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https://github.com/torvalds/linux
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87a93e4ece
This patch cleanups needed_headroom, needed_tailroom and hard_header_len fields for wpan and lowpan interfaces. For wpan interfaces the worst case mac header len should be part of needed_headroom, currently this is set as hard_header_len, but hard_header_len should be set to the minimum header length which xmit call assumes and this is the minimum frame length of 802.15.4. The hard_header_len value will check inside send callbacl of AF_PACKET raw sockets. For lowpan interfaces, if fragmentation isn't needed the skb will call dev_hard_header for 802154 layer and queue it afterwards. This happens without new skb allocation, so we need the same headroom and tailroom lengths like 802154 inside 802154 6lowpan layer. At least we assume as minimum header length an ipv6 header size. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
145 lines
4.4 KiB
C
145 lines
4.4 KiB
C
#ifndef __6LOWPAN_NHC_H
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#define __6LOWPAN_NHC_H
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#include <linux/skbuff.h>
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#include <linux/rbtree.h>
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#include <linux/module.h>
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#include <net/6lowpan.h>
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#include <net/ipv6.h>
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/**
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* LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct
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*
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* @__nhc: variable name of the lowpan_nhc struct.
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* @_name: const char * of common header compression name.
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* @_nexthdr: ipv6 nexthdr field for the header compression.
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* @_nexthdrlen: ipv6 nexthdr len for the reserved space.
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* @_idsetup: callback to setup id and mask values.
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* @_idlen: len for the next header id and mask, should be always the same.
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* @_uncompress: callback for uncompression call.
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* @_compress: callback for compression call.
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*/
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#define LOWPAN_NHC(__nhc, _name, _nexthdr, \
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_hdrlen, _idsetup, _idlen, \
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_uncompress, _compress) \
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static u8 __nhc##_val[_idlen]; \
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static u8 __nhc##_mask[_idlen]; \
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static struct lowpan_nhc __nhc = { \
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.name = _name, \
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.nexthdr = _nexthdr, \
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.nexthdrlen = _hdrlen, \
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.id = __nhc##_val, \
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.idmask = __nhc##_mask, \
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.idlen = _idlen, \
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.idsetup = _idsetup, \
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.uncompress = _uncompress, \
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.compress = _compress, \
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}
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#define module_lowpan_nhc(__nhc) \
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static int __init __nhc##_init(void) \
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{ \
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return lowpan_nhc_add(&(__nhc)); \
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} \
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module_init(__nhc##_init); \
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static void __exit __nhc##_exit(void) \
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{ \
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lowpan_nhc_del(&(__nhc)); \
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} \
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module_exit(__nhc##_exit);
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/**
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* struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation
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*
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* @node: holder for the rbtree.
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* @name: name of the specific next header compression
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* @nexthdr: next header value of the protocol which should be compressed.
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* @nexthdrlen: ipv6 nexthdr len for the reserved space.
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* @id: array for nhc id. Note this need to be in network byteorder.
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* @mask: array for nhc id mask. Note this need to be in network byteorder.
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* @len: the length of the next header id and mask.
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* @setup: callback to setup fill the next header id value and mask.
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* @compress: callback to do the header compression.
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* @uncompress: callback to do the header uncompression.
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*/
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struct lowpan_nhc {
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struct rb_node node;
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const char *name;
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const u8 nexthdr;
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const size_t nexthdrlen;
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u8 *id;
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u8 *idmask;
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const size_t idlen;
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void (*idsetup)(struct lowpan_nhc *nhc);
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int (*uncompress)(struct sk_buff *skb, size_t needed);
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int (*compress)(struct sk_buff *skb, u8 **hc_ptr);
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};
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/**
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* lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr.
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*
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* @nexthdr: ipv6 nexthdr value.
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*/
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struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr);
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/**
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* lowpan_nhc_check_compression - checks if we support compression format. If
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* we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be
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* set. If we don't support nexthdr will be added as inline data to the
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* 6LoWPAN header.
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*
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* @skb: skb of 6LoWPAN header to read nhc and replace header.
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* @hdr: ipv6hdr to check the nexthdr value
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* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
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* replaced header.
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* @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit
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*/
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int lowpan_nhc_check_compression(struct sk_buff *skb,
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const struct ipv6hdr *hdr, u8 **hc_ptr,
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u8 *iphc0);
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/**
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* lowpan_nhc_do_compression - calling compress callback for nhc
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*
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* @skb: skb of 6LoWPAN header to read nhc and replace header.
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* @hdr: ipv6hdr to set the nexthdr value
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* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
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* replaced header.
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*/
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int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
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u8 **hc_ptr);
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/**
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* lowpan_nhc_do_uncompression - calling uncompress callback for nhc
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*
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* @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions.
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* @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value.
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* @dev: netdevice for print logging information.
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* @hdr: ipv6hdr for setting nexthdr value.
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*/
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int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
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struct ipv6hdr *hdr);
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/**
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* lowpan_nhc_add - register a next header compression to framework
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*
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* @nhc: nhc which should be add.
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*/
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int lowpan_nhc_add(struct lowpan_nhc *nhc);
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/**
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* lowpan_nhc_del - delete a next header compression from framework
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*
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* @nhc: nhc which should be delete.
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*/
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void lowpan_nhc_del(struct lowpan_nhc *nhc);
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/**
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* lowpan_nhc_init - adding all default nhcs
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*/
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void lowpan_nhc_init(void);
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#endif /* __6LOWPAN_NHC_H */
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