r23410: Merge the core of the cluster code.

I'm 100% certain I've forgotten to merge something, but the main code
should be in. It's mainly in dbwrap_ctdb.c, ctdbd_conn.c and
messages_ctdbd.c.

There should be no changes to the non-cluster case, it does survive make
test on my laptop.

It survives some very basic tests with ctdbd enables, I did not do the
full test suite for clusters yet.

Phew...

Volker
(This used to be commit 15553d6327a3aecdd2b0b94a3656d04bf4106323)

1 files changed, 1167 insertions, 0 deletions

diff --git a/source3/lib/ctdbd_conn.c b/source3/lib/ctdbd_conn.c
new file mode 100644
index 0000000000..8c1aab8f37
--- /dev/null
+++ b/source3/lib/ctdbd_conn.c
@@ -0,0 +1,1167 @@
+/* 
+   Unix SMB/CIFS implementation.
+   Samba internal messaging functions
+   Copyright (C) 2007 by Volker Lendecke
+   Copyright (C) 2007 by Andrew Tridgell
+   
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+#ifdef CLUSTER_SUPPORT
+
+#include "librpc/gen_ndr/messaging.h"
+#include "librpc/gen_ndr/ndr_messaging.h"
+
+/* paths to these include files come from --with-ctdb= in configure */
+#include "ctdb.h"
+#include "ctdb_private.h"
+
+struct ctdbd_connection {
+	struct messaging_context *msg_ctx;
+	uint32 reqid;
+	uint32 our_vnn;
+	uint64 rand_srvid;
+	struct packet_context *pkt;
+	struct fd_event *fde;
+	
+	void (*release_ip_handler)(const char *ip_addr, void *private_data);
+	void *release_ip_priv;
+};
+
+static NTSTATUS ctdbd_control(struct ctdbd_connection *conn,
+			      uint32_t vnn, uint32 opcode, 
+			      uint64_t srvid, TDB_DATA data, 
+			      TALLOC_CTX *mem_ctx, TDB_DATA *outdata,
+			      int *cstatus);
+
+/*
+ * exit on fatal communications errors with the ctdbd daemon
+ */
+static void cluster_fatal(const char *why)
+{
+	DEBUG(0,("cluster fatal event: %s - exiting immediately\n", why));
+	/* we don't use smb_panic() as we don't want to delay to write
+	   a core file. We need to release this process id immediately
+	   so that someone else can take over without getting sharing
+	   violations */
+	_exit(0);
+}
+
+/*
+ * Register a srvid with ctdbd
+ */
+static NTSTATUS register_with_ctdbd(struct ctdbd_connection *conn,
+				    uint64_t srvid)
+{
+
+	int cstatus;
+	return ctdbd_control(conn, CTDB_CURRENT_NODE,
+			     CTDB_CONTROL_REGISTER_SRVID, srvid,
+			     tdb_null, NULL, NULL, &cstatus);
+}
+
+/*
+ * get our vnn from the cluster
+ */
+static NTSTATUS get_cluster_vnn(struct ctdbd_connection *conn, uint32 *vnn)
+{
+	int32_t cstatus=-1;
+	NTSTATUS status;
+	status = ctdbd_control(conn,
+			       CTDB_CURRENT_NODE, CTDB_CONTROL_GET_VNN, 0,
+			       tdb_null, NULL, NULL, &cstatus);
+	if (!NT_STATUS_IS_OK(status)) {
+		cluster_fatal("ctdbd_control failed\n");
+	}
+	*vnn = (uint32_t)cstatus;
+	return status;
+}
+
+uint32 ctdbd_vnn(const struct ctdbd_connection *conn)
+{
+	return conn->our_vnn;
+}
+
+/*
+ * Get us a ctdb connection
+ */
+
+static NTSTATUS ctdbd_connect(TALLOC_CTX *mem_ctx,
+			      struct packet_context **presult)
+{
+	struct packet_context *result;
+	const char *sockname = lp_ctdbd_socket();
+	struct sockaddr_un addr;
+	int fd;
+
+	if (!sockname || !*sockname) {
+		sockname = CTDB_PATH;
+	}
+
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1) {
+		DEBUG(3, ("Could not create socket: %s\n", strerror(errno)));
+		return map_nt_error_from_unix(errno);
+	}
+
+	ZERO_STRUCT(addr);
+	addr.sun_family = AF_UNIX;
+	strncpy(addr.sun_path, sockname, sizeof(addr.sun_path));
+
+	if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+		DEBUG(0, ("connect(%s) failed: %s\n", sockname,
+			  strerror(errno)));
+		close(fd);
+		return map_nt_error_from_unix(errno);
+	}
+
+	if (!(result = packet_init(mem_ctx, fd))) {
+		close(fd);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	*presult = result;
+	return NT_STATUS_OK;
+}
+
+/*
+ * Do we have a complete ctdb packet in the queue?
+ */
+
+static BOOL ctdb_req_complete(const struct data_blob *data,
+			      size_t *length,
+			      void *private_data)
+{
+	uint32 msglen;
+
+	if (data->length < sizeof(msglen)) {
+		return False;
+	}
+
+	msglen = *((uint32 *)data->data);
+
+	DEBUG(10, ("msglen = %d\n", msglen));
+
+	if (msglen < sizeof(struct ctdb_req_header)) {
+		DEBUG(0, ("Got invalid msglen: %d, expected at least %d for "
+			  "the req_header\n", msglen,
+			  sizeof(struct ctdb_req_header)));
+		cluster_fatal("ctdbd protocol error\n");
+	}
+
+	if (data->length >= msglen) {
+		*length = msglen;
+		return True;
+	}
+
+	return False;
+}
+
+/*
+ * State necessary to defer an incoming message while we are waiting for a
+ * ctdb reply.
+ */
+
+struct deferred_msg_state {
+	struct messaging_context *msg_ctx;
+	struct messaging_rec *rec;
+};
+
+/*
+ * Timed event handler for the deferred message
+ */
+
+static void deferred_message_dispatch(struct event_context *event_ctx,
+				      struct timed_event *te,
+				      const struct timeval *now,
+				      void *private_data)
+{
+	struct deferred_msg_state *state = talloc_get_type_abort(
+		private_data, struct deferred_msg_state);
+
+	messaging_dispatch_rec(state->msg_ctx, state->rec);
+	TALLOC_FREE(state);
+	TALLOC_FREE(te);
+}
+
+struct req_pull_state {
+	TALLOC_CTX *mem_ctx;
+	DATA_BLOB req;
+};
+
+/*
+ * Pull a ctdb request out of the incoming packet queue
+ */
+
+static NTSTATUS ctdb_req_pull(const struct data_blob *data,
+			      void *private_data)
+{
+	struct req_pull_state *state = (struct req_pull_state *)private_data;
+
+	state->req = data_blob_talloc(state->mem_ctx, data->data,
+				      data->length);
+	if (state->req.data == NULL) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	return NT_STATUS_OK;
+}
+
+/*
+ * Fetch a messaging_rec from an incoming ctdb style message
+ */
+
+static struct messaging_rec *ctdb_pull_messaging_rec(TALLOC_CTX *mem_ctx,
+						     size_t overall_length,
+						     struct ctdb_req_message *msg)
+{
+	struct messaging_rec *result;
+	DATA_BLOB blob;
+	NTSTATUS status;
+
+	if ((overall_length < offsetof(struct ctdb_req_message, data))
+	    || (overall_length
+		< offsetof(struct ctdb_req_message, data) + msg->datalen)) {
+
+		cluster_fatal("got invalid msg length");
+	}
+
+	if (!(result = TALLOC_P(mem_ctx, struct messaging_rec))) {
+		DEBUG(0, ("talloc failed\n"));
+		return NULL;
+	}
+
+	blob = data_blob_const(msg->data, msg->datalen);
+
+	status = ndr_pull_struct_blob(
+		&blob, result, result,
+		(ndr_pull_flags_fn_t)ndr_pull_messaging_rec);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("ndr_pull_struct_blob failed: %s\n",
+			  nt_errstr(status)));
+		TALLOC_FREE(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+/*
+ * Read a full ctdbd request. If we have a messaging context, defer incoming
+ * messages that might come in between.
+ */
+
+static NTSTATUS ctdb_read_req(struct ctdbd_connection *conn, uint32 reqid,
+			      TALLOC_CTX *mem_ctx, void *result)
+{
+	struct ctdb_req_header *hdr;
+	struct req_pull_state state;
+	NTSTATUS status;
+
+ again:
+
+	status = packet_fd_read_sync(conn->pkt);
+
+	if (NT_STATUS_EQUAL(status, NT_STATUS_NETWORK_BUSY)) {
+		/* EAGAIN */
+		goto again;
+	}
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("packet_fd_read failed: %s\n", nt_errstr(status)));
+		cluster_fatal("ctdbd died\n");
+	}
+
+	ZERO_STRUCT(state);
+	state.mem_ctx = mem_ctx;
+
+	if (!packet_handler(conn->pkt, ctdb_req_complete, ctdb_req_pull,
+			    &state, &status)) {
+		/*
+		 * Not enough data
+		 */
+		goto again;
+	}
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("Could not read packet: %s\n", nt_errstr(status)));
+		cluster_fatal("ctdbd died\n");
+	}
+
+	hdr = (struct ctdb_req_header *)state.req.data;
+
+	if (hdr->operation == CTDB_REQ_MESSAGE) {
+		struct timed_event *evt;
+		struct deferred_msg_state *msg_state;
+		struct ctdb_req_message *msg = (struct ctdb_req_message *)hdr;
+
+		if (conn->msg_ctx == NULL) {
+			DEBUG(1, ("Got a message without having a msg ctx, "
+				  "dropping msg %llu\n", msg->srvid));
+			goto again;
+		}
+		
+		if ((conn->release_ip_handler != NULL)
+		    && (msg->srvid == CTDB_SRVID_RELEASE_IP)) {
+			/* must be dispatched immediately */
+			DEBUG(10, ("received CTDB_SRVID_RELEASE_IP\n"));
+			conn->release_ip_handler((const char *)msg->data,
+						 conn->release_ip_priv);
+			TALLOC_FREE(hdr);
+			goto again;
+		}
+
+		if (!(msg_state = TALLOC_P(NULL, struct deferred_msg_state))) {
+			DEBUG(0, ("talloc failed\n"));
+			TALLOC_FREE(hdr);
+			goto again;
+		}
+
+		if (!(msg_state->rec = ctdb_pull_messaging_rec(
+			      msg_state, state.req.length, msg))) {
+			DEBUG(0, ("ctdbd_pull_messaging_rec failed\n"));
+			TALLOC_FREE(msg_state);
+			TALLOC_FREE(hdr);
+			goto again;
+		}
+
+		TALLOC_FREE(hdr);
+
+		msg_state->msg_ctx = conn->msg_ctx;
+		
+		/*
+		 * We're waiting for a call reply, but an async message has
+		 * crossed. Defer dispatching to the toplevel event loop.
+		 */
+		evt = event_add_timed(conn->msg_ctx->event_ctx,
+				      conn->msg_ctx->event_ctx,
+				      timeval_zero(),
+				      "deferred_message_dispatch",
+				      deferred_message_dispatch,
+				      msg_state);
+		if (evt == NULL) {
+			DEBUG(0, ("event_add_timed failed\n"));
+			TALLOC_FREE(msg_state);
+			TALLOC_FREE(hdr);
+			goto again;
+		}
+		
+		goto again;
+	}
+
+	if (hdr->reqid != reqid) {
+		/* we got the wrong reply */
+		DEBUG(0,("Discarding mismatched ctdb reqid %u should have "
+			 "been %u\n", hdr->reqid, reqid));
+		TALLOC_FREE(hdr);
+		goto again;
+	}
+
+	*((void **)result) = talloc_move(mem_ctx, &hdr);
+
+	return NT_STATUS_OK;
+}
+
+/*
+ * Get us a ctdbd connection
+ */
+
+NTSTATUS ctdbd_init_connection(TALLOC_CTX *mem_ctx,
+			       struct ctdbd_connection **pconn)
+{
+	struct ctdbd_connection *conn;
+	NTSTATUS status;
+
+	if (!(conn = TALLOC_ZERO_P(mem_ctx, struct ctdbd_connection))) {
+		DEBUG(0, ("talloc failed\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	status = ctdbd_connect(conn, &conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("ctdbd_connect failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	status = get_cluster_vnn(conn, &conn->our_vnn);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("get_cluster_vnn failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	generate_random_buffer((unsigned char *)&conn->rand_srvid,
+			       sizeof(conn->rand_srvid));
+
+	status = register_with_ctdbd(conn, conn->rand_srvid);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(5, ("Could not register random srvid: %s\n",
+			  nt_errstr(status)));
+		goto fail;
+	}
+
+	*pconn = conn;
+	return NT_STATUS_OK;
+
+ fail:
+	TALLOC_FREE(conn);
+	return status;
+}
+
+/*
+ * Get us a ctdbd connection and register us as a process
+ */
+
+NTSTATUS ctdbd_messaging_connection(TALLOC_CTX *mem_ctx,
+				    struct ctdbd_connection **pconn)
+{
+        struct ctdbd_connection *conn;
+	NTSTATUS status;
+
+	status = ctdbd_init_connection(mem_ctx, &conn);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	status = register_with_ctdbd(conn, (uint64_t)sys_getpid());
+	if (!NT_STATUS_IS_OK(status)) {
+		goto fail;
+	}
+
+	status = register_with_ctdbd(conn, MSG_SRVID_SAMBA);
+	if (!NT_STATUS_IS_OK(status)) {
+		goto fail;
+	}
+
+	*pconn = conn;
+	return NT_STATUS_OK;
+
+ fail:
+	TALLOC_FREE(conn);
+	return status;
+}
+
+/*
+ * Packet handler to receive and handle a ctdb message
+ */
+static NTSTATUS ctdb_handle_message(const struct data_blob *data,
+				    void *private_data)
+{
+	struct ctdbd_connection *conn = talloc_get_type_abort(
+		private_data, struct ctdbd_connection);
+	struct ctdb_req_message *msg;
+	struct messaging_rec *msg_rec;
+
+	msg = (struct ctdb_req_message *)data->data;
+
+	if (msg->hdr.operation != CTDB_REQ_MESSAGE) {
+		DEBUG(0, ("Received async msg of type %u, discarding\n",
+			  msg->hdr.operation));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	if ((conn->release_ip_handler != NULL)
+	    && (msg->srvid == CTDB_SRVID_RELEASE_IP)) {
+		/* must be dispatched immediately */
+		DEBUG(10, ("received CTDB_SRVID_RELEASE_IP\n"));
+		conn->release_ip_handler((const char *)msg->data,
+					 conn->release_ip_priv);
+		return NT_STATUS_OK;
+	}
+
+	SMB_ASSERT(conn->msg_ctx != NULL);
+
+	if (msg->srvid == CTDB_SRVID_RECONFIGURE) {
+		DEBUG(0,("Got cluster reconfigure message\n"));
+		/*
+		 * when the cluster is reconfigured, we need to clean the brl
+		 * database
+		 */
+		messaging_send(conn->msg_ctx, procid_self(),
+			       MSG_SMB_BRL_VALIDATE, &data_blob_null);
+
+		/*
+		 * it's possible that we have just rejoined the cluster after
+		 * an outage. In that case our pending locks could have been
+		 * removed from the lockdb, so retry them once more
+		 */
+		message_send_all(conn->msg_ctx, MSG_SMB_UNLOCK, NULL, 0, NULL);
+
+		return NT_STATUS_OK;
+		
+	}
+
+	/* only messages to our pid or the broadcast are valid here */
+	if (msg->srvid != sys_getpid() && msg->srvid != MSG_SRVID_SAMBA) {
+		DEBUG(0,("Got unexpected message with srvid=%llu\n", 
+			 (unsigned long long)msg->srvid));
+		return NT_STATUS_OK;
+	}
+
+	if (!(msg_rec = ctdb_pull_messaging_rec(NULL, data->length, msg))) {
+		DEBUG(10, ("ctdb_pull_messaging_rec failed\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	messaging_dispatch_rec(conn->msg_ctx, msg_rec);
+
+	TALLOC_FREE(msg_rec);
+	return NT_STATUS_OK;
+}
+
+/*
+ * The ctdbd socket is readable asynchronuously
+ */
+
+static void ctdbd_socket_handler(struct event_context *event_ctx,
+				 struct fd_event *event,
+				 uint16 flags,
+				 void *private_data)
+{
+	struct ctdbd_connection *conn = talloc_get_type_abort(
+		private_data, struct ctdbd_connection);
+
+	NTSTATUS status;
+
+	status = packet_fd_read(conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("packet_fd_read failed: %s\n", nt_errstr(status)));
+		cluster_fatal("ctdbd died\n");
+	}
+
+	while (packet_handler(conn->pkt, ctdb_req_complete,
+			      ctdb_handle_message, conn, &status)) {
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(10, ("could not handle incoming message: %s\n",
+				   nt_errstr(status)));
+		}
+	}
+}
+
+/*
+ * Prepare a ctdbd connection to receive messages
+ */
+
+NTSTATUS ctdbd_register_msg_ctx(struct ctdbd_connection *conn,
+				struct messaging_context *msg_ctx)
+{
+	SMB_ASSERT(conn->msg_ctx == NULL);
+	SMB_ASSERT(conn->fde == NULL);
+
+	if (!(conn->fde = event_add_fd(msg_ctx->event_ctx, conn,
+				       packet_get_fd(conn->pkt),
+				       EVENT_FD_READ,
+				       ctdbd_socket_handler,
+				       conn))) {
+		DEBUG(0, ("event_add_fd failed\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	conn->msg_ctx = msg_ctx;
+
+	return NT_STATUS_OK;
+}
+
+/*
+ * Send a messaging message across a ctdbd
+ */
+
+NTSTATUS ctdbd_messaging_send(struct ctdbd_connection *conn,
+			      uint32 dst_vnn, uint64 dst_srvid,
+			      struct messaging_rec *msg)
+{
+	struct ctdb_req_message r;
+	TALLOC_CTX *mem_ctx;
+	DATA_BLOB blob;
+	NTSTATUS status;
+
+	if (!(mem_ctx = talloc_init("ctdbd_messaging_send"))) {
+		DEBUG(0, ("talloc failed\n"));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	status = ndr_push_struct_blob(
+		&blob, mem_ctx, msg,
+		(ndr_push_flags_fn_t)ndr_push_messaging_rec);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("ndr_push_struct_blob failed: %s\n",
+			  nt_errstr(status)));
+		goto fail;
+	}
+
+	r.hdr.length = offsetof(struct ctdb_req_message, data) + blob.length;
+	r.hdr.ctdb_magic = CTDB_MAGIC;
+	r.hdr.ctdb_version = CTDB_VERSION;
+	r.hdr.generation = 1;
+	r.hdr.operation  = CTDB_REQ_MESSAGE;
+	r.hdr.destnode   = dst_vnn;
+	r.hdr.srcnode    = conn->our_vnn;
+	r.hdr.reqid      = 0;
+	r.srvid          = dst_srvid;
+	r.datalen        = blob.length;
+
+	status = packet_send(
+		conn->pkt, 2,
+		data_blob_const(&r, offsetof(struct ctdb_req_message, data)),
+		blob);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("packet_send failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	status = packet_flush(conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("write to ctdbd failed: %s\n", nt_errstr(status)));
+		cluster_fatal("cluster dispatch daemon msg write error\n");
+	}
+
+	status = NT_STATUS_OK;
+ fail:
+	TALLOC_FREE(mem_ctx);
+	return status;
+}
+
+/*
+ * send/recv a generic ctdb control message
+ */
+static NTSTATUS ctdbd_control(struct ctdbd_connection *conn,
+			      uint32_t vnn, uint32 opcode, 
+			      uint64_t srvid, TDB_DATA data, 
+			      TALLOC_CTX *mem_ctx, TDB_DATA *outdata,
+			      int *cstatus)
+{
+	struct ctdb_req_control req;
+	struct ctdb_reply_control *reply = NULL;
+	struct ctdbd_connection *new_conn = NULL;
+	NTSTATUS status;
+
+	if (conn == NULL) {
+		status = ctdbd_init_connection(NULL, &new_conn);
+
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(10, ("Could not init temp connection: %s\n",
+				   nt_errstr(status)));
+			goto fail;
+		}
+
+		conn = new_conn;
+	}
+
+	ZERO_STRUCT(req);
+	req.hdr.length = offsetof(struct ctdb_req_control, data) + data.dsize;
+	req.hdr.ctdb_magic   = CTDB_MAGIC;
+	req.hdr.ctdb_version = CTDB_VERSION;
+	req.hdr.operation    = CTDB_REQ_CONTROL;
+	req.hdr.reqid        = ++conn->reqid;
+	req.hdr.destnode     = vnn;
+	req.opcode           = opcode;
+	req.srvid            = srvid;
+	req.datalen          = data.dsize;
+
+	status = packet_send(
+		conn->pkt, 2,
+		data_blob_const(&req, offsetof(struct ctdb_req_control, data)),
+		data);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("packet_send failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	status = packet_flush(conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("write to ctdbd failed: %s\n", nt_errstr(status)));
+		cluster_fatal("cluster dispatch daemon control write error\n");
+	}
+
+	status = ctdb_read_req(conn, req.hdr.reqid, NULL, (void *)&reply);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("ctdb_read_req failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	if (reply->hdr.operation != CTDB_REPLY_CONTROL) {
+		DEBUG(0, ("received invalid reply\n"));
+		goto fail;
+	}
+
+	if (outdata) {
+		if (!(outdata->dptr = (uint8 *)talloc_memdup(
+			      mem_ctx, reply->data, reply->datalen))) {
+			TALLOC_FREE(reply);
+			return NT_STATUS_NO_MEMORY;
+		}
+		outdata->dsize = reply->datalen;
+	}
+	if (cstatus) {
+		(*cstatus) = reply->status;
+	}
+
+	status = NT_STATUS_OK;
+
+ fail:
+	TALLOC_FREE(new_conn);
+	TALLOC_FREE(reply);
+	return status;
+}
+
+/*
+ * see if a remote process exists
+ */
+BOOL ctdbd_process_exists(struct ctdbd_connection *conn, uint32 vnn, pid_t pid)
+{
+	NTSTATUS status;
+	TDB_DATA data;
+	int32_t cstatus;
+
+	data.dptr = (uint8_t*)&pid;
+	data.dsize = sizeof(pid);
+
+	status = ctdbd_control(conn, vnn, CTDB_CONTROL_PROCESS_EXISTS, 0,
+			       data, NULL, NULL, &cstatus);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, (__location__ " ctdb_control for process_exists "
+			  "failed\n"));
+		return False;
+	}
+
+	return cstatus == 0;
+}
+
+/*
+ * Get a db path
+ */
+char *ctdbd_dbpath(struct ctdbd_connection *conn,
+		   TALLOC_CTX *mem_ctx, uint32_t db_id)
+{
+	NTSTATUS status;
+	TDB_DATA data;
+	int32_t cstatus;
+
+	data.dptr = (uint8_t*)&db_id;
+	data.dsize = sizeof(db_id);
+
+	status = ctdbd_control(conn, CTDB_CURRENT_NODE,
+			       CTDB_CONTROL_GETDBPATH, 0, data, 
+			       mem_ctx, &data, &cstatus);
+	if (!NT_STATUS_IS_OK(status) || cstatus != 0) {
+		DEBUG(0,(__location__ " ctdb_control for getdbpath failed\n"));
+		return NULL;
+	}
+
+	return (char *)data.dptr;
+}
+
+/*
+ * attach to a ctdb database
+ */
+NTSTATUS ctdbd_db_attach(struct ctdbd_connection *conn,
+			 const char *name, uint32_t *db_id, int tdb_flags)
+{
+	NTSTATUS status;
+	TDB_DATA data;
+	int32_t cstatus;
+
+	data.dptr = (uint8_t*)name;
+	data.dsize = strlen(name)+1;
+
+	status = ctdbd_control(conn, CTDB_CURRENT_NODE,
+			       CTDB_CONTROL_DB_ATTACH, 0, data, 
+			       NULL, &data, &cstatus);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, (__location__ " ctdb_control for db_attach "
+			  "failed: %s\n", nt_errstr(status)));
+		return status;
+	}
+
+	if (cstatus != 0 || data.dsize != sizeof(uint32_t)) {
+		DEBUG(0,(__location__ " ctdb_control for db_attach failed\n"));
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	*db_id = *(uint32_t *)data.dptr;
+	talloc_free(data.dptr);
+
+	if (!(tdb_flags & TDB_SEQNUM)) {
+		return NT_STATUS_OK;
+	}
+
+	data.dptr = (uint8_t *)db_id;
+	data.dsize = sizeof(*db_id);
+
+	status = ctdbd_control(conn, CTDB_CURRENT_NODE,
+			       CTDB_CONTROL_ENABLE_SEQNUM, 0, data, 
+			       NULL, NULL, &cstatus);
+	if (!NT_STATUS_IS_OK(status) || cstatus != 0) {
+		DEBUG(0,(__location__ " ctdb_control for enable seqnum "
+			 "failed\n"));
+		return NT_STATUS_IS_OK(status) ? NT_STATUS_INTERNAL_ERROR :
+			status;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+ * force the migration of a record to this node
+ */
+NTSTATUS ctdbd_migrate(struct ctdbd_connection *conn, uint32 db_id,
+		       TDB_DATA key)
+{
+	struct ctdb_req_call req;
+	struct ctdb_reply_call *reply;
+	NTSTATUS status;
+
+	ZERO_STRUCT(req);
+	
+	req.hdr.length = offsetof(struct ctdb_req_call, data) + key.dsize;
+	req.hdr.ctdb_magic   = CTDB_MAGIC;
+	req.hdr.ctdb_version = CTDB_VERSION;
+	req.hdr.operation    = CTDB_REQ_CALL;
+	req.hdr.reqid        = ++conn->reqid;
+	req.flags            = CTDB_IMMEDIATE_MIGRATION;
+	req.callid           = CTDB_NULL_FUNC;
+	req.db_id            = db_id;
+	req.keylen           = key.dsize;
+
+	status = packet_send(
+		conn->pkt, 2,
+		data_blob_const(&req, offsetof(struct ctdb_req_call, data)),
+		key);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("packet_send failed: %s\n", nt_errstr(status)));
+		return status;
+	}
+
+	status = packet_flush(conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("write to ctdbd failed: %s\n", nt_errstr(status)));
+		cluster_fatal("cluster dispatch daemon control write error\n");
+	}
+
+	status = ctdb_read_req(conn, req.hdr.reqid, NULL, (void *)&reply);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("ctdb_read_req failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	if (reply->hdr.operation != CTDB_REPLY_CALL) {
+		DEBUG(0, ("received invalid reply\n"));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto fail;
+	}
+
+	status = NT_STATUS_OK;
+ fail:
+
+	TALLOC_FREE(reply);
+	return status;
+}
+
+/*
+ * remotely fetch a record without locking it or forcing a migration
+ */
+NTSTATUS ctdbd_fetch(struct ctdbd_connection *conn, uint32 db_id,
+		     TDB_DATA key, TALLOC_CTX *mem_ctx, TDB_DATA *data)
+{
+	struct ctdb_req_call req;
+	struct ctdb_reply_call *reply;
+	NTSTATUS status;
+
+	ZERO_STRUCT(req);
+	
+	req.hdr.length = offsetof(struct ctdb_req_call, data) + key.dsize;
+	req.hdr.ctdb_magic   = CTDB_MAGIC;
+	req.hdr.ctdb_version = CTDB_VERSION;
+	req.hdr.operation    = CTDB_REQ_CALL;
+	req.hdr.reqid        = ++conn->reqid;
+	req.flags            = 0;
+	req.callid           = CTDB_FETCH_FUNC;
+	req.db_id            = db_id;
+	req.keylen           = key.dsize;
+
+	status = packet_send(
+		conn->pkt, 2,
+		data_blob_const(&req, offsetof(struct ctdb_req_call, data)),
+		key);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("packet_send failed: %s\n", nt_errstr(status)));
+		return status;
+	}
+
+	status = packet_flush(conn->pkt);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(3, ("write to ctdbd failed: %s\n", nt_errstr(status)));
+		cluster_fatal("cluster dispatch daemon control write error\n");
+	}
+
+	status = ctdb_read_req(conn, req.hdr.reqid, NULL, (void *)&reply);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("ctdb_read_req failed: %s\n", nt_errstr(status)));
+		goto fail;
+	}
+
+	if (reply->hdr.operation != CTDB_REPLY_CALL) {
+		DEBUG(0, ("received invalid reply\n"));
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto fail;
+	}
+
+	data->dsize = reply->datalen;
+	if (data->dsize == 0) {
+		data->dptr = NULL;
+		goto done;
+	}
+
+	data->dptr = (uint8 *)talloc_memdup(mem_ctx, &reply->data[0],
+					    reply->datalen);
+	if (data->dptr == NULL) {
+		DEBUG(0, ("talloc failed\n"));
+		status = NT_STATUS_NO_MEMORY;
+		goto fail;
+	}
+
+ done:
+	status = NT_STATUS_OK;
+ fail:
+	TALLOC_FREE(reply);
+	return status;
+}
+
+struct ctdbd_traverse_state {
+	void (*fn)(TDB_DATA key, TDB_DATA data, void *private_data);
+	void *private_data;
+};
+
+/*
+ * Handle a traverse record coming in on the ctdbd connection
+ */
+
+static NTSTATUS ctdb_traverse_handler(const struct data_blob *blob,
+				      void *private_data)
+{
+	struct ctdbd_traverse_state *state =
+		(struct ctdbd_traverse_state *)private_data;
+
+	struct ctdb_req_message *m;
+	struct ctdb_rec_data *d;
+	TDB_DATA key, data;
+
+	m = (struct ctdb_req_message *)blob->data;
+
+	if (blob->length < sizeof(*m) || m->hdr.length != blob->length) {
+		DEBUG(0, ("Got invalid message of length %d\n",
+			  (int)blob->length));
+		return NT_STATUS_UNEXPECTED_IO_ERROR;
+	}
+
+	d = (struct ctdb_rec_data *)&m->data[0];
+	if (m->datalen < sizeof(uint32_t) || m->datalen != d->length) {
+		DEBUG(0, ("Got invalid traverse data of length %d\n",
+			  (int)m->datalen));
+		return NT_STATUS_UNEXPECTED_IO_ERROR;
+	}
+
+	key.dsize = d->keylen;
+	key.dptr  = &d->data[0];
+	data.dsize = d->datalen;
+	data.dptr = &d->data[d->keylen];		
+
+	if (key.dsize == 0 && data.dsize == 0) {
+		/* end of traverse */
+		return NT_STATUS_END_OF_FILE;
+	}
+
+	if (data.dsize < sizeof(struct ctdb_ltdb_header)) {
+		DEBUG(0, ("Got invalid ltdb header length %d\n",
+			  (int)data.dsize));
+		return NT_STATUS_UNEXPECTED_IO_ERROR;
+	}
+	data.dsize -= sizeof(struct ctdb_ltdb_header);
+	data.dptr += sizeof(struct ctdb_ltdb_header);
+
+	if (state->fn) {
+		state->fn(key, data, state->private_data);
+	}
+
+	return NT_STATUS_OK;
+}
+
+/*
+  Traverse a ctdb database. This uses a kind-of hackish way to open a second
+  connection to ctdbd to avoid the hairy recursive and async problems with
+  everything in-line.
+*/
+
+NTSTATUS ctdbd_traverse(uint32 db_id,
+			void (*fn)(TDB_DATA key, TDB_DATA data,
+				   void *private_data),
+			void *private_data)
+{
+	struct ctdbd_connection *conn;
+	NTSTATUS status;
+
+	TDB_DATA data;
+	struct ctdb_traverse_start t;
+	int cstatus;
+	struct ctdbd_traverse_state state;
+
+	status = ctdbd_init_connection(NULL, &conn);
+
+	t.db_id = db_id;
+	t.srvid = conn->rand_srvid;
+	t.reqid = ++conn->reqid;
+
+	data.dptr = (uint8_t *)&t;
+	data.dsize = sizeof(t);
+
+	status = ctdbd_control(conn, CTDB_CURRENT_NODE,
+			       CTDB_CONTROL_TRAVERSE_START, conn->rand_srvid,
+			       data, NULL, NULL, &cstatus);
+
+	if (!NT_STATUS_IS_OK(status) || (cstatus != 0)) {
+
+		DEBUG(0,("ctdbd_control failed: %s, %d\n", nt_errstr(status),
+			 cstatus));
+
+		if (NT_STATUS_IS_OK(status)) {
+			/*
+			 * We need a mapping here
+			 */
+			status = NT_STATUS_UNSUCCESSFUL;
+		}
+		goto done;
+	}
+
+	state.fn = fn;
+	state.private_data = private_data;
+
+	while (True) {
+
+		status = NT_STATUS_OK;
+
+		if (packet_handler(conn->pkt, ctdb_req_complete,
+				   ctdb_traverse_handler, &state, &status)) {
+
+			if (NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) {
+				status = NT_STATUS_OK;
+				break;
+			}
+
+			/*
+			 * There might be more in the queue
+			 */
+			continue;
+		}
+
+		if (!NT_STATUS_IS_OK(status)) {
+			break;
+		}
+
+		status = packet_fd_read_sync(conn->pkt);
+
+		if (NT_STATUS_EQUAL(status, NT_STATUS_END_OF_FILE)) {
+			status = NT_STATUS_OK;
+		}
+
+		if (!NT_STATUS_IS_OK(status)) {
+			cluster_fatal("ctdbd died\n");
+		}
+	}
+
+ done:
+	TALLOC_FREE(conn);
+	return status;
+}
+
+/*
+ * Register us as a server for a particular tcp connection
+ */
+
+NTSTATUS ctdbd_register_ips(struct ctdbd_connection *conn,
+			    const struct sockaddr_in *server,
+			    const struct sockaddr_in *client,
+			    void (*release_ip_handler)(const char *ip_addr,
+						       void *private_data),
+			    void *private_data)
+{
+	struct ctdb_control_tcp p;
+	TDB_DATA data;
+	NTSTATUS status;
+
+	/*
+	 * Only one connection so far
+	 */
+	SMB_ASSERT(conn->release_ip_handler == NULL);
+
+	/*
+	 * We want to be told about IP releases
+	 */
+
+	status = register_with_ctdbd(conn, CTDB_SRVID_RELEASE_IP);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	p.dest = *server;
+	p.src = *client;
+
+	/*
+	 * inform ctdb of our tcp connection, so if IP takeover happens ctdb
+	 * can send an extra ack to trigger a reset for our client, so it
+	 * immediately reconnects
+	 */
+	data.dptr = (uint8_t *)&p;
+	data.dsize = sizeof(p);
+
+	return ctdbd_control(conn, CTDB_CURRENT_NODE, 
+			     CTDB_CONTROL_TCP_CLIENT, 
+			     CTDB_CTRL_FLAG_NOREPLY, data, NULL, NULL, NULL);
+}
+
+/*
+ * We want to handle reconfigure events
+ */
+NTSTATUS ctdbd_register_reconfigure(struct ctdbd_connection *conn)
+{
+	return register_with_ctdbd(conn, CTDB_SRVID_RECONFIGURE);
+}
+
+#else
+
+NTSTATUS ctdbd_init_connection(TALLOC_CTX *mem_ctx,
+			       struct ctdbd_connection **pconn)
+{
+	return NT_STATUS_NOT_IMPLEMENTED;
+}
+
+#endif