tcp: Generalized TTL Security Mechanism

[deliverable/linux.git] / include / linux / can / dev.h

diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 1ed2a5cc03f5fb00dca89368b0d72cd42b85acf9..3db7767d2a175b9caf61ec4d98de415f7c24f6b6 100644 (file)
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -51,6 +51,15 @@ struct can_priv {
        struct sk_buff **echo_skb;
 };
 
+/*
+ * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
+ * to __u8 and ensure the dlc value to be max. 8 bytes.
+ *
+ * To be used in the CAN netdriver receive path to ensure conformance with
+ * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
+ */
+#define get_can_dlc(i) (min_t(__u8, (i), 8))
+
 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 void free_candev(struct net_device *dev);