212 lines
8 KiB
C
212 lines
8 KiB
C
/*
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* BIRD -- The Border Gateway Protocol
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*
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* (c) 2000 Martin Mares <mj@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#ifndef _BIRD_BGP_H_
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#define _BIRD_BGP_H_
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#include "nest/route.h"
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struct linpool;
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struct eattr;
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struct bgp_config {
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struct proto_config c;
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u32 local_as, remote_as;
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ip_addr remote_ip;
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int multihop; /* Number of hops if multihop */
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ip_addr multihop_via; /* Multihop: address to route to */
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ip_addr source_addr; /* Source address to use */
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int next_hop_self; /* Always set next hop to local IP address */
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int compare_path_lengths; /* Use path lengths when selecting best route */
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u32 default_local_pref; /* Default value for LOCAL_PREF attribute */
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u32 default_med; /* Default value for MULTI_EXIT_DISC attribute */
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int enable_as4; /* Enable local support for 4B AS numbers [RFC4893] */
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u32 rr_cluster_id; /* Route reflector cluster ID, if different from local ID */
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int rr_client; /* Whether neighbor is RR client of me */
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unsigned connect_retry_time;
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unsigned hold_time, initial_hold_time;
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unsigned keepalive_time;
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unsigned start_delay_time; /* Minimum delay between connects */
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unsigned error_amnesia_time; /* Errors are forgotten after */
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unsigned error_delay_time_min; /* Time to wait after an error is detected */
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unsigned error_delay_time_max;
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unsigned disable_after_error; /* Disable the protocol when error is detected */
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char *password; /* Password used for MD5 authentication */
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};
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struct bgp_conn {
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struct bgp_proto *bgp;
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struct birdsock *sk;
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unsigned int state; /* State of connection state machine */
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struct timer *connect_retry_timer;
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struct timer *hold_timer;
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struct timer *keepalive_timer;
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int packets_to_send; /* Bitmap of packet types to be sent */
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int notify_code, notify_subcode, notify_size;
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byte *notify_data;
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int error_flag; /* Error state, ignore all input */
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int primary; /* This connection is primary */
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u32 advertised_as; /* Temporary value for AS number received */
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unsigned hold_time, keepalive_time; /* Times calculated from my and neighbor's requirements */
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};
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struct bgp_proto {
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struct proto p;
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struct bgp_config *cf; /* Shortcut to BGP configuration */
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u32 local_as, remote_as;
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int is_internal; /* Internal BGP connection (local_as == remote_as) */
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int as4_support; /* Peer supports 4B AS numbers [RFC4893] */
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int as4_session; /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
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u32 local_id; /* BGP identifier of this router */
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u32 remote_id; /* BGP identifier of the neighbor */
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u32 rr_cluster_id; /* Route reflector cluster ID */
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int rr_client; /* Whether neighbor is RR client of me */
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struct bgp_conn *conn; /* Connection we have established */
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struct bgp_conn outgoing_conn; /* Outgoing connection we're working with */
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struct bgp_conn incoming_conn; /* Incoming connection we have neither accepted nor rejected yet */
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struct object_lock *lock; /* Lock for neighbor connection */
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ip_addr next_hop; /* Either the peer or multihop_via */
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struct neighbor *neigh; /* Neighbor entry corresponding to next_hop */
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ip_addr local_addr; /* Address of the local end of the link to next_hop */
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struct bgp_bucket **bucket_hash; /* Hash table of attribute buckets */
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unsigned int hash_size, hash_count, hash_limit;
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struct fib prefix_fib; /* Prefixes to be sent */
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list bucket_queue; /* Queue of buckets to send */
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struct bgp_bucket *withdraw_bucket; /* Withdrawn routes */
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unsigned startup_delay; /* Time to delay protocol startup by due to errors */
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bird_clock_t last_connect; /* Time of last connect attempt */
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#ifdef IPV6
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byte *mp_reach_start, *mp_unreach_start; /* Multiprotocol BGP attribute notes */
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unsigned mp_reach_len, mp_unreach_len;
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ip_addr local_link; /* Link-level version of local_addr */
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#endif
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};
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struct bgp_prefix {
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struct fib_node n; /* Node in prefix fib */
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node bucket_node; /* Node in per-bucket list */
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};
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struct bgp_bucket {
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node send_node; /* Node in send queue */
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struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */
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unsigned hash; /* Hash over extended attributes */
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list prefixes; /* Prefixes in this buckets */
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ea_list eattrs[0]; /* Per-bucket extended attributes */
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};
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#define BGP_PORT 179
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#define BGP_VERSION 4
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#define BGP_HEADER_LENGTH 19
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#define BGP_MAX_PACKET_LENGTH 4096
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#define BGP_RX_BUFFER_SIZE 4096
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#define BGP_TX_BUFFER_SIZE BGP_MAX_PACKET_LENGTH
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extern struct linpool *bgp_linpool;
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extern int bgp_as4_support;
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void bgp_start_timer(struct timer *t, int value);
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void bgp_check(struct bgp_config *c);
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void bgp_error(struct bgp_conn *c, unsigned code, unsigned subcode, byte *data, int len);
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void bgp_close_conn(struct bgp_conn *c);
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#ifdef LOCAL_DEBUG
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#define BGP_FORCE_DEBUG 1
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#else
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#define BGP_FORCE_DEBUG 0
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#endif
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#define BGP_TRACE(flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \
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log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
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/* attrs.c */
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void bgp_attach_attr(struct ea_list **to, struct linpool *pool, unsigned attr, uintptr_t val);
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byte *bgp_attach_attr_wa(struct ea_list **to, struct linpool *pool, unsigned attr, unsigned len);
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struct rta *bgp_decode_attrs(struct bgp_conn *conn, byte *a, unsigned int len, struct linpool *pool, int mandatory);
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int bgp_get_attr(struct eattr *e, byte *buf);
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int bgp_rte_better(struct rte *, struct rte *);
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void bgp_rt_notify(struct proto *, struct network *, struct rte *, struct rte *, struct ea_list *);
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int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *);
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void bgp_attr_init(struct bgp_proto *);
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unsigned int bgp_encode_attrs(struct bgp_proto *p, byte *w, ea_list *attrs, int remains);
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void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck);
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void bgp_get_route_info(struct rte *, byte *buf, struct ea_list *attrs);
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inline static void bgp_attach_attr_ip(struct ea_list **to, struct linpool *pool, unsigned attr, ip_addr a)
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{ *(ip_addr *) bgp_attach_attr_wa(to, pool, attr, sizeof(ip_addr)) = a; }
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/* packets.c */
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void bgp_schedule_packet(struct bgp_conn *conn, int type);
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void bgp_tx(struct birdsock *sk);
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int bgp_rx(struct birdsock *sk, int size);
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void bgp_log_error(struct bgp_proto *p, char *msg, unsigned code, unsigned subcode, byte *data, unsigned len);
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/* Packet types */
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#define PKT_OPEN 0x01
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#define PKT_UPDATE 0x02
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#define PKT_NOTIFICATION 0x03
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#define PKT_KEEPALIVE 0x04
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#define PKT_SCHEDULE_CLOSE 0x1f /* Used internally to schedule socket close */
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/* Attributes */
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#define BAF_OPTIONAL 0x80
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#define BAF_TRANSITIVE 0x40
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#define BAF_PARTIAL 0x20
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#define BAF_EXT_LEN 0x10
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#define BA_ORIGIN 0x01 /* [RFC1771] */ /* WM */
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#define BA_AS_PATH 0x02 /* WM */
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#define BA_NEXT_HOP 0x03 /* WM */
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#define BA_MULTI_EXIT_DISC 0x04 /* ON */
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#define BA_LOCAL_PREF 0x05 /* WD */
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#define BA_ATOMIC_AGGR 0x06 /* WD */
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#define BA_AGGREGATOR 0x07 /* OT */
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#define BA_COMMUNITY 0x08 /* [RFC1997] */ /* OT */
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#define BA_ORIGINATOR_ID 0x09 /* [RFC1966] */ /* ON */
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#define BA_CLUSTER_LIST 0x0a /* ON */
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/* We don't support these: */
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#define BA_DPA 0x0b /* ??? */
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#define BA_ADVERTISER 0x0c /* [RFC1863] */
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#define BA_RCID_PATH 0x0d
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#define BA_MP_REACH_NLRI 0x0e /* [RFC2283] */
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#define BA_MP_UNREACH_NLRI 0x0f
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#define BA_EXTENDED_COMM 0x10 /* draft-ramachandra-bgp-ext-communities */
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#define BA_AS4_PATH 0x11 /* [RFC4893] */
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#define BA_AS4_AGGREGATOR 0x12
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/* BGP states */
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#define BS_IDLE 0
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#define BS_CONNECT 1 /* Attempting to connect */
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#define BS_ACTIVE 2 /* Waiting for connection retry & listening */
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#define BS_OPENSENT 3
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#define BS_OPENCONFIRM 4
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#define BS_ESTABLISHED 5
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/* Well-known communities */
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#define BGP_COMM_NO_EXPORT 0xffffff01 /* Don't export outside local AS / confed. */
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#define BGP_COMM_NO_ADVERTISE 0xffffff02 /* Don't export at all */
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#define BGP_COMM_NO_EXPORT_SUBCONFED 0xffffff03 /* NO_EXPORT even in local confederation */
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/* Origins */
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#define ORIGIN_IGP 0
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#define ORIGIN_EGP 1
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#define ORIGIN_INCOMPLETE 2
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/* Address families */
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#define BGP_AF_IPV6 2
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#endif
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