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     /* Reference count of this attribute. */
  62     unsigned long refcnt;
  63     uint16_t                            type;
  64     uint16_t                            length;
  65     uint8_t                             value[1];       /* will be extended */
  66 };
  67
  68 #if ENABLE_BGP_VNC
  69 /*
  70  * old rfp<->rfapi representation
  71  */
  72 struct bgp_tea_options {
  73     struct bgp_tea_options *next;
  74     uint8_t               options_count;
  75     uint16_t              options_length; /* each TLV may be 256 in length */
  76     uint8_t               type;
  77     uint8_t               length;
  78     void                 *value; /* pointer to data */
  79 };
  80
  81 #endif
  82
  83 /* Additional/uncommon BGP attributes.
  84  * lazily allocated as and when a struct attr
  85  * requires it.
  86  */
  87 struct attr_extra
  88 {
  89   /* Multi-Protocol Nexthop, AFI IPv6 */
  90   struct in6_addr mp_nexthop_global;
  91   struct in6_addr mp_nexthop_local;
  92
  93   /* Extended Communities attribute. */
  94   struct ecommunity *ecommunity;
  95
  96   /* Large Communities attribute. */
  97   struct lcommunity *lcommunity;
  98
  99   /* Route-Reflector Cluster attribute */
 100   struct cluster_list *cluster;
 101
 102   /* Unknown transitive attribute. */
 103   struct transit *transit;
 104
 105   struct in_addr mp_nexthop_global_in;
 106
 107   /* Aggregator Router ID attribute */
 108   struct in_addr aggregator_addr;
 109
 110   /* Route Reflector Originator attribute */
 111   struct in_addr originator_id;
 112
 113   /* Local weight, not actually an attribute */
 114   u_int32_t weight;
 115
 116   /* Aggregator ASN */
 117   as_t aggregator_as;
 118
 119   /* MP Nexthop length */
 120   u_char mp_nexthop_len;
 121
 122   /* MP Nexthop preference */
 123   u_char mp_nexthop_prefer_global;
 124
 125   /* route tag */
 126   route_tag_t tag;
 127
 128   uint16_t                      encap_tunneltype;       /* grr */
 129   struct bgp_attr_encap_subtlv *encap_subtlvs;          /* rfc5512 */
 130
 131 #if ENABLE_BGP_VNC
 132   struct bgp_attr_encap_subtlv *vnc_subtlvs;            /* VNC-specific */
 133 #endif
 134 };
 135
 136 /* BGP core attribute structure. */
 137 struct attr
 138 {
 139   /* AS Path structure */
 140   struct aspath *aspath;
 141
 142   /* Community structure */
 143   struct community *community;
 144
 145   /* Lazily allocated pointer to extra attributes */
 146   struct attr_extra *extra;
 147
 148   /* Reference count of this attribute. */
 149   unsigned long refcnt;
 150
 151   /* Flag of attribute is set or not. */
 152   u_int32_t flag;
 153
 154   /* Apart from in6_addr, the remaining static attributes */
 155   struct in_addr nexthop;
 156   u_int32_t med;
 157   u_int32_t local_pref;
 158   ifindex_t nh_ifindex;
 159
 160   /* Path origin attribute */
 161   u_char origin;
 162
 163   /* has the route-map changed any attribute?
 164      Used on the peer outbound side. */
 165   u_int32_t rmap_change_flags;
 166 };
 167
 168 /* rmap_change_flags definition */
 169 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 170 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 171 #define BATTR_REFLECTED (1 << 2)
 172 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 173 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 174 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 175 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 176
 177 /* Router Reflector related structure. */
 178 struct cluster_list
 179 {
 180   unsigned long refcnt;
 181   int length;
 182   struct in_addr *list;
 183 };
 184
 185 /* Unknown transit attribute. */
 186 struct transit
 187 {
 188   unsigned long refcnt;
 189   int length;
 190   u_char *val;
 191 };
 192
 193 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 194
 195 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 196   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 197    (attr)->extra->cluster->length : 0)
 198
 199 typedef enum {
 200  BGP_ATTR_PARSE_PROCEED = 0,
 201  BGP_ATTR_PARSE_ERROR = -1,
 202  BGP_ATTR_PARSE_WITHDRAW = -2,
 203
 204  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 205  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 206 } bgp_attr_parse_ret_t;
 207
 208 struct bpacket_attr_vec_arr;
 209
 210 /* Prototypes. */
 211 extern void bgp_attr_init (void);
 212 extern void bgp_attr_finish (void);
 213 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 214                                            bgp_size_t, struct bgp_nlri *,
 215                                            struct bgp_nlri *);
 216 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 217 extern void bgp_attr_extra_free (struct attr *);
 218 extern void bgp_attr_dup (struct attr *, struct attr *);
 219 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 220 extern void bgp_attr_deep_free (struct attr *);
 221 extern struct attr *bgp_attr_intern (struct attr *attr);
 222 extern struct attr *bgp_attr_refcount (struct attr *attr);
 223 extern void bgp_attr_unintern_sub (struct attr *);
 224 extern void bgp_attr_unintern (struct attr **);
 225 extern void bgp_attr_flush (struct attr *);
 226 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 227 extern struct attr *bgp_attr_default_intern (u_char);
 228 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 229                                         struct aspath *,
 230                                         struct community *, int as_set, u_char);
 231 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 232                                         struct stream *, struct attr *,
 233                                         struct bpacket_attr_vec_arr *vecarr,
 234                                         struct prefix *, afi_t, safi_t,
 235                                         struct peer *, struct prefix_rd *,
 236                                         u_char *, int, u_int32_t);
 237 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 238                                   struct prefix *);
 239 extern int attrhash_cmp (const void *, const void *);
 240 extern unsigned int attrhash_key_make (void *);
 241 extern void attr_show_all (struct vty *);
 242 extern unsigned long int attr_count (void);
 243 extern unsigned long int attr_unknown_count (void);
 244
 245 /* Cluster list prototypes. */
 246 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 247 extern void cluster_unintern (struct cluster_list *);
 248
 249 /* Transit attribute prototypes. */
 250 void transit_unintern (struct transit *);
 251
 252 /* Below exported for unit-test purposes only */
 253 struct bgp_attr_parser_args {
 254   struct peer *peer;
 255   bgp_size_t length; /* attribute data length; */
 256   bgp_size_t total; /* total length, inc header */
 257   struct attr *attr;
 258   u_int8_t type;
 259   u_int8_t flags;
 260   u_char *startp;
 261 };
 262 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 263                                struct bgp_nlri *);
 264 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 265                                  struct bgp_nlri *);
 266
 267 extern struct bgp_attr_encap_subtlv *
 268 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 269
 270 extern void
 271 bgp_attr_flush_encap(struct attr *attr);
 272
 273 /**
 274  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 275  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 276  * one for each NLRI that needs to be encoded into the UPDATE message, and
 277  * finally the _end() function.
 278  */
 279 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 280                                       afi_t nh_afi,
 281                                       struct bpacket_attr_vec_arr *vecarr,
 282                                       struct attr *attr);
 283 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 284                                      struct prefix *p, struct prefix_rd *prd,
 285                                      u_char *tag, int addpath_encode,
 286                                      u_int32_t addpath_tx_id);
 287 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 288                                             struct prefix *p);
 289 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 290
 291 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 292                                           safi_t safi);
 293 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 294                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 295                              u_char *tag, int, u_int32_t);
 296 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 297
 298 static inline int
 299 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 300 {
 301   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 302            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 303            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 304            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 305            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED) ||
 306            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 307            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 308 }
 309
 310 #endif /* _QUAGGA_BGP_ATTR_H */