1/* BGP attributes.
2   Copyright (C) 1996, 97, 98 Kunihiro Ishiguro
3
4This file is part of GNU Zebra.
5
6GNU Zebra is free software; you can redistribute it and/or modify it
7under the terms of the GNU General Public License as published by the
8Free Software Foundation; either version 2, or (at your option) any
9later version.
10
11GNU Zebra is distributed in the hope that it will be useful, but
12WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU Zebra; see the file COPYING.  If not, write to the Free
18Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
1902111-1307, 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/* Additional/uncommon BGP attributes.
51 * lazily allocated as and when a struct attr
52 * requires it.
53 */
54struct attr_extra
55{
56  /* Multi-Protocol Nexthop, AFI IPv6 */
57#ifdef HAVE_IPV6
58  struct in6_addr mp_nexthop_global;
59  struct in6_addr mp_nexthop_local;
60#endif /* HAVE_IPV6 */
61
62  /* Extended Communities attribute. */
63  struct ecommunity *ecommunity;
64
65  /* Route-Reflector Cluster attribute */
66  struct cluster_list *cluster;
67
68  /* Unknown transitive attribute. */
69  struct transit *transit;
70
71  struct in_addr mp_nexthop_global_in;
72  struct in_addr mp_nexthop_local_in;
73
74  /* Aggregator Router ID attribute */
75  struct in_addr aggregator_addr;
76
77  /* Route Reflector Originator attribute */
78  struct in_addr originator_id;
79
80  /* Local weight, not actually an attribute */
81  u_int32_t weight;
82
83  /* Aggregator ASN */
84  as_t aggregator_as;
85
86  /* MP Nexthop length */
87  u_char mp_nexthop_len;
88};
89
90/* BGP core attribute structure. */
91struct attr
92{
93  /* AS Path structure */
94  struct aspath *aspath;
95
96  /* Community structure */
97  struct community *community;
98
99  /* Lazily allocated pointer to extra attributes */
100  struct attr_extra *extra;
101
102  /* Reference count of this attribute. */
103  unsigned long refcnt;
104
105  /* Flag of attribute is set or not. */
106  u_int32_t flag;
107
108  /* Apart from in6_addr, the remaining static attributes */
109  struct in_addr nexthop;
110  u_int32_t med;
111  u_int32_t local_pref;
112
113  /* Path origin attribute */
114  u_char origin;
115};
116
117/* Router Reflector related structure. */
118struct cluster_list
119{
120  unsigned long refcnt;
121  int length;
122  struct in_addr *list;
123};
124
125/* Unknown transit attribute. */
126struct transit
127{
128  unsigned long refcnt;
129  int length;
130  u_char *val;
131};
132
133#define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
134
135typedef enum {
136 BGP_ATTR_PARSE_PROCEED = 0,
137 BGP_ATTR_PARSE_ERROR = -1,
138 BGP_ATTR_PARSE_WITHDRAW = -2,
139
140 /* only used internally, send notify + convert to BGP_ATTR_PARSE_ERROR */
141 BGP_ATTR_PARSE_ERROR_NOTIFYPLS = -3,
142} bgp_attr_parse_ret_t;
143
144/* Prototypes. */
145extern void bgp_attr_init (void);
146extern void bgp_attr_finish (void);
147extern bgp_attr_parse_ret_t bgp_attr_parse (struct peer *, struct attr *,
148                                           bgp_size_t, struct bgp_nlri *,
149                                           struct bgp_nlri *);
150extern struct attr_extra *bgp_attr_extra_get (struct attr *);
151extern void bgp_attr_extra_free (struct attr *);
152extern void bgp_attr_dup (struct attr *, struct attr *);
153extern struct attr *bgp_attr_intern (struct attr *attr);
154extern void bgp_attr_unintern_sub (struct attr *);
155extern void bgp_attr_unintern (struct attr **);
156extern void bgp_attr_flush (struct attr *);
157extern struct attr *bgp_attr_default_set (struct attr *attr, u_char);
158extern struct attr *bgp_attr_default_intern (u_char);
159extern struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char,
160                                        struct aspath *,
161                                        struct community *, int as_set);
162extern bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *,
163					struct stream *, struct attr *,
164					struct prefix *, afi_t, safi_t,
165					struct peer *, struct prefix_rd *,
166					u_char *);
167extern void bgp_dump_routes_attr (struct stream *, struct attr *,
168				  struct prefix *);
169extern int attrhash_cmp (const void *, const void *);
170extern unsigned int attrhash_key_make (void *);
171extern void attr_show_all (struct vty *);
172extern unsigned long int attr_count (void);
173extern unsigned long int attr_unknown_count (void);
174
175/* Cluster list prototypes. */
176extern int cluster_loop_check (struct cluster_list *, struct in_addr);
177extern void cluster_unintern (struct cluster_list *);
178
179/* Transit attribute prototypes. */
180void transit_unintern (struct transit *);
181
182/* Below exported for unit-test purposes only */
183struct bgp_attr_parser_args {
184  struct peer *peer;
185  bgp_size_t length; /* attribute data length; */
186  bgp_size_t total; /* total length, inc header */
187  struct attr *attr;
188  u_int8_t type;
189  u_int8_t flags;
190  u_char *startp;
191};
192extern int bgp_mp_reach_parse (struct bgp_attr_parser_args *args,
193			       struct bgp_nlri *);
194extern int bgp_mp_unreach_parse (struct bgp_attr_parser_args *args,
195                                 struct bgp_nlri *);
196
197/**
198 * Set of functions to encode MP_REACH_NLRI and MP_UNREACH_NLRI attributes.
199 * Typical call sequence is to call _start(), followed by multiple _prefix(),
200 * one for each NLRI that needs to be encoded into the UPDATE message, and
201 * finally the _end() function.
202 */
203extern size_t bgp_packet_mpattr_start(struct stream *s, afi_t afi, safi_t safi,
204				      struct attr *attr);
205extern void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
206				     struct prefix *p, struct prefix_rd *prd,
207				     u_char *tag);
208extern void bgp_packet_mpattr_end(struct stream *s, size_t sizep);
209
210extern size_t bgp_packet_mpunreach_start (struct stream *s, afi_t afi,
211					  safi_t safi);
212extern void bgp_packet_mpunreach_prefix (struct stream *s, struct prefix *p,
213			     afi_t afi, safi_t safi, struct prefix_rd *prd,
214			     u_char *tag);
215extern void bgp_packet_mpunreach_end (struct stream *s, size_t attrlen_pnt);
216
217#endif /* _QUAGGA_BGP_ATTR_H */
218