Documentation/networking/6lowpan.txt

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