void
bgp_conn_enter_established_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
BGP_TRACE(D_EVENTS, "BGP session established");
DBG("BGP: UP!!!\n");
/* For multi-hop BGP sessions */
if (ipa_zero(p->source_addr))
p->source_addr = conn->sk->saddr;
p->conn = conn;
p->last_error_class = 0;
p->last_error_code = 0;
bgp_init_bucket_table(p);
bgp_init_prefix_table(p, 8);
int peer_gr_ready = conn->peer_gr_aware && !(conn->peer_gr_flags & BGP_GRF_RESTART);
if (p->p.gr_recovery && !peer_gr_ready)
proto_graceful_restart_unlock(&p->p);
if (p->p.gr_recovery && (p->cf->gr_mode == BGP_GR_ABLE) && peer_gr_ready)
p->p.gr_wait = 1;
if (p->gr_active)
tm_stop(p->gr_timer);
if (p->gr_active && (!conn->peer_gr_able || !(conn->peer_gr_aflags & BGP_GRF_FORWARDING)))
bgp_graceful_restart_done(p);
bgp_conn_set_state(conn, BS_ESTABLISHED);
proto_notify_state(&p->p, PS_UP);
}
static void
bgp_send_open(struct bgp_conn *conn)
{
conn->start_state = conn->bgp->start_state;
// Default values, possibly changed by receiving capabilities.
conn->advertised_as = 0;
conn->peer_refresh_support = 0;
conn->peer_as4_support = 0;
conn->peer_add_path = 0;
conn->peer_enhanced_refresh_support = 0;
conn->peer_gr_aware = 0;
conn->peer_gr_able = 0;
conn->peer_gr_time = 0;
conn->peer_gr_flags = 0;
conn->peer_gr_aflags = 0;
conn->peer_ext_messages_support = 0;
DBG("BGP: Sending open\n");
conn->sk->rx_hook = bgp_rx;
conn->sk->tx_hook = bgp_tx;
tm_stop(conn->connect_retry_timer);
bgp_schedule_packet(conn, PKT_OPEN);
bgp_conn_set_state(conn, BS_OPENSENT);
bgp_start_timer(conn->hold_timer, conn->bgp->cf->initial_hold_time);
}
static void
bgp_active(struct bgp_proto *p)
{
int delay = MAX(1, p->cf->start_delay_time);
struct bgp_conn *conn = &p->outgoing_conn;
BGP_TRACE(D_EVENTS, "Connect delayed by %d seconds", delay);
bgp_setup_conn(p, conn);
bgp_conn_set_state(conn, BS_ACTIVE);
bgp_start_timer(conn->connect_retry_timer, delay);
}
void
bgp_conn_enter_idle_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
int os = conn->state;
bgp_close_conn(conn);
bgp_conn_set_state(conn, BS_IDLE);
ev_schedule(p->event);
if (os == BS_ESTABLISHED)
bgp_conn_leave_established_state(p);
}
void
bgp_conn_enter_close_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
int os = conn->state;
bgp_conn_set_state(conn, BS_CLOSE);
tm_stop(conn->hold_timer);
tm_stop(conn->keepalive_timer);
conn->sk->rx_hook = NULL;
if (os == BS_ESTABLISHED)
bgp_conn_leave_established_state(p);
}
static void
bgp_send_open(struct bgp_conn *conn)
{
conn->start_state = conn->bgp->start_state;
conn->want_as4_support = conn->bgp->cf->enable_as4 && (conn->start_state != BSS_CONNECT_NOCAP);
conn->peer_as4_support = 0; // Default value, possibly changed by receiving capability.
conn->advertised_as = 0;
DBG("BGP: Sending open\n");
conn->sk->rx_hook = bgp_rx;
conn->sk->tx_hook = bgp_tx;
tm_stop(conn->connect_retry_timer);
bgp_schedule_packet(conn, PKT_OPEN);
bgp_conn_set_state(conn, BS_OPENSENT);
bgp_start_timer(conn->hold_timer, conn->bgp->cf->initial_hold_time);
}
void
bgp_conn_enter_close_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
int os = conn->state;
bgp_conn_set_state(conn, BS_CLOSE);
tm_stop(conn->keepalive_timer);
conn->sk->rx_hook = NULL;
/* Timeout for CLOSE state, if we cannot send notification soon then we just hangup */
bgp_start_timer(conn->hold_timer, 10);
if (os == BS_ESTABLISHED)
bgp_conn_leave_established_state(p);
}
/**
* bgp_connect - initiate an outgoing connection
* @p: BGP instance
*
* The bgp_connect() function creates a new &bgp_conn and initiates
* a TCP connection to the peer. The rest of connection setup is governed
* by the BGP state machine as described in the standard.
*/
static void
bgp_connect(struct bgp_proto *p) /* Enter Connect state and start establishing connection */
{
sock *s;
struct bgp_conn *conn = &p->outgoing_conn;
int hops = p->cf->multihop ? : 1;
DBG("BGP: Connecting\n");
s = sk_new(p->p.pool);
s->type = SK_TCP_ACTIVE;
s->saddr = p->source_addr;
s->daddr = p->cf->remote_ip;
s->iface = p->neigh ? p->neigh->iface : NULL;
s->dport = BGP_PORT;
s->ttl = p->cf->ttl_security ? 255 : hops;
s->rbsize = BGP_RX_BUFFER_SIZE;
s->tbsize = BGP_TX_BUFFER_SIZE;
s->tos = IP_PREC_INTERNET_CONTROL;
s->password = p->cf->password;
s->tx_hook = bgp_connected;
BGP_TRACE(D_EVENTS, "Connecting to %I%J from local address %I%J", s->daddr, p->cf->iface,
s->saddr, ipa_has_link_scope(s->saddr) ? s->iface : NULL);
bgp_setup_conn(p, conn);
bgp_setup_sk(conn, s);
bgp_conn_set_state(conn, BS_CONNECT);
if (sk_open(s) < 0)
{
bgp_sock_err(s, 0);
return;
}
/* Set minimal receive TTL if needed */
if (p->cf->ttl_security)
{
DBG("Setting minimum received TTL to %d", 256 - hops);
if (sk_set_min_ttl(s, 256 - hops) < 0)
{
log(L_ERR "TTL security configuration failed, closing session");
bgp_sock_err(s, 0);
return;
}
}
DBG("BGP: Waiting for connect success\n");
bgp_start_timer(conn->connect_retry_timer, p->cf->connect_retry_time);
}
void
bgp_conn_enter_established_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
BGP_TRACE(D_EVENTS, "BGP session established");
DBG("BGP: UP!!!\n");
/* For multi-hop BGP sessions */
if (ipa_zero(p->source_addr))
p->source_addr = conn->sk->saddr;
p->conn = conn;
p->last_error_class = 0;
p->last_error_code = 0;
bgp_attr_init(conn->bgp);
bgp_conn_set_state(conn, BS_ESTABLISHED);
proto_notify_state(&p->p, PS_UP);
}
/**
* bgp_connect - initiate an outgoing connection
* @p: BGP instance
*
* The bgp_connect() function creates a new &bgp_conn and initiates
* a TCP connection to the peer. The rest of connection setup is governed
* by the BGP state machine as described in the standard.
*/
static void
bgp_connect(struct bgp_proto *p) /* Enter Connect state and start establishing connection */
{
sock *s;
struct bgp_conn *conn = &p->outgoing_conn;
int hops = p->cf->multihop ? : 1;
DBG("BGP: Connecting\n");
s = sk_new(p->p.pool);
s->type = SK_TCP_ACTIVE;
s->saddr = p->source_addr;
s->daddr = p->cf->remote_ip;
s->dport = p->cf->remote_port;
s->iface = p->neigh ? p->neigh->iface : NULL;
s->ttl = p->cf->ttl_security ? 255 : hops;
s->rbsize = p->cf->enable_extended_messages ? BGP_RX_BUFFER_EXT_SIZE : BGP_RX_BUFFER_SIZE;
s->tbsize = p->cf->enable_extended_messages ? BGP_TX_BUFFER_EXT_SIZE : BGP_TX_BUFFER_SIZE;
s->tos = IP_PREC_INTERNET_CONTROL;
s->password = p->cf->password;
s->tx_hook = bgp_connected;
BGP_TRACE(D_EVENTS, "Connecting to %I%J from local address %I%J", s->daddr, p->cf->iface,
s->saddr, ipa_is_link_local(s->saddr) ? s->iface : NULL);
bgp_setup_conn(p, conn);
bgp_setup_sk(conn, s);
bgp_conn_set_state(conn, BS_CONNECT);
if (sk_open(s) < 0)
goto err;
/* Set minimal receive TTL if needed */
if (p->cf->ttl_security)
if (sk_set_min_ttl(s, 256 - hops) < 0)
goto err;
DBG("BGP: Waiting for connect success\n");
bgp_start_timer(conn->connect_retry_timer, p->cf->connect_retry_time);
return;
err:
sk_log_error(s, p->p.name);
bgp_sock_err(s, 0);
return;
}
void
bgp_conn_enter_established_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
BGP_TRACE(D_EVENTS, "BGP session established");
DBG("BGP: UP!!!\n");
/* For multi-hop BGP sessions */
if (ipa_zero(p->source_addr))
p->source_addr = conn->sk->saddr;
p->conn = conn;
p->last_error_class = 0;
p->last_error_code = 0;
p->feed_state = BFS_NONE;
p->load_state = BFS_NONE;
bgp_init_bucket_table(p);
bgp_init_prefix_table(p, 8);
int peer_gr_ready = conn->peer_gr_aware && !(conn->peer_gr_flags & BGP_GRF_RESTART);
if (p->p.gr_recovery && !peer_gr_ready)
proto_graceful_restart_unlock(&p->p);
if (p->p.gr_recovery && (p->cf->gr_mode == BGP_GR_ABLE) && peer_gr_ready)
p->p.gr_wait = 1;
if (p->gr_active)
tm_stop(p->gr_timer);
if (p->gr_active && (!conn->peer_gr_able || !(conn->peer_gr_aflags & BGP_GRF_FORWARDING)))
bgp_graceful_restart_done(p);
/* GR capability implies that neighbor will send End-of-RIB */
if (conn->peer_gr_aware)
p->load_state = BFS_LOADING;
/* proto_notify_state() will likely call bgp_feed_begin(), setting p->feed_state */
bgp_conn_set_state(conn, BS_ESTABLISHED);
proto_notify_state(&p->p, PS_UP);
}
void
bgp_conn_enter_openconfirm_state(struct bgp_conn *conn)
{
/* Really, most of the work is done in bgp_rx_open(). */
bgp_conn_set_state(conn, BS_OPENCONFIRM);
}