istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/hbone/server.go (about)

     1  // Copyright Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package hbone
    16  
    17  import (
    18  	"context"
    19  	"net"
    20  	"net/http"
    21  	"sync"
    22  	"time"
    23  
    24  	"golang.org/x/net/http2"
    25  
    26  	"istio.io/istio/pkg/h2c"
    27  )
    28  
    29  func NewServer() *http.Server {
    30  	// Need to set this to allow timeout on the read header
    31  	h1 := &http.Transport{
    32  		ExpectContinueTimeout: 3 * time.Second,
    33  	}
    34  	h2, _ := http2.ConfigureTransports(h1)
    35  	h2.ReadIdleTimeout = 10 * time.Minute // TODO: much larger to support long-lived connections
    36  	h2.AllowHTTP = true
    37  	h2Server := &http2.Server{}
    38  	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    39  		if r.Method == http.MethodConnect {
    40  			if handleConnect(w, r) {
    41  				return
    42  			}
    43  		} else {
    44  			log.Errorf("non-CONNECT: %v", r.Method)
    45  			w.WriteHeader(http.StatusMethodNotAllowed)
    46  		}
    47  	})
    48  	hs := &http.Server{
    49  		Handler: h2c.NewHandler(handler, h2Server),
    50  	}
    51  	return hs
    52  }
    53  
    54  func handleConnect(w http.ResponseWriter, r *http.Request) bool {
    55  	t0 := time.Now()
    56  	log.WithLabels("host", r.Host, "source", r.RemoteAddr).Info("Received CONNECT")
    57  	// Send headers back immediately so we can start getting the body
    58  	w.(http.Flusher).Flush()
    59  	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
    60  	defer cancel()
    61  
    62  	dst, err := (&net.Dialer{}).DialContext(ctx, "tcp", r.Host)
    63  	if err != nil {
    64  		w.WriteHeader(http.StatusServiceUnavailable)
    65  		log.Errorf("failed to dial upstream: %v", err)
    66  		return true
    67  	}
    68  	log.Infof("Connected to %v", r.Host)
    69  	w.WriteHeader(http.StatusOK)
    70  
    71  	wg := sync.WaitGroup{}
    72  	wg.Add(1)
    73  	go func() {
    74  		// downstream (hbone client) <-- upstream (app)
    75  		copyBuffered(w, dst, log.WithLabels("name", "dst to w"))
    76  		err = r.Body.Close()
    77  		if err != nil {
    78  			log.Infof("connection to hbone client is not closed: %v", err)
    79  		}
    80  		wg.Done()
    81  	}()
    82  	// downstream (hbone client) --> upstream (app)
    83  	copyBuffered(dst, r.Body, log.WithLabels("name", "body to dst"))
    84  	wg.Wait()
    85  	log.Infof("connection closed in %v", time.Since(t0))
    86  	return false
    87  }