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update.c revision 1.5
      1 /*	$NetBSD: update.c,v 1.5 2019/09/09 14:40:40 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
      5  *
      6  * This Source Code Form is subject to the terms of the Mozilla Public
      7  * License, v. 2.0. If a copy of the MPL was not distributed with this
      8  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9  *
     10  * See the COPYRIGHT file distributed with this work for additional
     11  * information regarding copyright ownership.
     12  */
     13 
     14 #include <config.h>
     15 
     16 #include <stdbool.h>
     17 #include <inttypes.h>
     18 
     19 #include <isc/netaddr.h>
     20 #include <isc/print.h>
     21 #include <isc/serial.h>
     22 #include <isc/stats.h>
     23 #include <isc/string.h>
     24 #include <isc/taskpool.h>
     25 #include <isc/util.h>
     26 
     27 #include <dns/db.h>
     28 #include <dns/dbiterator.h>
     29 #include <dns/diff.h>
     30 #include <dns/dnssec.h>
     31 #include <dns/events.h>
     32 #include <dns/fixedname.h>
     33 #include <dns/journal.h>
     34 #include <dns/keyvalues.h>
     35 #include <dns/message.h>
     36 #include <dns/nsec.h>
     37 #include <dns/nsec3.h>
     38 #include <dns/private.h>
     39 #include <dns/rdataclass.h>
     40 #include <dns/rdataset.h>
     41 #include <dns/rdatasetiter.h>
     42 #include <dns/rdatastruct.h>
     43 #include <dns/rdatatype.h>
     44 #include <dns/soa.h>
     45 #include <dns/ssu.h>
     46 #include <dns/tsig.h>
     47 #include <dns/update.h>
     48 #include <dns/view.h>
     49 #include <dns/zone.h>
     50 #include <dns/zt.h>
     51 
     52 #include <ns/client.h>
     53 #include <ns/interfacemgr.h>
     54 #include <ns/log.h>
     55 #include <ns/server.h>
     56 #include <ns/stats.h>
     57 #include <ns/update.h>
     58 
     59 #include <ns/pfilter.h>
     60 
     61 /*! \file
     62  * \brief
     63  * This module implements dynamic update as in RFC2136.
     64  */
     65 
     66 /*
     67  *  XXX TODO:
     68  * - document strict minimality
     69  */
     70 
     71 /**************************************************************************/
     72 
     73 /*%
     74  * Log level for tracing dynamic update protocol requests.
     75  */
     76 #define LOGLEVEL_PROTOCOL	ISC_LOG_INFO
     77 
     78 /*%
     79  * Log level for low-level debug tracing.
     80  */
     81 #define LOGLEVEL_DEBUG		ISC_LOG_DEBUG(8)
     82 
     83 /*%
     84  * Check an operation for failure.  These macros all assume that
     85  * the function using them has a 'result' variable and a 'failure'
     86  * label.
     87  */
     88 #define CHECK(op) \
     89 	do { result = (op); \
     90 		if (result != ISC_R_SUCCESS) goto failure; \
     91 	} while (0)
     92 
     93 /*%
     94  * Fail unconditionally with result 'code', which must not
     95  * be ISC_R_SUCCESS.  The reason for failure presumably has
     96  * been logged already.
     97  *
     98  * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
     99  * from complaining about "end-of-loop code not reached".
    100  */
    101 
    102 #define FAIL(code) \
    103 	do {							\
    104 		result = (code);				\
    105 		if (result != ISC_R_SUCCESS) goto failure;	\
    106 	} while (0)
    107 
    108 /*%
    109  * Fail unconditionally and log as a client error.
    110  * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
    111  * from complaining about "end-of-loop code not reached".
    112  */
    113 #define FAILC(code, msg) \
    114 	do {							\
    115 		const char *_what = "failed";			\
    116 		result = (code);				\
    117 		switch (result) {				\
    118 		case DNS_R_NXDOMAIN:				\
    119 		case DNS_R_YXDOMAIN:				\
    120 		case DNS_R_YXRRSET:				\
    121 		case DNS_R_NXRRSET:				\
    122 			_what = "unsuccessful";			\
    123 		}						\
    124 		update_log(client, zone, LOGLEVEL_PROTOCOL,	\
    125 			   "update %s: %s (%s)", _what,		\
    126 			   msg, isc_result_totext(result));	\
    127 		if (result != ISC_R_SUCCESS) goto failure;	\
    128 	} while (0)
    129 #define PREREQFAILC(code, msg) \
    130 	do {							\
    131 		inc_stats(client, zone, ns_statscounter_updatebadprereq); \
    132 		FAILC(code, msg);				\
    133 	} while (0)
    134 
    135 #define FAILN(code, name, msg) \
    136 	do {								\
    137 		const char *_what = "failed";				\
    138 		result = (code);					\
    139 		switch (result) {					\
    140 		case DNS_R_NXDOMAIN:					\
    141 		case DNS_R_YXDOMAIN:					\
    142 		case DNS_R_YXRRSET:					\
    143 		case DNS_R_NXRRSET:					\
    144 			_what = "unsuccessful";				\
    145 		}							\
    146 		if (isc_log_wouldlog(ns_lctx, LOGLEVEL_PROTOCOL)) {	\
    147 			char _nbuf[DNS_NAME_FORMATSIZE];		\
    148 			dns_name_format(name, _nbuf, sizeof(_nbuf));	\
    149 			update_log(client, zone, LOGLEVEL_PROTOCOL,	\
    150 				   "update %s: %s: %s (%s)", _what, _nbuf, \
    151 				   msg, isc_result_totext(result));	\
    152 		}							\
    153 		if (result != ISC_R_SUCCESS) goto failure;		\
    154 	} while (0)
    155 #define PREREQFAILN(code, name, msg) \
    156 	do {								\
    157 		inc_stats(client, zone, ns_statscounter_updatebadprereq); \
    158 		FAILN(code, name, msg);					\
    159 	} while (0)
    160 
    161 #define FAILNT(code, name, type, msg) \
    162 	do {								\
    163 		const char *_what = "failed";				\
    164 		result = (code);					\
    165 		switch (result) {					\
    166 		case DNS_R_NXDOMAIN:					\
    167 		case DNS_R_YXDOMAIN:					\
    168 		case DNS_R_YXRRSET:					\
    169 		case DNS_R_NXRRSET:					\
    170 			_what = "unsuccessful";				\
    171 		}							\
    172 		if (isc_log_wouldlog(ns_lctx, LOGLEVEL_PROTOCOL)) {	\
    173 			char _nbuf[DNS_NAME_FORMATSIZE];		\
    174 			char _tbuf[DNS_RDATATYPE_FORMATSIZE];		\
    175 			dns_name_format(name, _nbuf, sizeof(_nbuf));	\
    176 			dns_rdatatype_format(type, _tbuf, sizeof(_tbuf)); \
    177 			update_log(client, zone, LOGLEVEL_PROTOCOL,	\
    178 				   "update %s: %s/%s: %s (%s)",		\
    179 				   _what, _nbuf, _tbuf, msg,		\
    180 				   isc_result_totext(result));		\
    181 		}							\
    182 		if (result != ISC_R_SUCCESS) goto failure;		\
    183 	} while (0)
    184 #define PREREQFAILNT(code, name, type, msg)				\
    185 	do {								\
    186 		inc_stats(client, zone, ns_statscounter_updatebadprereq); \
    187 		FAILNT(code, name, type, msg);				\
    188 	} while (0)
    189 
    190 /*%
    191  * Fail unconditionally and log as a server error.
    192  * The test against ISC_R_SUCCESS is there to keep the Solaris compiler
    193  * from complaining about "end-of-loop code not reached".
    194  */
    195 #define FAILS(code, msg) \
    196 	do {							\
    197 		result = (code);				\
    198 		update_log(client, zone, LOGLEVEL_PROTOCOL,	\
    199 			   "error: %s: %s",			\
    200 			   msg, isc_result_totext(result));	\
    201 		if (result != ISC_R_SUCCESS) goto failure;	\
    202 	} while (0)
    203 
    204 /*
    205  * Return TRUE if NS_CLIENTATTR_TCP is set in the attributes other FALSE.
    206  */
    207 #define TCPCLIENT(client) (((client)->attributes & NS_CLIENTATTR_TCP) != 0)
    208 
    209 /**************************************************************************/
    210 
    211 typedef struct rr rr_t;
    212 
    213 struct rr {
    214 	/* dns_name_t name; */
    215 	uint32_t		ttl;
    216 	dns_rdata_t		rdata;
    217 };
    218 
    219 typedef struct update_event update_event_t;
    220 
    221 struct update_event {
    222 	ISC_EVENT_COMMON(update_event_t);
    223 	dns_zone_t		*zone;
    224 	isc_result_t		result;
    225 	dns_message_t		*answer;
    226 };
    227 
    228 /*%
    229  * Prepare an RR for the addition of the new RR 'ctx->update_rr',
    230  * with TTL 'ctx->update_rr_ttl', to its rdataset, by deleting
    231  * the RRs if it is replaced by the new RR or has a conflicting TTL.
    232  * The necessary changes are appended to ctx->del_diff and ctx->add_diff;
    233  * we need to do all deletions before any additions so that we don't run
    234  * into transient states with conflicting TTLs.
    235  */
    236 
    237 typedef struct {
    238 	dns_db_t *db;
    239 	dns_dbversion_t *ver;
    240 	dns_diff_t *diff;
    241 	dns_name_t *name;
    242 	dns_name_t *oldname;
    243 	dns_rdata_t *update_rr;
    244 	dns_ttl_t update_rr_ttl;
    245 	bool ignore_add;
    246 	dns_diff_t del_diff;
    247 	dns_diff_t add_diff;
    248 } add_rr_prepare_ctx_t;
    249 
    250 /**************************************************************************/
    251 /*
    252  * Forward declarations.
    253  */
    254 
    255 static void update_action(isc_task_t *task, isc_event_t *event);
    256 static void updatedone_action(isc_task_t *task, isc_event_t *event);
    257 static isc_result_t send_forward_event(ns_client_t *client, dns_zone_t *zone);
    258 static void forward_done(isc_task_t *task, isc_event_t *event);
    259 static isc_result_t add_rr_prepare_action(void *data, rr_t *rr);
    260 
    261 /**************************************************************************/
    262 
    263 static void
    264 update_log(ns_client_t *client, dns_zone_t *zone,
    265 	   int level, const char *fmt, ...) ISC_FORMAT_PRINTF(4, 5);
    266 
    267 static void
    268 update_log(ns_client_t *client, dns_zone_t *zone,
    269 	   int level, const char *fmt, ...)
    270 {
    271 	va_list ap;
    272 	char message[4096];
    273 	char namebuf[DNS_NAME_FORMATSIZE];
    274 	char classbuf[DNS_RDATACLASS_FORMATSIZE];
    275 
    276 	if (client == NULL) {
    277 		return;
    278 	}
    279 
    280 	if (isc_log_wouldlog(ns_lctx, level) == false) {
    281 		return;
    282 	}
    283 
    284 	va_start(ap, fmt);
    285 	vsnprintf(message, sizeof(message), fmt, ap);
    286 	va_end(ap);
    287 
    288 	if (zone != NULL) {
    289 		dns_name_format(dns_zone_getorigin(zone), namebuf,
    290 				sizeof(namebuf));
    291 		dns_rdataclass_format(dns_zone_getclass(zone), classbuf,
    292 				      sizeof(classbuf));
    293 
    294 		ns_client_log(client, NS_LOGCATEGORY_UPDATE,
    295 			      NS_LOGMODULE_UPDATE,
    296 			      level, "updating zone '%s/%s': %s",
    297 			      namebuf, classbuf, message);
    298 	} else {
    299 		ns_client_log(client, NS_LOGCATEGORY_UPDATE,
    300 			      NS_LOGMODULE_UPDATE,
    301 			      level, "%s", message);
    302 	}
    303 
    304 }
    305 
    306 static void
    307 update_log_cb(void *arg, dns_zone_t *zone, int level, const char *message) {
    308 	update_log(arg, zone, level, "%s", message);
    309 }
    310 
    311 /*%
    312  * Increment updated-related statistics counters.
    313  */
    314 static inline void
    315 inc_stats(ns_client_t *client, dns_zone_t *zone, isc_statscounter_t counter) {
    316 	ns_stats_increment(client->sctx->nsstats, counter);
    317 
    318 	if (zone != NULL) {
    319 		isc_stats_t *zonestats = dns_zone_getrequeststats(zone);
    320 		if (zonestats != NULL)
    321 			isc_stats_increment(zonestats, counter);
    322 	}
    323 }
    324 
    325 /*%
    326  * Check if we could have queried for the contents of this zone or
    327  * if the zone is potentially updateable.
    328  * If the zone can potentially be updated and the check failed then
    329  * log a error otherwise we log a informational message.
    330  */
    331 static isc_result_t
    332 checkqueryacl(ns_client_t *client, dns_acl_t *queryacl, dns_name_t *zonename,
    333 	      dns_acl_t *updateacl, dns_ssutable_t *ssutable)
    334 {
    335 	char namebuf[DNS_NAME_FORMATSIZE];
    336 	char classbuf[DNS_RDATACLASS_FORMATSIZE];
    337 	int level;
    338 	isc_result_t result;
    339 
    340 	result = ns_client_checkaclsilent(client, NULL, queryacl, true);
    341 	if (result != ISC_R_SUCCESS) {
    342 		pfilter_notify(result, client, "queryacl");
    343 		dns_name_format(zonename, namebuf, sizeof(namebuf));
    344 		dns_rdataclass_format(client->view->rdclass, classbuf,
    345 				      sizeof(classbuf));
    346 
    347 		level = (updateacl == NULL && ssutable == NULL) ?
    348 				ISC_LOG_INFO : ISC_LOG_ERROR;
    349 
    350 		ns_client_log(client, NS_LOGCATEGORY_UPDATE_SECURITY,
    351 			      NS_LOGMODULE_UPDATE, level,
    352 			      "update '%s/%s' denied due to allow-query",
    353 			      namebuf, classbuf);
    354 	} else if (updateacl == NULL && ssutable == NULL) {
    355 		pfilter_notify(result, client, "updateacl");
    356 		dns_name_format(zonename, namebuf, sizeof(namebuf));
    357 		dns_rdataclass_format(client->view->rdclass, classbuf,
    358 				      sizeof(classbuf));
    359 
    360 		result = DNS_R_REFUSED;
    361 		ns_client_log(client, NS_LOGCATEGORY_UPDATE_SECURITY,
    362 			      NS_LOGMODULE_UPDATE, ISC_LOG_INFO,
    363 			      "update '%s/%s' denied", namebuf, classbuf);
    364 	}
    365 	return (result);
    366 }
    367 
    368 /*%
    369  * Override the default acl logging when checking whether a client
    370  * can update the zone or whether we can forward the request to the
    371  * master based on IP address.
    372  *
    373  * 'message' contains the type of operation that is being attempted.
    374  * 'slave' indicates if this is a slave zone.  If 'acl' is NULL then
    375  * log at debug=3.
    376  * If the zone has no access controls configured ('acl' == NULL &&
    377  * 'has_ssutable == ISC_FALS) log the attempt at info, otherwise
    378  * at error.
    379  *
    380  * If the request was signed log that we received it.
    381  */
    382 static isc_result_t
    383 checkupdateacl(ns_client_t *client, dns_acl_t *acl, const char *message,
    384 	       dns_name_t *zonename, bool slave,
    385 	       bool has_ssutable)
    386 {
    387 	char namebuf[DNS_NAME_FORMATSIZE];
    388 	char classbuf[DNS_RDATACLASS_FORMATSIZE];
    389 	int level = ISC_LOG_ERROR;
    390 	const char *msg = "denied";
    391 	isc_result_t result;
    392 
    393 	if (slave && acl == NULL) {
    394 		result = DNS_R_NOTIMP;
    395 		level = ISC_LOG_DEBUG(3);
    396 		msg = "disabled";
    397 	} else {
    398 		result = ns_client_checkaclsilent(client, NULL, acl, false);
    399 		pfilter_notify(result, client, "updateacl");
    400 		if (result == ISC_R_SUCCESS) {
    401 			level = ISC_LOG_DEBUG(3);
    402 			msg = "approved";
    403 		} else if (acl == NULL && !has_ssutable) {
    404 			level = ISC_LOG_INFO;
    405 		}
    406 	}
    407 
    408 	if (client->signer != NULL) {
    409 		dns_name_format(client->signer, namebuf, sizeof(namebuf));
    410 		ns_client_log(client, NS_LOGCATEGORY_UPDATE_SECURITY,
    411 			      NS_LOGMODULE_UPDATE, ISC_LOG_INFO,
    412 			      "signer \"%s\" %s", namebuf, msg);
    413 	}
    414 
    415 	dns_name_format(zonename, namebuf, sizeof(namebuf));
    416 	dns_rdataclass_format(client->view->rdclass, classbuf,
    417 			      sizeof(classbuf));
    418 
    419 	ns_client_log(client, NS_LOGCATEGORY_UPDATE_SECURITY,
    420 		      NS_LOGMODULE_UPDATE, level, "%s '%s/%s' %s",
    421 		      message, namebuf, classbuf, msg);
    422 	return (result);
    423 }
    424 
    425 /*%
    426  * Update a single RR in version 'ver' of 'db' and log the
    427  * update in 'diff'.
    428  *
    429  * Ensures:
    430  * \li	'*tuple' == NULL.  Either the tuple is freed, or its
    431  *	ownership has been transferred to the diff.
    432  */
    433 static isc_result_t
    434 do_one_tuple(dns_difftuple_t **tuple, dns_db_t *db, dns_dbversion_t *ver,
    435 	     dns_diff_t *diff)
    436 {
    437 	dns_diff_t temp_diff;
    438 	isc_result_t result;
    439 
    440 	/*
    441 	 * Create a singleton diff.
    442 	 */
    443 	dns_diff_init(diff->mctx, &temp_diff);
    444 	ISC_LIST_APPEND(temp_diff.tuples, *tuple, link);
    445 
    446 	/*
    447 	 * Apply it to the database.
    448 	 */
    449 	result = dns_diff_apply(&temp_diff, db, ver);
    450 	ISC_LIST_UNLINK(temp_diff.tuples, *tuple, link);
    451 	if (result != ISC_R_SUCCESS) {
    452 		dns_difftuple_free(tuple);
    453 		return (result);
    454 	}
    455 
    456 	/*
    457 	 * Merge it into the current pending journal entry.
    458 	 */
    459 	dns_diff_appendminimal(diff, tuple);
    460 
    461 	/*
    462 	 * Do not clear temp_diff.
    463 	 */
    464 	return (ISC_R_SUCCESS);
    465 }
    466 
    467 /*%
    468  * Perform the updates in 'updates' in version 'ver' of 'db' and log the
    469  * update in 'diff'.
    470  *
    471  * Ensures:
    472  * \li	'updates' is empty.
    473  */
    474 static isc_result_t
    475 do_diff(dns_diff_t *updates, dns_db_t *db, dns_dbversion_t *ver,
    476 	dns_diff_t *diff)
    477 {
    478 	isc_result_t result;
    479 	while (! ISC_LIST_EMPTY(updates->tuples)) {
    480 		dns_difftuple_t *t = ISC_LIST_HEAD(updates->tuples);
    481 		ISC_LIST_UNLINK(updates->tuples, t, link);
    482 		CHECK(do_one_tuple(&t, db, ver, diff));
    483 	}
    484 	return (ISC_R_SUCCESS);
    485 
    486  failure:
    487 	dns_diff_clear(diff);
    488 	return (result);
    489 }
    490 
    491 static isc_result_t
    492 update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
    493 	      dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
    494 	      dns_rdata_t *rdata)
    495 {
    496 	dns_difftuple_t *tuple = NULL;
    497 	isc_result_t result;
    498 	result = dns_difftuple_create(diff->mctx, op,
    499 				      name, ttl, rdata, &tuple);
    500 	if (result != ISC_R_SUCCESS)
    501 		return (result);
    502 	return (do_one_tuple(&tuple, db, ver, diff));
    503 }
    504 
    505 /**************************************************************************/
    506 /*
    507  * Callback-style iteration over rdatasets and rdatas.
    508  *
    509  * foreach_rrset() can be used to iterate over the RRsets
    510  * of a name and call a callback function with each
    511  * one.  Similarly, foreach_rr() can be used to iterate
    512  * over the individual RRs at name, optionally restricted
    513  * to RRs of a given type.
    514  *
    515  * The callback functions are called "actions" and take
    516  * two arguments: a void pointer for passing arbitrary
    517  * context information, and a pointer to the current RRset
    518  * or RR.  By convention, their names end in "_action".
    519  */
    520 
    521 /*
    522  * XXXRTH  We might want to make this public somewhere in libdns.
    523  */
    524 
    525 /*%
    526  * Function type for foreach_rrset() iterator actions.
    527  */
    528 typedef isc_result_t rrset_func(void *data, dns_rdataset_t *rrset);
    529 
    530 /*%
    531  * Function type for foreach_rr() iterator actions.
    532  */
    533 typedef isc_result_t rr_func(void *data, rr_t *rr);
    534 
    535 /*%
    536  * Internal context struct for foreach_node_rr().
    537  */
    538 typedef struct {
    539 	rr_func *	rr_action;
    540 	void *		rr_action_data;
    541 } foreach_node_rr_ctx_t;
    542 
    543 /*%
    544  * Internal helper function for foreach_node_rr().
    545  */
    546 static isc_result_t
    547 foreach_node_rr_action(void *data, dns_rdataset_t *rdataset) {
    548 	isc_result_t result;
    549 	foreach_node_rr_ctx_t *ctx = data;
    550 	for (result = dns_rdataset_first(rdataset);
    551 	     result == ISC_R_SUCCESS;
    552 	     result = dns_rdataset_next(rdataset))
    553 	{
    554 		rr_t rr = { 0, DNS_RDATA_INIT };
    555 
    556 		dns_rdataset_current(rdataset, &rr.rdata);
    557 		rr.ttl = rdataset->ttl;
    558 		result = (*ctx->rr_action)(ctx->rr_action_data, &rr);
    559 		if (result != ISC_R_SUCCESS)
    560 			return (result);
    561 	}
    562 	if (result != ISC_R_NOMORE)
    563 		return (result);
    564 	return (ISC_R_SUCCESS);
    565 }
    566 
    567 /*%
    568  * For each rdataset of 'name' in 'ver' of 'db', call 'action'
    569  * with the rdataset and 'action_data' as arguments.  If the name
    570  * does not exist, do nothing.
    571  *
    572  * If 'action' returns an error, abort iteration and return the error.
    573  */
    574 static isc_result_t
    575 foreach_rrset(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    576 	      rrset_func *action, void *action_data)
    577 {
    578 	isc_result_t result;
    579 	dns_dbnode_t *node;
    580 	dns_rdatasetiter_t *iter;
    581 	dns_clientinfomethods_t cm;
    582 	dns_clientinfo_t ci;
    583 	dns_dbversion_t *oldver = NULL;
    584 
    585 	dns_clientinfomethods_init(&cm, ns_client_sourceip);
    586 
    587 	/*
    588 	 * Only set the clientinfo 'versionp' if the new version is
    589 	 * different from the current version
    590 	 */
    591 	dns_db_currentversion(db, &oldver);
    592 	dns_clientinfo_init(&ci, NULL, (ver != oldver) ? ver : NULL);
    593 	dns_db_closeversion(db, &oldver, false);
    594 
    595 	node = NULL;
    596 	result = dns_db_findnodeext(db, name, false, &cm, &ci, &node);
    597 	if (result == ISC_R_NOTFOUND)
    598 		return (ISC_R_SUCCESS);
    599 	if (result != ISC_R_SUCCESS)
    600 		return (result);
    601 
    602 	iter = NULL;
    603 	result = dns_db_allrdatasets(db, node, ver,
    604 				     (isc_stdtime_t) 0, &iter);
    605 	if (result != ISC_R_SUCCESS)
    606 		goto cleanup_node;
    607 
    608 	for (result = dns_rdatasetiter_first(iter);
    609 	     result == ISC_R_SUCCESS;
    610 	     result = dns_rdatasetiter_next(iter))
    611 	{
    612 		dns_rdataset_t rdataset;
    613 
    614 		dns_rdataset_init(&rdataset);
    615 		dns_rdatasetiter_current(iter, &rdataset);
    616 
    617 		result = (*action)(action_data, &rdataset);
    618 
    619 		dns_rdataset_disassociate(&rdataset);
    620 		if (result != ISC_R_SUCCESS)
    621 			goto cleanup_iterator;
    622 	}
    623 	if (result == ISC_R_NOMORE)
    624 		result = ISC_R_SUCCESS;
    625 
    626  cleanup_iterator:
    627 	dns_rdatasetiter_destroy(&iter);
    628 
    629  cleanup_node:
    630 	dns_db_detachnode(db, &node);
    631 
    632 	return (result);
    633 }
    634 
    635 /*%
    636  * For each RR of 'name' in 'ver' of 'db', call 'action'
    637  * with the RR and 'action_data' as arguments.  If the name
    638  * does not exist, do nothing.
    639  *
    640  * If 'action' returns an error, abort iteration
    641  * and return the error.
    642  */
    643 static isc_result_t
    644 foreach_node_rr(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    645 		rr_func *rr_action, void *rr_action_data)
    646 {
    647 	foreach_node_rr_ctx_t ctx;
    648 	ctx.rr_action = rr_action;
    649 	ctx.rr_action_data = rr_action_data;
    650 	return (foreach_rrset(db, ver, name,
    651 			      foreach_node_rr_action, &ctx));
    652 }
    653 
    654 
    655 /*%
    656  * For each of the RRs specified by 'db', 'ver', 'name', 'type',
    657  * (which can be dns_rdatatype_any to match any type), and 'covers', call
    658  * 'action' with the RR and 'action_data' as arguments. If the name
    659  * does not exist, or if no RRset of the given type exists at the name,
    660  * do nothing.
    661  *
    662  * If 'action' returns an error, abort iteration and return the error.
    663  */
    664 static isc_result_t
    665 foreach_rr(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    666 	   dns_rdatatype_t type, dns_rdatatype_t covers, rr_func *rr_action,
    667 	   void *rr_action_data)
    668 {
    669 
    670 	isc_result_t result;
    671 	dns_dbnode_t *node;
    672 	dns_rdataset_t rdataset;
    673 	dns_clientinfomethods_t cm;
    674 	dns_clientinfo_t ci;
    675 	dns_dbversion_t *oldver = NULL;
    676 	dns_fixedname_t fixed;
    677 
    678 	dns_clientinfomethods_init(&cm, ns_client_sourceip);
    679 
    680 	/*
    681 	 * Only set the clientinfo 'versionp' if the new version is
    682 	 * different from the current version
    683 	 */
    684 	dns_db_currentversion(db, &oldver);
    685 	dns_clientinfo_init(&ci, NULL, (ver != oldver) ? ver : NULL);
    686 	dns_db_closeversion(db, &oldver, false);
    687 
    688 	if (type == dns_rdatatype_any)
    689 		return (foreach_node_rr(db, ver, name,
    690 					rr_action, rr_action_data));
    691 
    692 	node = NULL;
    693 	if (type == dns_rdatatype_nsec3 ||
    694 	    (type == dns_rdatatype_rrsig && covers == dns_rdatatype_nsec3))
    695 		result = dns_db_findnsec3node(db, name, false, &node);
    696 	else
    697 		result = dns_db_findnodeext(db, name, false,
    698 					    &cm, &ci, &node);
    699 	if (result == ISC_R_NOTFOUND)
    700 		return (ISC_R_SUCCESS);
    701 	if (result != ISC_R_SUCCESS)
    702 		return (result);
    703 
    704 	dns_rdataset_init(&rdataset);
    705 	result = dns_db_findrdataset(db, node, ver, type, covers,
    706 				     (isc_stdtime_t) 0, &rdataset, NULL);
    707 	if (result == ISC_R_NOTFOUND) {
    708 		result = ISC_R_SUCCESS;
    709 		goto cleanup_node;
    710 	}
    711 	if (result != ISC_R_SUCCESS)
    712 		goto cleanup_node;
    713 
    714 	if (rr_action == add_rr_prepare_action) {
    715 		add_rr_prepare_ctx_t *ctx = rr_action_data;
    716 
    717 		ctx->oldname = dns_fixedname_initname(&fixed);
    718 		dns_name_copy(name, ctx->oldname, NULL);
    719 		dns_rdataset_getownercase(&rdataset, ctx->oldname);
    720 	}
    721 
    722 	for (result = dns_rdataset_first(&rdataset);
    723 	     result == ISC_R_SUCCESS;
    724 	     result = dns_rdataset_next(&rdataset))
    725 	{
    726 		rr_t rr = { 0, DNS_RDATA_INIT };
    727 		dns_rdataset_current(&rdataset, &rr.rdata);
    728 		rr.ttl = rdataset.ttl;
    729 		result = (*rr_action)(rr_action_data, &rr);
    730 		if (result != ISC_R_SUCCESS)
    731 			goto cleanup_rdataset;
    732 	}
    733 	if (result != ISC_R_NOMORE)
    734 		goto cleanup_rdataset;
    735 	result = ISC_R_SUCCESS;
    736 
    737  cleanup_rdataset:
    738 	dns_rdataset_disassociate(&rdataset);
    739  cleanup_node:
    740 	dns_db_detachnode(db, &node);
    741 
    742 	return (result);
    743 }
    744 
    745 /**************************************************************************/
    746 /*
    747  * Various tests on the database contents (for prerequisites, etc).
    748  */
    749 
    750 /*%
    751  * Function type for predicate functions that compare a database RR 'db_rr'
    752  * against an update RR 'update_rr'.
    753  */
    754 typedef bool rr_predicate(dns_rdata_t *update_rr, dns_rdata_t *db_rr);
    755 
    756 /*%
    757  * Helper function for rrset_exists().
    758  */
    759 static isc_result_t
    760 rrset_exists_action(void *data, rr_t *rr) {
    761 	UNUSED(data);
    762 	UNUSED(rr);
    763 	return (ISC_R_EXISTS);
    764 }
    765 
    766 /*%
    767  * Utility macro for RR existence checking functions.
    768  *
    769  * If the variable 'result' has the value ISC_R_EXISTS or
    770  * ISC_R_SUCCESS, set *exists to true or false,
    771  * respectively, and return success.
    772  *
    773  * If 'result' has any other value, there was a failure.
    774  * Return the failure result code and do not set *exists.
    775  *
    776  * This would be more readable as "do { if ... } while(0)",
    777  * but that form generates tons of warnings on Solaris 2.6.
    778  */
    779 #define RETURN_EXISTENCE_FLAG				\
    780 	return ((result == ISC_R_EXISTS) ?		\
    781 		(*exists = true, ISC_R_SUCCESS) :	\
    782 		((result == ISC_R_SUCCESS) ?		\
    783 		 (*exists = false, ISC_R_SUCCESS) :	\
    784 		 result))
    785 
    786 /*%
    787  * Set '*exists' to true iff an rrset of the given type exists,
    788  * to false otherwise.
    789  */
    790 static isc_result_t
    791 rrset_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    792 	     dns_rdatatype_t type, dns_rdatatype_t covers,
    793 	     bool *exists)
    794 {
    795 	isc_result_t result;
    796 	result = foreach_rr(db, ver, name, type, covers,
    797 			    rrset_exists_action, NULL);
    798 	RETURN_EXISTENCE_FLAG;
    799 }
    800 
    801 /*%
    802  * Helper function for cname_incompatible_rrset_exists.
    803  */
    804 static isc_result_t
    805 cname_compatibility_action(void *data, dns_rdataset_t *rrset) {
    806 	UNUSED(data);
    807 	if (rrset->type != dns_rdatatype_cname &&
    808 	    ! dns_rdatatype_atcname(rrset->type))
    809 	{
    810 		return (ISC_R_EXISTS);
    811 	}
    812 	return (ISC_R_SUCCESS);
    813 }
    814 
    815 /*%
    816  * Check whether there is an rrset incompatible with adding a CNAME RR,
    817  * i.e., anything but another CNAME (which can be replaced) or a
    818  * DNSSEC RR (which can coexist).
    819  *
    820  * If such an incompatible rrset exists, set '*exists' to true.
    821  * Otherwise, set it to false.
    822  */
    823 static isc_result_t
    824 cname_incompatible_rrset_exists(dns_db_t *db, dns_dbversion_t *ver,
    825 				dns_name_t *name, bool *exists) {
    826 	isc_result_t result;
    827 	result = foreach_rrset(db, ver, name,
    828 			       cname_compatibility_action, NULL);
    829 	RETURN_EXISTENCE_FLAG;
    830 }
    831 
    832 /*%
    833  * Helper function for rr_count().
    834  */
    835 static isc_result_t
    836 count_rr_action(void *data, rr_t *rr) {
    837 	int *countp = data;
    838 	UNUSED(rr);
    839 	(*countp)++;
    840 	return (ISC_R_SUCCESS);
    841 }
    842 
    843 /*%
    844  * Count the number of RRs of 'type' belonging to 'name' in 'ver' of 'db'.
    845  */
    846 static isc_result_t
    847 rr_count(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    848 	 dns_rdatatype_t type, dns_rdatatype_t covers, int *countp)
    849 {
    850 	*countp = 0;
    851 	return (foreach_rr(db, ver, name, type, covers,
    852 			   count_rr_action, countp));
    853 }
    854 
    855 /*%
    856  * Context struct and helper function for name_exists().
    857  */
    858 
    859 static isc_result_t
    860 name_exists_action(void *data, dns_rdataset_t *rrset) {
    861 	UNUSED(data);
    862 	UNUSED(rrset);
    863 	return (ISC_R_EXISTS);
    864 }
    865 
    866 /*%
    867  * Set '*exists' to true iff the given name exists, to false otherwise.
    868  */
    869 static isc_result_t
    870 name_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    871 	    bool *exists)
    872 {
    873 	isc_result_t result;
    874 	result = foreach_rrset(db, ver, name,
    875 			       name_exists_action, NULL);
    876 	RETURN_EXISTENCE_FLAG;
    877 }
    878 
    879 /*
    880  *	'ssu_check_t' is used to pass the arguments to
    881  *	dns_ssutable_checkrules() to the callback function
    882  *	ssu_checkrule().
    883  */
    884 typedef struct {
    885 	/* The ownername of the record to be updated. */
    886 	dns_name_t *name;
    887 
    888 	/* The signature's name if the request was signed. */
    889 	dns_name_t *signer;
    890 
    891 	/* The address of the client. */
    892 	isc_netaddr_t *addr;
    893 
    894 	/* The ACL environment */
    895 	dns_aclenv_t *aclenv;
    896 
    897 	/* Whether the request was sent via TCP. */
    898 	bool tcp;
    899 
    900 	/* The ssu table to check against. */
    901 	dns_ssutable_t *table;
    902 
    903 	/* the key used for TKEY requests */
    904 	dst_key_t *key;
    905 } ssu_check_t;
    906 
    907 static isc_result_t
    908 ssu_checkrule(void *data, dns_rdataset_t *rrset) {
    909 	ssu_check_t *ssuinfo = data;
    910 	bool result;
    911 
    912 	/*
    913 	 * If we're deleting all records, it's ok to delete RRSIG and NSEC even
    914 	 * if we're normally not allowed to.
    915 	 */
    916 	if (rrset->type == dns_rdatatype_rrsig ||
    917 	    rrset->type == dns_rdatatype_nsec)
    918 		return (ISC_R_SUCCESS);
    919 	result = dns_ssutable_checkrules(ssuinfo->table, ssuinfo->signer,
    920 					 ssuinfo->name, ssuinfo->addr,
    921 					 ssuinfo->tcp, ssuinfo->aclenv,
    922 					 rrset->type, ssuinfo->key);
    923 	return (result == true ? ISC_R_SUCCESS : ISC_R_FAILURE);
    924 }
    925 
    926 static bool
    927 ssu_checkall(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
    928 	     dns_ssutable_t *ssutable, dns_name_t *signer,
    929 	     isc_netaddr_t *addr, dns_aclenv_t *aclenv, bool tcp,
    930 	     dst_key_t *key)
    931 {
    932 	isc_result_t result;
    933 	ssu_check_t ssuinfo;
    934 
    935 	ssuinfo.name = name;
    936 	ssuinfo.table = ssutable;
    937 	ssuinfo.signer = signer;
    938 	ssuinfo.addr = addr;
    939 	ssuinfo.aclenv = aclenv;
    940 	ssuinfo.tcp = tcp;
    941 	ssuinfo.key = key;
    942 	result = foreach_rrset(db, ver, name, ssu_checkrule, &ssuinfo);
    943 	return (result == ISC_R_SUCCESS);
    944 }
    945 
    946 /**************************************************************************/
    947 /*
    948  * Checking of "RRset exists (value dependent)" prerequisites.
    949  *
    950  * In the RFC2136 section 3.2.5, this is the pseudocode involving
    951  * a variable called "temp", a mapping of <name, type> tuples to rrsets.
    952  *
    953  * Here, we represent the "temp" data structure as (non-minimal) "dns_diff_t"
    954  * where each tuple has op==DNS_DIFFOP_EXISTS.
    955  */
    956 
    957 
    958 /*%
    959  * Append a tuple asserting the existence of the RR with
    960  * 'name' and 'rdata' to 'diff'.
    961  */
    962 static isc_result_t
    963 temp_append(dns_diff_t *diff, dns_name_t *name, dns_rdata_t *rdata) {
    964 	isc_result_t result;
    965 	dns_difftuple_t *tuple = NULL;
    966 
    967 	REQUIRE(DNS_DIFF_VALID(diff));
    968 	CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_EXISTS,
    969 				   name, 0, rdata, &tuple));
    970 	ISC_LIST_APPEND(diff->tuples, tuple, link);
    971  failure:
    972 	return (result);
    973 }
    974 
    975 /*%
    976  * Compare two rdatasets represented as sorted lists of tuples.
    977  * All list elements must have the same owner name and type.
    978  * Return ISC_R_SUCCESS if the rdatasets are equal, rcode(dns_rcode_nxrrset)
    979  * if not.
    980  */
    981 static isc_result_t
    982 temp_check_rrset(dns_difftuple_t *a, dns_difftuple_t *b) {
    983 	for (;;) {
    984 		if (a == NULL || b == NULL)
    985 			break;
    986 		INSIST(a->op == DNS_DIFFOP_EXISTS &&
    987 		       b->op == DNS_DIFFOP_EXISTS);
    988 		INSIST(a->rdata.type == b->rdata.type);
    989 		INSIST(dns_name_equal(&a->name, &b->name));
    990 		if (dns_rdata_casecompare(&a->rdata, &b->rdata) != 0)
    991 			return (DNS_R_NXRRSET);
    992 		a = ISC_LIST_NEXT(a, link);
    993 		b = ISC_LIST_NEXT(b, link);
    994 	}
    995 	if (a != NULL || b != NULL)
    996 		return (DNS_R_NXRRSET);
    997 	return (ISC_R_SUCCESS);
    998 }
    999 
   1000 /*%
   1001  * A comparison function defining the sorting order for the entries
   1002  * in the "temp" data structure.  The major sort key is the owner name,
   1003  * followed by the type and rdata.
   1004  */
   1005 static int
   1006 temp_order(const void *av, const void *bv) {
   1007 	dns_difftuple_t const * const *ap = av;
   1008 	dns_difftuple_t const * const *bp = bv;
   1009 	dns_difftuple_t const *a = *ap;
   1010 	dns_difftuple_t const *b = *bp;
   1011 	int r;
   1012 	r = dns_name_compare(&a->name, &b->name);
   1013 	if (r != 0)
   1014 		return (r);
   1015 	r = (b->rdata.type - a->rdata.type);
   1016 	if (r != 0)
   1017 		return (r);
   1018 	r = dns_rdata_casecompare(&a->rdata, &b->rdata);
   1019 	return (r);
   1020 }
   1021 
   1022 /*%
   1023  * Check the "RRset exists (value dependent)" prerequisite information
   1024  * in 'temp' against the contents of the database 'db'.
   1025  *
   1026  * Return ISC_R_SUCCESS if the prerequisites are satisfied,
   1027  * rcode(dns_rcode_nxrrset) if not.
   1028  *
   1029  * 'temp' must be pre-sorted.
   1030  */
   1031 
   1032 static isc_result_t
   1033 temp_check(isc_mem_t *mctx, dns_diff_t *temp, dns_db_t *db,
   1034 	   dns_dbversion_t *ver, dns_name_t *tmpname, dns_rdatatype_t *typep)
   1035 {
   1036 	isc_result_t result;
   1037 	dns_name_t *name;
   1038 	dns_dbnode_t *node;
   1039 	dns_difftuple_t *t;
   1040 	dns_diff_t trash;
   1041 
   1042 	dns_diff_init(mctx, &trash);
   1043 
   1044 	/*
   1045 	 * For each name and type in the prerequisites,
   1046 	 * construct a sorted rdata list of the corresponding
   1047 	 * database contents, and compare the lists.
   1048 	 */
   1049 	t = ISC_LIST_HEAD(temp->tuples);
   1050 	while (t != NULL) {
   1051 		name = &t->name;
   1052 		(void)dns_name_copy(name, tmpname, NULL);
   1053 		*typep = t->rdata.type;
   1054 
   1055 		/* A new unique name begins here. */
   1056 		node = NULL;
   1057 		result = dns_db_findnode(db, name, false, &node);
   1058 		if (result == ISC_R_NOTFOUND) {
   1059 			dns_diff_clear(&trash);
   1060 			return (DNS_R_NXRRSET);
   1061 		}
   1062 		if (result != ISC_R_SUCCESS) {
   1063 			dns_diff_clear(&trash);
   1064 			return (result);
   1065 		}
   1066 
   1067 		/* A new unique type begins here. */
   1068 		while (t != NULL && dns_name_equal(&t->name, name)) {
   1069 			dns_rdatatype_t type, covers;
   1070 			dns_rdataset_t rdataset;
   1071 			dns_diff_t d_rrs; /* Database RRs with
   1072 						this name and type */
   1073 			dns_diff_t u_rrs; /* Update RRs with
   1074 						this name and type */
   1075 
   1076 			*typep = type = t->rdata.type;
   1077 			if (type == dns_rdatatype_rrsig ||
   1078 			    type == dns_rdatatype_sig)
   1079 				covers = dns_rdata_covers(&t->rdata);
   1080 			else if (type == dns_rdatatype_any) {
   1081 				dns_db_detachnode(db, &node);
   1082 				dns_diff_clear(&trash);
   1083 				return (DNS_R_NXRRSET);
   1084 			} else
   1085 				covers = 0;
   1086 
   1087 			/*
   1088 			 * Collect all database RRs for this name and type
   1089 			 * onto d_rrs and sort them.
   1090 			 */
   1091 			dns_rdataset_init(&rdataset);
   1092 			result = dns_db_findrdataset(db, node, ver, type,
   1093 						     covers, (isc_stdtime_t) 0,
   1094 						     &rdataset, NULL);
   1095 			if (result != ISC_R_SUCCESS) {
   1096 				dns_db_detachnode(db, &node);
   1097 				dns_diff_clear(&trash);
   1098 				return (DNS_R_NXRRSET);
   1099 			}
   1100 
   1101 			dns_diff_init(mctx, &d_rrs);
   1102 			dns_diff_init(mctx, &u_rrs);
   1103 
   1104 			for (result = dns_rdataset_first(&rdataset);
   1105 			     result == ISC_R_SUCCESS;
   1106 			     result = dns_rdataset_next(&rdataset))
   1107 			{
   1108 				dns_rdata_t rdata = DNS_RDATA_INIT;
   1109 				dns_rdataset_current(&rdataset, &rdata);
   1110 				result = temp_append(&d_rrs, name, &rdata);
   1111 				if (result != ISC_R_SUCCESS)
   1112 					goto failure;
   1113 			}
   1114 			if (result != ISC_R_NOMORE)
   1115 				goto failure;
   1116 			result = dns_diff_sort(&d_rrs, temp_order);
   1117 			if (result != ISC_R_SUCCESS)
   1118 				goto failure;
   1119 
   1120 			/*
   1121 			 * Collect all update RRs for this name and type
   1122 			 * onto u_rrs.  No need to sort them here -
   1123 			 * they are already sorted.
   1124 			 */
   1125 			while (t != NULL &&
   1126 			       dns_name_equal(&t->name, name) &&
   1127 			       t->rdata.type == type)
   1128 			{
   1129 				dns_difftuple_t *next =
   1130 					ISC_LIST_NEXT(t, link);
   1131 				ISC_LIST_UNLINK(temp->tuples, t, link);
   1132 				ISC_LIST_APPEND(u_rrs.tuples, t, link);
   1133 				t = next;
   1134 			}
   1135 
   1136 			/* Compare the two sorted lists. */
   1137 			result = temp_check_rrset(ISC_LIST_HEAD(u_rrs.tuples),
   1138 						  ISC_LIST_HEAD(d_rrs.tuples));
   1139 			if (result != ISC_R_SUCCESS)
   1140 				goto failure;
   1141 
   1142 			/*
   1143 			 * We are done with the tuples, but we can't free
   1144 			 * them yet because "name" still points into one
   1145 			 * of them.  Move them on a temporary list.
   1146 			 */
   1147 			ISC_LIST_APPENDLIST(trash.tuples, u_rrs.tuples, link);
   1148 			ISC_LIST_APPENDLIST(trash.tuples, d_rrs.tuples, link);
   1149 			dns_rdataset_disassociate(&rdataset);
   1150 
   1151 			continue;
   1152 
   1153 		    failure:
   1154 			dns_diff_clear(&d_rrs);
   1155 			dns_diff_clear(&u_rrs);
   1156 			dns_diff_clear(&trash);
   1157 			dns_rdataset_disassociate(&rdataset);
   1158 			dns_db_detachnode(db, &node);
   1159 			return (result);
   1160 		}
   1161 
   1162 		dns_db_detachnode(db, &node);
   1163 	}
   1164 
   1165 	dns_diff_clear(&trash);
   1166 	return (ISC_R_SUCCESS);
   1167 }
   1168 
   1169 /**************************************************************************/
   1170 /*
   1171  * Conditional deletion of RRs.
   1172  */
   1173 
   1174 /*%
   1175  * Context structure for delete_if().
   1176  */
   1177 
   1178 typedef struct {
   1179 	rr_predicate *predicate;
   1180 	dns_db_t *db;
   1181 	dns_dbversion_t *ver;
   1182 	dns_diff_t *diff;
   1183 	dns_name_t *name;
   1184 	dns_rdata_t *update_rr;
   1185 } conditional_delete_ctx_t;
   1186 
   1187 /*%
   1188  * Predicate functions for delete_if().
   1189  */
   1190 
   1191 /*%
   1192  * Return true iff 'db_rr' is neither a SOA nor an NS RR nor
   1193  * an RRSIG nor an NSEC3PARAM nor a NSEC.
   1194  */
   1195 static bool
   1196 type_not_soa_nor_ns_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
   1197 	UNUSED(update_rr);
   1198 	return ((db_rr->type != dns_rdatatype_soa &&
   1199 		 db_rr->type != dns_rdatatype_ns &&
   1200 		 db_rr->type != dns_rdatatype_nsec3param &&
   1201 		 db_rr->type != dns_rdatatype_rrsig &&
   1202 		 db_rr->type != dns_rdatatype_nsec) ?
   1203 		true : false);
   1204 }
   1205 
   1206 /*%
   1207  * Return true iff 'db_rr' is neither a RRSIG nor a NSEC.
   1208  */
   1209 static bool
   1210 type_not_dnssec(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
   1211 	UNUSED(update_rr);
   1212 	return ((db_rr->type != dns_rdatatype_rrsig &&
   1213 		 db_rr->type != dns_rdatatype_nsec) ?
   1214 		true : false);
   1215 }
   1216 
   1217 /*%
   1218  * Return true always.
   1219  */
   1220 static bool
   1221 true_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
   1222 	UNUSED(update_rr);
   1223 	UNUSED(db_rr);
   1224 	return (true);
   1225 }
   1226 
   1227 /*%
   1228  * Return true iff the two RRs have identical rdata.
   1229  */
   1230 static bool
   1231 rr_equal_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
   1232 	/*
   1233 	 * XXXRTH  This is not a problem, but we should consider creating
   1234 	 *         dns_rdata_equal() (that used dns_name_equal()), since it
   1235 	 *         would be faster.  Not a priority.
   1236 	 */
   1237 	return (dns_rdata_casecompare(update_rr, db_rr) == 0 ?
   1238 		true : false);
   1239 }
   1240 
   1241 /*%
   1242  * Return true iff 'update_rr' should replace 'db_rr' according
   1243  * to the special RFC2136 rules for CNAME, SOA, and WKS records.
   1244  *
   1245  * RFC2136 does not mention NSEC or DNAME, but multiple NSECs or DNAMEs
   1246  * make little sense, so we replace those, too.
   1247  *
   1248  * Additionally replace RRSIG that have been generated by the same key
   1249  * for the same type.  This simplifies refreshing a offline KSK by not
   1250  * requiring that the old RRSIG be deleted.  It also simplifies key
   1251  * rollover by only requiring that the new RRSIG be added.
   1252  */
   1253 static bool
   1254 replaces_p(dns_rdata_t *update_rr, dns_rdata_t *db_rr) {
   1255 	dns_rdata_rrsig_t updatesig, dbsig;
   1256 	isc_result_t result;
   1257 
   1258 	if (db_rr->type != update_rr->type)
   1259 		return (false);
   1260 	if (db_rr->type == dns_rdatatype_cname)
   1261 		return (true);
   1262 	if (db_rr->type == dns_rdatatype_dname)
   1263 		return (true);
   1264 	if (db_rr->type == dns_rdatatype_soa)
   1265 		return (true);
   1266 	if (db_rr->type == dns_rdatatype_nsec)
   1267 		return (true);
   1268 	if (db_rr->type == dns_rdatatype_rrsig) {
   1269 		/*
   1270 		 * Replace existing RRSIG with the same keyid,
   1271 		 * covered and algorithm.
   1272 		 */
   1273 		result = dns_rdata_tostruct(db_rr, &dbsig, NULL);
   1274 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
   1275 		result = dns_rdata_tostruct(update_rr, &updatesig, NULL);
   1276 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
   1277 		if (dbsig.keyid == updatesig.keyid &&
   1278 		    dbsig.covered == updatesig.covered &&
   1279 		    dbsig.algorithm == updatesig.algorithm)
   1280 			return (true);
   1281 	}
   1282 	if (db_rr->type == dns_rdatatype_wks) {
   1283 		/*
   1284 		 * Compare the address and protocol fields only.  These
   1285 		 * form the first five bytes of the RR data.  Do a
   1286 		 * raw binary comparison; unpacking the WKS RRs using
   1287 		 * dns_rdata_tostruct() might be cleaner in some ways.
   1288 		 */
   1289 		INSIST(db_rr->length >= 5 && update_rr->length >= 5);
   1290 		return (memcmp(db_rr->data, update_rr->data, 5) == 0 ?
   1291 			true : false);
   1292 	}
   1293 
   1294 	if (db_rr->type == dns_rdatatype_nsec3param) {
   1295 		if (db_rr->length != update_rr->length)
   1296 			return (false);
   1297 		INSIST(db_rr->length >= 4 && update_rr->length >= 4);
   1298 		/*
   1299 		 * Replace NSEC3PARAM records that only differ by the
   1300 		 * flags field.
   1301 		 */
   1302 		if (db_rr->data[0] == update_rr->data[0] &&
   1303 		    memcmp(db_rr->data+2, update_rr->data+2,
   1304 			   update_rr->length - 2) == 0)
   1305 			return (true);
   1306 	}
   1307 	return (false);
   1308 }
   1309 
   1310 /*%
   1311  * Internal helper function for delete_if().
   1312  */
   1313 static isc_result_t
   1314 delete_if_action(void *data, rr_t *rr) {
   1315 	conditional_delete_ctx_t *ctx = data;
   1316 	if ((*ctx->predicate)(ctx->update_rr, &rr->rdata)) {
   1317 		isc_result_t result;
   1318 		result = update_one_rr(ctx->db, ctx->ver, ctx->diff,
   1319 				       DNS_DIFFOP_DEL, ctx->name,
   1320 				       rr->ttl, &rr->rdata);
   1321 		return (result);
   1322 	} else {
   1323 		return (ISC_R_SUCCESS);
   1324 	}
   1325 }
   1326 
   1327 /*%
   1328  * Conditionally delete RRs.  Apply 'predicate' to the RRs
   1329  * specified by 'db', 'ver', 'name', and 'type' (which can
   1330  * be dns_rdatatype_any to match any type).  Delete those
   1331  * RRs for which the predicate returns true, and log the
   1332  * deletions in 'diff'.
   1333  */
   1334 static isc_result_t
   1335 delete_if(rr_predicate *predicate, dns_db_t *db, dns_dbversion_t *ver,
   1336 	  dns_name_t *name, dns_rdatatype_t type, dns_rdatatype_t covers,
   1337 	  dns_rdata_t *update_rr, dns_diff_t *diff)
   1338 {
   1339 	conditional_delete_ctx_t ctx;
   1340 	ctx.predicate = predicate;
   1341 	ctx.db = db;
   1342 	ctx.ver = ver;
   1343 	ctx.diff = diff;
   1344 	ctx.name = name;
   1345 	ctx.update_rr = update_rr;
   1346 	return (foreach_rr(db, ver, name, type, covers,
   1347 			   delete_if_action, &ctx));
   1348 }
   1349 
   1350 /**************************************************************************/
   1351 
   1352 static isc_result_t
   1353 add_rr_prepare_action(void *data, rr_t *rr) {
   1354 	isc_result_t result = ISC_R_SUCCESS;
   1355 	add_rr_prepare_ctx_t *ctx = data;
   1356 	dns_difftuple_t *tuple = NULL;
   1357 	bool equal, case_equal, ttl_equal;
   1358 
   1359 	/*
   1360 	 * Are the new and old cases equal?
   1361 	 */
   1362 	case_equal = dns_name_caseequal(ctx->name, ctx->oldname);
   1363 
   1364 	/*
   1365 	 * Are the ttl's equal?
   1366 	 */
   1367 	ttl_equal = rr->ttl == ctx->update_rr_ttl;
   1368 
   1369 	/*
   1370 	 * If the update RR is a "duplicate" of a existing RR,
   1371 	 * the update should be silently ignored.
   1372 	 */
   1373 	equal = (dns_rdata_casecompare(&rr->rdata, ctx->update_rr) == 0);
   1374 	if (equal && case_equal && ttl_equal) {
   1375 		ctx->ignore_add = true;
   1376 		return (ISC_R_SUCCESS);
   1377 	}
   1378 
   1379 	/*
   1380 	 * If this RR is "equal" to the update RR, it should
   1381 	 * be deleted before the update RR is added.
   1382 	 */
   1383 	if (replaces_p(ctx->update_rr, &rr->rdata)) {
   1384 		CHECK(dns_difftuple_create(ctx->del_diff.mctx, DNS_DIFFOP_DEL,
   1385 					   ctx->oldname, rr->ttl, &rr->rdata,
   1386 					   &tuple));
   1387 		dns_diff_append(&ctx->del_diff, &tuple);
   1388 		return (ISC_R_SUCCESS);
   1389 	}
   1390 
   1391 	/*
   1392 	 * If this RR differs in TTL or case from the update RR,
   1393 	 * its TTL and case must be adjusted.
   1394 	 */
   1395 	if (!ttl_equal || !case_equal) {
   1396 		CHECK(dns_difftuple_create(ctx->del_diff.mctx, DNS_DIFFOP_DEL,
   1397 					   ctx->oldname, rr->ttl, &rr->rdata,
   1398 					   &tuple));
   1399 		dns_diff_append(&ctx->del_diff, &tuple);
   1400 		if (!equal) {
   1401 			CHECK(dns_difftuple_create(ctx->add_diff.mctx,
   1402 						   DNS_DIFFOP_ADD, ctx->name,
   1403 						   ctx->update_rr_ttl,
   1404 						   &rr->rdata, &tuple));
   1405 			dns_diff_append(&ctx->add_diff, &tuple);
   1406 		}
   1407 	}
   1408  failure:
   1409 	return (result);
   1410 }
   1411 
   1412 /**************************************************************************/
   1413 /*
   1414  * Miscellaneous subroutines.
   1415  */
   1416 
   1417 /*%
   1418  * Extract a single update RR from 'section' of dynamic update message
   1419  * 'msg', with consistency checking.
   1420  *
   1421  * Stores the owner name, rdata, and TTL of the update RR at 'name',
   1422  * 'rdata', and 'ttl', respectively.
   1423  */
   1424 static void
   1425 get_current_rr(dns_message_t *msg, dns_section_t section,
   1426 	       dns_rdataclass_t zoneclass, dns_name_t **name,
   1427 	       dns_rdata_t *rdata, dns_rdatatype_t *covers,
   1428 	       dns_ttl_t *ttl, dns_rdataclass_t *update_class)
   1429 {
   1430 	dns_rdataset_t *rdataset;
   1431 	isc_result_t result;
   1432 	dns_message_currentname(msg, section, name);
   1433 	rdataset = ISC_LIST_HEAD((*name)->list);
   1434 	INSIST(rdataset != NULL);
   1435 	INSIST(ISC_LIST_NEXT(rdataset, link) == NULL);
   1436 	*covers = rdataset->covers;
   1437 	*ttl = rdataset->ttl;
   1438 	result = dns_rdataset_first(rdataset);
   1439 	INSIST(result == ISC_R_SUCCESS);
   1440 	dns_rdataset_current(rdataset, rdata);
   1441 	INSIST(dns_rdataset_next(rdataset) == ISC_R_NOMORE);
   1442 	*update_class = rdata->rdclass;
   1443 	rdata->rdclass = zoneclass;
   1444 }
   1445 
   1446 /*%
   1447  * Increment the SOA serial number of database 'db', version 'ver'.
   1448  * Replace the SOA record in the database, and log the
   1449  * change in 'diff'.
   1450  */
   1451 
   1452 	/*
   1453 	 * XXXRTH  Failures in this routine will be worth logging, when
   1454 	 *         we have a logging system.  Failure to find the zonename
   1455 	 *	   or the SOA rdataset warrant at least an UNEXPECTED_ERROR().
   1456 	 */
   1457 
   1458 static isc_result_t
   1459 update_soa_serial(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
   1460 		  isc_mem_t *mctx, dns_updatemethod_t method)
   1461 {
   1462 	dns_difftuple_t *deltuple = NULL;
   1463 	dns_difftuple_t *addtuple = NULL;
   1464 	uint32_t serial;
   1465 	isc_result_t result;
   1466 
   1467 	CHECK(dns_db_createsoatuple(db, ver, mctx, DNS_DIFFOP_DEL, &deltuple));
   1468 	CHECK(dns_difftuple_copy(deltuple, &addtuple));
   1469 	addtuple->op = DNS_DIFFOP_ADD;
   1470 
   1471 	serial = dns_soa_getserial(&addtuple->rdata);
   1472 	serial = dns_update_soaserial(serial, method);
   1473 	dns_soa_setserial(serial, &addtuple->rdata);
   1474 	CHECK(do_one_tuple(&deltuple, db, ver, diff));
   1475 	CHECK(do_one_tuple(&addtuple, db, ver, diff));
   1476 	result = ISC_R_SUCCESS;
   1477 
   1478  failure:
   1479 	if (addtuple != NULL)
   1480 		dns_difftuple_free(&addtuple);
   1481 	if (deltuple != NULL)
   1482 		dns_difftuple_free(&deltuple);
   1483 	return (result);
   1484 }
   1485 
   1486 /*%
   1487  * Check that the new SOA record at 'update_rdata' does not
   1488  * illegally cause the SOA serial number to decrease or stay
   1489  * unchanged relative to the existing SOA in 'db'.
   1490  *
   1491  * Sets '*ok' to true if the update is legal, false if not.
   1492  *
   1493  * William King points out that RFC2136 is inconsistent about
   1494  * the case where the serial number stays unchanged:
   1495  *
   1496  *   section 3.4.2.2 requires a server to ignore a SOA update request
   1497  *   if the serial number on the update SOA is less_than_or_equal to
   1498  *   the zone SOA serial.
   1499  *
   1500  *   section 3.6 requires a server to ignore a SOA update request if
   1501  *   the serial is less_than the zone SOA serial.
   1502  *
   1503  * Paul says 3.4.2.2 is correct.
   1504  *
   1505  */
   1506 static isc_result_t
   1507 check_soa_increment(dns_db_t *db, dns_dbversion_t *ver,
   1508 		    dns_rdata_t *update_rdata, bool *ok)
   1509 {
   1510 	uint32_t db_serial;
   1511 	uint32_t update_serial;
   1512 	isc_result_t result;
   1513 
   1514 	update_serial = dns_soa_getserial(update_rdata);
   1515 
   1516 	result = dns_db_getsoaserial(db, ver, &db_serial);
   1517 	if (result != ISC_R_SUCCESS)
   1518 		return (result);
   1519 
   1520 	if (DNS_SERIAL_GE(db_serial, update_serial)) {
   1521 		*ok = false;
   1522 	} else {
   1523 		*ok = true;
   1524 	}
   1525 
   1526 	return (ISC_R_SUCCESS);
   1527 
   1528 }
   1529 
   1530 /**************************************************************************/
   1531 /*%
   1532  * The actual update code in all its glory.  We try to follow
   1533  * the RFC2136 pseudocode as closely as possible.
   1534  */
   1535 
   1536 static isc_result_t
   1537 send_update_event(ns_client_t *client, dns_zone_t *zone) {
   1538 	isc_result_t result = ISC_R_SUCCESS;
   1539 	update_event_t *event = NULL;
   1540 	isc_task_t *zonetask = NULL;
   1541 	ns_client_t *evclient;
   1542 
   1543 	event = (update_event_t *)
   1544 		isc_event_allocate(client->mctx, client, DNS_EVENT_UPDATE,
   1545 				   update_action, NULL, sizeof(*event));
   1546 	if (event == NULL)
   1547 		FAIL(ISC_R_NOMEMORY);
   1548 	event->zone = zone;
   1549 	event->result = ISC_R_SUCCESS;
   1550 
   1551 	evclient = NULL;
   1552 	ns_client_attach(client, &evclient);
   1553 	INSIST(client->nupdates == 0);
   1554 	client->nupdates++;
   1555 	event->ev_arg = evclient;
   1556 
   1557 	dns_zone_gettask(zone, &zonetask);
   1558 	isc_task_send(zonetask, ISC_EVENT_PTR(&event));
   1559 
   1560  failure:
   1561 	if (event != NULL)
   1562 		isc_event_free(ISC_EVENT_PTR(&event));
   1563 	return (result);
   1564 }
   1565 
   1566 static void
   1567 respond(ns_client_t *client, isc_result_t result) {
   1568 	isc_result_t msg_result;
   1569 
   1570 	msg_result = dns_message_reply(client->message, true);
   1571 	if (msg_result != ISC_R_SUCCESS)
   1572 		goto msg_failure;
   1573 	client->message->rcode = dns_result_torcode(result);
   1574 
   1575 	ns_client_send(client);
   1576 	return;
   1577 
   1578  msg_failure:
   1579 	isc_log_write(ns_lctx, NS_LOGCATEGORY_UPDATE, NS_LOGMODULE_UPDATE,
   1580 		      ISC_LOG_ERROR,
   1581 		      "could not create update response message: %s",
   1582 		      isc_result_totext(msg_result));
   1583 	ns_client_next(client, msg_result);
   1584 }
   1585 
   1586 void
   1587 ns_update_start(ns_client_t *client, isc_result_t sigresult) {
   1588 	dns_message_t *request = client->message;
   1589 	isc_result_t result;
   1590 	dns_name_t *zonename;
   1591 	dns_rdataset_t *zone_rdataset;
   1592 	dns_zone_t *zone = NULL, *raw = NULL;
   1593 
   1594 	/*
   1595 	 * Interpret the zone section.
   1596 	 */
   1597 	result = dns_message_firstname(request, DNS_SECTION_ZONE);
   1598 	if (result != ISC_R_SUCCESS)
   1599 		FAILC(DNS_R_FORMERR, "update zone section empty");
   1600 
   1601 	/*
   1602 	 * The zone section must contain exactly one "question", and
   1603 	 * it must be of type SOA.
   1604 	 */
   1605 	zonename = NULL;
   1606 	dns_message_currentname(request, DNS_SECTION_ZONE, &zonename);
   1607 	zone_rdataset = ISC_LIST_HEAD(zonename->list);
   1608 	if (zone_rdataset->type != dns_rdatatype_soa)
   1609 		FAILC(DNS_R_FORMERR,
   1610 		      "update zone section contains non-SOA");
   1611 	if (ISC_LIST_NEXT(zone_rdataset, link) != NULL)
   1612 		FAILC(DNS_R_FORMERR,
   1613 		      "update zone section contains multiple RRs");
   1614 
   1615 	/* The zone section must have exactly one name. */
   1616 	result = dns_message_nextname(request, DNS_SECTION_ZONE);
   1617 	if (result != ISC_R_NOMORE)
   1618 		FAILC(DNS_R_FORMERR,
   1619 		      "update zone section contains multiple RRs");
   1620 
   1621 	result = dns_zt_find(client->view->zonetable, zonename, 0, NULL,
   1622 			     &zone);
   1623 	if (result != ISC_R_SUCCESS)
   1624 		FAILC(DNS_R_NOTAUTH, "not authoritative for update zone");
   1625 
   1626 	/*
   1627 	 * If there is a raw (unsigned) zone associated with this
   1628 	 * zone then it processes the UPDATE request.
   1629 	 */
   1630 	dns_zone_getraw(zone, &raw);
   1631 	if (raw != NULL) {
   1632 		dns_zone_detach(&zone);
   1633 		dns_zone_attach(raw, &zone);
   1634 		dns_zone_detach(&raw);
   1635 	}
   1636 
   1637 	switch(dns_zone_gettype(zone)) {
   1638 	case dns_zone_master:
   1639 	case dns_zone_dlz:
   1640 		/*
   1641 		 * We can now fail due to a bad signature as we now know
   1642 		 * that we are the master.
   1643 		 */
   1644 		if (sigresult != ISC_R_SUCCESS)
   1645 			FAIL(sigresult);
   1646 		CHECK(send_update_event(client, zone));
   1647 		break;
   1648 	case dns_zone_slave:
   1649 	case dns_zone_mirror:
   1650 		CHECK(checkupdateacl(client, dns_zone_getforwardacl(zone),
   1651 				     "update forwarding", zonename, true,
   1652 				     false));
   1653 		CHECK(send_forward_event(client, zone));
   1654 		break;
   1655 	default:
   1656 		FAILC(DNS_R_NOTAUTH, "not authoritative for update zone");
   1657 	}
   1658 	return;
   1659 
   1660  failure:
   1661 	if (result == DNS_R_REFUSED) {
   1662 		INSIST(dns_zone_gettype(zone) == dns_zone_slave ||
   1663 		       dns_zone_gettype(zone) == dns_zone_mirror);
   1664 		inc_stats(client, zone, ns_statscounter_updaterej);
   1665 	}
   1666 	/*
   1667 	 * We failed without having sent an update event to the zone.
   1668 	 * We are still in the client task context, so we can
   1669 	 * simply give an error response without switching tasks.
   1670 	 */
   1671 	respond(client, result);
   1672 	if (zone != NULL)
   1673 		dns_zone_detach(&zone);
   1674 }
   1675 
   1676 /*%
   1677  * DS records are not allowed to exist without corresponding NS records,
   1678  * RFC 3658, 2.2 Protocol Change,
   1679  * "DS RRsets MUST NOT appear at non-delegation points or at a zone's apex".
   1680  */
   1681 
   1682 static isc_result_t
   1683 remove_orphaned_ds(dns_db_t *db, dns_dbversion_t *newver, dns_diff_t *diff) {
   1684 	isc_result_t result;
   1685 	bool ns_exists;
   1686 	dns_difftuple_t *tupple;
   1687 	dns_diff_t temp_diff;
   1688 
   1689 	dns_diff_init(diff->mctx, &temp_diff);
   1690 
   1691 	for (tupple = ISC_LIST_HEAD(diff->tuples);
   1692 	     tupple != NULL;
   1693 	     tupple = ISC_LIST_NEXT(tupple, link)) {
   1694 		if (!((tupple->op == DNS_DIFFOP_DEL &&
   1695 		       tupple->rdata.type == dns_rdatatype_ns) ||
   1696 		      (tupple->op == DNS_DIFFOP_ADD &&
   1697 		       tupple->rdata.type == dns_rdatatype_ds)))
   1698 			continue;
   1699 		CHECK(rrset_exists(db, newver, &tupple->name,
   1700 				   dns_rdatatype_ns, 0, &ns_exists));
   1701 		if (ns_exists &&
   1702 		    !dns_name_equal(&tupple->name, dns_db_origin(db)))
   1703 			continue;
   1704 		CHECK(delete_if(true_p, db, newver, &tupple->name,
   1705 				dns_rdatatype_ds, 0, NULL, &temp_diff));
   1706 	}
   1707 	result = ISC_R_SUCCESS;
   1708 
   1709  failure:
   1710 	for (tupple = ISC_LIST_HEAD(temp_diff.tuples);
   1711 	     tupple != NULL;
   1712 	     tupple = ISC_LIST_HEAD(temp_diff.tuples)) {
   1713 		ISC_LIST_UNLINK(temp_diff.tuples, tupple, link);
   1714 		dns_diff_appendminimal(diff, &tupple);
   1715 	}
   1716 	return (result);
   1717 }
   1718 
   1719 /*
   1720  * This implements the post load integrity checks for mx records.
   1721  */
   1722 static isc_result_t
   1723 check_mx(ns_client_t *client, dns_zone_t *zone,
   1724 	 dns_db_t *db, dns_dbversion_t *newver, dns_diff_t *diff)
   1725 {
   1726 	char tmp[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:123.123.123.123.")];
   1727 	char ownerbuf[DNS_NAME_FORMATSIZE];
   1728 	char namebuf[DNS_NAME_FORMATSIZE];
   1729 	char altbuf[DNS_NAME_FORMATSIZE];
   1730 	dns_difftuple_t *t;
   1731 	dns_fixedname_t fixed;
   1732 	dns_name_t *foundname;
   1733 	dns_rdata_mx_t mx;
   1734 	dns_rdata_t rdata;
   1735 	bool ok = true;
   1736 	bool isaddress;
   1737 	isc_result_t result;
   1738 	struct in6_addr addr6;
   1739 	struct in_addr addr;
   1740 	dns_zoneopt_t options;
   1741 
   1742 	foundname = dns_fixedname_initname(&fixed);
   1743 	dns_rdata_init(&rdata);
   1744 	options = dns_zone_getoptions(zone);
   1745 
   1746 	for (t = ISC_LIST_HEAD(diff->tuples);
   1747 	     t != NULL;
   1748 	     t = ISC_LIST_NEXT(t, link)) {
   1749 		if (t->op != DNS_DIFFOP_ADD ||
   1750 		    t->rdata.type != dns_rdatatype_mx)
   1751 			continue;
   1752 
   1753 		result = dns_rdata_tostruct(&t->rdata, &mx, NULL);
   1754 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
   1755 		/*
   1756 		 * Check if we will error out if we attempt to reload the
   1757 		 * zone.
   1758 		 */
   1759 		dns_name_format(&mx.mx, namebuf, sizeof(namebuf));
   1760 		dns_name_format(&t->name, ownerbuf, sizeof(ownerbuf));
   1761 		isaddress = false;
   1762 		if ((options & DNS_ZONEOPT_CHECKMX) != 0 &&
   1763 		    strlcpy(tmp, namebuf, sizeof(tmp)) < sizeof(tmp)) {
   1764 			if (tmp[strlen(tmp) - 1] == '.')
   1765 				tmp[strlen(tmp) - 1] = '\0';
   1766 			if (inet_pton(AF_INET, tmp, &addr) == 1 ||
   1767 			    inet_pton(AF_INET6, tmp, &addr6) == 1)
   1768 				isaddress = true;
   1769 		}
   1770 
   1771 		if (isaddress && (options & DNS_ZONEOPT_CHECKMXFAIL) != 0) {
   1772 			update_log(client, zone, ISC_LOG_ERROR,
   1773 				   "%s/MX: '%s': %s",
   1774 				   ownerbuf, namebuf,
   1775 				   dns_result_totext(DNS_R_MXISADDRESS));
   1776 			ok = false;
   1777 		} else if (isaddress) {
   1778 			update_log(client, zone, ISC_LOG_WARNING,
   1779 				   "%s/MX: warning: '%s': %s",
   1780 				   ownerbuf, namebuf,
   1781 				   dns_result_totext(DNS_R_MXISADDRESS));
   1782 		}
   1783 
   1784 		/*
   1785 		 * Check zone integrity checks.
   1786 		 */
   1787 		if ((options & DNS_ZONEOPT_CHECKINTEGRITY) == 0)
   1788 			continue;
   1789 		result = dns_db_find(db, &mx.mx, newver, dns_rdatatype_a,
   1790 				     0, 0, NULL, foundname, NULL, NULL);
   1791 		if (result == ISC_R_SUCCESS)
   1792 			continue;
   1793 
   1794 		if (result == DNS_R_NXRRSET) {
   1795 			result = dns_db_find(db, &mx.mx, newver,
   1796 					     dns_rdatatype_aaaa,
   1797 					     0, 0, NULL, foundname,
   1798 					     NULL, NULL);
   1799 			if (result == ISC_R_SUCCESS)
   1800 				continue;
   1801 		}
   1802 
   1803 		if (result == DNS_R_NXRRSET || result == DNS_R_NXDOMAIN) {
   1804 			update_log(client, zone, ISC_LOG_ERROR,
   1805 				   "%s/MX '%s' has no address records "
   1806 				   "(A or AAAA)", ownerbuf, namebuf);
   1807 			ok = false;
   1808 		} else if (result == DNS_R_CNAME) {
   1809 			update_log(client, zone, ISC_LOG_ERROR,
   1810 				   "%s/MX '%s' is a CNAME (illegal)",
   1811 				   ownerbuf, namebuf);
   1812 			ok = false;
   1813 		} else if (result == DNS_R_DNAME) {
   1814 			dns_name_format(foundname, altbuf, sizeof altbuf);
   1815 			update_log(client, zone, ISC_LOG_ERROR,
   1816 				   "%s/MX '%s' is below a DNAME '%s' (illegal)",
   1817 				   ownerbuf, namebuf, altbuf);
   1818 			ok = false;
   1819 		}
   1820 	}
   1821 	return (ok ? ISC_R_SUCCESS : DNS_R_REFUSED);
   1822 }
   1823 
   1824 static isc_result_t
   1825 rr_exists(dns_db_t *db, dns_dbversion_t *ver, dns_name_t *name,
   1826 	  const dns_rdata_t *rdata, bool *flag)
   1827 {
   1828 	dns_rdataset_t rdataset;
   1829 	dns_dbnode_t *node = NULL;
   1830 	isc_result_t result;
   1831 
   1832 	dns_rdataset_init(&rdataset);
   1833 	if (rdata->type == dns_rdatatype_nsec3)
   1834 		CHECK(dns_db_findnsec3node(db, name, false, &node));
   1835 	else
   1836 		CHECK(dns_db_findnode(db, name, false, &node));
   1837 	result = dns_db_findrdataset(db, node, ver, rdata->type, 0,
   1838 				     (isc_stdtime_t) 0, &rdataset, NULL);
   1839 	if (result == ISC_R_NOTFOUND) {
   1840 		*flag = false;
   1841 		result = ISC_R_SUCCESS;
   1842 		goto failure;
   1843 	}
   1844 
   1845 	for (result = dns_rdataset_first(&rdataset);
   1846 	     result == ISC_R_SUCCESS;
   1847 	     result = dns_rdataset_next(&rdataset)) {
   1848 		dns_rdata_t myrdata = DNS_RDATA_INIT;
   1849 		dns_rdataset_current(&rdataset, &myrdata);
   1850 		if (!dns_rdata_casecompare(&myrdata, rdata))
   1851 			break;
   1852 	}
   1853 	dns_rdataset_disassociate(&rdataset);
   1854 	if (result == ISC_R_SUCCESS) {
   1855 		*flag = true;
   1856 	} else if (result == ISC_R_NOMORE) {
   1857 		*flag = false;
   1858 		result = ISC_R_SUCCESS;
   1859 	}
   1860 
   1861  failure:
   1862 	if (node != NULL)
   1863 		dns_db_detachnode(db, &node);
   1864 	return (result);
   1865 }
   1866 
   1867 static isc_result_t
   1868 get_iterations(dns_db_t *db, dns_dbversion_t *ver, dns_rdatatype_t privatetype,
   1869 	       unsigned int *iterationsp)
   1870 {
   1871 	dns_dbnode_t *node = NULL;
   1872 	dns_rdata_nsec3param_t nsec3param;
   1873 	dns_rdataset_t rdataset;
   1874 	isc_result_t result;
   1875 	unsigned int iterations = 0;
   1876 
   1877 	dns_rdataset_init(&rdataset);
   1878 
   1879 	result = dns_db_getoriginnode(db, &node);
   1880 	if (result != ISC_R_SUCCESS)
   1881 		return (result);
   1882 	result = dns_db_findrdataset(db, node, ver, dns_rdatatype_nsec3param,
   1883 				     0, (isc_stdtime_t) 0, &rdataset, NULL);
   1884 	if (result == ISC_R_NOTFOUND)
   1885 		goto try_private;
   1886 	if (result != ISC_R_SUCCESS)
   1887 		goto failure;
   1888 
   1889 	for (result = dns_rdataset_first(&rdataset);
   1890 	     result == ISC_R_SUCCESS;
   1891 	     result = dns_rdataset_next(&rdataset)) {
   1892 		dns_rdata_t rdata = DNS_RDATA_INIT;
   1893 		dns_rdataset_current(&rdataset, &rdata);
   1894 		CHECK(dns_rdata_tostruct(&rdata, &nsec3param, NULL));
   1895 		if ((nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0)
   1896 			continue;
   1897 		if (nsec3param.iterations > iterations)
   1898 			iterations = nsec3param.iterations;
   1899 	}
   1900 	if (result != ISC_R_NOMORE)
   1901 		goto failure;
   1902 
   1903 	dns_rdataset_disassociate(&rdataset);
   1904 
   1905  try_private:
   1906 	if (privatetype == 0)
   1907 		goto success;
   1908 
   1909 	result = dns_db_findrdataset(db, node, ver, privatetype,
   1910 				     0, (isc_stdtime_t) 0, &rdataset, NULL);
   1911 	if (result == ISC_R_NOTFOUND)
   1912 		goto success;
   1913 	if (result != ISC_R_SUCCESS)
   1914 		goto failure;
   1915 
   1916 	for (result = dns_rdataset_first(&rdataset);
   1917 	     result == ISC_R_SUCCESS;
   1918 	     result = dns_rdataset_next(&rdataset)) {
   1919 		unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
   1920 		dns_rdata_t private = DNS_RDATA_INIT;
   1921 		dns_rdata_t rdata = DNS_RDATA_INIT;
   1922 
   1923 		dns_rdataset_current(&rdataset, &rdata);
   1924 		if (!dns_nsec3param_fromprivate(&private, &rdata,
   1925 						buf, sizeof(buf)))
   1926 			continue;
   1927 		CHECK(dns_rdata_tostruct(&rdata, &nsec3param, NULL));
   1928 		if ((nsec3param.flags & DNS_NSEC3FLAG_REMOVE) != 0)
   1929 			continue;
   1930 		if (nsec3param.iterations > iterations)
   1931 			iterations = nsec3param.iterations;
   1932 	}
   1933 	if (result != ISC_R_NOMORE)
   1934 		goto failure;
   1935 
   1936  success:
   1937 	*iterationsp = iterations;
   1938 	result = ISC_R_SUCCESS;
   1939 
   1940  failure:
   1941 	if (node != NULL)
   1942 		dns_db_detachnode(db, &node);
   1943 	if (dns_rdataset_isassociated(&rdataset))
   1944 		dns_rdataset_disassociate(&rdataset);
   1945 	return (result);
   1946 }
   1947 
   1948 /*
   1949  * Prevent the zone entering a inconsistent state where
   1950  * NSEC only DNSKEYs are present with NSEC3 chains.
   1951  */
   1952 static isc_result_t
   1953 check_dnssec(ns_client_t *client, dns_zone_t *zone, dns_db_t *db,
   1954 	     dns_dbversion_t *ver, dns_diff_t *diff)
   1955 {
   1956 	dns_difftuple_t *tuple;
   1957 	bool nseconly = false, nsec3 = false;
   1958 	isc_result_t result;
   1959 	unsigned int iterations = 0, max;
   1960 	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
   1961 
   1962 	/* Scan the tuples for an NSEC-only DNSKEY or an NSEC3PARAM */
   1963 	for (tuple = ISC_LIST_HEAD(diff->tuples);
   1964 	     tuple != NULL;
   1965 	     tuple = ISC_LIST_NEXT(tuple, link)) {
   1966 		if (tuple->op != DNS_DIFFOP_ADD)
   1967 			continue;
   1968 
   1969 		if (tuple->rdata.type == dns_rdatatype_dnskey) {
   1970 			uint8_t alg;
   1971 			alg = tuple->rdata.data[3];
   1972 			if (alg == DST_ALG_RSASHA1) {
   1973 				nseconly = true;
   1974 				break;
   1975 			}
   1976 		} else if (tuple->rdata.type == dns_rdatatype_nsec3param) {
   1977 			nsec3 = true;
   1978 			break;
   1979 		}
   1980 	}
   1981 
   1982 	/* Check existing DB for NSEC-only DNSKEY */
   1983 	if (!nseconly) {
   1984 		result = dns_nsec_nseconly(db, ver, &nseconly);
   1985 
   1986 		/*
   1987 		 * An NSEC3PARAM update can proceed without a DNSKEY (it
   1988 		 * will trigger a delayed change), so we can ignore
   1989 		 * ISC_R_NOTFOUND here.
   1990 		 */
   1991 		if (result == ISC_R_NOTFOUND)
   1992 			result = ISC_R_SUCCESS;
   1993 
   1994 		CHECK(result);
   1995 	}
   1996 
   1997 	/* Check existing DB for NSEC3 */
   1998 	if (!nsec3)
   1999 		CHECK(dns_nsec3_activex(db, ver, false,
   2000 					privatetype, &nsec3));
   2001 
   2002 	/* Refuse to allow NSEC3 with NSEC-only keys */
   2003 	if (nseconly && nsec3) {
   2004 		update_log(client, zone, ISC_LOG_ERROR,
   2005 			   "NSEC only DNSKEYs and NSEC3 chains not allowed");
   2006 		result = DNS_R_REFUSED;
   2007 		goto failure;
   2008 	}
   2009 
   2010 	/* Verify NSEC3 params */
   2011 	CHECK(get_iterations(db, ver, privatetype, &iterations));
   2012 	CHECK(dns_nsec3_maxiterations(db, ver, client->mctx, &max));
   2013 	if (max != 0 && iterations > max) {
   2014 		update_log(client, zone, ISC_LOG_ERROR,
   2015 			   "too many NSEC3 iterations (%u) for "
   2016 			   "weakest DNSKEY (%u)", iterations, max);
   2017 		result = DNS_R_REFUSED;
   2018 		goto failure;
   2019 	}
   2020 
   2021  failure:
   2022 	return (result);
   2023 }
   2024 
   2025 /*
   2026  * Delay NSEC3PARAM changes as they need to be applied to the whole zone.
   2027  */
   2028 static isc_result_t
   2029 add_nsec3param_records(ns_client_t *client, dns_zone_t *zone, dns_db_t *db,
   2030 		       dns_dbversion_t *ver, dns_diff_t *diff)
   2031 {
   2032 	isc_result_t result = ISC_R_SUCCESS;
   2033 	dns_difftuple_t *tuple, *newtuple = NULL, *next;
   2034 	dns_rdata_t rdata = DNS_RDATA_INIT;
   2035 	unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE + 1];
   2036 	dns_diff_t temp_diff;
   2037 	dns_diffop_t op;
   2038 	bool flag;
   2039 	dns_name_t *name = dns_zone_getorigin(zone);
   2040 	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
   2041 	uint32_t ttl = 0;
   2042 	bool ttl_good = false;
   2043 
   2044 	update_log(client, zone, ISC_LOG_DEBUG(3),
   2045 		    "checking for NSEC3PARAM changes");
   2046 
   2047 	dns_diff_init(diff->mctx, &temp_diff);
   2048 
   2049 	/*
   2050 	 * Extract NSEC3PARAM tuples from list.
   2051 	 */
   2052 	for (tuple = ISC_LIST_HEAD(diff->tuples);
   2053 	     tuple != NULL;
   2054 	     tuple = next) {
   2055 
   2056 		next = ISC_LIST_NEXT(tuple, link);
   2057 
   2058 		if (tuple->rdata.type != dns_rdatatype_nsec3param ||
   2059 		    !dns_name_equal(name, &tuple->name))
   2060 			continue;
   2061 		ISC_LIST_UNLINK(diff->tuples, tuple, link);
   2062 		ISC_LIST_APPEND(temp_diff.tuples, tuple, link);
   2063 	}
   2064 
   2065 	/*
   2066 	 * Extract TTL changes pairs, we don't need to convert these to
   2067 	 * delayed changes.
   2068 	 */
   2069 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2070 	     tuple != NULL; tuple = next) {
   2071 		if (tuple->op == DNS_DIFFOP_ADD) {
   2072 			if (!ttl_good) {
   2073 				/*
   2074 				 * Any adds here will contain the final
   2075 				 * NSEC3PARAM RRset TTL.
   2076 				 */
   2077 				ttl = tuple->ttl;
   2078 				ttl_good = true;
   2079 			}
   2080 			/*
   2081 			 * Walk the temp_diff list looking for the
   2082 			 * corresponding delete.
   2083 			 */
   2084 			next = ISC_LIST_HEAD(temp_diff.tuples);
   2085 			while (next != NULL) {
   2086 				unsigned char *next_data = next->rdata.data;
   2087 				unsigned char *tuple_data = tuple->rdata.data;
   2088 				if (next->op == DNS_DIFFOP_DEL &&
   2089 				    next->rdata.length == tuple->rdata.length &&
   2090 				    !memcmp(next_data, tuple_data,
   2091 					    next->rdata.length)) {
   2092 					ISC_LIST_UNLINK(temp_diff.tuples, next,
   2093 							link);
   2094 					ISC_LIST_APPEND(diff->tuples, next,
   2095 							link);
   2096 					break;
   2097 				}
   2098 				next = ISC_LIST_NEXT(next, link);
   2099 			}
   2100 			/*
   2101 			 * If we have not found a pair move onto the next
   2102 			 * tuple.
   2103 			 */
   2104 			if (next == NULL) {
   2105 				next = ISC_LIST_NEXT(tuple, link);
   2106 				continue;
   2107 			}
   2108 			/*
   2109 			 * Find the next tuple to be processed before
   2110 			 * unlinking then complete moving the pair to 'diff'.
   2111 			 */
   2112 			next = ISC_LIST_NEXT(tuple, link);
   2113 			ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2114 			ISC_LIST_APPEND(diff->tuples, tuple, link);
   2115 		} else
   2116 			next = ISC_LIST_NEXT(tuple, link);
   2117 	}
   2118 
   2119 	/*
   2120 	 * Preserve any ongoing changes from a BIND 9.6.x upgrade.
   2121 	 *
   2122 	 * Any NSEC3PARAM records with flags other than OPTOUT named
   2123 	 * in managing and should not be touched so revert such changes
   2124 	 * taking into account any TTL change of the NSEC3PARAM RRset.
   2125 	 */
   2126 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2127 	     tuple != NULL; tuple = next) {
   2128 		next = ISC_LIST_NEXT(tuple, link);
   2129 		if ((tuple->rdata.data[1] & ~DNS_NSEC3FLAG_OPTOUT) != 0) {
   2130 			/*
   2131 			 * If we havn't had any adds then the tuple->ttl must
   2132 			 * be the original ttl and should be used for any
   2133 			 * future changes.
   2134 			 */
   2135 			if (!ttl_good) {
   2136 				ttl = tuple->ttl;
   2137 				ttl_good = true;
   2138 			}
   2139 			op = (tuple->op == DNS_DIFFOP_DEL) ?
   2140 			     DNS_DIFFOP_ADD : DNS_DIFFOP_DEL;
   2141 			CHECK(dns_difftuple_create(diff->mctx, op, name,
   2142 						   ttl, &tuple->rdata,
   2143 						   &newtuple));
   2144 			CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2145 			ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2146 			dns_diff_appendminimal(diff, &tuple);
   2147 		}
   2148 	}
   2149 
   2150 	/*
   2151 	 * We now have just the actual changes to the NSEC3PARAM RRset.
   2152 	 * Convert the adds to delayed adds and the deletions into delayed
   2153 	 * deletions.
   2154 	 */
   2155 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2156 	     tuple != NULL; tuple = next) {
   2157 		/*
   2158 		 * If we havn't had any adds then the tuple->ttl must be the
   2159 		 * original ttl and should be used for any future changes.
   2160 		 */
   2161 		if (!ttl_good) {
   2162 			ttl = tuple->ttl;
   2163 			ttl_good = true;
   2164 		}
   2165 		if (tuple->op == DNS_DIFFOP_ADD) {
   2166 			bool nseconly = false;
   2167 
   2168 			/*
   2169 			 * Look for any deletes which match this ADD ignoring
   2170 			 * flags.  We don't need to explictly remove them as
   2171 			 * they will be removed a side effect of processing
   2172 			 * the add.
   2173 			 */
   2174 			next = ISC_LIST_HEAD(temp_diff.tuples);
   2175 			while (next != NULL) {
   2176 				unsigned char *next_data = next->rdata.data;
   2177 				unsigned char *tuple_data = tuple->rdata.data;
   2178 				if (next->op != DNS_DIFFOP_DEL ||
   2179 				    next->rdata.length != tuple->rdata.length ||
   2180 				    next_data[0] != tuple_data[0] ||
   2181 				    next_data[2] != tuple_data[2] ||
   2182 				    next_data[3] != tuple_data[3] ||
   2183 				    memcmp(next_data + 4, tuple_data + 4,
   2184 					   tuple->rdata.length - 4)) {
   2185 					next = ISC_LIST_NEXT(next, link);
   2186 					continue;
   2187 				}
   2188 				ISC_LIST_UNLINK(temp_diff.tuples, next, link);
   2189 				ISC_LIST_APPEND(diff->tuples, next, link);
   2190 				next = ISC_LIST_HEAD(temp_diff.tuples);
   2191 			}
   2192 
   2193 			/*
   2194 			 * Create a private-type record to signal that
   2195 			 * we want a delayed NSEC3 chain add/delete
   2196 			 */
   2197 			dns_nsec3param_toprivate(&tuple->rdata, &rdata,
   2198 						 privatetype, buf, sizeof(buf));
   2199 			buf[2] |= DNS_NSEC3FLAG_CREATE;
   2200 
   2201 			/*
   2202 			 * If the zone is not currently capable of
   2203 			 * supporting an NSEC3 chain, then we set the
   2204 			 * INITIAL flag to indicate that these parameters
   2205 			 * are to be used later.
   2206 			 */
   2207 			result = dns_nsec_nseconly(db, ver, &nseconly);
   2208 			if (result == ISC_R_NOTFOUND || nseconly)
   2209 				buf[2] |= DNS_NSEC3FLAG_INITIAL;
   2210 
   2211 			/*
   2212 			 * See if this CREATE request already exists.
   2213 			 */
   2214 			CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2215 
   2216 			if (!flag) {
   2217 				CHECK(dns_difftuple_create(diff->mctx,
   2218 							   DNS_DIFFOP_ADD,
   2219 							   name, 0, &rdata,
   2220 							   &newtuple));
   2221 				CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2222 			}
   2223 
   2224 			/*
   2225 			 * Remove any existing CREATE request to add an
   2226 			 * otherwise indentical chain with a reversed
   2227 			 * OPTOUT state.
   2228 			 */
   2229 			buf[2] ^= DNS_NSEC3FLAG_OPTOUT;
   2230 			CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2231 
   2232 			if (flag) {
   2233 				CHECK(dns_difftuple_create(diff->mctx,
   2234 							   DNS_DIFFOP_DEL,
   2235 							   name, 0, &rdata,
   2236 							   &newtuple));
   2237 				CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2238 			}
   2239 
   2240 			/*
   2241 			 * Find the next tuple to be processed and remove the
   2242 			 * temporary add record.
   2243 			 */
   2244 			next = ISC_LIST_NEXT(tuple, link);
   2245 			CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_DEL,
   2246 						   name, ttl, &tuple->rdata,
   2247 						   &newtuple));
   2248 			CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2249 			ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2250 			dns_diff_appendminimal(diff, &tuple);
   2251 			dns_rdata_reset(&rdata);
   2252 		} else
   2253 			next = ISC_LIST_NEXT(tuple, link);
   2254 	}
   2255 
   2256 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2257 	     tuple != NULL; tuple = next) {
   2258 
   2259 		INSIST(ttl_good);
   2260 
   2261 		next = ISC_LIST_NEXT(tuple, link);
   2262 		/*
   2263 		 * See if we already have a REMOVE request in progress.
   2264 		 */
   2265 		dns_nsec3param_toprivate(&tuple->rdata, &rdata, privatetype,
   2266 					 buf, sizeof(buf));
   2267 
   2268 		buf[2] |= DNS_NSEC3FLAG_REMOVE | DNS_NSEC3FLAG_NONSEC;
   2269 
   2270 		CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2271 		if (!flag) {
   2272 			buf[2] &= ~DNS_NSEC3FLAG_NONSEC;
   2273 			CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2274 		}
   2275 
   2276 		if (!flag) {
   2277 			CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD,
   2278 						   name, 0, &rdata, &newtuple));
   2279 			CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2280 		}
   2281 		CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD, name,
   2282 					   ttl, &tuple->rdata, &newtuple));
   2283 		CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2284 		ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2285 		dns_diff_appendminimal(diff, &tuple);
   2286 		dns_rdata_reset(&rdata);
   2287 	}
   2288 
   2289 	result = ISC_R_SUCCESS;
   2290  failure:
   2291 	dns_diff_clear(&temp_diff);
   2292 	return (result);
   2293 }
   2294 
   2295 static isc_result_t
   2296 rollback_private(dns_db_t *db, dns_rdatatype_t privatetype,
   2297 		 dns_dbversion_t *ver, dns_diff_t *diff)
   2298 {
   2299 	dns_diff_t temp_diff;
   2300 	dns_diffop_t op;
   2301 	dns_difftuple_t *tuple, *newtuple = NULL, *next;
   2302 	dns_name_t *name = dns_db_origin(db);
   2303 	isc_mem_t *mctx = diff->mctx;
   2304 	isc_result_t result;
   2305 
   2306 	if (privatetype == 0)
   2307 		return (ISC_R_SUCCESS);
   2308 
   2309 	dns_diff_init(mctx, &temp_diff);
   2310 
   2311 	/*
   2312 	 * Extract the changes to be rolled back.
   2313 	 */
   2314 	for (tuple = ISC_LIST_HEAD(diff->tuples);
   2315 	     tuple != NULL; tuple = next) {
   2316 
   2317 		next = ISC_LIST_NEXT(tuple, link);
   2318 
   2319 		if (tuple->rdata.type != privatetype ||
   2320 		    !dns_name_equal(name, &tuple->name))
   2321 			continue;
   2322 
   2323 		/*
   2324 		 * Allow records which indicate that a zone has been
   2325 		 * signed with a DNSKEY to be removed.
   2326 		 */
   2327 		if (tuple->op == DNS_DIFFOP_DEL &&
   2328 		    tuple->rdata.length == 5 &&
   2329 		    tuple->rdata.data[0] != 0 &&
   2330 		    tuple->rdata.data[4] != 0)
   2331 			continue;
   2332 
   2333 		ISC_LIST_UNLINK(diff->tuples, tuple, link);
   2334 		ISC_LIST_PREPEND(temp_diff.tuples, tuple, link);
   2335 	}
   2336 
   2337 	/*
   2338 	 * Rollback the changes.
   2339 	 */
   2340 	while ((tuple = ISC_LIST_HEAD(temp_diff.tuples)) != NULL) {
   2341 		op = (tuple->op == DNS_DIFFOP_DEL) ?
   2342 		      DNS_DIFFOP_ADD : DNS_DIFFOP_DEL;
   2343 		CHECK(dns_difftuple_create(mctx, op, name, tuple->ttl,
   2344 					   &tuple->rdata, &newtuple));
   2345 		CHECK(do_one_tuple(&newtuple, db, ver, &temp_diff));
   2346 	}
   2347 	result = ISC_R_SUCCESS;
   2348 
   2349  failure:
   2350 	dns_diff_clear(&temp_diff);
   2351 	return (result);
   2352 }
   2353 
   2354 /*
   2355  * Add records to cause the delayed signing of the zone by added DNSKEY
   2356  * to remove the RRSIG records generated by a deleted DNSKEY.
   2357  */
   2358 static isc_result_t
   2359 add_signing_records(dns_db_t *db, dns_rdatatype_t privatetype,
   2360 		    dns_dbversion_t *ver, dns_diff_t *diff)
   2361 {
   2362 	dns_difftuple_t *tuple, *newtuple = NULL, *next;
   2363 	dns_rdata_dnskey_t dnskey;
   2364 	dns_rdata_t rdata = DNS_RDATA_INIT;
   2365 	bool flag;
   2366 	isc_region_t r;
   2367 	isc_result_t result = ISC_R_SUCCESS;
   2368 	uint16_t keyid;
   2369 	unsigned char buf[5];
   2370 	dns_name_t *name = dns_db_origin(db);
   2371 	dns_diff_t temp_diff;
   2372 
   2373 	dns_diff_init(diff->mctx, &temp_diff);
   2374 
   2375 	/*
   2376 	 * Extract the DNSKEY tuples from the list.
   2377 	 */
   2378 	for (tuple = ISC_LIST_HEAD(diff->tuples);
   2379 	     tuple != NULL; tuple = next) {
   2380 
   2381 		next = ISC_LIST_NEXT(tuple, link);
   2382 
   2383 		if (tuple->rdata.type != dns_rdatatype_dnskey)
   2384 			continue;
   2385 
   2386 		ISC_LIST_UNLINK(diff->tuples, tuple, link);
   2387 		ISC_LIST_APPEND(temp_diff.tuples, tuple, link);
   2388 	}
   2389 
   2390 	/*
   2391 	 * Extract TTL changes pairs, we don't need signing records for these.
   2392 	 */
   2393 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2394 	     tuple != NULL; tuple = next) {
   2395 		if (tuple->op == DNS_DIFFOP_ADD) {
   2396 			/*
   2397 			 * Walk the temp_diff list looking for the
   2398 			 * corresponding delete.
   2399 			 */
   2400 			next = ISC_LIST_HEAD(temp_diff.tuples);
   2401 			while (next != NULL) {
   2402 				unsigned char *next_data = next->rdata.data;
   2403 				unsigned char *tuple_data = tuple->rdata.data;
   2404 				if (next->op == DNS_DIFFOP_DEL &&
   2405 				    dns_name_equal(&tuple->name, &next->name) &&
   2406 				    next->rdata.length == tuple->rdata.length &&
   2407 				    !memcmp(next_data, tuple_data,
   2408 					    next->rdata.length)) {
   2409 					ISC_LIST_UNLINK(temp_diff.tuples, next,
   2410 							link);
   2411 					ISC_LIST_APPEND(diff->tuples, next,
   2412 							link);
   2413 					break;
   2414 				}
   2415 				next = ISC_LIST_NEXT(next, link);
   2416 			}
   2417 			/*
   2418 			 * If we have not found a pair move onto the next
   2419 			 * tuple.
   2420 			 */
   2421 			if (next == NULL) {
   2422 				next = ISC_LIST_NEXT(tuple, link);
   2423 				continue;
   2424 			}
   2425 			/*
   2426 			 * Find the next tuple to be processed before
   2427 			 * unlinking then complete moving the pair to 'diff'.
   2428 			 */
   2429 			next = ISC_LIST_NEXT(tuple, link);
   2430 			ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2431 			ISC_LIST_APPEND(diff->tuples, tuple, link);
   2432 		} else
   2433 			next = ISC_LIST_NEXT(tuple, link);
   2434 	}
   2435 
   2436 	/*
   2437 	 * Process the remaining DNSKEY entries.
   2438 	 */
   2439 	for (tuple = ISC_LIST_HEAD(temp_diff.tuples);
   2440 	     tuple != NULL;
   2441 	     tuple = ISC_LIST_HEAD(temp_diff.tuples)) {
   2442 
   2443 		ISC_LIST_UNLINK(temp_diff.tuples, tuple, link);
   2444 		ISC_LIST_APPEND(diff->tuples, tuple, link);
   2445 
   2446 		result = dns_rdata_tostruct(&tuple->rdata, &dnskey, NULL);
   2447 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
   2448 		if ((dnskey.flags &
   2449 		     (DNS_KEYFLAG_OWNERMASK|DNS_KEYTYPE_NOAUTH))
   2450 			 != DNS_KEYOWNER_ZONE)
   2451 			continue;
   2452 
   2453 		dns_rdata_toregion(&tuple->rdata, &r);
   2454 
   2455 		keyid = dst_region_computeid(&r);
   2456 
   2457 		buf[0] = dnskey.algorithm;
   2458 		buf[1] = (keyid & 0xff00) >> 8;
   2459 		buf[2] = (keyid & 0xff);
   2460 		buf[3] = (tuple->op == DNS_DIFFOP_ADD) ? 0 : 1;
   2461 		buf[4] = 0;
   2462 		rdata.data = buf;
   2463 		rdata.length = sizeof(buf);
   2464 		rdata.type = privatetype;
   2465 		rdata.rdclass = tuple->rdata.rdclass;
   2466 
   2467 		CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2468 		if (flag)
   2469 			continue;
   2470 		CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_ADD,
   2471 					   name, 0, &rdata, &newtuple));
   2472 		CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2473 		INSIST(newtuple == NULL);
   2474 		/*
   2475 		 * Remove any record which says this operation has already
   2476 		 * completed.
   2477 		 */
   2478 		buf[4] = 1;
   2479 		CHECK(rr_exists(db, ver, name, &rdata, &flag));
   2480 		if (flag) {
   2481 			CHECK(dns_difftuple_create(diff->mctx, DNS_DIFFOP_DEL,
   2482 						   name, 0, &rdata, &newtuple));
   2483 			CHECK(do_one_tuple(&newtuple, db, ver, diff));
   2484 			INSIST(newtuple == NULL);
   2485 		}
   2486 	}
   2487 
   2488  failure:
   2489 	dns_diff_clear(&temp_diff);
   2490 	return (result);
   2491 }
   2492 
   2493 static bool
   2494 isdnssec(dns_db_t *db, dns_dbversion_t *ver, dns_rdatatype_t privatetype) {
   2495 	isc_result_t result;
   2496 	bool build_nsec, build_nsec3;
   2497 
   2498 	if (dns_db_issecure(db))
   2499 		return (true);
   2500 
   2501 	result = dns_private_chains(db, ver, privatetype,
   2502 				    &build_nsec, &build_nsec3);
   2503 	RUNTIME_CHECK(result == ISC_R_SUCCESS);
   2504 	return (build_nsec || build_nsec3);
   2505 }
   2506 
   2507 static void
   2508 update_action(isc_task_t *task, isc_event_t *event) {
   2509 	update_event_t *uev = (update_event_t *) event;
   2510 	dns_zone_t *zone = uev->zone;
   2511 	ns_client_t *client = (ns_client_t *)event->ev_arg;
   2512 	isc_result_t result;
   2513 	dns_db_t *db = NULL;
   2514 	dns_dbversion_t *oldver = NULL;
   2515 	dns_dbversion_t *ver = NULL;
   2516 	dns_diff_t diff;	/* Pending updates. */
   2517 	dns_diff_t temp;	/* Pending RR existence assertions. */
   2518 	bool soa_serial_changed = false;
   2519 	isc_mem_t *mctx = client->mctx;
   2520 	dns_rdatatype_t covers;
   2521 	dns_message_t *request = client->message;
   2522 	dns_rdataclass_t zoneclass;
   2523 	dns_name_t *zonename;
   2524 	dns_ssutable_t *ssutable = NULL;
   2525 	dns_fixedname_t tmpnamefixed;
   2526 	dns_name_t *tmpname = NULL;
   2527 	dns_zoneopt_t options;
   2528 	dns_difftuple_t *tuple;
   2529 	dns_rdata_dnskey_t dnskey;
   2530 	bool had_dnskey;
   2531 	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
   2532 	dns_ttl_t maxttl = 0;
   2533 	uint32_t maxrecords;
   2534 	uint64_t records;
   2535 	dns_aclenv_t *env = ns_interfacemgr_getaclenv(client->interface->mgr);
   2536 
   2537 	INSIST(event->ev_type == DNS_EVENT_UPDATE);
   2538 
   2539 	dns_diff_init(mctx, &diff);
   2540 	dns_diff_init(mctx, &temp);
   2541 
   2542 	CHECK(dns_zone_getdb(zone, &db));
   2543 	zonename = dns_db_origin(db);
   2544 	zoneclass = dns_db_class(db);
   2545 	dns_zone_getssutable(zone, &ssutable);
   2546 
   2547 	/*
   2548 	 * Update message processing can leak record existance information
   2549 	 * so check that we are allowed to query this zone.  Additionally
   2550 	 * if we would refuse all updates for this zone we bail out here.
   2551 	 */
   2552 	CHECK(checkqueryacl(client, dns_zone_getqueryacl(zone), zonename,
   2553 			    dns_zone_getupdateacl(zone), ssutable));
   2554 
   2555 	/*
   2556 	 * Get old and new versions now that queryacl has been checked.
   2557 	 */
   2558 	dns_db_currentversion(db, &oldver);
   2559 	CHECK(dns_db_newversion(db, &ver));
   2560 
   2561 	/*
   2562 	 * Check prerequisites.
   2563 	 */
   2564 
   2565 	for (result = dns_message_firstname(request, DNS_SECTION_PREREQUISITE);
   2566 	     result == ISC_R_SUCCESS;
   2567 	     result = dns_message_nextname(request, DNS_SECTION_PREREQUISITE))
   2568 	{
   2569 		dns_name_t *name = NULL;
   2570 		dns_rdata_t rdata = DNS_RDATA_INIT;
   2571 		dns_ttl_t ttl;
   2572 		dns_rdataclass_t update_class;
   2573 		bool flag;
   2574 
   2575 		get_current_rr(request, DNS_SECTION_PREREQUISITE, zoneclass,
   2576 			       &name, &rdata, &covers, &ttl, &update_class);
   2577 
   2578 		if (ttl != 0)
   2579 			PREREQFAILC(DNS_R_FORMERR,
   2580 				    "prerequisite TTL is not zero");
   2581 
   2582 		if (! dns_name_issubdomain(name, zonename))
   2583 			PREREQFAILN(DNS_R_NOTZONE, name,
   2584 				    "prerequisite name is out of zone");
   2585 
   2586 		if (update_class == dns_rdataclass_any) {
   2587 			if (rdata.length != 0)
   2588 				PREREQFAILC(DNS_R_FORMERR,
   2589 				      "class ANY prerequisite "
   2590 				      "RDATA is not empty");
   2591 			if (rdata.type == dns_rdatatype_any) {
   2592 				CHECK(name_exists(db, ver, name, &flag));
   2593 				if (! flag) {
   2594 					PREREQFAILN(DNS_R_NXDOMAIN, name,
   2595 						    "'name in use' "
   2596 						    "prerequisite not "
   2597 						    "satisfied");
   2598 				}
   2599 			} else {
   2600 				CHECK(rrset_exists(db, ver, name,
   2601 						   rdata.type, covers, &flag));
   2602 				if (! flag) {
   2603 					/* RRset does not exist. */
   2604 					PREREQFAILNT(DNS_R_NXRRSET,
   2605 						     name, rdata.type,
   2606 					"'rrset exists (value independent)' "
   2607 					"prerequisite not satisfied");
   2608 				}
   2609 			}
   2610 		} else if (update_class == dns_rdataclass_none) {
   2611 			if (rdata.length != 0)
   2612 				PREREQFAILC(DNS_R_FORMERR,
   2613 					    "class NONE prerequisite "
   2614 					    "RDATA is not empty");
   2615 			if (rdata.type == dns_rdatatype_any) {
   2616 				CHECK(name_exists(db, ver, name, &flag));
   2617 				if (flag) {
   2618 					PREREQFAILN(DNS_R_YXDOMAIN, name,
   2619 						    "'name not in use' "
   2620 						    "prerequisite not "
   2621 						    "satisfied");
   2622 				}
   2623 			} else {
   2624 				CHECK(rrset_exists(db, ver, name,
   2625 						   rdata.type, covers, &flag));
   2626 				if (flag) {
   2627 					/* RRset exists. */
   2628 					PREREQFAILNT(DNS_R_YXRRSET, name,
   2629 						     rdata.type,
   2630 						     "'rrset does not exist' "
   2631 						     "prerequisite not "
   2632 						     "satisfied");
   2633 				}
   2634 			}
   2635 		} else if (update_class == zoneclass) {
   2636 			/* "temp<rr.name, rr.type> += rr;" */
   2637 			result = temp_append(&temp, name, &rdata);
   2638 			if (result != ISC_R_SUCCESS) {
   2639 				UNEXPECTED_ERROR(__FILE__, __LINE__,
   2640 					 "temp entry creation failed: %s",
   2641 						 dns_result_totext(result));
   2642 				FAIL(ISC_R_UNEXPECTED);
   2643 			}
   2644 		} else {
   2645 			PREREQFAILC(DNS_R_FORMERR, "malformed prerequisite");
   2646 		}
   2647 	}
   2648 	if (result != ISC_R_NOMORE)
   2649 		FAIL(result);
   2650 
   2651 	/*
   2652 	 * Perform the final check of the "rrset exists (value dependent)"
   2653 	 * prerequisites.
   2654 	 */
   2655 	if (ISC_LIST_HEAD(temp.tuples) != NULL) {
   2656 		dns_rdatatype_t type;
   2657 
   2658 		/*
   2659 		 * Sort the prerequisite records by owner name,
   2660 		 * type, and rdata.
   2661 		 */
   2662 		result = dns_diff_sort(&temp, temp_order);
   2663 		if (result != ISC_R_SUCCESS)
   2664 			FAILC(result, "'RRset exists (value dependent)' "
   2665 			      "prerequisite not satisfied");
   2666 
   2667 		tmpname = dns_fixedname_initname(&tmpnamefixed);
   2668 		result = temp_check(mctx, &temp, db, ver, tmpname, &type);
   2669 		if (result != ISC_R_SUCCESS)
   2670 			FAILNT(result, tmpname, type,
   2671 			       "'RRset exists (value dependent)' "
   2672 			       "prerequisite not satisfied");
   2673 	}
   2674 
   2675 	update_log(client, zone, LOGLEVEL_DEBUG,
   2676 		   "prerequisites are OK");
   2677 
   2678 	/*
   2679 	 * Check Requestor's Permissions.  It seems a bit silly to do this
   2680 	 * only after prerequisite testing, but that is what RFC2136 says.
   2681 	 */
   2682 	if (ssutable == NULL)
   2683 		CHECK(checkupdateacl(client, dns_zone_getupdateacl(zone),
   2684 				     "update", zonename, false, false));
   2685 	else if (client->signer == NULL && !TCPCLIENT(client))
   2686 		CHECK(checkupdateacl(client, NULL, "update", zonename,
   2687 				     false, true));
   2688 
   2689 	if (dns_zone_getupdatedisabled(zone))
   2690 		FAILC(DNS_R_REFUSED, "dynamic update temporarily disabled "
   2691 				     "because the zone is frozen.  Use "
   2692 				     "'rndc thaw' to re-enable updates.");
   2693 
   2694 	/*
   2695 	 * Perform the Update Section Prescan.
   2696 	 */
   2697 
   2698 	for (result = dns_message_firstname(request, DNS_SECTION_UPDATE);
   2699 	     result == ISC_R_SUCCESS;
   2700 	     result = dns_message_nextname(request, DNS_SECTION_UPDATE))
   2701 	{
   2702 		dns_name_t *name = NULL;
   2703 		dns_rdata_t rdata = DNS_RDATA_INIT;
   2704 		dns_ttl_t ttl;
   2705 		dns_rdataclass_t update_class;
   2706 		get_current_rr(request, DNS_SECTION_UPDATE, zoneclass,
   2707 			       &name, &rdata, &covers, &ttl, &update_class);
   2708 
   2709 		if (! dns_name_issubdomain(name, zonename))
   2710 			FAILC(DNS_R_NOTZONE,
   2711 			      "update RR is outside zone");
   2712 		if (update_class == zoneclass) {
   2713 			/*
   2714 			 * Check for meta-RRs.  The RFC2136 pseudocode says
   2715 			 * check for ANY|AXFR|MAILA|MAILB, but the text adds
   2716 			 * "or any other QUERY metatype"
   2717 			 */
   2718 			if (dns_rdatatype_ismeta(rdata.type)) {
   2719 				FAILC(DNS_R_FORMERR,
   2720 				      "meta-RR in update");
   2721 			}
   2722 			result = dns_zone_checknames(zone, name, &rdata);
   2723 			if (result != ISC_R_SUCCESS)
   2724 				FAIL(DNS_R_REFUSED);
   2725 		} else if (update_class == dns_rdataclass_any) {
   2726 			if (ttl != 0 || rdata.length != 0 ||
   2727 			    (dns_rdatatype_ismeta(rdata.type) &&
   2728 			     rdata.type != dns_rdatatype_any))
   2729 				FAILC(DNS_R_FORMERR,
   2730 				      "meta-RR in update");
   2731 		} else if (update_class == dns_rdataclass_none) {
   2732 			if (ttl != 0 ||
   2733 			    dns_rdatatype_ismeta(rdata.type))
   2734 				FAILC(DNS_R_FORMERR,
   2735 				      "meta-RR in update");
   2736 		} else {
   2737 			update_log(client, zone, ISC_LOG_WARNING,
   2738 				   "update RR has incorrect class %d",
   2739 				   update_class);
   2740 			FAIL(DNS_R_FORMERR);
   2741 		}
   2742 
   2743 		/*
   2744 		 * draft-ietf-dnsind-simple-secure-update-01 says
   2745 		 * "Unlike traditional dynamic update, the client
   2746 		 * is forbidden from updating NSEC records."
   2747 		 */
   2748 		if (rdata.type == dns_rdatatype_nsec3) {
   2749 			FAILC(DNS_R_REFUSED,
   2750 			      "explicit NSEC3 updates are not allowed "
   2751 			      "in secure zones");
   2752 		} else if (rdata.type == dns_rdatatype_nsec) {
   2753 			FAILC(DNS_R_REFUSED,
   2754 			      "explicit NSEC updates are not allowed "
   2755 			      "in secure zones");
   2756 		} else if (rdata.type == dns_rdatatype_rrsig &&
   2757 			   !dns_name_equal(name, zonename)) {
   2758 			FAILC(DNS_R_REFUSED,
   2759 			      "explicit RRSIG updates are currently "
   2760 			      "not supported in secure zones except "
   2761 			      "at the apex");
   2762 		}
   2763 
   2764 		if (ssutable != NULL) {
   2765 			isc_netaddr_t netaddr;
   2766 			dst_key_t *tsigkey = NULL;
   2767 			isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
   2768 
   2769 			if (client->message->tsigkey != NULL)
   2770 				tsigkey = client->message->tsigkey->key;
   2771 
   2772 			if (rdata.type != dns_rdatatype_any) {
   2773 				if (!dns_ssutable_checkrules
   2774 				(ssutable, client->signer, name, &netaddr,
   2775 				 TCPCLIENT(client),
   2776 				 env, rdata.type, tsigkey))
   2777 				{
   2778 					FAILC(DNS_R_REFUSED,
   2779 					      "rejected by secure update");
   2780 				}
   2781 			} else {
   2782 				if (!ssu_checkall(db, ver, name, ssutable,
   2783 						  client->signer,
   2784 						  &netaddr, env,
   2785 						  TCPCLIENT(client),
   2786 						  tsigkey))
   2787 				{
   2788 					FAILC(DNS_R_REFUSED,
   2789 					      "rejected by secure update");
   2790 				}
   2791 			}
   2792 		}
   2793 	}
   2794 	if (result != ISC_R_NOMORE)
   2795 		FAIL(result);
   2796 
   2797 	update_log(client, zone, LOGLEVEL_DEBUG,
   2798 		   "update section prescan OK");
   2799 
   2800 	/*
   2801 	 * Process the Update Section.
   2802 	 */
   2803 
   2804 	options = dns_zone_getoptions(zone);
   2805 	for (result = dns_message_firstname(request, DNS_SECTION_UPDATE);
   2806 	     result == ISC_R_SUCCESS;
   2807 	     result = dns_message_nextname(request, DNS_SECTION_UPDATE))
   2808 	{
   2809 		dns_name_t *name = NULL;
   2810 		dns_rdata_t rdata = DNS_RDATA_INIT;
   2811 		dns_ttl_t ttl;
   2812 		dns_rdataclass_t update_class;
   2813 		bool flag;
   2814 
   2815 		get_current_rr(request, DNS_SECTION_UPDATE, zoneclass,
   2816 			       &name, &rdata, &covers, &ttl, &update_class);
   2817 
   2818 		if (update_class == zoneclass) {
   2819 
   2820 			/*
   2821 			 * RFC1123 doesn't allow MF and MD in master zones.
   2822 			 */
   2823 			if (rdata.type == dns_rdatatype_md ||
   2824 			    rdata.type == dns_rdatatype_mf) {
   2825 				char typebuf[DNS_RDATATYPE_FORMATSIZE];
   2826 
   2827 				dns_rdatatype_format(rdata.type, typebuf,
   2828 						     sizeof(typebuf));
   2829 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   2830 					   "attempt to add %s ignored",
   2831 					   typebuf);
   2832 				continue;
   2833 			}
   2834 			if ((rdata.type == dns_rdatatype_ns ||
   2835 			     rdata.type == dns_rdatatype_dname) &&
   2836 			    dns_name_iswildcard(name)) {
   2837 				char typebuf[DNS_RDATATYPE_FORMATSIZE];
   2838 
   2839 				dns_rdatatype_format(rdata.type, typebuf,
   2840 						     sizeof(typebuf));
   2841 				update_log(client, zone,
   2842 					   LOGLEVEL_PROTOCOL,
   2843 					   "attempt to add wildcard %s record "
   2844 					   "ignored", typebuf);
   2845 				continue;
   2846 			}
   2847 			if (rdata.type == dns_rdatatype_cname) {
   2848 				CHECK(cname_incompatible_rrset_exists(db, ver,
   2849 								      name,
   2850 								      &flag));
   2851 				if (flag) {
   2852 					update_log(client, zone,
   2853 						   LOGLEVEL_PROTOCOL,
   2854 						   "attempt to add CNAME "
   2855 						   "alongside non-CNAME "
   2856 						   "ignored");
   2857 					continue;
   2858 				}
   2859 			} else {
   2860 				CHECK(rrset_exists(db, ver, name,
   2861 						   dns_rdatatype_cname, 0,
   2862 						   &flag));
   2863 				if (flag &&
   2864 				    ! dns_rdatatype_atcname(rdata.type))
   2865 				{
   2866 					update_log(client, zone,
   2867 						   LOGLEVEL_PROTOCOL,
   2868 						   "attempt to add non-CNAME "
   2869 						   "alongside CNAME ignored");
   2870 					continue;
   2871 				}
   2872 			}
   2873 			if (rdata.type == dns_rdatatype_soa) {
   2874 				bool ok;
   2875 				CHECK(rrset_exists(db, ver, name,
   2876 						   dns_rdatatype_soa, 0,
   2877 						   &flag));
   2878 				if (! flag) {
   2879 					update_log(client, zone,
   2880 						   LOGLEVEL_PROTOCOL,
   2881 						   "attempt to create 2nd "
   2882 						   "SOA ignored");
   2883 					continue;
   2884 				}
   2885 				CHECK(check_soa_increment(db, ver, &rdata,
   2886 							  &ok));
   2887 				if (! ok) {
   2888 					update_log(client, zone,
   2889 						   LOGLEVEL_PROTOCOL,
   2890 						   "SOA update failed to "
   2891 						   "increment serial, "
   2892 						   "ignoring it");
   2893 					continue;
   2894 				}
   2895 				soa_serial_changed = true;
   2896 			}
   2897 
   2898 			if (rdata.type == privatetype) {
   2899 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   2900 					   "attempt to add a private type "
   2901 					   "(%u) record rejected internal "
   2902 					   "use only", privatetype);
   2903 				continue;
   2904 			}
   2905 
   2906 			if (rdata.type == dns_rdatatype_nsec3param) {
   2907 				/*
   2908 				 * Ignore attempts to add NSEC3PARAM records
   2909 				 * with any flags other than OPTOUT.
   2910 				 */
   2911 				if ((rdata.data[1] &
   2912 				     ~DNS_NSEC3FLAG_OPTOUT) != 0)
   2913 				{
   2914 					update_log(client, zone,
   2915 						   LOGLEVEL_PROTOCOL,
   2916 						   "attempt to add NSEC3PARAM "
   2917 						   "record with non OPTOUT "
   2918 						   "flag");
   2919 					continue;
   2920 				}
   2921 			}
   2922 
   2923 			if ((options & DNS_ZONEOPT_CHECKWILDCARD) != 0 &&
   2924 			    dns_name_internalwildcard(name)) {
   2925 				char namestr[DNS_NAME_FORMATSIZE];
   2926 				dns_name_format(name, namestr,
   2927 						sizeof(namestr));
   2928 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   2929 					   "warning: ownername '%s' contains "
   2930 					   "a non-terminal wildcard", namestr);
   2931 			}
   2932 
   2933 			if ((options & DNS_ZONEOPT_CHECKTTL) != 0) {
   2934 				maxttl = dns_zone_getmaxttl(zone);
   2935 				if (ttl > maxttl) {
   2936 					ttl = maxttl;
   2937 					update_log(client, zone,
   2938 						   LOGLEVEL_PROTOCOL,
   2939 						   "reducing TTL to the "
   2940 						   "configured max-zone-ttl %d",
   2941 						   maxttl);
   2942 				}
   2943 			}
   2944 
   2945 			if (isc_log_wouldlog(ns_lctx, LOGLEVEL_PROTOCOL)) {
   2946 				char namestr[DNS_NAME_FORMATSIZE];
   2947 				char typestr[DNS_RDATATYPE_FORMATSIZE];
   2948 				char rdstr[2048];
   2949 				isc_buffer_t buf;
   2950 				int len = 0;
   2951 				const char *truncated = "";
   2952 
   2953 				dns_name_format(name, namestr, sizeof(namestr));
   2954 				dns_rdatatype_format(rdata.type, typestr,
   2955 						     sizeof(typestr));
   2956 				isc_buffer_init(&buf, rdstr, sizeof(rdstr));
   2957 				result = dns_rdata_totext(&rdata, NULL, &buf);
   2958 				if (result == ISC_R_NOSPACE) {
   2959 					len = (int)isc_buffer_usedlength(&buf);
   2960 					truncated = " [TRUNCATED]";
   2961 				} else if (result != ISC_R_SUCCESS) {
   2962 					snprintf(rdstr, sizeof(rdstr), "[dns_"
   2963 						 "rdata_totext failed: %s]",
   2964 						 dns_result_totext(result));
   2965 					len = strlen(rdstr);
   2966 				} else
   2967 					len = (int)isc_buffer_usedlength(&buf);
   2968 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   2969 					   "adding an RR at '%s' %s %.*s%s",
   2970 					   namestr, typestr, len, rdstr,
   2971 					   truncated);
   2972 			}
   2973 
   2974 			/* Prepare the affected RRset for the addition. */
   2975 			{
   2976 				add_rr_prepare_ctx_t ctx;
   2977 				ctx.db = db;
   2978 				ctx.ver = ver;
   2979 				ctx.diff = &diff;
   2980 				ctx.name = name;
   2981 				ctx.oldname = name;
   2982 				ctx.update_rr = &rdata;
   2983 				ctx.update_rr_ttl = ttl;
   2984 				ctx.ignore_add = false;
   2985 				dns_diff_init(mctx, &ctx.del_diff);
   2986 				dns_diff_init(mctx, &ctx.add_diff);
   2987 				CHECK(foreach_rr(db, ver, name, rdata.type,
   2988 						 covers, add_rr_prepare_action,
   2989 						 &ctx));
   2990 
   2991 				if (ctx.ignore_add) {
   2992 					dns_diff_clear(&ctx.del_diff);
   2993 					dns_diff_clear(&ctx.add_diff);
   2994 				} else {
   2995 					result = do_diff(&ctx.del_diff, db, ver,
   2996 							 &diff);
   2997 					if (result == ISC_R_SUCCESS) {
   2998 						result = do_diff(&ctx.add_diff,
   2999 								 db, ver,
   3000 								 &diff);
   3001 					}
   3002 					if (result != ISC_R_SUCCESS) {
   3003 						dns_diff_clear(&ctx.del_diff);
   3004 						dns_diff_clear(&ctx.add_diff);
   3005 						goto failure;
   3006 					}
   3007 					CHECK(update_one_rr(db, ver, &diff,
   3008 							    DNS_DIFFOP_ADD,
   3009 							    name, ttl, &rdata));
   3010 				}
   3011 			}
   3012 		} else if (update_class == dns_rdataclass_any) {
   3013 			if (rdata.type == dns_rdatatype_any) {
   3014 				if (isc_log_wouldlog(ns_lctx,
   3015 						     LOGLEVEL_PROTOCOL))
   3016 				{
   3017 					char namestr[DNS_NAME_FORMATSIZE];
   3018 					dns_name_format(name, namestr,
   3019 							sizeof(namestr));
   3020 					update_log(client, zone,
   3021 						   LOGLEVEL_PROTOCOL,
   3022 						   "delete all rrsets from "
   3023 						   "name '%s'", namestr);
   3024 				}
   3025 				if (dns_name_equal(name, zonename)) {
   3026 					CHECK(delete_if(type_not_soa_nor_ns_p,
   3027 							db, ver, name,
   3028 							dns_rdatatype_any, 0,
   3029 							&rdata, &diff));
   3030 				} else {
   3031 					CHECK(delete_if(type_not_dnssec,
   3032 							db, ver, name,
   3033 							dns_rdatatype_any, 0,
   3034 							&rdata, &diff));
   3035 				}
   3036 			} else if (dns_name_equal(name, zonename) &&
   3037 				   (rdata.type == dns_rdatatype_soa ||
   3038 				    rdata.type == dns_rdatatype_ns)) {
   3039 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   3040 					   "attempt to delete all SOA "
   3041 					   "or NS records ignored");
   3042 				continue;
   3043 			} else {
   3044 				if (isc_log_wouldlog(ns_lctx,
   3045 						     LOGLEVEL_PROTOCOL))
   3046 				{
   3047 					char namestr[DNS_NAME_FORMATSIZE];
   3048 					char typestr[DNS_RDATATYPE_FORMATSIZE];
   3049 					dns_name_format(name, namestr,
   3050 							sizeof(namestr));
   3051 					dns_rdatatype_format(rdata.type,
   3052 							     typestr,
   3053 							     sizeof(typestr));
   3054 					update_log(client, zone,
   3055 						   LOGLEVEL_PROTOCOL,
   3056 						   "deleting rrset at '%s' %s",
   3057 						   namestr, typestr);
   3058 				}
   3059 				CHECK(delete_if(true_p, db, ver, name,
   3060 						rdata.type, covers, &rdata,
   3061 						&diff));
   3062 			}
   3063 		} else if (update_class == dns_rdataclass_none) {
   3064 			char namestr[DNS_NAME_FORMATSIZE];
   3065 			char typestr[DNS_RDATATYPE_FORMATSIZE];
   3066 
   3067 			/*
   3068 			 * The (name == zonename) condition appears in
   3069 			 * RFC2136 3.4.2.4 but is missing from the pseudocode.
   3070 			 */
   3071 			if (dns_name_equal(name, zonename)) {
   3072 				if (rdata.type == dns_rdatatype_soa) {
   3073 					update_log(client, zone,
   3074 						   LOGLEVEL_PROTOCOL,
   3075 						   "attempt to delete SOA "
   3076 						   "ignored");
   3077 					continue;
   3078 				}
   3079 				if (rdata.type == dns_rdatatype_ns) {
   3080 					int count;
   3081 					CHECK(rr_count(db, ver, name,
   3082 						       dns_rdatatype_ns,
   3083 						       0, &count));
   3084 					if (count == 1) {
   3085 						update_log(client, zone,
   3086 							   LOGLEVEL_PROTOCOL,
   3087 							   "attempt to "
   3088 							   "delete last "
   3089 							   "NS ignored");
   3090 						continue;
   3091 					}
   3092 				}
   3093 			}
   3094 			dns_name_format(name, namestr, sizeof(namestr));
   3095 			dns_rdatatype_format(rdata.type, typestr,
   3096 					     sizeof(typestr));
   3097 			update_log(client, zone, LOGLEVEL_PROTOCOL,
   3098 				   "deleting an RR at %s %s", namestr, typestr);
   3099 			CHECK(delete_if(rr_equal_p, db, ver, name, rdata.type,
   3100 					covers, &rdata, &diff));
   3101 		}
   3102 	}
   3103 	if (result != ISC_R_NOMORE)
   3104 		FAIL(result);
   3105 
   3106 	/*
   3107 	 * Check that any changes to DNSKEY/NSEC3PARAM records make sense.
   3108 	 * If they don't then back out all changes to DNSKEY/NSEC3PARAM
   3109 	 * records.
   3110 	 */
   3111 	if (! ISC_LIST_EMPTY(diff.tuples))
   3112 		CHECK(check_dnssec(client, zone, db, ver, &diff));
   3113 
   3114 	if (! ISC_LIST_EMPTY(diff.tuples)) {
   3115 		unsigned int errors = 0;
   3116 		CHECK(dns_zone_nscheck(zone, db, ver, &errors));
   3117 		if (errors != 0) {
   3118 			update_log(client, zone, LOGLEVEL_PROTOCOL,
   3119 				   "update rejected: post update name server "
   3120 				   "sanity check failed");
   3121 			result = DNS_R_REFUSED;
   3122 			goto failure;
   3123 		}
   3124 	}
   3125 	if (! ISC_LIST_EMPTY(diff.tuples)) {
   3126 		result = dns_zone_cdscheck(zone, db, ver);
   3127 		if (result == DNS_R_BADCDS || result == DNS_R_BADCDNSKEY) {
   3128 			update_log(client, zone, LOGLEVEL_PROTOCOL,
   3129 				   "update rejected: bad %s RRset",
   3130 				   result == DNS_R_BADCDS ? "CDS" : "CDNSKEY");
   3131 			result = DNS_R_REFUSED;
   3132 			goto failure;
   3133 		}
   3134 		if (result != ISC_R_SUCCESS)
   3135 			goto failure;
   3136 
   3137 	}
   3138 
   3139 	/*
   3140 	 * If any changes were made, increment the SOA serial number,
   3141 	 * update RRSIGs and NSECs (if zone is secure), and write the update
   3142 	 * to the journal.
   3143 	 */
   3144 	if (! ISC_LIST_EMPTY(diff.tuples)) {
   3145 		char *journalfile;
   3146 		dns_journal_t *journal;
   3147 		bool has_dnskey;
   3148 
   3149 		/*
   3150 		 * Increment the SOA serial, but only if it was not
   3151 		 * changed as a result of an update operation.
   3152 		 */
   3153 		if (! soa_serial_changed) {
   3154 			CHECK(update_soa_serial(db, ver, &diff, mctx,
   3155 				       dns_zone_getserialupdatemethod(zone)));
   3156 		}
   3157 
   3158 		CHECK(check_mx(client, zone, db, ver, &diff));
   3159 
   3160 		CHECK(remove_orphaned_ds(db, ver, &diff));
   3161 
   3162 		CHECK(rrset_exists(db, ver, zonename, dns_rdatatype_dnskey,
   3163 				   0, &has_dnskey));
   3164 
   3165 #define ALLOW_SECURE_TO_INSECURE(zone) \
   3166 	((dns_zone_getoptions(zone) & DNS_ZONEOPT_SECURETOINSECURE) != 0)
   3167 
   3168 		CHECK(rrset_exists(db, oldver, zonename, dns_rdatatype_dnskey,
   3169 				   0, &had_dnskey));
   3170 		if (!ALLOW_SECURE_TO_INSECURE(zone)) {
   3171 			if (had_dnskey && !has_dnskey) {
   3172 				update_log(client, zone, LOGLEVEL_PROTOCOL,
   3173 					   "update rejected: all DNSKEY "
   3174 					   "records removed and "
   3175 					   "'dnssec-secure-to-insecure' "
   3176 					   "not set");
   3177 				result = DNS_R_REFUSED;
   3178 				goto failure;
   3179 			}
   3180 		}
   3181 
   3182 		CHECK(rollback_private(db, privatetype, ver, &diff));
   3183 
   3184 		CHECK(add_signing_records(db, privatetype, ver, &diff));
   3185 
   3186 		CHECK(add_nsec3param_records(client, zone, db, ver, &diff));
   3187 
   3188 		if (had_dnskey && !has_dnskey) {
   3189 			/*
   3190 			 * We are transitioning from secure to insecure.
   3191 			 * Cause all NSEC3 chains to be deleted.  When the
   3192 			 * the last signature for the DNSKEY records are
   3193 			 * remove any NSEC chain present will also be removed.
   3194 			 */
   3195 			 CHECK(dns_nsec3param_deletechains(db, ver, zone,
   3196 							   true, &diff));
   3197 		} else if (has_dnskey && isdnssec(db, ver, privatetype)) {
   3198 			uint32_t interval;
   3199 			dns_update_log_t log;
   3200 
   3201 			interval = dns_zone_getsigvalidityinterval(zone);
   3202 			log.func = update_log_cb;
   3203 			log.arg = client;
   3204 			result = dns_update_signatures(&log, zone, db, oldver,
   3205 						       ver, &diff, interval);
   3206 
   3207 			if (result != ISC_R_SUCCESS) {
   3208 				update_log(client, zone,
   3209 					   ISC_LOG_ERROR,
   3210 					   "RRSIG/NSEC/NSEC3 update failed: %s",
   3211 					   isc_result_totext(result));
   3212 				goto failure;
   3213 			}
   3214 		}
   3215 
   3216 		maxrecords = dns_zone_getmaxrecords(zone);
   3217 		if (maxrecords != 0U) {
   3218 			result = dns_db_getsize(db, ver, &records, NULL);
   3219 			if (result == ISC_R_SUCCESS && records > maxrecords) {
   3220 				update_log(client, zone, ISC_LOG_ERROR,
   3221 					   "records in zone (%"
   3222 					   PRIu64
   3223 					   ") exceeds max-records (%u)",
   3224 					   records, maxrecords);
   3225 				result = DNS_R_TOOMANYRECORDS;
   3226 				goto failure;
   3227 			}
   3228 		}
   3229 
   3230 		journalfile = dns_zone_getjournal(zone);
   3231 		if (journalfile != NULL) {
   3232 			update_log(client, zone, LOGLEVEL_DEBUG,
   3233 				   "writing journal %s", journalfile);
   3234 
   3235 			journal = NULL;
   3236 			result = dns_journal_open(mctx, journalfile,
   3237 						  DNS_JOURNAL_CREATE, &journal);
   3238 			if (result != ISC_R_SUCCESS)
   3239 				FAILS(result, "journal open failed");
   3240 
   3241 			result = dns_journal_write_transaction(journal, &diff);
   3242 			if (result != ISC_R_SUCCESS) {
   3243 				dns_journal_destroy(&journal);
   3244 				FAILS(result, "journal write failed");
   3245 			}
   3246 
   3247 			dns_journal_destroy(&journal);
   3248 		}
   3249 
   3250 		/*
   3251 		 * XXXRTH  Just a note that this committing code will have
   3252 		 *	   to change to handle databases that need two-phase
   3253 		 *	   commit, but this isn't a priority.
   3254 		 */
   3255 		update_log(client, zone, LOGLEVEL_DEBUG,
   3256 			   "committing update transaction");
   3257 
   3258 		dns_db_closeversion(db, &ver, true);
   3259 
   3260 		/*
   3261 		 * Mark the zone as dirty so that it will be written to disk.
   3262 		 */
   3263 		dns_zone_markdirty(zone);
   3264 
   3265 		/*
   3266 		 * Notify slaves of the change we just made.
   3267 		 */
   3268 		dns_zone_notify(zone);
   3269 
   3270 		/*
   3271 		 * Cause the zone to be signed with the key that we
   3272 		 * have just added or have the corresponding signatures
   3273 		 * deleted.
   3274 		 *
   3275 		 * Note: we are already committed to this course of action.
   3276 		 */
   3277 		for (tuple = ISC_LIST_HEAD(diff.tuples);
   3278 		     tuple != NULL;
   3279 		     tuple = ISC_LIST_NEXT(tuple, link)) {
   3280 			isc_region_t r;
   3281 			dns_secalg_t algorithm;
   3282 			uint16_t keyid;
   3283 
   3284 			if (tuple->rdata.type != dns_rdatatype_dnskey)
   3285 				continue;
   3286 
   3287 			dns_rdata_tostruct(&tuple->rdata, &dnskey, NULL);
   3288 			if ((dnskey.flags &
   3289 			     (DNS_KEYFLAG_OWNERMASK|DNS_KEYTYPE_NOAUTH))
   3290 				 != DNS_KEYOWNER_ZONE)
   3291 				continue;
   3292 
   3293 			dns_rdata_toregion(&tuple->rdata, &r);
   3294 			algorithm = dnskey.algorithm;
   3295 			keyid = dst_region_computeid(&r);
   3296 
   3297 			result = dns_zone_signwithkey(zone, algorithm, keyid,
   3298 					(tuple->op == DNS_DIFFOP_DEL));
   3299 			if (result != ISC_R_SUCCESS) {
   3300 				update_log(client, zone, ISC_LOG_ERROR,
   3301 					   "dns_zone_signwithkey failed: %s",
   3302 					   dns_result_totext(result));
   3303 			}
   3304 		}
   3305 
   3306 		/*
   3307 		 * Cause the zone to add/delete NSEC3 chains for the
   3308 		 * deferred NSEC3PARAM changes.
   3309 		 *
   3310 		 * Note: we are already committed to this course of action.
   3311 		 */
   3312 		for (tuple = ISC_LIST_HEAD(diff.tuples);
   3313 		     tuple != NULL;
   3314 		     tuple = ISC_LIST_NEXT(tuple, link)) {
   3315 			unsigned char buf[DNS_NSEC3PARAM_BUFFERSIZE];
   3316 			dns_rdata_t rdata = DNS_RDATA_INIT;
   3317 			dns_rdata_nsec3param_t nsec3param;
   3318 
   3319 			if (tuple->rdata.type != privatetype ||
   3320 			    tuple->op != DNS_DIFFOP_ADD)
   3321 				continue;
   3322 
   3323 			if (!dns_nsec3param_fromprivate(&tuple->rdata, &rdata,
   3324 						   buf, sizeof(buf)))
   3325 				continue;
   3326 			dns_rdata_tostruct(&rdata, &nsec3param, NULL);
   3327 			if (nsec3param.flags == 0)
   3328 				continue;
   3329 
   3330 			result = dns_zone_addnsec3chain(zone, &nsec3param);
   3331 			if (result != ISC_R_SUCCESS) {
   3332 				update_log(client, zone, ISC_LOG_ERROR,
   3333 					   "dns_zone_addnsec3chain failed: %s",
   3334 					   dns_result_totext(result));
   3335 			}
   3336 		}
   3337 	} else {
   3338 		update_log(client, zone, LOGLEVEL_DEBUG, "redundant request");
   3339 		dns_db_closeversion(db, &ver, true);
   3340 	}
   3341 	result = ISC_R_SUCCESS;
   3342 	goto common;
   3343 
   3344  failure:
   3345 	/*
   3346 	 * The reason for failure should have been logged at this point.
   3347 	 */
   3348 	if (ver != NULL) {
   3349 		update_log(client, zone, LOGLEVEL_DEBUG,
   3350 			   "rolling back");
   3351 		dns_db_closeversion(db, &ver, false);
   3352 	}
   3353 
   3354  common:
   3355 	dns_diff_clear(&temp);
   3356 	dns_diff_clear(&diff);
   3357 
   3358 	if (oldver != NULL)
   3359 		dns_db_closeversion(db, &oldver, false);
   3360 
   3361 	if (db != NULL)
   3362 		dns_db_detach(&db);
   3363 
   3364 	if (ssutable != NULL)
   3365 		dns_ssutable_detach(&ssutable);
   3366 
   3367 	isc_task_detach(&task);
   3368 	uev->result = result;
   3369 	if (zone != NULL)
   3370 		INSIST(uev->zone == zone); /* we use this later */
   3371 	uev->ev_type = DNS_EVENT_UPDATEDONE;
   3372 	uev->ev_action = updatedone_action;
   3373 	isc_task_send(client->task, &event);
   3374 
   3375 	INSIST(ver == NULL);
   3376 	INSIST(event == NULL);
   3377 }
   3378 
   3379 static void
   3380 updatedone_action(isc_task_t *task, isc_event_t *event) {
   3381 	update_event_t *uev = (update_event_t *) event;
   3382 	ns_client_t *client = (ns_client_t *) event->ev_arg;
   3383 
   3384 	UNUSED(task);
   3385 
   3386 	INSIST(event->ev_type == DNS_EVENT_UPDATEDONE);
   3387 	INSIST(task == client->task);
   3388 
   3389 	INSIST(client->nupdates > 0);
   3390 	switch (uev->result) {
   3391 	case ISC_R_SUCCESS:
   3392 		inc_stats(client, uev->zone, ns_statscounter_updatedone);
   3393 		break;
   3394 	case DNS_R_REFUSED:
   3395 		inc_stats(client, uev->zone, ns_statscounter_updaterej);
   3396 		break;
   3397 	default:
   3398 		inc_stats(client, uev->zone, ns_statscounter_updatefail);
   3399 		break;
   3400 	}
   3401 	if (uev->zone != NULL)
   3402 		dns_zone_detach(&uev->zone);
   3403 	client->nupdates--;
   3404 	respond(client, uev->result);
   3405 	isc_event_free(&event);
   3406 	ns_client_detach(&client);
   3407 }
   3408 
   3409 /*%
   3410  * Update forwarding support.
   3411  */
   3412 
   3413 static void
   3414 forward_fail(isc_task_t *task, isc_event_t *event) {
   3415 	ns_client_t *client = (ns_client_t *)event->ev_arg;
   3416 
   3417 	UNUSED(task);
   3418 
   3419 	INSIST(client->nupdates > 0);
   3420 	client->nupdates--;
   3421 	respond(client, DNS_R_SERVFAIL);
   3422 	isc_event_free(&event);
   3423 	ns_client_detach(&client);
   3424 }
   3425 
   3426 
   3427 static void
   3428 forward_callback(void *arg, isc_result_t result, dns_message_t *answer) {
   3429 	update_event_t *uev = arg;
   3430 	ns_client_t *client = uev->ev_arg;
   3431 	dns_zone_t *zone = uev->zone;
   3432 
   3433 	if (result != ISC_R_SUCCESS) {
   3434 		INSIST(answer == NULL);
   3435 		uev->ev_type = DNS_EVENT_UPDATEDONE;
   3436 		uev->ev_action = forward_fail;
   3437 		inc_stats(client, zone, ns_statscounter_updatefwdfail);
   3438 	} else {
   3439 		uev->ev_type = DNS_EVENT_UPDATEDONE;
   3440 		uev->ev_action = forward_done;
   3441 		uev->answer = answer;
   3442 		inc_stats(client, zone, ns_statscounter_updaterespfwd);
   3443 	}
   3444 	isc_task_send(client->task, ISC_EVENT_PTR(&uev));
   3445 	dns_zone_detach(&zone);
   3446 }
   3447 
   3448 static void
   3449 forward_done(isc_task_t *task, isc_event_t *event) {
   3450 	update_event_t *uev = (update_event_t *) event;
   3451 	ns_client_t *client = (ns_client_t *)event->ev_arg;
   3452 
   3453 	UNUSED(task);
   3454 
   3455 	INSIST(client->nupdates > 0);
   3456 	client->nupdates--;
   3457 	ns_client_sendraw(client, uev->answer);
   3458 	dns_message_destroy(&uev->answer);
   3459 	isc_event_free(&event);
   3460 	ns_client_detach(&client);
   3461 }
   3462 
   3463 static void
   3464 forward_action(isc_task_t *task, isc_event_t *event) {
   3465 	update_event_t *uev = (update_event_t *) event;
   3466 	dns_zone_t *zone = uev->zone;
   3467 	ns_client_t *client = (ns_client_t *)event->ev_arg;
   3468 	isc_result_t result;
   3469 
   3470 	result = dns_zone_forwardupdate(zone, client->message,
   3471 					forward_callback, event);
   3472 	if (result != ISC_R_SUCCESS) {
   3473 		uev->ev_type = DNS_EVENT_UPDATEDONE;
   3474 		uev->ev_action = forward_fail;
   3475 		isc_task_send(client->task, &event);
   3476 		inc_stats(client, zone, ns_statscounter_updatefwdfail);
   3477 		dns_zone_detach(&zone);
   3478 	} else
   3479 		inc_stats(client, zone, ns_statscounter_updatereqfwd);
   3480 	isc_task_detach(&task);
   3481 }
   3482 
   3483 static isc_result_t
   3484 send_forward_event(ns_client_t *client, dns_zone_t *zone) {
   3485 	char namebuf[DNS_NAME_FORMATSIZE];
   3486 	char classbuf[DNS_RDATACLASS_FORMATSIZE];
   3487 	isc_result_t result = ISC_R_SUCCESS;
   3488 	update_event_t *event = NULL;
   3489 	isc_task_t *zonetask = NULL;
   3490 	ns_client_t *evclient;
   3491 
   3492 	/*
   3493 	 * This may take some time so replace this client.
   3494 	 */
   3495 	if (!client->mortal && (client->attributes & NS_CLIENTATTR_TCP) == 0)
   3496 		CHECK(ns_client_replace(client));
   3497 
   3498 	event = (update_event_t *)
   3499 		isc_event_allocate(client->mctx, client, DNS_EVENT_UPDATE,
   3500 				   forward_action, NULL, sizeof(*event));
   3501 	if (event == NULL)
   3502 		FAIL(ISC_R_NOMEMORY);
   3503 	event->zone = zone;
   3504 	event->result = ISC_R_SUCCESS;
   3505 
   3506 	evclient = NULL;
   3507 	ns_client_attach(client, &evclient);
   3508 	INSIST(client->nupdates == 0);
   3509 	client->nupdates++;
   3510 	event->ev_arg = evclient;
   3511 
   3512 	dns_name_format(dns_zone_getorigin(zone), namebuf,
   3513 			sizeof(namebuf));
   3514 	dns_rdataclass_format(dns_zone_getclass(zone), classbuf,
   3515 			      sizeof(classbuf));
   3516 
   3517 	ns_client_log(client, NS_LOGCATEGORY_UPDATE, NS_LOGMODULE_UPDATE,
   3518 		      LOGLEVEL_PROTOCOL, "forwarding update for zone '%s/%s'",
   3519 		      namebuf, classbuf);
   3520 
   3521 	dns_zone_gettask(zone, &zonetask);
   3522 	isc_task_send(zonetask, ISC_EVENT_PTR(&event));
   3523 
   3524  failure:
   3525 	if (event != NULL)
   3526 		isc_event_free(ISC_EVENT_PTR(&event));
   3527 	return (result);
   3528 }
   3529