r21232: added a raw ctdb messaging api - allowing ctdb applications to take

advantage of the ctdb messaging layer for their own data
(This used to be commit b288ba05e5dc2aa5c8cd26eaee1c41b12e4996da)

6 files changed, 133 insertions, 14 deletions

diff --git a/source4/cluster/ctdb/common/ctdb.c b/source4/cluster/ctdb/common/ctdb.c
index ecef14bca4..9e92059b95 100644
--- a/source4/cluster/ctdb/common/ctdb.c
+++ b/source4/cluster/ctdb/common/ctdb.c
@@ -212,6 +212,10 @@ static void ctdb_recv_pkt(struct ctdb_context *ctdb, uint8_t *data, uint32_t len
 		ctdb_reply_dmaster(ctdb, hdr);
 		break;
 
+	case CTDB_REQ_MESSAGE:
+		ctdb_request_message(ctdb, hdr);
+		break;
+
 	default:
 		printf("Packet with unknown operation %d\n", hdr->operation);
 		talloc_free(hdr);
@@ -267,6 +271,20 @@ void ctdb_wait_loop(struct ctdb_context *ctdb)
 	}
 }
 
+
+/*
+  queue a packet or die
+*/
+void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
+{
+	struct ctdb_node *node;
+	node = ctdb->nodes[hdr->destnode];
+	if (ctdb->methods->queue_pkt(node, (uint8_t *)hdr, hdr->length) != 0) {
+		ctdb_fatal(ctdb, "Unable to queue packet\n");
+	}
+}
+
+
 static const struct ctdb_upcalls ctdb_upcalls = {
 	.recv_pkt       = ctdb_recv_pkt,
 	.node_dead      = ctdb_node_dead,
diff --git a/source4/cluster/ctdb/common/ctdb_call.c b/source4/cluster/ctdb/common/ctdb_call.c
index 0169baf906..fb29aad9ac 100644
--- a/source4/cluster/ctdb/common/ctdb_call.c
+++ b/source4/cluster/ctdb/common/ctdb_call.c
@@ -29,19 +29,6 @@
 #include "../include/ctdb_private.h"
 
 /*
-  queue a packet or die
-*/
-static void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
-{
-	struct ctdb_node *node;
-	node = ctdb->nodes[hdr->destnode];
-	if (ctdb->methods->queue_pkt(node, (uint8_t *)hdr, hdr->length) != 0) {
-		ctdb_fatal(ctdb, "Unable to queue packet\n");
-	}
-}
-
-
-/*
   local version of ctdb_call
 */
 static int ctdb_call_local(struct ctdb_context *ctdb, struct ctdb_call *call,
diff --git a/source4/cluster/ctdb/common/ctdb_message.c b/source4/cluster/ctdb/common/ctdb_message.c
new file mode 100644
index 0000000000..abdf9e6216
--- /dev/null
+++ b/source4/cluster/ctdb/common/ctdb_message.c
@@ -0,0 +1,91 @@
+/* 
+   ctdb_message protocol code
+
+   Copyright (C) Andrew Tridgell  2007
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+/*
+  see http://wiki.samba.org/index.php/Samba_%26_Clustering for
+  protocol design and packet details
+*/
+#include "includes.h"
+#include "lib/events/events.h"
+#include "lib/tdb/include/tdb.h"
+#include "system/network.h"
+#include "system/filesys.h"
+#include "../include/ctdb_private.h"
+
+
+/*
+  called when a CTDB_REQ_MESSAGE packet comes in
+
+  this dispatches the messages to the registered ctdb message handler
+*/
+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;
+	if (ctdb->message_handler == NULL) {
+		/* no registered message handler */
+		talloc_free(hdr);
+		return;
+	}
+	data.dptr = &c->data[0];
+	data.dsize = c->datalen;
+	ctdb->message_handler(ctdb, c->srvid, data, ctdb->message_private);
+	talloc_free(hdr);
+}
+
+
+/*
+  send a ctdb message
+*/
+int ctdb_send_message(struct ctdb_context *ctdb, uint32_t vnn,
+		      uint32_t srvid, uint32_t msg_type, TDB_DATA data)
+{
+	struct ctdb_req_message *r;
+	int len;
+
+	len = offsetof(struct ctdb_req_message, data) + data.dsize;
+	r = ctdb->methods->allocate_pkt(ctdb, len);
+	CTDB_NO_MEMORY(ctdb, r);
+
+	r->hdr.length    = len;
+	r->hdr.operation = CTDB_REQ_MESSAGE;
+	r->hdr.destnode  = vnn;
+	r->hdr.srcnode   = ctdb->vnn;
+	r->hdr.reqid     = 0;
+	r->srvid         = srvid;
+	r->datalen       = data.dsize;
+	memcpy(&r->data[0], data.dptr, data.dsize);
+	
+	ctdb_queue_packet(ctdb, &r->hdr);
+
+	talloc_free(r);
+	return 0;
+}
+
+/*
+  setup handler for receipt of ctdb messages from ctdb_send_message()
+*/
+int ctdb_set_message_handler(struct ctdb_context *ctdb, ctdb_message_fn_t handler,
+			     void *private)
+{
+	ctdb->message_handler = handler;
+	ctdb->message_private = private;
+	return 0;
+}
+
diff --git a/source4/cluster/ctdb/config.mk b/source4/cluster/ctdb/config.mk
index 90897eedd3..72d768659c 100644
--- a/source4/cluster/ctdb/config.mk
+++ b/source4/cluster/ctdb/config.mk
@@ -18,6 +18,7 @@ OBJ_FILES = \
 		ctdb_cluster.o \
 		common/ctdb.o \
 		common/ctdb_call.o \
+		common/ctdb_message.o \
 		common/ctdb_ltdb.o \
 		common/ctdb_util.o
 PRIVATE_DEPENDENCIES = ctdb_tcp
diff --git a/source4/cluster/ctdb/include/ctdb.h b/source4/cluster/ctdb/include/ctdb.h
index 7eebcb83db..335af83215 100644
--- a/source4/cluster/ctdb/include/ctdb.h
+++ b/source4/cluster/ctdb/include/ctdb.h
@@ -127,4 +127,14 @@ void ctdb_wait_loop(struct ctdb_context *ctdb);
 /* return vnn of this node */
 uint32_t ctdb_get_vnn(struct ctdb_context *ctdb);
 
+/* setup a handler for ctdb messages */
+typedef void (*ctdb_message_fn_t)(struct ctdb_context *, uint32_t srvid, 
+				  TDB_DATA data, void *);
+int ctdb_set_message_handler(struct ctdb_context *ctdb, ctdb_message_fn_t handler,
+			     void *private);
+
+/* send a ctdb message */
+int ctdb_send_message(struct ctdb_context *ctdb, uint32_t vnn,
+		      uint32_t srvid, uint32_t msg_type, TDB_DATA data);
+
 #endif
diff --git a/source4/cluster/ctdb/include/ctdb_private.h b/source4/cluster/ctdb/include/ctdb_private.h
index 977206f400..c863781c50 100644
--- a/source4/cluster/ctdb/include/ctdb_private.h
+++ b/source4/cluster/ctdb/include/ctdb_private.h
@@ -94,6 +94,8 @@ struct ctdb_context {
 	const struct ctdb_upcalls *upcalls; /* transport upcalls */
 	void *private; /* private to transport */
 	unsigned max_lacount;
+	ctdb_message_fn_t message_handler;
+	void *message_private;
 };
 
 #define CTDB_NO_MEMORY(ctdb, p) do { if (!(p)) { \
@@ -138,7 +140,8 @@ enum ctdb_operation {
 	CTDB_REPLY_REDIRECT = 2,
 	CTDB_REQ_DMASTER    = 3,
 	CTDB_REPLY_DMASTER  = 4,
-	CTDB_REPLY_ERROR    = 5
+	CTDB_REPLY_ERROR    = 5,
+	CTDB_REQ_MESSAGE    = 6
 };
 
 /*
@@ -193,6 +196,13 @@ struct ctdb_reply_dmaster {
 	uint8_t  data[1];
 };
 
+struct ctdb_req_message {
+	struct ctdb_req_header hdr;
+	uint32_t srvid;
+	uint32_t datalen;
+	uint8_t data[1];
+};
+
 /* internal prototypes */
 void ctdb_set_error(struct ctdb_context *ctdb, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
 void ctdb_fatal(struct ctdb_context *ctdb, const char *msg);
@@ -203,6 +213,7 @@ int ctdb_parse_address(struct ctdb_context *ctdb,
 uint32_t ctdb_hash(const TDB_DATA *key);
 void ctdb_request_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 void ctdb_request_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
+void ctdb_request_message(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 void ctdb_reply_dmaster(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 void ctdb_reply_call(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 void ctdb_reply_error(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
@@ -213,6 +224,7 @@ int ctdb_ltdb_fetch(struct ctdb_context *ctdb,
 		    TDB_DATA key, struct ctdb_ltdb_header *header, TDB_DATA *data);
 int ctdb_ltdb_store(struct ctdb_context *ctdb, TDB_DATA key, 
 		    struct ctdb_ltdb_header *header, TDB_DATA data);
+void ctdb_queue_packet(struct ctdb_context *ctdb, struct ctdb_req_header *hdr);
 
 
 #endif