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 /* Additional/uncommon BGP attributes.
  51  * lazily allocated as and when a struct attr
  52  * requires it.
  53  */
  54 struct attr_extra
  55 {
  56   /* Multi-Protocol Nexthop, AFI IPv6 */
  57 #ifdef HAVE_IPV6
  58   struct in6_addr mp_nexthop_global;
  59   struct in6_addr mp_nexthop_local;
  60 #endif /* HAVE_IPV6 */
  61
  62   /* Extended Communities attribute. */
  63   struct ecommunity *ecommunity;
  64
  65   /* Route-Reflector Cluster attribute */
  66   struct cluster_list *cluster;
  67
  68   /* Unknown transitive attribute. */
  69   struct transit *transit;
  70
  71   struct in_addr mp_nexthop_global_in;
  72   struct in_addr mp_nexthop_local_in;
  73
  74   /* Aggregator Router ID attribute */
  75   struct in_addr aggregator_addr;
  76
  77   /* Route Reflector Originator attribute */
  78   struct in_addr originator_id;
  79
  80   /* Local weight, not actually an attribute */
  81   u_int32_t weight;
  82
  83   /* Aggregator ASN */
  84   as_t aggregator_as;
  85
  86   /* MP Nexthop length */
  87   u_char mp_nexthop_len;
  88
  89   /* route tag */
  90   u_short tag;
  91 };
  92
  93 /* BGP core attribute structure. */
  94 struct attr
  95 {
  96   /* AS Path structure */
  97   struct aspath *aspath;
  98
  99   /* Community structure */
 100   struct community *community;
 101
 102   /* Lazily allocated pointer to extra attributes */
 103   struct attr_extra *extra;
 104
 105   /* Reference count of this attribute. */
 106   unsigned long refcnt;
 107
 108   /* Flag of attribute is set or not. */
 109   u_int32_t flag;
 110
 111   /* Apart from in6_addr, the remaining static attributes */
 112   struct in_addr nexthop;
 113   u_int32_t med;
 114   u_int32_t local_pref;
 115   u_int32_t nh_ifindex;
 116
 117   /* Path origin attribute */
 118   u_char origin;
 119
 120   /* has the route-map changed any attribute?
 121      Used on the peer outbound side. */
 122   u_int32_t rmap_change_flags;
 123 };
 124
 125 /* rmap_change_flags definition */
 126 #define BATTR_RMAP_NEXTHOP_CHANGED (1 << 0)
 127 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 128 #define BATTR_REFLECTED (1 << 2)
 129
 130 /* Router Reflector related structure. */
 131 struct cluster_list
 132 {
 133   unsigned long refcnt;
 134   int length;
 135   struct in_addr *list;
 136 };
 137
 138 /* Unknown transit attribute. */
 139 struct transit
 140 {
 141   unsigned long refcnt;
 142   int length;
 143   u_char *val;
 144 };
 145
 146 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 147
 148 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 149   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 150    (attr)->extra->cluster->length : 0)
 151
 152 typedef enum {
 153  BGP_ATTR_PARSE_PROCEED = 0,
 154  BGP_ATTR_PARSE_ERROR = -1,
 155  BGP_ATTR_PARSE_WITHDRAW = -2,
 156
 157  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 158  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 159 } bgp_attr_parse_ret_t;
 160
 161 struct bpacket_attr_vec_arr;
 162
 163 /* Prototypes. */
 164 extern void bgp_attr_init (void);
 165 extern void bgp_attr_finish (void);
 166 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 167                                            bgp_size_t, struct bgp_nlri *,
 168                                            struct bgp_nlri *);
 169 extern int bgp_attr_check (struct peer *, struct attr *);
 170 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 171 extern void bgp_attr_extra_free (struct attr *);
 172 extern void bgp_attr_dup (struct attr *, struct attr *);
 173 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 174 extern void bgp_attr_deep_free (struct attr *);
 175 extern struct attr *bgp_attr_intern (struct attr *attr);
 176 extern struct attr *bgp_attr_refcount (struct attr *attr);
 177 extern void bgp_attr_unintern_sub (struct attr *);
 178 extern void bgp_attr_unintern (struct attr **);
 179 extern void bgp_attr_flush (struct attr *);
 180 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 181 extern struct attr *bgp_attr_default_intern (u_char);
 182 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 183                                         struct aspath *,
 184                                         struct community *, int as_set, u_char);
 185 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 186                                         struct stream *, struct attr *,
 187                                         struct bpacket_attr_vec_arr *vecarr,
 188                                         struct prefix *, afi_t, safi_t,
 189                                         struct peer *, struct prefix_rd *,
 190                                         u_char *);
 191 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 192                                   struct prefix *);
 193 extern int attrhash_cmp (const void *, const void *);
 194 extern unsigned int attrhash_key_make (void *);
 195 extern void attr_show_all (struct vty *);
 196 extern unsigned long int attr_count (void);
 197 extern unsigned long int attr_unknown_count (void);
 198
 199 /* Cluster list prototypes. */
 200 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 201 extern void cluster_unintern (struct cluster_list *);
 202
 203 /* Transit attribute prototypes. */
 204 void transit_unintern (struct transit *);
 205
 206 /* Below exported for unit-test purposes only */
 207 struct bgp_attr_parser_args {
 208   struct peer *peer;
 209   bgp_size_t length; /* attribute data length; */
 210   bgp_size_t total; /* total length, inc header */
 211   struct attr *attr;
 212   u_int8_t type;
 213   u_int8_t flags;
 214   u_char *startp;
 215 };
 216 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 217                                struct bgp_nlri *);
 218 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 219                                  struct bgp_nlri *);
 220
 221 /**
 222  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 223  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 224  * one for each NLRI that needs to be encoded into the UPDATE message, and
 225  * finally the _end() function.
 226  */
 227 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 228                                       struct bpacket_attr_vec_arr *vecarr,
 229                                       struct attr *attr);
 230 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 231                                      struct prefix *p, struct prefix_rd *prd,
 232                                      u_char *tag);
 233 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 234
 235 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 236                                           safi_t safi);
 237 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 238                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 239                              u_char *tag);
 240 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 241
 242 #endif /* _QUAGGA_BGP_ATTR_H */