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-rw-r--r--include/linux/etherdevice.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index df8f88f63a70..1f833ebd71ed 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -38,6 +38,34 @@ int fwnode_get_mac_address(struct fwnode_handle *fwnode, char *addr);
u32 eth_get_headlen(const struct net_device *dev, const void *data, u32 len);
__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
+
+/**
+ * eth_type_trans_careful - eth_type_trans() for skbs coming from the stack
+ * @skb: buffer, possibly with less than ETH_HLEN bytes in its linear area
+ * @dev: receiving network device
+ *
+ * eth_type_trans() expects ETH_HLEN bytes in skb->head, which NIC drivers
+ * provide. Devices looping skbs from their transmit path back to the
+ * receive path (loopback, OVS internal ports) get skbs built by the stack,
+ * whose link-layer header might have been popped by tc or OVS actions.
+ *
+ * Sets skb->protocol on success.
+ *
+ * Return: SKB_NOT_DROPPED_YET on success, or a drop reason. In the latter
+ * case, the caller must free @skb.
+ */
+static inline enum skb_drop_reason
+eth_type_trans_careful(struct sk_buff *skb, struct net_device *dev)
+{
+ enum skb_drop_reason reason = pskb_may_pull_reason(skb, ETH_HLEN);
+
+ if (unlikely(reason))
+ return reason;
+
+ skb->protocol = eth_type_trans(skb, dev);
+ return SKB_NOT_DROPPED_YET;
+}
+
extern const struct header_ops eth_header_ops;
int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,