ipv6: Add a receive path hook for vti6 in xfrm6_mode_tunnel.

Add a receive path hook for the IPsec vritual tunnel interface.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index b8a9ed849801afa0283ac3f1511a2f56415ee8ca..6b82fdf4ba716898ea53fb0cf2e66690a66d1479 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1508,6 +1508,8 @@ int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family);
 void xfrm4_local_error(struct sk_buff *skb, u32 mtu);
 int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler);
 int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler);
+int xfrm6_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler);
+int xfrm6_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler);
 int xfrm6_extract_header(struct sk_buff *skb);
 int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb);
 int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi);

diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 4770d515c2c856684e93416d4696067cae7e3114..cb04f7a16b5e102f2944be051d61511d5645d3f7 100644 (file)
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -18,6 +18,65 @@
 #include <net/ipv6.h>
 #include <net/xfrm.h>
 
+/* Informational hook. The decap is still done here. */
+static struct xfrm_tunnel_notifier __rcu *rcv_notify_handlers __read_mostly;
+static DEFINE_MUTEX(xfrm6_mode_tunnel_input_mutex);
+
+int xfrm6_mode_tunnel_input_register(struct xfrm_tunnel_notifier *handler)
+{
+       struct xfrm_tunnel_notifier __rcu **pprev;
+       struct xfrm_tunnel_notifier *t;
+       int ret = -EEXIST;
+       int priority = handler->priority;
+
+       mutex_lock(&xfrm6_mode_tunnel_input_mutex);
+
+       for (pprev = &rcv_notify_handlers;
+            (t = rcu_dereference_protected(*pprev,
+            lockdep_is_held(&xfrm6_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(&xfrm6_mode_tunnel_input_mutex);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm6_mode_tunnel_input_register);
+
+int xfrm6_mode_tunnel_input_deregister(struct xfrm_tunnel_notifier *handler)
+{
+       struct xfrm_tunnel_notifier __rcu **pprev;
+       struct xfrm_tunnel_notifier *t;
+       int ret = -ENOENT;
+
+       mutex_lock(&xfrm6_mode_tunnel_input_mutex);
+       for (pprev = &rcv_notify_handlers;
+            (t = rcu_dereference_protected(*pprev,
+            lockdep_is_held(&xfrm6_mode_tunnel_input_mutex))) != NULL;
+            pprev = &t->next) {
+               if (t == handler) {
+                       *pprev = handler->next;
+                       ret = 0;
+                       break;
+               }
+       }
+       mutex_unlock(&xfrm6_mode_tunnel_input_mutex);
+       synchronize_net();
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xfrm6_mode_tunnel_input_deregister);
+
 static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
 {
        const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
@@ -63,8 +122,15 @@ static int xfrm6_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 xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 {
+       struct xfrm_tunnel_notifier *handler;
        int err = -EINVAL;
 
        if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
@@ -72,6 +138,9 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
        if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
                goto out;
 
+       for_each_input_rcu(rcv_notify_handlers, handler)
+               handler->handler(skb);
+
        err = skb_unclone(skb, GFP_ATOMIC);
        if (err)
                goto out;