[linux.git] / net / 6lowpan / nhc.h

/* SPDX-License-Identifier: GPL-2.0 */
#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>

/**
 * 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 function will return 0. If we
 *	don't support the nhc by nexthdr this function will return -ENOENT.
 *
 * @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.
 */
int lowpan_nhc_check_compression(struct sk_buff *skb,
				 const struct ipv6hdr *hdr, u8 **hc_ptr);

/**
 * 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,
				const 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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
92aa7c65 AA	2	#ifndef __6LOWPAN_NHC_H
	3	#define __6LOWPAN_NHC_H
	4
	5	#include <linux/skbuff.h>
	6	#include <linux/rbtree.h>
	7	#include <linux/module.h>
	8
	9	#include <net/6lowpan.h>
	10	#include <net/ipv6.h>
	11
92aa7c65 AA	12	/**
	13	* LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct
	14	*
	15	* @__nhc: variable name of the lowpan_nhc struct.
	16	* @_name: const char * of common header compression name.
	17	* @_nexthdr: ipv6 nexthdr field for the header compression.
	18	* @_nexthdrlen: ipv6 nexthdr len for the reserved space.
	19	* @_idsetup: callback to setup id and mask values.
	20	* @_idlen: len for the next header id and mask, should be always the same.
	21	* @_uncompress: callback for uncompression call.
	22	* @_compress: callback for compression call.
	23	*/
	24	#define LOWPAN_NHC(__nhc, _name, _nexthdr, \
	25	_hdrlen, _idsetup, _idlen, \
	26	_uncompress, _compress) \
	27	static u8 __nhc##_val[_idlen]; \
	28	static u8 __nhc##_mask[_idlen]; \
	29	static struct lowpan_nhc __nhc = { \
	30	.name = _name, \
	31	.nexthdr = _nexthdr, \
	32	.nexthdrlen = _hdrlen, \
	33	.id = __nhc##_val, \
	34	.idmask = __nhc##_mask, \
	35	.idlen = _idlen, \
	36	.idsetup = _idsetup, \
	37	.uncompress = _uncompress, \
	38	.compress = _compress, \
	39	}
	40
	41	#define module_lowpan_nhc(__nhc) \
	42	static int __init __nhc##_init(void) \
	43	{ \
	44	return lowpan_nhc_add(&(__nhc)); \
	45	} \
	46	module_init(__nhc##_init); \
	47	static void __exit __nhc##_exit(void) \
	48	{ \
	49	lowpan_nhc_del(&(__nhc)); \
	50	} \
	51	module_exit(__nhc##_exit);
	52
	53	/**
	54	* struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation
	55	*
	56	* @node: holder for the rbtree.
	57	* @name: name of the specific next header compression
	58	* @nexthdr: next header value of the protocol which should be compressed.
	59	* @nexthdrlen: ipv6 nexthdr len for the reserved space.
	60	* @id: array for nhc id. Note this need to be in network byteorder.
	61	* @mask: array for nhc id mask. Note this need to be in network byteorder.
	62	* @len: the length of the next header id and mask.
	63	* @setup: callback to setup fill the next header id value and mask.
	64	* @compress: callback to do the header compression.
	65	* @uncompress: callback to do the header uncompression.
	66	*/
	67	struct lowpan_nhc {
	68	struct rb_node node;
	69	const char *name;
	70	const u8 nexthdr;
	71	const size_t nexthdrlen;
	72	u8 *id;
	73	u8 *idmask;
	74	const size_t idlen;
	75
76	void (idsetup)(struct lowpan_nhc nhc);
77	int (uncompress)(struct sk_buff skb, size_t needed);
78	int (compress)(struct sk_buff skb, u8 **hc_ptr);
79	};
80
81	/**
82	* lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr.
83	*
84	* @nexthdr: ipv6 nexthdr value.
85	*/
86	struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr);
87
88	/**
89	* lowpan_nhc_check_compression - checks if we support compression format. If
607b0bd3 AA	90	* we support the nhc by nexthdr field, the function will return 0. If we
607b0bd3 AA	91	* don't support the nhc by nexthdr this function will return -ENOENT.
92aa7c65 AA	92	*
	93	* @skb: skb of 6LoWPAN header to read nhc and replace header.
	94	* @hdr: ipv6hdr to check the nexthdr value
	95	* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
	96	* replaced header.
92aa7c65 AA	97	*/
92aa7c65 AA	98	int lowpan_nhc_check_compression(struct sk_buff *skb,
607b0bd3	99	const struct ipv6hdr hdr, u8 *hc_ptr);
92aa7c65 AA	100
	101	/**
	102	* lowpan_nhc_do_compression - calling compress callback for nhc
	103	*
	104	* @skb: skb of 6LoWPAN header to read nhc and replace header.
	105	* @hdr: ipv6hdr to set the nexthdr value
	106	* @hc_ptr: pointer for 6LoWPAN header which should increment at the end of
	107	* replaced header.
	108	*/
	109	int lowpan_nhc_do_compression(struct sk_buff skb, const struct ipv6hdr hdr,
	110	u8 **hc_ptr);
	111
	112	/**
	113	* lowpan_nhc_do_uncompression - calling uncompress callback for nhc
	114	*
	115	* @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions.
	116	* @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value.
	117	* @dev: netdevice for print logging information.
	118	* @hdr: ipv6hdr for setting nexthdr value.
	119	*/
8911d774 AA	120	int lowpan_nhc_do_uncompression(struct sk_buff *skb,
8911d774 AA	121	const struct net_device *dev,
92aa7c65 AA	122	struct ipv6hdr *hdr);
	123
	124	/**
	125	* lowpan_nhc_add - register a next header compression to framework
	126	*
	127	* @nhc: nhc which should be add.
	128	*/
	129	int lowpan_nhc_add(struct lowpan_nhc *nhc);
	130
	131	/**
	132	* lowpan_nhc_del - delete a next header compression from framework
	133	*
	134	* @nhc: nhc which should be delete.
	135	*/
	136	void lowpan_nhc_del(struct lowpan_nhc *nhc);
	137
	138	/**
	139	* lowpan_nhc_init - adding all default nhcs
	140	*/
	141	void lowpan_nhc_init(void);
	142
	143	#endif /* __6LOWPAN_NHC_H */