Ensure no more than one response per request
Due to a retry loop in erlfb:transactional couchdb might try to send
multiple http responses for a single request which is clearly an
error.
This PR ensures the second attempt is prevented, closing the TCP
socket instead.
diff --git a/src/chttpd/src/chttpd.erl b/src/chttpd/src/chttpd.erl
index 53fdf98..ba26b2b 100644
--- a/src/chttpd/src/chttpd.erl
+++ b/src/chttpd/src/chttpd.erl
@@ -160,6 +160,7 @@
mochiweb_http:stop(?MODULE).
handle_request(MochiReq0) ->
+ couch_httpd:response_not_started(),
MochiReq = couch_httpd_vhost:dispatch_host(MochiReq0),
handle_request_int(MochiReq).
@@ -1330,8 +1331,10 @@
respond_(Req1, Code1, Headers1, Args1, Type).
respond_(#httpd{mochi_req = MochiReq}, Code, Headers, _Args, start_response) ->
+ couch_httpd:abort_if_response_already_started(),
MochiReq:start_response({Code, Headers});
respond_(#httpd{mochi_req = MochiReq}, Code, Headers, Args, Type) ->
+ couch_httpd:abort_if_response_already_started(),
MochiReq:Type({Code, Headers, Args}).
get_user(#httpd{user_ctx = #user_ctx{name = null}}) ->
diff --git a/src/chttpd/test/eunit/chttpd_handlers_tests.erl b/src/chttpd/test/eunit/chttpd_handlers_tests.erl
index 649d82e..489ff67 100644
--- a/src/chttpd/test/eunit/chttpd_handlers_tests.erl
+++ b/src/chttpd/test/eunit/chttpd_handlers_tests.erl
@@ -63,6 +63,15 @@
end).
+prevent_multiple_http_response_test() ->
+ ?assertEqual(undefined, couch_httpd:abort_if_response_already_started()),
+ ?assertEqual(true, couch_httpd:response_not_started()),
+ ?assertEqual(undefined, couch_httpd:abort_if_response_already_started()),
+ Err = multiple_responses_attempted,
+ ?assertThrow({http_abort, {mochiweb_response, _}, Err},
+ couch_httpd:abort_if_response_already_started()).
+
+
json_value(JSON, Keys) ->
couch_util:get_nested_json_value(JSON, Keys).
diff --git a/src/couch/src/couch_httpd.erl b/src/couch/src/couch_httpd.erl
index fd83c25..b90d6da 100644
--- a/src/couch/src/couch_httpd.erl
+++ b/src/couch/src/couch_httpd.erl
@@ -36,6 +36,7 @@
-export([validate_bind_address/1]).
-export([check_max_request_length/1]).
-export([maybe_decompress/2]).
+-export([response_not_started/0, abort_if_response_already_started/0]).
-define(HANDLER_NAME_IN_MODULE_POS, 6).
-define(MAX_DRAIN_BYTES, 1048576).
@@ -871,6 +872,7 @@
end.
http_respond_(#httpd{mochi_req = MochiReq}, Code, Headers, _Args, start_response) ->
+ abort_if_response_already_started(),
MochiReq:start_response({Code, Headers});
http_respond_(#httpd{mochi_req = MochiReq}, 413, Headers, Args, Type) ->
% Special handling for the 413 response. Make sure the socket is closed as
@@ -885,9 +887,24 @@
mochiweb_socket:recv(Socket, ?MAX_DRAIN_BYTES, ?MAX_DRAIN_TIME_MSEC),
Result;
http_respond_(#httpd{mochi_req = MochiReq}, Code, Headers, Args, Type) ->
+ abort_if_response_already_started(),
MochiReq:Type({Code, Headers, Args}).
+response_not_started() ->
+ erase(http_response_started).
+
+
+abort_if_response_already_started() ->
+ case get(http_response_started) of
+ undefined ->
+ put(http_response_started, true);
+ true ->
+ ErrResp = mochiweb:new_response({nil, 500, []}),
+ throw({http_abort, ErrResp, multiple_responses_attempted})
+ end.
+
+
%%%%%%%% module tests below %%%%%%%%
-ifdef(TEST).
