1 /* SPDX-License-Identifier: LGPL-2.1-only */
3  * lib/cache_mngt.c	Cache Management
10  * Copyright (c) 2003-2012 Thomas Graf <tgraf@suug.ch>
18  * - @core_doc{core_cache, Caching System}
23  * ------
25  * #include <netlink/cache.h>
29 #include <netlink-private/netlink.h>
31 #include <netlink/cache.h>
38  * @name Cache Operations Sets
42 static struct nl_cache_ops *__nl_cache_ops_lookup(const char *name)  in __nl_cache_ops_lookup()  argument
46 	for (ops = cache_ops; ops; ops = ops->co_next)  in __nl_cache_ops_lookup()
47 		if (!strcmp(ops->co_name, name))  in __nl_cache_ops_lookup()
55  * @arg ops		Cache operations
59 	ops->co_refcnt++;  in nl_cache_ops_get()
64  * @arg ops		Cache operations
68 	ops->co_refcnt--;  in nl_cache_ops_put()
72  * Lookup cache operations by name
73  * @arg name		name of the cache type
78  * @return The cache operations or NULL if not found.
80 struct nl_cache_ops *nl_cache_ops_lookup(const char *name)  in nl_cache_ops_lookup()  argument
85 	ops = __nl_cache_ops_lookup(name);  in nl_cache_ops_lookup()
92  * Lookup cache operations by name
93  * @arg name		name of the cache type
95  * @note The reference counter of the returned cache operation is incremented
98  * @return The cache operations or NULL if not found.
100 struct nl_cache_ops *nl_cache_ops_lookup_safe(const char *name)  in nl_cache_ops_lookup_safe()  argument
105 	if ((ops = __nl_cache_ops_lookup(name)))  in nl_cache_ops_lookup_safe()
117 	for (ops = cache_ops; ops; ops = ops->co_next) {  in __cache_ops_associate()
118 		if (ops->co_protocol != protocol)  in __cache_ops_associate()
121 		for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)  in __cache_ops_associate()
122 			if (ops->co_msgtypes[i].mt_id == msgtype)  in __cache_ops_associate()
130  * Associate protocol and message type to cache operations
139  * @return The cache operations or NULL if no match found.
153  * Associate protocol and message type to cache operations
157  * Searches the registered cache operations for a matching protocol
160  * @note The reference counter of the returned cache operation is incremented
163  * @return The cache operations or NULL if no no match was found.
178  * Lookup message type cache association
179  * @arg ops			cache operations
183  * cache operations.
186  *            to the lifetime of the underlying cache operations.
194 	for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)  in nl_msgtype_lookup()
195 		if (ops->co_msgtypes[i].mt_id == msgtype)  in nl_msgtype_lookup()
196 			return &ops->co_msgtypes[i];  in nl_msgtype_lookup()
206 	for (ops = cache_ops; ops; ops = ops->co_next)  in cache_ops_lookup_for_obj()
207 		if (ops->co_obj_ops == obj_ops)  in cache_ops_lookup_for_obj()
215  * Call a function for each registered cache operation
224 	for (ops = cache_ops; ops; ops = ops->co_next)  in nl_cache_ops_foreach()
231  * @arg ops		Cache ops
234  * The cache operation flags will be derived to all caches allocates
235  * based on this set of cache operations.
240 	ops->co_flags |= flags;  in nl_cache_ops_set_flags()
245  * Register a set of cache operations
246  * @arg ops		cache operations
249  * a certain cache type.
255 	if (!ops->co_name || !ops->co_obj_ops)  in nl_cache_mngt_register()
256 		return -NLE_INVAL;  in nl_cache_mngt_register()
259 	BUG_ON (ops->co_obj_ops->oo_keygen && !ops->co_obj_ops->oo_compare);  in nl_cache_mngt_register()
262 	if (__nl_cache_ops_lookup(ops->co_name)) {  in nl_cache_mngt_register()
264 		return -NLE_EXIST;  in nl_cache_mngt_register()
267 	ops->co_refcnt = 0;  in nl_cache_mngt_register()
268 	ops->co_next = cache_ops;  in nl_cache_mngt_register()
272 	NL_DBG(1, "Registered cache operations %s\n", ops->co_name);  in nl_cache_mngt_register()
278  * Unregister a set of cache operations
279  * @arg ops		cache operations
282  * cache operations is no longer available. The
283  * specified cache operations must have been registered
295 	if (ops->co_refcnt > 0) {  in nl_cache_mngt_unregister()
296 		err = -NLE_BUSY;  in nl_cache_mngt_unregister()
300 	for (tp = &cache_ops; (t=*tp) != NULL; tp = &t->co_next)  in nl_cache_mngt_unregister()
305 		err = -NLE_NOCACHE;  in nl_cache_mngt_unregister()
309 	NL_DBG(1, "Unregistered cache operations %s\n", ops->co_name);  in nl_cache_mngt_unregister()
311 	*tp = t->co_next;  in nl_cache_mngt_unregister()
321  * @name Global Cache Provisioning/Requiring
326  * Provide a cache for global use
327  * @arg cache		cache to provide
329  * Offers the specified cache to be used by other modules.
330  * Only one cache per type may be shared at a time,
333 void nl_cache_mngt_provide(struct nl_cache *cache)  in nl_cache_mngt_provide()  argument
339 	ops = cache_ops_lookup_for_obj(cache->c_ops->co_obj_ops);  in nl_cache_mngt_provide()
343 		nl_cache_get(cache);  in nl_cache_mngt_provide()
346 		 * Hold a reference to the cache operations to ensure the  in nl_cache_mngt_provide()
347 		 * ops don't go away while we use it to store the cache pointer.  in nl_cache_mngt_provide()
349 		if (!ops->co_major_cache)  in nl_cache_mngt_provide()
352 		ops->co_major_cache = cache;  in nl_cache_mngt_provide()
359  * Unprovide a cache for global use
360  * @arg cache		cache to unprovide
362  * Cancels the offer to use a cache globally. The
363  * cache will no longer be returned via lookups but
366 void nl_cache_mngt_unprovide(struct nl_cache *cache)  in nl_cache_mngt_unprovide()  argument
372 	ops = cache_ops_lookup_for_obj(cache->c_ops->co_obj_ops);  in nl_cache_mngt_unprovide()
375 	else if (ops->co_major_cache == cache) {  in nl_cache_mngt_unprovide()
376 		nl_cache_free(ops->co_major_cache);  in nl_cache_mngt_unprovide()
378 		ops->co_major_cache = NULL;  in nl_cache_mngt_unprovide()
384 struct nl_cache *__nl_cache_mngt_require(const char *name)  in __nl_cache_mngt_require()  argument
387 	struct nl_cache *cache = NULL;  in __nl_cache_mngt_require()  local
389 	ops = nl_cache_ops_lookup_safe(name);  in __nl_cache_mngt_require()
391 		cache = ops->co_major_cache;  in __nl_cache_mngt_require()
395 	return cache;  in __nl_cache_mngt_require()
399  * Return cache previously provided via nl_cache_mngt_provide()
400  * @arg name		Name of cache to lookup
407  * @return Pointer to cache or NULL if none registered
409 struct nl_cache *nl_cache_mngt_require(const char *name)  in nl_cache_mngt_require()  argument
411 	struct nl_cache *cache;  in nl_cache_mngt_require()  local
413 	if (!(cache = __nl_cache_mngt_require(name)))  in nl_cache_mngt_require()
416 		       "%s cache to be used for internal lookups.\nSee the "  in nl_cache_mngt_require()
417 		       " API documentation for more details.\n", name);  in nl_cache_mngt_require()
419 	return cache;  in nl_cache_mngt_require()
423  * Return cache previously provided via nl_cache_mngt_provide()
424  * @arg name		Name of cache to lookup
426  * @note The reference counter of the returned cache is incremented
429  * @return Pointer to cache or NULL if none registered
431 struct nl_cache *nl_cache_mngt_require_safe(const char *name)  in nl_cache_mngt_require_safe()  argument
433 	struct nl_cache *cache;  in nl_cache_mngt_require_safe()  local
435 	if ((cache = nl_cache_mngt_require(name)))  in nl_cache_mngt_require_safe()
436 		nl_cache_get(cache);  in nl_cache_mngt_require_safe()
438 	return cache;  in nl_cache_mngt_require_safe()