ferron/optional_modules/
rproxy.rs

1use std::collections::HashMap;
2use std::error::Error;
3use std::str::FromStr;
4use std::sync::Arc;
5use std::time::Duration;
6
7use crate::ferron_common::{
8  ErrorLogger, HyperUpgraded, RequestData, ResponseData, ServerConfig, ServerModule,
9  ServerModuleHandlers, SocketData,
10};
11use crate::ferron_common::{HyperResponse, WithRuntime};
12use async_trait::async_trait;
13use futures_util::{SinkExt, StreamExt};
14use http::header::SEC_WEBSOCKET_PROTOCOL;
15use http::uri::{PathAndQuery, Scheme};
16use http_body_util::combinators::BoxBody;
17use http_body_util::BodyExt;
18use hyper::body::Bytes;
19use hyper::client::conn::http1::SendRequest;
20use hyper::{header, Request, StatusCode, Uri};
21use hyper_tungstenite::HyperWebsocket;
22use hyper_util::rt::TokioIo;
23use rustls::pki_types::ServerName;
24use rustls::RootCertStore;
25use rustls_native_certs::load_native_certs;
26use tokio::io::{AsyncRead, AsyncWrite};
27use tokio::net::TcpStream;
28use tokio::runtime::Handle;
29use tokio::sync::RwLock;
30use tokio_rustls::TlsConnector;
31use tokio_tungstenite::tungstenite::client::IntoClientRequest;
32use tokio_tungstenite::tungstenite::ClientRequestBuilder;
33use tokio_tungstenite::Connector;
34
35use crate::ferron_util::no_server_verifier::NoServerVerifier;
36use crate::ferron_util::ttl_cache::TtlCache;
37
38const DEFAULT_CONCURRENT_CONNECTIONS_PER_HOST: u32 = 32;
39
40pub fn server_module_init(
41  config: &ServerConfig,
42) -> Result<Box<dyn ServerModule + Send + Sync>, Box<dyn Error + Send + Sync>> {
43  let mut roots: RootCertStore = RootCertStore::empty();
44  let certs_result = load_native_certs();
45  if !certs_result.errors.is_empty() {
46    Err(anyhow::anyhow!(format!(
47      "Couldn't load the native certificate store: {}",
48      certs_result.errors[0]
49    )))?
50  }
51  let certs = certs_result.certs;
52
53  for cert in certs {
54    match roots.add(cert) {
55      Ok(_) => (),
56      Err(err) => Err(anyhow::anyhow!(format!(
57        "Couldn't add a certificate to the certificate store: {}",
58        err
59      )))?,
60    }
61  }
62
63  let mut connections_vec = Vec::new();
64  for _ in 0..DEFAULT_CONCURRENT_CONNECTIONS_PER_HOST {
65    connections_vec.push(RwLock::new(HashMap::new()));
66  }
67  Ok(Box::new(ReverseProxyModule::new(
68    Arc::new(roots),
69    Arc::new(connections_vec),
70    Arc::new(RwLock::new(TtlCache::new(Duration::from_millis(
71      config["global"]["loadBalancerHealthCheckWindow"]
72        .as_i64()
73        .unwrap_or(5000) as u64,
74    )))),
75  )))
76}
77
78#[allow(clippy::type_complexity)]
79struct ReverseProxyModule {
80  roots: Arc<RootCertStore>,
81  connections: Arc<Vec<RwLock<HashMap<String, SendRequest<BoxBody<Bytes, std::io::Error>>>>>>,
82  failed_backends: Arc<RwLock<TtlCache<String, u64>>>,
83}
84
85impl ReverseProxyModule {
86  #[allow(clippy::type_complexity)]
87  fn new(
88    roots: Arc<RootCertStore>,
89    connections: Arc<Vec<RwLock<HashMap<String, SendRequest<BoxBody<Bytes, std::io::Error>>>>>>,
90    failed_backends: Arc<RwLock<TtlCache<String, u64>>>,
91  ) -> Self {
92    Self {
93      roots,
94      connections,
95      failed_backends,
96    }
97  }
98}
99
100impl ServerModule for ReverseProxyModule {
101  fn get_handlers(&self, handle: Handle) -> Box<dyn ServerModuleHandlers + Send> {
102    Box::new(ReverseProxyModuleHandlers {
103      roots: self.roots.clone(),
104      connections: self.connections.clone(),
105      failed_backends: self.failed_backends.clone(),
106      handle,
107    })
108  }
109}
110
111#[allow(clippy::type_complexity)]
112struct ReverseProxyModuleHandlers {
113  handle: Handle,
114  roots: Arc<RootCertStore>,
115  connections: Arc<Vec<RwLock<HashMap<String, SendRequest<BoxBody<Bytes, std::io::Error>>>>>>,
116  failed_backends: Arc<RwLock<TtlCache<String, u64>>>,
117}
118
119#[async_trait]
120impl ServerModuleHandlers for ReverseProxyModuleHandlers {
121  async fn request_handler(
122    &mut self,
123    request: RequestData,
124    config: &ServerConfig,
125    socket_data: &SocketData,
126    error_logger: &ErrorLogger,
127  ) -> Result<ResponseData, Box<dyn Error + Send + Sync>> {
128    WithRuntime::new(self.handle.clone(), async move {
129      let enable_health_check = config["enableLoadBalancerHealthCheck"]
130        .as_bool()
131        .unwrap_or(false);
132      let health_check_max_fails = config["loadBalancerHealthCheckMaximumFails"]
133        .as_i64()
134        .unwrap_or(3) as u64;
135      let disable_certificate_verification = config["disableProxyCertificateVerification"]
136        .as_bool()
137        .unwrap_or(false);
138      let proxy_intercept_errors = config["proxyInterceptErrors"].as_bool().unwrap_or(false);
139      if let Some(proxy_to) = determine_proxy_to(
140        config,
141        socket_data.encrypted,
142        &self.failed_backends,
143        enable_health_check,
144        health_check_max_fails,
145      )
146      .await
147      {
148        let (hyper_request, _, _, _) = request.into_parts();
149        let (mut hyper_request_parts, request_body) = hyper_request.into_parts();
150
151        let proxy_request_url = proxy_to.parse::<hyper::Uri>()?;
152        let scheme_str = proxy_request_url.scheme_str();
153        let mut encrypted = false;
154
155        match scheme_str {
156          Some("http") => {
157            encrypted = false;
158          }
159          Some("https") => {
160            encrypted = true;
161          }
162          _ => Err(anyhow::anyhow!(
163            "Only HTTP and HTTPS reverse proxy URLs are supported."
164          ))?,
165        };
166
167        let host = match proxy_request_url.host() {
168          Some(host) => host,
169          None => Err(anyhow::anyhow!(
170            "The reverse proxy URL doesn't include the host"
171          ))?,
172        };
173
174        let port = proxy_request_url.port_u16().unwrap_or(match scheme_str {
175          Some("http") => 80,
176          Some("https") => 443,
177          _ => 80,
178        });
179
180        let addr = format!("{}:{}", host, port);
181        let authority = proxy_request_url.authority().cloned();
182
183        let hyper_request_path = hyper_request_parts.uri.path();
184
185        let path = match hyper_request_path.as_bytes().first() {
186          Some(b'/') => {
187            let mut proxy_request_path = proxy_request_url.path();
188            while proxy_request_path.as_bytes().last().copied() == Some(b'/') {
189              proxy_request_path = &proxy_request_path[..(proxy_request_path.len() - 1)];
190            }
191            format!("{}{}", proxy_request_path, hyper_request_path)
192          }
193          _ => hyper_request_path.to_string(),
194        };
195
196        hyper_request_parts.uri = Uri::from_str(&format!(
197          "{}{}",
198          path,
199          match hyper_request_parts.uri.query() {
200            Some(query) => format!("?{}", query),
201            None => "".to_string(),
202          }
203        ))?;
204
205        let original_host = hyper_request_parts.headers.get(header::HOST).cloned();
206
207        // Host header for host identification
208        match authority {
209          Some(authority) => {
210            hyper_request_parts
211              .headers
212              .insert(header::HOST, authority.to_string().parse()?);
213          }
214          None => {
215            hyper_request_parts.headers.remove(header::HOST);
216          }
217        }
218
219        // Connection header to enable HTTP/1.1 keep-alive
220        hyper_request_parts
221          .headers
222          .insert(header::CONNECTION, "keep-alive".parse()?);
223
224        // X-Forwarded-* headers to send the client's data to a server that's behind the reverse proxy
225        hyper_request_parts.headers.insert(
226          "x-forwarded-for",
227          socket_data
228            .remote_addr
229            .ip()
230            .to_canonical()
231            .to_string()
232            .parse()?,
233        );
234
235        if socket_data.encrypted {
236          hyper_request_parts
237            .headers
238            .insert("x-forwarded-proto", "https".parse()?);
239        } else {
240          hyper_request_parts
241            .headers
242            .insert("x-forwarded-proto", "http".parse()?);
243        }
244
245        if let Some(original_host) = original_host {
246          hyper_request_parts
247            .headers
248            .insert("x-forwarded-host", original_host);
249        }
250
251        let proxy_request = Request::from_parts(hyper_request_parts, request_body);
252
253        let connections = &self.connections[rand::random_range(..self.connections.len())];
254
255        let rwlock_read = connections.read().await;
256        let sender_read_option = rwlock_read.get(&addr);
257
258        if let Some(sender_read) = sender_read_option {
259          if !sender_read.is_closed() {
260            drop(rwlock_read);
261            let mut rwlock_write = connections.write().await;
262            let sender_option = rwlock_write.get_mut(&addr);
263
264            if let Some(sender) = sender_option {
265              if !sender.is_closed() {
266                let result = http_proxy_kept_alive(
267                  sender,
268                  proxy_request,
269                  error_logger,
270                  proxy_intercept_errors,
271                )
272                .await;
273                drop(rwlock_write);
274                return result;
275              } else {
276                drop(rwlock_write);
277              }
278            } else {
279              drop(rwlock_write);
280            }
281          } else {
282            drop(rwlock_read);
283          }
284        } else {
285          drop(rwlock_read);
286        }
287
288        let stream = match TcpStream::connect(&addr).await {
289          Ok(stream) => stream,
290          Err(err) => {
291            if enable_health_check {
292              let mut failed_backends_write = self.failed_backends.write().await;
293              let proxy_to = proxy_to.clone();
294              let failed_attempts = failed_backends_write.get(&proxy_to);
295              failed_backends_write.insert(proxy_to, failed_attempts.map_or(1, |x| x + 1));
296            }
297            match err.kind() {
298              tokio::io::ErrorKind::ConnectionRefused
299              | tokio::io::ErrorKind::NotFound
300              | tokio::io::ErrorKind::HostUnreachable => {
301                error_logger
302                  .log(&format!("Service unavailable: {}", err))
303                  .await;
304                return Ok(
305                  ResponseData::builder_without_request()
306                    .status(StatusCode::SERVICE_UNAVAILABLE)
307                    .build(),
308                );
309              }
310              tokio::io::ErrorKind::TimedOut => {
311                error_logger.log(&format!("Gateway timeout: {}", err)).await;
312                return Ok(
313                  ResponseData::builder_without_request()
314                    .status(StatusCode::GATEWAY_TIMEOUT)
315                    .build(),
316                );
317              }
318              _ => {
319                error_logger.log(&format!("Bad gateway: {}", err)).await;
320                return Ok(
321                  ResponseData::builder_without_request()
322                    .status(StatusCode::BAD_GATEWAY)
323                    .build(),
324                );
325              }
326            };
327          }
328        };
329
330        match stream.set_nodelay(true) {
331          Ok(_) => (),
332          Err(err) => {
333            if enable_health_check {
334              let mut failed_backends_write = self.failed_backends.write().await;
335              let proxy_to = proxy_to.clone();
336              let failed_attempts = failed_backends_write.get(&proxy_to);
337              failed_backends_write.insert(proxy_to, failed_attempts.map_or(1, |x| x + 1));
338            }
339            error_logger.log(&format!("Bad gateway: {}", err)).await;
340            return Ok(
341              ResponseData::builder_without_request()
342                .status(StatusCode::BAD_GATEWAY)
343                .build(),
344            );
345          }
346        };
347
348        let failed_backends_option_borrowed = if enable_health_check {
349          Some(&*self.failed_backends)
350        } else {
351          None
352        };
353
354        if !encrypted {
355          http_proxy(
356            connections,
357            addr,
358            stream,
359            proxy_request,
360            error_logger,
361            proxy_to,
362            failed_backends_option_borrowed,
363            proxy_intercept_errors,
364          )
365          .await
366        } else {
367          let tls_client_config = (if disable_certificate_verification {
368            rustls::ClientConfig::builder()
369              .dangerous()
370              .with_custom_certificate_verifier(Arc::new(NoServerVerifier::new()))
371          } else {
372            rustls::ClientConfig::builder().with_root_certificates(self.roots.clone())
373          })
374          .with_no_client_auth();
375          let connector = TlsConnector::from(Arc::new(tls_client_config));
376          let domain = ServerName::try_from(host)?.to_owned();
377
378          let tls_stream = match connector.connect(domain, stream).await {
379            Ok(stream) => stream,
380            Err(err) => {
381              if enable_health_check {
382                let mut failed_backends_write = self.failed_backends.write().await;
383                let proxy_to = proxy_to.clone();
384                let failed_attempts = failed_backends_write.get(&proxy_to);
385                failed_backends_write.insert(proxy_to, failed_attempts.map_or(1, |x| x + 1));
386              }
387              error_logger.log(&format!("Bad gateway: {}", err)).await;
388              return Ok(
389                ResponseData::builder_without_request()
390                  .status(StatusCode::BAD_GATEWAY)
391                  .build(),
392              );
393            }
394          };
395
396          http_proxy(
397            connections,
398            addr,
399            tls_stream,
400            proxy_request,
401            error_logger,
402            proxy_to,
403            failed_backends_option_borrowed,
404            proxy_intercept_errors,
405          )
406          .await
407        }
408      } else {
409        Ok(ResponseData::builder(request).build())
410      }
411    })
412    .await
413  }
414
415  async fn proxy_request_handler(
416    &mut self,
417    request: RequestData,
418    _config: &ServerConfig,
419    _socket_data: &SocketData,
420    _error_logger: &ErrorLogger,
421  ) -> Result<ResponseData, Box<dyn Error + Send + Sync>> {
422    Ok(ResponseData::builder(request).build())
423  }
424
425  async fn response_modifying_handler(
426    &mut self,
427    response: HyperResponse,
428  ) -> Result<HyperResponse, Box<dyn Error + Send + Sync>> {
429    Ok(response)
430  }
431
432  async fn proxy_response_modifying_handler(
433    &mut self,
434    response: HyperResponse,
435  ) -> Result<HyperResponse, Box<dyn Error + Send + Sync>> {
436    Ok(response)
437  }
438
439  async fn connect_proxy_request_handler(
440    &mut self,
441    _upgraded_request: HyperUpgraded,
442    _connect_address: &str,
443    _config: &ServerConfig,
444    _socket_data: &SocketData,
445    _error_logger: &ErrorLogger,
446  ) -> Result<(), Box<dyn Error + Send + Sync>> {
447    Ok(())
448  }
449
450  fn does_connect_proxy_requests(&mut self) -> bool {
451    false
452  }
453
454  async fn websocket_request_handler(
455    &mut self,
456    websocket: HyperWebsocket,
457    uri: &hyper::Uri,
458    headers: &hyper::HeaderMap,
459    config: &ServerConfig,
460    socket_data: &SocketData,
461    error_logger: &ErrorLogger,
462  ) -> Result<(), Box<dyn Error + Send + Sync>> {
463    WithRuntime::new(self.handle.clone(), async move {
464      let enable_health_check = config["enableLoadBalancerHealthCheck"]
465        .as_bool()
466        .unwrap_or(false);
467      let health_check_max_fails = config["loadBalancerHealthCheckMaximumFails"]
468        .as_i64()
469        .unwrap_or(3) as u64;
470
471      let disable_certificate_verification = config["disableProxyCertificateVerification"]
472        .as_bool()
473        .unwrap_or(false);
474      if let Some(proxy_to) = determine_proxy_to(
475        config,
476        socket_data.encrypted,
477        &self.failed_backends,
478        enable_health_check,
479        health_check_max_fails,
480      )
481      .await
482      {
483        let proxy_request_url = proxy_to.parse::<hyper::Uri>()?;
484        let scheme_str = proxy_request_url.scheme_str();
485        let mut encrypted = false;
486
487        match scheme_str {
488          Some("http") => {
489            encrypted = false;
490          }
491          Some("https") => {
492            encrypted = true;
493          }
494          _ => Err(anyhow::anyhow!(
495            "Only HTTP and HTTPS reverse proxy URLs are supported."
496          ))?,
497        };
498
499        let request_path = uri.path();
500
501        let path = match request_path.as_bytes().first() {
502          Some(b'/') => {
503            let mut proxy_request_path = proxy_request_url.path();
504            while proxy_request_path.as_bytes().last().copied() == Some(b'/') {
505              proxy_request_path = &proxy_request_path[..(proxy_request_path.len() - 1)];
506            }
507            format!("{}{}", proxy_request_path, request_path)
508          }
509          _ => request_path.to_string(),
510        };
511
512        let mut proxy_request_url_parts = proxy_request_url.into_parts();
513        proxy_request_url_parts.scheme = if encrypted {
514          Some(Scheme::from_str("wss")?)
515        } else {
516          Some(Scheme::from_str("ws")?)
517        };
518        match uri.path_and_query() {
519          Some(path_and_query) => {
520            let path_and_query_string = match path_and_query.query() {
521              Some(query) => {
522                format!("{}?{}", path, query)
523              }
524              None => path,
525            };
526            proxy_request_url_parts.path_and_query =
527              Some(PathAndQuery::from_str(&path_and_query_string)?);
528          }
529          None => {
530            proxy_request_url_parts.path_and_query = Some(PathAndQuery::from_str(&path)?);
531          }
532        };
533
534        let proxy_request_url = hyper::Uri::from_parts(proxy_request_url_parts)?;
535
536        let connector = if !encrypted {
537          Connector::Plain
538        } else {
539          Connector::Rustls(Arc::new(
540            (if disable_certificate_verification {
541              rustls::ClientConfig::builder()
542                .dangerous()
543                .with_custom_certificate_verifier(Arc::new(NoServerVerifier::new()))
544            } else {
545              rustls::ClientConfig::builder().with_root_certificates(self.roots.clone())
546            })
547            .with_no_client_auth(),
548          ))
549        };
550
551        let mut proxy_request_builder = ClientRequestBuilder::new(proxy_request_url);
552        for (header_name, header_value) in headers {
553          let header_name_str = header_name.as_str();
554          if header_name == SEC_WEBSOCKET_PROTOCOL {
555            for subprotocol in String::from_utf8_lossy(header_value.as_bytes()).split(",") {
556              proxy_request_builder = proxy_request_builder.with_sub_protocol(subprotocol.trim());
557            }
558          } else if !header_name_str.starts_with("sec-websocket-")
559            && header_name_str != "x-forwarded-for"
560          {
561            proxy_request_builder = proxy_request_builder.with_header(
562              header_name_str,
563              String::from_utf8_lossy(header_value.as_bytes()),
564            );
565          }
566        }
567
568        // Add X-Forwarded-For header
569        proxy_request_builder = proxy_request_builder.with_header(
570          "x-forwarded-for",
571          socket_data.remote_addr.ip().to_canonical().to_string(),
572        );
573
574        let proxy_request_constructed = proxy_request_builder.into_client_request()?;
575
576        let client_bi_stream = websocket.await?;
577
578        let (proxy_bi_stream, _) = match tokio_tungstenite::connect_async_tls_with_config(
579          proxy_request_constructed,
580          None,
581          true,
582          Some(connector),
583        )
584        .await
585        {
586          Ok(data) => data,
587          Err(err) => {
588            error_logger
589              .log(&format!("Cannot connect to WebSocket server: {}", err))
590              .await;
591            return Ok(());
592          }
593        };
594
595        let (mut client_sink, mut client_stream) = client_bi_stream.split();
596        let (mut proxy_sink, mut proxy_stream) = proxy_bi_stream.split();
597
598        let client_to_proxy = async {
599          while let Some(Ok(value)) = client_stream.next().await {
600            if proxy_sink.send(value).await.is_err() {
601              break;
602            }
603          }
604        };
605
606        let proxy_to_client = async {
607          while let Some(Ok(value)) = proxy_stream.next().await {
608            if client_sink.send(value).await.is_err() {
609              break;
610            }
611          }
612        };
613
614        tokio::pin!(client_to_proxy);
615        tokio::pin!(proxy_to_client);
616
617        let client_to_proxy_first;
618        tokio::select! {
619          _ = &mut client_to_proxy => {
620            client_to_proxy_first = true;
621          }
622          _ = &mut proxy_to_client => {
623            client_to_proxy_first = false;
624          }
625        }
626
627        if client_to_proxy_first {
628          proxy_to_client.await;
629        } else {
630          client_to_proxy.await;
631        }
632      }
633
634      Ok(())
635    })
636    .await
637  }
638
639  fn does_websocket_requests(&mut self, config: &ServerConfig, socket_data: &SocketData) -> bool {
640    if socket_data.encrypted {
641      let secure_proxy_to = &config["secureProxyTo"];
642      if secure_proxy_to.as_vec().is_some() || secure_proxy_to.as_str().is_some() {
643        return true;
644      }
645    }
646
647    let proxy_to = &config["proxyTo"];
648    proxy_to.as_vec().is_some() || proxy_to.as_str().is_some()
649  }
650}
651
652async fn determine_proxy_to(
653  config: &ServerConfig,
654  encrypted: bool,
655  failed_backends: &RwLock<TtlCache<String, u64>>,
656  enable_health_check: bool,
657  health_check_max_fails: u64,
658) -> Option<String> {
659  let mut proxy_to = None;
660  // When the array is supplied with non-string values, the reverse proxy may have undesirable behavior
661  // The "proxyTo" and "secureProxyTo" are validated though.
662
663  if encrypted {
664    let secure_proxy_to_yaml = &config["secureProxyTo"];
665    if let Some(secure_proxy_to_vector) = secure_proxy_to_yaml.as_vec() {
666      if enable_health_check {
667        let mut secure_proxy_to_vector = secure_proxy_to_vector.clone();
668        loop {
669          if !secure_proxy_to_vector.is_empty() {
670            let index = rand::random_range(..secure_proxy_to_vector.len());
671            if let Some(secure_proxy_to) = secure_proxy_to_vector[index].as_str() {
672              proxy_to = Some(secure_proxy_to.to_string());
673              let failed_backends_read = failed_backends.read().await;
674              let failed_backend_fails =
675                match failed_backends_read.get(&secure_proxy_to.to_string()) {
676                  Some(fails) => fails,
677                  None => break,
678                };
679              if failed_backend_fails > health_check_max_fails {
680                secure_proxy_to_vector.remove(index);
681              } else {
682                break;
683              }
684            }
685          } else {
686            break;
687          }
688        }
689      } else if !secure_proxy_to_vector.is_empty() {
690        if let Some(secure_proxy_to) =
691          secure_proxy_to_vector[rand::random_range(..secure_proxy_to_vector.len())].as_str()
692        {
693          proxy_to = Some(secure_proxy_to.to_string());
694        }
695      }
696    } else if let Some(secure_proxy_to) = secure_proxy_to_yaml.as_str() {
697      proxy_to = Some(secure_proxy_to.to_string());
698    }
699  }
700
701  if proxy_to.is_none() {
702    let proxy_to_yaml = &config["proxyTo"];
703    if let Some(proxy_to_vector) = proxy_to_yaml.as_vec() {
704      if enable_health_check {
705        let mut proxy_to_vector = proxy_to_vector.clone();
706        loop {
707          if !proxy_to_vector.is_empty() {
708            let index = rand::random_range(..proxy_to_vector.len());
709            if let Some(proxy_to_str) = proxy_to_vector[index].as_str() {
710              proxy_to = Some(proxy_to_str.to_string());
711              let failed_backends_read = failed_backends.read().await;
712              let failed_backend_fails = match failed_backends_read.get(&proxy_to_str.to_string()) {
713                Some(fails) => fails,
714                None => break,
715              };
716              if failed_backend_fails > health_check_max_fails {
717                proxy_to_vector.remove(index);
718              } else {
719                break;
720              }
721            }
722          } else {
723            break;
724          }
725        }
726      } else if !proxy_to_vector.is_empty() {
727        if let Some(proxy_to_str) =
728          proxy_to_vector[rand::random_range(..proxy_to_vector.len())].as_str()
729        {
730          proxy_to = Some(proxy_to_str.to_string());
731        }
732      }
733    } else if let Some(proxy_to_str) = proxy_to_yaml.as_str() {
734      proxy_to = Some(proxy_to_str.to_string());
735    }
736  }
737
738  proxy_to
739}
740
741#[allow(clippy::too_many_arguments)]
742async fn http_proxy(
743  connections: &RwLock<HashMap<String, SendRequest<BoxBody<Bytes, std::io::Error>>>>,
744  connect_addr: String,
745  stream: impl AsyncRead + AsyncWrite + Send + Unpin + 'static,
746  proxy_request: Request<BoxBody<Bytes, std::io::Error>>,
747  error_logger: &ErrorLogger,
748  proxy_to: String,
749  failed_backends: Option<&tokio::sync::RwLock<TtlCache<std::string::String, u64>>>,
750  proxy_intercept_errors: bool,
751) -> Result<ResponseData, Box<dyn Error + Send + Sync>> {
752  let io = TokioIo::new(stream);
753
754  let (mut sender, conn) = match hyper::client::conn::http1::handshake(io).await {
755    Ok(data) => data,
756    Err(err) => {
757      if let Some(failed_backends) = failed_backends {
758        let mut failed_backends_write = failed_backends.write().await;
759        let failed_attempts = failed_backends_write.get(&proxy_to);
760        failed_backends_write.insert(proxy_to, failed_attempts.map_or(1, |x| x + 1));
761      }
762      error_logger.log(&format!("Bad gateway: {}", err)).await;
763      return Ok(
764        ResponseData::builder_without_request()
765          .status(StatusCode::BAD_GATEWAY)
766          .build(),
767      );
768    }
769  };
770
771  let send_request = sender.send_request(proxy_request);
772
773  let mut pinned_conn = Box::pin(conn);
774  tokio::pin!(send_request);
775
776  let response;
777
778  loop {
779    tokio::select! {
780      biased;
781
782      proxy_response = &mut send_request => {
783        let proxy_response = match proxy_response {
784          Ok(response) => response,
785          Err(err) => {
786            error_logger.log(&format!("Bad gateway: {}", err)).await;
787            return Ok(ResponseData::builder_without_request().status(StatusCode::BAD_GATEWAY).build());
788          }
789        };
790
791        let status_code = proxy_response.status();
792        response = if proxy_intercept_errors && status_code.as_u16() >= 400 {
793          ResponseData::builder_without_request()
794          .status(status_code)
795          .parallel_fn(async move {
796            pinned_conn.await.unwrap_or_default();
797          })
798          .build()
799        } else {
800          ResponseData::builder_without_request()
801          .response(proxy_response.map(|b| {
802            b.map_err(|e| std::io::Error::other(e.to_string()))
803              .boxed()
804          }))
805          .parallel_fn(async move {
806            pinned_conn.await.unwrap_or_default();
807          })
808          .build()
809        };
810
811        break;
812      },
813      state = &mut pinned_conn => {
814        if state.is_err() {
815          error_logger.log("Bad gateway: incomplete response").await;
816          return Ok(ResponseData::builder_without_request().status(StatusCode::BAD_GATEWAY).build());
817        }
818      },
819    };
820  }
821
822  if !sender.is_closed() {
823    let mut rwlock_write = connections.write().await;
824    rwlock_write.insert(connect_addr, sender);
825    drop(rwlock_write);
826  }
827
828  Ok(response)
829}
830
831async fn http_proxy_kept_alive(
832  sender: &mut SendRequest<BoxBody<Bytes, std::io::Error>>,
833  proxy_request: Request<BoxBody<Bytes, std::io::Error>>,
834  error_logger: &ErrorLogger,
835  proxy_intercept_errors: bool,
836) -> Result<ResponseData, Box<dyn Error + Send + Sync>> {
837  let proxy_response = match sender.send_request(proxy_request).await {
838    Ok(response) => response,
839    Err(err) => {
840      error_logger.log(&format!("Bad gateway: {}", err)).await;
841      return Ok(
842        ResponseData::builder_without_request()
843          .status(StatusCode::BAD_GATEWAY)
844          .build(),
845      );
846    }
847  };
848
849  let status_code = proxy_response.status();
850  let response = if proxy_intercept_errors && status_code.as_u16() >= 400 {
851    ResponseData::builder_without_request()
852      .status(status_code)
853      .build()
854  } else {
855    ResponseData::builder_without_request()
856      .response(proxy_response.map(|b| b.map_err(|e| std::io::Error::other(e.to_string())).boxed()))
857      .build()
858  };
859
860  Ok(response)
861}