/src/frr/bgpd/bgp_attr.h

Source
// SPDX-License-Identifier: GPL-2.0-or-later
/* BGP attributes.
 * Copyright (C) 1996, 97, 98 Kunihiro Ishiguro
 */

#ifndef _QUAGGA_BGP_ATTR_H
#define _QUAGGA_BGP_ATTR_H

#include "mpls.h"
#include "bgp_attr_evpn.h"
#include "bgpd/bgp_encap_types.h"
#include "srte.h"

/* Simple bit mapping. */
#define BITMAP_NBBY 8

#define SET_BITMAP(MAP, NUM)                                                   \
  SET_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))

#define CHECK_BITMAP(MAP, NUM)                                                 \
  CHECK_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))

#define BGP_MED_MAX UINT32_MAX

/* BGP Attribute type range. */
#define BGP_ATTR_TYPE_RANGE     256
#define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)

/* BGP Attribute flags. */
#define BGP_ATTR_FLAG_OPTIONAL  0x80  /* Attribute is optional. */
#define BGP_ATTR_FLAG_TRANS     0x40  /* Attribute is transitive. */
#define BGP_ATTR_FLAG_PARTIAL   0x20  /* Attribute is partial. */
#define BGP_ATTR_FLAG_EXTLEN    0x10  /* Extended length flag. */

/* BGP attribute header must bigger than 2. */
#define BGP_ATTR_MIN_LEN        3       /* Attribute flag, type length. */
#define BGP_ATTR_DEFAULT_WEIGHT 32768

/* Valid lengths for mp_nexthop_len */
#define BGP_ATTR_NHLEN_IPV4               IPV4_MAX_BYTELEN
#define BGP_ATTR_NHLEN_VPNV4              8+IPV4_MAX_BYTELEN
#define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
#define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
#define BGP_ATTR_NHLEN_VPNV6_GLOBAL       8+IPV6_MAX_BYTELEN
#define BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL ((8+IPV6_MAX_BYTELEN) * 2)

/* Prefix SID types */
#define BGP_PREFIX_SID_LABEL_INDEX     1
#define BGP_PREFIX_SID_IPV6            2
#define BGP_PREFIX_SID_ORIGINATOR_SRGB 3
#define BGP_PREFIX_SID_VPN_SID 4
#define BGP_PREFIX_SID_SRV6_L3_SERVICE 5
#define BGP_PREFIX_SID_SRV6_L2_SERVICE 6

#define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
#define BGP_PREFIX_SID_IPV6_LENGTH            19
#define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
#define BGP_PREFIX_SID_VPN_SID_LENGTH         19

/* SRv6 Service Sub-TLV types */
#define BGP_PREFIX_SID_SRV6_L3_SERVICE_SID_INFO 1
#define BGP_PREFIX_SID_SRV6_L3_SERVICE_SID_INFO_LENGTH 21

/* SRv6 Service Data Sub-Sub-TLV types */
#define BGP_PREFIX_SID_SRV6_L3_SERVICE_SID_STRUCTURE 1
#define BGP_PREFIX_SID_SRV6_L3_SERVICE_SID_STRUCTURE_LENGTH 6

#define BGP_ATTR_NH_AFI(afi, attr) \
  ((afi != AFI_L2VPN) ? afi : \
  ((attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV4) ? AFI_IP : AFI_IP6))

/* PMSI tunnel types (RFC 6514) */

struct bgp_attr_encap_subtlv {
  struct bgp_attr_encap_subtlv *next; /* for chaining */
  /* Reference count of this attribute. */
  unsigned long refcnt;
  uint16_t type;
  uint16_t length;
  uint8_t value[0]; /* will be extended */
};

#ifdef ENABLE_BGP_VNC
/*
 * old rfp<->rfapi representation
 */
struct bgp_tea_options {
  struct bgp_tea_options *next;
  uint8_t options_count;
  uint16_t options_length; /* each TLV may be 256 in length */
  uint8_t type;
  uint8_t length;
  void *value; /* pointer to data */
};

#endif

enum pta_type {
  PMSI_TNLTYPE_NO_INFO = 0,
  PMSI_TNLTYPE_RSVP_TE_P2MP,
  PMSI_TNLTYPE_MLDP_P2MP,
  PMSI_TNLTYPE_PIM_SSM,
  PMSI_TNLTYPE_PIM_SM,
  PMSI_TNLTYPE_PIM_BIDIR,
  PMSI_TNLTYPE_INGR_REPL,
  PMSI_TNLTYPE_MLDP_MP2MP,
  PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
};

/*
 * Prefix-SID type-4
 * SRv6-VPN-SID-TLV
 * draft-dawra-idr-srv6-vpn-04
 */
struct bgp_attr_srv6_vpn {
  unsigned long refcnt;
  uint8_t sid_flags;
  struct in6_addr sid;
};

/*
 * Prefix-SID type-5
 * SRv6-L3VPN-Service-TLV
 * draft-dawra-idr-srv6-vpn-05
 */
struct bgp_attr_srv6_l3vpn {
  unsigned long refcnt;
  uint8_t sid_flags;
  uint16_t endpoint_behavior;
  struct in6_addr sid;
  uint8_t loc_block_len;
  uint8_t loc_node_len;
  uint8_t func_len;
  uint8_t arg_len;
  uint8_t transposition_len;
  uint8_t transposition_offset;
};

/* BGP core attribute structure. */
struct attr {
  /* AS Path structure */
  struct aspath *aspath;

  /* Community structure */
  struct community *community;

  /* Reference count of this attribute. */
  unsigned long refcnt;

  /* Flag of attribute is set or not. */
  uint64_t flag;

  /* Apart from in6_addr, the remaining static attributes */
  struct in_addr nexthop;
  uint32_t med;
  uint32_t local_pref;
  ifindex_t nh_ifindex;

  /* Path origin attribute */
  uint8_t origin;

  /* PMSI tunnel type (RFC 6514). */
  enum pta_type pmsi_tnl_type;

  /* has the route-map changed any attribute?
     Used on the peer outbound side. */
  uint32_t rmap_change_flags;

  /* Multi-Protocol Nexthop, AFI IPv6 */
  struct in6_addr mp_nexthop_global;
  struct in6_addr mp_nexthop_local;

  /* ifIndex corresponding to mp_nexthop_local. */
  ifindex_t nh_lla_ifindex;

  /* Extended Communities attribute. */
  struct ecommunity *ecommunity;

  /* Extended Communities attribute. */
  struct ecommunity *ipv6_ecommunity;

  /* Large Communities attribute. */
  struct lcommunity *lcommunity;

  /* Route-Reflector Cluster attribute */
  struct cluster_list *cluster1;

  /* Unknown transitive attribute. */
  struct transit *transit;

  struct in_addr mp_nexthop_global_in;

  /* Aggregator Router ID attribute */
  struct in_addr aggregator_addr;

  /* Route Reflector Originator attribute */
  struct in_addr originator_id;

  /* Local weight, not actually an attribute */
  uint32_t weight;

  /* Aggregator ASN */
  as_t aggregator_as;

  /* MP Nexthop length */
  uint8_t mp_nexthop_len;

  /* MP Nexthop preference */
  uint8_t mp_nexthop_prefer_global;

  /* Static MAC for EVPN */
  uint8_t sticky;

  /* Flag for default gateway extended community in EVPN */
  uint8_t default_gw;

  /* NA router flag (R-bit) support in EVPN */
  uint8_t router_flag;

  /* ES info */
  uint8_t es_flags;
  /* Path is not "locally-active" on the advertising VTEP. This is
   * translated into an ARP-ND ECOM.
   */
#define ATTR_ES_PROXY_ADVERT (1 << 0)
  /* Destination ES is present locally. This flag is set on local
   * paths and sync paths
   */
#define ATTR_ES_IS_LOCAL (1 << 1)
  /* There are one or more non-best paths from ES peers. Note that
   * this flag is only set on the local MAC-IP paths in the VNI
   * route table (not set in the global routing table). And only
   * non-proxy advertisements from an ES peer can result in this
   * flag being set.
   */
#define ATTR_ES_PEER_ACTIVE (1 << 2)
  /* There are one or more non-best proxy paths from ES peers */
#define ATTR_ES_PEER_PROXY (1 << 3)
  /* An ES peer has router bit set - only applicable if
   * ATTR_ES_PEER_ACTIVE is set
   */
#define ATTR_ES_PEER_ROUTER (1 << 4)

  /* These two flags are only set on L3 routes installed in a
   * VRF as a result of EVPN MAC-IP route
   * XXX - while splitting up per-family attrs these need to be
   * classified as non-EVPN
   */
#define ATTR_ES_L3_NHG_USE (1 << 5)
#define ATTR_ES_L3_NHG_ACTIVE (1 << 6)
#define ATTR_ES_L3_NHG (ATTR_ES_L3_NHG_USE | ATTR_ES_L3_NHG_ACTIVE)

  /* route tag */
  route_tag_t tag;

  /* Label index */
  uint32_t label_index;

  /* MPLS label */
  mpls_label_t label;

  /* SRv6 VPN SID */
  struct bgp_attr_srv6_vpn *srv6_vpn;

  /* SRv6 L3VPN SID */
  struct bgp_attr_srv6_l3vpn *srv6_l3vpn;

  uint16_t encap_tunneltype;         /* grr */
  struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */

#ifdef ENABLE_BGP_VNC
  struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
#endif
  /* EVPN */
  struct bgp_route_evpn evpn_overlay;

  /* EVPN MAC Mobility sequence number, if any. */
  uint32_t mm_seqnum;
  /* highest MM sequence number rxed in a MAC-IP route from an
   * ES peer (this includes both proxy and non-proxy MAC-IP
   * advertisements from ES peers).
   * This is only applicable to local paths in the VNI routing
   * table and derived from other imported/non-best paths.
   */
  uint32_t mm_sync_seqnum;

  /* EVPN local router-mac */
  struct ethaddr rmac;

  /* Distance as applied by Route map */
  uint8_t distance;

  /* rmap set table */
  uint32_t rmap_table_id;

  /* Link bandwidth value, if any. */
  uint32_t link_bw;

  /* EVPN ES */
  esi_t esi;

  /* SR-TE Color */
  uint32_t srte_color;

  /* EVPN DF preference and algorithm for DF election on local ESs */
  uint16_t df_pref;
  uint8_t df_alg;

  /* Nexthop type */
  enum nexthop_types_t nh_type;

  /* If NEXTHOP_TYPE_BLACKHOLE, then blackhole type */
  enum blackhole_type bh_type;

  /* OTC value if set */
  uint32_t otc;

  /* AIGP Metric */
  uint64_t aigp_metric;
};

/* rmap_change_flags definition */
#define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
#define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
#define BATTR_REFLECTED (1 << 2)
#define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
#define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
#define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
#define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
#define BATTR_RMAP_LINK_BW_SET (1 << 7)
#define BATTR_RMAP_L3VPN_ACCEPT_GRE (1 << 8)
#define BATTR_RMAP_VPNV4_NHOP_CHANGED (1 << 9)
#define BATTR_RMAP_VPNV6_GLOBAL_NHOP_CHANGED (1 << 10)

/* Router Reflector related structure. */
struct cluster_list {
  unsigned long refcnt;
  int length;
  struct in_addr *list;
};

/* Unknown transit attribute. */
struct transit {
  unsigned long refcnt;
  int length;
  uint8_t *val;
};

/* "(void) 0" will generate a compiler error.  this is a safety check to
 * ensure we're not using a value that exceeds the bit size of attr->flag. */
#define ATTR_FLAG_BIT(X)                                                       \
  __builtin_choose_expr((X) >= 1 && (X) <= 64, 1ULL << ((X)-1), (void)0)

#define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
  (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
     ? bgp_attr_get_cluster((attr))->length                        \
     : 0)

enum bgp_attr_parse_ret {
  BGP_ATTR_PARSE_PROCEED = 0,
  BGP_ATTR_PARSE_ERROR = -1,
  BGP_ATTR_PARSE_WITHDRAW = -2,

  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
   */
  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
  BGP_ATTR_PARSE_EOR = -4,
};

struct bpacket_attr_vec_arr;

/* Prototypes. */
extern void bgp_attr_init(void);
extern void bgp_attr_finish(void);
extern enum bgp_attr_parse_ret
bgp_attr_parse(struct peer *peer, struct attr *attr, bgp_size_t size,
         struct bgp_nlri *mp_update, struct bgp_nlri *mp_withdraw);
extern struct attr *bgp_attr_intern(struct attr *attr);
extern void bgp_attr_unintern_sub(struct attr *attr);
extern void bgp_attr_unintern(struct attr **pattr);
extern void bgp_attr_flush(struct attr *attr);
extern struct attr *bgp_attr_default_set(struct attr *attr, struct bgp *bgp,
           uint8_t origin);
extern struct attr *bgp_attr_aggregate_intern(
  struct bgp *bgp, uint8_t origin, struct aspath *aspath,
  struct community *community, struct ecommunity *ecommunity,
  struct lcommunity *lcommunity, struct bgp_aggregate *aggregate,
  uint8_t atomic_aggregate, const struct prefix *p);
extern bgp_size_t bgp_packet_attribute(
  struct bgp *bgp, struct peer *peer, struct stream *s, struct attr *attr,
  struct bpacket_attr_vec_arr *vecarr, struct prefix *p, afi_t afi,
  safi_t safi, struct peer *from, struct prefix_rd *prd,
  mpls_label_t *label, uint32_t num_labels, bool addpath_capable,
  uint32_t addpath_tx_id, struct bgp_path_info *bpi);
extern void bgp_dump_routes_attr(struct stream *s, struct bgp_path_info *bpi,
         const struct prefix *p);
extern bool attrhash_cmp(const void *arg1, const void *arg2);
extern unsigned int attrhash_key_make(const void *p);
extern void attr_show_all(struct vty *vty);
extern unsigned long int attr_count(void);
extern unsigned long int attr_unknown_count(void);
extern void bgp_path_attribute_discard_vty(struct vty *vty, struct peer *peer,
             const char *discard_attrs, bool set);
extern void bgp_path_attribute_withdraw_vty(struct vty *vty, struct peer *peer,
              const char *withdraw_attrs,
              bool set);
extern enum bgp_attr_parse_ret bgp_attr_ignore(struct peer *peer, uint8_t type);

/* Cluster list prototypes. */
extern bool cluster_loop_check(struct cluster_list *cluster,
             struct in_addr originator);

/* Below exported for unit-test purposes only */
struct bgp_attr_parser_args {
  struct peer *peer;
  bgp_size_t length; /* attribute data length; */
  bgp_size_t total;  /* total length, inc header */
  struct attr *attr;
  uint8_t type;
  uint8_t flags;
  uint8_t *startp;
};
extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
            struct bgp_nlri *mp_update);
extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
        struct bgp_nlri *mp_withdraw);
extern enum bgp_attr_parse_ret
bgp_attr_prefix_sid(struct bgp_attr_parser_args *args);

extern struct bgp_attr_encap_subtlv *
encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);

extern void bgp_attr_flush_encap(struct attr *attr);

extern void bgp_attr_extcom_tunnel_type(struct attr *attr,
           bgp_encap_types *tunnel_type);

/**
 * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 * Typical call sequence is to call _start(), followed by multiple _prefix(),
 * one for each NLRI that needs to be encoded into the UPDATE message, and
 * finally the _end() function.
 */
extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
              afi_t afi, safi_t safi,
              struct bpacket_attr_vec_arr *vecarr,
              struct attr *attr);
extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
             const struct prefix *p,
             const struct prefix_rd *prd,
             mpls_label_t *label, uint32_t num_labels,
             bool addpath_capable,
             uint32_t addpath_tx_id, struct attr *);
extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
              const struct prefix *p);
extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);

extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
           safi_t safi);
extern void bgp_packet_mpunreach_prefix(
  struct stream *s, const struct prefix *p, afi_t afi, safi_t safi,
  const struct prefix_rd *prd, mpls_label_t *label, uint32_t num_labels,
  bool addpath_capable, uint32_t addpath_tx_id, struct attr *attr);
extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);

extern enum bgp_attr_parse_ret bgp_attr_nexthop_valid(struct peer *peer,
                  struct attr *attr);

static inline bool bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
           uint32_t in_rmap_flags)
{
  return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
     CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
     CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
     CHECK_FLAG(out_rmap_flags, BATTR_RMAP_VPNV4_NHOP_CHANGED) ||
     CHECK_FLAG(out_rmap_flags,
          BATTR_RMAP_VPNV6_GLOBAL_NHOP_CHANGED) ||
     CHECK_FLAG(out_rmap_flags,
          BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
     CHECK_FLAG(out_rmap_flags,
          BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED) ||
     CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
     CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
      ? true
      : false);
}

static inline uint32_t mac_mobility_seqnum(struct attr *attr)
{
  return (attr) ? attr->mm_seqnum : 0;
}

static inline enum pta_type bgp_attr_get_pmsi_tnl_type(struct attr *attr)
{
  return attr->pmsi_tnl_type;
}

static inline void bgp_attr_set_pmsi_tnl_type(struct attr *attr,
                enum pta_type pmsi_tnl_type)
{
  attr->pmsi_tnl_type = pmsi_tnl_type;
}

static inline struct ecommunity *
bgp_attr_get_ecommunity(const struct attr *attr)
{
  return attr->ecommunity;
}

static inline void bgp_attr_set_ecommunity(struct attr *attr,
             struct ecommunity *ecomm)
{
  attr->ecommunity = ecomm;

  if (ecomm)
    SET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES));
  else
    UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES));
}

static inline struct lcommunity *
bgp_attr_get_lcommunity(const struct attr *attr)
{
  return attr->lcommunity;
}

static inline void bgp_attr_set_lcommunity(struct attr *attr,
             struct lcommunity *lcomm)
{
  attr->lcommunity = lcomm;

  if (lcomm)
    SET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES));
  else
    UNSET_FLAG(attr->flag,
         ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES));
}

static inline struct community *bgp_attr_get_community(const struct attr *attr)
{
  return attr->community;
}

static inline void bgp_attr_set_community(struct attr *attr,
            struct community *comm)
{
  attr->community = comm;

  if (comm)
    SET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES));
  else
    UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES));
}

static inline struct ecommunity *
bgp_attr_get_ipv6_ecommunity(const struct attr *attr)
{
  return attr->ipv6_ecommunity;
}

static inline void bgp_attr_set_ipv6_ecommunity(struct attr *attr,
            struct ecommunity *ipv6_ecomm)
{
  attr->ipv6_ecommunity = ipv6_ecomm;

  if (ipv6_ecomm)
    SET_FLAG(attr->flag,
       ATTR_FLAG_BIT(BGP_ATTR_IPV6_EXT_COMMUNITIES));
  else
    UNSET_FLAG(attr->flag,
         ATTR_FLAG_BIT(BGP_ATTR_IPV6_EXT_COMMUNITIES));
}

static inline struct transit *bgp_attr_get_transit(const struct attr *attr)
{
  return attr->transit;
}

static inline void bgp_attr_set_transit(struct attr *attr,
          struct transit *transit)
{
  attr->transit = transit;
}

static inline uint64_t bgp_attr_get_aigp_metric(const struct attr *attr)
{
  return attr->aigp_metric;
}

static inline void bgp_attr_set_aigp_metric(struct attr *attr, uint64_t aigp)
{
  attr->aigp_metric = aigp;

  if (aigp)
    attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AIGP);
}

static inline struct cluster_list *bgp_attr_get_cluster(const struct attr *attr)
{
  return attr->cluster1;
}

static inline void bgp_attr_set_cluster(struct attr *attr,
          struct cluster_list *cl)
{
  attr->cluster1 = cl;
}

static inline const struct bgp_route_evpn *
bgp_attr_get_evpn_overlay(const struct attr *attr)
{
  return &attr->evpn_overlay;
}

static inline void bgp_attr_set_evpn_overlay(struct attr *attr,
               struct bgp_route_evpn *eo)
{
  memcpy(&attr->evpn_overlay, eo, sizeof(struct bgp_route_evpn));
}

static inline struct bgp_attr_encap_subtlv *
bgp_attr_get_vnc_subtlvs(const struct attr *attr)
{
#ifdef ENABLE_BGP_VNC
  return attr->vnc_subtlvs;
#else
  return NULL;
#endif
}

static inline void
bgp_attr_set_vnc_subtlvs(struct attr *attr,
       struct bgp_attr_encap_subtlv *vnc_subtlvs)
{
#ifdef ENABLE_BGP_VNC
  attr->vnc_subtlvs = vnc_subtlvs;
#endif
}

#endif /* _QUAGGA_BGP_ATTR_H */

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Created: 2026-01-21 06:59