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-rw-r--r--proto/bgp/attrs.c109
1 files changed, 61 insertions, 48 deletions
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index f330483..22c73ca 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -29,6 +29,7 @@ struct attr_desc {
int expected_length;
int expected_flags;
int type;
+ int allow_in_ebgp;
int (*validate)(struct bgp_proto *p, byte *attr, int len);
void (*format)(eattr *ea, byte *buf);
};
@@ -78,32 +79,24 @@ bgp_check_next_hop(struct bgp_proto *p, byte *a, int len)
return 8;
}
-static int
-bgp_check_local_pref(struct bgp_proto *p, byte *a, int len)
-{
- if (!p->is_internal) /* Ignore local preference from EBGP connections */
- return -1;
- return 0;
-}
-
static struct attr_desc bgp_attr_table[] = {
- { NULL, -1, 0, 0, /* Undefined */
+ { NULL, -1, 0, 0, 0, /* Undefined */
NULL, NULL },
- { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, /* BA_ORIGIN */
+ { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, 1, /* BA_ORIGIN */
bgp_check_origin, bgp_format_origin },
- { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, /* BA_AS_PATH */
+ { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, 1, /* BA_AS_PATH */
bgp_check_path, NULL },
- { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, /* BA_NEXT_HOP */
+ { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, 1, /* BA_NEXT_HOP */
bgp_check_next_hop, NULL },
- { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_MULTI_EXIT_DISC */
+ { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, 0, /* BA_MULTI_EXIT_DISC */
NULL, NULL },
- { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_LOCAL_PREF */
- bgp_check_local_pref, NULL },
- { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_ATOMIC_AGGR */
+ { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, 0, /* BA_LOCAL_PREF */
NULL, NULL },
- { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */
+ { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_ATOMIC_AGGR */
NULL, NULL },
- { "community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_INT_SET, /* BA_COMMUNITY */
+ { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_AGGREGATOR */
+ NULL, NULL },
+ { "community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_INT_SET, 1, /* BA_COMMUNITY */
NULL, NULL },
#if 0
{ 0, 0 }, /* BA_ORIGINATOR_ID */
@@ -308,10 +301,9 @@ static struct bgp_bucket *
bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp, int originate)
{
ea_list *t, *new;
- unsigned i, cnt;
+ unsigned i, cnt, hash, code;
eattr *a, *d;
u32 seen = 0;
- unsigned hash;
struct bgp_bucket *b;
/* Merge the attribute lists */
@@ -339,8 +331,14 @@ bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp, int originate)
#endif
if (EA_PROTO(a->id) != EAP_BGP)
continue;
- if (EA_ID(a->id) < 32)
- seen |= 1 << EA_ID(a->id);
+ code = EA_ID(a->id);
+ if (code < ARRAY_SIZE(bgp_attr_table))
+ {
+ if (!bgp_attr_table[code].allow_in_ebgp && !p->is_internal)
+ continue;
+ }
+ if (code < 32)
+ seen |= 1 << code;
*d = *a;
if ((d->type & EAF_ORIGINATED) && !originate && (d->flags & BAF_TRANSITIVE) && (d->flags & BAF_OPTIONAL))
d->flags |= BAF_PARTIAL;
@@ -562,20 +560,53 @@ bgp_rte_better(rte *new, rte *old)
{
struct bgp_proto *new_bgp = (struct bgp_proto *) new->attrs->proto;
struct bgp_proto *old_bgp = (struct bgp_proto *) old->attrs->proto;
- eattr *new_lpref = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF));
- eattr *old_lpref = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF));
+ eattr *x, *y;
+ u32 n, o;
/* Start with local preferences */
- if (new_lpref && old_lpref) /* Somebody might have undefined them */
+ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF));
+ y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF));
+ n = x ? x->u.data : new_bgp->cf->default_local_pref;
+ o = y ? y->u.data : old_bgp->cf->default_local_pref;
+ if (n > o)
+ return 1;
+ if (n < o)
+ return 0;
+
+ /* Use AS path lengths */
+ if (new_bgp->cf->compare_path_lengths || old_bgp->cf->compare_path_lengths)
{
- if (new_lpref->u.data > old_lpref->u.data)
+ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH));
+ y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH));
+ n = x ? as_path_getlen(x->u.ptr) : 100000;
+ o = y ? as_path_getlen(y->u.ptr) : 100000;
+ if (n < o)
return 1;
- if (new_lpref->u.data < old_lpref->u.data)
+ if (n > o)
return 0;
}
+ /* Use origins */
+ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN));
+ y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN));
+ n = x ? x->u.data : 2;
+ o = y ? y->u.data : 2;
+ if (n < o)
+ return 1;
+ if (n > o)
+ return 0;
+
+ /* Compare MED's */
+ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC));
+ y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC));
+ n = x ? x->u.data : new_bgp->cf->default_med;
+ o = y ? y->u.data : old_bgp->cf->default_med;
+ if (n < o)
+ return 1;
+ if (n > o)
+ return 0;
+
/* A tie breaking procedure according to RFC 1771, section 9.1.2.1 */
- /* FIXME: Look at MULTI_EXIT_DISC, take the lowest */
/* We don't have interior distances */
/* We prefer external peers */
if (new_bgp->is_internal > old_bgp->is_internal)
@@ -587,12 +618,6 @@ bgp_rte_better(rte *new, rte *old)
}
static int
-bgp_local_pref(struct bgp_proto *p, rta *a)
-{
- return 0; /* FIXME (should be compatible with Cisco defaults?) */
-}
-
-static int
bgp_path_loopy(struct bgp_proto *p, eattr *a)
{
byte *path = a->u.ptr->data;
@@ -680,6 +705,8 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin
{ errcode = 5; goto err; }
if ((desc->expected_flags ^ flags) & (BAF_OPTIONAL | BAF_TRANSITIVE))
{ errcode = 4; goto err; }
+ if (!desc->allow_in_ebgp && !bgp->is_internal)
+ continue;
if (desc->validate)
{
errcode = desc->validate(bgp, z, l);
@@ -747,20 +774,6 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin
}
}
- /* Assign local preference if none defined */
- if (!(seen[BA_LOCAL_PREF/8] & (1 << (BA_LOCAL_PREF%8))))
- {
- ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr));
- ea->next = a->eattrs;
- a->eattrs = ea;
- ea->flags = 0;
- ea->count = 1;
- ea->attrs[0].id = EA_CODE(EAP_BGP, BA_LOCAL_PREF);
- ea->attrs[0].flags = BAF_OPTIONAL;
- ea->attrs[0].type = EAF_TYPE_INT;
- ea->attrs[0].u.data = bgp_local_pref(bgp, a);
- }
-
/* If the AS path attribute contains our AS, reject the routes */
e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH));
ASSERT(e);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-04 22:11:35 +0100