s4:dsdb Handle backlinks for Windows 2000 level linked attributes
authorAndrew Bartlett <abartlet@samba.org>
Sun, 13 Jun 2010 05:54:23 +0000 (15:54 +1000)
committerAndrew Bartlett <abartlet@samba.org>
Tue, 15 Jun 2010 23:57:51 +0000 (09:57 +1000)
This revives the code from 5964acfa741d691c0196f91c0796122ec025f177,
before tridge and I simplified this too much, and removed the Windows
2000 functional level linked attribute support.

By telling the linked_attributes module that repl_meta_data has
handled the links, we avoid a conflict for the new style (functional
level 2003 and above) linked attributes.  However, we still need
backlinks for 2000 style linked attributes, so this allows that code
in the linked_attributes module to be revived to handle those.

Andrew Bartlett

source4/dsdb/samdb/ldb_modules/linked_attributes.c
source4/dsdb/samdb/ldb_modules/repl_meta_data.c

index 876ada6d2c7d1ef13bf9e60cf5796bb05a8b03a0..2da5a825830bbd765c21c5b680e2435a43fbb191 100644 (file)
 #include "librpc/gen_ndr/ndr_misc.h"
 #include "dsdb/samdb/ldb_modules/util.h"
 
+struct la_private {
+       struct la_context *la_list;
+};
+
+struct la_op_store {
+       struct la_op_store *next;
+       struct la_op_store *prev;
+       enum la_op {LA_OP_ADD, LA_OP_DEL} op;
+       struct GUID guid;
+       char *name;
+       char *value;
+};
+
+struct replace_context {
+       struct la_context *ac;
+       unsigned int num_elements;
+       struct ldb_message_element *el;
+};
+
+struct la_context {
+       struct la_context *next, *prev;
+       const struct dsdb_schema *schema;
+       struct ldb_module *module;
+       struct ldb_request *req;
+       struct ldb_dn *add_dn;
+       struct ldb_dn *del_dn;
+       struct replace_context *rc;
+       struct la_op_store *ops;
+       struct ldb_extended *op_response;
+       struct ldb_control **op_controls;
+};
+
+static struct la_context *linked_attributes_init(struct ldb_module *module,
+                                                struct ldb_request *req)
+{
+       struct ldb_context *ldb;
+       struct la_context *ac;
+
+       ldb = ldb_module_get_ctx(module);
+
+       ac = talloc_zero(req, struct la_context);
+       if (ac == NULL) {
+               ldb_oom(ldb);
+               return NULL;
+       }
+
+       ac->schema = dsdb_get_schema(ldb, ac);
+       ac->module = module;
+       ac->req = req;
+
+       return ac;
+}
+
+/*
+  turn a DN into a GUID
+ */
+static int la_guid_from_dn(struct la_context *ac, struct ldb_dn *dn, struct GUID *guid)
+{
+       int ret;
+       NTSTATUS status;
+
+       status = dsdb_get_extended_dn_guid(dn, guid, "GUID");
+       if (NT_STATUS_IS_OK(status)) {
+               return LDB_SUCCESS;
+       }
+       if (!NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
+               DEBUG(4,(__location__ ": Unable to parse GUID for dn %s\n",
+                        ldb_dn_get_linearized(dn)));
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       ret = dsdb_find_guid_by_dn(ldb_module_get_ctx(ac->module), dn, guid);
+       if (ret != LDB_SUCCESS) {
+               DEBUG(4,(__location__ ": Failed to find GUID for dn %s\n",
+                        ldb_dn_get_linearized(dn)));
+               return ret;
+       }
+       return LDB_SUCCESS;
+}
+
+
+/* Common routine to handle reading the attributes and creating a
+ * series of modify requests */
+static int la_store_op(struct la_context *ac,
+                      enum la_op op, struct ldb_val *dn,
+                      const char *name)
+{
+       struct ldb_context *ldb;
+       struct la_op_store *os;
+       struct ldb_dn *op_dn;
+       int ret;
+
+       ldb = ldb_module_get_ctx(ac->module);
+
+       op_dn = ldb_dn_from_ldb_val(ac, ldb, dn);
+       if (!op_dn) {
+               ldb_asprintf_errstring(ldb, 
+                                      "could not parse attribute as a DN");
+               return LDB_ERR_INVALID_DN_SYNTAX;
+       }
+
+       os = talloc_zero(ac, struct la_op_store);
+       if (!os) {
+               ldb_oom(ldb);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       os->op = op;
+
+       ret = la_guid_from_dn(ac, op_dn, &os->guid);
+       talloc_free(op_dn);
+       if (ret == LDB_ERR_NO_SUCH_OBJECT && ac->req->operation == LDB_DELETE) {
+               /* we are deleting an object, and we've found it has a
+                * forward link to a target that no longer
+                * exists. This is not an error in the delete, and we
+                * should just not do the deferred delete of the
+                * target attribute
+                */
+               talloc_free(os);
+               return LDB_SUCCESS;
+       }
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+
+       os->name = talloc_strdup(os, name);
+       if (!os->name) {
+               ldb_oom(ldb);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       /* Do deletes before adds */
+       if (op == LA_OP_ADD) {
+               DLIST_ADD_END(ac->ops, os, struct la_op_store *);
+       } else {
+               /* By adding to the head of the list, we do deletes before
+                * adds when processing a replace */
+               DLIST_ADD(ac->ops, os);
+       }
+
+       return LDB_SUCCESS;
+}
+
+static int la_queue_mod_request(struct la_context *ac);
+static int la_down_req(struct la_context *ac);
+
+
+
+/* add */
+static int linked_attributes_add(struct ldb_module *module, struct ldb_request *req)
+{
+       struct ldb_context *ldb;
+       const struct dsdb_attribute *target_attr;
+       struct la_context *ac;
+       const char *attr_name;
+       struct ldb_control *ctrl;
+       int ret;
+       int i, j;
+
+       ldb = ldb_module_get_ctx(module);
+
+       if (ldb_dn_is_special(req->op.add.message->dn)) {
+               /* do not manipulate our control entries */
+               return ldb_next_request(module, req);
+       }
+
+       if (!(ctrl = ldb_request_get_control(req, DSDB_CONTROL_APPLY_LINKS))) {
+               /* don't do anything special for linked attributes, repl_meta_data has done it */
+               return ldb_next_request(module, req);
+       }
+       ctrl->critical = false;
+
+       ac = linked_attributes_init(module, req);
+       if (!ac) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       if (!ac->schema) {
+               /* without schema, this doesn't make any sense */
+               talloc_free(ac);
+               return ldb_next_request(module, req);
+       }
+
+       /* Need to ensure we only have forward links being specified */
+       for (i=0; i < req->op.add.message->num_elements; i++) {
+               const struct ldb_message_element *el = &req->op.add.message->elements[i];
+               const struct dsdb_attribute *schema_attr
+                       = dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
+               if (!schema_attr) {
+                       ldb_asprintf_errstring(ldb, 
+                                              "attribute %s is not a valid attribute in schema", el->name);
+                       return LDB_ERR_OBJECT_CLASS_VIOLATION;                  
+               }
+               /* We have a valid attribute, now find out if it is a forward link */
+               if ((schema_attr->linkID == 0) || ((schema_attr->linkID & 1) == 1)) {
+                       continue;
+               }
+               
+               /* Even link IDs are for the originating attribute */
+               target_attr = dsdb_attribute_by_linkID(ac->schema, schema_attr->linkID + 1);
+               if (!target_attr) {
+                       /*
+                        * windows 2003 has a broken schema where
+                        * the definition of msDS-IsDomainFor
+                        * is missing (which is supposed to be
+                        * the backlink of the msDS-HasDomainNCs
+                        * attribute
+                        */
+                       continue;
+               }
+
+               attr_name = target_attr->lDAPDisplayName;
+
+               for (j = 0; j < el->num_values; j++) {
+                       ret = la_store_op(ac, LA_OP_ADD,
+                                         &el->values[j],
+                                         attr_name);
+                       if (ret != LDB_SUCCESS) {
+                               return ret;
+                       }
+               }
+       }
+
+       /* if no linked attributes are present continue */
+       if (ac->ops == NULL) {
+               /* nothing to do for this module, proceed */
+               talloc_free(ac);
+               return ldb_next_request(module, req);
+       }
+
+       /* start with the original request */
+       return la_down_req(ac);
+}
+
+/* For a delete or rename, we need to find out what linked attributes
+ * are currently on this DN, and then deal with them.  This is the
+ * callback to the base search */
+
+static int la_mod_search_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+       struct ldb_context *ldb;
+       const struct dsdb_attribute *schema_attr;
+       const struct dsdb_attribute *target_attr;
+       struct ldb_message_element *search_el;
+       struct replace_context *rc;
+       struct la_context *ac;
+       const char *attr_name;
+       int i, j;
+       int ret = LDB_SUCCESS;
+
+       ac = talloc_get_type(req->context, struct la_context);
+       ldb = ldb_module_get_ctx(ac->module);
+       rc = ac->rc;
+
+       if (!ares) {
+               return ldb_module_done(ac->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+       }
+       if (ares->error != LDB_SUCCESS) {
+               return ldb_module_done(ac->req, ares->controls,
+                                       ares->response, ares->error);
+       }
+
+       /* Only entries are interesting, and we only want the olddn */
+       switch (ares->type) {
+       case LDB_REPLY_ENTRY:
+
+               if (ldb_dn_compare(ares->message->dn, ac->req->op.mod.message->dn) != 0) {
+                       ldb_asprintf_errstring(ldb, 
+                                              "linked_attributes: %s is not the DN we were looking for", 
+                                              ldb_dn_get_linearized(ares->message->dn));
+                       /* Guh?  We only asked for this DN */
+                       talloc_free(ares);
+                       return ldb_module_done(ac->req, NULL, NULL,
+                                               LDB_ERR_OPERATIONS_ERROR);
+               }
+
+               ac->add_dn = ac->del_dn = talloc_steal(ac, ares->message->dn);
+
+               /* We don't populate 'rc' for ADD - it can't be deleting elements anyway */
+               for (i = 0; rc && i < rc->num_elements; i++) {
+
+                       schema_attr = dsdb_attribute_by_lDAPDisplayName(ac->schema, rc->el[i].name);
+                       if (!schema_attr) {
+                               ldb_asprintf_errstring(ldb,
+                                       "attribute %s is not a valid attribute in schema",
+                                       rc->el[i].name);
+                               talloc_free(ares);
+                               return ldb_module_done(ac->req, NULL, NULL,
+                                               LDB_ERR_OBJECT_CLASS_VIOLATION);
+                       }
+
+                       search_el = ldb_msg_find_element(ares->message,
+                                                        rc->el[i].name);
+
+                       /* See if this element already exists */
+                       /* otherwise just ignore as
+                        * the add has already been scheduled */
+                       if ( ! search_el) {
+                               continue;
+                       }
+
+                       target_attr = dsdb_attribute_by_linkID(ac->schema, schema_attr->linkID + 1);
+                       if (!target_attr) {
+                               /*
+                                * windows 2003 has a broken schema where
+                                * the definition of msDS-IsDomainFor
+                                * is missing (which is supposed to be
+                                * the backlink of the msDS-HasDomainNCs
+                                * attribute
+                                */
+                               continue;
+                       }
+                       attr_name = target_attr->lDAPDisplayName;
+
+                       /* Now we know what was there, we can remove it for the re-add */
+                       for (j = 0; j < search_el->num_values; j++) {
+                               ret = la_store_op(ac, LA_OP_DEL,
+                                                 &search_el->values[j],
+                                                 attr_name);
+                               if (ret != LDB_SUCCESS) {
+                                       talloc_free(ares);
+                                       return ldb_module_done(ac->req,
+                                                              NULL, NULL, ret);
+                               }
+                       }
+               }
+
+               break;
+
+       case LDB_REPLY_REFERRAL:
+               /* ignore */
+               break;
+
+       case LDB_REPLY_DONE:
+
+               talloc_free(ares);
+
+               if (ac->req->operation == LDB_ADD) {
+                       /* Start the modifies to the backlinks */
+                       ret = la_queue_mod_request(ac);
+
+                       if (ret != LDB_SUCCESS) {
+                               return ldb_module_done(ac->req, NULL, NULL,
+                                                      ret);
+                       }
+               } else {
+                       /* Start with the original request */
+                       ret = la_down_req(ac);
+                       if (ret != LDB_SUCCESS) {
+                               return ldb_module_done(ac->req, NULL, NULL, ret);
+                       }
+               }
+               return LDB_SUCCESS;
+       }
+
+       talloc_free(ares);
+       return ret;
+}
+
+
+/* modify */
+static int linked_attributes_modify(struct ldb_module *module, struct ldb_request *req)
+{
+       /* Look over list of modifications */
+       /* Find if any are for linked attributes */
+       /* Determine the effect of the modification */
+       /* Apply the modify to the linked entry */
+
+       struct ldb_context *ldb;
+       int i, j;
+       struct la_context *ac;
+       struct ldb_request *search_req;
+       const char **attrs;
+       struct ldb_control *ctrl;
+
+       int ret;
+
+       ldb = ldb_module_get_ctx(module);
+
+       if (ldb_dn_is_special(req->op.mod.message->dn)) {
+               /* do not manipulate our control entries */
+               return ldb_next_request(module, req);
+       }
+
+       if (!(ctrl = ldb_request_get_control(req, DSDB_CONTROL_APPLY_LINKS))) {
+               /* don't do anything special for linked attributes, repl_meta_data has done it */
+               return ldb_next_request(module, req);
+       }
+       ctrl->critical = false;
+
+       ac = linked_attributes_init(module, req);
+       if (!ac) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       if (!ac->schema) {
+               /* without schema, this doesn't make any sense */
+               return ldb_next_request(module, req);
+       }
+
+       ac->rc = talloc_zero(ac, struct replace_context);
+       if (!ac->rc) {
+               ldb_oom(ldb);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       for (i=0; i < req->op.mod.message->num_elements; i++) {
+               bool store_el = false;
+               const char *attr_name;
+               const struct dsdb_attribute *target_attr;
+               const struct ldb_message_element *el = &req->op.mod.message->elements[i];
+               const struct dsdb_attribute *schema_attr
+                       = dsdb_attribute_by_lDAPDisplayName(ac->schema, el->name);
+               if (!schema_attr) {
+                       ldb_asprintf_errstring(ldb, 
+                                              "attribute %s is not a valid attribute in schema", el->name);
+                       return LDB_ERR_OBJECT_CLASS_VIOLATION;                  
+               }
+               /* We have a valid attribute, now find out if it is a forward link
+                  (Even link IDs are for the originating attribute) */
+               if ((schema_attr->linkID == 0) || ((schema_attr->linkID & 1) == 1)) {
+                       continue;
+               }
+
+               /* Now find the target attribute */
+               target_attr = dsdb_attribute_by_linkID(ac->schema, schema_attr->linkID + 1);
+               if (!target_attr) {
+                       /*
+                        * windows 2003 has a broken schema where
+                        * the definition of msDS-IsDomainFor
+                        * is missing (which is supposed to be
+                        * the backlink of the msDS-HasDomainNCs
+                        * attribute
+                        */
+                       continue;
+               }
+
+               attr_name = target_attr->lDAPDisplayName;
+       
+               switch (el->flags & LDB_FLAG_MOD_MASK) {
+               case LDB_FLAG_MOD_REPLACE:
+                       /* treat as just a normal add the delete part is handled by the callback */
+                       store_el = true;
+
+                       /* break intentionally missing */
+
+               case LDB_FLAG_MOD_ADD:
+
+                       /* For each value being added, we need to setup the adds */
+                       for (j = 0; j < el->num_values; j++) {
+                               ret = la_store_op(ac, LA_OP_ADD,
+                                                 &el->values[j],
+                                                 attr_name);
+                               if (ret != LDB_SUCCESS) {
+                                       return ret;
+                               }
+                       }
+                       break;
+
+               case LDB_FLAG_MOD_DELETE:
+
+                       if (el->num_values) {
+                               /* For each value being deleted, we need to setup the delete */
+                               for (j = 0; j < el->num_values; j++) {
+                                       ret = la_store_op(ac, LA_OP_DEL,
+                                                         &el->values[j],
+                                                         attr_name);
+                                       if (ret != LDB_SUCCESS) {
+                                               return ret;
+                                       }
+                               }
+                       } else {
+                               /* Flag that there was a DELETE
+                                * without a value specified, so we
+                                * need to look for the old value */
+                               store_el = true;
+                       }
+
+                       break;
+               }
+
+               if (store_el) {
+                       struct ldb_message_element *search_el;
+
+                       search_el = talloc_realloc(ac->rc, ac->rc->el,
+                                                  struct ldb_message_element,
+                                                  ac->rc->num_elements +1);
+                       if (!search_el) {
+                               ldb_oom(ldb);
+                               return LDB_ERR_OPERATIONS_ERROR;
+                       }
+                       ac->rc->el = search_el;
+
+                       ac->rc->el[ac->rc->num_elements] = *el;
+                       ac->rc->num_elements++;
+               }
+       }
+       
+       if (ac->ops || ac->rc->el) {
+               /* both replace and delete without values are handled in the callback
+                * after the search on the entry to be modified is performed */
+               
+               attrs = talloc_array(ac->rc, const char *, ac->rc->num_elements + 1);
+               if (!attrs) {
+                       ldb_oom(ldb);
+                       return LDB_ERR_OPERATIONS_ERROR;
+               }
+               for (i = 0; ac->rc && i < ac->rc->num_elements; i++) {
+                       attrs[i] = ac->rc->el[i].name;
+               }
+               attrs[i] = NULL;
+               
+               /* The callback does all the hard work here */
+               ret = ldb_build_search_req(&search_req, ldb, ac,
+                                          req->op.mod.message->dn,
+                                          LDB_SCOPE_BASE,
+                                          "(objectClass=*)", attrs,
+                                          NULL,
+                                          ac, la_mod_search_callback,
+                                          req);
+
+               /* We need to figure out our own extended DN, to fill in as the backlink target */
+               if (ret == LDB_SUCCESS) {
+                       ret = ldb_request_add_control(search_req,
+                                                     LDB_CONTROL_EXTENDED_DN_OID,
+                                                     false, NULL);
+               }
+               if (ret == LDB_SUCCESS) {
+                       talloc_steal(search_req, attrs);
+                       
+                       ret = ldb_next_request(module, search_req);
+               }
+
+       } else {
+               /* nothing to do for this module, proceed */
+               talloc_free(ac);
+               ret = ldb_next_request(module, req);
+       }
+
+       return ret;
+}
 
 static int linked_attributes_fix_links(struct ldb_module *module,
                                       struct ldb_dn *old_dn, struct ldb_dn *new_dn,
@@ -190,7 +732,356 @@ static int linked_attributes_rename(struct ldb_module *module, struct ldb_reques
 }
 
 
+/* queue a linked attributes modify request in the la_private
+   structure */
+static int la_queue_mod_request(struct la_context *ac)
+{
+       struct la_private *la_private = 
+               talloc_get_type(ldb_module_get_private(ac->module), struct la_private);
+
+       if (la_private == NULL) {
+               ldb_debug(ldb_module_get_ctx(ac->module), LDB_DEBUG_ERROR, __location__ ": No la_private transaction setup\n");
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       talloc_steal(la_private, ac);
+       DLIST_ADD(la_private->la_list, ac);
+
+       return ldb_module_done(ac->req, ac->op_controls,
+                              ac->op_response, LDB_SUCCESS);
+}
+
+/* Having done the original operation, then try to fix up all the linked attributes for modify and delete */
+static int la_mod_del_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+       int ret;
+       struct la_context *ac;
+       struct ldb_context *ldb;
+
+       ac = talloc_get_type(req->context, struct la_context);
+       ldb = ldb_module_get_ctx(ac->module);
+
+       if (!ares) {
+               return ldb_module_done(ac->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+       }
+       if (ares->error != LDB_SUCCESS) {
+               return ldb_module_done(ac->req, ares->controls,
+                                       ares->response, ares->error);
+       }
+
+       if (ares->type != LDB_REPLY_DONE) {
+               ldb_set_errstring(ldb,
+                                 "invalid ldb_reply_type in callback");
+               talloc_free(ares);
+               return ldb_module_done(ac->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+       }
+       
+       ac->op_controls = talloc_steal(ac, ares->controls);
+       ac->op_response = talloc_steal(ac, ares->response);
+
+       /* If we have modfies to make, this is the time to do them for modify and delete */
+       ret = la_queue_mod_request(ac);
+       
+       if (ret != LDB_SUCCESS) {
+               return ldb_module_done(ac->req, NULL, NULL, ret);
+       }
+       talloc_free(ares);
+
+       /* la_queue_mod_request has already sent the callbacks */
+       return LDB_SUCCESS;
+
+}
+
+/* Having done the original add, then try to fix up all the linked attributes
+
+  This is done after the add so the links can get the extended DNs correctly.
+ */
+static int la_add_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+       int ret;
+       struct la_context *ac;
+       struct ldb_context *ldb;
+
+       ac = talloc_get_type(req->context, struct la_context);
+       ldb = ldb_module_get_ctx(ac->module);
+
+       if (!ares) {
+               return ldb_module_done(ac->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+       }
+       if (ares->error != LDB_SUCCESS) {
+               return ldb_module_done(ac->req, ares->controls,
+                                       ares->response, ares->error);
+       }
+
+       if (ares->type != LDB_REPLY_DONE) {
+               ldb_set_errstring(ldb,
+                                 "invalid ldb_reply_type in callback");
+               talloc_free(ares);
+               return ldb_module_done(ac->req, NULL, NULL,
+                                       LDB_ERR_OPERATIONS_ERROR);
+       }
+       
+       if (ac->ops) {
+               struct ldb_request *search_req;
+               static const char *attrs[] = { NULL };
+               
+               /* The callback does all the hard work here - we need
+                * the objectGUID and SID of the added record */
+               ret = ldb_build_search_req(&search_req, ldb, ac,
+                                          ac->req->op.add.message->dn,
+                                          LDB_SCOPE_BASE,
+                                          "(objectClass=*)", attrs,
+                                          NULL,
+                                          ac, la_mod_search_callback,
+                                          ac->req);
+               
+               if (ret == LDB_SUCCESS) {
+                       ret = ldb_request_add_control(search_req,
+                                                     LDB_CONTROL_EXTENDED_DN_OID,
+                                                     false, NULL);
+               }
+               if (ret != LDB_SUCCESS) {
+                       return ldb_module_done(ac->req, NULL, NULL,
+                                              ret);
+               }
+
+               ac->op_controls = talloc_steal(ac, ares->controls);
+               ac->op_response = talloc_steal(ac, ares->response);
+
+               return ldb_next_request(ac->module, search_req);
+               
+       } else {
+               return ldb_module_done(ac->req, ares->controls,
+                                      ares->response, ares->error);
+       }
+}
+
+/* Reconstruct the original request, but pointing at our local callback to finish things off */
+static int la_down_req(struct la_context *ac)
+{
+       struct ldb_request *down_req;
+       int ret;
+       struct ldb_context *ldb;
+
+       ldb = ldb_module_get_ctx(ac->module);
+
+       switch (ac->req->operation) {
+       case LDB_ADD:
+               ret = ldb_build_add_req(&down_req, ldb, ac,
+                                       ac->req->op.add.message,
+                                       ac->req->controls,
+                                       ac, la_add_callback,
+                                       ac->req);
+               break;
+       case LDB_MODIFY:
+               ret = ldb_build_mod_req(&down_req, ldb, ac,
+                                       ac->req->op.mod.message,
+                                       ac->req->controls,
+                                       ac, la_mod_del_callback,
+                                       ac->req);
+               break;
+       default:
+               ret = LDB_ERR_OPERATIONS_ERROR;
+       }
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+
+       return ldb_next_request(ac->module, down_req);
+}
+
+/*
+  use the GUID part of an extended DN to find the target DN, in case
+  it has moved
+ */
+static int la_find_dn_target(struct ldb_module *module, struct la_context *ac, 
+                            struct GUID *guid, struct ldb_dn **dn)
+{
+       return dsdb_find_dn_by_guid(ldb_module_get_ctx(ac->module), ac, guid, dn);
+}
+
+/* apply one la_context op change */
+static int la_do_op_request(struct ldb_module *module, struct la_context *ac, struct la_op_store *op)
+{
+       struct ldb_message_element *ret_el;
+       struct ldb_request *mod_req;
+       struct ldb_message *new_msg;
+       struct ldb_context *ldb;
+       int ret;
+
+       ldb = ldb_module_get_ctx(ac->module);
+
+       /* Create the modify request */
+       new_msg = ldb_msg_new(ac);
+       if (!new_msg) {
+               ldb_oom(ldb);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       ret = la_find_dn_target(module, ac, &op->guid, &new_msg->dn);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+
+       if (op->op == LA_OP_ADD) {
+               ret = ldb_msg_add_empty(new_msg, op->name,
+                                       LDB_FLAG_MOD_ADD, &ret_el);
+       } else {
+               ret = ldb_msg_add_empty(new_msg, op->name,
+                                       LDB_FLAG_MOD_DELETE, &ret_el);
+       }
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+       ret_el->values = talloc_array(new_msg, struct ldb_val, 1);
+       if (!ret_el->values) {
+               ldb_oom(ldb);
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+       ret_el->num_values = 1;
+       if (op->op == LA_OP_ADD) {
+               ret_el->values[0] = data_blob_string_const(ldb_dn_get_extended_linearized(new_msg, ac->add_dn, 1));
+       } else {
+               ret_el->values[0] = data_blob_string_const(ldb_dn_get_extended_linearized(new_msg, ac->del_dn, 1));
+       }
+
+#if 0
+       ldb_debug(ldb, LDB_DEBUG_WARNING,
+                 "link on %s %s: %s %s\n", 
+                 ldb_dn_get_linearized(new_msg->dn), ret_el->name, 
+                 ret_el->values[0].data, ac->ops->op == LA_OP_ADD ? "added" : "deleted");
+#endif 
+
+       ret = ldb_build_mod_req(&mod_req, ldb, op,
+                               new_msg,
+                               NULL,
+                               NULL, 
+                               ldb_op_default_callback,
+                               NULL);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+       talloc_steal(mod_req, new_msg);
+
+       if (DEBUGLVL(4)) {
+               DEBUG(4,("Applying linked attribute change:\n%s\n",
+                        ldb_ldif_message_string(ldb, op, LDB_CHANGETYPE_MODIFY, new_msg)));
+       }
+
+       /* Run the new request */
+       ret = ldb_next_request(module, mod_req);
+
+       /* we need to wait for this to finish, as we are being called
+          from the synchronous end_transaction hook of this module */
+       if (ret == LDB_SUCCESS) {
+               ret = ldb_wait(mod_req->handle, LDB_WAIT_ALL);
+       }
+
+       if (ret != LDB_SUCCESS) {
+               ldb_debug(ldb, LDB_DEBUG_WARNING, "Failed to apply linked attribute change '%s' %s\n",
+                         ldb_errstring(ldb),
+                         ldb_ldif_message_string(ldb, op, LDB_CHANGETYPE_MODIFY, new_msg));
+       }
+
+       return ret;
+}
+
+/* apply one set of la_context changes */
+static int la_do_mod_request(struct ldb_module *module, struct la_context *ac)
+{
+       struct la_op_store *op;
+
+       for (op = ac->ops; op; op=op->next) {
+               int ret = la_do_op_request(module, ac, op);
+               if (ret != LDB_SUCCESS) {
+                       if (ret != LDB_ERR_NO_SUCH_OBJECT) {
+                               return ret;
+                       }
+               }
+       }
+
+       return LDB_SUCCESS;
+}
+
+
+/*
+  we hook into the transaction operations to allow us to 
+  perform the linked attribute updates at the end of the whole
+  transaction. This allows a forward linked attribute to be created
+  before the target is created, as long as the target is created
+  in the same transaction
+ */
+static int linked_attributes_start_transaction(struct ldb_module *module)
+{
+       /* create our private structure for this transaction */
+       struct la_private *la_private = talloc_get_type(ldb_module_get_private(module),
+                                                       struct la_private);
+       talloc_free(la_private);
+       la_private = talloc(module, struct la_private);
+       if (la_private == NULL) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+       la_private->la_list = NULL;
+       ldb_module_set_private(module, la_private);
+       return ldb_next_start_trans(module);
+}
+
+/*
+  on prepare commit we loop over our queued la_context structures
+  and apply each of them
+ */
+static int linked_attributes_prepare_commit(struct ldb_module *module)
+{
+       struct la_private *la_private = 
+               talloc_get_type(ldb_module_get_private(module), struct la_private);
+       struct la_context *ac;
+
+       if (!la_private) {
+               /* prepare commit without begin_transaction - let someone else return the error, just don't segfault */
+               return ldb_next_prepare_commit(module);
+       }
+       /* walk the list backwards, to do the first entry first, as we
+        * added the entries with DLIST_ADD() which puts them at the
+        * start of the list */
+       for (ac = la_private->la_list; ac && ac->next; ac=ac->next) ;
+
+       for (; ac; ac=ac->prev) {
+               int ret;
+               ac->req = NULL;
+               ret = la_do_mod_request(module, ac);
+               if (ret != LDB_SUCCESS) {
+                       DEBUG(0,(__location__ ": Failed mod request ret=%d\n", ret));
+                       talloc_free(la_private);
+                       ldb_module_set_private(module, NULL);   
+                       return ret;
+               }
+       }
+
+       talloc_free(la_private);
+       ldb_module_set_private(module, NULL);   
+
+       return ldb_next_prepare_commit(module);
+}
+
+static int linked_attributes_del_transaction(struct ldb_module *module)
+{
+       struct la_private *la_private = 
+               talloc_get_type(ldb_module_get_private(module), struct la_private);
+       talloc_free(la_private);
+       ldb_module_set_private(module, NULL);
+       return ldb_next_del_trans(module);
+}
+
+
 _PUBLIC_ const struct ldb_module_ops ldb_linked_attributes_module_ops = {
        .name              = "linked_attributes",
-       .rename            = linked_attributes_rename,
+       .add               = linked_attributes_add,
+       .modify            = linked_attributes_modify,
+       .rename            = linked_attributes_rename,
+       .start_transaction = linked_attributes_start_transaction,
+       .prepare_commit    = linked_attributes_prepare_commit,
+       .del_transaction   = linked_attributes_del_transaction,
 };
index db2415b39714981489609f0fd7974a234d9e39c5..8994ee4014e826f07be5e84db0e5efb98aa15046 100644 (file)
@@ -50,8 +50,6 @@
 #include "libcli/security/security.h"
 #include "lib/util/tsort.h"
 
-#define W2K3_LINKED_ATTRIBUTES 1
-
 struct replmd_private {
        TALLOC_CTX *la_ctx;
        struct la_entry *la_list;
@@ -734,6 +732,7 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
        char *time_str;
        int ret;
        unsigned int i;
+       unsigned int functional_level;
        uint32_t ni=0;
        bool allow_add_guid = false;
        bool remove_current_guid = false;
@@ -753,6 +752,8 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
 
        ldb = ldb_module_get_ctx(module);
 
+       functional_level = dsdb_functional_level(ldb);
+
        ldb_debug(ldb, LDB_DEBUG_TRACE, "replmd_add\n");
 
        ac = replmd_ctx_init(module, req);
@@ -875,8 +876,7 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
                        continue;
                }
 
-#if W2K3_LINKED_ATTRIBUTES
-               if (sa->linkID != 0 && dsdb_functional_level(ldb) > DS_DOMAIN_FUNCTION_2000) {
+               if (sa->linkID != 0 && functional_level > DS_DOMAIN_FUNCTION_2000) {
                        ret = replmd_add_fix_la(module, e, ac->seq_num, our_invocation_id, t, &guid, sa);
                        if (ret != LDB_SUCCESS) {
                                talloc_free(ac);
@@ -886,7 +886,6 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
                           replPropertyMetaData in FL above w2k */
                        continue;
                }
-#endif
 
                m->attid                        = sa->attributeID_id;
                m->version                      = 1;
@@ -974,6 +973,14 @@ static int replmd_add(struct ldb_module *module, struct ldb_request *req)
                return ret;
        }
 
+       if (functional_level == DS_DOMAIN_FUNCTION_2000) {
+               ret = ldb_request_add_control(down_req, DSDB_CONTROL_APPLY_LINKS, false, NULL);
+               if (ret != LDB_SUCCESS) {
+                       talloc_free(ac);
+                       return ret;
+               }
+       }
+
        /* mark the control done */
        if (control) {
                control->critical = 0;
@@ -1021,7 +1028,6 @@ static int replmd_update_rpmd_element(struct ldb_context *ldb,
                if (a->attributeID_id == omd->ctr.ctr1.array[i].attid) break;
        }
 
-#if W2K3_LINKED_ATTRIBUTES
        if (a->linkID != 0 && dsdb_functional_level(ldb) > DS_DOMAIN_FUNCTION_2000) {
                /* linked attributes are not stored in
                   replPropertyMetaData in FL above w2k, but we do
@@ -1032,7 +1038,6 @@ static int replmd_update_rpmd_element(struct ldb_context *ldb,
                }
                return LDB_SUCCESS;
        }
-#endif
 
        if (i == omd->ctr.ctr1.count) {
                /* we need to add a new one */
@@ -1959,10 +1964,6 @@ static int replmd_modify_handle_linked_attribs(struct ldb_module *module,
                return LDB_SUCCESS;
        }
 
-#if !W2K3_LINKED_ATTRIBUTES
-       return LDB_SUCCESS;
-#endif
-
        if (dsdb_functional_level(ldb) == DS_DOMAIN_FUNCTION_2000) {
                /* don't do anything special for linked attributes */
                return LDB_SUCCESS;
@@ -2057,6 +2058,7 @@ static int replmd_modify(struct ldb_module *module, struct ldb_request *req)
        bool is_urgent = false;
        struct loadparm_context *lp_ctx;
        char *referral;
+       unsigned int functional_level;
 
        /* do not manipulate our control entries */
        if (ldb_dn_is_special(req->op.mod.message->dn)) {
@@ -2064,6 +2066,8 @@ static int replmd_modify(struct ldb_module *module, struct ldb_request *req)
        }
 
        ldb = ldb_module_get_ctx(module);
+       functional_level = dsdb_functional_level(ldb);
+
        lp_ctx = talloc_get_type(ldb_get_opaque(ldb, "loadparm"),
                                 struct loadparm_context);
 
@@ -2123,6 +2127,18 @@ static int replmd_modify(struct ldb_module *module, struct ldb_request *req)
                talloc_free(ac);
                return ret;
        }
+
+       /* If we are in functional level 2000, then
+        * replmd_modify_handle_linked_attribs will have done
+        * nothing */
+       if (functional_level == DS_DOMAIN_FUNCTION_2000) {
+               ret = ldb_request_add_control(down_req, DSDB_CONTROL_APPLY_LINKS, false, NULL);
+               if (ret != LDB_SUCCESS) {
+                       talloc_free(ac);
+                       return ret;
+               }
+       }
+
        talloc_steal(down_req, msg);
 
        /* we only change whenChanged and uSNChanged if the seq_num
@@ -3551,11 +3567,20 @@ static int replmd_extended_replicated_objects(struct ldb_module *module, struct
                if (!req->controls) return replmd_replicated_request_werror(ar, WERR_NOMEM);
        }
 
+       /* This allows layers further down to know if a change came in over replication */
        ret = ldb_request_add_control(req, DSDB_CONTROL_REPLICATED_UPDATE_OID, false, NULL);
        if (ret != LDB_SUCCESS) {
                return ret;
        }
 
+       /* If this change contained linked attributes in the body
+        * (rather than in the links section) we need to update
+        * backlinks in linked_attributes */
+       ret = ldb_request_add_control(req, DSDB_CONTROL_APPLY_LINKS, false, NULL);
+       if (ret != LDB_SUCCESS) {
+               return ret;
+       }
+
        ar->controls = req->controls;
        req->controls = ctrls;