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 #if ENABLE_BGP_VNC
  67 /*
  68  * old rfp<->rfapi representation
  69  */
  70 struct bgp_tea_options {
  71     struct bgp_tea_options *next;
  72     uint8_t               options_count;
  73     uint16_t              options_length; /* each TLV may be 256 in length */
  74     uint8_t               type;
  75     uint8_t               length;
  76     void                 *value; /* pointer to data */
  77 };
  78
  79 #endif
  80
  81 /* Additional/uncommon BGP attributes.
  82  * lazily allocated as and when a struct attr
  83  * requires it.
  84  */
  85 struct attr_extra
  86 {
  87   /* Multi-Protocol Nexthop, AFI IPv6 */
  88   struct in6_addr mp_nexthop_global;
  89   struct in6_addr mp_nexthop_local;
  90
  91   /* Extended Communities attribute. */
  92   struct ecommunity *ecommunity;
  93
  94   /* Route-Reflector Cluster attribute */
  95   struct cluster_list *cluster;
  96
  97   /* Unknown transitive attribute. */
  98   struct transit *transit;
  99
 100   struct in_addr mp_nexthop_global_in;
 101
 102   /* Aggregator Router ID attribute */
 103   struct in_addr aggregator_addr;
 104
 105   /* Route Reflector Originator attribute */
 106   struct in_addr originator_id;
 107
 108   /* Local weight, not actually an attribute */
 109   u_int32_t weight;
 110
 111   /* Aggregator ASN */
 112   as_t aggregator_as;
 113
 114   /* MP Nexthop length */
 115   u_char mp_nexthop_len;
 116
 117   /* MP Nexthop preference */
 118   u_char mp_nexthop_prefer_global;
 119
 120   /* route tag */
 121   route_tag_t tag;
 122
 123   uint16_t                      encap_tunneltype;       /* grr */
 124   struct bgp_attr_encap_subtlv *encap_subtlvs;          /* rfc5512 */
 125
 126 #if ENABLE_BGP_VNC
 127   struct bgp_attr_encap_subtlv *vnc_subtlvs;            /* VNC-specific */
 128 #endif
 129 };
 130
 131 /* BGP core attribute structure. */
 132 struct attr
 133 {
 134   /* AS Path structure */
 135   struct aspath *aspath;
 136
 137   /* Community structure */
 138   struct community *community;
 139
 140   /* Lazily allocated pointer to extra attributes */
 141   struct attr_extra *extra;
 142
 143   /* Reference count of this attribute. */
 144   unsigned long refcnt;
 145
 146   /* Flag of attribute is set or not. */
 147   u_int32_t flag;
 148
 149   /* Apart from in6_addr, the remaining static attributes */
 150   struct in_addr nexthop;
 151   u_int32_t med;
 152   u_int32_t local_pref;
 153   ifindex_t nh_ifindex;
 154
 155   /* Path origin attribute */
 156   u_char origin;
 157
 158   /* has the route-map changed any attribute?
 159      Used on the peer outbound side. */
 160   u_int32_t rmap_change_flags;
 161 };
 162
 163 /* rmap_change_flags definition */
 164 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 165 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 166 #define BATTR_REFLECTED (1 << 2)
 167 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 168 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 169 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 170 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 171
 172 /* Router Reflector related structure. */
 173 struct cluster_list
 174 {
 175   unsigned long refcnt;
 176   int length;
 177   struct in_addr *list;
 178 };
 179
 180 /* Unknown transit attribute. */
 181 struct transit
 182 {
 183   unsigned long refcnt;
 184   int length;
 185   u_char *val;
 186 };
 187
 188 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 189
 190 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 191   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 192    (attr)->extra->cluster->length : 0)
 193
 194 typedef enum {
 195  BGP_ATTR_PARSE_PROCEED = 0,
 196  BGP_ATTR_PARSE_ERROR = -1,
 197  BGP_ATTR_PARSE_WITHDRAW = -2,
 198
 199  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 200  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 201 } bgp_attr_parse_ret_t;
 202
 203 struct bpacket_attr_vec_arr;
 204
 205 /* Prototypes. */
 206 extern void bgp_attr_init (void);
 207 extern void bgp_attr_finish (void);
 208 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 209                                            bgp_size_t, struct bgp_nlri *,
 210                                            struct bgp_nlri *);
 211 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 212 extern void bgp_attr_extra_free (struct attr *);
 213 extern void bgp_attr_dup (struct attr *, struct attr *);
 214 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 215 extern void bgp_attr_deep_free (struct attr *);
 216 extern struct attr *bgp_attr_intern (struct attr *attr);
 217 extern struct attr *bgp_attr_refcount (struct attr *attr);
 218 extern void bgp_attr_unintern_sub (struct attr *);
 219 extern void bgp_attr_unintern (struct attr **);
 220 extern void bgp_attr_flush (struct attr *);
 221 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 222 extern struct attr *bgp_attr_default_intern (u_char);
 223 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 224                                         struct aspath *,
 225                                         struct community *, int as_set, u_char);
 226 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 227                                         struct stream *, struct attr *,
 228                                         struct bpacket_attr_vec_arr *vecarr,
 229                                         struct prefix *, afi_t, safi_t,
 230                                         struct peer *, struct prefix_rd *,
 231                                         u_char *, int, u_int32_t);
 232 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 233                                   struct prefix *);
 234 extern int attrhash_cmp (const void *, const void *);
 235 extern unsigned int attrhash_key_make (void *);
 236 extern void attr_show_all (struct vty *);
 237 extern unsigned long int attr_count (void);
 238 extern unsigned long int attr_unknown_count (void);
 239
 240 /* Cluster list prototypes. */
 241 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 242 extern void cluster_unintern (struct cluster_list *);
 243
 244 /* Transit attribute prototypes. */
 245 void transit_unintern (struct transit *);
 246
 247 /* Below exported for unit-test purposes only */
 248 struct bgp_attr_parser_args {
 249   struct peer *peer;
 250   bgp_size_t length; /* attribute data length; */
 251   bgp_size_t total; /* total length, inc header */
 252   struct attr *attr;
 253   u_int8_t type;
 254   u_int8_t flags;
 255   u_char *startp;
 256 };
 257 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 258                                struct bgp_nlri *);
 259 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 260                                  struct bgp_nlri *);
 261
 262 extern struct bgp_attr_encap_subtlv *
 263 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 264
 265 extern void
 266 bgp_attr_flush_encap(struct attr *attr);
 267
 268 /**
 269  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 270  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 271  * one for each NLRI that needs to be encoded into the UPDATE message, and
 272  * finally the _end() function.
 273  */
 274 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 275                                       afi_t nh_afi,
 276                                       struct bpacket_attr_vec_arr *vecarr,
 277                                       struct attr *attr);
 278 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 279                                      struct prefix *p, struct prefix_rd *prd,
 280                                      u_char *tag, int addpath_encode,
 281                                      u_int32_t addpath_tx_id);
 282 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 283                                             struct prefix *p);
 284 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 285
 286 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 287                                           safi_t safi);
 288 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 289                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 290                              u_char *tag, int, u_int32_t);
 291 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 292
 293 static inline int
 294 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 295 {
 296   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 297            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 298            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 299            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 300            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED) ||
 301            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 302            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 303 }
 304
 305 #endif /* _QUAGGA_BGP_ATTR_H */