Files
HomesteadGateway/ws/websocket.go

293 lines
8.6 KiB
Go

package ws
import (
"context"
"encoding/json"
"fmt"
"homestead/homestead_gateway/util/config"
"log/slog"
"net"
"net/http"
"os/signal"
"syscall"
"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]connectionMetaData),
bodySizeBytes: int64(cfg.BodySize) * 1024 * 1024,
port: cfg.HttpPort,
modHandler: modH,
botHandler: botH,
}
}
func (wsg *WebsocketGateway) Start() error {
ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
defer stop()
return wsg.Serve(ctx, fmt.Sprintf(":%d", wsg.port))
}
func (wsg *WebsocketGateway) Serve(ctx context.Context, listenAddr string) error {
mux := http.NewServeMux()
mux.HandleFunc("/push", wsg.handlePush)
mux.HandleFunc("/ready", wsg.handleReady)
mux.HandleFunc("/health", wsg.handleHealth)
mux.HandleFunc("/register", wsg.handleRegister)
srv := &http.Server{
Addr: listenAddr,
Handler: loggingMiddleware(wsg.logger, mux),
BaseContext: func(l net.Listener) context.Context { return ctx },
}
errCh := make(chan error, 1)
go wsg.listen(srv, listenAddr, errCh)
select {
case <-ctx.Done():
wsg.deafen(srv)
return nil
case err := <-errCh:
return err
}
}
//
func (wsg *WebsocketGateway) handlePush(w http.ResponseWriter, r *http.Request) {
conn, err := wsg.validateAndUpgradeConnection(w, r)
if err != nil {
return
}
if wsg.bodySizeBytes > 0 {
conn.SetReadLimit(wsg.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
})
typ, data, err := conn.ReadMessage()
if err != nil {
wsg.sendWebsocketError(conn, "Internal Server Error", 500)
wsg.logger.Error("Failed to read handshake.", "remote", conn.RemoteAddr().String(), "err", err)
return
}
if typ != websocket.TextMessage && typ != websocket.BinaryMessage {
wsg.sendWebsocketError(conn, "First message must be a handshake.", 400)
wsg.logger.Warn("Invalid handshake message type.", "remote", conn.RemoteAddr().String())
return
}
var handshake Handshake
if err := json.Unmarshal(data, &handshake); err != nil {
wsg.sendWebsocketError(conn, "Malformed handshake.", 400)
wsg.logger.Warn("Malformed handshake.", "remote", conn.RemoteAddr().String(), "err", err)
return
}
meta := connectionMetaData{connectionType: handshake.Type}
switch handshake.Type {
case "mod":
var mhs ModHandshake
if err := json.Unmarshal(handshake.Data, &mhs); err != nil {
wsg.sendWebsocketError(conn, "Malformed mod handshake.", 400)
wsg.logger.Warn("Malformed mod handshake.", "remote", conn.RemoteAddr().String(), "err", err)
return
}
meta.id = mhs.ServerID
if err = wsg.sendWebsocketResponse(conn, GatewayAck{Status: "connected", Type: "mod"}); err != nil {
return
}
wsg.registerConn(conn, meta)
wsg.logger.Info("Mod connected via Websocket.", "remote", conn.RemoteAddr().String(), "server_id", mhs.ServerID)
go wsg.modReadLoop(conn, meta) // replace with external handler mayhaps
case "bot":
var bhs BotHandshake
if err := json.Unmarshal(handshake.Data, &bhs); err != nil {
wsg.sendWebsocketError(conn, "Malformed bot handshake.", 400)
wsg.logger.Warn("Malformed bot handshake.", "remote", conn.RemoteAddr().String(), "err", err)
return
}
meta.id = bhs.BotID
if err = wsg.sendWebsocketResponse(conn, GatewayAck{Status: "connected", Type: "bot"}); err != nil {
return
}
wsg.registerConn(conn, meta)
wsg.logger.Info("Bot connected via Websocket.", "remote", conn.RemoteAddr().String(), "bot_id", bhs.BotID)
go wsg.botReadLoop(conn, meta) // replace with external handler mayhaps
default:
wsg.sendWebsocketError(conn, "Unknown handshake.", 400)
wsg.logger.Warn("Unknown connection type.", "remote", conn.RemoteAddr().String(), "type", handshake.Type)
return
}
}
func (wsg *WebsocketGateway) handleReady(w http.ResponseWriter, r *http.Request) {}
func (wsg *WebsocketGateway) handleHealth(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(200)
_ = json.NewEncoder(w).Encode(map[string]interface{}{"status": "healthy"})
}
func (wsg *WebsocketGateway) handleRegister(w http.ResponseWriter, r *http.Request) {}
//
func (wsg *WebsocketGateway) modReadLoop(c *websocket.Conn, meta connectionMetaData) {
defer func() {
wsg.unregisterConn(c)
_ = c.Close()
wsg.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) {
wsg.logger.Warn("unexpected mod close", "server_id", meta.id, "err", err)
} else {
wsg.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()})
wsg.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()})
wsg.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 := wsg.modHandler.Handle(context.Background(), msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "handler error: " + err.Error()})
wsg.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 {
wsg.logger.Debug("write ping failed", "server_id", meta.id, "err", err)
return
}
default:
}
}
}
func (wsg *WebsocketGateway) botReadLoop(c *websocket.Conn, meta connectionMetaData) {
defer func() {
wsg.unregisterConn(c)
_ = c.Close()
wsg.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) {
wsg.logger.Warn("unexpected bot close", "bot_id", meta.id, "err", err)
} else {
wsg.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()})
wsg.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()})
wsg.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 := wsg.botHandler.Handle(context.Background(), msg); err != nil {
_ = writeJSONSafe(c, map[string]string{"error": "handler error: " + err.Error()})
wsg.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 {
wsg.logger.Debug("write ping failed", "bot_id", meta.id, "err", err)
return
}
default:
}
}
}