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#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
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;
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
#endif /* included_vnet_sr_packet_h */
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