mapme.h

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/*
 * Copyright (c) 2017-2019 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.
 */
 
#ifndef HICN_MAPME_H
#define HICN_MAPME_H
 
#include <stdint.h>     // u32
#include <stdbool.h>
 
#include "common.h"
#include "protocol.h"
#include "ops.h"
 
typedef struct
{
  bool enabled;
  u32 timescale;
  u32 retx;
  bool discovery;
} hicn_mapme_conf_t;
 
static const hicn_mapme_conf_t hicn_mapme_conf = {
  ATTR_INIT (enabled, false),
  ATTR_INIT (timescale, 0),
  ATTR_INIT (retx, 50),
  ATTR_INIT (discovery, true),
};
 
typedef u32 seq_t;
 
typedef enum
{
  UNKNOWN,
  UPDATE,
  UPDATE_ACK,
  NOTIFICATION,
  NOTIFICATION_ACK,
} hicn_mapme_type_t;
 
typedef struct
{
  int protocol;
  hicn_mapme_type_t type;
  seq_t seq;
} mapme_params_t;
 
 
/* MAP-Me API */
size_t hicn_mapme_create_packet (u8 * buf, const hicn_prefix_t * prefix,
                 const mapme_params_t * params);
size_t hicn_mapme_create_ack (u8 * buf, const mapme_params_t * params);
int hicn_mapme_parse_packet (const u8 * packet, hicn_prefix_t * prefix,
                 mapme_params_t * params);
 
/* Implementation & parsing : ICMP Redirect */
 
#define HICN_MAPME_ACK_FLAG (0x20 | 0x60)
 
#define HICN_MAPME_ICMP_TYPE_IPV4     5
#define HICN_MAPME_ICMP_TYPE_IPV6     137
#define HICN_MAPME_ICMP_TYPE_ACK_IPV4 (HICN_MAPME_ICMP_TYPE_IPV4 | HICN_MAPME_ACK_FLAG)
#define HICN_MAPME_ICMP_TYPE_ACK_IPV6 (HICN_MAPME_ICMP_TYPE_IPV6 | HICN_MAPME_ACK_FLAG)
#define HICN_MAPME_ICMP_CODE 0  /* Redirect Datagrams for the Network (or subnet) */
 
#define HICN_MAPME_TYPE_IS_IU(type)     ((type == HICN_MAPME_ICMP_TYPE_IPV4)     || (type == HICN_MAPME_ICMP_TYPE_IPV6))
#define HICN_MAPME_TYPE_IS_IU_ACK(type) ((type == HICN_MAPME_ICMP_TYPE_ACK_IPV4) || (type == HICN_MAPME_ICMP_TYPE_ACK_IPV6))
 
#define HICN_MAPME_IS_IU(type, code) (HICN_MAPME_TYPE_IS_IU(type) && (code == HICN_MAPME_ICMP_CODE))
#define HICN_MAPME_IS_ACK(type, code) (HICN_MAPME_TYPE_IS_IU_ACK(type) && (code == HICN_MAPME_ICMP_CODE))
 
#define HICN_IS_MAPME(type, code) (HICN_MAPME_IS_IU(type, code) || HICN_MAPME_IS_ACK(type, code))
 
/* Fast check for ACK flag */
#define HICN_MAPME_IS_ACK_FAST(icmp_type) (icmp_type & HICN_MAPME_ACK_FLAG)
 
/* Default TTL */
#define HICN_MAPME_TTL 255  // typical for redirect (ref?)
 
/*
 * The length of the MAPME4 header struct must be 120 bytes.
 */
#define EXPECTED_MAPME_V4_HDRLEN 120
 
typedef struct
{
  _ipv4_header_t ip;
  _icmprd4_header_t icmp_rd;
  seq_t seq;
  u8 len;
  u8 _pad[3];
} hicn_mapme_v4_header_t;
 
/*
 * The length of the MAPME4 header struct must be  bytes.
 */
#define EXPECTED_MAPME_V6_HDRLEN 88
 
typedef struct
{
  _ipv6_header_t ip;
  _icmprd_header_t icmp_rd;
  seq_t seq;
  u8 len;
  u8 _pad[3];
} hicn_mapme_v6_header_t;
 
typedef union
{
  hicn_mapme_v4_header_t v4;
  hicn_mapme_v6_header_t v6;
} hicn_mapme_header_t;
 
#define HICN_MAPME_V4_HDRLEN sizeof(hicn_mapme_v4_header_t)
#define HICN_MAPME_V6_HDRLEN sizeof(hicn_mapme_v6_header_t)
 
static_assert (EXPECTED_MAPME_V4_HDRLEN == HICN_MAPME_V4_HDRLEN,
           "Size of MAPME_V4 struct does not match its expected size.");
static_assert (EXPECTED_MAPME_V6_HDRLEN == HICN_MAPME_V6_HDRLEN,
           "Size of MAPME_V6 struct does not match its expected size.");
 
#endif /* HICN_MAPME_H */
 
/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */