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
|
package smux
import (
"encoding/binary"
"fmt"
)
const (
version = 1
)
const ( // cmds
cmdSYN byte = iota // stream open
cmdFIN // stream close, a.k.a EOF mark
cmdPSH // data push
cmdNOP // no operation
)
const (
sizeOfVer = 1
sizeOfCmd = 1
sizeOfLength = 2
sizeOfSid = 4
headerSize = sizeOfVer + sizeOfCmd + sizeOfSid + sizeOfLength
)
// Frame defines a packet from or to be multiplexed into a single connection
type Frame struct {
ver byte
cmd byte
sid uint32
data []byte
}
func newFrame(cmd byte, sid uint32) Frame {
return Frame{ver: version, cmd: cmd, sid: sid}
}
type rawHeader []byte
func (h rawHeader) Version() byte {
return h[0]
}
func (h rawHeader) Cmd() byte {
return h[1]
}
func (h rawHeader) Length() uint16 {
return binary.LittleEndian.Uint16(h[2:])
}
func (h rawHeader) StreamID() uint32 {
return binary.LittleEndian.Uint32(h[4:])
}
func (h rawHeader) String() string {
return fmt.Sprintf("Version:%d Cmd:%d StreamID:%d Length:%d",
h.Version(), h.Cmd(), h.StreamID(), h.Length())
}
|
