BIER

- see draft-ietf-bier-mpls-encapsulation-10
- midpoint, head and tail functions
- supported payload protocols; IPv4 and IPv6 only.

Change-Id: I59d7363bb6fdfdce8e4016a68a9c8f5a5e5791cb
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/bier/bier_drop.c b/src/vnet/bier/bier_drop.c
new file mode 100644
index 0000000..eb873ac
--- /dev/null
+++ b/src/vnet/bier/bier_drop.c
@@ -0,0 +1,101 @@
+/*
+ * 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.
+ */
+
+#include <vnet/buffer.h>
+#include <vlib/vlib.h>
+#include <vnet/dpo/dpo.h>
+
+#include <vnet/bier/bier_hdr_inlines.h>
+
+typedef struct bier_drop_trace_t_
+{
+    index_t dpi;
+} bier_drop_trace_t;
+
+static void
+bier_drop_trace (vlib_main_t * vm,
+                 vlib_node_runtime_t * node,
+                 vlib_frame_t * frame)
+{
+  u32 *from, n_left;
+
+  n_left = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+  while (n_left >= 1)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      bier_drop_trace_t *t0;
+
+      bi0 = from[0];
+
+      b0 = vlib_get_buffer (vm, bi0);
+
+      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+      {
+          t0 = vlib_add_trace (vm, node, b0, sizeof(*t0));
+
+          t0->dpi = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
+      }
+      from += 1;
+      n_left -= 1;
+    }
+}
+
+static uword
+bier_drop (vlib_main_t * vm,
+           vlib_node_runtime_t * node,
+           vlib_frame_t * frame)
+{
+    u32 *buffers = vlib_frame_vector_args (frame);
+    uword n_packets = frame->n_vectors;
+
+    vlib_error_drop_buffers (vm, node, buffers,
+                             /* stride */ 1,
+                             n_packets,
+                             /* next */ 0,
+                             0, // bier_input_node.index,
+                             0);
+
+    if (node->flags & VLIB_NODE_FLAG_TRACE)
+        bier_drop_trace (vm, node, frame);
+
+    return n_packets;
+}
+
+static u8 *
+format_bier_drop_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  bier_drop_trace_t *t = va_arg (*args, bier_drop_trace_t *);
+
+  s = format (s, "dpo-idx %d", t->dpi);
+
+  return s;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (bier_drop_node, static) =
+{
+    .function = bier_drop,.
+    name = "bier-drop",
+    .vector_size = sizeof (u32),
+    .format_trace = format_bier_drop_trace,
+    .n_next_nodes = 1,
+    .next_nodes = {
+        [0] = "error-drop",
+    },
+};