From: Tomas Krizek <tomas.krizek@nic.cz>
Date: Mon, 15 Nov 2021 16:35:28 +0000 (+0100)
Subject: ede: handle stale answers
X-Git-Tag: v5.5.0~26^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4c81cb1a480f557e34d86abe4618584685da69ea;p=thirdparty%2Fknot-resolver.git

ede: handle stale answers
---

diff --git a/lib/cache/api.c b/lib/cache/api.c
index 0cc61582b..6421c66eb 100644
--- a/lib/cache/api.c
+++ b/lib/cache/api.c
@@ -237,8 +237,13 @@ int32_t get_new_ttl(const struct entry_h *entry, const struct kr_query *qry,
 	if (res < 0 && owner && qry && qry->stale_cb) {
 		/* Stale-serving decision, delegated to a callback. */
 		int res_stale = qry->stale_cb(res, owner, type, qry);
-		if (res_stale >= 0)
+		if (res_stale >= 0) {
+			VERBOSE_MSG(qry, "responding with stale answer\n");
+			/* LATER: Perhaps we could use a more specific Stale
+			 * NXDOMAIN Answer code for applicable responses. */
+			kr_request_set_extended_error(qry->request, KNOT_EDNS_EDE_STALE, NULL);
 			return res_stale;
+		}
 	}
 	return res;
 }
diff --git a/lib/resolve.c b/lib/resolve.c
index 187d7a22a..0e06fb720 100644
--- a/lib/resolve.c
+++ b/lib/resolve.c
@@ -1629,10 +1629,11 @@ static int ede_priority(int info_code)
 	case KNOT_EDNS_EDE_DS_DIGEST:
 		return 500;  /* Non-critical DNSSEC issues */
 	case KNOT_EDNS_EDE_STALE:
+	case KNOT_EDNS_EDE_STALE_NXD:
+		return 300;  /* Serve-stale answers. */
 	case KNOT_EDNS_EDE_INDETERMINATE:
 	case KNOT_EDNS_EDE_CACHED_ERR:
 	case KNOT_EDNS_EDE_NOT_READY:
-	case KNOT_EDNS_EDE_STALE_NXD:
 	case KNOT_EDNS_EDE_NOTAUTH:
 	case KNOT_EDNS_EDE_NOTSUP:
 	case KNOT_EDNS_EDE_NREACH_AUTH: