catalog: check catalog zone version

doc/configuration.rst

@@ -600,7 +600,8 @@ and ACLs. Being a catalog zone is indicated by setting the option
 :ref:`zone_catalog-template`. The difference is that standard DNS
 queries to a catalog zone are answered with REFUSED as if such a zone
 wouldn't exist, unless querying from an address with transfers enabled
-by ACL. The name of the catalog zone is arbitrary.
+by ACL. The name of the catalog zone is arbitrary. It's however required to
+include version record ``version 0 IN TXT "2"``.
 It's possible to configure more catalog zones.
 
 .. WARNING::

src/knot/updates/zone-update.c

@@ -717,19 +717,24 @@ static int update_catalog(conf_t *conf, zone_update_t *update)
 
 	int ret = KNOT_EOK;
 	if ((update->flags & UPDATE_INCREMENTAL)) {
-		ret = knot_cat_update_from_zone(update->zone->catalog_upd, update->change.remove, true, update->zone->catalog);
+		ret = knot_cat_update_from_zone(update->zone->catalog_upd, update->change.remove,
+		                                true, false, update->zone->catalog);
 		if (ret == KNOT_EOK) {
-			ret = knot_cat_update_from_zone(update->zone->catalog_upd, update->change.add, false, NULL);
+			ret = knot_cat_update_from_zone(update->zone->catalog_upd,
+			                                update->change.add, false, false, NULL);
 		}
 	} else {
 		ret = knot_cat_update_del_all(update->zone->catalog_upd, update->zone->catalog, update->zone->name);
 		if (ret == KNOT_EOK) {
-			ret = knot_cat_update_from_zone(update->zone->catalog_upd, update->zone->contents, false, NULL);
+			ret = knot_cat_update_from_zone(update->zone->catalog_upd,
+			                                update->zone->contents, false, true, NULL);
 		}
 	}
 
 	if (ret == KNOT_EOK) {
-		kill(getpid(), SIGUSR1);
+		if (kill(getpid(), SIGUSR1) != 0) {
+			ret = knot_map_errno();
+		}
 	}
 
 	return ret;
@@ -874,9 +879,12 @@ int zone_update_commit(conf_t *conf, zone_update_t *update)
 	zone_contents_t *old_contents;
 	old_contents = zone_switch_contents(update->zone, update->new_cont);
 
-	ret = commit_catalog(conf, update);
-	if (ret != KNOT_EOK) {
-		log_zone_warning(update->zone->name, "catalog zone not fully populated (%s)", knot_strerror(ret));
+	ret = update_catalog(conf, update);
+	if (ret == KNOT_EZONEINVAL) {
+		log_zone_warning(update->zone->name, "invalid catalog zone version");
+	} else if (ret != KNOT_EOK) {
+		log_zone_warning(update->zone->name, "catalog zone not fully populated (%s)",
+		                 knot_strerror(ret));
 	}
 
 	if (update->flags & (UPDATE_INCREMENTAL | UPDATE_HYBRID)) {

src/knot/zone/catalog.c

@@ -26,9 +26,33 @@
 #include "knot/zone/contents.h"
 
 #define CATALOG_VERSION "1.0"
+#define CATALOG_ZONE_VERSION "2" // must be just one char long
 
 const MDB_val knot_catalog_iter_prefix = { 1, "" };
 
+static bool check_zone_version(const zone_contents_t *zone)
+{
+	size_t zone_size = knot_dname_size(zone->apex->owner);
+	knot_dname_t sub[zone_size + 8];
+	memcpy(sub, "\x07""version", 8);
+	memcpy(sub + 8, zone->apex->owner, zone_size);
+
+	const zone_node_t *ver_node = zone_contents_find_node(zone, sub);
+	knot_rdataset_t *ver_rr = node_rdataset(ver_node, KNOT_RRTYPE_TXT);
+	if (ver_rr == NULL) {
+		return false;
+	}
+
+	knot_rdata_t *rd = ver_rr->rdata;
+	for (int i = 0; i < ver_rr->count; i++) {
+		if (rd->len == 2 && rd->data[1] == CATALOG_ZONE_VERSION[0]) {
+			return true;
+		}
+		rd = knot_rdataset_next(rd);
+	}
+	return false;
+}
+
 void knot_catalog_init(knot_catalog_t *cat, const char *path, size_t mapsize)
 {
 	knot_lmdb_init(&cat->db, path, mapsize, 0, NULL);
@@ -325,8 +349,12 @@ static int cat_update_add_node(zone_node_t *node, void *data)
 }
 
 int knot_cat_update_from_zone(knot_cat_update_t *u, struct zone_contents *zone,
-                              bool remove, knot_catalog_t *check)
+                              bool remove, bool check_ver, knot_catalog_t *check)
 {
+	if (check_ver && !check_zone_version(zone)) {
+		return KNOT_EZONEINVAL;
+	}
+
 	size_t zone_size = knot_dname_size(zone->apex->owner);
 	knot_dname_t sub[zone_size + 6];
 	memcpy(sub, "\x05""zones", 6);

src/knot/zone/catalog.h

@@ -101,7 +101,7 @@ knot_cat_upd_val_t *knot_cat_update_get(knot_cat_update_t *u, const knot_dname_t
 struct zone_contents;
 
 int knot_cat_update_from_zone(knot_cat_update_t *u, struct zone_contents *zone,
-                              bool remove, knot_catalog_t *check);
+                              bool remove, bool check_ver, knot_catalog_t *check);
 
 int knot_cat_update_del_all(knot_cat_update_t *u, knot_catalog_t *cat, const knot_dname_t *zone);
 

tests-extra/tests/zone/catalog/data/catalog1.zone

@@ -4,5 +4,6 @@ $TTL 0
 @ SOA ns admin 1 25 25 80 600
   NS ns
 ns AAAA ::0
+version TXT "2"
 foo.bar.zones PTR cataloged1.
 not.zones.in PTR not-cataloged1.