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/ip/lookup.c b/src/vnet/ip/lookup.c
index 734a4cd..6c5611d 100644
--- a/src/vnet/ip/lookup.c
+++ b/src/vnet/ip/lookup.c
@@ -43,6 +43,7 @@
 #include <vnet/fib/ip4_fib.h>
 #include <vnet/fib/ip6_fib.h>
 #include <vnet/mpls/mpls.h>
+#include <vnet/mfib/mfib_table.h>
 #include <vnet/dpo/drop_dpo.h>
 #include <vnet/dpo/classify_dpo.h>
 #include <vnet/dpo/punt_dpo.h>
@@ -258,6 +259,9 @@
     case IP_LOOKUP_NEXT_GLEAN:
       t = "glean";
       break;
+    case IP_LOOKUP_NEXT_MCAST:
+      t = "mcast";
+      break;
     case IP_LOOKUP_NEXT_REWRITE:
       break;
     }
@@ -767,6 +771,173 @@
 };
 /* *INDENT-ON* */
 
+clib_error_t *
+vnet_ip_mroute_cmd (vlib_main_t * vm,
+		    unformat_input_t * main_input, vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = NULL;
+  fib_route_path_t rpath;
+  u32 table_id, is_del;
+  vnet_main_t *vnm;
+  mfib_prefix_t pfx;
+  u32 fib_index;
+  mfib_itf_flags_t iflags = 0;
+  mfib_entry_flags_t eflags = 0;
+
+  vnm = vnet_get_main ();
+  is_del = 0;
+  table_id = 0;
+  memset (&pfx, 0, sizeof (pfx));
+  memset (&rpath, 0, sizeof (rpath));
+  rpath.frp_sw_if_index = ~0;
+
+  /* Get a line of input. */
+  if (!unformat_user (main_input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "table %d", &table_id))
+	;
+      else if (unformat (line_input, "del"))
+	is_del = 1;
+      else if (unformat (line_input, "add"))
+	is_del = 0;
+      else if (unformat (line_input, "%U %U",
+			 unformat_ip4_address,
+			 &pfx.fp_src_addr.ip4,
+			 unformat_ip4_address, &pfx.fp_grp_addr.ip4))
+	{
+	  pfx.fp_proto = FIB_PROTOCOL_IP4;
+	  pfx.fp_len = 64;
+	}
+      else if (unformat (line_input, "%U %U",
+			 unformat_ip6_address,
+			 &pfx.fp_src_addr.ip6,
+			 unformat_ip6_address, &pfx.fp_grp_addr.ip6))
+	{
+	  pfx.fp_proto = FIB_PROTOCOL_IP6;
+	  pfx.fp_len = 256;
+	}
+      else if (unformat (line_input, "%U/%d",
+			 unformat_ip4_address,
+			 &pfx.fp_grp_addr.ip4, &pfx.fp_len))
+	{
+	  pfx.fp_proto = FIB_PROTOCOL_IP4;
+	}
+      else if (unformat (line_input, "%U/%d",
+			 unformat_ip6_address,
+			 &pfx.fp_grp_addr.ip6, &pfx.fp_len))
+	{
+	  pfx.fp_proto = FIB_PROTOCOL_IP6;
+	}
+      else if (unformat (line_input, "%U",
+			 unformat_ip4_address, &pfx.fp_grp_addr.ip4))
+	{
+	  memset (&pfx.fp_src_addr.ip4, 0, sizeof (pfx.fp_src_addr.ip4));
+	  pfx.fp_proto = FIB_PROTOCOL_IP4;
+	  pfx.fp_len = 32;
+	}
+      else if (unformat (line_input, "%U",
+			 unformat_ip6_address, &pfx.fp_grp_addr.ip6))
+	{
+	  memset (&pfx.fp_src_addr.ip6, 0, sizeof (pfx.fp_src_addr.ip6));
+	  pfx.fp_proto = FIB_PROTOCOL_IP6;
+	  pfx.fp_len = 128;
+	}
+      else if (unformat (line_input, "via %U",
+			 unformat_vnet_sw_interface, vnm,
+			 &rpath.frp_sw_if_index))
+	{
+	  rpath.frp_weight = 1;
+	  rpath.frp_proto = FIB_PROTOCOL_IP4;
+	}
+      else if (unformat (line_input, "%U", unformat_mfib_itf_flags, &iflags))
+	;
+      else if (unformat (line_input, "%U",
+			 unformat_mfib_entry_flags, &eflags))
+	;
+      else
+	{
+	  error = unformat_parse_error (line_input);
+	  goto done;
+	}
+    }
+
+  unformat_free (line_input);
+
+  if (~0 == table_id)
+    {
+      /*
+       * if no table_id is passed we will manipulate the default
+       */
+      fib_index = 0;
+    }
+  else
+    {
+      fib_index = mfib_table_find (pfx.fp_proto, table_id);
+
+      if (~0 == fib_index)
+	{
+	  error = clib_error_return (0, "Nonexistent table id %d", table_id);
+	  goto done;
+	}
+    }
+
+  if (is_del && 0 == rpath.frp_weight)
+    {
+      mfib_table_entry_delete (fib_index, &pfx, MFIB_SOURCE_CLI);
+    }
+  else if (eflags)
+    {
+      mfib_table_entry_update (fib_index, &pfx, MFIB_SOURCE_CLI, eflags);
+    }
+  else
+    {
+      if (is_del)
+	mfib_table_entry_path_remove (fib_index,
+				      &pfx, MFIB_SOURCE_CLI, &rpath);
+      else
+	mfib_table_entry_path_update (fib_index,
+				      &pfx, MFIB_SOURCE_CLI, &rpath, iflags);
+    }
+
+done:
+  return error;
+}
+
+/*?
+ * This command is used to add or delete IPv4 or IPv6  multicastroutes. All
+ * IP Addresses ('<em><dst-ip-addr>/<width></em>',
+ * '<em><next-hop-ip-addr></em>' and '<em><adj-hop-ip-addr></em>')
+ * can be IPv4 or IPv6, but all must be of the same form in a single
+ * command. To display the current set of routes, use the commands
+ * '<em>show ip mfib</em>' and '<em>show ip6 mfib</em>'.
+ * The full set of support flags for interfaces and route is shown via;
+ * '<em>show mfib route flags</em>' and '<em>show mfib itf flags</em>'
+ * respectively.
+ * @cliexpar
+ * Example of how to add a forwarding interface to a route (and create the
+ * route if it does not exist)
+ * @cliexcmd{ip mroute add 232.1.1.1 via GigabitEthernet2/0/0 Forward}
+ * Example of how to add an accepting interface to a route (and create the
+ * route if it does not exist)
+ * @cliexcmd{ip mroute add 232.1.1.1 via GigabitEthernet2/0/1 Accept}
+ * Example of changing the route's flags to send signals via the API
+ * @cliexcmd{ip mroute add 232.1.1.1 Signal}
+
+ ?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (ip_mroute_command, static) =
+{
+  .path = "ip mroute",
+  .short_help = "ip mroute [add|del] <dst-ip-addr>/<width> [table <table-id>] [via <next-hop-ip-addr> [<interface>],",
+  .function = vnet_ip_mroute_cmd,
+  .is_mp_safe = 1,
+};
+/* *INDENT-ON* */
+
 /*
  * The next two routines address a longstanding script hemorrhoid.
  * Probing a v4 or v6 neighbor needs to appear to be synchronous,