From: Ondřej Surý <ondrej@isc.org>
Date: Thu, 14 May 2026 11:58:39 +0000 (+0200)
Subject: Open the stale-refresh-time window on any resolver failure
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=1af37e24b2bcbcd461366d5f52683fa87a211e19;p=thirdparty%2Fbind9.git

Open the stale-refresh-time window on any resolver failure

The TCP-fallback fix in the previous commits means a query that would
previously have timed out on UDP now actually escalates to TCP, and a
TCP-side failure surfaces a non-ISC_R_TIMEDOUT result code to
query_usestale().  The trigger for DNS_DBFIND_STALESTART was previously
narrowed to ISC_R_TIMEDOUT, so the stale-refresh-time window stopped
opening for those clients.

Broaden the condition to any failure that has already cleared the
upstream DUPLICATE/DROP filtering in query_usestale() — the spirit of
the window is "the resolver tried and could not get a fresh answer",
not "the resolver timed out specifically".

Co-authored-by: Evan Hunt <each@isc.org>
Assisted-by: Claude:claude-opus-4-7
---

diff --git a/lib/ns/query.c b/lib/ns/query.c
index fbb9e8213b4..28cbf992502 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -7375,10 +7375,10 @@ query_usestale(query_ctx_t *qctx, isc_result_t result) {
 		}
 
 		/*
-		 * Start the stale-refresh-time window in case there was a
-		 * resolver query timeout.
+		 * Start the stale-refresh-time window as there appears
+		 * to have been a resolver query failure.
 		 */
-		if (qctx->resuming && result == ISC_R_TIMEDOUT) {
+		if (qctx->resuming) {
 			qctx->client->query.dboptions |= DNS_DBFIND_STALESTART;
 		}
 		return true;