adb.c

bind-3.2.

static isc_result_t
set_target(dns_adb_t *adb, dns_name_t *name, dns_name_t *fname,
	   dns_rdataset_t *rdataset, dns_name_t *target)
{
	isc_result_t result;
	dns_namereln_t namereln;
	unsigned int nlabels, nbits;
	int order;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_fixedname_t fixed1, fixed2;
	dns_name_t *prefix, *new_target;

	REQUIRE(dns_name_countlabels(target) == 0);

	if (rdataset->type == dns_rdatatype_cname) {
		dns_rdata_cname_t cname;

		/*
		 * Copy the CNAME's target into the target name.
		 */
		result = dns_rdataset_first(rdataset);
		if (result != ISC_R_SUCCESS)
			return (result);
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_tostruct(&rdata, &cname, NULL);
		if (result != ISC_R_SUCCESS)
			return (result);
		result = dns_name_dup(&cname.cname, adb->mctx, target);
		dns_rdata_freestruct(&cname);
		if (result != ISC_R_SUCCESS)
			return (result);
	} else {
		dns_rdata_dname_t dname;

		INSIST(rdataset->type == dns_rdatatype_dname);
		namereln = dns_name_fullcompare(name, fname, &order,
						&nlabels, &nbits);
		INSIST(namereln == dns_namereln_subdomain);
		/*
		 * Get the target name of the DNAME.
		 */
		result = dns_rdataset_first(rdataset);
		if (result != ISC_R_SUCCESS)
			return (result);
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_tostruct(&rdata, &dname, NULL);
		if (result != ISC_R_SUCCESS)
			return (result);
		/*
		 * Construct the new target name.
		 */
		dns_fixedname_init(&fixed1);
		prefix = dns_fixedname_name(&fixed1);
		dns_fixedname_init(&fixed2);
		new_target = dns_fixedname_name(&fixed2);
		result = dns_name_split(name, nlabels, nbits, prefix, NULL);
		if (result != ISC_R_SUCCESS) {
			dns_rdata_freestruct(&dname);
			return (result);
		}
		result = dns_name_concatenate(prefix, &dname.dname, new_target,
					      NULL);
		dns_rdata_freestruct(&dname);
		if (result != ISC_R_SUCCESS)
			return (result);
		result = dns_name_dup(new_target, adb->mctx, target);
		if (result != ISC_R_SUCCESS)
			return (result);
	}

	return (ISC_R_SUCCESS);
}

/*
 * Assumes nothing is locked, since this is called by the client.
 */
static void
event_free(isc_event_t *event) {
	dns_adbfind_t *find;

	INSIST(event != NULL);
	find = event->ev_destroy_arg;
	INSIST(DNS_ADBFIND_VALID(find));

	LOCK(&find->lock);
	find->flags |= FIND_EVENT_FREED;
	event->ev_destroy_arg = NULL;
	UNLOCK(&find->lock);
}

/*
 * Assumes the name bucket is locked.
 */
static void
clean_finds_at_name(dns_adbname_t *name, isc_eventtype_t evtype,
		    unsigned int addrs)
{
	isc_event_t *ev;
	isc_task_t *task;
	dns_adbfind_t *find;
	dns_adbfind_t *next_find;
	isc_boolean_t process;
	unsigned int wanted, notify;

	DP(ENTER_LEVEL,
	   "ENTER clean_finds_at_name, name %p, evtype %08x, addrs %08x",
	   name, evtype, addrs);

	find = ISC_LIST_HEAD(name->finds);
	while (find != NULL) {
		LOCK(&find->lock);
		next_find = ISC_LIST_NEXT(find, plink);

		process = ISC_FALSE;
		wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
		notify = wanted & addrs;

		switch (evtype) {
		case DNS_EVENT_ADBMOREADDRESSES:
			DP(3, "DNS_EVENT_ADBMOREADDRESSES");
			if ((notify) != 0) {
				find->flags &= ~addrs;
				process = ISC_TRUE;
			}
			break;
		case DNS_EVENT_ADBNOMOREADDRESSES:
			DP(3, "DNS_EVENT_ADBNOMOREADDRESSES");
			find->flags &= ~addrs;
			wanted = find->flags & DNS_ADBFIND_ADDRESSMASK;
			if (wanted == 0)
				process = ISC_TRUE;
			break;
		default:
			find->flags &= ~addrs;
			process = ISC_TRUE;
		}

		if (process) {
			DP(DEF_LEVEL, "cfan: processing find %p", find);
			/*
			 * Unlink the find from the name, letting the caller
			 * call dns_adb_destroyfind() on it to clean it up
			 * later.
			 */
			ISC_LIST_UNLINK(name->finds, find, plink);
			find->adbname = NULL;
			find->name_bucket = DNS_ADB_INVALIDBUCKET;

			INSIST(!FIND_EVENTSENT(find));

			ev = &find->event;
			task = ev->ev_sender;
			ev->ev_sender = find;
			find->result_v4 = find_err_map[name->fetch_err];
			find->result_v6 = find_err_map[name->fetch6_err];
			ev->ev_type = evtype;
			ev->ev_destroy = event_free;
			ev->ev_destroy_arg = find;

			DP(DEF_LEVEL,
			   "Sending event %p to task %p for find %p",
			   ev, task, find);

			isc_task_sendanddetach(&task, (isc_event_t **)&ev);
		} else {
			DP(DEF_LEVEL, "cfan: skipping find %p", find);
		}

		UNLOCK(&find->lock);
		find = next_find;
	}

	DP(ENTER_LEVEL, "EXIT clean_finds_at_name, name %p", name);
}

static inline void
check_exit(dns_adb_t *adb) {
	isc_event_t *event;
	/*
	 * The caller must be holding the adb lock.
	 */
	if (adb->shutting_down) {
		/*
		 * If there aren't any external references either, we're
		 * done.  Send the control event to initiate shutdown.
		 */
		INSIST(!adb->cevent_sent);	/* Sanity check. */
		event = &adb->cevent;
		isc_task_send(adb->task, &event);
		adb->cevent_sent = ISC_TRUE;
	}
}

static inline isc_boolean_t
dec_adb_irefcnt(dns_adb_t *adb) {
	isc_event_t *event;
	isc_task_t *etask;
	isc_boolean_t result = ISC_FALSE;

	LOCK(&adb->reflock);

	INSIST(adb->irefcnt > 0);
	adb->irefcnt--;

	if (adb->irefcnt == 0) {
		event = ISC_LIST_HEAD(adb->whenshutdown);
		while (event != NULL) {
			ISC_LIST_UNLINK(adb->whenshutdown, event, ev_link);
			etask = event->ev_sender;
			event->ev_sender = adb;
			isc_task_sendanddetach(&etask, &event);
			event = ISC_LIST_HEAD(adb->whenshutdown);
		}
	}

	if (adb->irefcnt == 0 && adb->erefcnt == 0)
		result = ISC_TRUE;
	UNLOCK(&adb->reflock);
	return (result);
}

static inline void
inc_adb_irefcnt(dns_adb_t *adb) {
	LOCK(&adb->reflock);
	adb->irefcnt++;
	UNLOCK(&adb->reflock);
}

static inline void
inc_adb_erefcnt(dns_adb_t *adb) {
	LOCK(&adb->reflock);
	adb->erefcnt++;
	UNLOCK(&adb->reflock);
}

static inline void
inc_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
	int bucket;

	bucket = entry->lock_bucket;

	if (lock)
		LOCK(&adb->entrylocks[bucket]);

	entry->refcnt++;

	if (lock)
		UNLOCK(&adb->entrylocks[bucket]);
}

static inline isc_boolean_t
dec_entry_refcnt(dns_adb_t *adb, dns_adbentry_t *entry, isc_boolean_t lock) {
	int bucket;
	isc_boolean_t destroy_entry;
	isc_boolean_t result = ISC_FALSE;

	bucket = entry->lock_bucket;

	if (lock)
		LOCK(&adb->entrylocks[bucket]);

	INSIST(entry->refcnt > 0);
	entry->refcnt--;

	destroy_entry = ISC_FALSE;
	if (entry->refcnt == 0 &&
	    (adb->entry_sd[bucket] || entry->expires == 0)) {
		destroy_entry = ISC_TRUE;
		result = unlink_entry(adb, entry);
	}

	if (lock)
		UNLOCK(&adb->entrylocks[bucket]);

	if (!destroy_entry)
		return (result);

	entry->lock_bucket = DNS_ADB_INVALIDBUCKET;

	free_adbentry(adb, &entry);
	if (result)
		result =dec_adb_irefcnt(adb);
	
	return (result);
}

static inline dns_adbname_t *
new_adbname(dns_adb_t *adb, dns_name_t *dnsname) {
	dns_adbname_t *name;

	name = isc_mempool_get(adb->nmp);
	if (name == NULL)
		return (NULL);

	dns_name_init(&name->name, NULL);
	if (dns_name_dup(dnsname, adb->mctx, &name->name) != ISC_R_SUCCESS) {
		isc_mempool_put(adb->nmp, name);
		return (NULL);
	}
	dns_name_init(&name->target, NULL);
	name->magic = DNS_ADBNAME_MAGIC;
	name->adb = adb;
	name->partial_result = 0;
	name->flags = 0;
	name->expire_v4 = INT_MAX;
	name->expire_v6 = INT_MAX;
	name->expire_target = INT_MAX;
	name->chains = 0;
	name->lock_bucket = DNS_ADB_INVALIDBUCKET;
	ISC_LIST_INIT(name->v4);
	ISC_LIST_INIT(name->v6);
	name->fetch_a = NULL;
	name->fetch_aaaa = NULL;
	ISC_LIST_INIT(name->fetches_a6);
	name->fetch_err = FIND_ERR_UNEXPECTED;
	name->fetch6_err = FIND_ERR_UNEXPECTED;
	ISC_LIST_INIT(name->finds);
	ISC_LINK_INIT(name, plink);

	return (name);
}

static inline void
free_adbname(dns_adb_t *adb, dns_adbname_t **name) {
	dns_adbname_t *n;

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

	INSIST(!NAME_HAS_V4(n));
	INSIST(!NAME_HAS_V6(n));
	INSIST(!NAME_FETCH(n));
	INSIST(ISC_LIST_EMPTY(n->finds));
	INSIST(!ISC_LINK_LINKED(n, plink));
	INSIST(n->lock_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(n->adb == adb);

	n->magic = 0;
	dns_name_free(&n->name, adb->mctx);

	isc_mempool_put(adb->nmp, n);
}

static inline dns_adbnamehook_t *
new_adbnamehook(dns_adb_t *adb, dns_adbentry_t *entry) {
	dns_adbnamehook_t *nh;

	nh = isc_mempool_get(adb->nhmp);
	if (nh == NULL)
		return (NULL);

	nh->magic = DNS_ADBNAMEHOOK_MAGIC;
	nh->entry = entry;
	ISC_LINK_INIT(nh, plink);

	return (nh);
}

static inline void
free_adbnamehook(dns_adb_t *adb, dns_adbnamehook_t **namehook) {
	dns_adbnamehook_t *nh;

	INSIST(namehook != NULL && DNS_ADBNAMEHOOK_VALID(*namehook));
	nh = *namehook;
	*namehook = NULL;

	INSIST(nh->entry == NULL);
	INSIST(!ISC_LINK_LINKED(nh, plink));

	nh->magic = 0;
	isc_mempool_put(adb->nhmp, nh);
}

static inline dns_adbzoneinfo_t *
new_adbzoneinfo(dns_adb_t *adb, dns_name_t *zone) {
	dns_adbzoneinfo_t *zi;

	zi = isc_mempool_get(adb->zimp);
	if (zi == NULL)
		return (NULL);

	dns_name_init(&zi->zone, NULL);
	if (dns_name_dup(zone, adb->mctx, &zi->zone) != ISC_R_SUCCESS) {
		isc_mempool_put(adb->zimp, zi);
		return (NULL);
	}

	zi->magic = DNS_ADBZONEINFO_MAGIC;
	zi->lame_timer = 0;
	ISC_LINK_INIT(zi, plink);

	return (zi);
}

static inline void
free_adbzoneinfo(dns_adb_t *adb, dns_adbzoneinfo_t **zoneinfo) {
	dns_adbzoneinfo_t *zi;

	INSIST(zoneinfo != NULL && DNS_ADBZONEINFO_VALID(*zoneinfo));
	zi = *zoneinfo;
	*zoneinfo = NULL;

	INSIST(!ISC_LINK_LINKED(zi, plink));

	dns_name_free(&zi->zone, adb->mctx);

	zi->magic = 0;

	isc_mempool_put(adb->zimp, zi);
}

static inline dns_adbentry_t *
new_adbentry(dns_adb_t *adb) {
	dns_adbentry_t *e;
	isc_uint32_t r;

	e = isc_mempool_get(adb->emp);
	if (e == NULL)
		return (NULL);

	e->magic = DNS_ADBENTRY_MAGIC;
	e->lock_bucket = DNS_ADB_INVALIDBUCKET;
	e->refcnt = 0;
	e->flags = 0;
	isc_random_get(&r);
	e->srtt = (r & 0x1f) + 1;
	e->expires = 0;
	ISC_LIST_INIT(e->zoneinfo);
	ISC_LINK_INIT(e, plink);

	return (e);
}

static inline void
free_adbentry(dns_adb_t *adb, dns_adbentry_t **entry) {
	dns_adbentry_t *e;
	dns_adbzoneinfo_t *zi;

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

	INSIST(e->lock_bucket == DNS_ADB_INVALIDBUCKET);
	INSIST(e->refcnt == 0);
	INSIST(!ISC_LINK_LINKED(e, plink));

	e->magic = 0;

	zi = ISC_LIST_HEAD(e->zoneinfo);
	while (zi != NULL) {
		ISC_LIST_UNLINK(e->zoneinfo, zi, plink);
		free_adbzoneinfo(adb, &zi);
		zi = ISC_LIST_HEAD(e->zoneinfo);
	}

	isc_mempool_put(adb->emp, e);
}

static inline dns_adbfind_t *
new_adbfind(dns_adb_t *adb) {
	dns_adbfind_t *h;
	isc_result_t result;

	h = isc_mempool_get(adb->ahmp);
	if (h == NULL)
		return (NULL);

	/*
	 * Public members.
	 */
	h->magic = 0;
	h->adb = adb;
	h->partial_result = 0;
	h->options = 0;
	h->flags = 0;
	h->result_v4 = ISC_R_UNEXPECTED;
	h->result_v6 = ISC_R_UNEXPECTED;
	ISC_LINK_INIT(h, publink);
	ISC_LINK_INIT(h, plink);
	ISC_LIST_INIT(h->list);
	h->adbname = NULL;
	h->name_bucket = DNS_ADB_INVALIDBUCKET;

	/*
	 * private members
	 */
	result = isc_mutex_init(&h->lock);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init failed in new_adbfind()");
		isc_mempool_put(adb->ahmp, h);
		return (NULL);
	}

	ISC_EVENT_INIT(&h->event, sizeof (isc_event_t), 0, 0, 0, NULL, NULL,
		       NULL, NULL, h);

	inc_adb_irefcnt(adb);
	h->magic = DNS_ADBFIND_MAGIC;
	return (h);
}

static inline dns_adbfetch_t *
new_adbfetch(dns_adb_t *adb) {
	dns_adbfetch_t *f;

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

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