xfrm: Introduce xfrm_input_afinfo to access the the callbacks properly

IPv6 can be build as a module, so we need mechanism to access
the address family dependent callback functions properly.
Therefore we introduce xfrm_input_afinfo, similar to that
what we have for the address family dependent part of
policies and states.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Steffen Klassert 2014-03-14 07:28:07 +01:00
parent 870a2df4ca
commit 2f32b51b60
4 changed files with 99 additions and 13 deletions

View file

@ -16,6 +16,81 @@
static struct kmem_cache *secpath_cachep __read_mostly;
static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
static struct xfrm_input_afinfo __rcu *xfrm_input_afinfo[NPROTO];
int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo)
{
int err = 0;
if (unlikely(afinfo == NULL))
return -EINVAL;
if (unlikely(afinfo->family >= NPROTO))
return -EAFNOSUPPORT;
spin_lock_bh(&xfrm_input_afinfo_lock);
if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
err = -ENOBUFS;
else
rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
spin_unlock_bh(&xfrm_input_afinfo_lock);
return err;
}
EXPORT_SYMBOL(xfrm_input_register_afinfo);
int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo)
{
int err = 0;
if (unlikely(afinfo == NULL))
return -EINVAL;
if (unlikely(afinfo->family >= NPROTO))
return -EAFNOSUPPORT;
spin_lock_bh(&xfrm_input_afinfo_lock);
if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
err = -EINVAL;
else
RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
}
spin_unlock_bh(&xfrm_input_afinfo_lock);
synchronize_rcu();
return err;
}
EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
static struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
{
struct xfrm_input_afinfo *afinfo;
if (unlikely(family >= NPROTO))
return NULL;
rcu_read_lock();
afinfo = rcu_dereference(xfrm_input_afinfo[family]);
if (unlikely(!afinfo))
rcu_read_unlock();
return afinfo;
}
static void xfrm_input_put_afinfo(struct xfrm_input_afinfo *afinfo)
{
rcu_read_unlock();
}
static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
int err)
{
int ret;
struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
if (!afinfo)
return -EAFNOSUPPORT;
ret = afinfo->callback(skb, protocol, err);
xfrm_input_put_afinfo(afinfo);
return ret;
}
void __secpath_destroy(struct sec_path *sp)
{
int i;