git.bitcoin.ninja 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 use std::fmt;
   9 #[cfg(not(feature = "tokio"))]
  10 use std::io::Write;
  11 use std::net::{SocketAddr, ToSocketAddrs};
  12 use std::time::Duration;
  13
  14 #[cfg(feature = "tokio")]
  15 use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt};
  16 #[cfg(feature = "tokio")]
  17 use tokio::net::TcpStream;
  18
  19 #[cfg(not(feature = "tokio"))]
  20 use std::io::BufRead;
  21 use std::io::Read;
  22 #[cfg(not(feature = "tokio"))]
  23 use std::net::TcpStream;
  24
  25 /// Timeout for operations on TCP streams.
  26 const TCP_STREAM_TIMEOUT: Duration = Duration::from_secs(5);
  27
  28 /// Timeout for reading the first byte of a response. This is separate from the general read
  29 /// timeout as it is not uncommon for Bitcoin Core to be blocked waiting on UTXO cache flushes for
  30 /// upwards of 10 minutes on slow devices (e.g. RPis with SSDs over USB). Note that we always retry
  31 /// once when we time out, so the maximum time we allow Bitcoin Core to block for is twice this
  32 /// value.
  33 const TCP_STREAM_RESPONSE_TIMEOUT: Duration = Duration::from_secs(300);
  34
  35 /// Maximum HTTP message header size in bytes.
  36 const MAX_HTTP_MESSAGE_HEADER_SIZE: usize = 8192;
  37
  38 /// Maximum HTTP message body size in bytes. Enough for a hex-encoded block in JSON format and any
  39 /// overhead for HTTP chunked transfer encoding.
  40 const MAX_HTTP_MESSAGE_BODY_SIZE: usize = 2 * 4_000_000 + 32_000;
  41
  42 /// Endpoint for interacting with an HTTP-based API.
  43 #[derive(Debug)]
  44 pub struct HttpEndpoint {
  45         host: String,
  46         port: Option<u16>,
  47         path: String,
  48 }
  49
  50 impl HttpEndpoint {
  51         /// Creates an endpoint for the given host and default HTTP port.
  52         pub fn for_host(host: String) -> Self {
  53                 Self {
  54                         host,
  55                         port: None,
  56                         path: String::from("/"),
  57                 }
  58         }
  59
  60         /// Specifies a port to use with the endpoint.
  61         pub fn with_port(mut self, port: u16) -> Self {
  62                 self.port = Some(port);
  63                 self
  64         }
  65
  66         /// Specifies a path to use with the endpoint.
  67         pub fn with_path(mut self, path: String) -> Self {
  68                 self.path = path;
  69                 self
  70         }
  71
  72         /// Returns the endpoint host.
  73         pub fn host(&self) -> &str {
  74                 &self.host
  75         }
  76
  77         /// Returns the endpoint port.
  78         pub fn port(&self) -> u16 {
  79                 match self.port {
  80                         None => 80,
  81                         Some(port) => port,
  82                 }
  83         }
  84
  85         /// Returns the endpoint path.
  86         pub fn path(&self) -> &str {
  87                 &self.path
  88         }
  89 }
  90
  91 impl<'a> std::net::ToSocketAddrs for &'a HttpEndpoint {
  92         type Iter = <(&'a str, u16) as std::net::ToSocketAddrs>::Iter;
  93
  94         fn to_socket_addrs(&self) -> std::io::Result<Self::Iter> {
  95                 (self.host(), self.port()).to_socket_addrs()
  96         }
  97 }
  98
  99 /// Client for making HTTP requests.
 100 pub(crate) struct HttpClient {
 101         address: SocketAddr,
 102         stream: TcpStream,
 103 }
 104
 105 impl HttpClient {
 106         /// Opens a connection to an HTTP endpoint.
 107         pub fn connect<E: ToSocketAddrs>(endpoint: E) -> std::io::Result<Self> {
 108                 let address = match endpoint.to_socket_addrs()?.next() {
 109                         None => {
 110                                 return Err(std::io::Error::new(std::io::ErrorKind::InvalidInput, "could not resolve to any addresses"));
 111                         },
 112                         Some(address) => address,
 113                 };
 114                 let stream = std::net::TcpStream::connect_timeout(&address, TCP_STREAM_TIMEOUT)?;
 115                 stream.set_read_timeout(Some(TCP_STREAM_TIMEOUT))?;
 116                 stream.set_write_timeout(Some(TCP_STREAM_TIMEOUT))?;
 117
 118                 #[cfg(feature = "tokio")]
 119                 let stream = {
 120                         stream.set_nonblocking(true)?;
 121                         TcpStream::from_std(stream)?
 122                 };
 123
 124                 Ok(Self { address, stream })
 125         }
 126
 127         /// Sends a `GET` request for a resource identified by `uri` at the `host`.
 128         ///
 129         /// Returns the response body in `F` format.
 130         #[allow(dead_code)]
 131         pub async fn get<F>(&mut self, uri: &str, host: &str) -> std::io::Result<F>
 132         where F: TryFrom<Vec<u8>, Error = std::io::Error> {
 133                 let request = format!(
 134                         "GET {} HTTP/1.1\r\n\
 135                          Host: {}\r\n\
 136                          Connection: keep-alive\r\n\
 137                          \r\n", uri, host);
 138                 let response_body = self.send_request_with_retry(&request).await?;
 139                 F::try_from(response_body)
 140         }
 141
 142         /// Sends a `POST` request for a resource identified by `uri` at the `host` using the given HTTP
 143         /// authentication credentials.
 144         ///
 145         /// The request body consists of the provided JSON `content`. Returns the response body in `F`
 146         /// format.
 147         #[allow(dead_code)]
 148         pub async fn post<F>(&mut self, uri: &str, host: &str, auth: &str, content: serde_json::Value) -> std::io::Result<F>
 149         where F: TryFrom<Vec<u8>, Error = std::io::Error> {
 150                 let content = content.to_string();
 151                 let request = format!(
 152                         "POST {} HTTP/1.1\r\n\
 153                          Host: {}\r\n\
 154                          Authorization: {}\r\n\
 155                          Connection: keep-alive\r\n\
 156                          Content-Type: application/json\r\n\
 157                          Content-Length: {}\r\n\
 158                          \r\n\
 159                          {}", uri, host, auth, content.len(), content);
 160                 let response_body = self.send_request_with_retry(&request).await?;
 161                 F::try_from(response_body)
 162         }
 163
 164         /// Sends an HTTP request message and reads the response, returning its body. Attempts to
 165         /// reconnect and retry if the connection has been closed.
 166         async fn send_request_with_retry(&mut self, request: &str) -> std::io::Result<Vec<u8>> {
 167                 match self.send_request(request).await {
 168                         Ok(bytes) => Ok(bytes),
 169                         Err(_) => {
 170                                 // Reconnect and retry on fail. This can happen if the connection was closed after
 171                                 // the keep-alive limits are reached, or generally if the request timed out due to
 172                                 // Bitcoin Core being stuck on a long-running operation or its RPC queue being
 173                                 // full.
 174                                 // Block 100ms before retrying the request as in many cases the source of the error
 175                                 // may be persistent for some time.
 176                                 #[cfg(feature = "tokio")]
 177                                 tokio::time::sleep(Duration::from_millis(100)).await;
 178                                 #[cfg(not(feature = "tokio"))]
 179                                 std::thread::sleep(Duration::from_millis(100));
 180                                 *self = Self::connect(self.address)?;
 181                                 self.send_request(request).await
 182                         },
 183                 }
 184         }
 185
 186         /// Sends an HTTP request message and reads the response, returning its body.
 187         async fn send_request(&mut self, request: &str) -> std::io::Result<Vec<u8>> {
 188                 self.write_request(request).await?;
 189                 self.read_response().await
 190         }
 191
 192         /// Writes an HTTP request message.
 193         async fn write_request(&mut self, request: &str) -> std::io::Result<()> {
 194                 #[cfg(feature = "tokio")]
 195                 {
 196                         self.stream.write_all(request.as_bytes()).await?;
 197                         self.stream.flush().await
 198                 }
 199                 #[cfg(not(feature = "tokio"))]
 200                 {
 201                         self.stream.write_all(request.as_bytes())?;
 202                         self.stream.flush()
 203                 }
 204         }
 205
 206         /// Reads an HTTP response message.
 207         async fn read_response(&mut self) -> std::io::Result<Vec<u8>> {
 208                 #[cfg(feature = "tokio")]
 209                 let stream = self.stream.split().0;
 210                 #[cfg(not(feature = "tokio"))]
 211                 let stream = std::io::Read::by_ref(&mut self.stream);
 212
 213                 let limited_stream = stream.take(MAX_HTTP_MESSAGE_HEADER_SIZE as u64);
 214
 215                 #[cfg(feature = "tokio")]
 216                 let mut reader = tokio::io::BufReader::new(limited_stream);
 217                 #[cfg(not(feature = "tokio"))]
 218                 let mut reader = std::io::BufReader::new(limited_stream);
 219
 220                 macro_rules! read_line {
 221                         () => { read_line!(0) };
 222                         ($retry_count: expr) => { {
 223                                 let mut line = String::new();
 224                                 let mut timeout_count: u64 = 0;
 225                                 let bytes_read = loop {
 226                                         #[cfg(feature = "tokio")]
 227                                         let read_res = reader.read_line(&mut line).await;
 228                                         #[cfg(not(feature = "tokio"))]
 229                                         let read_res = reader.read_line(&mut line);
 230                                         match read_res {
 231                                                 Ok(bytes_read) => break bytes_read,
 232                                                 Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
 233                                                         timeout_count += 1;
 234                                                         if timeout_count > $retry_count {
 235                                                                 return Err(e);
 236                                                         } else {
 237                                                                 continue;
 238                                                         }
 239                                                 }
 240                                                 Err(e) => return Err(e),
 241                                         }
 242                                 };
 243
 244                                 match bytes_read {
 245                                         0 => None,
 246                                         _ => {
 247                                                 // Remove trailing CRLF
 248                                                 if line.ends_with('\n') { line.pop(); if line.ends_with('\r') { line.pop(); } }
 249                                                 Some(line)
 250                                         },
 251                                 }
 252                         } }
 253                 }
 254
 255                 // Read and parse status line
 256                 // Note that we allow retrying a few times to reach TCP_STREAM_RESPONSE_TIMEOUT.
 257                 let status_line = read_line!(TCP_STREAM_RESPONSE_TIMEOUT.as_secs() / TCP_STREAM_TIMEOUT.as_secs())
 258                         .ok_or(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "no status line"))?;
 259                 let status = HttpStatus::parse(&status_line)?;
 260
 261                 // Read and parse relevant headers
 262                 let mut message_length = HttpMessageLength::Empty;
 263                 loop {
 264                         let line = read_line!()
 265                                 .ok_or(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "no headers"))?;
 266                         if line.is_empty() { break; }
 267
 268                         let header = HttpHeader::parse(&line)?;
 269                         if header.has_name("Content-Length") {
 270                                 let length = header.value.parse()
 271                                         .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
 272                                 if let HttpMessageLength::Empty = message_length {
 273                                         message_length = HttpMessageLength::ContentLength(length);
 274                                 }
 275                                 continue;
 276                         }
 277
 278                         if header.has_name("Transfer-Encoding") {
 279                                 message_length = HttpMessageLength::TransferEncoding(header.value.into());
 280                                 continue;
 281                         }
 282                 }
 283
 284                 // Read message body
 285                 let read_limit = MAX_HTTP_MESSAGE_BODY_SIZE - reader.buffer().len();
 286                 reader.get_mut().set_limit(read_limit as u64);
 287                 let contents = match message_length {
 288                         HttpMessageLength::Empty => { Vec::new() },
 289                         HttpMessageLength::ContentLength(length) => {
 290                                 if length == 0 || length > MAX_HTTP_MESSAGE_BODY_SIZE {
 291                                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "out of range"))
 292                                 } else {
 293                                         let mut content = vec![0; length];
 294                                         #[cfg(feature = "tokio")]
 295                                         reader.read_exact(&mut content[..]).await?;
 296                                         #[cfg(not(feature = "tokio"))]
 297                                         reader.read_exact(&mut content[..])?;
 298                                         content
 299                                 }
 300                         },
 301                         HttpMessageLength::TransferEncoding(coding) => {
 302                                 if !coding.eq_ignore_ascii_case("chunked") {
 303                                         return Err(std::io::Error::new(
 304                                                 std::io::ErrorKind::InvalidInput, "unsupported transfer coding"))
 305                                 } else {
 306                                         let mut content = Vec::new();
 307                                         #[cfg(feature = "tokio")]
 308                                         {
 309                                                 // Since chunked_transfer doesn't have an async interface, only use it to
 310                                                 // determine the size of each chunk to read.
 311                                                 //
 312                                                 // TODO: Replace with an async interface when available.
 313                                                 // https://github.com/frewsxcv/rust-chunked-transfer/issues/7
 314                                                 loop {
 315                                                         // Read the chunk header which contains the chunk size.
 316                                                         let mut chunk_header = String::new();
 317                                                         reader.read_line(&mut chunk_header).await?;
 318                                                         if chunk_header == "0\r\n" {
 319                                                                 // Read the terminator chunk since the decoder consumes the CRLF
 320                                                                 // immediately when this chunk is encountered.
 321                                                                 reader.read_line(&mut chunk_header).await?;
 322                                                         }
 323
 324                                                         // Decode the chunk header to obtain the chunk size.
 325                                                         let mut buffer = Vec::new();
 326                                                         let mut decoder = chunked_transfer::Decoder::new(chunk_header.as_bytes());
 327                                                         decoder.read_to_end(&mut buffer)?;
 328
 329                                                         // Read the chunk body.
 330                                                         let chunk_size = match decoder.remaining_chunks_size() {
 331                                                                 None => break,
 332                                                                 Some(chunk_size) => chunk_size,
 333                                                         };
 334                                                         let chunk_offset = content.len();
 335                                                         content.resize(chunk_offset + chunk_size + "\r\n".len(), 0);
 336                                                         reader.read_exact(&mut content[chunk_offset..]).await?;
 337                                                         content.resize(chunk_offset + chunk_size, 0);
 338                                                 }
 339                                                 content
 340                                         }
 341                                         #[cfg(not(feature = "tokio"))]
 342                                         {
 343                                                 let mut decoder = chunked_transfer::Decoder::new(reader);
 344                                                 decoder.read_to_end(&mut content)?;
 345                                                 content
 346                                         }
 347                                 }
 348                         },
 349                 };
 350
 351                 if !status.is_ok() {
 352                         // TODO: Handle 3xx redirection responses.
 353                         let error = HttpError {
 354                                 status_code: status.code.to_string(),
 355                                 contents,
 356                         };
 357                         return Err(std::io::Error::new(std::io::ErrorKind::Other, error));
 358                 }
 359
 360                 Ok(contents)
 361         }
 362 }
 363
 364 /// HTTP error consisting of a status code and body contents.
 365 #[derive(Debug)]
 366 pub(crate) struct HttpError {
 367         pub(crate) status_code: String,
 368         pub(crate) contents: Vec<u8>,
 369 }
 370
 371 impl std::error::Error for HttpError {}
 372
 373 impl fmt::Display for HttpError {
 374         fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 375                 let contents = String::from_utf8_lossy(&self.contents);
 376                 write!(f, "status_code: {}, contents: {}", self.status_code, contents)
 377         }
 378 }
 379
 380 /// HTTP response status code as defined by [RFC 7231].
 381 ///
 382 /// [RFC 7231]: https://tools.ietf.org/html/rfc7231#section-6
 383 struct HttpStatus<'a> {
 384         code: &'a str,
 385 }
 386
 387 impl<'a> HttpStatus<'a> {
 388         /// Parses an HTTP status line as defined by [RFC 7230].
 389         ///
 390         /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.1.2
 391         fn parse(line: &'a String) -> std::io::Result<HttpStatus<'a>> {
 392                 let mut tokens = line.splitn(3, ' ');
 393
 394                 let http_version = tokens.next()
 395                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no HTTP-Version"))?;
 396                 if !http_version.eq_ignore_ascii_case("HTTP/1.1") &&
 397                         !http_version.eq_ignore_ascii_case("HTTP/1.0") {
 398                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid HTTP-Version"));
 399                 }
 400
 401                 let code = tokens.next()
 402                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no Status-Code"))?;
 403                 if code.len() != 3 || !code.chars().all(|c| c.is_ascii_digit()) {
 404                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "invalid Status-Code"));
 405                 }
 406
 407                 let _reason = tokens.next()
 408                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no Reason-Phrase"))?;
 409
 410                 Ok(Self { code })
 411         }
 412
 413         /// Returns whether the status is successful (i.e., 2xx status class).
 414         fn is_ok(&self) -> bool {
 415                 self.code.starts_with('2')
 416         }
 417 }
 418
 419 /// HTTP response header as defined by [RFC 7231].
 420 ///
 421 /// [RFC 7231]: https://tools.ietf.org/html/rfc7231#section-7
 422 struct HttpHeader<'a> {
 423         name: &'a str,
 424         value: &'a str,
 425 }
 426
 427 impl<'a> HttpHeader<'a> {
 428         /// Parses an HTTP header field as defined by [RFC 7230].
 429         ///
 430         /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.2
 431         fn parse(line: &'a String) -> std::io::Result<HttpHeader<'a>> {
 432                 let mut tokens = line.splitn(2, ':');
 433                 let name = tokens.next()
 434                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no header name"))?;
 435                 let value = tokens.next()
 436                         .ok_or(std::io::Error::new(std::io::ErrorKind::InvalidData, "no header value"))?
 437                         .trim_start();
 438                 Ok(Self { name, value })
 439         }
 440
 441         /// Returns whether the header field has the given name.
 442         fn has_name(&self, name: &str) -> bool {
 443                 self.name.eq_ignore_ascii_case(name)
 444         }
 445 }
 446
 447 /// HTTP message body length as defined by [RFC 7230].
 448 ///
 449 /// [RFC 7230]: https://tools.ietf.org/html/rfc7230#section-3.3.3
 450 enum HttpMessageLength {
 451         Empty,
 452         ContentLength(usize),
 453         TransferEncoding(String),
 454 }
 455
 456 /// An HTTP response body in binary format.
 457 pub struct BinaryResponse(pub Vec<u8>);
 458
 459 /// An HTTP response body in JSON format.
 460 pub struct JsonResponse(pub serde_json::Value);
 461
 462 /// Interprets bytes from an HTTP response body as binary data.
 463 impl TryFrom<Vec<u8>> for BinaryResponse {
 464         type Error = std::io::Error;
 465
 466         fn try_from(bytes: Vec<u8>) -> std::io::Result<Self> {
 467                 Ok(BinaryResponse(bytes))
 468         }
 469 }
 470
 471 /// Interprets bytes from an HTTP response body as a JSON value.
 472 impl TryFrom<Vec<u8>> for JsonResponse {
 473         type Error = std::io::Error;
 474
 475         fn try_from(bytes: Vec<u8>) -> std::io::Result<Self> {
 476                 Ok(JsonResponse(serde_json::from_slice(&bytes)?))
 477         }
 478 }
 479
 480 #[cfg(test)]
 481 mod endpoint_tests {
 482         use super::HttpEndpoint;
 483
 484         #[test]
 485         fn with_default_port() {
 486                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 487                 assert_eq!(endpoint.host(), "foo.com");
 488                 assert_eq!(endpoint.port(), 80);
 489         }
 490
 491         #[test]
 492         fn with_custom_port() {
 493                 let endpoint = HttpEndpoint::for_host("foo.com".into()).with_port(8080);
 494                 assert_eq!(endpoint.host(), "foo.com");
 495                 assert_eq!(endpoint.port(), 8080);
 496         }
 497
 498         #[test]
 499         fn with_uri_path() {
 500                 let endpoint = HttpEndpoint::for_host("foo.com".into()).with_path("/path".into());
 501                 assert_eq!(endpoint.host(), "foo.com");
 502                 assert_eq!(endpoint.path(), "/path");
 503         }
 504
 505         #[test]
 506         fn without_uri_path() {
 507                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 508                 assert_eq!(endpoint.host(), "foo.com");
 509                 assert_eq!(endpoint.path(), "/");
 510         }
 511
 512         #[test]
 513         fn convert_to_socket_addrs() {
 514                 let endpoint = HttpEndpoint::for_host("foo.com".into());
 515                 let host = endpoint.host();
 516                 let port = endpoint.port();
 517
 518                 use std::net::ToSocketAddrs;
 519                 match (&endpoint).to_socket_addrs() {
 520                         Err(e) => panic!("Unexpected error: {:?}", e),
 521                         Ok(mut socket_addrs) => {
 522                                 match socket_addrs.next() {
 523                                         None => panic!("Expected socket address"),
 524                                         Some(addr) => {
 525                                                 assert_eq!(addr, (host, port).to_socket_addrs().unwrap().next().unwrap());
 526                                                 assert!(socket_addrs.next().is_none());
 527                                         }
 528                                 }
 529                         }
 530                 }
 531         }
 532 }
 533
 534 #[cfg(test)]
 535 pub(crate) mod client_tests {
 536         use super::*;
 537         use std::io::BufRead;
 538         use std::io::Write;
 539
 540         /// Server for handling HTTP client requests with a stock response.
 541         pub struct HttpServer {
 542                 address: std::net::SocketAddr,
 543                 handler: std::thread::JoinHandle<()>,
 544                 shutdown: std::sync::Arc<std::sync::atomic::AtomicBool>,
 545         }
 546
 547         /// Body of HTTP response messages.
 548         pub enum MessageBody<T: ToString> {
 549                 Empty,
 550                 Content(T),
 551                 ChunkedContent(T),
 552         }
 553
 554         impl HttpServer {
 555                 fn responding_with_body<T: ToString>(status: &str, body: MessageBody<T>) -> Self {
 556                         let response = match body {
 557                                 MessageBody::Empty => format!("{}\r\n\r\n", status),
 558                                 MessageBody::Content(body) => {
 559                                         let body = body.to_string();
 560                                         format!(
 561                                                 "{}\r\n\
 562                                                  Content-Length: {}\r\n\
 563                                                  \r\n\
 564                                                  {}", status, body.len(), body)
 565                                 },
 566                                 MessageBody::ChunkedContent(body) => {
 567                                         let mut chuncked_body = Vec::new();
 568                                         {
 569                                                 use chunked_transfer::Encoder;
 570                                                 let mut encoder = Encoder::with_chunks_size(&mut chuncked_body, 8);
 571                                                 encoder.write_all(body.to_string().as_bytes()).unwrap();
 572                                         }
 573                                         format!(
 574                                                 "{}\r\n\
 575                                                  Transfer-Encoding: chunked\r\n\
 576                                                  \r\n\
 577                                                  {}", status, String::from_utf8(chuncked_body).unwrap())
 578                                 },
 579                         };
 580                         HttpServer::responding_with(response)
 581                 }
 582
 583                 pub fn responding_with_ok<T: ToString>(body: MessageBody<T>) -> Self {
 584                         HttpServer::responding_with_body("HTTP/1.1 200 OK", body)
 585                 }
 586
 587                 pub fn responding_with_not_found() -> Self {
 588                         HttpServer::responding_with_body::<String>("HTTP/1.1 404 Not Found", MessageBody::Empty)
 589                 }
 590
 591                 pub fn responding_with_server_error<T: ToString>(content: T) -> Self {
 592                         let body = MessageBody::Content(content);
 593                         HttpServer::responding_with_body("HTTP/1.1 500 Internal Server Error", body)
 594                 }
 595
 596                 fn responding_with(response: String) -> Self {
 597                         let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
 598                         let address = listener.local_addr().unwrap();
 599
 600                         let shutdown = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
 601                         let shutdown_signaled = std::sync::Arc::clone(&shutdown);
 602                         let handler = std::thread::spawn(move || {
 603                                 for stream in listener.incoming() {
 604                                         let mut stream = stream.unwrap();
 605                                         stream.set_write_timeout(Some(TCP_STREAM_TIMEOUT)).unwrap();
 606
 607                                         let lines_read = std::io::BufReader::new(&stream)
 608                                                 .lines()
 609                                                 .take_while(|line| !line.as_ref().unwrap().is_empty())
 610                                                 .count();
 611                                         if lines_read == 0 { continue; }
 612
 613                                         for chunk in response.as_bytes().chunks(16) {
 614                                                 if shutdown_signaled.load(std::sync::atomic::Ordering::SeqCst) {
 615                                                         return;
 616                                                 } else {
 617                                                         if let Err(_) = stream.write(chunk) { break; }
 618                                                         if let Err(_) = stream.flush() { break; }
 619                                                 }
 620                                         }
 621                                 }
 622                         });
 623
 624                         Self { address, handler, shutdown }
 625                 }
 626
 627                 fn shutdown(self) {
 628                         self.shutdown.store(true, std::sync::atomic::Ordering::SeqCst);
 629                         self.handler.join().unwrap();
 630                 }
 631
 632                 pub fn endpoint(&self) -> HttpEndpoint {
 633                         HttpEndpoint::for_host(self.address.ip().to_string()).with_port(self.address.port())
 634                 }
 635         }
 636
 637         #[test]
 638         fn connect_to_unresolvable_host() {
 639                 match HttpClient::connect(("example.invalid", 80)) {
 640                         Err(e) => {
 641                                 assert!(e.to_string().contains("failed to lookup address information") ||
 642                                         e.to_string().contains("No such host"), "{:?}", e);
 643                         },
 644                         Ok(_) => panic!("Expected error"),
 645                 }
 646         }
 647
 648         #[test]
 649         fn connect_with_no_socket_address() {
 650                 match HttpClient::connect(&vec![][..]) {
 651                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::InvalidInput),
 652                         Ok(_) => panic!("Expected error"),
 653                 }
 654         }
 655
 656         #[test]
 657         fn connect_with_unknown_server() {
 658                 match HttpClient::connect(("::", 80)) {
 659                         #[cfg(target_os = "windows")]
 660                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::AddrNotAvailable),
 661                         #[cfg(not(target_os = "windows"))]
 662                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::ConnectionRefused),
 663                         Ok(_) => panic!("Expected error"),
 664                 }
 665         }
 666
 667         #[tokio::test]
 668         async fn connect_with_valid_endpoint() {
 669                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 670
 671                 match HttpClient::connect(&server.endpoint()) {
 672                         Err(e) => panic!("Unexpected error: {:?}", e),
 673                         Ok(_) => {},
 674                 }
 675         }
 676
 677         #[tokio::test]
 678         async fn read_empty_message() {
 679                 let server = HttpServer::responding_with("".to_string());
 680
 681                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 682                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 683                         Err(e) => {
 684                                 assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof);
 685                                 assert_eq!(e.get_ref().unwrap().to_string(), "no status line");
 686                         },
 687                         Ok(_) => panic!("Expected error"),
 688                 }
 689         }
 690
 691         #[tokio::test]
 692         async fn read_incomplete_message() {
 693                 let server = HttpServer::responding_with("HTTP/1.1 200 OK".to_string());
 694
 695                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 696                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 697                         Err(e) => {
 698                                 assert_eq!(e.kind(), std::io::ErrorKind::UnexpectedEof);
 699                                 assert_eq!(e.get_ref().unwrap().to_string(), "no headers");
 700                         },
 701                         Ok(_) => panic!("Expected error"),
 702                 }
 703         }
 704
 705         #[tokio::test]
 706         async fn read_too_large_message_headers() {
 707                 let response = format!(
 708                         "HTTP/1.1 302 Found\r\n\
 709                          Location: {}\r\n\
 710                          \r\n", "Z".repeat(MAX_HTTP_MESSAGE_HEADER_SIZE));
 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::UnexpectedEof);
 717                                 assert_eq!(e.get_ref().unwrap().to_string(), "no headers");
 718                         },
 719                         Ok(_) => panic!("Expected error"),
 720                 }
 721         }
 722
 723         #[tokio::test]
 724         async fn read_too_large_message_body() {
 725                 let body = "Z".repeat(MAX_HTTP_MESSAGE_BODY_SIZE + 1);
 726                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Content(body));
 727
 728                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 729                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 730                         Err(e) => {
 731                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidData);
 732                                 assert_eq!(e.get_ref().unwrap().to_string(), "out of range");
 733                         },
 734                         Ok(_) => panic!("Expected error"),
 735                 }
 736                 server.shutdown();
 737         }
 738
 739         #[tokio::test]
 740         async fn read_message_with_unsupported_transfer_coding() {
 741                 let response = String::from(
 742                         "HTTP/1.1 200 OK\r\n\
 743                          Transfer-Encoding: gzip\r\n\
 744                          \r\n\
 745                          foobar");
 746                 let server = HttpServer::responding_with(response);
 747
 748                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 749                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 750                         Err(e) => {
 751                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidInput);
 752                                 assert_eq!(e.get_ref().unwrap().to_string(), "unsupported transfer coding");
 753                         },
 754                         Ok(_) => panic!("Expected error"),
 755                 }
 756         }
 757
 758         #[tokio::test]
 759         async fn read_error() {
 760                 let server = HttpServer::responding_with_server_error("foo");
 761
 762                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 763                 match client.get::<JsonResponse>("/foo", "foo.com").await {
 764                         Err(e) => {
 765                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
 766                                 let http_error = e.into_inner().unwrap().downcast::<HttpError>().unwrap();
 767                                 assert_eq!(http_error.status_code, "500");
 768                                 assert_eq!(http_error.contents, "foo".as_bytes());
 769                         },
 770                         Ok(_) => panic!("Expected error"),
 771                 }
 772         }
 773
 774         #[tokio::test]
 775         async fn read_empty_message_body() {
 776                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 777
 778                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 779                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 780                         Err(e) => panic!("Unexpected error: {:?}", e),
 781                         Ok(bytes) => assert_eq!(bytes.0, Vec::<u8>::new()),
 782                 }
 783         }
 784
 785         #[tokio::test]
 786         async fn read_message_body_with_length() {
 787                 let body = "foo bar baz qux".repeat(32);
 788                 let content = MessageBody::Content(body.clone());
 789                 let server = HttpServer::responding_with_ok::<String>(content);
 790
 791                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 792                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 793                         Err(e) => panic!("Unexpected error: {:?}", e),
 794                         Ok(bytes) => assert_eq!(bytes.0, body.as_bytes()),
 795                 }
 796         }
 797
 798         #[tokio::test]
 799         async fn read_chunked_message_body() {
 800                 let body = "foo bar baz qux".repeat(32);
 801                 let chunked_content = MessageBody::ChunkedContent(body.clone());
 802                 let server = HttpServer::responding_with_ok::<String>(chunked_content);
 803
 804                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 805                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 806                         Err(e) => panic!("Unexpected error: {:?}", e),
 807                         Ok(bytes) => assert_eq!(bytes.0, body.as_bytes()),
 808                 }
 809         }
 810
 811         #[tokio::test]
 812         async fn reconnect_closed_connection() {
 813                 let server = HttpServer::responding_with_ok::<String>(MessageBody::Empty);
 814
 815                 let mut client = HttpClient::connect(&server.endpoint()).unwrap();
 816                 assert!(client.get::<BinaryResponse>("/foo", "foo.com").await.is_ok());
 817                 match client.get::<BinaryResponse>("/foo", "foo.com").await {
 818                         Err(e) => panic!("Unexpected error: {:?}", e),
 819                         Ok(bytes) => assert_eq!(bytes.0, Vec::<u8>::new()),
 820                 }
 821         }
 822
 823         #[test]
 824         fn from_bytes_into_binary_response() {
 825                 let bytes = b"foo";
 826                 match BinaryResponse::try_from(bytes.to_vec()) {
 827                         Err(e) => panic!("Unexpected error: {:?}", e),
 828                         Ok(response) => assert_eq!(&response.0, bytes),
 829                 }
 830         }
 831
 832         #[test]
 833         fn from_invalid_bytes_into_json_response() {
 834                 let json = serde_json::json!({ "result": 42 });
 835                 match JsonResponse::try_from(json.to_string().as_bytes()[..5].to_vec()) {
 836                         Err(_) => {},
 837                         Ok(_) => panic!("Expected error"),
 838                 }
 839         }
 840
 841         #[test]
 842         fn from_valid_bytes_into_json_response() {
 843                 let json = serde_json::json!({ "result": 42 });
 844                 match JsonResponse::try_from(json.to_string().as_bytes().to_vec()) {
 845                         Err(e) => panic!("Unexpected error: {:?}", e),
 846                         Ok(response) => assert_eq!(response.0, json),
 847                 }
 848         }
 849 }