Merge branch 'master' of ctdb into 'master' of samba

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Michael Adam <obnox@samba.org>

1 files changed, 286 insertions, 0 deletions

diff --git a/ctdb/common/ctdb_message.c b/ctdb/common/ctdb_message.c
new file mode 100644
index 0000000000..0e19761da3
--- /dev/null
+++ b/ctdb/common/ctdb_message.c
@@ -0,0 +1,286 @@
+/* 
+   ctdb_message protocol code
+
+   Copyright (C) Andrew Tridgell  2007
+   Copyright (C) Amitay Isaacs  2013
+
+   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/>.
+*/
+/*
+  see http://wiki.samba.org/index.php/Samba_%26_Clustering for
+  protocol design and packet details
+*/
+#include "includes.h"
+#include "tdb.h"
+#include "system/network.h"
+#include "system/filesys.h"
+#include "../include/ctdb_private.h"
+#include "lib/util/dlinklist.h"
+
+static int message_list_db_init(struct ctdb_context *ctdb)
+{
+	ctdb->message_list_indexdb = tdb_open("messagedb", 8192,
+					      TDB_INTERNAL|
+					      TDB_INCOMPATIBLE_HASH|
+					      TDB_DISALLOW_NESTING,
+					      O_RDWR|O_CREAT, 0);
+	if (ctdb->message_list_indexdb == NULL) {
+		DEBUG(DEBUG_ERR, ("Failed to create message list indexdb\n"));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_add(struct ctdb_context *ctdb, uint64_t srvid,
+			       struct ctdb_message_list_header *h)
+{
+	int ret;
+	TDB_DATA key, data;
+
+	if (ctdb->message_list_indexdb == NULL) {
+		ret = message_list_db_init(ctdb);
+		if (ret < 0) {
+			return -1;
+		}
+	}
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	data.dptr = (uint8_t *)&h;
+	data.dsize = sizeof(struct ctdb_message_list_header *);
+
+	ret = tdb_store(ctdb->message_list_indexdb, key, data, TDB_INSERT);
+	if (ret < 0) {
+		DEBUG(DEBUG_ERR, ("Failed to add message list handler (%s)\n",
+				  tdb_errorstr(ctdb->message_list_indexdb)));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_delete(struct ctdb_context *ctdb, uint64_t srvid)
+{
+	int ret;
+	TDB_DATA key;
+
+	if (ctdb->message_list_indexdb == NULL) {
+		return -1;
+	}
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	ret = tdb_delete(ctdb->message_list_indexdb, key);
+	if (ret < 0) {
+		DEBUG(DEBUG_ERR, ("Failed to delete message list handler (%s)\n",
+				  tdb_errorstr(ctdb->message_list_indexdb)));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int message_list_db_fetch_parser(TDB_DATA key, TDB_DATA data,
+					void *private_data)
+{
+	struct ctdb_message_list_header **h =
+		(struct ctdb_message_list_header **)private_data;
+
+	if (data.dsize != sizeof(struct ctdb_message_list_header *)) {
+		return -1;
+	}
+
+	*h = *(struct ctdb_message_list_header **)data.dptr;
+	return 0;
+}
+
+static int message_list_db_fetch(struct ctdb_context *ctdb, uint64_t srvid,
+				 struct ctdb_message_list_header **h)
+{
+	TDB_DATA key;
+
+	if (ctdb->message_list_indexdb == NULL) {
+		return -1;
+	}
+
+	key.dptr = (uint8_t *)&srvid;
+	key.dsize = sizeof(uint64_t);
+
+	return tdb_parse_record(ctdb->message_list_indexdb, key,
+				message_list_db_fetch_parser, h);
+}
+
+/*
+  this dispatches the messages to the registered ctdb message handler
+*/
+int ctdb_dispatch_message(struct ctdb_context *ctdb, uint64_t srvid, TDB_DATA data)
+{
+	struct ctdb_message_list_header *h;
+	struct ctdb_message_list *m;
+	uint64_t srvid_all = CTDB_SRVID_ALL;
+	int ret;
+
+	ret = message_list_db_fetch(ctdb, srvid, &h);
+	if (ret == 0) {
+		for (m=h->m; m; m=m->next) {
+			m->message_handler(ctdb, srvid, data, m->message_private);
+		}
+	}
+
+	ret = message_list_db_fetch(ctdb, srvid_all, &h);
+	if (ret == 0) {
+		for(m=h->m; m; m=m->next) {
+			m->message_handler(ctdb, srvid, data, m->message_private);
+		}
+	}
+
+	return 0;
+}
+
+/*
+  called when a CTDB_REQ_MESSAGE packet comes in
+*/
+void ctdb_request_message(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
+{
+	struct ctdb_req_message *c = (struct ctdb_req_message *)hdr;
+	TDB_DATA data;
+
+	data.dsize = c->datalen;
+	data.dptr = talloc_memdup(c, &c->data[0], c->datalen);
+
+	ctdb_dispatch_message(ctdb, c->srvid, data);
+}
+
+/*
+ * When header is freed, remove all the srvid handlers
+ */
+static int message_header_destructor(struct ctdb_message_list_header *h)
+{
+	struct ctdb_message_list *m;
+
+	while (h->m != NULL) {
+		m = h->m;
+		DLIST_REMOVE(h->m, m);
+		TALLOC_FREE(m);
+	}
+
+	message_list_db_delete(h->ctdb, h->srvid);
+	DLIST_REMOVE(h->ctdb->message_list_header, h);
+
+	return 0;
+}
+
+/*
+  when a client goes away, we need to remove its srvid handler from the list
+ */
+static int message_handler_destructor(struct ctdb_message_list *m)
+{
+	struct ctdb_message_list_header *h = m->h;
+
+	DLIST_REMOVE(h->m, m);
+	if (h->m == NULL) {
+		talloc_free(h);
+	}
+	return 0;
+}
+
+/*
+  setup handler for receipt of ctdb messages from ctdb_send_message()
+*/
+int ctdb_register_message_handler(struct ctdb_context *ctdb, 
+				  TALLOC_CTX *mem_ctx,
+				  uint64_t srvid,
+				  ctdb_msg_fn_t handler,
+				  void *private_data)
+{
+	struct ctdb_message_list_header *h;
+	struct ctdb_message_list *m;
+	int ret;
+
+	m = talloc_zero(mem_ctx, struct ctdb_message_list);
+	CTDB_NO_MEMORY(ctdb, m);
+
+	m->message_handler = handler;
+	m->message_private = private_data;
+
+	ret = message_list_db_fetch(ctdb, srvid, &h);
+	if (ret != 0) {
+		/* srvid not registered yet */
+		h = talloc_zero(ctdb, struct ctdb_message_list_header);
+		CTDB_NO_MEMORY(ctdb, h);
+
+		h->ctdb = ctdb;
+		h->srvid = srvid;
+
+		ret = message_list_db_add(ctdb, srvid, h);
+		if (ret < 0) {
+			talloc_free(m);
+			talloc_free(h);
+			return -1;
+		}
+
+		DLIST_ADD(ctdb->message_list_header, h);
+		talloc_set_destructor(h, message_header_destructor);
+	}
+
+	m->h = h;
+	DLIST_ADD(h->m, m);
+	talloc_set_destructor(m, message_handler_destructor);
+	return 0;
+}
+
+
+/*
+  setup handler for receipt of ctdb messages from ctdb_send_message()
+*/
+int ctdb_deregister_message_handler(struct ctdb_context *ctdb, uint64_t srvid, void *private_data)
+{
+	struct ctdb_message_list_header *h;
+	struct ctdb_message_list *m;
+	int ret;
+
+	ret = message_list_db_fetch(ctdb, srvid, &h);
+	if (ret != 0) {
+		return -1;
+	}
+
+	for (m=h->m; m; m=m->next) {
+		if (m->message_private == private_data) {
+			talloc_free(m);
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+
+/*
+ * check if the given srvid exists
+ */
+bool ctdb_check_message_handler(struct ctdb_context *ctdb, uint64_t srvid)
+{
+	struct ctdb_message_list_header *h;
+	int ret;
+
+	ret = message_list_db_fetch(ctdb, srvid, &h);
+	if (ret != 0 || h->m == NULL) {
+		return false;
+	}
+
+	return true;
+}