From 41de5e78d0f792586487e33a8b1e2a0cf405e0be Mon Sep 17 00:00:00 2001
From: Holger Weiss <holger@zedat.fu-berlin.de>
Date: Mon, 27 Mar 2017 23:19:11 +0200
Subject: [PATCH] ejabberd_http: Add "custom_headers" option

If the new listener option "custom_headers" is specified, include those
headers with the HTTP(S) response.

Closes #517.
---
 src/ejabberd_http.erl | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/ejabberd_http.erl b/src/ejabberd_http.erl
index 4b1242568..4c5dd8ebe 100644
--- a/src/ejabberd_http.erl
+++ b/src/ejabberd_http.erl
@@ -68,6 +68,7 @@
 		end_of_request = false,
 		options = [],
 		default_host,
+		custom_headers,
 		trail = <<>>,
 		addr_re
 	       }).
@@ -167,10 +168,15 @@ init({SockMod, Socket}, Opts) ->
     DefaultHost = gen_mod:get_opt(default_host, Opts, fun(A) -> A end, undefined),
     {ok, RE} = re:compile(<<"^(?:\\[(.*?)\\]|(.*?))(?::(\\d+))?$">>),
 
+    CustomHeaders = gen_mod:get_opt(custom_headers, Opts,
+				    fun(L) when is_list(L) -> L end,
+				    []),
+
     ?INFO_MSG("started: ~p", [{SockMod1, Socket1}]),
     State = #state{sockmod = SockMod1,
                    socket = Socket1,
                    default_host = DefaultHost,
+		   custom_headers = CustomHeaders,
 		   options = Opts,
 		   request_handlers = RequestHandlers,
 		   addr_re = RE},
@@ -309,6 +315,7 @@ process_header(State, Data) ->
 		       trail = State3#state.trail,
 		       options = State#state.options,
 		       default_host = State#state.default_host,
+		       custom_headers = State#state.custom_headers,
 		       request_handlers = State#state.request_handlers,
 		       addr_re = State#state.addr_re};
 	    _ ->
@@ -316,6 +323,7 @@ process_header(State, Data) ->
 		       trail = State3#state.trail,
 		       options = State#state.options,
 		       default_host = State#state.default_host,
+		       custom_headers = State#state.custom_headers,
 		       request_handlers = State#state.request_handlers,
 		       addr_re = State#state.addr_re}
 	  end;
@@ -323,6 +331,7 @@ process_header(State, Data) ->
 	  #state{end_of_request = true,
 		 options = State#state.options,
 		 default_host = State#state.default_host,
+		 custom_headers = State#state.custom_headers,
 		 request_handlers = State#state.request_handlers,
 		 addr_re = State#state.addr_re}
     end.
@@ -446,6 +455,7 @@ process_request(#state{request_method = Method,
 		       request_tp = TP,
 		       request_headers = RequestHeaders,
 		       request_handlers = RequestHandlers,
+		       custom_headers = CustomHeaders,
 		       trail = Trail} = State) ->
     case extract_path_query(State) of
 	{State2, false} ->
@@ -478,18 +488,21 @@ process_request(#state{request_method = Method,
                                ip = IP},
 	    Res = case process(RequestHandlers, Request, Socket, SockMod, Trail) of
 		      El when is_record(El, xmlel) ->
-			  make_xhtml_output(State, 200, [], El);
+			  make_xhtml_output(State, 200, CustomHeaders, El);
 		      {Status, Headers, El}
 			when is_record(El, xmlel) ->
-			  make_xhtml_output(State, Status, Headers, El);
+			  make_xhtml_output(State, Status,
+					    Headers ++ CustomHeaders, El);
 		      Output when is_binary(Output) or is_list(Output) ->
-			  make_text_output(State, 200, [], Output);
+			  make_text_output(State, 200, CustomHeaders, Output);
 		      {Status, Headers, Output}
 			when is_binary(Output) or is_list(Output) ->
-			  make_text_output(State, Status, Headers, Output);
+			  make_text_output(State, Status,
+					   Headers ++ CustomHeaders, Output);
 		      {Status, Reason, Headers, Output}
 			when is_binary(Output) or is_list(Output) ->
-			  make_text_output(State, Status, Reason, Headers, Output);
+			  make_text_output(State, Status, Reason,
+					   Headers ++ CustomHeaders, Output);
 		      _ ->
 			  none
 		  end,
@@ -497,7 +510,7 @@ process_request(#state{request_method = Method,
     end.
 
 make_bad_request(State) ->
-    make_xhtml_output(State, 400, [],
+    make_xhtml_output(State, 400, State#state.custom_headers,
 		      ejabberd_web:make_xhtml([#xmlel{name = <<"h1">>,
 						      attrs = [],
 						      children =