adb.c

bind-3.2.

	f->fetch = NULL;

	f->namehook = new_adbnamehook(adb, NULL);
	if (f->namehook == NULL)
		goto err;

	f->entry = new_adbentry(adb);
	if (f->entry == NULL)
		goto err;

	dns_rdataset_init(&f->rdataset);

	f->magic = DNS_ADBFETCH_MAGIC;

	return (f);

 err:
	if (f->namehook != NULL)
		free_adbnamehook(adb, &f->namehook);
	if (f->entry != NULL)
		free_adbentry(adb, &f->entry);
	isc_mempool_put(adb->afmp, f);
	return (NULL);
}

static inline void
free_adbfetch(dns_adb_t *adb, dns_adbfetch_t **fetch) {
	dns_adbfetch_t *f;

	INSIST(fetch != NULL && DNS_ADBFETCH_VALID(*fetch));
	f = *fetch;
	*fetch = NULL;

	f->magic = 0;

	if (f->namehook != NULL)
		free_adbnamehook(adb, &f->namehook);
	if (f->entry != NULL)
		free_adbentry(adb, &f->entry);

	if (dns_rdataset_isassociated(&f->rdataset))
		dns_rdataset_disassociate(&f->rdataset);

	isc_mempool_put(adb->afmp, f);
}

/*
 * Caller must be holding the name lock.
 */
static isc_result_t
a6find(void *arg, dns_name_t *a6name, dns_rdatatype_t type, isc_stdtime_t now,
       dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset)
{
	dns_adbname_t *name;
	dns_adb_t *adb;
	isc_result_t result;

	name = arg;
	INSIST(DNS_ADBNAME_VALID(name));
	adb = name->adb;
	INSIST(DNS_ADB_VALID(adb));

	result = dns_view_simplefind(adb->view, a6name, type, now,
				     DNS_DBFIND_GLUEOK, ISC_FALSE,
				     rdataset, sigrdataset);
	if (result == DNS_R_GLUE)
		result = ISC_R_SUCCESS;
	return (result);
}

/*
 * Caller must be holding the name lock.
 */
static void
a6missing(dns_a6context_t *a6ctx, dns_name_t *a6name) {
	dns_adbname_t *name;
	dns_adb_t *adb;
	dns_adbfetch6_t *fetch;
	isc_result_t result;

	name = a6ctx->arg;
	INSIST(DNS_ADBNAME_VALID(name));
	adb = name->adb;
	INSIST(DNS_ADB_VALID(adb));

	fetch = new_adbfetch6(adb, name, a6ctx);
	if (fetch == NULL) {
		name->partial_result |= DNS_ADBFIND_INET6;
		return;
	}

	result = dns_resolver_createfetch(adb->view->resolver, a6name,
					  dns_rdatatype_a6,
					  NULL, NULL, NULL, 0,
					  adb->task, fetch_callback_a6,
					  name, &fetch->rdataset, NULL,
					  &fetch->fetch);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	name->chains = a6ctx->chains;
	ISC_LIST_APPEND(name->fetches_a6, fetch, plink);

 cleanup:
	if (result != ISC_R_SUCCESS) {
		free_adbfetch6(adb, &fetch);
		name->partial_result |= DNS_ADBFIND_INET6;
	}
}

static inline dns_adbfetch6_t *
new_adbfetch6(dns_adb_t *adb, dns_adbname_t *name, dns_a6context_t *a6ctx) {
	dns_adbfetch6_t *f;

	f = isc_mempool_get(adb->af6mp);
	if (f == NULL)
		return (NULL);

	f->magic = 0;
	f->namehook = NULL;
	f->entry = NULL;
	f->fetch = NULL;
	f->flags = 0;

	f->namehook = new_adbnamehook(adb, NULL);
	if (f->namehook == NULL)
		goto err;

	f->entry = new_adbentry(adb);
	if (f->entry == NULL)
		goto err;

	dns_rdataset_init(&f->rdataset);

	dns_a6_init(&f->a6ctx, a6find, NULL, import_a6,
		    a6missing, name);
	if (a6ctx != NULL)
		dns_a6_copy(a6ctx, &f->a6ctx);

	ISC_LINK_INIT(f, plink);
	f->magic = DNS_ADBFETCH6_MAGIC;

	return (f);

 err:
	if (f->namehook != NULL)
		free_adbnamehook(adb, &f->namehook);
	if (f->entry != NULL)
		free_adbentry(adb, &f->entry);
	isc_mempool_put(adb->af6mp, f);
	return (NULL);
}

static inline void
free_adbfetch6(dns_adb_t *adb, dns_adbfetch6_t **fetch) {
	dns_adbfetch6_t *f;

	INSIST(fetch != NULL && DNS_ADBFETCH6_VALID(*fetch));
	f = *fetch;
	*fetch = NULL;

	f->magic = 0;

	if (f->namehook != NULL)
		free_adbnamehook(adb, &f->namehook);
	if (f->entry != NULL)
		free_adbentry(adb, &f->entry);

	if (dns_rdataset_isassociated(&f->rdataset))
		dns_rdataset_disassociate(&f->rdataset);

	isc_mempool_put(adb->af6mp, f);
}

static inline isc_boolean_t
free_adbfind(dns_adb_t *adb, dns_adbfind_t **findp) {
	dns_adbfind_t *find;

	INSIST(findp != NULL && DNS_ADBFIND_VALID(*findp));
	find = *findp;
	*findp = NULL;

	INSIST(!FIND_HAS_ADDRS(find));
	INSIST(!ISC_LINK_LINKED(find, publink));
	INSIST(!ISC_LINK_LINKED(find, plink));
	INSIST(find->name_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(find->adbname == NULL);

	find->magic = 0;

	DESTROYLOCK(&find->lock);
	isc_mempool_put(adb->ahmp, find);
	return (dec_adb_irefcnt(adb));
}

/*
 * Copy bits from the entry into the newly allocated addrinfo.  The entry
 * must be locked, and the reference count must be bumped up by one
 * if this function returns a valid pointer.
 */
static inline dns_adbaddrinfo_t *
new_adbaddrinfo(dns_adb_t *adb, dns_adbentry_t *entry, in_port_t port) {
	dns_adbaddrinfo_t *ai;

	ai = isc_mempool_get(adb->aimp);
	if (ai == NULL)
		return (NULL);

	ai->magic = DNS_ADBADDRINFO_MAGIC;
	ai->sockaddr = entry->sockaddr;
	isc_sockaddr_setport(&ai->sockaddr, port);
	ai->srtt = entry->srtt;
	ai->flags = entry->flags;
	ai->entry = entry;
	ISC_LINK_INIT(ai, publink);

	return (ai);
}

static inline void
free_adbaddrinfo(dns_adb_t *adb, dns_adbaddrinfo_t **ainfo) {
	dns_adbaddrinfo_t *ai;

	INSIST(ainfo != NULL && DNS_ADBADDRINFO_VALID(*ainfo));
	ai = *ainfo;
	*ainfo = NULL;

	INSIST(ai->entry == NULL);
	INSIST(!ISC_LINK_LINKED(ai, publink));

	ai->magic = 0;

	isc_mempool_put(adb->aimp, ai);
}

/*
 * Search for the name.  NOTE:  The bucket is kept locked on both
 * success and failure, so it must always be unlocked by the caller!
 *
 * On the first call to this function, *bucketp must be set to
 * DNS_ADB_INVALIDBUCKET.
 */
static inline dns_adbname_t *
find_name_and_lock(dns_adb_t *adb, dns_name_t *name,
		   unsigned int options, int *bucketp)
{
	dns_adbname_t *adbname;
	int bucket;

	bucket = dns_fullname_hash(name, ISC_FALSE) % NBUCKETS;

	if (*bucketp == DNS_ADB_INVALIDBUCKET) {
		LOCK(&adb->namelocks[bucket]);
		*bucketp = bucket;
	} else if (*bucketp != bucket) {
		UNLOCK(&adb->namelocks[*bucketp]);
		LOCK(&adb->namelocks[bucket]);
		*bucketp = bucket;
	}

	adbname = ISC_LIST_HEAD(adb->names[bucket]);
	while (adbname != NULL) {
		if (!NAME_DEAD(adbname)) {
			if (dns_name_equal(name, &adbname->name)
			    && GLUEHINT_OK(adbname, options)
			    && STARTATZONE_MATCHES(adbname, options))
				return (adbname);
		}
		adbname = ISC_LIST_NEXT(adbname, plink);
	}

	return (NULL);
}

/*
 * Search for the address.  NOTE:  The bucket is kept locked on both
 * success and failure, so it must always be unlocked by the caller.
 *
 * On the first call to this function, *bucketp must be set to
 * DNS_ADB_INVALIDBUCKET.  This will cause a lock to occur.  On
 * later calls (within the same "lock path") it can be left alone, so
 * if this function is called multiple times locking is only done if
 * the bucket changes.
 */
static inline dns_adbentry_t *
find_entry_and_lock(dns_adb_t *adb, isc_sockaddr_t *addr, int *bucketp) {
	dns_adbentry_t *entry;
	int bucket;

	bucket = isc_sockaddr_hash(addr, ISC_TRUE) % NBUCKETS;

	if (*bucketp == DNS_ADB_INVALIDBUCKET) {
		LOCK(&adb->entrylocks[bucket]);
		*bucketp = bucket;
	} else if (*bucketp != bucket) {
		UNLOCK(&adb->entrylocks[*bucketp]);
		LOCK(&adb->entrylocks[bucket]);
		*bucketp = bucket;
	}

	entry = ISC_LIST_HEAD(adb->entries[bucket]);
	while (entry != NULL) {
		if (isc_sockaddr_equal(addr, &entry->sockaddr))
			return (entry);
		entry = ISC_LIST_NEXT(entry, plink);
	}

	return (NULL);
}

/*
 * Entry bucket MUST be locked!
 */
static isc_boolean_t
entry_is_bad_for_zone(dns_adb_t *adb, dns_adbentry_t *entry, dns_name_t *zone,
		      isc_stdtime_t now)
{
	dns_adbzoneinfo_t *zi, *next_zi;
	isc_boolean_t is_bad;

	is_bad = ISC_FALSE;

	zi = ISC_LIST_HEAD(entry->zoneinfo);
	if (zi == NULL)
		return (ISC_FALSE);
	while (zi != NULL) {
		next_zi = ISC_LIST_NEXT(zi, plink);

		/*
		 * Has the entry expired?
		 */
		if (zi->lame_timer < now) {
			ISC_LIST_UNLINK(entry->zoneinfo, zi, plink);
			free_adbzoneinfo(adb, &zi);
		}

		/*
		 * Order tests from least to most expensive.
		 */
		if (zi != NULL && !is_bad) {
			if (dns_name_equal(zone, &zi->zone))
				is_bad = ISC_TRUE;
		}

		zi = next_zi;
	}

	return (is_bad);
}

static void
copy_namehook_lists(dns_adb_t *adb, dns_adbfind_t *find, dns_name_t *zone,
		    dns_adbname_t *name, isc_stdtime_t now)
{
	dns_adbnamehook_t *namehook;
	dns_adbaddrinfo_t *addrinfo;
	dns_adbentry_t *entry;
	int bucket;

	bucket = DNS_ADB_INVALIDBUCKET;

	if (find->options & DNS_ADBFIND_INET) {
		namehook = ISC_LIST_HEAD(name->v4);
		while (namehook != NULL) {
			entry = namehook->entry;
			bucket = entry->lock_bucket;
			LOCK(&adb->entrylocks[bucket]);

			if (!FIND_RETURNLAME(find)
			    && entry_is_bad_for_zone(adb, entry, zone, now)) {
				find->options |= DNS_ADBFIND_LAMEPRUNED;
				goto nextv4;
			}
			addrinfo = new_adbaddrinfo(adb, entry, find->port);
			if (addrinfo == NULL) {
				find->partial_result |= DNS_ADBFIND_INET;
				goto out;
			}
			/*
			 * Found a valid entry.  Add it to the find's list.
			 */
			inc_entry_refcnt(adb, entry, ISC_FALSE);
			ISC_LIST_APPEND(find->list, addrinfo, publink);
			addrinfo = NULL;
		nextv4:
			UNLOCK(&adb->entrylocks[bucket]);
			bucket = DNS_ADB_INVALIDBUCKET;
			namehook = ISC_LIST_NEXT(namehook, plink);
		}
	}

	if (find->options & DNS_ADBFIND_INET6) {
		namehook = ISC_LIST_HEAD(name->v6);
		while (namehook != NULL) {
			entry = namehook->entry;
			bucket = entry->lock_bucket;
			LOCK(&adb->entrylocks[bucket]);

			if (entry_is_bad_for_zone(adb, entry, zone, now))
				goto nextv6;
			addrinfo = new_adbaddrinfo(adb, entry, find->port);
			if (addrinfo == NULL) {
				find->partial_result |= DNS_ADBFIND_INET6;
				goto out;
			}
			/*
			 * Found a valid entry.  Add it to the find's list.
			 */
			inc_entry_refcnt(adb, entry, ISC_FALSE);
			ISC_LIST_APPEND(find->list, addrinfo, publink);
			addrinfo = NULL;
		nextv6:
			UNLOCK(&adb->entrylocks[bucket]);
			bucket = DNS_ADB_INVALIDBUCKET;
			namehook = ISC_LIST_NEXT(namehook, plink);
		}
	}

 out:
	if (bucket != DNS_ADB_INVALIDBUCKET)
		UNLOCK(&adb->entrylocks[bucket]);
}

static void
shutdown_task(isc_task_t *task, isc_event_t *ev) {
	dns_adb_t *adb;

	UNUSED(task);

	adb = ev->ev_arg;
	INSIST(DNS_ADB_VALID(adb));

	/*
	 * Kill the timer, and then the ADB itself.  Note that this implies
	 * that this task was the one scheduled to get timer events.  If
	 * this is not true (and it is unfortunate there is no way to INSIST()
	 * this) badness will occur.
	 */
	LOCK(&adb->lock);
	isc_timer_detach(&adb->timer);
	UNLOCK(&adb->lock);
	isc_event_free(&ev);
	destroy(adb);
}

/*
 * name bucket must be locked; adb may be locked; no other locks held.
 */
static isc_boolean_t
check_expire_name(dns_adbname_t **namep, isc_stdtime_t now) {
	dns_adbname_t *name;
	isc_result_t result = ISC_FALSE;

	INSIST(namep != NULL && DNS_ADBNAME_VALID(*namep));
	name = *namep;

	if (NAME_HAS_V4(name) || NAME_HAS_V6(name))
		return (result);
	if (NAME_FETCH(name))
		return (result);
	if (!EXPIRE_OK(name->expire_v4, now))
		return (result);
	if (!EXPIRE_OK(name->expire_v6, now))
		return (result);
	if (!EXPIRE_OK(name->expire_target, now))
		return (result);

	/*
	 * The name is empty.  Delete it.
	 */
	result = kill_name(&name, DNS_EVENT_ADBEXPIRED);
	*namep = NULL;

	/*
	 * Our caller, or one of its callers, will be calling check_exit() at
	 * some point, so we don't need to do it here.
	 */
	return (result);
}

/*
 * entry bucket must be locked; adb may be locked; no other locks held.
 */
static isc_boolean_t
check_expire_entry(dns_adb_t *adb, dns_adbentry_t **entryp, isc_stdtime_t now)
{
	dns_adbentry_t *entry;
	isc_boolean_t result = ISC_FALSE;

	INSIST(entryp != NULL && DNS_ADBENTRY_VALID(*entryp));
	entry = *entryp;

	if (entry->refcnt != 0)
		return (result);
	if (entry->expires == 0 || entry->expires > now)
		return (result);

	/*
	 * The entry is not in use.  Delete it.
	 */
	DP(DEF_LEVEL, "killing entry %p", entry);
	INSIST(ISC_LINK_LINKED(entry, plink));
	result = unlink_entry(adb, entry);
	free_adbentry(adb, &entry);
	if (result)
		dec_adb_irefcnt(adb);
	*entryp = NULL;
	return (result);
}

/*
 * ADB must be locked, and no other locks held.
 */
static isc_boolean_t
cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now) {