FD.io VPP  v21.01.1
Vector Packet Processing
sr_packet.h
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1 #ifndef included_vnet_sr_packet_h
2 #define included_vnet_sr_packet_h
3 
4 #include <vnet/ip/ip.h>
5 
6 /*
7  * ipv6 segment-routing header format
8  *
9  * Copyright (c) 2013 Cisco and/or its affiliates.
10  * Licensed under the Apache License, Version 2.0 (the "License");
11  * you may not use this file except in compliance with the License.
12  * You may obtain a copy of the License at:
13  *
14  * http://www.apache.org/licenses/LICENSE-2.0
15  *
16  * Unless required by applicable law or agreed to in writing, software
17  * distributed under the License is distributed on an "AS IS" BASIS,
18  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  * See the License for the specific language governing permissions and
20  * limitations under the License.
21  */
22 
23 /*
24  * The Segment Routing Header (SRH) is defined as follows:
25  *
26  * 0 1 2 3
27  * 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
28  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
29  * | Next Header | Hdr Ext Len | Routing Type | Segments Left |
30  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
31  * | Last Entry | Flags | Tag |
32  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
33  * | |
34  * | Segment List[0] (128 bits IPv6 address) |
35  * | |
36  * | |
37  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
38  * | |
39  * | |
40  * ...
41  * | |
42  * | |
43  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44  * | |
45  * | Segment List[n] (128 bits IPv6 address) |
46  * | |
47  * | |
48  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
49  * // //
50  * // Optional Type Length Value objects (variable) //
51  * // //
52  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
53  *
54  * where:
55  *
56  * o Next Header: 8-bit selector. Identifies the type of header
57  * immediately following the SRH.
58  *
59  * o Hdr Ext Len: 8-bit unsigned integer, is the length of the SRH
60  * header in 8-octet units, not including the first 8 octets.
61  *
62  * o Routing Type: TBD, to be assigned by IANA (suggested value: 4).
63  *
64  * o Segments Left. Defined in [RFC8200], it contains the index, in
65  * the Segment List, of the next segment to inspect. Segments Left
66  * is decremented at each segment.
67  *
68  * o Last Entry: contains the index (zero based), in the Segment List,
69  * of the the last element of the Segment List
70  *
71  * o Flags: 8 bits of flags. Following flags are defined:
72  *
73  * 0 1 2 3 4 5 6 7
74  * +-+-+-+-+-+-+-+-+
75  * |U|P|O|A|H| U |
76  * +-+-+-+-+-+-+-+-+
77  *
78  * U: Unused and for future use. SHOULD be unset on transmission
79  * and MUST be ignored on receipt.
80  *
81  * P-flag: Protected flag. Set when the packet has been rerouted
82  * through FRR mechanism by an SR endpoint node.
83  *
84  * O-flag: OAM flag. When set, it indicates that this packet is
85  * an operations and management (OAM) packet.
86  *
87  * A-flag: Alert flag. If present, it means important Type Length
88  * Value (TLV) objects are present. See Section 3.1 for details
89  * on TLVs objects.
90  *
91  * H-flag: HMAC flag. If set, the HMAC TLV is present and is
92  * encoded as the last TLV of the SRH. In other words, the last
93  * 36 octets of the SRH represent the HMAC information. See
94  * Section 3.1.5 for details on the HMAC TLV.
95  *
96  * o Tag: tag a packet as part of a class or group of packets, e.g.,
97  * packets sharing the same set of properties. When tag is not used
98  * at source it MUST be set to zero on transmission. When tag is not
99  * used during SRH Processing it SHOULD be ignored.
100  *
101  * o Segment List[n]: 128 bit IPv6 addresses representing the nth
102  * segment in the Segment List. The Segment List is encoded starting
103  * from the last segment of the path. I.e., the first element of the
104  * segment list (Segment List [0]) contains the last segment of the
105  * path while the last segment of the Segment List (Segment List[n])
106  * contains the first segment of the path. The index contained in
107  * "Segments Left" identifies the current active segment.
108  *
109  * o Type Length Value (TLV) are described in Section 3.1.
110  *
111  */
112 
113 #ifndef IPPROTO_IPV6_ROUTE
114 #define IPPROTO_IPV6_ROUTE 43
115 #endif
116 
117 #define ROUTING_HEADER_TYPE_SR 4
118 
119 typedef struct
120 {
121  /* Protocol for next header. */
123  /*
124  * Length of routing header in 8 octet units,
125  * not including the first 8 octets
126  */
128 
129  /* Type of routing header; type 4 = segement routing */
131 
132  /* Next segment in the segment list */
134 
135  /* Pointer to the first segment in the header */
137 
138  /* Flag bits */
139 #define IP6_SR_HEADER_FLAG_PROTECTED (0x40)
140 #define IP6_SR_HEADER_FLAG_OAM (0x20)
141 #define IP6_SR_HEADER_FLAG_ALERT (0x10)
142 #define IP6_SR_HEADER_FLAG_HMAC (0x80)
143 
144  /* values 0x0, 0x4 - 0x7 are reserved */
147 
148  /* The segment elts */
149  ip6_address_t segments[0];
150 } __attribute__ ((packed)) ip6_sr_header_t;
151 
152 typedef struct
153 {
156  u8 value[0];
157 } __attribute__ ((packed)) ip6_sr_tlv_t;
158 
159 /*
160 * fd.io coding-style-patch-verification: ON
161 *
162 * Local Variables:
163 * eval: (c-set-style "gnu")
164 * End:
165 */
166 
167 #endif /* included_vnet_sr_packet_h */
unsigned char u8
Definition: types.h:56
unsigned short u16
Definition: types.h:57
u8 value
Definition: qos.api:54