s4-repl: added a preiodic notification check to the repl task

The dreplsrv_notify code checks the partition uSN values every N
seconds, and if one has changed then it sends a DsReplicaSync to all
the replication partners listed in the repsTo attribute for the
partition.

source4/dsdb/config.mk

@@ -62,7 +62,8 @@ DREPL_SRV_OBJ_FILES = $(addprefix $(dsdbsrcdir)/repl/, \
 		drepl_periodic.o \
 		drepl_partitions.o \
 		drepl_out_pull.o \
-		drepl_out_helpers.o)
+		drepl_out_helpers.o \
+		drepl_notify.o)
 
 $(eval $(call proto_header_template,$(dsdbsrcdir)/repl/drepl_service_proto.h,$(DREPL_SRV_OBJ_FILES:.o=.c)))
 

source4/dsdb/repl/drepl_notify.c

@@ -0,0 +1,426 @@
+/* 
+   Unix SMB/CIFS mplementation.
+
+   DSDB replication service periodic notification handling
+   
+   Copyright (C) Andrew Tridgell 2009
+   based on drepl_periodic
+    
+   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 "includes.h"
+#include "lib/events/events.h"
+#include "dsdb/samdb/samdb.h"
+#include "auth/auth.h"
+#include "smbd/service.h"
+#include "lib/messaging/irpc.h"
+#include "dsdb/repl/drepl_service.h"
+#include "lib/ldb/include/ldb_errors.h"
+#include "../lib/util/dlinklist.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/gen_ndr/ndr_drsuapi.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
+#include "libcli/composite/composite.h"
+
+
+struct dreplsrv_op_notify_state {
+	struct composite_context *creq;
+
+	struct dreplsrv_out_connection *conn;
+
+	struct dreplsrv_drsuapi_connection *drsuapi;
+
+	struct drsuapi_DsBindInfoCtr bind_info_ctr;
+	struct drsuapi_DsBind bind_r;
+	struct dreplsrv_notify_operation *op;
+};
+
+/*
+  receive a DsReplicaSync reply
+ */
+static void dreplsrv_op_notify_replica_sync_recv(struct rpc_request *req)
+{
+	struct dreplsrv_op_notify_state *st = talloc_get_type(req->async.private_data,
+							      struct dreplsrv_op_notify_state);
+	struct composite_context *c = st->creq;
+	struct drsuapi_DsReplicaSync *r = talloc_get_type(req->ndr.struct_ptr,
+							  struct drsuapi_DsReplicaSync);
+
+	c->status = dcerpc_ndr_request_recv(req);
+	if (!composite_is_ok(c)) return;
+
+	if (!W_ERROR_IS_OK(r->out.result)) {
+		composite_error(c, werror_to_ntstatus(r->out.result));
+		return;
+	}
+
+	composite_done(c);
+}
+
+/*
+  send a DsReplicaSync
+*/
+static void dreplsrv_op_notify_replica_sync_send(struct dreplsrv_op_notify_state *st)
+{
+	struct composite_context *c = st->creq;
+	struct dreplsrv_partition *partition = st->op->source_dsa->partition;
+	struct dreplsrv_drsuapi_connection *drsuapi = st->op->source_dsa->conn->drsuapi;
+	struct rpc_request *req;
+	struct drsuapi_DsReplicaSync *r;
+
+	r = talloc_zero(st, struct drsuapi_DsReplicaSync);
+	if (composite_nomem(r, c)) return;
+
+	r->in.bind_handle	= &drsuapi->bind_handle;
+	r->in.level = 1;
+	r->in.req.req1.naming_context = &partition->nc;
+	r->in.req.req1.source_dsa_guid = st->op->service->ntds_guid;
+	r->in.req.req1.options = 
+		DRSUAPI_DS_REPLICA_SYNC_ASYNCHRONOUS_OPERATION |
+		DRSUAPI_DS_REPLICA_SYNC_WRITEABLE |
+		DRSUAPI_DS_REPLICA_SYNC_ALL_SOURCES;
+	
+
+	req = dcerpc_drsuapi_DsReplicaSync_send(drsuapi->pipe, r, r);
+	composite_continue_rpc(c, req, dreplsrv_op_notify_replica_sync_recv, st);
+}
+
+/*
+  called when we have an established connection
+ */
+static void dreplsrv_op_notify_connect_recv(struct composite_context *creq)
+{
+	struct dreplsrv_op_notify_state *st = talloc_get_type(creq->async.private_data,
+							      struct dreplsrv_op_notify_state);
+	struct composite_context *c = st->creq;
+
+	c->status = dreplsrv_out_drsuapi_recv(creq);
+	if (!composite_is_ok(c)) return;
+
+	dreplsrv_op_notify_replica_sync_send(st);
+}
+
+/*
+  start the ReplicaSync async call
+ */
+static struct composite_context *dreplsrv_op_notify_send(struct dreplsrv_notify_operation *op)
+{
+	struct composite_context *c;
+	struct composite_context *creq;
+	struct dreplsrv_op_notify_state *st;
+
+	c = composite_create(op, op->service->task->event_ctx);
+	if (c == NULL) return NULL;
+
+	st = talloc_zero(c, struct dreplsrv_op_notify_state);
+	if (composite_nomem(st, c)) return c;
+
+	st->creq	= c;
+	st->op		= op;
+
+	creq = dreplsrv_out_drsuapi_send(op->source_dsa->conn);
+	composite_continue(c, creq, dreplsrv_op_notify_connect_recv, st);
+
+	return c;
+}
+
+static void dreplsrv_notify_del_repsTo(struct dreplsrv_notify_operation *op)
+{
+	uint32_t count;
+	struct repsFromToBlob *reps;
+	WERROR werr;
+	struct dreplsrv_service *s = op->service;
+	int i;
+
+	werr = dsdb_loadreps(s->samdb, op, op->source_dsa->partition->dn, "repsTo", &reps, &count);
+	if (!W_ERROR_IS_OK(werr)) {
+		DEBUG(0,(__location__ ": Failed to load repsTo for %s\n",
+			 ldb_dn_get_linearized(op->source_dsa->partition->dn)));
+		return;
+	}
+
+	for (i=0; i<count; i++) {
+		if (GUID_compare(&reps[i].ctr.ctr1.source_dsa_obj_guid, 
+				 &op->source_dsa->repsFrom1->source_dsa_obj_guid) == 0) {
+			memmove(&reps[i], &reps[i+1],
+				sizeof(reps[i])*(count-(i+1)));
+			count--;
+		}
+	}
+
+	werr = dsdb_savereps(s->samdb, op, op->source_dsa->partition->dn, "repsTo", reps, count);
+	if (!W_ERROR_IS_OK(werr)) {
+		DEBUG(0,(__location__ ": Failed to save repsTo for %s\n",
+			 ldb_dn_get_linearized(op->source_dsa->partition->dn)));
+		return;
+	}
+}
+
+/*
+  called when a notify operation has completed
+ */
+static void dreplsrv_notify_op_callback(struct dreplsrv_notify_operation *op)
+{
+	NTSTATUS status;
+	struct dreplsrv_service *s = op->service;
+
+	status = composite_wait(op->creq);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("dreplsrv_notify: Failed to send DsReplicaSync to %s - %s\n",
+			 op->source_dsa->repsFrom1->other_info->dns_name,
+			 nt_errstr(status)));
+	} else {
+		DEBUG(2,("dreplsrv_notify: DsReplicaSync OK for %s\n",
+			 op->source_dsa->repsFrom1->other_info->dns_name));
+		op->source_dsa->notify_uSN = op->uSN;
+		/* delete the repsTo for this replication partner in the
+		   partition, as we have successfully told him to sync */
+		dreplsrv_notify_del_repsTo(op);
+	}
+	talloc_free(op->creq);
+
+	talloc_free(op);
+	s->ops.n_current = NULL;
+	dreplsrv_notify_run_ops(s);
+}
+
+
+static void dreplsrv_notify_op_callback_creq(struct composite_context *creq)
+{
+	struct dreplsrv_notify_operation *op = talloc_get_type(creq->async.private_data,
+							       struct dreplsrv_notify_operation);
+	dreplsrv_notify_op_callback(op);
+}
+
+/*
+  run any pending replica sync calls
+ */
+void dreplsrv_notify_run_ops(struct dreplsrv_service *s)
+{
+	struct dreplsrv_notify_operation *op;
+
+	if (s->ops.n_current || s->ops.current) {
+		/* if there's still one running, we're done */
+		return;
+	}
+
+	if (!s->ops.notifies) {
+		/* if there're no pending operations, we're done */
+		return;
+	}
+
+	op = s->ops.notifies;
+	s->ops.n_current = op;
+	DLIST_REMOVE(s->ops.notifies, op);
+
+	op->creq = dreplsrv_op_notify_send(op);
+	if (!op->creq) {
+		dreplsrv_notify_op_callback(op);
+		return;
+	}
+
+	op->creq->async.fn		= dreplsrv_notify_op_callback_creq;
+	op->creq->async.private_data	= op;
+}
+
+
+/*
+  find a source_dsa for a given guid
+ */
+static struct dreplsrv_partition_source_dsa *dreplsrv_find_source_dsa(struct dreplsrv_partition *p,
+								      struct GUID *guid)
+{
+	struct dreplsrv_partition_source_dsa *s;
+
+	for (s=p->sources; s; s=s->next) {
+		if (GUID_compare(&s->repsFrom1->source_dsa_obj_guid, guid) == 0) {
+			return s;
+		}
+	}
+	return NULL;
+}
+
+
+/*
+  schedule a replicaSync message
+ */
+static WERROR dreplsrv_schedule_notify_sync(struct dreplsrv_service *service,
+					    struct dreplsrv_partition *p,
+					    struct repsFromToBlob *reps,
+					    TALLOC_CTX *mem_ctx,
+					    uint64_t uSN)
+{
+	struct dreplsrv_notify_operation *op;
+	struct dreplsrv_partition_source_dsa *s;
+
+	s = dreplsrv_find_source_dsa(p, &reps->ctr.ctr1.source_dsa_obj_guid);
+	if (s == NULL) {
+		DEBUG(0,(__location__ ": Unable to find source_dsa for %s\n",
+			 GUID_string(mem_ctx, &reps->ctr.ctr1.source_dsa_obj_guid)));
+		return WERR_DS_UNAVAILABLE;
+	}
+
+	op = talloc_zero(mem_ctx, struct dreplsrv_notify_operation);
+	W_ERROR_HAVE_NO_MEMORY(op);
+
+	op->service	= service;
+	op->source_dsa	= s;
+	op->uSN         = uSN;
+
+	DLIST_ADD_END(service->ops.notifies, op, struct dreplsrv_notify_operation *);
+	talloc_steal(service, op);
+	return WERR_OK;
+}
+
+/*
+  see if a partition has a hugher uSN than what is in the repsTo and
+  if so then send a DsReplicaSync
+ */
+static WERROR dreplsrv_notify_check(struct dreplsrv_service *s, 
+				    struct dreplsrv_partition *p,
+				    TALLOC_CTX *mem_ctx)
+{
+	uint32_t count;
+	struct repsFromToBlob *reps;
+	WERROR werr;
+	uint64_t uSN;
+	int ret, i;
+
+	werr = dsdb_loadreps(s->samdb, mem_ctx, p->dn, "repsTo", &reps, &count);
+	if (!W_ERROR_IS_OK(werr)) {
+		DEBUG(0,(__location__ ": Failed to load repsTo for %s\n",
+			 ldb_dn_get_linearized(p->dn)));
+		return werr;
+	}
+
+	/* loads the partition uSNHighest */
+	ret = dsdb_load_partition_usn(s->samdb, p->dn, &uSN);
+	if (ret != LDB_SUCCESS || uSN == 0) {
+		/* nothing to do */
+		return WERR_OK;
+	}
+
+	/* see if any of our partners need some of our objects */
+	for (i=0; i<count; i++) {
+		struct dreplsrv_partition_source_dsa *sdsa;
+		sdsa = dreplsrv_find_source_dsa(p, &reps[i].ctr.ctr1.source_dsa_obj_guid);
+		if (sdsa == NULL) continue;
+		if (sdsa->notify_uSN < uSN) {
+			/* we need to tell this partner to replicate
+			   with us */
+			werr = dreplsrv_schedule_notify_sync(s, p, &reps[i], mem_ctx, uSN);
+			if (!W_ERROR_IS_OK(werr)) {
+				DEBUG(0,(__location__ ": Failed to setup notify to %s for %s\n",
+					 reps[i].ctr.ctr1.other_info->dns_name,
+					 ldb_dn_get_linearized(p->dn)));
+				return werr;
+			}
+		}
+	}
+
+
+	return WERR_OK;
+}
+
+/*
+  see if any of the partitions have changed, and if so then send a
+  DsReplicaSync to all the replica partners in the repsTo object
+ */
+static WERROR dreplsrv_notify_check_all(struct dreplsrv_service *s, TALLOC_CTX *mem_ctx)
+{
+	WERROR status;
+	struct dreplsrv_partition *p;
+
+	for (p = s->partitions; p; p = p->next) {
+		status = dreplsrv_notify_check(s, p, mem_ctx);
+		W_ERROR_NOT_OK_RETURN(status);
+	}
+
+	return WERR_OK;
+}
+
+static void dreplsrv_notify_run(struct dreplsrv_service *service);
+
+static void dreplsrv_notify_handler_te(struct tevent_context *ev, struct tevent_timer *te,
+				       struct timeval t, void *ptr)
+{
+	struct dreplsrv_service *service = talloc_get_type(ptr, struct dreplsrv_service);
+	WERROR status;
+
+	service->notify.te = NULL;
+
+	dreplsrv_notify_run(service);
+
+	status = dreplsrv_notify_schedule(service, service->notify.interval);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(service->task, win_errstr(status));
+		return;
+	}
+}
+
+WERROR dreplsrv_notify_schedule(struct dreplsrv_service *service, uint32_t next_interval)
+{
+	TALLOC_CTX *tmp_mem;
+	struct tevent_timer *new_te;
+	struct timeval next_time;
+
+	/* prevent looping */
+	if (next_interval == 0) next_interval = 1;
+
+	next_time = timeval_current_ofs(next_interval, 50);
+
+	if (service->notify.te) {
+		/*
+		 * if the timestamp of the new event is higher,
+		 * as current next we don't need to reschedule
+		 */
+		if (timeval_compare(&next_time, &service->notify.next_event) > 0) {
+			return WERR_OK;
+		}
+	}
+
+	/* reset the next scheduled timestamp */
+	service->notify.next_event = next_time;
+
+	new_te = event_add_timed(service->task->event_ctx, service,
+			         service->notify.next_event,
+			         dreplsrv_notify_handler_te, service);
+	W_ERROR_HAVE_NO_MEMORY(new_te);
+
+	tmp_mem = talloc_new(service);
+	DEBUG(2,("dreplsrv_notify_schedule(%u) %sscheduled for: %s\n",
+		next_interval,
+		(service->notify.te?"re":""),
+		nt_time_string(tmp_mem, timeval_to_nttime(&next_time))));
+	talloc_free(tmp_mem);
+
+	talloc_free(service->notify.te);
+	service->notify.te = new_te;
+
+	return WERR_OK;
+}
+
+static void dreplsrv_notify_run(struct dreplsrv_service *service)
+{
+	TALLOC_CTX *mem_ctx;
+
+	mem_ctx = talloc_new(service);
+	dreplsrv_notify_check_all(service, mem_ctx);
+	talloc_free(mem_ctx);
+
+	dreplsrv_run_pending_ops(service);
+	dreplsrv_notify_run_ops(service);
+}

source4/dsdb/repl/drepl_out_helpers.c

@@ -48,7 +48,7 @@ struct dreplsrv_out_drsuapi_state {
 
 static void dreplsrv_out_drsuapi_connect_recv(struct composite_context *creq);
 
-static struct composite_context *dreplsrv_out_drsuapi_send(struct dreplsrv_out_connection *conn)
+struct composite_context *dreplsrv_out_drsuapi_send(struct dreplsrv_out_connection *conn)
 {
 	struct composite_context *c;
 	struct composite_context *creq;
@@ -165,7 +165,7 @@ static void dreplsrv_out_drsuapi_bind_recv(struct rpc_request *req)
 	composite_done(c);
 }
 
-static NTSTATUS dreplsrv_out_drsuapi_recv(struct composite_context *c)
+NTSTATUS dreplsrv_out_drsuapi_recv(struct composite_context *c)
 {
 	NTSTATUS status;
 	struct dreplsrv_out_drsuapi_state *st = talloc_get_type(c->private_data,

source4/dsdb/repl/drepl_out_pull.c

@@ -125,6 +125,7 @@ done:
 	talloc_free(op);
 	s->ops.current = NULL;
 	dreplsrv_run_pending_ops(s);
+	dreplsrv_notify_run_ops(s);
 }
 
 static void dreplsrv_pending_op_callback_creq(struct composite_context *creq)
@@ -140,7 +141,7 @@ void dreplsrv_run_pending_ops(struct dreplsrv_service *s)
 	time_t t;
 	NTTIME now;
 
-	if (s->ops.current) {
+	if (s->ops.current || s->ops.n_current) {
 		/* if there's still one running, we're done */
 		return;
 	}

source4/dsdb/repl/drepl_periodic.c

@@ -110,4 +110,5 @@ static void dreplsrv_periodic_run(struct dreplsrv_service *service)
 	dreplsrv_refresh_partitions(service);
 
 	dreplsrv_run_pending_ops(service);
+	dreplsrv_notify_run_ops(service);
 }

source4/dsdb/repl/drepl_service.c

@@ -196,6 +196,16 @@ static void dreplsrv_task_init(struct task_server *task)
 		return;
 	}
 
+	service->notify.interval = lp_parm_int(task->lp_ctx, NULL, "dreplsrv", 
+					       "notify_interval", 5); /* in seconds */
+	status = dreplsrv_notify_schedule(service, service->notify.interval);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(task, talloc_asprintf(task,
+				      "dreplsrv: Failed to setup notify schedule: %s\n",
+				      win_errstr(status)));
+		return;
+	}
+
 	irpc_add_name(task->msg_ctx, "dreplsrv");
 
 	IRPC_REGISTER(task->msg_ctx, drsuapi, DRSUAPI_DSREPLICASYNC, drepl_replica_sync, service);

source4/dsdb/repl/drepl_service.h

@@ -69,6 +69,9 @@ struct dreplsrv_partition_source_dsa {
 	struct repsFromToBlob _repsFromBlob;
 	struct repsFromTo1 *repsFrom1;
 
+	/* the last uSN when we sent a notify */
+	uint64_t notify_uSN;
+	
 	/* the reference to the source_dsa and its outgoing connection */
 	struct dreplsrv_out_connection *conn;
 };
@@ -107,6 +110,17 @@ struct dreplsrv_out_operation {
 	struct composite_context *creq;
 };
 
+struct dreplsrv_notify_operation {
+	struct dreplsrv_notify_operation *prev, *next;
+
+	struct dreplsrv_service *service;
+	uint64_t uSN;
+
+	struct dreplsrv_partition_source_dsa *source_dsa;
+
+	struct composite_context *creq;
+};
+
 struct dreplsrv_service {
 	/* the whole drepl service is in one task */
 	struct task_server *task;
@@ -150,6 +164,23 @@ struct dreplsrv_service {
 		struct tevent_timer *te;
 	} periodic;
 
+	/* some stuff for notify processing */
+	struct {
+		/*
+		 * the interval between notify runs
+		 */
+		uint32_t interval;
+
+		/*
+		 * the timestamp for the next event,
+		 * this is the timstamp passed to event_add_timed()
+		 */
+		struct timeval next_event;
+
+		/* here we have a reference to the timed event the schedules the notifies */
+		struct tevent_timer *te;
+	} notify;
+
 	/*
 	 * the list of partitions we need to replicate
 	 */
@@ -166,6 +197,12 @@ struct dreplsrv_service {
 
 		/* the list of pending operations */
 		struct dreplsrv_out_operation *pending;
+
+		/* the list of pending notify operations */
+		struct dreplsrv_notify_operation *notifies;
+
+		/* an active notify operation */
+		struct dreplsrv_notify_operation *n_current;
 	} ops;
 };