gbp: add anonymous l3-out external interfaces

So far, GBP l3-out packets classification & policy relied on programmed
EP. All traffic to/from l3-out must go through a known EP.
This patch introduces a new feature where l3-out next-hops are only
known by their subnets (l3-out prefixes). As there are no longer known
EPs to program, an interface must be configured as external anonymous
l3-out. Packets classification & policy on this interface will rely on
the external subnets programmed in the BD VRF.
Note that contrary to all other interfaces in a GBP BD, external
anonymous l3-out interfaces have BD L2 learning turned on and rely on
ARP/ND.

Type: feature

Change-Id: Ieedb29dff4e967d08c4301e82d06bff450a63e5f
Signed-off-by: Benoît Ganne <bganne@cisco.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/src/plugins/gbp/gbp_policy_dpo.h b/src/plugins/gbp/gbp_policy_dpo.h
index 6b4f8c57fd0..1dc11ab2e32 100644
--- a/src/plugins/gbp/gbp_policy_dpo.h
+++ b/src/plugins/gbp/gbp_policy_dpo.h
@@ -17,6 +17,9 @@
 #define __GBP_POLICY_DPO_H__
 
 #include <vnet/dpo/dpo.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/fib/ip4_fib.h>
+#include <vnet/fib/ip6_fib.h>
 
 /**
  * @brief
@@ -81,6 +84,32 @@ gbp_policy_dpo_get (index_t index)
   return (pool_elt_at_index (gbp_policy_dpo_pool, index));
 }
 
+static_always_inline const gbp_policy_dpo_t *
+gbp_classify_get_gpd (const ip4_address_t * ip4, const ip6_address_t * ip6,
+		      const u32 fib_index)
+{
+  const gbp_policy_dpo_t *gpd;
+  const dpo_id_t *dpo;
+  const load_balance_t *lb;
+  u32 lbi;
+
+  if (ip4)
+    lbi = ip4_fib_forwarding_lookup (fib_index, ip4);
+  else if (ip6)
+    lbi = ip6_fib_table_fwding_lookup (&ip6_main, fib_index, ip6);
+  else
+    return 0;
+
+  lb = load_balance_get (lbi);
+  dpo = load_balance_get_bucket_i (lb, 0);
+
+  if (dpo->dpoi_type != gbp_policy_dpo_type)
+    return 0;
+
+  gpd = gbp_policy_dpo_get (dpo->dpoi_index);
+  return gpd;
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *