From 9c8309d4e129a994141871ffc5825b4f616c0b21 Mon Sep 17 00:00:00 2001 From: rofl0r Date: Thu, 10 Jul 2014 18:23:28 +0200 Subject: move files into toplevel dir --- cache.c | 839 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 839 insertions(+) create mode 100644 cache.c (limited to 'cache.c') diff --git a/cache.c b/cache.c new file mode 100644 index 0000000..0e14574 --- /dev/null +++ b/cache.c @@ -0,0 +1,839 @@ +/* + * 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 + */ + +/** + * @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 +#include +#include +#include +#include + +/** + * @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 + +/** @} */ -- cgit v1.2.1