s4:drsuapi/getncchanges.c - Update the list of operational attributes
[ira/wip.git] / source4 / rpc_server / drsuapi / getncchanges.c
index 14d4f0d6d12bc41abadd0d25d1497a0d239f60d3..488ecd129e6c505d3f5ec613c09608d53f062e16 100644 (file)
 */
 
 #include "includes.h"
-#include "librpc/gen_ndr/ndr_drsuapi.h"
 #include "rpc_server/dcerpc_server.h"
-#include "rpc_server/common/common.h"
 #include "dsdb/samdb/samdb.h"
-#include "lib/ldb/include/ldb_errors.h"
 #include "param/param.h"
 #include "librpc/gen_ndr/ndr_drsblobs.h"
-#include "auth/auth.h"
 #include "rpc_server/drsuapi/dcesrv_drsuapi.h"
 #include "rpc_server/dcerpc_server_proto.h"
 #include "../libcli/drsuapi/drsuapi.h"
-#include "../libcli/security/dom_sid.h"
 #include "libcli/security/security.h"
 
 /* 
@@ -44,7 +39,8 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
                                          struct ldb_dn *ncRoot_dn,
                                          struct dsdb_schema *schema,
                                          DATA_BLOB *session_key,
-                                         uint64_t highest_usn)
+                                         uint64_t highest_usn,
+                                         uint32_t replica_flags)
 {
        const struct ldb_val *md_value;
        int i, n;
@@ -54,6 +50,8 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
        uint32_t rid = 0;
        enum ndr_err_code ndr_err;
        uint32_t *attids;
+       const char *rdn;
+       const struct dsdb_attribute *rdn_sa;
 
        if (ldb_dn_compare(ncRoot_dn, msg->dn) == 0) {
                obj->is_nc_prefix = true;
@@ -61,7 +59,15 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
        } else {
                obj->is_nc_prefix = false;
                obj->parent_object_guid = talloc(obj, struct GUID);
+               if (obj->parent_object_guid == NULL) {
+                       return WERR_DS_DRA_INTERNAL_ERROR;
+               }
                *obj->parent_object_guid = samdb_result_guid(msg, "parentGUID");
+               if (GUID_all_zero(obj->parent_object_guid)) {
+                       DEBUG(0,(__location__ ": missing parentGUID for %s\n",
+                                ldb_dn_get_linearized(msg->dn)));
+                       return WERR_DS_DRA_INTERNAL_ERROR;
+               }
        }
        obj->next_object = NULL;
        
@@ -82,12 +88,44 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
                return WERR_DS_DRA_INTERNAL_ERROR;
        }
 
+       rdn = ldb_dn_get_rdn_name(msg->dn);
+       if (rdn == NULL) {
+               DEBUG(0,(__location__ ": No rDN for %s\n", ldb_dn_get_linearized(msg->dn)));
+               return WERR_DS_DRA_INTERNAL_ERROR;
+       }
+
+       rdn_sa = dsdb_attribute_by_lDAPDisplayName(schema, rdn);
+       if (rdn_sa == NULL) {
+               DEBUG(0,(__location__ ": Can't find dsds_attribute for rDN %s in %s\n", 
+                        rdn, ldb_dn_get_linearized(msg->dn)));
+               return WERR_DS_DRA_INTERNAL_ERROR;
+       }
+
        obj->meta_data_ctr = talloc(obj, struct drsuapi_DsReplicaMetaDataCtr);
        attids = talloc_array(obj, uint32_t, md.ctr.ctr1.count);
+
+       obj->object.identifier = talloc(obj, struct drsuapi_DsReplicaObjectIdentifier);
+       obj_dn = ldb_msg_find_attr_as_dn(sam_ctx, obj, msg, "distinguishedName");
+       obj->object.identifier->dn = ldb_dn_get_linearized(obj_dn);
+       obj->object.identifier->guid = samdb_result_guid(msg, "objectGUID");
+       sid = samdb_result_dom_sid(obj, msg, "objectSid");
+       if (sid) {
+               dom_sid_split_rid(NULL, sid, NULL, &rid);
+               obj->object.identifier->sid = *sid;
+       } else {
+               ZERO_STRUCT(obj->object.identifier->sid);
+       }
        
        obj->meta_data_ctr->meta_data = talloc_array(obj, struct drsuapi_DsReplicaMetaData, md.ctr.ctr1.count);
        for (n=i=0; i<md.ctr.ctr1.count; i++) {
-               if (md.ctr.ctr1.array[i].local_usn < highest_usn) continue;
+               /* if the attribute has not changed, and it is not the
+                  instanceType then don't include it */
+               if (md.ctr.ctr1.array[i].local_usn < highest_usn &&
+                   md.ctr.ctr1.array[i].attid != DRSUAPI_ATTRIBUTE_instanceType) continue;
+
+               /* don't include the rDN */
+               if (md.ctr.ctr1.array[i].attid == rdn_sa->attributeID_id) continue;
+
                obj->meta_data_ctr->meta_data[n].originating_change_time = md.ctr.ctr1.array[i].originating_change_time;
                obj->meta_data_ctr->meta_data[n].version = md.ctr.ctr1.array[i].version;
                obj->meta_data_ctr->meta_data[n].originating_invocation_id = md.ctr.ctr1.array[i].originating_invocation_id;
@@ -104,18 +142,7 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
 
        obj->meta_data_ctr->count = n;
 
-       obj->object.identifier = talloc(obj, struct drsuapi_DsReplicaObjectIdentifier);
-       obj_dn = ldb_msg_find_attr_as_dn(sam_ctx, obj, msg, "distinguishedName");
-       obj->object.identifier->dn = ldb_dn_get_linearized(obj_dn);
-       obj->object.identifier->guid = samdb_result_guid(msg, "objectGUID");
-       sid = samdb_result_dom_sid(obj, msg, "objectSid");
-       if (sid) {
-               dom_sid_split_rid(NULL, sid, NULL, &rid);
-               obj->object.identifier->sid = *sid;
-       } else {
-               ZERO_STRUCT(obj->object.identifier->sid);
-       }
-
+       obj->object.flags = DRSUAPI_DS_REPLICA_OBJECT_FROM_MASTER;
        obj->object.attribute_ctr.num_attributes = obj->meta_data_ctr->count;
        obj->object.attribute_ctr.attributes = talloc_array(obj, struct drsuapi_DsReplicaAttribute,
                                                            obj->object.attribute_ctr.num_attributes);
@@ -125,10 +152,10 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
         * be the same size and in the same order
         */
        for (i=0; i<obj->object.attribute_ctr.num_attributes; i++) {
-               const struct dsdb_attribute *sa;
                struct ldb_message_element *el;
                WERROR werr;
-
+               const struct dsdb_attribute *sa;
+       
                sa = dsdb_attribute_by_attributeID_id(schema, attids[i]);
                if (!sa) {
                        DEBUG(0,("Unable to find attributeID %u in schema\n", attids[i]));
@@ -137,7 +164,8 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
 
                el = ldb_msg_find_element(msg, sa->lDAPDisplayName);
                if (el == NULL) {
-                       DEBUG(0,("No element '%s' for attributeID %u in message\n", 
+                       /* this happens for attributes that have been removed */
+                       DEBUG(5,("No element '%s' for attributeID %u in message\n",
                                 sa->lDAPDisplayName, attids[i]));
                        ZERO_STRUCT(obj->object.attribute_ctr.attributes[i]);
                        obj->object.attribute_ctr.attributes[i].attid = attids[i];
@@ -149,7 +177,13 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
                                         sa->lDAPDisplayName, win_errstr(werr)));
                                return werr;
                        }
-
+                       /* if DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING is set
+                        * check if attribute is secret and send a null value
+                        */
+                       if (replica_flags & DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING) {
+                               drsuapi_process_secret_attribute(&obj->object.attribute_ctr.attributes[i],
+                                                                &obj->meta_data_ctr->meta_data[i]);
+                       }
                        /* some attributes needs to be encrypted
                           before being sent */
                        werr = drsuapi_encrypt_attribute(obj, session_key, rid, 
@@ -165,12 +199,6 @@ static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItem
        return WERR_OK;
 }
 
-static int replmd_drsuapi_DsReplicaCursor2_compare(const struct drsuapi_DsReplicaCursor2 *c1,
-                                                  const struct drsuapi_DsReplicaCursor2 *c2)
-{
-       return GUID_compare(&c1->source_dsa_invocation_id, &c2->source_dsa_invocation_id);
-}
-
 /*
   load replUpToDateVector from a DN
  */
@@ -219,14 +247,13 @@ static WERROR load_udv(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx,
  */
 static WERROR get_nc_changes_udv(struct ldb_context *sam_ctx,
                                 struct ldb_dn *ncRoot_dn,
-                                struct drsuapi_DsReplicaCursor2CtrEx *udv)
+                                struct drsuapi_DsReplicaCursor2CtrEx *udv,
+                                uint64_t highestUSN)
 {
        WERROR werr;
        struct drsuapi_DsReplicaCursor2 *tmp_cursor;
-       uint64_t highest_commited_usn;
        NTTIME now;
        time_t t = time(NULL);
-       int ret;
        struct replUpToDateVectorBlob ouv;
 
        werr = load_udv(sam_ctx, udv, ncRoot_dn, &ouv);
@@ -234,14 +261,9 @@ static WERROR get_nc_changes_udv(struct ldb_context *sam_ctx,
                return werr;
        }
        
-       ret = ldb_sequence_number(sam_ctx, LDB_SEQ_HIGHEST_SEQ, &highest_commited_usn);
-       if (ret != LDB_SUCCESS) {
-               return WERR_DS_DRA_INTERNAL_ERROR;
-       }
-
        tmp_cursor = talloc(udv, struct drsuapi_DsReplicaCursor2);
        tmp_cursor->source_dsa_invocation_id = *(samdb_ntds_invocation_id(sam_ctx));
-       tmp_cursor->highest_usn = highest_commited_usn;
+       tmp_cursor->highest_usn = highestUSN;
        unix_to_nt_time(&now, t);
        tmp_cursor->last_sync_success = now;
 
@@ -255,21 +277,29 @@ static WERROR get_nc_changes_udv(struct ldb_context *sam_ctx,
        
        qsort(udv->cursors, udv->count,
              sizeof(struct drsuapi_DsReplicaCursor2),
-             (comparison_fn_t)replmd_drsuapi_DsReplicaCursor2_compare);
+             (comparison_fn_t)drsuapi_DsReplicaCursor2_compare);
 
        return WERR_OK;
 }
 
+/* state of a partially completed getncchanges call */
+struct drsuapi_getncchanges_state {
+       struct ldb_result *site_res;
+       uint32_t num_sent;
+       struct ldb_dn *ncRoot_dn;
+       uint64_t min_usn;
+       uint64_t highest_usn;
+};
+
 /* 
   drsuapi_DsGetNCChanges
+
+  see MS-DRSR 4.1.10.5.2 for basic logic of this function
 */
 WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
                                     struct drsuapi_DsGetNCChanges *r)
 {
-       struct ldb_result *site_res;
        struct drsuapi_DsReplicaObjectIdentifier *ncRoot;
-       struct ldb_context *sam_ctx;
-       struct ldb_dn *ncRoot_dn;
        int ret;
        int i;
        struct dsdb_schema *schema;
@@ -277,48 +307,109 @@ WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_
        struct drsuapi_DsReplicaObjectListItemEx **currentObject;
        NTSTATUS status;
        DATA_BLOB session_key;
-       const char *attrs[] = { "*", "parentGUID", NULL };
+       const char *attrs[] = { "*", "distinguishedName",
+                               "nTSecurityDescriptor",
+                               "parentGUID",
+                               "replPropertyMetaData",
+                               "unicodePwd",
+                               "dBCSPwd",
+                               "ntPwdHistory",
+                               "lmPwdHistory",
+                               "supplementalCredentials",
+                               NULL };
        WERROR werr;
-       
+       struct dcesrv_handle *h;
+       struct drsuapi_bind_state *b_state;     
+       struct drsuapi_getncchanges_state *getnc_state;
+       struct drsuapi_DsGetNCChangesRequest8 *req8;
+       uint32_t options;
+
+       DCESRV_PULL_HANDLE_WERR(h, r->in.bind_handle, DRSUAPI_BIND_HANDLE);
+       b_state = h->data;
+
        *r->out.level_out = 6;
        /* TODO: linked attributes*/
        r->out.ctr->ctr6.linked_attributes_count = 0;
        r->out.ctr->ctr6.linked_attributes = NULL;
 
        r->out.ctr->ctr6.object_count = 0;
+       r->out.ctr->ctr6.nc_object_count = 0;
        r->out.ctr->ctr6.more_data = false;
        r->out.ctr->ctr6.uptodateness_vector = NULL;
 
-       /* Check request revision. */
+       /* a RODC doesn't allow for any replication */
+       if (samdb_rodc(ldb_get_opaque(b_state->sam_ctx, "loadparm"))) {
+               DEBUG(0,(__location__ ": DsGetNCChanges attempt on RODC\n"));
+               return WERR_DS_DRA_SOURCE_DISABLED;
+       }
+
+       /* Check request revision. 
+          TODO: Adding mappings to req8 from the other levels
+        */
        if (r->in.level != 8) {
+               DEBUG(0,(__location__ ": Request for DsGetNCChanges with unsupported level %u\n",
+                        r->in.level));
                return WERR_REVISION_MISMATCH;
        }
 
+       req8 = &r->in.req->req8;
+
         /* Perform access checks. */
-       if (r->in.req->req8.naming_context == NULL) {
+       /* TODO: we need to support a sync on a specific non-root
+        * DN. We'll need to find the real partition root here */
+       ncRoot = req8->naming_context;
+       if (ncRoot == NULL) {
+               DEBUG(0,(__location__ ": Request for DsGetNCChanges with no NC\n"));
                return WERR_DS_DRA_INVALID_PARAMETER;
        }
 
-       ncRoot = r->in.req->req8.naming_context;
-       if (ncRoot == NULL) {
-               return WERR_DS_DRA_BAD_NC;
+       if (samdb_ntds_options(b_state->sam_ctx, &options) != LDB_SUCCESS) {
+               return WERR_DS_DRA_INTERNAL_ERROR;
        }
+       
+       if ((options & DS_NTDSDSA_OPT_DISABLE_OUTBOUND_REPL) &&
+           !(req8->replica_flags & DRSUAPI_DRS_SYNC_FORCED)) {
+               return WERR_DS_DRA_SOURCE_DISABLED;
+       }
+
+
+       if (req8->replica_flags & DRSUAPI_DS_REPLICA_NEIGHBOUR_FULL_SYNC_PACKET) {
+               /* Ignore the _in_ uptpdateness vector*/
+               req8->uptodateness_vector = NULL;
+       } 
 
-       if (security_session_user_level(dce_call->conn->auth_state.session_info) <
-           SECURITY_DOMAIN_CONTROLLER) {
-               DEBUG(0,("getncchanges refused for security token\n"));
-               return WERR_DS_DRA_ACCESS_DENIED;
+       werr = drs_security_level_check(dce_call, "DsGetNCChanges");
+       if (!W_ERROR_IS_OK(werr)) {
+               return werr;
        }
 
-       /*
-        * connect to the samdb. TODO: We need to check that the caller
-        * has the rights to do this. This exposes all attributes,
-        * including all passwords.
-        */
-       sam_ctx = samdb_connect(mem_ctx, dce_call->event_ctx, dce_call->conn->dce_ctx->lp_ctx, 
-                               system_session(mem_ctx, dce_call->conn->dce_ctx->lp_ctx));
-       if (!sam_ctx) {
-               return WERR_FOOBAR;
+       getnc_state = b_state->getncchanges_state;
+
+       /* see if a previous replication has been abandoned */
+       if (getnc_state) {
+               struct ldb_dn *new_dn = ldb_dn_new(getnc_state, b_state->sam_ctx, ncRoot->dn);
+               if (ldb_dn_compare(new_dn, getnc_state->ncRoot_dn) != 0) {
+                       DEBUG(0,(__location__ ": DsGetNCChanges 2nd replication on different DN %s %s\n",
+                                ldb_dn_get_linearized(new_dn),
+                                ldb_dn_get_linearized(getnc_state->ncRoot_dn)));
+                       talloc_free(getnc_state);
+                       getnc_state = NULL;
+               }
+       }
+
+       if (getnc_state == NULL) {
+               getnc_state = talloc_zero(b_state, struct drsuapi_getncchanges_state);
+               if (getnc_state == NULL) {
+                       return WERR_NOMEM;
+               }
+               b_state->getncchanges_state = getnc_state;
+               getnc_state->ncRoot_dn = ldb_dn_new(getnc_state, b_state->sam_ctx, ncRoot->dn);
+       }
+
+       if (!ldb_dn_validate(getnc_state->ncRoot_dn) ||
+           ldb_dn_is_null(getnc_state->ncRoot_dn)) {
+               DEBUG(0,(__location__ ": Bad DN '%s'\n", ncRoot->dn));
+               return WERR_DS_DRA_INVALID_PARAMETER;
        }
 
        /* we need the session key for encrypting password attributes */
@@ -328,19 +419,51 @@ WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_
                return WERR_DS_DRA_INTERNAL_ERROR;              
        }
 
-       /* Construct response. */
-       ncRoot_dn = ldb_dn_new(mem_ctx, sam_ctx, ncRoot->dn);
-       ret = drsuapi_search_with_extended_dn(sam_ctx, mem_ctx, &site_res,
-                                             ncRoot_dn, LDB_SCOPE_SUBTREE, attrs,
-                                             "(uSNChanged>=%llu)", 
-                                             (unsigned long long)(r->in.req->req8.highwatermark.highest_usn+1));
-       if (ret != LDB_SUCCESS) {
-               return WERR_DS_DRA_INTERNAL_ERROR;
+       /* we don't yet support extended operations */
+       if (req8->extended_op != DRSUAPI_EXOP_NONE) {
+               DEBUG(0,(__location__ ": Request for DsGetNCChanges extended op 0x%x\n",
+                        (unsigned)req8->extended_op));
+               return WERR_DS_DRA_NOT_SUPPORTED;
        }
 
+       /* 
+          TODO: MS-DRSR section 4.1.10.1.1
+          Work out if this is the start of a new cycle */
+
+       if (getnc_state->site_res == NULL) {
+               char* search_filter;
+               enum ldb_scope scope = LDB_SCOPE_SUBTREE;
+
+               getnc_state->min_usn = req8->highwatermark.highest_usn;
+
+               /* Construct response. */
+               search_filter = talloc_asprintf(mem_ctx,
+                                               "(uSNChanged>=%llu)",
+                                               (unsigned long long)(getnc_state->min_usn+1));
+       
+               if (req8->replica_flags & DRSUAPI_DS_REPLICA_NEIGHBOUR_CRITICAL_ONLY) {
+                       search_filter = talloc_asprintf(mem_ctx,
+                                                       "(&%s(isCriticalSystemObject=TRUE))",
+                                                       search_filter);
+               }
+               
+               if (req8->replica_flags & DRSUAPI_DS_REPLICA_NEIGHBOUR_ASYNC_REP) {
+                       scope = LDB_SCOPE_BASE;
+               }
+               
+               DEBUG(6,(__location__ ": getncchanges on %s using filter %s\n",
+                        ldb_dn_get_linearized(getnc_state->ncRoot_dn), search_filter));
+               ret = drsuapi_search_with_extended_dn(b_state->sam_ctx, getnc_state, &getnc_state->site_res,
+                                                     getnc_state->ncRoot_dn, scope, attrs,
+                                                     "uSNChanged",
+                                                     search_filter);
+               if (ret != LDB_SUCCESS) {
+                       return WERR_DS_DRA_INTERNAL_ERROR;
+               }
+       }
 
        /* Prefix mapping */
-       schema = dsdb_get_schema(sam_ctx);
+       schema = dsdb_get_schema(b_state->sam_ctx);
        if (!schema) {
                DEBUG(0,("No schema in sam_ctx\n"));
                return WERR_DS_DRA_INTERNAL_ERROR;
@@ -349,41 +472,55 @@ WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_
        r->out.ctr->ctr6.naming_context = talloc(mem_ctx, struct drsuapi_DsReplicaObjectIdentifier);
        *r->out.ctr->ctr6.naming_context = *ncRoot;
 
+       if (dsdb_find_guid_by_dn(b_state->sam_ctx, getnc_state->ncRoot_dn, 
+                                &r->out.ctr->ctr6.naming_context->guid) != LDB_SUCCESS) {
+               DEBUG(0,(__location__ ": Failed to find GUID of ncRoot_dn %s\n",
+                        ldb_dn_get_linearized(getnc_state->ncRoot_dn)));
+               return WERR_DS_DRA_INTERNAL_ERROR;
+       }
+
+       /* find the SID if there is one */
+       dsdb_find_sid_by_dn(b_state->sam_ctx, getnc_state->ncRoot_dn, &r->out.ctr->ctr6.naming_context->sid);
+
        dsdb_get_oid_mappings_drsuapi(schema, true, mem_ctx, &ctr);
        r->out.ctr->ctr6.mapping_ctr = *ctr;
 
-       r->out.ctr->ctr6.source_dsa_guid = *(samdb_ntds_objectGUID(sam_ctx));
-       r->out.ctr->ctr6.source_dsa_invocation_id = *(samdb_ntds_invocation_id(sam_ctx));
+       r->out.ctr->ctr6.source_dsa_guid = *(samdb_ntds_objectGUID(b_state->sam_ctx));
+       r->out.ctr->ctr6.source_dsa_invocation_id = *(samdb_ntds_invocation_id(b_state->sam_ctx));
 
-       r->out.ctr->ctr6.old_highwatermark = r->in.req->req8.highwatermark;
-       r->out.ctr->ctr6.new_highwatermark = r->in.req->req8.highwatermark;
-
-       r->out.ctr->ctr6.uptodateness_vector = talloc(mem_ctx, struct drsuapi_DsReplicaCursor2CtrEx);
-       r->out.ctr->ctr6.uptodateness_vector->version = 2;
-       r->out.ctr->ctr6.uptodateness_vector->reserved1 = 0;
-       r->out.ctr->ctr6.uptodateness_vector->reserved2 = 0;
+       r->out.ctr->ctr6.old_highwatermark = req8->highwatermark;
+       r->out.ctr->ctr6.new_highwatermark = req8->highwatermark;
 
        r->out.ctr->ctr6.first_object = NULL;
        currentObject = &r->out.ctr->ctr6.first_object;
 
-       for(i=0; i<site_res->count; i++) {
+       for(i=getnc_state->num_sent; 
+           i<getnc_state->site_res->count && 
+                   (r->out.ctr->ctr6.object_count < req8->max_object_count);
+           i++) {
                int uSN;
                struct drsuapi_DsReplicaObjectListItemEx *obj;
                obj = talloc_zero(mem_ctx, struct drsuapi_DsReplicaObjectListItemEx);
 
-               uSN = ldb_msg_find_attr_as_int(site_res->msgs[i], "uSNChanged", -1);
-               if (uSN > r->out.ctr->ctr6.new_highwatermark.highest_usn) {
+               uSN = ldb_msg_find_attr_as_int(getnc_state->site_res->msgs[i], "uSNChanged", -1);
+               if (uSN > r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn) {
                        r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn = uSN;
-                       r->out.ctr->ctr6.new_highwatermark.highest_usn = uSN;
+               }
+               if (uSN > getnc_state->highest_usn) {
+                       getnc_state->highest_usn = uSN;
                }
 
-               werr = get_nc_changes_build_object(obj, site_res->msgs[i], sam_ctx, ncRoot_dn, 
-                                                  schema, &session_key, r->in.req->req8.highwatermark.highest_usn);
+               werr = get_nc_changes_build_object(obj, getnc_state->site_res->msgs[i], 
+                                                  b_state->sam_ctx, getnc_state->ncRoot_dn, 
+                                                  schema, &session_key, getnc_state->min_usn,
+                                                  req8->replica_flags);
                if (!W_ERROR_IS_OK(werr)) {
                        return werr;
                }
 
                if (obj->meta_data_ctr == NULL) {
+                       DEBUG(0,(__location__ ": getncchanges skipping send of object %s\n",
+                                ldb_dn_get_linearized(getnc_state->site_res->msgs[i]->dn)));
                        /* no attributes to send */
                        talloc_free(obj);
                        continue;
@@ -395,19 +532,59 @@ WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_
                currentObject = &obj->next_object;
        }
 
-       werr = get_nc_changes_udv(sam_ctx, ncRoot_dn, r->out.ctr->ctr6.uptodateness_vector);
-       if (!W_ERROR_IS_OK(werr)) {
-               return werr;
+       getnc_state->num_sent += r->out.ctr->ctr6.object_count;
+
+       r->out.ctr->ctr6.nc_object_count = getnc_state->site_res->count;
+
+       /* the client can us to call UpdateRefs on its behalf to
+          re-establish monitoring of the NC */
+       if ((req8->replica_flags & DRSUAPI_DRS_ADD_REF) && 
+           !GUID_all_zero(&req8->destination_dsa_guid)) {
+               struct drsuapi_DsReplicaUpdateRefsRequest1 ureq;
+               ureq.naming_context = ncRoot;
+               ureq.dest_dsa_dns_name = talloc_asprintf(mem_ctx, "%s._msdcs.%s",
+                                                        GUID_string(mem_ctx, &req8->destination_dsa_guid),
+                                                        lp_realm(dce_call->conn->dce_ctx->lp_ctx));
+               if (!ureq.dest_dsa_dns_name) {
+                       return WERR_NOMEM;
+               }
+               ureq.dest_dsa_guid = req8->destination_dsa_guid;
+               ureq.options = DRSUAPI_DS_REPLICA_UPDATE_ADD_REFERENCE |
+                       DRSUAPI_DS_REPLICA_UPDATE_ASYNCHRONOUS_OPERATION |
+                       DRSUAPI_DS_REPLICA_UPDATE_GETCHG_CHECK;
+               werr = drsuapi_UpdateRefs(b_state, mem_ctx, &ureq);
+               if (!W_ERROR_IS_OK(werr)) {
+                       DEBUG(0,(__location__ ": Failed UpdateRefs in DsGetNCChanges - %s\n",
+                                win_errstr(werr)));
+               }
        }
 
+       if (i < getnc_state->site_res->count) {
+               r->out.ctr->ctr6.more_data = true;
+       } else {
+               r->out.ctr->ctr6.uptodateness_vector = talloc(mem_ctx, struct drsuapi_DsReplicaCursor2CtrEx);
+               r->out.ctr->ctr6.uptodateness_vector->version = 2;
+               r->out.ctr->ctr6.uptodateness_vector->reserved1 = 0;
+               r->out.ctr->ctr6.uptodateness_vector->reserved2 = 0;
+
+               r->out.ctr->ctr6.new_highwatermark.highest_usn = r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn;
 
-       DEBUG(3,("DsGetNCChanges with uSNChanged >= %llu on %s gave %u objects\n", 
-                (unsigned long long)(r->in.req->req8.highwatermark.highest_usn+1),
-                ncRoot->dn, r->out.ctr->ctr6.object_count));
+               werr = get_nc_changes_udv(b_state->sam_ctx, getnc_state->ncRoot_dn, 
+                                         r->out.ctr->ctr6.uptodateness_vector,
+                                         getnc_state->highest_usn);
+               if (!W_ERROR_IS_OK(werr)) {
+                       return werr;
+               }
 
-       if (r->out.ctr->ctr6.object_count <= 10 && DEBUGLVL(6)) {
-               NDR_PRINT_FUNCTION_DEBUG(drsuapi_DsGetNCChanges, NDR_IN|NDR_OUT, r);
+               talloc_free(getnc_state);
+               b_state->getncchanges_state = NULL;
        }
 
+       DEBUG(2,("DsGetNCChanges with uSNChanged >= %llu flags 0x%08x on %s gave %u objects (done %d/%d)\n",
+                (unsigned long long)(req8->highwatermark.highest_usn+1),
+                req8->replica_flags,
+                ncRoot->dn, r->out.ctr->ctr6.object_count,
+                i, r->out.ctr->ctr6.more_data?getnc_state->site_res->count:i));
+
        return WERR_OK;
 }