Move LMDB common definitions in a dedicated header

As several places uses custom LMDB macros, this centralize those
definitions inside a dedicated `lib/isc/include/isc/lmdb.h` header
file, so future uses cases not DNS-centrics could fit into there as
well.

MDB_CREATE is removed as well because:

- it was useless (it's needed only for named DB, which is not the case
  for all use case so far)

- it was used in `mdb_env_open` which is not expecting this flag: it
  should be passed (if needed) to `mdb_dbi_open`. It was likely
  ignored so far.

bin/named/server.c

@@ -45,6 +45,7 @@
 #include <isc/httpd.h>
 #include <isc/job.h>
 #include <isc/lex.h>
+#include <isc/lmdb.h>
 #include <isc/loop.h>
 #include <isc/meminfo.h>
 #include <isc/netmgr.h>

bin/tools/named-nzd2nzf.c

@@ -11,13 +11,10 @@
  * information regarding copyright ownership.
  */
 
-#include <lmdb.h>
 #include <stdio.h>
 #include <stdlib.h>
-
 #include <isc/lib.h>
-
-/* Included just to get DNS_LMDB_FLAGS definition */
+#include <isc/lmdb.h>
 #include <dns/view.h>
 
 int

lib/dns/include/dns/view.h

@@ -248,17 +248,6 @@ struct dns_view {
 #define DNS_VIEWATTR_ADBSHUTDOWN 0x02
 #define DNS_VIEWATTR_REQSHUTDOWN 0x04
 
-#define DNS_LMDB_COMMON_FLAGS (MDB_CREATE | MDB_NOSUBDIR | MDB_NOLOCK)
-#ifndef __OpenBSD__
-#define DNS_LMDB_FLAGS (DNS_LMDB_COMMON_FLAGS)
-#else /* __OpenBSD__ */
-/*
- * OpenBSD does not have a unified buffer cache, which requires both reads and
- * writes to be performed using mmap().
- */
-#define DNS_LMDB_FLAGS (DNS_LMDB_COMMON_FLAGS | MDB_WRITEMAP)
-#endif /* __OpenBSD__ */
-
 void
 dns_view_create(isc_mem_t *mctx, isc_loopmgr_t *loopmgr,
 		dns_dispatchmgr_t *dispmgr, dns_rdataclass_t rdclass,

lib/dns/view.c

@@ -15,7 +15,6 @@
 
 #include <inttypes.h>
 #include <limits.h>
-#include <lmdb.h>
 #include <stdbool.h>
 
 #include <isc/atomic.h>
@@ -23,6 +22,7 @@
 #include <isc/file.h>
 #include <isc/hash.h>
 #include <isc/lex.h>
+#include <isc/lmdb.h>
 #include <isc/md.h>
 #include <isc/result.h>
 #include <isc/stats.h>

lib/isc/Makefile.am

@@ -45,6 +45,7 @@ libisc_la_HEADERS =			\
 	include/isc/lex.h		\
 	include/isc/lib.h		\
 	include/isc/list.h		\
+	include/isc/lmdb.h		\
 	include/isc/log.h		\
 	include/isc/loop.h		\
 	include/isc/magic.h		\

lib/isc/cfgmgr.c

@@ -11,17 +11,17 @@
  * information regarding copyright ownership.
  */
 
-#include <lmdb.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <isc/cfgmgr.h>
 #include <isc/list.h>
+#include <isc/lmdb.h>
 #include <isc/mem.h>
 #include <isc/random.h>
 #include <isc/thread.h>
 #include <isc/util.h>
-#include <isc/cfgmgr.h>
 
 /*
  * See MDB_MAXKEYSIZE documentation, but not accessible as defined in

lib/isc/include/isc/lmdb.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#pragma once
+
+#include <lmdb.h>
+
+#define DNS_LMDB_COMMON_FLAGS (MDB_NOSUBDIR | MDB_NOLOCK)
+#ifndef __OpenBSD__
+#define DNS_LMDB_FLAGS (DNS_LMDB_COMMON_FLAGS)
+#else /* __OpenBSD__ */
+/*
+ * OpenBSD does not have a unified buffer cache, which requires both reads and
+ * writes to be performed using mmap().
+ */
+#define DNS_LMDB_FLAGS (DNS_LMDB_COMMON_FLAGS | MDB_WRITEMAP)
+#endif /* __OpenBSD__ */