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/*
* 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 */
int capabilities; /* Enable capability handshake [RFC3392] */
int enable_as4; /* Enable local support for 4B AS numbers [RFC4893] */
u32 rr_cluster_id; /* Route reflector cluster ID, if different from local ID */
int rr_client; /* Whether neighbor is RR client of me */
int rs_client; /* Whether neighbor is RS client of me */
int advertise_ipv4; /* Whether we should add IPv4 capability advertisement to OPEN message */
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 */
char *password; /* Password used for MD5 authentication */
};
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;
struct event *tx_ev;
int packets_to_send; /* Bitmap of packet types to be sent */
int notify_code, notify_subcode, notify_size;
byte *notify_data;
u32 advertised_as; /* Temporary value for AS number received */
int start_state; /* protocol start_state snapshot when connection established */
int want_as4_support; /* Connection tries to establish AS4 session */
int peer_as4_support; /* Peer supports 4B AS numbers [RFC4893] */
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 start_state; /* Substates that partitions BS_START */
int is_internal; /* Internal BGP connection (local_as == remote_as) */
int as4_session; /* Session uses 4B AS numbers in AS_PATH (both sides support it) */
u32 local_id; /* BGP identifier of this router */
u32 remote_id; /* BGP identifier of the neighbor */
u32 rr_cluster_id; /* Route reflector cluster ID */
int rr_client; /* Whether neighbor is RR client of me */
int rs_client; /* Whether neighbor is RS client of me */
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 event *event; /* Event for respawning and shutting process */
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_proto_error; /* Time of last error that leads to protocol stop */
u8 last_error_class; /* Error class of last error */
u32 last_error_code; /* Error code of last error. BGP protocol errors
are encoded as (bgp_err_code << 16 | bgp_err_subcode) */
#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);
void bgp_update_startup_delay(struct bgp_proto *p, struct bgp_conn *conn, unsigned code, unsigned subcode);
void bgp_conn_enter_established_state(struct bgp_conn *conn);
void bgp_conn_enter_close_state(struct bgp_conn *conn);
void bgp_conn_enter_idle_state(struct bgp_conn *conn);
void bgp_store_error(struct bgp_proto *p, struct bgp_conn *c, u8 class, u32 code);
#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)
#define BGP_TRACE_RL(rl, flags, msg, args...) do { if ((p->p.debug & flags) || BGP_FORCE_DEBUG) \
log_rl(rl, L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
/* attrs.c */
void bgp_attach_attr(struct ea_list **to, struct linpool *pool, unsigned attr, uintptr_t val);
byte *bgp_attach_attr_wa(struct ea_list **to, struct linpool *pool, unsigned attr, unsigned len);
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 buflen);
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);
inline static void bgp_attach_attr_ip(struct ea_list **to, struct linpool *pool, unsigned attr, ip_addr a)
{ *(ip_addr *) bgp_attach_attr_wa(to, pool, attr, sizeof(ip_addr)) = a; }
/* packets.c */
void bgp_schedule_packet(struct bgp_conn *conn, int type);
void bgp_kick_tx(void *vconn);
void bgp_tx(struct birdsock *sk);
int bgp_rx(struct birdsock *sk, int size);
const byte * bgp_error_dsc(byte *buff, unsigned code, unsigned subcode);
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 connection 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
#define BS_CLOSE 6 /* Used during transition to BS_IDLE */
/* BGP start states
*
* Used in PS_START for fine-grained specification of starting state.
*
* When BGP protocol is started by core, it goes to BSS_PREPARE. When BGP protocol
* done what is neccessary to start itself (like acquiring the lock), it goes to BSS_CONNECT.
* When some connection attempt failed because of option or capability error, it goes to
* BSS_CONNECT_NOCAP.
*/
#define BSS_PREPARE 0 /* Used before ordinary BGP started, i. e. waiting for lock */
#define BSS_CONNECT 1 /* Ordinary BGP connecting */
#define BSS_CONNECT_NOCAP 2 /* Legacy BGP connecting (without capabilities) */
/* Error classes */
#define BE_NONE 0
#define BE_MISC 1 /* Miscellaneous error */
#define BE_SOCKET 2 /* Socket error */
#define BE_BGP_RX 3 /* BGP protocol error notification received */
#define BE_BGP_TX 4 /* BGP protocol error notification sent */
#define BE_AUTO_DOWN 5 /* Automatic shutdown */
#define BE_MAN_DOWN 6 /* Manual shutdown */
/* Misc error codes */
#define BEM_NEIGHBOR_LOST 1
#define BEM_INVALID_NEXT_HOP 2
#define BEM_INVALID_MD5 3 /* MD5 authentication kernel request failed (possibly not supported */
/* 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_IPV4 1
#define BGP_AF_IPV6 2
#endif
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