#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_extend.h>
-static __read_mostly LIST_HEAD(helpers);
+static DEFINE_MUTEX(nf_ct_helper_mutex);
+static struct hlist_head *nf_ct_helper_hash __read_mostly;
+static unsigned int nf_ct_helper_hsize __read_mostly;
+static unsigned int nf_ct_helper_count __read_mostly;
+static int nf_ct_helper_vmalloc;
-struct nf_conntrack_helper *
-__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple)
-{
- struct nf_conntrack_helper *h;
- struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) };
- list_for_each_entry(h, &helpers, list) {
- if (nf_ct_tuple_src_mask_cmp(tuple, &h->tuple, &mask))
- return h;
- }
- return NULL;
+/* Stupid hash, but collision free for the default registrations of the
+ * helpers currently in the kernel. */
+static unsigned int helper_hash(const struct nf_conntrack_tuple *tuple)
+{
+ return (((tuple->src.l3num << 8) | tuple->dst.protonum) ^
+ (__force __u16)tuple->src.u.all) % nf_ct_helper_hsize;
}
struct nf_conntrack_helper *
-nf_ct_helper_find_get( const struct nf_conntrack_tuple *tuple)
+__nf_ct_helper_find(const struct nf_conntrack_tuple *tuple)
{
struct nf_conntrack_helper *helper;
+ struct nf_conntrack_tuple_mask mask = { .src.u.all = htons(0xFFFF) };
+ struct hlist_node *n;
+ unsigned int h;
- /* need nf_conntrack_lock to assure that helper exists until
- * try_module_get() is called */
- read_lock_bh(&nf_conntrack_lock);
-
- helper = __nf_ct_helper_find(tuple);
- if (helper) {
- /* need to increase module usage count to assure helper will
- * not go away while the caller is e.g. busy putting a
- * conntrack in the hash that uses the helper */
- if (!try_module_get(helper->me))
- helper = NULL;
- }
-
- read_unlock_bh(&nf_conntrack_lock);
-
- return helper;
-}
-EXPORT_SYMBOL_GPL(nf_ct_helper_find_get);
+ if (!nf_ct_helper_count)
+ return NULL;
-void nf_ct_helper_put(struct nf_conntrack_helper *helper)
-{
- module_put(helper->me);
+ h = helper_hash(tuple);
+ hlist_for_each_entry_rcu(helper, n, &nf_ct_helper_hash[h], hnode) {
+ if (nf_ct_tuple_src_mask_cmp(tuple, &helper->tuple, &mask))
+ return helper;
+ }
+ return NULL;
}
-EXPORT_SYMBOL_GPL(nf_ct_helper_put);
+EXPORT_SYMBOL_GPL(__nf_ct_helper_find);
struct nf_conntrack_helper *
__nf_conntrack_helper_find_byname(const char *name)
{
struct nf_conntrack_helper *h;
+ struct hlist_node *n;
+ unsigned int i;
- list_for_each_entry(h, &helpers, list) {
- if (!strcmp(h->name, name))
- return h;
+ for (i = 0; i < nf_ct_helper_hsize; i++) {
+ hlist_for_each_entry_rcu(h, n, &nf_ct_helper_hash[i], hnode) {
+ if (!strcmp(h->name, name))
+ return h;
+ }
}
-
return NULL;
}
EXPORT_SYMBOL_GPL(__nf_conntrack_helper_find_byname);
+struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, gfp_t gfp)
+{
+ struct nf_conn_help *help;
+
+ help = nf_ct_ext_add(ct, NF_CT_EXT_HELPER, gfp);
+ if (help)
+ INIT_HLIST_HEAD(&help->expectations);
+ else
+ pr_debug("failed to add helper extension area");
+ return help;
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_ext_add);
+
static inline int unhelp(struct nf_conntrack_tuple_hash *i,
const struct nf_conntrack_helper *me)
{
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
- BUG_ON(me->timeout == 0);
+ unsigned int h = helper_hash(&me->tuple);
+
+ BUG_ON(me->expect_policy == NULL);
+ BUG_ON(me->expect_class_max >= NF_CT_MAX_EXPECT_CLASSES);
- write_lock_bh(&nf_conntrack_lock);
- list_add(&me->list, &helpers);
- write_unlock_bh(&nf_conntrack_lock);
+ mutex_lock(&nf_ct_helper_mutex);
+ hlist_add_head_rcu(&me->hnode, &nf_ct_helper_hash[h]);
+ nf_ct_helper_count++;
+ mutex_unlock(&nf_ct_helper_mutex);
return 0;
}
{
struct nf_conntrack_tuple_hash *h;
struct nf_conntrack_expect *exp;
- struct hlist_node *n, *next;
+ const struct hlist_node *n, *next;
unsigned int i;
- /* Need write lock here, to delete helper. */
- write_lock_bh(&nf_conntrack_lock);
- list_del(&me->list);
+ mutex_lock(&nf_ct_helper_mutex);
+ hlist_del_rcu(&me->hnode);
+ nf_ct_helper_count--;
+ mutex_unlock(&nf_ct_helper_mutex);
+
+ /* Make sure every nothing is still using the helper unless its a
+ * connection in the hash.
+ */
+ synchronize_rcu();
+
+ spin_lock_bh(&nf_conntrack_lock);
/* Get rid of expectations */
for (i = 0; i < nf_ct_expect_hsize; i++) {
hlist_for_each_entry(h, n, &nf_conntrack_hash[i], hnode)
unhelp(h, me);
}
- write_unlock_bh(&nf_conntrack_lock);
-
- /* Someone could be still looking at the helper in a bh. */
- synchronize_net();
+ spin_unlock_bh(&nf_conntrack_lock);
}
EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister);
.id = NF_CT_EXT_HELPER,
};
-int nf_conntrack_helper_init()
+int nf_conntrack_helper_init(void)
{
- return nf_ct_extend_register(&helper_extend);
+ int err;
+
+ nf_ct_helper_hsize = 1; /* gets rounded up to use one page */
+ nf_ct_helper_hash = nf_ct_alloc_hashtable(&nf_ct_helper_hsize,
+ &nf_ct_helper_vmalloc);
+ if (!nf_ct_helper_hash)
+ return -ENOMEM;
+
+ err = nf_ct_extend_register(&helper_extend);
+ if (err < 0)
+ goto err1;
+
+ return 0;
+
+err1:
+ nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc,
+ nf_ct_helper_hsize);
+ return err;
}
-void nf_conntrack_helper_fini()
+void nf_conntrack_helper_fini(void)
{
nf_ct_extend_unregister(&helper_extend);
+ nf_ct_free_hashtable(nf_ct_helper_hash, nf_ct_helper_vmalloc,
+ nf_ct_helper_hsize);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff