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              12
  53 #define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
  54 #define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
  55
  56 /* Additional/uncommon BGP attributes.
  57  * lazily allocated as and when a struct attr
  58  * requires it.
  59  */
  60 struct attr_extra
  61 {
  62   /* Multi-Protocol Nexthop, AFI IPv6 */
  63 #ifdef HAVE_IPV6
  64   struct in6_addr mp_nexthop_global;
  65   struct in6_addr mp_nexthop_local;
  66 #endif /* HAVE_IPV6 */
  67
  68   /* Extended Communities attribute. */
  69   struct ecommunity *ecommunity;
  70
  71   /* Route-Reflector Cluster attribute */
  72   struct cluster_list *cluster;
  73
  74   /* Unknown transitive attribute. */
  75   struct transit *transit;
  76
  77   struct in_addr mp_nexthop_global_in;
  78   struct in_addr mp_nexthop_local_in;
  79
  80   /* Aggregator Router ID attribute */
  81   struct in_addr aggregator_addr;
  82
  83   /* Route Reflector Originator attribute */
  84   struct in_addr originator_id;
  85
  86   /* Local weight, not actually an attribute */
  87   u_int32_t weight;
  88
  89   /* Aggregator ASN */
  90   as_t aggregator_as;
  91
  92   /* MP Nexthop length */
  93   u_char mp_nexthop_len;
  94
  95   /* route tag */
  96   u_short tag;
  97 };
  98
  99 /* BGP core attribute structure. */
 100 struct attr
 101 {
 102   /* AS Path structure */
 103   struct aspath *aspath;
 104
 105   /* Community structure */
 106   struct community *community;
 107
 108   /* Lazily allocated pointer to extra attributes */
 109   struct attr_extra *extra;
 110
 111   /* Reference count of this attribute. */
 112   unsigned long refcnt;
 113
 114   /* Flag of attribute is set or not. */
 115   u_int32_t flag;
 116
 117   /* Apart from in6_addr, the remaining static attributes */
 118   struct in_addr nexthop;
 119   u_int32_t med;
 120   u_int32_t local_pref;
 121   u_int32_t nh_ifindex;
 122
 123   /* Path origin attribute */
 124   u_char origin;
 125
 126   /* has the route-map changed any attribute?
 127      Used on the peer outbound side. */
 128   u_int32_t rmap_change_flags;
 129 };
 130
 131 /* rmap_change_flags definition */
 132 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 133 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 134 #define BATTR_REFLECTED (1 << 2)
 135 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 136 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 137 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 138
 139 /* Router Reflector related structure. */
 140 struct cluster_list
 141 {
 142   unsigned long refcnt;
 143   int length;
 144   struct in_addr *list;
 145 };
 146
 147 /* Unknown transit attribute. */
 148 struct transit
 149 {
 150   unsigned long refcnt;
 151   int length;
 152   u_char *val;
 153 };
 154
 155 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 156
 157 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 158   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 159    (attr)->extra->cluster->length : 0)
 160
 161 typedef enum {
 162  BGP_ATTR_PARSE_PROCEED = 0,
 163  BGP_ATTR_PARSE_ERROR = -1,
 164  BGP_ATTR_PARSE_WITHDRAW = -2,
 165
 166  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 167  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 168 } bgp_attr_parse_ret_t;
 169
 170 struct bpacket_attr_vec_arr;
 171
 172 /* Prototypes. */
 173 extern void bgp_attr_init (void);
 174 extern void bgp_attr_finish (void);
 175 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 176                                            bgp_size_t, struct bgp_nlri *,
 177                                            struct bgp_nlri *);
 178 extern int bgp_attr_check (struct peer *, struct attr *, bgp_size_t);
 179 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 180 extern void bgp_attr_extra_free (struct attr *);
 181 extern void bgp_attr_dup (struct attr *, struct attr *);
 182 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 183 extern void bgp_attr_deep_free (struct attr *);
 184 extern struct attr *bgp_attr_intern (struct attr *attr);
 185 extern struct attr *bgp_attr_refcount (struct attr *attr);
 186 extern void bgp_attr_unintern_sub (struct attr *);
 187 extern void bgp_attr_unintern (struct attr **);
 188 extern void bgp_attr_flush (struct attr *);
 189 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 190 extern struct attr *bgp_attr_default_intern (u_char);
 191 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 192                                         struct aspath *,
 193                                         struct community *, int as_set, u_char);
 194 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 195                                         struct stream *, struct attr *,
 196                                         struct bpacket_attr_vec_arr *vecarr,
 197                                         struct prefix *, afi_t, safi_t,
 198                                         struct peer *, struct prefix_rd *,
 199                                         u_char *, int, u_int32_t);
 200 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 201                                   struct prefix *);
 202 extern int attrhash_cmp (const void *, const void *);
 203 extern unsigned int attrhash_key_make (void *);
 204 extern void attr_show_all (struct vty *);
 205 extern unsigned long int attr_count (void);
 206 extern unsigned long int attr_unknown_count (void);
 207
 208 /* Cluster list prototypes. */
 209 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 210 extern void cluster_unintern (struct cluster_list *);
 211
 212 /* Transit attribute prototypes. */
 213 void transit_unintern (struct transit *);
 214
 215 /* Below exported for unit-test purposes only */
 216 struct bgp_attr_parser_args {
 217   struct peer *peer;
 218   bgp_size_t length; /* attribute data length; */
 219   bgp_size_t total; /* total length, inc header */
 220   struct attr *attr;
 221   u_int8_t type;
 222   u_int8_t flags;
 223   u_char *startp;
 224 };
 225 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 226                                struct bgp_nlri *);
 227 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 228                                  struct bgp_nlri *);
 229
 230 /**
 231  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 232  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 233  * one for each NLRI that needs to be encoded into the UPDATE message, and
 234  * finally the _end() function.
 235  */
 236 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 237                                       afi_t nh_afi,
 238                                       struct bpacket_attr_vec_arr *vecarr,
 239                                       struct attr *attr);
 240 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 241                                      struct prefix *p, struct prefix_rd *prd,
 242                                      u_char *tag, int addpath_encode,
 243                                      u_int32_t addpath_tx_id);
 244 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 245
 246 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 247                                           safi_t safi);
 248 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 249                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 250                              u_char *tag, int, u_int32_t);
 251 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 252
 253 static inline int
 254 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 255 {
 256   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 257            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 258            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 259            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 260            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 261            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 262 }
 263
 264 #endif /* _QUAGGA_BGP_ATTR_H */