BVI Interface

a new dedicated BVI interface as opposed to [re]using a loopback.

benefits:
 - removes ambiguity over the purpose of a loopback interface
 - TX node dedicated to BVI only functions.

Change-Id: I749d6b38440d450ac5b909a28053c75ec9df946a
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/src/vnet/l2/l2_bvi_node.c b/src/vnet/l2/l2_bvi_node.c
new file mode 100644
index 00000000000..dd7e1df46ce
--- /dev/null
+++ b/src/vnet/l2/l2_bvi_node.c
@@ -0,0 +1,116 @@
+/*
+ * l2_bvi.c : layer 2 Bridged Virtual Interface
+ *
+ * Copyright (c) 2013 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/l2/l2_bvi.h>
+
+/**
+ * send packets to l2-input.
+ */
+VNET_DEVICE_CLASS_TX_FN (bvi_device_class) (vlib_main_t * vm,
+					    vlib_node_runtime_t * node,
+					    vlib_frame_t * frame)
+{
+  u32 sw_if_indices[VLIB_FRAME_SIZE], *sw_if_index;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u16 nexts[VLIB_FRAME_SIZE];
+  u32 n_left, *from;
+
+  n_left = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+
+  vlib_get_buffers (vm, from, bufs, n_left);
+
+  b = bufs;
+  sw_if_index = sw_if_indices;
+
+  /* It's all going to l2-input */
+  clib_memset_u16 (nexts, 0, VLIB_FRAME_SIZE);
+
+  /*
+   * For each packet:
+   *  - fixup the L2 length of the packet
+   *  - set the RX interface (which the bridge will use) to the
+   *    TX interface (which routing has chosen)
+   *  - Set the TX interface to the special ID so the DP knows this is a BVI
+   * Don't counts packets and bytes, that's done in the bviX-output node
+   */
+  while (n_left >= 4)
+    {
+      /* Prefetch next iteration. */
+      if (PREDICT_TRUE (n_left >= 8))
+	{
+	  /* LOAD pre-fetch since meta and packet data is read */
+	  vlib_prefetch_buffer_header (b[4], LOAD);
+	  vlib_prefetch_buffer_header (b[5], LOAD);
+	  vlib_prefetch_buffer_header (b[6], LOAD);
+	  vlib_prefetch_buffer_header (b[7], LOAD);
+
+	  vlib_prefetch_buffer_data (b[4], LOAD);
+	  vlib_prefetch_buffer_data (b[5], LOAD);
+	  vlib_prefetch_buffer_data (b[6], LOAD);
+	  vlib_prefetch_buffer_data (b[7], LOAD);
+	}
+
+      vnet_update_l2_len (b[0]);
+      vnet_update_l2_len (b[1]);
+      vnet_update_l2_len (b[2]);
+      vnet_update_l2_len (b[3]);
+
+      sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
+      sw_if_index[1] = vnet_buffer (b[1])->sw_if_index[VLIB_TX];
+      sw_if_index[2] = vnet_buffer (b[2])->sw_if_index[VLIB_TX];
+      sw_if_index[3] = vnet_buffer (b[3])->sw_if_index[VLIB_TX];
+
+      vnet_buffer (b[0])->sw_if_index[VLIB_TX] = L2INPUT_BVI;
+      vnet_buffer (b[1])->sw_if_index[VLIB_TX] = L2INPUT_BVI;
+      vnet_buffer (b[2])->sw_if_index[VLIB_TX] = L2INPUT_BVI;
+      vnet_buffer (b[3])->sw_if_index[VLIB_TX] = L2INPUT_BVI;
+
+      vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index[0];
+      vnet_buffer (b[1])->sw_if_index[VLIB_RX] = sw_if_index[1];
+      vnet_buffer (b[2])->sw_if_index[VLIB_RX] = sw_if_index[2];
+      vnet_buffer (b[3])->sw_if_index[VLIB_RX] = sw_if_index[3];
+
+      b += 4;
+      n_left -= 4;
+      sw_if_index += 4;
+    }
+  while (n_left)
+    {
+      sw_if_index[0] = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
+      vnet_buffer (b[0])->sw_if_index[VLIB_TX] = L2INPUT_BVI;
+      vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index[0];
+
+      vnet_update_l2_len (b[0]);
+
+      b += 1;
+      n_left -= 1;
+      sw_if_index += 1;
+    }
+
+  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+
+  return frame->n_vectors;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */