ea9eb698b2
This patch adds a 6lowpan.txt into the networking documentation directory. Currently this documentation describes how the lowpan private data of net devices will be handled. Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Suggested-by: Jukka Rissanen <jukka.rissanen@linux.intel.com> Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
51 lines
1.4 KiB
Plaintext
51 lines
1.4 KiB
Plaintext
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Netdev private dataroom for 6lowpan interfaces:
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All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN,
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must have "struct lowpan_priv" placed at beginning of netdev_priv.
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The priv_size of each interface should be calculate by:
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dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA);
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Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct.
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To access the LL_PRIV_6LOWPAN_DATA structure you can cast:
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lowpan_priv(dev)-priv;
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to your LL_6LOWPAN_PRIV_DATA structure.
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Before registering the lowpan netdev interface you must run:
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lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR);
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wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of
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enum lowpan_lltypes.
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Example to evaluate the private usually you can do:
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static inline sturct lowpan_priv_foobar *
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lowpan_foobar_priv(struct net_device *dev)
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{
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return (sturct lowpan_priv_foobar *)lowpan_priv(dev)->priv;
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}
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switch (dev->type) {
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case ARPHRD_6LOWPAN:
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lowpan_priv = lowpan_priv(dev);
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/* do great stuff which is ARPHRD_6LOWPAN related */
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switch (lowpan_priv->lltype) {
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case LOWPAN_LLTYPE_FOOBAR:
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/* do 802.15.4 6LoWPAN handling here */
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lowpan_foobar_priv(dev)->bar = foo;
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break;
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...
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}
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break;
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...
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}
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In case of generic 6lowpan branch ("net/6lowpan") you can remove the check
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on ARPHRD_6LOWPAN, because you can be sure that these function are called
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by ARPHRD_6LOWPAN interfaces.
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