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
|
#ifndef included_vnet_sr_packet_h
#define included_vnet_sr_packet_h
#include <vnet/ip/ip.h>
/*
* ipv6 segment-routing header format
*
* Copyright (c) 2013 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* The Segment Routing Header (SRH) is defined as follows:
*
* 0 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Next Header | Hdr Ext Len | Routing Type | Segments Left |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Last Entry | Flags | Tag |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* | Segment List[0] (128 bits IPv6 address) |
* | |
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* | |
* ...
* | |
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* | Segment List[n] (128 bits IPv6 address) |
* | |
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* // //
* // Optional Type Length Value objects (variable) //
* // //
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* where:
*
* o Next Header: 8-bit selector. Identifies the type of header
* immediately following the SRH.
*
* o Hdr Ext Len: 8-bit unsigned integer, is the length of the SRH
* header in 8-octet units, not including the first 8 octets.
*
* o Routing Type: TBD, to be assigned by IANA (suggested value: 4).
*
* o Segments Left. Defined in [RFC8200], it contains the index, in
* the Segment List, of the next segment to inspect. Segments Left
* is decremented at each segment.
*
* o Last Entry: contains the index (zero based), in the Segment List,
* of the the last element of the Segment List
*
* o Flags: 8 bits of flags. Following flags are defined:
*
* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |U|P|O|A|H| U |
* +-+-+-+-+-+-+-+-+
*
* U: Unused and for future use. SHOULD be unset on transmission
* and MUST be ignored on receipt.
*
* P-flag: Protected flag. Set when the packet has been rerouted
* through FRR mechanism by an SR endpoint node.
*
* O-flag: OAM flag. When set, it indicates that this packet is
* an operations and management (OAM) packet.
*
* A-flag: Alert flag. If present, it means important Type Length
* Value (TLV) objects are present. See Section 3.1 for details
* on TLVs objects.
*
* H-flag: HMAC flag. If set, the HMAC TLV is present and is
* encoded as the last TLV of the SRH. In other words, the last
* 36 octets of the SRH represent the HMAC information. See
* Section 3.1.5 for details on the HMAC TLV.
*
* o Tag: tag a packet as part of a class or group of packets, e.g.,
* packets sharing the same set of properties. When tag is not used
* at source it MUST be set to zero on transmission. When tag is not
* used during SRH Processing it SHOULD be ignored.
*
* o Segment List[n]: 128 bit IPv6 addresses representing the nth
* segment in the Segment List. The Segment List is encoded starting
* from the last segment of the path. I.e., the first element of the
* segment list (Segment List [0]) contains the last segment of the
* path while the last segment of the Segment List (Segment List[n])
* contains the first segment of the path. The index contained in
* "Segments Left" identifies the current active segment.
*
* o Type Length Value (TLV) are described in Section 3.1.
*
*/
#ifndef IPPROTO_IPV6_ROUTE
#define IPPROTO_IPV6_ROUTE 43
#endif
#define ROUTING_HEADER_TYPE_SR 4
#define IP6_SRH_PT_TLV_TYPE 128
#define IP6_SRH_PT_TLV_LEN 14
typedef struct
{
/* Protocol for next header. */
u8 protocol;
/*
* Length of routing header in 8 octet units,
* not including the first 8 octets
*/
u8 length;
/* Type of routing header; type 4 = segement routing */
u8 type;
/* Next segment in the segment list */
u8 segments_left;
/* Pointer to the first segment in the header */
u8 last_entry;
/* Flag bits */
#define IP6_SR_HEADER_FLAG_PROTECTED (0x40)
#define IP6_SR_HEADER_FLAG_OAM (0x20)
#define IP6_SR_HEADER_FLAG_ALERT (0x10)
#define IP6_SR_HEADER_FLAG_HMAC (0x80)
/* values 0x0, 0x4 - 0x7 are reserved */
u8 flags;
u16 tag;
/* The segment elts */
ip6_address_t segments[0];
} __attribute__ ((packed)) ip6_sr_header_t;
typedef struct
{
u8 type;
u8 length;
u8 value[0];
} __attribute__ ((packed)) ip6_sr_tlv_t;
typedef struct
{
u32 sec;
u32 nsec;
} __attribute__ ((packed)) timestamp_64_t;
typedef struct
{
u8 type;
u8 length;
u16 id_ld;
timestamp_64_t t64;
u16 session_id;
u16 seq_num;
} __attribute__ ((packed)) ip6_sr_pt_tlv_t;
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
#endif /* included_vnet_sr_packet_h */
|
