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Use neighbor cache to track direct route to the peer or multihop destination.

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Calculate next_hop properly based on the local address we get from the
neighbor entry.
This commit is contained in:
Martin Mares 2000-04-10 11:21:40 +00:00
parent 287111fed1
commit 48e842cc98
4 changed files with 167 additions and 108 deletions
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81
proto/bgp/attrs.c
View File

@ -23,16 +23,20 @@ void
bgp_rt_notify(struct proto *P, net *n, rte *new, rte *old, ea_list *tmpa)
{
DBG("BGP: Got route %I/%d\n", n->n.prefix, n->n.pxlen);
/* FIXME: Normalize attributes */
/* FIXME: Check next hop */
/* FIXME: Someone might have undefined the mandatory attributes */
}
static ea_list *
bgp_create_attrs(struct bgp_proto *p, rte *e, ea_list *old, struct linpool *pool)
static int
bgp_create_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool)
{
ea_list *ea = lp_alloc(pool, sizeof(ea_list) + 3*sizeof(eattr));
eattr *a = ea->attrs;
rta *rta = e->attrs;
ea->next = old;
ea->next = *attrs;
*attrs = ea;
ea->flags = EALF_SORTED;
ea->count = 3;
@ -68,17 +72,14 @@ bgp_create_attrs(struct bgp_proto *p, rte *e, ea_list *old, struct linpool *pool
a->type = EAF_TYPE_IP_ADDRESS;
a->u.ptr = lp_alloc(pool, sizeof(struct adata) + sizeof(ip_addr));
a->u.ptr->length = sizeof(ip_addr);
/* FIXME: These rules are bogus!!! */
if (rta->dest == RTD_ROUTER)
*(ip_addr *)a->u.ptr->data = e->attrs->gw;
if (p->cf->next_hop_self ||
!p->is_internal ||
rta->dest != RTD_ROUTER)
*(ip_addr *)a->u.ptr->data = p->local_addr;
else
{
/* FIXME: Next hop == self ... how to do that? */
*(ip_addr *)a->u.ptr->data = IPA_NONE;
}
*(ip_addr *)a->u.ptr->data = e->attrs->gw;
return ea;
return 0; /* Leave decision to the filters */
}
ea_list *
@ -115,15 +116,37 @@ bgp_path_prepend(struct linpool *pool, eattr *a, ea_list *old, int as)
return e;
}
static ea_list *
bgp_update_attrs(struct bgp_proto *p, rte *e, ea_list *old, struct linpool *pool)
static int
bgp_update_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool)
{
eattr *a;
if (!p->is_internal)
old = bgp_path_prepend(pool, ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)), old, p->local_as);
*attrs = bgp_path_prepend(pool, ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)), *attrs, p->local_as);
/* FIXME: Set NEXT_HOP to self */
a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
if (a && (p->is_internal || (!p->is_internal && e->attrs->iface == p->neigh->iface)))
{
/* Leave the original next hop attribute, will check later where does it point */
}
else
{
/* Need to create new one */
ea_list *ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr));
ea->next = *attrs;
*attrs = ea;
ea->flags = EALF_SORTED;
ea->count = 1;
a = ea->attrs;
a->id = EA_CODE(EAP_BGP, BA_NEXT_HOP);
a->flags = BAF_TRANSITIVE;
a->type = EAF_TYPE_IP_ADDRESS;
a->u.ptr = lp_alloc(pool, sizeof(struct adata) + sizeof(ip_addr));
a->u.ptr->length = sizeof(ip_addr);
*(ip_addr *)a->u.ptr->data = p->local_addr;
}
return old;
return 0; /* Leave decision to the filters */
}
int
@ -133,19 +156,16 @@ bgp_import_control(struct proto *P, rte **new, ea_list **attrs, struct linpool *
struct bgp_proto *p = (struct bgp_proto *) P;
struct bgp_proto *new_bgp = (e->attrs->proto->proto == &proto_bgp) ? (struct bgp_proto *) e->attrs->proto : NULL;
if (e->attrs->dest != RTD_ROUTER) /* FIXME: This is a debugging kludge, remove some day */
if (p == new_bgp) /* Poison reverse updates */
return -1;
if (new_bgp)
{
if (p->local_as == new_bgp->local_as && p->is_internal && new_bgp->is_internal)
return -1; /* Don't redistribute internal routes with IBGP */
*attrs = bgp_update_attrs(p, e, *attrs, pool);
return bgp_update_attrs(p, e, attrs, pool);
}
else
*attrs = bgp_create_attrs(p, e, *attrs, pool);
if (p == new_bgp) /* FIXME: Use a more realistic check based on the NEXT_HOP attribute */
return 1;
return 0; /* Leave the decision to the filter */
return bgp_create_attrs(p, e, attrs, pool);
}
int
@ -284,7 +304,7 @@ static struct attr_desc bgp_attr_table[] = {
{ "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */
NULL, NULL },
#if 0
/* FIXME: Handle community lists */
/* FIXME: Handle community lists and remember to convert their endianity and normalize them */
{ 0, 0 }, /* BA_COMMUNITY */
{ 0, 0 }, /* BA_ORIGINATOR_ID */
{ 0, 0 }, /* BA_CLUSTER_LIST */
@ -443,19 +463,12 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin
e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
ASSERT(e);
nexthop = *(ip_addr *) e->u.ptr->data;
neigh = neigh_find(&bgp->p, &nexthop, 0);
if (!neigh)
if (ipa_equal(nexthop, bgp->local_addr))
{
if (bgp->cf->multihop)
neigh = neigh_find(&bgp->p, &bgp->cf->multihop_via, 0);
else
neigh = neigh_find(&bgp->p, &bgp->cf->remote_ip, 0);
}
if (!neigh || !neigh->iface)
{
DBG("BGP: No route to peer!\n"); /* FIXME */
DBG("BGP: Loop!\n"); /* FIXME */
return NULL;
}
neigh = neigh_find(&bgp->p, &nexthop, 0) ? : bgp->neigh;
a->gw = neigh->addr;
a->iface = neigh->iface;
return rta_lookup(a);

187
proto/bgp/bgp.c
View File

@ -26,25 +26,6 @@ static list bgp_list; /* List of active BGP instances */
static char *bgp_state_names[] = { "Idle", "Connect", "Active", "OpenSent", "OpenConfirm", "Established" };
static void bgp_connect(struct bgp_proto *p);
static void bgp_setup_sk(struct bgp_proto *p, struct bgp_conn *conn, sock *s);
static struct proto *
bgp_init(struct proto_config *C)
{
struct bgp_config *c = (struct bgp_config *) C;
struct proto *P = proto_new(C, sizeof(struct bgp_proto));
struct bgp_proto *p = (struct bgp_proto *) P;
P->rt_notify = bgp_rt_notify;
P->rte_better = bgp_rte_better;
P->import_control = bgp_import_control;
p->cf = c;
p->local_as = c->local_as;
p->remote_as = c->remote_as;
p->is_internal = (c->local_as == c->remote_as);
p->local_id = C->global->router_id;
return P;
}
void
bgp_close(struct bgp_proto *p)
@ -99,6 +80,27 @@ bgp_close_conn(struct bgp_conn *conn)
}
}
static int
bgp_graceful_close_conn(struct bgp_conn *c)
{
switch (c->state)
{
case BS_IDLE:
return 0;
case BS_CONNECT:
case BS_ACTIVE:
bgp_close_conn(c);
return 1;
case BS_OPENSENT:
case BS_OPENCONFIRM:
case BS_ESTABLISHED:
bgp_error(c, 6, 0, 0, 0);
return 1;
default:
bug("bgp_graceful_close_conn: Unknown state %d", c->state);
}
}
static void
bgp_send_open(struct bgp_conn *conn)
{
@ -152,33 +154,6 @@ bgp_sock_err(sock *sk, int err)
bgp_close_conn(conn);
}
static int
bgp_incoming_connection(sock *sk, int dummy)
{
node *n;
DBG("BGP: Incoming connection from %I port %d\n", sk->daddr, sk->dport);
WALK_LIST(n, bgp_list)
{
struct bgp_proto *p = SKIP_BACK(struct bgp_proto, bgp_node, n);
if (ipa_equal(p->cf->remote_ip, sk->daddr) && sk->dport == BGP_PORT)
{
DBG("BGP: Authorized\n");
if (p->incoming_conn.sk)
{
DBG("BGP: But one incoming connection already exists, how is that possible?\n");
break;
}
bgp_setup_sk(p, &p->incoming_conn, sk);
bgp_send_open(&p->incoming_conn);
return 0;
}
}
DBG("BGP: Unauthorized\n");
rfree(sk);
return 0;
}
static void
bgp_hold_timeout(timer *t)
{
@ -253,12 +228,38 @@ bgp_connect(struct bgp_proto *p) /* Enter Connect state and start establishing c
bgp_start_timer(conn->connect_retry_timer, p->cf->connect_retry_time);
}
static void
bgp_start_locked(struct object_lock *lock)
static int
bgp_incoming_connection(sock *sk, int dummy)
{
struct bgp_proto *p = lock->data;
node *n;
DBG("BGP: Got lock\n");
DBG("BGP: Incoming connection from %I port %d\n", sk->daddr, sk->dport);
WALK_LIST(n, bgp_list)
{
struct bgp_proto *p = SKIP_BACK(struct bgp_proto, bgp_node, n);
if (ipa_equal(p->cf->remote_ip, sk->daddr) && sk->dport == BGP_PORT)
{
DBG("BGP: Authorized\n");
if (p->incoming_conn.sk)
{
DBG("BGP: But one incoming connection already exists, how is that possible?\n");
break;
}
bgp_setup_sk(p, &p->incoming_conn, sk);
bgp_send_open(&p->incoming_conn);
return 0;
}
}
DBG("BGP: Unauthorized\n");
rfree(sk);
return 0;
}
static void
bgp_start_neighbor(struct bgp_proto *p)
{
p->local_addr = p->neigh->iface->addr->ip;
DBG("BGP: local=%I remote=%I\n", p->local_addr, p->next_hop);
if (!bgp_counter++)
init_list(&bgp_list);
if (!bgp_listen_sk)
@ -282,7 +283,49 @@ bgp_start_locked(struct object_lock *lock)
if (!bgp_linpool)
bgp_linpool = lp_new(&root_pool, 4080);
add_tail(&bgp_list, &p->bgp_node);
bgp_connect(p); /* FIXME: Use neighbor cache for fast up/down transitions? */
bgp_connect(p);
}
static void
bgp_neigh_notify(neighbor *n)
{
struct bgp_proto *p = (struct bgp_proto *) n->proto;
if (n->iface)
{
DBG("BGP: Neighbor is reachable\n");
bgp_start_neighbor(p);
}
else
{
DBG("BGP: Neighbor is unreachable\n");
/* Send cease packets, but don't wait for them to be delivered */
bgp_graceful_close_conn(&p->outgoing_conn);
bgp_graceful_close_conn(&p->incoming_conn);
proto_notify_state(&p->p, PS_DOWN);
/* FIXME: Remember to delay protocol startup here! */
}
}
static void
bgp_start_locked(struct object_lock *lock)
{
struct bgp_proto *p = lock->data;
struct bgp_config *cf = p->cf;
DBG("BGP: Got lock\n");
p->next_hop = cf->multihop ? cf->multihop_via : cf->remote_ip;
p->neigh = neigh_find(&p->p, &p->next_hop, NEF_STICKY);
if (!p->neigh)
{
log(L_ERR "%s: Invalid next hop %I", p->p.name, p->next_hop);
p->p.disabled = 1;
proto_notify_state(&p->p, PS_DOWN);
}
else if (p->neigh->iface)
bgp_start_neighbor(p);
else
DBG("BGP: Waiting for neighbor\n");
}
static int
@ -312,27 +355,6 @@ bgp_start(struct proto *P)
return PS_START;
}
static int
bgp_graceful_close(struct bgp_conn *c)
{
switch (c->state)
{
case BS_IDLE:
return 0;
case BS_CONNECT:
case BS_ACTIVE:
bgp_close_conn(c);
return 1;
case BS_OPENSENT:
case BS_OPENCONFIRM:
case BS_ESTABLISHED:
bgp_error(c, 6, 0, 0, 0);
return 1;
default:
bug("bgp_graceful_close: Unknown state %d", c->state);
}
}
static int
bgp_shutdown(struct proto *P)
{
@ -356,7 +378,7 @@ bgp_shutdown(struct proto *P)
else if (p->incoming_conn.state != BS_IDLE)
p->incoming_conn.primary = 1;
}
if (bgp_graceful_close(&p->outgoing_conn) || bgp_graceful_close(&p->incoming_conn))
if (bgp_graceful_close_conn(&p->outgoing_conn) || bgp_graceful_close_conn(&p->incoming_conn))
return p->p.proto_state;
else
{
@ -366,6 +388,25 @@ bgp_shutdown(struct proto *P)
}
}
static struct proto *
bgp_init(struct proto_config *C)
{
struct bgp_config *c = (struct bgp_config *) C;
struct proto *P = proto_new(C, sizeof(struct bgp_proto));
struct bgp_proto *p = (struct bgp_proto *) P;
P->rt_notify = bgp_rt_notify;
P->rte_better = bgp_rte_better;
P->import_control = bgp_import_control;
P->neigh_notify = bgp_neigh_notify;
p->cf = c;
p->local_as = c->local_as;
p->remote_as = c->remote_as;
p->is_internal = (c->local_as == c->remote_as);
p->local_id = C->global->router_id;
return P;
}
void
bgp_error(struct bgp_conn *c, unsigned code, unsigned subcode, unsigned data, unsigned len)
{

4
proto/bgp/bgp.h
View File

@ -18,6 +18,7 @@ struct bgp_config {
ip_addr remote_ip;
int multihop; /* Number of hops if multihop */
ip_addr multihop_via; /* Multihop: address to route to */
int next_hop_self; /* Always set next hop to local IP address */
unsigned connect_retry_time;
unsigned hold_time, initial_hold_time;
unsigned keepalive_time;
@ -49,6 +50,9 @@ struct bgp_proto {
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 */
};
#define BGP_PORT 179

3
proto/bgp/config.Y
View File

@ -15,7 +15,7 @@ CF_HDR
CF_DECLS
CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, KEEPALIVE,
MULTIHOP, STARTUP, VIA)
MULTIHOP, STARTUP, VIA, NEXT, HOP, SELF)
CF_GRAMMAR
@ -47,6 +47,7 @@ bgp_proto:
| bgp_proto CONNECT RETRY TIME NUM ';' { BGP_CFG->connect_retry_time = $5; }
| bgp_proto KEEPALIVE TIME NUM ';' { BGP_CFG->connect_retry_time = $4; }
| bgp_proto MULTIHOP NUM VIA IPA ';' { BGP_CFG->multihop = $3; BGP_CFG->multihop_via = $5; }
| bgp_proto NEXT HOP SELF ';' { BGP_CFG->next_hop_self = 1; }
;
CF_CODE