From 1104d9ba443a3972052ea4eaa01e51f9ee084652 Mon Sep 17 00:00:00 2001
From: Tom Herbert <tom@herbertland.com>
Date: Fri, 14 Oct 2016 11:25:36 -0700
Subject: [PATCH] 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>
---
include/net/lwtunnel.h | 7 +++----
net/core/lwtunnel.c | 13 +++++++++++++
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index ea3f80f58fd6d..67d235f43202a 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -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)
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index e5f84c26ba1a6..88fd64250b021 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -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;
--
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