FIB2.0: Adjacency complete pull model (VPP-487)

Change the adjacency completion model to pull not push.

A complete adjacency has a rewirte string, an incomplete one does not. the re-write string for a peer comes either from a discovery protocol (i.e. ARP/ND) or can be directly derived from the link type (i.e. GRE tunnels). Which method it is, is interface type specific.
For each packet type sent on a link to a peer there is a corresponding adjacency. For example, if there is a peer 10.0.0.1 on Eth0 and we need to send to it IPv4 and MPLS packets, there will be two adjacencies; one for the IPv4 and one for the MPLS packets. The adjacencies are thus distinguished by the packets the carry, this is known as the adjacency's 'link-type'. It is not an L3 packet type, since the adjacency can have a link type of Ethernet (for L2 over GRE).
The discovery protocols are not aware of all the link types required - only the FIB is. the FIB will create adjacencies as and when they are required, and it is thus then desirable to 'pull' from the discovery protocol the re-write required. The alternative (that we have now) is that the discovery protocol pushes (i.e. creates) adjacencies for each link type - this creates more adjacencies than we need.
To pull, FIB now requests from the interface-type to 'complete' the adjacency. The interface can then delegate to the discovery protocol (on ethernet links) or directly build the re-write (i.e on GRE).

Change-Id: I61451789ae03f26b1012d8d6524007b769b6c6ee
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/vnet/vnet/lisp-cp/lisp_types.c b/vnet/vnet/lisp-cp/lisp_types.c
index 1f527d6e92e..04b8462e4fc 100644
--- a/vnet/vnet/lisp-cp/lisp_types.c
+++ b/vnet/vnet/lisp-cp/lisp_types.c
@@ -698,7 +698,17 @@ ip_address_cmp (const ip_address_t * ip1, const ip_address_t * ip2)
 void
 ip_address_copy (ip_address_t * dst, const ip_address_t * src)
 {
-  clib_memcpy (dst, src, sizeof (ip_address_t));
+  if (IP4 == ip_addr_version (src))
+    {
+      /* don't copy any garbe from the union */
+      memset (dst, 0, sizeof (*dst));
+      dst->ip.v4 = src->ip.v4;
+      dst->version = IP4;
+    }
+  else
+    {
+      clib_memcpy (dst, src, sizeof (ip_address_t));
+    }
 }
 
 void
@@ -714,6 +724,26 @@ ip_address_set (ip_address_t * dst, const void *src, u8 version)
   ip_addr_version (dst) = version;
 }
 
+void
+ip_address_to_46 (const ip_address_t * addr,
+		  ip46_address_t * a, fib_protocol_t * proto)
+{
+  *proto = (IP4 == ip_addr_version (addr) ?
+	    FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6);
+  switch (*proto)
+    {
+    case FIB_PROTOCOL_IP4:
+      ip46_address_set_ip4 (a, &addr->ip.v4);
+      break;
+    case FIB_PROTOCOL_IP6:
+      a->ip6 = addr->ip.v6;
+      break;
+    default:
+      ASSERT (0);
+      break;
+    }
+}
+
 static void
 ip_prefix_normalize_ip4 (ip4_address_t * ip4, u8 preflen)
 {