mcstatus/client/client.go
Michael 049ab265d3 changes to protobuf buffers
Signed-off-by: Michael <michael.lindman@gmail.com>
2021-01-08 15:54:54 +00:00

98 lines
2.1 KiB
Go

package client
import (
"bytes"
"encoding/binary"
"net"
"strconv"
"time"
"git.0cd.xyz/michael/mcstatus/mcstatuspb"
"github.com/golang/protobuf/jsonpb"
)
// Client TCP client
type Client struct {
Addr string
Port int
Version uint64
Conn net.Conn
}
// New client connection
func New(addr string, port int, ver uint64) (*Client, error) {
conn, err := net.Dial("tcp", addr+":"+strconv.Itoa(port))
if err != nil {
return nil, err
}
return &Client{
Addr: addr,
Port: port,
Version: ver,
Conn: conn,
}, nil
}
func (client *Client) write() error {
if err := client.Conn.SetWriteDeadline(time.Now().Add(10 * time.Second)); err != nil {
return err
}
_, err := client.Conn.Write(handshake(client.Addr, client.Port, client.Version))
if err != nil {
if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
return err
}
return err
}
return nil
}
func (client *Client) read() (*mcstatuspb.Response, error) {
var response mcstatuspb.Response
buf := make([]byte, 1024)
n, err := client.Conn.Read(buf)
if err != nil {
if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
return nil, err
}
return nil, err
}
b := bytes.Split(buf[:n], []byte("{"))
ne := bytes.SplitAfterN(buf[:n], b[0], 2)
trim := bytes.TrimSuffix(ne[1], []byte("\x00"))
js := &jsonpb.Unmarshaler{AllowUnknownFields: true}
if err := js.Unmarshal(bytes.NewBuffer(trim), &response); err != nil {
return nil, err
}
return &response, nil
}
func packetlength(b ...[]byte) (length int) {
for _, bytes := range b {
length += len(bytes)
}
return length
}
func handshake(addr string, port int, ver uint64) []byte {
id := []byte{0x00}
state := []byte{0x01}
version := make([]byte, 2)
binary.PutUvarint(version, ver)
p := make([]byte, 2)
binary.BigEndian.PutUint16(p, uint16(port))
length := packetlength(id, version, []byte(addr), []byte(p), state) + 1
var handshake bytes.Buffer
handshake.WriteByte(byte(length))
handshake.Write(id)
handshake.Write(version)
handshake.WriteByte(byte(len(addr)))
handshake.WriteString(addr)
handshake.Write(p)
handshake.Write(state)
handshake.Write([]byte{0x01, 0x00})
return handshake.Bytes()
}