1.21.8 data

bot/pinglist.go

@@ -0,0 +1,137 @@
+package bot
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/Tnze/go-mc/data/packetid"
+	mcnet "github.com/Tnze/go-mc/net"
+	pk "github.com/Tnze/go-mc/net/packet"
+)
+
+// PingAndList check server status and list online player.
+// Returns a JSON data with server status, and the delay.
+//
+// For more information for JSON format, see https://wiki.vg/Server_List_Ping#Response
+func PingAndList(addr string) ([]byte, time.Duration, error) {
+	conn, err := mcnet.DialMC(addr)
+	if err != nil {
+		return nil, 0, LoginErr{"dial connection", err}
+	}
+	return pingAndList(context.Background(), addr, conn)
+}
+
+// PingAndListTimeout is the version of PingAndList with max request time.
+func PingAndListTimeout(addr string, timeout time.Duration) ([]byte, time.Duration, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	return PingAndListContext(ctx, addr)
+}
+
+func PingAndListContext(ctx context.Context, addr string) ([]byte, time.Duration, error) {
+	conn, err := mcnet.DefaultDialer.DialMCContext(ctx, addr)
+	if err != nil {
+		return nil, 0, err
+	}
+	return pingAndList(ctx, addr, conn)
+}
+
+func pingAndList(ctx context.Context, addr string, conn *mcnet.Conn) (data []byte, delay time.Duration, err error) {
+	if deadline, hasDeadline := ctx.Deadline(); hasDeadline {
+		if err := conn.Socket.SetDeadline(deadline); err != nil {
+			return nil, 0, err
+		}
+		defer func() {
+			// Reset deadline
+			if err2 := conn.Socket.SetDeadline(time.Time{}); err2 != nil {
+				if err == nil {
+					err = err2
+				}
+				return
+			}
+			// Map error type
+			if errors.Is(err, os.ErrDeadlineExceeded) {
+				err = context.DeadlineExceeded
+			}
+		}()
+	}
+	// Split Host and Port
+	host, portStr, err := net.SplitHostPort(addr)
+	var port uint64
+	if err != nil {
+		var addrErr *net.AddrError
+		const missingPort = "missing port in address"
+		if errors.As(err, &addrErr) && addrErr.Err == missingPort {
+			host, port, err = addr, DefaultPort, nil
+		} else {
+			return nil, 0, LoginErr{"split address", err}
+		}
+	} else {
+		port, err = strconv.ParseUint(portStr, 0, 16)
+		if err != nil {
+			return nil, 0, LoginErr{"parse port", err}
+		}
+	}
+
+	const Handshake = 0x00
+	// 握手
+	err = conn.WritePacket(pk.Marshal(
+		Handshake,                  // Handshake packet ID
+		pk.VarInt(ProtocolVersion), // Protocol version
+		pk.String(host),            // Server's address
+		pk.UnsignedShort(port),
+		pk.Byte(1),
+	))
+	if err != nil {
+		return nil, 0, fmt.Errorf("bot: send handshake packect fail: %v", err)
+	}
+
+	// LIST
+	// 请求服务器状态
+	err = conn.WritePacket(pk.Marshal(
+		packetid.ServerboundStatusStatusRequest,
+	))
+	if err != nil {
+		return nil, 0, fmt.Errorf("bot: send list packect fail: %v", err)
+	}
+
+	var p pk.Packet
+	// 服务器返回状态
+	if err := conn.ReadPacket(&p); err != nil {
+		return nil, 0, fmt.Errorf("bot: recv list packect fail: %v", err)
+	}
+	var s pk.String
+	err = p.Scan(&s)
+	if err != nil {
+		return nil, 0, fmt.Errorf("bot: scan list packect fail: %v", err)
+	}
+
+	// PING
+	startTime := time.Now()
+	err = conn.WritePacket(pk.Marshal(
+		packetid.ServerboundStatusPingRequest,
+		pk.Long(startTime.Unix()),
+	))
+	if err != nil {
+		return nil, 0, fmt.Errorf("bot: send ping packect fail: %v", err)
+	}
+
+	if err = conn.ReadPacket(&p); err != nil {
+		return nil, 0, fmt.Errorf("bot: recv pong packect fail: %v", err)
+	}
+	var t pk.Long
+	err = p.Scan(&t)
+	if err != nil {
+		return nil, 0, fmt.Errorf("bot: scan pong packect fail: %v", err)
+	}
+	if t != pk.Long(startTime.Unix()) {
+		return nil, 0, fmt.Errorf("bot: pong packect no match: %v", err)
+	}
+
+	return []byte(s), time.Since(startTime), err
+}