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bird/proto/bgp/bgp.c
Maria Matejka dd1f1c46cc Channel: configurable feed block size
2023-05-07 23:04:47 +02:00

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/*
* BIRD -- The Border Gateway Protocol
*
* (c) 2000 Martin Mares <mj@ucw.cz>
* (c) 2008--2016 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2008--2016 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Border Gateway Protocol
*
* The BGP protocol is implemented in three parts: |bgp.c| which takes care of
* the connection and most of the interface with BIRD core, |packets.c| handling
* both incoming and outgoing BGP packets and |attrs.c| containing functions for
* manipulation with BGP attribute lists.
*
* As opposed to the other existing routing daemons, BIRD has a sophisticated
* core architecture which is able to keep all the information needed by BGP in
* the primary routing table, therefore no complex data structures like a
* central BGP table are needed. This increases memory footprint of a BGP router
* with many connections, but not too much and, which is more important, it
* makes BGP much easier to implement.
*
* Each instance of BGP (corresponding to a single BGP peer) is described by a
* &bgp_proto structure to which are attached individual connections represented
* by &bgp_connection (usually, there exists only one connection, but during BGP
* session setup, there can be more of them). The connections are handled
* according to the BGP state machine defined in the RFC with all the timers and
* all the parameters configurable.
*
* In incoming direction, we listen on the connection's socket and each time we
* receive some input, we pass it to bgp_rx(). It decodes packet headers and the
* markers and passes complete packets to bgp_rx_packet() which distributes the
* packet according to its type.
*
* In outgoing direction, we gather all the routing updates and sort them to
* buckets (&bgp_bucket) according to their attributes (we keep a hash table for
* fast comparison of &rta's and a &fib which helps us to find if we already
* have another route for the same destination queued for sending, so that we
* can replace it with the new one immediately instead of sending both
* updates). There also exists a special bucket holding all the route
* withdrawals which cannot be queued anywhere else as they don't have any
* attributes. If we have any packet to send (due to either new routes or the
* connection tracking code wanting to send a Open, Keepalive or Notification
* message), we call bgp_schedule_packet() which sets the corresponding bit in a
* @packet_to_send bit field in &bgp_conn and as soon as the transmit socket
* buffer becomes empty, we call bgp_fire_tx(). It inspects state of all the
* packet type bits and calls the corresponding bgp_create_xx() functions,
* eventually rescheduling the same packet type if we have more data of the same
* type to send.
*
* The processing of attributes consists of two functions: bgp_decode_attrs()
* for checking of the attribute blocks and translating them to the language of
* BIRD's extended attributes and bgp_encode_attrs() which does the
* converse. Both functions are built around a @bgp_attr_table array describing
* all important characteristics of all known attributes. Unknown transitive
* attributes are attached to the route as %EAF_TYPE_OPAQUE byte streams.
*
* BGP protocol implements graceful restart in both restarting (local restart)
* and receiving (neighbor restart) roles. The first is handled mostly by the
* graceful restart code in the nest, BGP protocol just handles capabilities,
* sets @gr_wait and locks graceful restart until end-of-RIB mark is received.
* The second is implemented by internal restart of the BGP state to %BS_IDLE
* and protocol state to %PS_START, but keeping the protocol up from the core
* point of view and therefore maintaining received routes. Routing table
* refresh cycle (rt_refresh_begin(), rt_refresh_end()) is used for removing
* stale routes after reestablishment of BGP session during graceful restart.
*
* Supported standards:
* RFC 4271 - Border Gateway Protocol 4 (BGP)
* RFC 1997 - BGP Communities Attribute
* RFC 2385 - Protection of BGP Sessions via TCP MD5 Signature
* RFC 2545 - Use of BGP Multiprotocol Extensions for IPv6
* RFC 2918 - Route Refresh Capability
* RFC 3107 - Carrying Label Information in BGP
* RFC 4360 - BGP Extended Communities Attribute
* RFC 4364 - BGP/MPLS IPv4 Virtual Private Networks
* RFC 4456 - BGP Route Reflection
* RFC 4486 - Subcodes for BGP Cease Notification Message
* RFC 4659 - BGP/MPLS IPv6 Virtual Private Networks
* RFC 4724 - Graceful Restart Mechanism for BGP
* RFC 4760 - Multiprotocol extensions for BGP
* RFC 4798 - Connecting IPv6 Islands over IPv4 MPLS
* RFC 5065 - AS confederations for BGP
* RFC 5082 - Generalized TTL Security Mechanism
* RFC 5492 - Capabilities Advertisement with BGP
* RFC 5549 - Advertising IPv4 NLRI with an IPv6 Next Hop
* RFC 5575 - Dissemination of Flow Specification Rules
* RFC 5668 - 4-Octet AS Specific BGP Extended Community
* RFC 6286 - AS-Wide Unique BGP Identifier
* RFC 6608 - Subcodes for BGP Finite State Machine Error
* RFC 6793 - BGP Support for 4-Octet AS Numbers
* RFC 7311 - Accumulated IGP Metric Attribute for BGP
* RFC 7313 - Enhanced Route Refresh Capability for BGP
* RFC 7606 - Revised Error Handling for BGP UPDATE Messages
* RFC 7911 - Advertisement of Multiple Paths in BGP
* RFC 7947 - Internet Exchange BGP Route Server
* RFC 8092 - BGP Large Communities Attribute
* RFC 8203 - BGP Administrative Shutdown Communication
* RFC 8212 - Default EBGP Route Propagation Behavior without Policies
* RFC 8654 - Extended Message Support for BGP
* RFC 9072 - Extended Optional Parameters Length for BGP OPEN Message
* RFC 9117 - Revised Validation Procedure for BGP Flow Specifications
* RFC 9234 - Route Leak Prevention and Detection Using Roles
* draft-uttaro-idr-bgp-persistence-04
* draft-walton-bgp-hostname-capability-02
*/
#undef LOCAL_DEBUG
#include <stdlib.h>
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/rt.h"
#include "nest/cli.h"
#include "nest/locks.h"
#include "conf/conf.h"
#include "filter/filter.h"
#include "lib/socket.h"
#include "lib/resource.h"
#include "lib/string.h"
#include "bgp.h"
static void bgp_listen_create(void *);
static list STATIC_LIST_INIT(bgp_sockets); /* Global list of listening sockets */
static list STATIC_LIST_INIT(bgp_listen_pending); /* Global list of listening socket open requests */
static event bgp_listen_event = { .hook = bgp_listen_create };
static DOMAIN(rtable) bgp_listen_domain;
static pool *bgp_listen_pool;
static void bgp_connect(struct bgp_proto *p);
static void bgp_active(struct bgp_proto *p);
static void bgp_setup_conn(struct bgp_proto *p, struct bgp_conn *conn);
static void bgp_setup_sk(struct bgp_conn *conn, sock *s);
static void bgp_send_open(struct bgp_conn *conn);
static void bgp_update_bfd(struct bgp_proto *p, const struct bfd_options *bfd);
static int bgp_incoming_connection(sock *sk, uint dummy UNUSED);
static void bgp_listen_sock_err(sock *sk UNUSED, int err);
static void bgp_initiate_disable(struct bgp_proto *p, int err_val);
static void bgp_graceful_restart_feed(struct bgp_channel *c);
static inline int
bgp_setup_auth(struct bgp_proto *p, int enable)
{
/* Beware. This is done from main_birdloop and protocol birdloop is NOT ENTERED.
* Anyway, we are only accessing:
* - protocol config which can be changed only from main_birdloop (reconfig)
* - protocol listen socket which is always driven by main_birdloop
* - protocol name which is set on reconfig
*/
if (p->cf->password && p->listen.sock)
{
ip_addr prefix = p->cf->remote_ip;
int pxlen = -1;
if (p->cf->remote_range)
{
prefix = net_prefix(p->cf->remote_range);
pxlen = net_pxlen(p->cf->remote_range);
}
int rv = sk_set_md5_auth(p->listen.sock->sk,
p->cf->local_ip, prefix, pxlen, p->cf->iface,
enable ? p->cf->password : NULL, p->cf->setkey);
if (rv < 0)
sk_log_error(p->listen.sock->sk, p->p.name);
return rv;
}
else
return 0;
}
/**
* bgp_close - close a BGP instance
* @p: BGP instance
*
* This function frees and deconfigures shared BGP resources.
*/
static void
bgp_close(struct bgp_proto *p)
{
LOCK_DOMAIN(rtable, bgp_listen_domain);
struct bgp_listen_request *req = &p->listen;
struct bgp_socket *bs = req->sock;
if (bs)
{
req->sock = NULL;
rem_node(&req->n);
if (bs && EMPTY_LIST(bs->requests))
ev_send(&global_event_list, &bgp_listen_event);
}
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
}
/**
* bgp_open - open a BGP instance
* @p: BGP instance
*
* This function allocates and configures shared BGP resources, mainly listening
* sockets. Should be called as the last step during initialization (when lock
* is acquired and neighbor is ready). When error, caller should change state to
* PS_DOWN and return immediately.
*/
static void
bgp_open(struct bgp_proto *p)
{
LOCK_DOMAIN(rtable, bgp_listen_domain);
struct bgp_listen_request *req = &p->listen;
/* We assume that cf->iface is defined iff cf->local_ip is link-local */
req->iface = p->cf->strict_bind ? p->cf->iface : NULL;
req->vrf = p->p.vrf;
req->addr = p->cf->strict_bind ? p->cf->local_ip :
(p->ipv4 ? IPA_NONE4 : IPA_NONE6);
req->port = p->cf->local_port;
req->flags = p->cf->free_bind ? SKF_FREEBIND : 0;
BGP_TRACE(D_EVENTS, "Requesting listen socket at %I%J port %u", req->addr, req->iface, req->port);
add_tail(&bgp_listen_pending, &req->n);
ev_send(&global_event_list, &bgp_listen_event);
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
}
static void
bgp_listen_create(void *_ UNUSED)
{
ASSERT_DIE(birdloop_inside(&main_birdloop));
uint flag_mask = SKF_FREEBIND;
while (1) {
LOCK_DOMAIN(rtable, bgp_listen_domain);
if (EMPTY_LIST(bgp_listen_pending))
{
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
break;
}
/* Get the first request to match */
struct bgp_listen_request *req = HEAD(bgp_listen_pending);
struct bgp_proto *p = SKIP_BACK(struct bgp_proto, listen, req);
rem_node(&req->n);
/* First try to find existing socket */
struct bgp_socket *bs;
WALK_LIST(bs, bgp_sockets)
if (ipa_equal(bs->sk->saddr, req->addr) &&
(bs->sk->sport == req->port) &&
(bs->sk->iface == req->iface) &&
(bs->sk->vrf == req->vrf) &&
((bs->sk->flags & flag_mask) == req->flags))
break;
/* Not found any */
if (NODE_VALID(bs))
BGP_TRACE(D_EVENTS, "Found a listening socket: %p", bs);
else
{
/* Allocating new socket from global protocol pool.
* We can do this in main_birdloop. */
sock *sk = sk_new(bgp_listen_pool);
sk->type = SK_TCP_PASSIVE;
sk->ttl = 255;
sk->saddr = req->addr;
sk->sport = req->port;
sk->iface = req->iface;
sk->vrf = req->vrf;
sk->flags = req->flags;
sk->tos = IP_PREC_INTERNET_CONTROL;
sk->rbsize = BGP_RX_BUFFER_SIZE;
sk->tbsize = BGP_TX_BUFFER_SIZE;
sk->rx_hook = bgp_incoming_connection;
sk->err_hook = bgp_listen_sock_err;
if (sk_open(sk, &main_birdloop) < 0)
{
sk_log_error(sk, p->p.name);
log(L_ERR "%s: Cannot open listening socket", p->p.name);
sk_close(sk);
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
bgp_initiate_disable(p, BEM_NO_SOCKET);
continue;
}
bs = mb_allocz(bgp_listen_pool, sizeof(struct bgp_socket));
bs->sk = sk;
sk->data = bs;
init_list(&bs->requests);
add_tail(&bgp_sockets, &bs->n);
BGP_TRACE(D_EVENTS, "Created new listening socket: %p", bs);
}
req->sock = bs;
add_tail(&bs->requests, &req->n);
if (bgp_setup_auth(p, 1) < 0)
{
rem_node(&req->n);
req->sock = NULL;
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
bgp_initiate_disable(p, BEM_INVALID_MD5);
continue;
}
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
}
/* Cleanup leftover listening sockets */
LOCK_DOMAIN(rtable, bgp_listen_domain);
struct bgp_socket *bs;
node *nxt;
WALK_LIST_DELSAFE(bs, nxt, bgp_sockets)
if (EMPTY_LIST(bs->requests))
{
sk_close(bs->sk);
rem_node(&bs->n);
mb_free(bs);
}
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
}
static inline struct bgp_channel *
bgp_find_channel(struct bgp_proto *p, u32 afi)
{
struct bgp_channel *c;
BGP_WALK_CHANNELS(p, c)
if (c->afi == afi)
return c;
return NULL;
}
static void
bgp_startup(struct bgp_proto *p)
{
BGP_TRACE(D_EVENTS, "Started");
p->start_state = BSS_CONNECT;
if (!p->passive)
bgp_active(p);
if (p->postponed_sk)
{
/* Apply postponed incoming connection */
sk_reloop(p->postponed_sk, p->p.loop);
bgp_setup_conn(p, &p->incoming_conn);
bgp_setup_sk(&p->incoming_conn, p->postponed_sk);
bgp_send_open(&p->incoming_conn);
p->postponed_sk = NULL;
}
}
static void
bgp_startup_timeout(timer *t)
{
bgp_startup(t->data);
}
static void
bgp_initiate(struct bgp_proto *p)
{
bgp_open(p);
if (p->cf->bfd)
bgp_update_bfd(p, p->cf->bfd);
if (p->startup_delay)
{
p->start_state = BSS_DELAY;
BGP_TRACE(D_EVENTS, "Startup delayed by %d seconds due to errors", p->startup_delay);
bgp_start_timer(p, p->startup_timer, p->startup_delay);
}
else
bgp_startup(p);
}
static void
bgp_initiate_disable(struct bgp_proto *p, int err_val)
{
PROTO_LOCKED_FROM_MAIN(&p->p)
{
/* The protocol may be already down for another reason.
* Shutdown the protocol only if it isn't already shutting down. */
switch (p->p.proto_state)
{
case PS_START:
case PS_UP:
p->p.disabled = 1;
bgp_store_error(p, NULL, BE_MISC, err_val);
bgp_stop(p, err_val, NULL, 0);
}
}
}
/**
* bgp_start_timer - start a BGP timer
* @t: timer
* @value: time (in seconds) to fire (0 to disable the timer)
*
* This functions calls tm_start() on @t with time @value and the amount of
* randomization suggested by the BGP standard. Please use it for all BGP
* timers.
*/
void
bgp_start_timer(struct bgp_proto *p, timer *t, uint value)
{
if (value)
{
/* The randomization procedure is specified in RFC 4271 section 10 */
btime time = value S;
btime randomize = random() % ((time / 4) + 1);
tm_start_in(t, time - randomize, p->p.loop);
}
else
tm_stop(t);
}
/**
* bgp_close_conn - close a BGP connection
* @conn: connection to close
*
* This function takes a connection described by the &bgp_conn structure, closes
* its socket and frees all resources associated with it.
*/
void
bgp_close_conn(struct bgp_conn *conn)
{
// struct bgp_proto *p = conn->bgp;
DBG("BGP: Closing connection\n");
conn->packets_to_send = 0;
conn->channels_to_send = 0;
rfree(conn->connect_timer);
conn->connect_timer = NULL;
rfree(conn->keepalive_timer);
conn->keepalive_timer = NULL;
rfree(conn->hold_timer);
conn->hold_timer = NULL;
rfree(conn->tx_ev);
conn->tx_ev = NULL;
sk_close(conn->sk);
conn->sk = NULL;
mb_free(conn->local_caps);
conn->local_caps = NULL;
mb_free(conn->remote_caps);
conn->remote_caps = NULL;
}
/**
* bgp_update_startup_delay - update a startup delay
* @p: BGP instance
*
* This function updates a startup delay that is used to postpone next BGP
* connect. It also handles disable_after_error and might stop BGP instance
* when error happened and disable_after_error is on.
*
* It should be called when BGP protocol error happened.
*/
void
bgp_update_startup_delay(struct bgp_proto *p)
{
const struct bgp_config *cf = p->cf;
DBG("BGP: Updating startup delay\n");
if (p->last_proto_error && ((current_time() - p->last_proto_error) >= cf->error_amnesia_time S))
p->startup_delay = 0;
p->last_proto_error = current_time();
if (cf->disable_after_error)
{
p->startup_delay = 0;
p->p.disabled = 1;
return;
}
if (!p->startup_delay)
p->startup_delay = cf->error_delay_time_min;
else
p->startup_delay = MIN(2 * p->startup_delay, cf->error_delay_time_max);
}
static void
bgp_graceful_close_conn(struct bgp_conn *conn, int subcode, byte *data, uint len)
{
switch (conn->state)
{
case BS_IDLE:
case BS_CLOSE:
return;
case BS_CONNECT:
case BS_ACTIVE:
bgp_conn_enter_idle_state(conn);
return;
case BS_OPENSENT:
case BS_OPENCONFIRM:
case BS_ESTABLISHED:
if (subcode < 0)
{
bgp_conn_enter_close_state(conn);
bgp_schedule_packet(conn, NULL, PKT_SCHEDULE_CLOSE);
}
else
bgp_error(conn, 6, subcode, data, len);
return;
default:
bug("bgp_graceful_close_conn: Unknown state %d", conn->state);
}
}
static void
bgp_down(struct bgp_proto *p)
{
if (p->start_state > BSS_PREPARE)
{
bgp_setup_auth(p, 0);
bgp_close(p);
}
p->neigh = NULL;
BGP_TRACE(D_EVENTS, "Down");
proto_notify_state(&p->p, PS_DOWN);
}
static void
bgp_decision(void *vp)
{
struct bgp_proto *p = vp;
DBG("BGP: Decision start\n");
if ((p->p.proto_state == PS_START) &&
(p->outgoing_conn.state == BS_IDLE) &&
(p->incoming_conn.state != BS_OPENCONFIRM) &&
!p->passive)
bgp_active(p);
if ((p->p.proto_state == PS_STOP) &&
(p->outgoing_conn.state == BS_IDLE) &&
(p->incoming_conn.state == BS_IDLE))
bgp_down(p);
}
static struct bgp_proto *
bgp_spawn(struct bgp_proto *pp, ip_addr remote_ip)
{
struct symbol *sym;
char fmt[SYM_MAX_LEN];
bsprintf(fmt, "%s%%0%dd", pp->cf->dynamic_name, pp->cf->dynamic_name_digits);
/* This is hack, we would like to share config, but we need to copy it now */
new_config = config;
cfg_mem = config->mem;
conf_this_scope = config->root_scope;
sym = cf_default_name(fmt, &(pp->dynamic_name_counter));
proto_clone_config(sym, pp->p.cf);
new_config = NULL;
cfg_mem = NULL;
/* Just pass remote_ip to bgp_init() */
((struct bgp_config *) sym->proto)->remote_ip = remote_ip;
return (void *) proto_spawn(sym->proto, 0);
}
void
bgp_stop(struct bgp_proto *p, int subcode, byte *data, uint len)
{
proto_notify_state(&p->p, PS_STOP);
p->uncork_ev->data = NULL;
bgp_graceful_close_conn(&p->outgoing_conn, subcode, data, len);
bgp_graceful_close_conn(&p->incoming_conn, subcode, data, len);
struct bgp_channel *c;
WALK_LIST(c, p->p.channels)
if (c->ptx)
bgp_free_pending_tx(c);
proto_send_event(&p->p, p->event);
}
static inline void
bgp_conn_set_state(struct bgp_conn *conn, uint new_state)
{
if (conn->bgp->p.mrtdump & MD_STATES)
bgp_dump_state_change(conn, conn->state, new_state);
conn->state = new_state;
}
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);
}
static const struct bgp_af_caps dummy_af_caps = { };
static const struct bgp_af_caps basic_af_caps = { .ready = 1 };
void
bgp_conn_enter_established_state(struct bgp_conn *conn)
{
struct bgp_proto *p = conn->bgp;
struct bgp_caps *local = conn->local_caps;
struct bgp_caps *peer = conn->remote_caps;
struct bgp_channel *c;
BGP_TRACE(D_EVENTS, "BGP session established");
p->last_established = current_time();
p->stats.fsm_established_transitions++;
/* For multi-hop BGP sessions */
if (ipa_zero(p->local_ip))
p->local_ip = conn->sk->saddr;
/* For promiscuous sessions */
if (!p->remote_as)
p->remote_as = conn->received_as;
/* In case of LLv6 is not valid during BGP start */
if (ipa_zero(p->link_addr) && p->neigh && p->neigh->iface && p->neigh->iface->llv6)
p->link_addr = p->neigh->iface->llv6->ip;
conn->sk->fast_rx = 0;
p->conn = conn;
p->last_error_class = 0;
p->last_error_code = 0;
p->as4_session = conn->as4_session;
p->route_refresh = peer->route_refresh;
p->enhanced_refresh = local->enhanced_refresh && peer->enhanced_refresh;
/* Whether we may handle possible GR/LLGR of peer (it has some AF GR-able) */
p->gr_ready = p->llgr_ready = 0; /* Updated later */
/* Whether peer is ready to handle our GR recovery */
int peer_gr_ready = peer->gr_aware && !(peer->gr_flags & BGP_GRF_RESTART);
if (p->gr_active_num)
tm_stop(p->gr_timer);
/* Number of active channels */
int num = 0;
/* Summary state of ADD_PATH RX for active channels */
uint summary_add_path_rx = 0;
BGP_WALK_CHANNELS(p, c)
{
const struct bgp_af_caps *loc = bgp_find_af_caps(local, c->afi);
const struct bgp_af_caps *rem = bgp_find_af_caps(peer, c->afi);
/* Use default if capabilities were not announced */
if (!local->length && (c->afi == BGP_AF_IPV4))
loc = &basic_af_caps;
if (!peer->length && (c->afi == BGP_AF_IPV4))
rem = &basic_af_caps;
/* Ignore AFIs that were not announced in multiprotocol capability */
if (!loc || !loc->ready)
loc = &dummy_af_caps;
if (!rem || !rem->ready)
rem = &dummy_af_caps;
int active = loc->ready && rem->ready;
c->c.disabled = !active;
c->c.reloadable = p->route_refresh || ((c->c.in_keep & RIK_PREFILTER) == RIK_PREFILTER);
c->index = active ? num++ : 0;
c->feed_state = BFS_NONE;
c->load_state = BFS_NONE;
/* Channels where peer may do GR */
uint gr_ready = active && local->gr_aware && rem->gr_able;
uint llgr_ready = active && local->llgr_aware && rem->llgr_able;
c->gr_ready = gr_ready || llgr_ready;
p->gr_ready = p->gr_ready || c->gr_ready;
p->llgr_ready = p->llgr_ready || llgr_ready;
/* Remember last LLGR stale time */
c->stale_time = local->llgr_aware ? rem->llgr_time : 0;
/* Channels not able to recover gracefully */
if (p->p.gr_recovery && (!active || !peer_gr_ready))
channel_graceful_restart_unlock(&c->c);
/* Channels waiting for local convergence */
if (p->p.gr_recovery && loc->gr_able && peer_gr_ready)
c->c.gr_wait = 1;
/* Channels where regular graceful restart failed */
if ((c->gr_active == BGP_GRS_ACTIVE) &&
!(active && rem->gr_able && (rem->gr_af_flags & BGP_GRF_FORWARDING)))
bgp_graceful_restart_done(c);
/* Channels where regular long-lived restart failed */
if ((c->gr_active == BGP_GRS_LLGR) &&
!(active && rem->llgr_able && (rem->gr_af_flags & BGP_LLGRF_FORWARDING)))
bgp_graceful_restart_done(c);
/* GR capability implies that neighbor will send End-of-RIB */
if (peer->gr_aware)
c->load_state = BFS_LOADING;
c->ext_next_hop = c->cf->ext_next_hop && (bgp_channel_is_ipv6(c) || rem->ext_next_hop);
c->add_path_rx = (loc->add_path & BGP_ADD_PATH_RX) && (rem->add_path & BGP_ADD_PATH_TX);
c->add_path_tx = (loc->add_path & BGP_ADD_PATH_TX) && (rem->add_path & BGP_ADD_PATH_RX);
if (active)
summary_add_path_rx |= !c->add_path_rx ? 1 : 2;
/* Update RA mode */
if (c->add_path_tx)
c->c.ra_mode = RA_ANY;
else if (c->cf->secondary)
c->c.ra_mode = RA_ACCEPTED;
else
c->c.ra_mode = RA_OPTIMAL;
}
p->afi_map = mb_alloc(p->p.pool, num * sizeof(u32));
p->channel_map = mb_alloc(p->p.pool, num * sizeof(void *));
p->channel_count = num;
p->summary_add_path_rx = summary_add_path_rx;
BGP_WALK_CHANNELS(p, c)
{
if (c->c.disabled)
continue;
p->afi_map[c->index] = c->afi;
p->channel_map[c->index] = c;
}
/* proto_notify_state() will likely call bgp_feed_begin(), setting c->feed_state */
bgp_conn_set_state(conn, BS_ESTABLISHED);
proto_notify_state(&p->p, PS_UP);
}
static void
bgp_conn_leave_established_state(struct bgp_proto *p)
{
BGP_TRACE(D_EVENTS, "BGP session closed");
p->last_established = current_time();
p->conn = NULL;
if (p->p.proto_state == PS_UP)
bgp_stop(p, 0, NULL, 0);
}
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(p, conn->hold_timer, 10);
if (os == BS_ESTABLISHED)
bgp_conn_leave_established_state(p);
}
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);
proto_send_event(&p->p, p->event);
if (os == BS_ESTABLISHED)
bgp_conn_leave_established_state(p);
}
/**
* bgp_handle_graceful_restart - handle detected BGP graceful restart
* @p: BGP instance
*
* This function is called when a BGP graceful restart of the neighbor is
* detected (when the TCP connection fails or when a new TCP connection
* appears). The function activates processing of the restart - starts routing
* table refresh cycle and activates BGP restart timer. The protocol state goes
* back to %PS_START, but changing BGP state back to %BS_IDLE is left for the
* caller.
*/
void
bgp_handle_graceful_restart(struct bgp_proto *p)
{
ASSERT(p->conn && (p->conn->state == BS_ESTABLISHED) && p->gr_ready);
BGP_TRACE(D_EVENTS, "Neighbor graceful restart detected%s",
p->gr_active_num ? " - already pending" : "");
p->gr_active_num = 0;
struct bgp_channel *c;
BGP_WALK_CHANNELS(p, c)
{
/* FIXME: perhaps check for channel state instead of disabled flag? */
if (c->c.disabled)
continue;
if (c->gr_ready)
{
p->gr_active_num++;
switch (c->gr_active)
{
case BGP_GRS_NONE:
c->gr_active = BGP_GRS_ACTIVE;
/* fall through */
case BGP_GRS_ACTIVE:
rt_refresh_begin(&c->c.in_req);
break;
case BGP_GRS_LLGR:
rt_refresh_begin(&c->c.in_req);
bgp_graceful_restart_feed(c);
break;
}
}
else
{
/* Just flush the routes */
rt_refresh_begin(&c->c.in_req);
rt_refresh_end(&c->c.in_req);
}
/* Reset bucket and prefix tables */
bgp_free_pending_tx(c);
bgp_init_pending_tx(c);
c->packets_to_send = 0;
}
/* p->gr_ready -> at least one active channel is c->gr_ready */
ASSERT(p->gr_active_num > 0);
proto_notify_state(&p->p, PS_START);
tm_start_in(p->gr_timer, p->conn->remote_caps->gr_time S, p->p.loop);
}
static void
bgp_graceful_restart_feed_done(struct rt_export_request *req)
{
req->hook = NULL;
}
static void
bgp_graceful_restart_feed_dump_req(struct rt_export_request *req)
{
struct bgp_channel *c = SKIP_BACK(struct bgp_channel, stale_feed, req);
debug(" BGP-GR %s.%s export request %p\n", c->c.proto->name, c->c.name, req);
}
static void
bgp_graceful_restart_feed_log_state_change(struct rt_export_request *req, u8 state)
{
struct bgp_channel *c = SKIP_BACK(struct bgp_channel, stale_feed, req);
struct bgp_proto *p = (void *) c->c.proto;
BGP_TRACE(D_EVENTS, "Long-lived graceful restart export state changed to %s", rt_export_state_name(state));
if (state == TES_READY)
rt_stop_export(req, bgp_graceful_restart_feed_done);
}
static void
bgp_graceful_restart_drop_export(struct rt_export_request *req UNUSED, const net_addr *n UNUSED, struct rt_pending_export *rpe UNUSED)
{ /* Nothing to do */ }
static void
bgp_graceful_restart_feed(struct bgp_channel *c)
{
c->stale_feed = (struct rt_export_request) {
.name = "BGP-GR",
.list = proto_event_list(c->c.proto),
.pool = c->c.proto->pool,
.feed_block_size = c->c.feed_block_size,
.trace_routes = c->c.debug | c->c.proto->debug,
.dump_req = bgp_graceful_restart_feed_dump_req,
.log_state_change = bgp_graceful_restart_feed_log_state_change,
.export_bulk = bgp_rte_modify_stale,
.export_one = bgp_graceful_restart_drop_export,
};
rt_request_export(c->c.table, &c->stale_feed);
}
/**
* bgp_graceful_restart_done - finish active BGP graceful restart
* @c: BGP channel
*
* This function is called when the active BGP graceful restart of the neighbor
* should be finished for channel @c - either successfully (the neighbor sends
* all paths and reports end-of-RIB for given AFI/SAFI on the new session) or
* unsuccessfully (the neighbor does not support BGP graceful restart on the new
* session). The function ends the routing table refresh cycle.
*/
void
bgp_graceful_restart_done(struct bgp_channel *c)
{
struct bgp_proto *p = (void *) c->c.proto;
ASSERT(c->gr_active);
c->gr_active = 0;
p->gr_active_num--;
if (!p->gr_active_num)
BGP_TRACE(D_EVENTS, "Neighbor graceful restart done");
tm_stop(c->stale_timer);
rt_refresh_end(&c->c.in_req);
}
/**
* bgp_graceful_restart_timeout - timeout of graceful restart 'restart timer'
* @t: timer
*
* This function is a timeout hook for @gr_timer, implementing BGP restart time
* limit for reestablisment of the BGP session after the graceful restart. When
* fired, we just proceed with the usual protocol restart.
*/
static void
bgp_graceful_restart_timeout(timer *t)
{
struct bgp_proto *p = t->data;
BGP_TRACE(D_EVENTS, "Neighbor graceful restart timeout");
if (p->llgr_ready)
{
struct bgp_channel *c;
BGP_WALK_CHANNELS(p, c)
{
/* Channel is not in GR and is already flushed */
if (!c->gr_active)
continue;
/* Channel is already in LLGR from past restart */
if (c->gr_active == BGP_GRS_LLGR)
continue;
/* Channel is in GR, but does not support LLGR -> stop GR */
if (!c->stale_time)
{
bgp_graceful_restart_done(c);
continue;
}
/* Channel is in GR, and supports LLGR -> start LLGR */
c->gr_active = BGP_GRS_LLGR;
tm_start_in(c->stale_timer, c->stale_time S, p->p.loop);
bgp_graceful_restart_feed(c);
}
}
else
bgp_stop(p, 0, NULL, 0);
}
static void
bgp_long_lived_stale_timeout(timer *t)
{
struct bgp_channel *c = t->data;
struct bgp_proto *p = (void *) c->c.proto;
BGP_TRACE(D_EVENTS, "Long-lived stale timeout");
bgp_graceful_restart_done(c);
}
/**
* bgp_refresh_begin - start incoming enhanced route refresh sequence
* @c: BGP channel
*
* This function is called when an incoming enhanced route refresh sequence is
* started by the neighbor, demarcated by the BoRR packet. The function updates
* the load state and starts the routing table refresh cycle. Note that graceful
* restart also uses routing table refresh cycle, but RFC 7313 and load states
* ensure that these two sequences do not overlap.
*/
void
bgp_refresh_begin(struct bgp_channel *c)
{
struct bgp_proto *p = (void *) c->c.proto;
if (c->load_state == BFS_LOADING)
{ log(L_WARN "%s: BEGIN-OF-RR received before END-OF-RIB, ignoring", p->p.name); return; }
c->load_state = BFS_REFRESHING;
rt_refresh_begin(&c->c.in_req);
}
/**
* bgp_refresh_end - finish incoming enhanced route refresh sequence
* @c: BGP channel
*
* This function is called when an incoming enhanced route refresh sequence is
* finished by the neighbor, demarcated by the EoRR packet. The function updates
* the load state and ends the routing table refresh cycle. Routes not received
* during the sequence are removed by the nest.
*/
void
bgp_refresh_end(struct bgp_channel *c)
{
struct bgp_proto *p = (void *) c->c.proto;
if (c->load_state != BFS_REFRESHING)
{ log(L_WARN "%s: END-OF-RR received without prior BEGIN-OF-RR, ignoring", p->p.name); return; }
c->load_state = BFS_NONE;
rt_refresh_end(&c->c.in_req);
}
static void
bgp_send_open(struct bgp_conn *conn)
{
DBG("BGP: Sending open\n");
conn->sk->rx_hook = bgp_rx;
conn->sk->tx_hook = bgp_tx;
tm_stop(conn->connect_timer);
bgp_prepare_capabilities(conn);
bgp_schedule_packet(conn, NULL, PKT_OPEN);
bgp_conn_set_state(conn, BS_OPENSENT);
bgp_start_timer(conn->bgp, conn->hold_timer, conn->bgp->cf->initial_hold_time);
}
static void
bgp_connected(sock *sk)
{
struct bgp_conn *conn = sk->data;
struct bgp_proto *p = conn->bgp;
BGP_TRACE(D_EVENTS, "Connected");
bgp_send_open(conn);
}
static void
bgp_connect_timeout(timer *t)
{
struct bgp_conn *conn = t->data;
struct bgp_proto *p = conn->bgp;
DBG("BGP: connect_timeout\n");
if (p->p.proto_state == PS_START)
{
bgp_close_conn(conn);
bgp_connect(p);
}
else
bgp_conn_enter_idle_state(conn);
}
static void
bgp_sock_err(sock *sk, int err)
{
struct bgp_conn *conn = sk->data;
struct bgp_proto *p = conn->bgp;
/*
* This error hook may be called either asynchronously from main
* loop, or synchronously from sk_send(). But sk_send() is called
* only from bgp_tx() and bgp_kick_tx(), which are both called
* asynchronously from main loop. Moreover, they end if err hook is
* called. Therefore, we could suppose that it is always called
* asynchronously.
*/
bgp_store_error(p, conn, BE_SOCKET, err);
if (err)
BGP_TRACE(D_EVENTS, "Connection lost (%M)", err);
else
BGP_TRACE(D_EVENTS, "Connection closed");
if ((conn->state == BS_ESTABLISHED) && p->gr_ready)
bgp_handle_graceful_restart(p);
bgp_conn_enter_idle_state(conn);
}
static void
bgp_hold_timeout(timer *t)
{
struct bgp_conn *conn = t->data;
struct bgp_proto *p = conn->bgp;
DBG("BGP: Hold timeout\n");
/* We are already closing the connection - just do hangup */
if (conn->state == BS_CLOSE)
{
BGP_TRACE(D_EVENTS, "Connection stalled");
bgp_conn_enter_idle_state(conn);
return;
}
/* If there is something in input queue, we are probably congested
and perhaps just not processed BGP packets in time. */
if (sk_rx_ready(conn->sk) > 0)
bgp_start_timer(p, conn->hold_timer, 10);
else if ((conn->state == BS_ESTABLISHED) && p->llgr_ready)
{
BGP_TRACE(D_EVENTS, "Hold timer expired");
bgp_handle_graceful_restart(p);
bgp_conn_enter_idle_state(conn);
}
else
bgp_error(conn, 4, 0, NULL, 0);
}
static void
bgp_keepalive_timeout(timer *t)
{
struct bgp_conn *conn = t->data;
DBG("BGP: Keepalive timer\n");
bgp_schedule_packet(conn, NULL, PKT_KEEPALIVE);
/* Kick TX a bit faster */
if (ev_active(conn->tx_ev))
ev_run(conn->tx_ev);
}
static void
bgp_setup_conn(struct bgp_proto *p, struct bgp_conn *conn)
{
conn->sk = NULL;
conn->bgp = p;
conn->packets_to_send = 0;
conn->channels_to_send = 0;
conn->last_channel = 0;
conn->last_channel_count = 0;
conn->connect_timer = tm_new_init(p->p.pool, bgp_connect_timeout, conn, 0, 0);
conn->hold_timer = tm_new_init(p->p.pool, bgp_hold_timeout, conn, 0, 0);
conn->keepalive_timer = tm_new_init(p->p.pool, bgp_keepalive_timeout, conn, 0, 0);
conn->tx_ev = ev_new_init(p->p.pool, bgp_kick_tx, conn);
}
static void
bgp_setup_sk(struct bgp_conn *conn, sock *s)
{
s->data = conn;
s->err_hook = bgp_sock_err;
s->fast_rx = 1;
conn->sk = s;
}
static void
bgp_active(struct bgp_proto *p)
{
int delay = MAX(1, p->cf->connect_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(p, conn->connect_timer, delay);
}
/**
* 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 */
{
struct bgp_conn *conn = &p->outgoing_conn;
int hops = p->cf->multihop ? : 1;
DBG("BGP: Connecting\n");
sock *s = sk_new(p->p.pool);
s->type = SK_TCP_ACTIVE;
s->saddr = p->local_ip;
s->daddr = p->remote_ip;
s->dport = p->cf->remote_port;
s->iface = p->neigh ? p->neigh->iface : NULL;
s->vrf = p->p.vrf;
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;
s->flags = p->cf->free_bind ? SKF_FREEBIND : 0;
BGP_TRACE(D_EVENTS, "Connecting to %I%J from local address %I%J",
s->daddr, ipa_is_link_local(s->daddr) ? p->cf->iface : NULL,
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, p->p.loop) < 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(p, conn->connect_timer, p->cf->connect_retry_time);
return;
err:
sk_log_error(s, p->p.name);
bgp_sock_err(s, 0);
return;
}
static inline int bgp_is_dynamic(struct bgp_proto *p)
{ return ipa_zero(p->remote_ip); }
/**
* bgp_find_proto - find existing proto for incoming connection
* @sk: TCP socket
*
*/
static struct bgp_proto *
bgp_find_proto(sock *sk)
{
struct bgp_proto *best = NULL;
struct bgp_socket *bs = sk->data;
struct bgp_listen_request *req;
/* sk->iface is valid only if src or dst address is link-local */
int link = ipa_is_link_local(sk->saddr) || ipa_is_link_local(sk->daddr);
LOCK_DOMAIN(rtable, bgp_listen_domain);
WALK_LIST(req, bs->requests)
{
struct bgp_proto *p = SKIP_BACK(struct bgp_proto, listen, req);
if ((p->p.proto == &proto_bgp) &&
(ipa_equal(p->remote_ip, sk->daddr) || bgp_is_dynamic(p)) &&
(!p->cf->remote_range || ipa_in_netX(sk->daddr, p->cf->remote_range)) &&
(p->p.vrf == sk->vrf) &&
(p->cf->local_port == sk->sport) &&
(!link || (p->cf->iface == sk->iface)) &&
(ipa_zero(p->cf->local_ip) || ipa_equal(p->cf->local_ip, sk->saddr)))
{
best = p;
if (!bgp_is_dynamic(p))
break;
}
}
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
return best;
}
/**
* bgp_incoming_connection - handle an incoming connection
* @sk: TCP socket
* @dummy: unused
*
* This function serves as a socket hook for accepting of new BGP
* connections. It searches a BGP instance corresponding to the peer
* which has connected and if such an instance exists, it creates a
* &bgp_conn structure, attaches it to the instance and either sends
* an Open message or (if there already is an active connection) it
* closes the new connection by sending a Notification message.
*/
static int
bgp_incoming_connection(sock *sk, uint dummy UNUSED)
{
ASSERT_DIE(birdloop_inside(&main_birdloop));
struct bgp_proto *p;
int acc, hops;
DBG("BGP: Incoming connection from %I port %d\n", sk->daddr, sk->dport);
p = bgp_find_proto(sk);
if (!p)
{
log(L_WARN "BGP: Unexpected connect from unknown address %I%J (port %d)",
sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL, sk->dport);
LOCK_DOMAIN(rtable, bgp_listen_domain);
sk_close(sk);
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
return 0;
}
birdloop_enter(p->p.loop);
/*
* BIRD should keep multiple incoming connections in OpenSent state (for
* details RFC 4271 8.2.1 par 3), but it keeps just one. Duplicate incoming
* connections are rejected istead. The exception is the case where an
* incoming connection triggers a graceful restart.
*/
acc = (p->p.proto_state == PS_START || p->p.proto_state == PS_UP) &&
(p->start_state >= BSS_CONNECT) && (!p->incoming_conn.sk);
if (p->conn && (p->conn->state == BS_ESTABLISHED) && p->gr_ready)
{
bgp_store_error(p, NULL, BE_MISC, BEM_GRACEFUL_RESTART);
bgp_handle_graceful_restart(p);
bgp_conn_enter_idle_state(p->conn);
acc = 1;
/* There might be separate incoming connection in OpenSent state */
if (p->incoming_conn.state > BS_ACTIVE)
bgp_close_conn(&p->incoming_conn);
}
LOCK_DOMAIN(rtable, bgp_listen_domain);
BGP_TRACE(D_EVENTS, "Incoming connection from %I%J (port %d) %s",
sk->daddr, ipa_is_link_local(sk->daddr) ? sk->iface : NULL,
sk->dport, acc ? "accepted" : "rejected");
if (!acc)
{
sk_close(sk);
goto leave;
}
hops = p->cf->multihop ? : 1;
if (sk_set_ttl(sk, p->cf->ttl_security ? 255 : hops) < 0)
goto err;
if (p->cf->ttl_security)
if (sk_set_min_ttl(sk, 256 - hops) < 0)
goto err;
if (p->cf->enable_extended_messages)
{
sk->rbsize = BGP_RX_BUFFER_EXT_SIZE;
sk->tbsize = BGP_TX_BUFFER_EXT_SIZE;
sk_reallocate(sk);
}
/* For dynamic BGP, spawn new instance and postpone the socket */
if (bgp_is_dynamic(p))
{
p = bgp_spawn(p, sk->daddr);
p->postponed_sk = sk;
rmove(sk, p->p.pool);
goto leave;
}
rmove(sk, p->p.pool);
sk_reloop(sk, p->p.loop);
bgp_setup_conn(p, &p->incoming_conn);
bgp_setup_sk(&p->incoming_conn, sk);
bgp_send_open(&p->incoming_conn);
goto leave;
err:
sk_log_error(sk, p->p.name);
log(L_ERR "%s: Incoming connection aborted", p->p.name);
sk_close(sk);
leave:
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
birdloop_leave(p->p.loop);
return 0;
}
static void
bgp_listen_sock_err(sock *sk UNUSED, int err)
{
if (err == ECONNABORTED)
log(L_WARN "BGP: Incoming connection aborted");
else
log(L_ERR "BGP: Error on listening socket: %M", err);
}
static void
bgp_start_neighbor(struct bgp_proto *p)
{
/* Called only for single-hop BGP sessions */
if (ipa_zero(p->local_ip))
p->local_ip = p->neigh->ifa->ip;
if (ipa_is_link_local(p->local_ip))
p->link_addr = p->local_ip;
else if (p->neigh->iface->llv6)
p->link_addr = p->neigh->iface->llv6->ip;
bgp_initiate(p);
}
static void
bgp_neigh_notify(neighbor *n)
{
struct bgp_proto *p = (struct bgp_proto *) n->proto;
int ps = p->p.proto_state;
if (n != p->neigh)
return;
if ((ps == PS_DOWN) || (ps == PS_STOP))
return;
int prepare = (ps == PS_START) && (p->start_state == BSS_PREPARE);
if (n->scope <= 0)
{
if (!prepare)
{
BGP_TRACE(D_EVENTS, "Neighbor lost");
bgp_store_error(p, NULL, BE_MISC, BEM_NEIGHBOR_LOST);
/* Perhaps also run bgp_update_startup_delay(p)? */
bgp_stop(p, 0, NULL, 0);
}
}
else if (p->cf->check_link && !(n->iface->flags & IF_LINK_UP))
{
if (!prepare)
{
BGP_TRACE(D_EVENTS, "Link down");
bgp_store_error(p, NULL, BE_MISC, BEM_LINK_DOWN);
if (ps == PS_UP)
bgp_update_startup_delay(p);
bgp_stop(p, 0, NULL, 0);
}
}
else
{
if (prepare)
{
BGP_TRACE(D_EVENTS, "Neighbor ready");
bgp_start_neighbor(p);
}
}
}
static void
bgp_bfd_notify(struct bfd_request *req)
{
struct bgp_proto *p = req->data;
int ps = p->p.proto_state;
if (req->down && ((ps == PS_START) || (ps == PS_UP)))
{
BGP_TRACE(D_EVENTS, "BFD session down");
bgp_store_error(p, NULL, BE_MISC, BEM_BFD_DOWN);
if (req->opts.mode == BGP_BFD_GRACEFUL)
{
/* Trigger graceful restart */
if (p->conn && (p->conn->state == BS_ESTABLISHED) && p->gr_ready)
bgp_handle_graceful_restart(p);
if (p->incoming_conn.state > BS_IDLE)
bgp_conn_enter_idle_state(&p->incoming_conn);
if (p->outgoing_conn.state > BS_IDLE)
bgp_conn_enter_idle_state(&p->outgoing_conn);
}
else
{
/* Trigger session down */
if (ps == PS_UP)
bgp_update_startup_delay(p);
bgp_stop(p, 0, NULL, 0);
}
}
}
static void
bgp_update_bfd(struct bgp_proto *p, const struct bfd_options *bfd)
{
if (bfd && p->bfd_req)
{
BGP_TRACE(D_EVENTS, "Updating existing BFD request");
bfd_update_request(p->bfd_req, bfd);
}
if (bfd && !p->bfd_req && !bgp_is_dynamic(p))
{
p->bfd_req = bfd_request_session(p->p.pool, p->remote_ip, p->local_ip,
p->cf->multihop ? NULL : p->neigh->iface,
p->p.vrf, bgp_bfd_notify, p, p->p.loop, bfd);
BGP_TRACE(D_EVENTS, "Requesting a new BFD session");
}
if (!bfd && p->bfd_req)
{
BGP_TRACE(D_EVENTS, "Retracting the BFD request");
rfree(p->bfd_req);
p->bfd_req = NULL;
}
}
static void
bgp_reload_routes(struct channel *C)
{
struct bgp_proto *p = (void *) C->proto;
struct bgp_channel *c = (void *) C;
/* Ignore non-BGP channels */
if (C->channel != &channel_bgp)
return;
ASSERT(p->conn && p->route_refresh);
bgp_schedule_packet(p->conn, c, PKT_ROUTE_REFRESH);
}
static void
bgp_feed_begin(struct channel *C, int initial)
{
struct bgp_proto *p = (void *) C->proto;
struct bgp_channel *c = (void *) C;
/* Ignore non-BGP channels */
if (C->channel != &channel_bgp)
return;
/* This should not happen */
if (!p->conn)
return;
if (initial && p->cf->gr_mode)
c->feed_state = BFS_LOADING;
if (!initial && C->out_table)
{
c->feed_out_table = 1;
return;
}
/* It is refeed and both sides support enhanced route refresh */
if (!initial && p->enhanced_refresh)
{
/* BoRR must not be sent before End-of-RIB */
if (c->feed_state == BFS_LOADING || c->feed_state == BFS_LOADED)
return;
c->feed_state = BFS_REFRESHING;
bgp_schedule_packet(p->conn, c, PKT_BEGIN_REFRESH);
}
}
static void
bgp_feed_end(struct channel *C)
{
struct bgp_proto *p = (void *) C->proto;
struct bgp_channel *c = (void *) C;
/* Ignore non-BGP channels */
if (C->channel != &channel_bgp)
return;
if (c->feed_out_table)
{
c->feed_out_table = 0;
return;
}
/* This should not happen */
if (!p->conn)
return;
/* Non-demarcated feed ended, nothing to do */
if (c->feed_state == BFS_NONE)
return;
/* Schedule End-of-RIB packet */
if (c->feed_state == BFS_LOADING)
c->feed_state = BFS_LOADED;
/* Schedule EoRR packet */
if (c->feed_state == BFS_REFRESHING)
c->feed_state = BFS_REFRESHED;
/* Kick TX hook */
bgp_schedule_packet(p->conn, c, PKT_UPDATE);
}
static void
bgp_start_locked(void *_p)
{
struct bgp_proto *p = _p;
const struct bgp_config *cf = p->cf;
if (p->p.proto_state != PS_START)
{
DBG("BGP: Got lock in different state %d\n", p->p.proto_state);
return;
}
DBG("BGP: Got lock\n");
if (cf->multihop || bgp_is_dynamic(p))
{
/* Multi-hop sessions do not use neighbor entries */
bgp_initiate(p);
return;
}
neighbor *n = neigh_find(&p->p, p->remote_ip, cf->iface, NEF_STICKY);
if (!n)
{
log(L_ERR "%s: Invalid remote address %I%J", p->p.name, p->remote_ip, cf->iface);
/* As we do not start yet, we can just disable protocol */
p->p.disabled = 1;
bgp_store_error(p, NULL, BE_MISC, BEM_INVALID_NEXT_HOP);
proto_notify_state(&p->p, PS_DOWN);
return;
}
p->neigh = n;
if (n->scope <= 0)
BGP_TRACE(D_EVENTS, "Waiting for %I%J to become my neighbor", p->remote_ip, cf->iface);
else if (p->cf->check_link && !(n->iface->flags & IF_LINK_UP))
BGP_TRACE(D_EVENTS, "Waiting for link on %s", n->iface->name);
else
bgp_start_neighbor(p);
}
static int
bgp_start(struct proto *P)
{
struct bgp_proto *p = (struct bgp_proto *) P;
const struct bgp_config *cf = p->cf;
p->local_ip = cf->local_ip;
p->local_as = cf->local_as;
p->remote_as = cf->remote_as;
p->public_as = cf->local_as;
/* For dynamic BGP childs, remote_ip is already set */
if (ipa_nonzero(cf->remote_ip))
p->remote_ip = cf->remote_ip;
/* Confederation ID is used for truly external peers */
if (p->cf->confederation && !p->is_interior)
p->public_as = cf->confederation;
p->passive = cf->passive || bgp_is_dynamic(p);
p->start_state = BSS_PREPARE;
p->outgoing_conn.state = BS_IDLE;
p->incoming_conn.state = BS_IDLE;
p->neigh = NULL;
p->bfd_req = NULL;
p->postponed_sk = NULL;
p->gr_ready = 0;
p->gr_active_num = 0;
/* Reset some stats */
p->stats.rx_messages = p->stats.tx_messages = 0;
p->stats.rx_updates = p->stats.tx_updates = 0;
p->stats.rx_bytes = p->stats.tx_bytes = 0;
p->last_rx_update = 0;
p->event = ev_new_init(p->p.pool, bgp_decision, p);
p->uncork_ev = ev_new_init(p->p.pool, bgp_uncork, p);
p->startup_timer = tm_new_init(p->p.pool, bgp_startup_timeout, p, 0, 0);
p->gr_timer = tm_new_init(p->p.pool, bgp_graceful_restart_timeout, p, 0, 0);
p->local_id = proto_get_router_id(P->cf);
if (p->rr_client)
p->rr_cluster_id = p->cf->rr_cluster_id ? p->cf->rr_cluster_id : p->local_id;
p->remote_id = 0;
p->link_addr = IPA_NONE;
/* Lock all channels when in GR recovery mode */
if (p->p.gr_recovery && p->cf->gr_mode)
{
struct bgp_channel *c;
BGP_WALK_CHANNELS(p, c)
channel_graceful_restart_lock(&c->c);
}
/*
* Before attempting to create the connection, we need to lock the port,
* so that we are the only instance attempting to talk with that neighbor.
*/
struct object_lock *lock;
lock = p->lock = olock_new(P->pool_fragile);
lock->addr = p->remote_ip;
lock->port = p->cf->remote_port;
lock->iface = p->cf->iface;
lock->vrf = p->cf->iface ? NULL : p->p.vrf;
lock->type = OBJLOCK_TCP;
lock->event = (event) {
.hook = bgp_start_locked,
.data = p,
};
lock->target = proto_event_list(P);
/* For dynamic BGP, we use inst 1 to avoid collisions with regular BGP */
if (bgp_is_dynamic(p))
{
lock->addr = net_prefix(p->cf->remote_range);
lock->inst = 1;
}
olock_acquire(lock);
return PS_START;
}
extern int proto_restart;
static int
bgp_shutdown(struct proto *P)
{
struct bgp_proto *p = (struct bgp_proto *) P;
int subcode = 0;
char *message = NULL;
byte *data = NULL;
uint len = 0;
BGP_TRACE(D_EVENTS, "Shutdown requested");
switch (P->down_code)
{
case PDC_CF_REMOVE:
case PDC_CF_DISABLE:
subcode = 3; // Errcode 6, 3 - peer de-configured
break;
case PDC_CF_RESTART:
subcode = 6; // Errcode 6, 6 - other configuration change
break;
case PDC_CMD_DISABLE:
case PDC_CMD_SHUTDOWN:
shutdown:
subcode = 2; // Errcode 6, 2 - administrative shutdown
message = P->message;
break;
case PDC_CMD_RESTART:
subcode = 4; // Errcode 6, 4 - administrative reset
message = P->message;
break;
case PDC_CMD_GR_DOWN:
if ((p->cf->gr_mode != BGP_GR_ABLE) &&
(p->cf->llgr_mode != BGP_LLGR_ABLE))
goto shutdown;
subcode = -1; // Do not send NOTIFICATION, just close the connection
break;
case PDC_RX_LIMIT_HIT:
case PDC_IN_LIMIT_HIT:
subcode = 1; // Errcode 6, 1 - max number of prefixes reached
/* log message for compatibility */
log(L_WARN "%s: Route limit exceeded, shutting down", p->p.name);
goto limit;
case PDC_OUT_LIMIT_HIT:
subcode = proto_restart ? 4 : 2; // Administrative reset or shutdown
limit:
bgp_store_error(p, NULL, BE_AUTO_DOWN, BEA_ROUTE_LIMIT_EXCEEDED);
if (proto_restart)
bgp_update_startup_delay(p);
else
p->startup_delay = 0;
goto done;
}
bgp_store_error(p, NULL, BE_MAN_DOWN, 0);
p->startup_delay = 0;
/* RFC 8203 - shutdown communication */
if (message)
{
uint msg_len = strlen(message);
msg_len = MIN(msg_len, 255);
/* Buffer will be freed automatically by protocol shutdown */
data = mb_alloc(p->p.pool, msg_len + 1);
len = msg_len + 1;
data[0] = msg_len;
memcpy(data+1, message, msg_len);
}
done:
bgp_stop(p, subcode, data, len);
return p->p.proto_state;
}
struct rte_owner_class bgp_rte_owner_class = {
.get_route_info = bgp_get_route_info,
.rte_better = bgp_rte_better,
.rte_mergable = bgp_rte_mergable,
.rte_igp_metric = bgp_rte_igp_metric,
};
static struct proto *
bgp_init(struct proto_config *CF)
{
struct proto *P = proto_new(CF);
struct bgp_proto *p = (struct bgp_proto *) P;
struct bgp_config *cf = (struct bgp_config *) CF;
P->rt_notify = bgp_rt_notify;
P->preexport = bgp_preexport;
P->iface_sub.neigh_notify = bgp_neigh_notify;
P->reload_routes = bgp_reload_routes;
P->feed_begin = bgp_feed_begin;
P->feed_end = bgp_feed_end;
P->sources.class = &bgp_rte_owner_class;
P->sources.rte_recalculate = cf->deterministic_med ? bgp_rte_recalculate : NULL;
p->cf = cf;
p->is_internal = (cf->local_as == cf->remote_as);
p->is_interior = p->is_internal || cf->confederation_member;
p->rs_client = cf->rs_client;
p->rr_client = cf->rr_client;
p->ipv4 = ipa_nonzero(cf->remote_ip) ?
ipa_is_ip4(cf->remote_ip) :
(cf->remote_range && (cf->remote_range->type == NET_IP4));
p->remote_ip = cf->remote_ip;
p->remote_as = cf->remote_as;
/* Hack: We use cf->remote_ip just to pass remote_ip from bgp_spawn() */
if (cf->c.parent)
cf->remote_ip = IPA_NONE;
/* Add all channels */
struct bgp_channel_config *cc;
BGP_CF_WALK_CHANNELS(cf, cc)
proto_add_channel(P, &cc->c);
return P;
}
static void
bgp_channel_init(struct channel *C, struct channel_config *CF)
{
struct bgp_channel *c = (void *) C;
struct bgp_channel_config *cf = (void *) CF;
c->cf = cf;
c->afi = cf->afi;
c->desc = cf->desc;
if (cf->igp_table_ip4)
c->igp_table_ip4 = cf->igp_table_ip4->table;
if (cf->igp_table_ip6)
c->igp_table_ip6 = cf->igp_table_ip6->table;
if (cf->base_table)
c->base_table = cf->base_table->table;
}
static int
bgp_channel_start(struct channel *C)
{
struct bgp_proto *p = (void *) C->proto;
struct bgp_channel *c = (void *) C;
ip_addr src = p->local_ip;
if (c->igp_table_ip4)
rt_lock_table(c->igp_table_ip4);
if (c->igp_table_ip6)
rt_lock_table(c->igp_table_ip6);
if (c->base_table)
{
rt_lock_table(c->base_table);
rt_flowspec_link(c->base_table, c->c.table);
}
c->pool = p->p.pool; // XXXX
if (c->cf->export_table)
bgp_setup_out_table(c);
bgp_init_pending_tx(c);
c->stale_timer = tm_new_init(c->pool, bgp_long_lived_stale_timeout, c, 0, 0);
c->next_hop_addr = c->cf->next_hop_addr;
c->link_addr = IPA_NONE;
c->packets_to_send = 0;
/* Try to use source address as next hop address */
if (ipa_zero(c->next_hop_addr))
{
if (bgp_channel_is_ipv4(c) && (ipa_is_ip4(src) || c->ext_next_hop))
c->next_hop_addr = src;
if (bgp_channel_is_ipv6(c) && (ipa_is_ip6(src) || c->ext_next_hop))
c->next_hop_addr = src;
}
/* Use preferred addresses associated with interface / source address */
if (ipa_zero(c->next_hop_addr))
{
/* We know the iface for single-hop, we make lookup for multihop */
struct neighbor *nbr = p->neigh ?: neigh_find(&p->p, src, NULL, 0);
struct iface *iface = nbr ? nbr->iface : NULL;
if (bgp_channel_is_ipv4(c) && iface && iface->addr4)
c->next_hop_addr = iface->addr4->ip;
if (bgp_channel_is_ipv6(c) && iface && iface->addr6)
c->next_hop_addr = iface->addr6->ip;
}
/* Exit if no feasible next hop address is found */
if (ipa_zero(c->next_hop_addr))
{
log(L_WARN "%s: Missing next hop address", p->p.name);
return 0;
}
/* Set link-local address for IPv6 single-hop BGP */
if (ipa_is_ip6(c->next_hop_addr) && p->neigh)
{
c->link_addr = p->link_addr;
if (ipa_zero(c->link_addr))
log(L_WARN "%s: Missing link-local address", p->p.name);
}
/* Link local address is already in c->link_addr */
if (ipa_is_link_local(c->next_hop_addr))
c->next_hop_addr = IPA_NONE;
return 0; /* XXXX: Currently undefined */
}
static void
bgp_channel_shutdown(struct channel *C)
{
struct bgp_channel *c = (void *) C;
c->next_hop_addr = IPA_NONE;
c->link_addr = IPA_NONE;
c->packets_to_send = 0;
}
static void
bgp_channel_cleanup(struct channel *C)
{
struct bgp_channel *c = (void *) C;
if (c->igp_table_ip4)
rt_unlock_table(c->igp_table_ip4);
if (c->igp_table_ip6)
rt_unlock_table(c->igp_table_ip6);
if (c->base_table)
{
rt_flowspec_unlink(c->base_table, c->c.table);
rt_unlock_table(c->base_table);
}
c->index = 0;
/* Cleanup rest of bgp_channel starting at pool field */
memset(&(c->pool), 0, sizeof(struct bgp_channel) - OFFSETOF(struct bgp_channel, pool));
}
static inline struct bgp_channel_config *
bgp_find_channel_config(struct bgp_config *cf, u32 afi)
{
struct bgp_channel_config *cc;
BGP_CF_WALK_CHANNELS(cf, cc)
if (cc->afi == afi)
return cc;
return NULL;
}
struct rtable_config *
bgp_default_igp_table(struct bgp_config *cf, struct bgp_channel_config *cc, u32 type)
{
struct bgp_channel_config *cc2;
struct rtable_config *tab;
/* First, try table connected by the channel */
if (cc->c.table->addr_type == type)
return cc->c.table;
/* Find paired channel with the same SAFI but the other AFI */
u32 afi2 = cc->afi ^ 0x30000;
cc2 = bgp_find_channel_config(cf, afi2);
/* Second, try IGP table configured in the paired channel */
if (cc2 && (tab = (type == NET_IP4) ? cc2->igp_table_ip4 : cc2->igp_table_ip6))
return tab;
/* Third, try table connected by the paired channel */
if (cc2 && (cc2->c.table->addr_type == type))
return cc2->c.table;
/* Last, try default table of given type */
if (tab = rt_get_default_table(cf->c.global, type))
return tab;
cf_error("Undefined IGP table");
}
static struct rtable_config *
bgp_default_base_table(struct bgp_config *cf, struct bgp_channel_config *cc)
{
/* Expected table type */
u32 type = (cc->afi == BGP_AF_FLOW4) ? NET_IP4 : NET_IP6;
/* First, try appropriate IP channel */
u32 afi2 = BGP_AF(BGP_AFI(cc->afi), BGP_SAFI_UNICAST);
struct bgp_channel_config *cc2 = bgp_find_channel_config(cf, afi2);
if (cc2 && (cc2->c.table->addr_type == type))
return cc2->c.table;
/* Last, try default table of given type */
struct rtable_config *tab = rt_get_default_table(cf->c.global, type);
if (tab)
return tab;
cf_error("Undefined base table");
}
void
bgp_postconfig(struct proto_config *CF)
{
struct bgp_config *cf = (void *) CF;
/* Do not check templates at all */
if (cf->c.class == SYM_TEMPLATE)
return;
/* Handle undefined remote_as, zero should mean unspecified external */
if (!cf->remote_as && (cf->peer_type == BGP_PT_INTERNAL))
cf->remote_as = cf->local_as;
int internal = (cf->local_as == cf->remote_as);
int interior = internal || cf->confederation_member;
/* EBGP direct by default, IBGP multihop by default */
if (cf->multihop < 0)
cf->multihop = internal ? 64 : 0;
/* LLGR mode default based on GR mode */
if (cf->llgr_mode < 0)
cf->llgr_mode = cf->gr_mode ? BGP_LLGR_AWARE : 0;
/* Link check for single-hop BGP by default */
if (cf->check_link < 0)
cf->check_link = !cf->multihop;
if (!cf->local_as)
cf_error("Local AS number must be set");
if (ipa_zero(cf->remote_ip) && !cf->remote_range)
cf_error("Neighbor must be configured");
if (ipa_zero(cf->local_ip) && cf->strict_bind)
cf_error("Local address must be configured for strict bind");
if (!cf->remote_as && !cf->peer_type)
cf_error("Remote AS number (or peer type) must be set");
if ((cf->peer_type == BGP_PT_INTERNAL) && !internal)
cf_error("IBGP cannot have different ASNs");
if ((cf->peer_type == BGP_PT_EXTERNAL) && internal)
cf_error("EBGP cannot have the same ASNs");
if (!cf->iface && (ipa_is_link_local(cf->local_ip) ||
ipa_is_link_local(cf->remote_ip)))
cf_error("Link-local addresses require defined interface");
if (!(cf->capabilities && cf->enable_as4) && (cf->remote_as > 0xFFFF))
cf_error("Neighbor AS number out of range (AS4 not available)");
if (!internal && cf->rr_client)
cf_error("Only internal neighbor can be RR client");
if (internal && cf->rs_client)
cf_error("Only external neighbor can be RS client");
if (internal && (cf->local_role != BGP_ROLE_UNDEFINED))
cf_error("Local role cannot be set on IBGP sessions");
if (interior && (cf->local_role != BGP_ROLE_UNDEFINED))
log(L_WARN "BGP roles are not recommended to be used within AS confederations");
if (cf->require_roles && (cf->local_role == BGP_ROLE_UNDEFINED))
cf_error("Local role must be set if roles are required");
if (!cf->confederation && cf->confederation_member)
cf_error("Confederation ID must be set for member sessions");
if (cf->multihop && (ipa_is_link_local(cf->local_ip) ||
ipa_is_link_local(cf->remote_ip)))
cf_error("Multihop BGP cannot be used with link-local addresses");
if (cf->multihop && cf->iface)
cf_error("Multihop BGP cannot be bound to interface");
if (cf->multihop && cf->check_link)
cf_error("Multihop BGP cannot depend on link state");
if (cf->multihop && cf->bfd && ipa_zero(cf->local_ip))
cf_error("Multihop BGP with BFD requires specified local address");
if (!cf->gr_mode && cf->llgr_mode)
cf_error("Long-lived graceful restart requires basic graceful restart");
if (internal && cf->enforce_first_as)
cf_error("Enforce first AS check is requires EBGP sessions");
if (cf->keepalive_time > cf->hold_time)
cf_error("Keepalive time must be at most hold time");
if (cf->keepalive_time > (cf->hold_time / 2))
log(L_WARN "Keepalive time should be at most 1/2 of hold time");
if (cf->min_hold_time > cf->hold_time)
cf_error("Min hold time (%u) exceeds hold time (%u)",
cf->min_hold_time, cf->hold_time);
uint keepalive_time = cf->keepalive_time ?: cf->hold_time / 3;
if (cf->min_keepalive_time > keepalive_time)
cf_error("Min keepalive time (%u) exceeds keepalive time (%u)",
cf->min_keepalive_time, keepalive_time);
struct bgp_channel_config *cc;
BGP_CF_WALK_CHANNELS(cf, cc)
{
/* Handle undefined import filter */
if (cc->c.in_filter == FILTER_UNDEF)
if (interior)
cc->c.in_filter = FILTER_ACCEPT;
else
cf_error("EBGP requires explicit import policy");
/* Handle undefined export filter */
if (cc->c.out_filter == FILTER_UNDEF)
if (interior)
cc->c.out_filter = FILTER_REJECT;
else
cf_error("EBGP requires explicit export policy");
/* Disable after error incompatible with restart limit action */
if ((cc->c.in_limit.action == PLA_RESTART) && cf->disable_after_error)
cc->c.in_limit.action = PLA_DISABLE;
/* Different default based on rr_client, rs_client */
if (cc->next_hop_keep == 0xff)
cc->next_hop_keep = cf->rr_client ? NH_IBGP : (cf->rs_client ? NH_ALL : NH_NO);
/* Different default for gw_mode */
if (!cc->gw_mode)
cc->gw_mode = cf->multihop ? GW_RECURSIVE : GW_DIRECT;
/* Different default for next_hop_prefer */
if (!cc->next_hop_prefer)
cc->next_hop_prefer = (cc->gw_mode == GW_DIRECT) ? NHP_GLOBAL : NHP_LOCAL;
/* Defaults based on proto config */
if (cc->gr_able == 0xff)
cc->gr_able = (cf->gr_mode == BGP_GR_ABLE);
if (cc->llgr_able == 0xff)
cc->llgr_able = (cf->llgr_mode == BGP_LLGR_ABLE);
if (cc->llgr_time == ~0U)
cc->llgr_time = cf->llgr_time;
/* AIGP enabled by default on interior sessions */
if (cc->aigp == 0xff)
cc->aigp = interior;
/* Default values of IGP tables */
if ((cc->gw_mode == GW_RECURSIVE) && !cc->desc->no_igp)
{
if (!cc->igp_table_ip4 && (bgp_cc_is_ipv4(cc) || cc->ext_next_hop))
cc->igp_table_ip4 = bgp_default_igp_table(cf, cc, NET_IP4);
if (!cc->igp_table_ip6 && (bgp_cc_is_ipv6(cc) || cc->ext_next_hop))
cc->igp_table_ip6 = bgp_default_igp_table(cf, cc, NET_IP6);
if (cc->igp_table_ip4 && bgp_cc_is_ipv6(cc) && !cc->ext_next_hop)
cf_error("Mismatched IGP table type");
if (cc->igp_table_ip6 && bgp_cc_is_ipv4(cc) && !cc->ext_next_hop)
cf_error("Mismatched IGP table type");
}
/* Default value of base table */
if ((BGP_SAFI(cc->afi) == BGP_SAFI_FLOW) && cc->validate && !cc->base_table)
cc->base_table = bgp_default_base_table(cf, cc);
if (cc->base_table && !cc->base_table->trie_used)
cf_error("Flowspec validation requires base table (%s) with trie",
cc->base_table->name);
if (cf->multihop && (cc->gw_mode == GW_DIRECT))
cf_error("Multihop BGP cannot use direct gateway mode");
if ((cc->gw_mode == GW_RECURSIVE) && cc->c.table->sorted)
cf_error("BGP in recursive mode prohibits sorted table");
if (cf->deterministic_med && cc->c.table->sorted)
cf_error("BGP with deterministic MED prohibits sorted table");
if (cc->secondary && !cc->c.table->sorted)
cf_error("BGP with secondary option requires sorted table");
}
}
static int
bgp_reconfigure(struct proto *P, struct proto_config *CF)
{
struct bgp_proto *p = (void *) P;
const struct bgp_config *new = (void *) CF;
const struct bgp_config *old = p->cf;
if (proto_get_router_id(CF) != p->local_id)
return 0;
int same = !memcmp(((byte *) old) + sizeof(struct proto_config),
((byte *) new) + sizeof(struct proto_config),
// password item is last and must be checked separately
OFFSETOF(struct bgp_config, password) - sizeof(struct proto_config))
&& !bstrcmp(old->password, new->password)
&& ((!old->remote_range && !new->remote_range)
|| (old->remote_range && new->remote_range && net_equal(old->remote_range, new->remote_range)))
&& !bstrcmp(old->dynamic_name, new->dynamic_name)
&& (old->dynamic_name_digits == new->dynamic_name_digits);
/* FIXME: Move channel reconfiguration to generic protocol code ? */
struct channel *C, *C2;
struct bgp_channel_config *cc;
WALK_LIST(C, p->p.channels)
C->stale = 1;
BGP_CF_WALK_CHANNELS(new, cc)
{
C = (struct channel *) bgp_find_channel(p, cc->afi);
same = proto_configure_channel(P, &C, &cc->c) && same;
}
WALK_LIST_DELSAFE(C, C2, p->p.channels)
if (C->stale)
same = proto_configure_channel(P, &C, NULL) && same;
if (same && (p->start_state > BSS_PREPARE))
bgp_update_bfd(p, new->bfd);
/* We should update our copy of configuration ptr as old configuration will be freed */
if (same)
p->cf = new;
/* Reset name counter */
p->dynamic_name_counter = 0;
return same;
}
#define TABLE(cf, NAME) ((cf)->NAME ? (cf)->NAME->table : NULL )
static int
bgp_channel_reconfigure(struct channel *C, struct channel_config *CC, int *import_changed, int *export_changed)
{
struct bgp_proto *p = (void *) C->proto;
struct bgp_channel *c = (void *) C;
struct bgp_channel_config *new = (void *) CC;
struct bgp_channel_config *old = c->cf;
if ((new->secondary != old->secondary) ||
(new->validate != old->validate) ||
(new->gr_able != old->gr_able) ||
(new->llgr_able != old->llgr_able) ||
(new->llgr_time != old->llgr_time) ||
(new->ext_next_hop != old->ext_next_hop) ||
(new->add_path != old->add_path) ||
(new->export_table != old->export_table) ||
(TABLE(new, igp_table_ip4) != TABLE(old, igp_table_ip4)) ||
(TABLE(new, igp_table_ip6) != TABLE(old, igp_table_ip6)) ||
(TABLE(new, base_table) != TABLE(old, base_table)))
return 0;
if (new->mandatory && !old->mandatory && (C->channel_state != CS_UP))
return 0;
if ((new->gw_mode != old->gw_mode) ||
(new->next_hop_prefer != old->next_hop_prefer) ||
(new->aigp != old->aigp) ||
(new->cost != old->cost))
{
/* If import table is active and route refresh is possible, we just ask for route refresh */
if ((c->c.in_keep & RIK_PREFILTER) && (c->c.channel_state == CS_UP) && p->route_refresh)
bgp_schedule_packet(p->conn, c, PKT_ROUTE_REFRESH);
/* Otherwise we do complete reload */
else
*import_changed = 1;
}
if (!ipa_equal(new->next_hop_addr, old->next_hop_addr) ||
(new->next_hop_self != old->next_hop_self) ||
(new->next_hop_keep != old->next_hop_keep) ||
(new->aigp != old->aigp) ||
(new->aigp_originate != old->aigp_originate))
*export_changed = 1;
c->cf = new;
return 1;
}
static void
bgp_copy_config(struct proto_config *dest, struct proto_config *src)
{
struct bgp_config *d = (void *) dest;
struct bgp_config *s = (void *) src;
/* Copy BFD options */
if (s->bfd)
{
struct bfd_options *opts = cfg_alloc(sizeof(struct bfd_options));
memcpy(opts, s->bfd, sizeof(struct bfd_options));
d->bfd = opts;
}
}
/**
* bgp_error - report a protocol error
* @c: connection
* @code: error code (according to the RFC)
* @subcode: error sub-code
* @data: data to be passed in the Notification message
* @len: length of the data
*
* bgp_error() sends a notification packet to tell the other side that a protocol
* error has occurred (including the data considered erroneous if possible) and
* closes the connection.
*/
void
bgp_error(struct bgp_conn *c, uint code, uint subcode, byte *data, int len)
{
struct bgp_proto *p = c->bgp;
if (c->state == BS_CLOSE)
return;
bgp_log_error(p, BE_BGP_TX, "Error", code, subcode, data, ABS(len));
bgp_store_error(p, c, BE_BGP_TX, (code << 16) | subcode);
bgp_conn_enter_close_state(c);
c->notify_code = code;
c->notify_subcode = subcode;
c->notify_data = data;
c->notify_size = (len > 0) ? len : 0;
bgp_schedule_packet(c, NULL, PKT_NOTIFICATION);
if (code != 6)
{
bgp_update_startup_delay(p);
bgp_stop(p, 0, NULL, 0);
}
}
/**
* bgp_store_error - store last error for status report
* @p: BGP instance
* @c: connection
* @class: error class (BE_xxx constants)
* @code: error code (class specific)
*
* bgp_store_error() decides whether given error is interesting enough
* and store that error to last_error variables of @p
*/
void
bgp_store_error(struct bgp_proto *p, struct bgp_conn *c, u8 class, u32 code)
{
/* During PS_UP, we ignore errors on secondary connection */
if ((p->p.proto_state == PS_UP) && c && (c != p->conn))
return;
/* During PS_STOP, we ignore any errors, as we want to report
* the error that caused transition to PS_STOP
*/
if (p->p.proto_state == PS_STOP)
return;
p->last_error_class = class;
p->last_error_code = code;
}
static char *bgp_state_names[] = { "Idle", "Connect", "Active", "OpenSent", "OpenConfirm", "Established", "Close" };
static char *bgp_err_classes[] = { "", "Error: ", "Socket: ", "Received: ", "BGP Error: ", "Automatic shutdown: ", ""};
static char *bgp_misc_errors[] = { "", "Neighbor lost", "Invalid next hop", "Kernel MD5 auth failed", "No listening socket", "Link down", "BFD session down", "Graceful restart"};
static char *bgp_auto_errors[] = { "", "Route limit exceeded"};
static char *bgp_gr_states[] = { "None", "Regular", "Long-lived"};
static const char *
bgp_last_errmsg(struct bgp_proto *p)
{
switch (p->last_error_class)
{
case BE_MISC:
return bgp_misc_errors[p->last_error_code];
case BE_SOCKET:
return (p->last_error_code == 0) ? "Connection closed" : strerror(p->last_error_code);
case BE_BGP_RX:
case BE_BGP_TX:
return bgp_error_dsc(p->last_error_code >> 16, p->last_error_code & 0xFF);
case BE_AUTO_DOWN:
return bgp_auto_errors[p->last_error_code];
default:
return "";
}
}
static const char *
bgp_state_dsc(struct bgp_proto *p)
{
if (p->p.proto_state == PS_DOWN)
return "Down";
int state = MAX(p->incoming_conn.state, p->outgoing_conn.state);
if ((state == BS_IDLE) && (p->start_state >= BSS_CONNECT) && p->passive)
return "Passive";
return bgp_state_names[state];
}
static void
bgp_get_status(struct proto *P, byte *buf)
{
struct bgp_proto *p = (struct bgp_proto *) P;
const char *err1 = bgp_err_classes[p->last_error_class];
const char *err2 = bgp_last_errmsg(p);
if (P->proto_state == PS_DOWN)
bsprintf(buf, "%s%s", err1, err2);
else
bsprintf(buf, "%-14s%s%s", bgp_state_dsc(p), err1, err2);
}
static void
bgp_show_afis(int code, char *s, u32 *afis, uint count)
{
buffer b;
LOG_BUFFER_INIT(b);
buffer_puts(&b, s);
for (u32 *af = afis; af < (afis + count); af++)
{
const struct bgp_af_desc *desc = bgp_get_af_desc(*af);
if (desc)
buffer_print(&b, " %s", desc->name);
else
buffer_print(&b, " <%u/%u>", BGP_AFI(*af), BGP_SAFI(*af));
}
if (b.pos == b.end)
strcpy(b.end - 32, " ... <too long>");
cli_msg(code, b.start);
}
const char *
bgp_format_role_name(u8 role)
{
static const char *bgp_role_names[] = { "provider", "rs_server", "rs_client", "customer", "peer" };
if (role == BGP_ROLE_UNDEFINED) return "undefined";
if (role < ARRAY_SIZE(bgp_role_names)) return bgp_role_names[role];
return "?";
}
static void
bgp_show_capabilities(struct bgp_proto *p UNUSED, struct bgp_caps *caps)
{
struct bgp_af_caps *ac;
uint any_mp_bgp = 0;
uint any_gr_able = 0;
uint any_add_path = 0;
uint any_ext_next_hop = 0;
uint any_llgr_able = 0;
u32 *afl1 = alloca(caps->af_count * sizeof(u32));
u32 *afl2 = alloca(caps->af_count * sizeof(u32));
uint afn1, afn2;
WALK_AF_CAPS(caps, ac)
{
any_mp_bgp |= ac->ready;
any_gr_able |= ac->gr_able;
any_add_path |= ac->add_path;
any_ext_next_hop |= ac->ext_next_hop;
any_llgr_able |= ac->llgr_able;
}
if (any_mp_bgp)
{
cli_msg(-1006, " Multiprotocol");
afn1 = 0;
WALK_AF_CAPS(caps, ac)
if (ac->ready)
afl1[afn1++] = ac->afi;
bgp_show_afis(-1006, " AF announced:", afl1, afn1);
}
if (caps->route_refresh)
cli_msg(-1006, " Route refresh");
if (any_ext_next_hop)
{
cli_msg(-1006, " Extended next hop");
afn1 = 0;
WALK_AF_CAPS(caps, ac)
if (ac->ext_next_hop)
afl1[afn1++] = ac->afi;
bgp_show_afis(-1006, " IPv6 nexthop:", afl1, afn1);
}
if (caps->ext_messages)
cli_msg(-1006, " Extended message");
if (caps->gr_aware)
cli_msg(-1006, " Graceful restart");
if (any_gr_able)
{
/* Continues from gr_aware */
cli_msg(-1006, " Restart time: %u", caps->gr_time);
if (caps->gr_flags & BGP_GRF_RESTART)
cli_msg(-1006, " Restart recovery");
afn1 = afn2 = 0;
WALK_AF_CAPS(caps, ac)
{
if (ac->gr_able)
afl1[afn1++] = ac->afi;
if (ac->gr_af_flags & BGP_GRF_FORWARDING)
afl2[afn2++] = ac->afi;
}
bgp_show_afis(-1006, " AF supported:", afl1, afn1);
bgp_show_afis(-1006, " AF preserved:", afl2, afn2);
}
if (caps->as4_support)
cli_msg(-1006, " 4-octet AS numbers");
if (any_add_path)
{
cli_msg(-1006, " ADD-PATH");
afn1 = afn2 = 0;
WALK_AF_CAPS(caps, ac)
{
if (ac->add_path & BGP_ADD_PATH_RX)
afl1[afn1++] = ac->afi;
if (ac->add_path & BGP_ADD_PATH_TX)
afl2[afn2++] = ac->afi;
}
bgp_show_afis(-1006, " RX:", afl1, afn1);
bgp_show_afis(-1006, " TX:", afl2, afn2);
}
if (caps->enhanced_refresh)
cli_msg(-1006, " Enhanced refresh");
if (caps->llgr_aware)
cli_msg(-1006, " Long-lived graceful restart");
if (any_llgr_able)
{
u32 stale_time = 0;
afn1 = afn2 = 0;
WALK_AF_CAPS(caps, ac)
{
stale_time = MAX(stale_time, ac->llgr_time);
if (ac->llgr_able && ac->llgr_time)
afl1[afn1++] = ac->afi;
if (ac->llgr_flags & BGP_GRF_FORWARDING)
afl2[afn2++] = ac->afi;
}
/* Continues from llgr_aware */
cli_msg(-1006, " LL stale time: %u", stale_time);
bgp_show_afis(-1006, " AF supported:", afl1, afn1);
bgp_show_afis(-1006, " AF preserved:", afl2, afn2);
}
if (caps->hostname)
cli_msg(-1006, " Hostname: %s", caps->hostname);
if (caps->role != BGP_ROLE_UNDEFINED)
cli_msg(-1006, " Role: %s", bgp_format_role_name(caps->role));
}
static void
bgp_show_proto_info(struct proto *P)
{
struct bgp_proto *p = (struct bgp_proto *) P;
cli_msg(-1006, " BGP state: %s", bgp_state_dsc(p));
if (bgp_is_dynamic(p) && p->cf->remote_range)
cli_msg(-1006, " Neighbor range: %N", p->cf->remote_range);
else
cli_msg(-1006, " Neighbor address: %I%J", p->remote_ip, p->cf->iface);
if ((p->conn == &p->outgoing_conn) && (p->cf->remote_port != BGP_PORT))
cli_msg(-1006, " Neighbor port: %u", p->cf->remote_port);
cli_msg(-1006, " Neighbor AS: %u", p->remote_as);
cli_msg(-1006, " Local AS: %u", p->cf->local_as);
if (p->gr_active_num)
cli_msg(-1006, " Neighbor graceful restart active");
if (P->proto_state == PS_START)
{
struct bgp_conn *oc = &p->outgoing_conn;
if ((p->start_state < BSS_CONNECT) &&
(tm_active(p->startup_timer)))
cli_msg(-1006, " Error wait: %t/%u",
tm_remains(p->startup_timer), p->startup_delay);
if ((oc->state == BS_ACTIVE) &&
(tm_active(oc->connect_timer)))
cli_msg(-1006, " Connect delay: %t/%u",
tm_remains(oc->connect_timer), p->cf->connect_delay_time);
if (p->gr_active_num && tm_active(p->gr_timer))
cli_msg(-1006, " Restart timer: %t/-",
tm_remains(p->gr_timer));
}
else if (P->proto_state == PS_UP)
{
cli_msg(-1006, " Neighbor ID: %R", p->remote_id);
cli_msg(-1006, " Local capabilities");
bgp_show_capabilities(p, p->conn->local_caps);
cli_msg(-1006, " Neighbor capabilities");
bgp_show_capabilities(p, p->conn->remote_caps);
cli_msg(-1006, " Session: %s%s%s%s%s",
p->is_internal ? "internal" : "external",
p->cf->multihop ? " multihop" : "",
p->rr_client ? " route-reflector" : "",
p->rs_client ? " route-server" : "",
p->as4_session ? " AS4" : "");
cli_msg(-1006, " Source address: %I", p->local_ip);
cli_msg(-1006, " Hold timer: %t/%u",
tm_remains(p->conn->hold_timer), p->conn->hold_time);
cli_msg(-1006, " Keepalive timer: %t/%u",
tm_remains(p->conn->keepalive_timer), p->conn->keepalive_time);
cli_msg(-1006, " TX pending: %d bytes%s",
p->conn->sk->tpos - p->conn->sk->ttx,
ev_active(p->conn->tx_ev) ? " (refill scheduled)" : "");
}
#if 0
struct bgp_stats *s = &p->stats;
cli_msg(-1006, " FSM established transitions: %u",
s->fsm_established_transitions);
cli_msg(-1006, " Rcvd messages: %u total / %u updates / %lu bytes",
s->rx_messages, s->rx_updates, s->rx_bytes);
cli_msg(-1006, " Sent messages: %u total / %u updates / %lu bytes",
s->tx_messages, s->tx_updates, s->tx_bytes);
cli_msg(-1006, " Last rcvd update elapsed time: %t s",
p->last_rx_update ? (current_time() - p->last_rx_update) : 0);
#endif
if ((p->last_error_class != BE_NONE) &&
(p->last_error_class != BE_MAN_DOWN))
{
const char *err1 = bgp_err_classes[p->last_error_class];
const char *err2 = bgp_last_errmsg(p);
cli_msg(-1006, " Last error: %s%s", err1, err2);
}
{
struct bgp_channel *c;
WALK_LIST(c, p->p.channels)
{
channel_show_info(&c->c);
if (c->c.channel != &channel_bgp)
continue;
if (p->gr_active_num)
cli_msg(-1006, " Neighbor GR: %s", bgp_gr_states[c->gr_active]);
if (c->stale_timer && tm_active(c->stale_timer))
cli_msg(-1006, " LL stale timer: %t/-", tm_remains(c->stale_timer));
if (c->c.channel_state == CS_UP)
{
if (ipa_zero(c->link_addr))
cli_msg(-1006, " BGP Next hop: %I", c->next_hop_addr);
else
cli_msg(-1006, " BGP Next hop: %I %I", c->next_hop_addr, c->link_addr);
}
if (c->igp_table_ip4)
cli_msg(-1006, " IGP IPv4 table: %s", c->igp_table_ip4->name);
if (c->igp_table_ip6)
cli_msg(-1006, " IGP IPv6 table: %s", c->igp_table_ip6->name);
if (c->base_table)
cli_msg(-1006, " Base table: %s", c->base_table->name);
uint bucket_cnt = 0;
uint prefix_cnt = 0;
struct bgp_bucket *buck;
struct bgp_prefix *px;
if (c->ptx)
WALK_LIST(buck, c->ptx->bucket_queue)
{
bucket_cnt++;
WALK_LIST(px, buck->prefixes)
if (px->cur)
prefix_cnt++;
}
cli_msg(-1006, " Pending %u attribute sets with total %u prefixes to send",
bucket_cnt, prefix_cnt);
}
}
}
struct channel_class channel_bgp = {
.channel_size = sizeof(struct bgp_channel),
.config_size = sizeof(struct bgp_channel_config),
.init = bgp_channel_init,
.start = bgp_channel_start,
.shutdown = bgp_channel_shutdown,
.cleanup = bgp_channel_cleanup,
.reconfigure = bgp_channel_reconfigure,
};
struct protocol proto_bgp = {
.name = "BGP",
.template = "bgp%d",
.preference = DEF_PREF_BGP,
.channel_mask = NB_IP | NB_VPN | NB_FLOW,
.proto_size = sizeof(struct bgp_proto),
.config_size = sizeof(struct bgp_config),
.postconfig = bgp_postconfig,
.init = bgp_init,
.start = bgp_start,
.shutdown = bgp_shutdown,
.reconfigure = bgp_reconfigure,
.copy_config = bgp_copy_config,
.get_status = bgp_get_status,
.show_proto_info = bgp_show_proto_info
};
void bgp_build(void)
{
proto_build(&proto_bgp);
bgp_register_attrs();
bgp_listen_domain = DOMAIN_NEW(rtable);
LOCK_DOMAIN(rtable, bgp_listen_domain);
bgp_listen_pool = rp_new(proto_pool, bgp_listen_domain.rtable, "BGP Listen Sockets");
UNLOCK_DOMAIN(rtable, bgp_listen_domain);
}
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