From 5688f8d67907a0bc01bc60016217c32929eef5a4 Mon Sep 17 00:00:00 2001
From: FCS <fcs@rabe11.de>
Date: Sun, 30 Aug 2026 11:28:14 +0200
Subject: [PATCH] Verbesserung Redirect

---
 lib/webinterface/webinterface.cpp | 80 ++++++++++++++++++++++++++++++-
 1 file changed, 79 insertions(+), 1 deletion(-)

diff --git a/lib/webinterface/webinterface.cpp b/lib/webinterface/webinterface.cpp
index 1dbe0bc..d7d9f3d 100644
--- a/lib/webinterface/webinterface.cpp
+++ b/lib/webinterface/webinterface.cpp
@@ -78,6 +78,51 @@ String html_escape(const String &value)
   return escaped;
 }
 
+bool is_captive_portal_target(const String &host, const String &uri)
+{
+  String lowercase_host = host;
+  lowercase_host.toLowerCase();
+
+  String lowercase_uri = uri;
+  lowercase_uri.toLowerCase();
+
+  static const char *captive_hosts[] = {
+      "connectivitycheck.gstatic.com",
+      "clients3.google.com",
+      "google.com",
+      "www.google.com",
+      "msftconnecttest.com",
+      "msftncsi.com",
+      "captive.apple.com",
+      "www.apple.com",
+      "apple.com",
+      "connectivitycheck.android.com"};
+
+  for (const char *candidate : captive_hosts)
+  {
+    if (lowercase_host == candidate)
+      return true;
+  }
+
+  static const char *captive_paths[] = {
+      "/generate_204",
+      "/hotspot-detect.html",
+      "/library/test/success.html",
+      "/connecttest.txt",
+      "/redirect",
+      "/ncsi.txt",
+      "/success.txt",
+      "/wap"};
+
+  for (const char *candidate : captive_paths)
+  {
+    if (lowercase_uri == candidate)
+      return true;
+  }
+
+  return false;
+}
+
 void redirect_to_root(const String &message, bool success)
 {
   String location = String("/?status=") + (success ? "success" : "error") + "&msg=" + url_encode(message);
@@ -85,6 +130,21 @@ void redirect_to_root(const String &message, bool success)
   server.send(303, "text/plain; charset=utf-8", "");
 }
 
+void handle_captive_portal_redirect()
+{
+  String host = server.hostHeader();
+  String uri = server.uri();
+
+  if (is_captive_portal_target(host, uri))
+  {
+    server.sendHeader("Location", "/", true);
+    server.send(302, "text/plain; charset=utf-8", "");
+    return;
+  }
+
+  server.send(404, "text/plain; charset=utf-8", "Not Found");
+}
+
 void send_page(const String &message = String())
 {
   String page;
@@ -174,6 +234,9 @@ void handle_settings()
     return;
   }
 
+  const bool ap_name_changed = active_settings->access_point_name != updated.access_point_name;
+  const bool ap_password_changed = active_settings->access_point_password != updated.access_point_password;
+
   active_settings->callsign = updated.callsign;
   active_settings->access_point_name = updated.access_point_name;
   active_settings->access_point_password = updated.access_point_password;
@@ -186,7 +249,10 @@ void handle_settings()
   preferences.putInt("min", active_settings->min_speed);
   preferences.putInt("max", active_settings->max_speed);
   preferences.putUInt("active_time", active_settings->active_time_seconds);
-  access_point_restart_pending = true;
+
+  if (ap_name_changed || ap_password_changed)
+    access_point_restart_pending = true;
+
   redirect_to_root("Einstellungen gespeichert.", true);
 }
 
@@ -283,10 +349,22 @@ bool webinterface_begin(TelemetrySettings &settings)
     return false;
 
   access_point_started_ms = millis();
+  dns_server.start(53, "connectivitycheck.gstatic.com", WiFi.softAPIP());
+  dns_server.start(53, "clients3.google.com", WiFi.softAPIP());
+  dns_server.start(53, "msftconnecttest.com", WiFi.softAPIP());
+  dns_server.start(53, "msftncsi.com", WiFi.softAPIP());
+  dns_server.start(53, "captive.apple.com", WiFi.softAPIP());
+  dns_server.start(53, "apple.com", WiFi.softAPIP());
   dns_server.start(53, "*", WiFi.softAPIP());
   server.on("/", HTTP_GET, handle_root);
+  server.on("/generate_204", HTTP_GET, handle_captive_portal_redirect);
+  server.on("/hotspot-detect.html", HTTP_GET, handle_captive_portal_redirect);
+  server.on("/connecttest.txt", HTTP_GET, handle_captive_portal_redirect);
+  server.on("/ncsi.txt", HTTP_GET, handle_captive_portal_redirect);
+  server.on("/success.txt", HTTP_GET, handle_captive_portal_redirect);
   server.on("/settings", HTTP_POST, handle_settings);
   server.on("/update", HTTP_POST, handle_update_result, handle_update_upload);
+  server.onNotFound(handle_captive_portal_redirect);
   server.begin();
   Serial.print("Firmware-Version: ");
   Serial.println(firmware_version_string());