6lowpan: cleanup lowpan_header_decompress

This patch changes the lowpan_header_decompress function by removing
inklayer related information from parameters. This is currently for
supporting short and extended address for iphc handling in 802154.
We don't support short address handling anyway right now, but there
exists already code for handling short addresses in
lowpan_header_decompress.

The address parameters are also changed to a void pointer, so 6LoWPAN
linklayer specific code can put complex structures as these parameters
and cast it again inside the generic code by evaluating linklayer type
before. The order is also changed by destination address at first and
then source address, which is the same like all others functions where
destination is always the first, memcpy, dev_hard_header,
lowpan_header_compress, etc.

This patch also moves the fetching of iphc values from 6LoWPAN linklayer
specific code into the generic branch.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 18 insertions, 6 deletions

diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index 6f1e0bd3d211..ac30ad3d8cd3 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -319,12 +319,24 @@ static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
 
 void lowpan_netdev_setup(struct net_device *dev, enum lowpan_lltypes lltype);
 
-int
-lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
-			 const u8 *saddr, const u8 saddr_type,
-			 const u8 saddr_len, const u8 *daddr,
-			 const u8 daddr_type, const u8 daddr_len,
-			 u8 iphc0, u8 iphc1);
+/**
+ * lowpan_header_decompress - replace 6LoWPAN header with IPv6 header
+ *
+ * This function replaces the IPHC 6LoWPAN header which should be pointed at
+ * skb->data and skb_network_header, with the IPv6 header.
+ * It would be nice that the caller have the necessary headroom of IPv6 header
+ * and greatest Transport layer header, this would reduce the overhead for
+ * reallocate headroom.
+ *
+ * @skb: the buffer which should be manipulate.
+ * @dev: the lowpan net device pointer.
+ * @daddr: destination lladdr of mac header which is used for compression
+ *	methods.
+ * @saddr: source lladdr of mac header which is used for compression
+ *	methods.
+ */
+int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
+			     const void *daddr, const void *saddr);
 
 /**
  * lowpan_header_compress - replace IPv6 header with 6LoWPAN header