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path: root/net/ipv4/xfrm4_mode_tunnel.c
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Diffstat (limited to 'net/ipv4/xfrm4_mode_tunnel.c')
-rw-r--r--net/ipv4/xfrm4_mode_tunnel.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index ed4bf11ef9f4..ddee0a099a2c 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -15,6 +15,65 @@
#include <net/ip.h>
#include <net/xfrm.h>
+/* Informational hook. The decap is still done here. */
+static struct xfrm_tunnel __rcu *rcv_notify_handlers __read_mostly;
+static DEFINE_MUTEX(xfrm4_mode_tunnel_input_mutex);
+
+int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel *handler)
+{
+ struct xfrm_tunnel __rcu **pprev;
+ struct xfrm_tunnel *t;
+ int ret = -EEXIST;
+ int priority = handler->priority;
+
+ mutex_lock(&xfrm4_mode_tunnel_input_mutex);
+
+ for (pprev = &rcv_notify_handlers;
+ (t = rcu_dereference_protected(*pprev,
+ lockdep_is_held(&xfrm4_mode_tunnel_input_mutex))) != NULL;
+ pprev = &t->next) {
+ if (t->priority > priority)
+ break;
+ if (t->priority == priority)
+ goto err;
+
+ }
+
+ handler->next = *pprev;
+ rcu_assign_pointer(*pprev, handler);
+
+ ret = 0;
+
+err:
+ mutex_unlock(&xfrm4_mode_tunnel_input_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_register);
+
+int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel *handler)
+{
+ struct xfrm_tunnel __rcu **pprev;
+ struct xfrm_tunnel *t;
+ int ret = -ENOENT;
+
+ mutex_lock(&xfrm4_mode_tunnel_input_mutex);
+ for (pprev = &rcv_notify_handlers;
+ (t = rcu_dereference_protected(*pprev,
+ lockdep_is_held(&xfrm4_mode_tunnel_input_mutex))) != NULL;
+ pprev = &t->next) {
+ if (t == handler) {
+ *pprev = handler->next;
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&xfrm4_mode_tunnel_input_mutex);
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_deregister);
+
static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
{
struct iphdr *inner_iph = ipip_hdr(skb);
@@ -64,8 +123,14 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
return 0;
}
+#define for_each_input_rcu(head, handler) \
+ for (handler = rcu_dereference(head); \
+ handler != NULL; \
+ handler = rcu_dereference(handler->next))
+
static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
+ struct xfrm_tunnel *handler;
int err = -EINVAL;
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
@@ -74,6 +139,9 @@ static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto out;
+ for_each_input_rcu(rcv_notify_handlers, handler)
+ handler->handler(skb);
+
if (skb_cloned(skb) &&
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto out;