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
  17 along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #ifndef _QUAGGA_BGP_ATTR_H
  22 #define _QUAGGA_BGP_ATTR_H
  23
  24 /* Simple bit mapping. */
  25 #define BITMAP_NBBY 8
  26
  27 #define SET_BITMAP(MAP, NUM) \
  28         SET_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  29
  30 #define CHECK_BITMAP(MAP, NUM) \
  31         CHECK_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  32
  33 #define BGP_MED_MAX UINT32_MAX
  34
  35
  36 /* BGP Attribute type range. */
  37 #define BGP_ATTR_TYPE_RANGE     256
  38 #define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)
  39
  40 /* BGP Attribute flags. */
  41 #define BGP_ATTR_FLAG_OPTIONAL  0x80    /* Attribute is optional. */
  42 #define BGP_ATTR_FLAG_TRANS     0x40    /* Attribute is transitive. */
  43 #define BGP_ATTR_FLAG_PARTIAL   0x20    /* Attribute is partial. */
  44 #define BGP_ATTR_FLAG_EXTLEN    0x10    /* Extended length flag. */
  45
  46 /* BGP attribute header must bigger than 2. */
  47 #define BGP_ATTR_MIN_LEN        3       /* Attribute flag, type length. */
  48 #define BGP_ATTR_DEFAULT_WEIGHT 32768
  49
  50 /* Valid lengths for mp_nexthop_len */
  51 #define BGP_ATTR_NHLEN_IPV4               IPV4_MAX_BYTELEN
  52 #define BGP_ATTR_NHLEN_VPNV4              8+IPV4_MAX_BYTELEN
  53 #define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
  54 #define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
  55 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL       8+IPV6_MAX_BYTELEN
  56 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL ((8+IPV6_MAX_BYTELEN) * 2)
  57
  58
  59 struct bgp_attr_encap_subtlv {
  60     struct bgp_attr_encap_subtlv        *next;          /* for chaining */
  61     uint16_t                            type;
  62     uint16_t                            length;
  63     uint8_t                             value[1];       /* will be extended */
  64 };
  65
  66 /* Additional/uncommon BGP attributes.
  67  * lazily allocated as and when a struct attr
  68  * requires it.
  69  */
  70 struct attr_extra
  71 {
  72   /* Multi-Protocol Nexthop, AFI IPv6 */
  73   struct in6_addr mp_nexthop_global;
  74   struct in6_addr mp_nexthop_local;
  75
  76   /* Extended Communities attribute. */
  77   struct ecommunity *ecommunity;
  78
  79   /* Route-Reflector Cluster attribute */
  80   struct cluster_list *cluster;
  81
  82   /* Unknown transitive attribute. */
  83   struct transit *transit;
  84
  85   struct in_addr mp_nexthop_global_in;
  86
  87   /* Aggregator Router ID attribute */
  88   struct in_addr aggregator_addr;
  89
  90   /* Route Reflector Originator attribute */
  91   struct in_addr originator_id;
  92
  93   /* Local weight, not actually an attribute */
  94   u_int32_t weight;
  95
  96   /* Aggregator ASN */
  97   as_t aggregator_as;
  98
  99   /* MP Nexthop length */
 100   u_char mp_nexthop_len;
 101
 102   /* MP Nexthop preference */
 103   u_char mp_nexthop_prefer_global;
 104
 105   /* route tag */
 106   u_short tag;
 107
 108   uint16_t                      encap_tunneltype;       /* grr */
 109   struct bgp_attr_encap_subtlv *encap_subtlvs;          /* rfc5512 */
 110 };
 111
 112 /* BGP core attribute structure. */
 113 struct attr
 114 {
 115   /* AS Path structure */
 116   struct aspath *aspath;
 117
 118   /* Community structure */
 119   struct community *community;
 120
 121   /* Lazily allocated pointer to extra attributes */
 122   struct attr_extra *extra;
 123
 124   /* Reference count of this attribute. */
 125   unsigned long refcnt;
 126
 127   /* Flag of attribute is set or not. */
 128   u_int32_t flag;
 129
 130   /* Apart from in6_addr, the remaining static attributes */
 131   struct in_addr nexthop;
 132   u_int32_t med;
 133   u_int32_t local_pref;
 134   u_int32_t nh_ifindex;
 135
 136   /* Path origin attribute */
 137   u_char origin;
 138
 139   /* has the route-map changed any attribute?
 140      Used on the peer outbound side. */
 141   u_int32_t rmap_change_flags;
 142 };
 143
 144 /* rmap_change_flags definition */
 145 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 146 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 147 #define BATTR_REFLECTED (1 << 2)
 148 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 149 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 150 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 151
 152 /* Router Reflector related structure. */
 153 struct cluster_list
 154 {
 155   unsigned long refcnt;
 156   int length;
 157   struct in_addr *list;
 158 };
 159
 160 /* Unknown transit attribute. */
 161 struct transit
 162 {
 163   unsigned long refcnt;
 164   int length;
 165   u_char *val;
 166 };
 167
 168 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 169
 170 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 171   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 172    (attr)->extra->cluster->length : 0)
 173
 174 typedef enum {
 175  BGP_ATTR_PARSE_PROCEED = 0,
 176  BGP_ATTR_PARSE_ERROR = -1,
 177  BGP_ATTR_PARSE_WITHDRAW = -2,
 178
 179  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 180  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 181 } bgp_attr_parse_ret_t;
 182
 183 struct bpacket_attr_vec_arr;
 184
 185 /* Prototypes. */
 186 extern void bgp_attr_init (void);
 187 extern void bgp_attr_finish (void);
 188 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 189                                            bgp_size_t, struct bgp_nlri *,
 190                                            struct bgp_nlri *);
 191 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 192 extern void bgp_attr_extra_free (struct attr *);
 193 extern void bgp_attr_dup (struct attr *, struct attr *);
 194 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 195 extern void bgp_attr_deep_free (struct attr *);
 196 extern struct attr *bgp_attr_intern (struct attr *attr);
 197 extern struct attr *bgp_attr_refcount (struct attr *attr);
 198 extern void bgp_attr_unintern_sub (struct attr *);
 199 extern void bgp_attr_unintern (struct attr **);
 200 extern void bgp_attr_flush (struct attr *);
 201 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 202 extern struct attr *bgp_attr_default_intern (u_char);
 203 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 204                                         struct aspath *,
 205                                         struct community *, int as_set, u_char);
 206 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 207                                         struct stream *, struct attr *,
 208                                         struct bpacket_attr_vec_arr *vecarr,
 209                                         struct prefix *, afi_t, safi_t,
 210                                         struct peer *, struct prefix_rd *,
 211                                         u_char *, int, u_int32_t);
 212 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 213                                   struct prefix *);
 214 extern int attrhash_cmp (const void *, const void *);
 215 extern unsigned int attrhash_key_make (void *);
 216 extern void attr_show_all (struct vty *);
 217 extern unsigned long int attr_count (void);
 218 extern unsigned long int attr_unknown_count (void);
 219
 220 /* Cluster list prototypes. */
 221 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 222 extern void cluster_unintern (struct cluster_list *);
 223
 224 /* Transit attribute prototypes. */
 225 void transit_unintern (struct transit *);
 226
 227 /* Below exported for unit-test purposes only */
 228 struct bgp_attr_parser_args {
 229   struct peer *peer;
 230   bgp_size_t length; /* attribute data length; */
 231   bgp_size_t total; /* total length, inc header */
 232   struct attr *attr;
 233   u_int8_t type;
 234   u_int8_t flags;
 235   u_char *startp;
 236 };
 237 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 238                                struct bgp_nlri *);
 239 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 240                                  struct bgp_nlri *);
 241
 242 extern struct bgp_attr_encap_subtlv *
 243 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 244
 245 extern void
 246 bgp_attr_flush_encap(struct attr *attr);
 247
 248 /**
 249  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 250  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 251  * one for each NLRI that needs to be encoded into the UPDATE message, and
 252  * finally the _end() function.
 253  */
 254 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 255                                       afi_t nh_afi,
 256                                       struct bpacket_attr_vec_arr *vecarr,
 257                                       struct attr *attr);
 258 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 259                                      struct prefix *p, struct prefix_rd *prd,
 260                                      u_char *tag, int addpath_encode,
 261                                      u_int32_t addpath_tx_id);
 262 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 263                                             struct prefix *p);
 264 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 265
 266 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 267                                           safi_t safi);
 268 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 269                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 270                              u_char *tag, int, u_int32_t);
 271 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 272
 273 static inline int
 274 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 275 {
 276   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 277            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 278            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 279            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 280            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 281            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 282 }
 283
 284 #endif /* _QUAGGA_BGP_ATTR_H */