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Diffstat (limited to 'src/vnet/sr/sr_packet.h')
| -rw-r--r-- | src/vnet/sr/sr_packet.h | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/vnet/sr/sr_packet.h b/src/vnet/sr/sr_packet.h new file mode 100644 index 00000000000..179b94c2dc7 --- /dev/null +++ b/src/vnet/sr/sr_packet.h @@ -0,0 +1,251 @@ +#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. + */ + +/** + * @file + * @brief The Segment Routing Header (SRH). + * + * The Segment Routing Header (SRH) is defined in the diagram below. + * + * + * 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 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | First Segment | Flags | HMAC Key ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | Segment List[0] (128 bits ipv6 address) | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | | + * ... + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | Segment List[n] (128 bits ipv6 address) | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | Policy List[0] (optional) | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | Policy List[1] (optional) | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | Policy List[2] (optional) | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | | + * | | + * | | + * | HMAC (256 bits) | + * | (optional) | + * | | + * | | + * | | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * 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 [RFC2460], it contains the index, in + * the Segment List, of the next segment to inspect. Segments Left + * is decremented at each segment and it is used as an index in the + * segment list. + * + * o First Segment: offset in the SRH, not including the first 8 octets + * and expressed in 16-octet units, pointing to the last element of + * the segment list, which is in fact the first segment of the + * segment routing path. + * + * o Flags: 16 bits of flags. Following flags are defined: + * + * 1 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |C|P|R|R| Policy Flags | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * C-flag: Clean-up flag. Set when the SRH has to be removed from + * the packet when packet reaches the last segment. + * + * P-flag: Protected flag. Set when the packet has been rerouted + * through FRR mechanism by a SR endpoint node. See Section 6.3 + * for more details. + * + * R-flags. Reserved and for future use. + * + * Policy Flags. Define the type of the IPv6 addresses encoded + * into the Policy List (see below). The following have been + * defined: + * + * Bits 4-6: determine the type of the first element after the + * segment list. + * + * Bits 7-9: determine the type of the second element. + * + * Bits 10-12: determine the type of the third element. + * + * Bits 13-15: determine the type of the fourth element. + * + * The following values are used for the type: + * + * 0x0: Not present. If value is set to 0x0, it means the + * element represented by these bits is not present. + * + * 0x1: SR Ingress. + * + * 0x2: SR Egress. + * + * 0x3: Original Source Address. + * + * o HMAC Key ID and HMAC field, and their use are defined in + * [I-D.vyncke-6man-segment-routing-security]. + * + * 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 Policy List. Optional addresses representing specific nodes in + * the SR path such as: + * + * SR Ingress: a 128 bit generic identifier representing the + * ingress in the SR domain (i.e.: it needs not to be a valid IPv6 + * address). + * + * SR Egress: a 128 bit generic identifier representing the egress + * in the SR domain (i.e.: it needs not to be a valid IPv6 + * address). + * + * Original Source Address: IPv6 address originally present in the + * SA field of the packet. + * + * The segments in the Policy List are encoded after the segment list + * and they are optional. If none are in the SRH, all bits of the + * Policy List Flags MUST be set to 0x0. + */ + +#ifndef IPPROTO_IPV6_ROUTE +#define IPPROTO_IPV6_ROUTE 43 +#endif + +#define ROUTING_HEADER_TYPE_SR 4 +/** + @brief SR header struct. +*/ +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; + + /** + * Policy list pointer: offset in the SRH of the policy + * list - in 16-octet units - not including the first 8 octets. + */ + u8 first_segment; + + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_CLEANUP (0x8000) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_PROTECTED (0x4000) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_RESERVED (0x3000) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_PL_ELT_NOT_PRESENT (0x0) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_PL_ELT_INGRESS_PE (0x1) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_PL_ELT_EGRESS_PE (0x2) + /** Flag bits */ +#define IP6_SR_HEADER_FLAG_PL_ELT_ORIG_SRC_ADDR (0x3) + /** values 0x4 - 0x7 are reserved */ + u16 flags; + u8 hmac_key; + + /** The segment + policy list elts */ + ip6_address_t segments[0]; +} __attribute__ ((packed)) ip6_sr_header_t; + +static inline int +ip6_sr_policy_list_shift_from_index (int pl_index) +{ + return (-3 * pl_index) + 12; +} + +/** pl_index is one-origined */ +static inline int +ip6_sr_policy_list_flags (u16 flags_host_byte_order, int pl_index) +{ + int shift; + + if (pl_index <= 0 || pl_index > 4) + return 0; + + shift = (-3 * pl_index) + 12; + flags_host_byte_order >>= shift; + + return (flags_host_byte_order & 7); +} + +#endif /* included_vnet_sr_packet_h */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |