1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
package handlers
import (
"encoding/base64"
"errors"
"fmt"
"strconv"
"strings"
"github.com/mimecast/dtail/internal/io/dlog"
"github.com/mimecast/dtail/internal/protocol"
user "github.com/mimecast/dtail/internal/user/server"
)
type protocolCodec struct {
user *user.User
}
func newProtocolCodec(user *user.User) protocolCodec {
return protocolCodec{user: user}
}
func (c protocolCodec) handleProtocolVersion(args []string) ([]string, int, string, error) {
argc := len(args)
var add string
if argc <= 2 || args[0] != "protocol" {
return args, argc, add, errors.New("unable to determine protocol version")
}
if args[1] != protocol.ProtocolCompat {
clientMajor, clientMinor := parseProtocolCompat(args[1])
serverMajor, serverMinor := parseProtocolCompat(protocol.ProtocolCompat)
if clientMajor <= 3 {
// Protocol version 3 or lower expect a newline as message separator
// One day (after 2 major versions) this exception may be removed!
add = "\n"
}
toUpdate := "client"
if clientMajor > serverMajor || (clientMajor == serverMajor && clientMinor > serverMinor) {
toUpdate = "server"
}
err := fmt.Errorf("the DTail server protocol version '%s' does not match "+
"client protocol version '%s', please update DTail %s",
protocol.ProtocolCompat, args[1], toUpdate)
return args, argc, add, err
}
return args[2:], argc - 2, add, nil
}
func parseProtocolCompat(version string) (int, int) {
major := 0
minor := 0
parts := strings.SplitN(version, ".", 2)
if len(parts) > 0 {
major, _ = strconv.Atoi(parts[0])
}
if len(parts) == 2 {
minor, _ = strconv.Atoi(parts[1])
}
return major, minor
}
func (c protocolCodec) handleBase64(args []string, argc int) ([]string, int, error) {
err := errors.New("unable to decode client message, DTail server and client " +
"versions may not be compatible")
if argc != 2 || args[0] != "base64" {
return args, argc, err
}
decoded, err := base64.StdEncoding.DecodeString(args[1])
if err != nil {
return args, argc, err
}
decodedStr := string(decoded)
args = strings.Split(decodedStr, " ")
argc = len(args)
dlog.Server.Trace(c.user, "Base64 decoded received command",
decodedStr, argc, args)
return args, argc, nil
}
|
