From: Colin Vidal <colin@isc.org>
Date: Sat, 28 Mar 2026 09:02:22 +0000 (+0100)
Subject: Add dns_adb_createaddrinfosfind() for address-based lookups
X-Git-Tag: v9.21.21~4^2~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cfac5f3974b1df6c6e21384467148ea146a1723f;p=thirdparty%2Fbind9.git

Add dns_adb_createaddrinfosfind() for address-based lookups

Add a new ADB API function that creates a find from a list of addresses
rather than by looking up nameserver names.  This enables the resolver
to handle address-based delegations (NS-based with glues or DELEG with
addresses) and name-based delegations uniformly (i.e. the list of finds
from ADB is handled the same way no matter the type of the delegation).
---

diff --git a/lib/dns/adb.c b/lib/dns/adb.c
index db984019e8e..6c02ed86a46 100644
--- a/lib/dns/adb.c
+++ b/lib/dns/adb.c
@@ -1714,6 +1714,86 @@ dns_adb_shutdown(dns_adb_t *adb) {
 	isc_async_run(isc_loop_main(), dns_adb_shutdown_async, adb);
 }
 
+static void
+findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *addr,
+	     dns_adbaddrinfo_t **adbaddrp, isc_stdtime_t now) {
+	dns_adbentry_t *adbentry = get_attached_and_locked_entry(adb, now,
+								 addr);
+
+	in_port_t port = isc_sockaddr_getport(addr);
+	*adbaddrp = new_adbaddrinfo(adb, adbentry, port);
+
+	UNLOCK(&adbentry->lock);
+	dns_adbentry_detach(&adbentry);
+}
+
+isc_result_t
+dns_adb_createaddrinfosfind(dns_adb_t *adb, isc_netaddrlist_t *addrs,
+			    in_port_t port, unsigned int options,
+			    isc_stdtime_t now, size_t maxaddrs,
+			    dns_adbfind_t **findp, size_t *findlen) {
+	isc_result_t result = ISC_R_SUCCESS;
+	dns_adbfind_t *find = NULL;
+	isc_sockaddr_t sockaddr = {};
+
+	REQUIRE(DNS_ADB_VALID(adb));
+	REQUIRE(addrs != NULL);
+	REQUIRE(findp != NULL && *findp == NULL);
+
+	rcu_read_lock();
+
+	if (atomic_load(&adb->shuttingdown)) {
+		CLEANUP(ISC_R_SHUTTINGDOWN);
+	}
+
+	if (now == 0) {
+		now = isc_stdtime_now();
+	}
+
+	find = new_adbfind(adb, port);
+	ISC_LIST_FOREACH(*addrs, addrlink, link) {
+		dns_adbaddrinfo_t *addrinfo = NULL;
+
+		sockaddr.type.sa.sa_family = addrlink->addr.family;
+		switch (addrlink->addr.family) {
+		case AF_INET:
+			if ((options & DNS_ADBFIND_INET) == 0) {
+				continue;
+			}
+			sockaddr.type.sin.sin_addr = addrlink->addr.type.in;
+			sockaddr.type.sin.sin_port = htons(port);
+			break;
+		case AF_INET6:
+			if ((options & DNS_ADBFIND_INET6) == 0) {
+				continue;
+			}
+			/*
+			 * TODO: findaddrinfo() compares the scope, this might
+			 * be a problem...
+			 */
+			sockaddr.type.sin6.sin6_addr = addrlink->addr.type.in6;
+			sockaddr.type.sin6.sin6_port = htons(port);
+
+			break;
+		default:
+			UNREACHABLE();
+		}
+
+		findaddrinfo(adb, &sockaddr, &addrinfo, now);
+		ISC_LIST_APPEND(find->list, addrinfo, publink);
+		(*findlen)++;
+
+		if (maxaddrs - *findlen == 0) {
+			break;
+		}
+	}
+
+	*findp = find;
+cleanup:
+	rcu_read_unlock();
+	return result;
+}
+
 /*
  * Look up the name in our internal database.
  *
@@ -3137,14 +3217,7 @@ dns_adb_findaddrinfo(dns_adb_t *adb, const isc_sockaddr_t *addr,
 		return ISC_R_SHUTTINGDOWN;
 	}
 
-	dns_adbentry_t *adbentry = get_attached_and_locked_entry(adb, now,
-								 addr);
-
-	in_port_t port = isc_sockaddr_getport(addr);
-	*adbaddrp = new_adbaddrinfo(adb, adbentry, port);
-
-	UNLOCK(&adbentry->lock);
-	dns_adbentry_detach(&adbentry);
+	findaddrinfo(adb, addr, adbaddrp, now);
 
 	rcu_read_unlock();
 
diff --git a/lib/dns/include/dns/adb.h b/lib/dns/include/dns/adb.h
index 399e665ee8b..157f8da0b2b 100644
--- a/lib/dns/include/dns/adb.h
+++ b/lib/dns/include/dns/adb.h
@@ -346,6 +346,18 @@ dns_adb_createfind(dns_adb_t *adb, isc_loop_t *loop, isc_job_cb cb, void *cbarg,
  *	returns.
  */
 
+isc_result_t
+dns_adb_createaddrinfosfind(dns_adb_t *adb, isc_netaddrlist_t *addrs,
+			    in_port_t port, unsigned int options,
+			    isc_stdtime_t now, size_t maxaddrs,
+			    dns_adbfind_t **findp, size_t *findlen);
+/*%<
+ * Variant of `dns_adb_createfind()` which actually internally looks up
+ * addresses only using `dns_adb_findaddrinfo()`. This enables the caller to
+ * abstract the origin of the find (i.e. it needs to be names to be looked up
+ * into `dns_adbaddrinfo_t`, or from net addrs) and handle it the same way.
+ */
+
 void
 dns_adb_cancelfind(dns_adbfind_t *find);
 /*%<