mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-18 17:54:13 +08:00
92aa7c65d2
This patch adds a generic next header compression layer interface. There exists various methods to do a header compression after 6LoWPAN header to save payload. This introduce a generic nhc header which allow a simple adding of a new header compression format instead of a static implementation inside the 6LoWPAN header compression and uncompression function. Signed-off-by: Alexander Aring <alex.aring@gmail.com> Cc: Martin Townsend <mtownsend1973@gmail.com> Reviewed-by: Stefan Schmidt <s.schmidt@samsung.com> Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
147 lines
4.4 KiB
C
147 lines
4.4 KiB
C
#ifndef __6LOWPAN_NHC_H
|
|
#define __6LOWPAN_NHC_H
|
|
|
|
#include <linux/skbuff.h>
|
|
#include <linux/rbtree.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <net/6lowpan.h>
|
|
#include <net/ipv6.h>
|
|
|
|
#define LOWPAN_NHC_MAX_ID_LEN 1
|
|
|
|
/**
|
|
* LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct
|
|
*
|
|
* @__nhc: variable name of the lowpan_nhc struct.
|
|
* @_name: const char * of common header compression name.
|
|
* @_nexthdr: ipv6 nexthdr field for the header compression.
|
|
* @_nexthdrlen: ipv6 nexthdr len for the reserved space.
|
|
* @_idsetup: callback to setup id and mask values.
|
|
* @_idlen: len for the next header id and mask, should be always the same.
|
|
* @_uncompress: callback for uncompression call.
|
|
* @_compress: callback for compression call.
|
|
*/
|
|
#define LOWPAN_NHC(__nhc, _name, _nexthdr, \
|
|
_hdrlen, _idsetup, _idlen, \
|
|
_uncompress, _compress) \
|
|
static u8 __nhc##_val[_idlen]; \
|
|
static u8 __nhc##_mask[_idlen]; \
|
|
static struct lowpan_nhc __nhc = { \
|
|
.name = _name, \
|
|
.nexthdr = _nexthdr, \
|
|
.nexthdrlen = _hdrlen, \
|
|
.id = __nhc##_val, \
|
|
.idmask = __nhc##_mask, \
|
|
.idlen = _idlen, \
|
|
.idsetup = _idsetup, \
|
|
.uncompress = _uncompress, \
|
|
.compress = _compress, \
|
|
}
|
|
|
|
#define module_lowpan_nhc(__nhc) \
|
|
static int __init __nhc##_init(void) \
|
|
{ \
|
|
return lowpan_nhc_add(&(__nhc)); \
|
|
} \
|
|
module_init(__nhc##_init); \
|
|
static void __exit __nhc##_exit(void) \
|
|
{ \
|
|
lowpan_nhc_del(&(__nhc)); \
|
|
} \
|
|
module_exit(__nhc##_exit);
|
|
|
|
/**
|
|
* struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation
|
|
*
|
|
* @node: holder for the rbtree.
|
|
* @name: name of the specific next header compression
|
|
* @nexthdr: next header value of the protocol which should be compressed.
|
|
* @nexthdrlen: ipv6 nexthdr len for the reserved space.
|
|
* @id: array for nhc id. Note this need to be in network byteorder.
|
|
* @mask: array for nhc id mask. Note this need to be in network byteorder.
|
|
* @len: the length of the next header id and mask.
|
|
* @setup: callback to setup fill the next header id value and mask.
|
|
* @compress: callback to do the header compression.
|
|
* @uncompress: callback to do the header uncompression.
|
|
*/
|
|
struct lowpan_nhc {
|
|
struct rb_node node;
|
|
const char *name;
|
|
const u8 nexthdr;
|
|
const size_t nexthdrlen;
|
|
u8 *id;
|
|
u8 *idmask;
|
|
const size_t idlen;
|
|
|
|
void (*idsetup)(struct lowpan_nhc *nhc);
|
|
int (*uncompress)(struct sk_buff *skb, size_t needed);
|
|
int (*compress)(struct sk_buff *skb, u8 **hc_ptr);
|
|
};
|
|
|
|
/**
|
|
* lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr.
|
|
*
|
|
* @nexthdr: ipv6 nexthdr value.
|
|
*/
|
|
struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr);
|
|
|
|
/**
|
|
* lowpan_nhc_check_compression - checks if we support compression format. If
|
|
* we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be
|
|
* set. If we don't support nexthdr will be added as inline data to the
|
|
* 6LoWPAN header.
|
|
*
|
|
* @skb: skb of 6LoWPAN header to read nhc and replace header.
|
|
* @hdr: ipv6hdr to check the nexthdr value
|
|
* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
|
|
* replaced header.
|
|
* @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit
|
|
*/
|
|
int lowpan_nhc_check_compression(struct sk_buff *skb,
|
|
const struct ipv6hdr *hdr, u8 **hc_ptr,
|
|
u8 *iphc0);
|
|
|
|
/**
|
|
* lowpan_nhc_do_compression - calling compress callback for nhc
|
|
*
|
|
* @skb: skb of 6LoWPAN header to read nhc and replace header.
|
|
* @hdr: ipv6hdr to set the nexthdr value
|
|
* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
|
|
* replaced header.
|
|
*/
|
|
int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr,
|
|
u8 **hc_ptr);
|
|
|
|
/**
|
|
* lowpan_nhc_do_uncompression - calling uncompress callback for nhc
|
|
*
|
|
* @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions.
|
|
* @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value.
|
|
* @dev: netdevice for print logging information.
|
|
* @hdr: ipv6hdr for setting nexthdr value.
|
|
*/
|
|
int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev,
|
|
struct ipv6hdr *hdr);
|
|
|
|
/**
|
|
* lowpan_nhc_add - register a next header compression to framework
|
|
*
|
|
* @nhc: nhc which should be add.
|
|
*/
|
|
int lowpan_nhc_add(struct lowpan_nhc *nhc);
|
|
|
|
/**
|
|
* lowpan_nhc_del - delete a next header compression from framework
|
|
*
|
|
* @nhc: nhc which should be delete.
|
|
*/
|
|
void lowpan_nhc_del(struct lowpan_nhc *nhc);
|
|
|
|
/**
|
|
* lowpan_nhc_init - adding all default nhcs
|
|
*/
|
|
void lowpan_nhc_init(void);
|
|
|
|
#endif /* __6LOWPAN_NHC_H */
|