From: Christopher Faulet <cfaulet@haproxy.com>
Date: Thu, 25 Jun 2020 13:55:11 +0000 (+0200)
Subject: BUG/MINOR: http-ana: Don't wait to send 1xx responses generated by HAProxy
X-Git-Tag: v2.2-dev11~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cf6898cd14a8c1c65ed164f3ae0907cfa8071feb;p=thirdparty%2Fhaproxy.git

BUG/MINOR: http-ana: Don't wait to send 1xx responses generated by HAProxy

When an informational response (1xx) is returned by HAProxy, we must be sure to
send it ASAP. To do so, CF_SEND_DONTWAIT flag must be set on the response
channel to instruct the stream-interface to not set the CO_SFL_MSG_MORE flag on
the transport layer. Otherwise the response delivery may be delayed, because of
the commit 8945bb6c0 ("BUG/MEDIUM: stream-int: fix loss of CO_SFL_MSG_MORE flag
in forwarding").

This patch may be backported as far as 1.9, for HTX part only. But this part has
changed in the 2.2, so it may be a bit tricky. Note it does not fix any known
bug on previous versions because the CO_SFL_MSG_MORE flag is ignored by the h1
mux.
---

diff --git a/src/http_ana.c b/src/http_ana.c
index 844da4995a..28377d6f37 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -4575,6 +4575,12 @@ int http_forward_proxy_resp(struct stream *s, int final)
 		channel_shutr_now(res);
 		res->flags |= CF_EOI; /* The response is terminated, add EOI */
 	}
+	else {
+		/* Send ASAP informational messages. Rely on CF_EOI for final
+		 * response.
+		 */
+		res->flags |= CF_SEND_DONTWAIT;
+	}
 
 	data = htx->data - co_data(res);
 	c_adv(res, data);