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third_party_libnl/lib/cache.c

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/* SPDX-License-Identifier: LGPL-2.1-only */
/*
* 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) 2003-2012 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
*
* Related sections in the development guide:
* - @core_doc{core_cache, Caching System}
*
* @{
*
* Header
* ------
* ~~~~{.c}
* #include <netlink/cache.h>
* ~~~~
*/
#include <netlink-private/netlink.h>
#include <netlink/netlink.h>
#include <netlink/cache.h>
#include <netlink/object.h>
#include <netlink/hashtable.h>
#include <netlink/utils.h>
/**
* @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_object *obj;
int nitems = 0;
if (cache->c_ops == NULL)
BUG();
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);
}
/** @} */
/**
* @name Cache Allocation/Deletion
* @{
*/
/**
* Allocate new cache
* @arg ops Cache operations
*
* Allocate and initialize a new cache based on the cache operations
* provided.
*
* @return Allocated cache or NULL if allocation failed.
*/
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;
cache->c_flags |= ops->co_flags;
cache->c_refcnt = 1;
/*
* If object type provides a hash keygen
* functions, allocate a hash table for the
* cache objects for faster lookups
*/
if (ops->co_obj_ops->oo_keygen) {
int hashtable_size;
if (ops->co_hash_size)
hashtable_size = ops->co_hash_size;
else
hashtable_size = NL_MAX_HASH_ENTRIES;
cache->hashtable = nl_hash_table_alloc(hashtable_size);
}
NL_DBG(2, "Allocated cache %p <%s>.\n", cache, nl_cache_name(cache));
return cache;
}
/**
* Allocate new cache and fill it
* @arg ops Cache operations
* @arg sock Netlink socket
* @arg result Result pointer
*
* Allocate new cache and fill it. Equivalent to calling:
* @code
* cache = nl_cache_alloc(ops);
* nl_cache_refill(sock, cache);
* @endcode
*
* @see nl_cache_alloc
*
* @return 0 on success or a negative error code.
*/
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;
}
/**
* Allocate new cache based on type name
* @arg kind Name of cache type
* @arg result Result pointer
*
* Lookup cache ops via nl_cache_ops_lookup() and allocate the cache
* by calling nl_cache_alloc(). Stores the allocated cache in the
* result pointer provided.
*
* @see nl_cache_alloc
*
* @return 0 on success or a negative error code.
*/
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_safe(kind);
if (!ops)
return -NLE_NOCACHE;
cache = nl_cache_alloc(ops);
nl_cache_ops_put(ops);
if (!cache)
return -NLE_NOMEM;
*result = cache;
return 0;
}
/**
* Allocate new cache containing a subset of an existing cache
* @arg orig Original cache to base new cache on
* @arg filter Filter defining the subset to be filled into the new cache
*
* Allocates a new cache matching the type of the cache specified by
* \p orig. Iterates over the \p orig cache applying the specified
* \p filter and copies all objects that match to the new cache.
*
* The copied objects are clones but do not contain a reference to each
* other. Later modifications to objects in the original cache will
* not affect objects in the 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 *obj;
if (!filter)
BUG();
cache = nl_cache_alloc(orig->c_ops);
if (!cache)
return NULL;
NL_DBG(2, "Filling subset of cache %p <%s> with filter %p into %p\n",
orig, nl_cache_name(orig), filter, cache);
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;
}
/**
* Allocate new cache and copy the contents of an existing cache
* @arg cache Original cache to base new cache on
*
* Allocates a new cache matching the type of the cache specified by
* \p cache. Iterates over the \p cache cache and copies all objects
* to the new cache.
*
* The copied objects are clones but do not contain a reference to each
* other. Later modifications to objects in the original cache will
* not affect objects in the new cache.
*
* @return A newly allocated cache or NULL.
*/
struct nl_cache *nl_cache_clone(struct nl_cache *cache)
{
struct nl_cache_ops *ops = nl_cache_get_ops(cache);
struct nl_cache *clone;
struct nl_object *obj;
clone = nl_cache_alloc(ops);
if (!clone)
return NULL;
NL_DBG(2, "Cloning %p into %p\n", cache, clone);
nl_list_for_each_entry(obj, &cache->c_items, ce_list)
nl_cache_add(clone, obj);
return clone;
}
/**
* Remove all objects of a cache.
* @arg cache Cache to clear
*
* The objects are unliked/removed from the cache by calling
* nl_cache_remove() on each object in the cache. If any of the objects
* to not contain any further references to them, those objects will
* be freed.
*
* Unlike with nl_cache_free(), the cache is not freed just emptied.
*/
void nl_cache_clear(struct nl_cache *cache)
{
struct nl_object *obj, *tmp;
NL_DBG(2, "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);
}
static void __nl_cache_free(struct nl_cache *cache)
{
nl_cache_clear(cache);
if (cache->hashtable)
nl_hash_table_free(cache->hashtable);
NL_DBG(2, "Freeing cache %p <%s>...\n", cache, nl_cache_name(cache));
free(cache);
}
/**
* Increase reference counter of cache
* @arg cache Cache
*/
void nl_cache_get(struct nl_cache *cache)
{
cache->c_refcnt++;
NL_DBG(3, "Incremented cache %p <%s> reference count to %d\n",
cache, nl_cache_name(cache), cache->c_refcnt);
}
/**
* Free a cache.
* @arg cache Cache to free.
*
* Calls nl_cache_clear() to remove all objects associated with the
* cache and frees the cache afterwards.
*
* @see nl_cache_clear()
*/
void nl_cache_free(struct nl_cache *cache)
{
if (!cache)
return;
cache->c_refcnt--;
NL_DBG(3, "Decremented cache %p <%s> reference count, %d remaining\n",
cache, nl_cache_name(cache), cache->c_refcnt);
if (cache->c_refcnt <= 0)
__nl_cache_free(cache);
}
void nl_cache_put(struct nl_cache *cache)
{
nl_cache_free(cache);
}
/** @} */
/**
* @name Cache Modifications
* @{
*/
static int __cache_add(struct nl_cache *cache, struct nl_object *obj)
{
int ret;
obj->ce_cache = cache;
if (cache->hashtable) {
ret = nl_hash_table_add(cache->hashtable, obj);
if (ret < 0) {
obj->ce_cache = NULL;
return ret;
}
}
nl_list_add_tail(&obj->ce_list, &cache->c_items);
cache->c_nitems++;
NL_DBG(3, "Added object %p to cache %p <%s>, nitems %d\n",
obj, cache, nl_cache_name(cache), cache->c_nitems);
return 0;
}
/**
* Add object to cache.
* @arg cache Cache
* @arg obj Object to be added to the cache
*
* Adds the object \p obj to the specified \p cache. In case the object
* is already associated with another cache, the object is cloned before
* adding it to the cache. In this case, the sole reference to the object
* will be the one of the cache. Therefore clearing/freeing the cache
* will result in the object being freed again.
*
* If the object has not been associated with a cache yet, the reference
* counter of the object is incremented to account for the additional
* reference.
*
* The type of the object and cache must match, otherwise an error is
* returned (-NLE_OBJ_MISMATCH).
*
* @see nl_cache_move()
*
* @return 0 or a negative error code.
*/
int nl_cache_add(struct nl_cache *cache, struct nl_object *obj)
{
struct nl_object *new;
int ret = 0;
if (cache->c_ops->co_obj_ops != obj->ce_ops)
return -NLE_OBJ_MISMATCH;
if (!nl_list_empty(&obj->ce_list)) {
NL_DBG(3, "Object %p already in cache, cloning new object\n", obj);
new = nl_object_clone(obj);
if (!new)
return -NLE_NOMEM;
} else {
nl_object_get(obj);
new = obj;
}
ret = __cache_add(cache, new);
if (ret < 0)
nl_object_put(new);
return ret;
}
/**
* Move object from one cache to another
* @arg cache Cache to move object to.
* @arg obj Object subject to be moved
*
* Removes the the specified object \p obj from its associated cache
* and moves it to another cache.
*
* If the object is not associated with a cache, the function behaves
* just like nl_cache_add().
*
* The type of the object and cache must match, otherwise an error is
* returned (-NLE_OBJ_MISMATCH).
*
* @see nl_cache_add()
*
* @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 from cache %p to cache %p\n",
obj, obj->ce_cache, 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);
}
/**
* Remove object from cache.
* @arg obj Object to remove from cache
*
* Removes the object \c obj from the cache it is associated with. The
* reference counter of the object will be decremented. If the reference
* to the object was the only one remaining, the object will be freed.
*
* If no cache is associated with the object, this function is a NOP.
*/
void nl_cache_remove(struct nl_object *obj)
{
int ret;
struct nl_cache *cache = obj->ce_cache;
if (cache == NULL)
return;
if (cache->hashtable) {
ret = nl_hash_table_del(cache->hashtable, obj);
if (ret < 0)
NL_DBG(2, "Failed to delete %p from cache %p <%s>.\n",
obj, cache, nl_cache_name(cache));
}
nl_list_del(&obj->ce_list);
obj->ce_cache = NULL;
nl_object_put(obj);
cache->c_nitems--;
NL_DBG(2, "Deleted object %p from cache %p <%s>.\n",
obj, cache, nl_cache_name(cache));
}
/** @} */
/**
* @name Synchronization
* @{
*/
/**
* Set synchronization arg1 of cache
* @arg cache Cache
* @arg arg argument
*
* Synchronization arguments are used to specify filters when
* requesting dumps from the kernel.
*/
void nl_cache_set_arg1(struct nl_cache *cache, int arg)
{
cache->c_iarg1 = arg;
}
/**
* Set synchronization arg2 of cache
* @arg cache Cache
* @arg arg argument
*
* Synchronization arguments are used to specify filters when
* requesting dumps from the kernel.
*/
void nl_cache_set_arg2(struct nl_cache *cache, int arg)
{
cache->c_iarg2 = arg;
}
/**
* Set cache flags
* @arg cache Cache
* @arg flags Flags
*/
void nl_cache_set_flags(struct nl_cache *cache, unsigned int flags)
{
cache->c_flags |= flags;
}
/**
* Invoke the request-update operation
* @arg sk Netlink socket.
* @arg cache Cache
*
* This function causes the \e request-update function of the cache
* operations to be invoked. This usually causes a dump request to
* be sent over the netlink socket which triggers the kernel to dump
* all objects of a specific type to be dumped onto the netlink
* socket for pickup.
*
* The behaviour of this function depends on the implemenation of
* the \e request_update function of each individual type of cache.
*
* This function will not have any effects on the cache (unless the
* request_update implementation of the cache operations does so).
*
* Use nl_cache_pickup() to pick-up (read) the objects from the socket
* and fill them into the cache.
*
* @see nl_cache_pickup(), nl_cache_resync()
*
* @return 0 on success or a negative error code. Some implementations
* of co_request_update() return a positive number on success that is
* the number of bytes sent. Treat any non-negative number as success too.
*/
static int nl_cache_request_full_dump(struct nl_sock *sk,
struct nl_cache *cache)
{
if (sk->s_proto != cache->c_ops->co_protocol)
return -NLE_PROTO_MISMATCH;
if (cache->c_ops->co_request_update == NULL)
return -NLE_OPNOTSUPP;
NL_DBG(2, "Requesting update from kernel for cache %p <%s>\n",
cache, nl_cache_name(cache));
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;
int ret = 0;
ret = nl_cache_parse(x->ops, &msg->nm_src, msg->nm_nlh, x->params);
if (ret == -NLE_EXIST)
return NL_SKIP;
else
return ret;
}
/** @endcond */
/**
* Pick-up a netlink request-update with your own parser
* @arg sk Netlink socket
* @arg cache Cache
* @arg param Parser parameters
*/
static 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(2, "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\n",
cache, nl_cache_name(cache), err, nl_geterror(err));
nl_cb_put(cb);
return err;
}
static int pickup_checkdup_cb(struct nl_object *c, struct nl_parser_param *p)
{
struct nl_cache *cache = (struct nl_cache *)p->pp_arg;
struct nl_object *old;
old = nl_cache_search(cache, c);
if (old) {
if (nl_object_update(old, c) == 0) {
nl_object_put(old);
return 0;
}
nl_cache_remove(old);
nl_object_put(old);
}
return nl_cache_add(cache, c);
}
static int pickup_cb(struct nl_object *c, struct nl_parser_param *p)
{
struct nl_cache *cache = p->pp_arg;
return nl_cache_add(cache, c);
}
static int __nl_cache_pickup(struct nl_sock *sk, struct nl_cache *cache,
int checkdup)
{
struct nl_parser_param p;
p.pp_cb = checkdup ? pickup_checkdup_cb : pickup_cb;
p.pp_arg = cache;
if (sk->s_proto != cache->c_ops->co_protocol)
return -NLE_PROTO_MISMATCH;
return __cache_pickup(sk, cache, &p);
}
/**
* 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_checkdup(struct nl_sock *sk, struct nl_cache *cache)
{
return __nl_cache_pickup(sk, cache, 1);
}
/**
* 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. If an old object with same key attributes is
* present in the cache, it is replaced with the new object.
* If the old object type supports an update operation, an update is
* attempted before a replace.
*
* @return 0 on success or a negative error code.
*/
int nl_cache_pickup(struct nl_sock *sk, struct nl_cache *cache)
{
return __nl_cache_pickup(sk, cache, 0);
}
static int cache_include(struct nl_cache *cache, struct nl_object *obj,
struct nl_msgtype *type, change_func_t cb,
change_func_v2_t cb_v2, void *data)
{
struct nl_object *old;
struct nl_object *clone = NULL;
uint64_t diff = 0;
switch (type->mt_act) {
case NL_ACT_NEW:
case NL_ACT_DEL:
old = nl_cache_search(cache, obj);
if (old) {
if (cb_v2 && old->ce_ops->oo_update) {
clone = nl_object_clone(old);
diff = nl_object_diff64(old, obj);
}
/*
* Some objects types might support merging the new
* object with the old existing cache object.
* Handle them first.
*/
if (nl_object_update(old, obj) == 0) {
if (cb_v2) {
cb_v2(cache, clone, obj, diff,
NL_ACT_CHANGE, data);
nl_object_put(clone);
} else if (cb)
cb(cache, old, NL_ACT_CHANGE, data);
nl_object_put(old);
return 0;
}
nl_object_put(clone);
nl_cache_remove(old);
if (type->mt_act == NL_ACT_DEL) {
if (cb_v2)
cb_v2(cache, old, NULL, 0, NL_ACT_DEL,
data);
else if (cb)
cb(cache, old, NL_ACT_DEL, data);
nl_object_put(old);
}
}
if (type->mt_act == NL_ACT_NEW) {
nl_cache_move(cache, obj);
if (old == NULL) {
if (cb_v2) {
cb_v2(cache, NULL, obj, 0, NL_ACT_NEW,
data);
} else if (cb)
cb(cache, obj, NL_ACT_NEW, data);
} else if (old) {
diff = 0;
if (cb || cb_v2)
diff = nl_object_diff64(old, obj);
if (diff && cb_v2) {
cb_v2(cache, old, obj, diff, NL_ACT_CHANGE,
data);
} else if (diff && cb)
cb(cache, obj, NL_ACT_CHANGE, data);
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, void *data)
{
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, NULL, data);
NL_DBG(3, "Object %p does not seem to belong to cache %p <%s>\n",
obj, cache, nl_cache_name(cache));
return -NLE_MSGTYPE_NOSUPPORT;
}
int nl_cache_include_v2(struct nl_cache *cache, struct nl_object *obj,
change_func_v2_t change_cb, void *data)
{
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],
NULL, change_cb, data);
NL_DBG(3, "Object %p does not seem to belong to cache %p <%s>\n",
obj, cache, nl_cache_name(cache));
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;
if (ca->ca_change_v2)
return nl_cache_include_v2(ca->ca_cache, c, ca->ca_change_v2,
ca->ca_change_data);
else
return nl_cache_include(ca->ca_cache, c, ca->ca_change,
ca->ca_change_data);
}
int nl_cache_resync(struct nl_sock *sk, struct nl_cache *cache,
change_func_t change_cb, void *data)
{
struct nl_object *obj, *next;
struct nl_af_group *grp;
struct nl_cache_assoc ca = {
.ca_cache = cache,
.ca_change = change_cb,
.ca_change_data = data,
};
struct nl_parser_param p = {
.pp_cb = resync_cb,
.pp_arg = &ca,
};
int err;
if (sk->s_proto != cache->c_ops->co_protocol)
return -NLE_PROTO_MISMATCH;
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);
grp = cache->c_ops->co_groups;
do {
if (grp && grp->ag_group &&
(cache->c_flags & NL_CACHE_AF_ITER))
nl_cache_set_arg1(cache, grp->ag_family);
restart:
err = nl_cache_request_full_dump(sk, cache);
if (err < 0)
goto errout;
err = __cache_pickup(sk, cache, &p);
if (err == -NLE_DUMP_INTR)
goto restart;
else if (err < 0)
goto errout;
if (grp)
grp++;
} while (grp && grp->ag_group &&
(cache->c_flags & NL_CACHE_AF_ITER));
nl_list_for_each_entry_safe(obj, next, &cache->c_items, ce_list) {
if (nl_object_is_marked(obj)) {
nl_object_get(obj);
nl_cache_remove(obj);
if (change_cb)
change_cb(cache, obj, NL_ACT_DEL, data);
nl_object_put(obj);
}
}
NL_DBG(1, "Finished resyncing %p <%s>\n", cache, nl_cache_name(cache));
err = 0;
errout:
return err;
}
/** @} */
/**
* @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. If an old object with same key
* attributes is present in the cache, it is replaced with the new object.
* If the old object type supports an update operation, an update is
* attempted before a replace.
*
* @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)
{
struct nl_af_group *grp;
int err;
if (sk->s_proto != cache->c_ops->co_protocol)
return -NLE_PROTO_MISMATCH;
nl_cache_clear(cache);
grp = cache->c_ops->co_groups;
do {
if (grp && grp->ag_group &&
(cache->c_flags & NL_CACHE_AF_ITER))
nl_cache_set_arg1(cache, grp->ag_family);
restart:
err = nl_cache_request_full_dump(sk, cache);
if (err < 0)
return err;
NL_DBG(2, "Updating cache %p <%s> for family %u, request sent, waiting for reply\n",
cache, nl_cache_name(cache), grp ? grp->ag_family : AF_UNSPEC);
err = nl_cache_pickup(sk, cache);
if (err == -NLE_DUMP_INTR) {
NL_DBG(2, "Dump interrupted, restarting!\n");
goto restart;
} else if (err < 0)
break;
if (grp)
grp++;
} while (grp && grp->ag_group &&
(cache->c_flags & NL_CACHE_AF_ITER));
return err;
}
/** @} */
/**
* @name Utillities
* @{
*/
static struct nl_object *__cache_fast_lookup(struct nl_cache *cache,
struct nl_object *needle)
{
struct nl_object *obj;
obj = nl_hash_table_lookup(cache->hashtable, needle);
if (obj) {
nl_object_get(obj);
return obj;
}
return NULL;
}
/**
* Search object in cache
* @arg cache Cache
* @arg needle Object to look for.
*
* Searches the cache for an object which matches the object \p needle.
* The function nl_object_identical() is used to determine if the
* objects match. If a matching object is found, the reference counter
* is incremented and the object is returned.
*
* Therefore, if an object is returned, the reference to the object
* must be returned by calling nl_object_put() after usage.
*
* @return Reference to object or NULL if not found.
*/
struct nl_object *nl_cache_search(struct nl_cache *cache,
struct nl_object *needle)
{
struct nl_object *obj;
if (cache->hashtable)
return __cache_fast_lookup(cache, needle);
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;
}
/**
* Find object in cache
* @arg cache Cache
* @arg filter object acting as a filter
*
* Searches the cache for an object which matches the object filter.
* If the filter attributes matches the object type id attributes,
* and the cache supports hash lookups, a faster hashtable lookup
* is used to return the object. Else, function nl_object_match_filter() is
* used to determine if the objects match. If a matching object is
* found, the reference counter is incremented and the object is returned.
*
* Therefore, if an object is returned, the reference to the object
* must be returned by calling nl_object_put() after usage.
*
* @return Reference to object or NULL if not found.
*/
struct nl_object *nl_cache_find(struct nl_cache *cache,
struct nl_object *filter)
{
struct nl_object *obj;
if (cache->c_ops == NULL)
BUG();
if ((nl_object_get_id_attrs(filter) == filter->ce_mask)
&& cache->hashtable)
return __cache_fast_lookup(cache, filter);
nl_list_for_each_entry(obj, &cache->c_items, ce_list) {
if (nl_object_match_filter(obj, filter)) {
nl_object_get(obj);
return obj;
}
}
return NULL;
}
/**
* Mark all objects of a cache
* @arg cache Cache
*
* Marks all objects of a cache by calling nl_object_mark() on each
* object associated with the cache.
*/
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> with 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;
if (params && params->dp_buf)
memset(params->dp_buf, 0, params->dp_buflen);
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;
if (cache->c_ops == NULL)
BUG();
nl_list_for_each_entry_safe(obj, tmp, &cache->c_items, ce_list) {
if (filter) {
int diff = nl_object_match_filter(obj, filter);
NL_DBG(3, "%p<->%p object difference: %x\n",
obj, filter, diff);
if (!diff)
continue;
}
/* Caller may hold obj for a long time */
nl_object_get(obj);
cb(obj, arg);
nl_object_put(obj);
}
}
/** @} */
/** @} */
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