hdr.h
9.87 KB
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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup net_ipv6_hdr IPv6 header
* @ingroup net_ipv6
* @brief IPv6 header types and helper functions
* @{
*
* @file
* @brief IPv6 header type and helper function definitions
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#ifndef NET_IPV6_HDR_H
#define NET_IPV6_HDR_H
#include <stdint.h>
#include "byteorder.h"
#include "net/inet_csum.h"
#include "net/ipv6/addr.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Data type to represent an IPv6 packet header
*
* @details The structure of the header is as follows:
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ {.unparsed}
* 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |Version| Traffic Class | Flow Label |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Payload Length | Next Header | Hop Limit |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | |
* + Source Address +
* | |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | |
* + Destination Address +
* | |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* @see <a href="http://tools.ietf.org/html/rfc2460#section-3">
* RFC 2460, section 3
* </a>
*/
typedef struct __attribute__((packed)) {
/**
* @brief Version, traffic class, and flow label
*
* @details The version are the 4 most significant bits, the traffic class
* the 8 next bit, and the remainding 20 bits are the flow label (see
* above).
*
* This module provides helper functions to set, get, and check these
* fields accordingly:
* * ipv6_hdr_set_version()
* * ipv6_hdr_get_version()
* * ipv6_hdr_is()
* * ipv6_hdr_set_tc()
* * ipv6_hdr_set_tc_ecn()
* * ipv6_hdr_set_tc_dscp()
* * ipv6_hdr_get_tc()
* * ipv6_hdr_get_tc_ecn()
* * ipv6_hdr_get_tc_dscp()
* * ipv6_hdr_set_fl()
* * ipv6_hdr_get_fl()
*/
network_uint32_t v_tc_fl;
network_uint16_t len; /**< payload length of this packet. */
uint8_t nh; /**< type of next header in this packet. */
uint8_t hl; /**< hop limit for this packet. */
ipv6_addr_t src; /**< source address of this packet. */
ipv6_addr_t dst; /**< destination address of this packet. */
} ipv6_hdr_t;
/**
* @brief Sets the version field of @p hdr to 6
*
* @param[out] hdr Pointer to an IPv6 header.
*/
static inline void ipv6_hdr_set_version(ipv6_hdr_t *hdr)
{
hdr->v_tc_fl.u8[0] &= 0x0f;
hdr->v_tc_fl.u8[0] |= 0x60;
}
/**
* @brief Gets the value of the version field of @p hdr
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return Value of the version field of @p hdr.
*/
static inline uint8_t ipv6_hdr_get_version(const ipv6_hdr_t *hdr)
{
return ((hdr->v_tc_fl.u8[0]) >> 4);
}
/**
* @brief Checks if the version field is set to 6
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return true, if version field is 6
* @return false, otherwise
*/
static inline bool ipv6_hdr_is(const ipv6_hdr_t *hdr)
{
return (((hdr->v_tc_fl.u8[0]) & 0xf0) == 0x60);
}
/**
* @brief Sets the traffic class field of @p hdr
*
* @param[out] hdr Pointer to an IPv6 header.
* @param[in] tc The new value for the traffic class field.
*/
static inline void ipv6_hdr_set_tc(ipv6_hdr_t *hdr, uint8_t tc)
{
hdr->v_tc_fl.u8[0] &= 0xf0;
hdr->v_tc_fl.u8[0] |= (0x0f & (tc >> 4));
hdr->v_tc_fl.u8[1] &= 0x0f;
hdr->v_tc_fl.u8[1] |= (0xf0 & (tc << 4));
}
/**
* @brief Sets the value of the Explicit Congestion Notification (ECN) part
* of the traffic class field of @p hdr
*
* @details The field is needed e.g. in context of 6LoWPAN header compression
*
* @see <a href="https://tools.ietf.org/html/rfc3168#section-5">
* RFC 3168, section 5
* </a>
*
* @param[out] hdr Pointer to an IPv6 header.
* @param[in] ecn The new value for the 2-bit ECN part of the traffic class
* field.
*/
static inline void ipv6_hdr_set_tc_ecn(ipv6_hdr_t *hdr, uint8_t ecn)
{
hdr->v_tc_fl.u8[0] &= 0xf3;
hdr->v_tc_fl.u8[0] |= (0x0c & (ecn << 2));
}
/**
* @brief Sets the value of the Differentiated Service Codepoint (DSCP) part
* of the traffic class field of @p hdr
*
* @details The field is needed e.g. in context of 6LoWPAN header compression
*
* @see <a href="https://tools.ietf.org/html/rfc2474#section-3">
* RFC 2474, section 3
* </a>
*
* @param[out] hdr Pointer to an IPv6 header.
* @param[in] dscp The new value for the 6-bit DSCP part of the traffic class
* field.
*/
static inline void ipv6_hdr_set_tc_dscp(ipv6_hdr_t *hdr, uint8_t dscp)
{
hdr->v_tc_fl.u8[0] &= 0xfc;
hdr->v_tc_fl.u8[0] |= (0x03 & (dscp >> 4));
hdr->v_tc_fl.u8[1] &= 0x0f;
hdr->v_tc_fl.u8[1] |= (0xf0 & (dscp << 4));
}
/**
* @brief Gets the value of the traffic class field of @p hdr
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return Value of the traffic class field of @p hdr.
*/
static inline uint8_t ipv6_hdr_get_tc(const ipv6_hdr_t *hdr)
{
return ((((hdr->v_tc_fl.u8[0]) & 0x0f) << 4) |
((hdr->v_tc_fl.u8[1] & 0xf0) >> 4));
}
/**
* @brief Gets the value of the Explicit Congestion Notification (ECN) part
* of the traffic class field of @p hdr
*
* @details The field is needed e.g. in context of 6LoWPAN header compression
*
* @see <a href="https://tools.ietf.org/html/rfc3168#section-5">
* RFC 3168, section 5
* </a>
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return Value of the ECN part of the traffic class field of @p hdr.
*/
static inline uint8_t ipv6_hdr_get_tc_ecn(const ipv6_hdr_t *hdr)
{
return (((hdr->v_tc_fl.u8[0]) & 0x0c) >> 2);
}
/**
* @brief Gets the value of the Differentiated Service Codepoint (DSCP) part
* of the traffic class field of @p hdr
*
* @details The field is needed e.g. in context of 6LoWPAN header compression
*
* @see <a href="https://tools.ietf.org/html/rfc2474#section-3">
* RFC 2474, section 3
* </a>
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return Value of the DSCP part of the traffic class field of @p hdr.
*/
static inline uint8_t ipv6_hdr_get_tc_dscp(const ipv6_hdr_t *hdr)
{
return ((((hdr->v_tc_fl.u8[0]) & 0x03) << 4) |
((hdr->v_tc_fl.u8[1] & 0xf0) >> 4));
}
/**
* @brief Sets the flow label field of @p hdr
*
* @param[out] hdr Pointer to an IPv6 header.
* @param[in] fl The new value for the flow label field in host byte order.
*/
static inline void ipv6_hdr_set_fl(ipv6_hdr_t *hdr, uint32_t fl)
{
hdr->v_tc_fl.u8[1] &= 0xf0;
hdr->v_tc_fl.u8[1] |= (0x0f & (byteorder_htonl(fl).u8[1]));
hdr->v_tc_fl.u16[1] = byteorder_htonl(fl).u16[1];
}
/**
* @brief Gets the value of the flow label field of @p hdr
*
* @param[in] hdr Pointer to an IPv6 header.
*
* @return Value of the flow label field of @p hdr.
*/
static inline uint32_t ipv6_hdr_get_fl(const ipv6_hdr_t *hdr)
{
return byteorder_ntohl(hdr->v_tc_fl) & 0x000fffff;
}
/**
* @brief Calculates the Internet Checksum for the IPv6 Pseudo Header.
*
* @see <a href="https://tools.ietf.org/html/rfc2460#section-8.1">
* RFC 2460, section 8.1
* </a>
*
* @param[in] sum Preinialized value of the sum.
* @param[in] prot_num The @ref net_protnum you want to calculate the
* checksum for. Can not be inferred from
* ipv6_hdr_t::nh, since it can be an IPv6 exentension
* header.
* @param[in] hdr An IPv6 header to derive the Pseudo Header from.
* @param[in] len The upper-layer packet length for the pseudo header.
* Can not be inferred from ipv6_hdr_t::len, since
* there can be extension headers between the IPv6 header
* and the payload.
*
* @return The non-normalized Internet Checksum of the given IPv6 pseudo header.
*/
static inline uint16_t ipv6_hdr_inet_csum(uint16_t sum, ipv6_hdr_t *hdr,
uint8_t prot_num, uint16_t len)
{
if ((sum + len + prot_num) > 0xffff) {
/* increment by one for overflow to keep it as 1's complement sum */
sum++;
}
return inet_csum(sum + len + prot_num, hdr->src.u8,
(2 * sizeof(ipv6_addr_t)));
}
/**
* @brief Outputs an IPv6 header to stdout.
*
* @param[in] hdr An IPv6 header.
*/
void ipv6_hdr_print(ipv6_hdr_t *hdr);
#ifdef __cplusplus
}
#endif
#endif /* NET_IPV6_HDR_H */
/** @} */