aggressive error handle

DnsForwarder/Program.cs

@@ -60,32 +60,45 @@ namespace DnsForwarder
 
         private static void Callback(IAsyncResult ar)
         {
+            var flagNextStarted = false;
             EndPoint from = new IPEndPoint(IPAddress.Any, 0);
-            var count = _listener.EndReceiveFrom(ar, ref from);
-            var buf = (byte[])ar.AsyncState;
+            string domain = null;
+            string target = null;
 
-            StartHandleRequest();
+            try
+            {
+                var count = _listener.EndReceiveFrom(ar, ref from);
 
-            var domain = ExtractDomainName(buf, count);
+                StartHandleRequest();
+                flagNextStarted = true;
 
-            var target = MatchServer(domain);
+                var buf = (byte[])ar.AsyncState;
+
+                domain = ExtractDomainName(buf);
+
+                target = MatchServer(domain);
 
-            try
-            {
                 var dnsResponse = GetDnsResponse(buf, count, target);
                 if (dnsResponse != null) _listener.SendTo(dnsResponse, from);
                 _consoleOutout.Add($"{DateTime.Now:yyyyMMdd HH:mm:ss} {from} [{target}]\t{domain}");
             }
             catch (Exception e)
             {
-                _consoleOutout.Add($"{DateTime.Now:yyyyMMdd HH:mm:ss} {from} [{target}]\t{domain} ERR:{e.Message}");
+                _consoleOutout.Add($"{DateTime.Now:yyyyMMdd HH:mm:ss} {from} [{target ?? "Unknown"}]\t{domain ?? "Unknown"} Err:{e.Message}");
+            }
+            catch
+            {
+                _consoleOutout.Add($"{DateTime.Now:yyyyMMdd HH:mm:ss} {from} [{target ?? "Unknown"}]\t{domain ?? "Unknown"} Err:Unknown");
+            }
+            finally
+            {
+                if (flagNextStarted == false) StartHandleRequest();
             }
         }
 
-        protected static string ExtractDomainName(byte[] buf, int count)
+        protected static string ExtractDomainName(byte[] buf)
         {
-            var lst = new List<byte[]>();
-
+            //seeking for end of domain
             var ptr = 12;
             while (buf[ptr] != 0)
             {
@@ -95,7 +108,7 @@ namespace DnsForwarder
             var bufDomain = new byte[ptr - 12];
             Array.Copy(buf, 12, bufDomain, 0, bufDomain.Length);
 
-            //dot fill
+            //fill dots
             ptr = 0;
             while (ptr < bufDomain.Length)
             {