rename /src to /internal (sorry i'll fix the prs)

internal/hub/ws/ws.go

@@ -0,0 +1,182 @@
+package ws
+
+import (
+	"errors"
+	"time"
+	"weak"
+
+	"github.com/henrygd/beszel/src/entities/system"
+
+	"github.com/henrygd/beszel/src/common"
+
+	"github.com/fxamacker/cbor/v2"
+	"github.com/lxzan/gws"
+	"golang.org/x/crypto/ssh"
+)
+
+const (
+	deadline = 70 * time.Second
+)
+
+// Handler implements the WebSocket event handler for agent connections.
+type Handler struct {
+	gws.BuiltinEventHandler
+}
+
+// WsConn represents a WebSocket connection to an agent.
+type WsConn struct {
+	conn         *gws.Conn
+	responseChan chan *gws.Message
+	DownChan     chan struct{}
+}
+
+// FingerprintRecord is fingerprints collection record data in the hub
+type FingerprintRecord struct {
+	Id          string `db:"id"`
+	SystemId    string `db:"system"`
+	Fingerprint string `db:"fingerprint"`
+	Token       string `db:"token"`
+}
+
+var upgrader *gws.Upgrader
+
+// GetUpgrader returns a singleton WebSocket upgrader instance.
+func GetUpgrader() *gws.Upgrader {
+	if upgrader != nil {
+		return upgrader
+	}
+	handler := &Handler{}
+	upgrader = gws.NewUpgrader(handler, &gws.ServerOption{})
+	return upgrader
+}
+
+// NewWsConnection creates a new WebSocket connection wrapper.
+func NewWsConnection(conn *gws.Conn) *WsConn {
+	return &WsConn{
+		conn:         conn,
+		responseChan: make(chan *gws.Message, 1),
+		DownChan:     make(chan struct{}, 1),
+	}
+}
+
+// OnOpen sets a deadline for the WebSocket connection.
+func (h *Handler) OnOpen(conn *gws.Conn) {
+	conn.SetDeadline(time.Now().Add(deadline))
+}
+
+// OnMessage routes incoming WebSocket messages to the response channel.
+func (h *Handler) OnMessage(conn *gws.Conn, message *gws.Message) {
+	conn.SetDeadline(time.Now().Add(deadline))
+	if message.Opcode != gws.OpcodeBinary || message.Data.Len() == 0 {
+		return
+	}
+	wsConn, ok := conn.Session().Load("wsConn")
+	if !ok {
+		_ = conn.WriteClose(1000, nil)
+		return
+	}
+	select {
+	case wsConn.(*WsConn).responseChan <- message:
+	default:
+		// close if the connection is not expecting a response
+		wsConn.(*WsConn).Close(nil)
+	}
+}
+
+// OnClose handles WebSocket connection closures and triggers system down status after delay.
+func (h *Handler) OnClose(conn *gws.Conn, err error) {
+	wsConn, ok := conn.Session().Load("wsConn")
+	if !ok {
+		return
+	}
+	wsConn.(*WsConn).conn = nil
+	// wait 5 seconds to allow reconnection before setting system down
+	// use a weak pointer to avoid keeping references if the system is removed
+	go func(downChan weak.Pointer[chan struct{}]) {
+		time.Sleep(5 * time.Second)
+		downChanValue := downChan.Value()
+		if downChanValue != nil {
+			*downChanValue <- struct{}{}
+		}
+	}(weak.Make(&wsConn.(*WsConn).DownChan))
+}
+
+// Close terminates the WebSocket connection gracefully.
+func (ws *WsConn) Close(msg []byte) {
+	if ws.IsConnected() {
+		ws.conn.WriteClose(1000, msg)
+	}
+}
+
+// Ping sends a ping frame to keep the connection alive.
+func (ws *WsConn) Ping() error {
+	ws.conn.SetDeadline(time.Now().Add(deadline))
+	return ws.conn.WritePing(nil)
+}
+
+// sendMessage encodes data to CBOR and sends it as a binary message to the agent.
+func (ws *WsConn) sendMessage(data common.HubRequest[any]) error {
+	if ws.conn == nil {
+		return gws.ErrConnClosed
+	}
+	bytes, err := cbor.Marshal(data)
+	if err != nil {
+		return err
+	}
+	return ws.conn.WriteMessage(gws.OpcodeBinary, bytes)
+}
+
+// RequestSystemData requests system metrics from the agent and unmarshals the response.
+func (ws *WsConn) RequestSystemData(data *system.CombinedData) error {
+	var message *gws.Message
+
+	ws.sendMessage(common.HubRequest[any]{
+		Action: common.GetData,
+	})
+	select {
+	case <-time.After(10 * time.Second):
+		ws.Close(nil)
+		return gws.ErrConnClosed
+	case message = <-ws.responseChan:
+	}
+	defer message.Close()
+	return cbor.Unmarshal(message.Data.Bytes(), data)
+}
+
+// GetFingerprint authenticates with the agent using SSH signature and returns the agent's fingerprint.
+func (ws *WsConn) GetFingerprint(token string, signer ssh.Signer, needSysInfo bool) (common.FingerprintResponse, error) {
+	var clientFingerprint common.FingerprintResponse
+	challenge := []byte(token)
+
+	signature, err := signer.Sign(nil, challenge)
+	if err != nil {
+		return clientFingerprint, err
+	}
+
+	err = ws.sendMessage(common.HubRequest[any]{
+		Action: common.CheckFingerprint,
+		Data: common.FingerprintRequest{
+			Signature:   signature.Blob,
+			NeedSysInfo: needSysInfo,
+		},
+	})
+	if err != nil {
+		return clientFingerprint, err
+	}
+
+	var message *gws.Message
+	select {
+	case message = <-ws.responseChan:
+	case <-time.After(10 * time.Second):
+		return clientFingerprint, errors.New("request expired")
+	}
+	defer message.Close()
+
+	err = cbor.Unmarshal(message.Data.Bytes(), &clientFingerprint)
+	return clientFingerprint, err
+}
+
+// IsConnected returns true if the WebSocket connection is active.
+func (ws *WsConn) IsConnected() bool {
+	return ws.conn != nil
+}