bgpd/bgp_attr.h

   1 /* BGP attributes.
   2  * Copyright (C) 1996, 97, 98 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _QUAGGA_BGP_ATTR_H
  22 #define _QUAGGA_BGP_ATTR_H
  23
  24 #include "mpls.h"
  25 #include "bgp_attr_evpn.h"
  26 #include "bgpd/bgp_encap_types.h"
  27 #include "srte.h"
  28
  29 /* Simple bit mapping. */
  30 #define BITMAP_NBBY 8
  31
  32 #define SET_BITMAP(MAP, NUM)                                                   \
  33         SET_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  34
  35 #define CHECK_BITMAP(MAP, NUM)                                                 \
  36         CHECK_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  37
  38 #define BGP_MED_MAX UINT32_MAX
  39
  40 /* BGP Attribute type range. */
  41 #define BGP_ATTR_TYPE_RANGE     256
  42 #define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)
  43
  44 /* BGP Attribute flags. */
  45 #define BGP_ATTR_FLAG_OPTIONAL  0x80    /* Attribute is optional. */
  46 #define BGP_ATTR_FLAG_TRANS     0x40    /* Attribute is transitive. */
  47 #define BGP_ATTR_FLAG_PARTIAL   0x20    /* Attribute is partial. */
  48 #define BGP_ATTR_FLAG_EXTLEN    0x10    /* Extended length flag. */
  49
  50 /* BGP attribute header must bigger than 2. */
  51 #define BGP_ATTR_MIN_LEN        3       /* Attribute flag, type length. */
  52 #define BGP_ATTR_DEFAULT_WEIGHT 32768
  53
  54 /* Valid lengths for mp_nexthop_len */
  55 #define BGP_ATTR_NHLEN_IPV4               IPV4_MAX_BYTELEN
  56 #define BGP_ATTR_NHLEN_VPNV4              8+IPV4_MAX_BYTELEN
  57 #define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
  58 #define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
  59 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL       8+IPV6_MAX_BYTELEN
  60 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL ((8+IPV6_MAX_BYTELEN) * 2)
  61
  62 /* Prefix SID types */
  63 #define BGP_PREFIX_SID_LABEL_INDEX     1
  64 #define BGP_PREFIX_SID_IPV6            2
  65 #define BGP_PREFIX_SID_ORIGINATOR_SRGB 3
  66 #define BGP_PREFIX_SID_VPN_SID 4
  67 #define BGP_PREFIX_SID_SRV6_L3_SERVICE 5
  68 #define BGP_PREFIX_SID_SRV6_L2_SERVICE 6
  69
  70 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
  71 #define BGP_PREFIX_SID_IPV6_LENGTH            19
  72 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
  73 #define BGP_PREFIX_SID_VPN_SID_LENGTH         19
  74 #define BGP_PREFIX_SID_SRV6_L3_SERVICE_LENGTH 21
  75
  76 #define BGP_ATTR_NH_AFI(afi, attr) \
  77         ((afi != AFI_L2VPN) ? afi : \
  78         ((attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV4) ? AFI_IP : AFI_IP6))
  79
  80 /* PMSI tunnel types (RFC 6514) */
  81
  82 struct bgp_attr_encap_subtlv {
  83         struct bgp_attr_encap_subtlv *next; /* for chaining */
  84         /* Reference count of this attribute. */
  85         unsigned long refcnt;
  86         uint16_t type;
  87         uint16_t length;
  88         uint8_t value[0]; /* will be extended */
  89 };
  90
  91 #ifdef ENABLE_BGP_VNC
  92 /*
  93  * old rfp<->rfapi representation
  94  */
  95 struct bgp_tea_options {
  96         struct bgp_tea_options *next;
  97         uint8_t options_count;
  98         uint16_t options_length; /* each TLV may be 256 in length */
  99         uint8_t type;
 100         uint8_t length;
 101         void *value; /* pointer to data */
 102 };
 103
 104 #endif
 105
 106 enum pta_type {
 107         PMSI_TNLTYPE_NO_INFO = 0,
 108         PMSI_TNLTYPE_RSVP_TE_P2MP,
 109         PMSI_TNLTYPE_MLDP_P2MP,
 110         PMSI_TNLTYPE_PIM_SSM,
 111         PMSI_TNLTYPE_PIM_SM,
 112         PMSI_TNLTYPE_PIM_BIDIR,
 113         PMSI_TNLTYPE_INGR_REPL,
 114         PMSI_TNLTYPE_MLDP_MP2MP,
 115         PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 116 };
 117
 118 /*
 119  * Prefix-SID type-4
 120  * SRv6-VPN-SID-TLV
 121  * draft-dawra-idr-srv6-vpn-04
 122  */
 123 struct bgp_attr_srv6_vpn {
 124         unsigned long refcnt;
 125         uint8_t sid_flags;
 126         struct in6_addr sid;
 127 };
 128
 129 /*
 130  * Prefix-SID type-5
 131  * SRv6-L3VPN-Service-TLV
 132  * draft-dawra-idr-srv6-vpn-05
 133  */
 134 struct bgp_attr_srv6_l3vpn {
 135         unsigned long refcnt;
 136         uint8_t sid_flags;
 137         uint16_t endpoint_behavior;
 138         struct in6_addr sid;
 139 };
 140
 141 /* BGP core attribute structure. */
 142 struct attr {
 143         /* AS Path structure */
 144         struct aspath *aspath;
 145
 146         /* Community structure */
 147         struct community *community;
 148
 149         /* Reference count of this attribute. */
 150         unsigned long refcnt;
 151
 152         /* Flag of attribute is set or not. */
 153         uint64_t flag;
 154
 155         /* Apart from in6_addr, the remaining static attributes */
 156         struct in_addr nexthop;
 157         uint32_t med;
 158         uint32_t local_pref;
 159         ifindex_t nh_ifindex;
 160
 161         /* Path origin attribute */
 162         uint8_t origin;
 163
 164         /* PMSI tunnel type (RFC 6514). */
 165         enum pta_type pmsi_tnl_type;
 166
 167         /* has the route-map changed any attribute?
 168            Used on the peer outbound side. */
 169         uint32_t rmap_change_flags;
 170
 171         /* Multi-Protocol Nexthop, AFI IPv6 */
 172         struct in6_addr mp_nexthop_global;
 173         struct in6_addr mp_nexthop_local;
 174
 175         /* ifIndex corresponding to mp_nexthop_local. */
 176         ifindex_t nh_lla_ifindex;
 177
 178         /* Extended Communities attribute. */
 179         struct ecommunity *ecommunity;
 180
 181         /* Extended Communities attribute. */
 182         struct ecommunity *ipv6_ecommunity;
 183
 184         /* Large Communities attribute. */
 185         struct lcommunity *lcommunity;
 186
 187         /* Route-Reflector Cluster attribute */
 188         struct cluster_list *cluster;
 189
 190         /* Unknown transitive attribute. */
 191         struct transit *transit;
 192
 193         struct in_addr mp_nexthop_global_in;
 194
 195         /* Aggregator Router ID attribute */
 196         struct in_addr aggregator_addr;
 197
 198         /* Route Reflector Originator attribute */
 199         struct in_addr originator_id;
 200
 201         /* Local weight, not actually an attribute */
 202         uint32_t weight;
 203
 204         /* Aggregator ASN */
 205         as_t aggregator_as;
 206
 207         /* MP Nexthop length */
 208         uint8_t mp_nexthop_len;
 209
 210         /* MP Nexthop preference */
 211         uint8_t mp_nexthop_prefer_global;
 212
 213         /* Static MAC for EVPN */
 214         uint8_t sticky;
 215
 216         /* Flag for default gateway extended community in EVPN */
 217         uint8_t default_gw;
 218
 219         /* NA router flag (R-bit) support in EVPN */
 220         uint8_t router_flag;
 221
 222         /* ES info */
 223         uint8_t es_flags;
 224         /* Path is not "locally-active" on the advertising VTEP. This is
 225          * translated into an ARP-ND ECOM.
 226          */
 227 #define ATTR_ES_PROXY_ADVERT (1 << 0)
 228         /* Destination ES is present locally. This flag is set on local
 229          * paths and sync paths
 230          */
 231 #define ATTR_ES_IS_LOCAL (1 << 1)
 232         /* There are one or more non-best paths from ES peers. Note that
 233          * this flag is only set on the local MAC-IP paths in the VNI
 234          * route table (not set in the global routing table). And only
 235          * non-proxy advertisements from an ES peer can result in this
 236          * flag being set.
 237          */
 238 #define ATTR_ES_PEER_ACTIVE (1 << 2)
 239         /* There are one or more non-best proxy paths from ES peers */
 240 #define ATTR_ES_PEER_PROXY (1 << 3)
 241         /* An ES peer has router bit set - only applicable if
 242          * ATTR_ES_PEER_ACTIVE is set
 243          */
 244 #define ATTR_ES_PEER_ROUTER (1 << 4)
 245
 246         /* route tag */
 247         route_tag_t tag;
 248
 249         /* Label index */
 250         uint32_t label_index;
 251
 252         /* MPLS label */
 253         mpls_label_t label;
 254
 255         /* SRv6 VPN SID */
 256         struct bgp_attr_srv6_vpn *srv6_vpn;
 257
 258         /* SRv6 L3VPN SID */
 259         struct bgp_attr_srv6_l3vpn *srv6_l3vpn;
 260
 261         uint16_t encap_tunneltype;                   /* grr */
 262         struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 263
 264 #ifdef ENABLE_BGP_VNC
 265         struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
 266 #endif
 267         /* EVPN */
 268         struct bgp_route_evpn evpn_overlay;
 269
 270         /* EVPN MAC Mobility sequence number, if any. */
 271         uint32_t mm_seqnum;
 272         /* highest MM sequence number rxed in a MAC-IP route from an
 273          * ES peer (this includes both proxy and non-proxy MAC-IP
 274          * advertisements from ES peers).
 275          * This is only applicable to local paths in the VNI routing
 276          * table and derived from other imported/non-best paths.
 277          */
 278         uint32_t mm_sync_seqnum;
 279
 280         /* EVPN local router-mac */
 281         struct ethaddr rmac;
 282
 283         /* Distance as applied by Route map */
 284         uint8_t distance;
 285
 286         /* rmap set table */
 287         uint32_t rmap_table_id;
 288
 289         /* Link bandwidth value, if any. */
 290         uint32_t link_bw;
 291
 292         /* EVPN ES */
 293         esi_t esi;
 294
 295         /* SR-TE Color */
 296         uint32_t srte_color;
 297
 298         /* EVPN DF preference and algorithm for DF election on local ESs */
 299         uint16_t df_pref;
 300         uint8_t df_alg;
 301 };
 302
 303 /* rmap_change_flags definition */
 304 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 305 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 306 #define BATTR_REFLECTED (1 << 2)
 307 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 308 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 309 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 310 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 311 #define BATTR_RMAP_LINK_BW_SET (1 << 7)
 312
 313 /* Router Reflector related structure. */
 314 struct cluster_list {
 315         unsigned long refcnt;
 316         int length;
 317         struct in_addr *list;
 318 };
 319
 320 /* Unknown transit attribute. */
 321 struct transit {
 322         unsigned long refcnt;
 323         int length;
 324         uint8_t *val;
 325 };
 326
 327 /* "(void) 0" will generate a compiler error.  this is a safety check to
 328  * ensure we're not using a value that exceeds the bit size of attr->flag. */
 329 #define ATTR_FLAG_BIT(X)                                                       \
 330         __builtin_choose_expr((X) >= 1 && (X) <= 64, 1ULL << ((X)-1), (void)0)
 331
 332 #define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
 333         (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
 334                  ? (attr)->cluster->length                                     \
 335                  : 0)
 336
 337 typedef enum {
 338         BGP_ATTR_PARSE_PROCEED = 0,
 339         BGP_ATTR_PARSE_ERROR = -1,
 340         BGP_ATTR_PARSE_WITHDRAW = -2,
 341
 342         /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
 343            */
 344         BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 345         BGP_ATTR_PARSE_EOR = -4,
 346 } bgp_attr_parse_ret_t;
 347
 348 struct bpacket_attr_vec_arr;
 349
 350 /* Prototypes. */
 351 extern void bgp_attr_init(void);
 352 extern void bgp_attr_finish(void);
 353 extern bgp_attr_parse_ret_t bgp_attr_parse(struct peer *, struct attr *,
 354                                            bgp_size_t, struct bgp_nlri *,
 355                                            struct bgp_nlri *);
 356 extern void bgp_attr_undup(struct attr *new, struct attr *old);
 357 extern struct attr *bgp_attr_intern(struct attr *attr);
 358 extern void bgp_attr_unintern_sub(struct attr *);
 359 extern void bgp_attr_unintern(struct attr **);
 360 extern void bgp_attr_flush(struct attr *);
 361 extern struct attr *bgp_attr_default_set(struct attr *attr, uint8_t);
 362 extern struct attr *bgp_attr_aggregate_intern(
 363         struct bgp *bgp, uint8_t origin, struct aspath *aspath,
 364         struct community *community, struct ecommunity *ecommunity,
 365         struct lcommunity *lcommunity, struct bgp_aggregate *aggregate,
 366         uint8_t atomic_aggregate, const struct prefix *p);
 367 extern bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *,
 368                                        struct stream *, struct attr *,
 369                                        struct bpacket_attr_vec_arr *vecarr,
 370                                        struct prefix *, afi_t, safi_t,
 371                                        struct peer *, struct prefix_rd *,
 372                                        mpls_label_t *, uint32_t, int, uint32_t);
 373 extern void bgp_dump_routes_attr(struct stream *s, struct attr *attr,
 374                                  const struct prefix *p);
 375 extern bool attrhash_cmp(const void *arg1, const void *arg2);
 376 extern unsigned int attrhash_key_make(const void *);
 377 extern void attr_show_all(struct vty *);
 378 extern unsigned long int attr_count(void);
 379 extern unsigned long int attr_unknown_count(void);
 380
 381 /* Cluster list prototypes. */
 382 extern bool cluster_loop_check(struct cluster_list *, struct in_addr);
 383
 384 /* Below exported for unit-test purposes only */
 385 struct bgp_attr_parser_args {
 386         struct peer *peer;
 387         bgp_size_t length; /* attribute data length; */
 388         bgp_size_t total;  /* total length, inc header */
 389         struct attr *attr;
 390         uint8_t type;
 391         uint8_t flags;
 392         uint8_t *startp;
 393 };
 394 extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 395                               struct bgp_nlri *);
 396 extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
 397                                 struct bgp_nlri *);
 398 extern bgp_attr_parse_ret_t
 399 bgp_attr_prefix_sid(struct bgp_attr_parser_args *args);
 400
 401 extern struct bgp_attr_encap_subtlv *
 402 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 403
 404 extern void bgp_attr_flush_encap(struct attr *attr);
 405
 406 extern void bgp_attr_extcom_tunnel_type(struct attr *attr,
 407                                          bgp_encap_types *tunnel_type);
 408
 409 /**
 410  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 411  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 412  * one for each NLRI that needs to be encoded into the UPDATE message, and
 413  * finally the _end() function.
 414  */
 415 extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
 416                                       afi_t afi, safi_t safi,
 417                                       struct bpacket_attr_vec_arr *vecarr,
 418                                       struct attr *attr);
 419 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 420                                      const struct prefix *p,
 421                                      const struct prefix_rd *prd,
 422                                      mpls_label_t *label, uint32_t num_labels,
 423                                      int addpath_encode, uint32_t addpath_tx_id,
 424                                      struct attr *);
 425 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 426                                             const struct prefix *p);
 427 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 428
 429 extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
 430                                          safi_t safi);
 431 extern void bgp_packet_mpunreach_prefix(
 432         struct stream *s, const struct prefix *p, afi_t afi, safi_t safi,
 433         const struct prefix_rd *prd, mpls_label_t *label, uint32_t num_labels,
 434         int addpath_encode, uint32_t addpath_tx_id, struct attr *attr);
 435 extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 436
 437 extern bgp_attr_parse_ret_t bgp_attr_nexthop_valid(struct peer *peer,
 438                                                    struct attr *attr);
 439
 440 static inline int bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
 441                                         uint32_t in_rmap_flags)
 442 {
 443         return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)
 444                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)
 445                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED)
 446                  || CHECK_FLAG(out_rmap_flags,
 447                                BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED)
 448                  || CHECK_FLAG(out_rmap_flags,
 449                                BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED)
 450                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED)
 451                  || CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
 452                         ? 1
 453                         : 0);
 454 }
 455
 456 static inline uint32_t mac_mobility_seqnum(struct attr *attr)
 457 {
 458         return (attr) ? attr->mm_seqnum : 0;
 459 }
 460 #endif /* _QUAGGA_BGP_ATTR_H */