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* lib/object.c Generic Cacheable Object
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation version 2.1
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* Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
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* @defgroup object Object
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#include <netlink-local.h>
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#include <netlink/netlink.h>
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#include <netlink/cache.h>
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#include <netlink/object.h>
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#include <netlink/utils.h>
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static inline struct nl_object_ops *obj_ops(struct nl_object *obj)
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* @name Object Creation/Deletion
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* Allocate a new object of kind specified by the operations handle
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* @arg ops cache operations handle
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* @return The new object or NULL
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struct nl_object *nl_object_alloc(struct nl_object_ops *ops)
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struct nl_object *new;
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if (ops->oo_size < sizeof(*new))
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new = calloc(1, ops->oo_size);
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nl_init_list_head(&new->ce_list);
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if (ops->oo_constructor)
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ops->oo_constructor(new);
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NL_DBG(4, "Allocated new object %p\n", new);
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* Allocate a new object of kind specified by the name
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* @arg kind name of object type
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* @return The new object or nULL
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int nl_object_alloc_name(const char *kind, struct nl_object **result)
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struct nl_cache_ops *ops;
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ops = nl_cache_ops_lookup(kind);
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return -NLE_OPNOTSUPP;
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if (!(*result = nl_object_alloc(ops->co_obj_ops)))
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struct nl_derived_object {
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* Allocate a new object and copy all data from an existing object
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* @arg obj object to inherite data from
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* @return The new object or NULL.
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struct nl_object *nl_object_clone(struct nl_object *obj)
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struct nl_object *new;
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struct nl_object_ops *ops = obj_ops(obj);
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int doff = offsetof(struct nl_derived_object, data);
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new = nl_object_alloc(ops);
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size = ops->oo_size - doff;
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new->ce_ops = obj->ce_ops;
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new->ce_msgtype = obj->ce_msgtype;
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new->ce_mask = obj->ce_mask;
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memcpy((void *)new + doff, (void *)obj + doff, size);
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if (ops->oo_clone(new, obj) < 0) {
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} else if (size && ops->oo_free_data)
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* Free a cacheable object
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* @arg obj object to free
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* @return 0 or a negative error code.
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void nl_object_free(struct nl_object *obj)
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struct nl_object_ops *ops = obj_ops(obj);
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if (obj->ce_refcnt > 0)
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NL_DBG(1, "Warning: Freeing object in use...\n");
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nl_cache_remove(obj);
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if (ops->oo_free_data)
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ops->oo_free_data(obj);
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NL_DBG(4, "Freed object %p\n", obj);
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* @name Reference Management
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* Acquire a reference on a object
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* @arg obj object to acquire reference from
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void nl_object_get(struct nl_object *obj)
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NL_DBG(4, "New reference to object %p, total %d\n",
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obj, obj->ce_refcnt);
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* Release a reference from an object
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* @arg obj object to release reference from
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void nl_object_put(struct nl_object *obj)
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NL_DBG(4, "Returned object reference %p, %d remaining\n",
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obj, obj->ce_refcnt);
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if (obj->ce_refcnt < 0)
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if (obj->ce_refcnt <= 0)
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* Check whether this object is used by multiple users
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* @arg obj object to check
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* @return true or false
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int nl_object_shared(struct nl_object *obj)
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return obj->ce_refcnt > 1;
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* @arg obj Object to mark
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void nl_object_mark(struct nl_object *obj)
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obj->ce_flags |= NL_OBJ_MARK;
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* Remove mark from object
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* @arg obj Object to unmark
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void nl_object_unmark(struct nl_object *obj)
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obj->ce_flags &= ~NL_OBJ_MARK;
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* Return true if object is marked
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* @arg obj Object to check
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* @return true if object is marked, otherwise false
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int nl_object_is_marked(struct nl_object *obj)
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return (obj->ce_flags & NL_OBJ_MARK);
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* Dump this object according to the specified parameters
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* @arg obj object to dump
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* @arg params dumping parameters
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void nl_object_dump(struct nl_object *obj, struct nl_dump_params *params)
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dump_from_ops(obj, params);
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* Check if the identifiers of two objects are identical
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* @arg b another object of same type
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* @return true if both objects have equal identifiers, otherwise false.
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int nl_object_identical(struct nl_object *a, struct nl_object *b)
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struct nl_object_ops *ops = obj_ops(a);
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/* Both objects must be of same type */
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if (ops != obj_ops(b))
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req_attrs = ops->oo_id_attrs;
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req_attrs = a->ce_mask & b->ce_mask;
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/* Both objects must provide all required attributes to uniquely
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* identify an object */
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if ((a->ce_mask & req_attrs) != req_attrs ||
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(b->ce_mask & req_attrs) != req_attrs)
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/* Can't judge unless we can compare */
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if (ops->oo_compare == NULL)
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return !(ops->oo_compare(a, b, req_attrs, 0));
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* Compute bitmask representing difference in attribute values
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* @arg b another object of same type
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* The bitmask returned is specific to an object type, each bit set represents
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* an attribute which mismatches in either of the two objects. Unavailability
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* of an attribute in one object and presence in the other is regarded a
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* @return Bitmask describing differences or 0 if they are completely identical.
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uint32_t nl_object_diff(struct nl_object *a, struct nl_object *b)
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struct nl_object_ops *ops = obj_ops(a);
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if (ops != obj_ops(b) || ops->oo_compare == NULL)
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return ops->oo_compare(a, b, ~0, 0);
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* Match a filter against an object
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* @arg obj object to check
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* @arg filter object of same type acting as filter
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* @return 1 if the object matches the filter or 0
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* if no filter procedure is available or if the
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* filter does not match.
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int nl_object_match_filter(struct nl_object *obj, struct nl_object *filter)
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struct nl_object_ops *ops = obj_ops(obj);
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if (ops != obj_ops(filter) || ops->oo_compare == NULL)
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return !(ops->oo_compare(obj, filter, filter->ce_mask,
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* Convert bitmask of attributes to a character string
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* @arg obj object of same type as attribute bitmask
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* @arg attrs bitmask of attribute types
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* @arg buf destination buffer
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* @arg len length of destination buffer
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* Converts the bitmask of attribute types into a list of attribute
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* names separated by comas.
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* @return destination buffer.
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char *nl_object_attrs2str(struct nl_object *obj, uint32_t attrs,
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char *buf, size_t len)
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struct nl_object_ops *ops = obj_ops(obj);
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if (ops->oo_attrs2str != NULL)
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return ops->oo_attrs2str(attrs, buf, len);
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* Return list of attributes present in an object
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* @arg buf destination buffer
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* @arg len length of destination buffer
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* @return destination buffer.
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char *nl_object_attr_list(struct nl_object *obj, char *buf, size_t len)
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return nl_object_attrs2str(obj, obj->ce_mask, buf, len);
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int nl_object_get_refcnt(struct nl_object *obj)
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return obj->ce_refcnt;
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struct nl_cache *nl_object_get_cache(struct nl_object *obj)
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return obj->ce_cache;