lwtunnel: Add destroy state operation

Users of lwt tunnels may set up some secondary state in build_state
function. Add a corresponding destroy_state function to allow users to
clean up state. This destroy state function is called from lwstate_free.
Also, we now free lwstate using kfree_rcu so user can assume structure
is not freed before rcu.

Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2016-10-14 11:25:36 -07:00 committed by David S. Miller
parent 02dc7658c7
commit 1104d9ba44
2 changed files with 16 additions and 4 deletions

View File

@ -29,6 +29,7 @@ struct lwtunnel_state {
int (*orig_input)(struct sk_buff *);
int len;
__u16 headroom;
struct rcu_head rcu;
__u8 data[0];
};
@ -36,6 +37,7 @@ struct lwtunnel_encap_ops {
int (*build_state)(struct net_device *dev, struct nlattr *encap,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts);
void (*destroy_state)(struct lwtunnel_state *lws);
int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
int (*input)(struct sk_buff *skb);
int (*fill_encap)(struct sk_buff *skb,
@ -46,10 +48,7 @@ struct lwtunnel_encap_ops {
};
#ifdef CONFIG_LWTUNNEL
static inline void lwtstate_free(struct lwtunnel_state *lws)
{
kfree(lws);
}
void lwtstate_free(struct lwtunnel_state *lws);
static inline struct lwtunnel_state *
lwtstate_get(struct lwtunnel_state *lws)

View File

@ -130,6 +130,19 @@ int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
}
EXPORT_SYMBOL(lwtunnel_build_state);
void lwtstate_free(struct lwtunnel_state *lws)
{
const struct lwtunnel_encap_ops *ops = lwtun_encaps[lws->type];
if (ops->destroy_state) {
ops->destroy_state(lws);
kfree_rcu(lws, rcu);
} else {
kfree(lws);
}
}
EXPORT_SYMBOL(lwtstate_free);
int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate)
{
const struct lwtunnel_encap_ops *ops;