IP Multicast FIB (mfib)

 - IPv[46] mfib tables with support for (*,G/m), (*,G) and (S,G) exact and longest prefix match
 - Replication represented via a new replicate DPO.
 - RPF configuration and data-plane checking
 - data-plane signals sent to listening control planes.

The functions of multicast forwarding entries differ from their unicast conterparts, so we introduce a new mfib_table_t and mfib_entry_t objects. However, we re-use the fib_path_list to resolve and build the entry's output list. the fib_path_list provides the service to construct a replicate DPO for multicast.

'make tests' is added to with two new suites; TEST=mfib, this is invocation of the CLI command 'test mfib' which deals with many path add/remove, flag set/unset scenarios, TEST=ip-mcast, data-plane forwarding tests.

Updated applications to use the new MIFB functions;
  - IPv6 NS/RA.
  - DHCPv6
 unit tests for these are undated accordingly.

Change-Id: I49ec37b01f1b170335a5697541c8fd30e6d3a961
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/mfib/ip6_mfib.h b/src/vnet/mfib/ip6_mfib.h
new file mode 100644
index 0000000..d91af46
--- /dev/null
+++ b/src/vnet/mfib/ip6_mfib.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * @brief The IPv4 Multicast-FIB
+ *
+ * FIXME
+ *
+ * This IPv4 FIB is used by the protocol independent FIB. So directly using
+ * this APIs in client code is not encouraged. However, this IPv4 FIB can be
+ * used if all the client wants is an IPv4 prefix data-base
+ */
+
+#ifndef __IP6_MFIB_H__
+#define __IP6_MFIB_H__
+
+#include <vlib/vlib.h>
+#include <vnet/ip/ip.h>
+
+#include <vnet/mfib/mfib_table.h>
+
+extern fib_node_index_t ip6_mfib_table_lookup(const ip6_mfib_t *fib,
+                                              const ip6_address_t *src,
+                                              const ip6_address_t *grp,
+                                              u32 len);
+extern fib_node_index_t ip6_mfib_table_lookup_exact_match(const ip6_mfib_t *fib,
+                                                          const ip6_address_t *grp,
+                                                          const ip6_address_t *src,
+                                                          u32 len);
+
+extern void ip6_mfib_table_entry_remove(ip6_mfib_t *fib,
+                                        const ip6_address_t *grp,
+                                        const ip6_address_t *src,
+                                        u32 len);
+
+extern void ip6_mfib_table_entry_insert(ip6_mfib_t *fib,
+                                        const ip6_address_t *grp,
+                                        const ip6_address_t *src,
+                                        u32 len,
+                                        fib_node_index_t fib_entry_index);
+extern void ip6_mfib_table_destroy(ip6_mfib_t *fib);
+
+/**
+ * @brief
+ *  Add/remove the interface from the accepting list of the special MFIB entries
+ */
+extern void ip6_mfib_interface_enable_disable(u32 sw_if_index,
+                                              int is_enable);
+
+/**
+ * @brief Get the FIB at the given index
+ */
+static inline ip6_mfib_t *
+ip6_mfib_get (u32 index)
+{
+    return (&(pool_elt_at_index(ip6_main.mfibs, index)->v6));
+}
+
+/**
+ * @brief Get or create an IPv4 fib.
+ *
+ * Get or create an IPv4 fib with the provided table ID.
+ *
+ * @param table_id
+ *      When set to \c ~0, an arbitrary and unused fib ID is picked
+ *      and can be retrieved with \c ret->table_id.
+ *      Otherwise, the fib ID to be used to retrieve or create the desired fib.
+ * @returns A pointer to the retrieved or created fib.
+ *
+ */
+extern u32 ip6_mfib_table_find_or_create_and_lock(u32 table_id);
+extern u32 ip6_mfib_table_create_and_lock(void);
+
+
+static inline
+u32 ip6_mfib_index_from_table_id (u32 table_id)
+{
+  ip6_main_t * im = &ip6_main;
+  uword * p;
+
+  p = hash_get (im->mfib_index_by_table_id, table_id);
+  if (!p)
+    return ~0;
+
+  return p[0];
+}
+
+extern u32 ip6_mfib_table_get_index_for_sw_if_index(u32 sw_if_index);
+
+/**
+ * @brief Data-plane lookup function
+ */
+extern fib_node_index_t ip6_mfib_table_lookup2(const ip6_mfib_t *mfib,
+                                               const ip6_address_t *src,
+                                               const ip6_address_t *grp);
+
+#endif
+