From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Wed, 25 Apr 2018 09:15:38 +0000 (+0200)
Subject: WIP: add forgotten file
X-Git-Tag: v2.4.0~19^2~42
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c39c7dc23d303aa67e79c40bbde8cafcfe01fea3;p=thirdparty%2Fknot-resolver.git

WIP: add forgotten file
---

diff --git a/lib/cache/nsec3.c b/lib/cache/nsec3.c
new file mode 100644
index 000000000..dd1ad8951
--- /dev/null
+++ b/lib/cache/nsec3.c
@@ -0,0 +1,74 @@
+/*  Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/** @file
+ * Implementation of NSEC3 handling.  Prototypes in ./impl.h
+ */
+
+#include "lib/cache/impl.h"
+#include "lib/dnssec/nsec.h"
+
+int nsec3_encloser(struct key *k, struct answer *ans,
+		   const int sname_labels, int *clencl_labels,
+		   knot_db_val_t *cover_low_kwz, knot_db_val_t *cover_hi_kwz,
+		   const struct kr_query *qry, struct kr_cache *cache)
+{
+	/* Basic sanity check. */
+	const bool ok = k && ans && clencl_labels && cover_low_kwz && cover_hi_kwz
+			&& qry && cache;
+	if (!ok) {
+		assert(!EINVAL);
+		return kr_error(EINVAL);
+	}
+	// FIXME get *nsec_p - possibly just add to the parameter list
+
+	/*** Find and cover the next closer name - cycle: name starting at sname,
+	 * proceeding while longer than zname, shortening by one label on step.
+	 * Each iteration: */
+		/*** 1. compute NSEC3 hash of the name with nsec_p. */
+		/*** 2. find a previous-or-equal NSEC3 in cache covering the name,
+		 * checking TTL etc.
+		 * Exit if match is found (may have NODATA proof if the first iteration),
+		 * break if cover is found. */
+
+	/*** One more step but searching for match this time
+	 * - that's the closest (provable) encloser. */
+
+	assert(false);
+	return -ENOSYS;
+}
+
+int nsec3_src_synth(struct key *k, struct answer *ans, const knot_dname_t *clencl_name,
+		    knot_db_val_t cover_low_kwz, knot_db_val_t cover_hi_kwz,
+		    const struct kr_query *qry, struct kr_cache *cache)
+{
+	/* Construct key for the source of synthesis.
+	 *
+	 * It's possible that all that follows in this function might be
+	 * completely the same as for NSEC -> probably some code sharing. */
+
+	/* Check if our covering NSEC3 also covers/matches SS (and exit).
+	 * That's unlikely except in tiny zones, but we want to avoid
+	 * duplicities in answer anyway. */
+
+	/* Find the NSEC3 in cache (or exit). */
+
+	/* Handle the two cases: covered and matched. */
+
+	assert(false);
+	return -ENOSYS;
+}
+