From: Mark Andrews <marka@isc.org>
Date: Thu, 27 Mar 2025 05:37:02 +0000 (+1100)
Subject: Extract and send server cookie with BADVERS retry
X-Git-Tag: v9.21.8~26^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44140cad3b8e6567ec77175332f9da58da9d0617;p=thirdparty%2Fbind9.git

Extract and send server cookie with BADVERS retry

A BADVERS response can also include EDNS SERVER COOKIE.  Extract
that from the OPT record and use it when resending the request.
---

diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 0bc839c121c..e9696ab1d2c 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -4269,6 +4269,12 @@ recv_done(isc_nmhandle_t *handle, isc_result_t eresult, isc_region_t *region,
 		dighost_comments(l, "BADVERS, retrying with EDNS version %u.",
 				 (unsigned int)newedns);
 		l->edns = newedns;
+		/*
+		 * Extract the server cookie so it can be sent in the retry.
+		 */
+		if (l->cookie == NULL && l->sendcookie) {
+			process_opt(l, msg);
+		}
 		n = requeue_lookup(l, true);
 		if (l->trace && l->trace_root) {
 			n->rdtype = l->qrdtype;