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
  66 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
  67 #define BGP_PREFIX_SID_IPV6_LENGTH            19
  68 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
  69
  70 /* PMSI tunnel types (RFC 6514) */
  71
  72 struct bgp_attr_encap_subtlv {
  73         struct bgp_attr_encap_subtlv *next; /* for chaining */
  74         /* Reference count of this attribute. */
  75         unsigned long refcnt;
  76         uint16_t type;
  77         uint16_t length;
  78         uint8_t value[0]; /* will be extended */
  79 };
  80
  81 #if ENABLE_BGP_VNC
  82 /*
  83  * old rfp<->rfapi representation
  84  */
  85 struct bgp_tea_options {
  86         struct bgp_tea_options *next;
  87         uint8_t options_count;
  88         uint16_t options_length; /* each TLV may be 256 in length */
  89         uint8_t type;
  90         uint8_t length;
  91         void *value; /* pointer to data */
  92 };
  93
  94 #endif
  95
  96 enum pta_type {
  97         PMSI_TNLTYPE_NO_INFO = 0,
  98         PMSI_TNLTYPE_RSVP_TE_P2MP,
  99         PMSI_TNLTYPE_MLDP_P2MP,
 100         PMSI_TNLTYPE_PIM_SSM,
 101         PMSI_TNLTYPE_PIM_SM,
 102         PMSI_TNLTYPE_PIM_BIDIR,
 103         PMSI_TNLTYPE_INGR_REPL,
 104         PMSI_TNLTYPE_MLDP_MP2MP,
 105         PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 106 };
 107
 108 /* BGP core attribute structure. */
 109 struct attr {
 110         /* AS Path structure */
 111         struct aspath *aspath;
 112
 113         /* Community structure */
 114         struct community *community;
 115
 116         /* Reference count of this attribute. */
 117         unsigned long refcnt;
 118
 119         /* Flag of attribute is set or not. */
 120         uint64_t flag;
 121
 122         /* Apart from in6_addr, the remaining static attributes */
 123         struct in_addr nexthop;
 124         uint32_t med;
 125         uint32_t local_pref;
 126         ifindex_t nh_ifindex;
 127
 128         /* Path origin attribute */
 129         uint8_t origin;
 130
 131         /* PMSI tunnel type (RFC 6514). */
 132         enum pta_type pmsi_tnl_type;
 133
 134         /* has the route-map changed any attribute?
 135            Used on the peer outbound side. */
 136         uint32_t rmap_change_flags;
 137
 138         /* Multi-Protocol Nexthop, AFI IPv6 */
 139         struct in6_addr mp_nexthop_global;
 140         struct in6_addr mp_nexthop_local;
 141
 142         /* ifIndex corresponding to mp_nexthop_local. */
 143         ifindex_t nh_lla_ifindex;
 144
 145         /* Extended Communities attribute. */
 146         struct ecommunity *ecommunity;
 147
 148         /* Large Communities attribute. */
 149         struct lcommunity *lcommunity;
 150
 151         /* Route-Reflector Cluster attribute */
 152         struct cluster_list *cluster;
 153
 154         /* Unknown transitive attribute. */
 155         struct transit *transit;
 156
 157         struct in_addr mp_nexthop_global_in;
 158
 159         /* Aggregator Router ID attribute */
 160         struct in_addr aggregator_addr;
 161
 162         /* Route Reflector Originator attribute */
 163         struct in_addr originator_id;
 164
 165         /* Local weight, not actually an attribute */
 166         uint32_t weight;
 167
 168         /* Aggregator ASN */
 169         as_t aggregator_as;
 170
 171         /* MP Nexthop length */
 172         uint8_t mp_nexthop_len;
 173
 174         /* MP Nexthop preference */
 175         uint8_t mp_nexthop_prefer_global;
 176
 177         /* Static MAC for EVPN */
 178         uint8_t sticky;
 179
 180         /* Flag for default gateway extended community in EVPN */
 181         uint8_t default_gw;
 182
 183         /* NA router flag (R-bit) support in EVPN */
 184         uint8_t router_flag;
 185
 186         /* route tag */
 187         route_tag_t tag;
 188
 189         /* Label index */
 190         uint32_t label_index;
 191
 192         /* MPLS label */
 193         mpls_label_t label;
 194
 195         uint16_t encap_tunneltype;                   /* grr */
 196         struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 197
 198 #if ENABLE_BGP_VNC
 199         struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
 200 #endif
 201         /* EVPN */
 202         struct bgp_route_evpn evpn_overlay;
 203
 204         /* EVPN MAC Mobility sequence number, if any. */
 205         uint32_t mm_seqnum;
 206
 207         /* EVPN local router-mac */
 208         struct ethaddr rmac;
 209
 210         /* Distance as applied by Route map */
 211         uint8_t distance;
 212 };
 213
 214 /* rmap_change_flags definition */
 215 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 216 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 217 #define BATTR_REFLECTED (1 << 2)
 218 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 219 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 220 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 221 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 222
 223 /* Router Reflector related structure. */
 224 struct cluster_list {
 225         unsigned long refcnt;
 226         int length;
 227         struct in_addr *list;
 228 };
 229
 230 /* Unknown transit attribute. */
 231 struct transit {
 232         unsigned long refcnt;
 233         int length;
 234         uint8_t *val;
 235 };
 236
 237 /* "(void) 0" will generate a compiler error.  this is a safety check to
 238  * ensure we're not using a value that exceeds the bit size of attr->flag. */
 239 #define ATTR_FLAG_BIT(X)                                                       \
 240         __builtin_choose_expr((X) >= 1 && (X) <= 64, 1ULL << ((X)-1), (void)0)
 241
 242 #define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
 243         (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
 244                  ? (attr)->cluster->length                                     \
 245                  : 0)
 246
 247 typedef enum {
 248         BGP_ATTR_PARSE_PROCEED = 0,
 249         BGP_ATTR_PARSE_ERROR = -1,
 250         BGP_ATTR_PARSE_WITHDRAW = -2,
 251
 252         /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
 253            */
 254         BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 255         BGP_ATTR_PARSE_EOR = -4,
 256 } bgp_attr_parse_ret_t;
 257
 258 struct bpacket_attr_vec_arr;
 259
 260 /* Prototypes. */
 261 extern void bgp_attr_init(void);
 262 extern void bgp_attr_finish(void);
 263 extern bgp_attr_parse_ret_t bgp_attr_parse(struct peer *, struct attr *,
 264                                            bgp_size_t, struct bgp_nlri *,
 265                                            struct bgp_nlri *);
 266 extern void bgp_attr_dup(struct attr *, struct attr *);
 267 extern void bgp_attr_undup(struct attr *new, struct attr *old);
 268 extern struct attr *bgp_attr_intern(struct attr *attr);
 269 extern void bgp_attr_unintern_sub(struct attr *);
 270 extern void bgp_attr_unintern(struct attr **);
 271 extern void bgp_attr_flush(struct attr *);
 272 extern struct attr *bgp_attr_default_set(struct attr *attr, uint8_t);
 273 extern struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
 274                                               struct aspath *aspath,
 275                                               struct community *community,
 276                                               struct ecommunity *ecommunity,
 277                                               struct lcommunity *lcommunity,
 278                                               struct bgp_aggregate *aggregate,
 279                                               uint8_t atomic_aggregate,
 280                                               struct prefix *p);
 281 extern bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *,
 282                                        struct stream *, struct attr *,
 283                                        struct bpacket_attr_vec_arr *vecarr,
 284                                        struct prefix *, afi_t, safi_t,
 285                                        struct peer *, struct prefix_rd *,
 286                                        mpls_label_t *, uint32_t, int, uint32_t);
 287 extern void bgp_dump_routes_attr(struct stream *, struct attr *,
 288                                  struct prefix *);
 289 extern bool attrhash_cmp(const void *arg1, const void *arg2);
 290 extern unsigned int attrhash_key_make(const void *);
 291 extern void attr_show_all(struct vty *);
 292 extern unsigned long int attr_count(void);
 293 extern unsigned long int attr_unknown_count(void);
 294
 295 /* Cluster list prototypes. */
 296 extern int cluster_loop_check(struct cluster_list *, struct in_addr);
 297 extern void cluster_unintern(struct cluster_list *);
 298
 299 /* Transit attribute prototypes. */
 300 void transit_unintern(struct transit *);
 301
 302 /* Below exported for unit-test purposes only */
 303 struct bgp_attr_parser_args {
 304         struct peer *peer;
 305         bgp_size_t length; /* attribute data length; */
 306         bgp_size_t total;  /* total length, inc header */
 307         struct attr *attr;
 308         uint8_t type;
 309         uint8_t flags;
 310         uint8_t *startp;
 311 };
 312 extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 313                               struct bgp_nlri *);
 314 extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
 315                                 struct bgp_nlri *);
 316 extern bgp_attr_parse_ret_t
 317 bgp_attr_prefix_sid(int32_t tlength, struct bgp_attr_parser_args *args,
 318                     struct bgp_nlri *mp_update);
 319
 320 extern struct bgp_attr_encap_subtlv *
 321 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 322
 323 extern void bgp_attr_flush_encap(struct attr *attr);
 324
 325 extern void bgp_attr_extcom_tunnel_type(struct attr *attr,
 326                                          bgp_encap_types *tunnel_type);
 327
 328 /**
 329  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 330  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 331  * one for each NLRI that needs to be encoded into the UPDATE message, and
 332  * finally the _end() function.
 333  */
 334 extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
 335                                       afi_t afi, safi_t safi,
 336                                       struct bpacket_attr_vec_arr *vecarr,
 337                                       struct attr *attr);
 338 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 339                                      struct prefix *p, struct prefix_rd *prd,
 340                                      mpls_label_t *label, uint32_t num_labels,
 341                                      int addpath_encode, uint32_t addpath_tx_id,
 342                                      struct attr *);
 343 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 344                                             struct prefix *p);
 345 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 346
 347 extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
 348                                          safi_t safi);
 349 extern void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p,
 350                                         afi_t afi, safi_t safi,
 351                                         struct prefix_rd *prd, mpls_label_t *,
 352                                         uint32_t, int, uint32_t, struct attr *);
 353 extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 354
 355 extern bgp_attr_parse_ret_t bgp_attr_nexthop_valid(struct peer *peer,
 356                                                    struct attr *attr);
 357
 358 static inline int bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
 359                                         uint32_t in_rmap_flags)
 360 {
 361         return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)
 362                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)
 363                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED)
 364                  || CHECK_FLAG(out_rmap_flags,
 365                                BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED)
 366                  || CHECK_FLAG(out_rmap_flags,
 367                                BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED)
 368                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED)
 369                  || CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
 370                         ? 1
 371                         : 0);
 372 }
 373
 374 static inline uint32_t mac_mobility_seqnum(struct attr *attr)
 375 {
 376         return (attr) ? attr->mm_seqnum : 0;
 377 }
 378
 379 #endif /* _QUAGGA_BGP_ATTR_H */