/
connect.go
92 lines (83 loc) · 2.65 KB
/
connect.go
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/*
* Copyright (c) 2002-2020 "Neo4j,"
* Neo4j Sweden AB [http://neo4j.com]
*
* This file is part of Neo4j.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package bolt
import (
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"github.com/neo4j/neo4j-go-driver/neo4j/internal/db"
"github.com/neo4j/neo4j-go-driver/neo4j/internal/log"
)
type Logger interface {
ConnectError(c net.Conn, err error)
ConnectionError(c db.Connection, err error)
ConnectionInfo(c db.Connection, msg string, args ...interface{})
}
// Negotiate version of bolt protocol.
// Returns instance of bolt protocol implmenting low-level abstract db connection interface.
func Connect(serverName string, conn net.Conn, auth map[string]interface{}, log log.Logger) (db.Connection, error) {
// Perform Bolt handshake to negotiate version
// Send handshake to server
handshake := []byte{
0x60, 0x60, 0xb0, 0x17, // Magic: GoGoBolt
0x00, 0x00, 0x00, 0x04, // Versions in priority order, big endian.
0x00, 0x00, 0x00, 0x03,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00}
_, err := conn.Write(handshake)
if err != nil {
return nil, err
}
// Receive accepted server version
buf := make([]byte, 4)
_, err = io.ReadFull(conn, buf)
if err != nil {
return nil, err
}
logId := "boltconnect@" + serverName
// Parse received version and construct the correct instance
ver := binary.BigEndian.Uint32(buf)
switch ver {
case 3:
// Handover rest of connection handshaking
boltConn := NewBolt3(serverName, conn, log)
err = boltConn.connect(auth)
if err != nil {
return nil, err
}
log.Infof(logId, "Connected to %s", boltConn.ServerVersion())
return boltConn, nil
case 4:
// Handover rest of connection handshaking
boltConn := NewBolt4(serverName, conn, log)
err = boltConn.connect(auth)
if err != nil {
return nil, err
}
return boltConn, nil
case 0:
err = errors.New("Server did not accept any of the requested Bolt protocol versions. Only Neo4j version 3.5 and version 4 currently supports Bolt protocol version 3")
default:
err = errors.New(fmt.Sprintf("Server responded with unsupported version %d", ver))
}
log.Error(logId, err)
return nil, err
}