std::io::BufReader::new(&stream)
 576                                                 .lines()
 577                                                 .take_while(|line| !line.as_ref().unwrap().is_empty())
 578                                                 .count();
 579                                         if lines_read == 0 { continue; }
 580
 581                                         for chunk in response.as_bytes().chunks(16) {
 582                                                 if shutdown_signaled.load(std::sync::atomic::Ordering::SeqCst) {
 583                                                         return;
 584                                                 } else {
 585                                                         if let Err(_) = stream.write(chunk) { break; }
 586                                                         if let Err(_) = stream.flush() { break; }
 587                                                 }
 588                                         }
 589                                 }
 590                         });
 591
 592                         Self { address, handler, shutdown }
 593                 }
 594
 595                 fn shutdown(self) {
 596                         self.shutdown.store(true, std::sync::atomic::Ordering::SeqCst);
 597                         self.handler.join().unwrap();
 598                 }
 599
 600                 pub fn endpoint(&self) -> HttpEndpoint {
 601                         HttpEndpoint::for_host(self.address.ip().to_string()).with_port(self.address.port())
 602                 }
 603         }
 604
 605         #[test]
 606         fn connect_to_unresolvable_host() {
 607                 match HttpClient::connect(("example.invalid", 80)) {
 608                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::Other),
 609                         Ok(_) => panic!("Expected error"),
 610                 }
 611         }
 612
 613         #[test]
 614         fn connect_with_no_socket_address() {
 615                 match HttpClient::connect(&vec![][..]) {
 616                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::InvalidInput),
 617                         Ok(_) => panic!("Expected error"),
 618                 }
 619         }
 620
 621         #[test]
 622         fn connect_with_unknown_server() {
 623                 match HttpClient::connect(("::", 80)) {
 624                         #[cfg(target_os = "windows")]
 625                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::AddrNotAvailable),
 626                         #[cfg(not(target_os = "windows"))]
 627                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::ConnectionRefused),
 628                         Ok(_) => panic!("Expected error"),
 629                 }
 630         }
 631
 632         #[tokio::test]
 633         async fn connect_with_valid_endpoint() {
 634                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 635
 636                 match HttpClient::connect(&server.endpoint()) {
 637                         Err(e) => panic!("Unexpected error: {:?}", e),
 638                         Ok(_) => {},
 639                 }
 640         }
 641
 642         #[tokio::test]
 643         async fn read_empty_message() {
 644                 let server = HttpServer::responding_with("".to_string());
 645
 646                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 647                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 648                         Err(e) => {
 649                                 assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof);
 650                                 assert_eq!(e.get_ref().unwrap().to_string(), "no status line");
 651                         },
 652                         Ok(_) => panic!("Expected error"),
 653                 }
 654         }
 655
 656         #[tokio::test]
 657         async fn read_incomplete_message() {
 658                 let server = HttpServer::responding_with("HTTP/1.1 200 OK".to_string());
 659
 660                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 661                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 662                         Err(e) => {
 663                                 assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof);
 664                                 assert_eq!(e.get_ref().unwrap().to_string(), "no headers");
 665                         },
 666                         Ok(_) => panic!("Expected error"),
 667                 }
 668         }
 669
 670         #[tokio::test]
 671         async fn read_too_large_message_headers() {
 672                 let response = format!(
 673                         "HTTP/1.1 302 Found\r\n\
 674                          Location: {}\r\n\
 675                          \r\n", "Z".repeat(MAX_HTTP_MESSAGE_HEADER_SIZE));
 676                 let server = HttpServer::responding_with(response);
 677
 678                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 679                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 680                         Err(e) => {
 681                                 assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof);
 682                                 assert_eq!(e.get_ref().unwrap().to_string(), "no headers");
 683                         },
 684                         Ok(_) => panic!("Expected error"),
 685                 }
 686         }
 687
 688         #[tokio::test]
 689         async fn read_too_large_message_body() {
 690                 let body = "Z".repeat(MAX_HTTP_MESSAGE_BODY_SIZE + 1);
 691                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Content(body));
 692
 693                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 694                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 695                         Err(e) => {
 696                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidData);
 697                                 assert_eq!(e.get_ref().unwrap().to_string(), "out of range");
 698                         },
 699                         Ok(_) => panic!("Expected error"),
 700                 }
 701                 server.shutdown();
 702         }
 703
 704         #[tokio::test]
 705         async fn read_message_with_unsupported_transfer_coding() {
 706                 let response = String::from(
 707                         "HTTP/1.1 200 OK\r\n\
 708                          Transfer-Encoding: gzip\r\n\
 709                          \r\n\
 710                          foobar");
 711                 let server = HttpServer::responding_with(response);
 712
 713                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 714                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 715                         Err(e) => {
 716                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidInput);
 717                                 assert_eq!(e.get_ref().unwrap().to_string(), "unsupported transfer coding");
 718                         },
 719                         Ok(_) => panic!("Expected error"),
 720                 }
 721         }
 722
 723         #[tokio::test]
 724         async fn read_empty_message_body() {
 725                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 726
 727                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 728                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 729                         Err(e) => panic!("Unexpected error: {:?}", e),
 730                         Ok(bytes) => assert_eq!(bytes.0, Vec::<u8>::new()),
 731                 }
 732         }
 733
 734         #[tokio::test]
 735         async fn read_message_body_with_length() {
 736                 let body = "foo bar baz qux".repeat(32);
 737                 let content = MessageBody::Content(body.clone());
 738                 let server = HttpServer::responding_with_ok::<String>(content);
 739
 740                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 741                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 742                         Err(e) => panic!("Unexpected error: {:?}", e),
 743                         Ok(bytes) => assert_eq!(bytes.0, body.as_bytes()),
 744                 }
 745         }
 746
 747         #[tokio::test]
 748         async fn read_chunked_message_body() {
 749                 let body = "foo bar baz qux".repeat(32);
 750                 let chunked_content = MessageBody::ChunkedContent(body.clone());
 751                 let server = HttpServer::responding_with_ok::<String>(chunked_content);
 752
 753                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 754                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 755                         Err(e) => panic!("Unexpected error: {:?}", e),
 756                         Ok(bytes) => assert_eq!(bytes.0, body.as_bytes()),
 757                 }
 758         }
 759
 760         #[tokio::test]
 761         async fn reconnect_closed_connection() {
 762                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 763
 764                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 765                 assert!(client.get::<BinaryResponse>("/foo", "foo.com").await.is_ok());
 766                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 767                         Err(e) => panic!("Unexpected error: {:?}", e),
 768                         Ok(bytes) => assert_eq!(bytes.0, Vec::<u8>::new()),
 769                 }
 770         }
 771
 772         #[test]
 773         fn from_bytes_into_binary_response() {
 774                 let bytes = b"foo";
 775                 match BinaryResponse::try_from(bytes.to_vec()) {
 776                         Err(e) => panic!("Unexpected error: {:?}", e),
 777                         Ok(response) => assert_eq!(&response.0, bytes),
 778                 }
 779         }
 780
 781         #[test]
 782         fn from_invalid_bytes_into_json_response() {
 783                 let json = serde_json::json!({ "result": 42 });
 784                 match JsonResponse::try_from(json.to_string().as_bytes()[..5].to_vec()) {
 785                         Err(_) => {},
 786                         Ok(_) => panic!("Expected error"),
 787                 }
 788         }
 789
 790         #[test]
 791         fn from_valid_bytes_into_json_response() {
 792                 let json = serde_json::json!({ "result": 42 });
 793                 match JsonResponse::try_from(json.to_string().as_bytes().to_vec()) {
 794                         Err(e) => panic!("Unexpected error: {:?}", e),
 795                         Ok(response) => assert_eq!(response.0, json),
 796                 }
 797         }
 798 }