Files
HomesteadGateway/ws/websocket.go
2025-12-01 13:40:58 +01:00

280 lines
8.4 KiB
Go

package ws
import (
"context"
"encoding/json"
"errors"
"homestead/homestead_gateway/util/config"
"log/slog"
"net"
"net/http"
"time"
"github.com/gorilla/websocket"
)
func NewWsGateway(cfg config.GatewayConfig, logger *slog.Logger, closefn func() error, modH ModHandler, botH BotHandler) *WebsocketGateway {
return &WebsocketGateway{
logger: logger,
closefn: closefn,
apiKey: cfg.Websocket,
upgrader: websocket.Upgrader{
ReadBufferSize: 1024,
WriteBufferSize: 1024,
CheckOrigin: func(r *http.Request) bool {
return true // local by default; change for production
},
},
conns: make(map[*websocket.Conn]connMetadata),
bodySizeBytes: int64(cfg.BodySize) * 1024 * 1024,
port: cfg.HttpPort,
modHandler: modH,
botHandler: botH,
}
}
func (g *WebsocketGateway) Serve(ctx context.Context, listenAddr string) error {
mux := http.NewServeMux()
mux.HandleFunc("/ws", g.handleWS)
mux.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
_, _ = w.Write([]byte("ok"))
})
srv := &http.Server{
Addr: listenAddr,
Handler: loggingMiddleware(g.logger, mux),
BaseContext: func(l net.Listener) context.Context { return ctx },
}
errCh := make(chan error, 1)
go func() {
g.logger.Info("ws gateway listening", "addr", listenAddr)
if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
errCh <- err
}
close(errCh)
}()
select {
case <-ctx.Done():
shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
g.logger.Info("shutting down http server")
_ = srv.Shutdown(shutdownCtx)
g.closeAll()
return nil
case err := <-errCh:
return err
}
}
func (g *WebsocketGateway) handleWS(w http.ResponseWriter, r *http.Request) {
if !g.validateApiKey(r) {
http.Error(w, "unauthorized", http.StatusUnauthorized)
g.logger.Warn("ws auth failed", "remote", r.RemoteAddr)
return
}
conn, err := g.upgrader.Upgrade(w, r, nil)
if err != nil {
g.logger.Error("ws upgrade error", err, "remote", r.RemoteAddr)
return
}
// Configure read limits & pong handler
if g.bodySizeBytes > 0 {
conn.SetReadLimit(g.bodySizeBytes)
} else {
conn.SetReadLimit(1 << 20) // sensible default 1MiB
}
_ = conn.SetReadDeadline(time.Now().Add(60 * time.Second))
conn.SetPongHandler(func(appData string) error {
_ = conn.SetReadDeadline(time.Now().Add(60 * time.Second))
return nil
})
// First message must be a handshake identifying the connection type
typ, data, err := conn.ReadMessage()
if err != nil {
g.logger.Error("failed to read handshake", "err", err, "remote", conn.RemoteAddr().String())
_ = conn.Close()
return
}
if typ != websocket.TextMessage && typ != websocket.BinaryMessage {
g.logger.Warn("invalid handshake message type", "remote", conn.RemoteAddr().String())
_ = writeJSONSafe(conn, map[string]string{"error": "first message must be handshake"})
_ = conn.Close()
return
}
var envelope MessageEnvelope
if err := json.Unmarshal(data, &envelope); err != nil {
g.logger.Warn("invalid handshake json", "err", err, "remote", conn.RemoteAddr().String())
_ = writeJSONSafe(conn, map[string]string{"error": "invalid handshake: " + err.Error()})
_ = conn.Close()
return
}
meta := connMetadata{connType: envelope.Type}
// Validate handshake based on type
switch envelope.Type {
case "mod":
var hs ModHandshake
if err := json.Unmarshal(envelope.Data, &hs); err != nil {
g.logger.Warn("invalid mod handshake", "err", err, "remote", conn.RemoteAddr().String())
_ = writeJSONSafe(conn, map[string]string{"error": "invalid mod handshake: " + err.Error()})
_ = conn.Close()
return
}
meta.id = hs.ServerID
g.registerConn(conn, meta)
g.logger.Info("mod connected", "server_id", hs.ServerID, "remote", conn.RemoteAddr().String())
go g.modReadLoop(conn, meta)
case "bot":
var hs BotHandshake
if err := json.Unmarshal(envelope.Data, &hs); err != nil {
g.logger.Warn("invalid bot handshake", "err", err, "remote", conn.RemoteAddr().String())
_ = writeJSONSafe(conn, map[string]string{"error": "invalid bot handshake: " + err.Error()})
_ = conn.Close()
return
}
meta.id = hs.BotID
g.registerConn(conn, meta)
g.logger.Info("bot connected", "bot_id", hs.BotID, "remote", conn.RemoteAddr().String())
go g.botReadLoop(conn, meta)
default:
g.logger.Warn("unknown connection type", "type", envelope.Type, "remote", conn.RemoteAddr().String())
_ = writeJSONSafe(conn, map[string]string{"error": "unknown connection type: " + envelope.Type})
_ = conn.Close()
return
}
}
func (g *WebsocketGateway) modReadLoop(c *websocket.Conn, meta connMetadata) {
defer func() {
g.unregisterConn(c)
_ = c.Close()
g.logger.Info("mod disconnected", "server_id", meta.id, "remote", c.RemoteAddr().String())
}()
pingTicker := time.NewTicker(30 * time.Second)
defer pingTicker.Stop()
for {
typ, data, err := c.ReadMessage()
if err != nil {
if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseNormalClosure) {
g.logger.Warn("unexpected mod close", "server_id", meta.id, "err", err)
} else {
g.logger.Debug("mod read error", "server_id", meta.id, "err", err)
}
return
}
if typ != websocket.TextMessage && typ != websocket.BinaryMessage {
continue
}
var msg GatewayModMessageIn
if err := json.Unmarshal(data, &msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "invalid json: " + err.Error()})
g.logger.Warn("invalid json from mod", "server_id", meta.id, "remote", c.RemoteAddr().String(), "err", err)
continue
}
msg.ReceivedAt = time.Now().UTC()
if err := msg.Validate(); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": err.Error()})
g.logger.Warn("mod message validation failed", "server_id", meta.id, "remote", c.RemoteAddr().String(), "err", err)
continue
}
// Handle the message (forward to bot, enrich, etc.)
if err := g.modHandler.Handle(context.Background(), msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "handler error: " + err.Error()})
g.logger.Error("mod handler error", "server_id", meta.id, "err", err)
continue
}
_ = writeJSONSafe(c, map[string]string{"status": "ok"})
// Handle pings
select {
case <-pingTicker.C:
_ = c.SetWriteDeadline(time.Now().Add(5 * time.Second))
if err := c.WriteMessage(websocket.PingMessage, nil); err != nil {
g.logger.Debug("write ping failed", "server_id", meta.id, "err", err)
return
}
default:
}
}
}
func (g *WebsocketGateway) botReadLoop(c *websocket.Conn, meta connMetadata) {
defer func() {
g.unregisterConn(c)
_ = c.Close()
g.logger.Info("bot disconnected", "bot_id", meta.id, "remote", c.RemoteAddr().String())
}()
pingTicker := time.NewTicker(30 * time.Second)
defer pingTicker.Stop()
for {
typ, data, err := c.ReadMessage()
if err != nil {
if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseNormalClosure) {
g.logger.Warn("unexpected bot close", "bot_id", meta.id, "err", err)
} else {
g.logger.Debug("bot read error", "bot_id", meta.id, "err", err)
}
return
}
if typ != websocket.TextMessage && typ != websocket.BinaryMessage {
continue
}
var msg GatewayBotMessageIn
if err := json.Unmarshal(data, &msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "invalid json: " + err.Error()})
g.logger.Warn("invalid json from bot", "bot_id", meta.id, "remote", c.RemoteAddr().String(), "err", err)
continue
}
msg.ReceivedAt = time.Now().UTC()
if err := msg.Validate(); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": err.Error()})
g.logger.Warn("bot message validation failed", "bot_id", meta.id, "remote", c.RemoteAddr().String(), "err", err)
continue
}
// Handle the message (forward to mod, enrich, etc.)
if err := g.botHandler.Handle(context.Background(), msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "handler error: " + err.Error()})
g.logger.Error("bot handler error", "bot_id", meta.id, "err", err)
continue
}
_ = writeJSONSafe(c, map[string]string{"status": "ok"})
// Handle pings
select {
case <-pingTicker.C:
_ = c.SetWriteDeadline(time.Now().Add(5 * time.Second))
if err := c.WriteMessage(websocket.PingMessage, nil); err != nil {
g.logger.Debug("write ping failed", "bot_id", meta.id, "err", err)
return
}
default:
}
}
}