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bgpd: fix VRF leaking with 'network import-check' (3/4)

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If 'bgp network import-check' is defined on the source BGP session,
prefixes that are defined with the network command cannot be leaked to
the other VRFs BGP table even if they are present in the origin VRF RIB
if the 'rt import' statement is defined after the 'network <prefix>'
ones.

When a prefix nexthop is updated, update the prefix route leaking. The
current state of nexthop validation is now stored in the attributes of
the bgp path info. Attributes are compared with the previous ones at
route leaking update so that a nexthop validation change now triggers
the update of destination VRF BGP table.

Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
This commit is contained in:
Louis Scalbert 2022-04-29 14:26:04 +02:00
parent bb71bc02fd
commit 879bfc01c8
4 changed files with 40 additions and 5 deletions
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1
bgpd/bgp_attr.c
View file

@ -864,6 +864,7 @@ bool attrhash_cmp(const void *p1, const void *p2)
attr1->df_alg == attr2->df_alg &&
attr1->nh_ifindex == attr2->nh_ifindex &&
attr1->nh_lla_ifindex == attr2->nh_lla_ifindex &&
attr1->nh_flags == attr2->nh_flags &&
attr1->distance == attr2->distance &&
srv6_l3vpn_same(attr1->srv6_l3vpn, attr2->srv6_l3vpn) &&
srv6_vpn_same(attr1->srv6_vpn, attr2->srv6_vpn) &&

3
bgpd/bgp_attr.h
View file

@ -155,6 +155,9 @@ struct attr {
uint32_t med;
uint32_t local_pref;
ifindex_t nh_ifindex;
uint8_t nh_flags;
#define BGP_ATTR_NH_VALID 0x01
/* Path origin attribute */
uint8_t origin;

17
bgpd/bgp_mplsvpn.c
View file

@ -2090,6 +2090,7 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp, /* to */
uint32_t num_labels = 0;
int nexthop_self_flag = 1;
struct bgp_path_info *bpi_ultimate = NULL;
struct bgp_path_info *bpi;
int origin_local = 0;
struct bgp *src_vrf;
struct interface *ifp;
@ -2179,6 +2180,20 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp, /* to */
community_strip_accept_own(&static_attr);
bn = bgp_afi_node_get(to_bgp->rib[afi][safi], afi, safi, p, NULL);
for (bpi = bgp_dest_get_bgp_path_info(bn); bpi; bpi = bpi->next) {
if (bpi->extra && bpi->extra->vrfleak &&
bpi->extra->vrfleak->parent == path_vpn)
break;
}
if (bpi && leak_update_nexthop_valid(to_bgp, bn, &static_attr, afi, safi,
path_vpn, bpi, src_vrf, p, debug))
SET_FLAG(static_attr.nh_flags, BGP_ATTR_NH_VALID);
else
UNSET_FLAG(static_attr.nh_flags, BGP_ATTR_NH_VALID);
/*
* Nexthop: stash and clear
*
@ -2271,8 +2286,6 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp, /* to */
new_attr = bgp_attr_intern(&static_attr);
bgp_attr_flush(&static_attr);
bn = bgp_afi_node_get(to_bgp->rib[afi][safi], afi, safi, p, NULL);
/*
* ensure labels are copied
*

24
bgpd/bgp_nht.c
View file

@ -903,7 +903,10 @@ void bgp_nexthop_update(struct vrf *vrf, struct prefix *match,
{
struct bgp_nexthop_cache_head *tree = NULL;
struct bgp_nexthop_cache *bnc_nhc, *bnc_import;
struct bgp *bgp;
struct bgp *bgp, *bgp_default;
struct bgp_path_info *pi;
struct bgp_dest *dest;
safi_t safi;
afi_t afi;
if (!vrf->info) {
@ -928,9 +931,24 @@ void bgp_nexthop_update(struct vrf *vrf, struct prefix *match,
tree = &bgp->import_check_table[afi];
bnc_import = bnc_find(tree, match, nhr->srte_color, 0);
if (bnc_import)
if (bnc_import) {
bgp_process_nexthop_update(bnc_import, nhr, true);
else if (BGP_DEBUG(nht, NHT))
bgp_default = bgp_get_default();
safi = nhr->safi;
if (bgp != bgp_default && bgp->rib[afi][safi]) {
dest = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi,
match, NULL);
for (pi = bgp_dest_get_bgp_path_info(dest); pi;
pi = pi->next)
if (pi->peer == bgp->peer_self &&
pi->type == ZEBRA_ROUTE_BGP &&
pi->sub_type == BGP_ROUTE_STATIC)
vpn_leak_from_vrf_update(bgp_default,
bgp, pi);
}
} else if (BGP_DEBUG(nht, NHT))
zlog_debug("parse nexthop update %pFX(%u)(%s): bnc info not found for import check",
&nhr->prefix, nhr->srte_color,
bgp->name_pretty);