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 "bgp_attr_evpn.h"
  25
  26 /* Simple bit mapping. */
  27 #define BITMAP_NBBY 8
  28
  29 #define SET_BITMAP(MAP, NUM) \
  30         SET_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  31
  32 #define CHECK_BITMAP(MAP, NUM) \
  33         CHECK_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  34
  35 #define BGP_MED_MAX UINT32_MAX
  36
  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 struct bgp_attr_encap_subtlv {
  70     struct bgp_attr_encap_subtlv        *next;          /* for chaining */
  71     /* Reference count of this attribute. */
  72     unsigned long refcnt;
  73     uint16_t                            type;
  74     uint16_t                            length;
  75     uint8_t                             value[1];       /* will be extended */
  76 };
  77
  78 #if ENABLE_BGP_VNC
  79 /*
  80  * old rfp<->rfapi representation
  81  */
  82 struct bgp_tea_options {
  83     struct bgp_tea_options *next;
  84     uint8_t               options_count;
  85     uint16_t              options_length; /* each TLV may be 256 in length */
  86     uint8_t               type;
  87     uint8_t               length;
  88     void                 *value; /* pointer to data */
  89 };
  90
  91 #endif
  92
  93 /* Overlay Index Info */
  94 struct overlay_index
  95 {
  96   struct eth_segment_id eth_s_id;
  97   union gw_addr gw_ip;
  98 };
  99
 100 /* Additional/uncommon BGP attributes.
 101  * lazily allocated as and when a struct attr
 102  * requires it.
 103  */
 104 struct attr_extra
 105 {
 106   /* Multi-Protocol Nexthop, AFI IPv6 */
 107   struct in6_addr mp_nexthop_global;
 108   struct in6_addr mp_nexthop_local;
 109
 110   /* Extended Communities attribute. */
 111   struct ecommunity *ecommunity;
 112
 113   /* Large Communities attribute. */
 114   struct lcommunity *lcommunity;
 115
 116   /* Route-Reflector Cluster attribute */
 117   struct cluster_list *cluster;
 118
 119   /* Unknown transitive attribute. */
 120   struct transit *transit;
 121
 122   struct in_addr mp_nexthop_global_in;
 123
 124   /* Aggregator Router ID attribute */
 125   struct in_addr aggregator_addr;
 126
 127   /* Route Reflector Originator attribute */
 128   struct in_addr originator_id;
 129
 130   /* Local weight, not actually an attribute */
 131   u_int32_t weight;
 132
 133   /* Aggregator ASN */
 134   as_t aggregator_as;
 135
 136   /* MP Nexthop length */
 137   u_char mp_nexthop_len;
 138
 139   /* MP Nexthop preference */
 140   u_char mp_nexthop_prefer_global;
 141
 142   /* route tag */
 143   route_tag_t tag;
 144
 145   /* Label index */
 146   u_int32_t label_index;
 147
 148   uint16_t                      encap_tunneltype;       /* grr */
 149   struct bgp_attr_encap_subtlv *encap_subtlvs;          /* rfc5512 */
 150
 151 #if ENABLE_BGP_VNC
 152   struct bgp_attr_encap_subtlv *vnc_subtlvs;            /* VNC-specific */
 153 #endif
 154   /* EVPN */
 155   struct overlay_index evpn_overlay;
 156 };
 157
 158 /* BGP core attribute structure. */
 159 struct attr
 160 {
 161   /* AS Path structure */
 162   struct aspath *aspath;
 163
 164   /* Community structure */
 165   struct community *community;
 166
 167   /* Lazily allocated pointer to extra attributes */
 168   struct attr_extra *extra;
 169
 170   /* Reference count of this attribute. */
 171   unsigned long refcnt;
 172
 173   /* Flag of attribute is set or not. */
 174   uint64_t flag;
 175
 176   /* Apart from in6_addr, the remaining static attributes */
 177   struct in_addr nexthop;
 178   u_int32_t med;
 179   u_int32_t local_pref;
 180   ifindex_t nh_ifindex;
 181
 182   /* Path origin attribute */
 183   u_char origin;
 184
 185   /* has the route-map changed any attribute?
 186      Used on the peer outbound side. */
 187   u_int32_t rmap_change_flags;
 188 };
 189
 190 /* rmap_change_flags definition */
 191 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 192 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 193 #define BATTR_REFLECTED (1 << 2)
 194 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 195 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 196 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 197 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 198
 199 /* Router Reflector related structure. */
 200 struct cluster_list
 201 {
 202   unsigned long refcnt;
 203   int length;
 204   struct in_addr *list;
 205 };
 206
 207 /* Unknown transit attribute. */
 208 struct transit
 209 {
 210   unsigned long refcnt;
 211   int length;
 212   u_char *val;
 213 };
 214
 215 #define ATTR_FLAG_BIT(X)  (1ULL << ((X) - 1))
 216
 217 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 218   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 219    (attr)->extra->cluster->length : 0)
 220
 221 typedef enum {
 222  BGP_ATTR_PARSE_PROCEED = 0,
 223  BGP_ATTR_PARSE_ERROR = -1,
 224  BGP_ATTR_PARSE_WITHDRAW = -2,
 225
 226  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 227  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 228 } bgp_attr_parse_ret_t;
 229
 230 struct bpacket_attr_vec_arr;
 231
 232 /* Prototypes. */
 233 extern void bgp_attr_init (void);
 234 extern void bgp_attr_finish (void);
 235 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 236                                            bgp_size_t, struct bgp_nlri *,
 237                                            struct bgp_nlri *);
 238 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 239 extern void bgp_attr_extra_free (struct attr *);
 240 extern void bgp_attr_dup (struct attr *, struct attr *);
 241 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 242 extern void bgp_attr_deep_free (struct attr *);
 243 extern struct attr *bgp_attr_intern (struct attr *attr);
 244 extern struct attr *bgp_attr_refcount (struct attr *attr);
 245 extern void bgp_attr_unintern_sub (struct attr *);
 246 extern void bgp_attr_unintern (struct attr **);
 247 extern void bgp_attr_flush (struct attr *);
 248 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 249 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 250                                         struct aspath *,
 251                                         struct community *, int as_set, u_char);
 252 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 253                                         struct stream *, struct attr *,
 254                                         struct bpacket_attr_vec_arr *vecarr,
 255                                         struct prefix *, afi_t, safi_t,
 256                                         struct peer *, struct prefix_rd *,
 257                                         u_char *, int, u_int32_t);
 258 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 259                                   struct prefix *);
 260 extern int attrhash_cmp (const void *, const void *);
 261 extern unsigned int attrhash_key_make (void *);
 262 extern void attr_show_all (struct vty *);
 263 extern unsigned long int attr_count (void);
 264 extern unsigned long int attr_unknown_count (void);
 265
 266 /* Cluster list prototypes. */
 267 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 268 extern void cluster_unintern (struct cluster_list *);
 269
 270 /* Transit attribute prototypes. */
 271 void transit_unintern (struct transit *);
 272
 273 /* Below exported for unit-test purposes only */
 274 struct bgp_attr_parser_args {
 275   struct peer *peer;
 276   bgp_size_t length; /* attribute data length; */
 277   bgp_size_t total; /* total length, inc header */
 278   struct attr *attr;
 279   u_int8_t type;
 280   u_int8_t flags;
 281   u_char *startp;
 282 };
 283 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 284                                struct bgp_nlri *);
 285 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 286                                  struct bgp_nlri *);
 287
 288 extern struct bgp_attr_encap_subtlv *
 289 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 290
 291 extern void
 292 bgp_attr_flush_encap(struct attr *attr);
 293
 294 /**
 295  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 296  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 297  * one for each NLRI that needs to be encoded into the UPDATE message, and
 298  * finally the _end() function.
 299  */
 300 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 301                                       afi_t nh_afi,
 302                                       struct bpacket_attr_vec_arr *vecarr,
 303                                       struct attr *attr);
 304 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 305                                      struct prefix *p, struct prefix_rd *prd,
 306                                      u_char *tag, int addpath_encode,
 307                                      u_int32_t addpath_tx_id,
 308                                      struct attr *);
 309 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 310                                             struct prefix *p);
 311 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 312
 313 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 314                                           safi_t safi);
 315 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 316                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 317                              u_char *tag, int, u_int32_t, struct attr *);
 318 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 319
 320 static inline int
 321 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 322 {
 323   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 324            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 325            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 326            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 327            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED) ||
 328            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 329            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 330 }
 331
 332 #endif /* _QUAGGA_BGP_ATTR_H */