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 #include "bgp_attr_evpn.h"
  25
  26 /* Simple bit mapping. */
  27 #define BITMAP_NBBY 8
  28
  29 #define SET_BITMAP(MAP, NUM) \
  30         SET_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  31
  32 #define CHECK_BITMAP(MAP, NUM) \
  33         CHECK_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  34
  35 #define BGP_MED_MAX UINT32_MAX
  36
  37
  38 /* BGP Attribute type range. */
  39 #define BGP_ATTR_TYPE_RANGE     256
  40 #define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)
  41
  42 /* BGP Attribute flags. */
  43 #define BGP_ATTR_FLAG_OPTIONAL  0x80    /* Attribute is optional. */
  44 #define BGP_ATTR_FLAG_TRANS     0x40    /* Attribute is transitive. */
  45 #define BGP_ATTR_FLAG_PARTIAL   0x20    /* Attribute is partial. */
  46 #define BGP_ATTR_FLAG_EXTLEN    0x10    /* Extended length flag. */
  47
  48 /* BGP attribute header must bigger than 2. */
  49 #define BGP_ATTR_MIN_LEN        3       /* Attribute flag, type length. */
  50 #define BGP_ATTR_DEFAULT_WEIGHT 32768
  51
  52 /* Valid lengths for mp_nexthop_len */
  53 #define BGP_ATTR_NHLEN_IPV4               IPV4_MAX_BYTELEN
  54 #define BGP_ATTR_NHLEN_VPNV4              8+IPV4_MAX_BYTELEN
  55 #define BGP_ATTR_NHLEN_IPV6_GLOBAL        IPV6_MAX_BYTELEN
  56 #define BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL (IPV6_MAX_BYTELEN * 2)
  57 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL       8+IPV6_MAX_BYTELEN
  58 #define BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL ((8+IPV6_MAX_BYTELEN) * 2)
  59
  60
  61 struct bgp_attr_encap_subtlv {
  62     struct bgp_attr_encap_subtlv        *next;          /* for chaining */
  63     /* Reference count of this attribute. */
  64     unsigned long refcnt;
  65     uint16_t                            type;
  66     uint16_t                            length;
  67     uint8_t                             value[1];       /* will be extended */
  68 };
  69
  70 #if ENABLE_BGP_VNC
  71 /*
  72  * old rfp<->rfapi representation
  73  */
  74 struct bgp_tea_options {
  75     struct bgp_tea_options *next;
  76     uint8_t               options_count;
  77     uint16_t              options_length; /* each TLV may be 256 in length */
  78     uint8_t               type;
  79     uint8_t               length;
  80     void                 *value; /* pointer to data */
  81 };
  82
  83 #endif
  84
  85 /* Overlay Index Info */
  86 struct overlay_index
  87 {
  88   struct eth_segment_id eth_s_id;
  89   union gw_addr gw_ip;
  90 };
  91
  92 /* Additional/uncommon BGP attributes.
  93  * lazily allocated as and when a struct attr
  94  * requires it.
  95  */
  96 struct attr_extra
  97 {
  98   /* Multi-Protocol Nexthop, AFI IPv6 */
  99   struct in6_addr mp_nexthop_global;
 100   struct in6_addr mp_nexthop_local;
 101
 102   /* Extended Communities attribute. */
 103   struct ecommunity *ecommunity;
 104
 105   /* Large Communities attribute. */
 106   struct lcommunity *lcommunity;
 107
 108   /* Route-Reflector Cluster attribute */
 109   struct cluster_list *cluster;
 110
 111   /* Unknown transitive attribute. */
 112   struct transit *transit;
 113
 114   struct in_addr mp_nexthop_global_in;
 115
 116   /* Aggregator Router ID attribute */
 117   struct in_addr aggregator_addr;
 118
 119   /* Route Reflector Originator attribute */
 120   struct in_addr originator_id;
 121
 122   /* Local weight, not actually an attribute */
 123   u_int32_t weight;
 124
 125   /* Aggregator ASN */
 126   as_t aggregator_as;
 127
 128   /* MP Nexthop length */
 129   u_char mp_nexthop_len;
 130
 131   /* MP Nexthop preference */
 132   u_char mp_nexthop_prefer_global;
 133
 134   /* route tag */
 135   route_tag_t tag;
 136
 137   uint16_t                      encap_tunneltype;       /* grr */
 138   struct bgp_attr_encap_subtlv *encap_subtlvs;          /* rfc5512 */
 139
 140 #if ENABLE_BGP_VNC
 141   struct bgp_attr_encap_subtlv *vnc_subtlvs;            /* VNC-specific */
 142 #endif
 143   /* EVPN */
 144   struct overlay_index evpn_overlay;
 145 };
 146
 147 /* BGP core attribute structure. */
 148 struct attr
 149 {
 150   /* AS Path structure */
 151   struct aspath *aspath;
 152
 153   /* Community structure */
 154   struct community *community;
 155
 156   /* Lazily allocated pointer to extra attributes */
 157   struct attr_extra *extra;
 158
 159   /* Reference count of this attribute. */
 160   unsigned long refcnt;
 161
 162   /* Flag of attribute is set or not. */
 163   u_int32_t flag;
 164
 165   /* Apart from in6_addr, the remaining static attributes */
 166   struct in_addr nexthop;
 167   u_int32_t med;
 168   u_int32_t local_pref;
 169   ifindex_t nh_ifindex;
 170
 171   /* Path origin attribute */
 172   u_char origin;
 173
 174   /* has the route-map changed any attribute?
 175      Used on the peer outbound side. */
 176   u_int32_t rmap_change_flags;
 177 };
 178
 179 /* rmap_change_flags definition */
 180 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 181 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 182 #define BATTR_REFLECTED (1 << 2)
 183 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 184 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 185 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 186 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 187
 188 /* Router Reflector related structure. */
 189 struct cluster_list
 190 {
 191   unsigned long refcnt;
 192   int length;
 193   struct in_addr *list;
 194 };
 195
 196 /* Unknown transit attribute. */
 197 struct transit
 198 {
 199   unsigned long refcnt;
 200   int length;
 201   u_char *val;
 202 };
 203
 204 #define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
 205
 206 #define BGP_CLUSTER_LIST_LENGTH(attr)                           \
 207   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?      \
 208    (attr)->extra->cluster->length : 0)
 209
 210 typedef enum {
 211  BGP_ATTR_PARSE_PROCEED = 0,
 212  BGP_ATTR_PARSE_ERROR = -1,
 213  BGP_ATTR_PARSE_WITHDRAW = -2,
 214
 215  /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
 216  BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 217 } bgp_attr_parse_ret_t;
 218
 219 struct bpacket_attr_vec_arr;
 220
 221 /* Prototypes. */
 222 extern void bgp_attr_init (void);
 223 extern void bgp_attr_finish (void);
 224 extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
 225                                            bgp_size_t, struct bgp_nlri *,
 226                                            struct bgp_nlri *);
 227 extern struct attr_extra *bgp_attr_extra_get (struct attr *);
 228 extern void bgp_attr_extra_free (struct attr *);
 229 extern void bgp_attr_dup (struct attr *, struct attr *);
 230 extern void bgp_attr_deep_dup (struct attr *, struct attr *);
 231 extern void bgp_attr_deep_free (struct attr *);
 232 extern struct attr *bgp_attr_intern (struct attr *attr);
 233 extern struct attr *bgp_attr_refcount (struct attr *attr);
 234 extern void bgp_attr_unintern_sub (struct attr *);
 235 extern void bgp_attr_unintern (struct attr **);
 236 extern void bgp_attr_flush (struct attr *);
 237 extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
 238 extern struct attr *bgp_attr_default_intern (u_char);
 239 extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
 240                                         struct aspath *,
 241                                         struct community *, int as_set, u_char);
 242 extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
 243                                         struct stream *, struct attr *,
 244                                         struct bpacket_attr_vec_arr *vecarr,
 245                                         struct prefix *, afi_t, safi_t,
 246                                         struct peer *, struct prefix_rd *,
 247                                         u_char *, int, u_int32_t);
 248 extern void bgp_dump_routes_attr (struct stream *, struct attr *,
 249                                   struct prefix *);
 250 extern int attrhash_cmp (const void *, const void *);
 251 extern unsigned int attrhash_key_make (void *);
 252 extern void attr_show_all (struct vty *);
 253 extern unsigned long int attr_count (void);
 254 extern unsigned long int attr_unknown_count (void);
 255
 256 /* Cluster list prototypes. */
 257 extern int cluster_loop_check (struct cluster_list *, struct in_addr);
 258 extern void cluster_unintern (struct cluster_list *);
 259
 260 /* Transit attribute prototypes. */
 261 void transit_unintern (struct transit *);
 262
 263 /* Below exported for unit-test purposes only */
 264 struct bgp_attr_parser_args {
 265   struct peer *peer;
 266   bgp_size_t length; /* attribute data length; */
 267   bgp_size_t total; /* total length, inc header */
 268   struct attr *attr;
 269   u_int8_t type;
 270   u_int8_t flags;
 271   u_char *startp;
 272 };
 273 extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
 274                                struct bgp_nlri *);
 275 extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
 276                                  struct bgp_nlri *);
 277
 278 extern struct bgp_attr_encap_subtlv *
 279 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 280
 281 extern void
 282 bgp_attr_flush_encap(struct attr *attr);
 283
 284 /**
 285  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 286  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 287  * one for each NLRI that needs to be encoded into the UPDATE message, and
 288  * finally the _end() function.
 289  */
 290 extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
 291                                       afi_t nh_afi,
 292                                       struct bpacket_attr_vec_arr *vecarr,
 293                                       struct attr *attr);
 294 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 295                                      struct prefix *p, struct prefix_rd *prd,
 296                                      u_char *tag, int addpath_encode,
 297                                      u_int32_t addpath_tx_id,
 298                                      struct attr *);
 299 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 300                                             struct prefix *p);
 301 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 302
 303 extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
 304                                           safi_t safi);
 305 extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
 306                              afi_t afi, safi_t safi, struct prefix_rd *prd,
 307                              u_char *tag, int, u_int32_t, struct attr *);
 308 extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
 309
 310 static inline int
 311 bgp_rmap_nhop_changed(u_int32_t out_rmap_flags, u_int32_t in_rmap_flags)
 312 {
 313   return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS) ||
 314            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED) ||
 315            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED) ||
 316            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED) ||
 317            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED) ||
 318            CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED) ||
 319            CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)) ? 1 : 0);
 320 }
 321
 322 #endif /* _QUAGGA_BGP_ATTR_H */