1.. SPDX-License-Identifier: GPL-2.0 2 3============================================== 4Netdev private dataroom for 6lowpan interfaces 5============================================== 6 7All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN, 8must have "struct lowpan_priv" placed at beginning of netdev_priv. 9 10The priv_size of each interface should be calculate by:: 11 12 dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA); 13 14Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct. 15To access the LL_PRIV_6LOWPAN_DATA structure you can cast:: 16 17 lowpan_priv(dev)-priv; 18 19to your LL_6LOWPAN_PRIV_DATA structure. 20 21Before registering the lowpan netdev interface you must run:: 22 23 lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR); 24 25wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of 26enum lowpan_lltypes. 27 28Example to evaluate the private usually you can do:: 29 30 static inline struct lowpan_priv_foobar * 31 lowpan_foobar_priv(struct net_device *dev) 32 { 33 return (struct lowpan_priv_foobar *)lowpan_priv(dev)->priv; 34 } 35 36 switch (dev->type) { 37 case ARPHRD_6LOWPAN: 38 lowpan_priv = lowpan_priv(dev); 39 /* do great stuff which is ARPHRD_6LOWPAN related */ 40 switch (lowpan_priv->lltype) { 41 case LOWPAN_LLTYPE_FOOBAR: 42 /* do 802.15.4 6LoWPAN handling here */ 43 lowpan_foobar_priv(dev)->bar = foo; 44 break; 45 ... 46 } 47 break; 48 ... 49 } 50 51In case of generic 6lowpan branch ("net/6lowpan") you can remove the check 52on ARPHRD_6LOWPAN, because you can be sure that these function are called 53by ARPHRD_6LOWPAN interfaces. 54