mirror/labs-bird
1
0
Fork 0
mirror of https://gitlab.labs.nic.cz/labs/bird.git synced 2024-05-11 16:54:54 +00:00
Code Releases Activity

MPLS: Add support for per-VRF labeling policy

Browse Source 
The new labeling policy MPLS_POLICY_VRF assigns one label to all routes
(from the same FEC map associated with one VRF), while replaces their
next hops with a lookup to a VRF table. This is useful for L3VPN
protocol.
This commit is contained in:
Ondrej Zajicek
2022-10-01 22:38:49 +02:00
parent 9d456d5366
commit 9ca86ef69c
4 changed files with 53 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
nest/mpls.c
View File

@@ -52,14 +52,16 @@
* map, which can be used by the protocols that work with IP-prefix-based FECs.
*
* The FEC map keeps hash tables of FECs (struct &mpls_fec) based on network
* prefix, next hop eattr and assigned label. It has three labeling policies:
* prefix, next hop eattr and assigned label. It has three general labeling policies:
* static assignment (%MPLS_POLICY_STATIC), per-prefix policy (%MPLS_POLICY_PREFIX),
* and aggregating policy (%MPLS_POLICY_AGGREGATE). In per-prefix policy, each
* distinct LSP is a separate FEC and uses a separate label, which is kept even
* if the next hop of the LSP changes. In aggregating policy, LSPs with a same
* next hop form one FEC and use one label, but when a next hop (or remote
* label) of such LSP changes then the LSP must be moved to a different FEC and
* assigned a different label.
* assigned a different label. There is also a special VRF policy (%MPLS_POLICY_VRF)
* applicable for L3VPN protocols, which uses one label for all routes from a VRF,
* while replacing the original next hop with lookup in the VRF.
*
* The overall process works this way: A protocol wants to announce a LSP route,
* it does that by announcing e.g. IP route with %EA_MPLS_POLICY attribute.
@@ -746,6 +748,28 @@ mpls_get_fec_by_rta(struct mpls_fec_map *m, const rta *src, u32 class_id)
return fec;
}
struct mpls_fec *
mpls_get_fec_for_vrf(struct mpls_fec_map *m)
{
struct mpls_fec *fec = m->vrf_fec;
if (fec)
return fec;
fec = sl_allocz(mpls_slab(m, 0));
fec->label = mpls_new_label(m->domain, m->handle);
fec->policy = MPLS_POLICY_VRF;
fec->iface = m->vrf_iface;
DBG("New FEC vrf %u\n", fec->label);
m->vrf_fec = fec;
HASH_INSERT2(m->label_hash, LABEL, m->pool, fec);
return fec;
}
void
mpls_free_fec(struct mpls_fec_map *m, struct mpls_fec *fec)
{
@@ -771,6 +795,11 @@ mpls_free_fec(struct mpls_fec_map *m, struct mpls_fec *fec)
HASH_REMOVE2(m->rta_hash, RTA, m->pool, fec);
break;
case MPLS_POLICY_VRF:
ASSERT(m->vrf_fec == fec);
m->vrf_fec = NULL;
break;
default:
bug("Unknown fec type");
}
@@ -892,6 +921,13 @@ mpls_apply_fec(rte *r, struct mpls_fec *fec, linpool *lp)
r->attrs->eattrs = ea;
if (fec->policy == MPLS_POLICY_VRF)
{
r->attrs->hostentry = NULL;
r->attrs->dest = RTD_UNICAST;
r->attrs->nh = (struct nexthop) { .iface = fec->iface };
}
if (rta_is_cached(old_attrs))
{
r->attrs = rta_lookup(r->attrs);
@@ -907,7 +943,6 @@ mpls_handle_rte(struct mpls_fec_map *m, const net_addr *n, rte *r, linpool *lp,
struct mpls_fec *fec = NULL;
/* Select FEC for route */
uint policy = ea_get_int(r->attrs->eattrs, EA_MPLS_POLICY, 0);
switch (policy)
@@ -935,6 +970,13 @@ mpls_handle_rte(struct mpls_fec_map *m, const net_addr *n, rte *r, linpool *lp,
fec = mpls_get_fec_by_rta(m, r->attrs, class);
break;
case MPLS_POLICY_VRF:
if (!m->vrf_iface)
return;
fec = mpls_get_fec_for_vrf(m);
break;
default:
log(L_WARN "Route %N has invalid MPLS policy %u", n, policy);
return;