From: Mark Andrews <marka@isc.org>
Date: Mon, 6 Nov 2023 15:10:45 +0000 (+1100)
Subject: Extend dns_message_setopt to clear the opt record
X-Git-Tag: v9.19.22~73^2~2
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=1b6f70076aed04526fea3f9c7a6d35ba684df876;p=thirdparty%2Fbind9.git

Extend dns_message_setopt to clear the opt record

Use NULL to signal that the opt record, if any, set on the
message be removed.
---

diff --git a/lib/dns/include/dns/message.h b/lib/dns/include/dns/message.h
index cda53f3c8ce..14c987f649f 100644
--- a/lib/dns/include/dns/message.h
+++ b/lib/dns/include/dns/message.h
@@ -1114,14 +1114,14 @@ dns_message_getopt(dns_message_t *msg);
 isc_result_t
 dns_message_setopt(dns_message_t *msg, dns_rdataset_t *opt);
 /*%<
- * Set the OPT record for 'msg'.
+ * Set/clear the OPT record for 'msg'.
  *
  * Requires:
  *
  *\li	'msg' is a valid message with rendering intent
  *	and no sections have been rendered.
  *
- *\li	'opt' is a valid OPT record.
+ *\li	'opt' is a valid OPT record or NULL.
  *
  * Ensures:
  *
diff --git a/lib/dns/message.c b/lib/dns/message.c
index e61f6b6142c..f5fc1cad9ab 100644
--- a/lib/dns/message.c
+++ b/lib/dns/message.c
@@ -2707,12 +2707,17 @@ dns_message_setopt(dns_message_t *msg, dns_rdataset_t *opt) {
 	 */
 
 	REQUIRE(DNS_MESSAGE_VALID(msg));
-	REQUIRE(opt->type == dns_rdatatype_opt);
+	REQUIRE(opt == NULL || DNS_RDATASET_VALID(opt));
+	REQUIRE(opt == NULL || opt->type == dns_rdatatype_opt);
 	REQUIRE(msg->from_to_wire == DNS_MESSAGE_INTENTRENDER);
 	REQUIRE(msg->state == DNS_SECTION_ANY);
 
 	msgresetopt(msg);
 
+	if (opt == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
 	result = dns_rdataset_first(opt);
 	if (result != ISC_R_SUCCESS) {
 		goto cleanup;