From 2fbb9b9ce1b55257c3aad6a43df8f0c08456db2f Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 31 Jul 2014 08:54:17 +0200
Subject: [PATCH] s4:dns_server: make sure dns_common_lookup() doesn't return
 tombstones

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 a0a81ab01cb1d509b04f9af25177c8e0941b43aa)
---
 source4/dns_server/dns_utils.c        |  3 +-
 source4/dns_server/dnsserver_common.c | 53 ++++++++++++++++++++++++++++++++---
 source4/dns_server/dnsserver_common.h |  3 +-
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/source4/dns_server/dns_utils.c b/source4/dns_server/dns_utils.c
index c3a27fea5bb..c757c157626 100644
--- a/source4/dns_server/dns_utils.c
+++ b/source4/dns_server/dns_utils.c
@@ -154,7 +154,8 @@ WERROR dns_lookup_records(struct dns_server *dns,
 			  struct dnsp_DnssrvRpcRecord **records,
 			  uint16_t *rec_count)
 {
-	return dns_common_lookup(dns->samdb, mem_ctx, dn, records, rec_count);
+	return dns_common_lookup(dns->samdb, mem_ctx, dn,
+				 records, rec_count, NULL);
 }
 
 WERROR dns_replace_records(struct dns_server *dns,
diff --git a/source4/dns_server/dnsserver_common.c b/source4/dns_server/dnsserver_common.c
index 3a777e5c1eb..28667343471 100644
--- a/source4/dns_server/dnsserver_common.c
+++ b/source4/dns_server/dnsserver_common.c
@@ -104,10 +104,12 @@ WERROR dns_common_lookup(struct ldb_context *samdb,
 			 TALLOC_CTX *mem_ctx,
 			 struct ldb_dn *dn,
 			 struct dnsp_DnssrvRpcRecord **records,
-			 uint16_t *num_records)
+			 uint16_t *num_records,
+			 bool *tombstoned)
 {
 	static const char * const attrs[] = {
 		"dnsRecord",
+		"dNSTombstoned",
 		NULL
 	};
 	int ret;
@@ -118,9 +120,16 @@ WERROR dns_common_lookup(struct ldb_context *samdb,
 	*records = NULL;
 	*num_records = 0;
 
-	ret = dsdb_search_one(samdb, mem_ctx, &msg, dn,
-			      LDB_SCOPE_BASE, attrs, 0,
-			      "(objectClass=dnsNode)");
+	if (tombstoned != NULL) {
+		*tombstoned = false;
+		ret = dsdb_search_one(samdb, mem_ctx, &msg, dn,
+			LDB_SCOPE_BASE, attrs, 0,
+			"(objectClass=dnsNode)");
+	} else {
+		ret = dsdb_search_one(samdb, mem_ctx, &msg, dn,
+			LDB_SCOPE_BASE, attrs, 0,
+			"(&(objectClass=dnsNode)(!(dNSTombstoned=TRUE)))");
+	}
 	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
 		return WERR_DNS_ERROR_NAME_DOES_NOT_EXIST;
 	}
@@ -130,9 +139,45 @@ WERROR dns_common_lookup(struct ldb_context *samdb,
 		return DNS_ERR(NAME_ERROR);
 	}
 
+	if (tombstoned != NULL) {
+		*tombstoned = ldb_msg_find_attr_as_bool(msg,
+					"dNSTombstoned", false);
+	}
+
 	el = ldb_msg_find_element(msg, "dnsRecord");
 	if (el == NULL) {
 		TALLOC_FREE(msg);
+		if (tombstoned != NULL) {
+			struct dnsp_DnssrvRpcRecord *recs;
+			/*
+			 * records produced by older Samba releases
+			 * keep dnsNode objects without dnsRecord and
+			 * without setting dNSTombstoned=TRUE.
+			 *
+			 * We just pretend they're tombstones.
+			 */
+			recs = talloc_array(mem_ctx,
+					    struct dnsp_DnssrvRpcRecord,
+					    1);
+			if (recs == NULL) {
+				return WERR_NOMEM;
+			}
+			recs[0] = (struct dnsp_DnssrvRpcRecord) {
+				.wType = DNS_TYPE_TOMBSTONE,
+				/*
+				 * A value of timestamp != 0
+				 * indicated that the object was already
+				 * a tombstone, this will be used
+				 * in dns_common_replace()
+				 */
+				.data.timestamp = 1,
+			};
+
+			*tombstoned = true;
+			*records = recs;
+			*num_records = 1;
+			return WERR_OK;
+		}
 		return DNS_ERR(NAME_ERROR);
 	}
 
diff --git a/source4/dns_server/dnsserver_common.h b/source4/dns_server/dnsserver_common.h
index 1117ad11910..becd243f6a9 100644
--- a/source4/dns_server/dnsserver_common.h
+++ b/source4/dns_server/dnsserver_common.h
@@ -36,7 +36,8 @@ WERROR dns_common_lookup(struct ldb_context *samdb,
 			 TALLOC_CTX *mem_ctx,
 			 struct ldb_dn *dn,
 			 struct dnsp_DnssrvRpcRecord **records,
-			 uint16_t *num_records);
+			 uint16_t *num_records,
+			 bool *tombstoned);
 
 WERROR dns_common_replace(struct ldb_context *samdb,
 			  TALLOC_CTX *mem_ctx,
-- 
2.11.4.GIT