github.com/erda-project/erda-infra@v1.0.9/providers/remote-forward/client/provider.go (about)

     1  // Copyright (c) 2021 Terminus, Inc.
     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 client
    16  
    17  import (
    18  	"encoding/hex"
    19  	"errors"
    20  	"fmt"
    21  	"net"
    22  	"os"
    23  	"reflect"
    24  	"time"
    25  
    26  	"github.com/erda-project/erda-infra/base/logs"
    27  	"github.com/erda-project/erda-infra/base/servicehub"
    28  	forward "github.com/erda-project/erda-infra/providers/remote-forward"
    29  	yamux "github.com/hashicorp/yamux"
    30  	uuid "github.com/satori/go.uuid"
    31  )
    32  
    33  // Interface .
    34  type Interface interface {
    35  	RemoteShadowAddr() string
    36  	Values() map[string]interface{}
    37  }
    38  
    39  var _ (Interface) = (*provider)(nil)
    40  
    41  type config struct {
    42  	RemoteAddr       string `file:"remote_addr"`
    43  	RemoteShadowAddr string `file:"remote_shadow_addr"`
    44  	TargetAddr       string `file:"target_addr"`
    45  	Name             string `file:"name"`
    46  	Token            string `file:"token"`
    47  }
    48  
    49  type provider struct {
    50  	Cfg      *config
    51  	Log      logs.Logger
    52  	conn     net.Conn
    53  	response *forward.ResponseHeader
    54  }
    55  
    56  func (p *provider) RemoteShadowAddr() string       { return p.response.ShadowAddr }
    57  func (p *provider) Values() map[string]interface{} { return p.response.Values }
    58  
    59  func (p *provider) Init(ctx servicehub.Context) error {
    60  	if len(p.Cfg.Name) <= 0 {
    61  		hostname, err := os.Hostname()
    62  		if err == nil {
    63  			p.Cfg.Name = fmt.Sprintf("%s@%s->%s", hex.EncodeToString(uuid.NewV4().Bytes()[8:16]), hostname, p.Cfg.TargetAddr)
    64  		} else {
    65  			p.Cfg.Name = hex.EncodeToString(uuid.NewV4().Bytes())
    66  		}
    67  		p.Log.Infof("forward name is %q", p.Cfg.Name)
    68  	}
    69  	conn, err := net.Dial("tcp", p.Cfg.RemoteAddr)
    70  	if err != nil {
    71  		return fmt.Errorf("failed to connect remote forward server: %s", err)
    72  	}
    73  	p.conn = conn
    74  	p.response, err = p.handshake(conn)
    75  	if err != nil {
    76  		return err
    77  	}
    78  	return nil
    79  }
    80  
    81  func (p *provider) Start() error {
    82  	conn := p.conn
    83  	session, err := yamux.Server(conn, nil)
    84  	if err != nil {
    85  		if errors.Is(err, net.ErrClosed) {
    86  			return nil
    87  		}
    88  		return err
    89  	}
    90  	defer session.Close()
    91  	defer conn.Close()
    92  	for {
    93  		conn, err := session.Accept()
    94  		if err != nil {
    95  			if errors.Is(err, net.ErrClosed) {
    96  				return nil
    97  			}
    98  			return err
    99  		}
   100  		go p.handleConn(conn)
   101  	}
   102  }
   103  
   104  func (p *provider) Close() error {
   105  	if p.conn != nil {
   106  		conn := p.conn
   107  		p.conn = nil
   108  		err := conn.Close()
   109  		if !errors.Is(err, net.ErrClosed) {
   110  			return err
   111  		}
   112  	}
   113  	return nil
   114  }
   115  
   116  func (p *provider) handshake(conn net.Conn) (resp *forward.ResponseHeader, err error) {
   117  	defer func() {
   118  		if err != nil {
   119  			err = fmt.Errorf("handshake error: %w", err)
   120  		}
   121  	}()
   122  	err = conn.SetDeadline(time.Now().Add(60 * time.Second))
   123  	if err != nil {
   124  		return nil, err
   125  	}
   126  	err = forward.EncodeRequestHeader(conn, &forward.RequestHeader{
   127  		Version:    forward.ProtocolVersion,
   128  		Name:       p.Cfg.Name,
   129  		Token:      p.Cfg.Token,
   130  		ShadowAddr: p.Cfg.RemoteShadowAddr,
   131  	})
   132  	if err != nil {
   133  		return nil, err
   134  	}
   135  	resp, err = forward.DecodeResponseHeader(conn)
   136  	if err != nil {
   137  		return nil, err
   138  	}
   139  	if len(resp.Error) > 0 {
   140  		return nil, errors.New(resp.Error)
   141  	}
   142  	err = conn.SetDeadline(time.Time{})
   143  	if err != nil {
   144  		return nil, err
   145  	}
   146  	p.Log.Infof("remote shadow addr: %s", resp.ShadowAddr)
   147  	return resp, nil
   148  }
   149  
   150  func (p *provider) handleConn(conn net.Conn) {
   151  	defer conn.Close()
   152  	localConn, err := net.Dial("tcp", p.Cfg.TargetAddr)
   153  	if err != nil {
   154  		p.Log.Error(err)
   155  		return
   156  	}
   157  	defer localConn.Close()
   158  	p.Log.Debugf("forward %s -> %s", conn.RemoteAddr(), p.Cfg.TargetAddr)
   159  	forward.Pipe(p.Log, conn, localConn)
   160  }
   161  
   162  func init() {
   163  	servicehub.Register("remote-forward-client", &servicehub.Spec{
   164  		Services:   []string{"remote-forward-client"},
   165  		Types:      []reflect.Type{reflect.TypeOf((*Interface)(nil)).Elem()},
   166  		ConfigFunc: func() interface{} { return &config{} },
   167  		Creator: func() servicehub.Provider {
   168  			return &provider{}
   169  		},
   170  	})
   171  }