getncchanges.c: Rename anc_cache to obj_cache

When we add GET_TGT support we will reuse the ancestor cache and it
should work the same way - if we've already sent an object because it
was needed for resolving a child object or a link target, then there's
no point sending it again.

This just renames anc_cache --> obj_cache.

An extra is_get_anc flag has been added to getnc_state - once GET_TGT
support is added, we can't assume GET_ANC based solely on the existence
of the obj_cache.

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

diff --git a/source4/rpc_server/drsuapi/getncchanges.c b/source4/rpc_server/drsuapi/getncchanges.c
index cc41abbc2271001cc83e334f68e361d313385af3..7acab667a24682f058b7232b7abc8ae1550762ca 100644 (file)
--- a/source4/rpc_server/drsuapi/getncchanges.c
+++ b/source4/rpc_server/drsuapi/getncchanges.c
@@ -47,13 +47,14 @@
 
 /* state of a partially completed getncchanges call */
 struct drsuapi_getncchanges_state {
-       struct db_context *anc_cache;
+       struct db_context *obj_cache;
        struct GUID *guids;
        uint32_t num_records;
        uint32_t num_processed;
        struct ldb_dn *ncRoot_dn;
        struct GUID ncRoot_guid;
        bool is_schema_nc;
+       bool is_get_anc;
        uint64_t min_usn;
        uint64_t max_usn;
        struct drsuapi_DsReplicaHighWaterMark last_hwm;
@@ -1935,7 +1936,12 @@ static void dcesrv_drsuapi_update_highwatermark(const struct ldb_message *msg,
        hwm->reserved_usn = 0;
 }
 
-static WERROR dcesrv_drsuapi_anc_cache_add(struct db_context *anc_cache,
+/**
+ * Adds an object's GUID to the cache of objects already sent.
+ * This avoids us sending the same object multiple times when
+ * the GetNCChanges request uses a flag like GET_ANC.
+ */
+static WERROR dcesrv_drsuapi_obj_cache_add(struct db_context *obj_cache,
                                           const struct GUID *guid)
 {
        enum ndr_err_code ndr_err;
@@ -1960,7 +1966,7 @@ static WERROR dcesrv_drsuapi_anc_cache_add(struct db_context *anc_cache,
                return WERR_DS_DRA_INTERNAL_ERROR;
        }
 
-       status = dbwrap_store(anc_cache, key, val, TDB_REPLACE);
+       status = dbwrap_store(obj_cache, key, val, TDB_REPLACE);
        if (!NT_STATUS_IS_OK(status)) {
                return WERR_DS_DRA_INTERNAL_ERROR;
        }
@@ -1968,7 +1974,11 @@ static WERROR dcesrv_drsuapi_anc_cache_add(struct db_context *anc_cache,
        return WERR_OK;
 }
 
-static WERROR dcesrv_drsuapi_anc_cache_exists(struct db_context *anc_cache,
+/**
+ * Checks if the object with the GUID specified already exists in the
+ * object cache, i.e. it's already been sent in a GetNCChanges response.
+ */
+static WERROR dcesrv_drsuapi_obj_cache_exists(struct db_context *obj_cache,
                                              const struct GUID *guid)
 {
        enum ndr_err_code ndr_err;
@@ -1989,7 +1999,7 @@ static WERROR dcesrv_drsuapi_anc_cache_exists(struct db_context *anc_cache,
                return WERR_DS_DRA_INTERNAL_ERROR;
        }
 
-       exists = dbwrap_exists(anc_cache, key);
+       exists = dbwrap_exists(obj_cache, key);
        if (!exists) {
                return WERR_OBJECT_NOT_FOUND;
        }
@@ -2497,10 +2507,11 @@ allowed:
                if (req10->extended_op != DRSUAPI_EXOP_NONE) {
                        /* Do nothing */
                } else if (req10->replica_flags & DRSUAPI_DRS_GET_ANC) {
-                       getnc_state->anc_cache = db_open_rbt(getnc_state);
-                       if (getnc_state->anc_cache == NULL) {
+                       getnc_state->obj_cache = db_open_rbt(getnc_state);
+                       if (getnc_state->obj_cache == NULL) {
                                return WERR_NOT_ENOUGH_MEMORY;
                        }
+                       getnc_state->is_get_anc = true;
                }
        }
 
@@ -2650,8 +2661,8 @@ allowed:
                 * an object, we don't need to do anything more,
                 * as we've already added the links.
                 */
-               if (getnc_state->anc_cache != NULL) {
-                       werr = dcesrv_drsuapi_anc_cache_exists(getnc_state->anc_cache,
+               if (getnc_state->obj_cache != NULL) {
+                       werr = dcesrv_drsuapi_obj_cache_exists(getnc_state->obj_cache,
                                                               &getnc_state->guids[i]);
                        if (W_ERROR_EQUAL(werr, WERR_OBJECT_NAME_EXISTS)) {
                                dcesrv_drsuapi_update_highwatermark(msg,
@@ -2707,14 +2718,16 @@ allowed:
 
                new_objs = obj;
 
-               if (getnc_state->anc_cache != NULL) {
-                       werr = dcesrv_drsuapi_anc_cache_add(getnc_state->anc_cache,
+               if (getnc_state->obj_cache != NULL) {
+                       werr = dcesrv_drsuapi_obj_cache_add(getnc_state->obj_cache,
                                                            &getnc_state->guids[i]);
                        if (!W_ERROR_IS_OK(werr)) {
                                return werr;
                        }
 
-                       next_anc_guid = obj->parent_object_guid;
+                       if (getnc_state->is_get_anc) {
+                               next_anc_guid = obj->parent_object_guid;
+                       }
                }
 
                while (next_anc_guid != NULL) {
@@ -2723,7 +2736,7 @@ allowed:
                        struct ldb_result *anc_res = NULL;
                        struct ldb_dn *anc_dn = NULL;
 
-                       werr = dcesrv_drsuapi_anc_cache_exists(getnc_state->anc_cache,
+                       werr = dcesrv_drsuapi_obj_cache_exists(getnc_state->obj_cache,
                                                               next_anc_guid);
                        if (W_ERROR_EQUAL(werr, WERR_OBJECT_NAME_EXISTS)) {
                                /*
@@ -2810,7 +2823,7 @@ allowed:
                         * Regardless of if we actually use it or not,
                         * we add it to the cache so we don't look at it again
                         */
-                       werr = dcesrv_drsuapi_anc_cache_add(getnc_state->anc_cache,
+                       werr = dcesrv_drsuapi_obj_cache_add(getnc_state->obj_cache,
                                                            next_anc_guid);
                        if (!W_ERROR_IS_OK(werr)) {
                                return werr;