istio.io/istio@v0.0.0-20240520182934-d79c90f27776/pkg/test/echo/server/forwarder/udp.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 forwarder
    16  
    17  import (
    18  	"bytes"
    19  	"context"
    20  	"fmt"
    21  	"io"
    22  	"net"
    23  	"net/http"
    24  	"strings"
    25  
    26  	"istio.io/istio/pkg/test/echo"
    27  	"istio.io/istio/pkg/test/echo/common"
    28  	"istio.io/istio/pkg/test/echo/proto"
    29  )
    30  
    31  var _ protocol = &udpProtocol{}
    32  
    33  type udpProtocol struct {
    34  	e *executor
    35  }
    36  
    37  func newUDPProtocol(e *executor) protocol {
    38  	return &udpProtocol{e: e}
    39  }
    40  
    41  func (c *udpProtocol) ForwardEcho(ctx context.Context, cfg *Config) (*proto.ForwardEchoResponse, error) {
    42  	return doForward(ctx, cfg, c.e, c.makeRequest)
    43  }
    44  
    45  func (c *udpProtocol) makeRequest(ctx context.Context, cfg *Config, requestID int) (string, error) {
    46  	conn, err := newUDPConnection(cfg)
    47  	if err != nil {
    48  		return "", err
    49  	}
    50  	defer func() { _ = conn.Close() }()
    51  
    52  	msgBuilder := strings.Builder{}
    53  	echo.ForwarderURLField.WriteForRequest(&msgBuilder, requestID, cfg.Request.Url)
    54  
    55  	if cfg.Request.Message != "" {
    56  		echo.ForwarderMessageField.WriteForRequest(&msgBuilder, requestID, cfg.Request.Message)
    57  	}
    58  
    59  	// Apply per-request timeout to calculate deadline for reads/writes.
    60  	ctx, cancel := context.WithTimeout(ctx, cfg.timeout)
    61  	defer cancel()
    62  
    63  	// Apply the deadline to the connection.
    64  	deadline, _ := ctx.Deadline()
    65  	if err := conn.SetWriteDeadline(deadline); err != nil {
    66  		return msgBuilder.String(), err
    67  	}
    68  	if err := conn.SetReadDeadline(deadline); err != nil {
    69  		return msgBuilder.String(), err
    70  	}
    71  
    72  	// Make sure the client writes something to the buffer
    73  	message := "HelloWorld"
    74  	if cfg.Request.Message != "" {
    75  		message = cfg.Request.Message
    76  	}
    77  
    78  	if _, err := conn.Write([]byte(message + "\n")); err != nil {
    79  		fwLog.Warnf("UDP write failed: %v", err)
    80  		return msgBuilder.String(), err
    81  	}
    82  	var resBuffer bytes.Buffer
    83  	buf := make([]byte, 1024+len(message))
    84  	n, err := conn.Read(buf)
    85  	if err != nil && err != io.EOF {
    86  		fwLog.Warnf("UDP read failed (already read %d bytes): %v", len(resBuffer.String()), err)
    87  		return msgBuilder.String(), err
    88  	}
    89  	resBuffer.Write(buf[:n])
    90  
    91  	// format the output for forwarder response
    92  	for _, line := range strings.Split(string(buf[:n]), "\n") {
    93  		if line != "" {
    94  			echo.WriteBodyLine(&msgBuilder, requestID, line)
    95  		}
    96  	}
    97  
    98  	msg := msgBuilder.String()
    99  	expected := fmt.Sprintf("%s=%d", string(echo.StatusCodeField), http.StatusOK)
   100  	if cfg.Request.ExpectedResponse != nil {
   101  		expected = cfg.Request.ExpectedResponse.GetValue()
   102  	}
   103  	if !strings.Contains(msg, expected) {
   104  		return msg, fmt.Errorf("expect to recv message with %s, got %s. Return EOF", expected, msg)
   105  	}
   106  	return msg, nil
   107  }
   108  
   109  func (c *udpProtocol) Close() error {
   110  	return nil
   111  }
   112  
   113  func newUDPConnection(cfg *Config) (net.Conn, error) {
   114  	address := cfg.Request.Url[len(cfg.scheme+"://"):]
   115  
   116  	if cfg.secure {
   117  		return nil, fmt.Errorf("TLS not available")
   118  	}
   119  
   120  	ctx, cancel := context.WithTimeout(context.Background(), common.ConnectionTimeout)
   121  	defer cancel()
   122  	return newDialer(cfg).DialContext(ctx, "udp", address)
   123  }