Add AsyncSocketExceptionType for early data rejection.

Summary: To be used to signal that data that was sent as TLS 1.3 early data was lost. This needs its own exception type as it requires special handling (ie it should usually be retried immediately).

Reviewed By: siyengar

Differential Revision: D5869914

fbshipit-source-id: ca0d8ef19cb991e9d6ffe0f8c99abfb03b748ce6

folly/io/async/AsyncSocketException.h

@@ -40,7 +40,8 @@ class AsyncSocketException : public std::runtime_error {
     SSL_ERROR = 12,
     COULD_NOT_BIND = 13,
     SASL_HANDSHAKE_TIMEOUT = 14,
-    NETWORK_ERROR = 15
+    NETWORK_ERROR = 15,
+    EARLY_DATA_REJECTED = 16,
   };
 
   AsyncSocketException(AsyncSocketExceptionType type,
@@ -100,6 +101,8 @@ class AsyncSocketException : public std::runtime_error {
         return "SASL handshake timeout";
       case NETWORK_ERROR:
         return "Network error";
+      case EARLY_DATA_REJECTED:
+        return "Early data rejected";
       default:
         return "(Invalid exception type)";
     }