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 along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _QUAGGA_BGP_ATTR_H
  22 #define _QUAGGA_BGP_ATTR_H
  23
  24 #include "mpls.h"
  25 #include "bgp_attr_evpn.h"
  26
  27 /* Simple bit mapping. */
  28 #define BITMAP_NBBY 8
  29
  30 #define SET_BITMAP(MAP, NUM)                                                   \
  31         SET_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  32
  33 #define CHECK_BITMAP(MAP, NUM)                                                 \
  34         CHECK_FLAG(MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))
  35
  36 #define BGP_MED_MAX UINT32_MAX
  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 /* Prefix SID types */
  61 #define BGP_PREFIX_SID_LABEL_INDEX     1
  62 #define BGP_PREFIX_SID_IPV6            2
  63 #define BGP_PREFIX_SID_ORIGINATOR_SRGB 3
  64
  65 #define BGP_PREFIX_SID_LABEL_INDEX_LENGTH      7
  66 #define BGP_PREFIX_SID_IPV6_LENGTH            19
  67 #define BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH  6
  68
  69 struct bgp_attr_encap_subtlv {
  70         struct bgp_attr_encap_subtlv *next; /* for chaining */
  71         /* Reference count of this attribute. */
  72         unsigned long refcnt;
  73         uint16_t type;
  74         uint16_t length;
  75         uint8_t value[0]; /* will be extended */
  76 };
  77
  78 #if ENABLE_BGP_VNC
  79 /*
  80  * old rfp<->rfapi representation
  81  */
  82 struct bgp_tea_options {
  83         struct bgp_tea_options *next;
  84         uint8_t options_count;
  85         uint16_t options_length; /* each TLV may be 256 in length */
  86         uint8_t type;
  87         uint8_t length;
  88         void *value; /* pointer to data */
  89 };
  90
  91 #endif
  92
  93 /* Overlay Index Info */
  94 struct overlay_index {
  95         struct eth_segment_id eth_s_id;
  96         union gw_addr gw_ip;
  97 };
  98
  99 /* BGP core attribute structure. */
 100 struct attr {
 101         /* AS Path structure */
 102         struct aspath *aspath;
 103
 104         /* Community structure */
 105         struct community *community;
 106
 107         /* Reference count of this attribute. */
 108         unsigned long refcnt;
 109
 110         /* Flag of attribute is set or not. */
 111         uint64_t flag;
 112
 113         /* Apart from in6_addr, the remaining static attributes */
 114         struct in_addr nexthop;
 115         u_int32_t med;
 116         u_int32_t local_pref;
 117         ifindex_t nh_ifindex;
 118
 119         /* Path origin attribute */
 120         u_char origin;
 121
 122         /* has the route-map changed any attribute?
 123            Used on the peer outbound side. */
 124         u_int32_t rmap_change_flags;
 125
 126         /* Multi-Protocol Nexthop, AFI IPv6 */
 127         struct in6_addr mp_nexthop_global;
 128         struct in6_addr mp_nexthop_local;
 129
 130         /* Extended Communities attribute. */
 131         struct ecommunity *ecommunity;
 132
 133         /* Large Communities attribute. */
 134         struct lcommunity *lcommunity;
 135
 136         /* Route-Reflector Cluster attribute */
 137         struct cluster_list *cluster;
 138
 139         /* Unknown transitive attribute. */
 140         struct transit *transit;
 141
 142         struct in_addr mp_nexthop_global_in;
 143
 144         /* Aggregator Router ID attribute */
 145         struct in_addr aggregator_addr;
 146
 147         /* Route Reflector Originator attribute */
 148         struct in_addr originator_id;
 149
 150         /* Local weight, not actually an attribute */
 151         u_int32_t weight;
 152
 153         /* Aggregator ASN */
 154         as_t aggregator_as;
 155
 156         /* MP Nexthop length */
 157         u_char mp_nexthop_len;
 158
 159         /* MP Nexthop preference */
 160         u_char mp_nexthop_prefer_global;
 161
 162         /* Static MAC for EVPN */
 163         u_char sticky;
 164
 165         /* route tag */
 166         route_tag_t tag;
 167
 168         /* Label index */
 169         u_int32_t label_index;
 170
 171         /* MPLS label */
 172         mpls_label_t label;
 173
 174         uint16_t encap_tunneltype;                   /* grr */
 175         struct bgp_attr_encap_subtlv *encap_subtlvs; /* rfc5512 */
 176
 177 #if ENABLE_BGP_VNC
 178         struct bgp_attr_encap_subtlv *vnc_subtlvs; /* VNC-specific */
 179 #endif
 180         /* EVPN */
 181         struct overlay_index evpn_overlay;
 182
 183         /* EVPN MAC Mobility sequence number, if any. */
 184         u_int32_t mm_seqnum;
 185 };
 186
 187 /* rmap_change_flags definition */
 188 #define BATTR_RMAP_IPV4_NHOP_CHANGED (1 << 0)
 189 #define BATTR_RMAP_NEXTHOP_PEER_ADDRESS (1 << 1)
 190 #define BATTR_REFLECTED (1 << 2)
 191 #define BATTR_RMAP_NEXTHOP_UNCHANGED (1 << 3)
 192 #define BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED (1 << 4)
 193 #define BATTR_RMAP_IPV6_LL_NHOP_CHANGED (1 << 5)
 194 #define BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED (1 << 6)
 195
 196 /* Router Reflector related structure. */
 197 struct cluster_list {
 198         unsigned long refcnt;
 199         int length;
 200         struct in_addr *list;
 201 };
 202
 203 /* Unknown transit attribute. */
 204 struct transit {
 205         unsigned long refcnt;
 206         int length;
 207         u_char *val;
 208 };
 209
 210 /* "(void) 0" will generate a compiler error.  this is a safety check to
 211  * ensure we're not using a value that exceeds the bit size of attr->flag. */
 212 #define ATTR_FLAG_BIT(X) \
 213         __builtin_choose_expr((X) >= 1 && (X) <= 64, \
 214                               1ULL << ((X) - 1), \
 215                               (void) 0)
 216
 217 #define BGP_CLUSTER_LIST_LENGTH(attr)                                          \
 218         (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST))                 \
 219                  ? (attr)->cluster->length                                     \
 220                  : 0)
 221
 222 typedef enum {
 223         BGP_ATTR_PARSE_PROCEED = 0,
 224         BGP_ATTR_PARSE_ERROR = -1,
 225         BGP_ATTR_PARSE_WITHDRAW = -2,
 226
 227         /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR
 228            */
 229         BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
 230         BGP_ATTR_PARSE_EOR = -4,
 231 } bgp_attr_parse_ret_t;
 232
 233 struct bpacket_attr_vec_arr;
 234
 235 /* Prototypes. */
 236 extern void bgp_attr_init(void);
 237 extern void bgp_attr_finish(void);
 238 extern bgp_attr_parse_ret_t bgp_attr_parse(struct peer *, struct attr *,
 239                                            bgp_size_t, struct bgp_nlri *,
 240                                            struct bgp_nlri *);
 241 extern void bgp_attr_dup(struct attr *, struct attr *);
 242 extern void bgp_attr_undup(struct attr *new, struct attr *old);
 243 extern struct attr *bgp_attr_intern(struct attr *attr);
 244 extern void bgp_attr_unintern_sub(struct attr *);
 245 extern void bgp_attr_unintern(struct attr **);
 246 extern void bgp_attr_flush(struct attr *);
 247 extern struct attr *bgp_attr_default_set(struct attr *attr, u_char);
 248 extern struct attr *bgp_attr_aggregate_intern(struct bgp *, u_char,
 249                                               struct aspath *,
 250                                               struct community *, int as_set,
 251                                               u_char);
 252 extern bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *,
 253                                        struct stream *, struct attr *,
 254                                        struct bpacket_attr_vec_arr *vecarr,
 255                                        struct prefix *, afi_t, safi_t,
 256                                        struct peer *, struct prefix_rd *,
 257                                        mpls_label_t *, int, u_int32_t);
 258 extern void bgp_dump_routes_attr(struct stream *, struct attr *,
 259                                  struct prefix *);
 260 extern int attrhash_cmp(const void *, const void *);
 261 extern unsigned int attrhash_key_make(void *);
 262 extern void attr_show_all(struct vty *);
 263 extern unsigned long int attr_count(void);
 264 extern unsigned long int attr_unknown_count(void);
 265
 266 /* Cluster list prototypes. */
 267 extern int cluster_loop_check(struct cluster_list *, struct in_addr);
 268 extern void cluster_unintern(struct cluster_list *);
 269
 270 /* Transit attribute prototypes. */
 271 void transit_unintern(struct transit *);
 272
 273 /* Below exported for unit-test purposes only */
 274 struct bgp_attr_parser_args {
 275         struct peer *peer;
 276         bgp_size_t length; /* attribute data length; */
 277         bgp_size_t total;  /* total length, inc header */
 278         struct attr *attr;
 279         u_int8_t type;
 280         u_int8_t flags;
 281         u_char *startp;
 282 };
 283 extern int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 284                               struct bgp_nlri *);
 285 extern int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
 286                                 struct bgp_nlri *);
 287
 288 extern struct bgp_attr_encap_subtlv *
 289 encap_tlv_dup(struct bgp_attr_encap_subtlv *orig);
 290
 291 extern void bgp_attr_flush_encap(struct attr *attr);
 292
 293 /**
 294  * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
 295  * Typical call sequence is to call _start(), followed by multiple _prefix(),
 296  * one for each NLRI that needs to be encoded into the UPDATE message, and
 297  * finally the _end() function.
 298  */
 299 extern size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer,
 300                                       afi_t afi, safi_t safi,
 301                                       struct bpacket_attr_vec_arr *vecarr,
 302                                       struct attr *attr);
 303 extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
 304                                      struct prefix *p, struct prefix_rd *prd,
 305                                      mpls_label_t *label, int addpath_encode,
 306                                      u_int32_t addpath_tx_id, struct attr *);
 307 extern size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi,
 308                                             struct prefix *p);
 309 extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
 310
 311 extern size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi,
 312                                          safi_t safi);
 313 extern void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p,
 314                                         afi_t afi, safi_t safi,
 315                                         struct prefix_rd *prd, mpls_label_t *,
 316                                         int, u_int32_t, struct attr *);
 317 extern void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt);
 318
 319 static inline int bgp_rmap_nhop_changed(u_int32_t out_rmap_flags,
 320                                         u_int32_t in_rmap_flags)
 321 {
 322         return ((CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_PEER_ADDRESS)
 323                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED)
 324                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV4_NHOP_CHANGED)
 325                  || CHECK_FLAG(out_rmap_flags,
 326                                BATTR_RMAP_IPV6_GLOBAL_NHOP_CHANGED)
 327                  || CHECK_FLAG(out_rmap_flags,
 328                                BATTR_RMAP_IPV6_PREFER_GLOBAL_CHANGED)
 329                  || CHECK_FLAG(out_rmap_flags, BATTR_RMAP_IPV6_LL_NHOP_CHANGED)
 330                  || CHECK_FLAG(in_rmap_flags, BATTR_RMAP_NEXTHOP_UNCHANGED))
 331                         ? 1
 332                         : 0);
 333 }
 334
 335 static inline u_int32_t mac_mobility_seqnum(struct attr *attr)
 336 {
 337         return (attr) ? attr->mm_seqnum : 0;
 338 }
 339
 340 #endif /* _QUAGGA_BGP_ATTR_H */