feat: 实现 WebSocket、mochi broker 与下行发布

internal/broker/ws.go

@@ -0,0 +1,41 @@
+package broker
+
+import (
+	"context"
+	"net"
+	"net/http"
+
+	"git.asio.asia/nixevol/NixMsg/internal/listener"
+	"github.com/coder/websocket"
+)
+
+// WSHandler 返回 /mqtt 的 WebSocket 升级处理。
+// Accept 时 InsecureSkipVerify=true；之后检查 Subprotocol==mqtt。
+// NetConn 使用 Background 派生的 context，不用请求 Context。
+func (b *Broker) WSHandler(proxies *listener.ProxySet) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		c, err := websocket.Accept(w, r, &websocket.AcceptOptions{
+			Subprotocols:       []string{"mqtt"},
+			InsecureSkipVerify: true,
+		})
+		if err != nil {
+			return
+		}
+		if c.Subprotocol() != "mqtt" {
+			_ = c.Close(websocket.StatusPolicyViolation, "subprotocol must be mqtt")
+			return
+		}
+
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		nc := websocket.NetConn(ctx, c, websocket.MessageBinary)
+		if proxies != nil {
+			ip := proxies.ClientIP(r)
+			if ip != "" {
+				nc = listener.WithRemoteAddr(nc, &net.TCPAddr{IP: net.ParseIP(ip)})
+			}
+		}
+		_ = b.AttachWS(nc)
+	})
+}