1
2Netdev private dataroom for 6lowpan interfaces:
3
4All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN,
5must have "struct lowpan_priv" placed at beginning of netdev_priv.
6
7The priv_size of each interface should be calculate by:
8
9 dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA);
10
11Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct.
12To access the LL_PRIV_6LOWPAN_DATA structure you can cast:
13
14 lowpan_priv(dev)-priv;
15
16to your LL_6LOWPAN_PRIV_DATA structure.
17
18Before registering the lowpan netdev interface you must run:
19
20 lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR);
21
22wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of
23enum lowpan_lltypes.
24
25Example to evaluate the private usually you can do:
26
27static inline struct lowpan_priv_foobar *
28lowpan_foobar_priv(struct net_device *dev)
29{
30	return (struct lowpan_priv_foobar *)lowpan_priv(dev)->priv;
31}
32
33switch (dev->type) {
34case ARPHRD_6LOWPAN:
35	lowpan_priv = lowpan_priv(dev);
36	/* do great stuff which is ARPHRD_6LOWPAN related */
37	switch (lowpan_priv->lltype) {
38	case LOWPAN_LLTYPE_FOOBAR:
39		/* do 802.15.4 6LoWPAN handling here */
40		lowpan_foobar_priv(dev)->bar = foo;
41		break;
42	...
43	}
44	break;
45...
46}
47
48In case of generic 6lowpan branch ("net/6lowpan") you can remove the check
49on ARPHRD_6LOWPAN, because you can be sure that these function are called
50by ARPHRD_6LOWPAN interfaces.
51