From: Emeric Brun <ebrun@haproxy.com>
Date: Thu, 4 Mar 2021 09:27:10 +0000 (+0100)
Subject: BUG/MEDIUM: peers: stop considering ack messages teaching a full resync
X-Git-Tag: v2.4-dev18~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b0d60bed36cfbfead5a35e6a9520e8d5e9345a7f;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: peers: stop considering ack messages teaching a full resync

The re-con cursor was updated receiving any ack message
even if we are pushing a complete resync to a peer. This cursor
is reset at the end of the resync but if the connection is broken
during resync, we could re-start at an unwanted point.

With this patch, the peer stops to consider ack messages pushing
a resync since the resync process has is own acknowlegement and
is always restarted from the beginning in case of broken connection.

This patch should be backported on all supported branches ( >= 1.6 )
---

diff --git a/src/peers.c b/src/peers.c
index cff5696b82..69c228796c 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1813,6 +1813,10 @@ static inline int peer_treat_ackmsg(struct appctx *appctx, struct peer *p,
 	uint32_t update;
 	struct shared_table *st;
 
+	/* ignore ack during teaching process */
+	if (p->flags & PEER_F_TEACH_PROCESS)
+		return 1;
+
 	table_id = intdecode(msg_cur, msg_end);
 	if (!*msg_cur || (*msg_cur + sizeof(update) > msg_end)) {
 		/* malformed message */