the files

2026-10-14 06:59:51 +02:00
parent f6175893fc
commit 2040419525
1855 changed files with 6735668 additions and 0 deletions
@@ -0,0 +1,87 @@
+using System.Net;
+using System.Net.Sockets;
+
+namespace Campus_live_rewrite.api.server
+{
+    /// <summary>
+    /// Which CDN base /ns hands the client: ConfigCampus.CdnBaseUrl (its own host - needed for
+    /// avatar bundles to load, see the comment there) once that host is proven to work, else
+    /// ConfigCampus.CdnFallbackUrl. A CDN URL the client cannot use stops the game at "Launch
+    /// validation failed" (it fetches /cdn/config/... during boot), so the switch is never
+    /// taken on trust: every 5 minutes the host must (1) resolve in DNS to one of the API
+    /// host's addresses and (2) answer a /cdn request with 200 over https with a certificate
+    /// that validates for that name. The https check is dialled to the local Caddy (127.0.0.1)
+    /// with the real hostname as SNI/Host, so it does not depend on the VPS reaching its own
+    /// public IP.
+    /// </summary>
+    public static class CdnHost
+    {
+        private static volatile string _current = ConfigCampus.CdnFallbackUrl;
+        private static string? _lastState;
+
+        public static string Current => _current;
+
+        public static void Start()
+        {
+            _ = Task.Run(async () =>
+            {
+                while (true)
+                {
+                    try { await Probe(); }
+                    catch (Exception ex) { Report($"probe error: {ex.Message}", ConfigCampus.CdnFallbackUrl); }
+                    await Task.Delay(TimeSpan.FromMinutes(5));
+                }
+            });
+        }
+
+        private static async Task Probe()
+        {
+            var cdn = new Uri(ConfigCampus.CdnBaseUrl);
+            var api = new Uri(ConfigCampus.CdnFallbackUrl);
+            if (cdn.Scheme != Uri.UriSchemeHttps) { Report("CdnBaseUrl is not https (the client rejects it)", api.ToString()); return; }
+            if (string.Equals(cdn.Host, api.Host, StringComparison.OrdinalIgnoreCase)) { Report("CdnBaseUrl is on the API host", ConfigCampus.CdnBaseUrl); return; }
+
+            IPAddress[] cdnIps, apiIps;
+            try { cdnIps = await Dns.GetHostAddressesAsync(cdn.Host); }
+            catch (Exception ex) { Report($"{cdn.Host} does not resolve ({ex.Message.Trim()})", ConfigCampus.CdnFallbackUrl); return; }
+            apiIps = await Dns.GetHostAddressesAsync(api.Host);
+            if (!cdnIps.Any(a => apiIps.Contains(a)))
+            {
+                Report($"{cdn.Host} resolves to {string.Join(",", cdnIps.Select(a => a.ToString()))}, not this server", ConfigCampus.CdnFallbackUrl);
+                return;
+            }
+
+            var handler = new SocketsHttpHandler
+            {
+                ConnectCallback = async (ctx, ct) =>
+                {
+                    var s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
+                    try { await s.ConnectAsync(IPAddress.Loopback, cdn.Port, ct); return new NetworkStream(s, ownsSocket: true); }
+                    catch { s.Dispose(); throw; }
+                },
+            };
+            using var http = new HttpClient(handler) { Timeout = TimeSpan.FromSeconds(10) };
+            var probe = new Uri(cdn, cdn.AbsolutePath.TrimEnd('/') + "/config/LoadingScreenTipData");
+            try
+            {
+                using var resp = await http.GetAsync(probe, HttpCompletionOption.ResponseHeadersRead);
+                if (resp.StatusCode != HttpStatusCode.OK) { Report($"{probe} answered {(int)resp.StatusCode}", ConfigCampus.CdnFallbackUrl); return; }
+            }
+            catch (Exception ex)
+            {
+                Report($"{probe} failed over https ({(ex.InnerException ?? ex).Message.Trim()})", ConfigCampus.CdnFallbackUrl);
+                return;
+            }
+            Report($"{cdn.Host} is live", ConfigCampus.CdnBaseUrl);
+        }
+
+        private static void Report(string why, string url)
+        {
+            _current = url;
+            string state = url + " | " + why;
+            if (state == _lastState) return;
+            _lastState = state;
+            Console.WriteLine($"[cdn-host] advertising {url} - {why}");
+        }
+    }
+}