--- /dev/null
+/*
+ * lib/cache.c Caching Module
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
+ */
+
+/**
+ * @ingroup cache_mngt
+ * @defgroup cache Cache
+ *
+ * @code
+ * Cache Management | | Type Specific Cache Operations
+ *
+ * | | +----------------+ +------------+
+ * | request update | | msg_parser |
+ * | | +----------------+ +------------+
+ * +- - - - -^- - - - - - - -^- -|- - - -
+ * nl_cache_update: | | | |
+ * 1) --------- co_request_update ------+ | |
+ * | | |
+ * 2) destroy old cache +----------- pp_cb ---------|---+
+ * | | |
+ * 3) ---------- nl_recvmsgs ----------+ +- cb_valid -+
+ * +--------------+ | | | |
+ * | nl_cache_add |<-----+ + - - -v- -|- - - - - - - - - - -
+ * +--------------+ | | +-------------+
+ * | nl_recvmsgs |
+ * | | +-----|-^-----+
+ * +---v-|---+
+ * | | | nl_recv |
+ * +---------+
+ * | | Core Netlink
+ * @endcode
+ *
+ * @{
+ */
+
+#include <netlink-local.h>
+#include <netlink/netlink.h>
+#include <netlink/cache.h>
+#include <netlink/object.h>
+#include <netlink/utils.h>
+
+/**
+ * @name Access Functions
+ * @{
+ */
+
+#ifdef disabled
+/**
+ * Return the number of items in the cache
+ * @arg cache cache handle
+ */
+int nl_cache_nitems(struct nl_cache *cache)
+{
+ return cache->c_nitems;
+}
+
+/**
+ * Return the number of items matching a filter in the cache
+ * @arg cache Cache object.
+ * @arg filter Filter object.
+ */
+int nl_cache_nitems_filter(struct nl_cache *cache, struct nl_object *filter)
+{
+ struct nl_object_ops *ops;
+ struct nl_object *obj;
+ int nitems = 0;
+
+ if (cache->c_ops == NULL)
+ BUG();
+
+ ops = cache->c_ops->co_obj_ops;
+
+ nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
+ if (filter && !nl_object_match_filter(obj, filter))
+ continue;
+
+ nitems++;
+ }
+
+ return nitems;
+}
+
+/**
+ * Returns \b true if the cache is empty.
+ * @arg cache Cache to check
+ * @return \a true if the cache is empty, otherwise \b false is returned.
+ */
+int nl_cache_is_empty(struct nl_cache *cache)
+{
+ return nl_list_empty(&cache->c_items);
+}
+
+/**
+ * Return the operations set of the cache
+ * @arg cache cache handle
+ */
+struct nl_cache_ops *nl_cache_get_ops(struct nl_cache *cache)
+{
+ return cache->c_ops;
+}
+
+/**
+ * Return the first element in the cache
+ * @arg cache cache handle
+ */
+struct nl_object *nl_cache_get_first(struct nl_cache *cache)
+{
+ if (nl_list_empty(&cache->c_items))
+ return NULL;
+
+ return nl_list_entry(cache->c_items.next,
+ struct nl_object, ce_list);
+}
+
+/**
+ * Return the last element in the cache
+ * @arg cache cache handle
+ */
+struct nl_object *nl_cache_get_last(struct nl_cache *cache)
+{
+ if (nl_list_empty(&cache->c_items))
+ return NULL;
+
+ return nl_list_entry(cache->c_items.prev,
+ struct nl_object, ce_list);
+}
+
+/**
+ * Return the next element in the cache
+ * @arg obj current object
+ */
+struct nl_object *nl_cache_get_next(struct nl_object *obj)
+{
+ if (nl_list_at_tail(obj, &obj->ce_cache->c_items, ce_list))
+ return NULL;
+ else
+ return nl_list_entry(obj->ce_list.next,
+ struct nl_object, ce_list);
+}
+
+/**
+ * Return the previous element in the cache
+ * @arg obj current object
+ */
+struct nl_object *nl_cache_get_prev(struct nl_object *obj)
+{
+ if (nl_list_at_head(obj, &obj->ce_cache->c_items, ce_list))
+ return NULL;
+ else
+ return nl_list_entry(obj->ce_list.prev,
+ struct nl_object, ce_list);
+}
+#endif
+
+/** @} */
+
+/**
+ * @name Cache Creation/Deletion
+ * @{
+ */
+
+/**
+ * Allocate an empty cache
+ * @arg ops cache operations to base the cache on
+ *
+ * @return A newly allocated and initialized cache.
+ */
+struct nl_cache *nl_cache_alloc(struct nl_cache_ops *ops)
+{
+ struct nl_cache *cache;
+
+ cache = calloc(1, sizeof(*cache));
+ if (!cache)
+ return NULL;
+
+ nl_init_list_head(&cache->c_items);
+ cache->c_ops = ops;
+
+ NL_DBG(2, "Allocated cache %p <%s>.\n", cache, nl_cache_name(cache));
+
+ return cache;
+}
+
+int nl_cache_alloc_and_fill(struct nl_cache_ops *ops, struct nl_sock *sock,
+ struct nl_cache **result)
+{
+ struct nl_cache *cache;
+ int err;
+
+ if (!(cache = nl_cache_alloc(ops)))
+ return -NLE_NOMEM;
+
+ if (sock && (err = nl_cache_refill(sock, cache)) < 0) {
+ nl_cache_free(cache);
+ return err;
+ }
+
+ *result = cache;
+ return 0;
+}
+
+#ifdef disabled
+/**
+ * Allocate an empty cache based on type name
+ * @arg kind Name of cache type
+ * @return A newly allocated and initialized cache.
+ */
+int nl_cache_alloc_name(const char *kind, struct nl_cache **result)
+{
+ struct nl_cache_ops *ops;
+ struct nl_cache *cache;
+
+ ops = nl_cache_ops_lookup(kind);
+ if (!ops)
+ return -NLE_NOCACHE;
+
+ if (!(cache = nl_cache_alloc(ops)))
+ return -NLE_NOMEM;
+
+ *result = cache;
+ return 0;
+}
+
+/**
+ * Allocate a new cache containing a subset of a cache
+ * @arg orig Original cache to be based on
+ * @arg filter Filter defining the subset to be filled into new cache
+ * @return A newly allocated cache or NULL.
+ */
+struct nl_cache *nl_cache_subset(struct nl_cache *orig,
+ struct nl_object *filter)
+{
+ struct nl_cache *cache;
+ struct nl_object_ops *ops;
+ struct nl_object *obj;
+
+ if (!filter)
+ BUG();
+
+ cache = nl_cache_alloc(orig->c_ops);
+ if (!cache)
+ return NULL;
+
+ ops = orig->c_ops->co_obj_ops;
+
+ nl_list_for_each_entry(obj, &orig->c_items, ce_list) {
+ if (!nl_object_match_filter(obj, filter))
+ continue;
+
+ nl_cache_add(cache, obj);
+ }
+
+ return cache;
+}
+#endif
+
+/**
+ * Clear a cache.
+ * @arg cache cache to clear
+ *
+ * Removes all elements of a cache.
+ */
+void nl_cache_clear(struct nl_cache *cache)
+{
+ struct nl_object *obj, *tmp;
+
+ NL_DBG(1, "Clearing cache %p <%s>...\n", cache, nl_cache_name(cache));
+
+ nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list)
+ nl_cache_remove(obj);
+}
+
+/**
+ * Free a cache.
+ * @arg cache Cache to free.
+ *
+ * Removes all elements of a cache and frees all memory.
+ *
+ * @note Use this function if you are working with allocated caches.
+ */
+void nl_cache_free(struct nl_cache *cache)
+{
+ if (!cache)
+ return;
+
+ nl_cache_clear(cache);
+ NL_DBG(1, "Freeing cache %p <%s>...\n", cache, nl_cache_name(cache));
+ free(cache);
+}
+
+/** @} */
+
+/**
+ * @name Cache Modifications
+ * @{
+ */
+
+static int __cache_add(struct nl_cache *cache, struct nl_object *obj)
+{
+ obj->ce_cache = cache;
+
+ nl_list_add_tail(&obj->ce_list, &cache->c_items);
+ cache->c_nitems++;
+
+ NL_DBG(1, "Added %p to cache %p <%s>.\n",
+ obj, cache, nl_cache_name(cache));
+
+ return 0;
+}
+
+/**
+ * Add object to a cache.
+ * @arg cache Cache to add object to
+ * @arg obj Object to be added to the cache
+ *
+ * Adds the given object to the specified cache. The object is cloned
+ * if it has been added to another cache already.
+ *
+ * @return 0 or a negative error code.
+ */
+int nl_cache_add(struct nl_cache *cache, struct nl_object *obj)
+{
+ struct nl_object *new;
+
+ if (cache->c_ops->co_obj_ops != obj->ce_ops)
+ return -NLE_OBJ_MISMATCH;
+
+ if (!nl_list_empty(&obj->ce_list)) {
+ new = nl_object_clone(obj);
+ if (!new)
+ return -NLE_NOMEM;
+ } else {
+ nl_object_get(obj);
+ new = obj;
+ }
+
+ return __cache_add(cache, new);
+}
+
+#ifdef disabled
+/**
+ * Move object from one cache to another
+ * @arg cache Cache to move object to.
+ * @arg obj Object subject to be moved
+ *
+ * Removes the given object from its associated cache if needed
+ * and adds it to the new cache.
+ *
+ * @return 0 on success or a negative error code.
+ */
+int nl_cache_move(struct nl_cache *cache, struct nl_object *obj)
+{
+ if (cache->c_ops->co_obj_ops != obj->ce_ops)
+ return -NLE_OBJ_MISMATCH;
+
+ NL_DBG(3, "Moving object %p to cache %p\n", obj, cache);
+
+ /* Acquire reference, if already in a cache this will be
+ * reverted during removal */
+ nl_object_get(obj);
+
+ if (!nl_list_empty(&obj->ce_list))
+ nl_cache_remove(obj);
+
+ return __cache_add(cache, obj);
+}
+#endif
+
+/**
+ * Removes an object from a cache.
+ * @arg obj Object to remove from its cache
+ *
+ * Removes the object \c obj from the cache it is assigned to, since
+ * an object can only be assigned to one cache at a time, the cache
+ * must ne be passed along with it.
+ */
+void nl_cache_remove(struct nl_object *obj)
+{
+ struct nl_cache *cache = obj->ce_cache;
+
+ if (cache == NULL)
+ return;
+
+ nl_list_del(&obj->ce_list);
+ obj->ce_cache = NULL;
+ nl_object_put(obj);
+ cache->c_nitems--;
+
+ NL_DBG(1, "Deleted %p from cache %p <%s>.\n",
+ obj, cache, nl_cache_name(cache));
+}
+
+#ifdef disabled
+/**
+ * Search for an object in a cache
+ * @arg cache Cache to search in.
+ * @arg needle Object to look for.
+ *
+ * Iterates over the cache and looks for an object with identical
+ * identifiers as the needle.
+ *
+ * @return Reference to object or NULL if not found.
+ * @note The returned object must be returned via nl_object_put().
+ */
+struct nl_object *nl_cache_search(struct nl_cache *cache,
+ struct nl_object *needle)
+{
+ struct nl_object *obj;
+
+ nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
+ if (nl_object_identical(obj, needle)) {
+ nl_object_get(obj);
+ return obj;
+ }
+ }
+
+ return NULL;
+}
+#endif
+
+/** @} */
+
+/**
+ * @name Synchronization
+ * @{
+ */
+
+/**
+ * Request a full dump from the kernel to fill a cache
+ * @arg sk Netlink socket.
+ * @arg cache Cache subjected to be filled.
+ *
+ * Send a dumping request to the kernel causing it to dump all objects
+ * related to the specified cache to the netlink socket.
+ *
+ * Use nl_cache_pickup() to read the objects from the socket and fill them
+ * into a cache.
+ */
+int nl_cache_request_full_dump(struct nl_sock *sk, struct nl_cache *cache)
+{
+ NL_DBG(2, "Requesting dump from kernel for cache %p <%s>...\n",
+ cache, nl_cache_name(cache));
+
+ if (cache->c_ops->co_request_update == NULL)
+ return -NLE_OPNOTSUPP;
+
+ return cache->c_ops->co_request_update(cache, sk);
+}
+
+/** @cond SKIP */
+struct update_xdata {
+ struct nl_cache_ops *ops;
+ struct nl_parser_param *params;
+};
+
+static int update_msg_parser(struct nl_msg *msg, void *arg)
+{
+ struct update_xdata *x = arg;
+
+ return nl_cache_parse(x->ops, &msg->nm_src, msg->nm_nlh, x->params);
+}
+/** @endcond */
+
+int __cache_pickup(struct nl_sock *sk, struct nl_cache *cache,
+ struct nl_parser_param *param)
+{
+ int err;
+ struct nl_cb *cb;
+ struct update_xdata x = {
+ .ops = cache->c_ops,
+ .params = param,
+ };
+
+ NL_DBG(1, "Picking up answer for cache %p <%s>...\n",
+ cache, nl_cache_name(cache));
+
+ cb = nl_cb_clone(sk->s_cb);
+ if (cb == NULL)
+ return -NLE_NOMEM;
+
+ nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, update_msg_parser, &x);
+
+ err = nl_recvmsgs(sk, cb);
+ if (err < 0)
+ NL_DBG(2, "While picking up for %p <%s>, recvmsgs() returned " \
+ "%d: %s", cache, nl_cache_name(cache),
+ err, nl_geterror(err));
+
+ nl_cb_put(cb);
+
+ return err;
+}
+
+static int pickup_cb(struct nl_object *c, struct nl_parser_param *p)
+{
+ return nl_cache_add((struct nl_cache *) p->pp_arg, c);
+}
+
+/**
+ * Pickup a netlink dump response and put it into a cache.
+ * @arg sk Netlink socket.
+ * @arg cache Cache to put items into.
+ *
+ * Waits for netlink messages to arrive, parses them and puts them into
+ * the specified cache.
+ *
+ * @return 0 on success or a negative error code.
+ */
+int nl_cache_pickup(struct nl_sock *sk, struct nl_cache *cache)
+{
+ struct nl_parser_param p = {
+ .pp_cb = pickup_cb,
+ .pp_arg = cache,
+ };
+
+ return __cache_pickup(sk, cache, &p);
+}
+
+#ifdef disabled
+static int cache_include(struct nl_cache *cache, struct nl_object *obj,
+ struct nl_msgtype *type, change_func_t cb)
+{
+ struct nl_object *old;
+
+ switch (type->mt_act) {
+ case NL_ACT_NEW:
+ case NL_ACT_DEL:
+ old = nl_cache_search(cache, obj);
+ if (old) {
+ nl_cache_remove(old);
+ if (type->mt_act == NL_ACT_DEL) {
+ if (cb)
+ cb(cache, old, NL_ACT_DEL);
+ nl_object_put(old);
+ }
+ }
+
+ if (type->mt_act == NL_ACT_NEW) {
+ nl_cache_move(cache, obj);
+ if (old == NULL && cb)
+ cb(cache, obj, NL_ACT_NEW);
+ else if (old) {
+ if (nl_object_diff(old, obj) && cb)
+ cb(cache, obj, NL_ACT_CHANGE);
+
+ nl_object_put(old);
+ }
+ }
+ break;
+ default:
+ NL_DBG(2, "Unknown action associated to object %p\n", obj);
+ return 0;
+ }
+
+ return 0;
+}
+
+int nl_cache_include(struct nl_cache *cache, struct nl_object *obj,
+ change_func_t change_cb)
+{
+ struct nl_cache_ops *ops = cache->c_ops;
+ int i;
+
+ if (ops->co_obj_ops != obj->ce_ops)
+ return -NLE_OBJ_MISMATCH;
+
+ for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)
+ if (ops->co_msgtypes[i].mt_id == obj->ce_msgtype)
+ return cache_include(cache, obj, &ops->co_msgtypes[i],
+ change_cb);
+
+ return -NLE_MSGTYPE_NOSUPPORT;
+}
+
+static int resync_cb(struct nl_object *c, struct nl_parser_param *p)
+{
+ struct nl_cache_assoc *ca = p->pp_arg;
+
+ return nl_cache_include(ca->ca_cache, c, ca->ca_change);
+}
+
+int nl_cache_resync(struct nl_sock *sk, struct nl_cache *cache,
+ change_func_t change_cb)
+{
+ struct nl_object *obj, *next;
+ struct nl_cache_assoc ca = {
+ .ca_cache = cache,
+ .ca_change = change_cb,
+ };
+ struct nl_parser_param p = {
+ .pp_cb = resync_cb,
+ .pp_arg = &ca,
+ };
+ int err;
+
+ NL_DBG(1, "Resyncing cache %p <%s>...\n", cache, nl_cache_name(cache));
+
+ /* Mark all objects so we can see if some of them are obsolete */
+ nl_cache_mark_all(cache);
+
+ err = nl_cache_request_full_dump(sk, cache);
+ if (err < 0)
+ goto errout;
+
+ err = __cache_pickup(sk, cache, &p);
+ if (err < 0)
+ goto errout;
+
+ nl_list_for_each_entry_safe(obj, next, &cache->c_items, ce_list)
+ if (nl_object_is_marked(obj))
+ nl_cache_remove(obj);
+
+ NL_DBG(1, "Finished resyncing %p <%s>\n", cache, nl_cache_name(cache));
+
+ err = 0;
+errout:
+ return err;
+}
+#endif
+
+/** @} */
+
+/**
+ * @name Parsing
+ * @{
+ */
+
+/** @cond SKIP */
+int nl_cache_parse(struct nl_cache_ops *ops, struct sockaddr_nl *who,
+ struct nlmsghdr *nlh, struct nl_parser_param *params)
+{
+ int i, err;
+
+ if (!nlmsg_valid_hdr(nlh, ops->co_hdrsize))
+ return -NLE_MSG_TOOSHORT;
+
+ for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++) {
+ if (ops->co_msgtypes[i].mt_id == nlh->nlmsg_type) {
+ err = ops->co_msg_parser(ops, who, nlh, params);
+ if (err != -NLE_OPNOTSUPP)
+ goto errout;
+ }
+ }
+
+
+ err = -NLE_MSGTYPE_NOSUPPORT;
+errout:
+ return err;
+}
+/** @endcond */
+
+/**
+ * Parse a netlink message and add it to the cache.
+ * @arg cache cache to add element to
+ * @arg msg netlink message
+ *
+ * Parses a netlink message by calling the cache specific message parser
+ * and adds the new element to the cache.
+ *
+ * @return 0 or a negative error code.
+ */
+int nl_cache_parse_and_add(struct nl_cache *cache, struct nl_msg *msg)
+{
+ struct nl_parser_param p = {
+ .pp_cb = pickup_cb,
+ .pp_arg = cache,
+ };
+
+ return nl_cache_parse(cache->c_ops, NULL, nlmsg_hdr(msg), &p);
+}
+
+/**
+ * (Re)fill a cache with the contents in the kernel.
+ * @arg sk Netlink socket.
+ * @arg cache cache to update
+ *
+ * Clears the specified cache and fills it with the current state in
+ * the kernel.
+ *
+ * @return 0 or a negative error code.
+ */
+int nl_cache_refill(struct nl_sock *sk, struct nl_cache *cache)
+{
+ int err;
+
+ err = nl_cache_request_full_dump(sk, cache);
+ if (err < 0)
+ return err;
+
+ NL_DBG(2, "Upading cache %p <%s>, request sent, waiting for dump...\n",
+ cache, nl_cache_name(cache));
+ nl_cache_clear(cache);
+
+ return nl_cache_pickup(sk, cache);
+}
+
+/** @} */
+#ifdef disabled
+
+/**
+ * @name Utillities
+ * @{
+ */
+
+/**
+ * Mark all objects in a cache
+ * @arg cache Cache to mark all objects in
+ */
+void nl_cache_mark_all(struct nl_cache *cache)
+{
+ struct nl_object *obj;
+
+ NL_DBG(2, "Marking all objects in cache %p <%s>...\n",
+ cache, nl_cache_name(cache));
+
+ nl_list_for_each_entry(obj, &cache->c_items, ce_list)
+ nl_object_mark(obj);
+}
+
+/** @} */
+
+/**
+ * @name Dumping
+ * @{
+ */
+/**
+ * Dump all elements of a cache.
+ * @arg cache cache to dump
+ * @arg params dumping parameters
+ *
+ * Dumps all elements of the \a cache to the file descriptor \a fd.
+ */
+void nl_cache_dump(struct nl_cache *cache, struct nl_dump_params *params)
+{
+ nl_cache_dump_filter(cache, params, NULL);
+}
+
+/**
+ * Dump all elements of a cache (filtered).
+ * @arg cache cache to dump
+ * @arg params dumping parameters (optional)
+ * @arg filter filter object
+ *
+ * Dumps all elements of the \a cache to the file descriptor \a fd
+ * given they match the given filter \a filter.
+ */
+void nl_cache_dump_filter(struct nl_cache *cache,
+ struct nl_dump_params *params,
+ struct nl_object *filter)
+{
+ int type = params ? params->dp_type : NL_DUMP_DETAILS;
+ struct nl_object_ops *ops;
+ struct nl_object *obj;
+
+ NL_DBG(2, "Dumping cache %p <%s> filter %p\n",
+ cache, nl_cache_name(cache), filter);
+
+ if (type > NL_DUMP_MAX || type < 0)
+ BUG();
+
+ if (cache->c_ops == NULL)
+ BUG();
+
+ ops = cache->c_ops->co_obj_ops;
+ if (!ops->oo_dump[type])
+ return;
+
+ nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
+ if (filter && !nl_object_match_filter(obj, filter))
+ continue;
+
+ NL_DBG(4, "Dumping object %p...\n", obj);
+ dump_from_ops(obj, params);
+ }
+}
+
+/** @} */
+
+/**
+ * @name Iterators
+ * @{
+ */
+
+/**
+ * Call a callback on each element of the cache.
+ * @arg cache cache to iterate on
+ * @arg cb callback function
+ * @arg arg argument passed to callback function
+ *
+ * Calls a callback function \a cb on each element of the \a cache.
+ * The argument \a arg is passed on the callback function.
+ */
+void nl_cache_foreach(struct nl_cache *cache,
+ void (*cb)(struct nl_object *, void *), void *arg)
+{
+ nl_cache_foreach_filter(cache, NULL, cb, arg);
+}
+
+/**
+ * Call a callback on each element of the cache (filtered).
+ * @arg cache cache to iterate on
+ * @arg filter filter object
+ * @arg cb callback function
+ * @arg arg argument passed to callback function
+ *
+ * Calls a callback function \a cb on each element of the \a cache
+ * that matches the \a filter. The argument \a arg is passed on
+ * to the callback function.
+ */
+void nl_cache_foreach_filter(struct nl_cache *cache, struct nl_object *filter,
+ void (*cb)(struct nl_object *, void *), void *arg)
+{
+ struct nl_object *obj, *tmp;
+ struct nl_object_ops *ops;
+
+ if (cache->c_ops == NULL)
+ BUG();
+
+ ops = cache->c_ops->co_obj_ops;
+
+ nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list) {
+ if (filter && !nl_object_match_filter(obj, filter))
+ continue;
+
+ cb(obj, arg);
+ }
+}
+
+/** @} */
+#endif
+
+/** @} */
projects / openwrt.git / blobdiff