eigrp_const.h

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * EIGRP Definition of Constants.
 * Copyright (C) 2013-2016
 * Authors:
 *   Donnie Savage
 *   Jan Janovic
 *   Matej Perina
 *   Peter Orsag
 *   Peter Paluch
 *   Frantisek Gazo
 *   Tomas Hvorkovy
 *   Martin Kontsek
 *   Lukas Koribsky
 */
#ifndef _ZEBRA_EIGRP_CONST_H_
#define _ZEBRA_EIGRP_CONST_H_

#ifndef FALSE
#define FALSE 0 // Everyone should know whats FALSE
#endif
#ifndef TRUE
#define TRUE 1 // And, likewise, whats TRUE
#endif

/* Default protocol, port number. */
#ifndef IPPROTO_EIGRPIGP
#define IPPROTO_EIGRPIGP 88
#endif /* IPPROTO_EIGRPIGP */

#define EIGRP_MULTICAST_ADDRESS 0xe000000A /*224.0.0.10*/
#define EIGRP_HEADER_VERSION 2

#define EIGRP_NEIGHBOR_DOWN 0
#define EIGRP_NEIGHBOR_PENDING 1
#define EIGRP_NEIGHBOR_UP 2
#define EIGRP_NEIGHBOR_STATE_MAX 3

/*Packet requiring ack will be retransmitted again after this time*/
#define EIGRP_PACKET_RETRANS_TIME 2 /* in seconds */
#define EIGRP_PACKET_RETRANS_MAX 16 /* number of retrans attempts */
#define PLAINTEXT_LENGTH 81

/*Metric variance multiplier*/
#define EIGRP_VARIANCE_DEFAULT 1
#define EIGRP_MAX_PATHS_DEFAULT 4

/* Return values of functions involved in packet verification */
#define MSG_OK 0
#define MSG_NG 1

#define EIGRP_AUTH_MD5_TLV_SIZE 40
#define EIGRP_AUTH_SHA256_TLV_SIZE 56

/*Cisco routers use only first 44 bytes of basic hello for their MD5
 * calculations*/
#define EIGRP_MD5_BASIC_COMPUTE 44
#define EIGRP_MD5_UPDATE_INIT_COMPUTE 40

#define EIGRP_AUTH_BASIC_HELLO_FLAG 0x01
#define EIGRP_AUTH_TID_HELLO_FLAG 0x02
#define EIGRP_AUTH_UPDATE_INIT_FLAG 0x04
#define EIGRP_AUTH_UPDATE_FLAG 0x08
#define EIGRP_AUTH_EXTRA_SALT_FLAG 0x10

#define EIGRP_NEXT_SEQUENCE_TLV_SIZE 8

/* IP TTL for EIGRP protocol. */
#define EIGRP_IP_TTL 1

/* VTY port number. */
#define EIGRP_VTY_PORT 2613

/* Default configuration file name for eigrp. */
#define EIGRP_DEFAULT_CONFIG "eigrpd.conf"

#define EIGRP_HELLO_INTERVAL_DEFAULT 5
#define EIGRP_HELLO_NORMAL 0x00
#define EIGRP_HELLO_GRACEFUL_SHUTDOWN 0x01
#define EIGRP_HELLO_ADD_SEQUENCE 0x02
#define EIGRP_HELLO_GRACEFUL_SHUTDOWN_NBR 0x04
#define EIGRP_HOLD_INTERVAL_DEFAULT 15


#define EIGRP_MAX_METRIC 0xffffffffU /*4294967295*/
enum metric_change { METRIC_DECREASE, METRIC_SAME, METRIC_INCREASE };

#define DEFAULT_ROUTE ZEBRA_ROUTE_MAX
#define DEFAULT_ROUTE_TYPE(T) ((T) == DEFAULT_ROUTE)

/* interface defaults */
#define EIGRP_BANDWIDTH_DEFAULT 100000
#define EIGRP_DELAY_DEFAULT 10
#define EIGRP_RELIABILITY_DEFAULT 255
#define EIGRP_LOAD_DEFAULT 1

#define INTERFACE_DOWN_BY_ZEBRA 1
#define INTERFACE_DOWN_BY_VTY 2
#define INTERFACE_DOWN_BY_FINAL 3

/* EIGRP Network Type. */
#define EIGRP_IFTYPE_NONE 0
#define EIGRP_IFTYPE_POINTOPOINT 1
#define EIGRP_IFTYPE_BROADCAST 2
#define EIGRP_IFTYPE_NBMA 3
#define EIGRP_IFTYPE_POINTOMULTIPOINT 4
#define EIGRP_IFTYPE_LOOPBACK 5
#define EIGRP_IFTYPE_MAX 6

#define EIGRP_INTF_ACTIVE 0
#define EIGRP_INTF_PASSIVE 1

/* EIGRP TT destination type */
#define EIGRP_TOPOLOGY_TYPE_CONNECTED 0	      // Connected network
#define EIGRP_TOPOLOGY_TYPE_REMOTE 1	      // Remote internal network
#define EIGRP_TOPOLOGY_TYPE_REMOTE_EXTERNAL 2 // Remote external network

/*EIGRP TT entry flags*/
#define EIGRP_ROUTE_DESCRIPTOR_SUCCESSOR_FLAG (1 << 0)
#define EIGRP_ROUTE_DESCRIPTOR_FSUCCESSOR_FLAG (1 << 1)
#define EIGRP_ROUTE_DESCRIPTOR_INTABLE_FLAG (1 << 2)
#define EIGRP_ROUTE_DESCRIPTOR_EXTERNAL_FLAG (1 << 3)

/*EIGRP FSM state count, event count*/
#define EIGRP_FSM_STATE_MAX 5
#define EIGRP_FSM_EVENT_MAX 16

/*EEGRP FSM states*/
enum eigrp_fsm_states {
	EIGRP_FSM_STATE_PASSIVE,
	EIGRP_FSM_STATE_ACTIVE_0,
	EIGRP_FSM_STATE_ACTIVE_1,
	EIGRP_FSM_STATE_ACTIVE_2,
	EIGRP_FSM_STATE_ACTIVE_3,
};

/*EIGRP FSM events return values*/
#define EIGRP_FSM_NEED_UPDATE 1
#define EIGRP_FSM_NEED_QUERY 2

/*EIGRP FSM events*/
enum eigrp_fsm_events {
	/*
	 * Input event other than query from succ,
	 * FC is not satisfied
	 */
	EIGRP_FSM_EVENT_NQ_FCN,

	/* last reply, FD is reset */
	EIGRP_FSM_EVENT_LR,

	/* Query from succ, FC not satisfied */
	EIGRP_FSM_EVENT_Q_FCN,

	/* last reply, FC satisfied with current value of FDij */
	EIGRP_FSM_EVENT_LR_FCS,

	/* distance increase while in a active state */
	EIGRP_FSM_EVENT_DINC,

	/* Query from succ while in active state */
	EIGRP_FSM_EVENT_QACT,

	/* last reply, FC not satisfied */
	EIGRP_FSM_EVENT_LR_FCN,

	/*
	 * state not changed
	 * usually by receiving not last reply
	 */
	EIGRP_FSM_KEEP_STATE,
};

/**
 * External routes originate from some other protocol - these are them
 */
#define NULL_PROTID 0	/*!< unknown protocol */
#define IGRP_PROTID 1	/*!< IGRP.. whos your daddy! */
#define EIGRP_PROTID 2	/*!< EIGRP - Just flat out the best */
#define STATIC_PROTID 3 /*!< Statically configured source */
#define RIP_PROTID 4	/*!< Routing Information Protocol */
#define HELLO_PROTID 5	/*!< Hello? RFC-891 you there? */
#define OSPF_PROTID 6	/*!< OSPF - Open Shortest Path First */
#define ISIS_PROTID 7	/*!< Intermediate System To Intermediate System */
#define EGP_PROTID 8	/*!< Exterior Gateway Protocol */
#define BGP_PROTID 9	/*!< Border Gateway Protocol */
#define IDRP_PROTID 10	/*!< InterDomain Routing Protocol */
#define CONN_PROTID 11	/*!< Connected source */

/*
 * metric k-value defaults
 */
#define EIGRP_K1_DEFAULT 1 //!< unweighed inverse bandwidth
#define EIGRP_K2_DEFAULT 0 //!< no loading term
#define EIGRP_K3_DEFAULT 1 //!< unweighted delay
#define EIGRP_K4_DEFAULT 0 //!< no reliability term
#define EIGRP_K5_DEFAULT 0 //!< no reliability term
#define EIGRP_K6_DEFAULT 0 //!< do not add in extended metrics

/*
 * EIGRP Fixed header
 */
#define EIGRP_HEADER_LEN 20U
#define EIGRP_PACKET_MAX_LEN 65535U /* includes IP Header size. */

#define EIGRP_TLV_HDR_LENGTH 4

/**
 * EIGRP Packet Opcodes
 */
#define EIGRP_OPC_UPDATE 1    /*!< packet containing routing information */
#define EIGRP_OPC_REQUEST 2   /*!< sent to request one or more routes */
#define EIGRP_OPC_QUERY 3     /*!< sent when a routing is in active start */
#define EIGRP_OPC_REPLY 4     /*!< sent in response to a query */
#define EIGRP_OPC_HELLO 5     /*!< sent to maintain a peering session */
#define EIGRP_OPC_IPXSAP 6    /*!< IPX SAP information */
#define EIGRP_OPC_PROBE 7     /*!< for test purposes   */
#define EIGRP_OPC_ACK 8	      /*!< acknowledge         */
#define EIGRP_OPC_SIAQUERY 10 /*!< QUERY - with relaxed restrictions */
#define EIGRP_OPC_SIAREPLY                                                     \
	11 /*!< REPLY - may contain old routing information */

/**
 * EIGRP TLV Range definitions
 *      PDM             TLV Range
 *      General         0x0000
 *      IPv4            0x0100                  ** TLVs for one and all
 *      ATALK           0x0200                  ** legacy
 *      IPX             0x0300                  ** discontinued
 *      IPv6            0x0400                  ** legacy
 *      Multiprotocol   0x0600                  ** wide metrics
 *      MultiTopology   0x00f0                  ** deprecated
 *
 */
#define EIGRP_TLV_RANGEMASK 0xff00 /*!< Mak for TLV type */
#define EIGRP_TLV_GENERAL 0x0000   /*!< General TLVs */

/**
 * Verson 1.2: Protocol Dependent TLV  Definitions
 * These are considered legacy and are only used for backward compatibility with
 * older Cisco Routers.  They should not be your first choice for packet coding
 */
#define EIGRP_TLV_IPv4 0x0100  /*!< Classic IPv4 TLV encoding */
#define EIGRP_TLV_ATALK 0x0200 /*!< Classic Appletalk TLV encoding*/
#define EIGRP_TLV_IPX 0x0300   /*!< Classic IPX TLV encoding */
#define EIGRP_TLV_IPv6 0x0400  /*!< Classic IPv6 TLV encoding */
#define EIGRP_TLV_MP 0x0600    /*!< Multiprotocol (Wide Metric) TLV encoding */

/**
 * Version 2.0: Multi-Protocol TLV Definitions
 * These are the current packet formats and should be used for packets
 */
#define EIGRP_TLV_MP 0x0600 /*!< Non-PDM specific encoding */

/**
 * TLV type definitions.  Generic (protocol-independent) TLV types are
 * defined here.  Protocol-specific ones are defined elsewhere.
 */
#define EIGRP_TLV_PARAMETER		(EIGRP_TLV_GENERAL | 0x0001) /*!< eigrp parameters */
#define EIGRP_TLV_PARAMETER_LEN		(12U)

#define EIGRP_TLV_AUTH			(EIGRP_TLV_GENERAL | 0x0002) /*!< authentication */
#define EIGRP_TLV_SEQ			(EIGRP_TLV_GENERAL | 0x0003)  /*!< sequenced packet */
#define EIGRP_TLV_SEQ_BASE_LEN		(5U)

#define EIGRP_TLV_SW_VERSION		(EIGRP_TLV_GENERAL | 0x0004) /*!< software version */
#define EIGRP_TLV_SW_VERSION_LEN	(8U)

#define EIGRP_TLV_NEXT_MCAST_SEQ	(EIGRP_TLV_GENERAL | 0x0005) /*!< sequence number */
#define EIGRP_TLV_PEER_TERMINATION	(EIGRP_TLV_GENERAL | 0x0007) /*!< peer termination */
#define EIGRP_TLV_PEER_TERMINATION_LEN	(9U)

#define EIGRP_TLV_PEER_TIDLIST		(EIGRP_TLV_GENERAL | 0x0008) /*!< peer sub-topology list */

/* Older cisco routers send TIDLIST value wrong,
 * adding for backwards compatibility */
#define EIGRP_TLV_PEER_MTRLIST		(EIGRP_TLV_GENERAL | 0x00f5)

/**
 * Route Based TLVs
 */
#define EIGRP_TLV_REQUEST 0x0001
#define EIGRP_TLV_INTERNAL 0x0002
#define EIGRP_TLV_EXTERNAL 0x0003
#define EIGRP_TLV_COMMUNITY 0x0004
#define EIGRP_TLV_TYPEMASK 0x000f

#define EIGRP_TLV_IPv4_REQ (EIGRP_TLV_IPv4 | EIGRP_TLV_REQUEST)
#define EIGRP_TLV_IPv4_INT (EIGRP_TLV_IPv4 | EIGRP_TLV_INTERNAL)
#define EIGRP_TLV_IPv4_EXT (EIGRP_TLV_IPv4 | EIGRP_TLV_EXTERNAL)
#define EIGRP_TLV_IPv4_COM (EIGRP_TLV_IPv4 | EIGRP_TLV_COMMUNITY)

#define EIGRP_TLV_IPv6_REQ (EIGRP_TLV_IPv6 | EIGRP_TLV_REQUEST)
#define EIGRP_TLV_IPv6_INT (EIGRP_TLV_IPv6 | EIGRP_TLV_INTERNAL)
#define EIGRP_TLV_IPv6_EXT (EIGRP_TLV_IPv6 | EIGRP_TLV_EXTERNAL)
#define EIGRP_TLV_IPv6_COM (EIGRP_TLV_IPv6 | EIGRP_TLV_COMMUNITY)

#define EIGRP_TLV_MP_REQ (EIGRP_TLV_MP | EIGRP_TLV_REQUEST)
#define EIGRP_TLV_MP_INT (EIGRP_TLV_MP | EIGRP_TLV_INTERNAL)
#define EIGRP_TLV_MP_EXT (EIGRP_TLV_MP | EIGRP_TLV_EXTERNAL)
#define EIGRP_TLV_MP_COM (EIGRP_TLV_MP | EIGRP_TLV_COMMUNITY)

#define EIGRP_TLV_IPV4_SIZE_GRT_24_BIT 0x001D
#define EIGRP_TLV_IPV4_SIZE_GRT_16_BIT 0x001C
#define EIGRP_TLV_IPV4_SIZE_GRT_8_BIT 0x001B
#define EIGRP_TLV_IPV4_SIZE_GRT_0_BIT 0x001A
#define EIGRP_TLV_MAX_IPV4_BYTE EIGRP_TLV_IPV4_SIZE_GRT_24_BIT

/* max number of TLV IPv4 prefixes in packet */
#define EIGRP_TLV_MAX_IPv4 25

/**
 *
 * extdata flag field definitions
 */
#define EIGRP_OPAQUE_EXT 0x01 /*!< Route is external */
#define EIGRP_OPAQUE_CD 0x02  /*!< Candidate default route */

/**
 * Address-Family types are taken from:
 *       http://www.iana.org/assignments/address-family-numbers
 * to provide a standards based exchange of AFI information between
 * EIGRP routers.
 */
#define EIGRP_AF_IPv4 1	      /*!< IPv4 (IP version 4) */
#define EIGRP_AF_IPv6 2	      /*!< IPv6 (IP version 6) */
#define EIGRP_AF_IPX 11	      /*!< IPX */
#define EIGRP_AF_ATALK 12     /*!< Appletalk */
#define EIGRP_SF_COMMON 16384 /*!< Cisco Service Family */
#define EIGRP_SF_IPv4 16385   /*!< Cisco IPv4 Service Family */
#define EIGRP_SF_IPv6 16386   /*!< Cisco IPv6 Service Family */

/**
 * Authentication types supported by EIGRP
 */
#define EIGRP_AUTH_TYPE_NONE 0
#define EIGRP_AUTH_TYPE_TEXT 1
#define EIGRP_AUTH_TYPE_MD5 2
#define EIGRP_AUTH_TYPE_MD5_LEN 16
#define EIGRP_AUTH_TYPE_SHA256 3
#define EIGRP_AUTH_TYPE_SHA256_LEN 32

/**
 * opaque flag field definitions
 */
#define EIGRP_OPAQUE_SRCWD 0x01	 /*!< Route Source Withdraw */
#define EIGRP_OPAQUE_ACTIVE 0x04 /*!< Route is currently in active state */
#define EIGRP_OPAQUE_REPL                                                      \
	0x08 /*!< Route is replicated from different tableid */

/**
 * pak flag bit field definitions - 0 (none)-7 source priority
 */
#define EIGRP_PRIV_DEFAULT 0x00 /* 0 (none)-7 source priority */
#define EIGRP_PRIV_LOW 0x01
#define EIGRP_PRIV_MEDIUM 0x04
#define EIGRP_PRIV_HIGH 0x07

/*
 * Init bit definition. First unicast transmitted Update has this
 * bit set in the flags field of the fixed header. It tells the neighbor
 * to down-load his topology table.
 */
#define EIGRP_INIT_FLAG 0x01

/*
 * CR bit (Conditionally Received) definition in flags field on header. Any
 * packets with the CR-bit set can be accepted by an EIGRP speaker if and
 * only if a previous Hello was received with the SEQUENCE_TYPE TLV present.
 *
 * This allows multicast to be transmitted in order and reliably at the
 * same time as unicast are transmitted.
 */
#define EIGRP_CR_FLAG 0x02

/*
 * RS bit.  The Restart flag is set in the hello and the init
 * update packets during the nsf signaling period.  A nsf-aware
 * router looks at the RS flag to detect if a peer is restarting
 * and maintain the adjacency. A restarting router looks at
 * this flag to determine if the peer is helping out with the restart.
 */
#define EIGRP_RS_FLAG 0x04

/*
 * EOT bit.  The End-of-Table flag marks the end of the start-up updates
 * sent to a new peer.  A nsf restarting router looks at this flag to
 * determine if it has finished receiving the start-up updates from all
 * peers.  A nsf-aware router waits for this flag before cleaning up
 * the stale routes from the restarting peer.
 */
#define EIGRP_EOT_FLAG 0x08

/**
 * EIGRP Virtual Router ID
 *
 * Define values to deal with EIGRP virtual router ids.  Virtual
 * router IDs are stored in the upper short of the EIGRP fixed packet
 * header.  The lower short of the packet header continues to be used
 * as asystem number.
 *
 * Virtual Router IDs are PDM-independent.  All PDMs will use
 * VRID_BASE to indicate the 'base' or 'legacy' EIGRP instance.
 * All PDMs need to initialize their vrid to VRID_BASE for compatibility
 * with legacy routers.
 * Once IPv6 supports 'MTR Multicast', it will use the same VRID as
 * IPv4.  No current plans to support VRIDs on IPX. :)
 * Initial usage of VRID is to signal usage of Multicast topology for
 * MTR.
 *
 * VRID_MCAST is a well known constant, other VRIDs will be determined
 * programmatic...
 *
 * With the addition of SAF the VRID space has been divided into two
 * segments 0x0000-0x7fff is for EIGRP and vNets, 0x8000-0xffff is
 * for saf and its associated vNets.
 */
#define EIGRP_VRID_MASK 0x8001
#define EIGRP_VRID_AF_BASE 0x0000
#define EIGRP_VRID_MCAST_BASE 0x0001
#define EIGRP_VRID_SF_BASE 0x8000

/* Extended Attributes for a destination */
#define EIGRP_ATTR_HDRLEN (2)
#define EIGRP_ATTR_MAXDATA (512)

#define EIGRP_ATTR_NOOP 0    /*!< No-Op used as offset padding */
#define EIGRP_ATTR_SCALED 1  /*!< Scaled metric values */
#define EIGRP_ATTR_TAG 2     /*!< Tag assigned by Admin for dest */
#define EIGRP_ATTR_COMM 3    /*!< Community attribute for dest */
#define EIGRP_ATTR_JITTER 4  /*!< Variation in path delay */
#define EIGRP_ATTR_QENERGY 5 /*!< Non-Active energy usage along path */
#define EIGRP_ATTR_ENERGY 6  /*!< Active energy usage along path */

/*
 * Begin EIGRP-BGP interoperability communities
 */
#define EIGRP_EXTCOMM_SOO_ASFMT 0x0003 /* Site-of-Origin, BGP AS format */
#define EIGRP_EXTCOMM_SOO_ADRFMT                                               \
	0x0103 /* Site-of-Origin, BGP/EIGRP addr format */

/*
 * EIGRP Specific communities
 */
#define EIGRP_EXTCOMM_EIGRP 0x8800 /* EIGRP route information appended*/
#define EIGRP_EXTCOMM_DAD 0x8801   /* EIGRP AS + Delay           */
#define EIGRP_EXTCOMM_VRHB 0x8802  /* EIGRP Vector: Reliability + Hop + BW */
#define EIGRP_EXTCOMM_SRLM 0x8803  /* EIGRP System: Reserve +Load + MTU   */
#define EIGRP_EXTCOMM_SAR 0x8804   /* EIGRP System: Remote AS + Remote ID  */
#define EIGRP_EXTCOMM_RPM 0x8805   /* EIGRP Remote: Protocol + Metric    */
#define EIGRP_EXTCOMM_VRR                                                      \
	0x8806 /* EIGRP Vecmet: Rsvd + (internal) Routerid                     \
		*/

/*
 * EIGRP Filter constants
 */
#define EIGRP_FILTER_IN 0
#define EIGRP_FILTER_OUT 1
#define EIGRP_FILTER_MAX 2

/*
 * EIGRP Filter constants
 */
#define EIGRP_HSROLE_DEFAULT EIGRP_HSROLE_SPOKE
#define EIGRP_HSROLE_HUB 0x01
#define EIGRP_HSROLE_SPOKE 0x02

#endif /* _ZEBRA_EIGRP_CONST_H_ */