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
  27 /* Simple bit mapping. */
  28 #define BITMAP_NBBY 8
  29
  30 #define SET_BITMAP(MAP, NUM)                                                   \
  31         SET_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  32
  33 #define CHECK_BITMAP(MAP, NUM)                                                 \
  34         CHECK_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  35
  36 #define BGP_MED_MAX UINT32_MAX
  37
  38 /* BGP Attribute type range. */
  39 #define BGP_ATTR_TYPE_RANGE     256
  40 #define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)
  41
  42 /* BGP Attribute flags. */
  43 #define BGP_ATTR_FLAG_OPTIONAL  0x80    /* Attribute is optional. */
  44 #define BGP_ATTR_FLAG_TRANS     0x40    /* Attribute is transitive. */
  45 #define BGP_ATTR_FLAG_PARTIAL   0x20    /* Attribute is partial. */
  46 #define BGP_ATTR_FLAG_EXTLEN    0x10    /* Extended length flag. */
  47
  48 /* BGP attribute header must bigger than 2. */
  49 #define BGP_ATTR_MIN_LEN        3       /* Attribute flag, type length. */
  50 #define BGP_ATTR_DEFAULT_WEIGHT 32768
  51
  52 /* Valid lengths for mp_nexthop_len */
  53 #define BGP_ATTR_NHLEN_IPV4               IPV4_MAX_BYTELEN
  54 #define BGP_ATTR_NHLEN_VPNV4              8+IPV4_MAX_BYTELEN
  55 #define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
  56 #define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
  57 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL       8+IPV6_MAX_BYTELEN
  58 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL ((8+IPV6_MAX_BYTELEN) * 2)
  59
  60 /* Prefix SID types */
  61 #define BGP_PREFIX_SID_LABEL_INDEX     1
  62 #define BGP_PREFIX_SID_IPV6            2
  63 #define BGP_PREFIX_SID_ORIGINATOR_SRGB 3
  64
  65 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
  66 #define BGP_PREFIX_SID_IPV6_LENGTH            19
  67 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
  68
  69 /* PMSI tunnel types (RFC 6514) */
  70
  71 struct bgp_attr_encap_subtlv {
  72         struct bgp_attr_encap_subtlv *next; /* for chaining */
  73         /* Reference count of this attribute. */
  74         unsigned long refcnt;
  75         uint16_t type;
  76         uint16_t length;
  77         uint8_t value[0]; /* will be extended */
  78 };
  79
  80 #if ENABLE_BGP_VNC
  81 /*
  82  * old rfp<->rfapi representation
  83  */
  84 struct bgp_tea_options {
  85         struct bgp_tea_options *next;
  86         uint8_t options_count;
  87         uint16_t options_length; /* each TLV may be 256 in length */
  88         uint8_t type;
  89         uint8_t length;
  90         void *value; /* pointer to data */
  91 };
  92
  93 #endif
  94
  95 enum pta_type {
  96         PMSI_TNLTYPE_NO_INFO = 0,
  97         PMSI_TNLTYPE_RSVP_TE_P2MP,
  98         PMSI_TNLTYPE_MLDP_P2MP,
  99         PMSI_TNLTYPE_PIM_SSM,
 100         PMSI_TNLTYPE_PIM_SM,
 101         PMSI_TNLTYPE_PIM_BIDIR,
 102         PMSI_TNLTYPE_INGR_REPL,
 103         PMSI_TNLTYPE_MLDP_MP2MP,
 104         PMSI_TNLTYPE_MAX = PMSI_TNLTYPE_MLDP_MP2MP
 105 };
 106
 107 /* BGP core attribute structure. */
 108 struct attr {
 109         /* AS Path structure */
 110         struct aspath *aspath;
 111
 112         /* Community structure */
 113         struct community *community;
 114
 115         /* Reference count of this attribute. */
 116         unsigned long refcnt;
 117
 118         /* Flag of attribute is set or not. */
 119         uint64_t flag;
 120
 121         /* Apart from in6_addr, the remaining static attributes */
 122         struct in_addr nexthop;
 123         uint32_t med;
 124         uint32_t local_pref;
 125         ifindex_t nh_ifindex;
 126
 127         /* Path origin attribute */
 128         uint8_t origin;
 129
 130         /* PMSI tunnel type (RFC 6514). */
 131         enum pta_type pmsi_tnl_type;
 132
 133         /* has the route-map changed any attribute?
 134            Used on the peer outbound side. */
 135         uint32_t rmap_change_flags;
 136
 137         /* Multi-Protocol Nexthop, AFI IPv6 */
 138         struct in6_addr mp_nexthop_global;
 139         struct in6_addr mp_nexthop_local;
 140
 141         /* ifIndex corresponding to mp_nexthop_local. */
 142         ifindex_t nh_lla_ifindex;
 143
 144         /* Extended Communities attribute. */
 145         struct ecommunity *ecommunity;
 146
 147         /* Large Communities attribute. */
 148         struct lcommunity *lcommunity;
 149
 150         /* Route-Reflector Cluster attribute */
 151         struct cluster_list *cluster;
 152
 153         /* Unknown transitive attribute. */
 154         struct transit *transit;
 155
 156         struct in_addr mp_nexthop_global_in;
 157
 158         /* Aggregator Router ID attribute */
 159         struct in_addr aggregator_addr;
 160
 161         /* Route Reflector Originator attribute */
 162         struct in_addr originator_id;
 163
 164         /* Local weight, not actually an attribute */
 165         uint32_t weight;
 166
 167         /* Aggregator ASN */
 168         as_t aggregator_as;
 169
 170         /* MP Nexthop length */
 171         uint8_t mp_nexthop_len;
 172
 173         /* MP Nexthop preference */
 174         uint8_t mp_nexthop_prefer_global;
 175
 176         /* Static MAC for EVPN */
 177         uint8_t sticky;
 178
 179         /* Flag for default gateway extended community in EVPN */
 180         uint8_t default_gw;
 181
 182         /* NA router flag (R-bit) support in EVPN */
 183         uint8_t router_flag;
 184
 185         /* route tag */
 186         route_tag_t tag;
 187
 188         /* Label index */
 189         uint32_t label_index;
 190
 191         /* MPLS label */
 192         mpls_label_t label;
 193
 194         uint16_t encap_tunneltype;                   /* grr */
 195         struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 196
 197 #if ENABLE_BGP_VNC
 198         struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
 199 #endif
 200         /* EVPN */
 201         struct bgp_route_evpn evpn_overlay;
 202
 203         /* EVPN MAC Mobility sequence number, if any. */
 204         uint32_t mm_seqnum;
 205
 206         /* EVPN local router-mac */
 207         struct ethaddr rmac;
 208 };
 209
 210 /* rmap_change_flags definition */
 211 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 212 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 213 #define BATTR_REFLECTED (1 << 2)
 214 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 215 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 216 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 217 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 218
 219 /* Router Reflector related structure. */
 220 struct cluster_list {
 221         unsigned long refcnt;
 222         int length;
 223         struct in_addr *list;
 224 };
 225
 226 /* Unknown transit attribute. */
 227 struct transit {
 228         unsigned long refcnt;
 229         int length;
 230         uint8_t *val;
 231 };
 232
 233 /* "(void) 0" will generate a compiler error.  this is a safety check to
 234  * ensure we're not using a value that exceeds the bit size of attr->flag. */
 235 #define ATTR_FLAG_BIT(X)                                                       \
 236         __builtin_choose_expr((X) >= 1 && (X) <= 64, 1ULL << ((X)-1), (void)0)
 237
 238 #define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
 239         (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
 240                  ? (attr)->cluster->length                                     \
 241                  : 0)
 242
 243 typedef enum {
 244         BGP_ATTR_PARSE_PROCEED = 0,
 245         BGP_ATTR_PARSE_ERROR = -1,
 246         BGP_ATTR_PARSE_WITHDRAW = -2,
 247
 248         /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
 249            */
 250         BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 251         BGP_ATTR_PARSE_EOR = -4,
 252 } bgp_attr_parse_ret_t;
 253
 254 struct bpacket_attr_vec_arr;
 255
 256 /* Prototypes. */
 257 extern void bgp_attr_init(void);
 258 extern void bgp_attr_finish(void);
 259 extern bgp_attr_parse_ret_t bgp_attr_parse(struct peer *, struct attr *,
 260                                            bgp_size_t, struct bgp_nlri *,
 261                                            struct bgp_nlri *);
 262 extern void bgp_attr_dup(struct attr *, struct attr *);
 263 extern void bgp_attr_undup(struct attr *new, struct attr *old);
 264 extern struct attr *bgp_attr_intern(struct attr *attr);
 265 extern void bgp_attr_unintern_sub(struct attr *);
 266 extern void bgp_attr_unintern(struct attr **);
 267 extern void bgp_attr_flush(struct attr *);
 268 extern struct attr *bgp_attr_default_set(struct attr *attr, uint8_t);
 269 extern struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
 270                                               struct aspath *aspath,
 271                                               struct community *community,
 272                                               struct ecommunity *ecommunity,
 273                                               struct lcommunity *lcommunity,
 274                                               int as_set,
 275                                               uint8_t atomic_aggregate);
 276 extern bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *,
 277                                        struct stream *, struct attr *,
 278                                        struct bpacket_attr_vec_arr *vecarr,
 279                                        struct prefix *, afi_t, safi_t,
 280                                        struct peer *, struct prefix_rd *,
 281                                        mpls_label_t *, uint32_t, int, uint32_t);
 282 extern void bgp_dump_routes_attr(struct stream *, struct attr *,
 283                                  struct prefix *);
 284 extern bool attrhash_cmp(const void *arg1, const void *arg2);
 285 extern unsigned int attrhash_key_make(void *);
 286 extern void attr_show_all(struct vty *);
 287 extern unsigned long int attr_count(void);
 288 extern unsigned long int attr_unknown_count(void);
 289
 290 /* Cluster list prototypes. */
 291 extern int cluster_loop_check(struct cluster_list *, struct in_addr);
 292 extern void cluster_unintern(struct cluster_list *);
 293
 294 /* Transit attribute prototypes. */
 295 void transit_unintern(struct transit *);
 296
 297 /* Below exported for unit-test purposes only */
 298 struct bgp_attr_parser_args {
 299         struct peer *peer;
 300         bgp_size_t length; /* attribute data length; */
 301         bgp_size_t total;  /* total length, inc header */
 302         struct attr *attr;
 303         uint8_t type;
 304         uint8_t flags;
 305         uint8_t *startp;
 306 };
 307 extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 308                               struct bgp_nlri *);
 309 extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
 310                                 struct bgp_nlri *);
 311 extern bgp_attr_parse_ret_t
 312 bgp_attr_prefix_sid(int32_t tlength, struct bgp_attr_parser_args *args,
 313                     struct bgp_nlri *mp_update);
 314
 315 extern struct bgp_attr_encap_subtlv *
 316 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 317
 318 extern void bgp_attr_flush_encap(struct attr *attr);
 319
 320 /**
 321  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 322  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 323  * one for each NLRI that needs to be encoded into the UPDATE message, and
 324  * finally the _end() function.
 325  */
 326 extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
 327                                       afi_t afi, safi_t safi,
 328                                       struct bpacket_attr_vec_arr *vecarr,
 329                                       struct attr *attr);
 330 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 331                                      struct prefix *p, struct prefix_rd *prd,
 332                                      mpls_label_t *label, uint32_t num_labels,
 333                                      int addpath_encode, uint32_t addpath_tx_id,
 334                                      struct attr *);
 335 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 336                                             struct prefix *p);
 337 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 338
 339 extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
 340                                          safi_t safi);
 341 extern void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p,
 342                                         afi_t afi, safi_t safi,
 343                                         struct prefix_rd *prd, mpls_label_t *,
 344                                         uint32_t, int, uint32_t, struct attr *);
 345 extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 346
 347 static inline int bgp_rmap_nhop_changed(uint32_t out_rmap_flags,
 348                                         uint32_t in_rmap_flags)
 349 {
 350         return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)
 351                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)
 352                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED)
 353                  || CHECK_FLAG(out_rmap_flags,
 354                                BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED)
 355                  || CHECK_FLAG(out_rmap_flags,
 356                                BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED)
 357                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED)
 358                  || CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
 359                         ? 1
 360                         : 0);
 361 }
 362
 363 static inline uint32_t mac_mobility_seqnum(struct attr *attr)
 364 {
 365         return (attr) ? attr->mm_seqnum : 0;
 366 }
 367
 368 #endif /* _QUAGGA_BGP_ATTR_H */