ssl: Add support for stateful logging

- Introduce stateful logging levels to the ssl application:
  The SSL option 'log_alert' sets log level to notice/warning
  if it is set to true/false. Default log level is notice.

- Add new SSL option 'log_level' that overrides the value of
  'log_alert'. Default value is notice.

- 'log_level' debug triggers verbose logging of TLS protocol
  messages and logging of ignored alerts in DTLS.

Change-Id: I28d3f4029a5d504ec612abe4b9ae0b7d9b115197

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/ssl/src/dtls_connection.erl b/lib/ssl/src/dtls_connection.erl
index 610ab9a51c..9596fe25c8 100644
--- a/lib/ssl/src/dtls_connection.erl
+++ b/lib/ssl/src/dtls_connection.erl
@@ -927,7 +927,7 @@ handle_own_alert(Alert, Version, StateName, #state{data_tag = udp,
                                                    ssl_options = Options} = State0) ->
     case ignore_alert(Alert, State0) of
         {true, State} ->
-            log_ignore_alert(Options#ssl_options.log_alert, StateName, Alert, Role),
+            log_ignore_alert(Options#ssl_options.log_level, StateName, Alert, Role),
             {next_state, StateName, State};
         {false, State} ->
             ssl_connection:handle_own_alert(Alert, Version, StateName, State)
@@ -1124,9 +1124,9 @@ is_ignore_alert(#alert{description = ?ILLEGAL_PARAMETER}) ->
 is_ignore_alert(_) ->
     false.
 
-log_ignore_alert(true, StateName, Alert, Role) ->
+log_ignore_alert(debug, StateName, Alert, Role) ->
     Txt = ssl_alert:alert_txt(Alert),
     ?LOG_ERROR("DTLS over UDP ~p: In state ~p ignored to send ALERT ~s as DoS-attack mitigation \n",
                  [Role, StateName, Txt]);
-log_ignore_alert(false, _, _,_) ->
+log_ignore_alert(_, _, _, _) ->
     ok.