s4:dns_server: map LDB_ERR_NO_SUCH_OBJECT to WERR_DNS_ERROR_NAME_DOES_NOT_EXIST

This is the correct fix for commit 8b24c43b382740106474e26dec59e1419ba77306
and Bug: https://bugzilla.samba.org/show_bug.cgi?id=9559

With this change we have a consistent behavior between internal server
and the bind dlz module. We keep a dangling LDAP object without
dnsRecord attribute arround forever. This will be fixed in the following
commits.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=10749

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Michael Adam <obnox@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit d0f424a23dc915d9fce625438d2bd63519757cba)

2 files changed, 24 insertions, 14 deletions

diff --git a/source4/dns_server/dns_update.c b/source4/dns_server/dns_update.c
index 9edc40bc341..c439d8d27ba 100644
--- a/source4/dns_server/dns_update.c
+++ b/source4/dns_server/dns_update.c
@@ -82,6 +82,9 @@ static WERROR check_one_prerequisite(struct dns_server *dns,
 			/*
 			 */
 			werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
+			if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
+				return DNS_ERR(NAME_ERROR);
+			}
 			W_ERROR_NOT_OK_RETURN(werror);
 
 			if (acount == 0) {
@@ -91,6 +94,9 @@ static WERROR check_one_prerequisite(struct dns_server *dns,
 			/*
 			 */
 			werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
+			if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
+				return DNS_ERR(NXRRSET);
+			}
 			if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 				return DNS_ERR(NXRRSET);
 			}
@@ -131,10 +137,11 @@ static WERROR check_one_prerequisite(struct dns_server *dns,
 			/*
 			 */
 			werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
+			if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
+				werror = WERR_OK;
+			}
 			if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 				werror = WERR_OK;
-				ans = NULL;
-				acount = 0;
 			}
 
 			for (i = 0; i < acount; i++) {
@@ -163,6 +170,9 @@ static WERROR check_one_prerequisite(struct dns_server *dns,
 	*final_result = false;
 
 	werror = dns_lookup_records(dns, mem_ctx, dn, &ans, &acount);
+	if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
+		return DNS_ERR(NXRRSET);
+	}
 	if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
 		return DNS_ERR(NXRRSET);
 	}
@@ -421,12 +431,13 @@ static WERROR handle_one_update(struct dns_server *dns,
 	W_ERROR_NOT_OK_RETURN(werror);
 
 	werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rcount);
-	if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
-		recs = NULL;
-		rcount = 0;
+	if (W_ERROR_EQUAL(werror, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST)) {
 		needs_add = true;
 		werror = WERR_OK;
 	}
+	if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
+		werror = WERR_OK;
+	}
 	W_ERROR_NOT_OK_RETURN(werror);
 
 	if (update->rr_class == zone->question_class) {
diff --git a/source4/dns_server/dns_utils.c b/source4/dns_server/dns_utils.c
index 86f7e7cd192..14ca2f41738 100644
--- a/source4/dns_server/dns_utils.c
+++ b/source4/dns_server/dns_utils.c
@@ -194,8 +194,14 @@ WERROR dns_lookup_records(struct dns_server *dns,
 	struct ldb_message *msg = NULL;
 	struct dnsp_DnssrvRpcRecord *recs;
 
+	*records = NULL;
+	*rec_count = 0;
+
 	ret = dsdb_search_one(dns->samdb, mem_ctx, &msg, dn,
 			      LDB_SCOPE_BASE, attrs, 0, "%s", "(objectClass=dnsNode)");
+	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
+		return WERR_DNS_ERROR_NAME_DOES_NOT_EXIST;
+	}
 	if (ret != LDB_SUCCESS) {
 		/* TODO: we need to check if there's a glue record we need to
 		 * create a referral to */
@@ -204,8 +210,6 @@ WERROR dns_lookup_records(struct dns_server *dns,
 
 	el = ldb_msg_find_element(msg, attrs[0]);
 	if (el == NULL) {
-		*records = NULL;
-		*rec_count = 0;
 		return DNS_ERR(NAME_ERROR);
 	}
 
@@ -278,13 +282,8 @@ WERROR dns_replace_records(struct dns_server *dns,
 		if (needs_add) {
 			return WERR_OK;
 		}
-		/* No entries left, delete the dnsNode object */
-		ret = ldb_delete(dns->samdb, msg->dn);
-		if (ret != LDB_SUCCESS) {
-			DEBUG(0, ("Deleting record failed; %d\n", ret));
-			return DNS_ERR(SERVER_FAILURE);
-		}
-		return WERR_OK;
+		/* TODO: Delete object? */
+		el->flags = LDB_FLAG_MOD_DELETE;
 	}
 
 	if (needs_add) {