6lowpan: handling 6lowpan fragmentation via inet_frag api

This patch drops the current way of 6lowpan fragmentation on receiving
side and replace it with a implementation which use the inet_frag api.
The old fragmentation handling has some race conditions and isn't
rfc4944 compatible. Also adding support to match fragments on
destination address, source address, tag value and datagram_size
which is missing in the current implementation.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ieee802154/Makefile b/net/ieee802154/Makefile
index 3d08adf..b113fc4 100644
--- a/net/ieee802154/Makefile
+++ b/net/ieee802154/Makefile
@@ -2,6 +2,6 @@
 obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o
 obj-$(CONFIG_6LOWPAN_IPHC) += 6lowpan_iphc.o
 
-6lowpan-y := 6lowpan_rtnl.o
+6lowpan-y := 6lowpan_rtnl.o reassembly.o
 ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o wpan-class.o
 af_802154-y := af_ieee802154.o raw.o dgram.o