1 files changed, 703 insertions, 0 deletions

diff --git a/lib/dns/nta.c b/lib/dns/nta.c
new file mode 100644
index 0000000..5614eb8
--- /dev/null
+++ b/lib/dns/nta.c
@@ -0,0 +1,703 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/buffer.h>
+#include <isc/log.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/rwlock.h>
+#include <isc/string.h>
+#include <isc/task.h>
+#include <isc/time.h>
+#include <isc/timer.h>
+#include <isc/util.h>
+
+#include <dns/db.h>
+#include <dns/fixedname.h>
+#include <dns/log.h>
+#include <dns/name.h>
+#include <dns/nta.h>
+#include <dns/rbt.h>
+#include <dns/rdataset.h>
+#include <dns/resolver.h>
+#include <dns/time.h>
+
+struct dns_nta {
+	unsigned int magic;
+	isc_refcount_t refcount;
+	dns_ntatable_t *ntatable;
+	bool forced;
+	isc_timer_t *timer;
+	dns_fetch_t *fetch;
+	dns_rdataset_t rdataset;
+	dns_rdataset_t sigrdataset;
+	dns_fixedname_t fn;
+	dns_name_t *name;
+	isc_stdtime_t expiry;
+};
+
+#define NTA_MAGIC     ISC_MAGIC('N', 'T', 'A', 'n')
+#define VALID_NTA(nn) ISC_MAGIC_VALID(nn, NTA_MAGIC)
+
+/*
+ * Obtain a reference to the nta object.  Released by
+ * nta_detach.
+ */
+static void
+nta_ref(dns_nta_t *nta) {
+	isc_refcount_increment(&nta->refcount);
+}
+
+static void
+nta_detach(isc_mem_t *mctx, dns_nta_t **ntap) {
+	REQUIRE(ntap != NULL && VALID_NTA(*ntap));
+	dns_nta_t *nta = *ntap;
+	*ntap = NULL;
+
+	if (isc_refcount_decrement(&nta->refcount) == 1) {
+		isc_refcount_destroy(&nta->refcount);
+		nta->magic = 0;
+		if (nta->timer != NULL) {
+			(void)isc_timer_reset(nta->timer,
+					      isc_timertype_inactive, NULL,
+					      NULL, true);
+			isc_timer_destroy(&nta->timer);
+		}
+		if (dns_rdataset_isassociated(&nta->rdataset)) {
+			dns_rdataset_disassociate(&nta->rdataset);
+		}
+		if (dns_rdataset_isassociated(&nta->sigrdataset)) {
+			dns_rdataset_disassociate(&nta->sigrdataset);
+		}
+		if (nta->fetch != NULL) {
+			dns_resolver_cancelfetch(nta->fetch);
+			dns_resolver_destroyfetch(&nta->fetch);
+		}
+		isc_mem_put(mctx, nta, sizeof(dns_nta_t));
+	}
+}
+
+static void
+free_nta(void *data, void *arg) {
+	dns_nta_t *nta = (dns_nta_t *)data;
+	isc_mem_t *mctx = (isc_mem_t *)arg;
+
+	nta_detach(mctx, &nta);
+}
+
+isc_result_t
+dns_ntatable_create(dns_view_t *view, isc_taskmgr_t *taskmgr,
+		    isc_timermgr_t *timermgr, dns_ntatable_t **ntatablep) {
+	dns_ntatable_t *ntatable;
+	isc_result_t result;
+
+	REQUIRE(ntatablep != NULL && *ntatablep == NULL);
+
+	ntatable = isc_mem_get(view->mctx, sizeof(*ntatable));
+
+	ntatable->task = NULL;
+	result = isc_task_create(taskmgr, 0, &ntatable->task);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_ntatable;
+	}
+	isc_task_setname(ntatable->task, "ntatable", ntatable);
+
+	ntatable->table = NULL;
+	result = dns_rbt_create(view->mctx, free_nta, view->mctx,
+				&ntatable->table);
+	if (result != ISC_R_SUCCESS) {
+		goto cleanup_task;
+	}
+
+	isc_rwlock_init(&ntatable->rwlock, 0, 0);
+
+	ntatable->shuttingdown = false;
+	ntatable->timermgr = timermgr;
+	ntatable->taskmgr = taskmgr;
+
+	ntatable->view = view;
+	isc_refcount_init(&ntatable->references, 1);
+
+	ntatable->magic = NTATABLE_MAGIC;
+	*ntatablep = ntatable;
+
+	return (ISC_R_SUCCESS);
+
+cleanup_task:
+	isc_task_detach(&ntatable->task);
+
+cleanup_ntatable:
+	isc_mem_put(view->mctx, ntatable, sizeof(*ntatable));
+
+	return (result);
+}
+
+void
+dns_ntatable_attach(dns_ntatable_t *source, dns_ntatable_t **targetp) {
+	REQUIRE(VALID_NTATABLE(source));
+	REQUIRE(targetp != NULL && *targetp == NULL);
+
+	isc_refcount_increment(&source->references);
+
+	*targetp = source;
+}
+
+void
+dns_ntatable_detach(dns_ntatable_t **ntatablep) {
+	dns_ntatable_t *ntatable;
+
+	REQUIRE(ntatablep != NULL && VALID_NTATABLE(*ntatablep));
+
+	ntatable = *ntatablep;
+	*ntatablep = NULL;
+
+	if (isc_refcount_decrement(&ntatable->references) == 1) {
+		dns_rbt_destroy(&ntatable->table);
+		isc_rwlock_destroy(&ntatable->rwlock);
+		isc_refcount_destroy(&ntatable->references);
+		if (ntatable->task != NULL) {
+			isc_task_detach(&ntatable->task);
+		}
+		ntatable->timermgr = NULL;
+		ntatable->taskmgr = NULL;
+		ntatable->magic = 0;
+		isc_mem_put(ntatable->view->mctx, ntatable, sizeof(*ntatable));
+	}
+}
+
+static void
+fetch_done(isc_task_t *task, isc_event_t *event) {
+	dns_fetchevent_t *devent = (dns_fetchevent_t *)event;
+	dns_nta_t *nta = devent->ev_arg;
+	isc_result_t eresult = devent->result;
+	dns_ntatable_t *ntatable = nta->ntatable;
+	dns_view_t *view = ntatable->view;
+	isc_stdtime_t now;
+
+	UNUSED(task);
+
+	if (dns_rdataset_isassociated(&nta->rdataset)) {
+		dns_rdataset_disassociate(&nta->rdataset);
+	}
+	if (dns_rdataset_isassociated(&nta->sigrdataset)) {
+		dns_rdataset_disassociate(&nta->sigrdataset);
+	}
+	if (nta->fetch == devent->fetch) {
+		nta->fetch = NULL;
+	}
+	dns_resolver_destroyfetch(&devent->fetch);
+
+	if (devent->node != NULL) {
+		dns_db_detachnode(devent->db, &devent->node);
+	}
+	if (devent->db != NULL) {
+		dns_db_detach(&devent->db);
+	}
+
+	isc_event_free(&event);
+	isc_stdtime_get(&now);
+
+	switch (eresult) {
+	case ISC_R_SUCCESS:
+	case DNS_R_NCACHENXDOMAIN:
+	case DNS_R_NXDOMAIN:
+	case DNS_R_NCACHENXRRSET:
+	case DNS_R_NXRRSET:
+		if (nta->expiry > now) {
+			nta->expiry = now;
+		}
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * If we're expiring before the next recheck, we might
+	 * as well stop the timer now.
+	 */
+	if (nta->timer != NULL && nta->expiry - now < view->nta_recheck) {
+		(void)isc_timer_reset(nta->timer, isc_timertype_inactive, NULL,
+				      NULL, true);
+	}
+	nta_detach(view->mctx, &nta);
+	dns_view_weakdetach(&view);
+}
+
+static void
+checkbogus(isc_task_t *task, isc_event_t *event) {
+	dns_nta_t *nta = event->ev_arg;
+	dns_ntatable_t *ntatable = nta->ntatable;
+	dns_view_t *view = NULL;
+	isc_result_t result;
+
+	if (nta->fetch != NULL) {
+		dns_resolver_cancelfetch(nta->fetch);
+		nta->fetch = NULL;
+	}
+	if (dns_rdataset_isassociated(&nta->rdataset)) {
+		dns_rdataset_disassociate(&nta->rdataset);
+	}
+	if (dns_rdataset_isassociated(&nta->sigrdataset)) {
+		dns_rdataset_disassociate(&nta->sigrdataset);
+	}
+
+	isc_event_free(&event);
+
+	nta_ref(nta);
+	dns_view_weakattach(ntatable->view, &view);
+	result = dns_resolver_createfetch(
+		view->resolver, nta->name, dns_rdatatype_nsec, NULL, NULL, NULL,
+		NULL, 0, DNS_FETCHOPT_NONTA, 0, NULL, task, fetch_done, nta,
+		&nta->rdataset, &nta->sigrdataset, &nta->fetch);
+	if (result != ISC_R_SUCCESS) {
+		nta_detach(view->mctx, &nta);
+		dns_view_weakdetach(&view);
+	}
+}
+
+static isc_result_t
+settimer(dns_ntatable_t *ntatable, dns_nta_t *nta, uint32_t lifetime) {
+	isc_result_t result;
+	isc_interval_t interval;
+	dns_view_t *view;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+	REQUIRE(VALID_NTA(nta));
+
+	if (ntatable->timermgr == NULL) {
+		return (ISC_R_SUCCESS);
+	}
+
+	view = ntatable->view;
+	if (view->nta_recheck == 0 || lifetime <= view->nta_recheck) {
+		return (ISC_R_SUCCESS);
+	}
+
+	isc_interval_set(&interval, view->nta_recheck, 0);
+	result = isc_timer_create(ntatable->timermgr, isc_timertype_ticker,
+				  NULL, &interval, ntatable->task, checkbogus,
+				  nta, &nta->timer);
+	if (result != ISC_R_SUCCESS) {
+		isc_timer_destroy(&nta->timer);
+	}
+	return (result);
+}
+
+static isc_result_t
+nta_create(dns_ntatable_t *ntatable, const dns_name_t *name,
+	   dns_nta_t **target) {
+	dns_nta_t *nta = NULL;
+	dns_view_t *view;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+	REQUIRE(target != NULL && *target == NULL);
+
+	view = ntatable->view;
+
+	nta = isc_mem_get(view->mctx, sizeof(dns_nta_t));
+
+	nta->ntatable = ntatable;
+	nta->expiry = 0;
+	nta->timer = NULL;
+	nta->fetch = NULL;
+	dns_rdataset_init(&nta->rdataset);
+	dns_rdataset_init(&nta->sigrdataset);
+
+	isc_refcount_init(&nta->refcount, 1);
+
+	nta->name = dns_fixedname_initname(&nta->fn);
+	dns_name_copy(name, nta->name);
+
+	nta->magic = NTA_MAGIC;
+
+	*target = nta;
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+dns_ntatable_add(dns_ntatable_t *ntatable, const dns_name_t *name, bool force,
+		 isc_stdtime_t now, uint32_t lifetime) {
+	isc_result_t result = ISC_R_SUCCESS;
+	dns_nta_t *nta = NULL;
+	dns_rbtnode_t *node;
+	dns_view_t *view;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+
+	view = ntatable->view;
+
+	RWLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+
+	if (ntatable->shuttingdown) {
+		goto unlock;
+	}
+
+	result = nta_create(ntatable, name, &nta);
+	if (result != ISC_R_SUCCESS) {
+		goto unlock;
+	}
+
+	nta->expiry = now + lifetime;
+	nta->forced = force;
+
+	node = NULL;
+	result = dns_rbt_addnode(ntatable->table, name, &node);
+	if (result == ISC_R_SUCCESS) {
+		if (!force) {
+			(void)settimer(ntatable, nta, lifetime);
+		}
+		node->data = nta;
+		nta = NULL;
+	} else if (result == ISC_R_EXISTS) {
+		dns_nta_t *n = node->data;
+		if (n == NULL) {
+			if (!force) {
+				(void)settimer(ntatable, nta, lifetime);
+			}
+			node->data = nta;
+			nta = NULL;
+		} else {
+			n->expiry = nta->expiry;
+			nta_detach(view->mctx, &nta);
+		}
+		result = ISC_R_SUCCESS;
+	}
+
+unlock:
+	RWUNLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+
+	if (nta != NULL) {
+		nta_detach(view->mctx, &nta);
+	}
+
+	return (result);
+}
+
+/*
+ * Caller must hold a write lock on rwlock.
+ */
+static isc_result_t
+deletenode(dns_ntatable_t *ntatable, const dns_name_t *name) {
+	isc_result_t result;
+	dns_rbtnode_t *node = NULL;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+	REQUIRE(name != NULL);
+
+	result = dns_rbt_findnode(ntatable->table, name, NULL, &node, NULL,
+				  DNS_RBTFIND_NOOPTIONS, NULL, NULL);
+	if (result == ISC_R_SUCCESS) {
+		if (node->data != NULL) {
+			result = dns_rbt_deletenode(ntatable->table, node,
+						    false);
+		} else {
+			result = ISC_R_NOTFOUND;
+		}
+	} else if (result == DNS_R_PARTIALMATCH) {
+		result = ISC_R_NOTFOUND;
+	}
+
+	return (result);
+}
+
+isc_result_t
+dns_ntatable_delete(dns_ntatable_t *ntatable, const dns_name_t *name) {
+	isc_result_t result;
+
+	RWLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+	result = deletenode(ntatable, name);
+	RWUNLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+
+	return (result);
+}
+
+bool
+dns_ntatable_covered(dns_ntatable_t *ntatable, isc_stdtime_t now,
+		     const dns_name_t *name, const dns_name_t *anchor) {
+	isc_result_t result;
+	dns_fixedname_t fn;
+	dns_rbtnode_t *node;
+	dns_name_t *foundname;
+	dns_nta_t *nta = NULL;
+	bool answer = false;
+	isc_rwlocktype_t locktype = isc_rwlocktype_read;
+
+	REQUIRE(ntatable == NULL || VALID_NTATABLE(ntatable));
+	REQUIRE(dns_name_isabsolute(name));
+
+	if (ntatable == NULL) {
+		return (false);
+	}
+
+	foundname = dns_fixedname_initname(&fn);
+
+relock:
+	RWLOCK(&ntatable->rwlock, locktype);
+again:
+	node = NULL;
+	result = dns_rbt_findnode(ntatable->table, name, foundname, &node, NULL,
+				  DNS_RBTFIND_NOOPTIONS, NULL, NULL);
+	if (result == DNS_R_PARTIALMATCH) {
+		if (dns_name_issubdomain(foundname, anchor)) {
+			result = ISC_R_SUCCESS;
+		}
+	}
+	if (result == ISC_R_SUCCESS) {
+		nta = (dns_nta_t *)node->data;
+		answer = (nta->expiry > now);
+	}
+
+	/* Deal with expired NTA */
+	if (result == ISC_R_SUCCESS && !answer) {
+		char nb[DNS_NAME_FORMATSIZE];
+
+		if (locktype == isc_rwlocktype_read) {
+			RWUNLOCK(&ntatable->rwlock, locktype);
+			locktype = isc_rwlocktype_write;
+			goto relock;
+		}
+
+		dns_name_format(foundname, nb, sizeof(nb));
+		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DNSSEC,
+			      DNS_LOGMODULE_NTA, ISC_LOG_INFO,
+			      "deleting expired NTA at %s", nb);
+
+		if (nta->timer != NULL) {
+			(void)isc_timer_reset(nta->timer,
+					      isc_timertype_inactive, NULL,
+					      NULL, true);
+			isc_timer_destroy(&nta->timer);
+		}
+
+		result = deletenode(ntatable, foundname);
+		if (result != ISC_R_SUCCESS) {
+			isc_log_write(dns_lctx, DNS_LOGCATEGORY_DNSSEC,
+				      DNS_LOGMODULE_NTA, ISC_LOG_INFO,
+				      "deleting NTA failed: %s",
+				      isc_result_totext(result));
+		}
+		goto again;
+	}
+	RWUNLOCK(&ntatable->rwlock, locktype);
+
+	return (answer);
+}
+
+static isc_result_t
+putstr(isc_buffer_t **b, const char *str) {
+	isc_result_t result;
+
+	result = isc_buffer_reserve(b, strlen(str));
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	}
+
+	isc_buffer_putstr(*b, str);
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+dns_ntatable_totext(dns_ntatable_t *ntatable, const char *view,
+		    isc_buffer_t **buf) {
+	isc_result_t result;
+	dns_rbtnode_t *node;
+	dns_rbtnodechain_t chain;
+	bool first = true;
+	isc_stdtime_t now;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+
+	isc_stdtime_get(&now);
+
+	RWLOCK(&ntatable->rwlock, isc_rwlocktype_read);
+	dns_rbtnodechain_init(&chain);
+	result = dns_rbtnodechain_first(&chain, ntatable->table, NULL, NULL);
+	if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
+		if (result == ISC_R_NOTFOUND) {
+			result = ISC_R_SUCCESS;
+		}
+		goto cleanup;
+	}
+	for (;;) {
+		dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+		if (node->data != NULL) {
+			dns_nta_t *n = (dns_nta_t *)node->data;
+			char nbuf[DNS_NAME_FORMATSIZE];
+			char tbuf[ISC_FORMATHTTPTIMESTAMP_SIZE];
+			char obuf[DNS_NAME_FORMATSIZE +
+				  ISC_FORMATHTTPTIMESTAMP_SIZE +
+				  sizeof("expired:  \n")];
+			dns_fixedname_t fn;
+			dns_name_t *name;
+			isc_time_t t;
+
+			name = dns_fixedname_initname(&fn);
+			dns_rbt_fullnamefromnode(node, name);
+			dns_name_format(name, nbuf, sizeof(nbuf));
+
+			if (n->expiry != 0xffffffffU) {
+				/* Normal NTA entries */
+				isc_time_set(&t, n->expiry, 0);
+				isc_time_formattimestamp(&t, tbuf,
+							 sizeof(tbuf));
+
+				snprintf(obuf, sizeof(obuf), "%s%s%s%s: %s %s",
+					 first ? "" : "\n", nbuf,
+					 view != NULL ? "/" : "",
+					 view != NULL ? view : "",
+					 n->expiry <= now ? "expired"
+							  : "expiry",
+					 tbuf);
+			} else {
+				/* "validate-except" entries */
+				snprintf(obuf, sizeof(obuf), "%s%s%s%s: %s",
+					 first ? "" : "\n", nbuf,
+					 view != NULL ? "/" : "",
+					 view != NULL ? view : "", "permanent");
+			}
+
+			first = false;
+			result = putstr(buf, obuf);
+			if (result != ISC_R_SUCCESS) {
+				goto cleanup;
+			}
+		}
+		result = dns_rbtnodechain_next(&chain, NULL, NULL);
+		if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
+			if (result == ISC_R_NOMORE) {
+				result = ISC_R_SUCCESS;
+			}
+			break;
+		}
+	}
+
+cleanup:
+	dns_rbtnodechain_invalidate(&chain);
+	RWUNLOCK(&ntatable->rwlock, isc_rwlocktype_read);
+	return (result);
+}
+
+isc_result_t
+dns_ntatable_save(dns_ntatable_t *ntatable, FILE *fp) {
+	isc_result_t result;
+	dns_rbtnode_t *node;
+	dns_rbtnodechain_t chain;
+	isc_stdtime_t now;
+	bool written = false;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+
+	isc_stdtime_get(&now);
+
+	RWLOCK(&ntatable->rwlock, isc_rwlocktype_read);
+	dns_rbtnodechain_init(&chain);
+	result = dns_rbtnodechain_first(&chain, ntatable->table, NULL, NULL);
+	if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
+		goto cleanup;
+	}
+
+	for (;;) {
+		dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+		if (node->data != NULL) {
+			isc_buffer_t b;
+			char nbuf[DNS_NAME_FORMATSIZE + 1], tbuf[80];
+			dns_fixedname_t fn;
+			dns_name_t *name;
+			dns_nta_t *n = (dns_nta_t *)node->data;
+
+			/*
+			 * Skip this node if the expiry is already in the
+			 * past, or if this is a "validate-except" entry.
+			 */
+			if (n->expiry <= now || n->expiry == 0xffffffffU) {
+				goto skip;
+			}
+
+			name = dns_fixedname_initname(&fn);
+			dns_rbt_fullnamefromnode(node, name);
+
+			isc_buffer_init(&b, nbuf, sizeof(nbuf));
+			result = dns_name_totext(name, false, &b);
+			if (result != ISC_R_SUCCESS) {
+				goto skip;
+			}
+
+			/* Zero terminate. */
+			isc_buffer_putuint8(&b, 0);
+
+			isc_buffer_init(&b, tbuf, sizeof(tbuf));
+			dns_time32_totext(n->expiry, &b);
+
+			/* Zero terminate. */
+			isc_buffer_putuint8(&b, 0);
+
+			fprintf(fp, "%s %s %s\n", nbuf,
+				n->forced ? "forced" : "regular", tbuf);
+			written = true;
+		}
+	skip:
+		result = dns_rbtnodechain_next(&chain, NULL, NULL);
+		if (result != ISC_R_SUCCESS && result != DNS_R_NEWORIGIN) {
+			if (result == ISC_R_NOMORE) {
+				result = ISC_R_SUCCESS;
+			}
+			break;
+		}
+	}
+
+cleanup:
+	dns_rbtnodechain_invalidate(&chain);
+	RWUNLOCK(&ntatable->rwlock, isc_rwlocktype_read);
+
+	if (result != ISC_R_SUCCESS) {
+		return (result);
+	} else {
+		return (written ? ISC_R_SUCCESS : ISC_R_NOTFOUND);
+	}
+}
+
+void
+dns_ntatable_shutdown(dns_ntatable_t *ntatable) {
+	isc_result_t result;
+	dns_rbtnode_t *node;
+	dns_rbtnodechain_t chain;
+
+	REQUIRE(VALID_NTATABLE(ntatable));
+
+	RWLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+	ntatable->shuttingdown = true;
+
+	dns_rbtnodechain_init(&chain);
+	result = dns_rbtnodechain_first(&chain, ntatable->table, NULL, NULL);
+	while (result == ISC_R_SUCCESS || result == DNS_R_NEWORIGIN) {
+		dns_rbtnodechain_current(&chain, NULL, NULL, &node);
+		if (node->data != NULL) {
+			dns_nta_t *nta = (dns_nta_t *)node->data;
+			if (nta->timer != NULL) {
+				(void)isc_timer_reset(nta->timer,
+						      isc_timertype_inactive,
+						      NULL, NULL, true);
+			}
+		}
+		result = dns_rbtnodechain_next(&chain, NULL, NULL);
+	}
+
+	dns_rbtnodechain_invalidate(&chain);
+	RWUNLOCK(&ntatable->rwlock, isc_rwlocktype_write);
+}