netfilter: ctnetlink: allow to set expectfn for expectations
This patch allows you to set expectfn which is specifically used
by the NAT side of most of the existing conntrack helpers.
I have added a symbol map that uses a string as key to look up for
the function that is attached to the expectation object. This is
the best solution I came out with to solve this issue.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index bbe23ba..436b7cb 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -181,6 +181,60 @@
}
}
+static LIST_HEAD(nf_ct_helper_expectfn_list);
+
+void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n)
+{
+ spin_lock_bh(&nf_conntrack_lock);
+ list_add_rcu(&n->head, &nf_ct_helper_expectfn_list);
+ spin_unlock_bh(&nf_conntrack_lock);
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_register);
+
+void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n)
+{
+ spin_lock_bh(&nf_conntrack_lock);
+ list_del_rcu(&n->head);
+ spin_unlock_bh(&nf_conntrack_lock);
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister);
+
+struct nf_ct_helper_expectfn *
+nf_ct_helper_expectfn_find_by_name(const char *name)
+{
+ struct nf_ct_helper_expectfn *cur;
+ bool found = false;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
+ if (!strcmp(cur->name, name)) {
+ found = true;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return found ? cur : NULL;
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name);
+
+struct nf_ct_helper_expectfn *
+nf_ct_helper_expectfn_find_by_symbol(const void *symbol)
+{
+ struct nf_ct_helper_expectfn *cur;
+ bool found = false;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
+ if (cur->expectfn == symbol) {
+ found = true;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return found ? cur : NULL;
+}
+EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);
+
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
unsigned int h = helper_hash(&me->tuple);