registry: Implement recursive deletes for ldb-backed registry.

When deleting a registry key that contains subkeys or values, Windows performs a
recursive deletion that removes any subkeys or values.  This update makes
deletes for an ldb-backed registry consistent with Windows.

Under ldb, the deletion is done using an explicit transaction.  If an error
occurs during the deletion the entire transaction is cancelled, leaving the
registry as it was before the deletions started.
(This used to be commit ca796c8fb10598674a5eef31d15863e79bcf3db8)

1 files changed, 116 insertions, 27 deletions

diff --git a/source4/lib/registry/ldb.c b/source4/lib/registry/ldb.c
index 0c8a55396e..31b78d8246 100644
--- a/source4/lib/registry/ldb.c
+++ b/source4/lib/registry/ldb.c
@@ -440,33 +440,6 @@ static WERROR ldb_add_key(TALLOC_CTX *mem_ctx, const struct hive_key *parent,
 	return WERR_OK;
 }
 
-static WERROR ldb_del_key(const struct hive_key *key, const char *name)
-{
-	int ret;
-	struct ldb_key_data *parentkd = talloc_get_type(key, struct ldb_key_data);
-	struct ldb_dn *ldap_path;
-	TALLOC_CTX *mem_ctx = talloc_init("ldb_del_key");
-
-	ldap_path = reg_path_to_ldb(mem_ctx, key, name, NULL);
-
-	ret = ldb_delete(parentkd->ldb, ldap_path);
-
-	talloc_free(mem_ctx);
-
-	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
-		return WERR_BADFILE;
-	} else if (ret != LDB_SUCCESS) {
-		DEBUG(1, ("ldb_del_key: %s\n", ldb_errstring(parentkd->ldb)));
-		return WERR_FOOBAR;
-	}
-
-	/* reset cache */
-	talloc_free(parentkd->subkeys);
-	parentkd->subkeys = NULL;
-
-	return WERR_OK;
-}
-
 static WERROR ldb_del_value (struct hive_key *key, const char *child)
 {
 	int ret;
@@ -499,6 +472,122 @@ static WERROR ldb_del_value (struct hive_key *key, const char *child)
 	return WERR_OK;
 }
 
+static WERROR ldb_del_key(const struct hive_key *key, const char *name)
+{
+	int i, ret;
+	struct ldb_key_data *parentkd = talloc_get_type(key, struct ldb_key_data);
+	struct ldb_dn *ldap_path;
+	TALLOC_CTX *mem_ctx = talloc_init("ldb_del_key");
+	struct ldb_context *c = parentkd->ldb;
+	struct ldb_result *res_keys;
+	struct ldb_result *res_vals;
+	WERROR werr;
+	struct hive_key *hk;
+
+	/* Verify key exists by opening it */
+	werr = ldb_open_key(mem_ctx, key, name, &hk);
+	if (!W_ERROR_IS_OK(werr)) {
+		talloc_free(mem_ctx);
+		return werr;
+	}
+
+	ldap_path = reg_path_to_ldb(mem_ctx, key, name, NULL);
+	if (!ldap_path) {
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	/* Search for subkeys */
+	ret = ldb_search(c, ldap_path, LDB_SCOPE_ONELEVEL,
+			 "(key=*)", NULL, &res_keys);
+
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0, ("Error getting subkeys for '%s': %s\n",
+		      ldb_dn_get_linearized(ldap_path), ldb_errstring(c)));
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	/* Search for values */
+	ret = ldb_search(c, ldap_path, LDB_SCOPE_ONELEVEL,
+			 "(value=*)", NULL, &res_vals);
+
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0, ("Error getting values for '%s': %s\n",
+		      ldb_dn_get_linearized(ldap_path), ldb_errstring(c)));
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	/* Start an explicit transaction */
+	ret = ldb_transaction_start(c);
+
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0, ("ldb_transaction_start: %s\n", ldb_errstring(c)));
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	if (res_keys->count || res_vals->count)
+	{
+		/* Delete any subkeys */
+		for (i = 0; i < res_keys->count; i++)
+		{
+			werr = ldb_del_key(hk, ldb_msg_find_attr_as_string(
+							res_keys->msgs[i],
+							"key", NULL));
+			if (!W_ERROR_IS_OK(werr)) {
+				ret = ldb_transaction_cancel(c);
+				talloc_free(mem_ctx);
+				return werr;
+			}
+		}
+
+		/* Delete any values */
+		for (i = 0; i < res_vals->count; i++)
+		{
+			werr = ldb_del_value(hk, ldb_msg_find_attr_as_string(
+							res_vals->msgs[i],
+							"value", NULL));
+			if (!W_ERROR_IS_OK(werr)) {
+				ret = ldb_transaction_cancel(c);
+				talloc_free(mem_ctx);
+				return werr;
+			}
+		}
+	}
+
+	/* Delete the key itself */
+	ret = ldb_delete(c, ldap_path);
+
+	if (ret != LDB_SUCCESS)
+	{
+		DEBUG(1, ("ldb_del_key: %s\n", ldb_errstring(c)));
+		ret = ldb_transaction_cancel(c);
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	/* Commit the transaction */
+	ret = ldb_transaction_commit(c);
+
+	if (ret != LDB_SUCCESS)
+	{
+		DEBUG(0, ("ldb_transaction_commit: %s\n", ldb_errstring(c)));
+		ret = ldb_transaction_cancel(c);
+		talloc_free(mem_ctx);
+		return WERR_FOOBAR;
+	}
+
+	talloc_free(mem_ctx);
+
+	/* reset cache */
+	talloc_free(parentkd->subkeys);
+	parentkd->subkeys = NULL;
+
+	return WERR_OK;
+}
+
 static WERROR ldb_set_value(struct hive_key *parent,
 			    const char *name, uint32_t type,
 			    const DATA_BLOB data)