feat: add return port listener for WAF async callbacks/alerts

config.go

@@ -12,6 +12,7 @@ import (
 type Config struct {
 	Enabled        bool   `json:"enabled"`
 	WAFURL         string `json:"waf_url"`
+	ReturnPort     int    `json:"return_port"`     // port for WAF async callbacks
 	HealthInterval int    `json:"health_interval"`
 	TimeoutMs      int    `json:"timeout_ms"`
 }

main.go

@@ -41,6 +41,20 @@ func main() {
 	// Start background health checker.
 	startHealthCheck()
 
+	// Return port listener for WAF async callbacks.
+	cfg := getConfig()
+	if cfg.ReturnPort > 0 {
+		go func() {
+			rmux := http.NewServeMux()
+			rmux.HandleFunc("/verdict", handleReturnVerdict)
+			addr := fmt.Sprintf(":%d", cfg.ReturnPort)
+			log.Printf("Firewall: return listener on %s", addr)
+			if err := http.ListenAndServe(addr, rmux); err != nil {
+				log.Printf("Firewall: return listener error: %v", err)
+			}
+		}()
+	}
+
 	mux := http.NewServeMux()
 
 	// Static capture handler — all proxied traffic hits this.
@@ -85,6 +99,9 @@ func handleSaveConfig(w http.ResponseWriter, r *http.Request) {
 	if u := r.FormValue("waf_url"); u != "" {
 		cfg.WAFURL = u
 	}
+	if v := r.FormValue("return_port"); v != "" {
+		fmt.Sscanf(v, "%d", &cfg.ReturnPort)
+	}
 	if v := r.FormValue("health_interval"); v != "" {
 		fmt.Sscanf(v, "%d", &cfg.HealthInterval)
 	}
@@ -105,6 +122,19 @@ func handleGetStats(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, metricsSnapshot())
 }
 
+func handleReturnVerdict(w http.ResponseWriter, r *http.Request) {
+	var v struct {
+		Verdict string `json:"verdict"`
+		Reason  string `json:"reason"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&v); err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "bad payload"})
+		return
+	}
+	log.Printf("Firewall: async verdict %s (reason=%s)", v.Verdict, v.Reason)
+	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
+}
+
 // --- Helpers ---
 
 func writeJSON(w http.ResponseWriter, status int, v interface{}) {

web/app.js

@@ -5,6 +5,7 @@ function loadConfig() {
     $('#fw-enabled').prop('checked', data.enabled);
     $('#enabled-label').text(data.enabled ? 'Firewall Enabled' : 'Firewall Disabled');
     $('#waf-url').val(data.waf_url);
+    $('#return-port').val(data.return_port);
     $('#health-interval').val(data.health_interval);
     $('#timeout-ms').val(data.timeout_ms);
   });
@@ -31,6 +32,7 @@ function saveConfig() {
     data: {
       enabled: $('#fw-enabled').is(':checked'),
       waf_url: $('#waf-url').val().trim(),
+      return_port: $('#return-port').val(),
       health_interval: $('#health-interval').val(),
       timeout_ms: $('#timeout-ms').val()
     },

web/index.html

@@ -31,6 +31,12 @@
         <small>The firewall service that inspects each request and returns a verdict.</small>
       </div>
 
+      <div class="field">
+        <label for="return-port">Return Port (async callbacks)</label>
+        <input type="number" id="return-port" placeholder="9090" min="1" max="65535">
+        <small>WAF sends async verdicts/alerts to this port.</small>
+      </div>
+
       <div class="field">
         <label for="health-interval">Health Check Interval (s)</label>
         <input type="number" id="health-interval" placeholder="5" min="1" max="60">