From: Martin Schwenke <mschwenke@ddn.com>
Date: Wed, 10 May 2023 02:21:07 +0000 (+1000)
Subject: ctdb-failover: Add ctdb_smnotify_helper
X-Git-Tag: tdb-1.4.13~1249
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d89506449fc01debc4013de9afe7f5784019806f;p=thirdparty%2Fsamba.git

ctdb-failover: Add ctdb_smnotify_helper

statd callout will shortly be updated to use NFS utils' sm-notify.
This tiny helper will be used to create on-disk state files used by
sm-notify.  These state files contain endian-specific fields, so
better to write a simple C implementation than to do crazy things in a
shell script (or call out to Python).

Signed-off-by: Martin Schwenke <mschwenke@ddn.com>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
---

diff --git a/ctdb/failover/smnotify_helper.c b/ctdb/failover/smnotify_helper.c
new file mode 100644
index 00000000000..539537bbb5c
--- /dev/null
+++ b/ctdb/failover/smnotify_helper.c
@@ -0,0 +1,81 @@
+/*
+   CTDB SM_NOTIFY helper for NFSv3 statd snippets
+
+   Copyright 2023, DataDirect Networks, Inc. All rights reserved.
+   Author: Martin Schwenke <mschwenke@ddn.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/network.h"
+
+#include "lib/util/sys_rw.h"
+
+static void print_monitor_line(const char *client_ip,
+			       const char *server_ip)
+{
+	/*
+	 * sm-notify doesn't read priv.  rpc.statd appears to use it
+	 * for uniqueness of multi-line files.
+	 */
+	const char *priv = "00000000000000000000000000000000";
+	/*
+	 * sm_mon_1_svc() takes care to write in this format, so let's
+	 * do that too, even though sm-notify ignores this field...
+	 */
+	uint32_t inaddr_loopback = htonl(INADDR_LOOPBACK);
+
+	printf("%08x %08x %08x %08x %s %s %s\n",
+	       inaddr_loopback,
+	       100021, /* NLM_PROG */
+	       4, /* SM_VERS */
+	       16,
+	       priv,
+	       client_ip,
+	       server_ip);
+}
+
+static void print_state(const char *state_str)
+{
+	int state = atoi(state_str);
+
+	/*
+	 * Uncomplicated binary output.  sm-notify just reads this as
+	 * an int via nsm_get_state().  This file will always be
+	 * created in a local temporary directory and is consumed by
+	 * sm-notify locally, so no inter-node endianness issues.
+	 */
+	sys_write(STDOUT_FILENO, &state, sizeof(state));
+}
+
+static void usage(const char *prog)
+{
+	printf("usage: %s { monitor <client-ip> <source-ip> | state <state> }\n",
+	       prog);
+	exit(1);
+}
+
+int main(int argc, const char *argv[])
+{
+	if (argc == 4 && strcmp(argv[1], "monitor") == 0) {
+		print_monitor_line(argv[2], argv[3]);
+	} else if (argc == 3 && strcmp(argv[1], "state") == 0) {
+		print_state(argv[2]);
+	} else {
+		usage(argv[0]);
+	}
+
+	return 0;
+}
diff --git a/ctdb/wscript b/ctdb/wscript
index 855989a2493..170965ac774 100644
--- a/ctdb/wscript
+++ b/ctdb/wscript
@@ -685,6 +685,11 @@ def build(bld):
                      includes='include',
                      install_path='${CTDB_HELPER_BINDIR}')
 
+    bld.SAMBA_BINARY('ctdb_smnotify_helper',
+                     source=('failover/smnotify_helper.c'),
+                     deps='sys_rw replace',
+                     install_path='${CTDB_HELPER_BINDIR}')
+
     bld.SAMBA_GENERATOR('ctdb-smnotify-h',
                         source='utils/smnotify/smnotify.x',
                         target='utils/smnotify/smnotify.h',