linked_attributes.c

samba最新软件

/* 
   ldb database library

   Copyright (C) Andrew Bartlett <[e-mail]> 2007

   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/>.
*/

/*
 *  Name: ldb
 *
 *  Component: ldb linked_attributes module
 *
 *  Description: Module to ensure linked attribute pairs remain in sync
 *
 *  Author: Andrew Bartlett
 */

#include "includes.h"
#include "ldb/include/ldb.h"
#include "ldb/include/ldb_errors.h"
#include "ldb/include/ldb_private.h"
#include "dsdb/samdb/samdb.h"

struct linked_attributes_context {
	enum la_step {LA_SEARCH, LA_DO_OPS, LA_DO_ORIG} step;
	struct ldb_module *module;
	struct ldb_handle *handle;
	struct ldb_request *orig_req;

	struct ldb_request *search_req;
	struct ldb_request **down_req;
	struct ldb_request *orig_down_req;

	int num_requests;
	int finished_requests;

	const char **linked_attrs;
};

struct replace_context {
	struct linked_attributes_context *ac;
	struct ldb_message_element *el;
};

static int linked_attributes_rename_del_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares);

static struct linked_attributes_context *linked_attributes_init_handle(struct ldb_request *req, 
								 struct ldb_module *module)
{
	struct linked_attributes_context *ac;
	struct ldb_handle *h;

	h = talloc_zero(req, struct ldb_handle);
	if (h == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		return NULL;
	}

	h->module = module;

	ac = talloc_zero(h, struct linked_attributes_context);
	if (ac == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		talloc_free(h);
		return NULL;
	}

	h->private_data	= ac;

	ac->module = module;
	ac->handle = h;
	ac->orig_req = req;
	
	ac->orig_down_req = talloc(ac, struct ldb_request);
	if (!ac->orig_down_req) {
		ldb_oom(ac->module->ldb);
		return NULL;
	}

	*ac->orig_down_req = *req;

	req->handle = h;

	return ac;
}

/* Common routine to handle reading the attributes and creating a
 * series of modify requests */

static int setup_modifies(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, 
			  struct linked_attributes_context *ac,
			  const struct ldb_message *msg, 
			  struct ldb_dn *olddn, struct ldb_dn *newdn) 
{
	int i, j, ret = LDB_SUCCESS;
	const struct dsdb_schema *schema = dsdb_get_schema(ldb);
	/* Look up each of the returned attributes */
	/* Find their schema */
	/* And it is an actual entry: now create a series of modify requests */
	for (i=0; i < msg->num_elements; i++) {
		int otherid;
		const struct dsdb_attribute *target_attr;
		const struct ldb_message_element *el = &msg->elements[i];
		const struct dsdb_attribute *schema_attr
			= dsdb_attribute_by_lDAPDisplayName(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, but if it's not linked they maybe we just got an extra return on our search... */
		if (schema_attr->linkID == 0) {
			continue;
		}
		
		/* Depending on which direction this link is in, we need to find it's partner */
		if ((schema_attr->linkID & 1) == 1) {
			otherid = schema_attr->linkID - 1;
		} else {
			otherid = schema_attr->linkID + 1;
		}
		
		/* Now find the target attribute */
		target_attr = dsdb_attribute_by_linkID(schema, otherid);
		if (!target_attr) {
			ldb_asprintf_errstring(ldb, 
					       "attribute %s does not have valid link target", el->name);
			return LDB_ERR_OBJECT_CLASS_VIOLATION;			
		}
		
		/* For each value being moded, we need to setup the modify */
		for (j=0; j < el->num_values; j++) {
			struct ldb_message_element *ret_el;
			struct ldb_request *new_req;
			struct ldb_message *new_msg;

			/* Create a spot in the list for the requests */
			ac->down_req = talloc_realloc(ac, ac->down_req, 
						      struct ldb_request *, ac->num_requests + 1);
			if (!ac->down_req) {
				ldb_oom(ldb);
				return LDB_ERR_OPERATIONS_ERROR;
			}

			/* Create the modify request */
			new_msg = ldb_msg_new(ac->down_req);
			if (!new_msg) {
				ldb_oom(ldb);
				return LDB_ERR_OPERATIONS_ERROR;
			}
			new_msg->dn = ldb_dn_new(new_msg, ldb, (char *)el->values[j].data);
			if (!new_msg->dn) {
				ldb_asprintf_errstring(ldb, 
						       "attribute %s value %s was not a valid DN", msg->elements[i].name,
						       el->values[j].data);
				return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
			}
			
			if (olddn) {
				ret = ldb_msg_add_empty(new_msg, target_attr->lDAPDisplayName, 
							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->values[0] = data_blob_string_const(ldb_dn_get_linearized(olddn));
				ret_el->num_values = 1;
			}
			
			if (newdn) {
				ret = ldb_msg_add_empty(new_msg, target_attr->lDAPDisplayName, 
							LDB_FLAG_MOD_ADD, &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->values[0] = data_blob_string_const(ldb_dn_get_linearized(newdn));
				ret_el->num_values = 1;
			}

			ret = ldb_build_mod_req(&new_req, ldb, ac->down_req,
						new_msg,
						NULL,
						NULL,
						NULL);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
			
			talloc_steal(new_req, new_msg);
			
			ldb_set_timeout_from_prev_req(ldb, ac->orig_req, new_req);
			
			ac->down_req[ac->num_requests] = new_req;
			ac->num_requests++;
			

			/* Run the new request */
			ret = ldb_next_request(ac->module, new_req);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
		}
	}
	return ret;
}

/* add */
static int linked_attributes_add(struct ldb_module *module, struct ldb_request *req)
{
	int i;
	struct linked_attributes_context *ac;

	const struct dsdb_schema *schema = dsdb_get_schema(module->ldb);
	if (!schema) {
		/* without schema, this doesn't make any sense */
		return ldb_next_request(module, req);
	}

	if (ldb_dn_is_special(req->op.mod.message->dn)) {
		/* do not manipulate our control entries */
		return ldb_next_request(module, req);
	}


	ac = linked_attributes_init_handle(req, module);
	if (!ac) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	
	ac->step = LA_DO_OPS;
	
	/* 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(schema, el->name);
		if (!schema_attr) {
			ldb_asprintf_errstring(module->ldb, 
					       "attribute %s is not a valid attribute in schema", req->op.add.message->elements[i].name);
			return LDB_ERR_OBJECT_CLASS_VIOLATION;			
		}
		/* We have a valid attribute, not find out if it is linked */
		if (schema_attr->linkID == 0) {
			continue;
		}
		
		if ((schema_attr->linkID & 1) == 1) {
			/* Odd is for the target.  Illigal to modify */
			ldb_asprintf_errstring(module->ldb, 
					       "attribute %s must not be modified directly, it is a linked attribute", req->op.add.message->elements[i].name);
			return LDB_ERR_UNWILLING_TO_PERFORM;
		}
		
		/* Even link IDs are for the originating attribute */
	}

	/* Now call the common routine to setup the modifies across all the attributes */
	return setup_modifies(module->ldb, ac, ac, req->op.add.message, NULL, req->op.add.message->dn);
}

struct merge {
	struct ldb_dn *dn;
	bool add;
	bool ignore;
};

static int merge_cmp(struct merge *merge1, struct merge *merge2) {
	int ret;
	ret = ldb_dn_compare(merge1->dn, merge2->dn);
	if (ret == 0) {
		if (merge1->add == merge2->add) {
			return 0;
		}
		if (merge1->add == true) {
			return 1;
		}
		return -1;
	}
	return ret;
}

static int linked_attributes_mod_replace_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares) 
{
	struct replace_context *ac2 = talloc_get_type(context, struct replace_context);
	struct linked_attributes_context *ac = ac2->ac;
    
	/* OK, we have one search result here: */

	/* Only entries are interesting, and we only want the olddn */
	if (ares->type == LDB_REPLY_ENTRY
	    && ldb_dn_compare(ares->message->dn, ac->orig_req->op.mod.message->dn) == 0) {
		/* only bother at all if there were some linked attributes found */
		struct ldb_message_element *search_el
			= ldb_msg_find_element(ares->message,
					       ac2->el->name);
		
		/* See if this element already exists */
		if (search_el) {

			struct merge *merged_list = NULL;

			int ret, size = 0, i;
			struct ldb_message *msg = ldb_msg_new(ac);
			if (!msg) {
				ldb_oom(ac->module->ldb);
				return LDB_ERR_OPERATIONS_ERROR;
			}

			/* Add all the existing elements, marking as 'proposed for delete' by setting .add = false */
			for (i=0; i < search_el->num_values; i++) {
				merged_list = talloc_realloc(ares, merged_list, struct merge, size + 1);
				merged_list[size].dn = ldb_dn_new(merged_list, ldb, (char *)search_el->values[i].data);
				merged_list[size].add = false;
				merged_list[size].ignore = false;
				size++;
			}

			/* Add all the new replacement elements, marking as 'proposed for add' by setting .add = true */
			for (i=0; i < ac2->el->num_values; i++) {
				merged_list = talloc_realloc(ares, merged_list, struct merge, size + 1);
				merged_list[size].dn = ldb_dn_new(merged_list, ldb, (char *)ac2->el->values[i].data);
				merged_list[size].add = true;
				merged_list[size].ignore = false;
				size++;
			}

			/* Sort the list, so we can pick out an add and delete for the same DN, and eliminate them */
			qsort(merged_list, size,
			      sizeof(*merged_list),
			      (comparison_fn_t)merge_cmp);

			/* Now things are sorted, it is trivial to mark pairs of DNs as 'ignore' */
			for (i=0; i + 1 < size; i++) {
				if (ldb_dn_compare(merged_list[i].dn, 
						   merged_list[i+1].dn) == 0 
				    /* Fortunetly the sort also sorts 'add == false' first */
				    && merged_list[i].add == false
				    && merged_list[i+1].add == true) {

					/* Mark as ignore, so we include neither in the actual operations */
					merged_list[i].ignore = true;
					merged_list[i+1].ignore = true;
				}
			}

			/* Arrange to delete anything the search found that we don't re-add */
			for (i=0; i < size; i++) {
				if (merged_list[i].ignore == false
				    && merged_list[i].add == false) {
					ldb_msg_add_steal_string(msg, search_el->name, 
								 ldb_dn_get_linearized(merged_list[i].dn));
				}
			}

			/* The DN to set on the linked attributes is the original DN of the modify message */
			msg->dn = ac->orig_req->op.mod.message->dn;
			
			ret = setup_modifies(ac->module->ldb, ac2, ac, msg, ares->message->dn, NULL);
			if (ret != LDB_SUCCESS) {
				return ret;
			}

			/* Now add links for all the actually new elements */
			for (i=0; i < size; i++) {
				if (merged_list[i].ignore == false && merged_list[i].add == true) {
					ldb_msg_add_steal_string(msg, search_el->name, 
								 ldb_dn_get_linearized(merged_list[i].dn));
				}
			}

			ret = setup_modifies(ac->module->ldb, ac2, ac, msg, NULL, ares->message->dn);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
			
			talloc_free(merged_list);

		} else {
			/* Looks like it doesn't exist, process like an 'add' */
			struct ldb_message *msg = ldb_msg_new(ac);
			if (!msg) {
				ldb_oom(ac->module->ldb);
				return LDB_ERR_OPERATIONS_ERROR;
			}
			msg->num_elements = 1;
			msg->elements = ac2->el;
			msg->dn = ac->orig_req->op.mod.message->dn;

			return setup_modifies(ac->module->ldb, ac2, ac, msg, NULL, ac->orig_req->op.mod.message->dn);
		}
		talloc_free(ares);
		return LDB_SUCCESS;
	} else if (ares->type == LDB_REPLY_ENTRY) {
		/* Guh?  We only asked for this DN */
		return LDB_ERR_OPERATIONS_ERROR;

	} else {
		talloc_free(ares);
		return LDB_SUCCESS;
	}
	
	
}
/* 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 */

	int i, j;
	struct linked_attributes_context *ac;

	const struct dsdb_schema *schema = dsdb_get_schema(module->ldb);
	if (!schema) {
		/* without schema, this doesn't make any sense */
		return ldb_next_request(module, req);
	}

	if (ldb_dn_is_special(req->op.mod.message->dn)) {
		/* do not manipulate our control entries */
		return ldb_next_request(module, req);
	}


	ac = linked_attributes_init_handle(req, module);
	if (!ac) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	
	/* prepare the first operation */
	ac->step = LA_DO_OPS;

	for (i=0; i < req->op.mod.message->num_elements; i++) {
		int ret;
		struct ldb_request *new_req;
		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(schema, el->name);
		if (!schema_attr) {
			ldb_asprintf_errstring(module->ldb, 
					       "attribute %s is not a valid attribute in schema", req->op.mod.message->elements[i].name);
			return LDB_ERR_OBJECT_CLASS_VIOLATION;			
		}
		/* We have a valid attribute, not find out if it is linked */
		if (schema_attr->linkID == 0) {
			continue;
		}
		
		if ((schema_attr->linkID & 1) == 1) {
			/* Odd is for the target.  Illigal to modify */
			ldb_asprintf_errstring(module->ldb, 
					       "attribute %s must not be modified directly, it is a linked attribute", req->op.mod.message->elements[i].name);
			return LDB_ERR_UNWILLING_TO_PERFORM;