1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
#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 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 */
|
