105 lines
2.5 KiB
Go
105 lines
2.5 KiB
Go
|
package payload
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"encoding/binary"
|
||
|
|
"io"
|
||
|
|
)
|
||
|
|
|
||
|
|
const minVersionSize = 27
|
||
|
|
|
||
|
|
// Version payload.
|
||
|
|
type Version struct {
|
||
|
|
// currently the version of the protocol is 0
|
||
|
|
Version uint32
|
||
|
|
// currently 1
|
||
|
|
Services uint64
|
||
|
|
// timestamp
|
||
|
|
Timestamp uint32
|
||
|
|
// port this server is listening on
|
||
|
|
Port uint16
|
||
|
|
// it's used to distinguish the node from public IP
|
||
|
|
Nonce uint32
|
||
|
|
// client id currently 6 bytes \v/NEO:2.6.0/
|
||
|
|
UserAgent []byte
|
||
|
|
// Height of the block chain
|
||
|
|
StartHeight uint32
|
||
|
|
// Whether to receive and forward
|
||
|
|
Relay bool
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewVersion returns a pointer to a Version payload.
|
||
|
|
func NewVersion(p uint16, ua string, h uint32, r bool) *Version {
|
||
|
|
return &Version{
|
||
|
|
Version: 0,
|
||
|
|
Services: 1,
|
||
|
|
Timestamp: 12345,
|
||
|
|
Port: p,
|
||
|
|
Nonce: 19110,
|
||
|
|
UserAgent: []byte(ua),
|
||
|
|
StartHeight: 0,
|
||
|
|
Relay: r,
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Size ..
|
||
|
|
func (p *Version) Size() uint32 {
|
||
|
|
n := minVersionSize + len(p.UserAgent)
|
||
|
|
return uint32(n)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Decode ..
|
||
|
|
func (p *Version) Decode(r io.Reader) error {
|
||
|
|
buf := new(bytes.Buffer)
|
||
|
|
if _, err := buf.ReadFrom(r); err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
|
||
|
|
b := buf.Bytes()
|
||
|
|
// 27 bytes for the fixed size fields + the length of the user agent
|
||
|
|
// which is kinda variable, according to the docs.
|
||
|
|
lenUA := len(b) - minVersionSize
|
||
|
|
|
||
|
|
p.Version = binary.LittleEndian.Uint32(b[0:4])
|
||
|
|
p.Services = binary.LittleEndian.Uint64(b[4:12])
|
||
|
|
p.Timestamp = binary.LittleEndian.Uint32(b[12:16])
|
||
|
|
// FIXME: port's byteorder should be big endian according to the docs.
|
||
|
|
// but when connecting to the privnet docker image it's little endian.
|
||
|
|
p.Port = binary.LittleEndian.Uint16(b[16:18])
|
||
|
|
p.Nonce = binary.LittleEndian.Uint32(b[18:22])
|
||
|
|
p.UserAgent = b[22 : 22+lenUA]
|
||
|
|
curlen := 22 + lenUA
|
||
|
|
p.StartHeight = binary.LittleEndian.Uint32(b[curlen : curlen+4])
|
||
|
|
p.Relay = b[len(b)-1 : len(b)][0] == 1
|
||
|
|
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// Encode ..
|
||
|
|
func (p *Version) Encode(w io.Writer) error {
|
||
|
|
buf := make([]byte, p.Size())
|
||
|
|
|
||
|
|
binary.LittleEndian.PutUint32(buf[0:4], p.Version)
|
||
|
|
binary.LittleEndian.PutUint64(buf[4:12], p.Services)
|
||
|
|
binary.LittleEndian.PutUint32(buf[12:16], p.Timestamp)
|
||
|
|
// FIXME: byte order (little / big)?
|
||
|
|
binary.LittleEndian.PutUint16(buf[16:18], p.Port)
|
||
|
|
binary.LittleEndian.PutUint32(buf[18:22], p.Nonce)
|
||
|
|
copy(buf[22:22+len(p.UserAgent)], p.UserAgent) //
|
||
|
|
curLen := 22 + len(p.UserAgent)
|
||
|
|
binary.LittleEndian.PutUint32(buf[curLen:curLen+4], p.StartHeight)
|
||
|
|
|
||
|
|
// yikes
|
||
|
|
var b []byte
|
||
|
|
if p.Relay {
|
||
|
|
b = []byte{1}
|
||
|
|
} else {
|
||
|
|
b = []byte{0}
|
||
|
|
}
|
||
|
|
|
||
|
|
copy(buf[curLen+4:len(buf)], b)
|
||
|
|
|
||
|
|
_, err := w.Write(buf)
|
||
|
|
return err
|
||
|
|
}
|