Merge remote-tracking branch 'lsk/v3.10/topic/gator' into linux-linaro-lsk

[firefly-linux-kernel-4.4.55.git] / include / linux / can / skb.h

diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 2f0543f7510c65aa71c5b5de43315da8d64c51aa..f9bbbb472663af08aef78ac152e8293f36736ea4 100644 (file)
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -11,7 +11,9 @@
 #define CAN_SKB_H
 
 #include <linux/types.h>
+#include <linux/skbuff.h>
 #include <linux/can.h>
+#include <net/sock.h>
 
 /*
  * The struct can_skb_priv is used to transport additional information along
@@ -42,4 +44,40 @@ static inline void can_skb_reserve(struct sk_buff *skb)
        skb_reserve(skb, sizeof(struct can_skb_priv));
 }
 
+static inline void can_skb_destructor(struct sk_buff *skb)
+{
+       sock_put(skb->sk);
+}
+
+static inline void can_skb_set_owner(struct sk_buff *skb, struct sock *sk)
+{
+       if (sk) {
+               sock_hold(sk);
+               skb->destructor = can_skb_destructor;
+               skb->sk = sk;
+       }
+}
+
+/*
+ * returns an unshared skb owned by the original sock to be echo'ed back
+ */
+static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
+{
+       if (skb_shared(skb)) {
+               struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
+
+               if (likely(nskb)) {
+                       can_skb_set_owner(nskb, skb->sk);
+                       consume_skb(skb);
+                       return nskb;
+               } else {
+                       kfree_skb(skb);
+                       return NULL;
+               }
+       }
+
+       /* we can assume to have an unshared skb with proper owner */
+       return skb;
+}
+
 #endif /* CAN_SKB_H */