1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/*
* BIRD -- The Border Gateway Protocol
*
* (c) 2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_BGP_H_
#define _BIRD_BGP_H_
#include "nest/route.h"
struct linpool;
struct eattr;
struct bgp_config {
struct proto_config c;
u32 local_as, remote_as;
ip_addr remote_ip;
int multihop; /* Number of hops if multihop */
ip_addr multihop_via; /* Multihop: address to route to */
ip_addr source_addr; /* Source address to use */
int next_hop_self; /* Always set next hop to local IP address */
int compare_path_lengths; /* Use path lengths when selecting best route */
u32 default_local_pref; /* Default value for LOCAL_PREF attribute */
u32 default_med; /* Default value for MULTI_EXIT_DISC attribute */
unsigned connect_retry_time;
unsigned hold_time, initial_hold_time;
unsigned keepalive_time;
unsigned start_delay_time; /* Minimum delay between connects */
unsigned error_amnesia_time; /* Errors are forgotten after */
unsigned error_delay_time_min; /* Time to wait after an error is detected */
unsigned error_delay_time_max;
unsigned disable_after_error; /* Disable the protocol when error is detected */
};
struct bgp_conn {
struct bgp_proto *bgp;
struct birdsock *sk;
unsigned int state; /* State of connection state machine */
struct timer *connect_retry_timer;
struct timer *hold_timer;
struct timer *keepalive_timer;
int packets_to_send; /* Bitmap of packet types to be sent */
int notify_code, notify_subcode, notify_size;
byte *notify_data;
int error_flag; /* Error state, ignore all input */
int primary; /* This connection is primary */
u32 advertised_as; /* Temporary value for AS number received */
unsigned hold_time, keepalive_time; /* Times calculated from my and neighbor's requirements */
};
struct bgp_proto {
struct proto p;
struct bgp_config *cf; /* Shortcut to BGP configuration */
u32 local_as, remote_as;
int is_internal; /* Internal BGP connection (local_as == remote_as) */
int as4_support; /* Peer supports 4B AS numbers [RFC4893] */
u32 local_id; /* BGP identifier of this router */
u32 remote_id; /* BGP identifier of the neighbor */
struct bgp_conn *conn; /* Connection we have established */
struct bgp_conn outgoing_conn; /* Outgoing connection we're working with */
struct bgp_conn incoming_conn; /* Incoming connection we have neither accepted nor rejected yet */
struct object_lock *lock; /* Lock for neighbor connection */
ip_addr next_hop; /* Either the peer or multihop_via */
struct neighbor *neigh; /* Neighbor entry corresponding to next_hop */
ip_addr local_addr; /* Address of the local end of the link to next_hop */
struct bgp_bucket **bucket_hash; /* Hash table of attribute buckets */
unsigned int hash_size, hash_count, hash_limit;
struct fib prefix_fib; /* Prefixes to be sent */
list bucket_queue; /* Queue of buckets to send */
struct bgp_bucket *withdraw_bucket; /* Withdrawn routes */
unsigned startup_delay; /* Time to delay protocol startup by due to errors */
bird_clock_t last_connect; /* Time of last connect attempt */
#ifdef IPV6
byte *mp_reach_start, *mp_unreach_start; /* Multiprotocol BGP attribute notes */
unsigned mp_reach_len, mp_unreach_len;
ip_addr local_link; /* Link-level version of local_addr */
#endif
};
struct bgp_prefix {
struct fib_node n; /* Node in prefix fib */
node bucket_node; /* Node in per-bucket list */
};
struct bgp_bucket {
node send_node; /* Node in send queue */
struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */
unsigned hash; /* Hash over extended attributes */
list prefixes; /* Prefixes in this buckets */
ea_list eattrs[0]; /* Per-bucket extended attributes */
};
#define BGP_PORT 179
#define BGP_VERSION 4
#define BGP_HEADER_LENGTH 19
#define BGP_MAX_PACKET_LENGTH 4096
#define BGP_RX_BUFFER_SIZE 4096
#define BGP_TX_BUFFER_SIZE BGP_MAX_PACKET_LENGTH
extern struct linpool *bgp_linpool;
extern int bgp_as4_support;
void bgp_start_timer(struct timer *t, int value);
void bgp_check(struct bgp_config *c);
void bgp_error(struct bgp_conn *c, unsigned code, unsigned subcode, byte *data, int len);
void bgp_close_conn(struct bgp_conn *c);
#ifdef LOCAL_DEBUG
#define BGP_FORCE_DEBUG 1
#else
#define BGP_FORCE_DEBUG 0
#endif
#define BGP_TRACE(flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \
log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
/* attrs.c */
byte *bgp_attach_attr(struct ea_list **to, struct linpool *, unsigned attr, unsigned val);
struct rta *bgp_decode_attrs(struct bgp_conn *conn, byte *a, unsigned int len, struct linpool *pool, int mandatory);
int bgp_get_attr(struct eattr *e, byte *buf);
int bgp_rte_better(struct rte *, struct rte *);
void bgp_rt_notify(struct proto *, struct network *, struct rte *, struct rte *, struct ea_list *);
int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *);
void bgp_attr_init(struct bgp_proto *);
unsigned int bgp_encode_attrs(struct bgp_proto *p, byte *w, ea_list *attrs, int remains);
void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck);
void bgp_get_route_info(struct rte *, byte *buf, struct ea_list *attrs);
/* packets.c */
void bgp_schedule_packet(struct bgp_conn *conn, int type);
void bgp_tx(struct birdsock *sk);
int bgp_rx(struct birdsock *sk, int size);
void bgp_log_error(struct bgp_proto *p, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len);
/* Packet types */
#define PKT_OPEN 0x01
#define PKT_UPDATE 0x02
#define PKT_NOTIFICATION 0x03
#define PKT_KEEPALIVE 0x04
#define PKT_SCHEDULE_CLOSE 0x1f /* Used internally to schedule socket close */
/* Attributes */
#define BAF_OPTIONAL 0x80
#define BAF_TRANSITIVE 0x40
#define BAF_PARTIAL 0x20
#define BAF_EXT_LEN 0x10
#define BA_ORIGIN 0x01 /* [RFC1771] */ /* WM */
#define BA_AS_PATH 0x02 /* WM */
#define BA_NEXT_HOP 0x03 /* WM */
#define BA_MULTI_EXIT_DISC 0x04 /* ON */
#define BA_LOCAL_PREF 0x05 /* WD */
#define BA_ATOMIC_AGGR 0x06 /* WD */
#define BA_AGGREGATOR 0x07 /* OT */
#define BA_COMMUNITY 0x08 /* [RFC1997] */ /* OT */
#define BA_ORIGINATOR_ID 0x09 /* [RFC1966] */ /* ON */
#define BA_CLUSTER_LIST 0x0a /* ON */
/* We don't support these: */
#define BA_DPA 0x0b /* ??? */
#define BA_ADVERTISER 0x0c /* [RFC1863] */
#define BA_RCID_PATH 0x0d
#define BA_MP_REACH_NLRI 0x0e /* [RFC2283] */
#define BA_MP_UNREACH_NLRI 0x0f
#define BA_EXTENDED_COMM 0x10 /* draft-ramachandra-bgp-ext-communities */
#define BA_AS4_PATH 0x11 /* [RFC4893] */
#define BA_AS4_AGGREGATOR 0x12
/* BGP states */
#define BS_IDLE 0
#define BS_CONNECT 1 /* Attempting to connect */
#define BS_ACTIVE 2 /* Waiting for connection retry & listening */
#define BS_OPENSENT 3
#define BS_OPENCONFIRM 4
#define BS_ESTABLISHED 5
/* Well-known communities */
#define BGP_COMM_NO_EXPORT 0xffffff01 /* Don't export outside local AS / confed. */
#define BGP_COMM_NO_ADVERTISE 0xffffff02 /* Don't export at all */
#define BGP_COMM_NO_EXPORT_SUBCONFED 0xffffff03 /* NO_EXPORT even in local confederation */
/* Origins */
#define ORIGIN_IGP 0
#define ORIGIN_EGP 1
#define ORIGIN_INCOMPLETE 2
/* Address families */
#define BGP_AF_IPV6 2
#endif
|
