BUG/MEDIUM: filters: Do not truncate HTTP response when body length is undefined

Some users have experienced some troubles using the compression filter when the
HTTP response body length is undefined. They complained about receiving
truncated responses.

In fact, the bug can be triggered if there is at least one filter attached to
the stream but none registered to analyze the HTTP response body. In this case,
when the body length is undefined, data should be forwarded without any
parsing. But, because of a wrong check, we were starting to parse them. Because
it was not expected, the end of response was not correctly detected and the
response could be truncted. So now, we rely on HAS_DATA_FILTER macro instead of
HAS_FILTER one to choose to parse HTTP response body or not.

Furthermore, in http_response_forward_body, the test to not forward the server
closure to the client has been updated to reflect conditions listed in the
associated comment.

And finally, in http_msg_forward_body, when the body length is undefined, we
continue the parsing it until the server closes the connection without any on
filters. So filters can safely stop to filter data during their parsing.

This fix should be backported in 1.7

diff --git a/src/proto_http.c b/src/proto_http.c
index 23a7dc452c540346feb4b791982ba464c6b33df2..80ba5660b4833e5ce6d6e0cba44ac44a4daab6c7 100644 (file)
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -6829,7 +6829,7 @@ int http_process_res_common(struct stream *s, struct channel *rep, int an_bit, s
        }
 
  skip_header_mangling:
-       if ((msg->flags & HTTP_MSGF_XFER_LEN) || HAS_FILTERS(s) ||
+       if ((msg->flags & HTTP_MSGF_XFER_LEN) || HAS_DATA_FILTERS(s, rep) ||
            (txn->flags & TX_CON_WANT_MSK) == TX_CON_WANT_TUN) {
                rep->analysers &= ~AN_RES_FLT_XFER_DATA;
                rep->analysers |= AN_RES_HTTP_XFER_BODY;
@@ -6980,8 +6980,8 @@ int http_response_forward_body(struct stream *s, struct channel *res, int an_bit
         * keep-alive is set on the client side or if there are filters
         * registered on the stream, we don't want to forward a close
         */
-       if ((msg->flags & HTTP_MSGF_TE_CHNK) || !msg->body_len ||
-           HAS_FILTERS(s) ||
+       if ((msg->flags & HTTP_MSGF_TE_CHNK) || !(msg->flags & HTTP_MSGF_XFER_LEN) ||
+           HAS_DATA_FILTERS(s, res) ||
            (txn->flags & TX_CON_WANT_MSK) == TX_CON_WANT_KAL ||
            (txn->flags & TX_CON_WANT_MSK) == TX_CON_WANT_SCL)
                channel_dont_close(res);
@@ -7073,11 +7073,10 @@ http_msg_forward_body(struct stream *s, struct http_msg *msg)
                goto missing_data_or_waiting;
        }
 
-       if (!(msg->flags & HTTP_MSGF_XFER_LEN) && !(chn->flags & CF_SHUTR) &&
-           HAS_DATA_FILTERS(s, chn)) {
-               /* The server still sending data that should be filtered */
+       /* The server still sending data that should be filtered */
+       if (!(msg->flags & HTTP_MSGF_XFER_LEN) && !(chn->flags & CF_SHUTR))
                goto missing_data_or_waiting;
-       }
+
        msg->msg_state = HTTP_MSG_ENDING;
 
   ending: