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_SRV6_L3_SERVICE 5
  66 #define BGP_PREFIX_SID_SRV6_L2_SERVICE 6
  67
  68 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
  69 #define BGP_PREFIX_SID_IPV6_LENGTH            19
  70 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
  71
  72 #define BGP_ATTR_NH_AFI(afi, attr) \
  73         ((afi != AFI_L2VPN) ? afi : \
  74         ((attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV4) ? AFI_IP : AFI_IP6))
  75
  76 /* PMSI tunnel types (RFC 6514) */
  77
  78 struct bgp_attr_encap_subtlv {
  79         struct bgp_attr_encap_subtlv *next; /* for chaining */
  80         /* Reference count of this attribute. */
  81         unsigned long refcnt;
  82         uint16_t type;
  83         uint16_t length;
  84         uint8_t value[0]; /* will be extended */
  85 };
  86
  87 #if ENABLE_BGP_VNC
  88 /*
  89  * old rfp<->rfapi representation
  90  */
  91 struct bgp_tea_options {
  92         struct bgp_tea_options *next;
  93         uint8_t options_count;
  94         uint16_t options_length; /* each TLV may be 256 in length */
  95         uint8_t type;
  96         uint8_t length;
  97         void *value; /* pointer to data */
  98 };
  99
 100 #endif
 101
 102 enum pta_type {
 103         PMSI_TNLTYPE_NO_INFO = 0,
 104         PMSI_TNLTYPE_RSVP_TE_P2MP,
 105         PMSI_TNLTYPE_MLDP_P2MP,
 106         PMSI_TNLTYPE_PIM_SSM,
 107         PMSI_TNLTYPE_PIM_SM,
 108         PMSI_TNLTYPE_PIM_BIDIR,
 109         PMSI_TNLTYPE_INGR_REPL,
 110         PMSI_TNLTYPE_MLDP_MP2MP,
 111         PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 112 };
 113
 114 /* BGP core attribute structure. */
 115 struct attr {
 116         /* AS Path structure */
 117         struct aspath *aspath;
 118
 119         /* Community structure */
 120         struct community *community;
 121
 122         /* Reference count of this attribute. */
 123         unsigned long refcnt;
 124
 125         /* Flag of attribute is set or not. */
 126         uint64_t flag;
 127
 128         /* Apart from in6_addr, the remaining static attributes */
 129         struct in_addr nexthop;
 130         uint32_t med;
 131         uint32_t local_pref;
 132         ifindex_t nh_ifindex;
 133
 134         /* Path origin attribute */
 135         uint8_t origin;
 136
 137         /* PMSI tunnel type (RFC 6514). */
 138         enum pta_type pmsi_tnl_type;
 139
 140         /* has the route-map changed any attribute?
 141            Used on the peer outbound side. */
 142         uint32_t rmap_change_flags;
 143
 144         /* Multi-Protocol Nexthop, AFI IPv6 */
 145         struct in6_addr mp_nexthop_global;
 146         struct in6_addr mp_nexthop_local;
 147
 148         /* ifIndex corresponding to mp_nexthop_local. */
 149         ifindex_t nh_lla_ifindex;
 150
 151         /* Extended Communities attribute. */
 152         struct ecommunity *ecommunity;
 153
 154         /* Large Communities attribute. */
 155         struct lcommunity *lcommunity;
 156
 157         /* Route-Reflector Cluster attribute */
 158         struct cluster_list *cluster;
 159
 160         /* Unknown transitive attribute. */
 161         struct transit *transit;
 162
 163         struct in_addr mp_nexthop_global_in;
 164
 165         /* Aggregator Router ID attribute */
 166         struct in_addr aggregator_addr;
 167
 168         /* Route Reflector Originator attribute */
 169         struct in_addr originator_id;
 170
 171         /* Local weight, not actually an attribute */
 172         uint32_t weight;
 173
 174         /* Aggregator ASN */
 175         as_t aggregator_as;
 176
 177         /* MP Nexthop length */
 178         uint8_t mp_nexthop_len;
 179
 180         /* MP Nexthop preference */
 181         uint8_t mp_nexthop_prefer_global;
 182
 183         /* Static MAC for EVPN */
 184         uint8_t sticky;
 185
 186         /* Flag for default gateway extended community in EVPN */
 187         uint8_t default_gw;
 188
 189         /* NA router flag (R-bit) support in EVPN */
 190         uint8_t router_flag;
 191
 192         /* route tag */
 193         route_tag_t tag;
 194
 195         /* Label index */
 196         uint32_t label_index;
 197
 198         /* MPLS label */
 199         mpls_label_t label;
 200
 201         uint16_t encap_tunneltype;                   /* grr */
 202         struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 203
 204 #if ENABLE_BGP_VNC
 205         struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
 206 #endif
 207         /* EVPN */
 208         struct bgp_route_evpn evpn_overlay;
 209
 210         /* EVPN MAC Mobility sequence number, if any. */
 211         uint32_t mm_seqnum;
 212
 213         /* EVPN local router-mac */
 214         struct ethaddr rmac;
 215
 216         /* Distance as applied by Route map */
 217         uint8_t distance;
 218
 219         /* rmap set table */
 220         uint32_t rmap_table_id;
 221 };
 222
 223 /* rmap_change_flags definition */
 224 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 225 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 226 #define BATTR_REFLECTED (1 << 2)
 227 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 228 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 229 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 230 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 231
 232 /* Router Reflector related structure. */
 233 struct cluster_list {
 234         unsigned long refcnt;
 235         int length;
 236         struct in_addr *list;
 237 };
 238
 239 /* Unknown transit attribute. */
 240 struct transit {
 241         unsigned long refcnt;
 242         int length;
 243         uint8_t *val;
 244 };
 245
 246 /* "(void) 0" will generate a compiler error.  this is a safety check to
 247  * ensure we're not using a value that exceeds the bit size of attr->flag. */
 248 #define ATTR_FLAG_BIT(X)                                                       \
 249         __builtin_choose_expr((X) >= 1 && (X) <= 64, 1ULL << ((X)-1), (void)0)
 250
 251 #define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
 252         (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
 253                  ? (attr)->cluster->length                                     \
 254                  : 0)
 255
 256 typedef enum {
 257         BGP_ATTR_PARSE_PROCEED = 0,
 258         BGP_ATTR_PARSE_ERROR = -1,
 259         BGP_ATTR_PARSE_WITHDRAW = -2,
 260
 261         /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
 262            */
 263         BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 264         BGP_ATTR_PARSE_EOR = -4,
 265 } bgp_attr_parse_ret_t;
 266
 267 struct bpacket_attr_vec_arr;
 268
 269 /* Prototypes. */
 270 extern void bgp_attr_init(void);
 271 extern void bgp_attr_finish(void);
 272 extern bgp_attr_parse_ret_t bgp_attr_parse(struct peer *, struct attr *,
 273                                            bgp_size_t, struct bgp_nlri *,
 274                                            struct bgp_nlri *);
 275 extern void bgp_attr_undup(struct attr *new, struct attr *old);
 276 extern struct attr *bgp_attr_intern(struct attr *attr);
 277 extern void bgp_attr_unintern_sub(struct attr *);
 278 extern void bgp_attr_unintern(struct attr **);
 279 extern void bgp_attr_flush(struct attr *);
 280 extern struct attr *bgp_attr_default_set(struct attr *attr, uint8_t);
 281 extern struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
 282                                               struct aspath *aspath,
 283                                               struct community *community,
 284                                               struct ecommunity *ecommunity,
 285                                               struct lcommunity *lcommunity,
 286                                               struct bgp_aggregate *aggregate,
 287                                               uint8_t atomic_aggregate,
 288                                               struct prefix *p);
 289 extern bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *,
 290                                        struct stream *, struct attr *,
 291                                        struct bpacket_attr_vec_arr *vecarr,
 292                                        struct prefix *, afi_t, safi_t,
 293                                        struct peer *, struct prefix_rd *,
 294                                        mpls_label_t *, uint32_t, int, uint32_t);
 295 extern void bgp_dump_routes_attr(struct stream *, struct attr *,
 296                                  struct prefix *);
 297 extern bool attrhash_cmp(const void *arg1, const void *arg2);
 298 extern unsigned int attrhash_key_make(const void *);
 299 extern void attr_show_all(struct vty *);
 300 extern unsigned long int attr_count(void);
 301 extern unsigned long int attr_unknown_count(void);
 302
 303 /* Cluster list prototypes. */
 304 extern int cluster_loop_check(struct cluster_list *, struct in_addr);
 305 extern void cluster_unintern(struct cluster_list *);
 306
 307 /* Below exported for unit-test purposes only */
 308 struct bgp_attr_parser_args {
 309         struct peer *peer;
 310         bgp_size_t length; /* attribute data length; */
 311         bgp_size_t total;  /* total length, inc header */
 312         struct attr *attr;
 313         uint8_t type;
 314         uint8_t flags;
 315         uint8_t *startp;
 316 };
 317 extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 318                               struct bgp_nlri *);
 319 extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
 320                                 struct bgp_nlri *);
 321 extern bgp_attr_parse_ret_t
 322 bgp_attr_prefix_sid(struct bgp_attr_parser_args *args,
 323                     struct bgp_nlri *mp_update);
 324
 325 extern struct bgp_attr_encap_subtlv *
 326 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 327
 328 extern void bgp_attr_flush_encap(struct attr *attr);
 329
 330 extern void bgp_attr_extcom_tunnel_type(struct attr *attr,
 331                                          bgp_encap_types *tunnel_type);
 332
 333 /**
 334  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 335  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 336  * one for each NLRI that needs to be encoded into the UPDATE message, and
 337  * finally the _end() function.
 338  */
 339 extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
 340                                       afi_t afi, safi_t safi,
 341                                       struct bpacket_attr_vec_arr *vecarr,
 342                                       struct attr *attr);
 343 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 344                                      struct prefix *p, struct prefix_rd *prd,
 345                                      mpls_label_t *label, uint32_t num_labels,
 346                                      int addpath_encode, uint32_t addpath_tx_id,
 347                                      struct attr *);
 348 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 349                                             struct prefix *p);
 350 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 351
 352 extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
 353                                          safi_t safi);
 354 extern void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p,
 355                                         afi_t afi, safi_t safi,
 356                                         struct prefix_rd *prd, mpls_label_t *,
 357                                         uint32_t, int, uint32_t, struct attr *);
 358 extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 359
 360 extern bgp_attr_parse_ret_t bgp_attr_nexthop_valid(struct peer *peer,
 361                                                    struct attr *attr);
 362
 363 static inline int bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
 364                                         uint32_t in_rmap_flags)
 365 {
 366         return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)
 367                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)
 368                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED)
 369                  || CHECK_FLAG(out_rmap_flags,
 370                                BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED)
 371                  || CHECK_FLAG(out_rmap_flags,
 372                                BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED)
 373                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED)
 374                  || CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
 375                         ? 1
 376                         : 0);
 377 }
 378
 379 static inline uint32_t mac_mobility_seqnum(struct attr *attr)
 380 {
 381         return (attr) ? attr->mm_seqnum : 0;
 382 }
 383
 384 #endif /* _QUAGGA_BGP_ATTR_H */