+++ /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) 2003-2006 Thomas Graf <tgraf@suug.ch>
- */
-
-/**
- * @ingroup utils
- * @defgroup cache Caching
- *
- * @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>
-
-static inline char *nl_cache_name(struct nl_cache *cache)
-{
- return cache->c_ops ? cache->c_ops->co_name : "unknown";
-}
-
-/**
- * @name Access Functions
- * @{
- */
-
-/**
- * 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_cache_ops *ops = cache->c_ops;
- struct nl_object *obj;
- int nitems = 0;
-
- nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
- if (filter && ops->co_filter && !ops->co_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);
-}
-
-/** @} */
-
-/**
- * @name Cache Creation/Deletion
- * @{
- */
-
-/**
- * Allocate an empty cache of no certain type
- *
- * @return A newly allocated and initialized cache.
- */
-struct nl_cache *nl_cache_alloc(void)
-{
- struct nl_cache *cache;
-
- cache = calloc(1, sizeof(*cache));
- if (!cache) {
- nl_errno(ENOMEM);
- return NULL;
- }
-
- nl_init_list_head(&cache->c_items);
- NL_DBG(2, "Allocated cache %p <%s>.\n", cache, nl_cache_name(cache));
-
- return cache;
-}
-
-/**
- * Allocate an empty cache based on cache operations
- * @arg ops cache operations to base the cache on
- * @return A newly allocated and initialized cache.
- */
-struct nl_cache *nl_cache_alloc_from_ops(struct nl_cache_ops *ops)
-{
- struct nl_cache *new;
-
- new = nl_cache_alloc();
- if (!new)
- return NULL;
-
- new->c_ops = ops;
-
- return new;
-}
-
-/**
- * Allocate an empty cache based on type name
- * @arg kind Name of cache type
- * @return A newly allocated and initialized cache.
- */
-struct nl_cache *nl_cache_alloc_name(const char *kind)
-{
- struct nl_cache_ops *ops;
-
- ops = nl_cache_mngt_lookup(kind);
- if (!ops) {
- nl_error(ENOENT, "Unable to lookup cache \"%s\"", kind);
- return NULL;
- }
-
- return nl_cache_alloc_from_ops(ops);
-}
-
-/**
- * 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_delete(cache, 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)
-{
- nl_cache_clear(cache);
- NL_DBG(1, "Freeing cache %p <%s>...\n", cache, nl_cache_name(cache));
- free(cache);
-}
-
-/** @} */
-
-/**
- * @name Cache Modifications
- * @{
- */
-
-/**
- * Add an element to the cache.
- * @arg cache cache to add a element to
- * @arg obj Common obj to be added to the cache
- *
- * Adds the object \c obj to the tail of the cache \c cache and. The
- * cache is enlarged as needed.
- *
- * @return 0 or a negative error code.
- */
-int nl_cache_add(struct nl_cache *cache, struct nl_object *obj)
-{
- struct nl_object *new;
-
- if (nl_object_shared(obj)) {
- new = nl_object_clone(obj);
- if (!new)
- return nl_errno(ENOMEM);
-
- nl_object_put(obj);
- } else
- new = obj;
-
- new->ce_cache = cache;
-
- nl_list_add_tail(&new->ce_list, &cache->c_items);
- cache->c_nitems++;
-
- NL_DBG(1, "Added %p to cache %p <%s>.\n",
- new, cache, nl_cache_name(cache));
-
- return 0;
-}
-
-static int subsys_parse_cb(struct nl_object *c, struct nl_parser_param *p)
-{
- return nl_cache_add((struct nl_cache *) p->pp_arg, c);
-}
-
-/** @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, len, err, hdrsize;
-
- hdrsize = ops->co_hdrsize;
- len = nlh->nlmsg_len - nlmsg_msg_size(hdrsize);
- if (len < 0) {
- err = nl_error(EINVAL, "netlink message too short to "
- "of kind %s", ops->co_name);
- goto errout;
- }
-
- for (i = 0; ops->co_msgtypes[i].mt_id >= 0; i++)
- if (ops->co_msgtypes[i].mt_id == nlh->nlmsg_type)
- return ops->co_msg_parser(who, nlh, params);
-
- err = nl_error(EINVAL, "Unsupported netlink message type %d",
- nlh->nlmsg_type);
-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 = subsys_parse_cb,
- .pp_arg = cache,
- };
-
- return nl_cache_parse(cache->c_ops, NULL, nlmsg_hdr(msg), &p);
-}
-
-/**
- * Delete an element from a cache.
- * @arg cache cache to delete the element from
- * @arg obj Object to delete
- *
- * Deletes the object \c obj from the cache \c cache.
- */
-void nl_cache_delete(struct nl_cache *cache, struct nl_object *obj)
-{
- if (obj->ce_cache != cache)
- BUG();
-
- 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));
-}
-
-/** @cond SKIP */
-struct update_xdata {
- struct nl_cache_ops *ops;
- struct nl_parser_param *params;
-};
-/** @endcond */
-
-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);
-}
-
-/**
- * Pickup a netlink dump response and put it into a cache.
- * @arg handle Netlink handle.
- * @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_handle *handle, struct nl_cache *cache)
-{
- int err;
- struct nl_cache_ops *ops = cache->c_ops;
- struct nl_cb *cb;
- struct nl_parser_param p = {
- .pp_cb = subsys_parse_cb,
- .pp_arg = cache,
- };
- struct update_xdata x = {
- .ops = ops,
- .params = &p,
- };
-
- NL_DBG(1, "Filling cache %p <%s>...\n", cache, nl_cache_name(cache));
-
- cb = nl_cb_clone(nl_handle_get_cb(handle));
- nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, update_msg_parser, &x);
-
- err = nl_recvmsgs(handle, 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());
-
- nl_cb_destroy(cb);
-
- return err;
-}
-
-/**
- * Update (synchronize) a local cache with the kernel.
- * @arg handle netlink handle
- * @arg cache cache to update
- *
- * Updates the local cache \c cache with the state in the kernel. During
- * this process the cache gets emptied and refilled with the new content
- * received from the kernel.
- *
- * @return 0 or a negative error code.
- */
-int nl_cache_update(struct nl_handle *handle, struct nl_cache *cache)
-{
- int err;
- struct nl_cache_ops *ops = cache->c_ops;
-
- err = ops->co_request_update(cache, handle);
- 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(handle, cache);
-}
-
-/** @} */
-
-/**
- * @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_DBG(1, "Dumping cache %p <%s>\n", cache, nl_cache_name(cache));
- 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_FULL;
- struct nl_cache_ops *ops = cache->c_ops;
- struct nl_object *obj;
-
- if (type > NL_DUMP_MAX || type < 0)
- BUG();
-
- if (!ops->co_dump[type])
- return;
-
- nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
- if (filter && obj->ce_ops != filter->ce_ops)
- continue;
-
- if (filter && ops->co_filter && !ops->co_filter(obj, filter))
- continue;
-
- 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_cache_ops *ops = cache->c_ops;
-
- nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list) {
- if (filter && ops->co_filter && !ops->co_filter(obj, filter))
- continue;
-
- cb(obj, arg);
- }
-}
-
-/** @} */
-
-/** @} */
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