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