1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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 | |
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 | * @_id: one byte nhc id value. |
20 | * @_idmask: one byte nhc id mask value. |
21 | * @_uncompress: callback for uncompression call. |
22 | * @_compress: callback for compression call. |
23 | */ |
24 | #define LOWPAN_NHC(__nhc, _name, _nexthdr, \ |
25 | _hdrlen, _id, _idmask, \ |
26 | _uncompress, _compress) \ |
27 | static const struct lowpan_nhc __nhc = { \ |
28 | .name = _name, \ |
29 | .nexthdr = _nexthdr, \ |
30 | .nexthdrlen = _hdrlen, \ |
31 | .id = _id, \ |
32 | .idmask = _idmask, \ |
33 | .uncompress = _uncompress, \ |
34 | .compress = _compress, \ |
35 | } |
36 | |
37 | #define module_lowpan_nhc(__nhc) \ |
38 | static int __init __nhc##_init(void) \ |
39 | { \ |
40 | return lowpan_nhc_add(&(__nhc)); \ |
41 | } \ |
42 | module_init(__nhc##_init); \ |
43 | static void __exit __nhc##_exit(void) \ |
44 | { \ |
45 | lowpan_nhc_del(&(__nhc)); \ |
46 | } \ |
47 | module_exit(__nhc##_exit); |
48 | |
49 | /** |
50 | * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation |
51 | * |
52 | * @name: name of the specific next header compression |
53 | * @nexthdr: next header value of the protocol which should be compressed. |
54 | * @nexthdrlen: ipv6 nexthdr len for the reserved space. |
55 | * @id: one byte nhc id value. |
56 | * @idmask: one byte nhc id mask value. |
57 | * @compress: callback to do the header compression. |
58 | * @uncompress: callback to do the header uncompression. |
59 | */ |
60 | struct lowpan_nhc { |
61 | const char *name; |
62 | u8 nexthdr; |
63 | size_t nexthdrlen; |
64 | u8 id; |
65 | u8 idmask; |
66 | |
67 | int (*uncompress)(struct sk_buff *skb, size_t needed); |
68 | int (*compress)(struct sk_buff *skb, u8 **hc_ptr); |
69 | }; |
70 | |
71 | /** |
72 | * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr. |
73 | * |
74 | * @nexthdr: ipv6 nexthdr value. |
75 | */ |
76 | struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr); |
77 | |
78 | /** |
79 | * lowpan_nhc_check_compression - checks if we support compression format. If |
80 | * we support the nhc by nexthdr field, the function will return 0. If we |
81 | * don't support the nhc by nexthdr this function will return -ENOENT. |
82 | * |
83 | * @skb: skb of 6LoWPAN header to read nhc and replace header. |
84 | * @hdr: ipv6hdr to check the nexthdr value |
85 | * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of |
86 | * replaced header. |
87 | */ |
88 | int lowpan_nhc_check_compression(struct sk_buff *skb, |
89 | const struct ipv6hdr *hdr, u8 **hc_ptr); |
90 | |
91 | /** |
92 | * lowpan_nhc_do_compression - calling compress callback for nhc |
93 | * |
94 | * @skb: skb of 6LoWPAN header to read nhc and replace header. |
95 | * @hdr: ipv6hdr to set the nexthdr value |
96 | * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of |
97 | * replaced header. |
98 | */ |
99 | int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, |
100 | u8 **hc_ptr); |
101 | |
102 | /** |
103 | * lowpan_nhc_do_uncompression - calling uncompress callback for nhc |
104 | * |
105 | * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions. |
106 | * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value. |
107 | * @dev: netdevice for print logging information. |
108 | * @hdr: ipv6hdr for setting nexthdr value. |
109 | */ |
110 | int lowpan_nhc_do_uncompression(struct sk_buff *skb, |
111 | const struct net_device *dev, |
112 | struct ipv6hdr *hdr); |
113 | |
114 | /** |
115 | * lowpan_nhc_add - register a next header compression to framework |
116 | * |
117 | * @nhc: nhc which should be add. |
118 | */ |
119 | int lowpan_nhc_add(const struct lowpan_nhc *nhc); |
120 | |
121 | /** |
122 | * lowpan_nhc_del - delete a next header compression from framework |
123 | * |
124 | * @nhc: nhc which should be delete. |
125 | */ |
126 | void lowpan_nhc_del(const struct lowpan_nhc *nhc); |
127 | |
128 | /** |
129 | * lowpan_nhc_init - adding all default nhcs |
130 | */ |
131 | void lowpan_nhc_init(void); |
132 | |
133 | #endif /* __6LOWPAN_NHC_H */ |
134 | |