From 95a8f583143a15b658625dde6e0a925359b55e63 Mon Sep 17 00:00:00 2001
From: Evgeniy Khramtsov <ekhramtsov@process-one.net>
Date: Tue, 28 Feb 2017 10:13:09 +0300
Subject: [PATCH] Improve logging of dialback failures

---
 src/mod_s2s_dialback.erl | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/mod_s2s_dialback.erl b/src/mod_s2s_dialback.erl
index d48bda2d9..4d9ae1af2 100644
--- a/src/mod_s2s_dialback.erl
+++ b/src/mod_s2s_dialback.erl
@@ -248,8 +248,10 @@ s2s_out_packet(#{server := LServer, remote_server := RServer} = State,
 	    State2 = ejabberd_s2s_out:handle_auth_success(<<"dialback">>, State1),
 	    ejabberd_s2s_out:establish(State2);
 	_ ->
-	    Reason = format_error(Result),
-	    ejabberd_s2s_out:handle_auth_failure(<<"dialback">>, {auth, Reason}, State1)
+	    Reason = str:format("Peer responded with error: ~s",
+				[format_error(Result)]),
+	    ejabberd_s2s_out:handle_auth_failure(
+	      <<"dialback">>, {auth, Reason}, State1)
     end;
 s2s_out_packet(State, Pkt) when is_record(Pkt, db_result);
 				is_record(Pkt, db_verify) ->
@@ -298,7 +300,8 @@ send_db_result(State, #db_verify{from = From, to = To,
 		       From, <<"dialback">>, undefined, State1),
 	    ejabberd_s2s_in:establish(State2);
 	_ ->
-	    Reason = format_error(Response),
+	    Reason = str:format("Verification failed: ~s",
+				[format_error(Response)]),
 	    ejabberd_s2s_in:handle_auth_failure(
 	      From, <<"dialback">>, Reason, State1)
     end.
@@ -334,10 +337,25 @@ format_error(#db_result{type = invalid}) ->
 format_error(#db_result{type = error, sub_els = Els}) ->
     %% TODO: improve xmpp.erl
     case xmpp:get_error(#message{sub_els = Els}) of
-	#stanza_error{reason = Reason} ->
-	    erlang:atom_to_binary(Reason, latin1);
+	#stanza_error{} = Err ->
+	    format_stanza_error(Err);
 	undefined ->
 	    <<"unrecognized error">>
     end;
 format_error(_) ->
     <<"unexpected dialback result">>.
+
+-spec format_stanza_error(stanza_error()) -> binary().
+format_stanza_error(#stanza_error{reason = Reason, text = Txt}) ->
+    Slogan = case Reason of
+		 undefined -> <<"no reason">>;
+		 #gone{} -> <<"gone">>;
+		 #redirect{} -> <<"redirect">>;
+		 _ -> erlang:atom_to_binary(Reason, latin1)
+	     end,
+    case Txt of
+	undefined -> Slogan;
+	#text{data = <<"">>} -> Slogan;
+	#text{data = Data} ->
+	    <<Data/binary, " (", Slogan/binary, ")">>
+    end.